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c906108c | 1 | \input texinfo @c -*-texinfo-*- |
618f726f | 2 | @c Copyright (C) 1988-2016 Free Software Foundation, Inc. |
c906108c | 3 | @c |
5d161b24 | 4 | @c %**start of header |
c906108c SS |
5 | @c makeinfo ignores cmds prev to setfilename, so its arg cannot make use |
6 | @c of @set vars. However, you can override filename with makeinfo -o. | |
7 | @setfilename gdb.info | |
8 | @c | |
43662968 | 9 | @c man begin INCLUDE |
c906108c | 10 | @include gdb-cfg.texi |
43662968 | 11 | @c man end |
c906108c | 12 | @c |
c906108c | 13 | @settitle Debugging with @value{GDBN} |
c906108c SS |
14 | @setchapternewpage odd |
15 | @c %**end of header | |
16 | ||
17 | @iftex | |
18 | @c @smallbook | |
19 | @c @cropmarks | |
20 | @end iftex | |
21 | ||
22 | @finalout | |
00595b5e EZ |
23 | @c To avoid file-name clashes between index.html and Index.html, when |
24 | @c the manual is produced on a Posix host and then moved to a | |
25 | @c case-insensitive filesystem (e.g., MS-Windows), we separate the | |
26 | @c indices into two: Concept Index and all the rest. | |
27 | @syncodeindex ky fn | |
28 | @syncodeindex tp fn | |
c906108c | 29 | |
41afff9a | 30 | @c readline appendices use @vindex, @findex and @ftable, |
48e934c6 | 31 | @c annotate.texi and gdbmi use @findex. |
00595b5e | 32 | @syncodeindex vr fn |
c906108c SS |
33 | |
34 | @c !!set GDB manual's edition---not the same as GDB version! | |
9fe8321b | 35 | @c This is updated by GNU Press. |
26829f2b | 36 | @set EDITION Tenth |
c906108c | 37 | |
87885426 FN |
38 | @c !!set GDB edit command default editor |
39 | @set EDITOR /bin/ex | |
c906108c | 40 | |
6c0e9fb3 | 41 | @c THIS MANUAL REQUIRES TEXINFO 4.0 OR LATER. |
c906108c | 42 | |
c906108c | 43 | @c This is a dir.info fragment to support semi-automated addition of |
6d2ebf8b | 44 | @c manuals to an info tree. |
03727ca6 | 45 | @dircategory Software development |
96a2c332 | 46 | @direntry |
03727ca6 | 47 | * Gdb: (gdb). The GNU debugger. |
6cb999f8 | 48 | * gdbserver: (gdb) Server. The GNU debugging server. |
96a2c332 SS |
49 | @end direntry |
50 | ||
a67ec3f4 | 51 | @copying |
43662968 | 52 | @c man begin COPYRIGHT |
618f726f | 53 | Copyright @copyright{} 1988-2016 Free Software Foundation, Inc. |
c906108c | 54 | |
e9c75b65 | 55 | Permission is granted to copy, distribute and/or modify this document |
4f5d9f07 | 56 | under the terms of the GNU Free Documentation License, Version 1.3 or |
e9c75b65 | 57 | any later version published by the Free Software Foundation; with the |
959acfd1 EZ |
58 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
59 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
60 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 61 | |
b8533aec DJ |
62 | (a) The FSF's Back-Cover Text is: ``You are free to copy and modify |
63 | this GNU Manual. Buying copies from GNU Press supports the FSF in | |
64 | developing GNU and promoting software freedom.'' | |
43662968 | 65 | @c man end |
a67ec3f4 JM |
66 | @end copying |
67 | ||
68 | @ifnottex | |
69 | This file documents the @sc{gnu} debugger @value{GDBN}. | |
70 | ||
71 | This is the @value{EDITION} Edition, of @cite{Debugging with | |
72 | @value{GDBN}: the @sc{gnu} Source-Level Debugger} for @value{GDBN} | |
73 | @ifset VERSION_PACKAGE | |
74 | @value{VERSION_PACKAGE} | |
75 | @end ifset | |
76 | Version @value{GDBVN}. | |
77 | ||
78 | @insertcopying | |
79 | @end ifnottex | |
c906108c SS |
80 | |
81 | @titlepage | |
82 | @title Debugging with @value{GDBN} | |
83 | @subtitle The @sc{gnu} Source-Level Debugger | |
c906108c | 84 | @sp 1 |
c906108c | 85 | @subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN} |
c16158bc JM |
86 | @ifset VERSION_PACKAGE |
87 | @sp 1 | |
88 | @subtitle @value{VERSION_PACKAGE} | |
89 | @end ifset | |
9e9c5ae7 | 90 | @author Richard Stallman, Roland Pesch, Stan Shebs, et al. |
c906108c | 91 | @page |
c906108c SS |
92 | @tex |
93 | {\parskip=0pt | |
c16158bc | 94 | \hfill (Send bugs and comments on @value{GDBN} to @value{BUGURL}.)\par |
c906108c SS |
95 | \hfill {\it Debugging with @value{GDBN}}\par |
96 | \hfill \TeX{}info \texinfoversion\par | |
97 | } | |
98 | @end tex | |
53a5351d | 99 | |
c906108c | 100 | @vskip 0pt plus 1filll |
c906108c | 101 | Published by the Free Software Foundation @* |
c02a867d EZ |
102 | 51 Franklin Street, Fifth Floor, |
103 | Boston, MA 02110-1301, USA@* | |
26829f2b | 104 | ISBN 978-0-9831592-3-0 @* |
e9c75b65 | 105 | |
a67ec3f4 | 106 | @insertcopying |
c906108c SS |
107 | @end titlepage |
108 | @page | |
109 | ||
6c0e9fb3 | 110 | @ifnottex |
6d2ebf8b SS |
111 | @node Top, Summary, (dir), (dir) |
112 | ||
c906108c SS |
113 | @top Debugging with @value{GDBN} |
114 | ||
115 | This file describes @value{GDBN}, the @sc{gnu} symbolic debugger. | |
116 | ||
c16158bc JM |
117 | This is the @value{EDITION} Edition, for @value{GDBN} |
118 | @ifset VERSION_PACKAGE | |
119 | @value{VERSION_PACKAGE} | |
120 | @end ifset | |
121 | Version @value{GDBVN}. | |
c906108c | 122 | |
618f726f | 123 | Copyright (C) 1988-2016 Free Software Foundation, Inc. |
6d2ebf8b | 124 | |
3fb6a982 JB |
125 | This edition of the GDB manual is dedicated to the memory of Fred |
126 | Fish. Fred was a long-standing contributor to GDB and to Free | |
127 | software in general. We will miss him. | |
128 | ||
6d2ebf8b SS |
129 | @menu |
130 | * Summary:: Summary of @value{GDBN} | |
131 | * Sample Session:: A sample @value{GDBN} session | |
132 | ||
133 | * Invocation:: Getting in and out of @value{GDBN} | |
134 | * Commands:: @value{GDBN} commands | |
135 | * Running:: Running programs under @value{GDBN} | |
136 | * Stopping:: Stopping and continuing | |
bacec72f | 137 | * Reverse Execution:: Running programs backward |
a2311334 | 138 | * Process Record and Replay:: Recording inferior's execution and replaying it |
6d2ebf8b SS |
139 | * Stack:: Examining the stack |
140 | * Source:: Examining source files | |
141 | * Data:: Examining data | |
edb3359d | 142 | * Optimized Code:: Debugging optimized code |
e2e0bcd1 | 143 | * Macros:: Preprocessor Macros |
b37052ae | 144 | * Tracepoints:: Debugging remote targets non-intrusively |
df0cd8c5 | 145 | * Overlays:: Debugging programs that use overlays |
6d2ebf8b SS |
146 | |
147 | * Languages:: Using @value{GDBN} with different languages | |
148 | ||
149 | * Symbols:: Examining the symbol table | |
150 | * Altering:: Altering execution | |
151 | * GDB Files:: @value{GDBN} files | |
152 | * Targets:: Specifying a debugging target | |
6b2f586d | 153 | * Remote Debugging:: Debugging remote programs |
6d2ebf8b SS |
154 | * Configurations:: Configuration-specific information |
155 | * Controlling GDB:: Controlling @value{GDBN} | |
d57a3c85 | 156 | * Extending GDB:: Extending @value{GDBN} |
21c294e6 | 157 | * Interpreters:: Command Interpreters |
c8f4133a | 158 | * TUI:: @value{GDBN} Text User Interface |
6d2ebf8b | 159 | * Emacs:: Using @value{GDBN} under @sc{gnu} Emacs |
7162c0ca | 160 | * GDB/MI:: @value{GDBN}'s Machine Interface. |
c8f4133a | 161 | * Annotations:: @value{GDBN}'s annotation interface. |
4efc6507 | 162 | * JIT Interface:: Using the JIT debugging interface. |
d1feda86 | 163 | * In-Process Agent:: In-Process Agent |
6d2ebf8b SS |
164 | |
165 | * GDB Bugs:: Reporting bugs in @value{GDBN} | |
6d2ebf8b | 166 | |
39037522 TT |
167 | @ifset SYSTEM_READLINE |
168 | * Command Line Editing: (rluserman). Command Line Editing | |
169 | * Using History Interactively: (history). Using History Interactively | |
170 | @end ifset | |
171 | @ifclear SYSTEM_READLINE | |
6d2ebf8b SS |
172 | * Command Line Editing:: Command Line Editing |
173 | * Using History Interactively:: Using History Interactively | |
39037522 | 174 | @end ifclear |
4ceed123 | 175 | * In Memoriam:: In Memoriam |
0869d01b | 176 | * Formatting Documentation:: How to format and print @value{GDBN} documentation |
6d2ebf8b | 177 | * Installing GDB:: Installing GDB |
eb12ee30 | 178 | * Maintenance Commands:: Maintenance Commands |
e0ce93ac | 179 | * Remote Protocol:: GDB Remote Serial Protocol |
f418dd93 | 180 | * Agent Expressions:: The GDB Agent Expression Mechanism |
23181151 DJ |
181 | * Target Descriptions:: How targets can describe themselves to |
182 | @value{GDBN} | |
07e059b5 VP |
183 | * Operating System Information:: Getting additional information from |
184 | the operating system | |
00bf0b85 | 185 | * Trace File Format:: GDB trace file format |
90476074 | 186 | * Index Section Format:: .gdb_index section format |
43662968 | 187 | * Man Pages:: Manual pages |
aab4e0ec AC |
188 | * Copying:: GNU General Public License says |
189 | how you can copy and share GDB | |
6826cf00 | 190 | * GNU Free Documentation License:: The license for this documentation |
00595b5e EZ |
191 | * Concept Index:: Index of @value{GDBN} concepts |
192 | * Command and Variable Index:: Index of @value{GDBN} commands, variables, | |
193 | functions, and Python data types | |
6d2ebf8b SS |
194 | @end menu |
195 | ||
6c0e9fb3 | 196 | @end ifnottex |
c906108c | 197 | |
449f3b6c | 198 | @contents |
449f3b6c | 199 | |
6d2ebf8b | 200 | @node Summary |
c906108c SS |
201 | @unnumbered Summary of @value{GDBN} |
202 | ||
203 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
204 | going on ``inside'' another program while it executes---or what another | |
205 | program was doing at the moment it crashed. | |
206 | ||
207 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
208 | these) to help you catch bugs in the act: | |
209 | ||
210 | @itemize @bullet | |
211 | @item | |
212 | Start your program, specifying anything that might affect its behavior. | |
213 | ||
214 | @item | |
215 | Make your program stop on specified conditions. | |
216 | ||
217 | @item | |
218 | Examine what has happened, when your program has stopped. | |
219 | ||
220 | @item | |
221 | Change things in your program, so you can experiment with correcting the | |
222 | effects of one bug and go on to learn about another. | |
223 | @end itemize | |
224 | ||
49efadf5 | 225 | You can use @value{GDBN} to debug programs written in C and C@t{++}. |
79a6e687 | 226 | For more information, see @ref{Supported Languages,,Supported Languages}. |
c906108c SS |
227 | For more information, see @ref{C,,C and C++}. |
228 | ||
6aecb9c2 JB |
229 | Support for D is partial. For information on D, see |
230 | @ref{D,,D}. | |
231 | ||
cce74817 | 232 | @cindex Modula-2 |
e632838e AC |
233 | Support for Modula-2 is partial. For information on Modula-2, see |
234 | @ref{Modula-2,,Modula-2}. | |
c906108c | 235 | |
f4b8a18d KW |
236 | Support for OpenCL C is partial. For information on OpenCL C, see |
237 | @ref{OpenCL C,,OpenCL C}. | |
238 | ||
cce74817 JM |
239 | @cindex Pascal |
240 | Debugging Pascal programs which use sets, subranges, file variables, or | |
241 | nested functions does not currently work. @value{GDBN} does not support | |
242 | entering expressions, printing values, or similar features using Pascal | |
243 | syntax. | |
c906108c | 244 | |
c906108c SS |
245 | @cindex Fortran |
246 | @value{GDBN} can be used to debug programs written in Fortran, although | |
53a5351d | 247 | it may be necessary to refer to some variables with a trailing |
cce74817 | 248 | underscore. |
c906108c | 249 | |
b37303ee AF |
250 | @value{GDBN} can be used to debug programs written in Objective-C, |
251 | using either the Apple/NeXT or the GNU Objective-C runtime. | |
252 | ||
c906108c SS |
253 | @menu |
254 | * Free Software:: Freely redistributable software | |
984359d2 | 255 | * Free Documentation:: Free Software Needs Free Documentation |
c906108c SS |
256 | * Contributors:: Contributors to GDB |
257 | @end menu | |
258 | ||
6d2ebf8b | 259 | @node Free Software |
79a6e687 | 260 | @unnumberedsec Free Software |
c906108c | 261 | |
5d161b24 | 262 | @value{GDBN} is @dfn{free software}, protected by the @sc{gnu} |
c906108c SS |
263 | General Public License |
264 | (GPL). The GPL gives you the freedom to copy or adapt a licensed | |
265 | program---but every person getting a copy also gets with it the | |
266 | freedom to modify that copy (which means that they must get access to | |
267 | the source code), and the freedom to distribute further copies. | |
268 | Typical software companies use copyrights to limit your freedoms; the | |
269 | Free Software Foundation uses the GPL to preserve these freedoms. | |
270 | ||
271 | Fundamentally, the General Public License is a license which says that | |
272 | you have these freedoms and that you cannot take these freedoms away | |
273 | from anyone else. | |
274 | ||
984359d2 | 275 | @node Free Documentation |
2666264b | 276 | @unnumberedsec Free Software Needs Free Documentation |
959acfd1 EZ |
277 | |
278 | The biggest deficiency in the free software community today is not in | |
279 | the software---it is the lack of good free documentation that we can | |
280 | include with the free software. Many of our most important | |
281 | programs do not come with free reference manuals and free introductory | |
282 | texts. Documentation is an essential part of any software package; | |
283 | when an important free software package does not come with a free | |
284 | manual and a free tutorial, that is a major gap. We have many such | |
285 | gaps today. | |
286 | ||
287 | Consider Perl, for instance. The tutorial manuals that people | |
288 | normally use are non-free. How did this come about? Because the | |
289 | authors of those manuals published them with restrictive terms---no | |
290 | copying, no modification, source files not available---which exclude | |
291 | them from the free software world. | |
292 | ||
293 | That wasn't the first time this sort of thing happened, and it was far | |
294 | from the last. Many times we have heard a GNU user eagerly describe a | |
295 | manual that he is writing, his intended contribution to the community, | |
296 | only to learn that he had ruined everything by signing a publication | |
297 | contract to make it non-free. | |
298 | ||
299 | Free documentation, like free software, is a matter of freedom, not | |
300 | price. The problem with the non-free manual is not that publishers | |
301 | charge a price for printed copies---that in itself is fine. (The Free | |
302 | Software Foundation sells printed copies of manuals, too.) The | |
303 | problem is the restrictions on the use of the manual. Free manuals | |
304 | are available in source code form, and give you permission to copy and | |
305 | modify. Non-free manuals do not allow this. | |
306 | ||
307 | The criteria of freedom for a free manual are roughly the same as for | |
308 | free software. Redistribution (including the normal kinds of | |
309 | commercial redistribution) must be permitted, so that the manual can | |
310 | accompany every copy of the program, both on-line and on paper. | |
311 | ||
312 | Permission for modification of the technical content is crucial too. | |
313 | When people modify the software, adding or changing features, if they | |
314 | are conscientious they will change the manual too---so they can | |
315 | provide accurate and clear documentation for the modified program. A | |
316 | manual that leaves you no choice but to write a new manual to document | |
317 | a changed version of the program is not really available to our | |
318 | community. | |
319 | ||
320 | Some kinds of limits on the way modification is handled are | |
321 | acceptable. For example, requirements to preserve the original | |
322 | author's copyright notice, the distribution terms, or the list of | |
323 | authors, are ok. It is also no problem to require modified versions | |
324 | to include notice that they were modified. Even entire sections that | |
325 | may not be deleted or changed are acceptable, as long as they deal | |
326 | with nontechnical topics (like this one). These kinds of restrictions | |
327 | are acceptable because they don't obstruct the community's normal use | |
328 | of the manual. | |
329 | ||
330 | However, it must be possible to modify all the @emph{technical} | |
331 | content of the manual, and then distribute the result in all the usual | |
332 | media, through all the usual channels. Otherwise, the restrictions | |
333 | obstruct the use of the manual, it is not free, and we need another | |
334 | manual to replace it. | |
335 | ||
336 | Please spread the word about this issue. Our community continues to | |
337 | lose manuals to proprietary publishing. If we spread the word that | |
338 | free software needs free reference manuals and free tutorials, perhaps | |
339 | the next person who wants to contribute by writing documentation will | |
340 | realize, before it is too late, that only free manuals contribute to | |
341 | the free software community. | |
342 | ||
343 | If you are writing documentation, please insist on publishing it under | |
344 | the GNU Free Documentation License or another free documentation | |
345 | license. Remember that this decision requires your approval---you | |
346 | don't have to let the publisher decide. Some commercial publishers | |
347 | will use a free license if you insist, but they will not propose the | |
348 | option; it is up to you to raise the issue and say firmly that this is | |
349 | what you want. If the publisher you are dealing with refuses, please | |
350 | try other publishers. If you're not sure whether a proposed license | |
42584a72 | 351 | is free, write to @email{licensing@@gnu.org}. |
959acfd1 EZ |
352 | |
353 | You can encourage commercial publishers to sell more free, copylefted | |
354 | manuals and tutorials by buying them, and particularly by buying | |
355 | copies from the publishers that paid for their writing or for major | |
356 | improvements. Meanwhile, try to avoid buying non-free documentation | |
357 | at all. Check the distribution terms of a manual before you buy it, | |
358 | and insist that whoever seeks your business must respect your freedom. | |
72c9928d EZ |
359 | Check the history of the book, and try to reward the publishers that |
360 | have paid or pay the authors to work on it. | |
959acfd1 EZ |
361 | |
362 | The Free Software Foundation maintains a list of free documentation | |
363 | published by other publishers, at | |
364 | @url{http://www.fsf.org/doc/other-free-books.html}. | |
365 | ||
6d2ebf8b | 366 | @node Contributors |
96a2c332 SS |
367 | @unnumberedsec Contributors to @value{GDBN} |
368 | ||
369 | Richard Stallman was the original author of @value{GDBN}, and of many | |
370 | other @sc{gnu} programs. Many others have contributed to its | |
371 | development. This section attempts to credit major contributors. One | |
372 | of the virtues of free software is that everyone is free to contribute | |
373 | to it; with regret, we cannot actually acknowledge everyone here. The | |
374 | file @file{ChangeLog} in the @value{GDBN} distribution approximates a | |
c906108c SS |
375 | blow-by-blow account. |
376 | ||
377 | Changes much prior to version 2.0 are lost in the mists of time. | |
378 | ||
379 | @quotation | |
380 | @emph{Plea:} Additions to this section are particularly welcome. If you | |
381 | or your friends (or enemies, to be evenhanded) have been unfairly | |
382 | omitted from this list, we would like to add your names! | |
383 | @end quotation | |
384 | ||
385 | So that they may not regard their many labors as thankless, we | |
386 | particularly thank those who shepherded @value{GDBN} through major | |
387 | releases: | |
7ba3cf9c | 388 | Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0); |
c906108c SS |
389 | Jim Blandy (release 4.18); |
390 | Jason Molenda (release 4.17); | |
391 | Stan Shebs (release 4.14); | |
392 | Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); | |
393 | Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); | |
394 | John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); | |
395 | Jim Kingdon (releases 3.5, 3.4, and 3.3); | |
396 | and Randy Smith (releases 3.2, 3.1, and 3.0). | |
397 | ||
398 | Richard Stallman, assisted at various times by Peter TerMaat, Chris | |
399 | Hanson, and Richard Mlynarik, handled releases through 2.8. | |
400 | ||
b37052ae EZ |
401 | Michael Tiemann is the author of most of the @sc{gnu} C@t{++} support |
402 | in @value{GDBN}, with significant additional contributions from Per | |
403 | Bothner and Daniel Berlin. James Clark wrote the @sc{gnu} C@t{++} | |
404 | demangler. Early work on C@t{++} was by Peter TerMaat (who also did | |
405 | much general update work leading to release 3.0). | |
c906108c | 406 | |
b37052ae | 407 | @value{GDBN} uses the BFD subroutine library to examine multiple |
c906108c SS |
408 | object-file formats; BFD was a joint project of David V. |
409 | Henkel-Wallace, Rich Pixley, Steve Chamberlain, and John Gilmore. | |
410 | ||
411 | David Johnson wrote the original COFF support; Pace Willison did | |
412 | the original support for encapsulated COFF. | |
413 | ||
0179ffac | 414 | Brent Benson of Harris Computer Systems contributed DWARF 2 support. |
c906108c SS |
415 | |
416 | Adam de Boor and Bradley Davis contributed the ISI Optimum V support. | |
417 | Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS | |
418 | support. | |
419 | Jean-Daniel Fekete contributed Sun 386i support. | |
420 | Chris Hanson improved the HP9000 support. | |
421 | Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. | |
422 | David Johnson contributed Encore Umax support. | |
423 | Jyrki Kuoppala contributed Altos 3068 support. | |
424 | Jeff Law contributed HP PA and SOM support. | |
425 | Keith Packard contributed NS32K support. | |
426 | Doug Rabson contributed Acorn Risc Machine support. | |
427 | Bob Rusk contributed Harris Nighthawk CX-UX support. | |
428 | Chris Smith contributed Convex support (and Fortran debugging). | |
429 | Jonathan Stone contributed Pyramid support. | |
430 | Michael Tiemann contributed SPARC support. | |
431 | Tim Tucker contributed support for the Gould NP1 and Gould Powernode. | |
432 | Pace Willison contributed Intel 386 support. | |
433 | Jay Vosburgh contributed Symmetry support. | |
a37295f9 | 434 | Marko Mlinar contributed OpenRISC 1000 support. |
c906108c | 435 | |
1104b9e7 | 436 | Andreas Schwab contributed M68K @sc{gnu}/Linux support. |
c906108c SS |
437 | |
438 | Rich Schaefer and Peter Schauer helped with support of SunOS shared | |
439 | libraries. | |
440 | ||
441 | Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree | |
442 | about several machine instruction sets. | |
443 | ||
444 | Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop | |
445 | remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM | |
446 | contributed remote debugging modules for the i960, VxWorks, A29K UDI, | |
447 | and RDI targets, respectively. | |
448 | ||
449 | Brian Fox is the author of the readline libraries providing | |
450 | command-line editing and command history. | |
451 | ||
7a292a7a SS |
452 | Andrew Beers of SUNY Buffalo wrote the language-switching code, the |
453 | Modula-2 support, and contributed the Languages chapter of this manual. | |
c906108c | 454 | |
5d161b24 | 455 | Fred Fish wrote most of the support for Unix System Vr4. |
b37052ae | 456 | He also enhanced the command-completion support to cover C@t{++} overloaded |
c906108c | 457 | symbols. |
c906108c | 458 | |
f24c5e49 KI |
459 | Hitachi America (now Renesas America), Ltd. sponsored the support for |
460 | H8/300, H8/500, and Super-H processors. | |
c906108c SS |
461 | |
462 | NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors. | |
463 | ||
f24c5e49 KI |
464 | Mitsubishi (now Renesas) sponsored the support for D10V, D30V, and M32R/D |
465 | processors. | |
c906108c SS |
466 | |
467 | Toshiba sponsored the support for the TX39 Mips processor. | |
468 | ||
469 | Matsushita sponsored the support for the MN10200 and MN10300 processors. | |
470 | ||
96a2c332 | 471 | Fujitsu sponsored the support for SPARClite and FR30 processors. |
c906108c SS |
472 | |
473 | Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware | |
474 | watchpoints. | |
475 | ||
476 | Michael Snyder added support for tracepoints. | |
477 | ||
478 | Stu Grossman wrote gdbserver. | |
479 | ||
480 | Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made | |
96a2c332 | 481 | nearly innumerable bug fixes and cleanups throughout @value{GDBN}. |
c906108c SS |
482 | |
483 | The following people at the Hewlett-Packard Company contributed | |
484 | support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0 | |
b37052ae | 485 | (narrow mode), HP's implementation of kernel threads, HP's aC@t{++} |
d0d5df6f AC |
486 | compiler, and the Text User Interface (nee Terminal User Interface): |
487 | Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann, | |
488 | Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase | |
489 | provided HP-specific information in this manual. | |
c906108c | 490 | |
b37052ae EZ |
491 | DJ Delorie ported @value{GDBN} to MS-DOS, for the DJGPP project. |
492 | Robert Hoehne made significant contributions to the DJGPP port. | |
493 | ||
96a2c332 SS |
494 | Cygnus Solutions has sponsored @value{GDBN} maintenance and much of its |
495 | development since 1991. Cygnus engineers who have worked on @value{GDBN} | |
2df3850c JM |
496 | fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin |
497 | Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim | |
498 | Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler, | |
499 | Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek | |
500 | Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In | |
501 | addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton, | |
502 | JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug | |
503 | Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff | |
504 | Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner, | |
505 | Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin | |
506 | Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela | |
507 | Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David | |
508 | Zuhn have made contributions both large and small. | |
c906108c | 509 | |
ffed4509 AC |
510 | Andrew Cagney, Fernando Nasser, and Elena Zannoni, while working for |
511 | Cygnus Solutions, implemented the original @sc{gdb/mi} interface. | |
512 | ||
e2e0bcd1 JB |
513 | Jim Blandy added support for preprocessor macros, while working for Red |
514 | Hat. | |
c906108c | 515 | |
a9967aef AC |
516 | Andrew Cagney designed @value{GDBN}'s architecture vector. Many |
517 | people including Andrew Cagney, Stephane Carrez, Randolph Chung, Nick | |
518 | Duffek, Richard Henderson, Mark Kettenis, Grace Sainsbury, Kei | |
519 | Sakamoto, Yoshinori Sato, Michael Snyder, Andreas Schwab, Jason | |
520 | Thorpe, Corinna Vinschen, Ulrich Weigand, and Elena Zannoni, helped | |
521 | with the migration of old architectures to this new framework. | |
522 | ||
c5e30d01 AC |
523 | Andrew Cagney completely re-designed and re-implemented @value{GDBN}'s |
524 | unwinder framework, this consisting of a fresh new design featuring | |
525 | frame IDs, independent frame sniffers, and the sentinel frame. Mark | |
526 | Kettenis implemented the @sc{dwarf 2} unwinder, Jeff Johnston the | |
527 | libunwind unwinder, and Andrew Cagney the dummy, sentinel, tramp, and | |
db2e3e2e | 528 | trad unwinders. The architecture-specific changes, each involving a |
c5e30d01 AC |
529 | complete rewrite of the architecture's frame code, were carried out by |
530 | Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane | |
531 | Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel | |
532 | Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei | |
533 | Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich | |
534 | Weigand. | |
535 | ||
ca3bf3bd DJ |
536 | Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from |
537 | Tensilica, Inc.@: contributed support for Xtensa processors. Others | |
538 | who have worked on the Xtensa port of @value{GDBN} in the past include | |
539 | Steve Tjiang, John Newlin, and Scott Foehner. | |
540 | ||
08be9d71 ME |
541 | Michael Eager and staff of Xilinx, Inc., contributed support for the |
542 | Xilinx MicroBlaze architecture. | |
543 | ||
6d2ebf8b | 544 | @node Sample Session |
c906108c SS |
545 | @chapter A Sample @value{GDBN} Session |
546 | ||
547 | You can use this manual at your leisure to read all about @value{GDBN}. | |
548 | However, a handful of commands are enough to get started using the | |
549 | debugger. This chapter illustrates those commands. | |
550 | ||
551 | @iftex | |
552 | In this sample session, we emphasize user input like this: @b{input}, | |
553 | to make it easier to pick out from the surrounding output. | |
554 | @end iftex | |
555 | ||
556 | @c FIXME: this example may not be appropriate for some configs, where | |
557 | @c FIXME...primary interest is in remote use. | |
558 | ||
559 | One of the preliminary versions of @sc{gnu} @code{m4} (a generic macro | |
560 | processor) exhibits the following bug: sometimes, when we change its | |
561 | quote strings from the default, the commands used to capture one macro | |
562 | definition within another stop working. In the following short @code{m4} | |
563 | session, we define a macro @code{foo} which expands to @code{0000}; we | |
564 | then use the @code{m4} built-in @code{defn} to define @code{bar} as the | |
565 | same thing. However, when we change the open quote string to | |
566 | @code{<QUOTE>} and the close quote string to @code{<UNQUOTE>}, the same | |
567 | procedure fails to define a new synonym @code{baz}: | |
568 | ||
569 | @smallexample | |
570 | $ @b{cd gnu/m4} | |
571 | $ @b{./m4} | |
572 | @b{define(foo,0000)} | |
573 | ||
574 | @b{foo} | |
575 | 0000 | |
576 | @b{define(bar,defn(`foo'))} | |
577 | ||
578 | @b{bar} | |
579 | 0000 | |
580 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
581 | ||
582 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
583 | @b{baz} | |
c8aa23ab | 584 | @b{Ctrl-d} |
c906108c SS |
585 | m4: End of input: 0: fatal error: EOF in string |
586 | @end smallexample | |
587 | ||
588 | @noindent | |
589 | Let us use @value{GDBN} to try to see what is going on. | |
590 | ||
c906108c SS |
591 | @smallexample |
592 | $ @b{@value{GDBP} m4} | |
593 | @c FIXME: this falsifies the exact text played out, to permit smallbook | |
594 | @c FIXME... format to come out better. | |
595 | @value{GDBN} is free software and you are welcome to distribute copies | |
5d161b24 | 596 | of it under certain conditions; type "show copying" to see |
c906108c | 597 | the conditions. |
5d161b24 | 598 | There is absolutely no warranty for @value{GDBN}; type "show warranty" |
c906108c SS |
599 | for details. |
600 | ||
601 | @value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc... | |
602 | (@value{GDBP}) | |
603 | @end smallexample | |
c906108c SS |
604 | |
605 | @noindent | |
606 | @value{GDBN} reads only enough symbol data to know where to find the | |
607 | rest when needed; as a result, the first prompt comes up very quickly. | |
608 | We now tell @value{GDBN} to use a narrower display width than usual, so | |
609 | that examples fit in this manual. | |
610 | ||
611 | @smallexample | |
612 | (@value{GDBP}) @b{set width 70} | |
613 | @end smallexample | |
614 | ||
615 | @noindent | |
616 | We need to see how the @code{m4} built-in @code{changequote} works. | |
617 | Having looked at the source, we know the relevant subroutine is | |
618 | @code{m4_changequote}, so we set a breakpoint there with the @value{GDBN} | |
619 | @code{break} command. | |
620 | ||
621 | @smallexample | |
622 | (@value{GDBP}) @b{break m4_changequote} | |
623 | Breakpoint 1 at 0x62f4: file builtin.c, line 879. | |
624 | @end smallexample | |
625 | ||
626 | @noindent | |
627 | Using the @code{run} command, we start @code{m4} running under @value{GDBN} | |
628 | control; as long as control does not reach the @code{m4_changequote} | |
629 | subroutine, the program runs as usual: | |
630 | ||
631 | @smallexample | |
632 | (@value{GDBP}) @b{run} | |
633 | Starting program: /work/Editorial/gdb/gnu/m4/m4 | |
634 | @b{define(foo,0000)} | |
635 | ||
636 | @b{foo} | |
637 | 0000 | |
638 | @end smallexample | |
639 | ||
640 | @noindent | |
641 | To trigger the breakpoint, we call @code{changequote}. @value{GDBN} | |
642 | suspends execution of @code{m4}, displaying information about the | |
643 | context where it stops. | |
644 | ||
645 | @smallexample | |
646 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
647 | ||
5d161b24 | 648 | Breakpoint 1, m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
649 | at builtin.c:879 |
650 | 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3)) | |
651 | @end smallexample | |
652 | ||
653 | @noindent | |
654 | Now we use the command @code{n} (@code{next}) to advance execution to | |
655 | the next line of the current function. | |
656 | ||
657 | @smallexample | |
658 | (@value{GDBP}) @b{n} | |
659 | 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\ | |
660 | : nil, | |
661 | @end smallexample | |
662 | ||
663 | @noindent | |
664 | @code{set_quotes} looks like a promising subroutine. We can go into it | |
665 | by using the command @code{s} (@code{step}) instead of @code{next}. | |
666 | @code{step} goes to the next line to be executed in @emph{any} | |
667 | subroutine, so it steps into @code{set_quotes}. | |
668 | ||
669 | @smallexample | |
670 | (@value{GDBP}) @b{s} | |
671 | set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
672 | at input.c:530 | |
673 | 530 if (lquote != def_lquote) | |
674 | @end smallexample | |
675 | ||
676 | @noindent | |
677 | The display that shows the subroutine where @code{m4} is now | |
678 | suspended (and its arguments) is called a stack frame display. It | |
679 | shows a summary of the stack. We can use the @code{backtrace} | |
680 | command (which can also be spelled @code{bt}), to see where we are | |
681 | in the stack as a whole: the @code{backtrace} command displays a | |
682 | stack frame for each active subroutine. | |
683 | ||
684 | @smallexample | |
685 | (@value{GDBP}) @b{bt} | |
686 | #0 set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
687 | at input.c:530 | |
5d161b24 | 688 | #1 0x6344 in m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
689 | at builtin.c:882 |
690 | #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242 | |
691 | #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30) | |
692 | at macro.c:71 | |
693 | #4 0x79dc in expand_input () at macro.c:40 | |
694 | #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195 | |
695 | @end smallexample | |
696 | ||
697 | @noindent | |
698 | We step through a few more lines to see what happens. The first two | |
699 | times, we can use @samp{s}; the next two times we use @code{n} to avoid | |
700 | falling into the @code{xstrdup} subroutine. | |
701 | ||
702 | @smallexample | |
703 | (@value{GDBP}) @b{s} | |
704 | 0x3b5c 532 if (rquote != def_rquote) | |
705 | (@value{GDBP}) @b{s} | |
706 | 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \ | |
707 | def_lquote : xstrdup(lq); | |
708 | (@value{GDBP}) @b{n} | |
709 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
710 | : xstrdup(rq); | |
711 | (@value{GDBP}) @b{n} | |
712 | 538 len_lquote = strlen(rquote); | |
713 | @end smallexample | |
714 | ||
715 | @noindent | |
716 | The last line displayed looks a little odd; we can examine the variables | |
717 | @code{lquote} and @code{rquote} to see if they are in fact the new left | |
718 | and right quotes we specified. We use the command @code{p} | |
719 | (@code{print}) to see their values. | |
720 | ||
721 | @smallexample | |
722 | (@value{GDBP}) @b{p lquote} | |
723 | $1 = 0x35d40 "<QUOTE>" | |
724 | (@value{GDBP}) @b{p rquote} | |
725 | $2 = 0x35d50 "<UNQUOTE>" | |
726 | @end smallexample | |
727 | ||
728 | @noindent | |
729 | @code{lquote} and @code{rquote} are indeed the new left and right quotes. | |
730 | To look at some context, we can display ten lines of source | |
731 | surrounding the current line with the @code{l} (@code{list}) command. | |
732 | ||
733 | @smallexample | |
734 | (@value{GDBP}) @b{l} | |
735 | 533 xfree(rquote); | |
736 | 534 | |
737 | 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\ | |
738 | : xstrdup (lq); | |
739 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
740 | : xstrdup (rq); | |
741 | 537 | |
742 | 538 len_lquote = strlen(rquote); | |
743 | 539 len_rquote = strlen(lquote); | |
744 | 540 @} | |
745 | 541 | |
746 | 542 void | |
747 | @end smallexample | |
748 | ||
749 | @noindent | |
750 | Let us step past the two lines that set @code{len_lquote} and | |
751 | @code{len_rquote}, and then examine the values of those variables. | |
752 | ||
753 | @smallexample | |
754 | (@value{GDBP}) @b{n} | |
755 | 539 len_rquote = strlen(lquote); | |
756 | (@value{GDBP}) @b{n} | |
757 | 540 @} | |
758 | (@value{GDBP}) @b{p len_lquote} | |
759 | $3 = 9 | |
760 | (@value{GDBP}) @b{p len_rquote} | |
761 | $4 = 7 | |
762 | @end smallexample | |
763 | ||
764 | @noindent | |
765 | That certainly looks wrong, assuming @code{len_lquote} and | |
766 | @code{len_rquote} are meant to be the lengths of @code{lquote} and | |
767 | @code{rquote} respectively. We can set them to better values using | |
768 | the @code{p} command, since it can print the value of | |
769 | any expression---and that expression can include subroutine calls and | |
770 | assignments. | |
771 | ||
772 | @smallexample | |
773 | (@value{GDBP}) @b{p len_lquote=strlen(lquote)} | |
774 | $5 = 7 | |
775 | (@value{GDBP}) @b{p len_rquote=strlen(rquote)} | |
776 | $6 = 9 | |
777 | @end smallexample | |
778 | ||
779 | @noindent | |
780 | Is that enough to fix the problem of using the new quotes with the | |
781 | @code{m4} built-in @code{defn}? We can allow @code{m4} to continue | |
782 | executing with the @code{c} (@code{continue}) command, and then try the | |
783 | example that caused trouble initially: | |
784 | ||
785 | @smallexample | |
786 | (@value{GDBP}) @b{c} | |
787 | Continuing. | |
788 | ||
789 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
790 | ||
791 | baz | |
792 | 0000 | |
793 | @end smallexample | |
794 | ||
795 | @noindent | |
796 | Success! The new quotes now work just as well as the default ones. The | |
797 | problem seems to have been just the two typos defining the wrong | |
798 | lengths. We allow @code{m4} exit by giving it an EOF as input: | |
799 | ||
800 | @smallexample | |
c8aa23ab | 801 | @b{Ctrl-d} |
c906108c SS |
802 | Program exited normally. |
803 | @end smallexample | |
804 | ||
805 | @noindent | |
806 | The message @samp{Program exited normally.} is from @value{GDBN}; it | |
807 | indicates @code{m4} has finished executing. We can end our @value{GDBN} | |
808 | session with the @value{GDBN} @code{quit} command. | |
809 | ||
810 | @smallexample | |
811 | (@value{GDBP}) @b{quit} | |
812 | @end smallexample | |
c906108c | 813 | |
6d2ebf8b | 814 | @node Invocation |
c906108c SS |
815 | @chapter Getting In and Out of @value{GDBN} |
816 | ||
817 | This chapter discusses how to start @value{GDBN}, and how to get out of it. | |
5d161b24 | 818 | The essentials are: |
c906108c | 819 | @itemize @bullet |
5d161b24 | 820 | @item |
53a5351d | 821 | type @samp{@value{GDBP}} to start @value{GDBN}. |
5d161b24 | 822 | @item |
c8aa23ab | 823 | type @kbd{quit} or @kbd{Ctrl-d} to exit. |
c906108c SS |
824 | @end itemize |
825 | ||
826 | @menu | |
827 | * Invoking GDB:: How to start @value{GDBN} | |
828 | * Quitting GDB:: How to quit @value{GDBN} | |
829 | * Shell Commands:: How to use shell commands inside @value{GDBN} | |
79a6e687 | 830 | * Logging Output:: How to log @value{GDBN}'s output to a file |
c906108c SS |
831 | @end menu |
832 | ||
6d2ebf8b | 833 | @node Invoking GDB |
c906108c SS |
834 | @section Invoking @value{GDBN} |
835 | ||
c906108c SS |
836 | Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started, |
837 | @value{GDBN} reads commands from the terminal until you tell it to exit. | |
838 | ||
839 | You can also run @code{@value{GDBP}} with a variety of arguments and options, | |
840 | to specify more of your debugging environment at the outset. | |
841 | ||
c906108c SS |
842 | The command-line options described here are designed |
843 | to cover a variety of situations; in some environments, some of these | |
5d161b24 | 844 | options may effectively be unavailable. |
c906108c SS |
845 | |
846 | The most usual way to start @value{GDBN} is with one argument, | |
847 | specifying an executable program: | |
848 | ||
474c8240 | 849 | @smallexample |
c906108c | 850 | @value{GDBP} @var{program} |
474c8240 | 851 | @end smallexample |
c906108c | 852 | |
c906108c SS |
853 | @noindent |
854 | You can also start with both an executable program and a core file | |
855 | specified: | |
856 | ||
474c8240 | 857 | @smallexample |
c906108c | 858 | @value{GDBP} @var{program} @var{core} |
474c8240 | 859 | @end smallexample |
c906108c SS |
860 | |
861 | You can, instead, specify a process ID as a second argument, if you want | |
862 | to debug a running process: | |
863 | ||
474c8240 | 864 | @smallexample |
c906108c | 865 | @value{GDBP} @var{program} 1234 |
474c8240 | 866 | @end smallexample |
c906108c SS |
867 | |
868 | @noindent | |
869 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
870 | named @file{1234}; @value{GDBN} does check for a core file first). | |
871 | ||
c906108c | 872 | Taking advantage of the second command-line argument requires a fairly |
2df3850c JM |
873 | complete operating system; when you use @value{GDBN} as a remote |
874 | debugger attached to a bare board, there may not be any notion of | |
875 | ``process'', and there is often no way to get a core dump. @value{GDBN} | |
876 | will warn you if it is unable to attach or to read core dumps. | |
c906108c | 877 | |
aa26fa3a TT |
878 | You can optionally have @code{@value{GDBP}} pass any arguments after the |
879 | executable file to the inferior using @code{--args}. This option stops | |
880 | option processing. | |
474c8240 | 881 | @smallexample |
3f94c067 | 882 | @value{GDBP} --args gcc -O2 -c foo.c |
474c8240 | 883 | @end smallexample |
aa26fa3a TT |
884 | This will cause @code{@value{GDBP}} to debug @code{gcc}, and to set |
885 | @code{gcc}'s command-line arguments (@pxref{Arguments}) to @samp{-O2 -c foo.c}. | |
886 | ||
96a2c332 | 887 | You can run @code{@value{GDBP}} without printing the front material, which describes |
adcc0a31 | 888 | @value{GDBN}'s non-warranty, by specifying @code{--silent} |
889 | (or @code{-q}/@code{--quiet}): | |
c906108c SS |
890 | |
891 | @smallexample | |
adcc0a31 | 892 | @value{GDBP} --silent |
c906108c SS |
893 | @end smallexample |
894 | ||
895 | @noindent | |
896 | You can further control how @value{GDBN} starts up by using command-line | |
897 | options. @value{GDBN} itself can remind you of the options available. | |
898 | ||
899 | @noindent | |
900 | Type | |
901 | ||
474c8240 | 902 | @smallexample |
c906108c | 903 | @value{GDBP} -help |
474c8240 | 904 | @end smallexample |
c906108c SS |
905 | |
906 | @noindent | |
907 | to display all available options and briefly describe their use | |
908 | (@samp{@value{GDBP} -h} is a shorter equivalent). | |
909 | ||
910 | All options and command line arguments you give are processed | |
911 | in sequential order. The order makes a difference when the | |
912 | @samp{-x} option is used. | |
913 | ||
914 | ||
915 | @menu | |
c906108c SS |
916 | * File Options:: Choosing files |
917 | * Mode Options:: Choosing modes | |
6fc08d32 | 918 | * Startup:: What @value{GDBN} does during startup |
c906108c SS |
919 | @end menu |
920 | ||
6d2ebf8b | 921 | @node File Options |
79a6e687 | 922 | @subsection Choosing Files |
c906108c | 923 | |
2df3850c | 924 | When @value{GDBN} starts, it reads any arguments other than options as |
c906108c SS |
925 | specifying an executable file and core file (or process ID). This is |
926 | the same as if the arguments were specified by the @samp{-se} and | |
d52fb0e9 | 927 | @samp{-c} (or @samp{-p}) options respectively. (@value{GDBN} reads the |
19837790 MS |
928 | first argument that does not have an associated option flag as |
929 | equivalent to the @samp{-se} option followed by that argument; and the | |
930 | second argument that does not have an associated option flag, if any, as | |
931 | equivalent to the @samp{-c}/@samp{-p} option followed by that argument.) | |
932 | If the second argument begins with a decimal digit, @value{GDBN} will | |
933 | first attempt to attach to it as a process, and if that fails, attempt | |
934 | to open it as a corefile. If you have a corefile whose name begins with | |
b383017d | 935 | a digit, you can prevent @value{GDBN} from treating it as a pid by |
c1468174 | 936 | prefixing it with @file{./}, e.g.@: @file{./12345}. |
7a292a7a SS |
937 | |
938 | If @value{GDBN} has not been configured to included core file support, | |
939 | such as for most embedded targets, then it will complain about a second | |
940 | argument and ignore it. | |
c906108c SS |
941 | |
942 | Many options have both long and short forms; both are shown in the | |
943 | following list. @value{GDBN} also recognizes the long forms if you truncate | |
944 | them, so long as enough of the option is present to be unambiguous. | |
945 | (If you prefer, you can flag option arguments with @samp{--} rather | |
946 | than @samp{-}, though we illustrate the more usual convention.) | |
947 | ||
d700128c EZ |
948 | @c NOTE: the @cindex entries here use double dashes ON PURPOSE. This |
949 | @c way, both those who look for -foo and --foo in the index, will find | |
950 | @c it. | |
951 | ||
c906108c SS |
952 | @table @code |
953 | @item -symbols @var{file} | |
954 | @itemx -s @var{file} | |
d700128c EZ |
955 | @cindex @code{--symbols} |
956 | @cindex @code{-s} | |
c906108c SS |
957 | Read symbol table from file @var{file}. |
958 | ||
959 | @item -exec @var{file} | |
960 | @itemx -e @var{file} | |
d700128c EZ |
961 | @cindex @code{--exec} |
962 | @cindex @code{-e} | |
7a292a7a SS |
963 | Use file @var{file} as the executable file to execute when appropriate, |
964 | and for examining pure data in conjunction with a core dump. | |
c906108c SS |
965 | |
966 | @item -se @var{file} | |
d700128c | 967 | @cindex @code{--se} |
c906108c SS |
968 | Read symbol table from file @var{file} and use it as the executable |
969 | file. | |
970 | ||
c906108c SS |
971 | @item -core @var{file} |
972 | @itemx -c @var{file} | |
d700128c EZ |
973 | @cindex @code{--core} |
974 | @cindex @code{-c} | |
b383017d | 975 | Use file @var{file} as a core dump to examine. |
c906108c | 976 | |
19837790 MS |
977 | @item -pid @var{number} |
978 | @itemx -p @var{number} | |
979 | @cindex @code{--pid} | |
980 | @cindex @code{-p} | |
981 | Connect to process ID @var{number}, as with the @code{attach} command. | |
c906108c SS |
982 | |
983 | @item -command @var{file} | |
984 | @itemx -x @var{file} | |
d700128c EZ |
985 | @cindex @code{--command} |
986 | @cindex @code{-x} | |
95433b34 JB |
987 | Execute commands from file @var{file}. The contents of this file is |
988 | evaluated exactly as the @code{source} command would. | |
8150ff9c | 989 | @xref{Command Files,, Command files}. |
c906108c | 990 | |
8a5a3c82 AS |
991 | @item -eval-command @var{command} |
992 | @itemx -ex @var{command} | |
993 | @cindex @code{--eval-command} | |
994 | @cindex @code{-ex} | |
995 | Execute a single @value{GDBN} command. | |
996 | ||
997 | This option may be used multiple times to call multiple commands. It may | |
998 | also be interleaved with @samp{-command} as required. | |
999 | ||
1000 | @smallexample | |
1001 | @value{GDBP} -ex 'target sim' -ex 'load' \ | |
1002 | -x setbreakpoints -ex 'run' a.out | |
1003 | @end smallexample | |
1004 | ||
8320cc4f JK |
1005 | @item -init-command @var{file} |
1006 | @itemx -ix @var{file} | |
1007 | @cindex @code{--init-command} | |
1008 | @cindex @code{-ix} | |
2d7b58e8 JK |
1009 | Execute commands from file @var{file} before loading the inferior (but |
1010 | after loading gdbinit files). | |
8320cc4f JK |
1011 | @xref{Startup}. |
1012 | ||
1013 | @item -init-eval-command @var{command} | |
1014 | @itemx -iex @var{command} | |
1015 | @cindex @code{--init-eval-command} | |
1016 | @cindex @code{-iex} | |
2d7b58e8 JK |
1017 | Execute a single @value{GDBN} command before loading the inferior (but |
1018 | after loading gdbinit files). | |
8320cc4f JK |
1019 | @xref{Startup}. |
1020 | ||
c906108c SS |
1021 | @item -directory @var{directory} |
1022 | @itemx -d @var{directory} | |
d700128c EZ |
1023 | @cindex @code{--directory} |
1024 | @cindex @code{-d} | |
4b505b12 | 1025 | Add @var{directory} to the path to search for source and script files. |
c906108c | 1026 | |
c906108c SS |
1027 | @item -r |
1028 | @itemx -readnow | |
d700128c EZ |
1029 | @cindex @code{--readnow} |
1030 | @cindex @code{-r} | |
c906108c SS |
1031 | Read each symbol file's entire symbol table immediately, rather than |
1032 | the default, which is to read it incrementally as it is needed. | |
1033 | This makes startup slower, but makes future operations faster. | |
53a5351d | 1034 | |
c906108c SS |
1035 | @end table |
1036 | ||
6d2ebf8b | 1037 | @node Mode Options |
79a6e687 | 1038 | @subsection Choosing Modes |
c906108c SS |
1039 | |
1040 | You can run @value{GDBN} in various alternative modes---for example, in | |
1041 | batch mode or quiet mode. | |
1042 | ||
1043 | @table @code | |
bf88dd68 | 1044 | @anchor{-nx} |
c906108c SS |
1045 | @item -nx |
1046 | @itemx -n | |
d700128c EZ |
1047 | @cindex @code{--nx} |
1048 | @cindex @code{-n} | |
07540c15 DE |
1049 | Do not execute commands found in any initialization file. |
1050 | There are three init files, loaded in the following order: | |
1051 | ||
1052 | @table @code | |
1053 | @item @file{system.gdbinit} | |
1054 | This is the system-wide init file. | |
1055 | Its location is specified with the @code{--with-system-gdbinit} | |
1056 | configure option (@pxref{System-wide configuration}). | |
1057 | It is loaded first when @value{GDBN} starts, before command line options | |
1058 | have been processed. | |
1059 | @item @file{~/.gdbinit} | |
1060 | This is the init file in your home directory. | |
1061 | It is loaded next, after @file{system.gdbinit}, and before | |
1062 | command options have been processed. | |
1063 | @item @file{./.gdbinit} | |
1064 | This is the init file in the current directory. | |
1065 | It is loaded last, after command line options other than @code{-x} and | |
1066 | @code{-ex} have been processed. Command line options @code{-x} and | |
1067 | @code{-ex} are processed last, after @file{./.gdbinit} has been loaded. | |
1068 | @end table | |
1069 | ||
1070 | For further documentation on startup processing, @xref{Startup}. | |
1071 | For documentation on how to write command files, | |
1072 | @xref{Command Files,,Command Files}. | |
1073 | ||
1074 | @anchor{-nh} | |
1075 | @item -nh | |
1076 | @cindex @code{--nh} | |
1077 | Do not execute commands found in @file{~/.gdbinit}, the init file | |
1078 | in your home directory. | |
1079 | @xref{Startup}. | |
c906108c SS |
1080 | |
1081 | @item -quiet | |
d700128c | 1082 | @itemx -silent |
c906108c | 1083 | @itemx -q |
d700128c EZ |
1084 | @cindex @code{--quiet} |
1085 | @cindex @code{--silent} | |
1086 | @cindex @code{-q} | |
c906108c SS |
1087 | ``Quiet''. Do not print the introductory and copyright messages. These |
1088 | messages are also suppressed in batch mode. | |
1089 | ||
1090 | @item -batch | |
d700128c | 1091 | @cindex @code{--batch} |
c906108c SS |
1092 | Run in batch mode. Exit with status @code{0} after processing all the |
1093 | command files specified with @samp{-x} (and all commands from | |
1094 | initialization files, if not inhibited with @samp{-n}). Exit with | |
1095 | nonzero status if an error occurs in executing the @value{GDBN} commands | |
5da1313b JK |
1096 | in the command files. Batch mode also disables pagination, sets unlimited |
1097 | terminal width and height @pxref{Screen Size}, and acts as if @kbd{set confirm | |
1098 | off} were in effect (@pxref{Messages/Warnings}). | |
c906108c | 1099 | |
2df3850c JM |
1100 | Batch mode may be useful for running @value{GDBN} as a filter, for |
1101 | example to download and run a program on another computer; in order to | |
1102 | make this more useful, the message | |
c906108c | 1103 | |
474c8240 | 1104 | @smallexample |
c906108c | 1105 | Program exited normally. |
474c8240 | 1106 | @end smallexample |
c906108c SS |
1107 | |
1108 | @noindent | |
2df3850c JM |
1109 | (which is ordinarily issued whenever a program running under |
1110 | @value{GDBN} control terminates) is not issued when running in batch | |
1111 | mode. | |
1112 | ||
1a088d06 AS |
1113 | @item -batch-silent |
1114 | @cindex @code{--batch-silent} | |
1115 | Run in batch mode exactly like @samp{-batch}, but totally silently. All | |
1116 | @value{GDBN} output to @code{stdout} is prevented (@code{stderr} is | |
1117 | unaffected). This is much quieter than @samp{-silent} and would be useless | |
1118 | for an interactive session. | |
1119 | ||
1120 | This is particularly useful when using targets that give @samp{Loading section} | |
1121 | messages, for example. | |
1122 | ||
1123 | Note that targets that give their output via @value{GDBN}, as opposed to | |
1124 | writing directly to @code{stdout}, will also be made silent. | |
1125 | ||
4b0ad762 AS |
1126 | @item -return-child-result |
1127 | @cindex @code{--return-child-result} | |
1128 | The return code from @value{GDBN} will be the return code from the child | |
1129 | process (the process being debugged), with the following exceptions: | |
1130 | ||
1131 | @itemize @bullet | |
1132 | @item | |
1133 | @value{GDBN} exits abnormally. E.g., due to an incorrect argument or an | |
1134 | internal error. In this case the exit code is the same as it would have been | |
1135 | without @samp{-return-child-result}. | |
1136 | @item | |
1137 | The user quits with an explicit value. E.g., @samp{quit 1}. | |
1138 | @item | |
1139 | The child process never runs, or is not allowed to terminate, in which case | |
1140 | the exit code will be -1. | |
1141 | @end itemize | |
1142 | ||
1143 | This option is useful in conjunction with @samp{-batch} or @samp{-batch-silent}, | |
1144 | when @value{GDBN} is being used as a remote program loader or simulator | |
1145 | interface. | |
1146 | ||
2df3850c JM |
1147 | @item -nowindows |
1148 | @itemx -nw | |
d700128c EZ |
1149 | @cindex @code{--nowindows} |
1150 | @cindex @code{-nw} | |
2df3850c | 1151 | ``No windows''. If @value{GDBN} comes with a graphical user interface |
96a2c332 | 1152 | (GUI) built in, then this option tells @value{GDBN} to only use the command-line |
2df3850c JM |
1153 | interface. If no GUI is available, this option has no effect. |
1154 | ||
1155 | @item -windows | |
1156 | @itemx -w | |
d700128c EZ |
1157 | @cindex @code{--windows} |
1158 | @cindex @code{-w} | |
2df3850c JM |
1159 | If @value{GDBN} includes a GUI, then this option requires it to be |
1160 | used if possible. | |
c906108c SS |
1161 | |
1162 | @item -cd @var{directory} | |
d700128c | 1163 | @cindex @code{--cd} |
c906108c SS |
1164 | Run @value{GDBN} using @var{directory} as its working directory, |
1165 | instead of the current directory. | |
1166 | ||
aae1c79a | 1167 | @item -data-directory @var{directory} |
8d551b02 | 1168 | @itemx -D @var{directory} |
aae1c79a | 1169 | @cindex @code{--data-directory} |
8d551b02 | 1170 | @cindex @code{-D} |
aae1c79a DE |
1171 | Run @value{GDBN} using @var{directory} as its data directory. |
1172 | The data directory is where @value{GDBN} searches for its | |
1173 | auxiliary files. @xref{Data Files}. | |
1174 | ||
c906108c SS |
1175 | @item -fullname |
1176 | @itemx -f | |
d700128c EZ |
1177 | @cindex @code{--fullname} |
1178 | @cindex @code{-f} | |
7a292a7a SS |
1179 | @sc{gnu} Emacs sets this option when it runs @value{GDBN} as a |
1180 | subprocess. It tells @value{GDBN} to output the full file name and line | |
1181 | number in a standard, recognizable fashion each time a stack frame is | |
1182 | displayed (which includes each time your program stops). This | |
1183 | recognizable format looks like two @samp{\032} characters, followed by | |
1184 | the file name, line number and character position separated by colons, | |
1185 | and a newline. The Emacs-to-@value{GDBN} interface program uses the two | |
1186 | @samp{\032} characters as a signal to display the source code for the | |
1187 | frame. | |
c906108c | 1188 | |
d700128c EZ |
1189 | @item -annotate @var{level} |
1190 | @cindex @code{--annotate} | |
1191 | This option sets the @dfn{annotation level} inside @value{GDBN}. Its | |
1192 | effect is identical to using @samp{set annotate @var{level}} | |
086432e2 AC |
1193 | (@pxref{Annotations}). The annotation @var{level} controls how much |
1194 | information @value{GDBN} prints together with its prompt, values of | |
1195 | expressions, source lines, and other types of output. Level 0 is the | |
1196 | normal, level 1 is for use when @value{GDBN} is run as a subprocess of | |
1197 | @sc{gnu} Emacs, level 3 is the maximum annotation suitable for programs | |
1198 | that control @value{GDBN}, and level 2 has been deprecated. | |
1199 | ||
265eeb58 | 1200 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 | 1201 | (@pxref{GDB/MI}). |
d700128c | 1202 | |
aa26fa3a TT |
1203 | @item --args |
1204 | @cindex @code{--args} | |
1205 | Change interpretation of command line so that arguments following the | |
1206 | executable file are passed as command line arguments to the inferior. | |
1207 | This option stops option processing. | |
1208 | ||
2df3850c JM |
1209 | @item -baud @var{bps} |
1210 | @itemx -b @var{bps} | |
d700128c EZ |
1211 | @cindex @code{--baud} |
1212 | @cindex @code{-b} | |
c906108c SS |
1213 | Set the line speed (baud rate or bits per second) of any serial |
1214 | interface used by @value{GDBN} for remote debugging. | |
c906108c | 1215 | |
f47b1503 AS |
1216 | @item -l @var{timeout} |
1217 | @cindex @code{-l} | |
1218 | Set the timeout (in seconds) of any communication used by @value{GDBN} | |
1219 | for remote debugging. | |
1220 | ||
c906108c | 1221 | @item -tty @var{device} |
d700128c EZ |
1222 | @itemx -t @var{device} |
1223 | @cindex @code{--tty} | |
1224 | @cindex @code{-t} | |
c906108c SS |
1225 | Run using @var{device} for your program's standard input and output. |
1226 | @c FIXME: kingdon thinks there is more to -tty. Investigate. | |
c906108c | 1227 | |
53a5351d | 1228 | @c resolve the situation of these eventually |
c4555f82 SC |
1229 | @item -tui |
1230 | @cindex @code{--tui} | |
d0d5df6f AC |
1231 | Activate the @dfn{Text User Interface} when starting. The Text User |
1232 | Interface manages several text windows on the terminal, showing | |
1233 | source, assembly, registers and @value{GDBN} command outputs | |
217bff3e JK |
1234 | (@pxref{TUI, ,@value{GDBN} Text User Interface}). Do not use this |
1235 | option if you run @value{GDBN} from Emacs (@pxref{Emacs, , | |
1236 | Using @value{GDBN} under @sc{gnu} Emacs}). | |
53a5351d | 1237 | |
d700128c EZ |
1238 | @item -interpreter @var{interp} |
1239 | @cindex @code{--interpreter} | |
1240 | Use the interpreter @var{interp} for interface with the controlling | |
1241 | program or device. This option is meant to be set by programs which | |
94bbb2c0 | 1242 | communicate with @value{GDBN} using it as a back end. |
21c294e6 | 1243 | @xref{Interpreters, , Command Interpreters}. |
94bbb2c0 | 1244 | |
da0f9dcd | 1245 | @samp{--interpreter=mi} (or @samp{--interpreter=mi2}) causes |
2fcf52f0 | 1246 | @value{GDBN} to use the @dfn{@sc{gdb/mi} interface} (@pxref{GDB/MI, , |
6b5e8c01 | 1247 | The @sc{gdb/mi} Interface}) included since @value{GDBN} version 6.0. The |
6c74ac8b AC |
1248 | previous @sc{gdb/mi} interface, included in @value{GDBN} version 5.3 and |
1249 | selected with @samp{--interpreter=mi1}, is deprecated. Earlier | |
1250 | @sc{gdb/mi} interfaces are no longer supported. | |
d700128c EZ |
1251 | |
1252 | @item -write | |
1253 | @cindex @code{--write} | |
1254 | Open the executable and core files for both reading and writing. This | |
1255 | is equivalent to the @samp{set write on} command inside @value{GDBN} | |
1256 | (@pxref{Patching}). | |
1257 | ||
1258 | @item -statistics | |
1259 | @cindex @code{--statistics} | |
1260 | This option causes @value{GDBN} to print statistics about time and | |
1261 | memory usage after it completes each command and returns to the prompt. | |
1262 | ||
1263 | @item -version | |
1264 | @cindex @code{--version} | |
1265 | This option causes @value{GDBN} to print its version number and | |
1266 | no-warranty blurb, and exit. | |
1267 | ||
6eaaf48b EZ |
1268 | @item -configuration |
1269 | @cindex @code{--configuration} | |
1270 | This option causes @value{GDBN} to print details about its build-time | |
1271 | configuration parameters, and then exit. These details can be | |
1272 | important when reporting @value{GDBN} bugs (@pxref{GDB Bugs}). | |
1273 | ||
c906108c SS |
1274 | @end table |
1275 | ||
6fc08d32 | 1276 | @node Startup |
79a6e687 | 1277 | @subsection What @value{GDBN} Does During Startup |
6fc08d32 EZ |
1278 | @cindex @value{GDBN} startup |
1279 | ||
1280 | Here's the description of what @value{GDBN} does during session startup: | |
1281 | ||
1282 | @enumerate | |
1283 | @item | |
1284 | Sets up the command interpreter as specified by the command line | |
1285 | (@pxref{Mode Options, interpreter}). | |
1286 | ||
1287 | @item | |
1288 | @cindex init file | |
098b41a6 JG |
1289 | Reads the system-wide @dfn{init file} (if @option{--with-system-gdbinit} was |
1290 | used when building @value{GDBN}; @pxref{System-wide configuration, | |
1291 | ,System-wide configuration and settings}) and executes all the commands in | |
1292 | that file. | |
1293 | ||
bf88dd68 | 1294 | @anchor{Home Directory Init File} |
098b41a6 JG |
1295 | @item |
1296 | Reads the init file (if any) in your home directory@footnote{On | |
6fc08d32 EZ |
1297 | DOS/Windows systems, the home directory is the one pointed to by the |
1298 | @code{HOME} environment variable.} and executes all the commands in | |
1299 | that file. | |
1300 | ||
2d7b58e8 JK |
1301 | @anchor{Option -init-eval-command} |
1302 | @item | |
1303 | Executes commands and command files specified by the @samp{-iex} and | |
1304 | @samp{-ix} options in their specified order. Usually you should use the | |
1305 | @samp{-ex} and @samp{-x} options instead, but this way you can apply | |
1306 | settings before @value{GDBN} init files get executed and before inferior | |
1307 | gets loaded. | |
1308 | ||
6fc08d32 EZ |
1309 | @item |
1310 | Processes command line options and operands. | |
1311 | ||
bf88dd68 | 1312 | @anchor{Init File in the Current Directory during Startup} |
6fc08d32 EZ |
1313 | @item |
1314 | Reads and executes the commands from init file (if any) in the current | |
bf88dd68 JK |
1315 | working directory as long as @samp{set auto-load local-gdbinit} is set to |
1316 | @samp{on} (@pxref{Init File in the Current Directory}). | |
1317 | This is only done if the current directory is | |
119b882a EZ |
1318 | different from your home directory. Thus, you can have more than one |
1319 | init file, one generic in your home directory, and another, specific | |
1320 | to the program you are debugging, in the directory where you invoke | |
6fc08d32 EZ |
1321 | @value{GDBN}. |
1322 | ||
a86caf66 DE |
1323 | @item |
1324 | If the command line specified a program to debug, or a process to | |
1325 | attach to, or a core file, @value{GDBN} loads any auto-loaded | |
1326 | scripts provided for the program or for its loaded shared libraries. | |
1327 | @xref{Auto-loading}. | |
1328 | ||
1329 | If you wish to disable the auto-loading during startup, | |
1330 | you must do something like the following: | |
1331 | ||
1332 | @smallexample | |
bf88dd68 | 1333 | $ gdb -iex "set auto-load python-scripts off" myprogram |
a86caf66 DE |
1334 | @end smallexample |
1335 | ||
8320cc4f JK |
1336 | Option @samp{-ex} does not work because the auto-loading is then turned |
1337 | off too late. | |
a86caf66 | 1338 | |
6fc08d32 | 1339 | @item |
6fe37d23 JK |
1340 | Executes commands and command files specified by the @samp{-ex} and |
1341 | @samp{-x} options in their specified order. @xref{Command Files}, for | |
1342 | more details about @value{GDBN} command files. | |
6fc08d32 EZ |
1343 | |
1344 | @item | |
1345 | Reads the command history recorded in the @dfn{history file}. | |
d620b259 | 1346 | @xref{Command History}, for more details about the command history and the |
6fc08d32 EZ |
1347 | files where @value{GDBN} records it. |
1348 | @end enumerate | |
1349 | ||
1350 | Init files use the same syntax as @dfn{command files} (@pxref{Command | |
1351 | Files}) and are processed by @value{GDBN} in the same way. The init | |
1352 | file in your home directory can set options (such as @samp{set | |
1353 | complaints}) that affect subsequent processing of command line options | |
1354 | and operands. Init files are not executed if you use the @samp{-nx} | |
79a6e687 | 1355 | option (@pxref{Mode Options, ,Choosing Modes}). |
6fc08d32 | 1356 | |
098b41a6 JG |
1357 | To display the list of init files loaded by gdb at startup, you |
1358 | can use @kbd{gdb --help}. | |
1359 | ||
6fc08d32 EZ |
1360 | @cindex init file name |
1361 | @cindex @file{.gdbinit} | |
119b882a | 1362 | @cindex @file{gdb.ini} |
8807d78b | 1363 | The @value{GDBN} init files are normally called @file{.gdbinit}. |
119b882a EZ |
1364 | The DJGPP port of @value{GDBN} uses the name @file{gdb.ini}, due to |
1365 | the limitations of file names imposed by DOS filesystems. The Windows | |
4d3f93a2 JB |
1366 | port of @value{GDBN} uses the standard name, but if it finds a |
1367 | @file{gdb.ini} file in your home directory, it warns you about that | |
1368 | and suggests to rename the file to the standard name. | |
119b882a | 1369 | |
6fc08d32 | 1370 | |
6d2ebf8b | 1371 | @node Quitting GDB |
c906108c SS |
1372 | @section Quitting @value{GDBN} |
1373 | @cindex exiting @value{GDBN} | |
1374 | @cindex leaving @value{GDBN} | |
1375 | ||
1376 | @table @code | |
1377 | @kindex quit @r{[}@var{expression}@r{]} | |
41afff9a | 1378 | @kindex q @r{(@code{quit})} |
96a2c332 SS |
1379 | @item quit @r{[}@var{expression}@r{]} |
1380 | @itemx q | |
1381 | To exit @value{GDBN}, use the @code{quit} command (abbreviated | |
c8aa23ab | 1382 | @code{q}), or type an end-of-file character (usually @kbd{Ctrl-d}). If you |
96a2c332 SS |
1383 | do not supply @var{expression}, @value{GDBN} will terminate normally; |
1384 | otherwise it will terminate using the result of @var{expression} as the | |
1385 | error code. | |
c906108c SS |
1386 | @end table |
1387 | ||
1388 | @cindex interrupt | |
c8aa23ab | 1389 | An interrupt (often @kbd{Ctrl-c}) does not exit from @value{GDBN}, but rather |
c906108c SS |
1390 | terminates the action of any @value{GDBN} command that is in progress and |
1391 | returns to @value{GDBN} command level. It is safe to type the interrupt | |
1392 | character at any time because @value{GDBN} does not allow it to take effect | |
1393 | until a time when it is safe. | |
1394 | ||
c906108c SS |
1395 | If you have been using @value{GDBN} to control an attached process or |
1396 | device, you can release it with the @code{detach} command | |
79a6e687 | 1397 | (@pxref{Attach, ,Debugging an Already-running Process}). |
c906108c | 1398 | |
6d2ebf8b | 1399 | @node Shell Commands |
79a6e687 | 1400 | @section Shell Commands |
c906108c SS |
1401 | |
1402 | If you need to execute occasional shell commands during your | |
1403 | debugging session, there is no need to leave or suspend @value{GDBN}; you can | |
1404 | just use the @code{shell} command. | |
1405 | ||
1406 | @table @code | |
1407 | @kindex shell | |
ed59ded5 | 1408 | @kindex ! |
c906108c | 1409 | @cindex shell escape |
ed59ded5 DE |
1410 | @item shell @var{command-string} |
1411 | @itemx !@var{command-string} | |
1412 | Invoke a standard shell to execute @var{command-string}. | |
1413 | Note that no space is needed between @code{!} and @var{command-string}. | |
c906108c | 1414 | If it exists, the environment variable @code{SHELL} determines which |
d4f3574e SS |
1415 | shell to run. Otherwise @value{GDBN} uses the default shell |
1416 | (@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.). | |
c906108c SS |
1417 | @end table |
1418 | ||
1419 | The utility @code{make} is often needed in development environments. | |
1420 | You do not have to use the @code{shell} command for this purpose in | |
1421 | @value{GDBN}: | |
1422 | ||
1423 | @table @code | |
1424 | @kindex make | |
1425 | @cindex calling make | |
1426 | @item make @var{make-args} | |
1427 | Execute the @code{make} program with the specified | |
1428 | arguments. This is equivalent to @samp{shell make @var{make-args}}. | |
1429 | @end table | |
1430 | ||
79a6e687 BW |
1431 | @node Logging Output |
1432 | @section Logging Output | |
0fac0b41 | 1433 | @cindex logging @value{GDBN} output |
9c16f35a | 1434 | @cindex save @value{GDBN} output to a file |
0fac0b41 DJ |
1435 | |
1436 | You may want to save the output of @value{GDBN} commands to a file. | |
1437 | There are several commands to control @value{GDBN}'s logging. | |
1438 | ||
1439 | @table @code | |
1440 | @kindex set logging | |
1441 | @item set logging on | |
1442 | Enable logging. | |
1443 | @item set logging off | |
1444 | Disable logging. | |
9c16f35a | 1445 | @cindex logging file name |
0fac0b41 DJ |
1446 | @item set logging file @var{file} |
1447 | Change the name of the current logfile. The default logfile is @file{gdb.txt}. | |
1448 | @item set logging overwrite [on|off] | |
1449 | By default, @value{GDBN} will append to the logfile. Set @code{overwrite} if | |
1450 | you want @code{set logging on} to overwrite the logfile instead. | |
1451 | @item set logging redirect [on|off] | |
1452 | By default, @value{GDBN} output will go to both the terminal and the logfile. | |
1453 | Set @code{redirect} if you want output to go only to the log file. | |
1454 | @kindex show logging | |
1455 | @item show logging | |
1456 | Show the current values of the logging settings. | |
1457 | @end table | |
1458 | ||
6d2ebf8b | 1459 | @node Commands |
c906108c SS |
1460 | @chapter @value{GDBN} Commands |
1461 | ||
1462 | You can abbreviate a @value{GDBN} command to the first few letters of the command | |
1463 | name, if that abbreviation is unambiguous; and you can repeat certain | |
1464 | @value{GDBN} commands by typing just @key{RET}. You can also use the @key{TAB} | |
1465 | key to get @value{GDBN} to fill out the rest of a word in a command (or to | |
1466 | show you the alternatives available, if there is more than one possibility). | |
1467 | ||
1468 | @menu | |
1469 | * Command Syntax:: How to give commands to @value{GDBN} | |
1470 | * Completion:: Command completion | |
1471 | * Help:: How to ask @value{GDBN} for help | |
1472 | @end menu | |
1473 | ||
6d2ebf8b | 1474 | @node Command Syntax |
79a6e687 | 1475 | @section Command Syntax |
c906108c SS |
1476 | |
1477 | A @value{GDBN} command is a single line of input. There is no limit on | |
1478 | how long it can be. It starts with a command name, which is followed by | |
1479 | arguments whose meaning depends on the command name. For example, the | |
1480 | command @code{step} accepts an argument which is the number of times to | |
1481 | step, as in @samp{step 5}. You can also use the @code{step} command | |
96a2c332 | 1482 | with no arguments. Some commands do not allow any arguments. |
c906108c SS |
1483 | |
1484 | @cindex abbreviation | |
1485 | @value{GDBN} command names may always be truncated if that abbreviation is | |
1486 | unambiguous. Other possible command abbreviations are listed in the | |
1487 | documentation for individual commands. In some cases, even ambiguous | |
1488 | abbreviations are allowed; for example, @code{s} is specially defined as | |
1489 | equivalent to @code{step} even though there are other commands whose | |
1490 | names start with @code{s}. You can test abbreviations by using them as | |
1491 | arguments to the @code{help} command. | |
1492 | ||
1493 | @cindex repeating commands | |
41afff9a | 1494 | @kindex RET @r{(repeat last command)} |
c906108c | 1495 | A blank line as input to @value{GDBN} (typing just @key{RET}) means to |
96a2c332 | 1496 | repeat the previous command. Certain commands (for example, @code{run}) |
c906108c SS |
1497 | will not repeat this way; these are commands whose unintentional |
1498 | repetition might cause trouble and which you are unlikely to want to | |
c45da7e6 EZ |
1499 | repeat. User-defined commands can disable this feature; see |
1500 | @ref{Define, dont-repeat}. | |
c906108c SS |
1501 | |
1502 | The @code{list} and @code{x} commands, when you repeat them with | |
1503 | @key{RET}, construct new arguments rather than repeating | |
1504 | exactly as typed. This permits easy scanning of source or memory. | |
1505 | ||
1506 | @value{GDBN} can also use @key{RET} in another way: to partition lengthy | |
1507 | output, in a way similar to the common utility @code{more} | |
79a6e687 | 1508 | (@pxref{Screen Size,,Screen Size}). Since it is easy to press one |
c906108c SS |
1509 | @key{RET} too many in this situation, @value{GDBN} disables command |
1510 | repetition after any command that generates this sort of display. | |
1511 | ||
41afff9a | 1512 | @kindex # @r{(a comment)} |
c906108c SS |
1513 | @cindex comment |
1514 | Any text from a @kbd{#} to the end of the line is a comment; it does | |
1515 | nothing. This is useful mainly in command files (@pxref{Command | |
79a6e687 | 1516 | Files,,Command Files}). |
c906108c | 1517 | |
88118b3a | 1518 | @cindex repeating command sequences |
c8aa23ab EZ |
1519 | @kindex Ctrl-o @r{(operate-and-get-next)} |
1520 | The @kbd{Ctrl-o} binding is useful for repeating a complex sequence of | |
7f9087cb | 1521 | commands. This command accepts the current line, like @key{RET}, and |
88118b3a TT |
1522 | then fetches the next line relative to the current line from the history |
1523 | for editing. | |
1524 | ||
6d2ebf8b | 1525 | @node Completion |
79a6e687 | 1526 | @section Command Completion |
c906108c SS |
1527 | |
1528 | @cindex completion | |
1529 | @cindex word completion | |
1530 | @value{GDBN} can fill in the rest of a word in a command for you, if there is | |
1531 | only one possibility; it can also show you what the valid possibilities | |
1532 | are for the next word in a command, at any time. This works for @value{GDBN} | |
1533 | commands, @value{GDBN} subcommands, and the names of symbols in your program. | |
1534 | ||
1535 | Press the @key{TAB} key whenever you want @value{GDBN} to fill out the rest | |
1536 | of a word. If there is only one possibility, @value{GDBN} fills in the | |
1537 | word, and waits for you to finish the command (or press @key{RET} to | |
1538 | enter it). For example, if you type | |
1539 | ||
1540 | @c FIXME "@key" does not distinguish its argument sufficiently to permit | |
1541 | @c complete accuracy in these examples; space introduced for clarity. | |
1542 | @c If texinfo enhancements make it unnecessary, it would be nice to | |
1543 | @c replace " @key" by "@key" in the following... | |
474c8240 | 1544 | @smallexample |
c906108c | 1545 | (@value{GDBP}) info bre @key{TAB} |
474c8240 | 1546 | @end smallexample |
c906108c SS |
1547 | |
1548 | @noindent | |
1549 | @value{GDBN} fills in the rest of the word @samp{breakpoints}, since that is | |
1550 | the only @code{info} subcommand beginning with @samp{bre}: | |
1551 | ||
474c8240 | 1552 | @smallexample |
c906108c | 1553 | (@value{GDBP}) info breakpoints |
474c8240 | 1554 | @end smallexample |
c906108c SS |
1555 | |
1556 | @noindent | |
1557 | You can either press @key{RET} at this point, to run the @code{info | |
1558 | breakpoints} command, or backspace and enter something else, if | |
1559 | @samp{breakpoints} does not look like the command you expected. (If you | |
1560 | were sure you wanted @code{info breakpoints} in the first place, you | |
1561 | might as well just type @key{RET} immediately after @samp{info bre}, | |
1562 | to exploit command abbreviations rather than command completion). | |
1563 | ||
1564 | If there is more than one possibility for the next word when you press | |
1565 | @key{TAB}, @value{GDBN} sounds a bell. You can either supply more | |
1566 | characters and try again, or just press @key{TAB} a second time; | |
1567 | @value{GDBN} displays all the possible completions for that word. For | |
1568 | example, you might want to set a breakpoint on a subroutine whose name | |
1569 | begins with @samp{make_}, but when you type @kbd{b make_@key{TAB}} @value{GDBN} | |
1570 | just sounds the bell. Typing @key{TAB} again displays all the | |
1571 | function names in your program that begin with those characters, for | |
1572 | example: | |
1573 | ||
474c8240 | 1574 | @smallexample |
c906108c SS |
1575 | (@value{GDBP}) b make_ @key{TAB} |
1576 | @exdent @value{GDBN} sounds bell; press @key{TAB} again, to see: | |
5d161b24 DB |
1577 | make_a_section_from_file make_environ |
1578 | make_abs_section make_function_type | |
1579 | make_blockvector make_pointer_type | |
1580 | make_cleanup make_reference_type | |
c906108c SS |
1581 | make_command make_symbol_completion_list |
1582 | (@value{GDBP}) b make_ | |
474c8240 | 1583 | @end smallexample |
c906108c SS |
1584 | |
1585 | @noindent | |
1586 | After displaying the available possibilities, @value{GDBN} copies your | |
1587 | partial input (@samp{b make_} in the example) so you can finish the | |
1588 | command. | |
1589 | ||
1590 | If you just want to see the list of alternatives in the first place, you | |
b37052ae | 1591 | can press @kbd{M-?} rather than pressing @key{TAB} twice. @kbd{M-?} |
7a292a7a | 1592 | means @kbd{@key{META} ?}. You can type this either by holding down a |
c906108c | 1593 | key designated as the @key{META} shift on your keyboard (if there is |
7a292a7a | 1594 | one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}. |
c906108c | 1595 | |
ef0b411a GB |
1596 | If the number of possible completions is large, @value{GDBN} will |
1597 | print as much of the list as it has collected, as well as a message | |
1598 | indicating that the list may be truncated. | |
1599 | ||
1600 | @smallexample | |
1601 | (@value{GDBP}) b m@key{TAB}@key{TAB} | |
1602 | main | |
1603 | <... the rest of the possible completions ...> | |
1604 | *** List may be truncated, max-completions reached. *** | |
1605 | (@value{GDBP}) b m | |
1606 | @end smallexample | |
1607 | ||
1608 | @noindent | |
1609 | This behavior can be controlled with the following commands: | |
1610 | ||
1611 | @table @code | |
1612 | @kindex set max-completions | |
1613 | @item set max-completions @var{limit} | |
1614 | @itemx set max-completions unlimited | |
1615 | Set the maximum number of completion candidates. @value{GDBN} will | |
1616 | stop looking for more completions once it collects this many candidates. | |
1617 | This is useful when completing on things like function names as collecting | |
1618 | all the possible candidates can be time consuming. | |
1619 | The default value is 200. A value of zero disables tab-completion. | |
1620 | Note that setting either no limit or a very large limit can make | |
1621 | completion slow. | |
1622 | @kindex show max-completions | |
1623 | @item show max-completions | |
1624 | Show the maximum number of candidates that @value{GDBN} will collect and show | |
1625 | during completion. | |
1626 | @end table | |
1627 | ||
c906108c SS |
1628 | @cindex quotes in commands |
1629 | @cindex completion of quoted strings | |
1630 | Sometimes the string you need, while logically a ``word'', may contain | |
7a292a7a SS |
1631 | parentheses or other characters that @value{GDBN} normally excludes from |
1632 | its notion of a word. To permit word completion to work in this | |
1633 | situation, you may enclose words in @code{'} (single quote marks) in | |
1634 | @value{GDBN} commands. | |
c906108c | 1635 | |
c906108c | 1636 | The most likely situation where you might need this is in typing the |
b37052ae EZ |
1637 | name of a C@t{++} function. This is because C@t{++} allows function |
1638 | overloading (multiple definitions of the same function, distinguished | |
1639 | by argument type). For example, when you want to set a breakpoint you | |
1640 | may need to distinguish whether you mean the version of @code{name} | |
1641 | that takes an @code{int} parameter, @code{name(int)}, or the version | |
1642 | that takes a @code{float} parameter, @code{name(float)}. To use the | |
1643 | word-completion facilities in this situation, type a single quote | |
1644 | @code{'} at the beginning of the function name. This alerts | |
1645 | @value{GDBN} that it may need to consider more information than usual | |
1646 | when you press @key{TAB} or @kbd{M-?} to request word completion: | |
c906108c | 1647 | |
474c8240 | 1648 | @smallexample |
96a2c332 | 1649 | (@value{GDBP}) b 'bubble( @kbd{M-?} |
c906108c SS |
1650 | bubble(double,double) bubble(int,int) |
1651 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1652 | @end smallexample |
c906108c SS |
1653 | |
1654 | In some cases, @value{GDBN} can tell that completing a name requires using | |
1655 | quotes. When this happens, @value{GDBN} inserts the quote for you (while | |
1656 | completing as much as it can) if you do not type the quote in the first | |
1657 | place: | |
1658 | ||
474c8240 | 1659 | @smallexample |
c906108c SS |
1660 | (@value{GDBP}) b bub @key{TAB} |
1661 | @exdent @value{GDBN} alters your input line to the following, and rings a bell: | |
1662 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1663 | @end smallexample |
c906108c SS |
1664 | |
1665 | @noindent | |
1666 | In general, @value{GDBN} can tell that a quote is needed (and inserts it) if | |
1667 | you have not yet started typing the argument list when you ask for | |
1668 | completion on an overloaded symbol. | |
1669 | ||
79a6e687 BW |
1670 | For more information about overloaded functions, see @ref{C Plus Plus |
1671 | Expressions, ,C@t{++} Expressions}. You can use the command @code{set | |
c906108c | 1672 | overload-resolution off} to disable overload resolution; |
79a6e687 | 1673 | see @ref{Debugging C Plus Plus, ,@value{GDBN} Features for C@t{++}}. |
c906108c | 1674 | |
65d12d83 TT |
1675 | @cindex completion of structure field names |
1676 | @cindex structure field name completion | |
1677 | @cindex completion of union field names | |
1678 | @cindex union field name completion | |
1679 | When completing in an expression which looks up a field in a | |
1680 | structure, @value{GDBN} also tries@footnote{The completer can be | |
1681 | confused by certain kinds of invalid expressions. Also, it only | |
1682 | examines the static type of the expression, not the dynamic type.} to | |
1683 | limit completions to the field names available in the type of the | |
1684 | left-hand-side: | |
1685 | ||
1686 | @smallexample | |
1687 | (@value{GDBP}) p gdb_stdout.@kbd{M-?} | |
01124a23 DE |
1688 | magic to_fputs to_rewind |
1689 | to_data to_isatty to_write | |
1690 | to_delete to_put to_write_async_safe | |
1691 | to_flush to_read | |
65d12d83 TT |
1692 | @end smallexample |
1693 | ||
1694 | @noindent | |
1695 | This is because the @code{gdb_stdout} is a variable of the type | |
1696 | @code{struct ui_file} that is defined in @value{GDBN} sources as | |
1697 | follows: | |
1698 | ||
1699 | @smallexample | |
1700 | struct ui_file | |
1701 | @{ | |
1702 | int *magic; | |
1703 | ui_file_flush_ftype *to_flush; | |
1704 | ui_file_write_ftype *to_write; | |
01124a23 | 1705 | ui_file_write_async_safe_ftype *to_write_async_safe; |
65d12d83 TT |
1706 | ui_file_fputs_ftype *to_fputs; |
1707 | ui_file_read_ftype *to_read; | |
1708 | ui_file_delete_ftype *to_delete; | |
1709 | ui_file_isatty_ftype *to_isatty; | |
1710 | ui_file_rewind_ftype *to_rewind; | |
1711 | ui_file_put_ftype *to_put; | |
1712 | void *to_data; | |
1713 | @} | |
1714 | @end smallexample | |
1715 | ||
c906108c | 1716 | |
6d2ebf8b | 1717 | @node Help |
79a6e687 | 1718 | @section Getting Help |
c906108c SS |
1719 | @cindex online documentation |
1720 | @kindex help | |
1721 | ||
5d161b24 | 1722 | You can always ask @value{GDBN} itself for information on its commands, |
c906108c SS |
1723 | using the command @code{help}. |
1724 | ||
1725 | @table @code | |
41afff9a | 1726 | @kindex h @r{(@code{help})} |
c906108c SS |
1727 | @item help |
1728 | @itemx h | |
1729 | You can use @code{help} (abbreviated @code{h}) with no arguments to | |
1730 | display a short list of named classes of commands: | |
1731 | ||
1732 | @smallexample | |
1733 | (@value{GDBP}) help | |
1734 | List of classes of commands: | |
1735 | ||
2df3850c | 1736 | aliases -- Aliases of other commands |
c906108c | 1737 | breakpoints -- Making program stop at certain points |
2df3850c | 1738 | data -- Examining data |
c906108c | 1739 | files -- Specifying and examining files |
2df3850c JM |
1740 | internals -- Maintenance commands |
1741 | obscure -- Obscure features | |
1742 | running -- Running the program | |
1743 | stack -- Examining the stack | |
c906108c SS |
1744 | status -- Status inquiries |
1745 | support -- Support facilities | |
12c27660 | 1746 | tracepoints -- Tracing of program execution without |
96a2c332 | 1747 | stopping the program |
c906108c | 1748 | user-defined -- User-defined commands |
c906108c | 1749 | |
5d161b24 | 1750 | Type "help" followed by a class name for a list of |
c906108c | 1751 | commands in that class. |
5d161b24 | 1752 | Type "help" followed by command name for full |
c906108c SS |
1753 | documentation. |
1754 | Command name abbreviations are allowed if unambiguous. | |
1755 | (@value{GDBP}) | |
1756 | @end smallexample | |
96a2c332 | 1757 | @c the above line break eliminates huge line overfull... |
c906108c SS |
1758 | |
1759 | @item help @var{class} | |
1760 | Using one of the general help classes as an argument, you can get a | |
1761 | list of the individual commands in that class. For example, here is the | |
1762 | help display for the class @code{status}: | |
1763 | ||
1764 | @smallexample | |
1765 | (@value{GDBP}) help status | |
1766 | Status inquiries. | |
1767 | ||
1768 | List of commands: | |
1769 | ||
1770 | @c Line break in "show" line falsifies real output, but needed | |
1771 | @c to fit in smallbook page size. | |
2df3850c | 1772 | info -- Generic command for showing things |
12c27660 | 1773 | about the program being debugged |
2df3850c | 1774 | show -- Generic command for showing things |
12c27660 | 1775 | about the debugger |
c906108c | 1776 | |
5d161b24 | 1777 | Type "help" followed by command name for full |
c906108c SS |
1778 | documentation. |
1779 | Command name abbreviations are allowed if unambiguous. | |
1780 | (@value{GDBP}) | |
1781 | @end smallexample | |
1782 | ||
1783 | @item help @var{command} | |
1784 | With a command name as @code{help} argument, @value{GDBN} displays a | |
1785 | short paragraph on how to use that command. | |
1786 | ||
6837a0a2 DB |
1787 | @kindex apropos |
1788 | @item apropos @var{args} | |
09d4efe1 | 1789 | The @code{apropos} command searches through all of the @value{GDBN} |
6837a0a2 | 1790 | commands, and their documentation, for the regular expression specified in |
99e008fe | 1791 | @var{args}. It prints out all matches found. For example: |
6837a0a2 DB |
1792 | |
1793 | @smallexample | |
16899756 | 1794 | apropos alias |
6837a0a2 DB |
1795 | @end smallexample |
1796 | ||
b37052ae EZ |
1797 | @noindent |
1798 | results in: | |
6837a0a2 DB |
1799 | |
1800 | @smallexample | |
6d2ebf8b | 1801 | @c @group |
16899756 DE |
1802 | alias -- Define a new command that is an alias of an existing command |
1803 | aliases -- Aliases of other commands | |
1804 | d -- Delete some breakpoints or auto-display expressions | |
1805 | del -- Delete some breakpoints or auto-display expressions | |
1806 | delete -- Delete some breakpoints or auto-display expressions | |
6d2ebf8b | 1807 | @c @end group |
6837a0a2 DB |
1808 | @end smallexample |
1809 | ||
c906108c SS |
1810 | @kindex complete |
1811 | @item complete @var{args} | |
1812 | The @code{complete @var{args}} command lists all the possible completions | |
1813 | for the beginning of a command. Use @var{args} to specify the beginning of the | |
1814 | command you want completed. For example: | |
1815 | ||
1816 | @smallexample | |
1817 | complete i | |
1818 | @end smallexample | |
1819 | ||
1820 | @noindent results in: | |
1821 | ||
1822 | @smallexample | |
1823 | @group | |
2df3850c JM |
1824 | if |
1825 | ignore | |
c906108c SS |
1826 | info |
1827 | inspect | |
c906108c SS |
1828 | @end group |
1829 | @end smallexample | |
1830 | ||
1831 | @noindent This is intended for use by @sc{gnu} Emacs. | |
1832 | @end table | |
1833 | ||
1834 | In addition to @code{help}, you can use the @value{GDBN} commands @code{info} | |
1835 | and @code{show} to inquire about the state of your program, or the state | |
1836 | of @value{GDBN} itself. Each command supports many topics of inquiry; this | |
1837 | manual introduces each of them in the appropriate context. The listings | |
00595b5e EZ |
1838 | under @code{info} and under @code{show} in the Command, Variable, and |
1839 | Function Index point to all the sub-commands. @xref{Command and Variable | |
1840 | Index}. | |
c906108c SS |
1841 | |
1842 | @c @group | |
1843 | @table @code | |
1844 | @kindex info | |
41afff9a | 1845 | @kindex i @r{(@code{info})} |
c906108c SS |
1846 | @item info |
1847 | This command (abbreviated @code{i}) is for describing the state of your | |
cda4ce5a | 1848 | program. For example, you can show the arguments passed to a function |
c906108c SS |
1849 | with @code{info args}, list the registers currently in use with @code{info |
1850 | registers}, or list the breakpoints you have set with @code{info breakpoints}. | |
1851 | You can get a complete list of the @code{info} sub-commands with | |
1852 | @w{@code{help info}}. | |
1853 | ||
1854 | @kindex set | |
1855 | @item set | |
5d161b24 | 1856 | You can assign the result of an expression to an environment variable with |
c906108c SS |
1857 | @code{set}. For example, you can set the @value{GDBN} prompt to a $-sign with |
1858 | @code{set prompt $}. | |
1859 | ||
1860 | @kindex show | |
1861 | @item show | |
5d161b24 | 1862 | In contrast to @code{info}, @code{show} is for describing the state of |
c906108c SS |
1863 | @value{GDBN} itself. |
1864 | You can change most of the things you can @code{show}, by using the | |
1865 | related command @code{set}; for example, you can control what number | |
1866 | system is used for displays with @code{set radix}, or simply inquire | |
1867 | which is currently in use with @code{show radix}. | |
1868 | ||
1869 | @kindex info set | |
1870 | To display all the settable parameters and their current | |
1871 | values, you can use @code{show} with no arguments; you may also use | |
1872 | @code{info set}. Both commands produce the same display. | |
1873 | @c FIXME: "info set" violates the rule that "info" is for state of | |
1874 | @c FIXME...program. Ck w/ GNU: "info set" to be called something else, | |
1875 | @c FIXME...or change desc of rule---eg "state of prog and debugging session"? | |
1876 | @end table | |
1877 | @c @end group | |
1878 | ||
6eaaf48b | 1879 | Here are several miscellaneous @code{show} subcommands, all of which are |
c906108c SS |
1880 | exceptional in lacking corresponding @code{set} commands: |
1881 | ||
1882 | @table @code | |
1883 | @kindex show version | |
9c16f35a | 1884 | @cindex @value{GDBN} version number |
c906108c SS |
1885 | @item show version |
1886 | Show what version of @value{GDBN} is running. You should include this | |
2df3850c JM |
1887 | information in @value{GDBN} bug-reports. If multiple versions of |
1888 | @value{GDBN} are in use at your site, you may need to determine which | |
1889 | version of @value{GDBN} you are running; as @value{GDBN} evolves, new | |
1890 | commands are introduced, and old ones may wither away. Also, many | |
1891 | system vendors ship variant versions of @value{GDBN}, and there are | |
96a2c332 | 1892 | variant versions of @value{GDBN} in @sc{gnu}/Linux distributions as well. |
2df3850c JM |
1893 | The version number is the same as the one announced when you start |
1894 | @value{GDBN}. | |
c906108c SS |
1895 | |
1896 | @kindex show copying | |
09d4efe1 | 1897 | @kindex info copying |
9c16f35a | 1898 | @cindex display @value{GDBN} copyright |
c906108c | 1899 | @item show copying |
09d4efe1 | 1900 | @itemx info copying |
c906108c SS |
1901 | Display information about permission for copying @value{GDBN}. |
1902 | ||
1903 | @kindex show warranty | |
09d4efe1 | 1904 | @kindex info warranty |
c906108c | 1905 | @item show warranty |
09d4efe1 | 1906 | @itemx info warranty |
2df3850c | 1907 | Display the @sc{gnu} ``NO WARRANTY'' statement, or a warranty, |
96a2c332 | 1908 | if your version of @value{GDBN} comes with one. |
2df3850c | 1909 | |
6eaaf48b EZ |
1910 | @kindex show configuration |
1911 | @item show configuration | |
1912 | Display detailed information about the way @value{GDBN} was configured | |
1913 | when it was built. This displays the optional arguments passed to the | |
1914 | @file{configure} script and also configuration parameters detected | |
1915 | automatically by @command{configure}. When reporting a @value{GDBN} | |
1916 | bug (@pxref{GDB Bugs}), it is important to include this information in | |
1917 | your report. | |
1918 | ||
c906108c SS |
1919 | @end table |
1920 | ||
6d2ebf8b | 1921 | @node Running |
c906108c SS |
1922 | @chapter Running Programs Under @value{GDBN} |
1923 | ||
1924 | When you run a program under @value{GDBN}, you must first generate | |
1925 | debugging information when you compile it. | |
7a292a7a SS |
1926 | |
1927 | You may start @value{GDBN} with its arguments, if any, in an environment | |
1928 | of your choice. If you are doing native debugging, you may redirect | |
1929 | your program's input and output, debug an already running process, or | |
1930 | kill a child process. | |
c906108c SS |
1931 | |
1932 | @menu | |
1933 | * Compilation:: Compiling for debugging | |
1934 | * Starting:: Starting your program | |
c906108c SS |
1935 | * Arguments:: Your program's arguments |
1936 | * Environment:: Your program's environment | |
c906108c SS |
1937 | |
1938 | * Working Directory:: Your program's working directory | |
1939 | * Input/Output:: Your program's input and output | |
1940 | * Attach:: Debugging an already-running process | |
1941 | * Kill Process:: Killing the child process | |
c906108c | 1942 | |
6c95b8df | 1943 | * Inferiors and Programs:: Debugging multiple inferiors and programs |
c906108c | 1944 | * Threads:: Debugging programs with multiple threads |
6c95b8df | 1945 | * Forks:: Debugging forks |
5c95884b | 1946 | * Checkpoint/Restart:: Setting a @emph{bookmark} to return to later |
c906108c SS |
1947 | @end menu |
1948 | ||
6d2ebf8b | 1949 | @node Compilation |
79a6e687 | 1950 | @section Compiling for Debugging |
c906108c SS |
1951 | |
1952 | In order to debug a program effectively, you need to generate | |
1953 | debugging information when you compile it. This debugging information | |
1954 | is stored in the object file; it describes the data type of each | |
1955 | variable or function and the correspondence between source line numbers | |
1956 | and addresses in the executable code. | |
1957 | ||
1958 | To request debugging information, specify the @samp{-g} option when you run | |
1959 | the compiler. | |
1960 | ||
514c4d71 | 1961 | Programs that are to be shipped to your customers are compiled with |
edb3359d | 1962 | optimizations, using the @samp{-O} compiler option. However, some |
514c4d71 EZ |
1963 | compilers are unable to handle the @samp{-g} and @samp{-O} options |
1964 | together. Using those compilers, you cannot generate optimized | |
c906108c SS |
1965 | executables containing debugging information. |
1966 | ||
514c4d71 | 1967 | @value{NGCC}, the @sc{gnu} C/C@t{++} compiler, supports @samp{-g} with or |
53a5351d JM |
1968 | without @samp{-O}, making it possible to debug optimized code. We |
1969 | recommend that you @emph{always} use @samp{-g} whenever you compile a | |
1970 | program. You may think your program is correct, but there is no sense | |
edb3359d | 1971 | in pushing your luck. For more information, see @ref{Optimized Code}. |
c906108c SS |
1972 | |
1973 | Older versions of the @sc{gnu} C compiler permitted a variant option | |
1974 | @w{@samp{-gg}} for debugging information. @value{GDBN} no longer supports this | |
1975 | format; if your @sc{gnu} C compiler has this option, do not use it. | |
1976 | ||
514c4d71 EZ |
1977 | @value{GDBN} knows about preprocessor macros and can show you their |
1978 | expansion (@pxref{Macros}). Most compilers do not include information | |
1979 | about preprocessor macros in the debugging information if you specify | |
e0f8f636 TT |
1980 | the @option{-g} flag alone. Version 3.1 and later of @value{NGCC}, |
1981 | the @sc{gnu} C compiler, provides macro information if you are using | |
1982 | the DWARF debugging format, and specify the option @option{-g3}. | |
1983 | ||
1984 | @xref{Debugging Options,,Options for Debugging Your Program or GCC, | |
1985 | gcc.info, Using the @sc{gnu} Compiler Collection (GCC)}, for more | |
1986 | information on @value{NGCC} options affecting debug information. | |
1987 | ||
1988 | You will have the best debugging experience if you use the latest | |
1989 | version of the DWARF debugging format that your compiler supports. | |
1990 | DWARF is currently the most expressive and best supported debugging | |
1991 | format in @value{GDBN}. | |
514c4d71 | 1992 | |
c906108c | 1993 | @need 2000 |
6d2ebf8b | 1994 | @node Starting |
79a6e687 | 1995 | @section Starting your Program |
c906108c SS |
1996 | @cindex starting |
1997 | @cindex running | |
1998 | ||
1999 | @table @code | |
2000 | @kindex run | |
41afff9a | 2001 | @kindex r @r{(@code{run})} |
c906108c SS |
2002 | @item run |
2003 | @itemx r | |
7a292a7a | 2004 | Use the @code{run} command to start your program under @value{GDBN}. |
deb8ff2b PA |
2005 | You must first specify the program name with an argument to |
2006 | @value{GDBN} (@pxref{Invocation, ,Getting In and Out of | |
2007 | @value{GDBN}}), or by using the @code{file} or @code{exec-file} | |
2008 | command (@pxref{Files, ,Commands to Specify Files}). | |
c906108c SS |
2009 | |
2010 | @end table | |
2011 | ||
c906108c SS |
2012 | If you are running your program in an execution environment that |
2013 | supports processes, @code{run} creates an inferior process and makes | |
8edfe269 DJ |
2014 | that process run your program. In some environments without processes, |
2015 | @code{run} jumps to the start of your program. Other targets, | |
2016 | like @samp{remote}, are always running. If you get an error | |
2017 | message like this one: | |
2018 | ||
2019 | @smallexample | |
2020 | The "remote" target does not support "run". | |
2021 | Try "help target" or "continue". | |
2022 | @end smallexample | |
2023 | ||
2024 | @noindent | |
2025 | then use @code{continue} to run your program. You may need @code{load} | |
2026 | first (@pxref{load}). | |
c906108c SS |
2027 | |
2028 | The execution of a program is affected by certain information it | |
2029 | receives from its superior. @value{GDBN} provides ways to specify this | |
2030 | information, which you must do @emph{before} starting your program. (You | |
2031 | can change it after starting your program, but such changes only affect | |
2032 | your program the next time you start it.) This information may be | |
2033 | divided into four categories: | |
2034 | ||
2035 | @table @asis | |
2036 | @item The @emph{arguments.} | |
2037 | Specify the arguments to give your program as the arguments of the | |
2038 | @code{run} command. If a shell is available on your target, the shell | |
2039 | is used to pass the arguments, so that you may use normal conventions | |
2040 | (such as wildcard expansion or variable substitution) in describing | |
2041 | the arguments. | |
2042 | In Unix systems, you can control which shell is used with the | |
98882a26 PA |
2043 | @code{SHELL} environment variable. If you do not define @code{SHELL}, |
2044 | @value{GDBN} uses the default shell (@file{/bin/sh}). You can disable | |
2045 | use of any shell with the @code{set startup-with-shell} command (see | |
2046 | below for details). | |
c906108c SS |
2047 | |
2048 | @item The @emph{environment.} | |
2049 | Your program normally inherits its environment from @value{GDBN}, but you can | |
2050 | use the @value{GDBN} commands @code{set environment} and @code{unset | |
2051 | environment} to change parts of the environment that affect | |
79a6e687 | 2052 | your program. @xref{Environment, ,Your Program's Environment}. |
c906108c SS |
2053 | |
2054 | @item The @emph{working directory.} | |
2055 | Your program inherits its working directory from @value{GDBN}. You can set | |
2056 | the @value{GDBN} working directory with the @code{cd} command in @value{GDBN}. | |
79a6e687 | 2057 | @xref{Working Directory, ,Your Program's Working Directory}. |
c906108c SS |
2058 | |
2059 | @item The @emph{standard input and output.} | |
2060 | Your program normally uses the same device for standard input and | |
2061 | standard output as @value{GDBN} is using. You can redirect input and output | |
2062 | in the @code{run} command line, or you can use the @code{tty} command to | |
2063 | set a different device for your program. | |
79a6e687 | 2064 | @xref{Input/Output, ,Your Program's Input and Output}. |
c906108c SS |
2065 | |
2066 | @cindex pipes | |
2067 | @emph{Warning:} While input and output redirection work, you cannot use | |
2068 | pipes to pass the output of the program you are debugging to another | |
2069 | program; if you attempt this, @value{GDBN} is likely to wind up debugging the | |
2070 | wrong program. | |
2071 | @end table | |
c906108c SS |
2072 | |
2073 | When you issue the @code{run} command, your program begins to execute | |
79a6e687 | 2074 | immediately. @xref{Stopping, ,Stopping and Continuing}, for discussion |
c906108c SS |
2075 | of how to arrange for your program to stop. Once your program has |
2076 | stopped, you may call functions in your program, using the @code{print} | |
2077 | or @code{call} commands. @xref{Data, ,Examining Data}. | |
2078 | ||
2079 | If the modification time of your symbol file has changed since the last | |
2080 | time @value{GDBN} read its symbols, @value{GDBN} discards its symbol | |
2081 | table, and reads it again. When it does this, @value{GDBN} tries to retain | |
2082 | your current breakpoints. | |
2083 | ||
4e8b0763 JB |
2084 | @table @code |
2085 | @kindex start | |
2086 | @item start | |
2087 | @cindex run to main procedure | |
2088 | The name of the main procedure can vary from language to language. | |
2089 | With C or C@t{++}, the main procedure name is always @code{main}, but | |
2090 | other languages such as Ada do not require a specific name for their | |
2091 | main procedure. The debugger provides a convenient way to start the | |
2092 | execution of the program and to stop at the beginning of the main | |
2093 | procedure, depending on the language used. | |
2094 | ||
2095 | The @samp{start} command does the equivalent of setting a temporary | |
2096 | breakpoint at the beginning of the main procedure and then invoking | |
2097 | the @samp{run} command. | |
2098 | ||
f018e82f EZ |
2099 | @cindex elaboration phase |
2100 | Some programs contain an @dfn{elaboration} phase where some startup code is | |
2101 | executed before the main procedure is called. This depends on the | |
2102 | languages used to write your program. In C@t{++}, for instance, | |
4e8b0763 JB |
2103 | constructors for static and global objects are executed before |
2104 | @code{main} is called. It is therefore possible that the debugger stops | |
2105 | before reaching the main procedure. However, the temporary breakpoint | |
2106 | will remain to halt execution. | |
2107 | ||
2108 | Specify the arguments to give to your program as arguments to the | |
2109 | @samp{start} command. These arguments will be given verbatim to the | |
2110 | underlying @samp{run} command. Note that the same arguments will be | |
2111 | reused if no argument is provided during subsequent calls to | |
2112 | @samp{start} or @samp{run}. | |
2113 | ||
2114 | It is sometimes necessary to debug the program during elaboration. In | |
2115 | these cases, using the @code{start} command would stop the execution of | |
2116 | your program too late, as the program would have already completed the | |
2117 | elaboration phase. Under these circumstances, insert breakpoints in your | |
2118 | elaboration code before running your program. | |
ccd213ac | 2119 | |
41ef2965 | 2120 | @anchor{set exec-wrapper} |
ccd213ac DJ |
2121 | @kindex set exec-wrapper |
2122 | @item set exec-wrapper @var{wrapper} | |
2123 | @itemx show exec-wrapper | |
2124 | @itemx unset exec-wrapper | |
2125 | When @samp{exec-wrapper} is set, the specified wrapper is used to | |
2126 | launch programs for debugging. @value{GDBN} starts your program | |
2127 | with a shell command of the form @kbd{exec @var{wrapper} | |
2128 | @var{program}}. Quoting is added to @var{program} and its | |
2129 | arguments, but not to @var{wrapper}, so you should add quotes if | |
2130 | appropriate for your shell. The wrapper runs until it executes | |
2131 | your program, and then @value{GDBN} takes control. | |
2132 | ||
2133 | You can use any program that eventually calls @code{execve} with | |
2134 | its arguments as a wrapper. Several standard Unix utilities do | |
2135 | this, e.g.@: @code{env} and @code{nohup}. Any Unix shell script ending | |
2136 | with @code{exec "$@@"} will also work. | |
2137 | ||
2138 | For example, you can use @code{env} to pass an environment variable to | |
2139 | the debugged program, without setting the variable in your shell's | |
2140 | environment: | |
2141 | ||
2142 | @smallexample | |
2143 | (@value{GDBP}) set exec-wrapper env 'LD_PRELOAD=libtest.so' | |
2144 | (@value{GDBP}) run | |
2145 | @end smallexample | |
2146 | ||
2147 | This command is available when debugging locally on most targets, excluding | |
2148 | @sc{djgpp}, Cygwin, MS Windows, and QNX Neutrino. | |
2149 | ||
98882a26 PA |
2150 | @kindex set startup-with-shell |
2151 | @item set startup-with-shell | |
2152 | @itemx set startup-with-shell on | |
2153 | @itemx set startup-with-shell off | |
2154 | @itemx show set startup-with-shell | |
2155 | On Unix systems, by default, if a shell is available on your target, | |
2156 | @value{GDBN}) uses it to start your program. Arguments of the | |
2157 | @code{run} command are passed to the shell, which does variable | |
2158 | substitution, expands wildcard characters and performs redirection of | |
2159 | I/O. In some circumstances, it may be useful to disable such use of a | |
2160 | shell, for example, when debugging the shell itself or diagnosing | |
2161 | startup failures such as: | |
2162 | ||
2163 | @smallexample | |
2164 | (@value{GDBP}) run | |
2165 | Starting program: ./a.out | |
2166 | During startup program terminated with signal SIGSEGV, Segmentation fault. | |
2167 | @end smallexample | |
2168 | ||
2169 | @noindent | |
2170 | which indicates the shell or the wrapper specified with | |
2171 | @samp{exec-wrapper} crashed, not your program. Most often, this is | |
afa332ce PA |
2172 | caused by something odd in your shell's non-interactive mode |
2173 | initialization file---such as @file{.cshrc} for C-shell, | |
2174 | $@file{.zshenv} for the Z shell, or the file specified in the | |
2175 | @samp{BASH_ENV} environment variable for BASH. | |
98882a26 | 2176 | |
6a3cb8e8 PA |
2177 | @anchor{set auto-connect-native-target} |
2178 | @kindex set auto-connect-native-target | |
2179 | @item set auto-connect-native-target | |
2180 | @itemx set auto-connect-native-target on | |
2181 | @itemx set auto-connect-native-target off | |
2182 | @itemx show auto-connect-native-target | |
2183 | ||
2184 | By default, if not connected to any target yet (e.g., with | |
2185 | @code{target remote}), the @code{run} command starts your program as a | |
2186 | native process under @value{GDBN}, on your local machine. If you're | |
2187 | sure you don't want to debug programs on your local machine, you can | |
2188 | tell @value{GDBN} to not connect to the native target automatically | |
2189 | with the @code{set auto-connect-native-target off} command. | |
2190 | ||
2191 | If @code{on}, which is the default, and if @value{GDBN} is not | |
2192 | connected to a target already, the @code{run} command automaticaly | |
2193 | connects to the native target, if one is available. | |
2194 | ||
2195 | If @code{off}, and if @value{GDBN} is not connected to a target | |
2196 | already, the @code{run} command fails with an error: | |
2197 | ||
2198 | @smallexample | |
2199 | (@value{GDBP}) run | |
2200 | Don't know how to run. Try "help target". | |
2201 | @end smallexample | |
2202 | ||
2203 | If @value{GDBN} is already connected to a target, @value{GDBN} always | |
2204 | uses it with the @code{run} command. | |
2205 | ||
2206 | In any case, you can explicitly connect to the native target with the | |
2207 | @code{target native} command. For example, | |
2208 | ||
2209 | @smallexample | |
2210 | (@value{GDBP}) set auto-connect-native-target off | |
2211 | (@value{GDBP}) run | |
2212 | Don't know how to run. Try "help target". | |
2213 | (@value{GDBP}) target native | |
2214 | (@value{GDBP}) run | |
2215 | Starting program: ./a.out | |
2216 | [Inferior 1 (process 10421) exited normally] | |
2217 | @end smallexample | |
2218 | ||
2219 | In case you connected explicitly to the @code{native} target, | |
2220 | @value{GDBN} remains connected even if all inferiors exit, ready for | |
2221 | the next @code{run} command. Use the @code{disconnect} command to | |
2222 | disconnect. | |
2223 | ||
2224 | Examples of other commands that likewise respect the | |
2225 | @code{auto-connect-native-target} setting: @code{attach}, @code{info | |
2226 | proc}, @code{info os}. | |
2227 | ||
10568435 JK |
2228 | @kindex set disable-randomization |
2229 | @item set disable-randomization | |
2230 | @itemx set disable-randomization on | |
2231 | This option (enabled by default in @value{GDBN}) will turn off the native | |
2232 | randomization of the virtual address space of the started program. This option | |
2233 | is useful for multiple debugging sessions to make the execution better | |
2234 | reproducible and memory addresses reusable across debugging sessions. | |
2235 | ||
03583c20 UW |
2236 | This feature is implemented only on certain targets, including @sc{gnu}/Linux. |
2237 | On @sc{gnu}/Linux you can get the same behavior using | |
10568435 JK |
2238 | |
2239 | @smallexample | |
2240 | (@value{GDBP}) set exec-wrapper setarch `uname -m` -R | |
2241 | @end smallexample | |
2242 | ||
2243 | @item set disable-randomization off | |
2244 | Leave the behavior of the started executable unchanged. Some bugs rear their | |
2245 | ugly heads only when the program is loaded at certain addresses. If your bug | |
2246 | disappears when you run the program under @value{GDBN}, that might be because | |
2247 | @value{GDBN} by default disables the address randomization on platforms, such | |
2248 | as @sc{gnu}/Linux, which do that for stand-alone programs. Use @kbd{set | |
2249 | disable-randomization off} to try to reproduce such elusive bugs. | |
2250 | ||
03583c20 UW |
2251 | On targets where it is available, virtual address space randomization |
2252 | protects the programs against certain kinds of security attacks. In these | |
10568435 JK |
2253 | cases the attacker needs to know the exact location of a concrete executable |
2254 | code. Randomizing its location makes it impossible to inject jumps misusing | |
2255 | a code at its expected addresses. | |
2256 | ||
2257 | Prelinking shared libraries provides a startup performance advantage but it | |
2258 | makes addresses in these libraries predictable for privileged processes by | |
2259 | having just unprivileged access at the target system. Reading the shared | |
2260 | library binary gives enough information for assembling the malicious code | |
2261 | misusing it. Still even a prelinked shared library can get loaded at a new | |
2262 | random address just requiring the regular relocation process during the | |
2263 | startup. Shared libraries not already prelinked are always loaded at | |
2264 | a randomly chosen address. | |
2265 | ||
2266 | Position independent executables (PIE) contain position independent code | |
2267 | similar to the shared libraries and therefore such executables get loaded at | |
2268 | a randomly chosen address upon startup. PIE executables always load even | |
2269 | already prelinked shared libraries at a random address. You can build such | |
2270 | executable using @command{gcc -fPIE -pie}. | |
2271 | ||
2272 | Heap (malloc storage), stack and custom mmap areas are always placed randomly | |
2273 | (as long as the randomization is enabled). | |
2274 | ||
2275 | @item show disable-randomization | |
2276 | Show the current setting of the explicit disable of the native randomization of | |
2277 | the virtual address space of the started program. | |
2278 | ||
4e8b0763 JB |
2279 | @end table |
2280 | ||
6d2ebf8b | 2281 | @node Arguments |
79a6e687 | 2282 | @section Your Program's Arguments |
c906108c SS |
2283 | |
2284 | @cindex arguments (to your program) | |
2285 | The arguments to your program can be specified by the arguments of the | |
5d161b24 | 2286 | @code{run} command. |
c906108c SS |
2287 | They are passed to a shell, which expands wildcard characters and |
2288 | performs redirection of I/O, and thence to your program. Your | |
2289 | @code{SHELL} environment variable (if it exists) specifies what shell | |
2290 | @value{GDBN} uses. If you do not define @code{SHELL}, @value{GDBN} uses | |
d4f3574e SS |
2291 | the default shell (@file{/bin/sh} on Unix). |
2292 | ||
2293 | On non-Unix systems, the program is usually invoked directly by | |
2294 | @value{GDBN}, which emulates I/O redirection via the appropriate system | |
2295 | calls, and the wildcard characters are expanded by the startup code of | |
2296 | the program, not by the shell. | |
c906108c SS |
2297 | |
2298 | @code{run} with no arguments uses the same arguments used by the previous | |
2299 | @code{run}, or those set by the @code{set args} command. | |
2300 | ||
c906108c | 2301 | @table @code |
41afff9a | 2302 | @kindex set args |
c906108c SS |
2303 | @item set args |
2304 | Specify the arguments to be used the next time your program is run. If | |
2305 | @code{set args} has no arguments, @code{run} executes your program | |
2306 | with no arguments. Once you have run your program with arguments, | |
2307 | using @code{set args} before the next @code{run} is the only way to run | |
2308 | it again without arguments. | |
2309 | ||
2310 | @kindex show args | |
2311 | @item show args | |
2312 | Show the arguments to give your program when it is started. | |
2313 | @end table | |
2314 | ||
6d2ebf8b | 2315 | @node Environment |
79a6e687 | 2316 | @section Your Program's Environment |
c906108c SS |
2317 | |
2318 | @cindex environment (of your program) | |
2319 | The @dfn{environment} consists of a set of environment variables and | |
2320 | their values. Environment variables conventionally record such things as | |
2321 | your user name, your home directory, your terminal type, and your search | |
2322 | path for programs to run. Usually you set up environment variables with | |
2323 | the shell and they are inherited by all the other programs you run. When | |
2324 | debugging, it can be useful to try running your program with a modified | |
2325 | environment without having to start @value{GDBN} over again. | |
2326 | ||
2327 | @table @code | |
2328 | @kindex path | |
2329 | @item path @var{directory} | |
2330 | Add @var{directory} to the front of the @code{PATH} environment variable | |
17cc6a06 EZ |
2331 | (the search path for executables) that will be passed to your program. |
2332 | The value of @code{PATH} used by @value{GDBN} does not change. | |
d4f3574e SS |
2333 | You may specify several directory names, separated by whitespace or by a |
2334 | system-dependent separator character (@samp{:} on Unix, @samp{;} on | |
2335 | MS-DOS and MS-Windows). If @var{directory} is already in the path, it | |
2336 | is moved to the front, so it is searched sooner. | |
c906108c SS |
2337 | |
2338 | You can use the string @samp{$cwd} to refer to whatever is the current | |
2339 | working directory at the time @value{GDBN} searches the path. If you | |
2340 | use @samp{.} instead, it refers to the directory where you executed the | |
2341 | @code{path} command. @value{GDBN} replaces @samp{.} in the | |
2342 | @var{directory} argument (with the current path) before adding | |
2343 | @var{directory} to the search path. | |
2344 | @c 'path' is explicitly nonrepeatable, but RMS points out it is silly to | |
2345 | @c document that, since repeating it would be a no-op. | |
2346 | ||
2347 | @kindex show paths | |
2348 | @item show paths | |
2349 | Display the list of search paths for executables (the @code{PATH} | |
2350 | environment variable). | |
2351 | ||
2352 | @kindex show environment | |
2353 | @item show environment @r{[}@var{varname}@r{]} | |
2354 | Print the value of environment variable @var{varname} to be given to | |
2355 | your program when it starts. If you do not supply @var{varname}, | |
2356 | print the names and values of all environment variables to be given to | |
2357 | your program. You can abbreviate @code{environment} as @code{env}. | |
2358 | ||
2359 | @kindex set environment | |
53a5351d | 2360 | @item set environment @var{varname} @r{[}=@var{value}@r{]} |
c906108c | 2361 | Set environment variable @var{varname} to @var{value}. The value |
41ef2965 | 2362 | changes for your program (and the shell @value{GDBN} uses to launch |
697aa1b7 | 2363 | it), not for @value{GDBN} itself. The @var{value} may be any string; the |
41ef2965 PA |
2364 | values of environment variables are just strings, and any |
2365 | interpretation is supplied by your program itself. The @var{value} | |
c906108c SS |
2366 | parameter is optional; if it is eliminated, the variable is set to a |
2367 | null value. | |
2368 | @c "any string" here does not include leading, trailing | |
2369 | @c blanks. Gnu asks: does anyone care? | |
2370 | ||
2371 | For example, this command: | |
2372 | ||
474c8240 | 2373 | @smallexample |
c906108c | 2374 | set env USER = foo |
474c8240 | 2375 | @end smallexample |
c906108c SS |
2376 | |
2377 | @noindent | |
d4f3574e | 2378 | tells the debugged program, when subsequently run, that its user is named |
c906108c SS |
2379 | @samp{foo}. (The spaces around @samp{=} are used for clarity here; they |
2380 | are not actually required.) | |
2381 | ||
41ef2965 PA |
2382 | Note that on Unix systems, @value{GDBN} runs your program via a shell, |
2383 | which also inherits the environment set with @code{set environment}. | |
2384 | If necessary, you can avoid that by using the @samp{env} program as a | |
2385 | wrapper instead of using @code{set environment}. @xref{set | |
2386 | exec-wrapper}, for an example doing just that. | |
2387 | ||
c906108c SS |
2388 | @kindex unset environment |
2389 | @item unset environment @var{varname} | |
2390 | Remove variable @var{varname} from the environment to be passed to your | |
2391 | program. This is different from @samp{set env @var{varname} =}; | |
2392 | @code{unset environment} removes the variable from the environment, | |
2393 | rather than assigning it an empty value. | |
2394 | @end table | |
2395 | ||
d4f3574e | 2396 | @emph{Warning:} On Unix systems, @value{GDBN} runs your program using |
afa332ce PA |
2397 | the shell indicated by your @code{SHELL} environment variable if it |
2398 | exists (or @code{/bin/sh} if not). If your @code{SHELL} variable | |
2399 | names a shell that runs an initialization file when started | |
2400 | non-interactively---such as @file{.cshrc} for C-shell, $@file{.zshenv} | |
2401 | for the Z shell, or the file specified in the @samp{BASH_ENV} | |
2402 | environment variable for BASH---any variables you set in that file | |
2403 | affect your program. You may wish to move setting of environment | |
2404 | variables to files that are only run when you sign on, such as | |
2405 | @file{.login} or @file{.profile}. | |
c906108c | 2406 | |
6d2ebf8b | 2407 | @node Working Directory |
79a6e687 | 2408 | @section Your Program's Working Directory |
c906108c SS |
2409 | |
2410 | @cindex working directory (of your program) | |
2411 | Each time you start your program with @code{run}, it inherits its | |
2412 | working directory from the current working directory of @value{GDBN}. | |
2413 | The @value{GDBN} working directory is initially whatever it inherited | |
2414 | from its parent process (typically the shell), but you can specify a new | |
2415 | working directory in @value{GDBN} with the @code{cd} command. | |
2416 | ||
2417 | The @value{GDBN} working directory also serves as a default for the commands | |
2418 | that specify files for @value{GDBN} to operate on. @xref{Files, ,Commands to | |
79a6e687 | 2419 | Specify Files}. |
c906108c SS |
2420 | |
2421 | @table @code | |
2422 | @kindex cd | |
721c2651 | 2423 | @cindex change working directory |
f3c8a52a JK |
2424 | @item cd @r{[}@var{directory}@r{]} |
2425 | Set the @value{GDBN} working directory to @var{directory}. If not | |
2426 | given, @var{directory} uses @file{'~'}. | |
c906108c SS |
2427 | |
2428 | @kindex pwd | |
2429 | @item pwd | |
2430 | Print the @value{GDBN} working directory. | |
2431 | @end table | |
2432 | ||
60bf7e09 EZ |
2433 | It is generally impossible to find the current working directory of |
2434 | the process being debugged (since a program can change its directory | |
2435 | during its run). If you work on a system where @value{GDBN} is | |
2436 | configured with the @file{/proc} support, you can use the @code{info | |
2437 | proc} command (@pxref{SVR4 Process Information}) to find out the | |
2438 | current working directory of the debuggee. | |
2439 | ||
6d2ebf8b | 2440 | @node Input/Output |
79a6e687 | 2441 | @section Your Program's Input and Output |
c906108c SS |
2442 | |
2443 | @cindex redirection | |
2444 | @cindex i/o | |
2445 | @cindex terminal | |
2446 | By default, the program you run under @value{GDBN} does input and output to | |
5d161b24 | 2447 | the same terminal that @value{GDBN} uses. @value{GDBN} switches the terminal |
c906108c SS |
2448 | to its own terminal modes to interact with you, but it records the terminal |
2449 | modes your program was using and switches back to them when you continue | |
2450 | running your program. | |
2451 | ||
2452 | @table @code | |
2453 | @kindex info terminal | |
2454 | @item info terminal | |
2455 | Displays information recorded by @value{GDBN} about the terminal modes your | |
2456 | program is using. | |
2457 | @end table | |
2458 | ||
2459 | You can redirect your program's input and/or output using shell | |
2460 | redirection with the @code{run} command. For example, | |
2461 | ||
474c8240 | 2462 | @smallexample |
c906108c | 2463 | run > outfile |
474c8240 | 2464 | @end smallexample |
c906108c SS |
2465 | |
2466 | @noindent | |
2467 | starts your program, diverting its output to the file @file{outfile}. | |
2468 | ||
2469 | @kindex tty | |
2470 | @cindex controlling terminal | |
2471 | Another way to specify where your program should do input and output is | |
2472 | with the @code{tty} command. This command accepts a file name as | |
2473 | argument, and causes this file to be the default for future @code{run} | |
2474 | commands. It also resets the controlling terminal for the child | |
2475 | process, for future @code{run} commands. For example, | |
2476 | ||
474c8240 | 2477 | @smallexample |
c906108c | 2478 | tty /dev/ttyb |
474c8240 | 2479 | @end smallexample |
c906108c SS |
2480 | |
2481 | @noindent | |
2482 | directs that processes started with subsequent @code{run} commands | |
2483 | default to do input and output on the terminal @file{/dev/ttyb} and have | |
2484 | that as their controlling terminal. | |
2485 | ||
2486 | An explicit redirection in @code{run} overrides the @code{tty} command's | |
2487 | effect on the input/output device, but not its effect on the controlling | |
2488 | terminal. | |
2489 | ||
2490 | When you use the @code{tty} command or redirect input in the @code{run} | |
2491 | command, only the input @emph{for your program} is affected. The input | |
3cb3b8df BR |
2492 | for @value{GDBN} still comes from your terminal. @code{tty} is an alias |
2493 | for @code{set inferior-tty}. | |
2494 | ||
2495 | @cindex inferior tty | |
2496 | @cindex set inferior controlling terminal | |
2497 | You can use the @code{show inferior-tty} command to tell @value{GDBN} to | |
2498 | display the name of the terminal that will be used for future runs of your | |
2499 | program. | |
2500 | ||
2501 | @table @code | |
2502 | @item set inferior-tty /dev/ttyb | |
2503 | @kindex set inferior-tty | |
2504 | Set the tty for the program being debugged to /dev/ttyb. | |
2505 | ||
2506 | @item show inferior-tty | |
2507 | @kindex show inferior-tty | |
2508 | Show the current tty for the program being debugged. | |
2509 | @end table | |
c906108c | 2510 | |
6d2ebf8b | 2511 | @node Attach |
79a6e687 | 2512 | @section Debugging an Already-running Process |
c906108c SS |
2513 | @kindex attach |
2514 | @cindex attach | |
2515 | ||
2516 | @table @code | |
2517 | @item attach @var{process-id} | |
2518 | This command attaches to a running process---one that was started | |
2519 | outside @value{GDBN}. (@code{info files} shows your active | |
2520 | targets.) The command takes as argument a process ID. The usual way to | |
09d4efe1 | 2521 | find out the @var{process-id} of a Unix process is with the @code{ps} utility, |
c906108c SS |
2522 | or with the @samp{jobs -l} shell command. |
2523 | ||
2524 | @code{attach} does not repeat if you press @key{RET} a second time after | |
2525 | executing the command. | |
2526 | @end table | |
2527 | ||
2528 | To use @code{attach}, your program must be running in an environment | |
2529 | which supports processes; for example, @code{attach} does not work for | |
2530 | programs on bare-board targets that lack an operating system. You must | |
2531 | also have permission to send the process a signal. | |
2532 | ||
2533 | When you use @code{attach}, the debugger finds the program running in | |
2534 | the process first by looking in the current working directory, then (if | |
2535 | the program is not found) by using the source file search path | |
79a6e687 | 2536 | (@pxref{Source Path, ,Specifying Source Directories}). You can also use |
c906108c SS |
2537 | the @code{file} command to load the program. @xref{Files, ,Commands to |
2538 | Specify Files}. | |
2539 | ||
2540 | The first thing @value{GDBN} does after arranging to debug the specified | |
2541 | process is to stop it. You can examine and modify an attached process | |
53a5351d JM |
2542 | with all the @value{GDBN} commands that are ordinarily available when |
2543 | you start processes with @code{run}. You can insert breakpoints; you | |
2544 | can step and continue; you can modify storage. If you would rather the | |
2545 | process continue running, you may use the @code{continue} command after | |
c906108c SS |
2546 | attaching @value{GDBN} to the process. |
2547 | ||
2548 | @table @code | |
2549 | @kindex detach | |
2550 | @item detach | |
2551 | When you have finished debugging the attached process, you can use the | |
2552 | @code{detach} command to release it from @value{GDBN} control. Detaching | |
2553 | the process continues its execution. After the @code{detach} command, | |
2554 | that process and @value{GDBN} become completely independent once more, and you | |
2555 | are ready to @code{attach} another process or start one with @code{run}. | |
2556 | @code{detach} does not repeat if you press @key{RET} again after | |
2557 | executing the command. | |
2558 | @end table | |
2559 | ||
159fcc13 JK |
2560 | If you exit @value{GDBN} while you have an attached process, you detach |
2561 | that process. If you use the @code{run} command, you kill that process. | |
2562 | By default, @value{GDBN} asks for confirmation if you try to do either of these | |
2563 | things; you can control whether or not you need to confirm by using the | |
2564 | @code{set confirm} command (@pxref{Messages/Warnings, ,Optional Warnings and | |
79a6e687 | 2565 | Messages}). |
c906108c | 2566 | |
6d2ebf8b | 2567 | @node Kill Process |
79a6e687 | 2568 | @section Killing the Child Process |
c906108c SS |
2569 | |
2570 | @table @code | |
2571 | @kindex kill | |
2572 | @item kill | |
2573 | Kill the child process in which your program is running under @value{GDBN}. | |
2574 | @end table | |
2575 | ||
2576 | This command is useful if you wish to debug a core dump instead of a | |
2577 | running process. @value{GDBN} ignores any core dump file while your program | |
2578 | is running. | |
2579 | ||
2580 | On some operating systems, a program cannot be executed outside @value{GDBN} | |
2581 | while you have breakpoints set on it inside @value{GDBN}. You can use the | |
2582 | @code{kill} command in this situation to permit running your program | |
2583 | outside the debugger. | |
2584 | ||
2585 | The @code{kill} command is also useful if you wish to recompile and | |
2586 | relink your program, since on many systems it is impossible to modify an | |
2587 | executable file while it is running in a process. In this case, when you | |
2588 | next type @code{run}, @value{GDBN} notices that the file has changed, and | |
2589 | reads the symbol table again (while trying to preserve your current | |
2590 | breakpoint settings). | |
2591 | ||
6c95b8df PA |
2592 | @node Inferiors and Programs |
2593 | @section Debugging Multiple Inferiors and Programs | |
b77209e0 | 2594 | |
6c95b8df PA |
2595 | @value{GDBN} lets you run and debug multiple programs in a single |
2596 | session. In addition, @value{GDBN} on some systems may let you run | |
2597 | several programs simultaneously (otherwise you have to exit from one | |
2598 | before starting another). In the most general case, you can have | |
2599 | multiple threads of execution in each of multiple processes, launched | |
2600 | from multiple executables. | |
b77209e0 PA |
2601 | |
2602 | @cindex inferior | |
2603 | @value{GDBN} represents the state of each program execution with an | |
2604 | object called an @dfn{inferior}. An inferior typically corresponds to | |
2605 | a process, but is more general and applies also to targets that do not | |
2606 | have processes. Inferiors may be created before a process runs, and | |
6c95b8df PA |
2607 | may be retained after a process exits. Inferiors have unique |
2608 | identifiers that are different from process ids. Usually each | |
2609 | inferior will also have its own distinct address space, although some | |
2610 | embedded targets may have several inferiors running in different parts | |
2611 | of a single address space. Each inferior may in turn have multiple | |
2612 | threads running in it. | |
b77209e0 | 2613 | |
6c95b8df PA |
2614 | To find out what inferiors exist at any moment, use @w{@code{info |
2615 | inferiors}}: | |
b77209e0 PA |
2616 | |
2617 | @table @code | |
2618 | @kindex info inferiors | |
2619 | @item info inferiors | |
2620 | Print a list of all inferiors currently being managed by @value{GDBN}. | |
3a1ff0b6 PA |
2621 | |
2622 | @value{GDBN} displays for each inferior (in this order): | |
2623 | ||
2624 | @enumerate | |
2625 | @item | |
2626 | the inferior number assigned by @value{GDBN} | |
2627 | ||
2628 | @item | |
2629 | the target system's inferior identifier | |
6c95b8df PA |
2630 | |
2631 | @item | |
2632 | the name of the executable the inferior is running. | |
2633 | ||
3a1ff0b6 PA |
2634 | @end enumerate |
2635 | ||
2636 | @noindent | |
2637 | An asterisk @samp{*} preceding the @value{GDBN} inferior number | |
2638 | indicates the current inferior. | |
2639 | ||
2640 | For example, | |
2277426b | 2641 | @end table |
3a1ff0b6 PA |
2642 | @c end table here to get a little more width for example |
2643 | ||
2644 | @smallexample | |
2645 | (@value{GDBP}) info inferiors | |
6c95b8df PA |
2646 | Num Description Executable |
2647 | 2 process 2307 hello | |
2648 | * 1 process 3401 goodbye | |
3a1ff0b6 | 2649 | @end smallexample |
2277426b PA |
2650 | |
2651 | To switch focus between inferiors, use the @code{inferior} command: | |
2652 | ||
2653 | @table @code | |
3a1ff0b6 PA |
2654 | @kindex inferior @var{infno} |
2655 | @item inferior @var{infno} | |
2656 | Make inferior number @var{infno} the current inferior. The argument | |
2657 | @var{infno} is the inferior number assigned by @value{GDBN}, as shown | |
2658 | in the first field of the @samp{info inferiors} display. | |
2277426b PA |
2659 | @end table |
2660 | ||
e3940304 PA |
2661 | @vindex $_inferior@r{, convenience variable} |
2662 | The debugger convenience variable @samp{$_inferior} contains the | |
2663 | number of the current inferior. You may find this useful in writing | |
2664 | breakpoint conditional expressions, command scripts, and so forth. | |
2665 | @xref{Convenience Vars,, Convenience Variables}, for general | |
2666 | information on convenience variables. | |
6c95b8df PA |
2667 | |
2668 | You can get multiple executables into a debugging session via the | |
2669 | @code{add-inferior} and @w{@code{clone-inferior}} commands. On some | |
2670 | systems @value{GDBN} can add inferiors to the debug session | |
2671 | automatically by following calls to @code{fork} and @code{exec}. To | |
2672 | remove inferiors from the debugging session use the | |
af624141 | 2673 | @w{@code{remove-inferiors}} command. |
6c95b8df PA |
2674 | |
2675 | @table @code | |
2676 | @kindex add-inferior | |
2677 | @item add-inferior [ -copies @var{n} ] [ -exec @var{executable} ] | |
2678 | Adds @var{n} inferiors to be run using @var{executable} as the | |
697aa1b7 | 2679 | executable; @var{n} defaults to 1. If no executable is specified, |
6c95b8df PA |
2680 | the inferiors begins empty, with no program. You can still assign or |
2681 | change the program assigned to the inferior at any time by using the | |
2682 | @code{file} command with the executable name as its argument. | |
2683 | ||
2684 | @kindex clone-inferior | |
2685 | @item clone-inferior [ -copies @var{n} ] [ @var{infno} ] | |
2686 | Adds @var{n} inferiors ready to execute the same program as inferior | |
697aa1b7 | 2687 | @var{infno}; @var{n} defaults to 1, and @var{infno} defaults to the |
6c95b8df PA |
2688 | number of the current inferior. This is a convenient command when you |
2689 | want to run another instance of the inferior you are debugging. | |
2690 | ||
2691 | @smallexample | |
2692 | (@value{GDBP}) info inferiors | |
2693 | Num Description Executable | |
2694 | * 1 process 29964 helloworld | |
2695 | (@value{GDBP}) clone-inferior | |
2696 | Added inferior 2. | |
2697 | 1 inferiors added. | |
2698 | (@value{GDBP}) info inferiors | |
2699 | Num Description Executable | |
2700 | 2 <null> helloworld | |
2701 | * 1 process 29964 helloworld | |
2702 | @end smallexample | |
2703 | ||
2704 | You can now simply switch focus to inferior 2 and run it. | |
2705 | ||
af624141 MS |
2706 | @kindex remove-inferiors |
2707 | @item remove-inferiors @var{infno}@dots{} | |
2708 | Removes the inferior or inferiors @var{infno}@dots{}. It is not | |
2709 | possible to remove an inferior that is running with this command. For | |
2710 | those, use the @code{kill} or @code{detach} command first. | |
6c95b8df PA |
2711 | |
2712 | @end table | |
2713 | ||
2714 | To quit debugging one of the running inferiors that is not the current | |
2715 | inferior, you can either detach from it by using the @w{@code{detach | |
2716 | inferior}} command (allowing it to run independently), or kill it | |
af624141 | 2717 | using the @w{@code{kill inferiors}} command: |
2277426b PA |
2718 | |
2719 | @table @code | |
af624141 MS |
2720 | @kindex detach inferiors @var{infno}@dots{} |
2721 | @item detach inferior @var{infno}@dots{} | |
2722 | Detach from the inferior or inferiors identified by @value{GDBN} | |
5e30da2c | 2723 | inferior number(s) @var{infno}@dots{}. Note that the inferior's entry |
af624141 MS |
2724 | still stays on the list of inferiors shown by @code{info inferiors}, |
2725 | but its Description will show @samp{<null>}. | |
2726 | ||
2727 | @kindex kill inferiors @var{infno}@dots{} | |
2728 | @item kill inferiors @var{infno}@dots{} | |
2729 | Kill the inferior or inferiors identified by @value{GDBN} inferior | |
2730 | number(s) @var{infno}@dots{}. Note that the inferior's entry still | |
2731 | stays on the list of inferiors shown by @code{info inferiors}, but its | |
2732 | Description will show @samp{<null>}. | |
2277426b PA |
2733 | @end table |
2734 | ||
6c95b8df | 2735 | After the successful completion of a command such as @code{detach}, |
af624141 | 2736 | @code{detach inferiors}, @code{kill} or @code{kill inferiors}, or after |
6c95b8df PA |
2737 | a normal process exit, the inferior is still valid and listed with |
2738 | @code{info inferiors}, ready to be restarted. | |
2739 | ||
2740 | ||
2277426b PA |
2741 | To be notified when inferiors are started or exit under @value{GDBN}'s |
2742 | control use @w{@code{set print inferior-events}}: | |
b77209e0 | 2743 | |
2277426b | 2744 | @table @code |
b77209e0 PA |
2745 | @kindex set print inferior-events |
2746 | @cindex print messages on inferior start and exit | |
2747 | @item set print inferior-events | |
2748 | @itemx set print inferior-events on | |
2749 | @itemx set print inferior-events off | |
2750 | The @code{set print inferior-events} command allows you to enable or | |
2751 | disable printing of messages when @value{GDBN} notices that new | |
2752 | inferiors have started or that inferiors have exited or have been | |
2753 | detached. By default, these messages will not be printed. | |
2754 | ||
2755 | @kindex show print inferior-events | |
2756 | @item show print inferior-events | |
2757 | Show whether messages will be printed when @value{GDBN} detects that | |
2758 | inferiors have started, exited or have been detached. | |
2759 | @end table | |
2760 | ||
6c95b8df PA |
2761 | Many commands will work the same with multiple programs as with a |
2762 | single program: e.g., @code{print myglobal} will simply display the | |
2763 | value of @code{myglobal} in the current inferior. | |
2764 | ||
2765 | ||
2766 | Occasionaly, when debugging @value{GDBN} itself, it may be useful to | |
2767 | get more info about the relationship of inferiors, programs, address | |
2768 | spaces in a debug session. You can do that with the @w{@code{maint | |
2769 | info program-spaces}} command. | |
2770 | ||
2771 | @table @code | |
2772 | @kindex maint info program-spaces | |
2773 | @item maint info program-spaces | |
2774 | Print a list of all program spaces currently being managed by | |
2775 | @value{GDBN}. | |
2776 | ||
2777 | @value{GDBN} displays for each program space (in this order): | |
2778 | ||
2779 | @enumerate | |
2780 | @item | |
2781 | the program space number assigned by @value{GDBN} | |
2782 | ||
2783 | @item | |
2784 | the name of the executable loaded into the program space, with e.g., | |
2785 | the @code{file} command. | |
2786 | ||
2787 | @end enumerate | |
2788 | ||
2789 | @noindent | |
2790 | An asterisk @samp{*} preceding the @value{GDBN} program space number | |
2791 | indicates the current program space. | |
2792 | ||
2793 | In addition, below each program space line, @value{GDBN} prints extra | |
2794 | information that isn't suitable to display in tabular form. For | |
2795 | example, the list of inferiors bound to the program space. | |
2796 | ||
2797 | @smallexample | |
2798 | (@value{GDBP}) maint info program-spaces | |
2799 | Id Executable | |
b05b1202 | 2800 | * 1 hello |
6c95b8df PA |
2801 | 2 goodbye |
2802 | Bound inferiors: ID 1 (process 21561) | |
6c95b8df PA |
2803 | @end smallexample |
2804 | ||
2805 | Here we can see that no inferior is running the program @code{hello}, | |
2806 | while @code{process 21561} is running the program @code{goodbye}. On | |
2807 | some targets, it is possible that multiple inferiors are bound to the | |
2808 | same program space. The most common example is that of debugging both | |
2809 | the parent and child processes of a @code{vfork} call. For example, | |
2810 | ||
2811 | @smallexample | |
2812 | (@value{GDBP}) maint info program-spaces | |
2813 | Id Executable | |
2814 | * 1 vfork-test | |
2815 | Bound inferiors: ID 2 (process 18050), ID 1 (process 18045) | |
2816 | @end smallexample | |
2817 | ||
2818 | Here, both inferior 2 and inferior 1 are running in the same program | |
2819 | space as a result of inferior 1 having executed a @code{vfork} call. | |
2820 | @end table | |
2821 | ||
6d2ebf8b | 2822 | @node Threads |
79a6e687 | 2823 | @section Debugging Programs with Multiple Threads |
c906108c SS |
2824 | |
2825 | @cindex threads of execution | |
2826 | @cindex multiple threads | |
2827 | @cindex switching threads | |
b1236ac3 | 2828 | In some operating systems, such as GNU/Linux and Solaris, a single program |
c906108c SS |
2829 | may have more than one @dfn{thread} of execution. The precise semantics |
2830 | of threads differ from one operating system to another, but in general | |
2831 | the threads of a single program are akin to multiple processes---except | |
2832 | that they share one address space (that is, they can all examine and | |
2833 | modify the same variables). On the other hand, each thread has its own | |
2834 | registers and execution stack, and perhaps private memory. | |
2835 | ||
2836 | @value{GDBN} provides these facilities for debugging multi-thread | |
2837 | programs: | |
2838 | ||
2839 | @itemize @bullet | |
2840 | @item automatic notification of new threads | |
5d5658a1 | 2841 | @item @samp{thread @var{thread-id}}, a command to switch among threads |
c906108c | 2842 | @item @samp{info threads}, a command to inquire about existing threads |
5d5658a1 | 2843 | @item @samp{thread apply [@var{thread-id-list}] [@var{all}] @var{args}}, |
c906108c SS |
2844 | a command to apply a command to a list of threads |
2845 | @item thread-specific breakpoints | |
93815fbf VP |
2846 | @item @samp{set print thread-events}, which controls printing of |
2847 | messages on thread start and exit. | |
17a37d48 PP |
2848 | @item @samp{set libthread-db-search-path @var{path}}, which lets |
2849 | the user specify which @code{libthread_db} to use if the default choice | |
2850 | isn't compatible with the program. | |
c906108c SS |
2851 | @end itemize |
2852 | ||
c906108c SS |
2853 | @cindex focus of debugging |
2854 | @cindex current thread | |
2855 | The @value{GDBN} thread debugging facility allows you to observe all | |
2856 | threads while your program runs---but whenever @value{GDBN} takes | |
2857 | control, one thread in particular is always the focus of debugging. | |
2858 | This thread is called the @dfn{current thread}. Debugging commands show | |
2859 | program information from the perspective of the current thread. | |
2860 | ||
41afff9a | 2861 | @cindex @code{New} @var{systag} message |
c906108c SS |
2862 | @cindex thread identifier (system) |
2863 | @c FIXME-implementors!! It would be more helpful if the [New...] message | |
2864 | @c included GDB's numeric thread handle, so you could just go to that | |
2865 | @c thread without first checking `info threads'. | |
2866 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2867 | the target system's identification for the thread with a message in the | |
697aa1b7 | 2868 | form @samp{[New @var{systag}]}, where @var{systag} is a thread identifier |
c906108c | 2869 | whose form varies depending on the particular system. For example, on |
8807d78b | 2870 | @sc{gnu}/Linux, you might see |
c906108c | 2871 | |
474c8240 | 2872 | @smallexample |
08e796bc | 2873 | [New Thread 0x41e02940 (LWP 25582)] |
474c8240 | 2874 | @end smallexample |
c906108c SS |
2875 | |
2876 | @noindent | |
b1236ac3 | 2877 | when @value{GDBN} notices a new thread. In contrast, on other systems, |
c906108c SS |
2878 | the @var{systag} is simply something like @samp{process 368}, with no |
2879 | further qualifier. | |
2880 | ||
2881 | @c FIXME!! (1) Does the [New...] message appear even for the very first | |
2882 | @c thread of a program, or does it only appear for the | |
6ca652b0 | 2883 | @c second---i.e.@: when it becomes obvious we have a multithread |
c906108c SS |
2884 | @c program? |
2885 | @c (2) *Is* there necessarily a first thread always? Or do some | |
2886 | @c multithread systems permit starting a program with multiple | |
5d161b24 | 2887 | @c threads ab initio? |
c906108c | 2888 | |
5d5658a1 PA |
2889 | @anchor{thread numbers} |
2890 | @cindex thread number, per inferior | |
c906108c | 2891 | @cindex thread identifier (GDB) |
5d5658a1 PA |
2892 | For debugging purposes, @value{GDBN} associates its own thread number |
2893 | ---always a single integer---with each thread of an inferior. This | |
2894 | number is unique between all threads of an inferior, but not unique | |
2895 | between threads of different inferiors. | |
2896 | ||
2897 | @cindex qualified thread ID | |
2898 | You can refer to a given thread in an inferior using the qualified | |
2899 | @var{inferior-num}.@var{thread-num} syntax, also known as | |
2900 | @dfn{qualified thread ID}, with @var{inferior-num} being the inferior | |
2901 | number and @var{thread-num} being the thread number of the given | |
2902 | inferior. For example, thread @code{2.3} refers to thread number 3 of | |
2903 | inferior 2. If you omit @var{inferior-num} (e.g., @code{thread 3}), | |
2904 | then @value{GDBN} infers you're referring to a thread of the current | |
2905 | inferior. | |
2906 | ||
2907 | Until you create a second inferior, @value{GDBN} does not show the | |
2908 | @var{inferior-num} part of thread IDs, even though you can always use | |
2909 | the full @var{inferior-num}.@var{thread-num} form to refer to threads | |
2910 | of inferior 1, the initial inferior. | |
2911 | ||
2912 | @anchor{thread ID lists} | |
2913 | @cindex thread ID lists | |
2914 | Some commands accept a space-separated @dfn{thread ID list} as | |
71ef29a8 PA |
2915 | argument. A list element can be: |
2916 | ||
2917 | @enumerate | |
2918 | @item | |
2919 | A thread ID as shown in the first field of the @samp{info threads} | |
2920 | display, with or without an inferior qualifier. E.g., @samp{2.1} or | |
2921 | @samp{1}. | |
2922 | ||
2923 | @item | |
2924 | A range of thread numbers, again with or without an inferior | |
2925 | qualifier, as in @var{inf}.@var{thr1}-@var{thr2} or | |
2926 | @var{thr1}-@var{thr2}. E.g., @samp{1.2-4} or @samp{2-4}. | |
2927 | ||
2928 | @item | |
2929 | All threads of an inferior, specified with a star wildcard, with or | |
2930 | without an inferior qualifier, as in @var{inf}.@code{*} (e.g., | |
2931 | @samp{1.*}) or @code{*}. The former refers to all threads of the | |
2932 | given inferior, and the latter form without an inferior qualifier | |
2933 | refers to all threads of the current inferior. | |
2934 | ||
2935 | @end enumerate | |
2936 | ||
2937 | For example, if the current inferior is 1, and inferior 7 has one | |
2938 | thread with ID 7.1, the thread list @samp{1 2-3 4.5 6.7-9 7.*} | |
2939 | includes threads 1 to 3 of inferior 1, thread 5 of inferior 4, threads | |
2940 | 7 to 9 of inferior 6 and all threads of inferior 7. That is, in | |
2941 | expanded qualified form, the same as @samp{1.1 1.2 1.3 4.5 6.7 6.8 6.9 | |
2942 | 7.1}. | |
2943 | ||
5d5658a1 PA |
2944 | |
2945 | @anchor{global thread numbers} | |
2946 | @cindex global thread number | |
2947 | @cindex global thread identifier (GDB) | |
2948 | In addition to a @emph{per-inferior} number, each thread is also | |
2949 | assigned a unique @emph{global} number, also known as @dfn{global | |
2950 | thread ID}, a single integer. Unlike the thread number component of | |
2951 | the thread ID, no two threads have the same global ID, even when | |
2952 | you're debugging multiple inferiors. | |
c906108c | 2953 | |
f4f4330e PA |
2954 | From @value{GDBN}'s perspective, a process always has at least one |
2955 | thread. In other words, @value{GDBN} assigns a thread number to the | |
2956 | program's ``main thread'' even if the program is not multi-threaded. | |
2957 | ||
5d5658a1 | 2958 | @vindex $_thread@r{, convenience variable} |
663f6d42 PA |
2959 | @vindex $_gthread@r{, convenience variable} |
2960 | The debugger convenience variables @samp{$_thread} and | |
2961 | @samp{$_gthread} contain, respectively, the per-inferior thread number | |
2962 | and the global thread number of the current thread. You may find this | |
5d5658a1 PA |
2963 | useful in writing breakpoint conditional expressions, command scripts, |
2964 | and so forth. @xref{Convenience Vars,, Convenience Variables}, for | |
2965 | general information on convenience variables. | |
2966 | ||
f303dbd6 PA |
2967 | If @value{GDBN} detects the program is multi-threaded, it augments the |
2968 | usual message about stopping at a breakpoint with the ID and name of | |
2969 | the thread that hit the breakpoint. | |
2970 | ||
2971 | @smallexample | |
2972 | Thread 2 "client" hit Breakpoint 1, send_message () at client.c:68 | |
2973 | @end smallexample | |
2974 | ||
2975 | Likewise when the program receives a signal: | |
2976 | ||
2977 | @smallexample | |
2978 | Thread 1 "main" received signal SIGINT, Interrupt. | |
2979 | @end smallexample | |
2980 | ||
c906108c SS |
2981 | @table @code |
2982 | @kindex info threads | |
5d5658a1 PA |
2983 | @item info threads @r{[}@var{thread-id-list}@r{]} |
2984 | ||
2985 | Display information about one or more threads. With no arguments | |
2986 | displays information about all threads. You can specify the list of | |
2987 | threads that you want to display using the thread ID list syntax | |
2988 | (@pxref{thread ID lists}). | |
2989 | ||
60f98dde | 2990 | @value{GDBN} displays for each thread (in this order): |
c906108c SS |
2991 | |
2992 | @enumerate | |
09d4efe1 | 2993 | @item |
5d5658a1 | 2994 | the per-inferior thread number assigned by @value{GDBN} |
c906108c | 2995 | |
c84f6bbf PA |
2996 | @item |
2997 | the global thread number assigned by @value{GDBN}, if the @samp{-gid} | |
2998 | option was specified | |
2999 | ||
09d4efe1 EZ |
3000 | @item |
3001 | the target system's thread identifier (@var{systag}) | |
c906108c | 3002 | |
4694da01 TT |
3003 | @item |
3004 | the thread's name, if one is known. A thread can either be named by | |
3005 | the user (see @code{thread name}, below), or, in some cases, by the | |
3006 | program itself. | |
3007 | ||
09d4efe1 EZ |
3008 | @item |
3009 | the current stack frame summary for that thread | |
c906108c SS |
3010 | @end enumerate |
3011 | ||
3012 | @noindent | |
3013 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
3014 | indicates the current thread. | |
3015 | ||
5d161b24 | 3016 | For example, |
c906108c SS |
3017 | @end table |
3018 | @c end table here to get a little more width for example | |
3019 | ||
3020 | @smallexample | |
3021 | (@value{GDBP}) info threads | |
13fd8b81 | 3022 | Id Target Id Frame |
c0ecb95f | 3023 | * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) |
b05b1202 PA |
3024 | 2 process 35 thread 23 0x34e5 in sigpause () |
3025 | 3 process 35 thread 27 0x34e5 in sigpause () | |
c906108c SS |
3026 | at threadtest.c:68 |
3027 | @end smallexample | |
53a5351d | 3028 | |
5d5658a1 PA |
3029 | If you're debugging multiple inferiors, @value{GDBN} displays thread |
3030 | IDs using the qualified @var{inferior-num}.@var{thread-num} format. | |
c84f6bbf PA |
3031 | Otherwise, only @var{thread-num} is shown. |
3032 | ||
3033 | If you specify the @samp{-gid} option, @value{GDBN} displays a column | |
3034 | indicating each thread's global thread ID: | |
5d5658a1 PA |
3035 | |
3036 | @smallexample | |
3037 | (@value{GDBP}) info threads | |
c84f6bbf PA |
3038 | Id GId Target Id Frame |
3039 | 1.1 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) | |
3040 | 1.2 3 process 35 thread 23 0x34e5 in sigpause () | |
3041 | 1.3 4 process 35 thread 27 0x34e5 in sigpause () | |
3042 | * 2.1 2 process 65 thread 1 main (argc=1, argv=0x7ffffff8) | |
5d5658a1 PA |
3043 | @end smallexample |
3044 | ||
c45da7e6 EZ |
3045 | On Solaris, you can display more information about user threads with a |
3046 | Solaris-specific command: | |
3047 | ||
3048 | @table @code | |
3049 | @item maint info sol-threads | |
3050 | @kindex maint info sol-threads | |
3051 | @cindex thread info (Solaris) | |
3052 | Display info on Solaris user threads. | |
3053 | @end table | |
3054 | ||
c906108c | 3055 | @table @code |
5d5658a1 PA |
3056 | @kindex thread @var{thread-id} |
3057 | @item thread @var{thread-id} | |
3058 | Make thread ID @var{thread-id} the current thread. The command | |
3059 | argument @var{thread-id} is the @value{GDBN} thread ID, as shown in | |
3060 | the first field of the @samp{info threads} display, with or without an | |
3061 | inferior qualifier (e.g., @samp{2.1} or @samp{1}). | |
3062 | ||
3063 | @value{GDBN} responds by displaying the system identifier of the | |
3064 | thread you selected, and its current stack frame summary: | |
c906108c SS |
3065 | |
3066 | @smallexample | |
c906108c | 3067 | (@value{GDBP}) thread 2 |
13fd8b81 TT |
3068 | [Switching to thread 2 (Thread 0xb7fdab70 (LWP 12747))] |
3069 | #0 some_function (ignore=0x0) at example.c:8 | |
3070 | 8 printf ("hello\n"); | |
c906108c SS |
3071 | @end smallexample |
3072 | ||
3073 | @noindent | |
3074 | As with the @samp{[New @dots{}]} message, the form of the text after | |
3075 | @samp{Switching to} depends on your system's conventions for identifying | |
5d161b24 | 3076 | threads. |
c906108c | 3077 | |
9c16f35a | 3078 | @kindex thread apply |
638ac427 | 3079 | @cindex apply command to several threads |
5d5658a1 | 3080 | @item thread apply [@var{thread-id-list} | all [-ascending]] @var{command} |
839c27b7 | 3081 | The @code{thread apply} command allows you to apply the named |
5d5658a1 PA |
3082 | @var{command} to one or more threads. Specify the threads that you |
3083 | want affected using the thread ID list syntax (@pxref{thread ID | |
3084 | lists}), or specify @code{all} to apply to all threads. To apply a | |
3085 | command to all threads in descending order, type @kbd{thread apply all | |
253828f1 JK |
3086 | @var{command}}. To apply a command to all threads in ascending order, |
3087 | type @kbd{thread apply all -ascending @var{command}}. | |
3088 | ||
93815fbf | 3089 | |
4694da01 TT |
3090 | @kindex thread name |
3091 | @cindex name a thread | |
3092 | @item thread name [@var{name}] | |
3093 | This command assigns a name to the current thread. If no argument is | |
3094 | given, any existing user-specified name is removed. The thread name | |
3095 | appears in the @samp{info threads} display. | |
3096 | ||
3097 | On some systems, such as @sc{gnu}/Linux, @value{GDBN} is able to | |
3098 | determine the name of the thread as given by the OS. On these | |
3099 | systems, a name specified with @samp{thread name} will override the | |
3100 | system-give name, and removing the user-specified name will cause | |
3101 | @value{GDBN} to once again display the system-specified name. | |
3102 | ||
60f98dde MS |
3103 | @kindex thread find |
3104 | @cindex search for a thread | |
3105 | @item thread find [@var{regexp}] | |
3106 | Search for and display thread ids whose name or @var{systag} | |
3107 | matches the supplied regular expression. | |
3108 | ||
3109 | As well as being the complement to the @samp{thread name} command, | |
3110 | this command also allows you to identify a thread by its target | |
3111 | @var{systag}. For instance, on @sc{gnu}/Linux, the target @var{systag} | |
3112 | is the LWP id. | |
3113 | ||
3114 | @smallexample | |
3115 | (@value{GDBN}) thread find 26688 | |
3116 | Thread 4 has target id 'Thread 0x41e02940 (LWP 26688)' | |
3117 | (@value{GDBN}) info thread 4 | |
3118 | Id Target Id Frame | |
3119 | 4 Thread 0x41e02940 (LWP 26688) 0x00000031ca6cd372 in select () | |
3120 | @end smallexample | |
3121 | ||
93815fbf VP |
3122 | @kindex set print thread-events |
3123 | @cindex print messages on thread start and exit | |
3124 | @item set print thread-events | |
3125 | @itemx set print thread-events on | |
3126 | @itemx set print thread-events off | |
3127 | The @code{set print thread-events} command allows you to enable or | |
3128 | disable printing of messages when @value{GDBN} notices that new threads have | |
3129 | started or that threads have exited. By default, these messages will | |
3130 | be printed if detection of these events is supported by the target. | |
3131 | Note that these messages cannot be disabled on all targets. | |
3132 | ||
3133 | @kindex show print thread-events | |
3134 | @item show print thread-events | |
3135 | Show whether messages will be printed when @value{GDBN} detects that threads | |
3136 | have started and exited. | |
c906108c SS |
3137 | @end table |
3138 | ||
79a6e687 | 3139 | @xref{Thread Stops,,Stopping and Starting Multi-thread Programs}, for |
c906108c SS |
3140 | more information about how @value{GDBN} behaves when you stop and start |
3141 | programs with multiple threads. | |
3142 | ||
79a6e687 | 3143 | @xref{Set Watchpoints,,Setting Watchpoints}, for information about |
c906108c | 3144 | watchpoints in programs with multiple threads. |
c906108c | 3145 | |
bf88dd68 | 3146 | @anchor{set libthread-db-search-path} |
17a37d48 PP |
3147 | @table @code |
3148 | @kindex set libthread-db-search-path | |
3149 | @cindex search path for @code{libthread_db} | |
3150 | @item set libthread-db-search-path @r{[}@var{path}@r{]} | |
3151 | If this variable is set, @var{path} is a colon-separated list of | |
3152 | directories @value{GDBN} will use to search for @code{libthread_db}. | |
3153 | If you omit @var{path}, @samp{libthread-db-search-path} will be reset to | |
98a5dd13 | 3154 | its default value (@code{$sdir:$pdir} on @sc{gnu}/Linux and Solaris systems). |
7e0396aa DE |
3155 | Internally, the default value comes from the @code{LIBTHREAD_DB_SEARCH_PATH} |
3156 | macro. | |
17a37d48 PP |
3157 | |
3158 | On @sc{gnu}/Linux and Solaris systems, @value{GDBN} uses a ``helper'' | |
3159 | @code{libthread_db} library to obtain information about threads in the | |
3160 | inferior process. @value{GDBN} will use @samp{libthread-db-search-path} | |
bf88dd68 JK |
3161 | to find @code{libthread_db}. @value{GDBN} also consults first if inferior |
3162 | specific thread debugging library loading is enabled | |
3163 | by @samp{set auto-load libthread-db} (@pxref{libthread_db.so.1 file}). | |
98a5dd13 DE |
3164 | |
3165 | A special entry @samp{$sdir} for @samp{libthread-db-search-path} | |
3166 | refers to the default system directories that are | |
bf88dd68 JK |
3167 | normally searched for loading shared libraries. The @samp{$sdir} entry |
3168 | is the only kind not needing to be enabled by @samp{set auto-load libthread-db} | |
3169 | (@pxref{libthread_db.so.1 file}). | |
98a5dd13 DE |
3170 | |
3171 | A special entry @samp{$pdir} for @samp{libthread-db-search-path} | |
3172 | refers to the directory from which @code{libpthread} | |
3173 | was loaded in the inferior process. | |
17a37d48 PP |
3174 | |
3175 | For any @code{libthread_db} library @value{GDBN} finds in above directories, | |
3176 | @value{GDBN} attempts to initialize it with the current inferior process. | |
3177 | If this initialization fails (which could happen because of a version | |
3178 | mismatch between @code{libthread_db} and @code{libpthread}), @value{GDBN} | |
3179 | will unload @code{libthread_db}, and continue with the next directory. | |
3180 | If none of @code{libthread_db} libraries initialize successfully, | |
3181 | @value{GDBN} will issue a warning and thread debugging will be disabled. | |
3182 | ||
3183 | Setting @code{libthread-db-search-path} is currently implemented | |
3184 | only on some platforms. | |
3185 | ||
3186 | @kindex show libthread-db-search-path | |
3187 | @item show libthread-db-search-path | |
3188 | Display current libthread_db search path. | |
02d868e8 PP |
3189 | |
3190 | @kindex set debug libthread-db | |
3191 | @kindex show debug libthread-db | |
3192 | @cindex debugging @code{libthread_db} | |
3193 | @item set debug libthread-db | |
3194 | @itemx show debug libthread-db | |
3195 | Turns on or off display of @code{libthread_db}-related events. | |
3196 | Use @code{1} to enable, @code{0} to disable. | |
17a37d48 PP |
3197 | @end table |
3198 | ||
6c95b8df PA |
3199 | @node Forks |
3200 | @section Debugging Forks | |
c906108c SS |
3201 | |
3202 | @cindex fork, debugging programs which call | |
3203 | @cindex multiple processes | |
3204 | @cindex processes, multiple | |
53a5351d JM |
3205 | On most systems, @value{GDBN} has no special support for debugging |
3206 | programs which create additional processes using the @code{fork} | |
3207 | function. When a program forks, @value{GDBN} will continue to debug the | |
3208 | parent process and the child process will run unimpeded. If you have | |
3209 | set a breakpoint in any code which the child then executes, the child | |
3210 | will get a @code{SIGTRAP} signal which (unless it catches the signal) | |
3211 | will cause it to terminate. | |
c906108c SS |
3212 | |
3213 | However, if you want to debug the child process there is a workaround | |
3214 | which isn't too painful. Put a call to @code{sleep} in the code which | |
3215 | the child process executes after the fork. It may be useful to sleep | |
3216 | only if a certain environment variable is set, or a certain file exists, | |
3217 | so that the delay need not occur when you don't want to run @value{GDBN} | |
3218 | on the child. While the child is sleeping, use the @code{ps} program to | |
3219 | get its process ID. Then tell @value{GDBN} (a new invocation of | |
3220 | @value{GDBN} if you are also debugging the parent process) to attach to | |
d4f3574e | 3221 | the child process (@pxref{Attach}). From that point on you can debug |
c906108c | 3222 | the child process just like any other process which you attached to. |
c906108c | 3223 | |
b1236ac3 PA |
3224 | On some systems, @value{GDBN} provides support for debugging programs |
3225 | that create additional processes using the @code{fork} or @code{vfork} | |
3226 | functions. On @sc{gnu}/Linux platforms, this feature is supported | |
19d9d4ef | 3227 | with kernel version 2.5.46 and later. |
c906108c | 3228 | |
19d9d4ef DB |
3229 | The fork debugging commands are supported in native mode and when |
3230 | connected to @code{gdbserver} in either @code{target remote} mode or | |
3231 | @code{target extended-remote} mode. | |
0d71eef5 | 3232 | |
c906108c SS |
3233 | By default, when a program forks, @value{GDBN} will continue to debug |
3234 | the parent process and the child process will run unimpeded. | |
3235 | ||
3236 | If you want to follow the child process instead of the parent process, | |
3237 | use the command @w{@code{set follow-fork-mode}}. | |
3238 | ||
3239 | @table @code | |
3240 | @kindex set follow-fork-mode | |
3241 | @item set follow-fork-mode @var{mode} | |
3242 | Set the debugger response to a program call of @code{fork} or | |
3243 | @code{vfork}. A call to @code{fork} or @code{vfork} creates a new | |
9c16f35a | 3244 | process. The @var{mode} argument can be: |
c906108c SS |
3245 | |
3246 | @table @code | |
3247 | @item parent | |
3248 | The original process is debugged after a fork. The child process runs | |
2df3850c | 3249 | unimpeded. This is the default. |
c906108c SS |
3250 | |
3251 | @item child | |
3252 | The new process is debugged after a fork. The parent process runs | |
3253 | unimpeded. | |
3254 | ||
c906108c SS |
3255 | @end table |
3256 | ||
9c16f35a | 3257 | @kindex show follow-fork-mode |
c906108c | 3258 | @item show follow-fork-mode |
2df3850c | 3259 | Display the current debugger response to a @code{fork} or @code{vfork} call. |
c906108c SS |
3260 | @end table |
3261 | ||
5c95884b MS |
3262 | @cindex debugging multiple processes |
3263 | On Linux, if you want to debug both the parent and child processes, use the | |
3264 | command @w{@code{set detach-on-fork}}. | |
3265 | ||
3266 | @table @code | |
3267 | @kindex set detach-on-fork | |
3268 | @item set detach-on-fork @var{mode} | |
3269 | Tells gdb whether to detach one of the processes after a fork, or | |
3270 | retain debugger control over them both. | |
3271 | ||
3272 | @table @code | |
3273 | @item on | |
3274 | The child process (or parent process, depending on the value of | |
3275 | @code{follow-fork-mode}) will be detached and allowed to run | |
3276 | independently. This is the default. | |
3277 | ||
3278 | @item off | |
3279 | Both processes will be held under the control of @value{GDBN}. | |
3280 | One process (child or parent, depending on the value of | |
3281 | @code{follow-fork-mode}) is debugged as usual, while the other | |
3282 | is held suspended. | |
3283 | ||
3284 | @end table | |
3285 | ||
11310833 NR |
3286 | @kindex show detach-on-fork |
3287 | @item show detach-on-fork | |
3288 | Show whether detach-on-fork mode is on/off. | |
5c95884b MS |
3289 | @end table |
3290 | ||
2277426b PA |
3291 | If you choose to set @samp{detach-on-fork} mode off, then @value{GDBN} |
3292 | will retain control of all forked processes (including nested forks). | |
3293 | You can list the forked processes under the control of @value{GDBN} by | |
3294 | using the @w{@code{info inferiors}} command, and switch from one fork | |
6c95b8df PA |
3295 | to another by using the @code{inferior} command (@pxref{Inferiors and |
3296 | Programs, ,Debugging Multiple Inferiors and Programs}). | |
5c95884b MS |
3297 | |
3298 | To quit debugging one of the forked processes, you can either detach | |
af624141 MS |
3299 | from it by using the @w{@code{detach inferiors}} command (allowing it |
3300 | to run independently), or kill it using the @w{@code{kill inferiors}} | |
6c95b8df PA |
3301 | command. @xref{Inferiors and Programs, ,Debugging Multiple Inferiors |
3302 | and Programs}. | |
5c95884b | 3303 | |
c906108c SS |
3304 | If you ask to debug a child process and a @code{vfork} is followed by an |
3305 | @code{exec}, @value{GDBN} executes the new target up to the first | |
3306 | breakpoint in the new target. If you have a breakpoint set on | |
3307 | @code{main} in your original program, the breakpoint will also be set on | |
3308 | the child process's @code{main}. | |
3309 | ||
2277426b PA |
3310 | On some systems, when a child process is spawned by @code{vfork}, you |
3311 | cannot debug the child or parent until an @code{exec} call completes. | |
c906108c SS |
3312 | |
3313 | If you issue a @code{run} command to @value{GDBN} after an @code{exec} | |
6c95b8df PA |
3314 | call executes, the new target restarts. To restart the parent |
3315 | process, use the @code{file} command with the parent executable name | |
3316 | as its argument. By default, after an @code{exec} call executes, | |
3317 | @value{GDBN} discards the symbols of the previous executable image. | |
3318 | You can change this behaviour with the @w{@code{set follow-exec-mode}} | |
3319 | command. | |
3320 | ||
3321 | @table @code | |
3322 | @kindex set follow-exec-mode | |
3323 | @item set follow-exec-mode @var{mode} | |
3324 | ||
3325 | Set debugger response to a program call of @code{exec}. An | |
3326 | @code{exec} call replaces the program image of a process. | |
3327 | ||
3328 | @code{follow-exec-mode} can be: | |
3329 | ||
3330 | @table @code | |
3331 | @item new | |
3332 | @value{GDBN} creates a new inferior and rebinds the process to this | |
3333 | new inferior. The program the process was running before the | |
3334 | @code{exec} call can be restarted afterwards by restarting the | |
3335 | original inferior. | |
3336 | ||
3337 | For example: | |
3338 | ||
3339 | @smallexample | |
3340 | (@value{GDBP}) info inferiors | |
3341 | (gdb) info inferior | |
3342 | Id Description Executable | |
3343 | * 1 <null> prog1 | |
3344 | (@value{GDBP}) run | |
3345 | process 12020 is executing new program: prog2 | |
3346 | Program exited normally. | |
3347 | (@value{GDBP}) info inferiors | |
3348 | Id Description Executable | |
c0ecb95f | 3349 | 1 <null> prog1 |
b05b1202 | 3350 | * 2 <null> prog2 |
6c95b8df PA |
3351 | @end smallexample |
3352 | ||
3353 | @item same | |
3354 | @value{GDBN} keeps the process bound to the same inferior. The new | |
3355 | executable image replaces the previous executable loaded in the | |
3356 | inferior. Restarting the inferior after the @code{exec} call, with | |
3357 | e.g., the @code{run} command, restarts the executable the process was | |
3358 | running after the @code{exec} call. This is the default mode. | |
3359 | ||
3360 | For example: | |
3361 | ||
3362 | @smallexample | |
3363 | (@value{GDBP}) info inferiors | |
3364 | Id Description Executable | |
3365 | * 1 <null> prog1 | |
3366 | (@value{GDBP}) run | |
3367 | process 12020 is executing new program: prog2 | |
3368 | Program exited normally. | |
3369 | (@value{GDBP}) info inferiors | |
3370 | Id Description Executable | |
3371 | * 1 <null> prog2 | |
3372 | @end smallexample | |
3373 | ||
3374 | @end table | |
3375 | @end table | |
c906108c | 3376 | |
19d9d4ef DB |
3377 | @code{follow-exec-mode} is supported in native mode and |
3378 | @code{target extended-remote} mode. | |
3379 | ||
c906108c SS |
3380 | You can use the @code{catch} command to make @value{GDBN} stop whenever |
3381 | a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set | |
79a6e687 | 3382 | Catchpoints, ,Setting Catchpoints}. |
c906108c | 3383 | |
5c95884b | 3384 | @node Checkpoint/Restart |
79a6e687 | 3385 | @section Setting a @emph{Bookmark} to Return to Later |
5c95884b MS |
3386 | |
3387 | @cindex checkpoint | |
3388 | @cindex restart | |
3389 | @cindex bookmark | |
3390 | @cindex snapshot of a process | |
3391 | @cindex rewind program state | |
3392 | ||
3393 | On certain operating systems@footnote{Currently, only | |
3394 | @sc{gnu}/Linux.}, @value{GDBN} is able to save a @dfn{snapshot} of a | |
3395 | program's state, called a @dfn{checkpoint}, and come back to it | |
3396 | later. | |
3397 | ||
3398 | Returning to a checkpoint effectively undoes everything that has | |
3399 | happened in the program since the @code{checkpoint} was saved. This | |
3400 | includes changes in memory, registers, and even (within some limits) | |
3401 | system state. Effectively, it is like going back in time to the | |
3402 | moment when the checkpoint was saved. | |
3403 | ||
3404 | Thus, if you're stepping thru a program and you think you're | |
3405 | getting close to the point where things go wrong, you can save | |
3406 | a checkpoint. Then, if you accidentally go too far and miss | |
3407 | the critical statement, instead of having to restart your program | |
3408 | from the beginning, you can just go back to the checkpoint and | |
3409 | start again from there. | |
3410 | ||
3411 | This can be especially useful if it takes a lot of time or | |
3412 | steps to reach the point where you think the bug occurs. | |
3413 | ||
3414 | To use the @code{checkpoint}/@code{restart} method of debugging: | |
3415 | ||
3416 | @table @code | |
3417 | @kindex checkpoint | |
3418 | @item checkpoint | |
3419 | Save a snapshot of the debugged program's current execution state. | |
3420 | The @code{checkpoint} command takes no arguments, but each checkpoint | |
3421 | is assigned a small integer id, similar to a breakpoint id. | |
3422 | ||
3423 | @kindex info checkpoints | |
3424 | @item info checkpoints | |
3425 | List the checkpoints that have been saved in the current debugging | |
3426 | session. For each checkpoint, the following information will be | |
3427 | listed: | |
3428 | ||
3429 | @table @code | |
3430 | @item Checkpoint ID | |
3431 | @item Process ID | |
3432 | @item Code Address | |
3433 | @item Source line, or label | |
3434 | @end table | |
3435 | ||
3436 | @kindex restart @var{checkpoint-id} | |
3437 | @item restart @var{checkpoint-id} | |
3438 | Restore the program state that was saved as checkpoint number | |
3439 | @var{checkpoint-id}. All program variables, registers, stack frames | |
3440 | etc.@: will be returned to the values that they had when the checkpoint | |
3441 | was saved. In essence, gdb will ``wind back the clock'' to the point | |
3442 | in time when the checkpoint was saved. | |
3443 | ||
3444 | Note that breakpoints, @value{GDBN} variables, command history etc. | |
3445 | are not affected by restoring a checkpoint. In general, a checkpoint | |
3446 | only restores things that reside in the program being debugged, not in | |
3447 | the debugger. | |
3448 | ||
b8db102d MS |
3449 | @kindex delete checkpoint @var{checkpoint-id} |
3450 | @item delete checkpoint @var{checkpoint-id} | |
5c95884b MS |
3451 | Delete the previously-saved checkpoint identified by @var{checkpoint-id}. |
3452 | ||
3453 | @end table | |
3454 | ||
3455 | Returning to a previously saved checkpoint will restore the user state | |
3456 | of the program being debugged, plus a significant subset of the system | |
3457 | (OS) state, including file pointers. It won't ``un-write'' data from | |
3458 | a file, but it will rewind the file pointer to the previous location, | |
3459 | so that the previously written data can be overwritten. For files | |
3460 | opened in read mode, the pointer will also be restored so that the | |
3461 | previously read data can be read again. | |
3462 | ||
3463 | Of course, characters that have been sent to a printer (or other | |
3464 | external device) cannot be ``snatched back'', and characters received | |
3465 | from eg.@: a serial device can be removed from internal program buffers, | |
3466 | but they cannot be ``pushed back'' into the serial pipeline, ready to | |
3467 | be received again. Similarly, the actual contents of files that have | |
3468 | been changed cannot be restored (at this time). | |
3469 | ||
3470 | However, within those constraints, you actually can ``rewind'' your | |
3471 | program to a previously saved point in time, and begin debugging it | |
3472 | again --- and you can change the course of events so as to debug a | |
3473 | different execution path this time. | |
3474 | ||
3475 | @cindex checkpoints and process id | |
3476 | Finally, there is one bit of internal program state that will be | |
3477 | different when you return to a checkpoint --- the program's process | |
3478 | id. Each checkpoint will have a unique process id (or @var{pid}), | |
3479 | and each will be different from the program's original @var{pid}. | |
3480 | If your program has saved a local copy of its process id, this could | |
3481 | potentially pose a problem. | |
3482 | ||
79a6e687 | 3483 | @subsection A Non-obvious Benefit of Using Checkpoints |
5c95884b MS |
3484 | |
3485 | On some systems such as @sc{gnu}/Linux, address space randomization | |
3486 | is performed on new processes for security reasons. This makes it | |
3487 | difficult or impossible to set a breakpoint, or watchpoint, on an | |
3488 | absolute address if you have to restart the program, since the | |
3489 | absolute location of a symbol will change from one execution to the | |
3490 | next. | |
3491 | ||
3492 | A checkpoint, however, is an @emph{identical} copy of a process. | |
3493 | Therefore if you create a checkpoint at (eg.@:) the start of main, | |
3494 | and simply return to that checkpoint instead of restarting the | |
3495 | process, you can avoid the effects of address randomization and | |
3496 | your symbols will all stay in the same place. | |
3497 | ||
6d2ebf8b | 3498 | @node Stopping |
c906108c SS |
3499 | @chapter Stopping and Continuing |
3500 | ||
3501 | The principal purposes of using a debugger are so that you can stop your | |
3502 | program before it terminates; or so that, if your program runs into | |
3503 | trouble, you can investigate and find out why. | |
3504 | ||
7a292a7a SS |
3505 | Inside @value{GDBN}, your program may stop for any of several reasons, |
3506 | such as a signal, a breakpoint, or reaching a new line after a | |
3507 | @value{GDBN} command such as @code{step}. You may then examine and | |
3508 | change variables, set new breakpoints or remove old ones, and then | |
3509 | continue execution. Usually, the messages shown by @value{GDBN} provide | |
3510 | ample explanation of the status of your program---but you can also | |
3511 | explicitly request this information at any time. | |
c906108c SS |
3512 | |
3513 | @table @code | |
3514 | @kindex info program | |
3515 | @item info program | |
3516 | Display information about the status of your program: whether it is | |
7a292a7a | 3517 | running or not, what process it is, and why it stopped. |
c906108c SS |
3518 | @end table |
3519 | ||
3520 | @menu | |
3521 | * Breakpoints:: Breakpoints, watchpoints, and catchpoints | |
3522 | * Continuing and Stepping:: Resuming execution | |
aad1c02c TT |
3523 | * Skipping Over Functions and Files:: |
3524 | Skipping over functions and files | |
c906108c | 3525 | * Signals:: Signals |
c906108c | 3526 | * Thread Stops:: Stopping and starting multi-thread programs |
c906108c SS |
3527 | @end menu |
3528 | ||
6d2ebf8b | 3529 | @node Breakpoints |
79a6e687 | 3530 | @section Breakpoints, Watchpoints, and Catchpoints |
c906108c SS |
3531 | |
3532 | @cindex breakpoints | |
3533 | A @dfn{breakpoint} makes your program stop whenever a certain point in | |
3534 | the program is reached. For each breakpoint, you can add conditions to | |
3535 | control in finer detail whether your program stops. You can set | |
3536 | breakpoints with the @code{break} command and its variants (@pxref{Set | |
79a6e687 | 3537 | Breaks, ,Setting Breakpoints}), to specify the place where your program |
c906108c SS |
3538 | should stop by line number, function name or exact address in the |
3539 | program. | |
3540 | ||
09d4efe1 | 3541 | On some systems, you can set breakpoints in shared libraries before |
b1236ac3 | 3542 | the executable is run. |
c906108c SS |
3543 | |
3544 | @cindex watchpoints | |
fd60e0df | 3545 | @cindex data breakpoints |
c906108c SS |
3546 | @cindex memory tracing |
3547 | @cindex breakpoint on memory address | |
3548 | @cindex breakpoint on variable modification | |
3549 | A @dfn{watchpoint} is a special breakpoint that stops your program | |
fd60e0df | 3550 | when the value of an expression changes. The expression may be a value |
0ced0c34 | 3551 | of a variable, or it could involve values of one or more variables |
fd60e0df EZ |
3552 | combined by operators, such as @samp{a + b}. This is sometimes called |
3553 | @dfn{data breakpoints}. You must use a different command to set | |
79a6e687 | 3554 | watchpoints (@pxref{Set Watchpoints, ,Setting Watchpoints}), but aside |
fd60e0df EZ |
3555 | from that, you can manage a watchpoint like any other breakpoint: you |
3556 | enable, disable, and delete both breakpoints and watchpoints using the | |
3557 | same commands. | |
c906108c SS |
3558 | |
3559 | You can arrange to have values from your program displayed automatically | |
3560 | whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,, | |
79a6e687 | 3561 | Automatic Display}. |
c906108c SS |
3562 | |
3563 | @cindex catchpoints | |
3564 | @cindex breakpoint on events | |
3565 | A @dfn{catchpoint} is another special breakpoint that stops your program | |
b37052ae | 3566 | when a certain kind of event occurs, such as the throwing of a C@t{++} |
c906108c SS |
3567 | exception or the loading of a library. As with watchpoints, you use a |
3568 | different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting | |
79a6e687 | 3569 | Catchpoints}), but aside from that, you can manage a catchpoint like any |
c906108c | 3570 | other breakpoint. (To stop when your program receives a signal, use the |
d4f3574e | 3571 | @code{handle} command; see @ref{Signals, ,Signals}.) |
c906108c SS |
3572 | |
3573 | @cindex breakpoint numbers | |
3574 | @cindex numbers for breakpoints | |
3575 | @value{GDBN} assigns a number to each breakpoint, watchpoint, or | |
3576 | catchpoint when you create it; these numbers are successive integers | |
3577 | starting with one. In many of the commands for controlling various | |
3578 | features of breakpoints you use the breakpoint number to say which | |
3579 | breakpoint you want to change. Each breakpoint may be @dfn{enabled} or | |
3580 | @dfn{disabled}; if disabled, it has no effect on your program until you | |
3581 | enable it again. | |
3582 | ||
c5394b80 JM |
3583 | @cindex breakpoint ranges |
3584 | @cindex ranges of breakpoints | |
3585 | Some @value{GDBN} commands accept a range of breakpoints on which to | |
3586 | operate. A breakpoint range is either a single breakpoint number, like | |
3587 | @samp{5}, or two such numbers, in increasing order, separated by a | |
3588 | hyphen, like @samp{5-7}. When a breakpoint range is given to a command, | |
d52fb0e9 | 3589 | all breakpoints in that range are operated on. |
c5394b80 | 3590 | |
c906108c SS |
3591 | @menu |
3592 | * Set Breaks:: Setting breakpoints | |
3593 | * Set Watchpoints:: Setting watchpoints | |
3594 | * Set Catchpoints:: Setting catchpoints | |
3595 | * Delete Breaks:: Deleting breakpoints | |
3596 | * Disabling:: Disabling breakpoints | |
3597 | * Conditions:: Break conditions | |
3598 | * Break Commands:: Breakpoint command lists | |
e7e0cddf | 3599 | * Dynamic Printf:: Dynamic printf |
6149aea9 | 3600 | * Save Breakpoints:: How to save breakpoints in a file |
62e5f89c | 3601 | * Static Probe Points:: Listing static probe points |
d4f3574e | 3602 | * Error in Breakpoints:: ``Cannot insert breakpoints'' |
79a6e687 | 3603 | * Breakpoint-related Warnings:: ``Breakpoint address adjusted...'' |
c906108c SS |
3604 | @end menu |
3605 | ||
6d2ebf8b | 3606 | @node Set Breaks |
79a6e687 | 3607 | @subsection Setting Breakpoints |
c906108c | 3608 | |
5d161b24 | 3609 | @c FIXME LMB what does GDB do if no code on line of breakpt? |
c906108c SS |
3610 | @c consider in particular declaration with/without initialization. |
3611 | @c | |
3612 | @c FIXME 2 is there stuff on this already? break at fun start, already init? | |
3613 | ||
3614 | @kindex break | |
41afff9a EZ |
3615 | @kindex b @r{(@code{break})} |
3616 | @vindex $bpnum@r{, convenience variable} | |
c906108c SS |
3617 | @cindex latest breakpoint |
3618 | Breakpoints are set with the @code{break} command (abbreviated | |
5d161b24 | 3619 | @code{b}). The debugger convenience variable @samp{$bpnum} records the |
f3b28801 | 3620 | number of the breakpoint you've set most recently; see @ref{Convenience |
79a6e687 | 3621 | Vars,, Convenience Variables}, for a discussion of what you can do with |
c906108c SS |
3622 | convenience variables. |
3623 | ||
c906108c | 3624 | @table @code |
2a25a5ba EZ |
3625 | @item break @var{location} |
3626 | Set a breakpoint at the given @var{location}, which can specify a | |
3627 | function name, a line number, or an address of an instruction. | |
3628 | (@xref{Specify Location}, for a list of all the possible ways to | |
3629 | specify a @var{location}.) The breakpoint will stop your program just | |
3630 | before it executes any of the code in the specified @var{location}. | |
3631 | ||
c906108c | 3632 | When using source languages that permit overloading of symbols, such as |
2a25a5ba | 3633 | C@t{++}, a function name may refer to more than one possible place to break. |
6ba66d6a JB |
3634 | @xref{Ambiguous Expressions,,Ambiguous Expressions}, for a discussion of |
3635 | that situation. | |
c906108c | 3636 | |
45ac276d | 3637 | It is also possible to insert a breakpoint that will stop the program |
2c88c651 JB |
3638 | only if a specific thread (@pxref{Thread-Specific Breakpoints}) |
3639 | or a specific task (@pxref{Ada Tasks}) hits that breakpoint. | |
45ac276d | 3640 | |
c906108c SS |
3641 | @item break |
3642 | When called without any arguments, @code{break} sets a breakpoint at | |
3643 | the next instruction to be executed in the selected stack frame | |
3644 | (@pxref{Stack, ,Examining the Stack}). In any selected frame but the | |
3645 | innermost, this makes your program stop as soon as control | |
3646 | returns to that frame. This is similar to the effect of a | |
3647 | @code{finish} command in the frame inside the selected frame---except | |
3648 | that @code{finish} does not leave an active breakpoint. If you use | |
3649 | @code{break} without an argument in the innermost frame, @value{GDBN} stops | |
3650 | the next time it reaches the current location; this may be useful | |
3651 | inside loops. | |
3652 | ||
3653 | @value{GDBN} normally ignores breakpoints when it resumes execution, until at | |
3654 | least one instruction has been executed. If it did not do this, you | |
3655 | would be unable to proceed past a breakpoint without first disabling the | |
3656 | breakpoint. This rule applies whether or not the breakpoint already | |
3657 | existed when your program stopped. | |
3658 | ||
3659 | @item break @dots{} if @var{cond} | |
3660 | Set a breakpoint with condition @var{cond}; evaluate the expression | |
3661 | @var{cond} each time the breakpoint is reached, and stop only if the | |
3662 | value is nonzero---that is, if @var{cond} evaluates as true. | |
3663 | @samp{@dots{}} stands for one of the possible arguments described | |
3664 | above (or no argument) specifying where to break. @xref{Conditions, | |
79a6e687 | 3665 | ,Break Conditions}, for more information on breakpoint conditions. |
c906108c SS |
3666 | |
3667 | @kindex tbreak | |
3668 | @item tbreak @var{args} | |
697aa1b7 | 3669 | Set a breakpoint enabled only for one stop. The @var{args} are the |
c906108c SS |
3670 | same as for the @code{break} command, and the breakpoint is set in the same |
3671 | way, but the breakpoint is automatically deleted after the first time your | |
79a6e687 | 3672 | program stops there. @xref{Disabling, ,Disabling Breakpoints}. |
c906108c | 3673 | |
c906108c | 3674 | @kindex hbreak |
ba04e063 | 3675 | @cindex hardware breakpoints |
c906108c | 3676 | @item hbreak @var{args} |
697aa1b7 | 3677 | Set a hardware-assisted breakpoint. The @var{args} are the same as for the |
d4f3574e | 3678 | @code{break} command and the breakpoint is set in the same way, but the |
c906108c SS |
3679 | breakpoint requires hardware support and some target hardware may not |
3680 | have this support. The main purpose of this is EPROM/ROM code | |
d4f3574e SS |
3681 | debugging, so you can set a breakpoint at an instruction without |
3682 | changing the instruction. This can be used with the new trap-generation | |
09d4efe1 | 3683 | provided by SPARClite DSU and most x86-based targets. These targets |
d4f3574e SS |
3684 | will generate traps when a program accesses some data or instruction |
3685 | address that is assigned to the debug registers. However the hardware | |
3686 | breakpoint registers can take a limited number of breakpoints. For | |
3687 | example, on the DSU, only two data breakpoints can be set at a time, and | |
3688 | @value{GDBN} will reject this command if more than two are used. Delete | |
3689 | or disable unused hardware breakpoints before setting new ones | |
79a6e687 BW |
3690 | (@pxref{Disabling, ,Disabling Breakpoints}). |
3691 | @xref{Conditions, ,Break Conditions}. | |
9c16f35a EZ |
3692 | For remote targets, you can restrict the number of hardware |
3693 | breakpoints @value{GDBN} will use, see @ref{set remote | |
3694 | hardware-breakpoint-limit}. | |
501eef12 | 3695 | |
c906108c SS |
3696 | @kindex thbreak |
3697 | @item thbreak @var{args} | |
697aa1b7 | 3698 | Set a hardware-assisted breakpoint enabled only for one stop. The @var{args} |
c906108c | 3699 | are the same as for the @code{hbreak} command and the breakpoint is set in |
5d161b24 | 3700 | the same way. However, like the @code{tbreak} command, |
c906108c SS |
3701 | the breakpoint is automatically deleted after the |
3702 | first time your program stops there. Also, like the @code{hbreak} | |
5d161b24 | 3703 | command, the breakpoint requires hardware support and some target hardware |
79a6e687 BW |
3704 | may not have this support. @xref{Disabling, ,Disabling Breakpoints}. |
3705 | See also @ref{Conditions, ,Break Conditions}. | |
c906108c SS |
3706 | |
3707 | @kindex rbreak | |
3708 | @cindex regular expression | |
8bd10a10 | 3709 | @cindex breakpoints at functions matching a regexp |
c45da7e6 | 3710 | @cindex set breakpoints in many functions |
c906108c | 3711 | @item rbreak @var{regex} |
c906108c | 3712 | Set breakpoints on all functions matching the regular expression |
11cf8741 JM |
3713 | @var{regex}. This command sets an unconditional breakpoint on all |
3714 | matches, printing a list of all breakpoints it set. Once these | |
3715 | breakpoints are set, they are treated just like the breakpoints set with | |
3716 | the @code{break} command. You can delete them, disable them, or make | |
3717 | them conditional the same way as any other breakpoint. | |
3718 | ||
3719 | The syntax of the regular expression is the standard one used with tools | |
3720 | like @file{grep}. Note that this is different from the syntax used by | |
3721 | shells, so for instance @code{foo*} matches all functions that include | |
3722 | an @code{fo} followed by zero or more @code{o}s. There is an implicit | |
3723 | @code{.*} leading and trailing the regular expression you supply, so to | |
3724 | match only functions that begin with @code{foo}, use @code{^foo}. | |
c906108c | 3725 | |
f7dc1244 | 3726 | @cindex non-member C@t{++} functions, set breakpoint in |
b37052ae | 3727 | When debugging C@t{++} programs, @code{rbreak} is useful for setting |
c906108c SS |
3728 | breakpoints on overloaded functions that are not members of any special |
3729 | classes. | |
c906108c | 3730 | |
f7dc1244 EZ |
3731 | @cindex set breakpoints on all functions |
3732 | The @code{rbreak} command can be used to set breakpoints in | |
3733 | @strong{all} the functions in a program, like this: | |
3734 | ||
3735 | @smallexample | |
3736 | (@value{GDBP}) rbreak . | |
3737 | @end smallexample | |
3738 | ||
8bd10a10 CM |
3739 | @item rbreak @var{file}:@var{regex} |
3740 | If @code{rbreak} is called with a filename qualification, it limits | |
3741 | the search for functions matching the given regular expression to the | |
3742 | specified @var{file}. This can be used, for example, to set breakpoints on | |
3743 | every function in a given file: | |
3744 | ||
3745 | @smallexample | |
3746 | (@value{GDBP}) rbreak file.c:. | |
3747 | @end smallexample | |
3748 | ||
3749 | The colon separating the filename qualifier from the regex may | |
3750 | optionally be surrounded by spaces. | |
3751 | ||
c906108c SS |
3752 | @kindex info breakpoints |
3753 | @cindex @code{$_} and @code{info breakpoints} | |
e5a67952 MS |
3754 | @item info breakpoints @r{[}@var{n}@dots{}@r{]} |
3755 | @itemx info break @r{[}@var{n}@dots{}@r{]} | |
c906108c | 3756 | Print a table of all breakpoints, watchpoints, and catchpoints set and |
45ac1734 | 3757 | not deleted. Optional argument @var{n} means print information only |
e5a67952 MS |
3758 | about the specified breakpoint(s) (or watchpoint(s) or catchpoint(s)). |
3759 | For each breakpoint, following columns are printed: | |
c906108c SS |
3760 | |
3761 | @table @emph | |
3762 | @item Breakpoint Numbers | |
3763 | @item Type | |
3764 | Breakpoint, watchpoint, or catchpoint. | |
3765 | @item Disposition | |
3766 | Whether the breakpoint is marked to be disabled or deleted when hit. | |
3767 | @item Enabled or Disabled | |
3768 | Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints | |
b3db7447 | 3769 | that are not enabled. |
c906108c | 3770 | @item Address |
fe6fbf8b | 3771 | Where the breakpoint is in your program, as a memory address. For a |
b3db7447 NR |
3772 | pending breakpoint whose address is not yet known, this field will |
3773 | contain @samp{<PENDING>}. Such breakpoint won't fire until a shared | |
3774 | library that has the symbol or line referred by breakpoint is loaded. | |
3775 | See below for details. A breakpoint with several locations will | |
3b784c4f | 3776 | have @samp{<MULTIPLE>} in this field---see below for details. |
c906108c SS |
3777 | @item What |
3778 | Where the breakpoint is in the source for your program, as a file and | |
2650777c JJ |
3779 | line number. For a pending breakpoint, the original string passed to |
3780 | the breakpoint command will be listed as it cannot be resolved until | |
3781 | the appropriate shared library is loaded in the future. | |
c906108c SS |
3782 | @end table |
3783 | ||
3784 | @noindent | |
83364271 LM |
3785 | If a breakpoint is conditional, there are two evaluation modes: ``host'' and |
3786 | ``target''. If mode is ``host'', breakpoint condition evaluation is done by | |
3787 | @value{GDBN} on the host's side. If it is ``target'', then the condition | |
3788 | is evaluated by the target. The @code{info break} command shows | |
3789 | the condition on the line following the affected breakpoint, together with | |
3790 | its condition evaluation mode in between parentheses. | |
3791 | ||
3792 | Breakpoint commands, if any, are listed after that. A pending breakpoint is | |
3793 | allowed to have a condition specified for it. The condition is not parsed for | |
3794 | validity until a shared library is loaded that allows the pending | |
3795 | breakpoint to resolve to a valid location. | |
c906108c SS |
3796 | |
3797 | @noindent | |
3798 | @code{info break} with a breakpoint | |
3799 | number @var{n} as argument lists only that breakpoint. The | |
3800 | convenience variable @code{$_} and the default examining-address for | |
3801 | the @code{x} command are set to the address of the last breakpoint | |
79a6e687 | 3802 | listed (@pxref{Memory, ,Examining Memory}). |
c906108c SS |
3803 | |
3804 | @noindent | |
3805 | @code{info break} displays a count of the number of times the breakpoint | |
3806 | has been hit. This is especially useful in conjunction with the | |
3807 | @code{ignore} command. You can ignore a large number of breakpoint | |
3808 | hits, look at the breakpoint info to see how many times the breakpoint | |
3809 | was hit, and then run again, ignoring one less than that number. This | |
3810 | will get you quickly to the last hit of that breakpoint. | |
816338b5 SS |
3811 | |
3812 | @noindent | |
3813 | For a breakpoints with an enable count (xref) greater than 1, | |
3814 | @code{info break} also displays that count. | |
3815 | ||
c906108c SS |
3816 | @end table |
3817 | ||
3818 | @value{GDBN} allows you to set any number of breakpoints at the same place in | |
3819 | your program. There is nothing silly or meaningless about this. When | |
3820 | the breakpoints are conditional, this is even useful | |
79a6e687 | 3821 | (@pxref{Conditions, ,Break Conditions}). |
c906108c | 3822 | |
2e9132cc EZ |
3823 | @cindex multiple locations, breakpoints |
3824 | @cindex breakpoints, multiple locations | |
fcda367b | 3825 | It is possible that a breakpoint corresponds to several locations |
fe6fbf8b VP |
3826 | in your program. Examples of this situation are: |
3827 | ||
3828 | @itemize @bullet | |
f8eba3c6 TT |
3829 | @item |
3830 | Multiple functions in the program may have the same name. | |
3831 | ||
fe6fbf8b VP |
3832 | @item |
3833 | For a C@t{++} constructor, the @value{NGCC} compiler generates several | |
3834 | instances of the function body, used in different cases. | |
3835 | ||
3836 | @item | |
3837 | For a C@t{++} template function, a given line in the function can | |
3838 | correspond to any number of instantiations. | |
3839 | ||
3840 | @item | |
3841 | For an inlined function, a given source line can correspond to | |
3842 | several places where that function is inlined. | |
fe6fbf8b VP |
3843 | @end itemize |
3844 | ||
3845 | In all those cases, @value{GDBN} will insert a breakpoint at all | |
f8eba3c6 | 3846 | the relevant locations. |
fe6fbf8b | 3847 | |
3b784c4f EZ |
3848 | A breakpoint with multiple locations is displayed in the breakpoint |
3849 | table using several rows---one header row, followed by one row for | |
3850 | each breakpoint location. The header row has @samp{<MULTIPLE>} in the | |
3851 | address column. The rows for individual locations contain the actual | |
3852 | addresses for locations, and show the functions to which those | |
3853 | locations belong. The number column for a location is of the form | |
fe6fbf8b VP |
3854 | @var{breakpoint-number}.@var{location-number}. |
3855 | ||
3856 | For example: | |
3b784c4f | 3857 | |
fe6fbf8b VP |
3858 | @smallexample |
3859 | Num Type Disp Enb Address What | |
3860 | 1 breakpoint keep y <MULTIPLE> | |
3861 | stop only if i==1 | |
3862 | breakpoint already hit 1 time | |
3863 | 1.1 y 0x080486a2 in void foo<int>() at t.cc:8 | |
3864 | 1.2 y 0x080486ca in void foo<double>() at t.cc:8 | |
3865 | @end smallexample | |
3866 | ||
3867 | Each location can be individually enabled or disabled by passing | |
3868 | @var{breakpoint-number}.@var{location-number} as argument to the | |
3b784c4f EZ |
3869 | @code{enable} and @code{disable} commands. Note that you cannot |
3870 | delete the individual locations from the list, you can only delete the | |
16bfc218 | 3871 | entire list of locations that belong to their parent breakpoint (with |
3b784c4f EZ |
3872 | the @kbd{delete @var{num}} command, where @var{num} is the number of |
3873 | the parent breakpoint, 1 in the above example). Disabling or enabling | |
3874 | the parent breakpoint (@pxref{Disabling}) affects all of the locations | |
3875 | that belong to that breakpoint. | |
fe6fbf8b | 3876 | |
2650777c | 3877 | @cindex pending breakpoints |
fe6fbf8b | 3878 | It's quite common to have a breakpoint inside a shared library. |
3b784c4f | 3879 | Shared libraries can be loaded and unloaded explicitly, |
fe6fbf8b VP |
3880 | and possibly repeatedly, as the program is executed. To support |
3881 | this use case, @value{GDBN} updates breakpoint locations whenever | |
3882 | any shared library is loaded or unloaded. Typically, you would | |
fcda367b | 3883 | set a breakpoint in a shared library at the beginning of your |
fe6fbf8b VP |
3884 | debugging session, when the library is not loaded, and when the |
3885 | symbols from the library are not available. When you try to set | |
3886 | breakpoint, @value{GDBN} will ask you if you want to set | |
3b784c4f | 3887 | a so called @dfn{pending breakpoint}---breakpoint whose address |
fe6fbf8b VP |
3888 | is not yet resolved. |
3889 | ||
3890 | After the program is run, whenever a new shared library is loaded, | |
3891 | @value{GDBN} reevaluates all the breakpoints. When a newly loaded | |
3892 | shared library contains the symbol or line referred to by some | |
3893 | pending breakpoint, that breakpoint is resolved and becomes an | |
3894 | ordinary breakpoint. When a library is unloaded, all breakpoints | |
3895 | that refer to its symbols or source lines become pending again. | |
3896 | ||
3897 | This logic works for breakpoints with multiple locations, too. For | |
3898 | example, if you have a breakpoint in a C@t{++} template function, and | |
3899 | a newly loaded shared library has an instantiation of that template, | |
3900 | a new location is added to the list of locations for the breakpoint. | |
3901 | ||
3902 | Except for having unresolved address, pending breakpoints do not | |
3903 | differ from regular breakpoints. You can set conditions or commands, | |
3904 | enable and disable them and perform other breakpoint operations. | |
3905 | ||
3906 | @value{GDBN} provides some additional commands for controlling what | |
3907 | happens when the @samp{break} command cannot resolve breakpoint | |
3908 | address specification to an address: | |
dd79a6cf JJ |
3909 | |
3910 | @kindex set breakpoint pending | |
3911 | @kindex show breakpoint pending | |
3912 | @table @code | |
3913 | @item set breakpoint pending auto | |
3914 | This is the default behavior. When @value{GDBN} cannot find the breakpoint | |
3915 | location, it queries you whether a pending breakpoint should be created. | |
3916 | ||
3917 | @item set breakpoint pending on | |
3918 | This indicates that an unrecognized breakpoint location should automatically | |
3919 | result in a pending breakpoint being created. | |
3920 | ||
3921 | @item set breakpoint pending off | |
3922 | This indicates that pending breakpoints are not to be created. Any | |
3923 | unrecognized breakpoint location results in an error. This setting does | |
3924 | not affect any pending breakpoints previously created. | |
3925 | ||
3926 | @item show breakpoint pending | |
3927 | Show the current behavior setting for creating pending breakpoints. | |
3928 | @end table | |
2650777c | 3929 | |
fe6fbf8b VP |
3930 | The settings above only affect the @code{break} command and its |
3931 | variants. Once breakpoint is set, it will be automatically updated | |
3932 | as shared libraries are loaded and unloaded. | |
2650777c | 3933 | |
765dc015 VP |
3934 | @cindex automatic hardware breakpoints |
3935 | For some targets, @value{GDBN} can automatically decide if hardware or | |
3936 | software breakpoints should be used, depending on whether the | |
3937 | breakpoint address is read-only or read-write. This applies to | |
3938 | breakpoints set with the @code{break} command as well as to internal | |
3939 | breakpoints set by commands like @code{next} and @code{finish}. For | |
fcda367b | 3940 | breakpoints set with @code{hbreak}, @value{GDBN} will always use hardware |
765dc015 VP |
3941 | breakpoints. |
3942 | ||
3943 | You can control this automatic behaviour with the following commands:: | |
3944 | ||
3945 | @kindex set breakpoint auto-hw | |
3946 | @kindex show breakpoint auto-hw | |
3947 | @table @code | |
3948 | @item set breakpoint auto-hw on | |
3949 | This is the default behavior. When @value{GDBN} sets a breakpoint, it | |
3950 | will try to use the target memory map to decide if software or hardware | |
3951 | breakpoint must be used. | |
3952 | ||
3953 | @item set breakpoint auto-hw off | |
3954 | This indicates @value{GDBN} should not automatically select breakpoint | |
3955 | type. If the target provides a memory map, @value{GDBN} will warn when | |
3956 | trying to set software breakpoint at a read-only address. | |
3957 | @end table | |
3958 | ||
74960c60 VP |
3959 | @value{GDBN} normally implements breakpoints by replacing the program code |
3960 | at the breakpoint address with a special instruction, which, when | |
3961 | executed, given control to the debugger. By default, the program | |
3962 | code is so modified only when the program is resumed. As soon as | |
3963 | the program stops, @value{GDBN} restores the original instructions. This | |
3964 | behaviour guards against leaving breakpoints inserted in the | |
3965 | target should gdb abrubptly disconnect. However, with slow remote | |
3966 | targets, inserting and removing breakpoint can reduce the performance. | |
3967 | This behavior can be controlled with the following commands:: | |
3968 | ||
3969 | @kindex set breakpoint always-inserted | |
3970 | @kindex show breakpoint always-inserted | |
3971 | @table @code | |
3972 | @item set breakpoint always-inserted off | |
33e5cbd6 PA |
3973 | All breakpoints, including newly added by the user, are inserted in |
3974 | the target only when the target is resumed. All breakpoints are | |
a25a5a45 | 3975 | removed from the target when it stops. This is the default mode. |
74960c60 VP |
3976 | |
3977 | @item set breakpoint always-inserted on | |
3978 | Causes all breakpoints to be inserted in the target at all times. If | |
3979 | the user adds a new breakpoint, or changes an existing breakpoint, the | |
3980 | breakpoints in the target are updated immediately. A breakpoint is | |
a25a5a45 | 3981 | removed from the target only when breakpoint itself is deleted. |
342cc091 | 3982 | @end table |
765dc015 | 3983 | |
83364271 LM |
3984 | @value{GDBN} handles conditional breakpoints by evaluating these conditions |
3985 | when a breakpoint breaks. If the condition is true, then the process being | |
3986 | debugged stops, otherwise the process is resumed. | |
3987 | ||
3988 | If the target supports evaluating conditions on its end, @value{GDBN} may | |
3989 | download the breakpoint, together with its conditions, to it. | |
3990 | ||
3991 | This feature can be controlled via the following commands: | |
3992 | ||
3993 | @kindex set breakpoint condition-evaluation | |
3994 | @kindex show breakpoint condition-evaluation | |
3995 | @table @code | |
3996 | @item set breakpoint condition-evaluation host | |
3997 | This option commands @value{GDBN} to evaluate the breakpoint | |
3998 | conditions on the host's side. Unconditional breakpoints are sent to | |
3999 | the target which in turn receives the triggers and reports them back to GDB | |
4000 | for condition evaluation. This is the standard evaluation mode. | |
4001 | ||
4002 | @item set breakpoint condition-evaluation target | |
4003 | This option commands @value{GDBN} to download breakpoint conditions | |
4004 | to the target at the moment of their insertion. The target | |
4005 | is responsible for evaluating the conditional expression and reporting | |
4006 | breakpoint stop events back to @value{GDBN} whenever the condition | |
4007 | is true. Due to limitations of target-side evaluation, some conditions | |
4008 | cannot be evaluated there, e.g., conditions that depend on local data | |
4009 | that is only known to the host. Examples include | |
4010 | conditional expressions involving convenience variables, complex types | |
4011 | that cannot be handled by the agent expression parser and expressions | |
4012 | that are too long to be sent over to the target, specially when the | |
4013 | target is a remote system. In these cases, the conditions will be | |
4014 | evaluated by @value{GDBN}. | |
4015 | ||
4016 | @item set breakpoint condition-evaluation auto | |
4017 | This is the default mode. If the target supports evaluating breakpoint | |
4018 | conditions on its end, @value{GDBN} will download breakpoint conditions to | |
4019 | the target (limitations mentioned previously apply). If the target does | |
4020 | not support breakpoint condition evaluation, then @value{GDBN} will fallback | |
4021 | to evaluating all these conditions on the host's side. | |
4022 | @end table | |
4023 | ||
4024 | ||
c906108c SS |
4025 | @cindex negative breakpoint numbers |
4026 | @cindex internal @value{GDBN} breakpoints | |
eb12ee30 AC |
4027 | @value{GDBN} itself sometimes sets breakpoints in your program for |
4028 | special purposes, such as proper handling of @code{longjmp} (in C | |
4029 | programs). These internal breakpoints are assigned negative numbers, | |
4030 | starting with @code{-1}; @samp{info breakpoints} does not display them. | |
c906108c | 4031 | You can see these breakpoints with the @value{GDBN} maintenance command |
eb12ee30 | 4032 | @samp{maint info breakpoints} (@pxref{maint info breakpoints}). |
c906108c SS |
4033 | |
4034 | ||
6d2ebf8b | 4035 | @node Set Watchpoints |
79a6e687 | 4036 | @subsection Setting Watchpoints |
c906108c SS |
4037 | |
4038 | @cindex setting watchpoints | |
c906108c SS |
4039 | You can use a watchpoint to stop execution whenever the value of an |
4040 | expression changes, without having to predict a particular place where | |
fd60e0df EZ |
4041 | this may happen. (This is sometimes called a @dfn{data breakpoint}.) |
4042 | The expression may be as simple as the value of a single variable, or | |
4043 | as complex as many variables combined by operators. Examples include: | |
4044 | ||
4045 | @itemize @bullet | |
4046 | @item | |
4047 | A reference to the value of a single variable. | |
4048 | ||
4049 | @item | |
4050 | An address cast to an appropriate data type. For example, | |
4051 | @samp{*(int *)0x12345678} will watch a 4-byte region at the specified | |
4052 | address (assuming an @code{int} occupies 4 bytes). | |
4053 | ||
4054 | @item | |
4055 | An arbitrarily complex expression, such as @samp{a*b + c/d}. The | |
4056 | expression can use any operators valid in the program's native | |
4057 | language (@pxref{Languages}). | |
4058 | @end itemize | |
c906108c | 4059 | |
fa4727a6 DJ |
4060 | You can set a watchpoint on an expression even if the expression can |
4061 | not be evaluated yet. For instance, you can set a watchpoint on | |
4062 | @samp{*global_ptr} before @samp{global_ptr} is initialized. | |
4063 | @value{GDBN} will stop when your program sets @samp{global_ptr} and | |
4064 | the expression produces a valid value. If the expression becomes | |
4065 | valid in some other way than changing a variable (e.g.@: if the memory | |
4066 | pointed to by @samp{*global_ptr} becomes readable as the result of a | |
4067 | @code{malloc} call), @value{GDBN} may not stop until the next time | |
4068 | the expression changes. | |
4069 | ||
82f2d802 EZ |
4070 | @cindex software watchpoints |
4071 | @cindex hardware watchpoints | |
c906108c | 4072 | Depending on your system, watchpoints may be implemented in software or |
2df3850c | 4073 | hardware. @value{GDBN} does software watchpointing by single-stepping your |
c906108c SS |
4074 | program and testing the variable's value each time, which is hundreds of |
4075 | times slower than normal execution. (But this may still be worth it, to | |
4076 | catch errors where you have no clue what part of your program is the | |
4077 | culprit.) | |
4078 | ||
b1236ac3 PA |
4079 | On some systems, such as most PowerPC or x86-based targets, |
4080 | @value{GDBN} includes support for hardware watchpoints, which do not | |
4081 | slow down the running of your program. | |
c906108c SS |
4082 | |
4083 | @table @code | |
4084 | @kindex watch | |
5d5658a1 | 4085 | @item watch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{thread-id}@r{]} @r{[}mask @var{maskvalue}@r{]} |
fd60e0df EZ |
4086 | Set a watchpoint for an expression. @value{GDBN} will break when the |
4087 | expression @var{expr} is written into by the program and its value | |
4088 | changes. The simplest (and the most popular) use of this command is | |
4089 | to watch the value of a single variable: | |
4090 | ||
4091 | @smallexample | |
4092 | (@value{GDBP}) watch foo | |
4093 | @end smallexample | |
c906108c | 4094 | |
5d5658a1 | 4095 | If the command includes a @code{@r{[}thread @var{thread-id}@r{]}} |
9c06b0b4 | 4096 | argument, @value{GDBN} breaks only when the thread identified by |
5d5658a1 | 4097 | @var{thread-id} changes the value of @var{expr}. If any other threads |
d8b2a693 JB |
4098 | change the value of @var{expr}, @value{GDBN} will not break. Note |
4099 | that watchpoints restricted to a single thread in this way only work | |
4100 | with Hardware Watchpoints. | |
4101 | ||
06a64a0b TT |
4102 | Ordinarily a watchpoint respects the scope of variables in @var{expr} |
4103 | (see below). The @code{-location} argument tells @value{GDBN} to | |
4104 | instead watch the memory referred to by @var{expr}. In this case, | |
4105 | @value{GDBN} will evaluate @var{expr}, take the address of the result, | |
4106 | and watch the memory at that address. The type of the result is used | |
4107 | to determine the size of the watched memory. If the expression's | |
4108 | result does not have an address, then @value{GDBN} will print an | |
4109 | error. | |
4110 | ||
9c06b0b4 TJB |
4111 | The @code{@r{[}mask @var{maskvalue}@r{]}} argument allows creation |
4112 | of masked watchpoints, if the current architecture supports this | |
4113 | feature (e.g., PowerPC Embedded architecture, see @ref{PowerPC | |
4114 | Embedded}.) A @dfn{masked watchpoint} specifies a mask in addition | |
4115 | to an address to watch. The mask specifies that some bits of an address | |
4116 | (the bits which are reset in the mask) should be ignored when matching | |
4117 | the address accessed by the inferior against the watchpoint address. | |
4118 | Thus, a masked watchpoint watches many addresses simultaneously---those | |
4119 | addresses whose unmasked bits are identical to the unmasked bits in the | |
4120 | watchpoint address. The @code{mask} argument implies @code{-location}. | |
4121 | Examples: | |
4122 | ||
4123 | @smallexample | |
4124 | (@value{GDBP}) watch foo mask 0xffff00ff | |
4125 | (@value{GDBP}) watch *0xdeadbeef mask 0xffffff00 | |
4126 | @end smallexample | |
4127 | ||
c906108c | 4128 | @kindex rwatch |
5d5658a1 | 4129 | @item rwatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{thread-id}@r{]} @r{[}mask @var{maskvalue}@r{]} |
09d4efe1 EZ |
4130 | Set a watchpoint that will break when the value of @var{expr} is read |
4131 | by the program. | |
c906108c SS |
4132 | |
4133 | @kindex awatch | |
5d5658a1 | 4134 | @item awatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{thread-id}@r{]} @r{[}mask @var{maskvalue}@r{]} |
09d4efe1 EZ |
4135 | Set a watchpoint that will break when @var{expr} is either read from |
4136 | or written into by the program. | |
c906108c | 4137 | |
e5a67952 MS |
4138 | @kindex info watchpoints @r{[}@var{n}@dots{}@r{]} |
4139 | @item info watchpoints @r{[}@var{n}@dots{}@r{]} | |
d77f58be SS |
4140 | This command prints a list of watchpoints, using the same format as |
4141 | @code{info break} (@pxref{Set Breaks}). | |
c906108c SS |
4142 | @end table |
4143 | ||
65d79d4b SDJ |
4144 | If you watch for a change in a numerically entered address you need to |
4145 | dereference it, as the address itself is just a constant number which will | |
4146 | never change. @value{GDBN} refuses to create a watchpoint that watches | |
4147 | a never-changing value: | |
4148 | ||
4149 | @smallexample | |
4150 | (@value{GDBP}) watch 0x600850 | |
4151 | Cannot watch constant value 0x600850. | |
4152 | (@value{GDBP}) watch *(int *) 0x600850 | |
4153 | Watchpoint 1: *(int *) 6293584 | |
4154 | @end smallexample | |
4155 | ||
c906108c SS |
4156 | @value{GDBN} sets a @dfn{hardware watchpoint} if possible. Hardware |
4157 | watchpoints execute very quickly, and the debugger reports a change in | |
4158 | value at the exact instruction where the change occurs. If @value{GDBN} | |
4159 | cannot set a hardware watchpoint, it sets a software watchpoint, which | |
4160 | executes more slowly and reports the change in value at the next | |
82f2d802 EZ |
4161 | @emph{statement}, not the instruction, after the change occurs. |
4162 | ||
82f2d802 EZ |
4163 | @cindex use only software watchpoints |
4164 | You can force @value{GDBN} to use only software watchpoints with the | |
4165 | @kbd{set can-use-hw-watchpoints 0} command. With this variable set to | |
4166 | zero, @value{GDBN} will never try to use hardware watchpoints, even if | |
4167 | the underlying system supports them. (Note that hardware-assisted | |
4168 | watchpoints that were set @emph{before} setting | |
4169 | @code{can-use-hw-watchpoints} to zero will still use the hardware | |
d3e8051b | 4170 | mechanism of watching expression values.) |
c906108c | 4171 | |
9c16f35a EZ |
4172 | @table @code |
4173 | @item set can-use-hw-watchpoints | |
4174 | @kindex set can-use-hw-watchpoints | |
4175 | Set whether or not to use hardware watchpoints. | |
4176 | ||
4177 | @item show can-use-hw-watchpoints | |
4178 | @kindex show can-use-hw-watchpoints | |
4179 | Show the current mode of using hardware watchpoints. | |
4180 | @end table | |
4181 | ||
4182 | For remote targets, you can restrict the number of hardware | |
4183 | watchpoints @value{GDBN} will use, see @ref{set remote | |
4184 | hardware-breakpoint-limit}. | |
4185 | ||
c906108c SS |
4186 | When you issue the @code{watch} command, @value{GDBN} reports |
4187 | ||
474c8240 | 4188 | @smallexample |
c906108c | 4189 | Hardware watchpoint @var{num}: @var{expr} |
474c8240 | 4190 | @end smallexample |
c906108c SS |
4191 | |
4192 | @noindent | |
4193 | if it was able to set a hardware watchpoint. | |
4194 | ||
7be570e7 JM |
4195 | Currently, the @code{awatch} and @code{rwatch} commands can only set |
4196 | hardware watchpoints, because accesses to data that don't change the | |
4197 | value of the watched expression cannot be detected without examining | |
4198 | every instruction as it is being executed, and @value{GDBN} does not do | |
4199 | that currently. If @value{GDBN} finds that it is unable to set a | |
4200 | hardware breakpoint with the @code{awatch} or @code{rwatch} command, it | |
4201 | will print a message like this: | |
4202 | ||
4203 | @smallexample | |
4204 | Expression cannot be implemented with read/access watchpoint. | |
4205 | @end smallexample | |
4206 | ||
4207 | Sometimes, @value{GDBN} cannot set a hardware watchpoint because the | |
4208 | data type of the watched expression is wider than what a hardware | |
4209 | watchpoint on the target machine can handle. For example, some systems | |
4210 | can only watch regions that are up to 4 bytes wide; on such systems you | |
4211 | cannot set hardware watchpoints for an expression that yields a | |
4212 | double-precision floating-point number (which is typically 8 bytes | |
4213 | wide). As a work-around, it might be possible to break the large region | |
4214 | into a series of smaller ones and watch them with separate watchpoints. | |
4215 | ||
4216 | If you set too many hardware watchpoints, @value{GDBN} might be unable | |
4217 | to insert all of them when you resume the execution of your program. | |
4218 | Since the precise number of active watchpoints is unknown until such | |
4219 | time as the program is about to be resumed, @value{GDBN} might not be | |
4220 | able to warn you about this when you set the watchpoints, and the | |
4221 | warning will be printed only when the program is resumed: | |
4222 | ||
4223 | @smallexample | |
4224 | Hardware watchpoint @var{num}: Could not insert watchpoint | |
4225 | @end smallexample | |
4226 | ||
4227 | @noindent | |
4228 | If this happens, delete or disable some of the watchpoints. | |
4229 | ||
fd60e0df EZ |
4230 | Watching complex expressions that reference many variables can also |
4231 | exhaust the resources available for hardware-assisted watchpoints. | |
4232 | That's because @value{GDBN} needs to watch every variable in the | |
4233 | expression with separately allocated resources. | |
4234 | ||
c906108c | 4235 | If you call a function interactively using @code{print} or @code{call}, |
2df3850c | 4236 | any watchpoints you have set will be inactive until @value{GDBN} reaches another |
c906108c SS |
4237 | kind of breakpoint or the call completes. |
4238 | ||
7be570e7 JM |
4239 | @value{GDBN} automatically deletes watchpoints that watch local |
4240 | (automatic) variables, or expressions that involve such variables, when | |
4241 | they go out of scope, that is, when the execution leaves the block in | |
4242 | which these variables were defined. In particular, when the program | |
4243 | being debugged terminates, @emph{all} local variables go out of scope, | |
4244 | and so only watchpoints that watch global variables remain set. If you | |
4245 | rerun the program, you will need to set all such watchpoints again. One | |
4246 | way of doing that would be to set a code breakpoint at the entry to the | |
4247 | @code{main} function and when it breaks, set all the watchpoints. | |
4248 | ||
c906108c SS |
4249 | @cindex watchpoints and threads |
4250 | @cindex threads and watchpoints | |
d983da9c DJ |
4251 | In multi-threaded programs, watchpoints will detect changes to the |
4252 | watched expression from every thread. | |
4253 | ||
4254 | @quotation | |
4255 | @emph{Warning:} In multi-threaded programs, software watchpoints | |
53a5351d JM |
4256 | have only limited usefulness. If @value{GDBN} creates a software |
4257 | watchpoint, it can only watch the value of an expression @emph{in a | |
4258 | single thread}. If you are confident that the expression can only | |
4259 | change due to the current thread's activity (and if you are also | |
4260 | confident that no other thread can become current), then you can use | |
4261 | software watchpoints as usual. However, @value{GDBN} may not notice | |
4262 | when a non-current thread's activity changes the expression. (Hardware | |
4263 | watchpoints, in contrast, watch an expression in all threads.) | |
c906108c | 4264 | @end quotation |
c906108c | 4265 | |
501eef12 AC |
4266 | @xref{set remote hardware-watchpoint-limit}. |
4267 | ||
6d2ebf8b | 4268 | @node Set Catchpoints |
79a6e687 | 4269 | @subsection Setting Catchpoints |
d4f3574e | 4270 | @cindex catchpoints, setting |
c906108c SS |
4271 | @cindex exception handlers |
4272 | @cindex event handling | |
4273 | ||
4274 | You can use @dfn{catchpoints} to cause the debugger to stop for certain | |
b37052ae | 4275 | kinds of program events, such as C@t{++} exceptions or the loading of a |
c906108c SS |
4276 | shared library. Use the @code{catch} command to set a catchpoint. |
4277 | ||
4278 | @table @code | |
4279 | @kindex catch | |
4280 | @item catch @var{event} | |
697aa1b7 | 4281 | Stop when @var{event} occurs. The @var{event} can be any of the following: |
591f19e8 | 4282 | |
c906108c | 4283 | @table @code |
cc16e6c9 TT |
4284 | @item throw @r{[}@var{regexp}@r{]} |
4285 | @itemx rethrow @r{[}@var{regexp}@r{]} | |
4286 | @itemx catch @r{[}@var{regexp}@r{]} | |
1a4f73eb TT |
4287 | @kindex catch throw |
4288 | @kindex catch rethrow | |
4289 | @kindex catch catch | |
4644b6e3 | 4290 | @cindex stop on C@t{++} exceptions |
591f19e8 TT |
4291 | The throwing, re-throwing, or catching of a C@t{++} exception. |
4292 | ||
cc16e6c9 TT |
4293 | If @var{regexp} is given, then only exceptions whose type matches the |
4294 | regular expression will be caught. | |
4295 | ||
72f1fe8a TT |
4296 | @vindex $_exception@r{, convenience variable} |
4297 | The convenience variable @code{$_exception} is available at an | |
4298 | exception-related catchpoint, on some systems. This holds the | |
4299 | exception being thrown. | |
4300 | ||
591f19e8 TT |
4301 | There are currently some limitations to C@t{++} exception handling in |
4302 | @value{GDBN}: | |
c906108c | 4303 | |
591f19e8 TT |
4304 | @itemize @bullet |
4305 | @item | |
4306 | The support for these commands is system-dependent. Currently, only | |
4307 | systems using the @samp{gnu-v3} C@t{++} ABI (@pxref{ABI}) are | |
4308 | supported. | |
4309 | ||
72f1fe8a | 4310 | @item |
cc16e6c9 TT |
4311 | The regular expression feature and the @code{$_exception} convenience |
4312 | variable rely on the presence of some SDT probes in @code{libstdc++}. | |
4313 | If these probes are not present, then these features cannot be used. | |
dee368d3 TT |
4314 | These probes were first available in the GCC 4.8 release, but whether |
4315 | or not they are available in your GCC also depends on how it was | |
4316 | built. | |
72f1fe8a TT |
4317 | |
4318 | @item | |
4319 | The @code{$_exception} convenience variable is only valid at the | |
4320 | instruction at which an exception-related catchpoint is set. | |
4321 | ||
591f19e8 TT |
4322 | @item |
4323 | When an exception-related catchpoint is hit, @value{GDBN} stops at a | |
4324 | location in the system library which implements runtime exception | |
4325 | support for C@t{++}, usually @code{libstdc++}. You can use @code{up} | |
4326 | (@pxref{Selection}) to get to your code. | |
4327 | ||
4328 | @item | |
4329 | If you call a function interactively, @value{GDBN} normally returns | |
4330 | control to you when the function has finished executing. If the call | |
4331 | raises an exception, however, the call may bypass the mechanism that | |
4332 | returns control to you and cause your program either to abort or to | |
4333 | simply continue running until it hits a breakpoint, catches a signal | |
4334 | that @value{GDBN} is listening for, or exits. This is the case even if | |
4335 | you set a catchpoint for the exception; catchpoints on exceptions are | |
4336 | disabled within interactive calls. @xref{Calling}, for information on | |
4337 | controlling this with @code{set unwind-on-terminating-exception}. | |
4338 | ||
4339 | @item | |
4340 | You cannot raise an exception interactively. | |
4341 | ||
4342 | @item | |
4343 | You cannot install an exception handler interactively. | |
4344 | @end itemize | |
c906108c | 4345 | |
8936fcda | 4346 | @item exception |
1a4f73eb | 4347 | @kindex catch exception |
8936fcda JB |
4348 | @cindex Ada exception catching |
4349 | @cindex catch Ada exceptions | |
4350 | An Ada exception being raised. If an exception name is specified | |
4351 | at the end of the command (eg @code{catch exception Program_Error}), | |
4352 | the debugger will stop only when this specific exception is raised. | |
4353 | Otherwise, the debugger stops execution when any Ada exception is raised. | |
4354 | ||
87f67dba JB |
4355 | When inserting an exception catchpoint on a user-defined exception whose |
4356 | name is identical to one of the exceptions defined by the language, the | |
4357 | fully qualified name must be used as the exception name. Otherwise, | |
4358 | @value{GDBN} will assume that it should stop on the pre-defined exception | |
4359 | rather than the user-defined one. For instance, assuming an exception | |
4360 | called @code{Constraint_Error} is defined in package @code{Pck}, then | |
4361 | the command to use to catch such exceptions is @kbd{catch exception | |
4362 | Pck.Constraint_Error}. | |
4363 | ||
8936fcda | 4364 | @item exception unhandled |
1a4f73eb | 4365 | @kindex catch exception unhandled |
8936fcda JB |
4366 | An exception that was raised but is not handled by the program. |
4367 | ||
4368 | @item assert | |
1a4f73eb | 4369 | @kindex catch assert |
8936fcda JB |
4370 | A failed Ada assertion. |
4371 | ||
c906108c | 4372 | @item exec |
1a4f73eb | 4373 | @kindex catch exec |
4644b6e3 | 4374 | @cindex break on fork/exec |
b1236ac3 | 4375 | A call to @code{exec}. |
c906108c | 4376 | |
a96d9b2e | 4377 | @item syscall |
ee8e71d4 | 4378 | @itemx syscall @r{[}@var{name} @r{|} @var{number}@r{]} @dots{} |
1a4f73eb | 4379 | @kindex catch syscall |
a96d9b2e SDJ |
4380 | @cindex break on a system call. |
4381 | A call to or return from a system call, a.k.a.@: @dfn{syscall}. A | |
4382 | syscall is a mechanism for application programs to request a service | |
4383 | from the operating system (OS) or one of the OS system services. | |
4384 | @value{GDBN} can catch some or all of the syscalls issued by the | |
4385 | debuggee, and show the related information for each syscall. If no | |
4386 | argument is specified, calls to and returns from all system calls | |
4387 | will be caught. | |
4388 | ||
4389 | @var{name} can be any system call name that is valid for the | |
4390 | underlying OS. Just what syscalls are valid depends on the OS. On | |
4391 | GNU and Unix systems, you can find the full list of valid syscall | |
4392 | names on @file{/usr/include/asm/unistd.h}. | |
4393 | ||
4394 | @c For MS-Windows, the syscall names and the corresponding numbers | |
4395 | @c can be found, e.g., on this URL: | |
4396 | @c http://www.metasploit.com/users/opcode/syscalls.html | |
4397 | @c but we don't support Windows syscalls yet. | |
4398 | ||
4399 | Normally, @value{GDBN} knows in advance which syscalls are valid for | |
4400 | each OS, so you can use the @value{GDBN} command-line completion | |
4401 | facilities (@pxref{Completion,, command completion}) to list the | |
4402 | available choices. | |
4403 | ||
4404 | You may also specify the system call numerically. A syscall's | |
4405 | number is the value passed to the OS's syscall dispatcher to | |
4406 | identify the requested service. When you specify the syscall by its | |
4407 | name, @value{GDBN} uses its database of syscalls to convert the name | |
4408 | into the corresponding numeric code, but using the number directly | |
4409 | may be useful if @value{GDBN}'s database does not have the complete | |
4410 | list of syscalls on your system (e.g., because @value{GDBN} lags | |
4411 | behind the OS upgrades). | |
4412 | ||
4413 | The example below illustrates how this command works if you don't provide | |
4414 | arguments to it: | |
4415 | ||
4416 | @smallexample | |
4417 | (@value{GDBP}) catch syscall | |
4418 | Catchpoint 1 (syscall) | |
4419 | (@value{GDBP}) r | |
4420 | Starting program: /tmp/catch-syscall | |
4421 | ||
4422 | Catchpoint 1 (call to syscall 'close'), \ | |
4423 | 0xffffe424 in __kernel_vsyscall () | |
4424 | (@value{GDBP}) c | |
4425 | Continuing. | |
4426 | ||
4427 | Catchpoint 1 (returned from syscall 'close'), \ | |
4428 | 0xffffe424 in __kernel_vsyscall () | |
4429 | (@value{GDBP}) | |
4430 | @end smallexample | |
4431 | ||
4432 | Here is an example of catching a system call by name: | |
4433 | ||
4434 | @smallexample | |
4435 | (@value{GDBP}) catch syscall chroot | |
4436 | Catchpoint 1 (syscall 'chroot' [61]) | |
4437 | (@value{GDBP}) r | |
4438 | Starting program: /tmp/catch-syscall | |
4439 | ||
4440 | Catchpoint 1 (call to syscall 'chroot'), \ | |
4441 | 0xffffe424 in __kernel_vsyscall () | |
4442 | (@value{GDBP}) c | |
4443 | Continuing. | |
4444 | ||
4445 | Catchpoint 1 (returned from syscall 'chroot'), \ | |
4446 | 0xffffe424 in __kernel_vsyscall () | |
4447 | (@value{GDBP}) | |
4448 | @end smallexample | |
4449 | ||
4450 | An example of specifying a system call numerically. In the case | |
4451 | below, the syscall number has a corresponding entry in the XML | |
4452 | file, so @value{GDBN} finds its name and prints it: | |
4453 | ||
4454 | @smallexample | |
4455 | (@value{GDBP}) catch syscall 252 | |
4456 | Catchpoint 1 (syscall(s) 'exit_group') | |
4457 | (@value{GDBP}) r | |
4458 | Starting program: /tmp/catch-syscall | |
4459 | ||
4460 | Catchpoint 1 (call to syscall 'exit_group'), \ | |
4461 | 0xffffe424 in __kernel_vsyscall () | |
4462 | (@value{GDBP}) c | |
4463 | Continuing. | |
4464 | ||
4465 | Program exited normally. | |
4466 | (@value{GDBP}) | |
4467 | @end smallexample | |
4468 | ||
4469 | However, there can be situations when there is no corresponding name | |
4470 | in XML file for that syscall number. In this case, @value{GDBN} prints | |
4471 | a warning message saying that it was not able to find the syscall name, | |
4472 | but the catchpoint will be set anyway. See the example below: | |
4473 | ||
4474 | @smallexample | |
4475 | (@value{GDBP}) catch syscall 764 | |
4476 | warning: The number '764' does not represent a known syscall. | |
4477 | Catchpoint 2 (syscall 764) | |
4478 | (@value{GDBP}) | |
4479 | @end smallexample | |
4480 | ||
4481 | If you configure @value{GDBN} using the @samp{--without-expat} option, | |
4482 | it will not be able to display syscall names. Also, if your | |
4483 | architecture does not have an XML file describing its system calls, | |
4484 | you will not be able to see the syscall names. It is important to | |
4485 | notice that these two features are used for accessing the syscall | |
4486 | name database. In either case, you will see a warning like this: | |
4487 | ||
4488 | @smallexample | |
4489 | (@value{GDBP}) catch syscall | |
4490 | warning: Could not open "syscalls/i386-linux.xml" | |
4491 | warning: Could not load the syscall XML file 'syscalls/i386-linux.xml'. | |
4492 | GDB will not be able to display syscall names. | |
4493 | Catchpoint 1 (syscall) | |
4494 | (@value{GDBP}) | |
4495 | @end smallexample | |
4496 | ||
4497 | Of course, the file name will change depending on your architecture and system. | |
4498 | ||
4499 | Still using the example above, you can also try to catch a syscall by its | |
4500 | number. In this case, you would see something like: | |
4501 | ||
4502 | @smallexample | |
4503 | (@value{GDBP}) catch syscall 252 | |
4504 | Catchpoint 1 (syscall(s) 252) | |
4505 | @end smallexample | |
4506 | ||
4507 | Again, in this case @value{GDBN} would not be able to display syscall's names. | |
4508 | ||
c906108c | 4509 | @item fork |
1a4f73eb | 4510 | @kindex catch fork |
b1236ac3 | 4511 | A call to @code{fork}. |
c906108c SS |
4512 | |
4513 | @item vfork | |
1a4f73eb | 4514 | @kindex catch vfork |
b1236ac3 | 4515 | A call to @code{vfork}. |
c906108c | 4516 | |
edcc5120 TT |
4517 | @item load @r{[}regexp@r{]} |
4518 | @itemx unload @r{[}regexp@r{]} | |
1a4f73eb TT |
4519 | @kindex catch load |
4520 | @kindex catch unload | |
edcc5120 TT |
4521 | The loading or unloading of a shared library. If @var{regexp} is |
4522 | given, then the catchpoint will stop only if the regular expression | |
4523 | matches one of the affected libraries. | |
4524 | ||
ab04a2af | 4525 | @item signal @r{[}@var{signal}@dots{} @r{|} @samp{all}@r{]} |
1a4f73eb | 4526 | @kindex catch signal |
ab04a2af TT |
4527 | The delivery of a signal. |
4528 | ||
4529 | With no arguments, this catchpoint will catch any signal that is not | |
4530 | used internally by @value{GDBN}, specifically, all signals except | |
4531 | @samp{SIGTRAP} and @samp{SIGINT}. | |
4532 | ||
4533 | With the argument @samp{all}, all signals, including those used by | |
4534 | @value{GDBN}, will be caught. This argument cannot be used with other | |
4535 | signal names. | |
4536 | ||
4537 | Otherwise, the arguments are a list of signal names as given to | |
4538 | @code{handle} (@pxref{Signals}). Only signals specified in this list | |
4539 | will be caught. | |
4540 | ||
4541 | One reason that @code{catch signal} can be more useful than | |
4542 | @code{handle} is that you can attach commands and conditions to the | |
4543 | catchpoint. | |
4544 | ||
4545 | When a signal is caught by a catchpoint, the signal's @code{stop} and | |
4546 | @code{print} settings, as specified by @code{handle}, are ignored. | |
4547 | However, whether the signal is still delivered to the inferior depends | |
4548 | on the @code{pass} setting; this can be changed in the catchpoint's | |
4549 | commands. | |
4550 | ||
c906108c SS |
4551 | @end table |
4552 | ||
4553 | @item tcatch @var{event} | |
1a4f73eb | 4554 | @kindex tcatch |
c906108c SS |
4555 | Set a catchpoint that is enabled only for one stop. The catchpoint is |
4556 | automatically deleted after the first time the event is caught. | |
4557 | ||
4558 | @end table | |
4559 | ||
4560 | Use the @code{info break} command to list the current catchpoints. | |
4561 | ||
c906108c | 4562 | |
6d2ebf8b | 4563 | @node Delete Breaks |
79a6e687 | 4564 | @subsection Deleting Breakpoints |
c906108c SS |
4565 | |
4566 | @cindex clearing breakpoints, watchpoints, catchpoints | |
4567 | @cindex deleting breakpoints, watchpoints, catchpoints | |
4568 | It is often necessary to eliminate a breakpoint, watchpoint, or | |
4569 | catchpoint once it has done its job and you no longer want your program | |
4570 | to stop there. This is called @dfn{deleting} the breakpoint. A | |
4571 | breakpoint that has been deleted no longer exists; it is forgotten. | |
4572 | ||
4573 | With the @code{clear} command you can delete breakpoints according to | |
4574 | where they are in your program. With the @code{delete} command you can | |
4575 | delete individual breakpoints, watchpoints, or catchpoints by specifying | |
4576 | their breakpoint numbers. | |
4577 | ||
4578 | It is not necessary to delete a breakpoint to proceed past it. @value{GDBN} | |
4579 | automatically ignores breakpoints on the first instruction to be executed | |
4580 | when you continue execution without changing the execution address. | |
4581 | ||
4582 | @table @code | |
4583 | @kindex clear | |
4584 | @item clear | |
4585 | Delete any breakpoints at the next instruction to be executed in the | |
79a6e687 | 4586 | selected stack frame (@pxref{Selection, ,Selecting a Frame}). When |
c906108c SS |
4587 | the innermost frame is selected, this is a good way to delete a |
4588 | breakpoint where your program just stopped. | |
4589 | ||
2a25a5ba EZ |
4590 | @item clear @var{location} |
4591 | Delete any breakpoints set at the specified @var{location}. | |
4592 | @xref{Specify Location}, for the various forms of @var{location}; the | |
4593 | most useful ones are listed below: | |
4594 | ||
4595 | @table @code | |
c906108c SS |
4596 | @item clear @var{function} |
4597 | @itemx clear @var{filename}:@var{function} | |
09d4efe1 | 4598 | Delete any breakpoints set at entry to the named @var{function}. |
c906108c SS |
4599 | |
4600 | @item clear @var{linenum} | |
4601 | @itemx clear @var{filename}:@var{linenum} | |
09d4efe1 EZ |
4602 | Delete any breakpoints set at or within the code of the specified |
4603 | @var{linenum} of the specified @var{filename}. | |
2a25a5ba | 4604 | @end table |
c906108c SS |
4605 | |
4606 | @cindex delete breakpoints | |
4607 | @kindex delete | |
41afff9a | 4608 | @kindex d @r{(@code{delete})} |
c5394b80 JM |
4609 | @item delete @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
4610 | Delete the breakpoints, watchpoints, or catchpoints of the breakpoint | |
4611 | ranges specified as arguments. If no argument is specified, delete all | |
c906108c SS |
4612 | breakpoints (@value{GDBN} asks confirmation, unless you have @code{set |
4613 | confirm off}). You can abbreviate this command as @code{d}. | |
4614 | @end table | |
4615 | ||
6d2ebf8b | 4616 | @node Disabling |
79a6e687 | 4617 | @subsection Disabling Breakpoints |
c906108c | 4618 | |
4644b6e3 | 4619 | @cindex enable/disable a breakpoint |
c906108c SS |
4620 | Rather than deleting a breakpoint, watchpoint, or catchpoint, you might |
4621 | prefer to @dfn{disable} it. This makes the breakpoint inoperative as if | |
4622 | it had been deleted, but remembers the information on the breakpoint so | |
4623 | that you can @dfn{enable} it again later. | |
4624 | ||
4625 | You disable and enable breakpoints, watchpoints, and catchpoints with | |
d77f58be SS |
4626 | the @code{enable} and @code{disable} commands, optionally specifying |
4627 | one or more breakpoint numbers as arguments. Use @code{info break} to | |
4628 | print a list of all breakpoints, watchpoints, and catchpoints if you | |
4629 | do not know which numbers to use. | |
c906108c | 4630 | |
3b784c4f EZ |
4631 | Disabling and enabling a breakpoint that has multiple locations |
4632 | affects all of its locations. | |
4633 | ||
816338b5 SS |
4634 | A breakpoint, watchpoint, or catchpoint can have any of several |
4635 | different states of enablement: | |
c906108c SS |
4636 | |
4637 | @itemize @bullet | |
4638 | @item | |
4639 | Enabled. The breakpoint stops your program. A breakpoint set | |
4640 | with the @code{break} command starts out in this state. | |
4641 | @item | |
4642 | Disabled. The breakpoint has no effect on your program. | |
4643 | @item | |
4644 | Enabled once. The breakpoint stops your program, but then becomes | |
d4f3574e | 4645 | disabled. |
c906108c | 4646 | @item |
816338b5 SS |
4647 | Enabled for a count. The breakpoint stops your program for the next |
4648 | N times, then becomes disabled. | |
4649 | @item | |
c906108c | 4650 | Enabled for deletion. The breakpoint stops your program, but |
d4f3574e SS |
4651 | immediately after it does so it is deleted permanently. A breakpoint |
4652 | set with the @code{tbreak} command starts out in this state. | |
c906108c SS |
4653 | @end itemize |
4654 | ||
4655 | You can use the following commands to enable or disable breakpoints, | |
4656 | watchpoints, and catchpoints: | |
4657 | ||
4658 | @table @code | |
c906108c | 4659 | @kindex disable |
41afff9a | 4660 | @kindex dis @r{(@code{disable})} |
c5394b80 | 4661 | @item disable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4662 | Disable the specified breakpoints---or all breakpoints, if none are |
4663 | listed. A disabled breakpoint has no effect but is not forgotten. All | |
4664 | options such as ignore-counts, conditions and commands are remembered in | |
4665 | case the breakpoint is enabled again later. You may abbreviate | |
4666 | @code{disable} as @code{dis}. | |
4667 | ||
c906108c | 4668 | @kindex enable |
c5394b80 | 4669 | @item enable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4670 | Enable the specified breakpoints (or all defined breakpoints). They |
4671 | become effective once again in stopping your program. | |
4672 | ||
c5394b80 | 4673 | @item enable @r{[}breakpoints@r{]} once @var{range}@dots{} |
c906108c SS |
4674 | Enable the specified breakpoints temporarily. @value{GDBN} disables any |
4675 | of these breakpoints immediately after stopping your program. | |
4676 | ||
816338b5 SS |
4677 | @item enable @r{[}breakpoints@r{]} count @var{count} @var{range}@dots{} |
4678 | Enable the specified breakpoints temporarily. @value{GDBN} records | |
4679 | @var{count} with each of the specified breakpoints, and decrements a | |
4680 | breakpoint's count when it is hit. When any count reaches 0, | |
4681 | @value{GDBN} disables that breakpoint. If a breakpoint has an ignore | |
4682 | count (@pxref{Conditions, ,Break Conditions}), that will be | |
4683 | decremented to 0 before @var{count} is affected. | |
4684 | ||
c5394b80 | 4685 | @item enable @r{[}breakpoints@r{]} delete @var{range}@dots{} |
c906108c SS |
4686 | Enable the specified breakpoints to work once, then die. @value{GDBN} |
4687 | deletes any of these breakpoints as soon as your program stops there. | |
09d4efe1 | 4688 | Breakpoints set by the @code{tbreak} command start out in this state. |
c906108c SS |
4689 | @end table |
4690 | ||
d4f3574e SS |
4691 | @c FIXME: I think the following ``Except for [...] @code{tbreak}'' is |
4692 | @c confusing: tbreak is also initially enabled. | |
c906108c | 4693 | Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks, |
79a6e687 | 4694 | ,Setting Breakpoints}), breakpoints that you set are initially enabled; |
c906108c SS |
4695 | subsequently, they become disabled or enabled only when you use one of |
4696 | the commands above. (The command @code{until} can set and delete a | |
4697 | breakpoint of its own, but it does not change the state of your other | |
4698 | breakpoints; see @ref{Continuing and Stepping, ,Continuing and | |
79a6e687 | 4699 | Stepping}.) |
c906108c | 4700 | |
6d2ebf8b | 4701 | @node Conditions |
79a6e687 | 4702 | @subsection Break Conditions |
c906108c SS |
4703 | @cindex conditional breakpoints |
4704 | @cindex breakpoint conditions | |
4705 | ||
4706 | @c FIXME what is scope of break condition expr? Context where wanted? | |
5d161b24 | 4707 | @c in particular for a watchpoint? |
c906108c SS |
4708 | The simplest sort of breakpoint breaks every time your program reaches a |
4709 | specified place. You can also specify a @dfn{condition} for a | |
4710 | breakpoint. A condition is just a Boolean expression in your | |
4711 | programming language (@pxref{Expressions, ,Expressions}). A breakpoint with | |
4712 | a condition evaluates the expression each time your program reaches it, | |
4713 | and your program stops only if the condition is @emph{true}. | |
4714 | ||
4715 | This is the converse of using assertions for program validation; in that | |
4716 | situation, you want to stop when the assertion is violated---that is, | |
4717 | when the condition is false. In C, if you want to test an assertion expressed | |
4718 | by the condition @var{assert}, you should set the condition | |
4719 | @samp{! @var{assert}} on the appropriate breakpoint. | |
4720 | ||
4721 | Conditions are also accepted for watchpoints; you may not need them, | |
4722 | since a watchpoint is inspecting the value of an expression anyhow---but | |
4723 | it might be simpler, say, to just set a watchpoint on a variable name, | |
4724 | and specify a condition that tests whether the new value is an interesting | |
4725 | one. | |
4726 | ||
4727 | Break conditions can have side effects, and may even call functions in | |
4728 | your program. This can be useful, for example, to activate functions | |
4729 | that log program progress, or to use your own print functions to | |
99e008fe | 4730 | format special data structures. The effects are completely predictable |
c906108c SS |
4731 | unless there is another enabled breakpoint at the same address. (In |
4732 | that case, @value{GDBN} might see the other breakpoint first and stop your | |
4733 | program without checking the condition of this one.) Note that | |
d4f3574e SS |
4734 | breakpoint commands are usually more convenient and flexible than break |
4735 | conditions for the | |
c906108c | 4736 | purpose of performing side effects when a breakpoint is reached |
79a6e687 | 4737 | (@pxref{Break Commands, ,Breakpoint Command Lists}). |
c906108c | 4738 | |
83364271 LM |
4739 | Breakpoint conditions can also be evaluated on the target's side if |
4740 | the target supports it. Instead of evaluating the conditions locally, | |
4741 | @value{GDBN} encodes the expression into an agent expression | |
4742 | (@pxref{Agent Expressions}) suitable for execution on the target, | |
4743 | independently of @value{GDBN}. Global variables become raw memory | |
4744 | locations, locals become stack accesses, and so forth. | |
4745 | ||
4746 | In this case, @value{GDBN} will only be notified of a breakpoint trigger | |
4747 | when its condition evaluates to true. This mechanism may provide faster | |
4748 | response times depending on the performance characteristics of the target | |
4749 | since it does not need to keep @value{GDBN} informed about | |
4750 | every breakpoint trigger, even those with false conditions. | |
4751 | ||
c906108c SS |
4752 | Break conditions can be specified when a breakpoint is set, by using |
4753 | @samp{if} in the arguments to the @code{break} command. @xref{Set | |
79a6e687 | 4754 | Breaks, ,Setting Breakpoints}. They can also be changed at any time |
c906108c | 4755 | with the @code{condition} command. |
53a5351d | 4756 | |
c906108c SS |
4757 | You can also use the @code{if} keyword with the @code{watch} command. |
4758 | The @code{catch} command does not recognize the @code{if} keyword; | |
4759 | @code{condition} is the only way to impose a further condition on a | |
4760 | catchpoint. | |
c906108c SS |
4761 | |
4762 | @table @code | |
4763 | @kindex condition | |
4764 | @item condition @var{bnum} @var{expression} | |
4765 | Specify @var{expression} as the break condition for breakpoint, | |
4766 | watchpoint, or catchpoint number @var{bnum}. After you set a condition, | |
4767 | breakpoint @var{bnum} stops your program only if the value of | |
4768 | @var{expression} is true (nonzero, in C). When you use | |
4769 | @code{condition}, @value{GDBN} checks @var{expression} immediately for | |
4770 | syntactic correctness, and to determine whether symbols in it have | |
d4f3574e SS |
4771 | referents in the context of your breakpoint. If @var{expression} uses |
4772 | symbols not referenced in the context of the breakpoint, @value{GDBN} | |
4773 | prints an error message: | |
4774 | ||
474c8240 | 4775 | @smallexample |
d4f3574e | 4776 | No symbol "foo" in current context. |
474c8240 | 4777 | @end smallexample |
d4f3574e SS |
4778 | |
4779 | @noindent | |
c906108c SS |
4780 | @value{GDBN} does |
4781 | not actually evaluate @var{expression} at the time the @code{condition} | |
d4f3574e SS |
4782 | command (or a command that sets a breakpoint with a condition, like |
4783 | @code{break if @dots{}}) is given, however. @xref{Expressions, ,Expressions}. | |
c906108c SS |
4784 | |
4785 | @item condition @var{bnum} | |
4786 | Remove the condition from breakpoint number @var{bnum}. It becomes | |
4787 | an ordinary unconditional breakpoint. | |
4788 | @end table | |
4789 | ||
4790 | @cindex ignore count (of breakpoint) | |
4791 | A special case of a breakpoint condition is to stop only when the | |
4792 | breakpoint has been reached a certain number of times. This is so | |
4793 | useful that there is a special way to do it, using the @dfn{ignore | |
4794 | count} of the breakpoint. Every breakpoint has an ignore count, which | |
4795 | is an integer. Most of the time, the ignore count is zero, and | |
4796 | therefore has no effect. But if your program reaches a breakpoint whose | |
4797 | ignore count is positive, then instead of stopping, it just decrements | |
4798 | the ignore count by one and continues. As a result, if the ignore count | |
4799 | value is @var{n}, the breakpoint does not stop the next @var{n} times | |
4800 | your program reaches it. | |
4801 | ||
4802 | @table @code | |
4803 | @kindex ignore | |
4804 | @item ignore @var{bnum} @var{count} | |
4805 | Set the ignore count of breakpoint number @var{bnum} to @var{count}. | |
4806 | The next @var{count} times the breakpoint is reached, your program's | |
4807 | execution does not stop; other than to decrement the ignore count, @value{GDBN} | |
4808 | takes no action. | |
4809 | ||
4810 | To make the breakpoint stop the next time it is reached, specify | |
4811 | a count of zero. | |
4812 | ||
4813 | When you use @code{continue} to resume execution of your program from a | |
4814 | breakpoint, you can specify an ignore count directly as an argument to | |
4815 | @code{continue}, rather than using @code{ignore}. @xref{Continuing and | |
79a6e687 | 4816 | Stepping,,Continuing and Stepping}. |
c906108c SS |
4817 | |
4818 | If a breakpoint has a positive ignore count and a condition, the | |
4819 | condition is not checked. Once the ignore count reaches zero, | |
4820 | @value{GDBN} resumes checking the condition. | |
4821 | ||
4822 | You could achieve the effect of the ignore count with a condition such | |
4823 | as @w{@samp{$foo-- <= 0}} using a debugger convenience variable that | |
4824 | is decremented each time. @xref{Convenience Vars, ,Convenience | |
79a6e687 | 4825 | Variables}. |
c906108c SS |
4826 | @end table |
4827 | ||
4828 | Ignore counts apply to breakpoints, watchpoints, and catchpoints. | |
4829 | ||
4830 | ||
6d2ebf8b | 4831 | @node Break Commands |
79a6e687 | 4832 | @subsection Breakpoint Command Lists |
c906108c SS |
4833 | |
4834 | @cindex breakpoint commands | |
4835 | You can give any breakpoint (or watchpoint or catchpoint) a series of | |
4836 | commands to execute when your program stops due to that breakpoint. For | |
4837 | example, you might want to print the values of certain expressions, or | |
4838 | enable other breakpoints. | |
4839 | ||
4840 | @table @code | |
4841 | @kindex commands | |
ca91424e | 4842 | @kindex end@r{ (breakpoint commands)} |
95a42b64 | 4843 | @item commands @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4844 | @itemx @dots{} @var{command-list} @dots{} |
4845 | @itemx end | |
95a42b64 | 4846 | Specify a list of commands for the given breakpoints. The commands |
c906108c SS |
4847 | themselves appear on the following lines. Type a line containing just |
4848 | @code{end} to terminate the commands. | |
4849 | ||
4850 | To remove all commands from a breakpoint, type @code{commands} and | |
4851 | follow it immediately with @code{end}; that is, give no commands. | |
4852 | ||
95a42b64 TT |
4853 | With no argument, @code{commands} refers to the last breakpoint, |
4854 | watchpoint, or catchpoint set (not to the breakpoint most recently | |
4855 | encountered). If the most recent breakpoints were set with a single | |
4856 | command, then the @code{commands} will apply to all the breakpoints | |
4857 | set by that command. This applies to breakpoints set by | |
86b17b60 PA |
4858 | @code{rbreak}, and also applies when a single @code{break} command |
4859 | creates multiple breakpoints (@pxref{Ambiguous Expressions,,Ambiguous | |
4860 | Expressions}). | |
c906108c SS |
4861 | @end table |
4862 | ||
4863 | Pressing @key{RET} as a means of repeating the last @value{GDBN} command is | |
4864 | disabled within a @var{command-list}. | |
4865 | ||
4866 | You can use breakpoint commands to start your program up again. Simply | |
4867 | use the @code{continue} command, or @code{step}, or any other command | |
4868 | that resumes execution. | |
4869 | ||
4870 | Any other commands in the command list, after a command that resumes | |
4871 | execution, are ignored. This is because any time you resume execution | |
4872 | (even with a simple @code{next} or @code{step}), you may encounter | |
4873 | another breakpoint---which could have its own command list, leading to | |
4874 | ambiguities about which list to execute. | |
4875 | ||
4876 | @kindex silent | |
4877 | If the first command you specify in a command list is @code{silent}, the | |
4878 | usual message about stopping at a breakpoint is not printed. This may | |
4879 | be desirable for breakpoints that are to print a specific message and | |
4880 | then continue. If none of the remaining commands print anything, you | |
4881 | see no sign that the breakpoint was reached. @code{silent} is | |
4882 | meaningful only at the beginning of a breakpoint command list. | |
4883 | ||
4884 | The commands @code{echo}, @code{output}, and @code{printf} allow you to | |
4885 | print precisely controlled output, and are often useful in silent | |
79a6e687 | 4886 | breakpoints. @xref{Output, ,Commands for Controlled Output}. |
c906108c SS |
4887 | |
4888 | For example, here is how you could use breakpoint commands to print the | |
4889 | value of @code{x} at entry to @code{foo} whenever @code{x} is positive. | |
4890 | ||
474c8240 | 4891 | @smallexample |
c906108c SS |
4892 | break foo if x>0 |
4893 | commands | |
4894 | silent | |
4895 | printf "x is %d\n",x | |
4896 | cont | |
4897 | end | |
474c8240 | 4898 | @end smallexample |
c906108c SS |
4899 | |
4900 | One application for breakpoint commands is to compensate for one bug so | |
4901 | you can test for another. Put a breakpoint just after the erroneous line | |
4902 | of code, give it a condition to detect the case in which something | |
4903 | erroneous has been done, and give it commands to assign correct values | |
4904 | to any variables that need them. End with the @code{continue} command | |
4905 | so that your program does not stop, and start with the @code{silent} | |
4906 | command so that no output is produced. Here is an example: | |
4907 | ||
474c8240 | 4908 | @smallexample |
c906108c SS |
4909 | break 403 |
4910 | commands | |
4911 | silent | |
4912 | set x = y + 4 | |
4913 | cont | |
4914 | end | |
474c8240 | 4915 | @end smallexample |
c906108c | 4916 | |
e7e0cddf SS |
4917 | @node Dynamic Printf |
4918 | @subsection Dynamic Printf | |
4919 | ||
4920 | @cindex dynamic printf | |
4921 | @cindex dprintf | |
4922 | The dynamic printf command @code{dprintf} combines a breakpoint with | |
4923 | formatted printing of your program's data to give you the effect of | |
4924 | inserting @code{printf} calls into your program on-the-fly, without | |
4925 | having to recompile it. | |
4926 | ||
4927 | In its most basic form, the output goes to the GDB console. However, | |
4928 | you can set the variable @code{dprintf-style} for alternate handling. | |
4929 | For instance, you can ask to format the output by calling your | |
4930 | program's @code{printf} function. This has the advantage that the | |
4931 | characters go to the program's output device, so they can recorded in | |
4932 | redirects to files and so forth. | |
4933 | ||
d3ce09f5 SS |
4934 | If you are doing remote debugging with a stub or agent, you can also |
4935 | ask to have the printf handled by the remote agent. In addition to | |
4936 | ensuring that the output goes to the remote program's device along | |
4937 | with any other output the program might produce, you can also ask that | |
4938 | the dprintf remain active even after disconnecting from the remote | |
4939 | target. Using the stub/agent is also more efficient, as it can do | |
4940 | everything without needing to communicate with @value{GDBN}. | |
4941 | ||
e7e0cddf SS |
4942 | @table @code |
4943 | @kindex dprintf | |
4944 | @item dprintf @var{location},@var{template},@var{expression}[,@var{expression}@dots{}] | |
4945 | Whenever execution reaches @var{location}, print the values of one or | |
4946 | more @var{expressions} under the control of the string @var{template}. | |
4947 | To print several values, separate them with commas. | |
4948 | ||
4949 | @item set dprintf-style @var{style} | |
4950 | Set the dprintf output to be handled in one of several different | |
4951 | styles enumerated below. A change of style affects all existing | |
4952 | dynamic printfs immediately. (If you need individual control over the | |
4953 | print commands, simply define normal breakpoints with | |
4954 | explicitly-supplied command lists.) | |
4955 | ||
4956 | @item gdb | |
4957 | @kindex dprintf-style gdb | |
4958 | Handle the output using the @value{GDBN} @code{printf} command. | |
4959 | ||
4960 | @item call | |
4961 | @kindex dprintf-style call | |
4962 | Handle the output by calling a function in your program (normally | |
4963 | @code{printf}). | |
4964 | ||
d3ce09f5 SS |
4965 | @item agent |
4966 | @kindex dprintf-style agent | |
4967 | Have the remote debugging agent (such as @code{gdbserver}) handle | |
4968 | the output itself. This style is only available for agents that | |
4969 | support running commands on the target. | |
4970 | ||
e7e0cddf SS |
4971 | @item set dprintf-function @var{function} |
4972 | Set the function to call if the dprintf style is @code{call}. By | |
4973 | default its value is @code{printf}. You may set it to any expression. | |
4974 | that @value{GDBN} can evaluate to a function, as per the @code{call} | |
4975 | command. | |
4976 | ||
4977 | @item set dprintf-channel @var{channel} | |
4978 | Set a ``channel'' for dprintf. If set to a non-empty value, | |
4979 | @value{GDBN} will evaluate it as an expression and pass the result as | |
4980 | a first argument to the @code{dprintf-function}, in the manner of | |
4981 | @code{fprintf} and similar functions. Otherwise, the dprintf format | |
4982 | string will be the first argument, in the manner of @code{printf}. | |
4983 | ||
4984 | As an example, if you wanted @code{dprintf} output to go to a logfile | |
4985 | that is a standard I/O stream assigned to the variable @code{mylog}, | |
4986 | you could do the following: | |
4987 | ||
4988 | @example | |
4989 | (gdb) set dprintf-style call | |
4990 | (gdb) set dprintf-function fprintf | |
4991 | (gdb) set dprintf-channel mylog | |
4992 | (gdb) dprintf 25,"at line 25, glob=%d\n",glob | |
4993 | Dprintf 1 at 0x123456: file main.c, line 25. | |
4994 | (gdb) info break | |
4995 | 1 dprintf keep y 0x00123456 in main at main.c:25 | |
4996 | call (void) fprintf (mylog,"at line 25, glob=%d\n",glob) | |
4997 | continue | |
4998 | (gdb) | |
4999 | @end example | |
5000 | ||
5001 | Note that the @code{info break} displays the dynamic printf commands | |
5002 | as normal breakpoint commands; you can thus easily see the effect of | |
5003 | the variable settings. | |
5004 | ||
d3ce09f5 SS |
5005 | @item set disconnected-dprintf on |
5006 | @itemx set disconnected-dprintf off | |
5007 | @kindex set disconnected-dprintf | |
5008 | Choose whether @code{dprintf} commands should continue to run if | |
5009 | @value{GDBN} has disconnected from the target. This only applies | |
5010 | if the @code{dprintf-style} is @code{agent}. | |
5011 | ||
5012 | @item show disconnected-dprintf off | |
5013 | @kindex show disconnected-dprintf | |
5014 | Show the current choice for disconnected @code{dprintf}. | |
5015 | ||
e7e0cddf SS |
5016 | @end table |
5017 | ||
5018 | @value{GDBN} does not check the validity of function and channel, | |
5019 | relying on you to supply values that are meaningful for the contexts | |
5020 | in which they are being used. For instance, the function and channel | |
5021 | may be the values of local variables, but if that is the case, then | |
5022 | all enabled dynamic prints must be at locations within the scope of | |
5023 | those locals. If evaluation fails, @value{GDBN} will report an error. | |
5024 | ||
6149aea9 PA |
5025 | @node Save Breakpoints |
5026 | @subsection How to save breakpoints to a file | |
5027 | ||
5028 | To save breakpoint definitions to a file use the @w{@code{save | |
5029 | breakpoints}} command. | |
5030 | ||
5031 | @table @code | |
5032 | @kindex save breakpoints | |
5033 | @cindex save breakpoints to a file for future sessions | |
5034 | @item save breakpoints [@var{filename}] | |
5035 | This command saves all current breakpoint definitions together with | |
5036 | their commands and ignore counts, into a file @file{@var{filename}} | |
5037 | suitable for use in a later debugging session. This includes all | |
5038 | types of breakpoints (breakpoints, watchpoints, catchpoints, | |
5039 | tracepoints). To read the saved breakpoint definitions, use the | |
5040 | @code{source} command (@pxref{Command Files}). Note that watchpoints | |
5041 | with expressions involving local variables may fail to be recreated | |
5042 | because it may not be possible to access the context where the | |
5043 | watchpoint is valid anymore. Because the saved breakpoint definitions | |
5044 | are simply a sequence of @value{GDBN} commands that recreate the | |
5045 | breakpoints, you can edit the file in your favorite editing program, | |
5046 | and remove the breakpoint definitions you're not interested in, or | |
5047 | that can no longer be recreated. | |
5048 | @end table | |
5049 | ||
62e5f89c SDJ |
5050 | @node Static Probe Points |
5051 | @subsection Static Probe Points | |
5052 | ||
5053 | @cindex static probe point, SystemTap | |
3133f8c1 | 5054 | @cindex static probe point, DTrace |
62e5f89c SDJ |
5055 | @value{GDBN} supports @dfn{SDT} probes in the code. @acronym{SDT} stands |
5056 | for Statically Defined Tracing, and the probes are designed to have a tiny | |
3133f8c1 JM |
5057 | runtime code and data footprint, and no dynamic relocations. |
5058 | ||
5059 | Currently, the following types of probes are supported on | |
5060 | ELF-compatible systems: | |
5061 | ||
5062 | @itemize @bullet | |
62e5f89c | 5063 | |
3133f8c1 JM |
5064 | @item @code{SystemTap} (@uref{http://sourceware.org/systemtap/}) |
5065 | @acronym{SDT} probes@footnote{See | |
62e5f89c | 5066 | @uref{http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps} |
3133f8c1 JM |
5067 | for more information on how to add @code{SystemTap} @acronym{SDT} |
5068 | probes in your applications.}. @code{SystemTap} probes are usable | |
5069 | from assembly, C and C@t{++} languages@footnote{See | |
5070 | @uref{http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation} | |
5071 | for a good reference on how the @acronym{SDT} probes are implemented.}. | |
5072 | ||
5073 | @item @code{DTrace} (@uref{http://oss.oracle.com/projects/DTrace}) | |
5074 | @acronym{USDT} probes. @code{DTrace} probes are usable from C and | |
5075 | C@t{++} languages. | |
5076 | @end itemize | |
62e5f89c SDJ |
5077 | |
5078 | @cindex semaphores on static probe points | |
3133f8c1 JM |
5079 | Some @code{SystemTap} probes have an associated semaphore variable; |
5080 | for instance, this happens automatically if you defined your probe | |
5081 | using a DTrace-style @file{.d} file. If your probe has a semaphore, | |
5082 | @value{GDBN} will automatically enable it when you specify a | |
5083 | breakpoint using the @samp{-probe-stap} notation. But, if you put a | |
5084 | breakpoint at a probe's location by some other method (e.g., | |
5085 | @code{break file:line}), then @value{GDBN} will not automatically set | |
5086 | the semaphore. @code{DTrace} probes do not support semaphores. | |
62e5f89c SDJ |
5087 | |
5088 | You can examine the available static static probes using @code{info | |
5089 | probes}, with optional arguments: | |
5090 | ||
5091 | @table @code | |
5092 | @kindex info probes | |
3133f8c1 JM |
5093 | @item info probes @r{[}@var{type}@r{]} @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]} |
5094 | If given, @var{type} is either @code{stap} for listing | |
5095 | @code{SystemTap} probes or @code{dtrace} for listing @code{DTrace} | |
5096 | probes. If omitted all probes are listed regardless of their types. | |
5097 | ||
62e5f89c SDJ |
5098 | If given, @var{provider} is a regular expression used to match against provider |
5099 | names when selecting which probes to list. If omitted, probes by all | |
5100 | probes from all providers are listed. | |
5101 | ||
5102 | If given, @var{name} is a regular expression to match against probe names | |
5103 | when selecting which probes to list. If omitted, probe names are not | |
5104 | considered when deciding whether to display them. | |
5105 | ||
5106 | If given, @var{objfile} is a regular expression used to select which | |
5107 | object files (executable or shared libraries) to examine. If not | |
5108 | given, all object files are considered. | |
5109 | ||
5110 | @item info probes all | |
5111 | List the available static probes, from all types. | |
5112 | @end table | |
5113 | ||
9aca2ff8 JM |
5114 | @cindex enabling and disabling probes |
5115 | Some probe points can be enabled and/or disabled. The effect of | |
5116 | enabling or disabling a probe depends on the type of probe being | |
3133f8c1 JM |
5117 | handled. Some @code{DTrace} probes can be enabled or |
5118 | disabled, but @code{SystemTap} probes cannot be disabled. | |
9aca2ff8 JM |
5119 | |
5120 | You can enable (or disable) one or more probes using the following | |
5121 | commands, with optional arguments: | |
5122 | ||
5123 | @table @code | |
5124 | @kindex enable probes | |
5125 | @item enable probes @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]} | |
5126 | If given, @var{provider} is a regular expression used to match against | |
5127 | provider names when selecting which probes to enable. If omitted, | |
5128 | all probes from all providers are enabled. | |
5129 | ||
5130 | If given, @var{name} is a regular expression to match against probe | |
5131 | names when selecting which probes to enable. If omitted, probe names | |
5132 | are not considered when deciding whether to enable them. | |
5133 | ||
5134 | If given, @var{objfile} is a regular expression used to select which | |
5135 | object files (executable or shared libraries) to examine. If not | |
5136 | given, all object files are considered. | |
5137 | ||
5138 | @kindex disable probes | |
5139 | @item disable probes @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]} | |
5140 | See the @code{enable probes} command above for a description of the | |
5141 | optional arguments accepted by this command. | |
5142 | @end table | |
5143 | ||
62e5f89c SDJ |
5144 | @vindex $_probe_arg@r{, convenience variable} |
5145 | A probe may specify up to twelve arguments. These are available at the | |
5146 | point at which the probe is defined---that is, when the current PC is | |
5147 | at the probe's location. The arguments are available using the | |
5148 | convenience variables (@pxref{Convenience Vars}) | |
3133f8c1 JM |
5149 | @code{$_probe_arg0}@dots{}@code{$_probe_arg11}. In @code{SystemTap} |
5150 | probes each probe argument is an integer of the appropriate size; | |
5151 | types are not preserved. In @code{DTrace} probes types are preserved | |
5152 | provided that they are recognized as such by @value{GDBN}; otherwise | |
5153 | the value of the probe argument will be a long integer. The | |
62e5f89c SDJ |
5154 | convenience variable @code{$_probe_argc} holds the number of arguments |
5155 | at the current probe point. | |
5156 | ||
5157 | These variables are always available, but attempts to access them at | |
5158 | any location other than a probe point will cause @value{GDBN} to give | |
5159 | an error message. | |
5160 | ||
5161 | ||
c906108c | 5162 | @c @ifclear BARETARGET |
6d2ebf8b | 5163 | @node Error in Breakpoints |
d4f3574e | 5164 | @subsection ``Cannot insert breakpoints'' |
c906108c | 5165 | |
fa3a767f PA |
5166 | If you request too many active hardware-assisted breakpoints and |
5167 | watchpoints, you will see this error message: | |
d4f3574e SS |
5168 | |
5169 | @c FIXME: the precise wording of this message may change; the relevant | |
5170 | @c source change is not committed yet (Sep 3, 1999). | |
5171 | @smallexample | |
5172 | Stopped; cannot insert breakpoints. | |
5173 | You may have requested too many hardware breakpoints and watchpoints. | |
5174 | @end smallexample | |
5175 | ||
5176 | @noindent | |
5177 | This message is printed when you attempt to resume the program, since | |
5178 | only then @value{GDBN} knows exactly how many hardware breakpoints and | |
5179 | watchpoints it needs to insert. | |
5180 | ||
5181 | When this message is printed, you need to disable or remove some of the | |
5182 | hardware-assisted breakpoints and watchpoints, and then continue. | |
5183 | ||
79a6e687 | 5184 | @node Breakpoint-related Warnings |
1485d690 KB |
5185 | @subsection ``Breakpoint address adjusted...'' |
5186 | @cindex breakpoint address adjusted | |
5187 | ||
5188 | Some processor architectures place constraints on the addresses at | |
5189 | which breakpoints may be placed. For architectures thus constrained, | |
5190 | @value{GDBN} will attempt to adjust the breakpoint's address to comply | |
5191 | with the constraints dictated by the architecture. | |
5192 | ||
5193 | One example of such an architecture is the Fujitsu FR-V. The FR-V is | |
5194 | a VLIW architecture in which a number of RISC-like instructions may be | |
5195 | bundled together for parallel execution. The FR-V architecture | |
5196 | constrains the location of a breakpoint instruction within such a | |
5197 | bundle to the instruction with the lowest address. @value{GDBN} | |
5198 | honors this constraint by adjusting a breakpoint's address to the | |
5199 | first in the bundle. | |
5200 | ||
5201 | It is not uncommon for optimized code to have bundles which contain | |
5202 | instructions from different source statements, thus it may happen that | |
5203 | a breakpoint's address will be adjusted from one source statement to | |
5204 | another. Since this adjustment may significantly alter @value{GDBN}'s | |
5205 | breakpoint related behavior from what the user expects, a warning is | |
5206 | printed when the breakpoint is first set and also when the breakpoint | |
5207 | is hit. | |
5208 | ||
5209 | A warning like the one below is printed when setting a breakpoint | |
5210 | that's been subject to address adjustment: | |
5211 | ||
5212 | @smallexample | |
5213 | warning: Breakpoint address adjusted from 0x00010414 to 0x00010410. | |
5214 | @end smallexample | |
5215 | ||
5216 | Such warnings are printed both for user settable and @value{GDBN}'s | |
5217 | internal breakpoints. If you see one of these warnings, you should | |
5218 | verify that a breakpoint set at the adjusted address will have the | |
5219 | desired affect. If not, the breakpoint in question may be removed and | |
b383017d | 5220 | other breakpoints may be set which will have the desired behavior. |
1485d690 KB |
5221 | E.g., it may be sufficient to place the breakpoint at a later |
5222 | instruction. A conditional breakpoint may also be useful in some | |
5223 | cases to prevent the breakpoint from triggering too often. | |
5224 | ||
5225 | @value{GDBN} will also issue a warning when stopping at one of these | |
5226 | adjusted breakpoints: | |
5227 | ||
5228 | @smallexample | |
5229 | warning: Breakpoint 1 address previously adjusted from 0x00010414 | |
5230 | to 0x00010410. | |
5231 | @end smallexample | |
5232 | ||
5233 | When this warning is encountered, it may be too late to take remedial | |
5234 | action except in cases where the breakpoint is hit earlier or more | |
5235 | frequently than expected. | |
d4f3574e | 5236 | |
6d2ebf8b | 5237 | @node Continuing and Stepping |
79a6e687 | 5238 | @section Continuing and Stepping |
c906108c SS |
5239 | |
5240 | @cindex stepping | |
5241 | @cindex continuing | |
5242 | @cindex resuming execution | |
5243 | @dfn{Continuing} means resuming program execution until your program | |
5244 | completes normally. In contrast, @dfn{stepping} means executing just | |
5245 | one more ``step'' of your program, where ``step'' may mean either one | |
5246 | line of source code, or one machine instruction (depending on what | |
7a292a7a SS |
5247 | particular command you use). Either when continuing or when stepping, |
5248 | your program may stop even sooner, due to a breakpoint or a signal. (If | |
d4f3574e | 5249 | it stops due to a signal, you may want to use @code{handle}, or use |
e5f8a7cc PA |
5250 | @samp{signal 0} to resume execution (@pxref{Signals, ,Signals}), |
5251 | or you may step into the signal's handler (@pxref{stepping and signal | |
5252 | handlers}).) | |
c906108c SS |
5253 | |
5254 | @table @code | |
5255 | @kindex continue | |
41afff9a EZ |
5256 | @kindex c @r{(@code{continue})} |
5257 | @kindex fg @r{(resume foreground execution)} | |
c906108c SS |
5258 | @item continue @r{[}@var{ignore-count}@r{]} |
5259 | @itemx c @r{[}@var{ignore-count}@r{]} | |
5260 | @itemx fg @r{[}@var{ignore-count}@r{]} | |
5261 | Resume program execution, at the address where your program last stopped; | |
5262 | any breakpoints set at that address are bypassed. The optional argument | |
5263 | @var{ignore-count} allows you to specify a further number of times to | |
5264 | ignore a breakpoint at this location; its effect is like that of | |
79a6e687 | 5265 | @code{ignore} (@pxref{Conditions, ,Break Conditions}). |
c906108c SS |
5266 | |
5267 | The argument @var{ignore-count} is meaningful only when your program | |
5268 | stopped due to a breakpoint. At other times, the argument to | |
5269 | @code{continue} is ignored. | |
5270 | ||
d4f3574e SS |
5271 | The synonyms @code{c} and @code{fg} (for @dfn{foreground}, as the |
5272 | debugged program is deemed to be the foreground program) are provided | |
5273 | purely for convenience, and have exactly the same behavior as | |
5274 | @code{continue}. | |
c906108c SS |
5275 | @end table |
5276 | ||
5277 | To resume execution at a different place, you can use @code{return} | |
79a6e687 | 5278 | (@pxref{Returning, ,Returning from a Function}) to go back to the |
c906108c | 5279 | calling function; or @code{jump} (@pxref{Jumping, ,Continuing at a |
79a6e687 | 5280 | Different Address}) to go to an arbitrary location in your program. |
c906108c SS |
5281 | |
5282 | A typical technique for using stepping is to set a breakpoint | |
79a6e687 | 5283 | (@pxref{Breakpoints, ,Breakpoints; Watchpoints; and Catchpoints}) at the |
c906108c SS |
5284 | beginning of the function or the section of your program where a problem |
5285 | is believed to lie, run your program until it stops at that breakpoint, | |
5286 | and then step through the suspect area, examining the variables that are | |
5287 | interesting, until you see the problem happen. | |
5288 | ||
5289 | @table @code | |
5290 | @kindex step | |
41afff9a | 5291 | @kindex s @r{(@code{step})} |
c906108c SS |
5292 | @item step |
5293 | Continue running your program until control reaches a different source | |
5294 | line, then stop it and return control to @value{GDBN}. This command is | |
5295 | abbreviated @code{s}. | |
5296 | ||
5297 | @quotation | |
5298 | @c "without debugging information" is imprecise; actually "without line | |
5299 | @c numbers in the debugging information". (gcc -g1 has debugging info but | |
5300 | @c not line numbers). But it seems complex to try to make that | |
5301 | @c distinction here. | |
5302 | @emph{Warning:} If you use the @code{step} command while control is | |
5303 | within a function that was compiled without debugging information, | |
5304 | execution proceeds until control reaches a function that does have | |
5305 | debugging information. Likewise, it will not step into a function which | |
5306 | is compiled without debugging information. To step through functions | |
5307 | without debugging information, use the @code{stepi} command, described | |
5308 | below. | |
5309 | @end quotation | |
5310 | ||
4a92d011 EZ |
5311 | The @code{step} command only stops at the first instruction of a source |
5312 | line. This prevents the multiple stops that could otherwise occur in | |
5313 | @code{switch} statements, @code{for} loops, etc. @code{step} continues | |
5314 | to stop if a function that has debugging information is called within | |
5315 | the line. In other words, @code{step} @emph{steps inside} any functions | |
5316 | called within the line. | |
c906108c | 5317 | |
d4f3574e SS |
5318 | Also, the @code{step} command only enters a function if there is line |
5319 | number information for the function. Otherwise it acts like the | |
5d161b24 | 5320 | @code{next} command. This avoids problems when using @code{cc -gl} |
eb17f351 | 5321 | on @acronym{MIPS} machines. Previously, @code{step} entered subroutines if there |
5d161b24 | 5322 | was any debugging information about the routine. |
c906108c SS |
5323 | |
5324 | @item step @var{count} | |
5325 | Continue running as in @code{step}, but do so @var{count} times. If a | |
7a292a7a SS |
5326 | breakpoint is reached, or a signal not related to stepping occurs before |
5327 | @var{count} steps, stepping stops right away. | |
c906108c SS |
5328 | |
5329 | @kindex next | |
41afff9a | 5330 | @kindex n @r{(@code{next})} |
c906108c SS |
5331 | @item next @r{[}@var{count}@r{]} |
5332 | Continue to the next source line in the current (innermost) stack frame. | |
7a292a7a SS |
5333 | This is similar to @code{step}, but function calls that appear within |
5334 | the line of code are executed without stopping. Execution stops when | |
5335 | control reaches a different line of code at the original stack level | |
5336 | that was executing when you gave the @code{next} command. This command | |
5337 | is abbreviated @code{n}. | |
c906108c SS |
5338 | |
5339 | An argument @var{count} is a repeat count, as for @code{step}. | |
5340 | ||
5341 | ||
5342 | @c FIX ME!! Do we delete this, or is there a way it fits in with | |
5343 | @c the following paragraph? --- Vctoria | |
5344 | @c | |
5345 | @c @code{next} within a function that lacks debugging information acts like | |
5346 | @c @code{step}, but any function calls appearing within the code of the | |
5347 | @c function are executed without stopping. | |
5348 | ||
d4f3574e SS |
5349 | The @code{next} command only stops at the first instruction of a |
5350 | source line. This prevents multiple stops that could otherwise occur in | |
4a92d011 | 5351 | @code{switch} statements, @code{for} loops, etc. |
c906108c | 5352 | |
b90a5f51 CF |
5353 | @kindex set step-mode |
5354 | @item set step-mode | |
5355 | @cindex functions without line info, and stepping | |
5356 | @cindex stepping into functions with no line info | |
5357 | @itemx set step-mode on | |
4a92d011 | 5358 | The @code{set step-mode on} command causes the @code{step} command to |
b90a5f51 CF |
5359 | stop at the first instruction of a function which contains no debug line |
5360 | information rather than stepping over it. | |
5361 | ||
4a92d011 EZ |
5362 | This is useful in cases where you may be interested in inspecting the |
5363 | machine instructions of a function which has no symbolic info and do not | |
5364 | want @value{GDBN} to automatically skip over this function. | |
b90a5f51 CF |
5365 | |
5366 | @item set step-mode off | |
4a92d011 | 5367 | Causes the @code{step} command to step over any functions which contains no |
b90a5f51 CF |
5368 | debug information. This is the default. |
5369 | ||
9c16f35a EZ |
5370 | @item show step-mode |
5371 | Show whether @value{GDBN} will stop in or step over functions without | |
5372 | source line debug information. | |
5373 | ||
c906108c | 5374 | @kindex finish |
8dfa32fc | 5375 | @kindex fin @r{(@code{finish})} |
c906108c SS |
5376 | @item finish |
5377 | Continue running until just after function in the selected stack frame | |
8dfa32fc JB |
5378 | returns. Print the returned value (if any). This command can be |
5379 | abbreviated as @code{fin}. | |
c906108c SS |
5380 | |
5381 | Contrast this with the @code{return} command (@pxref{Returning, | |
79a6e687 | 5382 | ,Returning from a Function}). |
c906108c SS |
5383 | |
5384 | @kindex until | |
41afff9a | 5385 | @kindex u @r{(@code{until})} |
09d4efe1 | 5386 | @cindex run until specified location |
c906108c SS |
5387 | @item until |
5388 | @itemx u | |
5389 | Continue running until a source line past the current line, in the | |
5390 | current stack frame, is reached. This command is used to avoid single | |
5391 | stepping through a loop more than once. It is like the @code{next} | |
5392 | command, except that when @code{until} encounters a jump, it | |
5393 | automatically continues execution until the program counter is greater | |
5394 | than the address of the jump. | |
5395 | ||
5396 | This means that when you reach the end of a loop after single stepping | |
5397 | though it, @code{until} makes your program continue execution until it | |
5398 | exits the loop. In contrast, a @code{next} command at the end of a loop | |
5399 | simply steps back to the beginning of the loop, which forces you to step | |
5400 | through the next iteration. | |
5401 | ||
5402 | @code{until} always stops your program if it attempts to exit the current | |
5403 | stack frame. | |
5404 | ||
5405 | @code{until} may produce somewhat counterintuitive results if the order | |
5406 | of machine code does not match the order of the source lines. For | |
5407 | example, in the following excerpt from a debugging session, the @code{f} | |
5408 | (@code{frame}) command shows that execution is stopped at line | |
5409 | @code{206}; yet when we use @code{until}, we get to line @code{195}: | |
5410 | ||
474c8240 | 5411 | @smallexample |
c906108c SS |
5412 | (@value{GDBP}) f |
5413 | #0 main (argc=4, argv=0xf7fffae8) at m4.c:206 | |
5414 | 206 expand_input(); | |
5415 | (@value{GDBP}) until | |
5416 | 195 for ( ; argc > 0; NEXTARG) @{ | |
474c8240 | 5417 | @end smallexample |
c906108c SS |
5418 | |
5419 | This happened because, for execution efficiency, the compiler had | |
5420 | generated code for the loop closure test at the end, rather than the | |
5421 | start, of the loop---even though the test in a C @code{for}-loop is | |
5422 | written before the body of the loop. The @code{until} command appeared | |
5423 | to step back to the beginning of the loop when it advanced to this | |
5424 | expression; however, it has not really gone to an earlier | |
5425 | statement---not in terms of the actual machine code. | |
5426 | ||
5427 | @code{until} with no argument works by means of single | |
5428 | instruction stepping, and hence is slower than @code{until} with an | |
5429 | argument. | |
5430 | ||
5431 | @item until @var{location} | |
5432 | @itemx u @var{location} | |
697aa1b7 EZ |
5433 | Continue running your program until either the specified @var{location} is |
5434 | reached, or the current stack frame returns. The location is any of | |
2a25a5ba EZ |
5435 | the forms described in @ref{Specify Location}. |
5436 | This form of the command uses temporary breakpoints, and | |
c60eb6f1 EZ |
5437 | hence is quicker than @code{until} without an argument. The specified |
5438 | location is actually reached only if it is in the current frame. This | |
5439 | implies that @code{until} can be used to skip over recursive function | |
5440 | invocations. For instance in the code below, if the current location is | |
5441 | line @code{96}, issuing @code{until 99} will execute the program up to | |
db2e3e2e | 5442 | line @code{99} in the same invocation of factorial, i.e., after the inner |
c60eb6f1 EZ |
5443 | invocations have returned. |
5444 | ||
5445 | @smallexample | |
5446 | 94 int factorial (int value) | |
5447 | 95 @{ | |
5448 | 96 if (value > 1) @{ | |
5449 | 97 value *= factorial (value - 1); | |
5450 | 98 @} | |
5451 | 99 return (value); | |
5452 | 100 @} | |
5453 | @end smallexample | |
5454 | ||
5455 | ||
5456 | @kindex advance @var{location} | |
984359d2 | 5457 | @item advance @var{location} |
09d4efe1 | 5458 | Continue running the program up to the given @var{location}. An argument is |
2a25a5ba EZ |
5459 | required, which should be of one of the forms described in |
5460 | @ref{Specify Location}. | |
5461 | Execution will also stop upon exit from the current stack | |
c60eb6f1 EZ |
5462 | frame. This command is similar to @code{until}, but @code{advance} will |
5463 | not skip over recursive function calls, and the target location doesn't | |
5464 | have to be in the same frame as the current one. | |
5465 | ||
c906108c SS |
5466 | |
5467 | @kindex stepi | |
41afff9a | 5468 | @kindex si @r{(@code{stepi})} |
c906108c | 5469 | @item stepi |
96a2c332 | 5470 | @itemx stepi @var{arg} |
c906108c SS |
5471 | @itemx si |
5472 | Execute one machine instruction, then stop and return to the debugger. | |
5473 | ||
5474 | It is often useful to do @samp{display/i $pc} when stepping by machine | |
5475 | instructions. This makes @value{GDBN} automatically display the next | |
5476 | instruction to be executed, each time your program stops. @xref{Auto | |
79a6e687 | 5477 | Display,, Automatic Display}. |
c906108c SS |
5478 | |
5479 | An argument is a repeat count, as in @code{step}. | |
5480 | ||
5481 | @need 750 | |
5482 | @kindex nexti | |
41afff9a | 5483 | @kindex ni @r{(@code{nexti})} |
c906108c | 5484 | @item nexti |
96a2c332 | 5485 | @itemx nexti @var{arg} |
c906108c SS |
5486 | @itemx ni |
5487 | Execute one machine instruction, but if it is a function call, | |
5488 | proceed until the function returns. | |
5489 | ||
5490 | An argument is a repeat count, as in @code{next}. | |
c1e36e3e PA |
5491 | |
5492 | @end table | |
5493 | ||
5494 | @anchor{range stepping} | |
5495 | @cindex range stepping | |
5496 | @cindex target-assisted range stepping | |
5497 | By default, and if available, @value{GDBN} makes use of | |
5498 | target-assisted @dfn{range stepping}. In other words, whenever you | |
5499 | use a stepping command (e.g., @code{step}, @code{next}), @value{GDBN} | |
5500 | tells the target to step the corresponding range of instruction | |
5501 | addresses instead of issuing multiple single-steps. This speeds up | |
5502 | line stepping, particularly for remote targets. Ideally, there should | |
5503 | be no reason you would want to turn range stepping off. However, it's | |
5504 | possible that a bug in the debug info, a bug in the remote stub (for | |
5505 | remote targets), or even a bug in @value{GDBN} could make line | |
5506 | stepping behave incorrectly when target-assisted range stepping is | |
5507 | enabled. You can use the following command to turn off range stepping | |
5508 | if necessary: | |
5509 | ||
5510 | @table @code | |
5511 | @kindex set range-stepping | |
5512 | @kindex show range-stepping | |
5513 | @item set range-stepping | |
5514 | @itemx show range-stepping | |
5515 | Control whether range stepping is enabled. | |
5516 | ||
5517 | If @code{on}, and the target supports it, @value{GDBN} tells the | |
5518 | target to step a range of addresses itself, instead of issuing | |
5519 | multiple single-steps. If @code{off}, @value{GDBN} always issues | |
5520 | single-steps, even if range stepping is supported by the target. The | |
5521 | default is @code{on}. | |
5522 | ||
c906108c SS |
5523 | @end table |
5524 | ||
aad1c02c TT |
5525 | @node Skipping Over Functions and Files |
5526 | @section Skipping Over Functions and Files | |
1bfeeb0f JL |
5527 | @cindex skipping over functions and files |
5528 | ||
5529 | The program you are debugging may contain some functions which are | |
5530 | uninteresting to debug. The @code{skip} comand lets you tell @value{GDBN} to | |
5531 | skip a function or all functions in a file when stepping. | |
5532 | ||
5533 | For example, consider the following C function: | |
5534 | ||
5535 | @smallexample | |
5536 | 101 int func() | |
5537 | 102 @{ | |
5538 | 103 foo(boring()); | |
5539 | 104 bar(boring()); | |
5540 | 105 @} | |
5541 | @end smallexample | |
5542 | ||
5543 | @noindent | |
5544 | Suppose you wish to step into the functions @code{foo} and @code{bar}, but you | |
5545 | are not interested in stepping through @code{boring}. If you run @code{step} | |
5546 | at line 103, you'll enter @code{boring()}, but if you run @code{next}, you'll | |
5547 | step over both @code{foo} and @code{boring}! | |
5548 | ||
5549 | One solution is to @code{step} into @code{boring} and use the @code{finish} | |
5550 | command to immediately exit it. But this can become tedious if @code{boring} | |
5551 | is called from many places. | |
5552 | ||
5553 | A more flexible solution is to execute @kbd{skip boring}. This instructs | |
5554 | @value{GDBN} never to step into @code{boring}. Now when you execute | |
5555 | @code{step} at line 103, you'll step over @code{boring} and directly into | |
5556 | @code{foo}. | |
5557 | ||
5558 | You can also instruct @value{GDBN} to skip all functions in a file, with, for | |
5559 | example, @code{skip file boring.c}. | |
5560 | ||
5561 | @table @code | |
5562 | @kindex skip function | |
5563 | @item skip @r{[}@var{linespec}@r{]} | |
5564 | @itemx skip function @r{[}@var{linespec}@r{]} | |
5565 | After running this command, the function named by @var{linespec} or the | |
5566 | function containing the line named by @var{linespec} will be skipped over when | |
983fb131 | 5567 | stepping. @xref{Specify Location}. |
1bfeeb0f JL |
5568 | |
5569 | If you do not specify @var{linespec}, the function you're currently debugging | |
5570 | will be skipped. | |
5571 | ||
5572 | (If you have a function called @code{file} that you want to skip, use | |
5573 | @kbd{skip function file}.) | |
5574 | ||
5575 | @kindex skip file | |
5576 | @item skip file @r{[}@var{filename}@r{]} | |
5577 | After running this command, any function whose source lives in @var{filename} | |
5578 | will be skipped over when stepping. | |
5579 | ||
5580 | If you do not specify @var{filename}, functions whose source lives in the file | |
5581 | you're currently debugging will be skipped. | |
5582 | @end table | |
5583 | ||
5584 | Skips can be listed, deleted, disabled, and enabled, much like breakpoints. | |
5585 | These are the commands for managing your list of skips: | |
5586 | ||
5587 | @table @code | |
5588 | @kindex info skip | |
5589 | @item info skip @r{[}@var{range}@r{]} | |
5590 | Print details about the specified skip(s). If @var{range} is not specified, | |
5591 | print a table with details about all functions and files marked for skipping. | |
5592 | @code{info skip} prints the following information about each skip: | |
5593 | ||
5594 | @table @emph | |
5595 | @item Identifier | |
5596 | A number identifying this skip. | |
5597 | @item Type | |
5598 | The type of this skip, either @samp{function} or @samp{file}. | |
5599 | @item Enabled or Disabled | |
5600 | Enabled skips are marked with @samp{y}. Disabled skips are marked with @samp{n}. | |
5601 | @item Address | |
5602 | For function skips, this column indicates the address in memory of the function | |
5603 | being skipped. If you've set a function skip on a function which has not yet | |
5604 | been loaded, this field will contain @samp{<PENDING>}. Once a shared library | |
5605 | which has the function is loaded, @code{info skip} will show the function's | |
5606 | address here. | |
5607 | @item What | |
5608 | For file skips, this field contains the filename being skipped. For functions | |
5609 | skips, this field contains the function name and its line number in the file | |
5610 | where it is defined. | |
5611 | @end table | |
5612 | ||
5613 | @kindex skip delete | |
5614 | @item skip delete @r{[}@var{range}@r{]} | |
5615 | Delete the specified skip(s). If @var{range} is not specified, delete all | |
5616 | skips. | |
5617 | ||
5618 | @kindex skip enable | |
5619 | @item skip enable @r{[}@var{range}@r{]} | |
5620 | Enable the specified skip(s). If @var{range} is not specified, enable all | |
5621 | skips. | |
5622 | ||
5623 | @kindex skip disable | |
5624 | @item skip disable @r{[}@var{range}@r{]} | |
5625 | Disable the specified skip(s). If @var{range} is not specified, disable all | |
5626 | skips. | |
5627 | ||
5628 | @end table | |
5629 | ||
6d2ebf8b | 5630 | @node Signals |
c906108c SS |
5631 | @section Signals |
5632 | @cindex signals | |
5633 | ||
5634 | A signal is an asynchronous event that can happen in a program. The | |
5635 | operating system defines the possible kinds of signals, and gives each | |
5636 | kind a name and a number. For example, in Unix @code{SIGINT} is the | |
c8aa23ab | 5637 | signal a program gets when you type an interrupt character (often @kbd{Ctrl-c}); |
c906108c SS |
5638 | @code{SIGSEGV} is the signal a program gets from referencing a place in |
5639 | memory far away from all the areas in use; @code{SIGALRM} occurs when | |
5640 | the alarm clock timer goes off (which happens only if your program has | |
5641 | requested an alarm). | |
5642 | ||
5643 | @cindex fatal signals | |
5644 | Some signals, including @code{SIGALRM}, are a normal part of the | |
5645 | functioning of your program. Others, such as @code{SIGSEGV}, indicate | |
d4f3574e | 5646 | errors; these signals are @dfn{fatal} (they kill your program immediately) if the |
c906108c SS |
5647 | program has not specified in advance some other way to handle the signal. |
5648 | @code{SIGINT} does not indicate an error in your program, but it is normally | |
5649 | fatal so it can carry out the purpose of the interrupt: to kill the program. | |
5650 | ||
5651 | @value{GDBN} has the ability to detect any occurrence of a signal in your | |
5652 | program. You can tell @value{GDBN} in advance what to do for each kind of | |
5653 | signal. | |
5654 | ||
5655 | @cindex handling signals | |
24f93129 EZ |
5656 | Normally, @value{GDBN} is set up to let the non-erroneous signals like |
5657 | @code{SIGALRM} be silently passed to your program | |
5658 | (so as not to interfere with their role in the program's functioning) | |
c906108c SS |
5659 | but to stop your program immediately whenever an error signal happens. |
5660 | You can change these settings with the @code{handle} command. | |
5661 | ||
5662 | @table @code | |
5663 | @kindex info signals | |
09d4efe1 | 5664 | @kindex info handle |
c906108c | 5665 | @item info signals |
96a2c332 | 5666 | @itemx info handle |
c906108c SS |
5667 | Print a table of all the kinds of signals and how @value{GDBN} has been told to |
5668 | handle each one. You can use this to see the signal numbers of all | |
5669 | the defined types of signals. | |
5670 | ||
45ac1734 EZ |
5671 | @item info signals @var{sig} |
5672 | Similar, but print information only about the specified signal number. | |
5673 | ||
d4f3574e | 5674 | @code{info handle} is an alias for @code{info signals}. |
c906108c | 5675 | |
ab04a2af TT |
5676 | @item catch signal @r{[}@var{signal}@dots{} @r{|} @samp{all}@r{]} |
5677 | Set a catchpoint for the indicated signals. @xref{Set Catchpoints}, | |
5678 | for details about this command. | |
5679 | ||
c906108c | 5680 | @kindex handle |
45ac1734 | 5681 | @item handle @var{signal} @r{[}@var{keywords}@dots{}@r{]} |
697aa1b7 | 5682 | Change the way @value{GDBN} handles signal @var{signal}. The @var{signal} |
5ece1a18 | 5683 | can be the number of a signal or its name (with or without the |
24f93129 | 5684 | @samp{SIG} at the beginning); a list of signal numbers of the form |
5ece1a18 | 5685 | @samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the |
45ac1734 EZ |
5686 | known signals. Optional arguments @var{keywords}, described below, |
5687 | say what change to make. | |
c906108c SS |
5688 | @end table |
5689 | ||
5690 | @c @group | |
5691 | The keywords allowed by the @code{handle} command can be abbreviated. | |
5692 | Their full names are: | |
5693 | ||
5694 | @table @code | |
5695 | @item nostop | |
5696 | @value{GDBN} should not stop your program when this signal happens. It may | |
5697 | still print a message telling you that the signal has come in. | |
5698 | ||
5699 | @item stop | |
5700 | @value{GDBN} should stop your program when this signal happens. This implies | |
5701 | the @code{print} keyword as well. | |
5702 | ||
5703 | @item print | |
5704 | @value{GDBN} should print a message when this signal happens. | |
5705 | ||
5706 | @item noprint | |
5707 | @value{GDBN} should not mention the occurrence of the signal at all. This | |
5708 | implies the @code{nostop} keyword as well. | |
5709 | ||
5710 | @item pass | |
5ece1a18 | 5711 | @itemx noignore |
c906108c SS |
5712 | @value{GDBN} should allow your program to see this signal; your program |
5713 | can handle the signal, or else it may terminate if the signal is fatal | |
5ece1a18 | 5714 | and not handled. @code{pass} and @code{noignore} are synonyms. |
c906108c SS |
5715 | |
5716 | @item nopass | |
5ece1a18 | 5717 | @itemx ignore |
c906108c | 5718 | @value{GDBN} should not allow your program to see this signal. |
5ece1a18 | 5719 | @code{nopass} and @code{ignore} are synonyms. |
c906108c SS |
5720 | @end table |
5721 | @c @end group | |
5722 | ||
d4f3574e SS |
5723 | When a signal stops your program, the signal is not visible to the |
5724 | program until you | |
c906108c SS |
5725 | continue. Your program sees the signal then, if @code{pass} is in |
5726 | effect for the signal in question @emph{at that time}. In other words, | |
5727 | after @value{GDBN} reports a signal, you can use the @code{handle} | |
5728 | command with @code{pass} or @code{nopass} to control whether your | |
5729 | program sees that signal when you continue. | |
5730 | ||
24f93129 EZ |
5731 | The default is set to @code{nostop}, @code{noprint}, @code{pass} for |
5732 | non-erroneous signals such as @code{SIGALRM}, @code{SIGWINCH} and | |
5733 | @code{SIGCHLD}, and to @code{stop}, @code{print}, @code{pass} for the | |
5734 | erroneous signals. | |
5735 | ||
c906108c SS |
5736 | You can also use the @code{signal} command to prevent your program from |
5737 | seeing a signal, or cause it to see a signal it normally would not see, | |
5738 | or to give it any signal at any time. For example, if your program stopped | |
5739 | due to some sort of memory reference error, you might store correct | |
5740 | values into the erroneous variables and continue, hoping to see more | |
5741 | execution; but your program would probably terminate immediately as | |
5742 | a result of the fatal signal once it saw the signal. To prevent this, | |
5743 | you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your | |
79a6e687 | 5744 | Program a Signal}. |
c906108c | 5745 | |
e5f8a7cc PA |
5746 | @cindex stepping and signal handlers |
5747 | @anchor{stepping and signal handlers} | |
5748 | ||
5749 | @value{GDBN} optimizes for stepping the mainline code. If a signal | |
5750 | that has @code{handle nostop} and @code{handle pass} set arrives while | |
5751 | a stepping command (e.g., @code{stepi}, @code{step}, @code{next}) is | |
5752 | in progress, @value{GDBN} lets the signal handler run and then resumes | |
5753 | stepping the mainline code once the signal handler returns. In other | |
5754 | words, @value{GDBN} steps over the signal handler. This prevents | |
5755 | signals that you've specified as not interesting (with @code{handle | |
5756 | nostop}) from changing the focus of debugging unexpectedly. Note that | |
5757 | the signal handler itself may still hit a breakpoint, stop for another | |
5758 | signal that has @code{handle stop} in effect, or for any other event | |
5759 | that normally results in stopping the stepping command sooner. Also | |
5760 | note that @value{GDBN} still informs you that the program received a | |
5761 | signal if @code{handle print} is set. | |
5762 | ||
5763 | @anchor{stepping into signal handlers} | |
5764 | ||
5765 | If you set @code{handle pass} for a signal, and your program sets up a | |
5766 | handler for it, then issuing a stepping command, such as @code{step} | |
5767 | or @code{stepi}, when your program is stopped due to the signal will | |
5768 | step @emph{into} the signal handler (if the target supports that). | |
5769 | ||
5770 | Likewise, if you use the @code{queue-signal} command to queue a signal | |
5771 | to be delivered to the current thread when execution of the thread | |
5772 | resumes (@pxref{Signaling, ,Giving your Program a Signal}), then a | |
5773 | stepping command will step into the signal handler. | |
5774 | ||
5775 | Here's an example, using @code{stepi} to step to the first instruction | |
5776 | of @code{SIGUSR1}'s handler: | |
5777 | ||
5778 | @smallexample | |
5779 | (@value{GDBP}) handle SIGUSR1 | |
5780 | Signal Stop Print Pass to program Description | |
5781 | SIGUSR1 Yes Yes Yes User defined signal 1 | |
5782 | (@value{GDBP}) c | |
5783 | Continuing. | |
5784 | ||
5785 | Program received signal SIGUSR1, User defined signal 1. | |
5786 | main () sigusr1.c:28 | |
5787 | 28 p = 0; | |
5788 | (@value{GDBP}) si | |
5789 | sigusr1_handler () at sigusr1.c:9 | |
5790 | 9 @{ | |
5791 | @end smallexample | |
5792 | ||
5793 | The same, but using @code{queue-signal} instead of waiting for the | |
5794 | program to receive the signal first: | |
5795 | ||
5796 | @smallexample | |
5797 | (@value{GDBP}) n | |
5798 | 28 p = 0; | |
5799 | (@value{GDBP}) queue-signal SIGUSR1 | |
5800 | (@value{GDBP}) si | |
5801 | sigusr1_handler () at sigusr1.c:9 | |
5802 | 9 @{ | |
5803 | (@value{GDBP}) | |
5804 | @end smallexample | |
5805 | ||
4aa995e1 PA |
5806 | @cindex extra signal information |
5807 | @anchor{extra signal information} | |
5808 | ||
5809 | On some targets, @value{GDBN} can inspect extra signal information | |
5810 | associated with the intercepted signal, before it is actually | |
5811 | delivered to the program being debugged. This information is exported | |
5812 | by the convenience variable @code{$_siginfo}, and consists of data | |
5813 | that is passed by the kernel to the signal handler at the time of the | |
5814 | receipt of a signal. The data type of the information itself is | |
5815 | target dependent. You can see the data type using the @code{ptype | |
5816 | $_siginfo} command. On Unix systems, it typically corresponds to the | |
5817 | standard @code{siginfo_t} type, as defined in the @file{signal.h} | |
5818 | system header. | |
5819 | ||
5820 | Here's an example, on a @sc{gnu}/Linux system, printing the stray | |
5821 | referenced address that raised a segmentation fault. | |
5822 | ||
5823 | @smallexample | |
5824 | @group | |
5825 | (@value{GDBP}) continue | |
5826 | Program received signal SIGSEGV, Segmentation fault. | |
5827 | 0x0000000000400766 in main () | |
5828 | 69 *(int *)p = 0; | |
5829 | (@value{GDBP}) ptype $_siginfo | |
5830 | type = struct @{ | |
5831 | int si_signo; | |
5832 | int si_errno; | |
5833 | int si_code; | |
5834 | union @{ | |
5835 | int _pad[28]; | |
5836 | struct @{...@} _kill; | |
5837 | struct @{...@} _timer; | |
5838 | struct @{...@} _rt; | |
5839 | struct @{...@} _sigchld; | |
5840 | struct @{...@} _sigfault; | |
5841 | struct @{...@} _sigpoll; | |
5842 | @} _sifields; | |
5843 | @} | |
5844 | (@value{GDBP}) ptype $_siginfo._sifields._sigfault | |
5845 | type = struct @{ | |
5846 | void *si_addr; | |
5847 | @} | |
5848 | (@value{GDBP}) p $_siginfo._sifields._sigfault.si_addr | |
5849 | $1 = (void *) 0x7ffff7ff7000 | |
5850 | @end group | |
5851 | @end smallexample | |
5852 | ||
5853 | Depending on target support, @code{$_siginfo} may also be writable. | |
5854 | ||
6d2ebf8b | 5855 | @node Thread Stops |
79a6e687 | 5856 | @section Stopping and Starting Multi-thread Programs |
c906108c | 5857 | |
0606b73b SL |
5858 | @cindex stopped threads |
5859 | @cindex threads, stopped | |
5860 | ||
5861 | @cindex continuing threads | |
5862 | @cindex threads, continuing | |
5863 | ||
5864 | @value{GDBN} supports debugging programs with multiple threads | |
5865 | (@pxref{Threads,, Debugging Programs with Multiple Threads}). There | |
5866 | are two modes of controlling execution of your program within the | |
5867 | debugger. In the default mode, referred to as @dfn{all-stop mode}, | |
5868 | when any thread in your program stops (for example, at a breakpoint | |
5869 | or while being stepped), all other threads in the program are also stopped by | |
5870 | @value{GDBN}. On some targets, @value{GDBN} also supports | |
5871 | @dfn{non-stop mode}, in which other threads can continue to run freely while | |
5872 | you examine the stopped thread in the debugger. | |
5873 | ||
5874 | @menu | |
5875 | * All-Stop Mode:: All threads stop when GDB takes control | |
5876 | * Non-Stop Mode:: Other threads continue to execute | |
5877 | * Background Execution:: Running your program asynchronously | |
5878 | * Thread-Specific Breakpoints:: Controlling breakpoints | |
5879 | * Interrupted System Calls:: GDB may interfere with system calls | |
d914c394 | 5880 | * Observer Mode:: GDB does not alter program behavior |
0606b73b SL |
5881 | @end menu |
5882 | ||
5883 | @node All-Stop Mode | |
5884 | @subsection All-Stop Mode | |
5885 | ||
5886 | @cindex all-stop mode | |
5887 | ||
5888 | In all-stop mode, whenever your program stops under @value{GDBN} for any reason, | |
5889 | @emph{all} threads of execution stop, not just the current thread. This | |
5890 | allows you to examine the overall state of the program, including | |
5891 | switching between threads, without worrying that things may change | |
5892 | underfoot. | |
5893 | ||
5894 | Conversely, whenever you restart the program, @emph{all} threads start | |
5895 | executing. @emph{This is true even when single-stepping} with commands | |
5896 | like @code{step} or @code{next}. | |
5897 | ||
5898 | In particular, @value{GDBN} cannot single-step all threads in lockstep. | |
5899 | Since thread scheduling is up to your debugging target's operating | |
5900 | system (not controlled by @value{GDBN}), other threads may | |
5901 | execute more than one statement while the current thread completes a | |
5902 | single step. Moreover, in general other threads stop in the middle of a | |
5903 | statement, rather than at a clean statement boundary, when the program | |
5904 | stops. | |
5905 | ||
5906 | You might even find your program stopped in another thread after | |
5907 | continuing or even single-stepping. This happens whenever some other | |
5908 | thread runs into a breakpoint, a signal, or an exception before the | |
5909 | first thread completes whatever you requested. | |
5910 | ||
5911 | @cindex automatic thread selection | |
5912 | @cindex switching threads automatically | |
5913 | @cindex threads, automatic switching | |
5914 | Whenever @value{GDBN} stops your program, due to a breakpoint or a | |
5915 | signal, it automatically selects the thread where that breakpoint or | |
5916 | signal happened. @value{GDBN} alerts you to the context switch with a | |
5917 | message such as @samp{[Switching to Thread @var{n}]} to identify the | |
5918 | thread. | |
5919 | ||
5920 | On some OSes, you can modify @value{GDBN}'s default behavior by | |
5921 | locking the OS scheduler to allow only a single thread to run. | |
5922 | ||
5923 | @table @code | |
5924 | @item set scheduler-locking @var{mode} | |
5925 | @cindex scheduler locking mode | |
5926 | @cindex lock scheduler | |
f2665db5 MM |
5927 | Set the scheduler locking mode. It applies to normal execution, |
5928 | record mode, and replay mode. If it is @code{off}, then there is no | |
5929 | locking and any thread may run at any time. If @code{on}, then only | |
5930 | the current thread may run when the inferior is resumed. The | |
5931 | @code{step} mode optimizes for single-stepping; it prevents other | |
5932 | threads from preempting the current thread while you are stepping, so | |
5933 | that the focus of debugging does not change unexpectedly. Other | |
5934 | threads never get a chance to run when you step, and they are | |
5935 | completely free to run when you use commands like @samp{continue}, | |
5936 | @samp{until}, or @samp{finish}. However, unless another thread hits a | |
5937 | breakpoint during its timeslice, @value{GDBN} does not change the | |
5938 | current thread away from the thread that you are debugging. The | |
5939 | @code{replay} mode behaves like @code{off} in record mode and like | |
5940 | @code{on} in replay mode. | |
0606b73b SL |
5941 | |
5942 | @item show scheduler-locking | |
5943 | Display the current scheduler locking mode. | |
5944 | @end table | |
5945 | ||
d4db2f36 PA |
5946 | @cindex resume threads of multiple processes simultaneously |
5947 | By default, when you issue one of the execution commands such as | |
5948 | @code{continue}, @code{next} or @code{step}, @value{GDBN} allows only | |
5949 | threads of the current inferior to run. For example, if @value{GDBN} | |
5950 | is attached to two inferiors, each with two threads, the | |
5951 | @code{continue} command resumes only the two threads of the current | |
5952 | inferior. This is useful, for example, when you debug a program that | |
5953 | forks and you want to hold the parent stopped (so that, for instance, | |
5954 | it doesn't run to exit), while you debug the child. In other | |
5955 | situations, you may not be interested in inspecting the current state | |
5956 | of any of the processes @value{GDBN} is attached to, and you may want | |
5957 | to resume them all until some breakpoint is hit. In the latter case, | |
5958 | you can instruct @value{GDBN} to allow all threads of all the | |
5959 | inferiors to run with the @w{@code{set schedule-multiple}} command. | |
5960 | ||
5961 | @table @code | |
5962 | @kindex set schedule-multiple | |
5963 | @item set schedule-multiple | |
5964 | Set the mode for allowing threads of multiple processes to be resumed | |
5965 | when an execution command is issued. When @code{on}, all threads of | |
5966 | all processes are allowed to run. When @code{off}, only the threads | |
5967 | of the current process are resumed. The default is @code{off}. The | |
5968 | @code{scheduler-locking} mode takes precedence when set to @code{on}, | |
5969 | or while you are stepping and set to @code{step}. | |
5970 | ||
5971 | @item show schedule-multiple | |
5972 | Display the current mode for resuming the execution of threads of | |
5973 | multiple processes. | |
5974 | @end table | |
5975 | ||
0606b73b SL |
5976 | @node Non-Stop Mode |
5977 | @subsection Non-Stop Mode | |
5978 | ||
5979 | @cindex non-stop mode | |
5980 | ||
5981 | @c This section is really only a place-holder, and needs to be expanded | |
97d8f0ee | 5982 | @c with more details. |
0606b73b SL |
5983 | |
5984 | For some multi-threaded targets, @value{GDBN} supports an optional | |
5985 | mode of operation in which you can examine stopped program threads in | |
5986 | the debugger while other threads continue to execute freely. This | |
97d8f0ee DE |
5987 | minimizes intrusion when debugging live systems, such as programs |
5988 | where some threads have real-time constraints or must continue to | |
0606b73b SL |
5989 | respond to external events. This is referred to as @dfn{non-stop} mode. |
5990 | ||
5991 | In non-stop mode, when a thread stops to report a debugging event, | |
5992 | @emph{only} that thread is stopped; @value{GDBN} does not stop other | |
5993 | threads as well, in contrast to the all-stop mode behavior. Additionally, | |
5994 | execution commands such as @code{continue} and @code{step} apply by default | |
5995 | only to the current thread in non-stop mode, rather than all threads as | |
5996 | in all-stop mode. This allows you to control threads explicitly in | |
97d8f0ee | 5997 | ways that are not possible in all-stop mode --- for example, stepping |
0606b73b | 5998 | one thread while allowing others to run freely, stepping |
97d8f0ee | 5999 | one thread while holding all others stopped, or stepping several threads |
0606b73b SL |
6000 | independently and simultaneously. |
6001 | ||
6002 | To enter non-stop mode, use this sequence of commands before you run | |
6003 | or attach to your program: | |
6004 | ||
0606b73b | 6005 | @smallexample |
0606b73b SL |
6006 | # If using the CLI, pagination breaks non-stop. |
6007 | set pagination off | |
6008 | ||
6009 | # Finally, turn it on! | |
6010 | set non-stop on | |
6011 | @end smallexample | |
6012 | ||
6013 | You can use these commands to manipulate the non-stop mode setting: | |
6014 | ||
6015 | @table @code | |
6016 | @kindex set non-stop | |
6017 | @item set non-stop on | |
6018 | Enable selection of non-stop mode. | |
6019 | @item set non-stop off | |
6020 | Disable selection of non-stop mode. | |
6021 | @kindex show non-stop | |
6022 | @item show non-stop | |
6023 | Show the current non-stop enablement setting. | |
6024 | @end table | |
6025 | ||
6026 | Note these commands only reflect whether non-stop mode is enabled, | |
97d8f0ee | 6027 | not whether the currently-executing program is being run in non-stop mode. |
0606b73b | 6028 | In particular, the @code{set non-stop} preference is only consulted when |
97d8f0ee | 6029 | @value{GDBN} starts or connects to the target program, and it is generally |
0606b73b SL |
6030 | not possible to switch modes once debugging has started. Furthermore, |
6031 | since not all targets support non-stop mode, even when you have enabled | |
6032 | non-stop mode, @value{GDBN} may still fall back to all-stop operation by | |
6033 | default. | |
6034 | ||
6035 | In non-stop mode, all execution commands apply only to the current thread | |
97d8f0ee | 6036 | by default. That is, @code{continue} only continues one thread. |
0606b73b SL |
6037 | To continue all threads, issue @code{continue -a} or @code{c -a}. |
6038 | ||
97d8f0ee | 6039 | You can use @value{GDBN}'s background execution commands |
0606b73b | 6040 | (@pxref{Background Execution}) to run some threads in the background |
97d8f0ee | 6041 | while you continue to examine or step others from @value{GDBN}. |
0606b73b SL |
6042 | The MI execution commands (@pxref{GDB/MI Program Execution}) are |
6043 | always executed asynchronously in non-stop mode. | |
6044 | ||
6045 | Suspending execution is done with the @code{interrupt} command when | |
97d8f0ee DE |
6046 | running in the background, or @kbd{Ctrl-c} during foreground execution. |
6047 | In all-stop mode, this stops the whole process; | |
6048 | but in non-stop mode the interrupt applies only to the current thread. | |
0606b73b SL |
6049 | To stop the whole program, use @code{interrupt -a}. |
6050 | ||
6051 | Other execution commands do not currently support the @code{-a} option. | |
6052 | ||
6053 | In non-stop mode, when a thread stops, @value{GDBN} doesn't automatically make | |
6054 | that thread current, as it does in all-stop mode. This is because the | |
97d8f0ee | 6055 | thread stop notifications are asynchronous with respect to @value{GDBN}'s |
0606b73b SL |
6056 | command interpreter, and it would be confusing if @value{GDBN} unexpectedly |
6057 | changed to a different thread just as you entered a command to operate on the | |
6058 | previously current thread. | |
6059 | ||
6060 | @node Background Execution | |
6061 | @subsection Background Execution | |
6062 | ||
6063 | @cindex foreground execution | |
6064 | @cindex background execution | |
6065 | @cindex asynchronous execution | |
6066 | @cindex execution, foreground, background and asynchronous | |
6067 | ||
6068 | @value{GDBN}'s execution commands have two variants: the normal | |
6069 | foreground (synchronous) behavior, and a background | |
97d8f0ee | 6070 | (asynchronous) behavior. In foreground execution, @value{GDBN} waits for |
0606b73b SL |
6071 | the program to report that some thread has stopped before prompting for |
6072 | another command. In background execution, @value{GDBN} immediately gives | |
6073 | a command prompt so that you can issue other commands while your program runs. | |
6074 | ||
32fc0df9 PA |
6075 | If the target doesn't support async mode, @value{GDBN} issues an error |
6076 | message if you attempt to use the background execution commands. | |
6077 | ||
0606b73b SL |
6078 | To specify background execution, add a @code{&} to the command. For example, |
6079 | the background form of the @code{continue} command is @code{continue&}, or | |
6080 | just @code{c&}. The execution commands that accept background execution | |
6081 | are: | |
6082 | ||
6083 | @table @code | |
6084 | @kindex run& | |
6085 | @item run | |
6086 | @xref{Starting, , Starting your Program}. | |
6087 | ||
6088 | @item attach | |
6089 | @kindex attach& | |
6090 | @xref{Attach, , Debugging an Already-running Process}. | |
6091 | ||
6092 | @item step | |
6093 | @kindex step& | |
6094 | @xref{Continuing and Stepping, step}. | |
6095 | ||
6096 | @item stepi | |
6097 | @kindex stepi& | |
6098 | @xref{Continuing and Stepping, stepi}. | |
6099 | ||
6100 | @item next | |
6101 | @kindex next& | |
6102 | @xref{Continuing and Stepping, next}. | |
6103 | ||
7ce58dd2 DE |
6104 | @item nexti |
6105 | @kindex nexti& | |
6106 | @xref{Continuing and Stepping, nexti}. | |
6107 | ||
0606b73b SL |
6108 | @item continue |
6109 | @kindex continue& | |
6110 | @xref{Continuing and Stepping, continue}. | |
6111 | ||
6112 | @item finish | |
6113 | @kindex finish& | |
6114 | @xref{Continuing and Stepping, finish}. | |
6115 | ||
6116 | @item until | |
6117 | @kindex until& | |
6118 | @xref{Continuing and Stepping, until}. | |
6119 | ||
6120 | @end table | |
6121 | ||
6122 | Background execution is especially useful in conjunction with non-stop | |
6123 | mode for debugging programs with multiple threads; see @ref{Non-Stop Mode}. | |
6124 | However, you can also use these commands in the normal all-stop mode with | |
6125 | the restriction that you cannot issue another execution command until the | |
6126 | previous one finishes. Examples of commands that are valid in all-stop | |
6127 | mode while the program is running include @code{help} and @code{info break}. | |
6128 | ||
6129 | You can interrupt your program while it is running in the background by | |
6130 | using the @code{interrupt} command. | |
6131 | ||
6132 | @table @code | |
6133 | @kindex interrupt | |
6134 | @item interrupt | |
6135 | @itemx interrupt -a | |
6136 | ||
97d8f0ee | 6137 | Suspend execution of the running program. In all-stop mode, |
0606b73b | 6138 | @code{interrupt} stops the whole process, but in non-stop mode, it stops |
97d8f0ee | 6139 | only the current thread. To stop the whole program in non-stop mode, |
0606b73b SL |
6140 | use @code{interrupt -a}. |
6141 | @end table | |
6142 | ||
0606b73b SL |
6143 | @node Thread-Specific Breakpoints |
6144 | @subsection Thread-Specific Breakpoints | |
6145 | ||
c906108c | 6146 | When your program has multiple threads (@pxref{Threads,, Debugging |
79a6e687 | 6147 | Programs with Multiple Threads}), you can choose whether to set |
c906108c SS |
6148 | breakpoints on all threads, or on a particular thread. |
6149 | ||
6150 | @table @code | |
6151 | @cindex breakpoints and threads | |
6152 | @cindex thread breakpoints | |
5d5658a1 PA |
6153 | @kindex break @dots{} thread @var{thread-id} |
6154 | @item break @var{location} thread @var{thread-id} | |
6155 | @itemx break @var{location} thread @var{thread-id} if @dots{} | |
629500fa | 6156 | @var{location} specifies source lines; there are several ways of |
2a25a5ba EZ |
6157 | writing them (@pxref{Specify Location}), but the effect is always to |
6158 | specify some source line. | |
c906108c | 6159 | |
5d5658a1 | 6160 | Use the qualifier @samp{thread @var{thread-id}} with a breakpoint command |
c906108c | 6161 | to specify that you only want @value{GDBN} to stop the program when a |
5d5658a1 PA |
6162 | particular thread reaches this breakpoint. The @var{thread-id} specifier |
6163 | is one of the thread identifiers assigned by @value{GDBN}, shown | |
697aa1b7 | 6164 | in the first column of the @samp{info threads} display. |
c906108c | 6165 | |
5d5658a1 | 6166 | If you do not specify @samp{thread @var{thread-id}} when you set a |
c906108c SS |
6167 | breakpoint, the breakpoint applies to @emph{all} threads of your |
6168 | program. | |
6169 | ||
6170 | You can use the @code{thread} qualifier on conditional breakpoints as | |
5d5658a1 | 6171 | well; in this case, place @samp{thread @var{thread-id}} before or |
b6199126 | 6172 | after the breakpoint condition, like this: |
c906108c SS |
6173 | |
6174 | @smallexample | |
2df3850c | 6175 | (@value{GDBP}) break frik.c:13 thread 28 if bartab > lim |
c906108c SS |
6176 | @end smallexample |
6177 | ||
6178 | @end table | |
6179 | ||
f4fb82a1 PA |
6180 | Thread-specific breakpoints are automatically deleted when |
6181 | @value{GDBN} detects the corresponding thread is no longer in the | |
6182 | thread list. For example: | |
6183 | ||
6184 | @smallexample | |
6185 | (@value{GDBP}) c | |
6186 | Thread-specific breakpoint 3 deleted - thread 28 no longer in the thread list. | |
6187 | @end smallexample | |
6188 | ||
6189 | There are several ways for a thread to disappear, such as a regular | |
6190 | thread exit, but also when you detach from the process with the | |
6191 | @code{detach} command (@pxref{Attach, ,Debugging an Already-running | |
6192 | Process}), or if @value{GDBN} loses the remote connection | |
6193 | (@pxref{Remote Debugging}), etc. Note that with some targets, | |
6194 | @value{GDBN} is only able to detect a thread has exited when the user | |
6195 | explictly asks for the thread list with the @code{info threads} | |
6196 | command. | |
6197 | ||
0606b73b SL |
6198 | @node Interrupted System Calls |
6199 | @subsection Interrupted System Calls | |
c906108c | 6200 | |
36d86913 MC |
6201 | @cindex thread breakpoints and system calls |
6202 | @cindex system calls and thread breakpoints | |
6203 | @cindex premature return from system calls | |
0606b73b SL |
6204 | There is an unfortunate side effect when using @value{GDBN} to debug |
6205 | multi-threaded programs. If one thread stops for a | |
36d86913 MC |
6206 | breakpoint, or for some other reason, and another thread is blocked in a |
6207 | system call, then the system call may return prematurely. This is a | |
6208 | consequence of the interaction between multiple threads and the signals | |
6209 | that @value{GDBN} uses to implement breakpoints and other events that | |
6210 | stop execution. | |
6211 | ||
6212 | To handle this problem, your program should check the return value of | |
6213 | each system call and react appropriately. This is good programming | |
6214 | style anyways. | |
6215 | ||
6216 | For example, do not write code like this: | |
6217 | ||
6218 | @smallexample | |
6219 | sleep (10); | |
6220 | @end smallexample | |
6221 | ||
6222 | The call to @code{sleep} will return early if a different thread stops | |
6223 | at a breakpoint or for some other reason. | |
6224 | ||
6225 | Instead, write this: | |
6226 | ||
6227 | @smallexample | |
6228 | int unslept = 10; | |
6229 | while (unslept > 0) | |
6230 | unslept = sleep (unslept); | |
6231 | @end smallexample | |
6232 | ||
6233 | A system call is allowed to return early, so the system is still | |
6234 | conforming to its specification. But @value{GDBN} does cause your | |
6235 | multi-threaded program to behave differently than it would without | |
6236 | @value{GDBN}. | |
6237 | ||
6238 | Also, @value{GDBN} uses internal breakpoints in the thread library to | |
6239 | monitor certain events such as thread creation and thread destruction. | |
6240 | When such an event happens, a system call in another thread may return | |
6241 | prematurely, even though your program does not appear to stop. | |
6242 | ||
d914c394 SS |
6243 | @node Observer Mode |
6244 | @subsection Observer Mode | |
6245 | ||
6246 | If you want to build on non-stop mode and observe program behavior | |
6247 | without any chance of disruption by @value{GDBN}, you can set | |
6248 | variables to disable all of the debugger's attempts to modify state, | |
6249 | whether by writing memory, inserting breakpoints, etc. These operate | |
6250 | at a low level, intercepting operations from all commands. | |
6251 | ||
6252 | When all of these are set to @code{off}, then @value{GDBN} is said to | |
6253 | be @dfn{observer mode}. As a convenience, the variable | |
6254 | @code{observer} can be set to disable these, plus enable non-stop | |
6255 | mode. | |
6256 | ||
6257 | Note that @value{GDBN} will not prevent you from making nonsensical | |
6258 | combinations of these settings. For instance, if you have enabled | |
6259 | @code{may-insert-breakpoints} but disabled @code{may-write-memory}, | |
6260 | then breakpoints that work by writing trap instructions into the code | |
6261 | stream will still not be able to be placed. | |
6262 | ||
6263 | @table @code | |
6264 | ||
6265 | @kindex observer | |
6266 | @item set observer on | |
6267 | @itemx set observer off | |
6268 | When set to @code{on}, this disables all the permission variables | |
6269 | below (except for @code{insert-fast-tracepoints}), plus enables | |
6270 | non-stop debugging. Setting this to @code{off} switches back to | |
6271 | normal debugging, though remaining in non-stop mode. | |
6272 | ||
6273 | @item show observer | |
6274 | Show whether observer mode is on or off. | |
6275 | ||
6276 | @kindex may-write-registers | |
6277 | @item set may-write-registers on | |
6278 | @itemx set may-write-registers off | |
6279 | This controls whether @value{GDBN} will attempt to alter the values of | |
6280 | registers, such as with assignment expressions in @code{print}, or the | |
6281 | @code{jump} command. It defaults to @code{on}. | |
6282 | ||
6283 | @item show may-write-registers | |
6284 | Show the current permission to write registers. | |
6285 | ||
6286 | @kindex may-write-memory | |
6287 | @item set may-write-memory on | |
6288 | @itemx set may-write-memory off | |
6289 | This controls whether @value{GDBN} will attempt to alter the contents | |
6290 | of memory, such as with assignment expressions in @code{print}. It | |
6291 | defaults to @code{on}. | |
6292 | ||
6293 | @item show may-write-memory | |
6294 | Show the current permission to write memory. | |
6295 | ||
6296 | @kindex may-insert-breakpoints | |
6297 | @item set may-insert-breakpoints on | |
6298 | @itemx set may-insert-breakpoints off | |
6299 | This controls whether @value{GDBN} will attempt to insert breakpoints. | |
6300 | This affects all breakpoints, including internal breakpoints defined | |
6301 | by @value{GDBN}. It defaults to @code{on}. | |
6302 | ||
6303 | @item show may-insert-breakpoints | |
6304 | Show the current permission to insert breakpoints. | |
6305 | ||
6306 | @kindex may-insert-tracepoints | |
6307 | @item set may-insert-tracepoints on | |
6308 | @itemx set may-insert-tracepoints off | |
6309 | This controls whether @value{GDBN} will attempt to insert (regular) | |
6310 | tracepoints at the beginning of a tracing experiment. It affects only | |
6311 | non-fast tracepoints, fast tracepoints being under the control of | |
6312 | @code{may-insert-fast-tracepoints}. It defaults to @code{on}. | |
6313 | ||
6314 | @item show may-insert-tracepoints | |
6315 | Show the current permission to insert tracepoints. | |
6316 | ||
6317 | @kindex may-insert-fast-tracepoints | |
6318 | @item set may-insert-fast-tracepoints on | |
6319 | @itemx set may-insert-fast-tracepoints off | |
6320 | This controls whether @value{GDBN} will attempt to insert fast | |
6321 | tracepoints at the beginning of a tracing experiment. It affects only | |
6322 | fast tracepoints, regular (non-fast) tracepoints being under the | |
6323 | control of @code{may-insert-tracepoints}. It defaults to @code{on}. | |
6324 | ||
6325 | @item show may-insert-fast-tracepoints | |
6326 | Show the current permission to insert fast tracepoints. | |
6327 | ||
6328 | @kindex may-interrupt | |
6329 | @item set may-interrupt on | |
6330 | @itemx set may-interrupt off | |
6331 | This controls whether @value{GDBN} will attempt to interrupt or stop | |
6332 | program execution. When this variable is @code{off}, the | |
6333 | @code{interrupt} command will have no effect, nor will | |
6334 | @kbd{Ctrl-c}. It defaults to @code{on}. | |
6335 | ||
6336 | @item show may-interrupt | |
6337 | Show the current permission to interrupt or stop the program. | |
6338 | ||
6339 | @end table | |
c906108c | 6340 | |
bacec72f MS |
6341 | @node Reverse Execution |
6342 | @chapter Running programs backward | |
6343 | @cindex reverse execution | |
6344 | @cindex running programs backward | |
6345 | ||
6346 | When you are debugging a program, it is not unusual to realize that | |
6347 | you have gone too far, and some event of interest has already happened. | |
6348 | If the target environment supports it, @value{GDBN} can allow you to | |
6349 | ``rewind'' the program by running it backward. | |
6350 | ||
6351 | A target environment that supports reverse execution should be able | |
6352 | to ``undo'' the changes in machine state that have taken place as the | |
6353 | program was executing normally. Variables, registers etc.@: should | |
6354 | revert to their previous values. Obviously this requires a great | |
6355 | deal of sophistication on the part of the target environment; not | |
6356 | all target environments can support reverse execution. | |
6357 | ||
6358 | When a program is executed in reverse, the instructions that | |
6359 | have most recently been executed are ``un-executed'', in reverse | |
6360 | order. The program counter runs backward, following the previous | |
6361 | thread of execution in reverse. As each instruction is ``un-executed'', | |
6362 | the values of memory and/or registers that were changed by that | |
6363 | instruction are reverted to their previous states. After executing | |
6364 | a piece of source code in reverse, all side effects of that code | |
6365 | should be ``undone'', and all variables should be returned to their | |
6366 | prior values@footnote{ | |
6367 | Note that some side effects are easier to undo than others. For instance, | |
6368 | memory and registers are relatively easy, but device I/O is hard. Some | |
6369 | targets may be able undo things like device I/O, and some may not. | |
6370 | ||
6371 | The contract between @value{GDBN} and the reverse executing target | |
6372 | requires only that the target do something reasonable when | |
6373 | @value{GDBN} tells it to execute backwards, and then report the | |
6374 | results back to @value{GDBN}. Whatever the target reports back to | |
6375 | @value{GDBN}, @value{GDBN} will report back to the user. @value{GDBN} | |
6376 | assumes that the memory and registers that the target reports are in a | |
6377 | consistant state, but @value{GDBN} accepts whatever it is given. | |
6378 | }. | |
6379 | ||
6380 | If you are debugging in a target environment that supports | |
6381 | reverse execution, @value{GDBN} provides the following commands. | |
6382 | ||
6383 | @table @code | |
6384 | @kindex reverse-continue | |
6385 | @kindex rc @r{(@code{reverse-continue})} | |
6386 | @item reverse-continue @r{[}@var{ignore-count}@r{]} | |
6387 | @itemx rc @r{[}@var{ignore-count}@r{]} | |
6388 | Beginning at the point where your program last stopped, start executing | |
6389 | in reverse. Reverse execution will stop for breakpoints and synchronous | |
6390 | exceptions (signals), just like normal execution. Behavior of | |
6391 | asynchronous signals depends on the target environment. | |
6392 | ||
6393 | @kindex reverse-step | |
6394 | @kindex rs @r{(@code{step})} | |
6395 | @item reverse-step @r{[}@var{count}@r{]} | |
6396 | Run the program backward until control reaches the start of a | |
6397 | different source line; then stop it, and return control to @value{GDBN}. | |
6398 | ||
6399 | Like the @code{step} command, @code{reverse-step} will only stop | |
6400 | at the beginning of a source line. It ``un-executes'' the previously | |
6401 | executed source line. If the previous source line included calls to | |
6402 | debuggable functions, @code{reverse-step} will step (backward) into | |
6403 | the called function, stopping at the beginning of the @emph{last} | |
6404 | statement in the called function (typically a return statement). | |
6405 | ||
6406 | Also, as with the @code{step} command, if non-debuggable functions are | |
6407 | called, @code{reverse-step} will run thru them backward without stopping. | |
6408 | ||
6409 | @kindex reverse-stepi | |
6410 | @kindex rsi @r{(@code{reverse-stepi})} | |
6411 | @item reverse-stepi @r{[}@var{count}@r{]} | |
6412 | Reverse-execute one machine instruction. Note that the instruction | |
6413 | to be reverse-executed is @emph{not} the one pointed to by the program | |
6414 | counter, but the instruction executed prior to that one. For instance, | |
6415 | if the last instruction was a jump, @code{reverse-stepi} will take you | |
6416 | back from the destination of the jump to the jump instruction itself. | |
6417 | ||
6418 | @kindex reverse-next | |
6419 | @kindex rn @r{(@code{reverse-next})} | |
6420 | @item reverse-next @r{[}@var{count}@r{]} | |
6421 | Run backward to the beginning of the previous line executed in | |
6422 | the current (innermost) stack frame. If the line contains function | |
6423 | calls, they will be ``un-executed'' without stopping. Starting from | |
6424 | the first line of a function, @code{reverse-next} will take you back | |
6425 | to the caller of that function, @emph{before} the function was called, | |
6426 | just as the normal @code{next} command would take you from the last | |
6427 | line of a function back to its return to its caller | |
16af530a | 6428 | @footnote{Unless the code is too heavily optimized.}. |
bacec72f MS |
6429 | |
6430 | @kindex reverse-nexti | |
6431 | @kindex rni @r{(@code{reverse-nexti})} | |
6432 | @item reverse-nexti @r{[}@var{count}@r{]} | |
6433 | Like @code{nexti}, @code{reverse-nexti} executes a single instruction | |
6434 | in reverse, except that called functions are ``un-executed'' atomically. | |
6435 | That is, if the previously executed instruction was a return from | |
540aa8e7 | 6436 | another function, @code{reverse-nexti} will continue to execute |
bacec72f MS |
6437 | in reverse until the call to that function (from the current stack |
6438 | frame) is reached. | |
6439 | ||
6440 | @kindex reverse-finish | |
6441 | @item reverse-finish | |
6442 | Just as the @code{finish} command takes you to the point where the | |
6443 | current function returns, @code{reverse-finish} takes you to the point | |
6444 | where it was called. Instead of ending up at the end of the current | |
6445 | function invocation, you end up at the beginning. | |
6446 | ||
6447 | @kindex set exec-direction | |
6448 | @item set exec-direction | |
6449 | Set the direction of target execution. | |
984359d2 | 6450 | @item set exec-direction reverse |
bacec72f MS |
6451 | @cindex execute forward or backward in time |
6452 | @value{GDBN} will perform all execution commands in reverse, until the | |
6453 | exec-direction mode is changed to ``forward''. Affected commands include | |
6454 | @code{step, stepi, next, nexti, continue, and finish}. The @code{return} | |
6455 | command cannot be used in reverse mode. | |
6456 | @item set exec-direction forward | |
6457 | @value{GDBN} will perform all execution commands in the normal fashion. | |
6458 | This is the default. | |
6459 | @end table | |
6460 | ||
c906108c | 6461 | |
a2311334 EZ |
6462 | @node Process Record and Replay |
6463 | @chapter Recording Inferior's Execution and Replaying It | |
53cc454a HZ |
6464 | @cindex process record and replay |
6465 | @cindex recording inferior's execution and replaying it | |
6466 | ||
8e05493c EZ |
6467 | On some platforms, @value{GDBN} provides a special @dfn{process record |
6468 | and replay} target that can record a log of the process execution, and | |
6469 | replay it later with both forward and reverse execution commands. | |
a2311334 EZ |
6470 | |
6471 | @cindex replay mode | |
6472 | When this target is in use, if the execution log includes the record | |
6473 | for the next instruction, @value{GDBN} will debug in @dfn{replay | |
6474 | mode}. In the replay mode, the inferior does not really execute code | |
6475 | instructions. Instead, all the events that normally happen during | |
6476 | code execution are taken from the execution log. While code is not | |
6477 | really executed in replay mode, the values of registers (including the | |
6478 | program counter register) and the memory of the inferior are still | |
8e05493c EZ |
6479 | changed as they normally would. Their contents are taken from the |
6480 | execution log. | |
a2311334 EZ |
6481 | |
6482 | @cindex record mode | |
6483 | If the record for the next instruction is not in the execution log, | |
6484 | @value{GDBN} will debug in @dfn{record mode}. In this mode, the | |
6485 | inferior executes normally, and @value{GDBN} records the execution log | |
6486 | for future replay. | |
6487 | ||
8e05493c EZ |
6488 | The process record and replay target supports reverse execution |
6489 | (@pxref{Reverse Execution}), even if the platform on which the | |
6490 | inferior runs does not. However, the reverse execution is limited in | |
6491 | this case by the range of the instructions recorded in the execution | |
6492 | log. In other words, reverse execution on platforms that don't | |
6493 | support it directly can only be done in the replay mode. | |
6494 | ||
6495 | When debugging in the reverse direction, @value{GDBN} will work in | |
6496 | replay mode as long as the execution log includes the record for the | |
6497 | previous instruction; otherwise, it will work in record mode, if the | |
6498 | platform supports reverse execution, or stop if not. | |
6499 | ||
a2311334 EZ |
6500 | For architecture environments that support process record and replay, |
6501 | @value{GDBN} provides the following commands: | |
53cc454a HZ |
6502 | |
6503 | @table @code | |
6504 | @kindex target record | |
59ea5688 MM |
6505 | @kindex target record-full |
6506 | @kindex target record-btrace | |
53cc454a | 6507 | @kindex record |
59ea5688 MM |
6508 | @kindex record full |
6509 | @kindex record btrace | |
f4abbc16 | 6510 | @kindex record btrace bts |
b20a6524 | 6511 | @kindex record btrace pt |
f4abbc16 | 6512 | @kindex record bts |
b20a6524 | 6513 | @kindex record pt |
53cc454a | 6514 | @kindex rec |
59ea5688 MM |
6515 | @kindex rec full |
6516 | @kindex rec btrace | |
f4abbc16 | 6517 | @kindex rec btrace bts |
b20a6524 | 6518 | @kindex rec btrace pt |
f4abbc16 | 6519 | @kindex rec bts |
b20a6524 | 6520 | @kindex rec pt |
59ea5688 MM |
6521 | @item record @var{method} |
6522 | This command starts the process record and replay target. The | |
6523 | recording method can be specified as parameter. Without a parameter | |
6524 | the command uses the @code{full} recording method. The following | |
6525 | recording methods are available: | |
a2311334 | 6526 | |
59ea5688 MM |
6527 | @table @code |
6528 | @item full | |
6529 | Full record/replay recording using @value{GDBN}'s software record and | |
6530 | replay implementation. This method allows replaying and reverse | |
6531 | execution. | |
6532 | ||
f4abbc16 | 6533 | @item btrace @var{format} |
52834460 MM |
6534 | Hardware-supported instruction recording. This method does not record |
6535 | data. Further, the data is collected in a ring buffer so old data will | |
b20a6524 MM |
6536 | be overwritten when the buffer is full. It allows limited reverse |
6537 | execution. Variables and registers are not available during reverse | |
6538 | execution. | |
59ea5688 | 6539 | |
f4abbc16 MM |
6540 | The recording format can be specified as parameter. Without a parameter |
6541 | the command chooses the recording format. The following recording | |
6542 | formats are available: | |
6543 | ||
6544 | @table @code | |
6545 | @item bts | |
6546 | @cindex branch trace store | |
6547 | Use the @dfn{Branch Trace Store} (@acronym{BTS}) recording format. In | |
6548 | this format, the processor stores a from/to record for each executed | |
6549 | branch in the btrace ring buffer. | |
b20a6524 MM |
6550 | |
6551 | @item pt | |
bc504a31 PA |
6552 | @cindex Intel Processor Trace |
6553 | Use the @dfn{Intel Processor Trace} recording format. In this | |
b20a6524 MM |
6554 | format, the processor stores the execution trace in a compressed form |
6555 | that is afterwards decoded by @value{GDBN}. | |
6556 | ||
6557 | The trace can be recorded with very low overhead. The compressed | |
6558 | trace format also allows small trace buffers to already contain a big | |
6559 | number of instructions compared to @acronym{BTS}. | |
6560 | ||
6561 | Decoding the recorded execution trace, on the other hand, is more | |
6562 | expensive than decoding @acronym{BTS} trace. This is mostly due to the | |
6563 | increased number of instructions to process. You should increase the | |
6564 | buffer-size with care. | |
f4abbc16 MM |
6565 | @end table |
6566 | ||
6567 | Not all recording formats may be available on all processors. | |
59ea5688 MM |
6568 | @end table |
6569 | ||
6570 | The process record and replay target can only debug a process that is | |
6571 | already running. Therefore, you need first to start the process with | |
6572 | the @kbd{run} or @kbd{start} commands, and then start the recording | |
6573 | with the @kbd{record @var{method}} command. | |
6574 | ||
a2311334 EZ |
6575 | @cindex displaced stepping, and process record and replay |
6576 | Displaced stepping (@pxref{Maintenance Commands,, displaced stepping}) | |
6577 | will be automatically disabled when process record and replay target | |
6578 | is started. That's because the process record and replay target | |
6579 | doesn't support displaced stepping. | |
6580 | ||
6581 | @cindex non-stop mode, and process record and replay | |
6582 | @cindex asynchronous execution, and process record and replay | |
6583 | If the inferior is in the non-stop mode (@pxref{Non-Stop Mode}) or in | |
59ea5688 MM |
6584 | the asynchronous execution mode (@pxref{Background Execution}), not |
6585 | all recording methods are available. The @code{full} recording method | |
6586 | does not support these two modes. | |
53cc454a HZ |
6587 | |
6588 | @kindex record stop | |
6589 | @kindex rec s | |
6590 | @item record stop | |
a2311334 EZ |
6591 | Stop the process record and replay target. When process record and |
6592 | replay target stops, the entire execution log will be deleted and the | |
6593 | inferior will either be terminated, or will remain in its final state. | |
53cc454a | 6594 | |
a2311334 EZ |
6595 | When you stop the process record and replay target in record mode (at |
6596 | the end of the execution log), the inferior will be stopped at the | |
6597 | next instruction that would have been recorded. In other words, if | |
6598 | you record for a while and then stop recording, the inferior process | |
6599 | will be left in the same state as if the recording never happened. | |
53cc454a | 6600 | |
a2311334 EZ |
6601 | On the other hand, if the process record and replay target is stopped |
6602 | while in replay mode (that is, not at the end of the execution log, | |
6603 | but at some earlier point), the inferior process will become ``live'' | |
6604 | at that earlier state, and it will then be possible to continue the | |
6605 | usual ``live'' debugging of the process from that state. | |
53cc454a | 6606 | |
a2311334 EZ |
6607 | When the inferior process exits, or @value{GDBN} detaches from it, |
6608 | process record and replay target will automatically stop itself. | |
53cc454a | 6609 | |
742ce053 MM |
6610 | @kindex record goto |
6611 | @item record goto | |
6612 | Go to a specific location in the execution log. There are several | |
6613 | ways to specify the location to go to: | |
6614 | ||
6615 | @table @code | |
6616 | @item record goto begin | |
6617 | @itemx record goto start | |
6618 | Go to the beginning of the execution log. | |
6619 | ||
6620 | @item record goto end | |
6621 | Go to the end of the execution log. | |
6622 | ||
6623 | @item record goto @var{n} | |
6624 | Go to instruction number @var{n} in the execution log. | |
6625 | @end table | |
6626 | ||
24e933df HZ |
6627 | @kindex record save |
6628 | @item record save @var{filename} | |
6629 | Save the execution log to a file @file{@var{filename}}. | |
6630 | Default filename is @file{gdb_record.@var{process_id}}, where | |
6631 | @var{process_id} is the process ID of the inferior. | |
6632 | ||
59ea5688 MM |
6633 | This command may not be available for all recording methods. |
6634 | ||
24e933df HZ |
6635 | @kindex record restore |
6636 | @item record restore @var{filename} | |
6637 | Restore the execution log from a file @file{@var{filename}}. | |
6638 | File must have been created with @code{record save}. | |
6639 | ||
59ea5688 MM |
6640 | @kindex set record full |
6641 | @item set record full insn-number-max @var{limit} | |
f81d1120 | 6642 | @itemx set record full insn-number-max unlimited |
59ea5688 MM |
6643 | Set the limit of instructions to be recorded for the @code{full} |
6644 | recording method. Default value is 200000. | |
53cc454a | 6645 | |
a2311334 EZ |
6646 | If @var{limit} is a positive number, then @value{GDBN} will start |
6647 | deleting instructions from the log once the number of the record | |
6648 | instructions becomes greater than @var{limit}. For every new recorded | |
6649 | instruction, @value{GDBN} will delete the earliest recorded | |
6650 | instruction to keep the number of recorded instructions at the limit. | |
6651 | (Since deleting recorded instructions loses information, @value{GDBN} | |
6652 | lets you control what happens when the limit is reached, by means of | |
6653 | the @code{stop-at-limit} option, described below.) | |
53cc454a | 6654 | |
f81d1120 PA |
6655 | If @var{limit} is @code{unlimited} or zero, @value{GDBN} will never |
6656 | delete recorded instructions from the execution log. The number of | |
6657 | recorded instructions is limited only by the available memory. | |
53cc454a | 6658 | |
59ea5688 MM |
6659 | @kindex show record full |
6660 | @item show record full insn-number-max | |
6661 | Show the limit of instructions to be recorded with the @code{full} | |
6662 | recording method. | |
53cc454a | 6663 | |
59ea5688 MM |
6664 | @item set record full stop-at-limit |
6665 | Control the behavior of the @code{full} recording method when the | |
6666 | number of recorded instructions reaches the limit. If ON (the | |
6667 | default), @value{GDBN} will stop when the limit is reached for the | |
6668 | first time and ask you whether you want to stop the inferior or | |
6669 | continue running it and recording the execution log. If you decide | |
6670 | to continue recording, each new recorded instruction will cause the | |
6671 | oldest one to be deleted. | |
53cc454a | 6672 | |
a2311334 EZ |
6673 | If this option is OFF, @value{GDBN} will automatically delete the |
6674 | oldest record to make room for each new one, without asking. | |
53cc454a | 6675 | |
59ea5688 | 6676 | @item show record full stop-at-limit |
a2311334 | 6677 | Show the current setting of @code{stop-at-limit}. |
53cc454a | 6678 | |
59ea5688 | 6679 | @item set record full memory-query |
bb08c432 | 6680 | Control the behavior when @value{GDBN} is unable to record memory |
59ea5688 MM |
6681 | changes caused by an instruction for the @code{full} recording method. |
6682 | If ON, @value{GDBN} will query whether to stop the inferior in that | |
6683 | case. | |
bb08c432 HZ |
6684 | |
6685 | If this option is OFF (the default), @value{GDBN} will automatically | |
6686 | ignore the effect of such instructions on memory. Later, when | |
6687 | @value{GDBN} replays this execution log, it will mark the log of this | |
6688 | instruction as not accessible, and it will not affect the replay | |
6689 | results. | |
6690 | ||
59ea5688 | 6691 | @item show record full memory-query |
bb08c432 HZ |
6692 | Show the current setting of @code{memory-query}. |
6693 | ||
67b5c0c1 MM |
6694 | @kindex set record btrace |
6695 | The @code{btrace} record target does not trace data. As a | |
6696 | convenience, when replaying, @value{GDBN} reads read-only memory off | |
6697 | the live program directly, assuming that the addresses of the | |
6698 | read-only areas don't change. This for example makes it possible to | |
6699 | disassemble code while replaying, but not to print variables. | |
6700 | In some cases, being able to inspect variables might be useful. | |
6701 | You can use the following command for that: | |
6702 | ||
6703 | @item set record btrace replay-memory-access | |
6704 | Control the behavior of the @code{btrace} recording method when | |
6705 | accessing memory during replay. If @code{read-only} (the default), | |
6706 | @value{GDBN} will only allow accesses to read-only memory. | |
6707 | If @code{read-write}, @value{GDBN} will allow accesses to read-only | |
6708 | and to read-write memory. Beware that the accessed memory corresponds | |
6709 | to the live target and not necessarily to the current replay | |
6710 | position. | |
6711 | ||
6712 | @kindex show record btrace | |
6713 | @item show record btrace replay-memory-access | |
6714 | Show the current setting of @code{replay-memory-access}. | |
6715 | ||
d33501a5 MM |
6716 | @kindex set record btrace bts |
6717 | @item set record btrace bts buffer-size @var{size} | |
6718 | @itemx set record btrace bts buffer-size unlimited | |
6719 | Set the requested ring buffer size for branch tracing in @acronym{BTS} | |
6720 | format. Default is 64KB. | |
6721 | ||
6722 | If @var{size} is a positive number, then @value{GDBN} will try to | |
6723 | allocate a buffer of at least @var{size} bytes for each new thread | |
6724 | that uses the btrace recording method and the @acronym{BTS} format. | |
6725 | The actually obtained buffer size may differ from the requested | |
6726 | @var{size}. Use the @code{info record} command to see the actual | |
6727 | buffer size for each thread that uses the btrace recording method and | |
6728 | the @acronym{BTS} format. | |
6729 | ||
6730 | If @var{limit} is @code{unlimited} or zero, @value{GDBN} will try to | |
6731 | allocate a buffer of 4MB. | |
6732 | ||
6733 | Bigger buffers mean longer traces. On the other hand, @value{GDBN} will | |
6734 | also need longer to process the branch trace data before it can be used. | |
6735 | ||
6736 | @item show record btrace bts buffer-size @var{size} | |
6737 | Show the current setting of the requested ring buffer size for branch | |
6738 | tracing in @acronym{BTS} format. | |
6739 | ||
b20a6524 MM |
6740 | @kindex set record btrace pt |
6741 | @item set record btrace pt buffer-size @var{size} | |
6742 | @itemx set record btrace pt buffer-size unlimited | |
bc504a31 | 6743 | Set the requested ring buffer size for branch tracing in Intel |
b20a6524 MM |
6744 | Processor Trace format. Default is 16KB. |
6745 | ||
6746 | If @var{size} is a positive number, then @value{GDBN} will try to | |
6747 | allocate a buffer of at least @var{size} bytes for each new thread | |
bc504a31 | 6748 | that uses the btrace recording method and the Intel Processor Trace |
b20a6524 MM |
6749 | format. The actually obtained buffer size may differ from the |
6750 | requested @var{size}. Use the @code{info record} command to see the | |
6751 | actual buffer size for each thread. | |
6752 | ||
6753 | If @var{limit} is @code{unlimited} or zero, @value{GDBN} will try to | |
6754 | allocate a buffer of 4MB. | |
6755 | ||
6756 | Bigger buffers mean longer traces. On the other hand, @value{GDBN} will | |
6757 | also need longer to process the branch trace data before it can be used. | |
6758 | ||
6759 | @item show record btrace pt buffer-size @var{size} | |
6760 | Show the current setting of the requested ring buffer size for branch | |
bc504a31 | 6761 | tracing in Intel Processor Trace format. |
b20a6524 | 6762 | |
29153c24 MS |
6763 | @kindex info record |
6764 | @item info record | |
59ea5688 MM |
6765 | Show various statistics about the recording depending on the recording |
6766 | method: | |
6767 | ||
6768 | @table @code | |
6769 | @item full | |
6770 | For the @code{full} recording method, it shows the state of process | |
6771 | record and its in-memory execution log buffer, including: | |
29153c24 MS |
6772 | |
6773 | @itemize @bullet | |
6774 | @item | |
6775 | Whether in record mode or replay mode. | |
6776 | @item | |
6777 | Lowest recorded instruction number (counting from when the current execution log started recording instructions). | |
6778 | @item | |
6779 | Highest recorded instruction number. | |
6780 | @item | |
6781 | Current instruction about to be replayed (if in replay mode). | |
6782 | @item | |
6783 | Number of instructions contained in the execution log. | |
6784 | @item | |
6785 | Maximum number of instructions that may be contained in the execution log. | |
6786 | @end itemize | |
53cc454a | 6787 | |
59ea5688 | 6788 | @item btrace |
d33501a5 MM |
6789 | For the @code{btrace} recording method, it shows: |
6790 | ||
6791 | @itemize @bullet | |
6792 | @item | |
6793 | Recording format. | |
6794 | @item | |
6795 | Number of instructions that have been recorded. | |
6796 | @item | |
6797 | Number of blocks of sequential control-flow formed by the recorded | |
6798 | instructions. | |
6799 | @item | |
6800 | Whether in record mode or replay mode. | |
6801 | @end itemize | |
6802 | ||
6803 | For the @code{bts} recording format, it also shows: | |
6804 | @itemize @bullet | |
6805 | @item | |
6806 | Size of the perf ring buffer. | |
6807 | @end itemize | |
b20a6524 MM |
6808 | |
6809 | For the @code{pt} recording format, it also shows: | |
6810 | @itemize @bullet | |
6811 | @item | |
6812 | Size of the perf ring buffer. | |
6813 | @end itemize | |
59ea5688 MM |
6814 | @end table |
6815 | ||
53cc454a HZ |
6816 | @kindex record delete |
6817 | @kindex rec del | |
6818 | @item record delete | |
a2311334 | 6819 | When record target runs in replay mode (``in the past''), delete the |
53cc454a | 6820 | subsequent execution log and begin to record a new execution log starting |
a2311334 | 6821 | from the current address. This means you will abandon the previously |
53cc454a | 6822 | recorded ``future'' and begin recording a new ``future''. |
59ea5688 MM |
6823 | |
6824 | @kindex record instruction-history | |
6825 | @kindex rec instruction-history | |
6826 | @item record instruction-history | |
6827 | Disassembles instructions from the recorded execution log. By | |
6828 | default, ten instructions are disassembled. This can be changed using | |
6829 | the @code{set record instruction-history-size} command. Instructions | |
da8c46d2 MM |
6830 | are printed in execution order. |
6831 | ||
0c532a29 MM |
6832 | It can also print mixed source+disassembly if you specify the the |
6833 | @code{/m} or @code{/s} modifier, and print the raw instructions in hex | |
6834 | as well as in symbolic form by specifying the @code{/r} modifier. | |
6835 | ||
6836 | The current position marker is printed for the instruction at the | |
6837 | current program counter value. This instruction can appear multiple | |
6838 | times in the trace and the current position marker will be printed | |
6839 | every time. To omit the current position marker, specify the | |
6840 | @code{/p} modifier. | |
6841 | ||
6842 | To better align the printed instructions when the trace contains | |
6843 | instructions from more than one function, the function name may be | |
6844 | omitted by specifying the @code{/f} modifier. | |
6845 | ||
da8c46d2 MM |
6846 | Speculatively executed instructions are prefixed with @samp{?}. This |
6847 | feature is not available for all recording formats. | |
6848 | ||
6849 | There are several ways to specify what part of the execution log to | |
6850 | disassemble: | |
59ea5688 MM |
6851 | |
6852 | @table @code | |
6853 | @item record instruction-history @var{insn} | |
6854 | Disassembles ten instructions starting from instruction number | |
6855 | @var{insn}. | |
6856 | ||
6857 | @item record instruction-history @var{insn}, +/-@var{n} | |
6858 | Disassembles @var{n} instructions around instruction number | |
6859 | @var{insn}. If @var{n} is preceded with @code{+}, disassembles | |
6860 | @var{n} instructions after instruction number @var{insn}. If | |
6861 | @var{n} is preceded with @code{-}, disassembles @var{n} | |
6862 | instructions before instruction number @var{insn}. | |
6863 | ||
6864 | @item record instruction-history | |
6865 | Disassembles ten more instructions after the last disassembly. | |
6866 | ||
6867 | @item record instruction-history - | |
6868 | Disassembles ten more instructions before the last disassembly. | |
6869 | ||
792005b0 | 6870 | @item record instruction-history @var{begin}, @var{end} |
59ea5688 MM |
6871 | Disassembles instructions beginning with instruction number |
6872 | @var{begin} until instruction number @var{end}. The instruction | |
0688d04e | 6873 | number @var{end} is included. |
59ea5688 MM |
6874 | @end table |
6875 | ||
6876 | This command may not be available for all recording methods. | |
6877 | ||
6878 | @kindex set record | |
f81d1120 PA |
6879 | @item set record instruction-history-size @var{size} |
6880 | @itemx set record instruction-history-size unlimited | |
59ea5688 MM |
6881 | Define how many instructions to disassemble in the @code{record |
6882 | instruction-history} command. The default value is 10. | |
f81d1120 | 6883 | A @var{size} of @code{unlimited} means unlimited instructions. |
59ea5688 MM |
6884 | |
6885 | @kindex show record | |
6886 | @item show record instruction-history-size | |
6887 | Show how many instructions to disassemble in the @code{record | |
6888 | instruction-history} command. | |
6889 | ||
6890 | @kindex record function-call-history | |
6891 | @kindex rec function-call-history | |
6892 | @item record function-call-history | |
6893 | Prints the execution history at function granularity. It prints one | |
6894 | line for each sequence of instructions that belong to the same | |
6895 | function giving the name of that function, the source lines | |
6896 | for this instruction sequence (if the @code{/l} modifier is | |
6897 | specified), and the instructions numbers that form the sequence (if | |
8710b709 MM |
6898 | the @code{/i} modifier is specified). The function names are indented |
6899 | to reflect the call stack depth if the @code{/c} modifier is | |
6900 | specified. The @code{/l}, @code{/i}, and @code{/c} modifiers can be | |
6901 | given together. | |
59ea5688 MM |
6902 | |
6903 | @smallexample | |
6904 | (@value{GDBP}) @b{list 1, 10} | |
6905 | 1 void foo (void) | |
6906 | 2 @{ | |
6907 | 3 @} | |
6908 | 4 | |
6909 | 5 void bar (void) | |
6910 | 6 @{ | |
6911 | 7 ... | |
6912 | 8 foo (); | |
6913 | 9 ... | |
6914 | 10 @} | |
8710b709 MM |
6915 | (@value{GDBP}) @b{record function-call-history /ilc} |
6916 | 1 bar inst 1,4 at foo.c:6,8 | |
6917 | 2 foo inst 5,10 at foo.c:2,3 | |
6918 | 3 bar inst 11,13 at foo.c:9,10 | |
59ea5688 MM |
6919 | @end smallexample |
6920 | ||
6921 | By default, ten lines are printed. This can be changed using the | |
6922 | @code{set record function-call-history-size} command. Functions are | |
6923 | printed in execution order. There are several ways to specify what | |
6924 | to print: | |
6925 | ||
6926 | @table @code | |
6927 | @item record function-call-history @var{func} | |
6928 | Prints ten functions starting from function number @var{func}. | |
6929 | ||
6930 | @item record function-call-history @var{func}, +/-@var{n} | |
6931 | Prints @var{n} functions around function number @var{func}. If | |
6932 | @var{n} is preceded with @code{+}, prints @var{n} functions after | |
6933 | function number @var{func}. If @var{n} is preceded with @code{-}, | |
6934 | prints @var{n} functions before function number @var{func}. | |
6935 | ||
6936 | @item record function-call-history | |
6937 | Prints ten more functions after the last ten-line print. | |
6938 | ||
6939 | @item record function-call-history - | |
6940 | Prints ten more functions before the last ten-line print. | |
6941 | ||
792005b0 | 6942 | @item record function-call-history @var{begin}, @var{end} |
59ea5688 | 6943 | Prints functions beginning with function number @var{begin} until |
0688d04e | 6944 | function number @var{end}. The function number @var{end} is included. |
59ea5688 MM |
6945 | @end table |
6946 | ||
6947 | This command may not be available for all recording methods. | |
6948 | ||
f81d1120 PA |
6949 | @item set record function-call-history-size @var{size} |
6950 | @itemx set record function-call-history-size unlimited | |
59ea5688 MM |
6951 | Define how many lines to print in the |
6952 | @code{record function-call-history} command. The default value is 10. | |
f81d1120 | 6953 | A size of @code{unlimited} means unlimited lines. |
59ea5688 MM |
6954 | |
6955 | @item show record function-call-history-size | |
6956 | Show how many lines to print in the | |
6957 | @code{record function-call-history} command. | |
53cc454a HZ |
6958 | @end table |
6959 | ||
6960 | ||
6d2ebf8b | 6961 | @node Stack |
c906108c SS |
6962 | @chapter Examining the Stack |
6963 | ||
6964 | When your program has stopped, the first thing you need to know is where it | |
6965 | stopped and how it got there. | |
6966 | ||
6967 | @cindex call stack | |
5d161b24 DB |
6968 | Each time your program performs a function call, information about the call |
6969 | is generated. | |
6970 | That information includes the location of the call in your program, | |
6971 | the arguments of the call, | |
c906108c | 6972 | and the local variables of the function being called. |
5d161b24 | 6973 | The information is saved in a block of data called a @dfn{stack frame}. |
c906108c SS |
6974 | The stack frames are allocated in a region of memory called the @dfn{call |
6975 | stack}. | |
6976 | ||
6977 | When your program stops, the @value{GDBN} commands for examining the | |
6978 | stack allow you to see all of this information. | |
6979 | ||
6980 | @cindex selected frame | |
6981 | One of the stack frames is @dfn{selected} by @value{GDBN} and many | |
6982 | @value{GDBN} commands refer implicitly to the selected frame. In | |
6983 | particular, whenever you ask @value{GDBN} for the value of a variable in | |
6984 | your program, the value is found in the selected frame. There are | |
6985 | special @value{GDBN} commands to select whichever frame you are | |
79a6e687 | 6986 | interested in. @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
6987 | |
6988 | When your program stops, @value{GDBN} automatically selects the | |
5d161b24 | 6989 | currently executing frame and describes it briefly, similar to the |
79a6e687 | 6990 | @code{frame} command (@pxref{Frame Info, ,Information about a Frame}). |
c906108c SS |
6991 | |
6992 | @menu | |
6993 | * Frames:: Stack frames | |
6994 | * Backtrace:: Backtraces | |
6995 | * Selection:: Selecting a frame | |
6996 | * Frame Info:: Information on a frame | |
0f59c28f | 6997 | * Frame Filter Management:: Managing frame filters |
c906108c SS |
6998 | |
6999 | @end menu | |
7000 | ||
6d2ebf8b | 7001 | @node Frames |
79a6e687 | 7002 | @section Stack Frames |
c906108c | 7003 | |
d4f3574e | 7004 | @cindex frame, definition |
c906108c SS |
7005 | @cindex stack frame |
7006 | The call stack is divided up into contiguous pieces called @dfn{stack | |
7007 | frames}, or @dfn{frames} for short; each frame is the data associated | |
7008 | with one call to one function. The frame contains the arguments given | |
7009 | to the function, the function's local variables, and the address at | |
7010 | which the function is executing. | |
7011 | ||
7012 | @cindex initial frame | |
7013 | @cindex outermost frame | |
7014 | @cindex innermost frame | |
7015 | When your program is started, the stack has only one frame, that of the | |
7016 | function @code{main}. This is called the @dfn{initial} frame or the | |
7017 | @dfn{outermost} frame. Each time a function is called, a new frame is | |
7018 | made. Each time a function returns, the frame for that function invocation | |
7019 | is eliminated. If a function is recursive, there can be many frames for | |
7020 | the same function. The frame for the function in which execution is | |
7021 | actually occurring is called the @dfn{innermost} frame. This is the most | |
7022 | recently created of all the stack frames that still exist. | |
7023 | ||
7024 | @cindex frame pointer | |
7025 | Inside your program, stack frames are identified by their addresses. A | |
7026 | stack frame consists of many bytes, each of which has its own address; each | |
7027 | kind of computer has a convention for choosing one byte whose | |
7028 | address serves as the address of the frame. Usually this address is kept | |
e09f16f9 EZ |
7029 | in a register called the @dfn{frame pointer register} |
7030 | (@pxref{Registers, $fp}) while execution is going on in that frame. | |
c906108c SS |
7031 | |
7032 | @cindex frame number | |
7033 | @value{GDBN} assigns numbers to all existing stack frames, starting with | |
7034 | zero for the innermost frame, one for the frame that called it, | |
7035 | and so on upward. These numbers do not really exist in your program; | |
7036 | they are assigned by @value{GDBN} to give you a way of designating stack | |
7037 | frames in @value{GDBN} commands. | |
7038 | ||
6d2ebf8b SS |
7039 | @c The -fomit-frame-pointer below perennially causes hbox overflow |
7040 | @c underflow problems. | |
c906108c SS |
7041 | @cindex frameless execution |
7042 | Some compilers provide a way to compile functions so that they operate | |
e22ea452 | 7043 | without stack frames. (For example, the @value{NGCC} option |
474c8240 | 7044 | @smallexample |
6d2ebf8b | 7045 | @samp{-fomit-frame-pointer} |
474c8240 | 7046 | @end smallexample |
6d2ebf8b | 7047 | generates functions without a frame.) |
c906108c SS |
7048 | This is occasionally done with heavily used library functions to save |
7049 | the frame setup time. @value{GDBN} has limited facilities for dealing | |
7050 | with these function invocations. If the innermost function invocation | |
7051 | has no stack frame, @value{GDBN} nevertheless regards it as though | |
7052 | it had a separate frame, which is numbered zero as usual, allowing | |
7053 | correct tracing of the function call chain. However, @value{GDBN} has | |
7054 | no provision for frameless functions elsewhere in the stack. | |
7055 | ||
6d2ebf8b | 7056 | @node Backtrace |
c906108c SS |
7057 | @section Backtraces |
7058 | ||
09d4efe1 EZ |
7059 | @cindex traceback |
7060 | @cindex call stack traces | |
c906108c SS |
7061 | A backtrace is a summary of how your program got where it is. It shows one |
7062 | line per frame, for many frames, starting with the currently executing | |
7063 | frame (frame zero), followed by its caller (frame one), and on up the | |
7064 | stack. | |
7065 | ||
1e611234 | 7066 | @anchor{backtrace-command} |
c906108c SS |
7067 | @table @code |
7068 | @kindex backtrace | |
41afff9a | 7069 | @kindex bt @r{(@code{backtrace})} |
c906108c SS |
7070 | @item backtrace |
7071 | @itemx bt | |
7072 | Print a backtrace of the entire stack: one line per frame for all | |
7073 | frames in the stack. | |
7074 | ||
7075 | You can stop the backtrace at any time by typing the system interrupt | |
c8aa23ab | 7076 | character, normally @kbd{Ctrl-c}. |
c906108c SS |
7077 | |
7078 | @item backtrace @var{n} | |
7079 | @itemx bt @var{n} | |
7080 | Similar, but print only the innermost @var{n} frames. | |
7081 | ||
7082 | @item backtrace -@var{n} | |
7083 | @itemx bt -@var{n} | |
7084 | Similar, but print only the outermost @var{n} frames. | |
0f061b69 NR |
7085 | |
7086 | @item backtrace full | |
0f061b69 | 7087 | @itemx bt full |
dd74f6ae NR |
7088 | @itemx bt full @var{n} |
7089 | @itemx bt full -@var{n} | |
697aa1b7 EZ |
7090 | Print the values of the local variables also. As described above, |
7091 | @var{n} specifies the number of frames to print. | |
1e611234 PM |
7092 | |
7093 | @item backtrace no-filters | |
7094 | @itemx bt no-filters | |
7095 | @itemx bt no-filters @var{n} | |
7096 | @itemx bt no-filters -@var{n} | |
7097 | @itemx bt no-filters full | |
7098 | @itemx bt no-filters full @var{n} | |
7099 | @itemx bt no-filters full -@var{n} | |
7100 | Do not run Python frame filters on this backtrace. @xref{Frame | |
7101 | Filter API}, for more information. Additionally use @ref{disable | |
7102 | frame-filter all} to turn off all frame filters. This is only | |
7103 | relevant when @value{GDBN} has been configured with @code{Python} | |
7104 | support. | |
c906108c SS |
7105 | @end table |
7106 | ||
7107 | @kindex where | |
7108 | @kindex info stack | |
c906108c SS |
7109 | The names @code{where} and @code{info stack} (abbreviated @code{info s}) |
7110 | are additional aliases for @code{backtrace}. | |
7111 | ||
839c27b7 EZ |
7112 | @cindex multiple threads, backtrace |
7113 | In a multi-threaded program, @value{GDBN} by default shows the | |
7114 | backtrace only for the current thread. To display the backtrace for | |
7115 | several or all of the threads, use the command @code{thread apply} | |
7116 | (@pxref{Threads, thread apply}). For example, if you type @kbd{thread | |
7117 | apply all backtrace}, @value{GDBN} will display the backtrace for all | |
7118 | the threads; this is handy when you debug a core dump of a | |
7119 | multi-threaded program. | |
7120 | ||
c906108c SS |
7121 | Each line in the backtrace shows the frame number and the function name. |
7122 | The program counter value is also shown---unless you use @code{set | |
7123 | print address off}. The backtrace also shows the source file name and | |
7124 | line number, as well as the arguments to the function. The program | |
7125 | counter value is omitted if it is at the beginning of the code for that | |
7126 | line number. | |
7127 | ||
7128 | Here is an example of a backtrace. It was made with the command | |
7129 | @samp{bt 3}, so it shows the innermost three frames. | |
7130 | ||
7131 | @smallexample | |
7132 | @group | |
5d161b24 | 7133 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) |
c906108c | 7134 | at builtin.c:993 |
4f5376b2 | 7135 | #1 0x6e38 in expand_macro (sym=0x2b600, data=...) at macro.c:242 |
c906108c SS |
7136 | #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08) |
7137 | at macro.c:71 | |
7138 | (More stack frames follow...) | |
7139 | @end group | |
7140 | @end smallexample | |
7141 | ||
7142 | @noindent | |
7143 | The display for frame zero does not begin with a program counter | |
7144 | value, indicating that your program has stopped at the beginning of the | |
7145 | code for line @code{993} of @code{builtin.c}. | |
7146 | ||
4f5376b2 JB |
7147 | @noindent |
7148 | The value of parameter @code{data} in frame 1 has been replaced by | |
7149 | @code{@dots{}}. By default, @value{GDBN} prints the value of a parameter | |
7150 | only if it is a scalar (integer, pointer, enumeration, etc). See command | |
7151 | @kbd{set print frame-arguments} in @ref{Print Settings} for more details | |
7152 | on how to configure the way function parameter values are printed. | |
7153 | ||
585fdaa1 | 7154 | @cindex optimized out, in backtrace |
18999be5 EZ |
7155 | @cindex function call arguments, optimized out |
7156 | If your program was compiled with optimizations, some compilers will | |
7157 | optimize away arguments passed to functions if those arguments are | |
7158 | never used after the call. Such optimizations generate code that | |
7159 | passes arguments through registers, but doesn't store those arguments | |
7160 | in the stack frame. @value{GDBN} has no way of displaying such | |
7161 | arguments in stack frames other than the innermost one. Here's what | |
7162 | such a backtrace might look like: | |
7163 | ||
7164 | @smallexample | |
7165 | @group | |
7166 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) | |
7167 | at builtin.c:993 | |
585fdaa1 PA |
7168 | #1 0x6e38 in expand_macro (sym=<optimized out>) at macro.c:242 |
7169 | #2 0x6840 in expand_token (obs=0x0, t=<optimized out>, td=0xf7fffb08) | |
18999be5 EZ |
7170 | at macro.c:71 |
7171 | (More stack frames follow...) | |
7172 | @end group | |
7173 | @end smallexample | |
7174 | ||
7175 | @noindent | |
7176 | The values of arguments that were not saved in their stack frames are | |
585fdaa1 | 7177 | shown as @samp{<optimized out>}. |
18999be5 EZ |
7178 | |
7179 | If you need to display the values of such optimized-out arguments, | |
7180 | either deduce that from other variables whose values depend on the one | |
7181 | you are interested in, or recompile without optimizations. | |
7182 | ||
a8f24a35 EZ |
7183 | @cindex backtrace beyond @code{main} function |
7184 | @cindex program entry point | |
7185 | @cindex startup code, and backtrace | |
25d29d70 AC |
7186 | Most programs have a standard user entry point---a place where system |
7187 | libraries and startup code transition into user code. For C this is | |
d416eeec EZ |
7188 | @code{main}@footnote{ |
7189 | Note that embedded programs (the so-called ``free-standing'' | |
7190 | environment) are not required to have a @code{main} function as the | |
7191 | entry point. They could even have multiple entry points.}. | |
7192 | When @value{GDBN} finds the entry function in a backtrace | |
25d29d70 AC |
7193 | it will terminate the backtrace, to avoid tracing into highly |
7194 | system-specific (and generally uninteresting) code. | |
7195 | ||
7196 | If you need to examine the startup code, or limit the number of levels | |
7197 | in a backtrace, you can change this behavior: | |
95f90d25 DJ |
7198 | |
7199 | @table @code | |
25d29d70 AC |
7200 | @item set backtrace past-main |
7201 | @itemx set backtrace past-main on | |
4644b6e3 | 7202 | @kindex set backtrace |
25d29d70 AC |
7203 | Backtraces will continue past the user entry point. |
7204 | ||
7205 | @item set backtrace past-main off | |
95f90d25 DJ |
7206 | Backtraces will stop when they encounter the user entry point. This is the |
7207 | default. | |
7208 | ||
25d29d70 | 7209 | @item show backtrace past-main |
4644b6e3 | 7210 | @kindex show backtrace |
25d29d70 AC |
7211 | Display the current user entry point backtrace policy. |
7212 | ||
2315ffec RC |
7213 | @item set backtrace past-entry |
7214 | @itemx set backtrace past-entry on | |
a8f24a35 | 7215 | Backtraces will continue past the internal entry point of an application. |
2315ffec RC |
7216 | This entry point is encoded by the linker when the application is built, |
7217 | and is likely before the user entry point @code{main} (or equivalent) is called. | |
7218 | ||
7219 | @item set backtrace past-entry off | |
d3e8051b | 7220 | Backtraces will stop when they encounter the internal entry point of an |
2315ffec RC |
7221 | application. This is the default. |
7222 | ||
7223 | @item show backtrace past-entry | |
7224 | Display the current internal entry point backtrace policy. | |
7225 | ||
25d29d70 AC |
7226 | @item set backtrace limit @var{n} |
7227 | @itemx set backtrace limit 0 | |
f81d1120 | 7228 | @itemx set backtrace limit unlimited |
25d29d70 | 7229 | @cindex backtrace limit |
f81d1120 PA |
7230 | Limit the backtrace to @var{n} levels. A value of @code{unlimited} |
7231 | or zero means unlimited levels. | |
95f90d25 | 7232 | |
25d29d70 AC |
7233 | @item show backtrace limit |
7234 | Display the current limit on backtrace levels. | |
95f90d25 DJ |
7235 | @end table |
7236 | ||
1b56eb55 JK |
7237 | You can control how file names are displayed. |
7238 | ||
7239 | @table @code | |
7240 | @item set filename-display | |
7241 | @itemx set filename-display relative | |
7242 | @cindex filename-display | |
7243 | Display file names relative to the compilation directory. This is the default. | |
7244 | ||
7245 | @item set filename-display basename | |
7246 | Display only basename of a filename. | |
7247 | ||
7248 | @item set filename-display absolute | |
7249 | Display an absolute filename. | |
7250 | ||
7251 | @item show filename-display | |
7252 | Show the current way to display filenames. | |
7253 | @end table | |
7254 | ||
6d2ebf8b | 7255 | @node Selection |
79a6e687 | 7256 | @section Selecting a Frame |
c906108c SS |
7257 | |
7258 | Most commands for examining the stack and other data in your program work on | |
7259 | whichever stack frame is selected at the moment. Here are the commands for | |
7260 | selecting a stack frame; all of them finish by printing a brief description | |
7261 | of the stack frame just selected. | |
7262 | ||
7263 | @table @code | |
d4f3574e | 7264 | @kindex frame@r{, selecting} |
41afff9a | 7265 | @kindex f @r{(@code{frame})} |
c906108c SS |
7266 | @item frame @var{n} |
7267 | @itemx f @var{n} | |
7268 | Select frame number @var{n}. Recall that frame zero is the innermost | |
7269 | (currently executing) frame, frame one is the frame that called the | |
7270 | innermost one, and so on. The highest-numbered frame is the one for | |
7271 | @code{main}. | |
7272 | ||
7c7f93f6 AB |
7273 | @item frame @var{stack-addr} [ @var{pc-addr} ] |
7274 | @itemx f @var{stack-addr} [ @var{pc-addr} ] | |
7275 | Select the frame at address @var{stack-addr}. This is useful mainly if the | |
c906108c SS |
7276 | chaining of stack frames has been damaged by a bug, making it |
7277 | impossible for @value{GDBN} to assign numbers properly to all frames. In | |
7278 | addition, this can be useful when your program has multiple stacks and | |
7c7f93f6 AB |
7279 | switches between them. The optional @var{pc-addr} can also be given to |
7280 | specify the value of PC for the stack frame. | |
c906108c SS |
7281 | |
7282 | @kindex up | |
7283 | @item up @var{n} | |
697aa1b7 EZ |
7284 | Move @var{n} frames up the stack; @var{n} defaults to 1. For positive |
7285 | numbers @var{n}, this advances toward the outermost frame, to higher | |
7286 | frame numbers, to frames that have existed longer. | |
c906108c SS |
7287 | |
7288 | @kindex down | |
41afff9a | 7289 | @kindex do @r{(@code{down})} |
c906108c | 7290 | @item down @var{n} |
697aa1b7 EZ |
7291 | Move @var{n} frames down the stack; @var{n} defaults to 1. For |
7292 | positive numbers @var{n}, this advances toward the innermost frame, to | |
7293 | lower frame numbers, to frames that were created more recently. | |
7294 | You may abbreviate @code{down} as @code{do}. | |
c906108c SS |
7295 | @end table |
7296 | ||
7297 | All of these commands end by printing two lines of output describing the | |
7298 | frame. The first line shows the frame number, the function name, the | |
7299 | arguments, and the source file and line number of execution in that | |
5d161b24 | 7300 | frame. The second line shows the text of that source line. |
c906108c SS |
7301 | |
7302 | @need 1000 | |
7303 | For example: | |
7304 | ||
7305 | @smallexample | |
7306 | @group | |
7307 | (@value{GDBP}) up | |
7308 | #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc) | |
7309 | at env.c:10 | |
7310 | 10 read_input_file (argv[i]); | |
7311 | @end group | |
7312 | @end smallexample | |
7313 | ||
7314 | After such a printout, the @code{list} command with no arguments | |
7315 | prints ten lines centered on the point of execution in the frame. | |
87885426 FN |
7316 | You can also edit the program at the point of execution with your favorite |
7317 | editing program by typing @code{edit}. | |
79a6e687 | 7318 | @xref{List, ,Printing Source Lines}, |
87885426 | 7319 | for details. |
c906108c SS |
7320 | |
7321 | @table @code | |
fc58fa65 AB |
7322 | @kindex select-frame |
7323 | @item select-frame | |
7324 | The @code{select-frame} command is a variant of @code{frame} that does | |
7325 | not display the new frame after selecting it. This command is | |
7326 | intended primarily for use in @value{GDBN} command scripts, where the | |
7327 | output might be unnecessary and distracting. | |
7328 | ||
c906108c SS |
7329 | @kindex down-silently |
7330 | @kindex up-silently | |
7331 | @item up-silently @var{n} | |
7332 | @itemx down-silently @var{n} | |
7333 | These two commands are variants of @code{up} and @code{down}, | |
7334 | respectively; they differ in that they do their work silently, without | |
7335 | causing display of the new frame. They are intended primarily for use | |
7336 | in @value{GDBN} command scripts, where the output might be unnecessary and | |
7337 | distracting. | |
7338 | @end table | |
7339 | ||
6d2ebf8b | 7340 | @node Frame Info |
79a6e687 | 7341 | @section Information About a Frame |
c906108c SS |
7342 | |
7343 | There are several other commands to print information about the selected | |
7344 | stack frame. | |
7345 | ||
7346 | @table @code | |
7347 | @item frame | |
7348 | @itemx f | |
7349 | When used without any argument, this command does not change which | |
7350 | frame is selected, but prints a brief description of the currently | |
7351 | selected stack frame. It can be abbreviated @code{f}. With an | |
7352 | argument, this command is used to select a stack frame. | |
79a6e687 | 7353 | @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
7354 | |
7355 | @kindex info frame | |
41afff9a | 7356 | @kindex info f @r{(@code{info frame})} |
c906108c SS |
7357 | @item info frame |
7358 | @itemx info f | |
7359 | This command prints a verbose description of the selected stack frame, | |
7360 | including: | |
7361 | ||
7362 | @itemize @bullet | |
5d161b24 DB |
7363 | @item |
7364 | the address of the frame | |
c906108c SS |
7365 | @item |
7366 | the address of the next frame down (called by this frame) | |
7367 | @item | |
7368 | the address of the next frame up (caller of this frame) | |
7369 | @item | |
7370 | the language in which the source code corresponding to this frame is written | |
7371 | @item | |
7372 | the address of the frame's arguments | |
7373 | @item | |
d4f3574e SS |
7374 | the address of the frame's local variables |
7375 | @item | |
c906108c SS |
7376 | the program counter saved in it (the address of execution in the caller frame) |
7377 | @item | |
7378 | which registers were saved in the frame | |
7379 | @end itemize | |
7380 | ||
7381 | @noindent The verbose description is useful when | |
7382 | something has gone wrong that has made the stack format fail to fit | |
7383 | the usual conventions. | |
7384 | ||
7385 | @item info frame @var{addr} | |
7386 | @itemx info f @var{addr} | |
7387 | Print a verbose description of the frame at address @var{addr}, without | |
7388 | selecting that frame. The selected frame remains unchanged by this | |
7389 | command. This requires the same kind of address (more than one for some | |
7390 | architectures) that you specify in the @code{frame} command. | |
79a6e687 | 7391 | @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
7392 | |
7393 | @kindex info args | |
7394 | @item info args | |
7395 | Print the arguments of the selected frame, each on a separate line. | |
7396 | ||
7397 | @item info locals | |
7398 | @kindex info locals | |
7399 | Print the local variables of the selected frame, each on a separate | |
7400 | line. These are all variables (declared either static or automatic) | |
7401 | accessible at the point of execution of the selected frame. | |
7402 | ||
c906108c SS |
7403 | @end table |
7404 | ||
fc58fa65 AB |
7405 | @node Frame Filter Management |
7406 | @section Management of Frame Filters. | |
7407 | @cindex managing frame filters | |
7408 | ||
7409 | Frame filters are Python based utilities to manage and decorate the | |
7410 | output of frames. @xref{Frame Filter API}, for further information. | |
7411 | ||
7412 | Managing frame filters is performed by several commands available | |
7413 | within @value{GDBN}, detailed here. | |
7414 | ||
7415 | @table @code | |
7416 | @kindex info frame-filter | |
7417 | @item info frame-filter | |
7418 | Print a list of installed frame filters from all dictionaries, showing | |
7419 | their name, priority and enabled status. | |
7420 | ||
7421 | @kindex disable frame-filter | |
7422 | @anchor{disable frame-filter all} | |
7423 | @item disable frame-filter @var{filter-dictionary} @var{filter-name} | |
7424 | Disable a frame filter in the dictionary matching | |
7425 | @var{filter-dictionary} and @var{filter-name}. The | |
7426 | @var{filter-dictionary} may be @code{all}, @code{global}, | |
7427 | @code{progspace}, or the name of the object file where the frame filter | |
7428 | dictionary resides. When @code{all} is specified, all frame filters | |
7429 | across all dictionaries are disabled. The @var{filter-name} is the name | |
7430 | of the frame filter and is used when @code{all} is not the option for | |
7431 | @var{filter-dictionary}. A disabled frame-filter is not deleted, it | |
7432 | may be enabled again later. | |
7433 | ||
7434 | @kindex enable frame-filter | |
7435 | @item enable frame-filter @var{filter-dictionary} @var{filter-name} | |
7436 | Enable a frame filter in the dictionary matching | |
7437 | @var{filter-dictionary} and @var{filter-name}. The | |
7438 | @var{filter-dictionary} may be @code{all}, @code{global}, | |
7439 | @code{progspace} or the name of the object file where the frame filter | |
7440 | dictionary resides. When @code{all} is specified, all frame filters across | |
7441 | all dictionaries are enabled. The @var{filter-name} is the name of the frame | |
7442 | filter and is used when @code{all} is not the option for | |
7443 | @var{filter-dictionary}. | |
7444 | ||
7445 | Example: | |
7446 | ||
7447 | @smallexample | |
7448 | (gdb) info frame-filter | |
7449 | ||
7450 | global frame-filters: | |
7451 | Priority Enabled Name | |
7452 | 1000 No PrimaryFunctionFilter | |
7453 | 100 Yes Reverse | |
7454 | ||
7455 | progspace /build/test frame-filters: | |
7456 | Priority Enabled Name | |
7457 | 100 Yes ProgspaceFilter | |
7458 | ||
7459 | objfile /build/test frame-filters: | |
7460 | Priority Enabled Name | |
7461 | 999 Yes BuildProgra Filter | |
7462 | ||
7463 | (gdb) disable frame-filter /build/test BuildProgramFilter | |
7464 | (gdb) info frame-filter | |
7465 | ||
7466 | global frame-filters: | |
7467 | Priority Enabled Name | |
7468 | 1000 No PrimaryFunctionFilter | |
7469 | 100 Yes Reverse | |
7470 | ||
7471 | progspace /build/test frame-filters: | |
7472 | Priority Enabled Name | |
7473 | 100 Yes ProgspaceFilter | |
7474 | ||
7475 | objfile /build/test frame-filters: | |
7476 | Priority Enabled Name | |
7477 | 999 No BuildProgramFilter | |
7478 | ||
7479 | (gdb) enable frame-filter global PrimaryFunctionFilter | |
7480 | (gdb) info frame-filter | |
7481 | ||
7482 | global frame-filters: | |
7483 | Priority Enabled Name | |
7484 | 1000 Yes PrimaryFunctionFilter | |
7485 | 100 Yes Reverse | |
7486 | ||
7487 | progspace /build/test frame-filters: | |
7488 | Priority Enabled Name | |
7489 | 100 Yes ProgspaceFilter | |
7490 | ||
7491 | objfile /build/test frame-filters: | |
7492 | Priority Enabled Name | |
7493 | 999 No BuildProgramFilter | |
7494 | @end smallexample | |
7495 | ||
7496 | @kindex set frame-filter priority | |
7497 | @item set frame-filter priority @var{filter-dictionary} @var{filter-name} @var{priority} | |
7498 | Set the @var{priority} of a frame filter in the dictionary matching | |
7499 | @var{filter-dictionary}, and the frame filter name matching | |
7500 | @var{filter-name}. The @var{filter-dictionary} may be @code{global}, | |
7501 | @code{progspace} or the name of the object file where the frame filter | |
7502 | dictionary resides. The @var{priority} is an integer. | |
7503 | ||
7504 | @kindex show frame-filter priority | |
7505 | @item show frame-filter priority @var{filter-dictionary} @var{filter-name} | |
7506 | Show the @var{priority} of a frame filter in the dictionary matching | |
7507 | @var{filter-dictionary}, and the frame filter name matching | |
7508 | @var{filter-name}. The @var{filter-dictionary} may be @code{global}, | |
7509 | @code{progspace} or the name of the object file where the frame filter | |
7510 | dictionary resides. | |
7511 | ||
7512 | Example: | |
7513 | ||
7514 | @smallexample | |
7515 | (gdb) info frame-filter | |
7516 | ||
7517 | global frame-filters: | |
7518 | Priority Enabled Name | |
7519 | 1000 Yes PrimaryFunctionFilter | |
7520 | 100 Yes Reverse | |
7521 | ||
7522 | progspace /build/test frame-filters: | |
7523 | Priority Enabled Name | |
7524 | 100 Yes ProgspaceFilter | |
7525 | ||
7526 | objfile /build/test frame-filters: | |
7527 | Priority Enabled Name | |
7528 | 999 No BuildProgramFilter | |
7529 | ||
7530 | (gdb) set frame-filter priority global Reverse 50 | |
7531 | (gdb) info frame-filter | |
7532 | ||
7533 | global frame-filters: | |
7534 | Priority Enabled Name | |
7535 | 1000 Yes PrimaryFunctionFilter | |
7536 | 50 Yes Reverse | |
7537 | ||
7538 | progspace /build/test frame-filters: | |
7539 | Priority Enabled Name | |
7540 | 100 Yes ProgspaceFilter | |
7541 | ||
7542 | objfile /build/test frame-filters: | |
7543 | Priority Enabled Name | |
7544 | 999 No BuildProgramFilter | |
7545 | @end smallexample | |
7546 | @end table | |
c906108c | 7547 | |
6d2ebf8b | 7548 | @node Source |
c906108c SS |
7549 | @chapter Examining Source Files |
7550 | ||
7551 | @value{GDBN} can print parts of your program's source, since the debugging | |
7552 | information recorded in the program tells @value{GDBN} what source files were | |
7553 | used to build it. When your program stops, @value{GDBN} spontaneously prints | |
7554 | the line where it stopped. Likewise, when you select a stack frame | |
79a6e687 | 7555 | (@pxref{Selection, ,Selecting a Frame}), @value{GDBN} prints the line where |
c906108c SS |
7556 | execution in that frame has stopped. You can print other portions of |
7557 | source files by explicit command. | |
7558 | ||
7a292a7a | 7559 | If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may |
d4f3574e | 7560 | prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using |
7a292a7a | 7561 | @value{GDBN} under @sc{gnu} Emacs}. |
c906108c SS |
7562 | |
7563 | @menu | |
7564 | * List:: Printing source lines | |
2a25a5ba | 7565 | * Specify Location:: How to specify code locations |
87885426 | 7566 | * Edit:: Editing source files |
c906108c | 7567 | * Search:: Searching source files |
c906108c SS |
7568 | * Source Path:: Specifying source directories |
7569 | * Machine Code:: Source and machine code | |
7570 | @end menu | |
7571 | ||
6d2ebf8b | 7572 | @node List |
79a6e687 | 7573 | @section Printing Source Lines |
c906108c SS |
7574 | |
7575 | @kindex list | |
41afff9a | 7576 | @kindex l @r{(@code{list})} |
c906108c | 7577 | To print lines from a source file, use the @code{list} command |
5d161b24 | 7578 | (abbreviated @code{l}). By default, ten lines are printed. |
2a25a5ba EZ |
7579 | There are several ways to specify what part of the file you want to |
7580 | print; see @ref{Specify Location}, for the full list. | |
c906108c SS |
7581 | |
7582 | Here are the forms of the @code{list} command most commonly used: | |
7583 | ||
7584 | @table @code | |
7585 | @item list @var{linenum} | |
7586 | Print lines centered around line number @var{linenum} in the | |
7587 | current source file. | |
7588 | ||
7589 | @item list @var{function} | |
7590 | Print lines centered around the beginning of function | |
7591 | @var{function}. | |
7592 | ||
7593 | @item list | |
7594 | Print more lines. If the last lines printed were printed with a | |
7595 | @code{list} command, this prints lines following the last lines | |
7596 | printed; however, if the last line printed was a solitary line printed | |
7597 | as part of displaying a stack frame (@pxref{Stack, ,Examining the | |
7598 | Stack}), this prints lines centered around that line. | |
7599 | ||
7600 | @item list - | |
7601 | Print lines just before the lines last printed. | |
7602 | @end table | |
7603 | ||
9c16f35a | 7604 | @cindex @code{list}, how many lines to display |
c906108c SS |
7605 | By default, @value{GDBN} prints ten source lines with any of these forms of |
7606 | the @code{list} command. You can change this using @code{set listsize}: | |
7607 | ||
7608 | @table @code | |
7609 | @kindex set listsize | |
7610 | @item set listsize @var{count} | |
f81d1120 | 7611 | @itemx set listsize unlimited |
c906108c SS |
7612 | Make the @code{list} command display @var{count} source lines (unless |
7613 | the @code{list} argument explicitly specifies some other number). | |
f81d1120 | 7614 | Setting @var{count} to @code{unlimited} or 0 means there's no limit. |
c906108c SS |
7615 | |
7616 | @kindex show listsize | |
7617 | @item show listsize | |
7618 | Display the number of lines that @code{list} prints. | |
7619 | @end table | |
7620 | ||
7621 | Repeating a @code{list} command with @key{RET} discards the argument, | |
7622 | so it is equivalent to typing just @code{list}. This is more useful | |
7623 | than listing the same lines again. An exception is made for an | |
7624 | argument of @samp{-}; that argument is preserved in repetition so that | |
7625 | each repetition moves up in the source file. | |
7626 | ||
c906108c | 7627 | In general, the @code{list} command expects you to supply zero, one or two |
629500fa | 7628 | @dfn{locations}. Locations specify source lines; there are several ways |
2a25a5ba EZ |
7629 | of writing them (@pxref{Specify Location}), but the effect is always |
7630 | to specify some source line. | |
7631 | ||
c906108c SS |
7632 | Here is a complete description of the possible arguments for @code{list}: |
7633 | ||
7634 | @table @code | |
629500fa KS |
7635 | @item list @var{location} |
7636 | Print lines centered around the line specified by @var{location}. | |
c906108c SS |
7637 | |
7638 | @item list @var{first},@var{last} | |
7639 | Print lines from @var{first} to @var{last}. Both arguments are | |
629500fa KS |
7640 | locations. When a @code{list} command has two locations, and the |
7641 | source file of the second location is omitted, this refers to | |
7642 | the same source file as the first location. | |
c906108c SS |
7643 | |
7644 | @item list ,@var{last} | |
7645 | Print lines ending with @var{last}. | |
7646 | ||
7647 | @item list @var{first}, | |
7648 | Print lines starting with @var{first}. | |
7649 | ||
7650 | @item list + | |
7651 | Print lines just after the lines last printed. | |
7652 | ||
7653 | @item list - | |
7654 | Print lines just before the lines last printed. | |
7655 | ||
7656 | @item list | |
7657 | As described in the preceding table. | |
7658 | @end table | |
7659 | ||
2a25a5ba EZ |
7660 | @node Specify Location |
7661 | @section Specifying a Location | |
7662 | @cindex specifying location | |
629500fa KS |
7663 | @cindex location |
7664 | @cindex source location | |
7665 | ||
7666 | @menu | |
7667 | * Linespec Locations:: Linespec locations | |
7668 | * Explicit Locations:: Explicit locations | |
7669 | * Address Locations:: Address locations | |
7670 | @end menu | |
c906108c | 7671 | |
2a25a5ba EZ |
7672 | Several @value{GDBN} commands accept arguments that specify a location |
7673 | of your program's code. Since @value{GDBN} is a source-level | |
629500fa KS |
7674 | debugger, a location usually specifies some line in the source code. |
7675 | Locations may be specified using three different formats: | |
7676 | linespec locations, explicit locations, or address locations. | |
c906108c | 7677 | |
629500fa KS |
7678 | @node Linespec Locations |
7679 | @subsection Linespec Locations | |
7680 | @cindex linespec locations | |
7681 | ||
7682 | A @dfn{linespec} is a colon-separated list of source location parameters such | |
7683 | as file name, function name, etc. Here are all the different ways of | |
7684 | specifying a linespec: | |
c906108c | 7685 | |
2a25a5ba EZ |
7686 | @table @code |
7687 | @item @var{linenum} | |
7688 | Specifies the line number @var{linenum} of the current source file. | |
c906108c | 7689 | |
2a25a5ba EZ |
7690 | @item -@var{offset} |
7691 | @itemx +@var{offset} | |
7692 | Specifies the line @var{offset} lines before or after the @dfn{current | |
7693 | line}. For the @code{list} command, the current line is the last one | |
7694 | printed; for the breakpoint commands, this is the line at which | |
7695 | execution stopped in the currently selected @dfn{stack frame} | |
7696 | (@pxref{Frames, ,Frames}, for a description of stack frames.) When | |
7697 | used as the second of the two linespecs in a @code{list} command, | |
7698 | this specifies the line @var{offset} lines up or down from the first | |
7699 | linespec. | |
7700 | ||
7701 | @item @var{filename}:@var{linenum} | |
7702 | Specifies the line @var{linenum} in the source file @var{filename}. | |
4aac40c8 TT |
7703 | If @var{filename} is a relative file name, then it will match any |
7704 | source file name with the same trailing components. For example, if | |
7705 | @var{filename} is @samp{gcc/expr.c}, then it will match source file | |
7706 | name of @file{/build/trunk/gcc/expr.c}, but not | |
7707 | @file{/build/trunk/libcpp/expr.c} or @file{/build/trunk/gcc/x-expr.c}. | |
c906108c SS |
7708 | |
7709 | @item @var{function} | |
7710 | Specifies the line that begins the body of the function @var{function}. | |
2a25a5ba | 7711 | For example, in C, this is the line with the open brace. |
c906108c | 7712 | |
9ef07c8c TT |
7713 | @item @var{function}:@var{label} |
7714 | Specifies the line where @var{label} appears in @var{function}. | |
7715 | ||
c906108c | 7716 | @item @var{filename}:@var{function} |
2a25a5ba EZ |
7717 | Specifies the line that begins the body of the function @var{function} |
7718 | in the file @var{filename}. You only need the file name with a | |
7719 | function name to avoid ambiguity when there are identically named | |
7720 | functions in different source files. | |
c906108c | 7721 | |
0f5238ed | 7722 | @item @var{label} |
629500fa KS |
7723 | Specifies the line at which the label named @var{label} appears |
7724 | in the function corresponding to the currently selected stack frame. | |
7725 | If there is no current selected stack frame (for instance, if the inferior | |
7726 | is not running), then @value{GDBN} will not search for a label. | |
7727 | ||
7728 | @cindex breakpoint at static probe point | |
7729 | @item -pstap|-probe-stap @r{[}@var{objfile}:@r{[}@var{provider}:@r{]}@r{]}@var{name} | |
7730 | The @sc{gnu}/Linux tool @code{SystemTap} provides a way for | |
7731 | applications to embed static probes. @xref{Static Probe Points}, for more | |
7732 | information on finding and using static probes. This form of linespec | |
7733 | specifies the location of such a static probe. | |
7734 | ||
7735 | If @var{objfile} is given, only probes coming from that shared library | |
7736 | or executable matching @var{objfile} as a regular expression are considered. | |
7737 | If @var{provider} is given, then only probes from that provider are considered. | |
7738 | If several probes match the spec, @value{GDBN} will insert a breakpoint at | |
7739 | each one of those probes. | |
7740 | @end table | |
7741 | ||
7742 | @node Explicit Locations | |
7743 | @subsection Explicit Locations | |
7744 | @cindex explicit locations | |
7745 | ||
7746 | @dfn{Explicit locations} allow the user to directly specify the source | |
7747 | location's parameters using option-value pairs. | |
7748 | ||
7749 | Explicit locations are useful when several functions, labels, or | |
7750 | file names have the same name (base name for files) in the program's | |
7751 | sources. In these cases, explicit locations point to the source | |
7752 | line you meant more accurately and unambiguously. Also, using | |
7753 | explicit locations might be faster in large programs. | |
7754 | ||
7755 | For example, the linespec @samp{foo:bar} may refer to a function @code{bar} | |
7756 | defined in the file named @file{foo} or the label @code{bar} in a function | |
7757 | named @code{foo}. @value{GDBN} must search either the file system or | |
7758 | the symbol table to know. | |
7759 | ||
7760 | The list of valid explicit location options is summarized in the | |
7761 | following table: | |
7762 | ||
7763 | @table @code | |
7764 | @item -source @var{filename} | |
7765 | The value specifies the source file name. To differentiate between | |
7766 | files with the same base name, prepend as many directories as is necessary | |
7767 | to uniquely identify the desired file, e.g., @file{foo/bar/baz.c}. Otherwise | |
7768 | @value{GDBN} will use the first file it finds with the given base | |
7769 | name. This option requires the use of either @code{-function} or @code{-line}. | |
7770 | ||
7771 | @item -function @var{function} | |
7772 | The value specifies the name of a function. Operations | |
7773 | on function locations unmodified by other options (such as @code{-label} | |
7774 | or @code{-line}) refer to the line that begins the body of the function. | |
7775 | In C, for example, this is the line with the open brace. | |
7776 | ||
7777 | @item -label @var{label} | |
7778 | The value specifies the name of a label. When the function | |
7779 | name is not specified, the label is searched in the function of the currently | |
7780 | selected stack frame. | |
7781 | ||
7782 | @item -line @var{number} | |
7783 | The value specifies a line offset for the location. The offset may either | |
7784 | be absolute (@code{-line 3}) or relative (@code{-line +3}), depending on | |
7785 | the command. When specified without any other options, the line offset is | |
7786 | relative to the current line. | |
7787 | @end table | |
7788 | ||
7789 | Explicit location options may be abbreviated by omitting any non-unique | |
7790 | trailing characters from the option name, e.g., @code{break -s main.c -li 3}. | |
7791 | ||
7792 | @node Address Locations | |
7793 | @subsection Address Locations | |
7794 | @cindex address locations | |
7795 | ||
7796 | @dfn{Address locations} indicate a specific program address. They have | |
7797 | the generalized form *@var{address}. | |
7798 | ||
7799 | For line-oriented commands, such as @code{list} and @code{edit}, this | |
7800 | specifies a source line that contains @var{address}. For @code{break} and | |
7801 | other breakpoint-oriented commands, this can be used to set breakpoints in | |
2a25a5ba EZ |
7802 | parts of your program which do not have debugging information or |
7803 | source files. | |
7804 | ||
7805 | Here @var{address} may be any expression valid in the current working | |
7806 | language (@pxref{Languages, working language}) that specifies a code | |
5fa54e5d | 7807 | address. In addition, as a convenience, @value{GDBN} extends the |
629500fa KS |
7808 | semantics of expressions used in locations to cover several situations |
7809 | that frequently occur during debugging. Here are the various forms | |
5fa54e5d | 7810 | of @var{address}: |
2a25a5ba EZ |
7811 | |
7812 | @table @code | |
7813 | @item @var{expression} | |
7814 | Any expression valid in the current working language. | |
7815 | ||
7816 | @item @var{funcaddr} | |
7817 | An address of a function or procedure derived from its name. In C, | |
7818 | C@t{++}, Java, Objective-C, Fortran, minimal, and assembly, this is | |
7819 | simply the function's name @var{function} (and actually a special case | |
7820 | of a valid expression). In Pascal and Modula-2, this is | |
7821 | @code{&@var{function}}. In Ada, this is @code{@var{function}'Address} | |
7822 | (although the Pascal form also works). | |
7823 | ||
7824 | This form specifies the address of the function's first instruction, | |
7825 | before the stack frame and arguments have been set up. | |
7826 | ||
9a284c97 | 7827 | @item '@var{filename}':@var{funcaddr} |
2a25a5ba EZ |
7828 | Like @var{funcaddr} above, but also specifies the name of the source |
7829 | file explicitly. This is useful if the name of the function does not | |
7830 | specify the function unambiguously, e.g., if there are several | |
7831 | functions with identical names in different source files. | |
c906108c SS |
7832 | @end table |
7833 | ||
87885426 | 7834 | @node Edit |
79a6e687 | 7835 | @section Editing Source Files |
87885426 FN |
7836 | @cindex editing source files |
7837 | ||
7838 | @kindex edit | |
7839 | @kindex e @r{(@code{edit})} | |
7840 | To edit the lines in a source file, use the @code{edit} command. | |
7841 | The editing program of your choice | |
7842 | is invoked with the current line set to | |
7843 | the active line in the program. | |
7844 | Alternatively, there are several ways to specify what part of the file you | |
2a25a5ba | 7845 | want to print if you want to see other parts of the program: |
87885426 FN |
7846 | |
7847 | @table @code | |
2a25a5ba EZ |
7848 | @item edit @var{location} |
7849 | Edit the source file specified by @code{location}. Editing starts at | |
7850 | that @var{location}, e.g., at the specified source line of the | |
7851 | specified file. @xref{Specify Location}, for all the possible forms | |
7852 | of the @var{location} argument; here are the forms of the @code{edit} | |
7853 | command most commonly used: | |
87885426 | 7854 | |
2a25a5ba | 7855 | @table @code |
87885426 FN |
7856 | @item edit @var{number} |
7857 | Edit the current source file with @var{number} as the active line number. | |
7858 | ||
7859 | @item edit @var{function} | |
7860 | Edit the file containing @var{function} at the beginning of its definition. | |
2a25a5ba | 7861 | @end table |
87885426 | 7862 | |
87885426 FN |
7863 | @end table |
7864 | ||
79a6e687 | 7865 | @subsection Choosing your Editor |
87885426 FN |
7866 | You can customize @value{GDBN} to use any editor you want |
7867 | @footnote{ | |
7868 | The only restriction is that your editor (say @code{ex}), recognizes the | |
7869 | following command-line syntax: | |
10998722 | 7870 | @smallexample |
87885426 | 7871 | ex +@var{number} file |
10998722 | 7872 | @end smallexample |
15387254 EZ |
7873 | The optional numeric value +@var{number} specifies the number of the line in |
7874 | the file where to start editing.}. | |
7875 | By default, it is @file{@value{EDITOR}}, but you can change this | |
10998722 AC |
7876 | by setting the environment variable @code{EDITOR} before using |
7877 | @value{GDBN}. For example, to configure @value{GDBN} to use the | |
7878 | @code{vi} editor, you could use these commands with the @code{sh} shell: | |
7879 | @smallexample | |
87885426 FN |
7880 | EDITOR=/usr/bin/vi |
7881 | export EDITOR | |
15387254 | 7882 | gdb @dots{} |
10998722 | 7883 | @end smallexample |
87885426 | 7884 | or in the @code{csh} shell, |
10998722 | 7885 | @smallexample |
87885426 | 7886 | setenv EDITOR /usr/bin/vi |
15387254 | 7887 | gdb @dots{} |
10998722 | 7888 | @end smallexample |
87885426 | 7889 | |
6d2ebf8b | 7890 | @node Search |
79a6e687 | 7891 | @section Searching Source Files |
15387254 | 7892 | @cindex searching source files |
c906108c SS |
7893 | |
7894 | There are two commands for searching through the current source file for a | |
7895 | regular expression. | |
7896 | ||
7897 | @table @code | |
7898 | @kindex search | |
7899 | @kindex forward-search | |
1e96de83 | 7900 | @kindex fo @r{(@code{forward-search})} |
c906108c SS |
7901 | @item forward-search @var{regexp} |
7902 | @itemx search @var{regexp} | |
7903 | The command @samp{forward-search @var{regexp}} checks each line, | |
7904 | starting with the one following the last line listed, for a match for | |
5d161b24 | 7905 | @var{regexp}. It lists the line that is found. You can use the |
c906108c SS |
7906 | synonym @samp{search @var{regexp}} or abbreviate the command name as |
7907 | @code{fo}. | |
7908 | ||
09d4efe1 | 7909 | @kindex reverse-search |
c906108c SS |
7910 | @item reverse-search @var{regexp} |
7911 | The command @samp{reverse-search @var{regexp}} checks each line, starting | |
7912 | with the one before the last line listed and going backward, for a match | |
7913 | for @var{regexp}. It lists the line that is found. You can abbreviate | |
7914 | this command as @code{rev}. | |
7915 | @end table | |
c906108c | 7916 | |
6d2ebf8b | 7917 | @node Source Path |
79a6e687 | 7918 | @section Specifying Source Directories |
c906108c SS |
7919 | |
7920 | @cindex source path | |
7921 | @cindex directories for source files | |
7922 | Executable programs sometimes do not record the directories of the source | |
7923 | files from which they were compiled, just the names. Even when they do, | |
7924 | the directories could be moved between the compilation and your debugging | |
7925 | session. @value{GDBN} has a list of directories to search for source files; | |
7926 | this is called the @dfn{source path}. Each time @value{GDBN} wants a source file, | |
7927 | it tries all the directories in the list, in the order they are present | |
0b66e38c EZ |
7928 | in the list, until it finds a file with the desired name. |
7929 | ||
7930 | For example, suppose an executable references the file | |
7931 | @file{/usr/src/foo-1.0/lib/foo.c}, and our source path is | |
7932 | @file{/mnt/cross}. The file is first looked up literally; if this | |
7933 | fails, @file{/mnt/cross/usr/src/foo-1.0/lib/foo.c} is tried; if this | |
7934 | fails, @file{/mnt/cross/foo.c} is opened; if this fails, an error | |
7935 | message is printed. @value{GDBN} does not look up the parts of the | |
7936 | source file name, such as @file{/mnt/cross/src/foo-1.0/lib/foo.c}. | |
7937 | Likewise, the subdirectories of the source path are not searched: if | |
7938 | the source path is @file{/mnt/cross}, and the binary refers to | |
7939 | @file{foo.c}, @value{GDBN} would not find it under | |
7940 | @file{/mnt/cross/usr/src/foo-1.0/lib}. | |
7941 | ||
7942 | Plain file names, relative file names with leading directories, file | |
7943 | names containing dots, etc.@: are all treated as described above; for | |
7944 | instance, if the source path is @file{/mnt/cross}, and the source file | |
7945 | is recorded as @file{../lib/foo.c}, @value{GDBN} would first try | |
7946 | @file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, and after | |
7947 | that---@file{/mnt/cross/foo.c}. | |
7948 | ||
7949 | Note that the executable search path is @emph{not} used to locate the | |
cd852561 | 7950 | source files. |
c906108c SS |
7951 | |
7952 | Whenever you reset or rearrange the source path, @value{GDBN} clears out | |
7953 | any information it has cached about where source files are found and where | |
7954 | each line is in the file. | |
7955 | ||
7956 | @kindex directory | |
7957 | @kindex dir | |
d4f3574e SS |
7958 | When you start @value{GDBN}, its source path includes only @samp{cdir} |
7959 | and @samp{cwd}, in that order. | |
c906108c SS |
7960 | To add other directories, use the @code{directory} command. |
7961 | ||
4b505b12 AS |
7962 | The search path is used to find both program source files and @value{GDBN} |
7963 | script files (read using the @samp{-command} option and @samp{source} command). | |
7964 | ||
30daae6c JB |
7965 | In addition to the source path, @value{GDBN} provides a set of commands |
7966 | that manage a list of source path substitution rules. A @dfn{substitution | |
7967 | rule} specifies how to rewrite source directories stored in the program's | |
7968 | debug information in case the sources were moved to a different | |
7969 | directory between compilation and debugging. A rule is made of | |
7970 | two strings, the first specifying what needs to be rewritten in | |
7971 | the path, and the second specifying how it should be rewritten. | |
7972 | In @ref{set substitute-path}, we name these two parts @var{from} and | |
7973 | @var{to} respectively. @value{GDBN} does a simple string replacement | |
7974 | of @var{from} with @var{to} at the start of the directory part of the | |
7975 | source file name, and uses that result instead of the original file | |
7976 | name to look up the sources. | |
7977 | ||
7978 | Using the previous example, suppose the @file{foo-1.0} tree has been | |
7979 | moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell | |
3f94c067 | 7980 | @value{GDBN} to replace @file{/usr/src} in all source path names with |
30daae6c JB |
7981 | @file{/mnt/cross}. The first lookup will then be |
7982 | @file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location | |
7983 | of @file{/usr/src/foo-1.0/lib/foo.c}. To define a source path | |
7984 | substitution rule, use the @code{set substitute-path} command | |
7985 | (@pxref{set substitute-path}). | |
7986 | ||
7987 | To avoid unexpected substitution results, a rule is applied only if the | |
7988 | @var{from} part of the directory name ends at a directory separator. | |
7989 | For instance, a rule substituting @file{/usr/source} into | |
7990 | @file{/mnt/cross} will be applied to @file{/usr/source/foo-1.0} but | |
7991 | not to @file{/usr/sourceware/foo-2.0}. And because the substitution | |
d3e8051b | 7992 | is applied only at the beginning of the directory name, this rule will |
30daae6c JB |
7993 | not be applied to @file{/root/usr/source/baz.c} either. |
7994 | ||
7995 | In many cases, you can achieve the same result using the @code{directory} | |
7996 | command. However, @code{set substitute-path} can be more efficient in | |
7997 | the case where the sources are organized in a complex tree with multiple | |
7998 | subdirectories. With the @code{directory} command, you need to add each | |
7999 | subdirectory of your project. If you moved the entire tree while | |
8000 | preserving its internal organization, then @code{set substitute-path} | |
8001 | allows you to direct the debugger to all the sources with one single | |
8002 | command. | |
8003 | ||
8004 | @code{set substitute-path} is also more than just a shortcut command. | |
8005 | The source path is only used if the file at the original location no | |
8006 | longer exists. On the other hand, @code{set substitute-path} modifies | |
8007 | the debugger behavior to look at the rewritten location instead. So, if | |
8008 | for any reason a source file that is not relevant to your executable is | |
8009 | located at the original location, a substitution rule is the only | |
3f94c067 | 8010 | method available to point @value{GDBN} at the new location. |
30daae6c | 8011 | |
29b0e8a2 JM |
8012 | @cindex @samp{--with-relocated-sources} |
8013 | @cindex default source path substitution | |
8014 | You can configure a default source path substitution rule by | |
8015 | configuring @value{GDBN} with the | |
8016 | @samp{--with-relocated-sources=@var{dir}} option. The @var{dir} | |
8017 | should be the name of a directory under @value{GDBN}'s configured | |
8018 | prefix (set with @samp{--prefix} or @samp{--exec-prefix}), and | |
8019 | directory names in debug information under @var{dir} will be adjusted | |
8020 | automatically if the installed @value{GDBN} is moved to a new | |
8021 | location. This is useful if @value{GDBN}, libraries or executables | |
8022 | with debug information and corresponding source code are being moved | |
8023 | together. | |
8024 | ||
c906108c SS |
8025 | @table @code |
8026 | @item directory @var{dirname} @dots{} | |
8027 | @item dir @var{dirname} @dots{} | |
8028 | Add directory @var{dirname} to the front of the source path. Several | |
d4f3574e SS |
8029 | directory names may be given to this command, separated by @samp{:} |
8030 | (@samp{;} on MS-DOS and MS-Windows, where @samp{:} usually appears as | |
8031 | part of absolute file names) or | |
c906108c SS |
8032 | whitespace. You may specify a directory that is already in the source |
8033 | path; this moves it forward, so @value{GDBN} searches it sooner. | |
8034 | ||
8035 | @kindex cdir | |
8036 | @kindex cwd | |
41afff9a | 8037 | @vindex $cdir@r{, convenience variable} |
d3e8051b | 8038 | @vindex $cwd@r{, convenience variable} |
c906108c SS |
8039 | @cindex compilation directory |
8040 | @cindex current directory | |
8041 | @cindex working directory | |
8042 | @cindex directory, current | |
8043 | @cindex directory, compilation | |
8044 | You can use the string @samp{$cdir} to refer to the compilation | |
8045 | directory (if one is recorded), and @samp{$cwd} to refer to the current | |
8046 | working directory. @samp{$cwd} is not the same as @samp{.}---the former | |
8047 | tracks the current working directory as it changes during your @value{GDBN} | |
8048 | session, while the latter is immediately expanded to the current | |
8049 | directory at the time you add an entry to the source path. | |
8050 | ||
8051 | @item directory | |
cd852561 | 8052 | Reset the source path to its default value (@samp{$cdir:$cwd} on Unix systems). This requires confirmation. |
c906108c SS |
8053 | |
8054 | @c RET-repeat for @code{directory} is explicitly disabled, but since | |
8055 | @c repeating it would be a no-op we do not say that. (thanks to RMS) | |
8056 | ||
99e7ae30 DE |
8057 | @item set directories @var{path-list} |
8058 | @kindex set directories | |
8059 | Set the source path to @var{path-list}. | |
8060 | @samp{$cdir:$cwd} are added if missing. | |
8061 | ||
c906108c SS |
8062 | @item show directories |
8063 | @kindex show directories | |
8064 | Print the source path: show which directories it contains. | |
30daae6c JB |
8065 | |
8066 | @anchor{set substitute-path} | |
8067 | @item set substitute-path @var{from} @var{to} | |
8068 | @kindex set substitute-path | |
8069 | Define a source path substitution rule, and add it at the end of the | |
8070 | current list of existing substitution rules. If a rule with the same | |
8071 | @var{from} was already defined, then the old rule is also deleted. | |
8072 | ||
8073 | For example, if the file @file{/foo/bar/baz.c} was moved to | |
8074 | @file{/mnt/cross/baz.c}, then the command | |
8075 | ||
8076 | @smallexample | |
c58b006b | 8077 | (@value{GDBP}) set substitute-path /foo/bar /mnt/cross |
30daae6c JB |
8078 | @end smallexample |
8079 | ||
8080 | @noindent | |
c58b006b | 8081 | will tell @value{GDBN} to replace @samp{/foo/bar} with |
30daae6c JB |
8082 | @samp{/mnt/cross}, which will allow @value{GDBN} to find the file |
8083 | @file{baz.c} even though it was moved. | |
8084 | ||
8085 | In the case when more than one substitution rule have been defined, | |
8086 | the rules are evaluated one by one in the order where they have been | |
8087 | defined. The first one matching, if any, is selected to perform | |
8088 | the substitution. | |
8089 | ||
8090 | For instance, if we had entered the following commands: | |
8091 | ||
8092 | @smallexample | |
8093 | (@value{GDBP}) set substitute-path /usr/src/include /mnt/include | |
8094 | (@value{GDBP}) set substitute-path /usr/src /mnt/src | |
8095 | @end smallexample | |
8096 | ||
8097 | @noindent | |
8098 | @value{GDBN} would then rewrite @file{/usr/src/include/defs.h} into | |
8099 | @file{/mnt/include/defs.h} by using the first rule. However, it would | |
8100 | use the second rule to rewrite @file{/usr/src/lib/foo.c} into | |
8101 | @file{/mnt/src/lib/foo.c}. | |
8102 | ||
8103 | ||
8104 | @item unset substitute-path [path] | |
8105 | @kindex unset substitute-path | |
8106 | If a path is specified, search the current list of substitution rules | |
8107 | for a rule that would rewrite that path. Delete that rule if found. | |
8108 | A warning is emitted by the debugger if no rule could be found. | |
8109 | ||
8110 | If no path is specified, then all substitution rules are deleted. | |
8111 | ||
8112 | @item show substitute-path [path] | |
8113 | @kindex show substitute-path | |
8114 | If a path is specified, then print the source path substitution rule | |
8115 | which would rewrite that path, if any. | |
8116 | ||
8117 | If no path is specified, then print all existing source path substitution | |
8118 | rules. | |
8119 | ||
c906108c SS |
8120 | @end table |
8121 | ||
8122 | If your source path is cluttered with directories that are no longer of | |
8123 | interest, @value{GDBN} may sometimes cause confusion by finding the wrong | |
8124 | versions of source. You can correct the situation as follows: | |
8125 | ||
8126 | @enumerate | |
8127 | @item | |
cd852561 | 8128 | Use @code{directory} with no argument to reset the source path to its default value. |
c906108c SS |
8129 | |
8130 | @item | |
8131 | Use @code{directory} with suitable arguments to reinstall the | |
8132 | directories you want in the source path. You can add all the | |
8133 | directories in one command. | |
8134 | @end enumerate | |
8135 | ||
6d2ebf8b | 8136 | @node Machine Code |
79a6e687 | 8137 | @section Source and Machine Code |
15387254 | 8138 | @cindex source line and its code address |
c906108c SS |
8139 | |
8140 | You can use the command @code{info line} to map source lines to program | |
8141 | addresses (and vice versa), and the command @code{disassemble} to display | |
91440f57 HZ |
8142 | a range of addresses as machine instructions. You can use the command |
8143 | @code{set disassemble-next-line} to set whether to disassemble next | |
8144 | source line when execution stops. When run under @sc{gnu} Emacs | |
d4f3574e | 8145 | mode, the @code{info line} command causes the arrow to point to the |
5d161b24 | 8146 | line specified. Also, @code{info line} prints addresses in symbolic form as |
c906108c SS |
8147 | well as hex. |
8148 | ||
8149 | @table @code | |
8150 | @kindex info line | |
629500fa | 8151 | @item info line @var{location} |
c906108c | 8152 | Print the starting and ending addresses of the compiled code for |
629500fa | 8153 | source line @var{location}. You can specify source lines in any of |
2a25a5ba | 8154 | the ways documented in @ref{Specify Location}. |
c906108c SS |
8155 | @end table |
8156 | ||
8157 | For example, we can use @code{info line} to discover the location of | |
8158 | the object code for the first line of function | |
8159 | @code{m4_changequote}: | |
8160 | ||
d4f3574e SS |
8161 | @c FIXME: I think this example should also show the addresses in |
8162 | @c symbolic form, as they usually would be displayed. | |
c906108c | 8163 | @smallexample |
96a2c332 | 8164 | (@value{GDBP}) info line m4_changequote |
c906108c SS |
8165 | Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350. |
8166 | @end smallexample | |
8167 | ||
8168 | @noindent | |
15387254 | 8169 | @cindex code address and its source line |
c906108c | 8170 | We can also inquire (using @code{*@var{addr}} as the form for |
629500fa | 8171 | @var{location}) what source line covers a particular address: |
c906108c SS |
8172 | @smallexample |
8173 | (@value{GDBP}) info line *0x63ff | |
8174 | Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404. | |
8175 | @end smallexample | |
8176 | ||
8177 | @cindex @code{$_} and @code{info line} | |
15387254 | 8178 | @cindex @code{x} command, default address |
41afff9a | 8179 | @kindex x@r{(examine), and} info line |
c906108c SS |
8180 | After @code{info line}, the default address for the @code{x} command |
8181 | is changed to the starting address of the line, so that @samp{x/i} is | |
8182 | sufficient to begin examining the machine code (@pxref{Memory, | |
79a6e687 | 8183 | ,Examining Memory}). Also, this address is saved as the value of the |
c906108c | 8184 | convenience variable @code{$_} (@pxref{Convenience Vars, ,Convenience |
79a6e687 | 8185 | Variables}). |
c906108c SS |
8186 | |
8187 | @table @code | |
8188 | @kindex disassemble | |
8189 | @cindex assembly instructions | |
8190 | @cindex instructions, assembly | |
8191 | @cindex machine instructions | |
8192 | @cindex listing machine instructions | |
8193 | @item disassemble | |
d14508fe | 8194 | @itemx disassemble /m |
6ff0ba5f | 8195 | @itemx disassemble /s |
9b117ef3 | 8196 | @itemx disassemble /r |
c906108c | 8197 | This specialized command dumps a range of memory as machine |
d14508fe | 8198 | instructions. It can also print mixed source+disassembly by specifying |
6ff0ba5f DE |
8199 | the @code{/m} or @code{/s} modifier and print the raw instructions in hex |
8200 | as well as in symbolic form by specifying the @code{/r} modifier. | |
d14508fe | 8201 | The default memory range is the function surrounding the |
c906108c SS |
8202 | program counter of the selected frame. A single argument to this |
8203 | command is a program counter value; @value{GDBN} dumps the function | |
21a0512e PP |
8204 | surrounding this value. When two arguments are given, they should |
8205 | be separated by a comma, possibly surrounded by whitespace. The | |
53a71c06 CR |
8206 | arguments specify a range of addresses to dump, in one of two forms: |
8207 | ||
8208 | @table @code | |
8209 | @item @var{start},@var{end} | |
8210 | the addresses from @var{start} (inclusive) to @var{end} (exclusive) | |
8211 | @item @var{start},+@var{length} | |
8212 | the addresses from @var{start} (inclusive) to | |
8213 | @code{@var{start}+@var{length}} (exclusive). | |
8214 | @end table | |
8215 | ||
8216 | @noindent | |
8217 | When 2 arguments are specified, the name of the function is also | |
8218 | printed (since there could be several functions in the given range). | |
21a0512e PP |
8219 | |
8220 | The argument(s) can be any expression yielding a numeric value, such as | |
8221 | @samp{0x32c4}, @samp{&main+10} or @samp{$pc - 8}. | |
2b28d209 PP |
8222 | |
8223 | If the range of memory being disassembled contains current program counter, | |
8224 | the instruction at that location is shown with a @code{=>} marker. | |
c906108c SS |
8225 | @end table |
8226 | ||
c906108c SS |
8227 | The following example shows the disassembly of a range of addresses of |
8228 | HP PA-RISC 2.0 code: | |
8229 | ||
8230 | @smallexample | |
21a0512e | 8231 | (@value{GDBP}) disas 0x32c4, 0x32e4 |
c906108c | 8232 | Dump of assembler code from 0x32c4 to 0x32e4: |
2b28d209 PP |
8233 | 0x32c4 <main+204>: addil 0,dp |
8234 | 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26 | |
8235 | 0x32cc <main+212>: ldil 0x3000,r31 | |
8236 | 0x32d0 <main+216>: ble 0x3f8(sr4,r31) | |
8237 | 0x32d4 <main+220>: ldo 0(r31),rp | |
8238 | 0x32d8 <main+224>: addil -0x800,dp | |
8239 | 0x32dc <main+228>: ldo 0x588(r1),r26 | |
8240 | 0x32e0 <main+232>: ldil 0x3000,r31 | |
c906108c SS |
8241 | End of assembler dump. |
8242 | @end smallexample | |
c906108c | 8243 | |
6ff0ba5f DE |
8244 | Here is an example showing mixed source+assembly for Intel x86 |
8245 | with @code{/m} or @code{/s}, when the program is stopped just after | |
8246 | function prologue in a non-optimized function with no inline code. | |
d14508fe DE |
8247 | |
8248 | @smallexample | |
8249 | (@value{GDBP}) disas /m main | |
8250 | Dump of assembler code for function main: | |
8251 | 5 @{ | |
9c419145 PP |
8252 | 0x08048330 <+0>: push %ebp |
8253 | 0x08048331 <+1>: mov %esp,%ebp | |
8254 | 0x08048333 <+3>: sub $0x8,%esp | |
8255 | 0x08048336 <+6>: and $0xfffffff0,%esp | |
8256 | 0x08048339 <+9>: sub $0x10,%esp | |
d14508fe DE |
8257 | |
8258 | 6 printf ("Hello.\n"); | |
9c419145 PP |
8259 | => 0x0804833c <+12>: movl $0x8048440,(%esp) |
8260 | 0x08048343 <+19>: call 0x8048284 <puts@@plt> | |
d14508fe DE |
8261 | |
8262 | 7 return 0; | |
8263 | 8 @} | |
9c419145 PP |
8264 | 0x08048348 <+24>: mov $0x0,%eax |
8265 | 0x0804834d <+29>: leave | |
8266 | 0x0804834e <+30>: ret | |
d14508fe DE |
8267 | |
8268 | End of assembler dump. | |
8269 | @end smallexample | |
8270 | ||
6ff0ba5f DE |
8271 | The @code{/m} option is deprecated as its output is not useful when |
8272 | there is either inlined code or re-ordered code. | |
8273 | The @code{/s} option is the preferred choice. | |
8274 | Here is an example for AMD x86-64 showing the difference between | |
8275 | @code{/m} output and @code{/s} output. | |
8276 | This example has one inline function defined in a header file, | |
8277 | and the code is compiled with @samp{-O2} optimization. | |
8278 | Note how the @code{/m} output is missing the disassembly of | |
8279 | several instructions that are present in the @code{/s} output. | |
8280 | ||
8281 | @file{foo.h}: | |
8282 | ||
8283 | @smallexample | |
8284 | int | |
8285 | foo (int a) | |
8286 | @{ | |
8287 | if (a < 0) | |
8288 | return a * 2; | |
8289 | if (a == 0) | |
8290 | return 1; | |
8291 | return a + 10; | |
8292 | @} | |
8293 | @end smallexample | |
8294 | ||
8295 | @file{foo.c}: | |
8296 | ||
8297 | @smallexample | |
8298 | #include "foo.h" | |
8299 | volatile int x, y; | |
8300 | int | |
8301 | main () | |
8302 | @{ | |
8303 | x = foo (y); | |
8304 | return 0; | |
8305 | @} | |
8306 | @end smallexample | |
8307 | ||
8308 | @smallexample | |
8309 | (@value{GDBP}) disas /m main | |
8310 | Dump of assembler code for function main: | |
8311 | 5 @{ | |
8312 | ||
8313 | 6 x = foo (y); | |
8314 | 0x0000000000400400 <+0>: mov 0x200c2e(%rip),%eax # 0x601034 <y> | |
8315 | 0x0000000000400417 <+23>: mov %eax,0x200c13(%rip) # 0x601030 <x> | |
8316 | ||
8317 | 7 return 0; | |
8318 | 8 @} | |
8319 | 0x000000000040041d <+29>: xor %eax,%eax | |
8320 | 0x000000000040041f <+31>: retq | |
8321 | 0x0000000000400420 <+32>: add %eax,%eax | |
8322 | 0x0000000000400422 <+34>: jmp 0x400417 <main+23> | |
8323 | ||
8324 | End of assembler dump. | |
8325 | (@value{GDBP}) disas /s main | |
8326 | Dump of assembler code for function main: | |
8327 | foo.c: | |
8328 | 5 @{ | |
8329 | 6 x = foo (y); | |
8330 | 0x0000000000400400 <+0>: mov 0x200c2e(%rip),%eax # 0x601034 <y> | |
8331 | ||
8332 | foo.h: | |
8333 | 4 if (a < 0) | |
8334 | 0x0000000000400406 <+6>: test %eax,%eax | |
8335 | 0x0000000000400408 <+8>: js 0x400420 <main+32> | |
8336 | ||
8337 | 6 if (a == 0) | |
8338 | 7 return 1; | |
8339 | 8 return a + 10; | |
8340 | 0x000000000040040a <+10>: lea 0xa(%rax),%edx | |
8341 | 0x000000000040040d <+13>: test %eax,%eax | |
8342 | 0x000000000040040f <+15>: mov $0x1,%eax | |
8343 | 0x0000000000400414 <+20>: cmovne %edx,%eax | |
8344 | ||
8345 | foo.c: | |
8346 | 6 x = foo (y); | |
8347 | 0x0000000000400417 <+23>: mov %eax,0x200c13(%rip) # 0x601030 <x> | |
8348 | ||
8349 | 7 return 0; | |
8350 | 8 @} | |
8351 | 0x000000000040041d <+29>: xor %eax,%eax | |
8352 | 0x000000000040041f <+31>: retq | |
8353 | ||
8354 | foo.h: | |
8355 | 5 return a * 2; | |
8356 | 0x0000000000400420 <+32>: add %eax,%eax | |
8357 | 0x0000000000400422 <+34>: jmp 0x400417 <main+23> | |
8358 | End of assembler dump. | |
8359 | @end smallexample | |
8360 | ||
53a71c06 CR |
8361 | Here is another example showing raw instructions in hex for AMD x86-64, |
8362 | ||
8363 | @smallexample | |
8364 | (gdb) disas /r 0x400281,+10 | |
8365 | Dump of assembler code from 0x400281 to 0x40028b: | |
8366 | 0x0000000000400281: 38 36 cmp %dh,(%rsi) | |
8367 | 0x0000000000400283: 2d 36 34 2e 73 sub $0x732e3436,%eax | |
8368 | 0x0000000000400288: 6f outsl %ds:(%rsi),(%dx) | |
8369 | 0x0000000000400289: 2e 32 00 xor %cs:(%rax),%al | |
8370 | End of assembler dump. | |
8371 | @end smallexample | |
8372 | ||
629500fa | 8373 | Addresses cannot be specified as a location (@pxref{Specify Location}). |
7e1e0340 DE |
8374 | So, for example, if you want to disassemble function @code{bar} |
8375 | in file @file{foo.c}, you must type @samp{disassemble 'foo.c'::bar} | |
8376 | and not @samp{disassemble foo.c:bar}. | |
8377 | ||
c906108c SS |
8378 | Some architectures have more than one commonly-used set of instruction |
8379 | mnemonics or other syntax. | |
8380 | ||
76d17f34 EZ |
8381 | For programs that were dynamically linked and use shared libraries, |
8382 | instructions that call functions or branch to locations in the shared | |
8383 | libraries might show a seemingly bogus location---it's actually a | |
8384 | location of the relocation table. On some architectures, @value{GDBN} | |
8385 | might be able to resolve these to actual function names. | |
8386 | ||
c906108c | 8387 | @table @code |
d4f3574e | 8388 | @kindex set disassembly-flavor |
d4f3574e SS |
8389 | @cindex Intel disassembly flavor |
8390 | @cindex AT&T disassembly flavor | |
8391 | @item set disassembly-flavor @var{instruction-set} | |
c906108c SS |
8392 | Select the instruction set to use when disassembling the |
8393 | program via the @code{disassemble} or @code{x/i} commands. | |
8394 | ||
8395 | Currently this command is only defined for the Intel x86 family. You | |
d4f3574e SS |
8396 | can set @var{instruction-set} to either @code{intel} or @code{att}. |
8397 | The default is @code{att}, the AT&T flavor used by default by Unix | |
8398 | assemblers for x86-based targets. | |
9c16f35a EZ |
8399 | |
8400 | @kindex show disassembly-flavor | |
8401 | @item show disassembly-flavor | |
8402 | Show the current setting of the disassembly flavor. | |
c906108c SS |
8403 | @end table |
8404 | ||
91440f57 HZ |
8405 | @table @code |
8406 | @kindex set disassemble-next-line | |
8407 | @kindex show disassemble-next-line | |
8408 | @item set disassemble-next-line | |
8409 | @itemx show disassemble-next-line | |
32ae1842 EZ |
8410 | Control whether or not @value{GDBN} will disassemble the next source |
8411 | line or instruction when execution stops. If ON, @value{GDBN} will | |
8412 | display disassembly of the next source line when execution of the | |
8413 | program being debugged stops. This is @emph{in addition} to | |
8414 | displaying the source line itself, which @value{GDBN} always does if | |
8415 | possible. If the next source line cannot be displayed for some reason | |
8416 | (e.g., if @value{GDBN} cannot find the source file, or there's no line | |
8417 | info in the debug info), @value{GDBN} will display disassembly of the | |
8418 | next @emph{instruction} instead of showing the next source line. If | |
8419 | AUTO, @value{GDBN} will display disassembly of next instruction only | |
8420 | if the source line cannot be displayed. This setting causes | |
8421 | @value{GDBN} to display some feedback when you step through a function | |
8422 | with no line info or whose source file is unavailable. The default is | |
8423 | OFF, which means never display the disassembly of the next line or | |
8424 | instruction. | |
91440f57 HZ |
8425 | @end table |
8426 | ||
c906108c | 8427 | |
6d2ebf8b | 8428 | @node Data |
c906108c SS |
8429 | @chapter Examining Data |
8430 | ||
8431 | @cindex printing data | |
8432 | @cindex examining data | |
8433 | @kindex print | |
8434 | @kindex inspect | |
c906108c | 8435 | The usual way to examine data in your program is with the @code{print} |
7a292a7a SS |
8436 | command (abbreviated @code{p}), or its synonym @code{inspect}. It |
8437 | evaluates and prints the value of an expression of the language your | |
8438 | program is written in (@pxref{Languages, ,Using @value{GDBN} with | |
78e2826b TT |
8439 | Different Languages}). It may also print the expression using a |
8440 | Python-based pretty-printer (@pxref{Pretty Printing}). | |
c906108c SS |
8441 | |
8442 | @table @code | |
d4f3574e SS |
8443 | @item print @var{expr} |
8444 | @itemx print /@var{f} @var{expr} | |
8445 | @var{expr} is an expression (in the source language). By default the | |
8446 | value of @var{expr} is printed in a format appropriate to its data type; | |
c906108c | 8447 | you can choose a different format by specifying @samp{/@var{f}}, where |
d4f3574e | 8448 | @var{f} is a letter specifying the format; see @ref{Output Formats,,Output |
79a6e687 | 8449 | Formats}. |
c906108c SS |
8450 | |
8451 | @item print | |
8452 | @itemx print /@var{f} | |
15387254 | 8453 | @cindex reprint the last value |
d4f3574e | 8454 | If you omit @var{expr}, @value{GDBN} displays the last value again (from the |
79a6e687 | 8455 | @dfn{value history}; @pxref{Value History, ,Value History}). This allows you to |
c906108c SS |
8456 | conveniently inspect the same value in an alternative format. |
8457 | @end table | |
8458 | ||
8459 | A more low-level way of examining data is with the @code{x} command. | |
8460 | It examines data in memory at a specified address and prints it in a | |
79a6e687 | 8461 | specified format. @xref{Memory, ,Examining Memory}. |
c906108c | 8462 | |
7a292a7a | 8463 | If you are interested in information about types, or about how the |
d4f3574e SS |
8464 | fields of a struct or a class are declared, use the @code{ptype @var{exp}} |
8465 | command rather than @code{print}. @xref{Symbols, ,Examining the Symbol | |
7a292a7a | 8466 | Table}. |
c906108c | 8467 | |
06fc020f SCR |
8468 | @cindex exploring hierarchical data structures |
8469 | @kindex explore | |
8470 | Another way of examining values of expressions and type information is | |
8471 | through the Python extension command @code{explore} (available only if | |
8472 | the @value{GDBN} build is configured with @code{--with-python}). It | |
8473 | offers an interactive way to start at the highest level (or, the most | |
8474 | abstract level) of the data type of an expression (or, the data type | |
8475 | itself) and explore all the way down to leaf scalar values/fields | |
8476 | embedded in the higher level data types. | |
8477 | ||
8478 | @table @code | |
8479 | @item explore @var{arg} | |
8480 | @var{arg} is either an expression (in the source language), or a type | |
8481 | visible in the current context of the program being debugged. | |
8482 | @end table | |
8483 | ||
8484 | The working of the @code{explore} command can be illustrated with an | |
8485 | example. If a data type @code{struct ComplexStruct} is defined in your | |
8486 | C program as | |
8487 | ||
8488 | @smallexample | |
8489 | struct SimpleStruct | |
8490 | @{ | |
8491 | int i; | |
8492 | double d; | |
8493 | @}; | |
8494 | ||
8495 | struct ComplexStruct | |
8496 | @{ | |
8497 | struct SimpleStruct *ss_p; | |
8498 | int arr[10]; | |
8499 | @}; | |
8500 | @end smallexample | |
8501 | ||
8502 | @noindent | |
8503 | followed by variable declarations as | |
8504 | ||
8505 | @smallexample | |
8506 | struct SimpleStruct ss = @{ 10, 1.11 @}; | |
8507 | struct ComplexStruct cs = @{ &ss, @{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 @} @}; | |
8508 | @end smallexample | |
8509 | ||
8510 | @noindent | |
8511 | then, the value of the variable @code{cs} can be explored using the | |
8512 | @code{explore} command as follows. | |
8513 | ||
8514 | @smallexample | |
8515 | (gdb) explore cs | |
8516 | The value of `cs' is a struct/class of type `struct ComplexStruct' with | |
8517 | the following fields: | |
8518 | ||
8519 | ss_p = <Enter 0 to explore this field of type `struct SimpleStruct *'> | |
8520 | arr = <Enter 1 to explore this field of type `int [10]'> | |
8521 | ||
8522 | Enter the field number of choice: | |
8523 | @end smallexample | |
8524 | ||
8525 | @noindent | |
8526 | Since the fields of @code{cs} are not scalar values, you are being | |
8527 | prompted to chose the field you want to explore. Let's say you choose | |
8528 | the field @code{ss_p} by entering @code{0}. Then, since this field is a | |
8529 | pointer, you will be asked if it is pointing to a single value. From | |
8530 | the declaration of @code{cs} above, it is indeed pointing to a single | |
8531 | value, hence you enter @code{y}. If you enter @code{n}, then you will | |
8532 | be asked if it were pointing to an array of values, in which case this | |
8533 | field will be explored as if it were an array. | |
8534 | ||
8535 | @smallexample | |
8536 | `cs.ss_p' is a pointer to a value of type `struct SimpleStruct' | |
8537 | Continue exploring it as a pointer to a single value [y/n]: y | |
8538 | The value of `*(cs.ss_p)' is a struct/class of type `struct | |
8539 | SimpleStruct' with the following fields: | |
8540 | ||
8541 | i = 10 .. (Value of type `int') | |
8542 | d = 1.1100000000000001 .. (Value of type `double') | |
8543 | ||
8544 | Press enter to return to parent value: | |
8545 | @end smallexample | |
8546 | ||
8547 | @noindent | |
8548 | If the field @code{arr} of @code{cs} was chosen for exploration by | |
8549 | entering @code{1} earlier, then since it is as array, you will be | |
8550 | prompted to enter the index of the element in the array that you want | |
8551 | to explore. | |
8552 | ||
8553 | @smallexample | |
8554 | `cs.arr' is an array of `int'. | |
8555 | Enter the index of the element you want to explore in `cs.arr': 5 | |
8556 | ||
8557 | `(cs.arr)[5]' is a scalar value of type `int'. | |
8558 | ||
8559 | (cs.arr)[5] = 4 | |
8560 | ||
8561 | Press enter to return to parent value: | |
8562 | @end smallexample | |
8563 | ||
8564 | In general, at any stage of exploration, you can go deeper towards the | |
8565 | leaf values by responding to the prompts appropriately, or hit the | |
8566 | return key to return to the enclosing data structure (the @i{higher} | |
8567 | level data structure). | |
8568 | ||
8569 | Similar to exploring values, you can use the @code{explore} command to | |
8570 | explore types. Instead of specifying a value (which is typically a | |
8571 | variable name or an expression valid in the current context of the | |
8572 | program being debugged), you specify a type name. If you consider the | |
8573 | same example as above, your can explore the type | |
8574 | @code{struct ComplexStruct} by passing the argument | |
8575 | @code{struct ComplexStruct} to the @code{explore} command. | |
8576 | ||
8577 | @smallexample | |
8578 | (gdb) explore struct ComplexStruct | |
8579 | @end smallexample | |
8580 | ||
8581 | @noindent | |
8582 | By responding to the prompts appropriately in the subsequent interactive | |
8583 | session, you can explore the type @code{struct ComplexStruct} in a | |
8584 | manner similar to how the value @code{cs} was explored in the above | |
8585 | example. | |
8586 | ||
8587 | The @code{explore} command also has two sub-commands, | |
8588 | @code{explore value} and @code{explore type}. The former sub-command is | |
8589 | a way to explicitly specify that value exploration of the argument is | |
8590 | being invoked, while the latter is a way to explicitly specify that type | |
8591 | exploration of the argument is being invoked. | |
8592 | ||
8593 | @table @code | |
8594 | @item explore value @var{expr} | |
8595 | @cindex explore value | |
8596 | This sub-command of @code{explore} explores the value of the | |
8597 | expression @var{expr} (if @var{expr} is an expression valid in the | |
8598 | current context of the program being debugged). The behavior of this | |
8599 | command is identical to that of the behavior of the @code{explore} | |
8600 | command being passed the argument @var{expr}. | |
8601 | ||
8602 | @item explore type @var{arg} | |
8603 | @cindex explore type | |
8604 | This sub-command of @code{explore} explores the type of @var{arg} (if | |
8605 | @var{arg} is a type visible in the current context of program being | |
8606 | debugged), or the type of the value/expression @var{arg} (if @var{arg} | |
8607 | is an expression valid in the current context of the program being | |
8608 | debugged). If @var{arg} is a type, then the behavior of this command is | |
8609 | identical to that of the @code{explore} command being passed the | |
8610 | argument @var{arg}. If @var{arg} is an expression, then the behavior of | |
8611 | this command will be identical to that of the @code{explore} command | |
8612 | being passed the type of @var{arg} as the argument. | |
8613 | @end table | |
8614 | ||
c906108c SS |
8615 | @menu |
8616 | * Expressions:: Expressions | |
6ba66d6a | 8617 | * Ambiguous Expressions:: Ambiguous Expressions |
c906108c SS |
8618 | * Variables:: Program variables |
8619 | * Arrays:: Artificial arrays | |
8620 | * Output Formats:: Output formats | |
8621 | * Memory:: Examining memory | |
8622 | * Auto Display:: Automatic display | |
8623 | * Print Settings:: Print settings | |
4c374409 | 8624 | * Pretty Printing:: Python pretty printing |
c906108c SS |
8625 | * Value History:: Value history |
8626 | * Convenience Vars:: Convenience variables | |
a72c3253 | 8627 | * Convenience Funs:: Convenience functions |
c906108c | 8628 | * Registers:: Registers |
c906108c | 8629 | * Floating Point Hardware:: Floating point hardware |
53c69bd7 | 8630 | * Vector Unit:: Vector Unit |
721c2651 | 8631 | * OS Information:: Auxiliary data provided by operating system |
29e57380 | 8632 | * Memory Region Attributes:: Memory region attributes |
16d9dec6 | 8633 | * Dump/Restore Files:: Copy between memory and a file |
384ee23f | 8634 | * Core File Generation:: Cause a program dump its core |
a0eb71c5 KB |
8635 | * Character Sets:: Debugging programs that use a different |
8636 | character set than GDB does | |
b12039c6 | 8637 | * Caching Target Data:: Data caching for targets |
08388c79 | 8638 | * Searching Memory:: Searching memory for a sequence of bytes |
c906108c SS |
8639 | @end menu |
8640 | ||
6d2ebf8b | 8641 | @node Expressions |
c906108c SS |
8642 | @section Expressions |
8643 | ||
8644 | @cindex expressions | |
8645 | @code{print} and many other @value{GDBN} commands accept an expression and | |
8646 | compute its value. Any kind of constant, variable or operator defined | |
8647 | by the programming language you are using is valid in an expression in | |
e2e0bcd1 JB |
8648 | @value{GDBN}. This includes conditional expressions, function calls, |
8649 | casts, and string constants. It also includes preprocessor macros, if | |
8650 | you compiled your program to include this information; see | |
8651 | @ref{Compilation}. | |
c906108c | 8652 | |
15387254 | 8653 | @cindex arrays in expressions |
d4f3574e SS |
8654 | @value{GDBN} supports array constants in expressions input by |
8655 | the user. The syntax is @{@var{element}, @var{element}@dots{}@}. For example, | |
63092375 DJ |
8656 | you can use the command @code{print @{1, 2, 3@}} to create an array |
8657 | of three integers. If you pass an array to a function or assign it | |
8658 | to a program variable, @value{GDBN} copies the array to memory that | |
8659 | is @code{malloc}ed in the target program. | |
c906108c | 8660 | |
c906108c SS |
8661 | Because C is so widespread, most of the expressions shown in examples in |
8662 | this manual are in C. @xref{Languages, , Using @value{GDBN} with Different | |
8663 | Languages}, for information on how to use expressions in other | |
8664 | languages. | |
8665 | ||
8666 | In this section, we discuss operators that you can use in @value{GDBN} | |
8667 | expressions regardless of your programming language. | |
8668 | ||
15387254 | 8669 | @cindex casts, in expressions |
c906108c SS |
8670 | Casts are supported in all languages, not just in C, because it is so |
8671 | useful to cast a number into a pointer in order to examine a structure | |
8672 | at that address in memory. | |
8673 | @c FIXME: casts supported---Mod2 true? | |
c906108c SS |
8674 | |
8675 | @value{GDBN} supports these operators, in addition to those common | |
8676 | to programming languages: | |
8677 | ||
8678 | @table @code | |
8679 | @item @@ | |
8680 | @samp{@@} is a binary operator for treating parts of memory as arrays. | |
79a6e687 | 8681 | @xref{Arrays, ,Artificial Arrays}, for more information. |
c906108c SS |
8682 | |
8683 | @item :: | |
8684 | @samp{::} allows you to specify a variable in terms of the file or | |
79a6e687 | 8685 | function where it is defined. @xref{Variables, ,Program Variables}. |
c906108c SS |
8686 | |
8687 | @cindex @{@var{type}@} | |
8688 | @cindex type casting memory | |
8689 | @cindex memory, viewing as typed object | |
8690 | @cindex casts, to view memory | |
8691 | @item @{@var{type}@} @var{addr} | |
8692 | Refers to an object of type @var{type} stored at address @var{addr} in | |
697aa1b7 EZ |
8693 | memory. The address @var{addr} may be any expression whose value is |
8694 | an integer or pointer (but parentheses are required around binary | |
8695 | operators, just as in a cast). This construct is allowed regardless | |
8696 | of what kind of data is normally supposed to reside at @var{addr}. | |
c906108c SS |
8697 | @end table |
8698 | ||
6ba66d6a JB |
8699 | @node Ambiguous Expressions |
8700 | @section Ambiguous Expressions | |
8701 | @cindex ambiguous expressions | |
8702 | ||
8703 | Expressions can sometimes contain some ambiguous elements. For instance, | |
8704 | some programming languages (notably Ada, C@t{++} and Objective-C) permit | |
8705 | a single function name to be defined several times, for application in | |
8706 | different contexts. This is called @dfn{overloading}. Another example | |
8707 | involving Ada is generics. A @dfn{generic package} is similar to C@t{++} | |
8708 | templates and is typically instantiated several times, resulting in | |
8709 | the same function name being defined in different contexts. | |
8710 | ||
8711 | In some cases and depending on the language, it is possible to adjust | |
8712 | the expression to remove the ambiguity. For instance in C@t{++}, you | |
8713 | can specify the signature of the function you want to break on, as in | |
8714 | @kbd{break @var{function}(@var{types})}. In Ada, using the fully | |
8715 | qualified name of your function often makes the expression unambiguous | |
8716 | as well. | |
8717 | ||
8718 | When an ambiguity that needs to be resolved is detected, the debugger | |
8719 | has the capability to display a menu of numbered choices for each | |
8720 | possibility, and then waits for the selection with the prompt @samp{>}. | |
8721 | The first option is always @samp{[0] cancel}, and typing @kbd{0 @key{RET}} | |
8722 | aborts the current command. If the command in which the expression was | |
8723 | used allows more than one choice to be selected, the next option in the | |
8724 | menu is @samp{[1] all}, and typing @kbd{1 @key{RET}} selects all possible | |
8725 | choices. | |
8726 | ||
8727 | For example, the following session excerpt shows an attempt to set a | |
8728 | breakpoint at the overloaded symbol @code{String::after}. | |
8729 | We choose three particular definitions of that function name: | |
8730 | ||
8731 | @c FIXME! This is likely to change to show arg type lists, at least | |
8732 | @smallexample | |
8733 | @group | |
8734 | (@value{GDBP}) b String::after | |
8735 | [0] cancel | |
8736 | [1] all | |
8737 | [2] file:String.cc; line number:867 | |
8738 | [3] file:String.cc; line number:860 | |
8739 | [4] file:String.cc; line number:875 | |
8740 | [5] file:String.cc; line number:853 | |
8741 | [6] file:String.cc; line number:846 | |
8742 | [7] file:String.cc; line number:735 | |
8743 | > 2 4 6 | |
8744 | Breakpoint 1 at 0xb26c: file String.cc, line 867. | |
8745 | Breakpoint 2 at 0xb344: file String.cc, line 875. | |
8746 | Breakpoint 3 at 0xafcc: file String.cc, line 846. | |
8747 | Multiple breakpoints were set. | |
8748 | Use the "delete" command to delete unwanted | |
8749 | breakpoints. | |
8750 | (@value{GDBP}) | |
8751 | @end group | |
8752 | @end smallexample | |
8753 | ||
8754 | @table @code | |
8755 | @kindex set multiple-symbols | |
8756 | @item set multiple-symbols @var{mode} | |
8757 | @cindex multiple-symbols menu | |
8758 | ||
8759 | This option allows you to adjust the debugger behavior when an expression | |
8760 | is ambiguous. | |
8761 | ||
8762 | By default, @var{mode} is set to @code{all}. If the command with which | |
8763 | the expression is used allows more than one choice, then @value{GDBN} | |
8764 | automatically selects all possible choices. For instance, inserting | |
8765 | a breakpoint on a function using an ambiguous name results in a breakpoint | |
8766 | inserted on each possible match. However, if a unique choice must be made, | |
8767 | then @value{GDBN} uses the menu to help you disambiguate the expression. | |
8768 | For instance, printing the address of an overloaded function will result | |
8769 | in the use of the menu. | |
8770 | ||
8771 | When @var{mode} is set to @code{ask}, the debugger always uses the menu | |
8772 | when an ambiguity is detected. | |
8773 | ||
8774 | Finally, when @var{mode} is set to @code{cancel}, the debugger reports | |
8775 | an error due to the ambiguity and the command is aborted. | |
8776 | ||
8777 | @kindex show multiple-symbols | |
8778 | @item show multiple-symbols | |
8779 | Show the current value of the @code{multiple-symbols} setting. | |
8780 | @end table | |
8781 | ||
6d2ebf8b | 8782 | @node Variables |
79a6e687 | 8783 | @section Program Variables |
c906108c SS |
8784 | |
8785 | The most common kind of expression to use is the name of a variable | |
8786 | in your program. | |
8787 | ||
8788 | Variables in expressions are understood in the selected stack frame | |
79a6e687 | 8789 | (@pxref{Selection, ,Selecting a Frame}); they must be either: |
c906108c SS |
8790 | |
8791 | @itemize @bullet | |
8792 | @item | |
8793 | global (or file-static) | |
8794 | @end itemize | |
8795 | ||
5d161b24 | 8796 | @noindent or |
c906108c SS |
8797 | |
8798 | @itemize @bullet | |
8799 | @item | |
8800 | visible according to the scope rules of the | |
8801 | programming language from the point of execution in that frame | |
5d161b24 | 8802 | @end itemize |
c906108c SS |
8803 | |
8804 | @noindent This means that in the function | |
8805 | ||
474c8240 | 8806 | @smallexample |
c906108c SS |
8807 | foo (a) |
8808 | int a; | |
8809 | @{ | |
8810 | bar (a); | |
8811 | @{ | |
8812 | int b = test (); | |
8813 | bar (b); | |
8814 | @} | |
8815 | @} | |
474c8240 | 8816 | @end smallexample |
c906108c SS |
8817 | |
8818 | @noindent | |
8819 | you can examine and use the variable @code{a} whenever your program is | |
8820 | executing within the function @code{foo}, but you can only use or | |
8821 | examine the variable @code{b} while your program is executing inside | |
8822 | the block where @code{b} is declared. | |
8823 | ||
8824 | @cindex variable name conflict | |
8825 | There is an exception: you can refer to a variable or function whose | |
8826 | scope is a single source file even if the current execution point is not | |
8827 | in this file. But it is possible to have more than one such variable or | |
8828 | function with the same name (in different source files). If that | |
8829 | happens, referring to that name has unpredictable effects. If you wish, | |
72384ba3 | 8830 | you can specify a static variable in a particular function or file by |
15387254 | 8831 | using the colon-colon (@code{::}) notation: |
c906108c | 8832 | |
d4f3574e | 8833 | @cindex colon-colon, context for variables/functions |
12c27660 | 8834 | @ifnotinfo |
c906108c | 8835 | @c info cannot cope with a :: index entry, but why deprive hard copy readers? |
41afff9a | 8836 | @cindex @code{::}, context for variables/functions |
12c27660 | 8837 | @end ifnotinfo |
474c8240 | 8838 | @smallexample |
c906108c SS |
8839 | @var{file}::@var{variable} |
8840 | @var{function}::@var{variable} | |
474c8240 | 8841 | @end smallexample |
c906108c SS |
8842 | |
8843 | @noindent | |
8844 | Here @var{file} or @var{function} is the name of the context for the | |
8845 | static @var{variable}. In the case of file names, you can use quotes to | |
8846 | make sure @value{GDBN} parses the file name as a single word---for example, | |
8847 | to print a global value of @code{x} defined in @file{f2.c}: | |
8848 | ||
474c8240 | 8849 | @smallexample |
c906108c | 8850 | (@value{GDBP}) p 'f2.c'::x |
474c8240 | 8851 | @end smallexample |
c906108c | 8852 | |
72384ba3 PH |
8853 | The @code{::} notation is normally used for referring to |
8854 | static variables, since you typically disambiguate uses of local variables | |
8855 | in functions by selecting the appropriate frame and using the | |
8856 | simple name of the variable. However, you may also use this notation | |
8857 | to refer to local variables in frames enclosing the selected frame: | |
8858 | ||
8859 | @smallexample | |
8860 | void | |
8861 | foo (int a) | |
8862 | @{ | |
8863 | if (a < 10) | |
8864 | bar (a); | |
8865 | else | |
8866 | process (a); /* Stop here */ | |
8867 | @} | |
8868 | ||
8869 | int | |
8870 | bar (int a) | |
8871 | @{ | |
8872 | foo (a + 5); | |
8873 | @} | |
8874 | @end smallexample | |
8875 | ||
8876 | @noindent | |
8877 | For example, if there is a breakpoint at the commented line, | |
8878 | here is what you might see | |
8879 | when the program stops after executing the call @code{bar(0)}: | |
8880 | ||
8881 | @smallexample | |
8882 | (@value{GDBP}) p a | |
8883 | $1 = 10 | |
8884 | (@value{GDBP}) p bar::a | |
8885 | $2 = 5 | |
8886 | (@value{GDBP}) up 2 | |
8887 | #2 0x080483d0 in foo (a=5) at foobar.c:12 | |
8888 | (@value{GDBP}) p a | |
8889 | $3 = 5 | |
8890 | (@value{GDBP}) p bar::a | |
8891 | $4 = 0 | |
8892 | @end smallexample | |
8893 | ||
b37052ae | 8894 | @cindex C@t{++} scope resolution |
805e1f19 TT |
8895 | These uses of @samp{::} are very rarely in conflict with the very |
8896 | similar use of the same notation in C@t{++}. When they are in | |
8897 | conflict, the C@t{++} meaning takes precedence; however, this can be | |
8898 | overridden by quoting the file or function name with single quotes. | |
8899 | ||
8900 | For example, suppose the program is stopped in a method of a class | |
8901 | that has a field named @code{includefile}, and there is also an | |
8902 | include file named @file{includefile} that defines a variable, | |
8903 | @code{some_global}. | |
8904 | ||
8905 | @smallexample | |
8906 | (@value{GDBP}) p includefile | |
8907 | $1 = 23 | |
8908 | (@value{GDBP}) p includefile::some_global | |
8909 | A syntax error in expression, near `'. | |
8910 | (@value{GDBP}) p 'includefile'::some_global | |
8911 | $2 = 27 | |
8912 | @end smallexample | |
c906108c SS |
8913 | |
8914 | @cindex wrong values | |
8915 | @cindex variable values, wrong | |
15387254 EZ |
8916 | @cindex function entry/exit, wrong values of variables |
8917 | @cindex optimized code, wrong values of variables | |
c906108c SS |
8918 | @quotation |
8919 | @emph{Warning:} Occasionally, a local variable may appear to have the | |
8920 | wrong value at certain points in a function---just after entry to a new | |
8921 | scope, and just before exit. | |
8922 | @end quotation | |
8923 | You may see this problem when you are stepping by machine instructions. | |
8924 | This is because, on most machines, it takes more than one instruction to | |
8925 | set up a stack frame (including local variable definitions); if you are | |
8926 | stepping by machine instructions, variables may appear to have the wrong | |
8927 | values until the stack frame is completely built. On exit, it usually | |
8928 | also takes more than one machine instruction to destroy a stack frame; | |
8929 | after you begin stepping through that group of instructions, local | |
8930 | variable definitions may be gone. | |
8931 | ||
8932 | This may also happen when the compiler does significant optimizations. | |
8933 | To be sure of always seeing accurate values, turn off all optimization | |
8934 | when compiling. | |
8935 | ||
d4f3574e SS |
8936 | @cindex ``No symbol "foo" in current context'' |
8937 | Another possible effect of compiler optimizations is to optimize | |
8938 | unused variables out of existence, or assign variables to registers (as | |
8939 | opposed to memory addresses). Depending on the support for such cases | |
8940 | offered by the debug info format used by the compiler, @value{GDBN} | |
8941 | might not be able to display values for such local variables. If that | |
8942 | happens, @value{GDBN} will print a message like this: | |
8943 | ||
474c8240 | 8944 | @smallexample |
d4f3574e | 8945 | No symbol "foo" in current context. |
474c8240 | 8946 | @end smallexample |
d4f3574e SS |
8947 | |
8948 | To solve such problems, either recompile without optimizations, or use a | |
8949 | different debug info format, if the compiler supports several such | |
e0f8f636 TT |
8950 | formats. @xref{Compilation}, for more information on choosing compiler |
8951 | options. @xref{C, ,C and C@t{++}}, for more information about debug | |
8952 | info formats that are best suited to C@t{++} programs. | |
d4f3574e | 8953 | |
ab1adacd EZ |
8954 | If you ask to print an object whose contents are unknown to |
8955 | @value{GDBN}, e.g., because its data type is not completely specified | |
8956 | by the debug information, @value{GDBN} will say @samp{<incomplete | |
8957 | type>}. @xref{Symbols, incomplete type}, for more about this. | |
8958 | ||
36b11add JK |
8959 | If you append @kbd{@@entry} string to a function parameter name you get its |
8960 | value at the time the function got called. If the value is not available an | |
8961 | error message is printed. Entry values are available only with some compilers. | |
8962 | Entry values are normally also printed at the function parameter list according | |
8963 | to @ref{set print entry-values}. | |
8964 | ||
8965 | @smallexample | |
8966 | Breakpoint 1, d (i=30) at gdb.base/entry-value.c:29 | |
8967 | 29 i++; | |
8968 | (gdb) next | |
8969 | 30 e (i); | |
8970 | (gdb) print i | |
8971 | $1 = 31 | |
8972 | (gdb) print i@@entry | |
8973 | $2 = 30 | |
8974 | @end smallexample | |
8975 | ||
3a60f64e JK |
8976 | Strings are identified as arrays of @code{char} values without specified |
8977 | signedness. Arrays of either @code{signed char} or @code{unsigned char} get | |
8978 | printed as arrays of 1 byte sized integers. @code{-fsigned-char} or | |
8979 | @code{-funsigned-char} @value{NGCC} options have no effect as @value{GDBN} | |
8980 | defines literal string type @code{"char"} as @code{char} without a sign. | |
8981 | For program code | |
8982 | ||
8983 | @smallexample | |
8984 | char var0[] = "A"; | |
8985 | signed char var1[] = "A"; | |
8986 | @end smallexample | |
8987 | ||
8988 | You get during debugging | |
8989 | @smallexample | |
8990 | (gdb) print var0 | |
8991 | $1 = "A" | |
8992 | (gdb) print var1 | |
8993 | $2 = @{65 'A', 0 '\0'@} | |
8994 | @end smallexample | |
8995 | ||
6d2ebf8b | 8996 | @node Arrays |
79a6e687 | 8997 | @section Artificial Arrays |
c906108c SS |
8998 | |
8999 | @cindex artificial array | |
15387254 | 9000 | @cindex arrays |
41afff9a | 9001 | @kindex @@@r{, referencing memory as an array} |
c906108c SS |
9002 | It is often useful to print out several successive objects of the |
9003 | same type in memory; a section of an array, or an array of | |
9004 | dynamically determined size for which only a pointer exists in the | |
9005 | program. | |
9006 | ||
9007 | You can do this by referring to a contiguous span of memory as an | |
9008 | @dfn{artificial array}, using the binary operator @samp{@@}. The left | |
9009 | operand of @samp{@@} should be the first element of the desired array | |
9010 | and be an individual object. The right operand should be the desired length | |
9011 | of the array. The result is an array value whose elements are all of | |
9012 | the type of the left argument. The first element is actually the left | |
9013 | argument; the second element comes from bytes of memory immediately | |
9014 | following those that hold the first element, and so on. Here is an | |
9015 | example. If a program says | |
9016 | ||
474c8240 | 9017 | @smallexample |
c906108c | 9018 | int *array = (int *) malloc (len * sizeof (int)); |
474c8240 | 9019 | @end smallexample |
c906108c SS |
9020 | |
9021 | @noindent | |
9022 | you can print the contents of @code{array} with | |
9023 | ||
474c8240 | 9024 | @smallexample |
c906108c | 9025 | p *array@@len |
474c8240 | 9026 | @end smallexample |
c906108c SS |
9027 | |
9028 | The left operand of @samp{@@} must reside in memory. Array values made | |
9029 | with @samp{@@} in this way behave just like other arrays in terms of | |
9030 | subscripting, and are coerced to pointers when used in expressions. | |
9031 | Artificial arrays most often appear in expressions via the value history | |
79a6e687 | 9032 | (@pxref{Value History, ,Value History}), after printing one out. |
c906108c SS |
9033 | |
9034 | Another way to create an artificial array is to use a cast. | |
9035 | This re-interprets a value as if it were an array. | |
9036 | The value need not be in memory: | |
474c8240 | 9037 | @smallexample |
c906108c SS |
9038 | (@value{GDBP}) p/x (short[2])0x12345678 |
9039 | $1 = @{0x1234, 0x5678@} | |
474c8240 | 9040 | @end smallexample |
c906108c SS |
9041 | |
9042 | As a convenience, if you leave the array length out (as in | |
c3f6f71d | 9043 | @samp{(@var{type}[])@var{value}}) @value{GDBN} calculates the size to fill |
c906108c | 9044 | the value (as @samp{sizeof(@var{value})/sizeof(@var{type})}: |
474c8240 | 9045 | @smallexample |
c906108c SS |
9046 | (@value{GDBP}) p/x (short[])0x12345678 |
9047 | $2 = @{0x1234, 0x5678@} | |
474c8240 | 9048 | @end smallexample |
c906108c SS |
9049 | |
9050 | Sometimes the artificial array mechanism is not quite enough; in | |
9051 | moderately complex data structures, the elements of interest may not | |
9052 | actually be adjacent---for example, if you are interested in the values | |
9053 | of pointers in an array. One useful work-around in this situation is | |
9054 | to use a convenience variable (@pxref{Convenience Vars, ,Convenience | |
79a6e687 | 9055 | Variables}) as a counter in an expression that prints the first |
c906108c SS |
9056 | interesting value, and then repeat that expression via @key{RET}. For |
9057 | instance, suppose you have an array @code{dtab} of pointers to | |
9058 | structures, and you are interested in the values of a field @code{fv} | |
9059 | in each structure. Here is an example of what you might type: | |
9060 | ||
474c8240 | 9061 | @smallexample |
c906108c SS |
9062 | set $i = 0 |
9063 | p dtab[$i++]->fv | |
9064 | @key{RET} | |
9065 | @key{RET} | |
9066 | @dots{} | |
474c8240 | 9067 | @end smallexample |
c906108c | 9068 | |
6d2ebf8b | 9069 | @node Output Formats |
79a6e687 | 9070 | @section Output Formats |
c906108c SS |
9071 | |
9072 | @cindex formatted output | |
9073 | @cindex output formats | |
9074 | By default, @value{GDBN} prints a value according to its data type. Sometimes | |
9075 | this is not what you want. For example, you might want to print a number | |
9076 | in hex, or a pointer in decimal. Or you might want to view data in memory | |
9077 | at a certain address as a character string or as an instruction. To do | |
9078 | these things, specify an @dfn{output format} when you print a value. | |
9079 | ||
9080 | The simplest use of output formats is to say how to print a value | |
9081 | already computed. This is done by starting the arguments of the | |
9082 | @code{print} command with a slash and a format letter. The format | |
9083 | letters supported are: | |
9084 | ||
9085 | @table @code | |
9086 | @item x | |
9087 | Regard the bits of the value as an integer, and print the integer in | |
9088 | hexadecimal. | |
9089 | ||
9090 | @item d | |
9091 | Print as integer in signed decimal. | |
9092 | ||
9093 | @item u | |
9094 | Print as integer in unsigned decimal. | |
9095 | ||
9096 | @item o | |
9097 | Print as integer in octal. | |
9098 | ||
9099 | @item t | |
9100 | Print as integer in binary. The letter @samp{t} stands for ``two''. | |
9101 | @footnote{@samp{b} cannot be used because these format letters are also | |
9102 | used with the @code{x} command, where @samp{b} stands for ``byte''; | |
79a6e687 | 9103 | see @ref{Memory,,Examining Memory}.} |
c906108c SS |
9104 | |
9105 | @item a | |
9106 | @cindex unknown address, locating | |
3d67e040 | 9107 | @cindex locate address |
c906108c SS |
9108 | Print as an address, both absolute in hexadecimal and as an offset from |
9109 | the nearest preceding symbol. You can use this format used to discover | |
9110 | where (in what function) an unknown address is located: | |
9111 | ||
474c8240 | 9112 | @smallexample |
c906108c SS |
9113 | (@value{GDBP}) p/a 0x54320 |
9114 | $3 = 0x54320 <_initialize_vx+396> | |
474c8240 | 9115 | @end smallexample |
c906108c | 9116 | |
3d67e040 EZ |
9117 | @noindent |
9118 | The command @code{info symbol 0x54320} yields similar results. | |
9119 | @xref{Symbols, info symbol}. | |
9120 | ||
c906108c | 9121 | @item c |
51274035 EZ |
9122 | Regard as an integer and print it as a character constant. This |
9123 | prints both the numerical value and its character representation. The | |
9124 | character representation is replaced with the octal escape @samp{\nnn} | |
9125 | for characters outside the 7-bit @sc{ascii} range. | |
c906108c | 9126 | |
ea37ba09 DJ |
9127 | Without this format, @value{GDBN} displays @code{char}, |
9128 | @w{@code{unsigned char}}, and @w{@code{signed char}} data as character | |
9129 | constants. Single-byte members of vectors are displayed as integer | |
9130 | data. | |
9131 | ||
c906108c SS |
9132 | @item f |
9133 | Regard the bits of the value as a floating point number and print | |
9134 | using typical floating point syntax. | |
ea37ba09 DJ |
9135 | |
9136 | @item s | |
9137 | @cindex printing strings | |
9138 | @cindex printing byte arrays | |
9139 | Regard as a string, if possible. With this format, pointers to single-byte | |
9140 | data are displayed as null-terminated strings and arrays of single-byte data | |
9141 | are displayed as fixed-length strings. Other values are displayed in their | |
9142 | natural types. | |
9143 | ||
9144 | Without this format, @value{GDBN} displays pointers to and arrays of | |
9145 | @code{char}, @w{@code{unsigned char}}, and @w{@code{signed char}} as | |
9146 | strings. Single-byte members of a vector are displayed as an integer | |
9147 | array. | |
a6bac58e | 9148 | |
6fbe845e AB |
9149 | @item z |
9150 | Like @samp{x} formatting, the value is treated as an integer and | |
9151 | printed as hexadecimal, but leading zeros are printed to pad the value | |
9152 | to the size of the integer type. | |
9153 | ||
a6bac58e TT |
9154 | @item r |
9155 | @cindex raw printing | |
9156 | Print using the @samp{raw} formatting. By default, @value{GDBN} will | |
78e2826b TT |
9157 | use a Python-based pretty-printer, if one is available (@pxref{Pretty |
9158 | Printing}). This typically results in a higher-level display of the | |
9159 | value's contents. The @samp{r} format bypasses any Python | |
9160 | pretty-printer which might exist. | |
c906108c SS |
9161 | @end table |
9162 | ||
9163 | For example, to print the program counter in hex (@pxref{Registers}), type | |
9164 | ||
474c8240 | 9165 | @smallexample |
c906108c | 9166 | p/x $pc |
474c8240 | 9167 | @end smallexample |
c906108c SS |
9168 | |
9169 | @noindent | |
9170 | Note that no space is required before the slash; this is because command | |
9171 | names in @value{GDBN} cannot contain a slash. | |
9172 | ||
9173 | To reprint the last value in the value history with a different format, | |
9174 | you can use the @code{print} command with just a format and no | |
9175 | expression. For example, @samp{p/x} reprints the last value in hex. | |
9176 | ||
6d2ebf8b | 9177 | @node Memory |
79a6e687 | 9178 | @section Examining Memory |
c906108c SS |
9179 | |
9180 | You can use the command @code{x} (for ``examine'') to examine memory in | |
9181 | any of several formats, independently of your program's data types. | |
9182 | ||
9183 | @cindex examining memory | |
9184 | @table @code | |
41afff9a | 9185 | @kindex x @r{(examine memory)} |
c906108c SS |
9186 | @item x/@var{nfu} @var{addr} |
9187 | @itemx x @var{addr} | |
9188 | @itemx x | |
9189 | Use the @code{x} command to examine memory. | |
9190 | @end table | |
9191 | ||
9192 | @var{n}, @var{f}, and @var{u} are all optional parameters that specify how | |
9193 | much memory to display and how to format it; @var{addr} is an | |
9194 | expression giving the address where you want to start displaying memory. | |
9195 | If you use defaults for @var{nfu}, you need not type the slash @samp{/}. | |
9196 | Several commands set convenient defaults for @var{addr}. | |
9197 | ||
9198 | @table @r | |
9199 | @item @var{n}, the repeat count | |
9200 | The repeat count is a decimal integer; the default is 1. It specifies | |
9201 | how much memory (counting by units @var{u}) to display. | |
9202 | @c This really is **decimal**; unaffected by 'set radix' as of GDB | |
9203 | @c 4.1.2. | |
9204 | ||
9205 | @item @var{f}, the display format | |
51274035 EZ |
9206 | The display format is one of the formats used by @code{print} |
9207 | (@samp{x}, @samp{d}, @samp{u}, @samp{o}, @samp{t}, @samp{a}, @samp{c}, | |
ea37ba09 DJ |
9208 | @samp{f}, @samp{s}), and in addition @samp{i} (for machine instructions). |
9209 | The default is @samp{x} (hexadecimal) initially. The default changes | |
9210 | each time you use either @code{x} or @code{print}. | |
c906108c SS |
9211 | |
9212 | @item @var{u}, the unit size | |
9213 | The unit size is any of | |
9214 | ||
9215 | @table @code | |
9216 | @item b | |
9217 | Bytes. | |
9218 | @item h | |
9219 | Halfwords (two bytes). | |
9220 | @item w | |
9221 | Words (four bytes). This is the initial default. | |
9222 | @item g | |
9223 | Giant words (eight bytes). | |
9224 | @end table | |
9225 | ||
9226 | Each time you specify a unit size with @code{x}, that size becomes the | |
9a22f0d0 PM |
9227 | default unit the next time you use @code{x}. For the @samp{i} format, |
9228 | the unit size is ignored and is normally not written. For the @samp{s} format, | |
9229 | the unit size defaults to @samp{b}, unless it is explicitly given. | |
9230 | Use @kbd{x /hs} to display 16-bit char strings and @kbd{x /ws} to display | |
9231 | 32-bit strings. The next use of @kbd{x /s} will again display 8-bit strings. | |
9232 | Note that the results depend on the programming language of the | |
9233 | current compilation unit. If the language is C, the @samp{s} | |
9234 | modifier will use the UTF-16 encoding while @samp{w} will use | |
9235 | UTF-32. The encoding is set by the programming language and cannot | |
9236 | be altered. | |
c906108c SS |
9237 | |
9238 | @item @var{addr}, starting display address | |
9239 | @var{addr} is the address where you want @value{GDBN} to begin displaying | |
9240 | memory. The expression need not have a pointer value (though it may); | |
9241 | it is always interpreted as an integer address of a byte of memory. | |
9242 | @xref{Expressions, ,Expressions}, for more information on expressions. The default for | |
9243 | @var{addr} is usually just after the last address examined---but several | |
9244 | other commands also set the default address: @code{info breakpoints} (to | |
9245 | the address of the last breakpoint listed), @code{info line} (to the | |
9246 | starting address of a line), and @code{print} (if you use it to display | |
9247 | a value from memory). | |
9248 | @end table | |
9249 | ||
9250 | For example, @samp{x/3uh 0x54320} is a request to display three halfwords | |
9251 | (@code{h}) of memory, formatted as unsigned decimal integers (@samp{u}), | |
9252 | starting at address @code{0x54320}. @samp{x/4xw $sp} prints the four | |
9253 | words (@samp{w}) of memory above the stack pointer (here, @samp{$sp}; | |
d4f3574e | 9254 | @pxref{Registers, ,Registers}) in hexadecimal (@samp{x}). |
c906108c SS |
9255 | |
9256 | Since the letters indicating unit sizes are all distinct from the | |
9257 | letters specifying output formats, you do not have to remember whether | |
9258 | unit size or format comes first; either order works. The output | |
9259 | specifications @samp{4xw} and @samp{4wx} mean exactly the same thing. | |
9260 | (However, the count @var{n} must come first; @samp{wx4} does not work.) | |
9261 | ||
9262 | Even though the unit size @var{u} is ignored for the formats @samp{s} | |
9263 | and @samp{i}, you might still want to use a count @var{n}; for example, | |
9264 | @samp{3i} specifies that you want to see three machine instructions, | |
a4642986 MR |
9265 | including any operands. For convenience, especially when used with |
9266 | the @code{display} command, the @samp{i} format also prints branch delay | |
9267 | slot instructions, if any, beyond the count specified, which immediately | |
9268 | follow the last instruction that is within the count. The command | |
9269 | @code{disassemble} gives an alternative way of inspecting machine | |
9270 | instructions; see @ref{Machine Code,,Source and Machine Code}. | |
c906108c SS |
9271 | |
9272 | All the defaults for the arguments to @code{x} are designed to make it | |
9273 | easy to continue scanning memory with minimal specifications each time | |
9274 | you use @code{x}. For example, after you have inspected three machine | |
9275 | instructions with @samp{x/3i @var{addr}}, you can inspect the next seven | |
9276 | with just @samp{x/7}. If you use @key{RET} to repeat the @code{x} command, | |
9277 | the repeat count @var{n} is used again; the other arguments default as | |
9278 | for successive uses of @code{x}. | |
9279 | ||
2b28d209 PP |
9280 | When examining machine instructions, the instruction at current program |
9281 | counter is shown with a @code{=>} marker. For example: | |
9282 | ||
9283 | @smallexample | |
9284 | (@value{GDBP}) x/5i $pc-6 | |
9285 | 0x804837f <main+11>: mov %esp,%ebp | |
9286 | 0x8048381 <main+13>: push %ecx | |
9287 | 0x8048382 <main+14>: sub $0x4,%esp | |
9288 | => 0x8048385 <main+17>: movl $0x8048460,(%esp) | |
9289 | 0x804838c <main+24>: call 0x80482d4 <puts@@plt> | |
9290 | @end smallexample | |
9291 | ||
c906108c SS |
9292 | @cindex @code{$_}, @code{$__}, and value history |
9293 | The addresses and contents printed by the @code{x} command are not saved | |
9294 | in the value history because there is often too much of them and they | |
9295 | would get in the way. Instead, @value{GDBN} makes these values available for | |
9296 | subsequent use in expressions as values of the convenience variables | |
9297 | @code{$_} and @code{$__}. After an @code{x} command, the last address | |
9298 | examined is available for use in expressions in the convenience variable | |
9299 | @code{$_}. The contents of that address, as examined, are available in | |
9300 | the convenience variable @code{$__}. | |
9301 | ||
9302 | If the @code{x} command has a repeat count, the address and contents saved | |
9303 | are from the last memory unit printed; this is not the same as the last | |
9304 | address printed if several units were printed on the last line of output. | |
9305 | ||
a86c90e6 SM |
9306 | @anchor{addressable memory unit} |
9307 | @cindex addressable memory unit | |
9308 | Most targets have an addressable memory unit size of 8 bits. This means | |
9309 | that to each memory address are associated 8 bits of data. Some | |
9310 | targets, however, have other addressable memory unit sizes. | |
9311 | Within @value{GDBN} and this document, the term | |
9312 | @dfn{addressable memory unit} (or @dfn{memory unit} for short) is used | |
9313 | when explicitly referring to a chunk of data of that size. The word | |
9314 | @dfn{byte} is used to refer to a chunk of data of 8 bits, regardless of | |
9315 | the addressable memory unit size of the target. For most systems, | |
9316 | addressable memory unit is a synonym of byte. | |
9317 | ||
09d4efe1 | 9318 | @cindex remote memory comparison |
936d2992 | 9319 | @cindex target memory comparison |
09d4efe1 | 9320 | @cindex verify remote memory image |
936d2992 | 9321 | @cindex verify target memory image |
09d4efe1 | 9322 | When you are debugging a program running on a remote target machine |
936d2992 PA |
9323 | (@pxref{Remote Debugging}), you may wish to verify the program's image |
9324 | in the remote machine's memory against the executable file you | |
9325 | downloaded to the target. Or, on any target, you may want to check | |
9326 | whether the program has corrupted its own read-only sections. The | |
9327 | @code{compare-sections} command is provided for such situations. | |
09d4efe1 EZ |
9328 | |
9329 | @table @code | |
9330 | @kindex compare-sections | |
95cf3b38 | 9331 | @item compare-sections @r{[}@var{section-name}@r{|}@code{-r}@r{]} |
09d4efe1 EZ |
9332 | Compare the data of a loadable section @var{section-name} in the |
9333 | executable file of the program being debugged with the same section in | |
936d2992 | 9334 | the target machine's memory, and report any mismatches. With no |
95cf3b38 | 9335 | arguments, compares all loadable sections. With an argument of |
936d2992 PA |
9336 | @code{-r}, compares all loadable read-only sections. |
9337 | ||
9338 | Note: for remote targets, this command can be accelerated if the | |
9339 | target supports computing the CRC checksum of a block of memory | |
9340 | (@pxref{qCRC packet}). | |
09d4efe1 EZ |
9341 | @end table |
9342 | ||
6d2ebf8b | 9343 | @node Auto Display |
79a6e687 | 9344 | @section Automatic Display |
c906108c SS |
9345 | @cindex automatic display |
9346 | @cindex display of expressions | |
9347 | ||
9348 | If you find that you want to print the value of an expression frequently | |
9349 | (to see how it changes), you might want to add it to the @dfn{automatic | |
9350 | display list} so that @value{GDBN} prints its value each time your program stops. | |
9351 | Each expression added to the list is given a number to identify it; | |
9352 | to remove an expression from the list, you specify that number. | |
9353 | The automatic display looks like this: | |
9354 | ||
474c8240 | 9355 | @smallexample |
c906108c SS |
9356 | 2: foo = 38 |
9357 | 3: bar[5] = (struct hack *) 0x3804 | |
474c8240 | 9358 | @end smallexample |
c906108c SS |
9359 | |
9360 | @noindent | |
9361 | This display shows item numbers, expressions and their current values. As with | |
9362 | displays you request manually using @code{x} or @code{print}, you can | |
9363 | specify the output format you prefer; in fact, @code{display} decides | |
ea37ba09 DJ |
9364 | whether to use @code{print} or @code{x} depending your format |
9365 | specification---it uses @code{x} if you specify either the @samp{i} | |
9366 | or @samp{s} format, or a unit size; otherwise it uses @code{print}. | |
c906108c SS |
9367 | |
9368 | @table @code | |
9369 | @kindex display | |
d4f3574e SS |
9370 | @item display @var{expr} |
9371 | Add the expression @var{expr} to the list of expressions to display | |
c906108c SS |
9372 | each time your program stops. @xref{Expressions, ,Expressions}. |
9373 | ||
9374 | @code{display} does not repeat if you press @key{RET} again after using it. | |
9375 | ||
d4f3574e | 9376 | @item display/@var{fmt} @var{expr} |
c906108c | 9377 | For @var{fmt} specifying only a display format and not a size or |
d4f3574e | 9378 | count, add the expression @var{expr} to the auto-display list but |
c906108c | 9379 | arrange to display it each time in the specified format @var{fmt}. |
79a6e687 | 9380 | @xref{Output Formats,,Output Formats}. |
c906108c SS |
9381 | |
9382 | @item display/@var{fmt} @var{addr} | |
9383 | For @var{fmt} @samp{i} or @samp{s}, or including a unit-size or a | |
9384 | number of units, add the expression @var{addr} as a memory address to | |
9385 | be examined each time your program stops. Examining means in effect | |
79a6e687 | 9386 | doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining Memory}. |
c906108c SS |
9387 | @end table |
9388 | ||
9389 | For example, @samp{display/i $pc} can be helpful, to see the machine | |
9390 | instruction about to be executed each time execution stops (@samp{$pc} | |
d4f3574e | 9391 | is a common name for the program counter; @pxref{Registers, ,Registers}). |
c906108c SS |
9392 | |
9393 | @table @code | |
9394 | @kindex delete display | |
9395 | @kindex undisplay | |
9396 | @item undisplay @var{dnums}@dots{} | |
9397 | @itemx delete display @var{dnums}@dots{} | |
c9174737 PA |
9398 | Remove items from the list of expressions to display. Specify the |
9399 | numbers of the displays that you want affected with the command | |
9400 | argument @var{dnums}. It can be a single display number, one of the | |
9401 | numbers shown in the first field of the @samp{info display} display; | |
9402 | or it could be a range of display numbers, as in @code{2-4}. | |
c906108c SS |
9403 | |
9404 | @code{undisplay} does not repeat if you press @key{RET} after using it. | |
9405 | (Otherwise you would just get the error @samp{No display number @dots{}}.) | |
9406 | ||
9407 | @kindex disable display | |
9408 | @item disable display @var{dnums}@dots{} | |
9409 | Disable the display of item numbers @var{dnums}. A disabled display | |
9410 | item is not printed automatically, but is not forgotten. It may be | |
c9174737 PA |
9411 | enabled again later. Specify the numbers of the displays that you |
9412 | want affected with the command argument @var{dnums}. It can be a | |
9413 | single display number, one of the numbers shown in the first field of | |
9414 | the @samp{info display} display; or it could be a range of display | |
9415 | numbers, as in @code{2-4}. | |
c906108c SS |
9416 | |
9417 | @kindex enable display | |
9418 | @item enable display @var{dnums}@dots{} | |
9419 | Enable display of item numbers @var{dnums}. It becomes effective once | |
9420 | again in auto display of its expression, until you specify otherwise. | |
c9174737 PA |
9421 | Specify the numbers of the displays that you want affected with the |
9422 | command argument @var{dnums}. It can be a single display number, one | |
9423 | of the numbers shown in the first field of the @samp{info display} | |
9424 | display; or it could be a range of display numbers, as in @code{2-4}. | |
c906108c SS |
9425 | |
9426 | @item display | |
9427 | Display the current values of the expressions on the list, just as is | |
9428 | done when your program stops. | |
9429 | ||
9430 | @kindex info display | |
9431 | @item info display | |
9432 | Print the list of expressions previously set up to display | |
9433 | automatically, each one with its item number, but without showing the | |
9434 | values. This includes disabled expressions, which are marked as such. | |
9435 | It also includes expressions which would not be displayed right now | |
9436 | because they refer to automatic variables not currently available. | |
9437 | @end table | |
9438 | ||
15387254 | 9439 | @cindex display disabled out of scope |
c906108c SS |
9440 | If a display expression refers to local variables, then it does not make |
9441 | sense outside the lexical context for which it was set up. Such an | |
9442 | expression is disabled when execution enters a context where one of its | |
9443 | variables is not defined. For example, if you give the command | |
9444 | @code{display last_char} while inside a function with an argument | |
9445 | @code{last_char}, @value{GDBN} displays this argument while your program | |
9446 | continues to stop inside that function. When it stops elsewhere---where | |
9447 | there is no variable @code{last_char}---the display is disabled | |
9448 | automatically. The next time your program stops where @code{last_char} | |
9449 | is meaningful, you can enable the display expression once again. | |
9450 | ||
6d2ebf8b | 9451 | @node Print Settings |
79a6e687 | 9452 | @section Print Settings |
c906108c SS |
9453 | |
9454 | @cindex format options | |
9455 | @cindex print settings | |
9456 | @value{GDBN} provides the following ways to control how arrays, structures, | |
9457 | and symbols are printed. | |
9458 | ||
9459 | @noindent | |
9460 | These settings are useful for debugging programs in any language: | |
9461 | ||
9462 | @table @code | |
4644b6e3 | 9463 | @kindex set print |
c906108c SS |
9464 | @item set print address |
9465 | @itemx set print address on | |
4644b6e3 | 9466 | @cindex print/don't print memory addresses |
c906108c SS |
9467 | @value{GDBN} prints memory addresses showing the location of stack |
9468 | traces, structure values, pointer values, breakpoints, and so forth, | |
9469 | even when it also displays the contents of those addresses. The default | |
9470 | is @code{on}. For example, this is what a stack frame display looks like with | |
9471 | @code{set print address on}: | |
9472 | ||
9473 | @smallexample | |
9474 | @group | |
9475 | (@value{GDBP}) f | |
9476 | #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>") | |
9477 | at input.c:530 | |
9478 | 530 if (lquote != def_lquote) | |
9479 | @end group | |
9480 | @end smallexample | |
9481 | ||
9482 | @item set print address off | |
9483 | Do not print addresses when displaying their contents. For example, | |
9484 | this is the same stack frame displayed with @code{set print address off}: | |
9485 | ||
9486 | @smallexample | |
9487 | @group | |
9488 | (@value{GDBP}) set print addr off | |
9489 | (@value{GDBP}) f | |
9490 | #0 set_quotes (lq="<<", rq=">>") at input.c:530 | |
9491 | 530 if (lquote != def_lquote) | |
9492 | @end group | |
9493 | @end smallexample | |
9494 | ||
9495 | You can use @samp{set print address off} to eliminate all machine | |
9496 | dependent displays from the @value{GDBN} interface. For example, with | |
9497 | @code{print address off}, you should get the same text for backtraces on | |
9498 | all machines---whether or not they involve pointer arguments. | |
9499 | ||
4644b6e3 | 9500 | @kindex show print |
c906108c SS |
9501 | @item show print address |
9502 | Show whether or not addresses are to be printed. | |
9503 | @end table | |
9504 | ||
9505 | When @value{GDBN} prints a symbolic address, it normally prints the | |
9506 | closest earlier symbol plus an offset. If that symbol does not uniquely | |
9507 | identify the address (for example, it is a name whose scope is a single | |
9508 | source file), you may need to clarify. One way to do this is with | |
9509 | @code{info line}, for example @samp{info line *0x4537}. Alternately, | |
9510 | you can set @value{GDBN} to print the source file and line number when | |
9511 | it prints a symbolic address: | |
9512 | ||
9513 | @table @code | |
c906108c | 9514 | @item set print symbol-filename on |
9c16f35a EZ |
9515 | @cindex source file and line of a symbol |
9516 | @cindex symbol, source file and line | |
c906108c SS |
9517 | Tell @value{GDBN} to print the source file name and line number of a |
9518 | symbol in the symbolic form of an address. | |
9519 | ||
9520 | @item set print symbol-filename off | |
9521 | Do not print source file name and line number of a symbol. This is the | |
9522 | default. | |
9523 | ||
c906108c SS |
9524 | @item show print symbol-filename |
9525 | Show whether or not @value{GDBN} will print the source file name and | |
9526 | line number of a symbol in the symbolic form of an address. | |
9527 | @end table | |
9528 | ||
9529 | Another situation where it is helpful to show symbol filenames and line | |
9530 | numbers is when disassembling code; @value{GDBN} shows you the line | |
9531 | number and source file that corresponds to each instruction. | |
9532 | ||
9533 | Also, you may wish to see the symbolic form only if the address being | |
9534 | printed is reasonably close to the closest earlier symbol: | |
9535 | ||
9536 | @table @code | |
c906108c | 9537 | @item set print max-symbolic-offset @var{max-offset} |
f81d1120 | 9538 | @itemx set print max-symbolic-offset unlimited |
4644b6e3 | 9539 | @cindex maximum value for offset of closest symbol |
c906108c SS |
9540 | Tell @value{GDBN} to only display the symbolic form of an address if the |
9541 | offset between the closest earlier symbol and the address is less than | |
f81d1120 PA |
9542 | @var{max-offset}. The default is @code{unlimited}, which tells @value{GDBN} |
9543 | to always print the symbolic form of an address if any symbol precedes | |
9544 | it. Zero is equivalent to @code{unlimited}. | |
c906108c | 9545 | |
c906108c SS |
9546 | @item show print max-symbolic-offset |
9547 | Ask how large the maximum offset is that @value{GDBN} prints in a | |
9548 | symbolic address. | |
9549 | @end table | |
9550 | ||
9551 | @cindex wild pointer, interpreting | |
9552 | @cindex pointer, finding referent | |
9553 | If you have a pointer and you are not sure where it points, try | |
9554 | @samp{set print symbol-filename on}. Then you can determine the name | |
9555 | and source file location of the variable where it points, using | |
9556 | @samp{p/a @var{pointer}}. This interprets the address in symbolic form. | |
9557 | For example, here @value{GDBN} shows that a variable @code{ptt} points | |
9558 | at another variable @code{t}, defined in @file{hi2.c}: | |
9559 | ||
474c8240 | 9560 | @smallexample |
c906108c SS |
9561 | (@value{GDBP}) set print symbol-filename on |
9562 | (@value{GDBP}) p/a ptt | |
9563 | $4 = 0xe008 <t in hi2.c> | |
474c8240 | 9564 | @end smallexample |
c906108c SS |
9565 | |
9566 | @quotation | |
9567 | @emph{Warning:} For pointers that point to a local variable, @samp{p/a} | |
9568 | does not show the symbol name and filename of the referent, even with | |
9569 | the appropriate @code{set print} options turned on. | |
9570 | @end quotation | |
9571 | ||
9cb709b6 TT |
9572 | You can also enable @samp{/a}-like formatting all the time using |
9573 | @samp{set print symbol on}: | |
9574 | ||
9575 | @table @code | |
9576 | @item set print symbol on | |
9577 | Tell @value{GDBN} to print the symbol corresponding to an address, if | |
9578 | one exists. | |
9579 | ||
9580 | @item set print symbol off | |
9581 | Tell @value{GDBN} not to print the symbol corresponding to an | |
9582 | address. In this mode, @value{GDBN} will still print the symbol | |
9583 | corresponding to pointers to functions. This is the default. | |
9584 | ||
9585 | @item show print symbol | |
9586 | Show whether @value{GDBN} will display the symbol corresponding to an | |
9587 | address. | |
9588 | @end table | |
9589 | ||
c906108c SS |
9590 | Other settings control how different kinds of objects are printed: |
9591 | ||
9592 | @table @code | |
c906108c SS |
9593 | @item set print array |
9594 | @itemx set print array on | |
4644b6e3 | 9595 | @cindex pretty print arrays |
c906108c SS |
9596 | Pretty print arrays. This format is more convenient to read, |
9597 | but uses more space. The default is off. | |
9598 | ||
9599 | @item set print array off | |
9600 | Return to compressed format for arrays. | |
9601 | ||
c906108c SS |
9602 | @item show print array |
9603 | Show whether compressed or pretty format is selected for displaying | |
9604 | arrays. | |
9605 | ||
3c9c013a JB |
9606 | @cindex print array indexes |
9607 | @item set print array-indexes | |
9608 | @itemx set print array-indexes on | |
9609 | Print the index of each element when displaying arrays. May be more | |
9610 | convenient to locate a given element in the array or quickly find the | |
9611 | index of a given element in that printed array. The default is off. | |
9612 | ||
9613 | @item set print array-indexes off | |
9614 | Stop printing element indexes when displaying arrays. | |
9615 | ||
9616 | @item show print array-indexes | |
9617 | Show whether the index of each element is printed when displaying | |
9618 | arrays. | |
9619 | ||
c906108c | 9620 | @item set print elements @var{number-of-elements} |
f81d1120 | 9621 | @itemx set print elements unlimited |
4644b6e3 | 9622 | @cindex number of array elements to print |
9c16f35a | 9623 | @cindex limit on number of printed array elements |
c906108c SS |
9624 | Set a limit on how many elements of an array @value{GDBN} will print. |
9625 | If @value{GDBN} is printing a large array, it stops printing after it has | |
9626 | printed the number of elements set by the @code{set print elements} command. | |
9627 | This limit also applies to the display of strings. | |
d4f3574e | 9628 | When @value{GDBN} starts, this limit is set to 200. |
f81d1120 PA |
9629 | Setting @var{number-of-elements} to @code{unlimited} or zero means |
9630 | that the number of elements to print is unlimited. | |
c906108c | 9631 | |
c906108c SS |
9632 | @item show print elements |
9633 | Display the number of elements of a large array that @value{GDBN} will print. | |
9634 | If the number is 0, then the printing is unlimited. | |
9635 | ||
b4740add | 9636 | @item set print frame-arguments @var{value} |
a0381d3a | 9637 | @kindex set print frame-arguments |
b4740add JB |
9638 | @cindex printing frame argument values |
9639 | @cindex print all frame argument values | |
9640 | @cindex print frame argument values for scalars only | |
9641 | @cindex do not print frame argument values | |
9642 | This command allows to control how the values of arguments are printed | |
9643 | when the debugger prints a frame (@pxref{Frames}). The possible | |
9644 | values are: | |
9645 | ||
9646 | @table @code | |
9647 | @item all | |
4f5376b2 | 9648 | The values of all arguments are printed. |
b4740add JB |
9649 | |
9650 | @item scalars | |
9651 | Print the value of an argument only if it is a scalar. The value of more | |
9652 | complex arguments such as arrays, structures, unions, etc, is replaced | |
4f5376b2 JB |
9653 | by @code{@dots{}}. This is the default. Here is an example where |
9654 | only scalar arguments are shown: | |
b4740add JB |
9655 | |
9656 | @smallexample | |
9657 | #1 0x08048361 in call_me (i=3, s=@dots{}, ss=0xbf8d508c, u=@dots{}, e=green) | |
9658 | at frame-args.c:23 | |
9659 | @end smallexample | |
9660 | ||
9661 | @item none | |
9662 | None of the argument values are printed. Instead, the value of each argument | |
9663 | is replaced by @code{@dots{}}. In this case, the example above now becomes: | |
9664 | ||
9665 | @smallexample | |
9666 | #1 0x08048361 in call_me (i=@dots{}, s=@dots{}, ss=@dots{}, u=@dots{}, e=@dots{}) | |
9667 | at frame-args.c:23 | |
9668 | @end smallexample | |
9669 | @end table | |
9670 | ||
4f5376b2 JB |
9671 | By default, only scalar arguments are printed. This command can be used |
9672 | to configure the debugger to print the value of all arguments, regardless | |
9673 | of their type. However, it is often advantageous to not print the value | |
9674 | of more complex parameters. For instance, it reduces the amount of | |
9675 | information printed in each frame, making the backtrace more readable. | |
9676 | Also, it improves performance when displaying Ada frames, because | |
9677 | the computation of large arguments can sometimes be CPU-intensive, | |
9678 | especially in large applications. Setting @code{print frame-arguments} | |
9679 | to @code{scalars} (the default) or @code{none} avoids this computation, | |
9680 | thus speeding up the display of each Ada frame. | |
b4740add JB |
9681 | |
9682 | @item show print frame-arguments | |
9683 | Show how the value of arguments should be displayed when printing a frame. | |
9684 | ||
e7045703 DE |
9685 | @item set print raw frame-arguments on |
9686 | Print frame arguments in raw, non pretty-printed, form. | |
9687 | ||
9688 | @item set print raw frame-arguments off | |
9689 | Print frame arguments in pretty-printed form, if there is a pretty-printer | |
9690 | for the value (@pxref{Pretty Printing}), | |
9691 | otherwise print the value in raw form. | |
9692 | This is the default. | |
9693 | ||
9694 | @item show print raw frame-arguments | |
9695 | Show whether to print frame arguments in raw form. | |
9696 | ||
36b11add | 9697 | @anchor{set print entry-values} |
e18b2753 JK |
9698 | @item set print entry-values @var{value} |
9699 | @kindex set print entry-values | |
9700 | Set printing of frame argument values at function entry. In some cases | |
9701 | @value{GDBN} can determine the value of function argument which was passed by | |
9702 | the function caller, even if the value was modified inside the called function | |
9703 | and therefore is different. With optimized code, the current value could be | |
9704 | unavailable, but the entry value may still be known. | |
9705 | ||
9706 | The default value is @code{default} (see below for its description). Older | |
9707 | @value{GDBN} behaved as with the setting @code{no}. Compilers not supporting | |
9708 | this feature will behave in the @code{default} setting the same way as with the | |
9709 | @code{no} setting. | |
9710 | ||
9711 | This functionality is currently supported only by DWARF 2 debugging format and | |
9712 | the compiler has to produce @samp{DW_TAG_GNU_call_site} tags. With | |
9713 | @value{NGCC}, you need to specify @option{-O -g} during compilation, to get | |
9714 | this information. | |
9715 | ||
9716 | The @var{value} parameter can be one of the following: | |
9717 | ||
9718 | @table @code | |
9719 | @item no | |
9720 | Print only actual parameter values, never print values from function entry | |
9721 | point. | |
9722 | @smallexample | |
9723 | #0 equal (val=5) | |
9724 | #0 different (val=6) | |
9725 | #0 lost (val=<optimized out>) | |
9726 | #0 born (val=10) | |
9727 | #0 invalid (val=<optimized out>) | |
9728 | @end smallexample | |
9729 | ||
9730 | @item only | |
9731 | Print only parameter values from function entry point. The actual parameter | |
9732 | values are never printed. | |
9733 | @smallexample | |
9734 | #0 equal (val@@entry=5) | |
9735 | #0 different (val@@entry=5) | |
9736 | #0 lost (val@@entry=5) | |
9737 | #0 born (val@@entry=<optimized out>) | |
9738 | #0 invalid (val@@entry=<optimized out>) | |
9739 | @end smallexample | |
9740 | ||
9741 | @item preferred | |
9742 | Print only parameter values from function entry point. If value from function | |
9743 | entry point is not known while the actual value is known, print the actual | |
9744 | value for such parameter. | |
9745 | @smallexample | |
9746 | #0 equal (val@@entry=5) | |
9747 | #0 different (val@@entry=5) | |
9748 | #0 lost (val@@entry=5) | |
9749 | #0 born (val=10) | |
9750 | #0 invalid (val@@entry=<optimized out>) | |
9751 | @end smallexample | |
9752 | ||
9753 | @item if-needed | |
9754 | Print actual parameter values. If actual parameter value is not known while | |
9755 | value from function entry point is known, print the entry point value for such | |
9756 | parameter. | |
9757 | @smallexample | |
9758 | #0 equal (val=5) | |
9759 | #0 different (val=6) | |
9760 | #0 lost (val@@entry=5) | |
9761 | #0 born (val=10) | |
9762 | #0 invalid (val=<optimized out>) | |
9763 | @end smallexample | |
9764 | ||
9765 | @item both | |
9766 | Always print both the actual parameter value and its value from function entry | |
9767 | point, even if values of one or both are not available due to compiler | |
9768 | optimizations. | |
9769 | @smallexample | |
9770 | #0 equal (val=5, val@@entry=5) | |
9771 | #0 different (val=6, val@@entry=5) | |
9772 | #0 lost (val=<optimized out>, val@@entry=5) | |
9773 | #0 born (val=10, val@@entry=<optimized out>) | |
9774 | #0 invalid (val=<optimized out>, val@@entry=<optimized out>) | |
9775 | @end smallexample | |
9776 | ||
9777 | @item compact | |
9778 | Print the actual parameter value if it is known and also its value from | |
9779 | function entry point if it is known. If neither is known, print for the actual | |
9780 | value @code{<optimized out>}. If not in MI mode (@pxref{GDB/MI}) and if both | |
9781 | values are known and identical, print the shortened | |
9782 | @code{param=param@@entry=VALUE} notation. | |
9783 | @smallexample | |
9784 | #0 equal (val=val@@entry=5) | |
9785 | #0 different (val=6, val@@entry=5) | |
9786 | #0 lost (val@@entry=5) | |
9787 | #0 born (val=10) | |
9788 | #0 invalid (val=<optimized out>) | |
9789 | @end smallexample | |
9790 | ||
9791 | @item default | |
9792 | Always print the actual parameter value. Print also its value from function | |
9793 | entry point, but only if it is known. If not in MI mode (@pxref{GDB/MI}) and | |
9794 | if both values are known and identical, print the shortened | |
9795 | @code{param=param@@entry=VALUE} notation. | |
9796 | @smallexample | |
9797 | #0 equal (val=val@@entry=5) | |
9798 | #0 different (val=6, val@@entry=5) | |
9799 | #0 lost (val=<optimized out>, val@@entry=5) | |
9800 | #0 born (val=10) | |
9801 | #0 invalid (val=<optimized out>) | |
9802 | @end smallexample | |
9803 | @end table | |
9804 | ||
9805 | For analysis messages on possible failures of frame argument values at function | |
9806 | entry resolution see @ref{set debug entry-values}. | |
9807 | ||
9808 | @item show print entry-values | |
9809 | Show the method being used for printing of frame argument values at function | |
9810 | entry. | |
9811 | ||
f81d1120 PA |
9812 | @item set print repeats @var{number-of-repeats} |
9813 | @itemx set print repeats unlimited | |
9c16f35a EZ |
9814 | @cindex repeated array elements |
9815 | Set the threshold for suppressing display of repeated array | |
d3e8051b | 9816 | elements. When the number of consecutive identical elements of an |
9c16f35a EZ |
9817 | array exceeds the threshold, @value{GDBN} prints the string |
9818 | @code{"<repeats @var{n} times>"}, where @var{n} is the number of | |
9819 | identical repetitions, instead of displaying the identical elements | |
f81d1120 PA |
9820 | themselves. Setting the threshold to @code{unlimited} or zero will |
9821 | cause all elements to be individually printed. The default threshold | |
9822 | is 10. | |
9c16f35a EZ |
9823 | |
9824 | @item show print repeats | |
9825 | Display the current threshold for printing repeated identical | |
9826 | elements. | |
9827 | ||
c906108c | 9828 | @item set print null-stop |
4644b6e3 | 9829 | @cindex @sc{null} elements in arrays |
c906108c | 9830 | Cause @value{GDBN} to stop printing the characters of an array when the first |
d4f3574e | 9831 | @sc{null} is encountered. This is useful when large arrays actually |
c906108c | 9832 | contain only short strings. |
d4f3574e | 9833 | The default is off. |
c906108c | 9834 | |
9c16f35a EZ |
9835 | @item show print null-stop |
9836 | Show whether @value{GDBN} stops printing an array on the first | |
9837 | @sc{null} character. | |
9838 | ||
c906108c | 9839 | @item set print pretty on |
9c16f35a EZ |
9840 | @cindex print structures in indented form |
9841 | @cindex indentation in structure display | |
5d161b24 | 9842 | Cause @value{GDBN} to print structures in an indented format with one member |
c906108c SS |
9843 | per line, like this: |
9844 | ||
9845 | @smallexample | |
9846 | @group | |
9847 | $1 = @{ | |
9848 | next = 0x0, | |
9849 | flags = @{ | |
9850 | sweet = 1, | |
9851 | sour = 1 | |
9852 | @}, | |
9853 | meat = 0x54 "Pork" | |
9854 | @} | |
9855 | @end group | |
9856 | @end smallexample | |
9857 | ||
9858 | @item set print pretty off | |
9859 | Cause @value{GDBN} to print structures in a compact format, like this: | |
9860 | ||
9861 | @smallexample | |
9862 | @group | |
9863 | $1 = @{next = 0x0, flags = @{sweet = 1, sour = 1@}, \ | |
9864 | meat = 0x54 "Pork"@} | |
9865 | @end group | |
9866 | @end smallexample | |
9867 | ||
9868 | @noindent | |
9869 | This is the default format. | |
9870 | ||
c906108c SS |
9871 | @item show print pretty |
9872 | Show which format @value{GDBN} is using to print structures. | |
9873 | ||
c906108c | 9874 | @item set print sevenbit-strings on |
4644b6e3 EZ |
9875 | @cindex eight-bit characters in strings |
9876 | @cindex octal escapes in strings | |
c906108c SS |
9877 | Print using only seven-bit characters; if this option is set, |
9878 | @value{GDBN} displays any eight-bit characters (in strings or | |
9879 | character values) using the notation @code{\}@var{nnn}. This setting is | |
9880 | best if you are working in English (@sc{ascii}) and you use the | |
9881 | high-order bit of characters as a marker or ``meta'' bit. | |
9882 | ||
9883 | @item set print sevenbit-strings off | |
9884 | Print full eight-bit characters. This allows the use of more | |
9885 | international character sets, and is the default. | |
9886 | ||
c906108c SS |
9887 | @item show print sevenbit-strings |
9888 | Show whether or not @value{GDBN} is printing only seven-bit characters. | |
9889 | ||
c906108c | 9890 | @item set print union on |
4644b6e3 | 9891 | @cindex unions in structures, printing |
9c16f35a EZ |
9892 | Tell @value{GDBN} to print unions which are contained in structures |
9893 | and other unions. This is the default setting. | |
c906108c SS |
9894 | |
9895 | @item set print union off | |
9c16f35a EZ |
9896 | Tell @value{GDBN} not to print unions which are contained in |
9897 | structures and other unions. @value{GDBN} will print @code{"@{...@}"} | |
9898 | instead. | |
c906108c | 9899 | |
c906108c SS |
9900 | @item show print union |
9901 | Ask @value{GDBN} whether or not it will print unions which are contained in | |
9c16f35a | 9902 | structures and other unions. |
c906108c SS |
9903 | |
9904 | For example, given the declarations | |
9905 | ||
9906 | @smallexample | |
9907 | typedef enum @{Tree, Bug@} Species; | |
9908 | typedef enum @{Big_tree, Acorn, Seedling@} Tree_forms; | |
5d161b24 | 9909 | typedef enum @{Caterpillar, Cocoon, Butterfly@} |
c906108c SS |
9910 | Bug_forms; |
9911 | ||
9912 | struct thing @{ | |
9913 | Species it; | |
9914 | union @{ | |
9915 | Tree_forms tree; | |
9916 | Bug_forms bug; | |
9917 | @} form; | |
9918 | @}; | |
9919 | ||
9920 | struct thing foo = @{Tree, @{Acorn@}@}; | |
9921 | @end smallexample | |
9922 | ||
9923 | @noindent | |
9924 | with @code{set print union on} in effect @samp{p foo} would print | |
9925 | ||
9926 | @smallexample | |
9927 | $1 = @{it = Tree, form = @{tree = Acorn, bug = Cocoon@}@} | |
9928 | @end smallexample | |
9929 | ||
9930 | @noindent | |
9931 | and with @code{set print union off} in effect it would print | |
9932 | ||
9933 | @smallexample | |
9934 | $1 = @{it = Tree, form = @{...@}@} | |
9935 | @end smallexample | |
9c16f35a EZ |
9936 | |
9937 | @noindent | |
9938 | @code{set print union} affects programs written in C-like languages | |
9939 | and in Pascal. | |
c906108c SS |
9940 | @end table |
9941 | ||
c906108c SS |
9942 | @need 1000 |
9943 | @noindent | |
b37052ae | 9944 | These settings are of interest when debugging C@t{++} programs: |
c906108c SS |
9945 | |
9946 | @table @code | |
4644b6e3 | 9947 | @cindex demangling C@t{++} names |
c906108c SS |
9948 | @item set print demangle |
9949 | @itemx set print demangle on | |
b37052ae | 9950 | Print C@t{++} names in their source form rather than in the encoded |
c906108c | 9951 | (``mangled'') form passed to the assembler and linker for type-safe |
d4f3574e | 9952 | linkage. The default is on. |
c906108c | 9953 | |
c906108c | 9954 | @item show print demangle |
b37052ae | 9955 | Show whether C@t{++} names are printed in mangled or demangled form. |
c906108c | 9956 | |
c906108c SS |
9957 | @item set print asm-demangle |
9958 | @itemx set print asm-demangle on | |
b37052ae | 9959 | Print C@t{++} names in their source form rather than their mangled form, even |
c906108c SS |
9960 | in assembler code printouts such as instruction disassemblies. |
9961 | The default is off. | |
9962 | ||
c906108c | 9963 | @item show print asm-demangle |
b37052ae | 9964 | Show whether C@t{++} names in assembly listings are printed in mangled |
c906108c SS |
9965 | or demangled form. |
9966 | ||
b37052ae EZ |
9967 | @cindex C@t{++} symbol decoding style |
9968 | @cindex symbol decoding style, C@t{++} | |
a8f24a35 | 9969 | @kindex set demangle-style |
c906108c SS |
9970 | @item set demangle-style @var{style} |
9971 | Choose among several encoding schemes used by different compilers to | |
b37052ae | 9972 | represent C@t{++} names. The choices for @var{style} are currently: |
c906108c SS |
9973 | |
9974 | @table @code | |
9975 | @item auto | |
9976 | Allow @value{GDBN} to choose a decoding style by inspecting your program. | |
891df0ea | 9977 | This is the default. |
c906108c SS |
9978 | |
9979 | @item gnu | |
b37052ae | 9980 | Decode based on the @sc{gnu} C@t{++} compiler (@code{g++}) encoding algorithm. |
c906108c SS |
9981 | |
9982 | @item hp | |
b37052ae | 9983 | Decode based on the HP ANSI C@t{++} (@code{aCC}) encoding algorithm. |
c906108c SS |
9984 | |
9985 | @item lucid | |
b37052ae | 9986 | Decode based on the Lucid C@t{++} compiler (@code{lcc}) encoding algorithm. |
c906108c SS |
9987 | |
9988 | @item arm | |
b37052ae | 9989 | Decode using the algorithm in the @cite{C@t{++} Annotated Reference Manual}. |
c906108c SS |
9990 | @strong{Warning:} this setting alone is not sufficient to allow |
9991 | debugging @code{cfront}-generated executables. @value{GDBN} would | |
9992 | require further enhancement to permit that. | |
9993 | ||
9994 | @end table | |
9995 | If you omit @var{style}, you will see a list of possible formats. | |
9996 | ||
c906108c | 9997 | @item show demangle-style |
b37052ae | 9998 | Display the encoding style currently in use for decoding C@t{++} symbols. |
c906108c | 9999 | |
c906108c SS |
10000 | @item set print object |
10001 | @itemx set print object on | |
4644b6e3 | 10002 | @cindex derived type of an object, printing |
9c16f35a | 10003 | @cindex display derived types |
c906108c SS |
10004 | When displaying a pointer to an object, identify the @emph{actual} |
10005 | (derived) type of the object rather than the @emph{declared} type, using | |
625c0d47 TT |
10006 | the virtual function table. Note that the virtual function table is |
10007 | required---this feature can only work for objects that have run-time | |
10008 | type identification; a single virtual method in the object's declared | |
8264ba82 AG |
10009 | type is sufficient. Note that this setting is also taken into account when |
10010 | working with variable objects via MI (@pxref{GDB/MI}). | |
c906108c SS |
10011 | |
10012 | @item set print object off | |
10013 | Display only the declared type of objects, without reference to the | |
10014 | virtual function table. This is the default setting. | |
10015 | ||
c906108c SS |
10016 | @item show print object |
10017 | Show whether actual, or declared, object types are displayed. | |
10018 | ||
c906108c SS |
10019 | @item set print static-members |
10020 | @itemx set print static-members on | |
4644b6e3 | 10021 | @cindex static members of C@t{++} objects |
b37052ae | 10022 | Print static members when displaying a C@t{++} object. The default is on. |
c906108c SS |
10023 | |
10024 | @item set print static-members off | |
b37052ae | 10025 | Do not print static members when displaying a C@t{++} object. |
c906108c | 10026 | |
c906108c | 10027 | @item show print static-members |
9c16f35a EZ |
10028 | Show whether C@t{++} static members are printed or not. |
10029 | ||
10030 | @item set print pascal_static-members | |
10031 | @itemx set print pascal_static-members on | |
d3e8051b EZ |
10032 | @cindex static members of Pascal objects |
10033 | @cindex Pascal objects, static members display | |
9c16f35a EZ |
10034 | Print static members when displaying a Pascal object. The default is on. |
10035 | ||
10036 | @item set print pascal_static-members off | |
10037 | Do not print static members when displaying a Pascal object. | |
10038 | ||
10039 | @item show print pascal_static-members | |
10040 | Show whether Pascal static members are printed or not. | |
c906108c SS |
10041 | |
10042 | @c These don't work with HP ANSI C++ yet. | |
c906108c SS |
10043 | @item set print vtbl |
10044 | @itemx set print vtbl on | |
4644b6e3 | 10045 | @cindex pretty print C@t{++} virtual function tables |
9c16f35a EZ |
10046 | @cindex virtual functions (C@t{++}) display |
10047 | @cindex VTBL display | |
b37052ae | 10048 | Pretty print C@t{++} virtual function tables. The default is off. |
c906108c | 10049 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 10050 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
10051 | |
10052 | @item set print vtbl off | |
b37052ae | 10053 | Do not pretty print C@t{++} virtual function tables. |
c906108c | 10054 | |
c906108c | 10055 | @item show print vtbl |
b37052ae | 10056 | Show whether C@t{++} virtual function tables are pretty printed, or not. |
c906108c | 10057 | @end table |
c906108c | 10058 | |
4c374409 JK |
10059 | @node Pretty Printing |
10060 | @section Pretty Printing | |
10061 | ||
10062 | @value{GDBN} provides a mechanism to allow pretty-printing of values using | |
10063 | Python code. It greatly simplifies the display of complex objects. This | |
10064 | mechanism works for both MI and the CLI. | |
10065 | ||
7b51bc51 DE |
10066 | @menu |
10067 | * Pretty-Printer Introduction:: Introduction to pretty-printers | |
10068 | * Pretty-Printer Example:: An example pretty-printer | |
10069 | * Pretty-Printer Commands:: Pretty-printer commands | |
10070 | @end menu | |
10071 | ||
10072 | @node Pretty-Printer Introduction | |
10073 | @subsection Pretty-Printer Introduction | |
10074 | ||
10075 | When @value{GDBN} prints a value, it first sees if there is a pretty-printer | |
10076 | registered for the value. If there is then @value{GDBN} invokes the | |
10077 | pretty-printer to print the value. Otherwise the value is printed normally. | |
10078 | ||
10079 | Pretty-printers are normally named. This makes them easy to manage. | |
10080 | The @samp{info pretty-printer} command will list all the installed | |
10081 | pretty-printers with their names. | |
10082 | If a pretty-printer can handle multiple data types, then its | |
10083 | @dfn{subprinters} are the printers for the individual data types. | |
10084 | Each such subprinter has its own name. | |
4e04c971 | 10085 | The format of the name is @var{printer-name};@var{subprinter-name}. |
7b51bc51 DE |
10086 | |
10087 | Pretty-printers are installed by @dfn{registering} them with @value{GDBN}. | |
10088 | Typically they are automatically loaded and registered when the corresponding | |
10089 | debug information is loaded, thus making them available without having to | |
10090 | do anything special. | |
10091 | ||
10092 | There are three places where a pretty-printer can be registered. | |
10093 | ||
10094 | @itemize @bullet | |
10095 | @item | |
10096 | Pretty-printers registered globally are available when debugging | |
10097 | all inferiors. | |
10098 | ||
10099 | @item | |
10100 | Pretty-printers registered with a program space are available only | |
10101 | when debugging that program. | |
10102 | @xref{Progspaces In Python}, for more details on program spaces in Python. | |
10103 | ||
10104 | @item | |
10105 | Pretty-printers registered with an objfile are loaded and unloaded | |
10106 | with the corresponding objfile (e.g., shared library). | |
10107 | @xref{Objfiles In Python}, for more details on objfiles in Python. | |
10108 | @end itemize | |
10109 | ||
10110 | @xref{Selecting Pretty-Printers}, for further information on how | |
10111 | pretty-printers are selected, | |
10112 | ||
10113 | @xref{Writing a Pretty-Printer}, for implementing pretty printers | |
10114 | for new types. | |
10115 | ||
10116 | @node Pretty-Printer Example | |
10117 | @subsection Pretty-Printer Example | |
10118 | ||
10119 | Here is how a C@t{++} @code{std::string} looks without a pretty-printer: | |
4c374409 JK |
10120 | |
10121 | @smallexample | |
10122 | (@value{GDBP}) print s | |
10123 | $1 = @{ | |
10124 | static npos = 4294967295, | |
10125 | _M_dataplus = @{ | |
10126 | <std::allocator<char>> = @{ | |
10127 | <__gnu_cxx::new_allocator<char>> = @{ | |
10128 | <No data fields>@}, <No data fields> | |
10129 | @}, | |
10130 | members of std::basic_string<char, std::char_traits<char>, | |
10131 | std::allocator<char> >::_Alloc_hider: | |
10132 | _M_p = 0x804a014 "abcd" | |
10133 | @} | |
10134 | @} | |
10135 | @end smallexample | |
10136 | ||
10137 | With a pretty-printer for @code{std::string} only the contents are printed: | |
10138 | ||
10139 | @smallexample | |
10140 | (@value{GDBP}) print s | |
10141 | $2 = "abcd" | |
10142 | @end smallexample | |
10143 | ||
7b51bc51 DE |
10144 | @node Pretty-Printer Commands |
10145 | @subsection Pretty-Printer Commands | |
10146 | @cindex pretty-printer commands | |
10147 | ||
10148 | @table @code | |
10149 | @kindex info pretty-printer | |
10150 | @item info pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
10151 | Print the list of installed pretty-printers. | |
10152 | This includes disabled pretty-printers, which are marked as such. | |
10153 | ||
10154 | @var{object-regexp} is a regular expression matching the objects | |
10155 | whose pretty-printers to list. | |
10156 | Objects can be @code{global}, the program space's file | |
10157 | (@pxref{Progspaces In Python}), | |
10158 | and the object files within that program space (@pxref{Objfiles In Python}). | |
10159 | @xref{Selecting Pretty-Printers}, for details on how @value{GDBN} | |
10160 | looks up a printer from these three objects. | |
10161 | ||
10162 | @var{name-regexp} is a regular expression matching the name of the printers | |
10163 | to list. | |
10164 | ||
10165 | @kindex disable pretty-printer | |
10166 | @item disable pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
10167 | Disable pretty-printers matching @var{object-regexp} and @var{name-regexp}. | |
10168 | A disabled pretty-printer is not forgotten, it may be enabled again later. | |
10169 | ||
10170 | @kindex enable pretty-printer | |
10171 | @item enable pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
10172 | Enable pretty-printers matching @var{object-regexp} and @var{name-regexp}. | |
10173 | @end table | |
10174 | ||
10175 | Example: | |
10176 | ||
10177 | Suppose we have three pretty-printers installed: one from library1.so | |
10178 | named @code{foo} that prints objects of type @code{foo}, and | |
10179 | another from library2.so named @code{bar} that prints two types of objects, | |
10180 | @code{bar1} and @code{bar2}. | |
10181 | ||
10182 | @smallexample | |
10183 | (gdb) info pretty-printer | |
10184 | library1.so: | |
10185 | foo | |
10186 | library2.so: | |
10187 | bar | |
10188 | bar1 | |
10189 | bar2 | |
10190 | (gdb) info pretty-printer library2 | |
10191 | library2.so: | |
10192 | bar | |
10193 | bar1 | |
10194 | bar2 | |
10195 | (gdb) disable pretty-printer library1 | |
10196 | 1 printer disabled | |
10197 | 2 of 3 printers enabled | |
10198 | (gdb) info pretty-printer | |
10199 | library1.so: | |
10200 | foo [disabled] | |
10201 | library2.so: | |
10202 | bar | |
10203 | bar1 | |
10204 | bar2 | |
10205 | (gdb) disable pretty-printer library2 bar:bar1 | |
10206 | 1 printer disabled | |
10207 | 1 of 3 printers enabled | |
10208 | (gdb) info pretty-printer library2 | |
10209 | library1.so: | |
10210 | foo [disabled] | |
10211 | library2.so: | |
10212 | bar | |
10213 | bar1 [disabled] | |
10214 | bar2 | |
10215 | (gdb) disable pretty-printer library2 bar | |
10216 | 1 printer disabled | |
10217 | 0 of 3 printers enabled | |
10218 | (gdb) info pretty-printer library2 | |
10219 | library1.so: | |
10220 | foo [disabled] | |
10221 | library2.so: | |
10222 | bar [disabled] | |
10223 | bar1 [disabled] | |
10224 | bar2 | |
10225 | @end smallexample | |
10226 | ||
10227 | Note that for @code{bar} the entire printer can be disabled, | |
10228 | as can each individual subprinter. | |
4c374409 | 10229 | |
6d2ebf8b | 10230 | @node Value History |
79a6e687 | 10231 | @section Value History |
c906108c SS |
10232 | |
10233 | @cindex value history | |
9c16f35a | 10234 | @cindex history of values printed by @value{GDBN} |
5d161b24 DB |
10235 | Values printed by the @code{print} command are saved in the @value{GDBN} |
10236 | @dfn{value history}. This allows you to refer to them in other expressions. | |
10237 | Values are kept until the symbol table is re-read or discarded | |
10238 | (for example with the @code{file} or @code{symbol-file} commands). | |
10239 | When the symbol table changes, the value history is discarded, | |
10240 | since the values may contain pointers back to the types defined in the | |
c906108c SS |
10241 | symbol table. |
10242 | ||
10243 | @cindex @code{$} | |
10244 | @cindex @code{$$} | |
10245 | @cindex history number | |
10246 | The values printed are given @dfn{history numbers} by which you can | |
10247 | refer to them. These are successive integers starting with one. | |
10248 | @code{print} shows you the history number assigned to a value by | |
10249 | printing @samp{$@var{num} = } before the value; here @var{num} is the | |
10250 | history number. | |
10251 | ||
10252 | To refer to any previous value, use @samp{$} followed by the value's | |
10253 | history number. The way @code{print} labels its output is designed to | |
10254 | remind you of this. Just @code{$} refers to the most recent value in | |
10255 | the history, and @code{$$} refers to the value before that. | |
10256 | @code{$$@var{n}} refers to the @var{n}th value from the end; @code{$$2} | |
10257 | is the value just prior to @code{$$}, @code{$$1} is equivalent to | |
10258 | @code{$$}, and @code{$$0} is equivalent to @code{$}. | |
10259 | ||
10260 | For example, suppose you have just printed a pointer to a structure and | |
10261 | want to see the contents of the structure. It suffices to type | |
10262 | ||
474c8240 | 10263 | @smallexample |
c906108c | 10264 | p *$ |
474c8240 | 10265 | @end smallexample |
c906108c SS |
10266 | |
10267 | If you have a chain of structures where the component @code{next} points | |
10268 | to the next one, you can print the contents of the next one with this: | |
10269 | ||
474c8240 | 10270 | @smallexample |
c906108c | 10271 | p *$.next |
474c8240 | 10272 | @end smallexample |
c906108c SS |
10273 | |
10274 | @noindent | |
10275 | You can print successive links in the chain by repeating this | |
10276 | command---which you can do by just typing @key{RET}. | |
10277 | ||
10278 | Note that the history records values, not expressions. If the value of | |
10279 | @code{x} is 4 and you type these commands: | |
10280 | ||
474c8240 | 10281 | @smallexample |
c906108c SS |
10282 | print x |
10283 | set x=5 | |
474c8240 | 10284 | @end smallexample |
c906108c SS |
10285 | |
10286 | @noindent | |
10287 | then the value recorded in the value history by the @code{print} command | |
10288 | remains 4 even though the value of @code{x} has changed. | |
10289 | ||
10290 | @table @code | |
10291 | @kindex show values | |
10292 | @item show values | |
10293 | Print the last ten values in the value history, with their item numbers. | |
10294 | This is like @samp{p@ $$9} repeated ten times, except that @code{show | |
10295 | values} does not change the history. | |
10296 | ||
10297 | @item show values @var{n} | |
10298 | Print ten history values centered on history item number @var{n}. | |
10299 | ||
10300 | @item show values + | |
10301 | Print ten history values just after the values last printed. If no more | |
10302 | values are available, @code{show values +} produces no display. | |
10303 | @end table | |
10304 | ||
10305 | Pressing @key{RET} to repeat @code{show values @var{n}} has exactly the | |
10306 | same effect as @samp{show values +}. | |
10307 | ||
6d2ebf8b | 10308 | @node Convenience Vars |
79a6e687 | 10309 | @section Convenience Variables |
c906108c SS |
10310 | |
10311 | @cindex convenience variables | |
9c16f35a | 10312 | @cindex user-defined variables |
c906108c SS |
10313 | @value{GDBN} provides @dfn{convenience variables} that you can use within |
10314 | @value{GDBN} to hold on to a value and refer to it later. These variables | |
10315 | exist entirely within @value{GDBN}; they are not part of your program, and | |
10316 | setting a convenience variable has no direct effect on further execution | |
10317 | of your program. That is why you can use them freely. | |
10318 | ||
10319 | Convenience variables are prefixed with @samp{$}. Any name preceded by | |
10320 | @samp{$} can be used for a convenience variable, unless it is one of | |
d4f3574e | 10321 | the predefined machine-specific register names (@pxref{Registers, ,Registers}). |
c906108c | 10322 | (Value history references, in contrast, are @emph{numbers} preceded |
79a6e687 | 10323 | by @samp{$}. @xref{Value History, ,Value History}.) |
c906108c SS |
10324 | |
10325 | You can save a value in a convenience variable with an assignment | |
10326 | expression, just as you would set a variable in your program. | |
10327 | For example: | |
10328 | ||
474c8240 | 10329 | @smallexample |
c906108c | 10330 | set $foo = *object_ptr |
474c8240 | 10331 | @end smallexample |
c906108c SS |
10332 | |
10333 | @noindent | |
10334 | would save in @code{$foo} the value contained in the object pointed to by | |
10335 | @code{object_ptr}. | |
10336 | ||
10337 | Using a convenience variable for the first time creates it, but its | |
10338 | value is @code{void} until you assign a new value. You can alter the | |
10339 | value with another assignment at any time. | |
10340 | ||
10341 | Convenience variables have no fixed types. You can assign a convenience | |
10342 | variable any type of value, including structures and arrays, even if | |
10343 | that variable already has a value of a different type. The convenience | |
10344 | variable, when used as an expression, has the type of its current value. | |
10345 | ||
10346 | @table @code | |
10347 | @kindex show convenience | |
f47f77df | 10348 | @cindex show all user variables and functions |
c906108c | 10349 | @item show convenience |
f47f77df DE |
10350 | Print a list of convenience variables used so far, and their values, |
10351 | as well as a list of the convenience functions. | |
d4f3574e | 10352 | Abbreviated @code{show conv}. |
53e5f3cf AS |
10353 | |
10354 | @kindex init-if-undefined | |
10355 | @cindex convenience variables, initializing | |
10356 | @item init-if-undefined $@var{variable} = @var{expression} | |
10357 | Set a convenience variable if it has not already been set. This is useful | |
10358 | for user-defined commands that keep some state. It is similar, in concept, | |
10359 | to using local static variables with initializers in C (except that | |
10360 | convenience variables are global). It can also be used to allow users to | |
10361 | override default values used in a command script. | |
10362 | ||
10363 | If the variable is already defined then the expression is not evaluated so | |
10364 | any side-effects do not occur. | |
c906108c SS |
10365 | @end table |
10366 | ||
10367 | One of the ways to use a convenience variable is as a counter to be | |
10368 | incremented or a pointer to be advanced. For example, to print | |
10369 | a field from successive elements of an array of structures: | |
10370 | ||
474c8240 | 10371 | @smallexample |
c906108c SS |
10372 | set $i = 0 |
10373 | print bar[$i++]->contents | |
474c8240 | 10374 | @end smallexample |
c906108c | 10375 | |
d4f3574e SS |
10376 | @noindent |
10377 | Repeat that command by typing @key{RET}. | |
c906108c SS |
10378 | |
10379 | Some convenience variables are created automatically by @value{GDBN} and given | |
10380 | values likely to be useful. | |
10381 | ||
10382 | @table @code | |
41afff9a | 10383 | @vindex $_@r{, convenience variable} |
c906108c SS |
10384 | @item $_ |
10385 | The variable @code{$_} is automatically set by the @code{x} command to | |
79a6e687 | 10386 | the last address examined (@pxref{Memory, ,Examining Memory}). Other |
c906108c SS |
10387 | commands which provide a default address for @code{x} to examine also |
10388 | set @code{$_} to that address; these commands include @code{info line} | |
10389 | and @code{info breakpoint}. The type of @code{$_} is @code{void *} | |
10390 | except when set by the @code{x} command, in which case it is a pointer | |
10391 | to the type of @code{$__}. | |
10392 | ||
41afff9a | 10393 | @vindex $__@r{, convenience variable} |
c906108c SS |
10394 | @item $__ |
10395 | The variable @code{$__} is automatically set by the @code{x} command | |
10396 | to the value found in the last address examined. Its type is chosen | |
10397 | to match the format in which the data was printed. | |
10398 | ||
10399 | @item $_exitcode | |
41afff9a | 10400 | @vindex $_exitcode@r{, convenience variable} |
0c557179 SDJ |
10401 | When the program being debugged terminates normally, @value{GDBN} |
10402 | automatically sets this variable to the exit code of the program, and | |
10403 | resets @code{$_exitsignal} to @code{void}. | |
10404 | ||
10405 | @item $_exitsignal | |
10406 | @vindex $_exitsignal@r{, convenience variable} | |
10407 | When the program being debugged dies due to an uncaught signal, | |
10408 | @value{GDBN} automatically sets this variable to that signal's number, | |
10409 | and resets @code{$_exitcode} to @code{void}. | |
10410 | ||
10411 | To distinguish between whether the program being debugged has exited | |
10412 | (i.e., @code{$_exitcode} is not @code{void}) or signalled (i.e., | |
10413 | @code{$_exitsignal} is not @code{void}), the convenience function | |
10414 | @code{$_isvoid} can be used (@pxref{Convenience Funs,, Convenience | |
10415 | Functions}). For example, considering the following source code: | |
10416 | ||
10417 | @smallexample | |
10418 | #include <signal.h> | |
10419 | ||
10420 | int | |
10421 | main (int argc, char *argv[]) | |
10422 | @{ | |
10423 | raise (SIGALRM); | |
10424 | return 0; | |
10425 | @} | |
10426 | @end smallexample | |
10427 | ||
10428 | A valid way of telling whether the program being debugged has exited | |
10429 | or signalled would be: | |
10430 | ||
10431 | @smallexample | |
10432 | (@value{GDBP}) define has_exited_or_signalled | |
10433 | Type commands for definition of ``has_exited_or_signalled''. | |
10434 | End with a line saying just ``end''. | |
10435 | >if $_isvoid ($_exitsignal) | |
10436 | >echo The program has exited\n | |
10437 | >else | |
10438 | >echo The program has signalled\n | |
10439 | >end | |
10440 | >end | |
10441 | (@value{GDBP}) run | |
10442 | Starting program: | |
10443 | ||
10444 | Program terminated with signal SIGALRM, Alarm clock. | |
10445 | The program no longer exists. | |
10446 | (@value{GDBP}) has_exited_or_signalled | |
10447 | The program has signalled | |
10448 | @end smallexample | |
10449 | ||
10450 | As can be seen, @value{GDBN} correctly informs that the program being | |
10451 | debugged has signalled, since it calls @code{raise} and raises a | |
10452 | @code{SIGALRM} signal. If the program being debugged had not called | |
10453 | @code{raise}, then @value{GDBN} would report a normal exit: | |
10454 | ||
10455 | @smallexample | |
10456 | (@value{GDBP}) has_exited_or_signalled | |
10457 | The program has exited | |
10458 | @end smallexample | |
4aa995e1 | 10459 | |
72f1fe8a TT |
10460 | @item $_exception |
10461 | The variable @code{$_exception} is set to the exception object being | |
10462 | thrown at an exception-related catchpoint. @xref{Set Catchpoints}. | |
10463 | ||
62e5f89c SDJ |
10464 | @item $_probe_argc |
10465 | @itemx $_probe_arg0@dots{}$_probe_arg11 | |
10466 | Arguments to a static probe. @xref{Static Probe Points}. | |
10467 | ||
0fb4aa4b PA |
10468 | @item $_sdata |
10469 | @vindex $_sdata@r{, inspect, convenience variable} | |
10470 | The variable @code{$_sdata} contains extra collected static tracepoint | |
10471 | data. @xref{Tracepoint Actions,,Tracepoint Action Lists}. Note that | |
10472 | @code{$_sdata} could be empty, if not inspecting a trace buffer, or | |
10473 | if extra static tracepoint data has not been collected. | |
10474 | ||
4aa995e1 PA |
10475 | @item $_siginfo |
10476 | @vindex $_siginfo@r{, convenience variable} | |
ec7e75e7 PP |
10477 | The variable @code{$_siginfo} contains extra signal information |
10478 | (@pxref{extra signal information}). Note that @code{$_siginfo} | |
10479 | could be empty, if the application has not yet received any signals. | |
10480 | For example, it will be empty before you execute the @code{run} command. | |
711e434b PM |
10481 | |
10482 | @item $_tlb | |
10483 | @vindex $_tlb@r{, convenience variable} | |
10484 | The variable @code{$_tlb} is automatically set when debugging | |
10485 | applications running on MS-Windows in native mode or connected to | |
10486 | gdbserver that supports the @code{qGetTIBAddr} request. | |
10487 | @xref{General Query Packets}. | |
10488 | This variable contains the address of the thread information block. | |
10489 | ||
e3940304 PA |
10490 | @item $_inferior |
10491 | The number of the current inferior. @xref{Inferiors and | |
10492 | Programs, ,Debugging Multiple Inferiors and Programs}. | |
10493 | ||
5d5658a1 PA |
10494 | @item $_thread |
10495 | The thread number of the current thread. @xref{thread numbers}. | |
10496 | ||
663f6d42 PA |
10497 | @item $_gthread |
10498 | The global number of the current thread. @xref{global thread numbers}. | |
10499 | ||
c906108c SS |
10500 | @end table |
10501 | ||
a72c3253 DE |
10502 | @node Convenience Funs |
10503 | @section Convenience Functions | |
10504 | ||
bc3b79fd TJB |
10505 | @cindex convenience functions |
10506 | @value{GDBN} also supplies some @dfn{convenience functions}. These | |
10507 | have a syntax similar to convenience variables. A convenience | |
10508 | function can be used in an expression just like an ordinary function; | |
10509 | however, a convenience function is implemented internally to | |
10510 | @value{GDBN}. | |
10511 | ||
a280dbd1 SDJ |
10512 | These functions do not require @value{GDBN} to be configured with |
10513 | @code{Python} support, which means that they are always available. | |
10514 | ||
10515 | @table @code | |
10516 | ||
10517 | @item $_isvoid (@var{expr}) | |
10518 | @findex $_isvoid@r{, convenience function} | |
10519 | Return one if the expression @var{expr} is @code{void}. Otherwise it | |
10520 | returns zero. | |
10521 | ||
10522 | A @code{void} expression is an expression where the type of the result | |
10523 | is @code{void}. For example, you can examine a convenience variable | |
10524 | (see @ref{Convenience Vars,, Convenience Variables}) to check whether | |
10525 | it is @code{void}: | |
10526 | ||
10527 | @smallexample | |
10528 | (@value{GDBP}) print $_exitcode | |
10529 | $1 = void | |
10530 | (@value{GDBP}) print $_isvoid ($_exitcode) | |
10531 | $2 = 1 | |
10532 | (@value{GDBP}) run | |
10533 | Starting program: ./a.out | |
10534 | [Inferior 1 (process 29572) exited normally] | |
10535 | (@value{GDBP}) print $_exitcode | |
10536 | $3 = 0 | |
10537 | (@value{GDBP}) print $_isvoid ($_exitcode) | |
10538 | $4 = 0 | |
10539 | @end smallexample | |
10540 | ||
10541 | In the example above, we used @code{$_isvoid} to check whether | |
10542 | @code{$_exitcode} is @code{void} before and after the execution of the | |
10543 | program being debugged. Before the execution there is no exit code to | |
10544 | be examined, therefore @code{$_exitcode} is @code{void}. After the | |
10545 | execution the program being debugged returned zero, therefore | |
10546 | @code{$_exitcode} is zero, which means that it is not @code{void} | |
10547 | anymore. | |
10548 | ||
10549 | The @code{void} expression can also be a call of a function from the | |
10550 | program being debugged. For example, given the following function: | |
10551 | ||
10552 | @smallexample | |
10553 | void | |
10554 | foo (void) | |
10555 | @{ | |
10556 | @} | |
10557 | @end smallexample | |
10558 | ||
10559 | The result of calling it inside @value{GDBN} is @code{void}: | |
10560 | ||
10561 | @smallexample | |
10562 | (@value{GDBP}) print foo () | |
10563 | $1 = void | |
10564 | (@value{GDBP}) print $_isvoid (foo ()) | |
10565 | $2 = 1 | |
10566 | (@value{GDBP}) set $v = foo () | |
10567 | (@value{GDBP}) print $v | |
10568 | $3 = void | |
10569 | (@value{GDBP}) print $_isvoid ($v) | |
10570 | $4 = 1 | |
10571 | @end smallexample | |
10572 | ||
10573 | @end table | |
10574 | ||
a72c3253 DE |
10575 | These functions require @value{GDBN} to be configured with |
10576 | @code{Python} support. | |
10577 | ||
10578 | @table @code | |
10579 | ||
10580 | @item $_memeq(@var{buf1}, @var{buf2}, @var{length}) | |
10581 | @findex $_memeq@r{, convenience function} | |
10582 | Returns one if the @var{length} bytes at the addresses given by | |
10583 | @var{buf1} and @var{buf2} are equal. | |
10584 | Otherwise it returns zero. | |
10585 | ||
10586 | @item $_regex(@var{str}, @var{regex}) | |
10587 | @findex $_regex@r{, convenience function} | |
10588 | Returns one if the string @var{str} matches the regular expression | |
10589 | @var{regex}. Otherwise it returns zero. | |
10590 | The syntax of the regular expression is that specified by @code{Python}'s | |
10591 | regular expression support. | |
10592 | ||
10593 | @item $_streq(@var{str1}, @var{str2}) | |
10594 | @findex $_streq@r{, convenience function} | |
10595 | Returns one if the strings @var{str1} and @var{str2} are equal. | |
10596 | Otherwise it returns zero. | |
10597 | ||
10598 | @item $_strlen(@var{str}) | |
10599 | @findex $_strlen@r{, convenience function} | |
10600 | Returns the length of string @var{str}. | |
10601 | ||
faa42425 DE |
10602 | @item $_caller_is(@var{name}@r{[}, @var{number_of_frames}@r{]}) |
10603 | @findex $_caller_is@r{, convenience function} | |
10604 | Returns one if the calling function's name is equal to @var{name}. | |
10605 | Otherwise it returns zero. | |
10606 | ||
10607 | If the optional argument @var{number_of_frames} is provided, | |
10608 | it is the number of frames up in the stack to look. | |
10609 | The default is 1. | |
10610 | ||
10611 | Example: | |
10612 | ||
10613 | @smallexample | |
10614 | (gdb) backtrace | |
10615 | #0 bottom_func () | |
10616 | at testsuite/gdb.python/py-caller-is.c:21 | |
10617 | #1 0x00000000004005a0 in middle_func () | |
10618 | at testsuite/gdb.python/py-caller-is.c:27 | |
10619 | #2 0x00000000004005ab in top_func () | |
10620 | at testsuite/gdb.python/py-caller-is.c:33 | |
10621 | #3 0x00000000004005b6 in main () | |
10622 | at testsuite/gdb.python/py-caller-is.c:39 | |
10623 | (gdb) print $_caller_is ("middle_func") | |
10624 | $1 = 1 | |
10625 | (gdb) print $_caller_is ("top_func", 2) | |
10626 | $1 = 1 | |
10627 | @end smallexample | |
10628 | ||
10629 | @item $_caller_matches(@var{regexp}@r{[}, @var{number_of_frames}@r{]}) | |
10630 | @findex $_caller_matches@r{, convenience function} | |
10631 | Returns one if the calling function's name matches the regular expression | |
10632 | @var{regexp}. Otherwise it returns zero. | |
10633 | ||
10634 | If the optional argument @var{number_of_frames} is provided, | |
10635 | it is the number of frames up in the stack to look. | |
10636 | The default is 1. | |
10637 | ||
10638 | @item $_any_caller_is(@var{name}@r{[}, @var{number_of_frames}@r{]}) | |
10639 | @findex $_any_caller_is@r{, convenience function} | |
10640 | Returns one if any calling function's name is equal to @var{name}. | |
10641 | Otherwise it returns zero. | |
10642 | ||
10643 | If the optional argument @var{number_of_frames} is provided, | |
10644 | it is the number of frames up in the stack to look. | |
10645 | The default is 1. | |
10646 | ||
10647 | This function differs from @code{$_caller_is} in that this function | |
10648 | checks all stack frames from the immediate caller to the frame specified | |
10649 | by @var{number_of_frames}, whereas @code{$_caller_is} only checks the | |
10650 | frame specified by @var{number_of_frames}. | |
10651 | ||
10652 | @item $_any_caller_matches(@var{regexp}@r{[}, @var{number_of_frames}@r{]}) | |
10653 | @findex $_any_caller_matches@r{, convenience function} | |
10654 | Returns one if any calling function's name matches the regular expression | |
10655 | @var{regexp}. Otherwise it returns zero. | |
10656 | ||
10657 | If the optional argument @var{number_of_frames} is provided, | |
10658 | it is the number of frames up in the stack to look. | |
10659 | The default is 1. | |
10660 | ||
10661 | This function differs from @code{$_caller_matches} in that this function | |
10662 | checks all stack frames from the immediate caller to the frame specified | |
10663 | by @var{number_of_frames}, whereas @code{$_caller_matches} only checks the | |
10664 | frame specified by @var{number_of_frames}. | |
10665 | ||
a72c3253 DE |
10666 | @end table |
10667 | ||
10668 | @value{GDBN} provides the ability to list and get help on | |
10669 | convenience functions. | |
10670 | ||
bc3b79fd TJB |
10671 | @table @code |
10672 | @item help function | |
10673 | @kindex help function | |
10674 | @cindex show all convenience functions | |
10675 | Print a list of all convenience functions. | |
10676 | @end table | |
10677 | ||
6d2ebf8b | 10678 | @node Registers |
c906108c SS |
10679 | @section Registers |
10680 | ||
10681 | @cindex registers | |
10682 | You can refer to machine register contents, in expressions, as variables | |
10683 | with names starting with @samp{$}. The names of registers are different | |
10684 | for each machine; use @code{info registers} to see the names used on | |
10685 | your machine. | |
10686 | ||
10687 | @table @code | |
10688 | @kindex info registers | |
10689 | @item info registers | |
10690 | Print the names and values of all registers except floating-point | |
c85508ee | 10691 | and vector registers (in the selected stack frame). |
c906108c SS |
10692 | |
10693 | @kindex info all-registers | |
10694 | @cindex floating point registers | |
10695 | @item info all-registers | |
10696 | Print the names and values of all registers, including floating-point | |
c85508ee | 10697 | and vector registers (in the selected stack frame). |
c906108c SS |
10698 | |
10699 | @item info registers @var{regname} @dots{} | |
10700 | Print the @dfn{relativized} value of each specified register @var{regname}. | |
5d161b24 | 10701 | As discussed in detail below, register values are normally relative to |
697aa1b7 | 10702 | the selected stack frame. The @var{regname} may be any register name valid on |
c906108c SS |
10703 | the machine you are using, with or without the initial @samp{$}. |
10704 | @end table | |
10705 | ||
f5b95c01 | 10706 | @anchor{standard registers} |
e09f16f9 EZ |
10707 | @cindex stack pointer register |
10708 | @cindex program counter register | |
10709 | @cindex process status register | |
10710 | @cindex frame pointer register | |
10711 | @cindex standard registers | |
c906108c SS |
10712 | @value{GDBN} has four ``standard'' register names that are available (in |
10713 | expressions) on most machines---whenever they do not conflict with an | |
10714 | architecture's canonical mnemonics for registers. The register names | |
10715 | @code{$pc} and @code{$sp} are used for the program counter register and | |
10716 | the stack pointer. @code{$fp} is used for a register that contains a | |
10717 | pointer to the current stack frame, and @code{$ps} is used for a | |
10718 | register that contains the processor status. For example, | |
10719 | you could print the program counter in hex with | |
10720 | ||
474c8240 | 10721 | @smallexample |
c906108c | 10722 | p/x $pc |
474c8240 | 10723 | @end smallexample |
c906108c SS |
10724 | |
10725 | @noindent | |
10726 | or print the instruction to be executed next with | |
10727 | ||
474c8240 | 10728 | @smallexample |
c906108c | 10729 | x/i $pc |
474c8240 | 10730 | @end smallexample |
c906108c SS |
10731 | |
10732 | @noindent | |
10733 | or add four to the stack pointer@footnote{This is a way of removing | |
10734 | one word from the stack, on machines where stacks grow downward in | |
10735 | memory (most machines, nowadays). This assumes that the innermost | |
10736 | stack frame is selected; setting @code{$sp} is not allowed when other | |
10737 | stack frames are selected. To pop entire frames off the stack, | |
10738 | regardless of machine architecture, use @code{return}; | |
79a6e687 | 10739 | see @ref{Returning, ,Returning from a Function}.} with |
c906108c | 10740 | |
474c8240 | 10741 | @smallexample |
c906108c | 10742 | set $sp += 4 |
474c8240 | 10743 | @end smallexample |
c906108c SS |
10744 | |
10745 | Whenever possible, these four standard register names are available on | |
10746 | your machine even though the machine has different canonical mnemonics, | |
10747 | so long as there is no conflict. The @code{info registers} command | |
10748 | shows the canonical names. For example, on the SPARC, @code{info | |
10749 | registers} displays the processor status register as @code{$psr} but you | |
d4f3574e SS |
10750 | can also refer to it as @code{$ps}; and on x86-based machines @code{$ps} |
10751 | is an alias for the @sc{eflags} register. | |
c906108c SS |
10752 | |
10753 | @value{GDBN} always considers the contents of an ordinary register as an | |
10754 | integer when the register is examined in this way. Some machines have | |
10755 | special registers which can hold nothing but floating point; these | |
10756 | registers are considered to have floating point values. There is no way | |
10757 | to refer to the contents of an ordinary register as floating point value | |
10758 | (although you can @emph{print} it as a floating point value with | |
10759 | @samp{print/f $@var{regname}}). | |
10760 | ||
10761 | Some registers have distinct ``raw'' and ``virtual'' data formats. This | |
10762 | means that the data format in which the register contents are saved by | |
10763 | the operating system is not the same one that your program normally | |
10764 | sees. For example, the registers of the 68881 floating point | |
10765 | coprocessor are always saved in ``extended'' (raw) format, but all C | |
10766 | programs expect to work with ``double'' (virtual) format. In such | |
5d161b24 | 10767 | cases, @value{GDBN} normally works with the virtual format only (the format |
c906108c SS |
10768 | that makes sense for your program), but the @code{info registers} command |
10769 | prints the data in both formats. | |
10770 | ||
36b80e65 EZ |
10771 | @cindex SSE registers (x86) |
10772 | @cindex MMX registers (x86) | |
10773 | Some machines have special registers whose contents can be interpreted | |
10774 | in several different ways. For example, modern x86-based machines | |
10775 | have SSE and MMX registers that can hold several values packed | |
10776 | together in several different formats. @value{GDBN} refers to such | |
10777 | registers in @code{struct} notation: | |
10778 | ||
10779 | @smallexample | |
10780 | (@value{GDBP}) print $xmm1 | |
10781 | $1 = @{ | |
10782 | v4_float = @{0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044@}, | |
10783 | v2_double = @{9.92129282474342e-303, 2.7585945287983262e-313@}, | |
10784 | v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000", | |
10785 | v8_int16 = @{0, 0, 14072, 315, 11, 0, 13, 0@}, | |
10786 | v4_int32 = @{0, 20657912, 11, 13@}, | |
10787 | v2_int64 = @{88725056443645952, 55834574859@}, | |
10788 | uint128 = 0x0000000d0000000b013b36f800000000 | |
10789 | @} | |
10790 | @end smallexample | |
10791 | ||
10792 | @noindent | |
10793 | To set values of such registers, you need to tell @value{GDBN} which | |
10794 | view of the register you wish to change, as if you were assigning | |
10795 | value to a @code{struct} member: | |
10796 | ||
10797 | @smallexample | |
10798 | (@value{GDBP}) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF | |
10799 | @end smallexample | |
10800 | ||
c906108c | 10801 | Normally, register values are relative to the selected stack frame |
79a6e687 | 10802 | (@pxref{Selection, ,Selecting a Frame}). This means that you get the |
c906108c SS |
10803 | value that the register would contain if all stack frames farther in |
10804 | were exited and their saved registers restored. In order to see the | |
10805 | true contents of hardware registers, you must select the innermost | |
10806 | frame (with @samp{frame 0}). | |
10807 | ||
901461f8 PA |
10808 | @cindex caller-saved registers |
10809 | @cindex call-clobbered registers | |
10810 | @cindex volatile registers | |
10811 | @cindex <not saved> values | |
10812 | Usually ABIs reserve some registers as not needed to be saved by the | |
10813 | callee (a.k.a.: ``caller-saved'', ``call-clobbered'' or ``volatile'' | |
10814 | registers). It may therefore not be possible for @value{GDBN} to know | |
10815 | the value a register had before the call (in other words, in the outer | |
10816 | frame), if the register value has since been changed by the callee. | |
10817 | @value{GDBN} tries to deduce where the inner frame saved | |
10818 | (``callee-saved'') registers, from the debug info, unwind info, or the | |
10819 | machine code generated by your compiler. If some register is not | |
10820 | saved, and @value{GDBN} knows the register is ``caller-saved'' (via | |
10821 | its own knowledge of the ABI, or because the debug/unwind info | |
10822 | explicitly says the register's value is undefined), @value{GDBN} | |
10823 | displays @w{@samp{<not saved>}} as the register's value. With targets | |
10824 | that @value{GDBN} has no knowledge of the register saving convention, | |
10825 | if a register was not saved by the callee, then its value and location | |
10826 | in the outer frame are assumed to be the same of the inner frame. | |
10827 | This is usually harmless, because if the register is call-clobbered, | |
10828 | the caller either does not care what is in the register after the | |
10829 | call, or has code to restore the value that it does care about. Note, | |
10830 | however, that if you change such a register in the outer frame, you | |
10831 | may also be affecting the inner frame. Also, the more ``outer'' the | |
10832 | frame is you're looking at, the more likely a call-clobbered | |
10833 | register's value is to be wrong, in the sense that it doesn't actually | |
10834 | represent the value the register had just before the call. | |
c906108c | 10835 | |
6d2ebf8b | 10836 | @node Floating Point Hardware |
79a6e687 | 10837 | @section Floating Point Hardware |
c906108c SS |
10838 | @cindex floating point |
10839 | ||
10840 | Depending on the configuration, @value{GDBN} may be able to give | |
10841 | you more information about the status of the floating point hardware. | |
10842 | ||
10843 | @table @code | |
10844 | @kindex info float | |
10845 | @item info float | |
10846 | Display hardware-dependent information about the floating | |
10847 | point unit. The exact contents and layout vary depending on the | |
10848 | floating point chip. Currently, @samp{info float} is supported on | |
10849 | the ARM and x86 machines. | |
10850 | @end table | |
c906108c | 10851 | |
e76f1f2e AC |
10852 | @node Vector Unit |
10853 | @section Vector Unit | |
10854 | @cindex vector unit | |
10855 | ||
10856 | Depending on the configuration, @value{GDBN} may be able to give you | |
10857 | more information about the status of the vector unit. | |
10858 | ||
10859 | @table @code | |
10860 | @kindex info vector | |
10861 | @item info vector | |
10862 | Display information about the vector unit. The exact contents and | |
10863 | layout vary depending on the hardware. | |
10864 | @end table | |
10865 | ||
721c2651 | 10866 | @node OS Information |
79a6e687 | 10867 | @section Operating System Auxiliary Information |
721c2651 EZ |
10868 | @cindex OS information |
10869 | ||
10870 | @value{GDBN} provides interfaces to useful OS facilities that can help | |
10871 | you debug your program. | |
10872 | ||
b383017d RM |
10873 | @cindex auxiliary vector |
10874 | @cindex vector, auxiliary | |
b383017d RM |
10875 | Some operating systems supply an @dfn{auxiliary vector} to programs at |
10876 | startup. This is akin to the arguments and environment that you | |
10877 | specify for a program, but contains a system-dependent variety of | |
10878 | binary values that tell system libraries important details about the | |
10879 | hardware, operating system, and process. Each value's purpose is | |
10880 | identified by an integer tag; the meanings are well-known but system-specific. | |
10881 | Depending on the configuration and operating system facilities, | |
9c16f35a EZ |
10882 | @value{GDBN} may be able to show you this information. For remote |
10883 | targets, this functionality may further depend on the remote stub's | |
427c3a89 DJ |
10884 | support of the @samp{qXfer:auxv:read} packet, see |
10885 | @ref{qXfer auxiliary vector read}. | |
b383017d RM |
10886 | |
10887 | @table @code | |
10888 | @kindex info auxv | |
10889 | @item info auxv | |
10890 | Display the auxiliary vector of the inferior, which can be either a | |
e4937fc1 | 10891 | live process or a core dump file. @value{GDBN} prints each tag value |
b383017d RM |
10892 | numerically, and also shows names and text descriptions for recognized |
10893 | tags. Some values in the vector are numbers, some bit masks, and some | |
e4937fc1 | 10894 | pointers to strings or other data. @value{GDBN} displays each value in the |
b383017d RM |
10895 | most appropriate form for a recognized tag, and in hexadecimal for |
10896 | an unrecognized tag. | |
10897 | @end table | |
10898 | ||
85d4a676 SS |
10899 | On some targets, @value{GDBN} can access operating system-specific |
10900 | information and show it to you. The types of information available | |
10901 | will differ depending on the type of operating system running on the | |
10902 | target. The mechanism used to fetch the data is described in | |
10903 | @ref{Operating System Information}. For remote targets, this | |
10904 | functionality depends on the remote stub's support of the | |
07e059b5 VP |
10905 | @samp{qXfer:osdata:read} packet, see @ref{qXfer osdata read}. |
10906 | ||
10907 | @table @code | |
a61408f8 | 10908 | @kindex info os |
85d4a676 SS |
10909 | @item info os @var{infotype} |
10910 | ||
10911 | Display OS information of the requested type. | |
a61408f8 | 10912 | |
85d4a676 SS |
10913 | On @sc{gnu}/Linux, the following values of @var{infotype} are valid: |
10914 | ||
10915 | @anchor{linux info os infotypes} | |
10916 | @table @code | |
d33279b3 AT |
10917 | @kindex info os cpus |
10918 | @item cpus | |
10919 | Display the list of all CPUs/cores. For each CPU/core, @value{GDBN} prints | |
10920 | the available fields from /proc/cpuinfo. For each supported architecture | |
10921 | different fields are available. Two common entries are processor which gives | |
10922 | CPU number and bogomips; a system constant that is calculated during | |
10923 | kernel initialization. | |
10924 | ||
10925 | @kindex info os files | |
10926 | @item files | |
10927 | Display the list of open file descriptors on the target. For each | |
10928 | file descriptor, @value{GDBN} prints the identifier of the process | |
10929 | owning the descriptor, the command of the owning process, the value | |
10930 | of the descriptor, and the target of the descriptor. | |
10931 | ||
10932 | @kindex info os modules | |
10933 | @item modules | |
10934 | Display the list of all loaded kernel modules on the target. For each | |
10935 | module, @value{GDBN} prints the module name, the size of the module in | |
10936 | bytes, the number of times the module is used, the dependencies of the | |
10937 | module, the status of the module, and the address of the loaded module | |
10938 | in memory. | |
10939 | ||
10940 | @kindex info os msg | |
10941 | @item msg | |
10942 | Display the list of all System V message queues on the target. For each | |
10943 | message queue, @value{GDBN} prints the message queue key, the message | |
10944 | queue identifier, the access permissions, the current number of bytes | |
10945 | on the queue, the current number of messages on the queue, the processes | |
10946 | that last sent and received a message on the queue, the user and group | |
10947 | of the owner and creator of the message queue, the times at which a | |
10948 | message was last sent and received on the queue, and the time at which | |
10949 | the message queue was last changed. | |
10950 | ||
07e059b5 | 10951 | @kindex info os processes |
85d4a676 | 10952 | @item processes |
07e059b5 | 10953 | Display the list of processes on the target. For each process, |
85d4a676 SS |
10954 | @value{GDBN} prints the process identifier, the name of the user, the |
10955 | command corresponding to the process, and the list of processor cores | |
10956 | that the process is currently running on. (To understand what these | |
10957 | properties mean, for this and the following info types, please consult | |
10958 | the general @sc{gnu}/Linux documentation.) | |
10959 | ||
10960 | @kindex info os procgroups | |
10961 | @item procgroups | |
10962 | Display the list of process groups on the target. For each process, | |
10963 | @value{GDBN} prints the identifier of the process group that it belongs | |
10964 | to, the command corresponding to the process group leader, the process | |
10965 | identifier, and the command line of the process. The list is sorted | |
10966 | first by the process group identifier, then by the process identifier, | |
10967 | so that processes belonging to the same process group are grouped together | |
10968 | and the process group leader is listed first. | |
10969 | ||
d33279b3 AT |
10970 | @kindex info os semaphores |
10971 | @item semaphores | |
10972 | Display the list of all System V semaphore sets on the target. For each | |
10973 | semaphore set, @value{GDBN} prints the semaphore set key, the semaphore | |
10974 | set identifier, the access permissions, the number of semaphores in the | |
10975 | set, the user and group of the owner and creator of the semaphore set, | |
10976 | and the times at which the semaphore set was operated upon and changed. | |
85d4a676 SS |
10977 | |
10978 | @kindex info os shm | |
10979 | @item shm | |
10980 | Display the list of all System V shared-memory regions on the target. | |
10981 | For each shared-memory region, @value{GDBN} prints the region key, | |
10982 | the shared-memory identifier, the access permissions, the size of the | |
10983 | region, the process that created the region, the process that last | |
10984 | attached to or detached from the region, the current number of live | |
10985 | attaches to the region, and the times at which the region was last | |
10986 | attached to, detach from, and changed. | |
10987 | ||
d33279b3 AT |
10988 | @kindex info os sockets |
10989 | @item sockets | |
10990 | Display the list of Internet-domain sockets on the target. For each | |
10991 | socket, @value{GDBN} prints the address and port of the local and | |
10992 | remote endpoints, the current state of the connection, the creator of | |
10993 | the socket, the IP address family of the socket, and the type of the | |
10994 | connection. | |
85d4a676 | 10995 | |
d33279b3 AT |
10996 | @kindex info os threads |
10997 | @item threads | |
10998 | Display the list of threads running on the target. For each thread, | |
10999 | @value{GDBN} prints the identifier of the process that the thread | |
11000 | belongs to, the command of the process, the thread identifier, and the | |
11001 | processor core that it is currently running on. The main thread of a | |
11002 | process is not listed. | |
85d4a676 SS |
11003 | @end table |
11004 | ||
11005 | @item info os | |
11006 | If @var{infotype} is omitted, then list the possible values for | |
11007 | @var{infotype} and the kind of OS information available for each | |
11008 | @var{infotype}. If the target does not return a list of possible | |
11009 | types, this command will report an error. | |
07e059b5 | 11010 | @end table |
721c2651 | 11011 | |
29e57380 | 11012 | @node Memory Region Attributes |
79a6e687 | 11013 | @section Memory Region Attributes |
29e57380 C |
11014 | @cindex memory region attributes |
11015 | ||
b383017d | 11016 | @dfn{Memory region attributes} allow you to describe special handling |
fd79ecee DJ |
11017 | required by regions of your target's memory. @value{GDBN} uses |
11018 | attributes to determine whether to allow certain types of memory | |
11019 | accesses; whether to use specific width accesses; and whether to cache | |
11020 | target memory. By default the description of memory regions is | |
11021 | fetched from the target (if the current target supports this), but the | |
11022 | user can override the fetched regions. | |
29e57380 C |
11023 | |
11024 | Defined memory regions can be individually enabled and disabled. When a | |
11025 | memory region is disabled, @value{GDBN} uses the default attributes when | |
11026 | accessing memory in that region. Similarly, if no memory regions have | |
11027 | been defined, @value{GDBN} uses the default attributes when accessing | |
11028 | all memory. | |
11029 | ||
b383017d | 11030 | When a memory region is defined, it is given a number to identify it; |
29e57380 C |
11031 | to enable, disable, or remove a memory region, you specify that number. |
11032 | ||
11033 | @table @code | |
11034 | @kindex mem | |
bfac230e | 11035 | @item mem @var{lower} @var{upper} @var{attributes}@dots{} |
09d4efe1 EZ |
11036 | Define a memory region bounded by @var{lower} and @var{upper} with |
11037 | attributes @var{attributes}@dots{}, and add it to the list of regions | |
11038 | monitored by @value{GDBN}. Note that @var{upper} == 0 is a special | |
d3e8051b | 11039 | case: it is treated as the target's maximum memory address. |
bfac230e | 11040 | (0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.) |
29e57380 | 11041 | |
fd79ecee DJ |
11042 | @item mem auto |
11043 | Discard any user changes to the memory regions and use target-supplied | |
11044 | regions, if available, or no regions if the target does not support. | |
11045 | ||
29e57380 C |
11046 | @kindex delete mem |
11047 | @item delete mem @var{nums}@dots{} | |
09d4efe1 EZ |
11048 | Remove memory regions @var{nums}@dots{} from the list of regions |
11049 | monitored by @value{GDBN}. | |
29e57380 C |
11050 | |
11051 | @kindex disable mem | |
11052 | @item disable mem @var{nums}@dots{} | |
09d4efe1 | 11053 | Disable monitoring of memory regions @var{nums}@dots{}. |
b383017d | 11054 | A disabled memory region is not forgotten. |
29e57380 C |
11055 | It may be enabled again later. |
11056 | ||
11057 | @kindex enable mem | |
11058 | @item enable mem @var{nums}@dots{} | |
09d4efe1 | 11059 | Enable monitoring of memory regions @var{nums}@dots{}. |
29e57380 C |
11060 | |
11061 | @kindex info mem | |
11062 | @item info mem | |
11063 | Print a table of all defined memory regions, with the following columns | |
09d4efe1 | 11064 | for each region: |
29e57380 C |
11065 | |
11066 | @table @emph | |
11067 | @item Memory Region Number | |
11068 | @item Enabled or Disabled. | |
b383017d | 11069 | Enabled memory regions are marked with @samp{y}. |
29e57380 C |
11070 | Disabled memory regions are marked with @samp{n}. |
11071 | ||
11072 | @item Lo Address | |
11073 | The address defining the inclusive lower bound of the memory region. | |
11074 | ||
11075 | @item Hi Address | |
11076 | The address defining the exclusive upper bound of the memory region. | |
11077 | ||
11078 | @item Attributes | |
11079 | The list of attributes set for this memory region. | |
11080 | @end table | |
11081 | @end table | |
11082 | ||
11083 | ||
11084 | @subsection Attributes | |
11085 | ||
b383017d | 11086 | @subsubsection Memory Access Mode |
29e57380 C |
11087 | The access mode attributes set whether @value{GDBN} may make read or |
11088 | write accesses to a memory region. | |
11089 | ||
11090 | While these attributes prevent @value{GDBN} from performing invalid | |
11091 | memory accesses, they do nothing to prevent the target system, I/O DMA, | |
359df76b | 11092 | etc.@: from accessing memory. |
29e57380 C |
11093 | |
11094 | @table @code | |
11095 | @item ro | |
11096 | Memory is read only. | |
11097 | @item wo | |
11098 | Memory is write only. | |
11099 | @item rw | |
6ca652b0 | 11100 | Memory is read/write. This is the default. |
29e57380 C |
11101 | @end table |
11102 | ||
11103 | @subsubsection Memory Access Size | |
d3e8051b | 11104 | The access size attribute tells @value{GDBN} to use specific sized |
29e57380 C |
11105 | accesses in the memory region. Often memory mapped device registers |
11106 | require specific sized accesses. If no access size attribute is | |
11107 | specified, @value{GDBN} may use accesses of any size. | |
11108 | ||
11109 | @table @code | |
11110 | @item 8 | |
11111 | Use 8 bit memory accesses. | |
11112 | @item 16 | |
11113 | Use 16 bit memory accesses. | |
11114 | @item 32 | |
11115 | Use 32 bit memory accesses. | |
11116 | @item 64 | |
11117 | Use 64 bit memory accesses. | |
11118 | @end table | |
11119 | ||
11120 | @c @subsubsection Hardware/Software Breakpoints | |
11121 | @c The hardware/software breakpoint attributes set whether @value{GDBN} | |
11122 | @c will use hardware or software breakpoints for the internal breakpoints | |
11123 | @c used by the step, next, finish, until, etc. commands. | |
11124 | @c | |
11125 | @c @table @code | |
11126 | @c @item hwbreak | |
b383017d | 11127 | @c Always use hardware breakpoints |
29e57380 C |
11128 | @c @item swbreak (default) |
11129 | @c @end table | |
11130 | ||
11131 | @subsubsection Data Cache | |
11132 | The data cache attributes set whether @value{GDBN} will cache target | |
11133 | memory. While this generally improves performance by reducing debug | |
11134 | protocol overhead, it can lead to incorrect results because @value{GDBN} | |
11135 | does not know about volatile variables or memory mapped device | |
11136 | registers. | |
11137 | ||
11138 | @table @code | |
11139 | @item cache | |
b383017d | 11140 | Enable @value{GDBN} to cache target memory. |
6ca652b0 EZ |
11141 | @item nocache |
11142 | Disable @value{GDBN} from caching target memory. This is the default. | |
29e57380 C |
11143 | @end table |
11144 | ||
4b5752d0 VP |
11145 | @subsection Memory Access Checking |
11146 | @value{GDBN} can be instructed to refuse accesses to memory that is | |
11147 | not explicitly described. This can be useful if accessing such | |
11148 | regions has undesired effects for a specific target, or to provide | |
11149 | better error checking. The following commands control this behaviour. | |
11150 | ||
11151 | @table @code | |
11152 | @kindex set mem inaccessible-by-default | |
11153 | @item set mem inaccessible-by-default [on|off] | |
11154 | If @code{on} is specified, make @value{GDBN} treat memory not | |
11155 | explicitly described by the memory ranges as non-existent and refuse accesses | |
11156 | to such memory. The checks are only performed if there's at least one | |
11157 | memory range defined. If @code{off} is specified, make @value{GDBN} | |
11158 | treat the memory not explicitly described by the memory ranges as RAM. | |
56cf5405 | 11159 | The default value is @code{on}. |
4b5752d0 VP |
11160 | @kindex show mem inaccessible-by-default |
11161 | @item show mem inaccessible-by-default | |
11162 | Show the current handling of accesses to unknown memory. | |
11163 | @end table | |
11164 | ||
11165 | ||
29e57380 | 11166 | @c @subsubsection Memory Write Verification |
b383017d | 11167 | @c The memory write verification attributes set whether @value{GDBN} |
29e57380 C |
11168 | @c will re-reads data after each write to verify the write was successful. |
11169 | @c | |
11170 | @c @table @code | |
11171 | @c @item verify | |
11172 | @c @item noverify (default) | |
11173 | @c @end table | |
11174 | ||
16d9dec6 | 11175 | @node Dump/Restore Files |
79a6e687 | 11176 | @section Copy Between Memory and a File |
16d9dec6 MS |
11177 | @cindex dump/restore files |
11178 | @cindex append data to a file | |
11179 | @cindex dump data to a file | |
11180 | @cindex restore data from a file | |
16d9dec6 | 11181 | |
df5215a6 JB |
11182 | You can use the commands @code{dump}, @code{append}, and |
11183 | @code{restore} to copy data between target memory and a file. The | |
11184 | @code{dump} and @code{append} commands write data to a file, and the | |
11185 | @code{restore} command reads data from a file back into the inferior's | |
cf75d6c3 AB |
11186 | memory. Files may be in binary, Motorola S-record, Intel hex, |
11187 | Tektronix Hex, or Verilog Hex format; however, @value{GDBN} can only | |
11188 | append to binary files, and cannot read from Verilog Hex files. | |
df5215a6 JB |
11189 | |
11190 | @table @code | |
11191 | ||
11192 | @kindex dump | |
11193 | @item dump @r{[}@var{format}@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
11194 | @itemx dump @r{[}@var{format}@r{]} value @var{filename} @var{expr} | |
11195 | Dump the contents of memory from @var{start_addr} to @var{end_addr}, | |
11196 | or the value of @var{expr}, to @var{filename} in the given format. | |
16d9dec6 | 11197 | |
df5215a6 | 11198 | The @var{format} parameter may be any one of: |
16d9dec6 | 11199 | @table @code |
df5215a6 JB |
11200 | @item binary |
11201 | Raw binary form. | |
11202 | @item ihex | |
11203 | Intel hex format. | |
11204 | @item srec | |
11205 | Motorola S-record format. | |
11206 | @item tekhex | |
11207 | Tektronix Hex format. | |
cf75d6c3 AB |
11208 | @item verilog |
11209 | Verilog Hex format. | |
df5215a6 JB |
11210 | @end table |
11211 | ||
11212 | @value{GDBN} uses the same definitions of these formats as the | |
11213 | @sc{gnu} binary utilities, like @samp{objdump} and @samp{objcopy}. If | |
11214 | @var{format} is omitted, @value{GDBN} dumps the data in raw binary | |
11215 | form. | |
11216 | ||
11217 | @kindex append | |
11218 | @item append @r{[}binary@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
11219 | @itemx append @r{[}binary@r{]} value @var{filename} @var{expr} | |
11220 | Append the contents of memory from @var{start_addr} to @var{end_addr}, | |
09d4efe1 | 11221 | or the value of @var{expr}, to the file @var{filename}, in raw binary form. |
df5215a6 JB |
11222 | (@value{GDBN} can only append data to files in raw binary form.) |
11223 | ||
11224 | @kindex restore | |
11225 | @item restore @var{filename} @r{[}binary@r{]} @var{bias} @var{start} @var{end} | |
11226 | Restore the contents of file @var{filename} into memory. The | |
11227 | @code{restore} command can automatically recognize any known @sc{bfd} | |
11228 | file format, except for raw binary. To restore a raw binary file you | |
11229 | must specify the optional keyword @code{binary} after the filename. | |
16d9dec6 | 11230 | |
b383017d | 11231 | If @var{bias} is non-zero, its value will be added to the addresses |
16d9dec6 MS |
11232 | contained in the file. Binary files always start at address zero, so |
11233 | they will be restored at address @var{bias}. Other bfd files have | |
11234 | a built-in location; they will be restored at offset @var{bias} | |
11235 | from that location. | |
11236 | ||
11237 | If @var{start} and/or @var{end} are non-zero, then only data between | |
11238 | file offset @var{start} and file offset @var{end} will be restored. | |
b383017d | 11239 | These offsets are relative to the addresses in the file, before |
16d9dec6 MS |
11240 | the @var{bias} argument is applied. |
11241 | ||
11242 | @end table | |
11243 | ||
384ee23f EZ |
11244 | @node Core File Generation |
11245 | @section How to Produce a Core File from Your Program | |
11246 | @cindex dump core from inferior | |
11247 | ||
11248 | A @dfn{core file} or @dfn{core dump} is a file that records the memory | |
11249 | image of a running process and its process status (register values | |
11250 | etc.). Its primary use is post-mortem debugging of a program that | |
11251 | crashed while it ran outside a debugger. A program that crashes | |
11252 | automatically produces a core file, unless this feature is disabled by | |
11253 | the user. @xref{Files}, for information on invoking @value{GDBN} in | |
11254 | the post-mortem debugging mode. | |
11255 | ||
11256 | Occasionally, you may wish to produce a core file of the program you | |
11257 | are debugging in order to preserve a snapshot of its state. | |
11258 | @value{GDBN} has a special command for that. | |
11259 | ||
11260 | @table @code | |
11261 | @kindex gcore | |
11262 | @kindex generate-core-file | |
11263 | @item generate-core-file [@var{file}] | |
11264 | @itemx gcore [@var{file}] | |
11265 | Produce a core dump of the inferior process. The optional argument | |
11266 | @var{file} specifies the file name where to put the core dump. If not | |
11267 | specified, the file name defaults to @file{core.@var{pid}}, where | |
11268 | @var{pid} is the inferior process ID. | |
11269 | ||
11270 | Note that this command is implemented only for some systems (as of | |
05b4bd79 | 11271 | this writing, @sc{gnu}/Linux, FreeBSD, Solaris, and S390). |
df8411da SDJ |
11272 | |
11273 | On @sc{gnu}/Linux, this command can take into account the value of the | |
11274 | file @file{/proc/@var{pid}/coredump_filter} when generating the core | |
11275 | dump (@pxref{set use-coredump-filter}). | |
11276 | ||
11277 | @kindex set use-coredump-filter | |
11278 | @anchor{set use-coredump-filter} | |
11279 | @item set use-coredump-filter on | |
11280 | @itemx set use-coredump-filter off | |
11281 | Enable or disable the use of the file | |
11282 | @file{/proc/@var{pid}/coredump_filter} when generating core dump | |
11283 | files. This file is used by the Linux kernel to decide what types of | |
11284 | memory mappings will be dumped or ignored when generating a core dump | |
11285 | file. @var{pid} is the process ID of a currently running process. | |
11286 | ||
11287 | To make use of this feature, you have to write in the | |
11288 | @file{/proc/@var{pid}/coredump_filter} file a value, in hexadecimal, | |
11289 | which is a bit mask representing the memory mapping types. If a bit | |
11290 | is set in the bit mask, then the memory mappings of the corresponding | |
11291 | types will be dumped; otherwise, they will be ignored. This | |
11292 | configuration is inherited by child processes. For more information | |
11293 | about the bits that can be set in the | |
11294 | @file{/proc/@var{pid}/coredump_filter} file, please refer to the | |
11295 | manpage of @code{core(5)}. | |
11296 | ||
11297 | By default, this option is @code{on}. If this option is turned | |
11298 | @code{off}, @value{GDBN} does not read the @file{coredump_filter} file | |
11299 | and instead uses the same default value as the Linux kernel in order | |
11300 | to decide which pages will be dumped in the core dump file. This | |
11301 | value is currently @code{0x33}, which means that bits @code{0} | |
11302 | (anonymous private mappings), @code{1} (anonymous shared mappings), | |
11303 | @code{4} (ELF headers) and @code{5} (private huge pages) are active. | |
11304 | This will cause these memory mappings to be dumped automatically. | |
384ee23f EZ |
11305 | @end table |
11306 | ||
a0eb71c5 KB |
11307 | @node Character Sets |
11308 | @section Character Sets | |
11309 | @cindex character sets | |
11310 | @cindex charset | |
11311 | @cindex translating between character sets | |
11312 | @cindex host character set | |
11313 | @cindex target character set | |
11314 | ||
11315 | If the program you are debugging uses a different character set to | |
11316 | represent characters and strings than the one @value{GDBN} uses itself, | |
11317 | @value{GDBN} can automatically translate between the character sets for | |
11318 | you. The character set @value{GDBN} uses we call the @dfn{host | |
11319 | character set}; the one the inferior program uses we call the | |
11320 | @dfn{target character set}. | |
11321 | ||
11322 | For example, if you are running @value{GDBN} on a @sc{gnu}/Linux system, which | |
11323 | uses the ISO Latin 1 character set, but you are using @value{GDBN}'s | |
ea35711c | 11324 | remote protocol (@pxref{Remote Debugging}) to debug a program |
a0eb71c5 KB |
11325 | running on an IBM mainframe, which uses the @sc{ebcdic} character set, |
11326 | then the host character set is Latin-1, and the target character set is | |
11327 | @sc{ebcdic}. If you give @value{GDBN} the command @code{set | |
e33d66ec | 11328 | target-charset EBCDIC-US}, then @value{GDBN} translates between |
a0eb71c5 KB |
11329 | @sc{ebcdic} and Latin 1 as you print character or string values, or use |
11330 | character and string literals in expressions. | |
11331 | ||
11332 | @value{GDBN} has no way to automatically recognize which character set | |
11333 | the inferior program uses; you must tell it, using the @code{set | |
11334 | target-charset} command, described below. | |
11335 | ||
11336 | Here are the commands for controlling @value{GDBN}'s character set | |
11337 | support: | |
11338 | ||
11339 | @table @code | |
11340 | @item set target-charset @var{charset} | |
11341 | @kindex set target-charset | |
10af6951 EZ |
11342 | Set the current target character set to @var{charset}. To display the |
11343 | list of supported target character sets, type | |
11344 | @kbd{@w{set target-charset @key{TAB}@key{TAB}}}. | |
a0eb71c5 | 11345 | |
a0eb71c5 KB |
11346 | @item set host-charset @var{charset} |
11347 | @kindex set host-charset | |
11348 | Set the current host character set to @var{charset}. | |
11349 | ||
11350 | By default, @value{GDBN} uses a host character set appropriate to the | |
11351 | system it is running on; you can override that default using the | |
732f6a93 TT |
11352 | @code{set host-charset} command. On some systems, @value{GDBN} cannot |
11353 | automatically determine the appropriate host character set. In this | |
11354 | case, @value{GDBN} uses @samp{UTF-8}. | |
a0eb71c5 KB |
11355 | |
11356 | @value{GDBN} can only use certain character sets as its host character | |
c1b6b909 | 11357 | set. If you type @kbd{@w{set host-charset @key{TAB}@key{TAB}}}, |
10af6951 | 11358 | @value{GDBN} will list the host character sets it supports. |
a0eb71c5 KB |
11359 | |
11360 | @item set charset @var{charset} | |
11361 | @kindex set charset | |
e33d66ec | 11362 | Set the current host and target character sets to @var{charset}. As |
10af6951 EZ |
11363 | above, if you type @kbd{@w{set charset @key{TAB}@key{TAB}}}, |
11364 | @value{GDBN} will list the names of the character sets that can be used | |
e33d66ec EZ |
11365 | for both host and target. |
11366 | ||
a0eb71c5 | 11367 | @item show charset |
a0eb71c5 | 11368 | @kindex show charset |
10af6951 | 11369 | Show the names of the current host and target character sets. |
e33d66ec | 11370 | |
10af6951 | 11371 | @item show host-charset |
a0eb71c5 | 11372 | @kindex show host-charset |
10af6951 | 11373 | Show the name of the current host character set. |
e33d66ec | 11374 | |
10af6951 | 11375 | @item show target-charset |
a0eb71c5 | 11376 | @kindex show target-charset |
10af6951 | 11377 | Show the name of the current target character set. |
a0eb71c5 | 11378 | |
10af6951 EZ |
11379 | @item set target-wide-charset @var{charset} |
11380 | @kindex set target-wide-charset | |
11381 | Set the current target's wide character set to @var{charset}. This is | |
11382 | the character set used by the target's @code{wchar_t} type. To | |
11383 | display the list of supported wide character sets, type | |
11384 | @kbd{@w{set target-wide-charset @key{TAB}@key{TAB}}}. | |
11385 | ||
11386 | @item show target-wide-charset | |
11387 | @kindex show target-wide-charset | |
11388 | Show the name of the current target's wide character set. | |
a0eb71c5 KB |
11389 | @end table |
11390 | ||
a0eb71c5 KB |
11391 | Here is an example of @value{GDBN}'s character set support in action. |
11392 | Assume that the following source code has been placed in the file | |
11393 | @file{charset-test.c}: | |
11394 | ||
11395 | @smallexample | |
11396 | #include <stdio.h> | |
11397 | ||
11398 | char ascii_hello[] | |
11399 | = @{72, 101, 108, 108, 111, 44, 32, 119, | |
11400 | 111, 114, 108, 100, 33, 10, 0@}; | |
11401 | char ibm1047_hello[] | |
11402 | = @{200, 133, 147, 147, 150, 107, 64, 166, | |
11403 | 150, 153, 147, 132, 90, 37, 0@}; | |
11404 | ||
11405 | main () | |
11406 | @{ | |
11407 | printf ("Hello, world!\n"); | |
11408 | @} | |
10998722 | 11409 | @end smallexample |
a0eb71c5 KB |
11410 | |
11411 | In this program, @code{ascii_hello} and @code{ibm1047_hello} are arrays | |
11412 | containing the string @samp{Hello, world!} followed by a newline, | |
11413 | encoded in the @sc{ascii} and @sc{ibm1047} character sets. | |
11414 | ||
11415 | We compile the program, and invoke the debugger on it: | |
11416 | ||
11417 | @smallexample | |
11418 | $ gcc -g charset-test.c -o charset-test | |
11419 | $ gdb -nw charset-test | |
11420 | GNU gdb 2001-12-19-cvs | |
11421 | Copyright 2001 Free Software Foundation, Inc. | |
11422 | @dots{} | |
f7dc1244 | 11423 | (@value{GDBP}) |
10998722 | 11424 | @end smallexample |
a0eb71c5 KB |
11425 | |
11426 | We can use the @code{show charset} command to see what character sets | |
11427 | @value{GDBN} is currently using to interpret and display characters and | |
11428 | strings: | |
11429 | ||
11430 | @smallexample | |
f7dc1244 | 11431 | (@value{GDBP}) show charset |
e33d66ec | 11432 | The current host and target character set is `ISO-8859-1'. |
f7dc1244 | 11433 | (@value{GDBP}) |
10998722 | 11434 | @end smallexample |
a0eb71c5 KB |
11435 | |
11436 | For the sake of printing this manual, let's use @sc{ascii} as our | |
11437 | initial character set: | |
11438 | @smallexample | |
f7dc1244 EZ |
11439 | (@value{GDBP}) set charset ASCII |
11440 | (@value{GDBP}) show charset | |
e33d66ec | 11441 | The current host and target character set is `ASCII'. |
f7dc1244 | 11442 | (@value{GDBP}) |
10998722 | 11443 | @end smallexample |
a0eb71c5 KB |
11444 | |
11445 | Let's assume that @sc{ascii} is indeed the correct character set for our | |
11446 | host system --- in other words, let's assume that if @value{GDBN} prints | |
11447 | characters using the @sc{ascii} character set, our terminal will display | |
11448 | them properly. Since our current target character set is also | |
11449 | @sc{ascii}, the contents of @code{ascii_hello} print legibly: | |
11450 | ||
11451 | @smallexample | |
f7dc1244 | 11452 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 11453 | $1 = 0x401698 "Hello, world!\n" |
f7dc1244 | 11454 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 11455 | $2 = 72 'H' |
f7dc1244 | 11456 | (@value{GDBP}) |
10998722 | 11457 | @end smallexample |
a0eb71c5 KB |
11458 | |
11459 | @value{GDBN} uses the target character set for character and string | |
11460 | literals you use in expressions: | |
11461 | ||
11462 | @smallexample | |
f7dc1244 | 11463 | (@value{GDBP}) print '+' |
a0eb71c5 | 11464 | $3 = 43 '+' |
f7dc1244 | 11465 | (@value{GDBP}) |
10998722 | 11466 | @end smallexample |
a0eb71c5 KB |
11467 | |
11468 | The @sc{ascii} character set uses the number 43 to encode the @samp{+} | |
11469 | character. | |
11470 | ||
11471 | @value{GDBN} relies on the user to tell it which character set the | |
11472 | target program uses. If we print @code{ibm1047_hello} while our target | |
11473 | character set is still @sc{ascii}, we get jibberish: | |
11474 | ||
11475 | @smallexample | |
f7dc1244 | 11476 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 11477 | $4 = 0x4016a8 "\310\205\223\223\226k@@\246\226\231\223\204Z%" |
f7dc1244 | 11478 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 11479 | $5 = 200 '\310' |
f7dc1244 | 11480 | (@value{GDBP}) |
10998722 | 11481 | @end smallexample |
a0eb71c5 | 11482 | |
e33d66ec | 11483 | If we invoke the @code{set target-charset} followed by @key{TAB}@key{TAB}, |
a0eb71c5 KB |
11484 | @value{GDBN} tells us the character sets it supports: |
11485 | ||
11486 | @smallexample | |
f7dc1244 | 11487 | (@value{GDBP}) set target-charset |
b383017d | 11488 | ASCII EBCDIC-US IBM1047 ISO-8859-1 |
f7dc1244 | 11489 | (@value{GDBP}) set target-charset |
10998722 | 11490 | @end smallexample |
a0eb71c5 KB |
11491 | |
11492 | We can select @sc{ibm1047} as our target character set, and examine the | |
11493 | program's strings again. Now the @sc{ascii} string is wrong, but | |
11494 | @value{GDBN} translates the contents of @code{ibm1047_hello} from the | |
11495 | target character set, @sc{ibm1047}, to the host character set, | |
11496 | @sc{ascii}, and they display correctly: | |
11497 | ||
11498 | @smallexample | |
f7dc1244 EZ |
11499 | (@value{GDBP}) set target-charset IBM1047 |
11500 | (@value{GDBP}) show charset | |
e33d66ec EZ |
11501 | The current host character set is `ASCII'. |
11502 | The current target character set is `IBM1047'. | |
f7dc1244 | 11503 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 11504 | $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012" |
f7dc1244 | 11505 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 11506 | $7 = 72 '\110' |
f7dc1244 | 11507 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 11508 | $8 = 0x4016a8 "Hello, world!\n" |
f7dc1244 | 11509 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 11510 | $9 = 200 'H' |
f7dc1244 | 11511 | (@value{GDBP}) |
10998722 | 11512 | @end smallexample |
a0eb71c5 KB |
11513 | |
11514 | As above, @value{GDBN} uses the target character set for character and | |
11515 | string literals you use in expressions: | |
11516 | ||
11517 | @smallexample | |
f7dc1244 | 11518 | (@value{GDBP}) print '+' |
a0eb71c5 | 11519 | $10 = 78 '+' |
f7dc1244 | 11520 | (@value{GDBP}) |
10998722 | 11521 | @end smallexample |
a0eb71c5 | 11522 | |
e33d66ec | 11523 | The @sc{ibm1047} character set uses the number 78 to encode the @samp{+} |
a0eb71c5 KB |
11524 | character. |
11525 | ||
b12039c6 YQ |
11526 | @node Caching Target Data |
11527 | @section Caching Data of Targets | |
11528 | @cindex caching data of targets | |
11529 | ||
11530 | @value{GDBN} caches data exchanged between the debugger and a target. | |
b26dfc9a YQ |
11531 | Each cache is associated with the address space of the inferior. |
11532 | @xref{Inferiors and Programs}, about inferior and address space. | |
b12039c6 YQ |
11533 | Such caching generally improves performance in remote debugging |
11534 | (@pxref{Remote Debugging}), because it reduces the overhead of the | |
11535 | remote protocol by bundling memory reads and writes into large chunks. | |
11536 | Unfortunately, simply caching everything would lead to incorrect results, | |
11537 | since @value{GDBN} does not necessarily know anything about volatile | |
11538 | values, memory-mapped I/O addresses, etc. Furthermore, in non-stop mode | |
11539 | (@pxref{Non-Stop Mode}) memory can be changed @emph{while} a gdb command | |
11540 | is executing. | |
29b090c0 DE |
11541 | Therefore, by default, @value{GDBN} only caches data |
11542 | known to be on the stack@footnote{In non-stop mode, it is moderately | |
11543 | rare for a running thread to modify the stack of a stopped thread | |
11544 | in a way that would interfere with a backtrace, and caching of | |
29453a14 YQ |
11545 | stack reads provides a significant speed up of remote backtraces.} or |
11546 | in the code segment. | |
29b090c0 | 11547 | Other regions of memory can be explicitly marked as |
27b81af3 | 11548 | cacheable; @pxref{Memory Region Attributes}. |
09d4efe1 EZ |
11549 | |
11550 | @table @code | |
11551 | @kindex set remotecache | |
11552 | @item set remotecache on | |
11553 | @itemx set remotecache off | |
4e5d721f DE |
11554 | This option no longer does anything; it exists for compatibility |
11555 | with old scripts. | |
09d4efe1 EZ |
11556 | |
11557 | @kindex show remotecache | |
11558 | @item show remotecache | |
4e5d721f DE |
11559 | Show the current state of the obsolete remotecache flag. |
11560 | ||
11561 | @kindex set stack-cache | |
11562 | @item set stack-cache on | |
11563 | @itemx set stack-cache off | |
6dd315ba YQ |
11564 | Enable or disable caching of stack accesses. When @code{on}, use |
11565 | caching. By default, this option is @code{on}. | |
4e5d721f DE |
11566 | |
11567 | @kindex show stack-cache | |
11568 | @item show stack-cache | |
11569 | Show the current state of data caching for memory accesses. | |
09d4efe1 | 11570 | |
29453a14 YQ |
11571 | @kindex set code-cache |
11572 | @item set code-cache on | |
11573 | @itemx set code-cache off | |
11574 | Enable or disable caching of code segment accesses. When @code{on}, | |
11575 | use caching. By default, this option is @code{on}. This improves | |
11576 | performance of disassembly in remote debugging. | |
11577 | ||
11578 | @kindex show code-cache | |
11579 | @item show code-cache | |
11580 | Show the current state of target memory cache for code segment | |
11581 | accesses. | |
11582 | ||
09d4efe1 | 11583 | @kindex info dcache |
4e5d721f | 11584 | @item info dcache @r{[}line@r{]} |
b26dfc9a YQ |
11585 | Print the information about the performance of data cache of the |
11586 | current inferior's address space. The information displayed | |
11587 | includes the dcache width and depth, and for each cache line, its | |
11588 | number, address, and how many times it was referenced. This | |
11589 | command is useful for debugging the data cache operation. | |
4e5d721f DE |
11590 | |
11591 | If a line number is specified, the contents of that line will be | |
11592 | printed in hex. | |
1a532630 PP |
11593 | |
11594 | @item set dcache size @var{size} | |
11595 | @cindex dcache size | |
11596 | @kindex set dcache size | |
11597 | Set maximum number of entries in dcache (dcache depth above). | |
11598 | ||
11599 | @item set dcache line-size @var{line-size} | |
11600 | @cindex dcache line-size | |
11601 | @kindex set dcache line-size | |
11602 | Set number of bytes each dcache entry caches (dcache width above). | |
11603 | Must be a power of 2. | |
11604 | ||
11605 | @item show dcache size | |
11606 | @kindex show dcache size | |
b12039c6 | 11607 | Show maximum number of dcache entries. @xref{Caching Target Data, info dcache}. |
1a532630 PP |
11608 | |
11609 | @item show dcache line-size | |
11610 | @kindex show dcache line-size | |
b12039c6 | 11611 | Show default size of dcache lines. |
1a532630 | 11612 | |
09d4efe1 EZ |
11613 | @end table |
11614 | ||
08388c79 DE |
11615 | @node Searching Memory |
11616 | @section Search Memory | |
11617 | @cindex searching memory | |
11618 | ||
11619 | Memory can be searched for a particular sequence of bytes with the | |
11620 | @code{find} command. | |
11621 | ||
11622 | @table @code | |
11623 | @kindex find | |
11624 | @item find @r{[}/@var{sn}@r{]} @var{start_addr}, +@var{len}, @var{val1} @r{[}, @var{val2}, @dots{}@r{]} | |
11625 | @itemx find @r{[}/@var{sn}@r{]} @var{start_addr}, @var{end_addr}, @var{val1} @r{[}, @var{val2}, @dots{}@r{]} | |
11626 | Search memory for the sequence of bytes specified by @var{val1}, @var{val2}, | |
11627 | etc. The search begins at address @var{start_addr} and continues for either | |
11628 | @var{len} bytes or through to @var{end_addr} inclusive. | |
11629 | @end table | |
11630 | ||
11631 | @var{s} and @var{n} are optional parameters. | |
11632 | They may be specified in either order, apart or together. | |
11633 | ||
11634 | @table @r | |
11635 | @item @var{s}, search query size | |
11636 | The size of each search query value. | |
11637 | ||
11638 | @table @code | |
11639 | @item b | |
11640 | bytes | |
11641 | @item h | |
11642 | halfwords (two bytes) | |
11643 | @item w | |
11644 | words (four bytes) | |
11645 | @item g | |
11646 | giant words (eight bytes) | |
11647 | @end table | |
11648 | ||
11649 | All values are interpreted in the current language. | |
11650 | This means, for example, that if the current source language is C/C@t{++} | |
11651 | then searching for the string ``hello'' includes the trailing '\0'. | |
11652 | ||
11653 | If the value size is not specified, it is taken from the | |
11654 | value's type in the current language. | |
11655 | This is useful when one wants to specify the search | |
11656 | pattern as a mixture of types. | |
11657 | Note that this means, for example, that in the case of C-like languages | |
11658 | a search for an untyped 0x42 will search for @samp{(int) 0x42} | |
11659 | which is typically four bytes. | |
11660 | ||
11661 | @item @var{n}, maximum number of finds | |
11662 | The maximum number of matches to print. The default is to print all finds. | |
11663 | @end table | |
11664 | ||
11665 | You can use strings as search values. Quote them with double-quotes | |
11666 | (@code{"}). | |
11667 | The string value is copied into the search pattern byte by byte, | |
11668 | regardless of the endianness of the target and the size specification. | |
11669 | ||
11670 | The address of each match found is printed as well as a count of the | |
11671 | number of matches found. | |
11672 | ||
11673 | The address of the last value found is stored in convenience variable | |
11674 | @samp{$_}. | |
11675 | A count of the number of matches is stored in @samp{$numfound}. | |
11676 | ||
11677 | For example, if stopped at the @code{printf} in this function: | |
11678 | ||
11679 | @smallexample | |
11680 | void | |
11681 | hello () | |
11682 | @{ | |
11683 | static char hello[] = "hello-hello"; | |
11684 | static struct @{ char c; short s; int i; @} | |
11685 | __attribute__ ((packed)) mixed | |
11686 | = @{ 'c', 0x1234, 0x87654321 @}; | |
11687 | printf ("%s\n", hello); | |
11688 | @} | |
11689 | @end smallexample | |
11690 | ||
11691 | @noindent | |
11692 | you get during debugging: | |
11693 | ||
11694 | @smallexample | |
11695 | (gdb) find &hello[0], +sizeof(hello), "hello" | |
11696 | 0x804956d <hello.1620+6> | |
11697 | 1 pattern found | |
11698 | (gdb) find &hello[0], +sizeof(hello), 'h', 'e', 'l', 'l', 'o' | |
11699 | 0x8049567 <hello.1620> | |
11700 | 0x804956d <hello.1620+6> | |
11701 | 2 patterns found | |
11702 | (gdb) find /b1 &hello[0], +sizeof(hello), 'h', 0x65, 'l' | |
11703 | 0x8049567 <hello.1620> | |
11704 | 1 pattern found | |
11705 | (gdb) find &mixed, +sizeof(mixed), (char) 'c', (short) 0x1234, (int) 0x87654321 | |
11706 | 0x8049560 <mixed.1625> | |
11707 | 1 pattern found | |
11708 | (gdb) print $numfound | |
11709 | $1 = 1 | |
11710 | (gdb) print $_ | |
11711 | $2 = (void *) 0x8049560 | |
11712 | @end smallexample | |
a0eb71c5 | 11713 | |
edb3359d DJ |
11714 | @node Optimized Code |
11715 | @chapter Debugging Optimized Code | |
11716 | @cindex optimized code, debugging | |
11717 | @cindex debugging optimized code | |
11718 | ||
11719 | Almost all compilers support optimization. With optimization | |
11720 | disabled, the compiler generates assembly code that corresponds | |
11721 | directly to your source code, in a simplistic way. As the compiler | |
11722 | applies more powerful optimizations, the generated assembly code | |
11723 | diverges from your original source code. With help from debugging | |
11724 | information generated by the compiler, @value{GDBN} can map from | |
11725 | the running program back to constructs from your original source. | |
11726 | ||
11727 | @value{GDBN} is more accurate with optimization disabled. If you | |
11728 | can recompile without optimization, it is easier to follow the | |
11729 | progress of your program during debugging. But, there are many cases | |
11730 | where you may need to debug an optimized version. | |
11731 | ||
11732 | When you debug a program compiled with @samp{-g -O}, remember that the | |
11733 | optimizer has rearranged your code; the debugger shows you what is | |
11734 | really there. Do not be too surprised when the execution path does not | |
11735 | exactly match your source file! An extreme example: if you define a | |
11736 | variable, but never use it, @value{GDBN} never sees that | |
11737 | variable---because the compiler optimizes it out of existence. | |
11738 | ||
11739 | Some things do not work as well with @samp{-g -O} as with just | |
11740 | @samp{-g}, particularly on machines with instruction scheduling. If in | |
11741 | doubt, recompile with @samp{-g} alone, and if this fixes the problem, | |
11742 | please report it to us as a bug (including a test case!). | |
11743 | @xref{Variables}, for more information about debugging optimized code. | |
11744 | ||
11745 | @menu | |
11746 | * Inline Functions:: How @value{GDBN} presents inlining | |
111c6489 | 11747 | * Tail Call Frames:: @value{GDBN} analysis of jumps to functions |
edb3359d DJ |
11748 | @end menu |
11749 | ||
11750 | @node Inline Functions | |
11751 | @section Inline Functions | |
11752 | @cindex inline functions, debugging | |
11753 | ||
11754 | @dfn{Inlining} is an optimization that inserts a copy of the function | |
11755 | body directly at each call site, instead of jumping to a shared | |
11756 | routine. @value{GDBN} displays inlined functions just like | |
11757 | non-inlined functions. They appear in backtraces. You can view their | |
11758 | arguments and local variables, step into them with @code{step}, skip | |
11759 | them with @code{next}, and escape from them with @code{finish}. | |
11760 | You can check whether a function was inlined by using the | |
11761 | @code{info frame} command. | |
11762 | ||
11763 | For @value{GDBN} to support inlined functions, the compiler must | |
11764 | record information about inlining in the debug information --- | |
11765 | @value{NGCC} using the @sc{dwarf 2} format does this, and several | |
11766 | other compilers do also. @value{GDBN} only supports inlined functions | |
11767 | when using @sc{dwarf 2}. Versions of @value{NGCC} before 4.1 | |
11768 | do not emit two required attributes (@samp{DW_AT_call_file} and | |
11769 | @samp{DW_AT_call_line}); @value{GDBN} does not display inlined | |
11770 | function calls with earlier versions of @value{NGCC}. It instead | |
11771 | displays the arguments and local variables of inlined functions as | |
11772 | local variables in the caller. | |
11773 | ||
11774 | The body of an inlined function is directly included at its call site; | |
11775 | unlike a non-inlined function, there are no instructions devoted to | |
11776 | the call. @value{GDBN} still pretends that the call site and the | |
11777 | start of the inlined function are different instructions. Stepping to | |
11778 | the call site shows the call site, and then stepping again shows | |
11779 | the first line of the inlined function, even though no additional | |
11780 | instructions are executed. | |
11781 | ||
11782 | This makes source-level debugging much clearer; you can see both the | |
11783 | context of the call and then the effect of the call. Only stepping by | |
11784 | a single instruction using @code{stepi} or @code{nexti} does not do | |
11785 | this; single instruction steps always show the inlined body. | |
11786 | ||
11787 | There are some ways that @value{GDBN} does not pretend that inlined | |
11788 | function calls are the same as normal calls: | |
11789 | ||
11790 | @itemize @bullet | |
edb3359d DJ |
11791 | @item |
11792 | Setting breakpoints at the call site of an inlined function may not | |
11793 | work, because the call site does not contain any code. @value{GDBN} | |
11794 | may incorrectly move the breakpoint to the next line of the enclosing | |
11795 | function, after the call. This limitation will be removed in a future | |
11796 | version of @value{GDBN}; until then, set a breakpoint on an earlier line | |
11797 | or inside the inlined function instead. | |
11798 | ||
11799 | @item | |
11800 | @value{GDBN} cannot locate the return value of inlined calls after | |
11801 | using the @code{finish} command. This is a limitation of compiler-generated | |
11802 | debugging information; after @code{finish}, you can step to the next line | |
11803 | and print a variable where your program stored the return value. | |
11804 | ||
11805 | @end itemize | |
11806 | ||
111c6489 JK |
11807 | @node Tail Call Frames |
11808 | @section Tail Call Frames | |
11809 | @cindex tail call frames, debugging | |
11810 | ||
11811 | Function @code{B} can call function @code{C} in its very last statement. In | |
11812 | unoptimized compilation the call of @code{C} is immediately followed by return | |
11813 | instruction at the end of @code{B} code. Optimizing compiler may replace the | |
11814 | call and return in function @code{B} into one jump to function @code{C} | |
11815 | instead. Such use of a jump instruction is called @dfn{tail call}. | |
11816 | ||
11817 | During execution of function @code{C}, there will be no indication in the | |
11818 | function call stack frames that it was tail-called from @code{B}. If function | |
11819 | @code{A} regularly calls function @code{B} which tail-calls function @code{C}, | |
11820 | then @value{GDBN} will see @code{A} as the caller of @code{C}. However, in | |
11821 | some cases @value{GDBN} can determine that @code{C} was tail-called from | |
11822 | @code{B}, and it will then create fictitious call frame for that, with the | |
11823 | return address set up as if @code{B} called @code{C} normally. | |
11824 | ||
11825 | This functionality is currently supported only by DWARF 2 debugging format and | |
11826 | the compiler has to produce @samp{DW_TAG_GNU_call_site} tags. With | |
11827 | @value{NGCC}, you need to specify @option{-O -g} during compilation, to get | |
11828 | this information. | |
11829 | ||
11830 | @kbd{info frame} command (@pxref{Frame Info}) will indicate the tail call frame | |
11831 | kind by text @code{tail call frame} such as in this sample @value{GDBN} output: | |
11832 | ||
11833 | @smallexample | |
11834 | (gdb) x/i $pc - 2 | |
11835 | 0x40066b <b(int, double)+11>: jmp 0x400640 <c(int, double)> | |
11836 | (gdb) info frame | |
11837 | Stack level 1, frame at 0x7fffffffda30: | |
11838 | rip = 0x40066d in b (amd64-entry-value.cc:59); saved rip 0x4004c5 | |
11839 | tail call frame, caller of frame at 0x7fffffffda30 | |
11840 | source language c++. | |
11841 | Arglist at unknown address. | |
11842 | Locals at unknown address, Previous frame's sp is 0x7fffffffda30 | |
11843 | @end smallexample | |
11844 | ||
11845 | The detection of all the possible code path executions can find them ambiguous. | |
11846 | There is no execution history stored (possible @ref{Reverse Execution} is never | |
11847 | used for this purpose) and the last known caller could have reached the known | |
11848 | callee by multiple different jump sequences. In such case @value{GDBN} still | |
11849 | tries to show at least all the unambiguous top tail callers and all the | |
11850 | unambiguous bottom tail calees, if any. | |
11851 | ||
11852 | @table @code | |
e18b2753 | 11853 | @anchor{set debug entry-values} |
111c6489 JK |
11854 | @item set debug entry-values |
11855 | @kindex set debug entry-values | |
11856 | When set to on, enables printing of analysis messages for both frame argument | |
11857 | values at function entry and tail calls. It will show all the possible valid | |
11858 | tail calls code paths it has considered. It will also print the intersection | |
11859 | of them with the final unambiguous (possibly partial or even empty) code path | |
11860 | result. | |
11861 | ||
11862 | @item show debug entry-values | |
11863 | @kindex show debug entry-values | |
11864 | Show the current state of analysis messages printing for both frame argument | |
11865 | values at function entry and tail calls. | |
11866 | @end table | |
11867 | ||
11868 | The analysis messages for tail calls can for example show why the virtual tail | |
11869 | call frame for function @code{c} has not been recognized (due to the indirect | |
11870 | reference by variable @code{x}): | |
11871 | ||
11872 | @smallexample | |
11873 | static void __attribute__((noinline, noclone)) c (void); | |
11874 | void (*x) (void) = c; | |
11875 | static void __attribute__((noinline, noclone)) a (void) @{ x++; @} | |
11876 | static void __attribute__((noinline, noclone)) c (void) @{ a (); @} | |
11877 | int main (void) @{ x (); return 0; @} | |
11878 | ||
11879 | Breakpoint 1, DW_OP_GNU_entry_value resolving cannot find | |
11880 | DW_TAG_GNU_call_site 0x40039a in main | |
11881 | a () at t.c:3 | |
11882 | 3 static void __attribute__((noinline, noclone)) a (void) @{ x++; @} | |
11883 | (gdb) bt | |
11884 | #0 a () at t.c:3 | |
11885 | #1 0x000000000040039a in main () at t.c:5 | |
11886 | @end smallexample | |
11887 | ||
11888 | Another possibility is an ambiguous virtual tail call frames resolution: | |
11889 | ||
11890 | @smallexample | |
11891 | int i; | |
11892 | static void __attribute__((noinline, noclone)) f (void) @{ i++; @} | |
11893 | static void __attribute__((noinline, noclone)) e (void) @{ f (); @} | |
11894 | static void __attribute__((noinline, noclone)) d (void) @{ f (); @} | |
11895 | static void __attribute__((noinline, noclone)) c (void) @{ d (); @} | |
11896 | static void __attribute__((noinline, noclone)) b (void) | |
11897 | @{ if (i) c (); else e (); @} | |
11898 | static void __attribute__((noinline, noclone)) a (void) @{ b (); @} | |
11899 | int main (void) @{ a (); return 0; @} | |
11900 | ||
11901 | tailcall: initial: 0x4004d2(a) 0x4004ce(b) 0x4004b2(c) 0x4004a2(d) | |
11902 | tailcall: compare: 0x4004d2(a) 0x4004cc(b) 0x400492(e) | |
11903 | tailcall: reduced: 0x4004d2(a) | | |
11904 | (gdb) bt | |
11905 | #0 f () at t.c:2 | |
11906 | #1 0x00000000004004d2 in a () at t.c:8 | |
11907 | #2 0x0000000000400395 in main () at t.c:9 | |
11908 | @end smallexample | |
11909 | ||
5048e516 JK |
11910 | @set CALLSEQ1A @code{main@value{ARROW}a@value{ARROW}b@value{ARROW}c@value{ARROW}d@value{ARROW}f} |
11911 | @set CALLSEQ2A @code{main@value{ARROW}a@value{ARROW}b@value{ARROW}e@value{ARROW}f} | |
11912 | ||
11913 | @c Convert CALLSEQ#A to CALLSEQ#B depending on HAVE_MAKEINFO_CLICK. | |
11914 | @ifset HAVE_MAKEINFO_CLICK | |
11915 | @set ARROW @click{} | |
11916 | @set CALLSEQ1B @clicksequence{@value{CALLSEQ1A}} | |
11917 | @set CALLSEQ2B @clicksequence{@value{CALLSEQ2A}} | |
11918 | @end ifset | |
11919 | @ifclear HAVE_MAKEINFO_CLICK | |
11920 | @set ARROW -> | |
11921 | @set CALLSEQ1B @value{CALLSEQ1A} | |
11922 | @set CALLSEQ2B @value{CALLSEQ2A} | |
11923 | @end ifclear | |
11924 | ||
11925 | Frames #0 and #2 are real, #1 is a virtual tail call frame. | |
11926 | The code can have possible execution paths @value{CALLSEQ1B} or | |
11927 | @value{CALLSEQ2B}, @value{GDBN} cannot find which one from the inferior state. | |
111c6489 JK |
11928 | |
11929 | @code{initial:} state shows some random possible calling sequence @value{GDBN} | |
11930 | has found. It then finds another possible calling sequcen - that one is | |
11931 | prefixed by @code{compare:}. The non-ambiguous intersection of these two is | |
11932 | printed as the @code{reduced:} calling sequence. That one could have many | |
11933 | futher @code{compare:} and @code{reduced:} statements as long as there remain | |
11934 | any non-ambiguous sequence entries. | |
11935 | ||
11936 | For the frame of function @code{b} in both cases there are different possible | |
11937 | @code{$pc} values (@code{0x4004cc} or @code{0x4004ce}), therefore this frame is | |
11938 | also ambigous. The only non-ambiguous frame is the one for function @code{a}, | |
11939 | therefore this one is displayed to the user while the ambiguous frames are | |
11940 | omitted. | |
edb3359d | 11941 | |
e18b2753 JK |
11942 | There can be also reasons why printing of frame argument values at function |
11943 | entry may fail: | |
11944 | ||
11945 | @smallexample | |
11946 | int v; | |
11947 | static void __attribute__((noinline, noclone)) c (int i) @{ v++; @} | |
11948 | static void __attribute__((noinline, noclone)) a (int i); | |
11949 | static void __attribute__((noinline, noclone)) b (int i) @{ a (i); @} | |
11950 | static void __attribute__((noinline, noclone)) a (int i) | |
11951 | @{ if (i) b (i - 1); else c (0); @} | |
11952 | int main (void) @{ a (5); return 0; @} | |
11953 | ||
11954 | (gdb) bt | |
11955 | #0 c (i=i@@entry=0) at t.c:2 | |
11956 | #1 0x0000000000400428 in a (DW_OP_GNU_entry_value resolving has found | |
11957 | function "a" at 0x400420 can call itself via tail calls | |
11958 | i=<optimized out>) at t.c:6 | |
11959 | #2 0x000000000040036e in main () at t.c:7 | |
11960 | @end smallexample | |
11961 | ||
11962 | @value{GDBN} cannot find out from the inferior state if and how many times did | |
11963 | function @code{a} call itself (via function @code{b}) as these calls would be | |
11964 | tail calls. Such tail calls would modify thue @code{i} variable, therefore | |
11965 | @value{GDBN} cannot be sure the value it knows would be right - @value{GDBN} | |
11966 | prints @code{<optimized out>} instead. | |
11967 | ||
e2e0bcd1 JB |
11968 | @node Macros |
11969 | @chapter C Preprocessor Macros | |
11970 | ||
49efadf5 | 11971 | Some languages, such as C and C@t{++}, provide a way to define and invoke |
e2e0bcd1 JB |
11972 | ``preprocessor macros'' which expand into strings of tokens. |
11973 | @value{GDBN} can evaluate expressions containing macro invocations, show | |
11974 | the result of macro expansion, and show a macro's definition, including | |
11975 | where it was defined. | |
11976 | ||
11977 | You may need to compile your program specially to provide @value{GDBN} | |
11978 | with information about preprocessor macros. Most compilers do not | |
11979 | include macros in their debugging information, even when you compile | |
11980 | with the @option{-g} flag. @xref{Compilation}. | |
11981 | ||
11982 | A program may define a macro at one point, remove that definition later, | |
11983 | and then provide a different definition after that. Thus, at different | |
11984 | points in the program, a macro may have different definitions, or have | |
11985 | no definition at all. If there is a current stack frame, @value{GDBN} | |
11986 | uses the macros in scope at that frame's source code line. Otherwise, | |
11987 | @value{GDBN} uses the macros in scope at the current listing location; | |
11988 | see @ref{List}. | |
11989 | ||
e2e0bcd1 JB |
11990 | Whenever @value{GDBN} evaluates an expression, it always expands any |
11991 | macro invocations present in the expression. @value{GDBN} also provides | |
11992 | the following commands for working with macros explicitly. | |
11993 | ||
11994 | @table @code | |
11995 | ||
11996 | @kindex macro expand | |
11997 | @cindex macro expansion, showing the results of preprocessor | |
11998 | @cindex preprocessor macro expansion, showing the results of | |
11999 | @cindex expanding preprocessor macros | |
12000 | @item macro expand @var{expression} | |
12001 | @itemx macro exp @var{expression} | |
12002 | Show the results of expanding all preprocessor macro invocations in | |
12003 | @var{expression}. Since @value{GDBN} simply expands macros, but does | |
12004 | not parse the result, @var{expression} need not be a valid expression; | |
12005 | it can be any string of tokens. | |
12006 | ||
09d4efe1 | 12007 | @kindex macro exp1 |
e2e0bcd1 JB |
12008 | @item macro expand-once @var{expression} |
12009 | @itemx macro exp1 @var{expression} | |
4644b6e3 | 12010 | @cindex expand macro once |
e2e0bcd1 JB |
12011 | @i{(This command is not yet implemented.)} Show the results of |
12012 | expanding those preprocessor macro invocations that appear explicitly in | |
12013 | @var{expression}. Macro invocations appearing in that expansion are | |
12014 | left unchanged. This command allows you to see the effect of a | |
12015 | particular macro more clearly, without being confused by further | |
12016 | expansions. Since @value{GDBN} simply expands macros, but does not | |
12017 | parse the result, @var{expression} need not be a valid expression; it | |
12018 | can be any string of tokens. | |
12019 | ||
475b0867 | 12020 | @kindex info macro |
e2e0bcd1 | 12021 | @cindex macro definition, showing |
9b158ba0 | 12022 | @cindex definition of a macro, showing |
12023 | @cindex macros, from debug info | |
71eba9c2 | 12024 | @item info macro [-a|-all] [--] @var{macro} |
12025 | Show the current definition or all definitions of the named @var{macro}, | |
12026 | and describe the source location or compiler command-line where that | |
12027 | definition was established. The optional double dash is to signify the end of | |
12028 | argument processing and the beginning of @var{macro} for non C-like macros where | |
12029 | the macro may begin with a hyphen. | |
e2e0bcd1 | 12030 | |
9b158ba0 | 12031 | @kindex info macros |
629500fa | 12032 | @item info macros @var{location} |
9b158ba0 | 12033 | Show all macro definitions that are in effect at the location specified |
629500fa | 12034 | by @var{location}, and describe the source location or compiler |
9b158ba0 | 12035 | command-line where those definitions were established. |
12036 | ||
e2e0bcd1 JB |
12037 | @kindex macro define |
12038 | @cindex user-defined macros | |
12039 | @cindex defining macros interactively | |
12040 | @cindex macros, user-defined | |
12041 | @item macro define @var{macro} @var{replacement-list} | |
12042 | @itemx macro define @var{macro}(@var{arglist}) @var{replacement-list} | |
d7d9f01e TT |
12043 | Introduce a definition for a preprocessor macro named @var{macro}, |
12044 | invocations of which are replaced by the tokens given in | |
12045 | @var{replacement-list}. The first form of this command defines an | |
12046 | ``object-like'' macro, which takes no arguments; the second form | |
12047 | defines a ``function-like'' macro, which takes the arguments given in | |
12048 | @var{arglist}. | |
12049 | ||
12050 | A definition introduced by this command is in scope in every | |
12051 | expression evaluated in @value{GDBN}, until it is removed with the | |
12052 | @code{macro undef} command, described below. The definition overrides | |
12053 | all definitions for @var{macro} present in the program being debugged, | |
12054 | as well as any previous user-supplied definition. | |
e2e0bcd1 JB |
12055 | |
12056 | @kindex macro undef | |
12057 | @item macro undef @var{macro} | |
d7d9f01e TT |
12058 | Remove any user-supplied definition for the macro named @var{macro}. |
12059 | This command only affects definitions provided with the @code{macro | |
12060 | define} command, described above; it cannot remove definitions present | |
12061 | in the program being debugged. | |
e2e0bcd1 | 12062 | |
09d4efe1 EZ |
12063 | @kindex macro list |
12064 | @item macro list | |
d7d9f01e | 12065 | List all the macros defined using the @code{macro define} command. |
e2e0bcd1 JB |
12066 | @end table |
12067 | ||
12068 | @cindex macros, example of debugging with | |
12069 | Here is a transcript showing the above commands in action. First, we | |
12070 | show our source files: | |
12071 | ||
12072 | @smallexample | |
12073 | $ cat sample.c | |
12074 | #include <stdio.h> | |
12075 | #include "sample.h" | |
12076 | ||
12077 | #define M 42 | |
12078 | #define ADD(x) (M + x) | |
12079 | ||
12080 | main () | |
12081 | @{ | |
12082 | #define N 28 | |
12083 | printf ("Hello, world!\n"); | |
12084 | #undef N | |
12085 | printf ("We're so creative.\n"); | |
12086 | #define N 1729 | |
12087 | printf ("Goodbye, world!\n"); | |
12088 | @} | |
12089 | $ cat sample.h | |
12090 | #define Q < | |
12091 | $ | |
12092 | @end smallexample | |
12093 | ||
e0f8f636 TT |
12094 | Now, we compile the program using the @sc{gnu} C compiler, |
12095 | @value{NGCC}. We pass the @option{-gdwarf-2}@footnote{This is the | |
12096 | minimum. Recent versions of @value{NGCC} support @option{-gdwarf-3} | |
12097 | and @option{-gdwarf-4}; we recommend always choosing the most recent | |
12098 | version of DWARF.} @emph{and} @option{-g3} flags to ensure the compiler | |
12099 | includes information about preprocessor macros in the debugging | |
e2e0bcd1 JB |
12100 | information. |
12101 | ||
12102 | @smallexample | |
12103 | $ gcc -gdwarf-2 -g3 sample.c -o sample | |
12104 | $ | |
12105 | @end smallexample | |
12106 | ||
12107 | Now, we start @value{GDBN} on our sample program: | |
12108 | ||
12109 | @smallexample | |
12110 | $ gdb -nw sample | |
12111 | GNU gdb 2002-05-06-cvs | |
12112 | Copyright 2002 Free Software Foundation, Inc. | |
12113 | GDB is free software, @dots{} | |
f7dc1244 | 12114 | (@value{GDBP}) |
e2e0bcd1 JB |
12115 | @end smallexample |
12116 | ||
12117 | We can expand macros and examine their definitions, even when the | |
12118 | program is not running. @value{GDBN} uses the current listing position | |
12119 | to decide which macro definitions are in scope: | |
12120 | ||
12121 | @smallexample | |
f7dc1244 | 12122 | (@value{GDBP}) list main |
e2e0bcd1 JB |
12123 | 3 |
12124 | 4 #define M 42 | |
12125 | 5 #define ADD(x) (M + x) | |
12126 | 6 | |
12127 | 7 main () | |
12128 | 8 @{ | |
12129 | 9 #define N 28 | |
12130 | 10 printf ("Hello, world!\n"); | |
12131 | 11 #undef N | |
12132 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 12133 | (@value{GDBP}) info macro ADD |
e2e0bcd1 JB |
12134 | Defined at /home/jimb/gdb/macros/play/sample.c:5 |
12135 | #define ADD(x) (M + x) | |
f7dc1244 | 12136 | (@value{GDBP}) info macro Q |
e2e0bcd1 JB |
12137 | Defined at /home/jimb/gdb/macros/play/sample.h:1 |
12138 | included at /home/jimb/gdb/macros/play/sample.c:2 | |
12139 | #define Q < | |
f7dc1244 | 12140 | (@value{GDBP}) macro expand ADD(1) |
e2e0bcd1 | 12141 | expands to: (42 + 1) |
f7dc1244 | 12142 | (@value{GDBP}) macro expand-once ADD(1) |
e2e0bcd1 | 12143 | expands to: once (M + 1) |
f7dc1244 | 12144 | (@value{GDBP}) |
e2e0bcd1 JB |
12145 | @end smallexample |
12146 | ||
d7d9f01e | 12147 | In the example above, note that @code{macro expand-once} expands only |
e2e0bcd1 JB |
12148 | the macro invocation explicit in the original text --- the invocation of |
12149 | @code{ADD} --- but does not expand the invocation of the macro @code{M}, | |
12150 | which was introduced by @code{ADD}. | |
12151 | ||
3f94c067 BW |
12152 | Once the program is running, @value{GDBN} uses the macro definitions in |
12153 | force at the source line of the current stack frame: | |
e2e0bcd1 JB |
12154 | |
12155 | @smallexample | |
f7dc1244 | 12156 | (@value{GDBP}) break main |
e2e0bcd1 | 12157 | Breakpoint 1 at 0x8048370: file sample.c, line 10. |
f7dc1244 | 12158 | (@value{GDBP}) run |
b383017d | 12159 | Starting program: /home/jimb/gdb/macros/play/sample |
e2e0bcd1 JB |
12160 | |
12161 | Breakpoint 1, main () at sample.c:10 | |
12162 | 10 printf ("Hello, world!\n"); | |
f7dc1244 | 12163 | (@value{GDBP}) |
e2e0bcd1 JB |
12164 | @end smallexample |
12165 | ||
12166 | At line 10, the definition of the macro @code{N} at line 9 is in force: | |
12167 | ||
12168 | @smallexample | |
f7dc1244 | 12169 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
12170 | Defined at /home/jimb/gdb/macros/play/sample.c:9 |
12171 | #define N 28 | |
f7dc1244 | 12172 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 12173 | expands to: 28 < 42 |
f7dc1244 | 12174 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 12175 | $1 = 1 |
f7dc1244 | 12176 | (@value{GDBP}) |
e2e0bcd1 JB |
12177 | @end smallexample |
12178 | ||
12179 | As we step over directives that remove @code{N}'s definition, and then | |
12180 | give it a new definition, @value{GDBN} finds the definition (or lack | |
12181 | thereof) in force at each point: | |
12182 | ||
12183 | @smallexample | |
f7dc1244 | 12184 | (@value{GDBP}) next |
e2e0bcd1 JB |
12185 | Hello, world! |
12186 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 12187 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
12188 | The symbol `N' has no definition as a C/C++ preprocessor macro |
12189 | at /home/jimb/gdb/macros/play/sample.c:12 | |
f7dc1244 | 12190 | (@value{GDBP}) next |
e2e0bcd1 JB |
12191 | We're so creative. |
12192 | 14 printf ("Goodbye, world!\n"); | |
f7dc1244 | 12193 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
12194 | Defined at /home/jimb/gdb/macros/play/sample.c:13 |
12195 | #define N 1729 | |
f7dc1244 | 12196 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 12197 | expands to: 1729 < 42 |
f7dc1244 | 12198 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 12199 | $2 = 0 |
f7dc1244 | 12200 | (@value{GDBP}) |
e2e0bcd1 JB |
12201 | @end smallexample |
12202 | ||
484086b7 JK |
12203 | In addition to source files, macros can be defined on the compilation command |
12204 | line using the @option{-D@var{name}=@var{value}} syntax. For macros defined in | |
12205 | such a way, @value{GDBN} displays the location of their definition as line zero | |
12206 | of the source file submitted to the compiler. | |
12207 | ||
12208 | @smallexample | |
12209 | (@value{GDBP}) info macro __STDC__ | |
12210 | Defined at /home/jimb/gdb/macros/play/sample.c:0 | |
12211 | -D__STDC__=1 | |
12212 | (@value{GDBP}) | |
12213 | @end smallexample | |
12214 | ||
e2e0bcd1 | 12215 | |
b37052ae EZ |
12216 | @node Tracepoints |
12217 | @chapter Tracepoints | |
12218 | @c This chapter is based on the documentation written by Michael | |
12219 | @c Snyder, David Taylor, Jim Blandy, and Elena Zannoni. | |
12220 | ||
12221 | @cindex tracepoints | |
12222 | In some applications, it is not feasible for the debugger to interrupt | |
12223 | the program's execution long enough for the developer to learn | |
12224 | anything helpful about its behavior. If the program's correctness | |
12225 | depends on its real-time behavior, delays introduced by a debugger | |
12226 | might cause the program to change its behavior drastically, or perhaps | |
12227 | fail, even when the code itself is correct. It is useful to be able | |
12228 | to observe the program's behavior without interrupting it. | |
12229 | ||
12230 | Using @value{GDBN}'s @code{trace} and @code{collect} commands, you can | |
12231 | specify locations in the program, called @dfn{tracepoints}, and | |
12232 | arbitrary expressions to evaluate when those tracepoints are reached. | |
12233 | Later, using the @code{tfind} command, you can examine the values | |
12234 | those expressions had when the program hit the tracepoints. The | |
12235 | expressions may also denote objects in memory---structures or arrays, | |
12236 | for example---whose values @value{GDBN} should record; while visiting | |
12237 | a particular tracepoint, you may inspect those objects as if they were | |
12238 | in memory at that moment. However, because @value{GDBN} records these | |
12239 | values without interacting with you, it can do so quickly and | |
12240 | unobtrusively, hopefully not disturbing the program's behavior. | |
12241 | ||
12242 | The tracepoint facility is currently available only for remote | |
9d29849a JB |
12243 | targets. @xref{Targets}. In addition, your remote target must know |
12244 | how to collect trace data. This functionality is implemented in the | |
12245 | remote stub; however, none of the stubs distributed with @value{GDBN} | |
12246 | support tracepoints as of this writing. The format of the remote | |
12247 | packets used to implement tracepoints are described in @ref{Tracepoint | |
12248 | Packets}. | |
b37052ae | 12249 | |
00bf0b85 SS |
12250 | It is also possible to get trace data from a file, in a manner reminiscent |
12251 | of corefiles; you specify the filename, and use @code{tfind} to search | |
12252 | through the file. @xref{Trace Files}, for more details. | |
12253 | ||
b37052ae EZ |
12254 | This chapter describes the tracepoint commands and features. |
12255 | ||
12256 | @menu | |
b383017d RM |
12257 | * Set Tracepoints:: |
12258 | * Analyze Collected Data:: | |
12259 | * Tracepoint Variables:: | |
00bf0b85 | 12260 | * Trace Files:: |
b37052ae EZ |
12261 | @end menu |
12262 | ||
12263 | @node Set Tracepoints | |
12264 | @section Commands to Set Tracepoints | |
12265 | ||
12266 | Before running such a @dfn{trace experiment}, an arbitrary number of | |
1042e4c0 SS |
12267 | tracepoints can be set. A tracepoint is actually a special type of |
12268 | breakpoint (@pxref{Set Breaks}), so you can manipulate it using | |
12269 | standard breakpoint commands. For instance, as with breakpoints, | |
12270 | tracepoint numbers are successive integers starting from one, and many | |
12271 | of the commands associated with tracepoints take the tracepoint number | |
12272 | as their argument, to identify which tracepoint to work on. | |
b37052ae EZ |
12273 | |
12274 | For each tracepoint, you can specify, in advance, some arbitrary set | |
12275 | of data that you want the target to collect in the trace buffer when | |
12276 | it hits that tracepoint. The collected data can include registers, | |
12277 | local variables, or global data. Later, you can use @value{GDBN} | |
12278 | commands to examine the values these data had at the time the | |
12279 | tracepoint was hit. | |
12280 | ||
7d13fe92 SS |
12281 | Tracepoints do not support every breakpoint feature. Ignore counts on |
12282 | tracepoints have no effect, and tracepoints cannot run @value{GDBN} | |
12283 | commands when they are hit. Tracepoints may not be thread-specific | |
12284 | either. | |
1042e4c0 | 12285 | |
7a697b8d SS |
12286 | @cindex fast tracepoints |
12287 | Some targets may support @dfn{fast tracepoints}, which are inserted in | |
12288 | a different way (such as with a jump instead of a trap), that is | |
12289 | faster but possibly restricted in where they may be installed. | |
12290 | ||
0fb4aa4b PA |
12291 | @cindex static tracepoints |
12292 | @cindex markers, static tracepoints | |
12293 | @cindex probing markers, static tracepoints | |
12294 | Regular and fast tracepoints are dynamic tracing facilities, meaning | |
12295 | that they can be used to insert tracepoints at (almost) any location | |
12296 | in the target. Some targets may also support controlling @dfn{static | |
12297 | tracepoints} from @value{GDBN}. With static tracing, a set of | |
12298 | instrumentation points, also known as @dfn{markers}, are embedded in | |
12299 | the target program, and can be activated or deactivated by name or | |
12300 | address. These are usually placed at locations which facilitate | |
12301 | investigating what the target is actually doing. @value{GDBN}'s | |
12302 | support for static tracing includes being able to list instrumentation | |
12303 | points, and attach them with @value{GDBN} defined high level | |
12304 | tracepoints that expose the whole range of convenience of | |
8786b2bd | 12305 | @value{GDBN}'s tracepoints support. Namely, support for collecting |
0fb4aa4b PA |
12306 | registers values and values of global or local (to the instrumentation |
12307 | point) variables; tracepoint conditions and trace state variables. | |
12308 | The act of installing a @value{GDBN} static tracepoint on an | |
12309 | instrumentation point, or marker, is referred to as @dfn{probing} a | |
12310 | static tracepoint marker. | |
12311 | ||
fa593d66 PA |
12312 | @code{gdbserver} supports tracepoints on some target systems. |
12313 | @xref{Server,,Tracepoints support in @code{gdbserver}}. | |
12314 | ||
b37052ae EZ |
12315 | This section describes commands to set tracepoints and associated |
12316 | conditions and actions. | |
12317 | ||
12318 | @menu | |
b383017d RM |
12319 | * Create and Delete Tracepoints:: |
12320 | * Enable and Disable Tracepoints:: | |
12321 | * Tracepoint Passcounts:: | |
782b2b07 | 12322 | * Tracepoint Conditions:: |
f61e138d | 12323 | * Trace State Variables:: |
b383017d RM |
12324 | * Tracepoint Actions:: |
12325 | * Listing Tracepoints:: | |
0fb4aa4b | 12326 | * Listing Static Tracepoint Markers:: |
79a6e687 | 12327 | * Starting and Stopping Trace Experiments:: |
c9429232 | 12328 | * Tracepoint Restrictions:: |
b37052ae EZ |
12329 | @end menu |
12330 | ||
12331 | @node Create and Delete Tracepoints | |
12332 | @subsection Create and Delete Tracepoints | |
12333 | ||
12334 | @table @code | |
12335 | @cindex set tracepoint | |
12336 | @kindex trace | |
1042e4c0 | 12337 | @item trace @var{location} |
b37052ae | 12338 | The @code{trace} command is very similar to the @code{break} command. |
629500fa KS |
12339 | Its argument @var{location} can be any valid location. |
12340 | @xref{Specify Location}. The @code{trace} command defines a tracepoint, | |
12341 | which is a point in the target program where the debugger will briefly stop, | |
12342 | collect some data, and then allow the program to continue. Setting a tracepoint | |
12343 | or changing its actions takes effect immediately if the remote stub | |
1e4d1764 YQ |
12344 | supports the @samp{InstallInTrace} feature (@pxref{install tracepoint |
12345 | in tracing}). | |
12346 | If remote stub doesn't support the @samp{InstallInTrace} feature, all | |
12347 | these changes don't take effect until the next @code{tstart} | |
1042e4c0 | 12348 | command, and once a trace experiment is running, further changes will |
bfccc43c YQ |
12349 | not have any effect until the next trace experiment starts. In addition, |
12350 | @value{GDBN} supports @dfn{pending tracepoints}---tracepoints whose | |
12351 | address is not yet resolved. (This is similar to pending breakpoints.) | |
12352 | Pending tracepoints are not downloaded to the target and not installed | |
12353 | until they are resolved. The resolution of pending tracepoints requires | |
12354 | @value{GDBN} support---when debugging with the remote target, and | |
12355 | @value{GDBN} disconnects from the remote stub (@pxref{disconnected | |
12356 | tracing}), pending tracepoints can not be resolved (and downloaded to | |
12357 | the remote stub) while @value{GDBN} is disconnected. | |
b37052ae EZ |
12358 | |
12359 | Here are some examples of using the @code{trace} command: | |
12360 | ||
12361 | @smallexample | |
12362 | (@value{GDBP}) @b{trace foo.c:121} // a source file and line number | |
12363 | ||
12364 | (@value{GDBP}) @b{trace +2} // 2 lines forward | |
12365 | ||
12366 | (@value{GDBP}) @b{trace my_function} // first source line of function | |
12367 | ||
12368 | (@value{GDBP}) @b{trace *my_function} // EXACT start address of function | |
12369 | ||
12370 | (@value{GDBP}) @b{trace *0x2117c4} // an address | |
12371 | @end smallexample | |
12372 | ||
12373 | @noindent | |
12374 | You can abbreviate @code{trace} as @code{tr}. | |
12375 | ||
782b2b07 SS |
12376 | @item trace @var{location} if @var{cond} |
12377 | Set a tracepoint with condition @var{cond}; evaluate the expression | |
12378 | @var{cond} each time the tracepoint is reached, and collect data only | |
12379 | if the value is nonzero---that is, if @var{cond} evaluates as true. | |
12380 | @xref{Tracepoint Conditions, ,Tracepoint Conditions}, for more | |
12381 | information on tracepoint conditions. | |
12382 | ||
7a697b8d SS |
12383 | @item ftrace @var{location} [ if @var{cond} ] |
12384 | @cindex set fast tracepoint | |
74c761c1 | 12385 | @cindex fast tracepoints, setting |
7a697b8d SS |
12386 | @kindex ftrace |
12387 | The @code{ftrace} command sets a fast tracepoint. For targets that | |
12388 | support them, fast tracepoints will use a more efficient but possibly | |
12389 | less general technique to trigger data collection, such as a jump | |
12390 | instruction instead of a trap, or some sort of hardware support. It | |
12391 | may not be possible to create a fast tracepoint at the desired | |
12392 | location, in which case the command will exit with an explanatory | |
12393 | message. | |
12394 | ||
12395 | @value{GDBN} handles arguments to @code{ftrace} exactly as for | |
12396 | @code{trace}. | |
12397 | ||
405f8e94 SS |
12398 | On 32-bit x86-architecture systems, fast tracepoints normally need to |
12399 | be placed at an instruction that is 5 bytes or longer, but can be | |
12400 | placed at 4-byte instructions if the low 64K of memory of the target | |
12401 | program is available to install trampolines. Some Unix-type systems, | |
12402 | such as @sc{gnu}/Linux, exclude low addresses from the program's | |
12403 | address space; but for instance with the Linux kernel it is possible | |
12404 | to let @value{GDBN} use this area by doing a @command{sysctl} command | |
12405 | to set the @code{mmap_min_addr} kernel parameter, as in | |
12406 | ||
12407 | @example | |
12408 | sudo sysctl -w vm.mmap_min_addr=32768 | |
12409 | @end example | |
12410 | ||
12411 | @noindent | |
12412 | which sets the low address to 32K, which leaves plenty of room for | |
12413 | trampolines. The minimum address should be set to a page boundary. | |
12414 | ||
0fb4aa4b | 12415 | @item strace @var{location} [ if @var{cond} ] |
74c761c1 PA |
12416 | @cindex set static tracepoint |
12417 | @cindex static tracepoints, setting | |
12418 | @cindex probe static tracepoint marker | |
0fb4aa4b PA |
12419 | @kindex strace |
12420 | The @code{strace} command sets a static tracepoint. For targets that | |
12421 | support it, setting a static tracepoint probes a static | |
12422 | instrumentation point, or marker, found at @var{location}. It may not | |
12423 | be possible to set a static tracepoint at the desired location, in | |
12424 | which case the command will exit with an explanatory message. | |
12425 | ||
12426 | @value{GDBN} handles arguments to @code{strace} exactly as for | |
12427 | @code{trace}, with the addition that the user can also specify | |
12428 | @code{-m @var{marker}} as @var{location}. This probes the marker | |
12429 | identified by the @var{marker} string identifier. This identifier | |
12430 | depends on the static tracepoint backend library your program is | |
12431 | using. You can find all the marker identifiers in the @samp{ID} field | |
12432 | of the @code{info static-tracepoint-markers} command output. | |
12433 | @xref{Listing Static Tracepoint Markers,,Listing Static Tracepoint | |
12434 | Markers}. For example, in the following small program using the UST | |
12435 | tracing engine: | |
12436 | ||
12437 | @smallexample | |
12438 | main () | |
12439 | @{ | |
12440 | trace_mark(ust, bar33, "str %s", "FOOBAZ"); | |
12441 | @} | |
12442 | @end smallexample | |
12443 | ||
12444 | @noindent | |
12445 | the marker id is composed of joining the first two arguments to the | |
12446 | @code{trace_mark} call with a slash, which translates to: | |
12447 | ||
12448 | @smallexample | |
12449 | (@value{GDBP}) info static-tracepoint-markers | |
12450 | Cnt Enb ID Address What | |
12451 | 1 n ust/bar33 0x0000000000400ddc in main at stexample.c:22 | |
12452 | Data: "str %s" | |
12453 | [etc...] | |
12454 | @end smallexample | |
12455 | ||
12456 | @noindent | |
12457 | so you may probe the marker above with: | |
12458 | ||
12459 | @smallexample | |
12460 | (@value{GDBP}) strace -m ust/bar33 | |
12461 | @end smallexample | |
12462 | ||
12463 | Static tracepoints accept an extra collect action --- @code{collect | |
12464 | $_sdata}. This collects arbitrary user data passed in the probe point | |
12465 | call to the tracing library. In the UST example above, you'll see | |
12466 | that the third argument to @code{trace_mark} is a printf-like format | |
12467 | string. The user data is then the result of running that formating | |
12468 | string against the following arguments. Note that @code{info | |
12469 | static-tracepoint-markers} command output lists that format string in | |
12470 | the @samp{Data:} field. | |
12471 | ||
12472 | You can inspect this data when analyzing the trace buffer, by printing | |
12473 | the $_sdata variable like any other variable available to | |
12474 | @value{GDBN}. @xref{Tracepoint Actions,,Tracepoint Action Lists}. | |
12475 | ||
b37052ae EZ |
12476 | @vindex $tpnum |
12477 | @cindex last tracepoint number | |
12478 | @cindex recent tracepoint number | |
12479 | @cindex tracepoint number | |
12480 | The convenience variable @code{$tpnum} records the tracepoint number | |
12481 | of the most recently set tracepoint. | |
12482 | ||
12483 | @kindex delete tracepoint | |
12484 | @cindex tracepoint deletion | |
12485 | @item delete tracepoint @r{[}@var{num}@r{]} | |
12486 | Permanently delete one or more tracepoints. With no argument, the | |
1042e4c0 SS |
12487 | default is to delete all tracepoints. Note that the regular |
12488 | @code{delete} command can remove tracepoints also. | |
b37052ae EZ |
12489 | |
12490 | Examples: | |
12491 | ||
12492 | @smallexample | |
12493 | (@value{GDBP}) @b{delete trace 1 2 3} // remove three tracepoints | |
12494 | ||
12495 | (@value{GDBP}) @b{delete trace} // remove all tracepoints | |
12496 | @end smallexample | |
12497 | ||
12498 | @noindent | |
12499 | You can abbreviate this command as @code{del tr}. | |
12500 | @end table | |
12501 | ||
12502 | @node Enable and Disable Tracepoints | |
12503 | @subsection Enable and Disable Tracepoints | |
12504 | ||
1042e4c0 SS |
12505 | These commands are deprecated; they are equivalent to plain @code{disable} and @code{enable}. |
12506 | ||
b37052ae EZ |
12507 | @table @code |
12508 | @kindex disable tracepoint | |
12509 | @item disable tracepoint @r{[}@var{num}@r{]} | |
12510 | Disable tracepoint @var{num}, or all tracepoints if no argument | |
12511 | @var{num} is given. A disabled tracepoint will have no effect during | |
d248b706 | 12512 | a trace experiment, but it is not forgotten. You can re-enable |
b37052ae | 12513 | a disabled tracepoint using the @code{enable tracepoint} command. |
d248b706 KY |
12514 | If the command is issued during a trace experiment and the debug target |
12515 | has support for disabling tracepoints during a trace experiment, then the | |
12516 | change will be effective immediately. Otherwise, it will be applied to the | |
12517 | next trace experiment. | |
b37052ae EZ |
12518 | |
12519 | @kindex enable tracepoint | |
12520 | @item enable tracepoint @r{[}@var{num}@r{]} | |
d248b706 KY |
12521 | Enable tracepoint @var{num}, or all tracepoints. If this command is |
12522 | issued during a trace experiment and the debug target supports enabling | |
12523 | tracepoints during a trace experiment, then the enabled tracepoints will | |
12524 | become effective immediately. Otherwise, they will become effective the | |
12525 | next time a trace experiment is run. | |
b37052ae EZ |
12526 | @end table |
12527 | ||
12528 | @node Tracepoint Passcounts | |
12529 | @subsection Tracepoint Passcounts | |
12530 | ||
12531 | @table @code | |
12532 | @kindex passcount | |
12533 | @cindex tracepoint pass count | |
12534 | @item passcount @r{[}@var{n} @r{[}@var{num}@r{]]} | |
12535 | Set the @dfn{passcount} of a tracepoint. The passcount is a way to | |
12536 | automatically stop a trace experiment. If a tracepoint's passcount is | |
12537 | @var{n}, then the trace experiment will be automatically stopped on | |
12538 | the @var{n}'th time that tracepoint is hit. If the tracepoint number | |
12539 | @var{num} is not specified, the @code{passcount} command sets the | |
12540 | passcount of the most recently defined tracepoint. If no passcount is | |
12541 | given, the trace experiment will run until stopped explicitly by the | |
12542 | user. | |
12543 | ||
12544 | Examples: | |
12545 | ||
12546 | @smallexample | |
b383017d | 12547 | (@value{GDBP}) @b{passcount 5 2} // Stop on the 5th execution of |
6826cf00 | 12548 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// tracepoint 2} |
b37052ae EZ |
12549 | |
12550 | (@value{GDBP}) @b{passcount 12} // Stop on the 12th execution of the | |
6826cf00 | 12551 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// most recently defined tracepoint.} |
b37052ae EZ |
12552 | (@value{GDBP}) @b{trace foo} |
12553 | (@value{GDBP}) @b{pass 3} | |
12554 | (@value{GDBP}) @b{trace bar} | |
12555 | (@value{GDBP}) @b{pass 2} | |
12556 | (@value{GDBP}) @b{trace baz} | |
12557 | (@value{GDBP}) @b{pass 1} // Stop tracing when foo has been | |
6826cf00 EZ |
12558 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// executed 3 times OR when bar has} |
12559 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// been executed 2 times} | |
12560 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// OR when baz has been executed 1 time.} | |
b37052ae EZ |
12561 | @end smallexample |
12562 | @end table | |
12563 | ||
782b2b07 SS |
12564 | @node Tracepoint Conditions |
12565 | @subsection Tracepoint Conditions | |
12566 | @cindex conditional tracepoints | |
12567 | @cindex tracepoint conditions | |
12568 | ||
12569 | The simplest sort of tracepoint collects data every time your program | |
12570 | reaches a specified place. You can also specify a @dfn{condition} for | |
12571 | a tracepoint. A condition is just a Boolean expression in your | |
12572 | programming language (@pxref{Expressions, ,Expressions}). A | |
12573 | tracepoint with a condition evaluates the expression each time your | |
12574 | program reaches it, and data collection happens only if the condition | |
12575 | is true. | |
12576 | ||
12577 | Tracepoint conditions can be specified when a tracepoint is set, by | |
12578 | using @samp{if} in the arguments to the @code{trace} command. | |
12579 | @xref{Create and Delete Tracepoints, ,Setting Tracepoints}. They can | |
12580 | also be set or changed at any time with the @code{condition} command, | |
12581 | just as with breakpoints. | |
12582 | ||
12583 | Unlike breakpoint conditions, @value{GDBN} does not actually evaluate | |
12584 | the conditional expression itself. Instead, @value{GDBN} encodes the | |
6dcd5565 | 12585 | expression into an agent expression (@pxref{Agent Expressions}) |
782b2b07 SS |
12586 | suitable for execution on the target, independently of @value{GDBN}. |
12587 | Global variables become raw memory locations, locals become stack | |
12588 | accesses, and so forth. | |
12589 | ||
12590 | For instance, suppose you have a function that is usually called | |
12591 | frequently, but should not be called after an error has occurred. You | |
12592 | could use the following tracepoint command to collect data about calls | |
12593 | of that function that happen while the error code is propagating | |
12594 | through the program; an unconditional tracepoint could end up | |
12595 | collecting thousands of useless trace frames that you would have to | |
12596 | search through. | |
12597 | ||
12598 | @smallexample | |
12599 | (@value{GDBP}) @kbd{trace normal_operation if errcode > 0} | |
12600 | @end smallexample | |
12601 | ||
f61e138d SS |
12602 | @node Trace State Variables |
12603 | @subsection Trace State Variables | |
12604 | @cindex trace state variables | |
12605 | ||
12606 | A @dfn{trace state variable} is a special type of variable that is | |
12607 | created and managed by target-side code. The syntax is the same as | |
12608 | that for GDB's convenience variables (a string prefixed with ``$''), | |
12609 | but they are stored on the target. They must be created explicitly, | |
12610 | using a @code{tvariable} command. They are always 64-bit signed | |
12611 | integers. | |
12612 | ||
12613 | Trace state variables are remembered by @value{GDBN}, and downloaded | |
12614 | to the target along with tracepoint information when the trace | |
12615 | experiment starts. There are no intrinsic limits on the number of | |
12616 | trace state variables, beyond memory limitations of the target. | |
12617 | ||
12618 | @cindex convenience variables, and trace state variables | |
12619 | Although trace state variables are managed by the target, you can use | |
12620 | them in print commands and expressions as if they were convenience | |
12621 | variables; @value{GDBN} will get the current value from the target | |
12622 | while the trace experiment is running. Trace state variables share | |
12623 | the same namespace as other ``$'' variables, which means that you | |
12624 | cannot have trace state variables with names like @code{$23} or | |
12625 | @code{$pc}, nor can you have a trace state variable and a convenience | |
12626 | variable with the same name. | |
12627 | ||
12628 | @table @code | |
12629 | ||
12630 | @item tvariable $@var{name} [ = @var{expression} ] | |
12631 | @kindex tvariable | |
12632 | The @code{tvariable} command creates a new trace state variable named | |
12633 | @code{$@var{name}}, and optionally gives it an initial value of | |
697aa1b7 | 12634 | @var{expression}. The @var{expression} is evaluated when this command is |
f61e138d SS |
12635 | entered; the result will be converted to an integer if possible, |
12636 | otherwise @value{GDBN} will report an error. A subsequent | |
12637 | @code{tvariable} command specifying the same name does not create a | |
12638 | variable, but instead assigns the supplied initial value to the | |
12639 | existing variable of that name, overwriting any previous initial | |
12640 | value. The default initial value is 0. | |
12641 | ||
12642 | @item info tvariables | |
12643 | @kindex info tvariables | |
12644 | List all the trace state variables along with their initial values. | |
12645 | Their current values may also be displayed, if the trace experiment is | |
12646 | currently running. | |
12647 | ||
12648 | @item delete tvariable @r{[} $@var{name} @dots{} @r{]} | |
12649 | @kindex delete tvariable | |
12650 | Delete the given trace state variables, or all of them if no arguments | |
12651 | are specified. | |
12652 | ||
12653 | @end table | |
12654 | ||
b37052ae EZ |
12655 | @node Tracepoint Actions |
12656 | @subsection Tracepoint Action Lists | |
12657 | ||
12658 | @table @code | |
12659 | @kindex actions | |
12660 | @cindex tracepoint actions | |
12661 | @item actions @r{[}@var{num}@r{]} | |
12662 | This command will prompt for a list of actions to be taken when the | |
12663 | tracepoint is hit. If the tracepoint number @var{num} is not | |
12664 | specified, this command sets the actions for the one that was most | |
12665 | recently defined (so that you can define a tracepoint and then say | |
12666 | @code{actions} without bothering about its number). You specify the | |
12667 | actions themselves on the following lines, one action at a time, and | |
12668 | terminate the actions list with a line containing just @code{end}. So | |
7d13fe92 | 12669 | far, the only defined actions are @code{collect}, @code{teval}, and |
b37052ae EZ |
12670 | @code{while-stepping}. |
12671 | ||
5a9351ae SS |
12672 | @code{actions} is actually equivalent to @code{commands} (@pxref{Break |
12673 | Commands, ,Breakpoint Command Lists}), except that only the defined | |
12674 | actions are allowed; any other @value{GDBN} command is rejected. | |
12675 | ||
b37052ae EZ |
12676 | @cindex remove actions from a tracepoint |
12677 | To remove all actions from a tracepoint, type @samp{actions @var{num}} | |
12678 | and follow it immediately with @samp{end}. | |
12679 | ||
12680 | @smallexample | |
12681 | (@value{GDBP}) @b{collect @var{data}} // collect some data | |
12682 | ||
6826cf00 | 12683 | (@value{GDBP}) @b{while-stepping 5} // single-step 5 times, collect data |
b37052ae | 12684 | |
6826cf00 | 12685 | (@value{GDBP}) @b{end} // signals the end of actions. |
b37052ae EZ |
12686 | @end smallexample |
12687 | ||
12688 | In the following example, the action list begins with @code{collect} | |
12689 | commands indicating the things to be collected when the tracepoint is | |
12690 | hit. Then, in order to single-step and collect additional data | |
12691 | following the tracepoint, a @code{while-stepping} command is used, | |
7d13fe92 SS |
12692 | followed by the list of things to be collected after each step in a |
12693 | sequence of single steps. The @code{while-stepping} command is | |
12694 | terminated by its own separate @code{end} command. Lastly, the action | |
12695 | list is terminated by an @code{end} command. | |
b37052ae EZ |
12696 | |
12697 | @smallexample | |
12698 | (@value{GDBP}) @b{trace foo} | |
12699 | (@value{GDBP}) @b{actions} | |
12700 | Enter actions for tracepoint 1, one per line: | |
12701 | > collect bar,baz | |
12702 | > collect $regs | |
12703 | > while-stepping 12 | |
5a9351ae | 12704 | > collect $pc, arr[i] |
b37052ae EZ |
12705 | > end |
12706 | end | |
12707 | @end smallexample | |
12708 | ||
12709 | @kindex collect @r{(tracepoints)} | |
3065dfb6 | 12710 | @item collect@r{[}/@var{mods}@r{]} @var{expr1}, @var{expr2}, @dots{} |
b37052ae EZ |
12711 | Collect values of the given expressions when the tracepoint is hit. |
12712 | This command accepts a comma-separated list of any valid expressions. | |
12713 | In addition to global, static, or local variables, the following | |
12714 | special arguments are supported: | |
12715 | ||
12716 | @table @code | |
12717 | @item $regs | |
0fb4aa4b | 12718 | Collect all registers. |
b37052ae EZ |
12719 | |
12720 | @item $args | |
0fb4aa4b | 12721 | Collect all function arguments. |
b37052ae EZ |
12722 | |
12723 | @item $locals | |
0fb4aa4b PA |
12724 | Collect all local variables. |
12725 | ||
6710bf39 SS |
12726 | @item $_ret |
12727 | Collect the return address. This is helpful if you want to see more | |
12728 | of a backtrace. | |
12729 | ||
62e5f89c SDJ |
12730 | @item $_probe_argc |
12731 | Collects the number of arguments from the static probe at which the | |
12732 | tracepoint is located. | |
12733 | @xref{Static Probe Points}. | |
12734 | ||
12735 | @item $_probe_arg@var{n} | |
12736 | @var{n} is an integer between 0 and 11. Collects the @var{n}th argument | |
12737 | from the static probe at which the tracepoint is located. | |
12738 | @xref{Static Probe Points}. | |
12739 | ||
0fb4aa4b PA |
12740 | @item $_sdata |
12741 | @vindex $_sdata@r{, collect} | |
12742 | Collect static tracepoint marker specific data. Only available for | |
12743 | static tracepoints. @xref{Tracepoint Actions,,Tracepoint Action | |
12744 | Lists}. On the UST static tracepoints library backend, an | |
12745 | instrumentation point resembles a @code{printf} function call. The | |
12746 | tracing library is able to collect user specified data formatted to a | |
12747 | character string using the format provided by the programmer that | |
12748 | instrumented the program. Other backends have similar mechanisms. | |
12749 | Here's an example of a UST marker call: | |
12750 | ||
12751 | @smallexample | |
12752 | const char master_name[] = "$your_name"; | |
12753 | trace_mark(channel1, marker1, "hello %s", master_name) | |
12754 | @end smallexample | |
12755 | ||
12756 | In this case, collecting @code{$_sdata} collects the string | |
12757 | @samp{hello $yourname}. When analyzing the trace buffer, you can | |
12758 | inspect @samp{$_sdata} like any other variable available to | |
12759 | @value{GDBN}. | |
b37052ae EZ |
12760 | @end table |
12761 | ||
12762 | You can give several consecutive @code{collect} commands, each one | |
12763 | with a single argument, or one @code{collect} command with several | |
5a9351ae | 12764 | arguments separated by commas; the effect is the same. |
b37052ae | 12765 | |
3065dfb6 SS |
12766 | The optional @var{mods} changes the usual handling of the arguments. |
12767 | @code{s} requests that pointers to chars be handled as strings, in | |
12768 | particular collecting the contents of the memory being pointed at, up | |
12769 | to the first zero. The upper bound is by default the value of the | |
12770 | @code{print elements} variable; if @code{s} is followed by a decimal | |
12771 | number, that is the upper bound instead. So for instance | |
12772 | @samp{collect/s25 mystr} collects as many as 25 characters at | |
12773 | @samp{mystr}. | |
12774 | ||
f5c37c66 EZ |
12775 | The command @code{info scope} (@pxref{Symbols, info scope}) is |
12776 | particularly useful for figuring out what data to collect. | |
12777 | ||
6da95a67 SS |
12778 | @kindex teval @r{(tracepoints)} |
12779 | @item teval @var{expr1}, @var{expr2}, @dots{} | |
12780 | Evaluate the given expressions when the tracepoint is hit. This | |
12781 | command accepts a comma-separated list of expressions. The results | |
12782 | are discarded, so this is mainly useful for assigning values to trace | |
12783 | state variables (@pxref{Trace State Variables}) without adding those | |
12784 | values to the trace buffer, as would be the case if the @code{collect} | |
12785 | action were used. | |
12786 | ||
b37052ae EZ |
12787 | @kindex while-stepping @r{(tracepoints)} |
12788 | @item while-stepping @var{n} | |
c9429232 | 12789 | Perform @var{n} single-step instruction traces after the tracepoint, |
7d13fe92 | 12790 | collecting new data after each step. The @code{while-stepping} |
c9429232 SS |
12791 | command is followed by the list of what to collect while stepping |
12792 | (followed by its own @code{end} command): | |
b37052ae EZ |
12793 | |
12794 | @smallexample | |
12795 | > while-stepping 12 | |
12796 | > collect $regs, myglobal | |
12797 | > end | |
12798 | > | |
12799 | @end smallexample | |
12800 | ||
12801 | @noindent | |
7d13fe92 SS |
12802 | Note that @code{$pc} is not automatically collected by |
12803 | @code{while-stepping}; you need to explicitly collect that register if | |
12804 | you need it. You may abbreviate @code{while-stepping} as @code{ws} or | |
b37052ae | 12805 | @code{stepping}. |
236f1d4d SS |
12806 | |
12807 | @item set default-collect @var{expr1}, @var{expr2}, @dots{} | |
12808 | @kindex set default-collect | |
12809 | @cindex default collection action | |
12810 | This variable is a list of expressions to collect at each tracepoint | |
12811 | hit. It is effectively an additional @code{collect} action prepended | |
12812 | to every tracepoint action list. The expressions are parsed | |
12813 | individually for each tracepoint, so for instance a variable named | |
12814 | @code{xyz} may be interpreted as a global for one tracepoint, and a | |
12815 | local for another, as appropriate to the tracepoint's location. | |
12816 | ||
12817 | @item show default-collect | |
12818 | @kindex show default-collect | |
12819 | Show the list of expressions that are collected by default at each | |
12820 | tracepoint hit. | |
12821 | ||
b37052ae EZ |
12822 | @end table |
12823 | ||
12824 | @node Listing Tracepoints | |
12825 | @subsection Listing Tracepoints | |
12826 | ||
12827 | @table @code | |
e5a67952 MS |
12828 | @kindex info tracepoints @r{[}@var{n}@dots{}@r{]} |
12829 | @kindex info tp @r{[}@var{n}@dots{}@r{]} | |
b37052ae | 12830 | @cindex information about tracepoints |
e5a67952 | 12831 | @item info tracepoints @r{[}@var{num}@dots{}@r{]} |
1042e4c0 SS |
12832 | Display information about the tracepoint @var{num}. If you don't |
12833 | specify a tracepoint number, displays information about all the | |
12834 | tracepoints defined so far. The format is similar to that used for | |
12835 | @code{info breakpoints}; in fact, @code{info tracepoints} is the same | |
12836 | command, simply restricting itself to tracepoints. | |
12837 | ||
12838 | A tracepoint's listing may include additional information specific to | |
12839 | tracing: | |
b37052ae EZ |
12840 | |
12841 | @itemize @bullet | |
12842 | @item | |
b37052ae | 12843 | its passcount as given by the @code{passcount @var{n}} command |
f2a8bc8a YQ |
12844 | |
12845 | @item | |
12846 | the state about installed on target of each location | |
b37052ae EZ |
12847 | @end itemize |
12848 | ||
12849 | @smallexample | |
12850 | (@value{GDBP}) @b{info trace} | |
1042e4c0 SS |
12851 | Num Type Disp Enb Address What |
12852 | 1 tracepoint keep y 0x0804ab57 in foo() at main.cxx:7 | |
5a9351ae SS |
12853 | while-stepping 20 |
12854 | collect globfoo, $regs | |
12855 | end | |
12856 | collect globfoo2 | |
12857 | end | |
1042e4c0 | 12858 | pass count 1200 |
f2a8bc8a YQ |
12859 | 2 tracepoint keep y <MULTIPLE> |
12860 | collect $eip | |
12861 | 2.1 y 0x0804859c in func4 at change-loc.h:35 | |
12862 | installed on target | |
12863 | 2.2 y 0xb7ffc480 in func4 at change-loc.h:35 | |
12864 | installed on target | |
12865 | 2.3 y <PENDING> set_tracepoint | |
12866 | 3 tracepoint keep y 0x080485b1 in foo at change-loc.c:29 | |
12867 | not installed on target | |
b37052ae EZ |
12868 | (@value{GDBP}) |
12869 | @end smallexample | |
12870 | ||
12871 | @noindent | |
12872 | This command can be abbreviated @code{info tp}. | |
12873 | @end table | |
12874 | ||
0fb4aa4b PA |
12875 | @node Listing Static Tracepoint Markers |
12876 | @subsection Listing Static Tracepoint Markers | |
12877 | ||
12878 | @table @code | |
12879 | @kindex info static-tracepoint-markers | |
12880 | @cindex information about static tracepoint markers | |
12881 | @item info static-tracepoint-markers | |
12882 | Display information about all static tracepoint markers defined in the | |
12883 | program. | |
12884 | ||
12885 | For each marker, the following columns are printed: | |
12886 | ||
12887 | @table @emph | |
12888 | @item Count | |
12889 | An incrementing counter, output to help readability. This is not a | |
12890 | stable identifier. | |
12891 | @item ID | |
12892 | The marker ID, as reported by the target. | |
12893 | @item Enabled or Disabled | |
12894 | Probed markers are tagged with @samp{y}. @samp{n} identifies marks | |
12895 | that are not enabled. | |
12896 | @item Address | |
12897 | Where the marker is in your program, as a memory address. | |
12898 | @item What | |
12899 | Where the marker is in the source for your program, as a file and line | |
12900 | number. If the debug information included in the program does not | |
12901 | allow @value{GDBN} to locate the source of the marker, this column | |
12902 | will be left blank. | |
12903 | @end table | |
12904 | ||
12905 | @noindent | |
12906 | In addition, the following information may be printed for each marker: | |
12907 | ||
12908 | @table @emph | |
12909 | @item Data | |
12910 | User data passed to the tracing library by the marker call. In the | |
12911 | UST backend, this is the format string passed as argument to the | |
12912 | marker call. | |
12913 | @item Static tracepoints probing the marker | |
12914 | The list of static tracepoints attached to the marker. | |
12915 | @end table | |
12916 | ||
12917 | @smallexample | |
12918 | (@value{GDBP}) info static-tracepoint-markers | |
12919 | Cnt ID Enb Address What | |
12920 | 1 ust/bar2 y 0x0000000000400e1a in main at stexample.c:25 | |
12921 | Data: number1 %d number2 %d | |
12922 | Probed by static tracepoints: #2 | |
12923 | 2 ust/bar33 n 0x0000000000400c87 in main at stexample.c:24 | |
12924 | Data: str %s | |
12925 | (@value{GDBP}) | |
12926 | @end smallexample | |
12927 | @end table | |
12928 | ||
79a6e687 BW |
12929 | @node Starting and Stopping Trace Experiments |
12930 | @subsection Starting and Stopping Trace Experiments | |
b37052ae EZ |
12931 | |
12932 | @table @code | |
f196051f | 12933 | @kindex tstart [ @var{notes} ] |
b37052ae EZ |
12934 | @cindex start a new trace experiment |
12935 | @cindex collected data discarded | |
12936 | @item tstart | |
f196051f SS |
12937 | This command starts the trace experiment, and begins collecting data. |
12938 | It has the side effect of discarding all the data collected in the | |
12939 | trace buffer during the previous trace experiment. If any arguments | |
12940 | are supplied, they are taken as a note and stored with the trace | |
12941 | experiment's state. The notes may be arbitrary text, and are | |
12942 | especially useful with disconnected tracing in a multi-user context; | |
12943 | the notes can explain what the trace is doing, supply user contact | |
12944 | information, and so forth. | |
12945 | ||
12946 | @kindex tstop [ @var{notes} ] | |
b37052ae EZ |
12947 | @cindex stop a running trace experiment |
12948 | @item tstop | |
f196051f SS |
12949 | This command stops the trace experiment. If any arguments are |
12950 | supplied, they are recorded with the experiment as a note. This is | |
12951 | useful if you are stopping a trace started by someone else, for | |
12952 | instance if the trace is interfering with the system's behavior and | |
12953 | needs to be stopped quickly. | |
b37052ae | 12954 | |
68c71a2e | 12955 | @strong{Note}: a trace experiment and data collection may stop |
b37052ae EZ |
12956 | automatically if any tracepoint's passcount is reached |
12957 | (@pxref{Tracepoint Passcounts}), or if the trace buffer becomes full. | |
12958 | ||
12959 | @kindex tstatus | |
12960 | @cindex status of trace data collection | |
12961 | @cindex trace experiment, status of | |
12962 | @item tstatus | |
12963 | This command displays the status of the current trace data | |
12964 | collection. | |
12965 | @end table | |
12966 | ||
12967 | Here is an example of the commands we described so far: | |
12968 | ||
12969 | @smallexample | |
12970 | (@value{GDBP}) @b{trace gdb_c_test} | |
12971 | (@value{GDBP}) @b{actions} | |
12972 | Enter actions for tracepoint #1, one per line. | |
12973 | > collect $regs,$locals,$args | |
12974 | > while-stepping 11 | |
12975 | > collect $regs | |
12976 | > end | |
12977 | > end | |
12978 | (@value{GDBP}) @b{tstart} | |
12979 | [time passes @dots{}] | |
12980 | (@value{GDBP}) @b{tstop} | |
12981 | @end smallexample | |
12982 | ||
03f2bd59 | 12983 | @anchor{disconnected tracing} |
d5551862 SS |
12984 | @cindex disconnected tracing |
12985 | You can choose to continue running the trace experiment even if | |
12986 | @value{GDBN} disconnects from the target, voluntarily or | |
12987 | involuntarily. For commands such as @code{detach}, the debugger will | |
12988 | ask what you want to do with the trace. But for unexpected | |
12989 | terminations (@value{GDBN} crash, network outage), it would be | |
12990 | unfortunate to lose hard-won trace data, so the variable | |
12991 | @code{disconnected-tracing} lets you decide whether the trace should | |
12992 | continue running without @value{GDBN}. | |
12993 | ||
12994 | @table @code | |
12995 | @item set disconnected-tracing on | |
12996 | @itemx set disconnected-tracing off | |
12997 | @kindex set disconnected-tracing | |
12998 | Choose whether a tracing run should continue to run if @value{GDBN} | |
12999 | has disconnected from the target. Note that @code{detach} or | |
13000 | @code{quit} will ask you directly what to do about a running trace no | |
13001 | matter what this variable's setting, so the variable is mainly useful | |
13002 | for handling unexpected situations, such as loss of the network. | |
13003 | ||
13004 | @item show disconnected-tracing | |
13005 | @kindex show disconnected-tracing | |
13006 | Show the current choice for disconnected tracing. | |
13007 | ||
13008 | @end table | |
13009 | ||
13010 | When you reconnect to the target, the trace experiment may or may not | |
13011 | still be running; it might have filled the trace buffer in the | |
13012 | meantime, or stopped for one of the other reasons. If it is running, | |
13013 | it will continue after reconnection. | |
13014 | ||
13015 | Upon reconnection, the target will upload information about the | |
13016 | tracepoints in effect. @value{GDBN} will then compare that | |
13017 | information to the set of tracepoints currently defined, and attempt | |
13018 | to match them up, allowing for the possibility that the numbers may | |
13019 | have changed due to creation and deletion in the meantime. If one of | |
13020 | the target's tracepoints does not match any in @value{GDBN}, the | |
13021 | debugger will create a new tracepoint, so that you have a number with | |
13022 | which to specify that tracepoint. This matching-up process is | |
13023 | necessarily heuristic, and it may result in useless tracepoints being | |
13024 | created; you may simply delete them if they are of no use. | |
b37052ae | 13025 | |
4daf5ac0 SS |
13026 | @cindex circular trace buffer |
13027 | If your target agent supports a @dfn{circular trace buffer}, then you | |
13028 | can run a trace experiment indefinitely without filling the trace | |
13029 | buffer; when space runs out, the agent deletes already-collected trace | |
13030 | frames, oldest first, until there is enough room to continue | |
13031 | collecting. This is especially useful if your tracepoints are being | |
13032 | hit too often, and your trace gets terminated prematurely because the | |
13033 | buffer is full. To ask for a circular trace buffer, simply set | |
81896e36 | 13034 | @samp{circular-trace-buffer} to on. You can set this at any time, |
4daf5ac0 SS |
13035 | including during tracing; if the agent can do it, it will change |
13036 | buffer handling on the fly, otherwise it will not take effect until | |
13037 | the next run. | |
13038 | ||
13039 | @table @code | |
13040 | @item set circular-trace-buffer on | |
13041 | @itemx set circular-trace-buffer off | |
13042 | @kindex set circular-trace-buffer | |
13043 | Choose whether a tracing run should use a linear or circular buffer | |
13044 | for trace data. A linear buffer will not lose any trace data, but may | |
13045 | fill up prematurely, while a circular buffer will discard old trace | |
13046 | data, but it will have always room for the latest tracepoint hits. | |
13047 | ||
13048 | @item show circular-trace-buffer | |
13049 | @kindex show circular-trace-buffer | |
13050 | Show the current choice for the trace buffer. Note that this may not | |
13051 | match the agent's current buffer handling, nor is it guaranteed to | |
13052 | match the setting that might have been in effect during a past run, | |
13053 | for instance if you are looking at frames from a trace file. | |
13054 | ||
13055 | @end table | |
13056 | ||
f6f899bf HAQ |
13057 | @table @code |
13058 | @item set trace-buffer-size @var{n} | |
f81d1120 | 13059 | @itemx set trace-buffer-size unlimited |
f6f899bf HAQ |
13060 | @kindex set trace-buffer-size |
13061 | Request that the target use a trace buffer of @var{n} bytes. Not all | |
13062 | targets will honor the request; they may have a compiled-in size for | |
13063 | the trace buffer, or some other limitation. Set to a value of | |
f81d1120 PA |
13064 | @code{unlimited} or @code{-1} to let the target use whatever size it |
13065 | likes. This is also the default. | |
f6f899bf HAQ |
13066 | |
13067 | @item show trace-buffer-size | |
13068 | @kindex show trace-buffer-size | |
13069 | Show the current requested size for the trace buffer. Note that this | |
13070 | will only match the actual size if the target supports size-setting, | |
13071 | and was able to handle the requested size. For instance, if the | |
13072 | target can only change buffer size between runs, this variable will | |
13073 | not reflect the change until the next run starts. Use @code{tstatus} | |
13074 | to get a report of the actual buffer size. | |
13075 | @end table | |
13076 | ||
f196051f SS |
13077 | @table @code |
13078 | @item set trace-user @var{text} | |
13079 | @kindex set trace-user | |
13080 | ||
13081 | @item show trace-user | |
13082 | @kindex show trace-user | |
13083 | ||
13084 | @item set trace-notes @var{text} | |
13085 | @kindex set trace-notes | |
13086 | Set the trace run's notes. | |
13087 | ||
13088 | @item show trace-notes | |
13089 | @kindex show trace-notes | |
13090 | Show the trace run's notes. | |
13091 | ||
13092 | @item set trace-stop-notes @var{text} | |
13093 | @kindex set trace-stop-notes | |
13094 | Set the trace run's stop notes. The handling of the note is as for | |
13095 | @code{tstop} arguments; the set command is convenient way to fix a | |
13096 | stop note that is mistaken or incomplete. | |
13097 | ||
13098 | @item show trace-stop-notes | |
13099 | @kindex show trace-stop-notes | |
13100 | Show the trace run's stop notes. | |
13101 | ||
13102 | @end table | |
13103 | ||
c9429232 SS |
13104 | @node Tracepoint Restrictions |
13105 | @subsection Tracepoint Restrictions | |
13106 | ||
13107 | @cindex tracepoint restrictions | |
13108 | There are a number of restrictions on the use of tracepoints. As | |
13109 | described above, tracepoint data gathering occurs on the target | |
13110 | without interaction from @value{GDBN}. Thus the full capabilities of | |
13111 | the debugger are not available during data gathering, and then at data | |
13112 | examination time, you will be limited by only having what was | |
13113 | collected. The following items describe some common problems, but it | |
13114 | is not exhaustive, and you may run into additional difficulties not | |
13115 | mentioned here. | |
13116 | ||
13117 | @itemize @bullet | |
13118 | ||
13119 | @item | |
13120 | Tracepoint expressions are intended to gather objects (lvalues). Thus | |
13121 | the full flexibility of GDB's expression evaluator is not available. | |
13122 | You cannot call functions, cast objects to aggregate types, access | |
13123 | convenience variables or modify values (except by assignment to trace | |
13124 | state variables). Some language features may implicitly call | |
13125 | functions (for instance Objective-C fields with accessors), and therefore | |
13126 | cannot be collected either. | |
13127 | ||
13128 | @item | |
13129 | Collection of local variables, either individually or in bulk with | |
13130 | @code{$locals} or @code{$args}, during @code{while-stepping} may | |
13131 | behave erratically. The stepping action may enter a new scope (for | |
13132 | instance by stepping into a function), or the location of the variable | |
13133 | may change (for instance it is loaded into a register). The | |
13134 | tracepoint data recorded uses the location information for the | |
13135 | variables that is correct for the tracepoint location. When the | |
13136 | tracepoint is created, it is not possible, in general, to determine | |
13137 | where the steps of a @code{while-stepping} sequence will advance the | |
13138 | program---particularly if a conditional branch is stepped. | |
13139 | ||
13140 | @item | |
13141 | Collection of an incompletely-initialized or partially-destroyed object | |
13142 | may result in something that @value{GDBN} cannot display, or displays | |
13143 | in a misleading way. | |
13144 | ||
13145 | @item | |
13146 | When @value{GDBN} displays a pointer to character it automatically | |
13147 | dereferences the pointer to also display characters of the string | |
13148 | being pointed to. However, collecting the pointer during tracing does | |
13149 | not automatically collect the string. You need to explicitly | |
13150 | dereference the pointer and provide size information if you want to | |
13151 | collect not only the pointer, but the memory pointed to. For example, | |
13152 | @code{*ptr@@50} can be used to collect the 50 element array pointed to | |
13153 | by @code{ptr}. | |
13154 | ||
13155 | @item | |
13156 | It is not possible to collect a complete stack backtrace at a | |
13157 | tracepoint. Instead, you may collect the registers and a few hundred | |
d99f7e48 | 13158 | bytes from the stack pointer with something like @code{*(unsigned char *)$esp@@300} |
c9429232 SS |
13159 | (adjust to use the name of the actual stack pointer register on your |
13160 | target architecture, and the amount of stack you wish to capture). | |
13161 | Then the @code{backtrace} command will show a partial backtrace when | |
13162 | using a trace frame. The number of stack frames that can be examined | |
13163 | depends on the sizes of the frames in the collected stack. Note that | |
13164 | if you ask for a block so large that it goes past the bottom of the | |
13165 | stack, the target agent may report an error trying to read from an | |
13166 | invalid address. | |
13167 | ||
af54718e SS |
13168 | @item |
13169 | If you do not collect registers at a tracepoint, @value{GDBN} can | |
13170 | infer that the value of @code{$pc} must be the same as the address of | |
13171 | the tracepoint and use that when you are looking at a trace frame | |
13172 | for that tracepoint. However, this cannot work if the tracepoint has | |
13173 | multiple locations (for instance if it was set in a function that was | |
13174 | inlined), or if it has a @code{while-stepping} loop. In those cases | |
13175 | @value{GDBN} will warn you that it can't infer @code{$pc}, and default | |
13176 | it to zero. | |
13177 | ||
c9429232 SS |
13178 | @end itemize |
13179 | ||
b37052ae | 13180 | @node Analyze Collected Data |
79a6e687 | 13181 | @section Using the Collected Data |
b37052ae EZ |
13182 | |
13183 | After the tracepoint experiment ends, you use @value{GDBN} commands | |
13184 | for examining the trace data. The basic idea is that each tracepoint | |
13185 | collects a trace @dfn{snapshot} every time it is hit and another | |
13186 | snapshot every time it single-steps. All these snapshots are | |
13187 | consecutively numbered from zero and go into a buffer, and you can | |
13188 | examine them later. The way you examine them is to @dfn{focus} on a | |
13189 | specific trace snapshot. When the remote stub is focused on a trace | |
13190 | snapshot, it will respond to all @value{GDBN} requests for memory and | |
13191 | registers by reading from the buffer which belongs to that snapshot, | |
13192 | rather than from @emph{real} memory or registers of the program being | |
13193 | debugged. This means that @strong{all} @value{GDBN} commands | |
13194 | (@code{print}, @code{info registers}, @code{backtrace}, etc.) will | |
13195 | behave as if we were currently debugging the program state as it was | |
13196 | when the tracepoint occurred. Any requests for data that are not in | |
13197 | the buffer will fail. | |
13198 | ||
13199 | @menu | |
13200 | * tfind:: How to select a trace snapshot | |
13201 | * tdump:: How to display all data for a snapshot | |
6149aea9 | 13202 | * save tracepoints:: How to save tracepoints for a future run |
b37052ae EZ |
13203 | @end menu |
13204 | ||
13205 | @node tfind | |
13206 | @subsection @code{tfind @var{n}} | |
13207 | ||
13208 | @kindex tfind | |
13209 | @cindex select trace snapshot | |
13210 | @cindex find trace snapshot | |
13211 | The basic command for selecting a trace snapshot from the buffer is | |
13212 | @code{tfind @var{n}}, which finds trace snapshot number @var{n}, | |
13213 | counting from zero. If no argument @var{n} is given, the next | |
13214 | snapshot is selected. | |
13215 | ||
13216 | Here are the various forms of using the @code{tfind} command. | |
13217 | ||
13218 | @table @code | |
13219 | @item tfind start | |
13220 | Find the first snapshot in the buffer. This is a synonym for | |
13221 | @code{tfind 0} (since 0 is the number of the first snapshot). | |
13222 | ||
13223 | @item tfind none | |
13224 | Stop debugging trace snapshots, resume @emph{live} debugging. | |
13225 | ||
13226 | @item tfind end | |
13227 | Same as @samp{tfind none}. | |
13228 | ||
13229 | @item tfind | |
13230 | No argument means find the next trace snapshot. | |
13231 | ||
13232 | @item tfind - | |
13233 | Find the previous trace snapshot before the current one. This permits | |
13234 | retracing earlier steps. | |
13235 | ||
13236 | @item tfind tracepoint @var{num} | |
13237 | Find the next snapshot associated with tracepoint @var{num}. Search | |
13238 | proceeds forward from the last examined trace snapshot. If no | |
13239 | argument @var{num} is given, it means find the next snapshot collected | |
13240 | for the same tracepoint as the current snapshot. | |
13241 | ||
13242 | @item tfind pc @var{addr} | |
13243 | Find the next snapshot associated with the value @var{addr} of the | |
13244 | program counter. Search proceeds forward from the last examined trace | |
13245 | snapshot. If no argument @var{addr} is given, it means find the next | |
13246 | snapshot with the same value of PC as the current snapshot. | |
13247 | ||
13248 | @item tfind outside @var{addr1}, @var{addr2} | |
13249 | Find the next snapshot whose PC is outside the given range of | |
081dfbf7 | 13250 | addresses (exclusive). |
b37052ae EZ |
13251 | |
13252 | @item tfind range @var{addr1}, @var{addr2} | |
13253 | Find the next snapshot whose PC is between @var{addr1} and | |
081dfbf7 | 13254 | @var{addr2} (inclusive). |
b37052ae EZ |
13255 | |
13256 | @item tfind line @r{[}@var{file}:@r{]}@var{n} | |
13257 | Find the next snapshot associated with the source line @var{n}. If | |
13258 | the optional argument @var{file} is given, refer to line @var{n} in | |
13259 | that source file. Search proceeds forward from the last examined | |
13260 | trace snapshot. If no argument @var{n} is given, it means find the | |
13261 | next line other than the one currently being examined; thus saying | |
13262 | @code{tfind line} repeatedly can appear to have the same effect as | |
13263 | stepping from line to line in a @emph{live} debugging session. | |
13264 | @end table | |
13265 | ||
13266 | The default arguments for the @code{tfind} commands are specifically | |
13267 | designed to make it easy to scan through the trace buffer. For | |
13268 | instance, @code{tfind} with no argument selects the next trace | |
13269 | snapshot, and @code{tfind -} with no argument selects the previous | |
13270 | trace snapshot. So, by giving one @code{tfind} command, and then | |
13271 | simply hitting @key{RET} repeatedly you can examine all the trace | |
13272 | snapshots in order. Or, by saying @code{tfind -} and then hitting | |
13273 | @key{RET} repeatedly you can examine the snapshots in reverse order. | |
13274 | The @code{tfind line} command with no argument selects the snapshot | |
13275 | for the next source line executed. The @code{tfind pc} command with | |
13276 | no argument selects the next snapshot with the same program counter | |
13277 | (PC) as the current frame. The @code{tfind tracepoint} command with | |
13278 | no argument selects the next trace snapshot collected by the same | |
13279 | tracepoint as the current one. | |
13280 | ||
13281 | In addition to letting you scan through the trace buffer manually, | |
13282 | these commands make it easy to construct @value{GDBN} scripts that | |
13283 | scan through the trace buffer and print out whatever collected data | |
13284 | you are interested in. Thus, if we want to examine the PC, FP, and SP | |
13285 | registers from each trace frame in the buffer, we can say this: | |
13286 | ||
13287 | @smallexample | |
13288 | (@value{GDBP}) @b{tfind start} | |
13289 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
13290 | > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \ | |
13291 | $trace_frame, $pc, $sp, $fp | |
13292 | > tfind | |
13293 | > end | |
13294 | ||
13295 | Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44 | |
13296 | Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44 | |
13297 | Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44 | |
13298 | Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44 | |
13299 | Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44 | |
13300 | Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44 | |
13301 | Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44 | |
13302 | Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44 | |
13303 | Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44 | |
13304 | Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44 | |
13305 | Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14 | |
13306 | @end smallexample | |
13307 | ||
13308 | Or, if we want to examine the variable @code{X} at each source line in | |
13309 | the buffer: | |
13310 | ||
13311 | @smallexample | |
13312 | (@value{GDBP}) @b{tfind start} | |
13313 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
13314 | > printf "Frame %d, X == %d\n", $trace_frame, X | |
13315 | > tfind line | |
13316 | > end | |
13317 | ||
13318 | Frame 0, X = 1 | |
13319 | Frame 7, X = 2 | |
13320 | Frame 13, X = 255 | |
13321 | @end smallexample | |
13322 | ||
13323 | @node tdump | |
13324 | @subsection @code{tdump} | |
13325 | @kindex tdump | |
13326 | @cindex dump all data collected at tracepoint | |
13327 | @cindex tracepoint data, display | |
13328 | ||
13329 | This command takes no arguments. It prints all the data collected at | |
13330 | the current trace snapshot. | |
13331 | ||
13332 | @smallexample | |
13333 | (@value{GDBP}) @b{trace 444} | |
13334 | (@value{GDBP}) @b{actions} | |
13335 | Enter actions for tracepoint #2, one per line: | |
13336 | > collect $regs, $locals, $args, gdb_long_test | |
13337 | > end | |
13338 | ||
13339 | (@value{GDBP}) @b{tstart} | |
13340 | ||
13341 | (@value{GDBP}) @b{tfind line 444} | |
13342 | #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66) | |
13343 | at gdb_test.c:444 | |
13344 | 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ) | |
13345 | ||
13346 | (@value{GDBP}) @b{tdump} | |
13347 | Data collected at tracepoint 2, trace frame 1: | |
13348 | d0 0xc4aa0085 -995491707 | |
13349 | d1 0x18 24 | |
13350 | d2 0x80 128 | |
13351 | d3 0x33 51 | |
13352 | d4 0x71aea3d 119204413 | |
13353 | d5 0x22 34 | |
13354 | d6 0xe0 224 | |
13355 | d7 0x380035 3670069 | |
13356 | a0 0x19e24a 1696330 | |
13357 | a1 0x3000668 50333288 | |
13358 | a2 0x100 256 | |
13359 | a3 0x322000 3284992 | |
13360 | a4 0x3000698 50333336 | |
13361 | a5 0x1ad3cc 1758156 | |
13362 | fp 0x30bf3c 0x30bf3c | |
13363 | sp 0x30bf34 0x30bf34 | |
13364 | ps 0x0 0 | |
13365 | pc 0x20b2c8 0x20b2c8 | |
13366 | fpcontrol 0x0 0 | |
13367 | fpstatus 0x0 0 | |
13368 | fpiaddr 0x0 0 | |
13369 | p = 0x20e5b4 "gdb-test" | |
13370 | p1 = (void *) 0x11 | |
13371 | p2 = (void *) 0x22 | |
13372 | p3 = (void *) 0x33 | |
13373 | p4 = (void *) 0x44 | |
13374 | p5 = (void *) 0x55 | |
13375 | p6 = (void *) 0x66 | |
13376 | gdb_long_test = 17 '\021' | |
13377 | ||
13378 | (@value{GDBP}) | |
13379 | @end smallexample | |
13380 | ||
af54718e SS |
13381 | @code{tdump} works by scanning the tracepoint's current collection |
13382 | actions and printing the value of each expression listed. So | |
13383 | @code{tdump} can fail, if after a run, you change the tracepoint's | |
13384 | actions to mention variables that were not collected during the run. | |
13385 | ||
13386 | Also, for tracepoints with @code{while-stepping} loops, @code{tdump} | |
13387 | uses the collected value of @code{$pc} to distinguish between trace | |
13388 | frames that were collected at the tracepoint hit, and frames that were | |
13389 | collected while stepping. This allows it to correctly choose whether | |
13390 | to display the basic list of collections, or the collections from the | |
13391 | body of the while-stepping loop. However, if @code{$pc} was not collected, | |
13392 | then @code{tdump} will always attempt to dump using the basic collection | |
13393 | list, and may fail if a while-stepping frame does not include all the | |
13394 | same data that is collected at the tracepoint hit. | |
13395 | @c This is getting pretty arcane, example would be good. | |
13396 | ||
6149aea9 PA |
13397 | @node save tracepoints |
13398 | @subsection @code{save tracepoints @var{filename}} | |
13399 | @kindex save tracepoints | |
b37052ae EZ |
13400 | @kindex save-tracepoints |
13401 | @cindex save tracepoints for future sessions | |
13402 | ||
13403 | This command saves all current tracepoint definitions together with | |
13404 | their actions and passcounts, into a file @file{@var{filename}} | |
13405 | suitable for use in a later debugging session. To read the saved | |
13406 | tracepoint definitions, use the @code{source} command (@pxref{Command | |
6149aea9 PA |
13407 | Files}). The @w{@code{save-tracepoints}} command is a deprecated |
13408 | alias for @w{@code{save tracepoints}} | |
b37052ae EZ |
13409 | |
13410 | @node Tracepoint Variables | |
13411 | @section Convenience Variables for Tracepoints | |
13412 | @cindex tracepoint variables | |
13413 | @cindex convenience variables for tracepoints | |
13414 | ||
13415 | @table @code | |
13416 | @vindex $trace_frame | |
13417 | @item (int) $trace_frame | |
13418 | The current trace snapshot (a.k.a.@: @dfn{frame}) number, or -1 if no | |
13419 | snapshot is selected. | |
13420 | ||
13421 | @vindex $tracepoint | |
13422 | @item (int) $tracepoint | |
13423 | The tracepoint for the current trace snapshot. | |
13424 | ||
13425 | @vindex $trace_line | |
13426 | @item (int) $trace_line | |
13427 | The line number for the current trace snapshot. | |
13428 | ||
13429 | @vindex $trace_file | |
13430 | @item (char []) $trace_file | |
13431 | The source file for the current trace snapshot. | |
13432 | ||
13433 | @vindex $trace_func | |
13434 | @item (char []) $trace_func | |
13435 | The name of the function containing @code{$tracepoint}. | |
13436 | @end table | |
13437 | ||
13438 | Note: @code{$trace_file} is not suitable for use in @code{printf}, | |
13439 | use @code{output} instead. | |
13440 | ||
13441 | Here's a simple example of using these convenience variables for | |
13442 | stepping through all the trace snapshots and printing some of their | |
f61e138d SS |
13443 | data. Note that these are not the same as trace state variables, |
13444 | which are managed by the target. | |
b37052ae EZ |
13445 | |
13446 | @smallexample | |
13447 | (@value{GDBP}) @b{tfind start} | |
13448 | ||
13449 | (@value{GDBP}) @b{while $trace_frame != -1} | |
13450 | > output $trace_file | |
13451 | > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint | |
13452 | > tfind | |
13453 | > end | |
13454 | @end smallexample | |
13455 | ||
00bf0b85 SS |
13456 | @node Trace Files |
13457 | @section Using Trace Files | |
13458 | @cindex trace files | |
13459 | ||
13460 | In some situations, the target running a trace experiment may no | |
13461 | longer be available; perhaps it crashed, or the hardware was needed | |
13462 | for a different activity. To handle these cases, you can arrange to | |
13463 | dump the trace data into a file, and later use that file as a source | |
13464 | of trace data, via the @code{target tfile} command. | |
13465 | ||
13466 | @table @code | |
13467 | ||
13468 | @kindex tsave | |
13469 | @item tsave [ -r ] @var{filename} | |
d0353e76 | 13470 | @itemx tsave [-ctf] @var{dirname} |
00bf0b85 SS |
13471 | Save the trace data to @var{filename}. By default, this command |
13472 | assumes that @var{filename} refers to the host filesystem, so if | |
13473 | necessary @value{GDBN} will copy raw trace data up from the target and | |
13474 | then save it. If the target supports it, you can also supply the | |
13475 | optional argument @code{-r} (``remote'') to direct the target to save | |
13476 | the data directly into @var{filename} in its own filesystem, which may be | |
13477 | more efficient if the trace buffer is very large. (Note, however, that | |
13478 | @code{target tfile} can only read from files accessible to the host.) | |
d0353e76 YQ |
13479 | By default, this command will save trace frame in tfile format. |
13480 | You can supply the optional argument @code{-ctf} to save date in CTF | |
13481 | format. The @dfn{Common Trace Format} (CTF) is proposed as a trace format | |
13482 | that can be shared by multiple debugging and tracing tools. Please go to | |
13483 | @indicateurl{http://www.efficios.com/ctf} to get more information. | |
00bf0b85 SS |
13484 | |
13485 | @kindex target tfile | |
13486 | @kindex tfile | |
393fd4c3 YQ |
13487 | @kindex target ctf |
13488 | @kindex ctf | |
00bf0b85 | 13489 | @item target tfile @var{filename} |
393fd4c3 YQ |
13490 | @itemx target ctf @var{dirname} |
13491 | Use the file named @var{filename} or directory named @var{dirname} as | |
13492 | a source of trace data. Commands that examine data work as they do with | |
13493 | a live target, but it is not possible to run any new trace experiments. | |
13494 | @code{tstatus} will report the state of the trace run at the moment | |
13495 | the data was saved, as well as the current trace frame you are examining. | |
697aa1b7 | 13496 | Both @var{filename} and @var{dirname} must be on a filesystem accessible to |
393fd4c3 YQ |
13497 | the host. |
13498 | ||
13499 | @smallexample | |
13500 | (@value{GDBP}) target ctf ctf.ctf | |
13501 | (@value{GDBP}) tfind | |
13502 | Found trace frame 0, tracepoint 2 | |
13503 | 39 ++a; /* set tracepoint 1 here */ | |
13504 | (@value{GDBP}) tdump | |
13505 | Data collected at tracepoint 2, trace frame 0: | |
13506 | i = 0 | |
13507 | a = 0 | |
13508 | b = 1 '\001' | |
13509 | c = @{"123", "456", "789", "123", "456", "789"@} | |
13510 | d = @{@{@{a = 1, b = 2@}, @{a = 3, b = 4@}@}, @{@{a = 5, b = 6@}, @{a = 7, b = 8@}@}@} | |
13511 | (@value{GDBP}) p b | |
13512 | $1 = 1 | |
13513 | @end smallexample | |
00bf0b85 SS |
13514 | |
13515 | @end table | |
13516 | ||
df0cd8c5 JB |
13517 | @node Overlays |
13518 | @chapter Debugging Programs That Use Overlays | |
13519 | @cindex overlays | |
13520 | ||
13521 | If your program is too large to fit completely in your target system's | |
13522 | memory, you can sometimes use @dfn{overlays} to work around this | |
13523 | problem. @value{GDBN} provides some support for debugging programs that | |
13524 | use overlays. | |
13525 | ||
13526 | @menu | |
13527 | * How Overlays Work:: A general explanation of overlays. | |
13528 | * Overlay Commands:: Managing overlays in @value{GDBN}. | |
13529 | * Automatic Overlay Debugging:: @value{GDBN} can find out which overlays are | |
13530 | mapped by asking the inferior. | |
13531 | * Overlay Sample Program:: A sample program using overlays. | |
13532 | @end menu | |
13533 | ||
13534 | @node How Overlays Work | |
13535 | @section How Overlays Work | |
13536 | @cindex mapped overlays | |
13537 | @cindex unmapped overlays | |
13538 | @cindex load address, overlay's | |
13539 | @cindex mapped address | |
13540 | @cindex overlay area | |
13541 | ||
13542 | Suppose you have a computer whose instruction address space is only 64 | |
13543 | kilobytes long, but which has much more memory which can be accessed by | |
13544 | other means: special instructions, segment registers, or memory | |
13545 | management hardware, for example. Suppose further that you want to | |
13546 | adapt a program which is larger than 64 kilobytes to run on this system. | |
13547 | ||
13548 | One solution is to identify modules of your program which are relatively | |
13549 | independent, and need not call each other directly; call these modules | |
13550 | @dfn{overlays}. Separate the overlays from the main program, and place | |
13551 | their machine code in the larger memory. Place your main program in | |
13552 | instruction memory, but leave at least enough space there to hold the | |
13553 | largest overlay as well. | |
13554 | ||
13555 | Now, to call a function located in an overlay, you must first copy that | |
13556 | overlay's machine code from the large memory into the space set aside | |
13557 | for it in the instruction memory, and then jump to its entry point | |
13558 | there. | |
13559 | ||
c928edc0 AC |
13560 | @c NB: In the below the mapped area's size is greater or equal to the |
13561 | @c size of all overlays. This is intentional to remind the developer | |
13562 | @c that overlays don't necessarily need to be the same size. | |
13563 | ||
474c8240 | 13564 | @smallexample |
df0cd8c5 | 13565 | @group |
c928edc0 AC |
13566 | Data Instruction Larger |
13567 | Address Space Address Space Address Space | |
13568 | +-----------+ +-----------+ +-----------+ | |
13569 | | | | | | | | |
13570 | +-----------+ +-----------+ +-----------+<-- overlay 1 | |
13571 | | program | | main | .----| overlay 1 | load address | |
13572 | | variables | | program | | +-----------+ | |
13573 | | and heap | | | | | | | |
13574 | +-----------+ | | | +-----------+<-- overlay 2 | |
13575 | | | +-----------+ | | | load address | |
13576 | +-----------+ | | | .-| overlay 2 | | |
13577 | | | | | | | | |
13578 | mapped --->+-----------+ | | +-----------+ | |
13579 | address | | | | | | | |
13580 | | overlay | <-' | | | | |
13581 | | area | <---' +-----------+<-- overlay 3 | |
13582 | | | <---. | | load address | |
13583 | +-----------+ `--| overlay 3 | | |
13584 | | | | | | |
13585 | +-----------+ | | | |
13586 | +-----------+ | |
13587 | | | | |
13588 | +-----------+ | |
13589 | ||
13590 | @anchor{A code overlay}A code overlay | |
df0cd8c5 | 13591 | @end group |
474c8240 | 13592 | @end smallexample |
df0cd8c5 | 13593 | |
c928edc0 AC |
13594 | The diagram (@pxref{A code overlay}) shows a system with separate data |
13595 | and instruction address spaces. To map an overlay, the program copies | |
13596 | its code from the larger address space to the instruction address space. | |
13597 | Since the overlays shown here all use the same mapped address, only one | |
13598 | may be mapped at a time. For a system with a single address space for | |
13599 | data and instructions, the diagram would be similar, except that the | |
13600 | program variables and heap would share an address space with the main | |
13601 | program and the overlay area. | |
df0cd8c5 JB |
13602 | |
13603 | An overlay loaded into instruction memory and ready for use is called a | |
13604 | @dfn{mapped} overlay; its @dfn{mapped address} is its address in the | |
13605 | instruction memory. An overlay not present (or only partially present) | |
13606 | in instruction memory is called @dfn{unmapped}; its @dfn{load address} | |
13607 | is its address in the larger memory. The mapped address is also called | |
13608 | the @dfn{virtual memory address}, or @dfn{VMA}; the load address is also | |
13609 | called the @dfn{load memory address}, or @dfn{LMA}. | |
13610 | ||
13611 | Unfortunately, overlays are not a completely transparent way to adapt a | |
13612 | program to limited instruction memory. They introduce a new set of | |
13613 | global constraints you must keep in mind as you design your program: | |
13614 | ||
13615 | @itemize @bullet | |
13616 | ||
13617 | @item | |
13618 | Before calling or returning to a function in an overlay, your program | |
13619 | must make sure that overlay is actually mapped. Otherwise, the call or | |
13620 | return will transfer control to the right address, but in the wrong | |
13621 | overlay, and your program will probably crash. | |
13622 | ||
13623 | @item | |
13624 | If the process of mapping an overlay is expensive on your system, you | |
13625 | will need to choose your overlays carefully to minimize their effect on | |
13626 | your program's performance. | |
13627 | ||
13628 | @item | |
13629 | The executable file you load onto your system must contain each | |
13630 | overlay's instructions, appearing at the overlay's load address, not its | |
13631 | mapped address. However, each overlay's instructions must be relocated | |
13632 | and its symbols defined as if the overlay were at its mapped address. | |
13633 | You can use GNU linker scripts to specify different load and relocation | |
13634 | addresses for pieces of your program; see @ref{Overlay Description,,, | |
13635 | ld.info, Using ld: the GNU linker}. | |
13636 | ||
13637 | @item | |
13638 | The procedure for loading executable files onto your system must be able | |
13639 | to load their contents into the larger address space as well as the | |
13640 | instruction and data spaces. | |
13641 | ||
13642 | @end itemize | |
13643 | ||
13644 | The overlay system described above is rather simple, and could be | |
13645 | improved in many ways: | |
13646 | ||
13647 | @itemize @bullet | |
13648 | ||
13649 | @item | |
13650 | If your system has suitable bank switch registers or memory management | |
13651 | hardware, you could use those facilities to make an overlay's load area | |
13652 | contents simply appear at their mapped address in instruction space. | |
13653 | This would probably be faster than copying the overlay to its mapped | |
13654 | area in the usual way. | |
13655 | ||
13656 | @item | |
13657 | If your overlays are small enough, you could set aside more than one | |
13658 | overlay area, and have more than one overlay mapped at a time. | |
13659 | ||
13660 | @item | |
13661 | You can use overlays to manage data, as well as instructions. In | |
13662 | general, data overlays are even less transparent to your design than | |
13663 | code overlays: whereas code overlays only require care when you call or | |
13664 | return to functions, data overlays require care every time you access | |
13665 | the data. Also, if you change the contents of a data overlay, you | |
13666 | must copy its contents back out to its load address before you can copy a | |
13667 | different data overlay into the same mapped area. | |
13668 | ||
13669 | @end itemize | |
13670 | ||
13671 | ||
13672 | @node Overlay Commands | |
13673 | @section Overlay Commands | |
13674 | ||
13675 | To use @value{GDBN}'s overlay support, each overlay in your program must | |
13676 | correspond to a separate section of the executable file. The section's | |
13677 | virtual memory address and load memory address must be the overlay's | |
13678 | mapped and load addresses. Identifying overlays with sections allows | |
13679 | @value{GDBN} to determine the appropriate address of a function or | |
13680 | variable, depending on whether the overlay is mapped or not. | |
13681 | ||
13682 | @value{GDBN}'s overlay commands all start with the word @code{overlay}; | |
13683 | you can abbreviate this as @code{ov} or @code{ovly}. The commands are: | |
13684 | ||
13685 | @table @code | |
13686 | @item overlay off | |
4644b6e3 | 13687 | @kindex overlay |
df0cd8c5 JB |
13688 | Disable @value{GDBN}'s overlay support. When overlay support is |
13689 | disabled, @value{GDBN} assumes that all functions and variables are | |
13690 | always present at their mapped addresses. By default, @value{GDBN}'s | |
13691 | overlay support is disabled. | |
13692 | ||
13693 | @item overlay manual | |
df0cd8c5 JB |
13694 | @cindex manual overlay debugging |
13695 | Enable @dfn{manual} overlay debugging. In this mode, @value{GDBN} | |
13696 | relies on you to tell it which overlays are mapped, and which are not, | |
13697 | using the @code{overlay map-overlay} and @code{overlay unmap-overlay} | |
13698 | commands described below. | |
13699 | ||
13700 | @item overlay map-overlay @var{overlay} | |
13701 | @itemx overlay map @var{overlay} | |
df0cd8c5 JB |
13702 | @cindex map an overlay |
13703 | Tell @value{GDBN} that @var{overlay} is now mapped; @var{overlay} must | |
13704 | be the name of the object file section containing the overlay. When an | |
13705 | overlay is mapped, @value{GDBN} assumes it can find the overlay's | |
13706 | functions and variables at their mapped addresses. @value{GDBN} assumes | |
13707 | that any other overlays whose mapped ranges overlap that of | |
13708 | @var{overlay} are now unmapped. | |
13709 | ||
13710 | @item overlay unmap-overlay @var{overlay} | |
13711 | @itemx overlay unmap @var{overlay} | |
df0cd8c5 JB |
13712 | @cindex unmap an overlay |
13713 | Tell @value{GDBN} that @var{overlay} is no longer mapped; @var{overlay} | |
13714 | must be the name of the object file section containing the overlay. | |
13715 | When an overlay is unmapped, @value{GDBN} assumes it can find the | |
13716 | overlay's functions and variables at their load addresses. | |
13717 | ||
13718 | @item overlay auto | |
df0cd8c5 JB |
13719 | Enable @dfn{automatic} overlay debugging. In this mode, @value{GDBN} |
13720 | consults a data structure the overlay manager maintains in the inferior | |
13721 | to see which overlays are mapped. For details, see @ref{Automatic | |
13722 | Overlay Debugging}. | |
13723 | ||
13724 | @item overlay load-target | |
13725 | @itemx overlay load | |
df0cd8c5 JB |
13726 | @cindex reloading the overlay table |
13727 | Re-read the overlay table from the inferior. Normally, @value{GDBN} | |
13728 | re-reads the table @value{GDBN} automatically each time the inferior | |
13729 | stops, so this command should only be necessary if you have changed the | |
13730 | overlay mapping yourself using @value{GDBN}. This command is only | |
13731 | useful when using automatic overlay debugging. | |
13732 | ||
13733 | @item overlay list-overlays | |
13734 | @itemx overlay list | |
13735 | @cindex listing mapped overlays | |
13736 | Display a list of the overlays currently mapped, along with their mapped | |
13737 | addresses, load addresses, and sizes. | |
13738 | ||
13739 | @end table | |
13740 | ||
13741 | Normally, when @value{GDBN} prints a code address, it includes the name | |
13742 | of the function the address falls in: | |
13743 | ||
474c8240 | 13744 | @smallexample |
f7dc1244 | 13745 | (@value{GDBP}) print main |
df0cd8c5 | 13746 | $3 = @{int ()@} 0x11a0 <main> |
474c8240 | 13747 | @end smallexample |
df0cd8c5 JB |
13748 | @noindent |
13749 | When overlay debugging is enabled, @value{GDBN} recognizes code in | |
13750 | unmapped overlays, and prints the names of unmapped functions with | |
13751 | asterisks around them. For example, if @code{foo} is a function in an | |
13752 | unmapped overlay, @value{GDBN} prints it this way: | |
13753 | ||
474c8240 | 13754 | @smallexample |
f7dc1244 | 13755 | (@value{GDBP}) overlay list |
df0cd8c5 | 13756 | No sections are mapped. |
f7dc1244 | 13757 | (@value{GDBP}) print foo |
df0cd8c5 | 13758 | $5 = @{int (int)@} 0x100000 <*foo*> |
474c8240 | 13759 | @end smallexample |
df0cd8c5 JB |
13760 | @noindent |
13761 | When @code{foo}'s overlay is mapped, @value{GDBN} prints the function's | |
13762 | name normally: | |
13763 | ||
474c8240 | 13764 | @smallexample |
f7dc1244 | 13765 | (@value{GDBP}) overlay list |
b383017d | 13766 | Section .ov.foo.text, loaded at 0x100000 - 0x100034, |
df0cd8c5 | 13767 | mapped at 0x1016 - 0x104a |
f7dc1244 | 13768 | (@value{GDBP}) print foo |
df0cd8c5 | 13769 | $6 = @{int (int)@} 0x1016 <foo> |
474c8240 | 13770 | @end smallexample |
df0cd8c5 JB |
13771 | |
13772 | When overlay debugging is enabled, @value{GDBN} can find the correct | |
13773 | address for functions and variables in an overlay, whether or not the | |
13774 | overlay is mapped. This allows most @value{GDBN} commands, like | |
13775 | @code{break} and @code{disassemble}, to work normally, even on unmapped | |
13776 | code. However, @value{GDBN}'s breakpoint support has some limitations: | |
13777 | ||
13778 | @itemize @bullet | |
13779 | @item | |
13780 | @cindex breakpoints in overlays | |
13781 | @cindex overlays, setting breakpoints in | |
13782 | You can set breakpoints in functions in unmapped overlays, as long as | |
13783 | @value{GDBN} can write to the overlay at its load address. | |
13784 | @item | |
13785 | @value{GDBN} can not set hardware or simulator-based breakpoints in | |
13786 | unmapped overlays. However, if you set a breakpoint at the end of your | |
13787 | overlay manager (and tell @value{GDBN} which overlays are now mapped, if | |
13788 | you are using manual overlay management), @value{GDBN} will re-set its | |
13789 | breakpoints properly. | |
13790 | @end itemize | |
13791 | ||
13792 | ||
13793 | @node Automatic Overlay Debugging | |
13794 | @section Automatic Overlay Debugging | |
13795 | @cindex automatic overlay debugging | |
13796 | ||
13797 | @value{GDBN} can automatically track which overlays are mapped and which | |
13798 | are not, given some simple co-operation from the overlay manager in the | |
13799 | inferior. If you enable automatic overlay debugging with the | |
13800 | @code{overlay auto} command (@pxref{Overlay Commands}), @value{GDBN} | |
13801 | looks in the inferior's memory for certain variables describing the | |
13802 | current state of the overlays. | |
13803 | ||
13804 | Here are the variables your overlay manager must define to support | |
13805 | @value{GDBN}'s automatic overlay debugging: | |
13806 | ||
13807 | @table @asis | |
13808 | ||
13809 | @item @code{_ovly_table}: | |
13810 | This variable must be an array of the following structures: | |
13811 | ||
474c8240 | 13812 | @smallexample |
df0cd8c5 JB |
13813 | struct |
13814 | @{ | |
13815 | /* The overlay's mapped address. */ | |
13816 | unsigned long vma; | |
13817 | ||
13818 | /* The size of the overlay, in bytes. */ | |
13819 | unsigned long size; | |
13820 | ||
13821 | /* The overlay's load address. */ | |
13822 | unsigned long lma; | |
13823 | ||
13824 | /* Non-zero if the overlay is currently mapped; | |
13825 | zero otherwise. */ | |
13826 | unsigned long mapped; | |
13827 | @} | |
474c8240 | 13828 | @end smallexample |
df0cd8c5 JB |
13829 | |
13830 | @item @code{_novlys}: | |
13831 | This variable must be a four-byte signed integer, holding the total | |
13832 | number of elements in @code{_ovly_table}. | |
13833 | ||
13834 | @end table | |
13835 | ||
13836 | To decide whether a particular overlay is mapped or not, @value{GDBN} | |
13837 | looks for an entry in @w{@code{_ovly_table}} whose @code{vma} and | |
13838 | @code{lma} members equal the VMA and LMA of the overlay's section in the | |
13839 | executable file. When @value{GDBN} finds a matching entry, it consults | |
13840 | the entry's @code{mapped} member to determine whether the overlay is | |
13841 | currently mapped. | |
13842 | ||
81d46470 | 13843 | In addition, your overlay manager may define a function called |
def71bfa | 13844 | @code{_ovly_debug_event}. If this function is defined, @value{GDBN} |
81d46470 MS |
13845 | will silently set a breakpoint there. If the overlay manager then |
13846 | calls this function whenever it has changed the overlay table, this | |
13847 | will enable @value{GDBN} to accurately keep track of which overlays | |
13848 | are in program memory, and update any breakpoints that may be set | |
b383017d | 13849 | in overlays. This will allow breakpoints to work even if the |
81d46470 MS |
13850 | overlays are kept in ROM or other non-writable memory while they |
13851 | are not being executed. | |
df0cd8c5 JB |
13852 | |
13853 | @node Overlay Sample Program | |
13854 | @section Overlay Sample Program | |
13855 | @cindex overlay example program | |
13856 | ||
13857 | When linking a program which uses overlays, you must place the overlays | |
13858 | at their load addresses, while relocating them to run at their mapped | |
13859 | addresses. To do this, you must write a linker script (@pxref{Overlay | |
13860 | Description,,, ld.info, Using ld: the GNU linker}). Unfortunately, | |
13861 | since linker scripts are specific to a particular host system, target | |
13862 | architecture, and target memory layout, this manual cannot provide | |
13863 | portable sample code demonstrating @value{GDBN}'s overlay support. | |
13864 | ||
13865 | However, the @value{GDBN} source distribution does contain an overlaid | |
13866 | program, with linker scripts for a few systems, as part of its test | |
13867 | suite. The program consists of the following files from | |
13868 | @file{gdb/testsuite/gdb.base}: | |
13869 | ||
13870 | @table @file | |
13871 | @item overlays.c | |
13872 | The main program file. | |
13873 | @item ovlymgr.c | |
13874 | A simple overlay manager, used by @file{overlays.c}. | |
13875 | @item foo.c | |
13876 | @itemx bar.c | |
13877 | @itemx baz.c | |
13878 | @itemx grbx.c | |
13879 | Overlay modules, loaded and used by @file{overlays.c}. | |
13880 | @item d10v.ld | |
13881 | @itemx m32r.ld | |
13882 | Linker scripts for linking the test program on the @code{d10v-elf} | |
13883 | and @code{m32r-elf} targets. | |
13884 | @end table | |
13885 | ||
13886 | You can build the test program using the @code{d10v-elf} GCC | |
13887 | cross-compiler like this: | |
13888 | ||
474c8240 | 13889 | @smallexample |
df0cd8c5 JB |
13890 | $ d10v-elf-gcc -g -c overlays.c |
13891 | $ d10v-elf-gcc -g -c ovlymgr.c | |
13892 | $ d10v-elf-gcc -g -c foo.c | |
13893 | $ d10v-elf-gcc -g -c bar.c | |
13894 | $ d10v-elf-gcc -g -c baz.c | |
13895 | $ d10v-elf-gcc -g -c grbx.c | |
13896 | $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \ | |
13897 | baz.o grbx.o -Wl,-Td10v.ld -o overlays | |
474c8240 | 13898 | @end smallexample |
df0cd8c5 JB |
13899 | |
13900 | The build process is identical for any other architecture, except that | |
13901 | you must substitute the appropriate compiler and linker script for the | |
13902 | target system for @code{d10v-elf-gcc} and @code{d10v.ld}. | |
13903 | ||
13904 | ||
6d2ebf8b | 13905 | @node Languages |
c906108c SS |
13906 | @chapter Using @value{GDBN} with Different Languages |
13907 | @cindex languages | |
13908 | ||
c906108c SS |
13909 | Although programming languages generally have common aspects, they are |
13910 | rarely expressed in the same manner. For instance, in ANSI C, | |
13911 | dereferencing a pointer @code{p} is accomplished by @code{*p}, but in | |
13912 | Modula-2, it is accomplished by @code{p^}. Values can also be | |
5d161b24 | 13913 | represented (and displayed) differently. Hex numbers in C appear as |
c906108c | 13914 | @samp{0x1ae}, while in Modula-2 they appear as @samp{1AEH}. |
c906108c SS |
13915 | |
13916 | @cindex working language | |
13917 | Language-specific information is built into @value{GDBN} for some languages, | |
13918 | allowing you to express operations like the above in your program's | |
13919 | native language, and allowing @value{GDBN} to output values in a manner | |
13920 | consistent with the syntax of your program's native language. The | |
13921 | language you use to build expressions is called the @dfn{working | |
13922 | language}. | |
13923 | ||
13924 | @menu | |
13925 | * Setting:: Switching between source languages | |
13926 | * Show:: Displaying the language | |
c906108c | 13927 | * Checks:: Type and range checks |
79a6e687 BW |
13928 | * Supported Languages:: Supported languages |
13929 | * Unsupported Languages:: Unsupported languages | |
c906108c SS |
13930 | @end menu |
13931 | ||
6d2ebf8b | 13932 | @node Setting |
79a6e687 | 13933 | @section Switching Between Source Languages |
c906108c SS |
13934 | |
13935 | There are two ways to control the working language---either have @value{GDBN} | |
13936 | set it automatically, or select it manually yourself. You can use the | |
13937 | @code{set language} command for either purpose. On startup, @value{GDBN} | |
13938 | defaults to setting the language automatically. The working language is | |
13939 | used to determine how expressions you type are interpreted, how values | |
13940 | are printed, etc. | |
13941 | ||
13942 | In addition to the working language, every source file that | |
13943 | @value{GDBN} knows about has its own working language. For some object | |
13944 | file formats, the compiler might indicate which language a particular | |
13945 | source file is in. However, most of the time @value{GDBN} infers the | |
13946 | language from the name of the file. The language of a source file | |
b37052ae | 13947 | controls whether C@t{++} names are demangled---this way @code{backtrace} can |
c906108c | 13948 | show each frame appropriately for its own language. There is no way to |
d4f3574e SS |
13949 | set the language of a source file from within @value{GDBN}, but you can |
13950 | set the language associated with a filename extension. @xref{Show, , | |
79a6e687 | 13951 | Displaying the Language}. |
c906108c SS |
13952 | |
13953 | This is most commonly a problem when you use a program, such | |
5d161b24 | 13954 | as @code{cfront} or @code{f2c}, that generates C but is written in |
c906108c SS |
13955 | another language. In that case, make the |
13956 | program use @code{#line} directives in its C output; that way | |
13957 | @value{GDBN} will know the correct language of the source code of the original | |
13958 | program, and will display that source code, not the generated C code. | |
13959 | ||
13960 | @menu | |
13961 | * Filenames:: Filename extensions and languages. | |
13962 | * Manually:: Setting the working language manually | |
13963 | * Automatically:: Having @value{GDBN} infer the source language | |
13964 | @end menu | |
13965 | ||
6d2ebf8b | 13966 | @node Filenames |
79a6e687 | 13967 | @subsection List of Filename Extensions and Languages |
c906108c SS |
13968 | |
13969 | If a source file name ends in one of the following extensions, then | |
13970 | @value{GDBN} infers that its language is the one indicated. | |
13971 | ||
13972 | @table @file | |
e07c999f PH |
13973 | @item .ada |
13974 | @itemx .ads | |
13975 | @itemx .adb | |
13976 | @itemx .a | |
13977 | Ada source file. | |
c906108c SS |
13978 | |
13979 | @item .c | |
13980 | C source file | |
13981 | ||
13982 | @item .C | |
13983 | @itemx .cc | |
13984 | @itemx .cp | |
13985 | @itemx .cpp | |
13986 | @itemx .cxx | |
13987 | @itemx .c++ | |
b37052ae | 13988 | C@t{++} source file |
c906108c | 13989 | |
6aecb9c2 JB |
13990 | @item .d |
13991 | D source file | |
13992 | ||
b37303ee AF |
13993 | @item .m |
13994 | Objective-C source file | |
13995 | ||
c906108c SS |
13996 | @item .f |
13997 | @itemx .F | |
13998 | Fortran source file | |
13999 | ||
c906108c SS |
14000 | @item .mod |
14001 | Modula-2 source file | |
c906108c SS |
14002 | |
14003 | @item .s | |
14004 | @itemx .S | |
14005 | Assembler source file. This actually behaves almost like C, but | |
14006 | @value{GDBN} does not skip over function prologues when stepping. | |
14007 | @end table | |
14008 | ||
14009 | In addition, you may set the language associated with a filename | |
79a6e687 | 14010 | extension. @xref{Show, , Displaying the Language}. |
c906108c | 14011 | |
6d2ebf8b | 14012 | @node Manually |
79a6e687 | 14013 | @subsection Setting the Working Language |
c906108c SS |
14014 | |
14015 | If you allow @value{GDBN} to set the language automatically, | |
14016 | expressions are interpreted the same way in your debugging session and | |
14017 | your program. | |
14018 | ||
14019 | @kindex set language | |
14020 | If you wish, you may set the language manually. To do this, issue the | |
14021 | command @samp{set language @var{lang}}, where @var{lang} is the name of | |
5d161b24 | 14022 | a language, such as |
c906108c | 14023 | @code{c} or @code{modula-2}. |
c906108c SS |
14024 | For a list of the supported languages, type @samp{set language}. |
14025 | ||
c906108c SS |
14026 | Setting the language manually prevents @value{GDBN} from updating the working |
14027 | language automatically. This can lead to confusion if you try | |
14028 | to debug a program when the working language is not the same as the | |
14029 | source language, when an expression is acceptable to both | |
14030 | languages---but means different things. For instance, if the current | |
14031 | source file were written in C, and @value{GDBN} was parsing Modula-2, a | |
14032 | command such as: | |
14033 | ||
474c8240 | 14034 | @smallexample |
c906108c | 14035 | print a = b + c |
474c8240 | 14036 | @end smallexample |
c906108c SS |
14037 | |
14038 | @noindent | |
14039 | might not have the effect you intended. In C, this means to add | |
14040 | @code{b} and @code{c} and place the result in @code{a}. The result | |
14041 | printed would be the value of @code{a}. In Modula-2, this means to compare | |
14042 | @code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value. | |
c906108c | 14043 | |
6d2ebf8b | 14044 | @node Automatically |
79a6e687 | 14045 | @subsection Having @value{GDBN} Infer the Source Language |
c906108c SS |
14046 | |
14047 | To have @value{GDBN} set the working language automatically, use | |
14048 | @samp{set language local} or @samp{set language auto}. @value{GDBN} | |
14049 | then infers the working language. That is, when your program stops in a | |
14050 | frame (usually by encountering a breakpoint), @value{GDBN} sets the | |
14051 | working language to the language recorded for the function in that | |
14052 | frame. If the language for a frame is unknown (that is, if the function | |
14053 | or block corresponding to the frame was defined in a source file that | |
14054 | does not have a recognized extension), the current working language is | |
14055 | not changed, and @value{GDBN} issues a warning. | |
14056 | ||
14057 | This may not seem necessary for most programs, which are written | |
14058 | entirely in one source language. However, program modules and libraries | |
14059 | written in one source language can be used by a main program written in | |
14060 | a different source language. Using @samp{set language auto} in this | |
14061 | case frees you from having to set the working language manually. | |
14062 | ||
6d2ebf8b | 14063 | @node Show |
79a6e687 | 14064 | @section Displaying the Language |
c906108c SS |
14065 | |
14066 | The following commands help you find out which language is the | |
14067 | working language, and also what language source files were written in. | |
14068 | ||
c906108c SS |
14069 | @table @code |
14070 | @item show language | |
403cb6b1 | 14071 | @anchor{show language} |
9c16f35a | 14072 | @kindex show language |
c906108c SS |
14073 | Display the current working language. This is the |
14074 | language you can use with commands such as @code{print} to | |
14075 | build and compute expressions that may involve variables in your program. | |
14076 | ||
14077 | @item info frame | |
4644b6e3 | 14078 | @kindex info frame@r{, show the source language} |
5d161b24 | 14079 | Display the source language for this frame. This language becomes the |
c906108c | 14080 | working language if you use an identifier from this frame. |
79a6e687 | 14081 | @xref{Frame Info, ,Information about a Frame}, to identify the other |
c906108c SS |
14082 | information listed here. |
14083 | ||
14084 | @item info source | |
4644b6e3 | 14085 | @kindex info source@r{, show the source language} |
c906108c | 14086 | Display the source language of this source file. |
5d161b24 | 14087 | @xref{Symbols, ,Examining the Symbol Table}, to identify the other |
c906108c SS |
14088 | information listed here. |
14089 | @end table | |
14090 | ||
14091 | In unusual circumstances, you may have source files with extensions | |
14092 | not in the standard list. You can then set the extension associated | |
14093 | with a language explicitly: | |
14094 | ||
c906108c | 14095 | @table @code |
09d4efe1 | 14096 | @item set extension-language @var{ext} @var{language} |
9c16f35a | 14097 | @kindex set extension-language |
09d4efe1 EZ |
14098 | Tell @value{GDBN} that source files with extension @var{ext} are to be |
14099 | assumed as written in the source language @var{language}. | |
c906108c SS |
14100 | |
14101 | @item info extensions | |
9c16f35a | 14102 | @kindex info extensions |
c906108c SS |
14103 | List all the filename extensions and the associated languages. |
14104 | @end table | |
14105 | ||
6d2ebf8b | 14106 | @node Checks |
79a6e687 | 14107 | @section Type and Range Checking |
c906108c | 14108 | |
c906108c SS |
14109 | Some languages are designed to guard you against making seemingly common |
14110 | errors through a series of compile- and run-time checks. These include | |
a451cb65 | 14111 | checking the type of arguments to functions and operators and making |
c906108c SS |
14112 | sure mathematical overflows are caught at run time. Checks such as |
14113 | these help to ensure a program's correctness once it has been compiled | |
a451cb65 | 14114 | by eliminating type mismatches and providing active checks for range |
c906108c SS |
14115 | errors when your program is running. |
14116 | ||
a451cb65 KS |
14117 | By default @value{GDBN} checks for these errors according to the |
14118 | rules of the current source language. Although @value{GDBN} does not check | |
14119 | the statements in your program, it can check expressions entered directly | |
14120 | into @value{GDBN} for evaluation via the @code{print} command, for example. | |
c906108c SS |
14121 | |
14122 | @menu | |
14123 | * Type Checking:: An overview of type checking | |
14124 | * Range Checking:: An overview of range checking | |
14125 | @end menu | |
14126 | ||
14127 | @cindex type checking | |
14128 | @cindex checks, type | |
6d2ebf8b | 14129 | @node Type Checking |
79a6e687 | 14130 | @subsection An Overview of Type Checking |
c906108c | 14131 | |
a451cb65 | 14132 | Some languages, such as C and C@t{++}, are strongly typed, meaning that the |
c906108c SS |
14133 | arguments to operators and functions have to be of the correct type, |
14134 | otherwise an error occurs. These checks prevent type mismatch | |
14135 | errors from ever causing any run-time problems. For example, | |
14136 | ||
14137 | @smallexample | |
a451cb65 KS |
14138 | int klass::my_method(char *b) @{ return b ? 1 : 2; @} |
14139 | ||
14140 | (@value{GDBP}) print obj.my_method (0) | |
14141 | $1 = 2 | |
c906108c | 14142 | @exdent but |
a451cb65 KS |
14143 | (@value{GDBP}) print obj.my_method (0x1234) |
14144 | Cannot resolve method klass::my_method to any overloaded instance | |
c906108c SS |
14145 | @end smallexample |
14146 | ||
a451cb65 KS |
14147 | The second example fails because in C@t{++} the integer constant |
14148 | @samp{0x1234} is not type-compatible with the pointer parameter type. | |
c906108c | 14149 | |
a451cb65 KS |
14150 | For the expressions you use in @value{GDBN} commands, you can tell |
14151 | @value{GDBN} to not enforce strict type checking or | |
5d161b24 | 14152 | to treat any mismatches as errors and abandon the expression; |
a451cb65 KS |
14153 | When type checking is disabled, @value{GDBN} successfully evaluates |
14154 | expressions like the second example above. | |
c906108c | 14155 | |
a451cb65 | 14156 | Even if type checking is off, there may be other reasons |
5d161b24 DB |
14157 | related to type that prevent @value{GDBN} from evaluating an expression. |
14158 | For instance, @value{GDBN} does not know how to add an @code{int} and | |
14159 | a @code{struct foo}. These particular type errors have nothing to do | |
a451cb65 KS |
14160 | with the language in use and usually arise from expressions which make |
14161 | little sense to evaluate anyway. | |
c906108c | 14162 | |
a451cb65 | 14163 | @value{GDBN} provides some additional commands for controlling type checking: |
c906108c | 14164 | |
c906108c SS |
14165 | @kindex set check type |
14166 | @kindex show check type | |
14167 | @table @code | |
c906108c SS |
14168 | @item set check type on |
14169 | @itemx set check type off | |
a451cb65 | 14170 | Set strict type checking on or off. If any type mismatches occur in |
d4f3574e | 14171 | evaluating an expression while type checking is on, @value{GDBN} prints a |
c906108c SS |
14172 | message and aborts evaluation of the expression. |
14173 | ||
a451cb65 KS |
14174 | @item show check type |
14175 | Show the current setting of type checking and whether @value{GDBN} | |
14176 | is enforcing strict type checking rules. | |
c906108c SS |
14177 | @end table |
14178 | ||
14179 | @cindex range checking | |
14180 | @cindex checks, range | |
6d2ebf8b | 14181 | @node Range Checking |
79a6e687 | 14182 | @subsection An Overview of Range Checking |
c906108c SS |
14183 | |
14184 | In some languages (such as Modula-2), it is an error to exceed the | |
14185 | bounds of a type; this is enforced with run-time checks. Such range | |
14186 | checking is meant to ensure program correctness by making sure | |
14187 | computations do not overflow, or indices on an array element access do | |
14188 | not exceed the bounds of the array. | |
14189 | ||
14190 | For expressions you use in @value{GDBN} commands, you can tell | |
14191 | @value{GDBN} to treat range errors in one of three ways: ignore them, | |
14192 | always treat them as errors and abandon the expression, or issue | |
14193 | warnings but evaluate the expression anyway. | |
14194 | ||
14195 | A range error can result from numerical overflow, from exceeding an | |
14196 | array index bound, or when you type a constant that is not a member | |
14197 | of any type. Some languages, however, do not treat overflows as an | |
14198 | error. In many implementations of C, mathematical overflow causes the | |
14199 | result to ``wrap around'' to lower values---for example, if @var{m} is | |
14200 | the largest integer value, and @var{s} is the smallest, then | |
14201 | ||
474c8240 | 14202 | @smallexample |
c906108c | 14203 | @var{m} + 1 @result{} @var{s} |
474c8240 | 14204 | @end smallexample |
c906108c SS |
14205 | |
14206 | This, too, is specific to individual languages, and in some cases | |
79a6e687 BW |
14207 | specific to individual compilers or machines. @xref{Supported Languages, , |
14208 | Supported Languages}, for further details on specific languages. | |
c906108c SS |
14209 | |
14210 | @value{GDBN} provides some additional commands for controlling the range checker: | |
14211 | ||
c906108c SS |
14212 | @kindex set check range |
14213 | @kindex show check range | |
14214 | @table @code | |
14215 | @item set check range auto | |
14216 | Set range checking on or off based on the current working language. | |
79a6e687 | 14217 | @xref{Supported Languages, ,Supported Languages}, for the default settings for |
c906108c SS |
14218 | each language. |
14219 | ||
14220 | @item set check range on | |
14221 | @itemx set check range off | |
14222 | Set range checking on or off, overriding the default setting for the | |
14223 | current working language. A warning is issued if the setting does not | |
c3f6f71d JM |
14224 | match the language default. If a range error occurs and range checking is on, |
14225 | then a message is printed and evaluation of the expression is aborted. | |
c906108c SS |
14226 | |
14227 | @item set check range warn | |
14228 | Output messages when the @value{GDBN} range checker detects a range error, | |
14229 | but attempt to evaluate the expression anyway. Evaluating the | |
14230 | expression may still be impossible for other reasons, such as accessing | |
14231 | memory that the process does not own (a typical example from many Unix | |
14232 | systems). | |
14233 | ||
14234 | @item show range | |
14235 | Show the current setting of the range checker, and whether or not it is | |
14236 | being set automatically by @value{GDBN}. | |
14237 | @end table | |
c906108c | 14238 | |
79a6e687 BW |
14239 | @node Supported Languages |
14240 | @section Supported Languages | |
c906108c | 14241 | |
a766d390 DE |
14242 | @value{GDBN} supports C, C@t{++}, D, Go, Objective-C, Fortran, Java, |
14243 | OpenCL C, Pascal, assembly, Modula-2, and Ada. | |
cce74817 | 14244 | @c This is false ... |
c906108c SS |
14245 | Some @value{GDBN} features may be used in expressions regardless of the |
14246 | language you use: the @value{GDBN} @code{@@} and @code{::} operators, | |
14247 | and the @samp{@{type@}addr} construct (@pxref{Expressions, | |
14248 | ,Expressions}) can be used with the constructs of any supported | |
14249 | language. | |
14250 | ||
14251 | The following sections detail to what degree each source language is | |
14252 | supported by @value{GDBN}. These sections are not meant to be language | |
14253 | tutorials or references, but serve only as a reference guide to what the | |
14254 | @value{GDBN} expression parser accepts, and what input and output | |
14255 | formats should look like for different languages. There are many good | |
14256 | books written on each of these languages; please look to these for a | |
14257 | language reference or tutorial. | |
14258 | ||
c906108c | 14259 | @menu |
b37303ee | 14260 | * C:: C and C@t{++} |
6aecb9c2 | 14261 | * D:: D |
a766d390 | 14262 | * Go:: Go |
b383017d | 14263 | * Objective-C:: Objective-C |
f4b8a18d | 14264 | * OpenCL C:: OpenCL C |
09d4efe1 | 14265 | * Fortran:: Fortran |
9c16f35a | 14266 | * Pascal:: Pascal |
b37303ee | 14267 | * Modula-2:: Modula-2 |
e07c999f | 14268 | * Ada:: Ada |
c906108c SS |
14269 | @end menu |
14270 | ||
6d2ebf8b | 14271 | @node C |
b37052ae | 14272 | @subsection C and C@t{++} |
7a292a7a | 14273 | |
b37052ae EZ |
14274 | @cindex C and C@t{++} |
14275 | @cindex expressions in C or C@t{++} | |
c906108c | 14276 | |
b37052ae | 14277 | Since C and C@t{++} are so closely related, many features of @value{GDBN} apply |
c906108c SS |
14278 | to both languages. Whenever this is the case, we discuss those languages |
14279 | together. | |
14280 | ||
41afff9a EZ |
14281 | @cindex C@t{++} |
14282 | @cindex @code{g++}, @sc{gnu} C@t{++} compiler | |
b37052ae EZ |
14283 | @cindex @sc{gnu} C@t{++} |
14284 | The C@t{++} debugging facilities are jointly implemented by the C@t{++} | |
14285 | compiler and @value{GDBN}. Therefore, to debug your C@t{++} code | |
14286 | effectively, you must compile your C@t{++} programs with a supported | |
14287 | C@t{++} compiler, such as @sc{gnu} @code{g++}, or the HP ANSI C@t{++} | |
c906108c SS |
14288 | compiler (@code{aCC}). |
14289 | ||
c906108c | 14290 | @menu |
b37052ae EZ |
14291 | * C Operators:: C and C@t{++} operators |
14292 | * C Constants:: C and C@t{++} constants | |
79a6e687 | 14293 | * C Plus Plus Expressions:: C@t{++} expressions |
b37052ae EZ |
14294 | * C Defaults:: Default settings for C and C@t{++} |
14295 | * C Checks:: C and C@t{++} type and range checks | |
c906108c | 14296 | * Debugging C:: @value{GDBN} and C |
79a6e687 | 14297 | * Debugging C Plus Plus:: @value{GDBN} features for C@t{++} |
febe4383 | 14298 | * Decimal Floating Point:: Numbers in Decimal Floating Point format |
c906108c | 14299 | @end menu |
c906108c | 14300 | |
6d2ebf8b | 14301 | @node C Operators |
79a6e687 | 14302 | @subsubsection C and C@t{++} Operators |
7a292a7a | 14303 | |
b37052ae | 14304 | @cindex C and C@t{++} operators |
c906108c SS |
14305 | |
14306 | Operators must be defined on values of specific types. For instance, | |
14307 | @code{+} is defined on numbers, but not on structures. Operators are | |
5d161b24 | 14308 | often defined on groups of types. |
c906108c | 14309 | |
b37052ae | 14310 | For the purposes of C and C@t{++}, the following definitions hold: |
c906108c SS |
14311 | |
14312 | @itemize @bullet | |
53a5351d | 14313 | |
c906108c | 14314 | @item |
c906108c | 14315 | @emph{Integral types} include @code{int} with any of its storage-class |
b37052ae | 14316 | specifiers; @code{char}; @code{enum}; and, for C@t{++}, @code{bool}. |
c906108c SS |
14317 | |
14318 | @item | |
d4f3574e SS |
14319 | @emph{Floating-point types} include @code{float}, @code{double}, and |
14320 | @code{long double} (if supported by the target platform). | |
c906108c SS |
14321 | |
14322 | @item | |
53a5351d | 14323 | @emph{Pointer types} include all types defined as @code{(@var{type} *)}. |
c906108c SS |
14324 | |
14325 | @item | |
14326 | @emph{Scalar types} include all of the above. | |
53a5351d | 14327 | |
c906108c SS |
14328 | @end itemize |
14329 | ||
14330 | @noindent | |
14331 | The following operators are supported. They are listed here | |
14332 | in order of increasing precedence: | |
14333 | ||
14334 | @table @code | |
14335 | @item , | |
14336 | The comma or sequencing operator. Expressions in a comma-separated list | |
14337 | are evaluated from left to right, with the result of the entire | |
14338 | expression being the last expression evaluated. | |
14339 | ||
14340 | @item = | |
14341 | Assignment. The value of an assignment expression is the value | |
14342 | assigned. Defined on scalar types. | |
14343 | ||
14344 | @item @var{op}= | |
14345 | Used in an expression of the form @w{@code{@var{a} @var{op}= @var{b}}}, | |
14346 | and translated to @w{@code{@var{a} = @var{a op b}}}. | |
697aa1b7 | 14347 | @w{@code{@var{op}=}} and @code{=} have the same precedence. The operator |
c906108c SS |
14348 | @var{op} is any one of the operators @code{|}, @code{^}, @code{&}, |
14349 | @code{<<}, @code{>>}, @code{+}, @code{-}, @code{*}, @code{/}, @code{%}. | |
14350 | ||
14351 | @item ?: | |
14352 | The ternary operator. @code{@var{a} ? @var{b} : @var{c}} can be thought | |
697aa1b7 EZ |
14353 | of as: if @var{a} then @var{b} else @var{c}. The argument @var{a} |
14354 | should be of an integral type. | |
c906108c SS |
14355 | |
14356 | @item || | |
14357 | Logical @sc{or}. Defined on integral types. | |
14358 | ||
14359 | @item && | |
14360 | Logical @sc{and}. Defined on integral types. | |
14361 | ||
14362 | @item | | |
14363 | Bitwise @sc{or}. Defined on integral types. | |
14364 | ||
14365 | @item ^ | |
14366 | Bitwise exclusive-@sc{or}. Defined on integral types. | |
14367 | ||
14368 | @item & | |
14369 | Bitwise @sc{and}. Defined on integral types. | |
14370 | ||
14371 | @item ==@r{, }!= | |
14372 | Equality and inequality. Defined on scalar types. The value of these | |
14373 | expressions is 0 for false and non-zero for true. | |
14374 | ||
14375 | @item <@r{, }>@r{, }<=@r{, }>= | |
14376 | Less than, greater than, less than or equal, greater than or equal. | |
14377 | Defined on scalar types. The value of these expressions is 0 for false | |
14378 | and non-zero for true. | |
14379 | ||
14380 | @item <<@r{, }>> | |
14381 | left shift, and right shift. Defined on integral types. | |
14382 | ||
14383 | @item @@ | |
14384 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
14385 | ||
14386 | @item +@r{, }- | |
14387 | Addition and subtraction. Defined on integral types, floating-point types and | |
14388 | pointer types. | |
14389 | ||
14390 | @item *@r{, }/@r{, }% | |
14391 | Multiplication, division, and modulus. Multiplication and division are | |
14392 | defined on integral and floating-point types. Modulus is defined on | |
14393 | integral types. | |
14394 | ||
14395 | @item ++@r{, }-- | |
14396 | Increment and decrement. When appearing before a variable, the | |
14397 | operation is performed before the variable is used in an expression; | |
14398 | when appearing after it, the variable's value is used before the | |
14399 | operation takes place. | |
14400 | ||
14401 | @item * | |
14402 | Pointer dereferencing. Defined on pointer types. Same precedence as | |
14403 | @code{++}. | |
14404 | ||
14405 | @item & | |
14406 | Address operator. Defined on variables. Same precedence as @code{++}. | |
14407 | ||
b37052ae EZ |
14408 | For debugging C@t{++}, @value{GDBN} implements a use of @samp{&} beyond what is |
14409 | allowed in the C@t{++} language itself: you can use @samp{&(&@var{ref})} | |
b17828ca | 14410 | to examine the address |
b37052ae | 14411 | where a C@t{++} reference variable (declared with @samp{&@var{ref}}) is |
c906108c | 14412 | stored. |
c906108c SS |
14413 | |
14414 | @item - | |
14415 | Negative. Defined on integral and floating-point types. Same | |
14416 | precedence as @code{++}. | |
14417 | ||
14418 | @item ! | |
14419 | Logical negation. Defined on integral types. Same precedence as | |
14420 | @code{++}. | |
14421 | ||
14422 | @item ~ | |
14423 | Bitwise complement operator. Defined on integral types. Same precedence as | |
14424 | @code{++}. | |
14425 | ||
14426 | ||
14427 | @item .@r{, }-> | |
14428 | Structure member, and pointer-to-structure member. For convenience, | |
14429 | @value{GDBN} regards the two as equivalent, choosing whether to dereference a | |
14430 | pointer based on the stored type information. | |
14431 | Defined on @code{struct} and @code{union} data. | |
14432 | ||
c906108c SS |
14433 | @item .*@r{, }->* |
14434 | Dereferences of pointers to members. | |
c906108c SS |
14435 | |
14436 | @item [] | |
14437 | Array indexing. @code{@var{a}[@var{i}]} is defined as | |
14438 | @code{*(@var{a}+@var{i})}. Same precedence as @code{->}. | |
14439 | ||
14440 | @item () | |
14441 | Function parameter list. Same precedence as @code{->}. | |
14442 | ||
c906108c | 14443 | @item :: |
b37052ae | 14444 | C@t{++} scope resolution operator. Defined on @code{struct}, @code{union}, |
7a292a7a | 14445 | and @code{class} types. |
c906108c SS |
14446 | |
14447 | @item :: | |
7a292a7a SS |
14448 | Doubled colons also represent the @value{GDBN} scope operator |
14449 | (@pxref{Expressions, ,Expressions}). Same precedence as @code{::}, | |
14450 | above. | |
c906108c SS |
14451 | @end table |
14452 | ||
c906108c SS |
14453 | If an operator is redefined in the user code, @value{GDBN} usually |
14454 | attempts to invoke the redefined version instead of using the operator's | |
14455 | predefined meaning. | |
c906108c | 14456 | |
6d2ebf8b | 14457 | @node C Constants |
79a6e687 | 14458 | @subsubsection C and C@t{++} Constants |
c906108c | 14459 | |
b37052ae | 14460 | @cindex C and C@t{++} constants |
c906108c | 14461 | |
b37052ae | 14462 | @value{GDBN} allows you to express the constants of C and C@t{++} in the |
c906108c | 14463 | following ways: |
c906108c SS |
14464 | |
14465 | @itemize @bullet | |
14466 | @item | |
14467 | Integer constants are a sequence of digits. Octal constants are | |
6ca652b0 EZ |
14468 | specified by a leading @samp{0} (i.e.@: zero), and hexadecimal constants |
14469 | by a leading @samp{0x} or @samp{0X}. Constants may also end with a letter | |
c906108c SS |
14470 | @samp{l}, specifying that the constant should be treated as a |
14471 | @code{long} value. | |
14472 | ||
14473 | @item | |
14474 | Floating point constants are a sequence of digits, followed by a decimal | |
14475 | point, followed by a sequence of digits, and optionally followed by an | |
14476 | exponent. An exponent is of the form: | |
14477 | @samp{@w{e@r{[[}+@r{]|}-@r{]}@var{nnn}}}, where @var{nnn} is another | |
14478 | sequence of digits. The @samp{+} is optional for positive exponents. | |
d4f3574e SS |
14479 | A floating-point constant may also end with a letter @samp{f} or |
14480 | @samp{F}, specifying that the constant should be treated as being of | |
14481 | the @code{float} (as opposed to the default @code{double}) type; or with | |
14482 | a letter @samp{l} or @samp{L}, which specifies a @code{long double} | |
14483 | constant. | |
c906108c SS |
14484 | |
14485 | @item | |
14486 | Enumerated constants consist of enumerated identifiers, or their | |
14487 | integral equivalents. | |
14488 | ||
14489 | @item | |
14490 | Character constants are a single character surrounded by single quotes | |
14491 | (@code{'}), or a number---the ordinal value of the corresponding character | |
d4f3574e | 14492 | (usually its @sc{ascii} value). Within quotes, the single character may |
c906108c SS |
14493 | be represented by a letter or by @dfn{escape sequences}, which are of |
14494 | the form @samp{\@var{nnn}}, where @var{nnn} is the octal representation | |
14495 | of the character's ordinal value; or of the form @samp{\@var{x}}, where | |
14496 | @samp{@var{x}} is a predefined special character---for example, | |
14497 | @samp{\n} for newline. | |
14498 | ||
e0f8f636 TT |
14499 | Wide character constants can be written by prefixing a character |
14500 | constant with @samp{L}, as in C. For example, @samp{L'x'} is the wide | |
14501 | form of @samp{x}. The target wide character set is used when | |
14502 | computing the value of this constant (@pxref{Character Sets}). | |
14503 | ||
c906108c | 14504 | @item |
96a2c332 SS |
14505 | String constants are a sequence of character constants surrounded by |
14506 | double quotes (@code{"}). Any valid character constant (as described | |
14507 | above) may appear. Double quotes within the string must be preceded by | |
14508 | a backslash, so for instance @samp{"a\"b'c"} is a string of five | |
14509 | characters. | |
c906108c | 14510 | |
e0f8f636 TT |
14511 | Wide string constants can be written by prefixing a string constant |
14512 | with @samp{L}, as in C. The target wide character set is used when | |
14513 | computing the value of this constant (@pxref{Character Sets}). | |
14514 | ||
c906108c SS |
14515 | @item |
14516 | Pointer constants are an integral value. You can also write pointers | |
14517 | to constants using the C operator @samp{&}. | |
14518 | ||
14519 | @item | |
14520 | Array constants are comma-separated lists surrounded by braces @samp{@{} | |
14521 | and @samp{@}}; for example, @samp{@{1,2,3@}} is a three-element array of | |
14522 | integers, @samp{@{@{1,2@}, @{3,4@}, @{5,6@}@}} is a three-by-two array, | |
14523 | and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers. | |
14524 | @end itemize | |
14525 | ||
79a6e687 BW |
14526 | @node C Plus Plus Expressions |
14527 | @subsubsection C@t{++} Expressions | |
b37052ae EZ |
14528 | |
14529 | @cindex expressions in C@t{++} | |
14530 | @value{GDBN} expression handling can interpret most C@t{++} expressions. | |
14531 | ||
0179ffac DC |
14532 | @cindex debugging C@t{++} programs |
14533 | @cindex C@t{++} compilers | |
14534 | @cindex debug formats and C@t{++} | |
14535 | @cindex @value{NGCC} and C@t{++} | |
c906108c | 14536 | @quotation |
e0f8f636 TT |
14537 | @emph{Warning:} @value{GDBN} can only debug C@t{++} code if you use |
14538 | the proper compiler and the proper debug format. Currently, | |
14539 | @value{GDBN} works best when debugging C@t{++} code that is compiled | |
14540 | with the most recent version of @value{NGCC} possible. The DWARF | |
14541 | debugging format is preferred; @value{NGCC} defaults to this on most | |
14542 | popular platforms. Other compilers and/or debug formats are likely to | |
14543 | work badly or not at all when using @value{GDBN} to debug C@t{++} | |
14544 | code. @xref{Compilation}. | |
c906108c | 14545 | @end quotation |
c906108c SS |
14546 | |
14547 | @enumerate | |
14548 | ||
14549 | @cindex member functions | |
14550 | @item | |
14551 | Member function calls are allowed; you can use expressions like | |
14552 | ||
474c8240 | 14553 | @smallexample |
c906108c | 14554 | count = aml->GetOriginal(x, y) |
474c8240 | 14555 | @end smallexample |
c906108c | 14556 | |
41afff9a | 14557 | @vindex this@r{, inside C@t{++} member functions} |
b37052ae | 14558 | @cindex namespace in C@t{++} |
c906108c SS |
14559 | @item |
14560 | While a member function is active (in the selected stack frame), your | |
14561 | expressions have the same namespace available as the member function; | |
14562 | that is, @value{GDBN} allows implicit references to the class instance | |
e0f8f636 TT |
14563 | pointer @code{this} following the same rules as C@t{++}. @code{using} |
14564 | declarations in the current scope are also respected by @value{GDBN}. | |
c906108c | 14565 | |
c906108c | 14566 | @cindex call overloaded functions |
d4f3574e | 14567 | @cindex overloaded functions, calling |
b37052ae | 14568 | @cindex type conversions in C@t{++} |
c906108c SS |
14569 | @item |
14570 | You can call overloaded functions; @value{GDBN} resolves the function | |
d4f3574e | 14571 | call to the right definition, with some restrictions. @value{GDBN} does not |
c906108c SS |
14572 | perform overload resolution involving user-defined type conversions, |
14573 | calls to constructors, or instantiations of templates that do not exist | |
14574 | in the program. It also cannot handle ellipsis argument lists or | |
14575 | default arguments. | |
14576 | ||
14577 | It does perform integral conversions and promotions, floating-point | |
14578 | promotions, arithmetic conversions, pointer conversions, conversions of | |
14579 | class objects to base classes, and standard conversions such as those of | |
14580 | functions or arrays to pointers; it requires an exact match on the | |
14581 | number of function arguments. | |
14582 | ||
14583 | Overload resolution is always performed, unless you have specified | |
79a6e687 BW |
14584 | @code{set overload-resolution off}. @xref{Debugging C Plus Plus, |
14585 | ,@value{GDBN} Features for C@t{++}}. | |
c906108c | 14586 | |
d4f3574e | 14587 | You must specify @code{set overload-resolution off} in order to use an |
c906108c SS |
14588 | explicit function signature to call an overloaded function, as in |
14589 | @smallexample | |
14590 | p 'foo(char,int)'('x', 13) | |
14591 | @end smallexample | |
d4f3574e | 14592 | |
c906108c | 14593 | The @value{GDBN} command-completion facility can simplify this; |
79a6e687 | 14594 | see @ref{Completion, ,Command Completion}. |
c906108c | 14595 | |
c906108c SS |
14596 | @cindex reference declarations |
14597 | @item | |
b37052ae EZ |
14598 | @value{GDBN} understands variables declared as C@t{++} references; you can use |
14599 | them in expressions just as you do in C@t{++} source---they are automatically | |
c906108c SS |
14600 | dereferenced. |
14601 | ||
14602 | In the parameter list shown when @value{GDBN} displays a frame, the values of | |
14603 | reference variables are not displayed (unlike other variables); this | |
14604 | avoids clutter, since references are often used for large structures. | |
14605 | The @emph{address} of a reference variable is always shown, unless | |
14606 | you have specified @samp{set print address off}. | |
14607 | ||
14608 | @item | |
b37052ae | 14609 | @value{GDBN} supports the C@t{++} name resolution operator @code{::}---your |
c906108c SS |
14610 | expressions can use it just as expressions in your program do. Since |
14611 | one scope may be defined in another, you can use @code{::} repeatedly if | |
14612 | necessary, for example in an expression like | |
14613 | @samp{@var{scope1}::@var{scope2}::@var{name}}. @value{GDBN} also allows | |
b37052ae | 14614 | resolving name scope by reference to source files, in both C and C@t{++} |
79a6e687 | 14615 | debugging (@pxref{Variables, ,Program Variables}). |
c906108c | 14616 | |
e0f8f636 TT |
14617 | @item |
14618 | @value{GDBN} performs argument-dependent lookup, following the C@t{++} | |
14619 | specification. | |
14620 | @end enumerate | |
c906108c | 14621 | |
6d2ebf8b | 14622 | @node C Defaults |
79a6e687 | 14623 | @subsubsection C and C@t{++} Defaults |
7a292a7a | 14624 | |
b37052ae | 14625 | @cindex C and C@t{++} defaults |
c906108c | 14626 | |
a451cb65 KS |
14627 | If you allow @value{GDBN} to set range checking automatically, it |
14628 | defaults to @code{off} whenever the working language changes to | |
b37052ae | 14629 | C or C@t{++}. This happens regardless of whether you or @value{GDBN} |
c906108c | 14630 | selects the working language. |
c906108c SS |
14631 | |
14632 | If you allow @value{GDBN} to set the language automatically, it | |
14633 | recognizes source files whose names end with @file{.c}, @file{.C}, or | |
14634 | @file{.cc}, etc, and when @value{GDBN} enters code compiled from one of | |
b37052ae | 14635 | these files, it sets the working language to C or C@t{++}. |
79a6e687 | 14636 | @xref{Automatically, ,Having @value{GDBN} Infer the Source Language}, |
c906108c SS |
14637 | for further details. |
14638 | ||
6d2ebf8b | 14639 | @node C Checks |
79a6e687 | 14640 | @subsubsection C and C@t{++} Type and Range Checks |
7a292a7a | 14641 | |
b37052ae | 14642 | @cindex C and C@t{++} checks |
c906108c | 14643 | |
a451cb65 KS |
14644 | By default, when @value{GDBN} parses C or C@t{++} expressions, strict type |
14645 | checking is used. However, if you turn type checking off, @value{GDBN} | |
14646 | will allow certain non-standard conversions, such as promoting integer | |
14647 | constants to pointers. | |
c906108c SS |
14648 | |
14649 | Range checking, if turned on, is done on mathematical operations. Array | |
14650 | indices are not checked, since they are often used to index a pointer | |
14651 | that is not itself an array. | |
c906108c | 14652 | |
6d2ebf8b | 14653 | @node Debugging C |
c906108c | 14654 | @subsubsection @value{GDBN} and C |
c906108c SS |
14655 | |
14656 | The @code{set print union} and @code{show print union} commands apply to | |
14657 | the @code{union} type. When set to @samp{on}, any @code{union} that is | |
7a292a7a SS |
14658 | inside a @code{struct} or @code{class} is also printed. Otherwise, it |
14659 | appears as @samp{@{...@}}. | |
c906108c SS |
14660 | |
14661 | The @code{@@} operator aids in the debugging of dynamic arrays, formed | |
14662 | with pointers and a memory allocation function. @xref{Expressions, | |
14663 | ,Expressions}. | |
14664 | ||
79a6e687 BW |
14665 | @node Debugging C Plus Plus |
14666 | @subsubsection @value{GDBN} Features for C@t{++} | |
c906108c | 14667 | |
b37052ae | 14668 | @cindex commands for C@t{++} |
7a292a7a | 14669 | |
b37052ae EZ |
14670 | Some @value{GDBN} commands are particularly useful with C@t{++}, and some are |
14671 | designed specifically for use with C@t{++}. Here is a summary: | |
c906108c SS |
14672 | |
14673 | @table @code | |
14674 | @cindex break in overloaded functions | |
14675 | @item @r{breakpoint menus} | |
14676 | When you want a breakpoint in a function whose name is overloaded, | |
6ba66d6a JB |
14677 | @value{GDBN} has the capability to display a menu of possible breakpoint |
14678 | locations to help you specify which function definition you want. | |
14679 | @xref{Ambiguous Expressions,,Ambiguous Expressions}. | |
c906108c | 14680 | |
b37052ae | 14681 | @cindex overloading in C@t{++} |
c906108c SS |
14682 | @item rbreak @var{regex} |
14683 | Setting breakpoints using regular expressions is helpful for setting | |
14684 | breakpoints on overloaded functions that are not members of any special | |
14685 | classes. | |
79a6e687 | 14686 | @xref{Set Breaks, ,Setting Breakpoints}. |
c906108c | 14687 | |
b37052ae | 14688 | @cindex C@t{++} exception handling |
c906108c | 14689 | @item catch throw |
591f19e8 | 14690 | @itemx catch rethrow |
c906108c | 14691 | @itemx catch catch |
b37052ae | 14692 | Debug C@t{++} exception handling using these commands. @xref{Set |
79a6e687 | 14693 | Catchpoints, , Setting Catchpoints}. |
c906108c SS |
14694 | |
14695 | @cindex inheritance | |
14696 | @item ptype @var{typename} | |
14697 | Print inheritance relationships as well as other information for type | |
14698 | @var{typename}. | |
14699 | @xref{Symbols, ,Examining the Symbol Table}. | |
14700 | ||
c4aeac85 TT |
14701 | @item info vtbl @var{expression}. |
14702 | The @code{info vtbl} command can be used to display the virtual | |
14703 | method tables of the object computed by @var{expression}. This shows | |
14704 | one entry per virtual table; there may be multiple virtual tables when | |
14705 | multiple inheritance is in use. | |
14706 | ||
439250fb DE |
14707 | @cindex C@t{++} demangling |
14708 | @item demangle @var{name} | |
14709 | Demangle @var{name}. | |
14710 | @xref{Symbols}, for a more complete description of the @code{demangle} command. | |
14711 | ||
b37052ae | 14712 | @cindex C@t{++} symbol display |
c906108c SS |
14713 | @item set print demangle |
14714 | @itemx show print demangle | |
14715 | @itemx set print asm-demangle | |
14716 | @itemx show print asm-demangle | |
b37052ae EZ |
14717 | Control whether C@t{++} symbols display in their source form, both when |
14718 | displaying code as C@t{++} source and when displaying disassemblies. | |
79a6e687 | 14719 | @xref{Print Settings, ,Print Settings}. |
c906108c SS |
14720 | |
14721 | @item set print object | |
14722 | @itemx show print object | |
14723 | Choose whether to print derived (actual) or declared types of objects. | |
79a6e687 | 14724 | @xref{Print Settings, ,Print Settings}. |
c906108c SS |
14725 | |
14726 | @item set print vtbl | |
14727 | @itemx show print vtbl | |
14728 | Control the format for printing virtual function tables. | |
79a6e687 | 14729 | @xref{Print Settings, ,Print Settings}. |
c906108c | 14730 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 14731 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
14732 | |
14733 | @kindex set overload-resolution | |
d4f3574e | 14734 | @cindex overloaded functions, overload resolution |
c906108c | 14735 | @item set overload-resolution on |
b37052ae | 14736 | Enable overload resolution for C@t{++} expression evaluation. The default |
c906108c SS |
14737 | is on. For overloaded functions, @value{GDBN} evaluates the arguments |
14738 | and searches for a function whose signature matches the argument types, | |
79a6e687 BW |
14739 | using the standard C@t{++} conversion rules (see @ref{C Plus Plus |
14740 | Expressions, ,C@t{++} Expressions}, for details). | |
14741 | If it cannot find a match, it emits a message. | |
c906108c SS |
14742 | |
14743 | @item set overload-resolution off | |
b37052ae | 14744 | Disable overload resolution for C@t{++} expression evaluation. For |
c906108c SS |
14745 | overloaded functions that are not class member functions, @value{GDBN} |
14746 | chooses the first function of the specified name that it finds in the | |
14747 | symbol table, whether or not its arguments are of the correct type. For | |
14748 | overloaded functions that are class member functions, @value{GDBN} | |
14749 | searches for a function whose signature @emph{exactly} matches the | |
14750 | argument types. | |
c906108c | 14751 | |
9c16f35a EZ |
14752 | @kindex show overload-resolution |
14753 | @item show overload-resolution | |
14754 | Show the current setting of overload resolution. | |
14755 | ||
c906108c SS |
14756 | @item @r{Overloaded symbol names} |
14757 | You can specify a particular definition of an overloaded symbol, using | |
b37052ae | 14758 | the same notation that is used to declare such symbols in C@t{++}: type |
c906108c SS |
14759 | @code{@var{symbol}(@var{types})} rather than just @var{symbol}. You can |
14760 | also use the @value{GDBN} command-line word completion facilities to list the | |
14761 | available choices, or to finish the type list for you. | |
79a6e687 | 14762 | @xref{Completion,, Command Completion}, for details on how to do this. |
c906108c | 14763 | @end table |
c906108c | 14764 | |
febe4383 TJB |
14765 | @node Decimal Floating Point |
14766 | @subsubsection Decimal Floating Point format | |
14767 | @cindex decimal floating point format | |
14768 | ||
14769 | @value{GDBN} can examine, set and perform computations with numbers in | |
14770 | decimal floating point format, which in the C language correspond to the | |
14771 | @code{_Decimal32}, @code{_Decimal64} and @code{_Decimal128} types as | |
14772 | specified by the extension to support decimal floating-point arithmetic. | |
14773 | ||
14774 | There are two encodings in use, depending on the architecture: BID (Binary | |
14775 | Integer Decimal) for x86 and x86-64, and DPD (Densely Packed Decimal) for | |
4ac33720 UW |
14776 | PowerPC and S/390. @value{GDBN} will use the appropriate encoding for the |
14777 | configured target. | |
febe4383 TJB |
14778 | |
14779 | Because of a limitation in @file{libdecnumber}, the library used by @value{GDBN} | |
14780 | to manipulate decimal floating point numbers, it is not possible to convert | |
14781 | (using a cast, for example) integers wider than 32-bit to decimal float. | |
14782 | ||
14783 | In addition, in order to imitate @value{GDBN}'s behaviour with binary floating | |
14784 | point computations, error checking in decimal float operations ignores | |
14785 | underflow, overflow and divide by zero exceptions. | |
14786 | ||
4acd40f3 | 14787 | In the PowerPC architecture, @value{GDBN} provides a set of pseudo-registers |
99e008fe EZ |
14788 | to inspect @code{_Decimal128} values stored in floating point registers. |
14789 | See @ref{PowerPC,,PowerPC} for more details. | |
4acd40f3 | 14790 | |
6aecb9c2 JB |
14791 | @node D |
14792 | @subsection D | |
14793 | ||
14794 | @cindex D | |
14795 | @value{GDBN} can be used to debug programs written in D and compiled with | |
14796 | GDC, LDC or DMD compilers. Currently @value{GDBN} supports only one D | |
14797 | specific feature --- dynamic arrays. | |
14798 | ||
a766d390 DE |
14799 | @node Go |
14800 | @subsection Go | |
14801 | ||
14802 | @cindex Go (programming language) | |
14803 | @value{GDBN} can be used to debug programs written in Go and compiled with | |
14804 | @file{gccgo} or @file{6g} compilers. | |
14805 | ||
14806 | Here is a summary of the Go-specific features and restrictions: | |
14807 | ||
14808 | @table @code | |
14809 | @cindex current Go package | |
14810 | @item The current Go package | |
14811 | The name of the current package does not need to be specified when | |
14812 | specifying global variables and functions. | |
14813 | ||
14814 | For example, given the program: | |
14815 | ||
14816 | @example | |
14817 | package main | |
14818 | var myglob = "Shall we?" | |
14819 | func main () @{ | |
14820 | // ... | |
14821 | @} | |
14822 | @end example | |
14823 | ||
14824 | When stopped inside @code{main} either of these work: | |
14825 | ||
14826 | @example | |
14827 | (gdb) p myglob | |
14828 | (gdb) p main.myglob | |
14829 | @end example | |
14830 | ||
14831 | @cindex builtin Go types | |
14832 | @item Builtin Go types | |
14833 | The @code{string} type is recognized by @value{GDBN} and is printed | |
14834 | as a string. | |
14835 | ||
14836 | @cindex builtin Go functions | |
14837 | @item Builtin Go functions | |
14838 | The @value{GDBN} expression parser recognizes the @code{unsafe.Sizeof} | |
14839 | function and handles it internally. | |
a766d390 DE |
14840 | |
14841 | @cindex restrictions on Go expressions | |
14842 | @item Restrictions on Go expressions | |
14843 | All Go operators are supported except @code{&^}. | |
14844 | The Go @code{_} ``blank identifier'' is not supported. | |
14845 | Automatic dereferencing of pointers is not supported. | |
50f042b9 | 14846 | @end table |
a766d390 | 14847 | |
b37303ee AF |
14848 | @node Objective-C |
14849 | @subsection Objective-C | |
14850 | ||
14851 | @cindex Objective-C | |
14852 | This section provides information about some commands and command | |
721c2651 EZ |
14853 | options that are useful for debugging Objective-C code. See also |
14854 | @ref{Symbols, info classes}, and @ref{Symbols, info selectors}, for a | |
14855 | few more commands specific to Objective-C support. | |
b37303ee AF |
14856 | |
14857 | @menu | |
b383017d RM |
14858 | * Method Names in Commands:: |
14859 | * The Print Command with Objective-C:: | |
b37303ee AF |
14860 | @end menu |
14861 | ||
c8f4133a | 14862 | @node Method Names in Commands |
b37303ee AF |
14863 | @subsubsection Method Names in Commands |
14864 | ||
14865 | The following commands have been extended to accept Objective-C method | |
14866 | names as line specifications: | |
14867 | ||
14868 | @kindex clear@r{, and Objective-C} | |
14869 | @kindex break@r{, and Objective-C} | |
14870 | @kindex info line@r{, and Objective-C} | |
14871 | @kindex jump@r{, and Objective-C} | |
14872 | @kindex list@r{, and Objective-C} | |
14873 | @itemize | |
14874 | @item @code{clear} | |
14875 | @item @code{break} | |
14876 | @item @code{info line} | |
14877 | @item @code{jump} | |
14878 | @item @code{list} | |
14879 | @end itemize | |
14880 | ||
14881 | A fully qualified Objective-C method name is specified as | |
14882 | ||
14883 | @smallexample | |
14884 | -[@var{Class} @var{methodName}] | |
14885 | @end smallexample | |
14886 | ||
c552b3bb JM |
14887 | where the minus sign is used to indicate an instance method and a |
14888 | plus sign (not shown) is used to indicate a class method. The class | |
14889 | name @var{Class} and method name @var{methodName} are enclosed in | |
14890 | brackets, similar to the way messages are specified in Objective-C | |
14891 | source code. For example, to set a breakpoint at the @code{create} | |
14892 | instance method of class @code{Fruit} in the program currently being | |
14893 | debugged, enter: | |
b37303ee AF |
14894 | |
14895 | @smallexample | |
14896 | break -[Fruit create] | |
14897 | @end smallexample | |
14898 | ||
14899 | To list ten program lines around the @code{initialize} class method, | |
14900 | enter: | |
14901 | ||
14902 | @smallexample | |
14903 | list +[NSText initialize] | |
14904 | @end smallexample | |
14905 | ||
c552b3bb JM |
14906 | In the current version of @value{GDBN}, the plus or minus sign is |
14907 | required. In future versions of @value{GDBN}, the plus or minus | |
14908 | sign will be optional, but you can use it to narrow the search. It | |
14909 | is also possible to specify just a method name: | |
b37303ee AF |
14910 | |
14911 | @smallexample | |
14912 | break create | |
14913 | @end smallexample | |
14914 | ||
14915 | You must specify the complete method name, including any colons. If | |
14916 | your program's source files contain more than one @code{create} method, | |
14917 | you'll be presented with a numbered list of classes that implement that | |
14918 | method. Indicate your choice by number, or type @samp{0} to exit if | |
14919 | none apply. | |
14920 | ||
14921 | As another example, to clear a breakpoint established at the | |
14922 | @code{makeKeyAndOrderFront:} method of the @code{NSWindow} class, enter: | |
14923 | ||
14924 | @smallexample | |
14925 | clear -[NSWindow makeKeyAndOrderFront:] | |
14926 | @end smallexample | |
14927 | ||
14928 | @node The Print Command with Objective-C | |
14929 | @subsubsection The Print Command With Objective-C | |
721c2651 | 14930 | @cindex Objective-C, print objects |
c552b3bb JM |
14931 | @kindex print-object |
14932 | @kindex po @r{(@code{print-object})} | |
b37303ee | 14933 | |
c552b3bb | 14934 | The print command has also been extended to accept methods. For example: |
b37303ee AF |
14935 | |
14936 | @smallexample | |
c552b3bb | 14937 | print -[@var{object} hash] |
b37303ee AF |
14938 | @end smallexample |
14939 | ||
14940 | @cindex print an Objective-C object description | |
c552b3bb JM |
14941 | @cindex @code{_NSPrintForDebugger}, and printing Objective-C objects |
14942 | @noindent | |
14943 | will tell @value{GDBN} to send the @code{hash} message to @var{object} | |
14944 | and print the result. Also, an additional command has been added, | |
14945 | @code{print-object} or @code{po} for short, which is meant to print | |
14946 | the description of an object. However, this command may only work | |
14947 | with certain Objective-C libraries that have a particular hook | |
14948 | function, @code{_NSPrintForDebugger}, defined. | |
b37303ee | 14949 | |
f4b8a18d KW |
14950 | @node OpenCL C |
14951 | @subsection OpenCL C | |
14952 | ||
14953 | @cindex OpenCL C | |
14954 | This section provides information about @value{GDBN}s OpenCL C support. | |
14955 | ||
14956 | @menu | |
14957 | * OpenCL C Datatypes:: | |
14958 | * OpenCL C Expressions:: | |
14959 | * OpenCL C Operators:: | |
14960 | @end menu | |
14961 | ||
14962 | @node OpenCL C Datatypes | |
14963 | @subsubsection OpenCL C Datatypes | |
14964 | ||
14965 | @cindex OpenCL C Datatypes | |
14966 | @value{GDBN} supports the builtin scalar and vector datatypes specified | |
14967 | by OpenCL 1.1. In addition the half- and double-precision floating point | |
14968 | data types of the @code{cl_khr_fp16} and @code{cl_khr_fp64} OpenCL | |
14969 | extensions are also known to @value{GDBN}. | |
14970 | ||
14971 | @node OpenCL C Expressions | |
14972 | @subsubsection OpenCL C Expressions | |
14973 | ||
14974 | @cindex OpenCL C Expressions | |
14975 | @value{GDBN} supports accesses to vector components including the access as | |
14976 | lvalue where possible. Since OpenCL C is based on C99 most C expressions | |
14977 | supported by @value{GDBN} can be used as well. | |
14978 | ||
14979 | @node OpenCL C Operators | |
14980 | @subsubsection OpenCL C Operators | |
14981 | ||
14982 | @cindex OpenCL C Operators | |
14983 | @value{GDBN} supports the operators specified by OpenCL 1.1 for scalar and | |
14984 | vector data types. | |
14985 | ||
09d4efe1 EZ |
14986 | @node Fortran |
14987 | @subsection Fortran | |
14988 | @cindex Fortran-specific support in @value{GDBN} | |
14989 | ||
814e32d7 WZ |
14990 | @value{GDBN} can be used to debug programs written in Fortran, but it |
14991 | currently supports only the features of Fortran 77 language. | |
14992 | ||
14993 | @cindex trailing underscore, in Fortran symbols | |
14994 | Some Fortran compilers (@sc{gnu} Fortran 77 and Fortran 95 compilers | |
14995 | among them) append an underscore to the names of variables and | |
14996 | functions. When you debug programs compiled by those compilers, you | |
14997 | will need to refer to variables and functions with a trailing | |
14998 | underscore. | |
14999 | ||
15000 | @menu | |
15001 | * Fortran Operators:: Fortran operators and expressions | |
15002 | * Fortran Defaults:: Default settings for Fortran | |
79a6e687 | 15003 | * Special Fortran Commands:: Special @value{GDBN} commands for Fortran |
814e32d7 WZ |
15004 | @end menu |
15005 | ||
15006 | @node Fortran Operators | |
79a6e687 | 15007 | @subsubsection Fortran Operators and Expressions |
814e32d7 WZ |
15008 | |
15009 | @cindex Fortran operators and expressions | |
15010 | ||
15011 | Operators must be defined on values of specific types. For instance, | |
15012 | @code{+} is defined on numbers, but not on characters or other non- | |
ff2587ec | 15013 | arithmetic types. Operators are often defined on groups of types. |
814e32d7 WZ |
15014 | |
15015 | @table @code | |
15016 | @item ** | |
99e008fe | 15017 | The exponentiation operator. It raises the first operand to the power |
814e32d7 WZ |
15018 | of the second one. |
15019 | ||
15020 | @item : | |
15021 | The range operator. Normally used in the form of array(low:high) to | |
15022 | represent a section of array. | |
68837c9d MD |
15023 | |
15024 | @item % | |
15025 | The access component operator. Normally used to access elements in derived | |
15026 | types. Also suitable for unions. As unions aren't part of regular Fortran, | |
15027 | this can only happen when accessing a register that uses a gdbarch-defined | |
15028 | union type. | |
814e32d7 WZ |
15029 | @end table |
15030 | ||
15031 | @node Fortran Defaults | |
15032 | @subsubsection Fortran Defaults | |
15033 | ||
15034 | @cindex Fortran Defaults | |
15035 | ||
15036 | Fortran symbols are usually case-insensitive, so @value{GDBN} by | |
15037 | default uses case-insensitive matches for Fortran symbols. You can | |
15038 | change that with the @samp{set case-insensitive} command, see | |
15039 | @ref{Symbols}, for the details. | |
15040 | ||
79a6e687 BW |
15041 | @node Special Fortran Commands |
15042 | @subsubsection Special Fortran Commands | |
814e32d7 WZ |
15043 | |
15044 | @cindex Special Fortran commands | |
15045 | ||
db2e3e2e BW |
15046 | @value{GDBN} has some commands to support Fortran-specific features, |
15047 | such as displaying common blocks. | |
814e32d7 | 15048 | |
09d4efe1 EZ |
15049 | @table @code |
15050 | @cindex @code{COMMON} blocks, Fortran | |
15051 | @kindex info common | |
15052 | @item info common @r{[}@var{common-name}@r{]} | |
15053 | This command prints the values contained in the Fortran @code{COMMON} | |
15054 | block whose name is @var{common-name}. With no argument, the names of | |
d52fb0e9 | 15055 | all @code{COMMON} blocks visible at the current program location are |
09d4efe1 EZ |
15056 | printed. |
15057 | @end table | |
15058 | ||
9c16f35a EZ |
15059 | @node Pascal |
15060 | @subsection Pascal | |
15061 | ||
15062 | @cindex Pascal support in @value{GDBN}, limitations | |
15063 | Debugging Pascal programs which use sets, subranges, file variables, or | |
15064 | nested functions does not currently work. @value{GDBN} does not support | |
15065 | entering expressions, printing values, or similar features using Pascal | |
15066 | syntax. | |
15067 | ||
15068 | The Pascal-specific command @code{set print pascal_static-members} | |
15069 | controls whether static members of Pascal objects are displayed. | |
15070 | @xref{Print Settings, pascal_static-members}. | |
15071 | ||
09d4efe1 | 15072 | @node Modula-2 |
c906108c | 15073 | @subsection Modula-2 |
7a292a7a | 15074 | |
d4f3574e | 15075 | @cindex Modula-2, @value{GDBN} support |
c906108c SS |
15076 | |
15077 | The extensions made to @value{GDBN} to support Modula-2 only support | |
15078 | output from the @sc{gnu} Modula-2 compiler (which is currently being | |
15079 | developed). Other Modula-2 compilers are not currently supported, and | |
15080 | attempting to debug executables produced by them is most likely | |
15081 | to give an error as @value{GDBN} reads in the executable's symbol | |
15082 | table. | |
15083 | ||
15084 | @cindex expressions in Modula-2 | |
15085 | @menu | |
15086 | * M2 Operators:: Built-in operators | |
15087 | * Built-In Func/Proc:: Built-in functions and procedures | |
15088 | * M2 Constants:: Modula-2 constants | |
72019c9c | 15089 | * M2 Types:: Modula-2 types |
c906108c SS |
15090 | * M2 Defaults:: Default settings for Modula-2 |
15091 | * Deviations:: Deviations from standard Modula-2 | |
15092 | * M2 Checks:: Modula-2 type and range checks | |
15093 | * M2 Scope:: The scope operators @code{::} and @code{.} | |
15094 | * GDB/M2:: @value{GDBN} and Modula-2 | |
15095 | @end menu | |
15096 | ||
6d2ebf8b | 15097 | @node M2 Operators |
c906108c SS |
15098 | @subsubsection Operators |
15099 | @cindex Modula-2 operators | |
15100 | ||
15101 | Operators must be defined on values of specific types. For instance, | |
15102 | @code{+} is defined on numbers, but not on structures. Operators are | |
15103 | often defined on groups of types. For the purposes of Modula-2, the | |
15104 | following definitions hold: | |
15105 | ||
15106 | @itemize @bullet | |
15107 | ||
15108 | @item | |
15109 | @emph{Integral types} consist of @code{INTEGER}, @code{CARDINAL}, and | |
15110 | their subranges. | |
15111 | ||
15112 | @item | |
15113 | @emph{Character types} consist of @code{CHAR} and its subranges. | |
15114 | ||
15115 | @item | |
15116 | @emph{Floating-point types} consist of @code{REAL}. | |
15117 | ||
15118 | @item | |
15119 | @emph{Pointer types} consist of anything declared as @code{POINTER TO | |
15120 | @var{type}}. | |
15121 | ||
15122 | @item | |
15123 | @emph{Scalar types} consist of all of the above. | |
15124 | ||
15125 | @item | |
15126 | @emph{Set types} consist of @code{SET} and @code{BITSET} types. | |
15127 | ||
15128 | @item | |
15129 | @emph{Boolean types} consist of @code{BOOLEAN}. | |
15130 | @end itemize | |
15131 | ||
15132 | @noindent | |
15133 | The following operators are supported, and appear in order of | |
15134 | increasing precedence: | |
15135 | ||
15136 | @table @code | |
15137 | @item , | |
15138 | Function argument or array index separator. | |
15139 | ||
15140 | @item := | |
15141 | Assignment. The value of @var{var} @code{:=} @var{value} is | |
15142 | @var{value}. | |
15143 | ||
15144 | @item <@r{, }> | |
15145 | Less than, greater than on integral, floating-point, or enumerated | |
15146 | types. | |
15147 | ||
15148 | @item <=@r{, }>= | |
96a2c332 | 15149 | Less than or equal to, greater than or equal to |
c906108c SS |
15150 | on integral, floating-point and enumerated types, or set inclusion on |
15151 | set types. Same precedence as @code{<}. | |
15152 | ||
15153 | @item =@r{, }<>@r{, }# | |
15154 | Equality and two ways of expressing inequality, valid on scalar types. | |
15155 | Same precedence as @code{<}. In @value{GDBN} scripts, only @code{<>} is | |
15156 | available for inequality, since @code{#} conflicts with the script | |
15157 | comment character. | |
15158 | ||
15159 | @item IN | |
15160 | Set membership. Defined on set types and the types of their members. | |
15161 | Same precedence as @code{<}. | |
15162 | ||
15163 | @item OR | |
15164 | Boolean disjunction. Defined on boolean types. | |
15165 | ||
15166 | @item AND@r{, }& | |
d4f3574e | 15167 | Boolean conjunction. Defined on boolean types. |
c906108c SS |
15168 | |
15169 | @item @@ | |
15170 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
15171 | ||
15172 | @item +@r{, }- | |
15173 | Addition and subtraction on integral and floating-point types, or union | |
15174 | and difference on set types. | |
15175 | ||
15176 | @item * | |
15177 | Multiplication on integral and floating-point types, or set intersection | |
15178 | on set types. | |
15179 | ||
15180 | @item / | |
15181 | Division on floating-point types, or symmetric set difference on set | |
15182 | types. Same precedence as @code{*}. | |
15183 | ||
15184 | @item DIV@r{, }MOD | |
15185 | Integer division and remainder. Defined on integral types. Same | |
15186 | precedence as @code{*}. | |
15187 | ||
15188 | @item - | |
99e008fe | 15189 | Negative. Defined on @code{INTEGER} and @code{REAL} data. |
c906108c SS |
15190 | |
15191 | @item ^ | |
15192 | Pointer dereferencing. Defined on pointer types. | |
15193 | ||
15194 | @item NOT | |
15195 | Boolean negation. Defined on boolean types. Same precedence as | |
15196 | @code{^}. | |
15197 | ||
15198 | @item . | |
15199 | @code{RECORD} field selector. Defined on @code{RECORD} data. Same | |
15200 | precedence as @code{^}. | |
15201 | ||
15202 | @item [] | |
15203 | Array indexing. Defined on @code{ARRAY} data. Same precedence as @code{^}. | |
15204 | ||
15205 | @item () | |
15206 | Procedure argument list. Defined on @code{PROCEDURE} objects. Same precedence | |
15207 | as @code{^}. | |
15208 | ||
15209 | @item ::@r{, }. | |
15210 | @value{GDBN} and Modula-2 scope operators. | |
15211 | @end table | |
15212 | ||
15213 | @quotation | |
72019c9c | 15214 | @emph{Warning:} Set expressions and their operations are not yet supported, so @value{GDBN} |
c906108c SS |
15215 | treats the use of the operator @code{IN}, or the use of operators |
15216 | @code{+}, @code{-}, @code{*}, @code{/}, @code{=}, , @code{<>}, @code{#}, | |
15217 | @code{<=}, and @code{>=} on sets as an error. | |
15218 | @end quotation | |
15219 | ||
cb51c4e0 | 15220 | |
6d2ebf8b | 15221 | @node Built-In Func/Proc |
79a6e687 | 15222 | @subsubsection Built-in Functions and Procedures |
cb51c4e0 | 15223 | @cindex Modula-2 built-ins |
c906108c SS |
15224 | |
15225 | Modula-2 also makes available several built-in procedures and functions. | |
15226 | In describing these, the following metavariables are used: | |
15227 | ||
15228 | @table @var | |
15229 | ||
15230 | @item a | |
15231 | represents an @code{ARRAY} variable. | |
15232 | ||
15233 | @item c | |
15234 | represents a @code{CHAR} constant or variable. | |
15235 | ||
15236 | @item i | |
15237 | represents a variable or constant of integral type. | |
15238 | ||
15239 | @item m | |
15240 | represents an identifier that belongs to a set. Generally used in the | |
15241 | same function with the metavariable @var{s}. The type of @var{s} should | |
15242 | be @code{SET OF @var{mtype}} (where @var{mtype} is the type of @var{m}). | |
15243 | ||
15244 | @item n | |
15245 | represents a variable or constant of integral or floating-point type. | |
15246 | ||
15247 | @item r | |
15248 | represents a variable or constant of floating-point type. | |
15249 | ||
15250 | @item t | |
15251 | represents a type. | |
15252 | ||
15253 | @item v | |
15254 | represents a variable. | |
15255 | ||
15256 | @item x | |
15257 | represents a variable or constant of one of many types. See the | |
15258 | explanation of the function for details. | |
15259 | @end table | |
15260 | ||
15261 | All Modula-2 built-in procedures also return a result, described below. | |
15262 | ||
15263 | @table @code | |
15264 | @item ABS(@var{n}) | |
15265 | Returns the absolute value of @var{n}. | |
15266 | ||
15267 | @item CAP(@var{c}) | |
15268 | If @var{c} is a lower case letter, it returns its upper case | |
c3f6f71d | 15269 | equivalent, otherwise it returns its argument. |
c906108c SS |
15270 | |
15271 | @item CHR(@var{i}) | |
15272 | Returns the character whose ordinal value is @var{i}. | |
15273 | ||
15274 | @item DEC(@var{v}) | |
c3f6f71d | 15275 | Decrements the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
15276 | |
15277 | @item DEC(@var{v},@var{i}) | |
15278 | Decrements the value in the variable @var{v} by @var{i}. Returns the | |
15279 | new value. | |
15280 | ||
15281 | @item EXCL(@var{m},@var{s}) | |
15282 | Removes the element @var{m} from the set @var{s}. Returns the new | |
15283 | set. | |
15284 | ||
15285 | @item FLOAT(@var{i}) | |
15286 | Returns the floating point equivalent of the integer @var{i}. | |
15287 | ||
15288 | @item HIGH(@var{a}) | |
15289 | Returns the index of the last member of @var{a}. | |
15290 | ||
15291 | @item INC(@var{v}) | |
c3f6f71d | 15292 | Increments the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
15293 | |
15294 | @item INC(@var{v},@var{i}) | |
15295 | Increments the value in the variable @var{v} by @var{i}. Returns the | |
15296 | new value. | |
15297 | ||
15298 | @item INCL(@var{m},@var{s}) | |
15299 | Adds the element @var{m} to the set @var{s} if it is not already | |
15300 | there. Returns the new set. | |
15301 | ||
15302 | @item MAX(@var{t}) | |
15303 | Returns the maximum value of the type @var{t}. | |
15304 | ||
15305 | @item MIN(@var{t}) | |
15306 | Returns the minimum value of the type @var{t}. | |
15307 | ||
15308 | @item ODD(@var{i}) | |
15309 | Returns boolean TRUE if @var{i} is an odd number. | |
15310 | ||
15311 | @item ORD(@var{x}) | |
15312 | Returns the ordinal value of its argument. For example, the ordinal | |
697aa1b7 EZ |
15313 | value of a character is its @sc{ascii} value (on machines supporting |
15314 | the @sc{ascii} character set). The argument @var{x} must be of an | |
15315 | ordered type, which include integral, character and enumerated types. | |
c906108c SS |
15316 | |
15317 | @item SIZE(@var{x}) | |
697aa1b7 EZ |
15318 | Returns the size of its argument. The argument @var{x} can be a |
15319 | variable or a type. | |
c906108c SS |
15320 | |
15321 | @item TRUNC(@var{r}) | |
15322 | Returns the integral part of @var{r}. | |
15323 | ||
844781a1 | 15324 | @item TSIZE(@var{x}) |
697aa1b7 EZ |
15325 | Returns the size of its argument. The argument @var{x} can be a |
15326 | variable or a type. | |
844781a1 | 15327 | |
c906108c SS |
15328 | @item VAL(@var{t},@var{i}) |
15329 | Returns the member of the type @var{t} whose ordinal value is @var{i}. | |
15330 | @end table | |
15331 | ||
15332 | @quotation | |
15333 | @emph{Warning:} Sets and their operations are not yet supported, so | |
15334 | @value{GDBN} treats the use of procedures @code{INCL} and @code{EXCL} as | |
15335 | an error. | |
15336 | @end quotation | |
15337 | ||
15338 | @cindex Modula-2 constants | |
6d2ebf8b | 15339 | @node M2 Constants |
c906108c SS |
15340 | @subsubsection Constants |
15341 | ||
15342 | @value{GDBN} allows you to express the constants of Modula-2 in the following | |
15343 | ways: | |
15344 | ||
15345 | @itemize @bullet | |
15346 | ||
15347 | @item | |
15348 | Integer constants are simply a sequence of digits. When used in an | |
15349 | expression, a constant is interpreted to be type-compatible with the | |
15350 | rest of the expression. Hexadecimal integers are specified by a | |
15351 | trailing @samp{H}, and octal integers by a trailing @samp{B}. | |
15352 | ||
15353 | @item | |
15354 | Floating point constants appear as a sequence of digits, followed by a | |
15355 | decimal point and another sequence of digits. An optional exponent can | |
15356 | then be specified, in the form @samp{E@r{[}+@r{|}-@r{]}@var{nnn}}, where | |
15357 | @samp{@r{[}+@r{|}-@r{]}@var{nnn}} is the desired exponent. All of the | |
15358 | digits of the floating point constant must be valid decimal (base 10) | |
15359 | digits. | |
15360 | ||
15361 | @item | |
15362 | Character constants consist of a single character enclosed by a pair of | |
15363 | like quotes, either single (@code{'}) or double (@code{"}). They may | |
c3f6f71d | 15364 | also be expressed by their ordinal value (their @sc{ascii} value, usually) |
c906108c SS |
15365 | followed by a @samp{C}. |
15366 | ||
15367 | @item | |
15368 | String constants consist of a sequence of characters enclosed by a | |
15369 | pair of like quotes, either single (@code{'}) or double (@code{"}). | |
15370 | Escape sequences in the style of C are also allowed. @xref{C | |
79a6e687 | 15371 | Constants, ,C and C@t{++} Constants}, for a brief explanation of escape |
c906108c SS |
15372 | sequences. |
15373 | ||
15374 | @item | |
15375 | Enumerated constants consist of an enumerated identifier. | |
15376 | ||
15377 | @item | |
15378 | Boolean constants consist of the identifiers @code{TRUE} and | |
15379 | @code{FALSE}. | |
15380 | ||
15381 | @item | |
15382 | Pointer constants consist of integral values only. | |
15383 | ||
15384 | @item | |
15385 | Set constants are not yet supported. | |
15386 | @end itemize | |
15387 | ||
72019c9c GM |
15388 | @node M2 Types |
15389 | @subsubsection Modula-2 Types | |
15390 | @cindex Modula-2 types | |
15391 | ||
15392 | Currently @value{GDBN} can print the following data types in Modula-2 | |
15393 | syntax: array types, record types, set types, pointer types, procedure | |
15394 | types, enumerated types, subrange types and base types. You can also | |
15395 | print the contents of variables declared using these type. | |
15396 | This section gives a number of simple source code examples together with | |
15397 | sample @value{GDBN} sessions. | |
15398 | ||
15399 | The first example contains the following section of code: | |
15400 | ||
15401 | @smallexample | |
15402 | VAR | |
15403 | s: SET OF CHAR ; | |
15404 | r: [20..40] ; | |
15405 | @end smallexample | |
15406 | ||
15407 | @noindent | |
15408 | and you can request @value{GDBN} to interrogate the type and value of | |
15409 | @code{r} and @code{s}. | |
15410 | ||
15411 | @smallexample | |
15412 | (@value{GDBP}) print s | |
15413 | @{'A'..'C', 'Z'@} | |
15414 | (@value{GDBP}) ptype s | |
15415 | SET OF CHAR | |
15416 | (@value{GDBP}) print r | |
15417 | 21 | |
15418 | (@value{GDBP}) ptype r | |
15419 | [20..40] | |
15420 | @end smallexample | |
15421 | ||
15422 | @noindent | |
15423 | Likewise if your source code declares @code{s} as: | |
15424 | ||
15425 | @smallexample | |
15426 | VAR | |
15427 | s: SET ['A'..'Z'] ; | |
15428 | @end smallexample | |
15429 | ||
15430 | @noindent | |
15431 | then you may query the type of @code{s} by: | |
15432 | ||
15433 | @smallexample | |
15434 | (@value{GDBP}) ptype s | |
15435 | type = SET ['A'..'Z'] | |
15436 | @end smallexample | |
15437 | ||
15438 | @noindent | |
15439 | Note that at present you cannot interactively manipulate set | |
15440 | expressions using the debugger. | |
15441 | ||
15442 | The following example shows how you might declare an array in Modula-2 | |
15443 | and how you can interact with @value{GDBN} to print its type and contents: | |
15444 | ||
15445 | @smallexample | |
15446 | VAR | |
15447 | s: ARRAY [-10..10] OF CHAR ; | |
15448 | @end smallexample | |
15449 | ||
15450 | @smallexample | |
15451 | (@value{GDBP}) ptype s | |
15452 | ARRAY [-10..10] OF CHAR | |
15453 | @end smallexample | |
15454 | ||
15455 | Note that the array handling is not yet complete and although the type | |
15456 | is printed correctly, expression handling still assumes that all | |
15457 | arrays have a lower bound of zero and not @code{-10} as in the example | |
844781a1 | 15458 | above. |
72019c9c GM |
15459 | |
15460 | Here are some more type related Modula-2 examples: | |
15461 | ||
15462 | @smallexample | |
15463 | TYPE | |
15464 | colour = (blue, red, yellow, green) ; | |
15465 | t = [blue..yellow] ; | |
15466 | VAR | |
15467 | s: t ; | |
15468 | BEGIN | |
15469 | s := blue ; | |
15470 | @end smallexample | |
15471 | ||
15472 | @noindent | |
15473 | The @value{GDBN} interaction shows how you can query the data type | |
15474 | and value of a variable. | |
15475 | ||
15476 | @smallexample | |
15477 | (@value{GDBP}) print s | |
15478 | $1 = blue | |
15479 | (@value{GDBP}) ptype t | |
15480 | type = [blue..yellow] | |
15481 | @end smallexample | |
15482 | ||
15483 | @noindent | |
15484 | In this example a Modula-2 array is declared and its contents | |
15485 | displayed. Observe that the contents are written in the same way as | |
15486 | their @code{C} counterparts. | |
15487 | ||
15488 | @smallexample | |
15489 | VAR | |
15490 | s: ARRAY [1..5] OF CARDINAL ; | |
15491 | BEGIN | |
15492 | s[1] := 1 ; | |
15493 | @end smallexample | |
15494 | ||
15495 | @smallexample | |
15496 | (@value{GDBP}) print s | |
15497 | $1 = @{1, 0, 0, 0, 0@} | |
15498 | (@value{GDBP}) ptype s | |
15499 | type = ARRAY [1..5] OF CARDINAL | |
15500 | @end smallexample | |
15501 | ||
15502 | The Modula-2 language interface to @value{GDBN} also understands | |
15503 | pointer types as shown in this example: | |
15504 | ||
15505 | @smallexample | |
15506 | VAR | |
15507 | s: POINTER TO ARRAY [1..5] OF CARDINAL ; | |
15508 | BEGIN | |
15509 | NEW(s) ; | |
15510 | s^[1] := 1 ; | |
15511 | @end smallexample | |
15512 | ||
15513 | @noindent | |
15514 | and you can request that @value{GDBN} describes the type of @code{s}. | |
15515 | ||
15516 | @smallexample | |
15517 | (@value{GDBP}) ptype s | |
15518 | type = POINTER TO ARRAY [1..5] OF CARDINAL | |
15519 | @end smallexample | |
15520 | ||
15521 | @value{GDBN} handles compound types as we can see in this example. | |
15522 | Here we combine array types, record types, pointer types and subrange | |
15523 | types: | |
15524 | ||
15525 | @smallexample | |
15526 | TYPE | |
15527 | foo = RECORD | |
15528 | f1: CARDINAL ; | |
15529 | f2: CHAR ; | |
15530 | f3: myarray ; | |
15531 | END ; | |
15532 | ||
15533 | myarray = ARRAY myrange OF CARDINAL ; | |
15534 | myrange = [-2..2] ; | |
15535 | VAR | |
15536 | s: POINTER TO ARRAY myrange OF foo ; | |
15537 | @end smallexample | |
15538 | ||
15539 | @noindent | |
15540 | and you can ask @value{GDBN} to describe the type of @code{s} as shown | |
15541 | below. | |
15542 | ||
15543 | @smallexample | |
15544 | (@value{GDBP}) ptype s | |
15545 | type = POINTER TO ARRAY [-2..2] OF foo = RECORD | |
15546 | f1 : CARDINAL; | |
15547 | f2 : CHAR; | |
15548 | f3 : ARRAY [-2..2] OF CARDINAL; | |
15549 | END | |
15550 | @end smallexample | |
15551 | ||
6d2ebf8b | 15552 | @node M2 Defaults |
79a6e687 | 15553 | @subsubsection Modula-2 Defaults |
c906108c SS |
15554 | @cindex Modula-2 defaults |
15555 | ||
15556 | If type and range checking are set automatically by @value{GDBN}, they | |
15557 | both default to @code{on} whenever the working language changes to | |
d4f3574e | 15558 | Modula-2. This happens regardless of whether you or @value{GDBN} |
c906108c SS |
15559 | selected the working language. |
15560 | ||
15561 | If you allow @value{GDBN} to set the language automatically, then entering | |
15562 | code compiled from a file whose name ends with @file{.mod} sets the | |
79a6e687 BW |
15563 | working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} |
15564 | Infer the Source Language}, for further details. | |
c906108c | 15565 | |
6d2ebf8b | 15566 | @node Deviations |
79a6e687 | 15567 | @subsubsection Deviations from Standard Modula-2 |
c906108c SS |
15568 | @cindex Modula-2, deviations from |
15569 | ||
15570 | A few changes have been made to make Modula-2 programs easier to debug. | |
15571 | This is done primarily via loosening its type strictness: | |
15572 | ||
15573 | @itemize @bullet | |
15574 | @item | |
15575 | Unlike in standard Modula-2, pointer constants can be formed by | |
15576 | integers. This allows you to modify pointer variables during | |
15577 | debugging. (In standard Modula-2, the actual address contained in a | |
15578 | pointer variable is hidden from you; it can only be modified | |
15579 | through direct assignment to another pointer variable or expression that | |
15580 | returned a pointer.) | |
15581 | ||
15582 | @item | |
15583 | C escape sequences can be used in strings and characters to represent | |
15584 | non-printable characters. @value{GDBN} prints out strings with these | |
15585 | escape sequences embedded. Single non-printable characters are | |
15586 | printed using the @samp{CHR(@var{nnn})} format. | |
15587 | ||
15588 | @item | |
15589 | The assignment operator (@code{:=}) returns the value of its right-hand | |
15590 | argument. | |
15591 | ||
15592 | @item | |
15593 | All built-in procedures both modify @emph{and} return their argument. | |
15594 | @end itemize | |
15595 | ||
6d2ebf8b | 15596 | @node M2 Checks |
79a6e687 | 15597 | @subsubsection Modula-2 Type and Range Checks |
c906108c SS |
15598 | @cindex Modula-2 checks |
15599 | ||
15600 | @quotation | |
15601 | @emph{Warning:} in this release, @value{GDBN} does not yet perform type or | |
15602 | range checking. | |
15603 | @end quotation | |
15604 | @c FIXME remove warning when type/range checks added | |
15605 | ||
15606 | @value{GDBN} considers two Modula-2 variables type equivalent if: | |
15607 | ||
15608 | @itemize @bullet | |
15609 | @item | |
15610 | They are of types that have been declared equivalent via a @code{TYPE | |
15611 | @var{t1} = @var{t2}} statement | |
15612 | ||
15613 | @item | |
15614 | They have been declared on the same line. (Note: This is true of the | |
15615 | @sc{gnu} Modula-2 compiler, but it may not be true of other compilers.) | |
15616 | @end itemize | |
15617 | ||
15618 | As long as type checking is enabled, any attempt to combine variables | |
15619 | whose types are not equivalent is an error. | |
15620 | ||
15621 | Range checking is done on all mathematical operations, assignment, array | |
15622 | index bounds, and all built-in functions and procedures. | |
15623 | ||
6d2ebf8b | 15624 | @node M2 Scope |
79a6e687 | 15625 | @subsubsection The Scope Operators @code{::} and @code{.} |
c906108c | 15626 | @cindex scope |
41afff9a | 15627 | @cindex @code{.}, Modula-2 scope operator |
c906108c SS |
15628 | @cindex colon, doubled as scope operator |
15629 | @ifinfo | |
41afff9a | 15630 | @vindex colon-colon@r{, in Modula-2} |
c906108c SS |
15631 | @c Info cannot handle :: but TeX can. |
15632 | @end ifinfo | |
a67ec3f4 | 15633 | @ifnotinfo |
41afff9a | 15634 | @vindex ::@r{, in Modula-2} |
a67ec3f4 | 15635 | @end ifnotinfo |
c906108c SS |
15636 | |
15637 | There are a few subtle differences between the Modula-2 scope operator | |
15638 | (@code{.}) and the @value{GDBN} scope operator (@code{::}). The two have | |
15639 | similar syntax: | |
15640 | ||
474c8240 | 15641 | @smallexample |
c906108c SS |
15642 | |
15643 | @var{module} . @var{id} | |
15644 | @var{scope} :: @var{id} | |
474c8240 | 15645 | @end smallexample |
c906108c SS |
15646 | |
15647 | @noindent | |
15648 | where @var{scope} is the name of a module or a procedure, | |
15649 | @var{module} the name of a module, and @var{id} is any declared | |
15650 | identifier within your program, except another module. | |
15651 | ||
15652 | Using the @code{::} operator makes @value{GDBN} search the scope | |
15653 | specified by @var{scope} for the identifier @var{id}. If it is not | |
15654 | found in the specified scope, then @value{GDBN} searches all scopes | |
15655 | enclosing the one specified by @var{scope}. | |
15656 | ||
15657 | Using the @code{.} operator makes @value{GDBN} search the current scope for | |
15658 | the identifier specified by @var{id} that was imported from the | |
15659 | definition module specified by @var{module}. With this operator, it is | |
15660 | an error if the identifier @var{id} was not imported from definition | |
15661 | module @var{module}, or if @var{id} is not an identifier in | |
15662 | @var{module}. | |
15663 | ||
6d2ebf8b | 15664 | @node GDB/M2 |
c906108c SS |
15665 | @subsubsection @value{GDBN} and Modula-2 |
15666 | ||
15667 | Some @value{GDBN} commands have little use when debugging Modula-2 programs. | |
15668 | Five subcommands of @code{set print} and @code{show print} apply | |
b37052ae | 15669 | specifically to C and C@t{++}: @samp{vtbl}, @samp{demangle}, |
c906108c | 15670 | @samp{asm-demangle}, @samp{object}, and @samp{union}. The first four |
b37052ae | 15671 | apply to C@t{++}, and the last to the C @code{union} type, which has no direct |
c906108c SS |
15672 | analogue in Modula-2. |
15673 | ||
15674 | The @code{@@} operator (@pxref{Expressions, ,Expressions}), while available | |
d4f3574e | 15675 | with any language, is not useful with Modula-2. Its |
c906108c | 15676 | intent is to aid the debugging of @dfn{dynamic arrays}, which cannot be |
b37052ae | 15677 | created in Modula-2 as they can in C or C@t{++}. However, because an |
c906108c | 15678 | address can be specified by an integral constant, the construct |
d4f3574e | 15679 | @samp{@{@var{type}@}@var{adrexp}} is still useful. |
c906108c SS |
15680 | |
15681 | @cindex @code{#} in Modula-2 | |
15682 | In @value{GDBN} scripts, the Modula-2 inequality operator @code{#} is | |
15683 | interpreted as the beginning of a comment. Use @code{<>} instead. | |
c906108c | 15684 | |
e07c999f PH |
15685 | @node Ada |
15686 | @subsection Ada | |
15687 | @cindex Ada | |
15688 | ||
15689 | The extensions made to @value{GDBN} for Ada only support | |
15690 | output from the @sc{gnu} Ada (GNAT) compiler. | |
15691 | Other Ada compilers are not currently supported, and | |
15692 | attempting to debug executables produced by them is most likely | |
15693 | to be difficult. | |
15694 | ||
15695 | ||
15696 | @cindex expressions in Ada | |
15697 | @menu | |
15698 | * Ada Mode Intro:: General remarks on the Ada syntax | |
15699 | and semantics supported by Ada mode | |
15700 | in @value{GDBN}. | |
15701 | * Omissions from Ada:: Restrictions on the Ada expression syntax. | |
15702 | * Additions to Ada:: Extensions of the Ada expression syntax. | |
3685b09f PMR |
15703 | * Overloading support for Ada:: Support for expressions involving overloaded |
15704 | subprograms. | |
e07c999f | 15705 | * Stopping Before Main Program:: Debugging the program during elaboration. |
58d06528 | 15706 | * Ada Exceptions:: Ada Exceptions |
20924a55 JB |
15707 | * Ada Tasks:: Listing and setting breakpoints in tasks. |
15708 | * Ada Tasks and Core Files:: Tasking Support when Debugging Core Files | |
6e1bb179 JB |
15709 | * Ravenscar Profile:: Tasking Support when using the Ravenscar |
15710 | Profile | |
e07c999f PH |
15711 | * Ada Glitches:: Known peculiarities of Ada mode. |
15712 | @end menu | |
15713 | ||
15714 | @node Ada Mode Intro | |
15715 | @subsubsection Introduction | |
15716 | @cindex Ada mode, general | |
15717 | ||
15718 | The Ada mode of @value{GDBN} supports a fairly large subset of Ada expression | |
15719 | syntax, with some extensions. | |
15720 | The philosophy behind the design of this subset is | |
15721 | ||
15722 | @itemize @bullet | |
15723 | @item | |
15724 | That @value{GDBN} should provide basic literals and access to operations for | |
15725 | arithmetic, dereferencing, field selection, indexing, and subprogram calls, | |
15726 | leaving more sophisticated computations to subprograms written into the | |
15727 | program (which therefore may be called from @value{GDBN}). | |
15728 | ||
15729 | @item | |
15730 | That type safety and strict adherence to Ada language restrictions | |
15731 | are not particularly important to the @value{GDBN} user. | |
15732 | ||
15733 | @item | |
15734 | That brevity is important to the @value{GDBN} user. | |
15735 | @end itemize | |
15736 | ||
f3a2dd1a JB |
15737 | Thus, for brevity, the debugger acts as if all names declared in |
15738 | user-written packages are directly visible, even if they are not visible | |
15739 | according to Ada rules, thus making it unnecessary to fully qualify most | |
15740 | names with their packages, regardless of context. Where this causes | |
15741 | ambiguity, @value{GDBN} asks the user's intent. | |
e07c999f PH |
15742 | |
15743 | The debugger will start in Ada mode if it detects an Ada main program. | |
15744 | As for other languages, it will enter Ada mode when stopped in a program that | |
15745 | was translated from an Ada source file. | |
15746 | ||
15747 | While in Ada mode, you may use `@t{--}' for comments. This is useful | |
15748 | mostly for documenting command files. The standard @value{GDBN} comment | |
15749 | (@samp{#}) still works at the beginning of a line in Ada mode, but not in the | |
15750 | middle (to allow based literals). | |
15751 | ||
e07c999f PH |
15752 | @node Omissions from Ada |
15753 | @subsubsection Omissions from Ada | |
15754 | @cindex Ada, omissions from | |
15755 | ||
15756 | Here are the notable omissions from the subset: | |
15757 | ||
15758 | @itemize @bullet | |
15759 | @item | |
15760 | Only a subset of the attributes are supported: | |
15761 | ||
15762 | @itemize @minus | |
15763 | @item | |
15764 | @t{'First}, @t{'Last}, and @t{'Length} | |
15765 | on array objects (not on types and subtypes). | |
15766 | ||
15767 | @item | |
15768 | @t{'Min} and @t{'Max}. | |
15769 | ||
15770 | @item | |
15771 | @t{'Pos} and @t{'Val}. | |
15772 | ||
15773 | @item | |
15774 | @t{'Tag}. | |
15775 | ||
15776 | @item | |
15777 | @t{'Range} on array objects (not subtypes), but only as the right | |
15778 | operand of the membership (@code{in}) operator. | |
15779 | ||
15780 | @item | |
15781 | @t{'Access}, @t{'Unchecked_Access}, and | |
15782 | @t{'Unrestricted_Access} (a GNAT extension). | |
15783 | ||
15784 | @item | |
15785 | @t{'Address}. | |
15786 | @end itemize | |
15787 | ||
15788 | @item | |
15789 | The names in | |
15790 | @code{Characters.Latin_1} are not available and | |
15791 | concatenation is not implemented. Thus, escape characters in strings are | |
15792 | not currently available. | |
15793 | ||
15794 | @item | |
15795 | Equality tests (@samp{=} and @samp{/=}) on arrays test for bitwise | |
15796 | equality of representations. They will generally work correctly | |
15797 | for strings and arrays whose elements have integer or enumeration types. | |
15798 | They may not work correctly for arrays whose element | |
15799 | types have user-defined equality, for arrays of real values | |
15800 | (in particular, IEEE-conformant floating point, because of negative | |
15801 | zeroes and NaNs), and for arrays whose elements contain unused bits with | |
15802 | indeterminate values. | |
15803 | ||
15804 | @item | |
15805 | The other component-by-component array operations (@code{and}, @code{or}, | |
15806 | @code{xor}, @code{not}, and relational tests other than equality) | |
15807 | are not implemented. | |
15808 | ||
15809 | @item | |
860701dc PH |
15810 | @cindex array aggregates (Ada) |
15811 | @cindex record aggregates (Ada) | |
15812 | @cindex aggregates (Ada) | |
15813 | There is limited support for array and record aggregates. They are | |
15814 | permitted only on the right sides of assignments, as in these examples: | |
15815 | ||
15816 | @smallexample | |
077e0a52 JB |
15817 | (@value{GDBP}) set An_Array := (1, 2, 3, 4, 5, 6) |
15818 | (@value{GDBP}) set An_Array := (1, others => 0) | |
15819 | (@value{GDBP}) set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6) | |
15820 | (@value{GDBP}) set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9)) | |
15821 | (@value{GDBP}) set A_Record := (1, "Peter", True); | |
15822 | (@value{GDBP}) set A_Record := (Name => "Peter", Id => 1, Alive => True) | |
860701dc PH |
15823 | @end smallexample |
15824 | ||
15825 | Changing a | |
15826 | discriminant's value by assigning an aggregate has an | |
15827 | undefined effect if that discriminant is used within the record. | |
15828 | However, you can first modify discriminants by directly assigning to | |
15829 | them (which normally would not be allowed in Ada), and then performing an | |
15830 | aggregate assignment. For example, given a variable @code{A_Rec} | |
15831 | declared to have a type such as: | |
15832 | ||
15833 | @smallexample | |
15834 | type Rec (Len : Small_Integer := 0) is record | |
15835 | Id : Integer; | |
15836 | Vals : IntArray (1 .. Len); | |
15837 | end record; | |
15838 | @end smallexample | |
15839 | ||
15840 | you can assign a value with a different size of @code{Vals} with two | |
15841 | assignments: | |
15842 | ||
15843 | @smallexample | |
077e0a52 JB |
15844 | (@value{GDBP}) set A_Rec.Len := 4 |
15845 | (@value{GDBP}) set A_Rec := (Id => 42, Vals => (1, 2, 3, 4)) | |
860701dc PH |
15846 | @end smallexample |
15847 | ||
15848 | As this example also illustrates, @value{GDBN} is very loose about the usual | |
15849 | rules concerning aggregates. You may leave out some of the | |
15850 | components of an array or record aggregate (such as the @code{Len} | |
15851 | component in the assignment to @code{A_Rec} above); they will retain their | |
15852 | original values upon assignment. You may freely use dynamic values as | |
15853 | indices in component associations. You may even use overlapping or | |
15854 | redundant component associations, although which component values are | |
15855 | assigned in such cases is not defined. | |
e07c999f PH |
15856 | |
15857 | @item | |
15858 | Calls to dispatching subprograms are not implemented. | |
15859 | ||
15860 | @item | |
15861 | The overloading algorithm is much more limited (i.e., less selective) | |
ae21e955 BW |
15862 | than that of real Ada. It makes only limited use of the context in |
15863 | which a subexpression appears to resolve its meaning, and it is much | |
15864 | looser in its rules for allowing type matches. As a result, some | |
15865 | function calls will be ambiguous, and the user will be asked to choose | |
15866 | the proper resolution. | |
e07c999f PH |
15867 | |
15868 | @item | |
15869 | The @code{new} operator is not implemented. | |
15870 | ||
15871 | @item | |
15872 | Entry calls are not implemented. | |
15873 | ||
15874 | @item | |
15875 | Aside from printing, arithmetic operations on the native VAX floating-point | |
15876 | formats are not supported. | |
15877 | ||
15878 | @item | |
15879 | It is not possible to slice a packed array. | |
158c7665 PH |
15880 | |
15881 | @item | |
15882 | The names @code{True} and @code{False}, when not part of a qualified name, | |
15883 | are interpreted as if implicitly prefixed by @code{Standard}, regardless of | |
15884 | context. | |
15885 | Should your program | |
15886 | redefine these names in a package or procedure (at best a dubious practice), | |
15887 | you will have to use fully qualified names to access their new definitions. | |
e07c999f PH |
15888 | @end itemize |
15889 | ||
15890 | @node Additions to Ada | |
15891 | @subsubsection Additions to Ada | |
15892 | @cindex Ada, deviations from | |
15893 | ||
15894 | As it does for other languages, @value{GDBN} makes certain generic | |
15895 | extensions to Ada (@pxref{Expressions}): | |
15896 | ||
15897 | @itemize @bullet | |
15898 | @item | |
ae21e955 BW |
15899 | If the expression @var{E} is a variable residing in memory (typically |
15900 | a local variable or array element) and @var{N} is a positive integer, | |
15901 | then @code{@var{E}@@@var{N}} displays the values of @var{E} and the | |
15902 | @var{N}-1 adjacent variables following it in memory as an array. In | |
15903 | Ada, this operator is generally not necessary, since its prime use is | |
15904 | in displaying parts of an array, and slicing will usually do this in | |
15905 | Ada. However, there are occasional uses when debugging programs in | |
15906 | which certain debugging information has been optimized away. | |
e07c999f PH |
15907 | |
15908 | @item | |
ae21e955 BW |
15909 | @code{@var{B}::@var{var}} means ``the variable named @var{var} that |
15910 | appears in function or file @var{B}.'' When @var{B} is a file name, | |
15911 | you must typically surround it in single quotes. | |
e07c999f PH |
15912 | |
15913 | @item | |
15914 | The expression @code{@{@var{type}@} @var{addr}} means ``the variable of type | |
15915 | @var{type} that appears at address @var{addr}.'' | |
15916 | ||
15917 | @item | |
15918 | A name starting with @samp{$} is a convenience variable | |
15919 | (@pxref{Convenience Vars}) or a machine register (@pxref{Registers}). | |
15920 | @end itemize | |
15921 | ||
ae21e955 BW |
15922 | In addition, @value{GDBN} provides a few other shortcuts and outright |
15923 | additions specific to Ada: | |
e07c999f PH |
15924 | |
15925 | @itemize @bullet | |
15926 | @item | |
15927 | The assignment statement is allowed as an expression, returning | |
15928 | its right-hand operand as its value. Thus, you may enter | |
15929 | ||
15930 | @smallexample | |
077e0a52 JB |
15931 | (@value{GDBP}) set x := y + 3 |
15932 | (@value{GDBP}) print A(tmp := y + 1) | |
e07c999f PH |
15933 | @end smallexample |
15934 | ||
15935 | @item | |
15936 | The semicolon is allowed as an ``operator,'' returning as its value | |
15937 | the value of its right-hand operand. | |
15938 | This allows, for example, | |
15939 | complex conditional breaks: | |
15940 | ||
15941 | @smallexample | |
077e0a52 JB |
15942 | (@value{GDBP}) break f |
15943 | (@value{GDBP}) condition 1 (report(i); k += 1; A(k) > 100) | |
e07c999f PH |
15944 | @end smallexample |
15945 | ||
15946 | @item | |
15947 | Rather than use catenation and symbolic character names to introduce special | |
15948 | characters into strings, one may instead use a special bracket notation, | |
15949 | which is also used to print strings. A sequence of characters of the form | |
15950 | @samp{["@var{XX}"]} within a string or character literal denotes the | |
15951 | (single) character whose numeric encoding is @var{XX} in hexadecimal. The | |
15952 | sequence of characters @samp{["""]} also denotes a single quotation mark | |
15953 | in strings. For example, | |
15954 | @smallexample | |
15955 | "One line.["0a"]Next line.["0a"]" | |
15956 | @end smallexample | |
15957 | @noindent | |
ae21e955 BW |
15958 | contains an ASCII newline character (@code{Ada.Characters.Latin_1.LF}) |
15959 | after each period. | |
e07c999f PH |
15960 | |
15961 | @item | |
15962 | The subtype used as a prefix for the attributes @t{'Pos}, @t{'Min}, and | |
15963 | @t{'Max} is optional (and is ignored in any case). For example, it is valid | |
15964 | to write | |
15965 | ||
15966 | @smallexample | |
077e0a52 | 15967 | (@value{GDBP}) print 'max(x, y) |
e07c999f PH |
15968 | @end smallexample |
15969 | ||
15970 | @item | |
15971 | When printing arrays, @value{GDBN} uses positional notation when the | |
15972 | array has a lower bound of 1, and uses a modified named notation otherwise. | |
ae21e955 BW |
15973 | For example, a one-dimensional array of three integers with a lower bound |
15974 | of 3 might print as | |
e07c999f PH |
15975 | |
15976 | @smallexample | |
15977 | (3 => 10, 17, 1) | |
15978 | @end smallexample | |
15979 | ||
15980 | @noindent | |
15981 | That is, in contrast to valid Ada, only the first component has a @code{=>} | |
15982 | clause. | |
15983 | ||
15984 | @item | |
15985 | You may abbreviate attributes in expressions with any unique, | |
15986 | multi-character subsequence of | |
15987 | their names (an exact match gets preference). | |
15988 | For example, you may use @t{a'len}, @t{a'gth}, or @t{a'lh} | |
15989 | in place of @t{a'length}. | |
15990 | ||
15991 | @item | |
15992 | @cindex quoting Ada internal identifiers | |
15993 | Since Ada is case-insensitive, the debugger normally maps identifiers you type | |
15994 | to lower case. The GNAT compiler uses upper-case characters for | |
15995 | some of its internal identifiers, which are normally of no interest to users. | |
15996 | For the rare occasions when you actually have to look at them, | |
15997 | enclose them in angle brackets to avoid the lower-case mapping. | |
15998 | For example, | |
15999 | @smallexample | |
077e0a52 | 16000 | (@value{GDBP}) print <JMPBUF_SAVE>[0] |
e07c999f PH |
16001 | @end smallexample |
16002 | ||
16003 | @item | |
16004 | Printing an object of class-wide type or dereferencing an | |
16005 | access-to-class-wide value will display all the components of the object's | |
16006 | specific type (as indicated by its run-time tag). Likewise, component | |
16007 | selection on such a value will operate on the specific type of the | |
16008 | object. | |
16009 | ||
16010 | @end itemize | |
16011 | ||
3685b09f PMR |
16012 | @node Overloading support for Ada |
16013 | @subsubsection Overloading support for Ada | |
16014 | @cindex overloading, Ada | |
16015 | ||
16016 | The debugger supports limited overloading. Given a subprogram call in which | |
16017 | the function symbol has multiple definitions, it will use the number of | |
16018 | actual parameters and some information about their types to attempt to narrow | |
16019 | the set of definitions. It also makes very limited use of context, preferring | |
16020 | procedures to functions in the context of the @code{call} command, and | |
16021 | functions to procedures elsewhere. | |
16022 | ||
16023 | If, after narrowing, the set of matching definitions still contains more than | |
16024 | one definition, @value{GDBN} will display a menu to query which one it should | |
16025 | use, for instance: | |
16026 | ||
16027 | @smallexample | |
16028 | (@value{GDBP}) print f(1) | |
16029 | Multiple matches for f | |
16030 | [0] cancel | |
16031 | [1] foo.f (integer) return boolean at foo.adb:23 | |
16032 | [2] foo.f (foo.new_integer) return boolean at foo.adb:28 | |
16033 | > | |
16034 | @end smallexample | |
16035 | ||
16036 | In this case, just select one menu entry either to cancel expression evaluation | |
16037 | (type @kbd{0} and press @key{RET}) or to continue evaluation with a specific | |
16038 | instance (type the corresponding number and press @key{RET}). | |
16039 | ||
16040 | Here are a couple of commands to customize @value{GDBN}'s behavior in this | |
16041 | case: | |
16042 | ||
16043 | @table @code | |
16044 | ||
16045 | @kindex set ada print-signatures | |
16046 | @item set ada print-signatures | |
16047 | Control whether parameter types and return types are displayed in overloads | |
16048 | selection menus. It is @code{on} by default. | |
16049 | @xref{Overloading support for Ada}. | |
16050 | ||
16051 | @kindex show ada print-signatures | |
16052 | @item show ada print-signatures | |
16053 | Show the current setting for displaying parameter types and return types in | |
16054 | overloads selection menu. | |
16055 | @xref{Overloading support for Ada}. | |
16056 | ||
16057 | @end table | |
16058 | ||
e07c999f PH |
16059 | @node Stopping Before Main Program |
16060 | @subsubsection Stopping at the Very Beginning | |
16061 | ||
16062 | @cindex breakpointing Ada elaboration code | |
16063 | It is sometimes necessary to debug the program during elaboration, and | |
16064 | before reaching the main procedure. | |
16065 | As defined in the Ada Reference | |
16066 | Manual, the elaboration code is invoked from a procedure called | |
16067 | @code{adainit}. To run your program up to the beginning of | |
16068 | elaboration, simply use the following two commands: | |
16069 | @code{tbreak adainit} and @code{run}. | |
16070 | ||
58d06528 JB |
16071 | @node Ada Exceptions |
16072 | @subsubsection Ada Exceptions | |
16073 | ||
16074 | A command is provided to list all Ada exceptions: | |
16075 | ||
16076 | @table @code | |
16077 | @kindex info exceptions | |
16078 | @item info exceptions | |
16079 | @itemx info exceptions @var{regexp} | |
16080 | The @code{info exceptions} command allows you to list all Ada exceptions | |
16081 | defined within the program being debugged, as well as their addresses. | |
16082 | With a regular expression, @var{regexp}, as argument, only those exceptions | |
16083 | whose names match @var{regexp} are listed. | |
16084 | @end table | |
16085 | ||
16086 | Below is a small example, showing how the command can be used, first | |
16087 | without argument, and next with a regular expression passed as an | |
16088 | argument. | |
16089 | ||
16090 | @smallexample | |
16091 | (@value{GDBP}) info exceptions | |
16092 | All defined Ada exceptions: | |
16093 | constraint_error: 0x613da0 | |
16094 | program_error: 0x613d20 | |
16095 | storage_error: 0x613ce0 | |
16096 | tasking_error: 0x613ca0 | |
16097 | const.aint_global_e: 0x613b00 | |
16098 | (@value{GDBP}) info exceptions const.aint | |
16099 | All Ada exceptions matching regular expression "const.aint": | |
16100 | constraint_error: 0x613da0 | |
16101 | const.aint_global_e: 0x613b00 | |
16102 | @end smallexample | |
16103 | ||
16104 | It is also possible to ask @value{GDBN} to stop your program's execution | |
16105 | when an exception is raised. For more details, see @ref{Set Catchpoints}. | |
16106 | ||
20924a55 JB |
16107 | @node Ada Tasks |
16108 | @subsubsection Extensions for Ada Tasks | |
16109 | @cindex Ada, tasking | |
16110 | ||
16111 | Support for Ada tasks is analogous to that for threads (@pxref{Threads}). | |
16112 | @value{GDBN} provides the following task-related commands: | |
16113 | ||
16114 | @table @code | |
16115 | @kindex info tasks | |
16116 | @item info tasks | |
16117 | This command shows a list of current Ada tasks, as in the following example: | |
16118 | ||
16119 | ||
16120 | @smallexample | |
16121 | @iftex | |
16122 | @leftskip=0.5cm | |
16123 | @end iftex | |
16124 | (@value{GDBP}) info tasks | |
16125 | ID TID P-ID Pri State Name | |
16126 | 1 8088000 0 15 Child Activation Wait main_task | |
16127 | 2 80a4000 1 15 Accept Statement b | |
16128 | 3 809a800 1 15 Child Activation Wait a | |
32cd1edc | 16129 | * 4 80ae800 3 15 Runnable c |
20924a55 JB |
16130 | |
16131 | @end smallexample | |
16132 | ||
16133 | @noindent | |
16134 | In this listing, the asterisk before the last task indicates it to be the | |
16135 | task currently being inspected. | |
16136 | ||
16137 | @table @asis | |
16138 | @item ID | |
16139 | Represents @value{GDBN}'s internal task number. | |
16140 | ||
16141 | @item TID | |
16142 | The Ada task ID. | |
16143 | ||
16144 | @item P-ID | |
16145 | The parent's task ID (@value{GDBN}'s internal task number). | |
16146 | ||
16147 | @item Pri | |
16148 | The base priority of the task. | |
16149 | ||
16150 | @item State | |
16151 | Current state of the task. | |
16152 | ||
16153 | @table @code | |
16154 | @item Unactivated | |
16155 | The task has been created but has not been activated. It cannot be | |
16156 | executing. | |
16157 | ||
20924a55 JB |
16158 | @item Runnable |
16159 | The task is not blocked for any reason known to Ada. (It may be waiting | |
16160 | for a mutex, though.) It is conceptually "executing" in normal mode. | |
16161 | ||
16162 | @item Terminated | |
16163 | The task is terminated, in the sense of ARM 9.3 (5). Any dependents | |
16164 | that were waiting on terminate alternatives have been awakened and have | |
16165 | terminated themselves. | |
16166 | ||
16167 | @item Child Activation Wait | |
16168 | The task is waiting for created tasks to complete activation. | |
16169 | ||
16170 | @item Accept Statement | |
16171 | The task is waiting on an accept or selective wait statement. | |
16172 | ||
16173 | @item Waiting on entry call | |
16174 | The task is waiting on an entry call. | |
16175 | ||
16176 | @item Async Select Wait | |
16177 | The task is waiting to start the abortable part of an asynchronous | |
16178 | select statement. | |
16179 | ||
16180 | @item Delay Sleep | |
16181 | The task is waiting on a select statement with only a delay | |
16182 | alternative open. | |
16183 | ||
16184 | @item Child Termination Wait | |
16185 | The task is sleeping having completed a master within itself, and is | |
16186 | waiting for the tasks dependent on that master to become terminated or | |
16187 | waiting on a terminate Phase. | |
16188 | ||
16189 | @item Wait Child in Term Alt | |
16190 | The task is sleeping waiting for tasks on terminate alternatives to | |
16191 | finish terminating. | |
16192 | ||
16193 | @item Accepting RV with @var{taskno} | |
16194 | The task is accepting a rendez-vous with the task @var{taskno}. | |
16195 | @end table | |
16196 | ||
16197 | @item Name | |
16198 | Name of the task in the program. | |
16199 | ||
16200 | @end table | |
16201 | ||
16202 | @kindex info task @var{taskno} | |
16203 | @item info task @var{taskno} | |
16204 | This command shows detailled informations on the specified task, as in | |
16205 | the following example: | |
16206 | @smallexample | |
16207 | @iftex | |
16208 | @leftskip=0.5cm | |
16209 | @end iftex | |
16210 | (@value{GDBP}) info tasks | |
16211 | ID TID P-ID Pri State Name | |
16212 | 1 8077880 0 15 Child Activation Wait main_task | |
32cd1edc | 16213 | * 2 807c468 1 15 Runnable task_1 |
20924a55 JB |
16214 | (@value{GDBP}) info task 2 |
16215 | Ada Task: 0x807c468 | |
16216 | Name: task_1 | |
16217 | Thread: 0x807f378 | |
16218 | Parent: 1 (main_task) | |
16219 | Base Priority: 15 | |
16220 | State: Runnable | |
16221 | @end smallexample | |
16222 | ||
16223 | @item task | |
16224 | @kindex task@r{ (Ada)} | |
16225 | @cindex current Ada task ID | |
16226 | This command prints the ID of the current task. | |
16227 | ||
16228 | @smallexample | |
16229 | @iftex | |
16230 | @leftskip=0.5cm | |
16231 | @end iftex | |
16232 | (@value{GDBP}) info tasks | |
16233 | ID TID P-ID Pri State Name | |
16234 | 1 8077870 0 15 Child Activation Wait main_task | |
32cd1edc | 16235 | * 2 807c458 1 15 Runnable t |
20924a55 JB |
16236 | (@value{GDBP}) task |
16237 | [Current task is 2] | |
16238 | @end smallexample | |
16239 | ||
16240 | @item task @var{taskno} | |
16241 | @cindex Ada task switching | |
5d5658a1 | 16242 | This command is like the @code{thread @var{thread-id}} |
20924a55 JB |
16243 | command (@pxref{Threads}). It switches the context of debugging |
16244 | from the current task to the given task. | |
16245 | ||
16246 | @smallexample | |
16247 | @iftex | |
16248 | @leftskip=0.5cm | |
16249 | @end iftex | |
16250 | (@value{GDBP}) info tasks | |
16251 | ID TID P-ID Pri State Name | |
16252 | 1 8077870 0 15 Child Activation Wait main_task | |
32cd1edc | 16253 | * 2 807c458 1 15 Runnable t |
20924a55 JB |
16254 | (@value{GDBP}) task 1 |
16255 | [Switching to task 1] | |
16256 | #0 0x8067726 in pthread_cond_wait () | |
16257 | (@value{GDBP}) bt | |
16258 | #0 0x8067726 in pthread_cond_wait () | |
16259 | #1 0x8056714 in system.os_interface.pthread_cond_wait () | |
16260 | #2 0x805cb63 in system.task_primitives.operations.sleep () | |
16261 | #3 0x806153e in system.tasking.stages.activate_tasks () | |
16262 | #4 0x804aacc in un () at un.adb:5 | |
16263 | @end smallexample | |
16264 | ||
629500fa KS |
16265 | @item break @var{location} task @var{taskno} |
16266 | @itemx break @var{location} task @var{taskno} if @dots{} | |
45ac276d JB |
16267 | @cindex breakpoints and tasks, in Ada |
16268 | @cindex task breakpoints, in Ada | |
16269 | @kindex break @dots{} task @var{taskno}@r{ (Ada)} | |
16270 | These commands are like the @code{break @dots{} thread @dots{}} | |
697aa1b7 | 16271 | command (@pxref{Thread Stops}). The |
629500fa | 16272 | @var{location} argument specifies source lines, as described |
45ac276d JB |
16273 | in @ref{Specify Location}. |
16274 | ||
16275 | Use the qualifier @samp{task @var{taskno}} with a breakpoint command | |
16276 | to specify that you only want @value{GDBN} to stop the program when a | |
697aa1b7 | 16277 | particular Ada task reaches this breakpoint. The @var{taskno} is one of the |
45ac276d JB |
16278 | numeric task identifiers assigned by @value{GDBN}, shown in the first |
16279 | column of the @samp{info tasks} display. | |
16280 | ||
16281 | If you do not specify @samp{task @var{taskno}} when you set a | |
16282 | breakpoint, the breakpoint applies to @emph{all} tasks of your | |
16283 | program. | |
16284 | ||
16285 | You can use the @code{task} qualifier on conditional breakpoints as | |
16286 | well; in this case, place @samp{task @var{taskno}} before the | |
16287 | breakpoint condition (before the @code{if}). | |
16288 | ||
16289 | For example, | |
16290 | ||
16291 | @smallexample | |
16292 | @iftex | |
16293 | @leftskip=0.5cm | |
16294 | @end iftex | |
16295 | (@value{GDBP}) info tasks | |
16296 | ID TID P-ID Pri State Name | |
16297 | 1 140022020 0 15 Child Activation Wait main_task | |
16298 | 2 140045060 1 15 Accept/Select Wait t2 | |
16299 | 3 140044840 1 15 Runnable t1 | |
16300 | * 4 140056040 1 15 Runnable t3 | |
16301 | (@value{GDBP}) b 15 task 2 | |
16302 | Breakpoint 5 at 0x120044cb0: file test_task_debug.adb, line 15. | |
16303 | (@value{GDBP}) cont | |
16304 | Continuing. | |
16305 | task # 1 running | |
16306 | task # 2 running | |
16307 | ||
16308 | Breakpoint 5, test_task_debug () at test_task_debug.adb:15 | |
16309 | 15 flush; | |
16310 | (@value{GDBP}) info tasks | |
16311 | ID TID P-ID Pri State Name | |
16312 | 1 140022020 0 15 Child Activation Wait main_task | |
16313 | * 2 140045060 1 15 Runnable t2 | |
16314 | 3 140044840 1 15 Runnable t1 | |
16315 | 4 140056040 1 15 Delay Sleep t3 | |
16316 | @end smallexample | |
20924a55 JB |
16317 | @end table |
16318 | ||
16319 | @node Ada Tasks and Core Files | |
16320 | @subsubsection Tasking Support when Debugging Core Files | |
16321 | @cindex Ada tasking and core file debugging | |
16322 | ||
16323 | When inspecting a core file, as opposed to debugging a live program, | |
16324 | tasking support may be limited or even unavailable, depending on | |
16325 | the platform being used. | |
16326 | For instance, on x86-linux, the list of tasks is available, but task | |
32a8097b | 16327 | switching is not supported. |
20924a55 | 16328 | |
32a8097b | 16329 | On certain platforms, the debugger needs to perform some |
20924a55 JB |
16330 | memory writes in order to provide Ada tasking support. When inspecting |
16331 | a core file, this means that the core file must be opened with read-write | |
16332 | privileges, using the command @samp{"set write on"} (@pxref{Patching}). | |
16333 | Under these circumstances, you should make a backup copy of the core | |
16334 | file before inspecting it with @value{GDBN}. | |
16335 | ||
6e1bb179 JB |
16336 | @node Ravenscar Profile |
16337 | @subsubsection Tasking Support when using the Ravenscar Profile | |
16338 | @cindex Ravenscar Profile | |
16339 | ||
16340 | The @dfn{Ravenscar Profile} is a subset of the Ada tasking features, | |
16341 | specifically designed for systems with safety-critical real-time | |
16342 | requirements. | |
16343 | ||
16344 | @table @code | |
16345 | @kindex set ravenscar task-switching on | |
16346 | @cindex task switching with program using Ravenscar Profile | |
16347 | @item set ravenscar task-switching on | |
16348 | Allows task switching when debugging a program that uses the Ravenscar | |
16349 | Profile. This is the default. | |
16350 | ||
16351 | @kindex set ravenscar task-switching off | |
16352 | @item set ravenscar task-switching off | |
16353 | Turn off task switching when debugging a program that uses the Ravenscar | |
16354 | Profile. This is mostly intended to disable the code that adds support | |
16355 | for the Ravenscar Profile, in case a bug in either @value{GDBN} or in | |
16356 | the Ravenscar runtime is preventing @value{GDBN} from working properly. | |
16357 | To be effective, this command should be run before the program is started. | |
16358 | ||
16359 | @kindex show ravenscar task-switching | |
16360 | @item show ravenscar task-switching | |
16361 | Show whether it is possible to switch from task to task in a program | |
16362 | using the Ravenscar Profile. | |
16363 | ||
16364 | @end table | |
16365 | ||
e07c999f PH |
16366 | @node Ada Glitches |
16367 | @subsubsection Known Peculiarities of Ada Mode | |
16368 | @cindex Ada, problems | |
16369 | ||
16370 | Besides the omissions listed previously (@pxref{Omissions from Ada}), | |
16371 | we know of several problems with and limitations of Ada mode in | |
16372 | @value{GDBN}, | |
16373 | some of which will be fixed with planned future releases of the debugger | |
16374 | and the GNU Ada compiler. | |
16375 | ||
16376 | @itemize @bullet | |
e07c999f PH |
16377 | @item |
16378 | Static constants that the compiler chooses not to materialize as objects in | |
16379 | storage are invisible to the debugger. | |
16380 | ||
16381 | @item | |
16382 | Named parameter associations in function argument lists are ignored (the | |
16383 | argument lists are treated as positional). | |
16384 | ||
16385 | @item | |
16386 | Many useful library packages are currently invisible to the debugger. | |
16387 | ||
16388 | @item | |
16389 | Fixed-point arithmetic, conversions, input, and output is carried out using | |
16390 | floating-point arithmetic, and may give results that only approximate those on | |
16391 | the host machine. | |
16392 | ||
e07c999f PH |
16393 | @item |
16394 | The GNAT compiler never generates the prefix @code{Standard} for any of | |
16395 | the standard symbols defined by the Ada language. @value{GDBN} knows about | |
16396 | this: it will strip the prefix from names when you use it, and will never | |
16397 | look for a name you have so qualified among local symbols, nor match against | |
16398 | symbols in other packages or subprograms. If you have | |
16399 | defined entities anywhere in your program other than parameters and | |
16400 | local variables whose simple names match names in @code{Standard}, | |
16401 | GNAT's lack of qualification here can cause confusion. When this happens, | |
16402 | you can usually resolve the confusion | |
16403 | by qualifying the problematic names with package | |
16404 | @code{Standard} explicitly. | |
16405 | @end itemize | |
16406 | ||
95433b34 JB |
16407 | Older versions of the compiler sometimes generate erroneous debugging |
16408 | information, resulting in the debugger incorrectly printing the value | |
16409 | of affected entities. In some cases, the debugger is able to work | |
16410 | around an issue automatically. In other cases, the debugger is able | |
16411 | to work around the issue, but the work-around has to be specifically | |
16412 | enabled. | |
16413 | ||
16414 | @kindex set ada trust-PAD-over-XVS | |
16415 | @kindex show ada trust-PAD-over-XVS | |
16416 | @table @code | |
16417 | ||
16418 | @item set ada trust-PAD-over-XVS on | |
16419 | Configure GDB to strictly follow the GNAT encoding when computing the | |
16420 | value of Ada entities, particularly when @code{PAD} and @code{PAD___XVS} | |
16421 | types are involved (see @code{ada/exp_dbug.ads} in the GCC sources for | |
16422 | a complete description of the encoding used by the GNAT compiler). | |
16423 | This is the default. | |
16424 | ||
16425 | @item set ada trust-PAD-over-XVS off | |
16426 | This is related to the encoding using by the GNAT compiler. If @value{GDBN} | |
16427 | sometimes prints the wrong value for certain entities, changing @code{ada | |
16428 | trust-PAD-over-XVS} to @code{off} activates a work-around which may fix | |
16429 | the issue. It is always safe to set @code{ada trust-PAD-over-XVS} to | |
16430 | @code{off}, but this incurs a slight performance penalty, so it is | |
16431 | recommended to leave this setting to @code{on} unless necessary. | |
16432 | ||
16433 | @end table | |
16434 | ||
c6044dd1 JB |
16435 | @cindex GNAT descriptive types |
16436 | @cindex GNAT encoding | |
16437 | Internally, the debugger also relies on the compiler following a number | |
16438 | of conventions known as the @samp{GNAT Encoding}, all documented in | |
16439 | @file{gcc/ada/exp_dbug.ads} in the GCC sources. This encoding describes | |
16440 | how the debugging information should be generated for certain types. | |
16441 | In particular, this convention makes use of @dfn{descriptive types}, | |
16442 | which are artificial types generated purely to help the debugger. | |
16443 | ||
16444 | These encodings were defined at a time when the debugging information | |
16445 | format used was not powerful enough to describe some of the more complex | |
16446 | types available in Ada. Since DWARF allows us to express nearly all | |
16447 | Ada features, the long-term goal is to slowly replace these descriptive | |
16448 | types by their pure DWARF equivalent. To facilitate that transition, | |
16449 | a new maintenance option is available to force the debugger to ignore | |
16450 | those descriptive types. It allows the user to quickly evaluate how | |
16451 | well @value{GDBN} works without them. | |
16452 | ||
16453 | @table @code | |
16454 | ||
16455 | @kindex maint ada set ignore-descriptive-types | |
16456 | @item maintenance ada set ignore-descriptive-types [on|off] | |
16457 | Control whether the debugger should ignore descriptive types. | |
16458 | The default is not to ignore descriptives types (@code{off}). | |
16459 | ||
16460 | @kindex maint ada show ignore-descriptive-types | |
16461 | @item maintenance ada show ignore-descriptive-types | |
16462 | Show if descriptive types are ignored by @value{GDBN}. | |
16463 | ||
16464 | @end table | |
16465 | ||
79a6e687 BW |
16466 | @node Unsupported Languages |
16467 | @section Unsupported Languages | |
4e562065 JB |
16468 | |
16469 | @cindex unsupported languages | |
16470 | @cindex minimal language | |
16471 | In addition to the other fully-supported programming languages, | |
16472 | @value{GDBN} also provides a pseudo-language, called @code{minimal}. | |
16473 | It does not represent a real programming language, but provides a set | |
16474 | of capabilities close to what the C or assembly languages provide. | |
16475 | This should allow most simple operations to be performed while debugging | |
16476 | an application that uses a language currently not supported by @value{GDBN}. | |
16477 | ||
16478 | If the language is set to @code{auto}, @value{GDBN} will automatically | |
16479 | select this language if the current frame corresponds to an unsupported | |
16480 | language. | |
16481 | ||
6d2ebf8b | 16482 | @node Symbols |
c906108c SS |
16483 | @chapter Examining the Symbol Table |
16484 | ||
d4f3574e | 16485 | The commands described in this chapter allow you to inquire about the |
c906108c SS |
16486 | symbols (names of variables, functions and types) defined in your |
16487 | program. This information is inherent in the text of your program and | |
16488 | does not change as your program executes. @value{GDBN} finds it in your | |
16489 | program's symbol table, in the file indicated when you started @value{GDBN} | |
79a6e687 BW |
16490 | (@pxref{File Options, ,Choosing Files}), or by one of the |
16491 | file-management commands (@pxref{Files, ,Commands to Specify Files}). | |
c906108c SS |
16492 | |
16493 | @cindex symbol names | |
16494 | @cindex names of symbols | |
16495 | @cindex quoting names | |
16496 | Occasionally, you may need to refer to symbols that contain unusual | |
16497 | characters, which @value{GDBN} ordinarily treats as word delimiters. The | |
16498 | most frequent case is in referring to static variables in other | |
79a6e687 | 16499 | source files (@pxref{Variables,,Program Variables}). File names |
c906108c SS |
16500 | are recorded in object files as debugging symbols, but @value{GDBN} would |
16501 | ordinarily parse a typical file name, like @file{foo.c}, as the three words | |
16502 | @samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize | |
16503 | @samp{foo.c} as a single symbol, enclose it in single quotes; for example, | |
16504 | ||
474c8240 | 16505 | @smallexample |
c906108c | 16506 | p 'foo.c'::x |
474c8240 | 16507 | @end smallexample |
c906108c SS |
16508 | |
16509 | @noindent | |
16510 | looks up the value of @code{x} in the scope of the file @file{foo.c}. | |
16511 | ||
16512 | @table @code | |
a8f24a35 EZ |
16513 | @cindex case-insensitive symbol names |
16514 | @cindex case sensitivity in symbol names | |
16515 | @kindex set case-sensitive | |
16516 | @item set case-sensitive on | |
16517 | @itemx set case-sensitive off | |
16518 | @itemx set case-sensitive auto | |
16519 | Normally, when @value{GDBN} looks up symbols, it matches their names | |
16520 | with case sensitivity determined by the current source language. | |
16521 | Occasionally, you may wish to control that. The command @code{set | |
16522 | case-sensitive} lets you do that by specifying @code{on} for | |
16523 | case-sensitive matches or @code{off} for case-insensitive ones. If | |
16524 | you specify @code{auto}, case sensitivity is reset to the default | |
16525 | suitable for the source language. The default is case-sensitive | |
16526 | matches for all languages except for Fortran, for which the default is | |
16527 | case-insensitive matches. | |
16528 | ||
9c16f35a EZ |
16529 | @kindex show case-sensitive |
16530 | @item show case-sensitive | |
a8f24a35 EZ |
16531 | This command shows the current setting of case sensitivity for symbols |
16532 | lookups. | |
16533 | ||
53342f27 TT |
16534 | @kindex set print type methods |
16535 | @item set print type methods | |
16536 | @itemx set print type methods on | |
16537 | @itemx set print type methods off | |
16538 | Normally, when @value{GDBN} prints a class, it displays any methods | |
16539 | declared in that class. You can control this behavior either by | |
16540 | passing the appropriate flag to @code{ptype}, or using @command{set | |
16541 | print type methods}. Specifying @code{on} will cause @value{GDBN} to | |
16542 | display the methods; this is the default. Specifying @code{off} will | |
16543 | cause @value{GDBN} to omit the methods. | |
16544 | ||
16545 | @kindex show print type methods | |
16546 | @item show print type methods | |
16547 | This command shows the current setting of method display when printing | |
16548 | classes. | |
16549 | ||
16550 | @kindex set print type typedefs | |
16551 | @item set print type typedefs | |
16552 | @itemx set print type typedefs on | |
16553 | @itemx set print type typedefs off | |
16554 | ||
16555 | Normally, when @value{GDBN} prints a class, it displays any typedefs | |
16556 | defined in that class. You can control this behavior either by | |
16557 | passing the appropriate flag to @code{ptype}, or using @command{set | |
16558 | print type typedefs}. Specifying @code{on} will cause @value{GDBN} to | |
16559 | display the typedef definitions; this is the default. Specifying | |
16560 | @code{off} will cause @value{GDBN} to omit the typedef definitions. | |
16561 | Note that this controls whether the typedef definition itself is | |
16562 | printed, not whether typedef names are substituted when printing other | |
16563 | types. | |
16564 | ||
16565 | @kindex show print type typedefs | |
16566 | @item show print type typedefs | |
16567 | This command shows the current setting of typedef display when | |
16568 | printing classes. | |
16569 | ||
c906108c | 16570 | @kindex info address |
b37052ae | 16571 | @cindex address of a symbol |
c906108c SS |
16572 | @item info address @var{symbol} |
16573 | Describe where the data for @var{symbol} is stored. For a register | |
16574 | variable, this says which register it is kept in. For a non-register | |
16575 | local variable, this prints the stack-frame offset at which the variable | |
16576 | is always stored. | |
16577 | ||
16578 | Note the contrast with @samp{print &@var{symbol}}, which does not work | |
16579 | at all for a register variable, and for a stack local variable prints | |
16580 | the exact address of the current instantiation of the variable. | |
16581 | ||
3d67e040 | 16582 | @kindex info symbol |
b37052ae | 16583 | @cindex symbol from address |
9c16f35a | 16584 | @cindex closest symbol and offset for an address |
3d67e040 EZ |
16585 | @item info symbol @var{addr} |
16586 | Print the name of a symbol which is stored at the address @var{addr}. | |
16587 | If no symbol is stored exactly at @var{addr}, @value{GDBN} prints the | |
16588 | nearest symbol and an offset from it: | |
16589 | ||
474c8240 | 16590 | @smallexample |
3d67e040 EZ |
16591 | (@value{GDBP}) info symbol 0x54320 |
16592 | _initialize_vx + 396 in section .text | |
474c8240 | 16593 | @end smallexample |
3d67e040 EZ |
16594 | |
16595 | @noindent | |
16596 | This is the opposite of the @code{info address} command. You can use | |
16597 | it to find out the name of a variable or a function given its address. | |
16598 | ||
c14c28ba PP |
16599 | For dynamically linked executables, the name of executable or shared |
16600 | library containing the symbol is also printed: | |
16601 | ||
16602 | @smallexample | |
16603 | (@value{GDBP}) info symbol 0x400225 | |
16604 | _start + 5 in section .text of /tmp/a.out | |
16605 | (@value{GDBP}) info symbol 0x2aaaac2811cf | |
16606 | __read_nocancel + 6 in section .text of /usr/lib64/libc.so.6 | |
16607 | @end smallexample | |
16608 | ||
439250fb DE |
16609 | @kindex demangle |
16610 | @cindex demangle | |
16611 | @item demangle @r{[}-l @var{language}@r{]} @r{[}@var{--}@r{]} @var{name} | |
16612 | Demangle @var{name}. | |
16613 | If @var{language} is provided it is the name of the language to demangle | |
16614 | @var{name} in. Otherwise @var{name} is demangled in the current language. | |
16615 | ||
16616 | The @samp{--} option specifies the end of options, | |
16617 | and is useful when @var{name} begins with a dash. | |
16618 | ||
16619 | The parameter @code{demangle-style} specifies how to interpret the kind | |
16620 | of mangling used. @xref{Print Settings}. | |
16621 | ||
c906108c | 16622 | @kindex whatis |
53342f27 | 16623 | @item whatis[/@var{flags}] [@var{arg}] |
177bc839 JK |
16624 | Print the data type of @var{arg}, which can be either an expression |
16625 | or a name of a data type. With no argument, print the data type of | |
16626 | @code{$}, the last value in the value history. | |
16627 | ||
16628 | If @var{arg} is an expression (@pxref{Expressions, ,Expressions}), it | |
16629 | is not actually evaluated, and any side-effecting operations (such as | |
16630 | assignments or function calls) inside it do not take place. | |
16631 | ||
16632 | If @var{arg} is a variable or an expression, @code{whatis} prints its | |
16633 | literal type as it is used in the source code. If the type was | |
16634 | defined using a @code{typedef}, @code{whatis} will @emph{not} print | |
16635 | the data type underlying the @code{typedef}. If the type of the | |
16636 | variable or the expression is a compound data type, such as | |
16637 | @code{struct} or @code{class}, @code{whatis} never prints their | |
16638 | fields or methods. It just prints the @code{struct}/@code{class} | |
16639 | name (a.k.a.@: its @dfn{tag}). If you want to see the members of | |
16640 | such a compound data type, use @code{ptype}. | |
16641 | ||
16642 | If @var{arg} is a type name that was defined using @code{typedef}, | |
16643 | @code{whatis} @dfn{unrolls} only one level of that @code{typedef}. | |
16644 | Unrolling means that @code{whatis} will show the underlying type used | |
16645 | in the @code{typedef} declaration of @var{arg}. However, if that | |
16646 | underlying type is also a @code{typedef}, @code{whatis} will not | |
16647 | unroll it. | |
16648 | ||
16649 | For C code, the type names may also have the form @samp{class | |
16650 | @var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union | |
16651 | @var{union-tag}} or @samp{enum @var{enum-tag}}. | |
c906108c | 16652 | |
53342f27 TT |
16653 | @var{flags} can be used to modify how the type is displayed. |
16654 | Available flags are: | |
16655 | ||
16656 | @table @code | |
16657 | @item r | |
16658 | Display in ``raw'' form. Normally, @value{GDBN} substitutes template | |
16659 | parameters and typedefs defined in a class when printing the class' | |
16660 | members. The @code{/r} flag disables this. | |
16661 | ||
16662 | @item m | |
16663 | Do not print methods defined in the class. | |
16664 | ||
16665 | @item M | |
16666 | Print methods defined in the class. This is the default, but the flag | |
16667 | exists in case you change the default with @command{set print type methods}. | |
16668 | ||
16669 | @item t | |
16670 | Do not print typedefs defined in the class. Note that this controls | |
16671 | whether the typedef definition itself is printed, not whether typedef | |
16672 | names are substituted when printing other types. | |
16673 | ||
16674 | @item T | |
16675 | Print typedefs defined in the class. This is the default, but the flag | |
16676 | exists in case you change the default with @command{set print type typedefs}. | |
16677 | @end table | |
16678 | ||
c906108c | 16679 | @kindex ptype |
53342f27 | 16680 | @item ptype[/@var{flags}] [@var{arg}] |
62f3a2ba FF |
16681 | @code{ptype} accepts the same arguments as @code{whatis}, but prints a |
16682 | detailed description of the type, instead of just the name of the type. | |
16683 | @xref{Expressions, ,Expressions}. | |
c906108c | 16684 | |
177bc839 JK |
16685 | Contrary to @code{whatis}, @code{ptype} always unrolls any |
16686 | @code{typedef}s in its argument declaration, whether the argument is | |
16687 | a variable, expression, or a data type. This means that @code{ptype} | |
16688 | of a variable or an expression will not print literally its type as | |
16689 | present in the source code---use @code{whatis} for that. @code{typedef}s at | |
16690 | the pointer or reference targets are also unrolled. Only @code{typedef}s of | |
16691 | fields, methods and inner @code{class typedef}s of @code{struct}s, | |
16692 | @code{class}es and @code{union}s are not unrolled even with @code{ptype}. | |
16693 | ||
c906108c SS |
16694 | For example, for this variable declaration: |
16695 | ||
474c8240 | 16696 | @smallexample |
177bc839 JK |
16697 | typedef double real_t; |
16698 | struct complex @{ real_t real; double imag; @}; | |
16699 | typedef struct complex complex_t; | |
16700 | complex_t var; | |
16701 | real_t *real_pointer_var; | |
474c8240 | 16702 | @end smallexample |
c906108c SS |
16703 | |
16704 | @noindent | |
16705 | the two commands give this output: | |
16706 | ||
474c8240 | 16707 | @smallexample |
c906108c | 16708 | @group |
177bc839 JK |
16709 | (@value{GDBP}) whatis var |
16710 | type = complex_t | |
16711 | (@value{GDBP}) ptype var | |
16712 | type = struct complex @{ | |
16713 | real_t real; | |
16714 | double imag; | |
16715 | @} | |
16716 | (@value{GDBP}) whatis complex_t | |
16717 | type = struct complex | |
16718 | (@value{GDBP}) whatis struct complex | |
c906108c | 16719 | type = struct complex |
177bc839 | 16720 | (@value{GDBP}) ptype struct complex |
c906108c | 16721 | type = struct complex @{ |
177bc839 | 16722 | real_t real; |
c906108c SS |
16723 | double imag; |
16724 | @} | |
177bc839 JK |
16725 | (@value{GDBP}) whatis real_pointer_var |
16726 | type = real_t * | |
16727 | (@value{GDBP}) ptype real_pointer_var | |
16728 | type = double * | |
c906108c | 16729 | @end group |
474c8240 | 16730 | @end smallexample |
c906108c SS |
16731 | |
16732 | @noindent | |
16733 | As with @code{whatis}, using @code{ptype} without an argument refers to | |
16734 | the type of @code{$}, the last value in the value history. | |
16735 | ||
ab1adacd EZ |
16736 | @cindex incomplete type |
16737 | Sometimes, programs use opaque data types or incomplete specifications | |
16738 | of complex data structure. If the debug information included in the | |
16739 | program does not allow @value{GDBN} to display a full declaration of | |
16740 | the data type, it will say @samp{<incomplete type>}. For example, | |
16741 | given these declarations: | |
16742 | ||
16743 | @smallexample | |
16744 | struct foo; | |
16745 | struct foo *fooptr; | |
16746 | @end smallexample | |
16747 | ||
16748 | @noindent | |
16749 | but no definition for @code{struct foo} itself, @value{GDBN} will say: | |
16750 | ||
16751 | @smallexample | |
ddb50cd7 | 16752 | (@value{GDBP}) ptype foo |
ab1adacd EZ |
16753 | $1 = <incomplete type> |
16754 | @end smallexample | |
16755 | ||
16756 | @noindent | |
16757 | ``Incomplete type'' is C terminology for data types that are not | |
16758 | completely specified. | |
16759 | ||
c906108c SS |
16760 | @kindex info types |
16761 | @item info types @var{regexp} | |
16762 | @itemx info types | |
09d4efe1 EZ |
16763 | Print a brief description of all types whose names match the regular |
16764 | expression @var{regexp} (or all types in your program, if you supply | |
16765 | no argument). Each complete typename is matched as though it were a | |
16766 | complete line; thus, @samp{i type value} gives information on all | |
16767 | types in your program whose names include the string @code{value}, but | |
16768 | @samp{i type ^value$} gives information only on types whose complete | |
16769 | name is @code{value}. | |
c906108c SS |
16770 | |
16771 | This command differs from @code{ptype} in two ways: first, like | |
16772 | @code{whatis}, it does not print a detailed description; second, it | |
16773 | lists all source files where a type is defined. | |
16774 | ||
18a9fc12 TT |
16775 | @kindex info type-printers |
16776 | @item info type-printers | |
16777 | Versions of @value{GDBN} that ship with Python scripting enabled may | |
16778 | have ``type printers'' available. When using @command{ptype} or | |
16779 | @command{whatis}, these printers are consulted when the name of a type | |
16780 | is needed. @xref{Type Printing API}, for more information on writing | |
16781 | type printers. | |
16782 | ||
16783 | @code{info type-printers} displays all the available type printers. | |
16784 | ||
16785 | @kindex enable type-printer | |
16786 | @kindex disable type-printer | |
16787 | @item enable type-printer @var{name}@dots{} | |
16788 | @item disable type-printer @var{name}@dots{} | |
16789 | These commands can be used to enable or disable type printers. | |
16790 | ||
b37052ae EZ |
16791 | @kindex info scope |
16792 | @cindex local variables | |
09d4efe1 | 16793 | @item info scope @var{location} |
b37052ae | 16794 | List all the variables local to a particular scope. This command |
09d4efe1 EZ |
16795 | accepts a @var{location} argument---a function name, a source line, or |
16796 | an address preceded by a @samp{*}, and prints all the variables local | |
2a25a5ba EZ |
16797 | to the scope defined by that location. (@xref{Specify Location}, for |
16798 | details about supported forms of @var{location}.) For example: | |
b37052ae EZ |
16799 | |
16800 | @smallexample | |
16801 | (@value{GDBP}) @b{info scope command_line_handler} | |
16802 | Scope for command_line_handler: | |
16803 | Symbol rl is an argument at stack/frame offset 8, length 4. | |
16804 | Symbol linebuffer is in static storage at address 0x150a18, length 4. | |
16805 | Symbol linelength is in static storage at address 0x150a1c, length 4. | |
16806 | Symbol p is a local variable in register $esi, length 4. | |
16807 | Symbol p1 is a local variable in register $ebx, length 4. | |
16808 | Symbol nline is a local variable in register $edx, length 4. | |
16809 | Symbol repeat is a local variable at frame offset -8, length 4. | |
16810 | @end smallexample | |
16811 | ||
f5c37c66 EZ |
16812 | @noindent |
16813 | This command is especially useful for determining what data to collect | |
16814 | during a @dfn{trace experiment}, see @ref{Tracepoint Actions, | |
16815 | collect}. | |
16816 | ||
c906108c SS |
16817 | @kindex info source |
16818 | @item info source | |
919d772c JB |
16819 | Show information about the current source file---that is, the source file for |
16820 | the function containing the current point of execution: | |
16821 | @itemize @bullet | |
16822 | @item | |
16823 | the name of the source file, and the directory containing it, | |
16824 | @item | |
16825 | the directory it was compiled in, | |
16826 | @item | |
16827 | its length, in lines, | |
16828 | @item | |
16829 | which programming language it is written in, | |
16830 | @item | |
b6577aab DE |
16831 | if the debug information provides it, the program that compiled the file |
16832 | (which may include, e.g., the compiler version and command line arguments), | |
16833 | @item | |
919d772c JB |
16834 | whether the executable includes debugging information for that file, and |
16835 | if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and | |
16836 | @item | |
16837 | whether the debugging information includes information about | |
16838 | preprocessor macros. | |
16839 | @end itemize | |
16840 | ||
c906108c SS |
16841 | |
16842 | @kindex info sources | |
16843 | @item info sources | |
16844 | Print the names of all source files in your program for which there is | |
16845 | debugging information, organized into two lists: files whose symbols | |
16846 | have already been read, and files whose symbols will be read when needed. | |
16847 | ||
16848 | @kindex info functions | |
16849 | @item info functions | |
16850 | Print the names and data types of all defined functions. | |
16851 | ||
16852 | @item info functions @var{regexp} | |
16853 | Print the names and data types of all defined functions | |
16854 | whose names contain a match for regular expression @var{regexp}. | |
16855 | Thus, @samp{info fun step} finds all functions whose names | |
16856 | include @code{step}; @samp{info fun ^step} finds those whose names | |
b383017d | 16857 | start with @code{step}. If a function name contains characters |
c1468174 | 16858 | that conflict with the regular expression language (e.g.@: |
1c5dfdad | 16859 | @samp{operator*()}), they may be quoted with a backslash. |
c906108c SS |
16860 | |
16861 | @kindex info variables | |
16862 | @item info variables | |
0fe7935b | 16863 | Print the names and data types of all variables that are defined |
6ca652b0 | 16864 | outside of functions (i.e.@: excluding local variables). |
c906108c SS |
16865 | |
16866 | @item info variables @var{regexp} | |
16867 | Print the names and data types of all variables (except for local | |
16868 | variables) whose names contain a match for regular expression | |
16869 | @var{regexp}. | |
16870 | ||
b37303ee | 16871 | @kindex info classes |
721c2651 | 16872 | @cindex Objective-C, classes and selectors |
b37303ee AF |
16873 | @item info classes |
16874 | @itemx info classes @var{regexp} | |
16875 | Display all Objective-C classes in your program, or | |
16876 | (with the @var{regexp} argument) all those matching a particular regular | |
16877 | expression. | |
16878 | ||
16879 | @kindex info selectors | |
16880 | @item info selectors | |
16881 | @itemx info selectors @var{regexp} | |
16882 | Display all Objective-C selectors in your program, or | |
16883 | (with the @var{regexp} argument) all those matching a particular regular | |
16884 | expression. | |
16885 | ||
c906108c SS |
16886 | @ignore |
16887 | This was never implemented. | |
16888 | @kindex info methods | |
16889 | @item info methods | |
16890 | @itemx info methods @var{regexp} | |
16891 | The @code{info methods} command permits the user to examine all defined | |
b37052ae EZ |
16892 | methods within C@t{++} program, or (with the @var{regexp} argument) a |
16893 | specific set of methods found in the various C@t{++} classes. Many | |
16894 | C@t{++} classes provide a large number of methods. Thus, the output | |
c906108c SS |
16895 | from the @code{ptype} command can be overwhelming and hard to use. The |
16896 | @code{info-methods} command filters the methods, printing only those | |
16897 | which match the regular-expression @var{regexp}. | |
16898 | @end ignore | |
16899 | ||
9c16f35a | 16900 | @cindex opaque data types |
c906108c SS |
16901 | @kindex set opaque-type-resolution |
16902 | @item set opaque-type-resolution on | |
16903 | Tell @value{GDBN} to resolve opaque types. An opaque type is a type | |
16904 | declared as a pointer to a @code{struct}, @code{class}, or | |
16905 | @code{union}---for example, @code{struct MyType *}---that is used in one | |
16906 | source file although the full declaration of @code{struct MyType} is in | |
16907 | another source file. The default is on. | |
16908 | ||
16909 | A change in the setting of this subcommand will not take effect until | |
16910 | the next time symbols for a file are loaded. | |
16911 | ||
16912 | @item set opaque-type-resolution off | |
16913 | Tell @value{GDBN} not to resolve opaque types. In this case, the type | |
16914 | is printed as follows: | |
16915 | @smallexample | |
16916 | @{<no data fields>@} | |
16917 | @end smallexample | |
16918 | ||
16919 | @kindex show opaque-type-resolution | |
16920 | @item show opaque-type-resolution | |
16921 | Show whether opaque types are resolved or not. | |
c906108c | 16922 | |
770e7fc7 DE |
16923 | @kindex set print symbol-loading |
16924 | @cindex print messages when symbols are loaded | |
16925 | @item set print symbol-loading | |
16926 | @itemx set print symbol-loading full | |
16927 | @itemx set print symbol-loading brief | |
16928 | @itemx set print symbol-loading off | |
16929 | The @code{set print symbol-loading} command allows you to control the | |
16930 | printing of messages when @value{GDBN} loads symbol information. | |
16931 | By default a message is printed for the executable and one for each | |
16932 | shared library, and normally this is what you want. However, when | |
16933 | debugging apps with large numbers of shared libraries these messages | |
16934 | can be annoying. | |
16935 | When set to @code{brief} a message is printed for each executable, | |
16936 | and when @value{GDBN} loads a collection of shared libraries at once | |
16937 | it will only print one message regardless of the number of shared | |
16938 | libraries. When set to @code{off} no messages are printed. | |
16939 | ||
16940 | @kindex show print symbol-loading | |
16941 | @item show print symbol-loading | |
16942 | Show whether messages will be printed when a @value{GDBN} command | |
16943 | entered from the keyboard causes symbol information to be loaded. | |
16944 | ||
c906108c SS |
16945 | @kindex maint print symbols |
16946 | @cindex symbol dump | |
16947 | @kindex maint print psymbols | |
16948 | @cindex partial symbol dump | |
7c57fa1e YQ |
16949 | @kindex maint print msymbols |
16950 | @cindex minimal symbol dump | |
c906108c SS |
16951 | @item maint print symbols @var{filename} |
16952 | @itemx maint print psymbols @var{filename} | |
16953 | @itemx maint print msymbols @var{filename} | |
16954 | Write a dump of debugging symbol data into the file @var{filename}. | |
16955 | These commands are used to debug the @value{GDBN} symbol-reading code. Only | |
16956 | symbols with debugging data are included. If you use @samp{maint print | |
16957 | symbols}, @value{GDBN} includes all the symbols for which it has already | |
16958 | collected full details: that is, @var{filename} reflects symbols for | |
16959 | only those files whose symbols @value{GDBN} has read. You can use the | |
16960 | command @code{info sources} to find out which files these are. If you | |
16961 | use @samp{maint print psymbols} instead, the dump shows information about | |
16962 | symbols that @value{GDBN} only knows partially---that is, symbols defined in | |
16963 | files that @value{GDBN} has skimmed, but not yet read completely. Finally, | |
16964 | @samp{maint print msymbols} dumps just the minimal symbol information | |
16965 | required for each object file from which @value{GDBN} has read some symbols. | |
79a6e687 | 16966 | @xref{Files, ,Commands to Specify Files}, for a discussion of how |
c906108c | 16967 | @value{GDBN} reads symbols (in the description of @code{symbol-file}). |
44ea7b70 | 16968 | |
5e7b2f39 JB |
16969 | @kindex maint info symtabs |
16970 | @kindex maint info psymtabs | |
44ea7b70 JB |
16971 | @cindex listing @value{GDBN}'s internal symbol tables |
16972 | @cindex symbol tables, listing @value{GDBN}'s internal | |
16973 | @cindex full symbol tables, listing @value{GDBN}'s internal | |
16974 | @cindex partial symbol tables, listing @value{GDBN}'s internal | |
5e7b2f39 JB |
16975 | @item maint info symtabs @r{[} @var{regexp} @r{]} |
16976 | @itemx maint info psymtabs @r{[} @var{regexp} @r{]} | |
44ea7b70 JB |
16977 | |
16978 | List the @code{struct symtab} or @code{struct partial_symtab} | |
16979 | structures whose names match @var{regexp}. If @var{regexp} is not | |
16980 | given, list them all. The output includes expressions which you can | |
16981 | copy into a @value{GDBN} debugging this one to examine a particular | |
16982 | structure in more detail. For example: | |
16983 | ||
16984 | @smallexample | |
5e7b2f39 | 16985 | (@value{GDBP}) maint info psymtabs dwarf2read |
44ea7b70 JB |
16986 | @{ objfile /home/gnu/build/gdb/gdb |
16987 | ((struct objfile *) 0x82e69d0) | |
b383017d | 16988 | @{ psymtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
16989 | ((struct partial_symtab *) 0x8474b10) |
16990 | readin no | |
16991 | fullname (null) | |
16992 | text addresses 0x814d3c8 -- 0x8158074 | |
16993 | globals (* (struct partial_symbol **) 0x8507a08 @@ 9) | |
16994 | statics (* (struct partial_symbol **) 0x40e95b78 @@ 2882) | |
16995 | dependencies (none) | |
16996 | @} | |
16997 | @} | |
5e7b2f39 | 16998 | (@value{GDBP}) maint info symtabs |
44ea7b70 JB |
16999 | (@value{GDBP}) |
17000 | @end smallexample | |
17001 | @noindent | |
17002 | We see that there is one partial symbol table whose filename contains | |
17003 | the string @samp{dwarf2read}, belonging to the @samp{gdb} executable; | |
17004 | and we see that @value{GDBN} has not read in any symtabs yet at all. | |
17005 | If we set a breakpoint on a function, that will cause @value{GDBN} to | |
17006 | read the symtab for the compilation unit containing that function: | |
17007 | ||
17008 | @smallexample | |
17009 | (@value{GDBP}) break dwarf2_psymtab_to_symtab | |
17010 | Breakpoint 1 at 0x814e5da: file /home/gnu/src/gdb/dwarf2read.c, | |
17011 | line 1574. | |
5e7b2f39 | 17012 | (@value{GDBP}) maint info symtabs |
b383017d | 17013 | @{ objfile /home/gnu/build/gdb/gdb |
44ea7b70 | 17014 | ((struct objfile *) 0x82e69d0) |
b383017d | 17015 | @{ symtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
17016 | ((struct symtab *) 0x86c1f38) |
17017 | dirname (null) | |
17018 | fullname (null) | |
17019 | blockvector ((struct blockvector *) 0x86c1bd0) (primary) | |
1b39d5c0 | 17020 | linetable ((struct linetable *) 0x8370fa0) |
44ea7b70 JB |
17021 | debugformat DWARF 2 |
17022 | @} | |
17023 | @} | |
b383017d | 17024 | (@value{GDBP}) |
44ea7b70 | 17025 | @end smallexample |
44ea7b70 | 17026 | |
f57d2163 DE |
17027 | @kindex maint set symbol-cache-size |
17028 | @cindex symbol cache size | |
17029 | @item maint set symbol-cache-size @var{size} | |
17030 | Set the size of the symbol cache to @var{size}. | |
17031 | The default size is intended to be good enough for debugging | |
17032 | most applications. This option exists to allow for experimenting | |
17033 | with different sizes. | |
17034 | ||
17035 | @kindex maint show symbol-cache-size | |
17036 | @item maint show symbol-cache-size | |
17037 | Show the size of the symbol cache. | |
17038 | ||
17039 | @kindex maint print symbol-cache | |
17040 | @cindex symbol cache, printing its contents | |
17041 | @item maint print symbol-cache | |
17042 | Print the contents of the symbol cache. | |
17043 | This is useful when debugging symbol cache issues. | |
17044 | ||
17045 | @kindex maint print symbol-cache-statistics | |
17046 | @cindex symbol cache, printing usage statistics | |
17047 | @item maint print symbol-cache-statistics | |
17048 | Print symbol cache usage statistics. | |
17049 | This helps determine how well the cache is being utilized. | |
17050 | ||
17051 | @kindex maint flush-symbol-cache | |
17052 | @cindex symbol cache, flushing | |
17053 | @item maint flush-symbol-cache | |
17054 | Flush the contents of the symbol cache, all entries are removed. | |
17055 | This command is useful when debugging the symbol cache. | |
17056 | It is also useful when collecting performance data. | |
17057 | ||
17058 | @end table | |
6a3ca067 | 17059 | |
6d2ebf8b | 17060 | @node Altering |
c906108c SS |
17061 | @chapter Altering Execution |
17062 | ||
17063 | Once you think you have found an error in your program, you might want to | |
17064 | find out for certain whether correcting the apparent error would lead to | |
17065 | correct results in the rest of the run. You can find the answer by | |
17066 | experiment, using the @value{GDBN} features for altering execution of the | |
17067 | program. | |
17068 | ||
17069 | For example, you can store new values into variables or memory | |
7a292a7a SS |
17070 | locations, give your program a signal, restart it at a different |
17071 | address, or even return prematurely from a function. | |
c906108c SS |
17072 | |
17073 | @menu | |
17074 | * Assignment:: Assignment to variables | |
17075 | * Jumping:: Continuing at a different address | |
c906108c | 17076 | * Signaling:: Giving your program a signal |
c906108c SS |
17077 | * Returning:: Returning from a function |
17078 | * Calling:: Calling your program's functions | |
17079 | * Patching:: Patching your program | |
bb2ec1b3 | 17080 | * Compiling and Injecting Code:: Compiling and injecting code in @value{GDBN} |
c906108c SS |
17081 | @end menu |
17082 | ||
6d2ebf8b | 17083 | @node Assignment |
79a6e687 | 17084 | @section Assignment to Variables |
c906108c SS |
17085 | |
17086 | @cindex assignment | |
17087 | @cindex setting variables | |
17088 | To alter the value of a variable, evaluate an assignment expression. | |
17089 | @xref{Expressions, ,Expressions}. For example, | |
17090 | ||
474c8240 | 17091 | @smallexample |
c906108c | 17092 | print x=4 |
474c8240 | 17093 | @end smallexample |
c906108c SS |
17094 | |
17095 | @noindent | |
17096 | stores the value 4 into the variable @code{x}, and then prints the | |
5d161b24 | 17097 | value of the assignment expression (which is 4). |
c906108c SS |
17098 | @xref{Languages, ,Using @value{GDBN} with Different Languages}, for more |
17099 | information on operators in supported languages. | |
c906108c SS |
17100 | |
17101 | @kindex set variable | |
17102 | @cindex variables, setting | |
17103 | If you are not interested in seeing the value of the assignment, use the | |
17104 | @code{set} command instead of the @code{print} command. @code{set} is | |
17105 | really the same as @code{print} except that the expression's value is | |
17106 | not printed and is not put in the value history (@pxref{Value History, | |
79a6e687 | 17107 | ,Value History}). The expression is evaluated only for its effects. |
c906108c | 17108 | |
c906108c SS |
17109 | If the beginning of the argument string of the @code{set} command |
17110 | appears identical to a @code{set} subcommand, use the @code{set | |
17111 | variable} command instead of just @code{set}. This command is identical | |
17112 | to @code{set} except for its lack of subcommands. For example, if your | |
17113 | program has a variable @code{width}, you get an error if you try to set | |
17114 | a new value with just @samp{set width=13}, because @value{GDBN} has the | |
17115 | command @code{set width}: | |
17116 | ||
474c8240 | 17117 | @smallexample |
c906108c SS |
17118 | (@value{GDBP}) whatis width |
17119 | type = double | |
17120 | (@value{GDBP}) p width | |
17121 | $4 = 13 | |
17122 | (@value{GDBP}) set width=47 | |
17123 | Invalid syntax in expression. | |
474c8240 | 17124 | @end smallexample |
c906108c SS |
17125 | |
17126 | @noindent | |
17127 | The invalid expression, of course, is @samp{=47}. In | |
17128 | order to actually set the program's variable @code{width}, use | |
17129 | ||
474c8240 | 17130 | @smallexample |
c906108c | 17131 | (@value{GDBP}) set var width=47 |
474c8240 | 17132 | @end smallexample |
53a5351d | 17133 | |
c906108c SS |
17134 | Because the @code{set} command has many subcommands that can conflict |
17135 | with the names of program variables, it is a good idea to use the | |
17136 | @code{set variable} command instead of just @code{set}. For example, if | |
17137 | your program has a variable @code{g}, you run into problems if you try | |
17138 | to set a new value with just @samp{set g=4}, because @value{GDBN} has | |
17139 | the command @code{set gnutarget}, abbreviated @code{set g}: | |
17140 | ||
474c8240 | 17141 | @smallexample |
c906108c SS |
17142 | @group |
17143 | (@value{GDBP}) whatis g | |
17144 | type = double | |
17145 | (@value{GDBP}) p g | |
17146 | $1 = 1 | |
17147 | (@value{GDBP}) set g=4 | |
2df3850c | 17148 | (@value{GDBP}) p g |
c906108c SS |
17149 | $2 = 1 |
17150 | (@value{GDBP}) r | |
17151 | The program being debugged has been started already. | |
17152 | Start it from the beginning? (y or n) y | |
17153 | Starting program: /home/smith/cc_progs/a.out | |
6d2ebf8b SS |
17154 | "/home/smith/cc_progs/a.out": can't open to read symbols: |
17155 | Invalid bfd target. | |
c906108c SS |
17156 | (@value{GDBP}) show g |
17157 | The current BFD target is "=4". | |
17158 | @end group | |
474c8240 | 17159 | @end smallexample |
c906108c SS |
17160 | |
17161 | @noindent | |
17162 | The program variable @code{g} did not change, and you silently set the | |
17163 | @code{gnutarget} to an invalid value. In order to set the variable | |
17164 | @code{g}, use | |
17165 | ||
474c8240 | 17166 | @smallexample |
c906108c | 17167 | (@value{GDBP}) set var g=4 |
474c8240 | 17168 | @end smallexample |
c906108c SS |
17169 | |
17170 | @value{GDBN} allows more implicit conversions in assignments than C; you can | |
17171 | freely store an integer value into a pointer variable or vice versa, | |
17172 | and you can convert any structure to any other structure that is the | |
17173 | same length or shorter. | |
17174 | @comment FIXME: how do structs align/pad in these conversions? | |
17175 | @comment /doc@cygnus.com 18dec1990 | |
17176 | ||
17177 | To store values into arbitrary places in memory, use the @samp{@{@dots{}@}} | |
17178 | construct to generate a value of specified type at a specified address | |
17179 | (@pxref{Expressions, ,Expressions}). For example, @code{@{int@}0x83040} refers | |
17180 | to memory location @code{0x83040} as an integer (which implies a certain size | |
17181 | and representation in memory), and | |
17182 | ||
474c8240 | 17183 | @smallexample |
c906108c | 17184 | set @{int@}0x83040 = 4 |
474c8240 | 17185 | @end smallexample |
c906108c SS |
17186 | |
17187 | @noindent | |
17188 | stores the value 4 into that memory location. | |
17189 | ||
6d2ebf8b | 17190 | @node Jumping |
79a6e687 | 17191 | @section Continuing at a Different Address |
c906108c SS |
17192 | |
17193 | Ordinarily, when you continue your program, you do so at the place where | |
17194 | it stopped, with the @code{continue} command. You can instead continue at | |
17195 | an address of your own choosing, with the following commands: | |
17196 | ||
17197 | @table @code | |
17198 | @kindex jump | |
c1d780c2 | 17199 | @kindex j @r{(@code{jump})} |
629500fa | 17200 | @item jump @var{location} |
c1d780c2 | 17201 | @itemx j @var{location} |
629500fa KS |
17202 | Resume execution at @var{location}. Execution stops again immediately |
17203 | if there is a breakpoint there. @xref{Specify Location}, for a description | |
17204 | of the different forms of @var{location}. It is common | |
2a25a5ba EZ |
17205 | practice to use the @code{tbreak} command in conjunction with |
17206 | @code{jump}. @xref{Set Breaks, ,Setting Breakpoints}. | |
c906108c SS |
17207 | |
17208 | The @code{jump} command does not change the current stack frame, or | |
17209 | the stack pointer, or the contents of any memory location or any | |
629500fa | 17210 | register other than the program counter. If @var{location} is in |
c906108c SS |
17211 | a different function from the one currently executing, the results may |
17212 | be bizarre if the two functions expect different patterns of arguments or | |
17213 | of local variables. For this reason, the @code{jump} command requests | |
17214 | confirmation if the specified line is not in the function currently | |
17215 | executing. However, even bizarre results are predictable if you are | |
17216 | well acquainted with the machine-language code of your program. | |
c906108c SS |
17217 | @end table |
17218 | ||
53a5351d JM |
17219 | On many systems, you can get much the same effect as the @code{jump} |
17220 | command by storing a new value into the register @code{$pc}. The | |
17221 | difference is that this does not start your program running; it only | |
17222 | changes the address of where it @emph{will} run when you continue. For | |
17223 | example, | |
c906108c | 17224 | |
474c8240 | 17225 | @smallexample |
c906108c | 17226 | set $pc = 0x485 |
474c8240 | 17227 | @end smallexample |
c906108c SS |
17228 | |
17229 | @noindent | |
17230 | makes the next @code{continue} command or stepping command execute at | |
17231 | address @code{0x485}, rather than at the address where your program stopped. | |
79a6e687 | 17232 | @xref{Continuing and Stepping, ,Continuing and Stepping}. |
c906108c SS |
17233 | |
17234 | The most common occasion to use the @code{jump} command is to back | |
17235 | up---perhaps with more breakpoints set---over a portion of a program | |
17236 | that has already executed, in order to examine its execution in more | |
17237 | detail. | |
17238 | ||
c906108c | 17239 | @c @group |
6d2ebf8b | 17240 | @node Signaling |
79a6e687 | 17241 | @section Giving your Program a Signal |
9c16f35a | 17242 | @cindex deliver a signal to a program |
c906108c SS |
17243 | |
17244 | @table @code | |
17245 | @kindex signal | |
17246 | @item signal @var{signal} | |
70509625 | 17247 | Resume execution where your program is stopped, but immediately give it the |
697aa1b7 | 17248 | signal @var{signal}. The @var{signal} can be the name or the number of a |
c906108c SS |
17249 | signal. For example, on many systems @code{signal 2} and @code{signal |
17250 | SIGINT} are both ways of sending an interrupt signal. | |
17251 | ||
17252 | Alternatively, if @var{signal} is zero, continue execution without | |
17253 | giving a signal. This is useful when your program stopped on account of | |
ae606bee | 17254 | a signal and would ordinarily see the signal when resumed with the |
c906108c SS |
17255 | @code{continue} command; @samp{signal 0} causes it to resume without a |
17256 | signal. | |
17257 | ||
70509625 PA |
17258 | @emph{Note:} When resuming a multi-threaded program, @var{signal} is |
17259 | delivered to the currently selected thread, not the thread that last | |
17260 | reported a stop. This includes the situation where a thread was | |
17261 | stopped due to a signal. So if you want to continue execution | |
17262 | suppressing the signal that stopped a thread, you should select that | |
17263 | same thread before issuing the @samp{signal 0} command. If you issue | |
17264 | the @samp{signal 0} command with another thread as the selected one, | |
17265 | @value{GDBN} detects that and asks for confirmation. | |
17266 | ||
c906108c SS |
17267 | Invoking the @code{signal} command is not the same as invoking the |
17268 | @code{kill} utility from the shell. Sending a signal with @code{kill} | |
17269 | causes @value{GDBN} to decide what to do with the signal depending on | |
17270 | the signal handling tables (@pxref{Signals}). The @code{signal} command | |
17271 | passes the signal directly to your program. | |
17272 | ||
81219e53 DE |
17273 | @code{signal} does not repeat when you press @key{RET} a second time |
17274 | after executing the command. | |
17275 | ||
17276 | @kindex queue-signal | |
17277 | @item queue-signal @var{signal} | |
17278 | Queue @var{signal} to be delivered immediately to the current thread | |
17279 | when execution of the thread resumes. The @var{signal} can be the name or | |
17280 | the number of a signal. For example, on many systems @code{signal 2} and | |
17281 | @code{signal SIGINT} are both ways of sending an interrupt signal. | |
17282 | The handling of the signal must be set to pass the signal to the program, | |
17283 | otherwise @value{GDBN} will report an error. | |
17284 | You can control the handling of signals from @value{GDBN} with the | |
17285 | @code{handle} command (@pxref{Signals}). | |
17286 | ||
17287 | Alternatively, if @var{signal} is zero, any currently queued signal | |
17288 | for the current thread is discarded and when execution resumes no signal | |
17289 | will be delivered. This is useful when your program stopped on account | |
17290 | of a signal and would ordinarily see the signal when resumed with the | |
17291 | @code{continue} command. | |
17292 | ||
17293 | This command differs from the @code{signal} command in that the signal | |
17294 | is just queued, execution is not resumed. And @code{queue-signal} cannot | |
17295 | be used to pass a signal whose handling state has been set to @code{nopass} | |
17296 | (@pxref{Signals}). | |
17297 | @end table | |
17298 | @c @end group | |
c906108c | 17299 | |
e5f8a7cc PA |
17300 | @xref{stepping into signal handlers}, for information on how stepping |
17301 | commands behave when the thread has a signal queued. | |
17302 | ||
6d2ebf8b | 17303 | @node Returning |
79a6e687 | 17304 | @section Returning from a Function |
c906108c SS |
17305 | |
17306 | @table @code | |
17307 | @cindex returning from a function | |
17308 | @kindex return | |
17309 | @item return | |
17310 | @itemx return @var{expression} | |
17311 | You can cancel execution of a function call with the @code{return} | |
17312 | command. If you give an | |
17313 | @var{expression} argument, its value is used as the function's return | |
17314 | value. | |
17315 | @end table | |
17316 | ||
17317 | When you use @code{return}, @value{GDBN} discards the selected stack frame | |
17318 | (and all frames within it). You can think of this as making the | |
17319 | discarded frame return prematurely. If you wish to specify a value to | |
17320 | be returned, give that value as the argument to @code{return}. | |
17321 | ||
17322 | This pops the selected stack frame (@pxref{Selection, ,Selecting a | |
79a6e687 | 17323 | Frame}), and any other frames inside of it, leaving its caller as the |
c906108c SS |
17324 | innermost remaining frame. That frame becomes selected. The |
17325 | specified value is stored in the registers used for returning values | |
17326 | of functions. | |
17327 | ||
17328 | The @code{return} command does not resume execution; it leaves the | |
17329 | program stopped in the state that would exist if the function had just | |
17330 | returned. In contrast, the @code{finish} command (@pxref{Continuing | |
79a6e687 | 17331 | and Stepping, ,Continuing and Stepping}) resumes execution until the |
c906108c SS |
17332 | selected stack frame returns naturally. |
17333 | ||
61ff14c6 JK |
17334 | @value{GDBN} needs to know how the @var{expression} argument should be set for |
17335 | the inferior. The concrete registers assignment depends on the OS ABI and the | |
17336 | type being returned by the selected stack frame. For example it is common for | |
17337 | OS ABI to return floating point values in FPU registers while integer values in | |
17338 | CPU registers. Still some ABIs return even floating point values in CPU | |
17339 | registers. Larger integer widths (such as @code{long long int}) also have | |
17340 | specific placement rules. @value{GDBN} already knows the OS ABI from its | |
17341 | current target so it needs to find out also the type being returned to make the | |
17342 | assignment into the right register(s). | |
17343 | ||
17344 | Normally, the selected stack frame has debug info. @value{GDBN} will always | |
17345 | use the debug info instead of the implicit type of @var{expression} when the | |
17346 | debug info is available. For example, if you type @kbd{return -1}, and the | |
17347 | function in the current stack frame is declared to return a @code{long long | |
17348 | int}, @value{GDBN} transparently converts the implicit @code{int} value of -1 | |
17349 | into a @code{long long int}: | |
17350 | ||
17351 | @smallexample | |
17352 | Breakpoint 1, func () at gdb.base/return-nodebug.c:29 | |
17353 | 29 return 31; | |
17354 | (@value{GDBP}) return -1 | |
17355 | Make func return now? (y or n) y | |
17356 | #0 0x004004f6 in main () at gdb.base/return-nodebug.c:43 | |
17357 | 43 printf ("result=%lld\n", func ()); | |
17358 | (@value{GDBP}) | |
17359 | @end smallexample | |
17360 | ||
17361 | However, if the selected stack frame does not have a debug info, e.g., if the | |
17362 | function was compiled without debug info, @value{GDBN} has to find out the type | |
17363 | to return from user. Specifying a different type by mistake may set the value | |
17364 | in different inferior registers than the caller code expects. For example, | |
17365 | typing @kbd{return -1} with its implicit type @code{int} would set only a part | |
17366 | of a @code{long long int} result for a debug info less function (on 32-bit | |
17367 | architectures). Therefore the user is required to specify the return type by | |
17368 | an appropriate cast explicitly: | |
17369 | ||
17370 | @smallexample | |
17371 | Breakpoint 2, 0x0040050b in func () | |
17372 | (@value{GDBP}) return -1 | |
17373 | Return value type not available for selected stack frame. | |
17374 | Please use an explicit cast of the value to return. | |
17375 | (@value{GDBP}) return (long long int) -1 | |
17376 | Make selected stack frame return now? (y or n) y | |
17377 | #0 0x00400526 in main () | |
17378 | (@value{GDBP}) | |
17379 | @end smallexample | |
17380 | ||
6d2ebf8b | 17381 | @node Calling |
79a6e687 | 17382 | @section Calling Program Functions |
c906108c | 17383 | |
f8568604 | 17384 | @table @code |
c906108c | 17385 | @cindex calling functions |
f8568604 EZ |
17386 | @cindex inferior functions, calling |
17387 | @item print @var{expr} | |
d3e8051b | 17388 | Evaluate the expression @var{expr} and display the resulting value. |
697aa1b7 | 17389 | The expression may include calls to functions in the program being |
f8568604 EZ |
17390 | debugged. |
17391 | ||
c906108c | 17392 | @kindex call |
c906108c SS |
17393 | @item call @var{expr} |
17394 | Evaluate the expression @var{expr} without displaying @code{void} | |
17395 | returned values. | |
c906108c SS |
17396 | |
17397 | You can use this variant of the @code{print} command if you want to | |
f8568604 EZ |
17398 | execute a function from your program that does not return anything |
17399 | (a.k.a.@: @dfn{a void function}), but without cluttering the output | |
17400 | with @code{void} returned values that @value{GDBN} will otherwise | |
17401 | print. If the result is not void, it is printed and saved in the | |
17402 | value history. | |
17403 | @end table | |
17404 | ||
9c16f35a EZ |
17405 | It is possible for the function you call via the @code{print} or |
17406 | @code{call} command to generate a signal (e.g., if there's a bug in | |
17407 | the function, or if you passed it incorrect arguments). What happens | |
17408 | in that case is controlled by the @code{set unwindonsignal} command. | |
17409 | ||
7cd1089b PM |
17410 | Similarly, with a C@t{++} program it is possible for the function you |
17411 | call via the @code{print} or @code{call} command to generate an | |
17412 | exception that is not handled due to the constraints of the dummy | |
17413 | frame. In this case, any exception that is raised in the frame, but has | |
17414 | an out-of-frame exception handler will not be found. GDB builds a | |
17415 | dummy-frame for the inferior function call, and the unwinder cannot | |
17416 | seek for exception handlers outside of this dummy-frame. What happens | |
17417 | in that case is controlled by the | |
17418 | @code{set unwind-on-terminating-exception} command. | |
17419 | ||
9c16f35a EZ |
17420 | @table @code |
17421 | @item set unwindonsignal | |
17422 | @kindex set unwindonsignal | |
17423 | @cindex unwind stack in called functions | |
17424 | @cindex call dummy stack unwinding | |
17425 | Set unwinding of the stack if a signal is received while in a function | |
17426 | that @value{GDBN} called in the program being debugged. If set to on, | |
17427 | @value{GDBN} unwinds the stack it created for the call and restores | |
17428 | the context to what it was before the call. If set to off (the | |
17429 | default), @value{GDBN} stops in the frame where the signal was | |
17430 | received. | |
17431 | ||
17432 | @item show unwindonsignal | |
17433 | @kindex show unwindonsignal | |
17434 | Show the current setting of stack unwinding in the functions called by | |
17435 | @value{GDBN}. | |
7cd1089b PM |
17436 | |
17437 | @item set unwind-on-terminating-exception | |
17438 | @kindex set unwind-on-terminating-exception | |
17439 | @cindex unwind stack in called functions with unhandled exceptions | |
17440 | @cindex call dummy stack unwinding on unhandled exception. | |
17441 | Set unwinding of the stack if a C@t{++} exception is raised, but left | |
17442 | unhandled while in a function that @value{GDBN} called in the program being | |
17443 | debugged. If set to on (the default), @value{GDBN} unwinds the stack | |
17444 | it created for the call and restores the context to what it was before | |
17445 | the call. If set to off, @value{GDBN} the exception is delivered to | |
17446 | the default C@t{++} exception handler and the inferior terminated. | |
17447 | ||
17448 | @item show unwind-on-terminating-exception | |
17449 | @kindex show unwind-on-terminating-exception | |
17450 | Show the current setting of stack unwinding in the functions called by | |
17451 | @value{GDBN}. | |
17452 | ||
9c16f35a EZ |
17453 | @end table |
17454 | ||
f8568604 EZ |
17455 | @cindex weak alias functions |
17456 | Sometimes, a function you wish to call is actually a @dfn{weak alias} | |
17457 | for another function. In such case, @value{GDBN} might not pick up | |
17458 | the type information, including the types of the function arguments, | |
17459 | which causes @value{GDBN} to call the inferior function incorrectly. | |
17460 | As a result, the called function will function erroneously and may | |
17461 | even crash. A solution to that is to use the name of the aliased | |
17462 | function instead. | |
c906108c | 17463 | |
6d2ebf8b | 17464 | @node Patching |
79a6e687 | 17465 | @section Patching Programs |
7a292a7a | 17466 | |
c906108c SS |
17467 | @cindex patching binaries |
17468 | @cindex writing into executables | |
c906108c | 17469 | @cindex writing into corefiles |
c906108c | 17470 | |
7a292a7a SS |
17471 | By default, @value{GDBN} opens the file containing your program's |
17472 | executable code (or the corefile) read-only. This prevents accidental | |
17473 | alterations to machine code; but it also prevents you from intentionally | |
17474 | patching your program's binary. | |
c906108c SS |
17475 | |
17476 | If you'd like to be able to patch the binary, you can specify that | |
17477 | explicitly with the @code{set write} command. For example, you might | |
17478 | want to turn on internal debugging flags, or even to make emergency | |
17479 | repairs. | |
17480 | ||
17481 | @table @code | |
17482 | @kindex set write | |
17483 | @item set write on | |
17484 | @itemx set write off | |
7a292a7a | 17485 | If you specify @samp{set write on}, @value{GDBN} opens executable and |
20924a55 | 17486 | core files for both reading and writing; if you specify @kbd{set write |
c906108c SS |
17487 | off} (the default), @value{GDBN} opens them read-only. |
17488 | ||
17489 | If you have already loaded a file, you must load it again (using the | |
7a292a7a SS |
17490 | @code{exec-file} or @code{core-file} command) after changing @code{set |
17491 | write}, for your new setting to take effect. | |
c906108c SS |
17492 | |
17493 | @item show write | |
17494 | @kindex show write | |
7a292a7a SS |
17495 | Display whether executable files and core files are opened for writing |
17496 | as well as reading. | |
c906108c SS |
17497 | @end table |
17498 | ||
bb2ec1b3 TT |
17499 | @node Compiling and Injecting Code |
17500 | @section Compiling and injecting code in @value{GDBN} | |
17501 | @cindex injecting code | |
17502 | @cindex writing into executables | |
17503 | @cindex compiling code | |
17504 | ||
17505 | @value{GDBN} supports on-demand compilation and code injection into | |
17506 | programs running under @value{GDBN}. GCC 5.0 or higher built with | |
17507 | @file{libcc1.so} must be installed for this functionality to be enabled. | |
17508 | This functionality is implemented with the following commands. | |
17509 | ||
17510 | @table @code | |
17511 | @kindex compile code | |
17512 | @item compile code @var{source-code} | |
17513 | @itemx compile code -raw @var{--} @var{source-code} | |
17514 | Compile @var{source-code} with the compiler language found as the current | |
17515 | language in @value{GDBN} (@pxref{Languages}). If compilation and | |
17516 | injection is not supported with the current language specified in | |
17517 | @value{GDBN}, or the compiler does not support this feature, an error | |
17518 | message will be printed. If @var{source-code} compiles and links | |
17519 | successfully, @value{GDBN} will load the object-code emitted, | |
17520 | and execute it within the context of the currently selected inferior. | |
17521 | It is important to note that the compiled code is executed immediately. | |
17522 | After execution, the compiled code is removed from @value{GDBN} and any | |
17523 | new types or variables you have defined will be deleted. | |
17524 | ||
17525 | The command allows you to specify @var{source-code} in two ways. | |
17526 | The simplest method is to provide a single line of code to the command. | |
17527 | E.g.: | |
17528 | ||
17529 | @smallexample | |
17530 | compile code printf ("hello world\n"); | |
17531 | @end smallexample | |
17532 | ||
17533 | If you specify options on the command line as well as source code, they | |
17534 | may conflict. The @samp{--} delimiter can be used to separate options | |
17535 | from actual source code. E.g.: | |
17536 | ||
17537 | @smallexample | |
17538 | compile code -r -- printf ("hello world\n"); | |
17539 | @end smallexample | |
17540 | ||
17541 | Alternatively you can enter source code as multiple lines of text. To | |
17542 | enter this mode, invoke the @samp{compile code} command without any text | |
17543 | following the command. This will start the multiple-line editor and | |
17544 | allow you to type as many lines of source code as required. When you | |
17545 | have completed typing, enter @samp{end} on its own line to exit the | |
17546 | editor. | |
17547 | ||
17548 | @smallexample | |
17549 | compile code | |
17550 | >printf ("hello\n"); | |
17551 | >printf ("world\n"); | |
17552 | >end | |
17553 | @end smallexample | |
17554 | ||
17555 | Specifying @samp{-raw}, prohibits @value{GDBN} from wrapping the | |
17556 | provided @var{source-code} in a callable scope. In this case, you must | |
17557 | specify the entry point of the code by defining a function named | |
17558 | @code{_gdb_expr_}. The @samp{-raw} code cannot access variables of the | |
17559 | inferior. Using @samp{-raw} option may be needed for example when | |
17560 | @var{source-code} requires @samp{#include} lines which may conflict with | |
17561 | inferior symbols otherwise. | |
17562 | ||
17563 | @kindex compile file | |
17564 | @item compile file @var{filename} | |
17565 | @itemx compile file -raw @var{filename} | |
17566 | Like @code{compile code}, but take the source code from @var{filename}. | |
17567 | ||
17568 | @smallexample | |
17569 | compile file /home/user/example.c | |
17570 | @end smallexample | |
17571 | @end table | |
17572 | ||
36de76f9 JK |
17573 | @table @code |
17574 | @item compile print @var{expr} | |
17575 | @itemx compile print /@var{f} @var{expr} | |
17576 | Compile and execute @var{expr} with the compiler language found as the | |
17577 | current language in @value{GDBN} (@pxref{Languages}). By default the | |
17578 | value of @var{expr} is printed in a format appropriate to its data type; | |
17579 | you can choose a different format by specifying @samp{/@var{f}}, where | |
17580 | @var{f} is a letter specifying the format; see @ref{Output Formats,,Output | |
17581 | Formats}. | |
17582 | ||
17583 | @item compile print | |
17584 | @itemx compile print /@var{f} | |
17585 | @cindex reprint the last value | |
17586 | Alternatively you can enter the expression (source code producing it) as | |
17587 | multiple lines of text. To enter this mode, invoke the @samp{compile print} | |
17588 | command without any text following the command. This will start the | |
17589 | multiple-line editor. | |
17590 | @end table | |
17591 | ||
e7a8570f JK |
17592 | @noindent |
17593 | The process of compiling and injecting the code can be inspected using: | |
17594 | ||
17595 | @table @code | |
17596 | @anchor{set debug compile} | |
17597 | @item set debug compile | |
17598 | @cindex compile command debugging info | |
17599 | Turns on or off display of @value{GDBN} process of compiling and | |
17600 | injecting the code. The default is off. | |
17601 | ||
17602 | @item show debug compile | |
17603 | Displays the current state of displaying @value{GDBN} process of | |
17604 | compiling and injecting the code. | |
17605 | @end table | |
17606 | ||
17607 | @subsection Compilation options for the @code{compile} command | |
17608 | ||
17609 | @value{GDBN} needs to specify the right compilation options for the code | |
17610 | to be injected, in part to make its ABI compatible with the inferior | |
17611 | and in part to make the injected code compatible with @value{GDBN}'s | |
17612 | injecting process. | |
17613 | ||
17614 | @noindent | |
17615 | The options used, in increasing precedence: | |
17616 | ||
17617 | @table @asis | |
17618 | @item target architecture and OS options (@code{gdbarch}) | |
17619 | These options depend on target processor type and target operating | |
17620 | system, usually they specify at least 32-bit (@code{-m32}) or 64-bit | |
17621 | (@code{-m64}) compilation option. | |
17622 | ||
17623 | @item compilation options recorded in the target | |
17624 | @value{NGCC} (since version 4.7) stores the options used for compilation | |
17625 | into @code{DW_AT_producer} part of DWARF debugging information according | |
17626 | to the @value{NGCC} option @code{-grecord-gcc-switches}. One has to | |
17627 | explicitly specify @code{-g} during inferior compilation otherwise | |
17628 | @value{NGCC} produces no DWARF. This feature is only relevant for | |
17629 | platforms where @code{-g} produces DWARF by default, otherwise one may | |
17630 | try to enforce DWARF by using @code{-gdwarf-4}. | |
17631 | ||
17632 | @item compilation options set by @code{set compile-args} | |
17633 | @end table | |
17634 | ||
17635 | @noindent | |
17636 | You can override compilation options using the following command: | |
17637 | ||
17638 | @table @code | |
17639 | @item set compile-args | |
17640 | @cindex compile command options override | |
17641 | Set compilation options used for compiling and injecting code with the | |
17642 | @code{compile} commands. These options override any conflicting ones | |
17643 | from the target architecture and/or options stored during inferior | |
17644 | compilation. | |
17645 | ||
17646 | @item show compile-args | |
17647 | Displays the current state of compilation options override. | |
17648 | This does not show all the options actually used during compilation, | |
17649 | use @ref{set debug compile} for that. | |
17650 | @end table | |
17651 | ||
bb2ec1b3 TT |
17652 | @subsection Caveats when using the @code{compile} command |
17653 | ||
17654 | There are a few caveats to keep in mind when using the @code{compile} | |
17655 | command. As the caveats are different per language, the table below | |
17656 | highlights specific issues on a per language basis. | |
17657 | ||
17658 | @table @asis | |
17659 | @item C code examples and caveats | |
17660 | When the language in @value{GDBN} is set to @samp{C}, the compiler will | |
17661 | attempt to compile the source code with a @samp{C} compiler. The source | |
17662 | code provided to the @code{compile} command will have much the same | |
17663 | access to variables and types as it normally would if it were part of | |
17664 | the program currently being debugged in @value{GDBN}. | |
17665 | ||
17666 | Below is a sample program that forms the basis of the examples that | |
17667 | follow. This program has been compiled and loaded into @value{GDBN}, | |
17668 | much like any other normal debugging session. | |
17669 | ||
17670 | @smallexample | |
17671 | void function1 (void) | |
17672 | @{ | |
17673 | int i = 42; | |
17674 | printf ("function 1\n"); | |
17675 | @} | |
17676 | ||
17677 | void function2 (void) | |
17678 | @{ | |
17679 | int j = 12; | |
17680 | function1 (); | |
17681 | @} | |
17682 | ||
17683 | int main(void) | |
17684 | @{ | |
17685 | int k = 6; | |
17686 | int *p; | |
17687 | function2 (); | |
17688 | return 0; | |
17689 | @} | |
17690 | @end smallexample | |
17691 | ||
17692 | For the purposes of the examples in this section, the program above has | |
17693 | been compiled, loaded into @value{GDBN}, stopped at the function | |
17694 | @code{main}, and @value{GDBN} is awaiting input from the user. | |
17695 | ||
17696 | To access variables and types for any program in @value{GDBN}, the | |
17697 | program must be compiled and packaged with debug information. The | |
17698 | @code{compile} command is not an exception to this rule. Without debug | |
17699 | information, you can still use the @code{compile} command, but you will | |
17700 | be very limited in what variables and types you can access. | |
17701 | ||
17702 | So with that in mind, the example above has been compiled with debug | |
17703 | information enabled. The @code{compile} command will have access to | |
17704 | all variables and types (except those that may have been optimized | |
17705 | out). Currently, as @value{GDBN} has stopped the program in the | |
17706 | @code{main} function, the @code{compile} command would have access to | |
17707 | the variable @code{k}. You could invoke the @code{compile} command | |
17708 | and type some source code to set the value of @code{k}. You can also | |
17709 | read it, or do anything with that variable you would normally do in | |
17710 | @code{C}. Be aware that changes to inferior variables in the | |
17711 | @code{compile} command are persistent. In the following example: | |
17712 | ||
17713 | @smallexample | |
17714 | compile code k = 3; | |
17715 | @end smallexample | |
17716 | ||
17717 | @noindent | |
17718 | the variable @code{k} is now 3. It will retain that value until | |
17719 | something else in the example program changes it, or another | |
17720 | @code{compile} command changes it. | |
17721 | ||
17722 | Normal scope and access rules apply to source code compiled and | |
17723 | injected by the @code{compile} command. In the example, the variables | |
17724 | @code{j} and @code{k} are not accessible yet, because the program is | |
17725 | currently stopped in the @code{main} function, where these variables | |
17726 | are not in scope. Therefore, the following command | |
17727 | ||
17728 | @smallexample | |
17729 | compile code j = 3; | |
17730 | @end smallexample | |
17731 | ||
17732 | @noindent | |
17733 | will result in a compilation error message. | |
17734 | ||
17735 | Once the program is continued, execution will bring these variables in | |
17736 | scope, and they will become accessible; then the code you specify via | |
17737 | the @code{compile} command will be able to access them. | |
17738 | ||
17739 | You can create variables and types with the @code{compile} command as | |
17740 | part of your source code. Variables and types that are created as part | |
17741 | of the @code{compile} command are not visible to the rest of the program for | |
17742 | the duration of its run. This example is valid: | |
17743 | ||
17744 | @smallexample | |
17745 | compile code int ff = 5; printf ("ff is %d\n", ff); | |
17746 | @end smallexample | |
17747 | ||
17748 | However, if you were to type the following into @value{GDBN} after that | |
17749 | command has completed: | |
17750 | ||
17751 | @smallexample | |
17752 | compile code printf ("ff is %d\n'', ff); | |
17753 | @end smallexample | |
17754 | ||
17755 | @noindent | |
17756 | a compiler error would be raised as the variable @code{ff} no longer | |
17757 | exists. Object code generated and injected by the @code{compile} | |
17758 | command is removed when its execution ends. Caution is advised | |
17759 | when assigning to program variables values of variables created by the | |
17760 | code submitted to the @code{compile} command. This example is valid: | |
17761 | ||
17762 | @smallexample | |
17763 | compile code int ff = 5; k = ff; | |
17764 | @end smallexample | |
17765 | ||
17766 | The value of the variable @code{ff} is assigned to @code{k}. The variable | |
17767 | @code{k} does not require the existence of @code{ff} to maintain the value | |
17768 | it has been assigned. However, pointers require particular care in | |
17769 | assignment. If the source code compiled with the @code{compile} command | |
17770 | changed the address of a pointer in the example program, perhaps to a | |
17771 | variable created in the @code{compile} command, that pointer would point | |
17772 | to an invalid location when the command exits. The following example | |
17773 | would likely cause issues with your debugged program: | |
17774 | ||
17775 | @smallexample | |
17776 | compile code int ff = 5; p = &ff; | |
17777 | @end smallexample | |
17778 | ||
17779 | In this example, @code{p} would point to @code{ff} when the | |
17780 | @code{compile} command is executing the source code provided to it. | |
17781 | However, as variables in the (example) program persist with their | |
17782 | assigned values, the variable @code{p} would point to an invalid | |
17783 | location when the command exists. A general rule should be followed | |
17784 | in that you should either assign @code{NULL} to any assigned pointers, | |
17785 | or restore a valid location to the pointer before the command exits. | |
17786 | ||
17787 | Similar caution must be exercised with any structs, unions, and typedefs | |
17788 | defined in @code{compile} command. Types defined in the @code{compile} | |
17789 | command will no longer be available in the next @code{compile} command. | |
17790 | Therefore, if you cast a variable to a type defined in the | |
17791 | @code{compile} command, care must be taken to ensure that any future | |
17792 | need to resolve the type can be achieved. | |
17793 | ||
17794 | @smallexample | |
17795 | (gdb) compile code static struct a @{ int a; @} v = @{ 42 @}; argv = &v; | |
17796 | (gdb) compile code printf ("%d\n", ((struct a *) argv)->a); | |
17797 | gdb command line:1:36: error: dereferencing pointer to incomplete type ‘struct a’ | |
17798 | Compilation failed. | |
17799 | (gdb) compile code struct a @{ int a; @}; printf ("%d\n", ((struct a *) argv)->a); | |
17800 | 42 | |
17801 | @end smallexample | |
17802 | ||
17803 | Variables that have been optimized away by the compiler are not | |
17804 | accessible to the code submitted to the @code{compile} command. | |
17805 | Access to those variables will generate a compiler error which @value{GDBN} | |
17806 | will print to the console. | |
17807 | @end table | |
17808 | ||
e7a8570f JK |
17809 | @subsection Compiler search for the @code{compile} command |
17810 | ||
17811 | @value{GDBN} needs to find @value{NGCC} for the inferior being debugged which | |
17812 | may not be obvious for remote targets of different architecture than where | |
17813 | @value{GDBN} is running. Environment variable @code{PATH} (@code{PATH} from | |
17814 | shell that executed @value{GDBN}, not the one set by @value{GDBN} | |
17815 | command @code{set environment}). @xref{Environment}. @code{PATH} on | |
17816 | @value{GDBN} host is searched for @value{NGCC} binary matching the | |
17817 | target architecture and operating system. | |
17818 | ||
17819 | Specifically @code{PATH} is searched for binaries matching regular expression | |
17820 | @code{@var{arch}(-[^-]*)?-@var{os}-gcc} according to the inferior target being | |
17821 | debugged. @var{arch} is processor name --- multiarch is supported, so for | |
17822 | example both @code{i386} and @code{x86_64} targets look for pattern | |
17823 | @code{(x86_64|i.86)} and both @code{s390} and @code{s390x} targets look | |
17824 | for pattern @code{s390x?}. @var{os} is currently supported only for | |
17825 | pattern @code{linux(-gnu)?}. | |
17826 | ||
6d2ebf8b | 17827 | @node GDB Files |
c906108c SS |
17828 | @chapter @value{GDBN} Files |
17829 | ||
7a292a7a SS |
17830 | @value{GDBN} needs to know the file name of the program to be debugged, |
17831 | both in order to read its symbol table and in order to start your | |
17832 | program. To debug a core dump of a previous run, you must also tell | |
17833 | @value{GDBN} the name of the core dump file. | |
c906108c SS |
17834 | |
17835 | @menu | |
17836 | * Files:: Commands to specify files | |
2b4bf6af | 17837 | * File Caching:: Information about @value{GDBN}'s file caching |
5b5d99cf | 17838 | * Separate Debug Files:: Debugging information in separate files |
608e2dbb | 17839 | * MiniDebugInfo:: Debugging information in a special section |
9291a0cd | 17840 | * Index Files:: Index files speed up GDB |
c906108c | 17841 | * Symbol Errors:: Errors reading symbol files |
b14b1491 | 17842 | * Data Files:: GDB data files |
c906108c SS |
17843 | @end menu |
17844 | ||
6d2ebf8b | 17845 | @node Files |
79a6e687 | 17846 | @section Commands to Specify Files |
c906108c | 17847 | |
7a292a7a | 17848 | @cindex symbol table |
c906108c | 17849 | @cindex core dump file |
7a292a7a SS |
17850 | |
17851 | You may want to specify executable and core dump file names. The usual | |
17852 | way to do this is at start-up time, using the arguments to | |
17853 | @value{GDBN}'s start-up commands (@pxref{Invocation, , Getting In and | |
17854 | Out of @value{GDBN}}). | |
c906108c SS |
17855 | |
17856 | Occasionally it is necessary to change to a different file during a | |
397ca115 EZ |
17857 | @value{GDBN} session. Or you may run @value{GDBN} and forget to |
17858 | specify a file you want to use. Or you are debugging a remote target | |
79a6e687 BW |
17859 | via @code{gdbserver} (@pxref{Server, file, Using the @code{gdbserver} |
17860 | Program}). In these situations the @value{GDBN} commands to specify | |
0869d01b | 17861 | new files are useful. |
c906108c SS |
17862 | |
17863 | @table @code | |
17864 | @cindex executable file | |
17865 | @kindex file | |
17866 | @item file @var{filename} | |
17867 | Use @var{filename} as the program to be debugged. It is read for its | |
17868 | symbols and for the contents of pure memory. It is also the program | |
17869 | executed when you use the @code{run} command. If you do not specify a | |
5d161b24 DB |
17870 | directory and the file is not found in the @value{GDBN} working directory, |
17871 | @value{GDBN} uses the environment variable @code{PATH} as a list of | |
17872 | directories to search, just as the shell does when looking for a program | |
17873 | to run. You can change the value of this variable, for both @value{GDBN} | |
c906108c SS |
17874 | and your program, using the @code{path} command. |
17875 | ||
fc8be69e EZ |
17876 | @cindex unlinked object files |
17877 | @cindex patching object files | |
17878 | You can load unlinked object @file{.o} files into @value{GDBN} using | |
17879 | the @code{file} command. You will not be able to ``run'' an object | |
17880 | file, but you can disassemble functions and inspect variables. Also, | |
17881 | if the underlying BFD functionality supports it, you could use | |
17882 | @kbd{gdb -write} to patch object files using this technique. Note | |
17883 | that @value{GDBN} can neither interpret nor modify relocations in this | |
17884 | case, so branches and some initialized variables will appear to go to | |
17885 | the wrong place. But this feature is still handy from time to time. | |
17886 | ||
c906108c SS |
17887 | @item file |
17888 | @code{file} with no argument makes @value{GDBN} discard any information it | |
17889 | has on both executable file and the symbol table. | |
17890 | ||
17891 | @kindex exec-file | |
17892 | @item exec-file @r{[} @var{filename} @r{]} | |
17893 | Specify that the program to be run (but not the symbol table) is found | |
17894 | in @var{filename}. @value{GDBN} searches the environment variable @code{PATH} | |
17895 | if necessary to locate your program. Omitting @var{filename} means to | |
17896 | discard information on the executable file. | |
17897 | ||
17898 | @kindex symbol-file | |
17899 | @item symbol-file @r{[} @var{filename} @r{]} | |
17900 | Read symbol table information from file @var{filename}. @code{PATH} is | |
17901 | searched when necessary. Use the @code{file} command to get both symbol | |
17902 | table and program to run from the same file. | |
17903 | ||
17904 | @code{symbol-file} with no argument clears out @value{GDBN} information on your | |
17905 | program's symbol table. | |
17906 | ||
ae5a43e0 DJ |
17907 | The @code{symbol-file} command causes @value{GDBN} to forget the contents of |
17908 | some breakpoints and auto-display expressions. This is because they may | |
17909 | contain pointers to the internal data recording symbols and data types, | |
17910 | which are part of the old symbol table data being discarded inside | |
17911 | @value{GDBN}. | |
c906108c SS |
17912 | |
17913 | @code{symbol-file} does not repeat if you press @key{RET} again after | |
17914 | executing it once. | |
17915 | ||
17916 | When @value{GDBN} is configured for a particular environment, it | |
17917 | understands debugging information in whatever format is the standard | |
17918 | generated for that environment; you may use either a @sc{gnu} compiler, or | |
17919 | other compilers that adhere to the local conventions. | |
c906108c | 17920 | Best results are usually obtained from @sc{gnu} compilers; for example, |
e22ea452 | 17921 | using @code{@value{NGCC}} you can generate debugging information for |
c906108c | 17922 | optimized code. |
c906108c SS |
17923 | |
17924 | For most kinds of object files, with the exception of old SVR3 systems | |
17925 | using COFF, the @code{symbol-file} command does not normally read the | |
17926 | symbol table in full right away. Instead, it scans the symbol table | |
17927 | quickly to find which source files and which symbols are present. The | |
17928 | details are read later, one source file at a time, as they are needed. | |
17929 | ||
17930 | The purpose of this two-stage reading strategy is to make @value{GDBN} | |
17931 | start up faster. For the most part, it is invisible except for | |
17932 | occasional pauses while the symbol table details for a particular source | |
17933 | file are being read. (The @code{set verbose} command can turn these | |
17934 | pauses into messages if desired. @xref{Messages/Warnings, ,Optional | |
79a6e687 | 17935 | Warnings and Messages}.) |
c906108c | 17936 | |
c906108c SS |
17937 | We have not implemented the two-stage strategy for COFF yet. When the |
17938 | symbol table is stored in COFF format, @code{symbol-file} reads the | |
17939 | symbol table data in full right away. Note that ``stabs-in-COFF'' | |
17940 | still does the two-stage strategy, since the debug info is actually | |
17941 | in stabs format. | |
17942 | ||
17943 | @kindex readnow | |
17944 | @cindex reading symbols immediately | |
17945 | @cindex symbols, reading immediately | |
6ac33a4e TT |
17946 | @item symbol-file @r{[} -readnow @r{]} @var{filename} |
17947 | @itemx file @r{[} -readnow @r{]} @var{filename} | |
c906108c SS |
17948 | You can override the @value{GDBN} two-stage strategy for reading symbol |
17949 | tables by using the @samp{-readnow} option with any of the commands that | |
17950 | load symbol table information, if you want to be sure @value{GDBN} has the | |
5d161b24 | 17951 | entire symbol table available. |
c906108c | 17952 | |
c906108c SS |
17953 | @c FIXME: for now no mention of directories, since this seems to be in |
17954 | @c flux. 13mar1992 status is that in theory GDB would look either in | |
17955 | @c current dir or in same dir as myprog; but issues like competing | |
17956 | @c GDB's, or clutter in system dirs, mean that in practice right now | |
17957 | @c only current dir is used. FFish says maybe a special GDB hierarchy | |
17958 | @c (eg rooted in val of env var GDBSYMS) could exist for mappable symbol | |
17959 | @c files. | |
17960 | ||
c906108c | 17961 | @kindex core-file |
09d4efe1 | 17962 | @item core-file @r{[}@var{filename}@r{]} |
4644b6e3 | 17963 | @itemx core |
c906108c SS |
17964 | Specify the whereabouts of a core dump file to be used as the ``contents |
17965 | of memory''. Traditionally, core files contain only some parts of the | |
17966 | address space of the process that generated them; @value{GDBN} can access the | |
17967 | executable file itself for other parts. | |
17968 | ||
17969 | @code{core-file} with no argument specifies that no core file is | |
17970 | to be used. | |
17971 | ||
17972 | Note that the core file is ignored when your program is actually running | |
7a292a7a SS |
17973 | under @value{GDBN}. So, if you have been running your program and you |
17974 | wish to debug a core file instead, you must kill the subprocess in which | |
17975 | the program is running. To do this, use the @code{kill} command | |
79a6e687 | 17976 | (@pxref{Kill Process, ,Killing the Child Process}). |
c906108c | 17977 | |
c906108c SS |
17978 | @kindex add-symbol-file |
17979 | @cindex dynamic linking | |
17980 | @item add-symbol-file @var{filename} @var{address} | |
a94ab193 | 17981 | @itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} |
24bdad53 | 17982 | @itemx add-symbol-file @var{filename} @var{address} -s @var{section} @var{address} @dots{} |
96a2c332 SS |
17983 | The @code{add-symbol-file} command reads additional symbol table |
17984 | information from the file @var{filename}. You would use this command | |
17985 | when @var{filename} has been dynamically loaded (by some other means) | |
697aa1b7 | 17986 | into the program that is running. The @var{address} should give the memory |
96a2c332 | 17987 | address at which the file has been loaded; @value{GDBN} cannot figure |
d167840f | 17988 | this out for itself. You can additionally specify an arbitrary number |
24bdad53 | 17989 | of @samp{-s @var{section} @var{address}} pairs, to give an explicit |
d167840f EZ |
17990 | section name and base address for that section. You can specify any |
17991 | @var{address} as an expression. | |
c906108c SS |
17992 | |
17993 | The symbol table of the file @var{filename} is added to the symbol table | |
17994 | originally read with the @code{symbol-file} command. You can use the | |
96a2c332 | 17995 | @code{add-symbol-file} command any number of times; the new symbol data |
98297bf6 NB |
17996 | thus read is kept in addition to the old. |
17997 | ||
17998 | Changes can be reverted using the command @code{remove-symbol-file}. | |
c906108c | 17999 | |
17d9d558 JB |
18000 | @cindex relocatable object files, reading symbols from |
18001 | @cindex object files, relocatable, reading symbols from | |
18002 | @cindex reading symbols from relocatable object files | |
18003 | @cindex symbols, reading from relocatable object files | |
18004 | @cindex @file{.o} files, reading symbols from | |
18005 | Although @var{filename} is typically a shared library file, an | |
18006 | executable file, or some other object file which has been fully | |
18007 | relocated for loading into a process, you can also load symbolic | |
18008 | information from relocatable @file{.o} files, as long as: | |
18009 | ||
18010 | @itemize @bullet | |
18011 | @item | |
18012 | the file's symbolic information refers only to linker symbols defined in | |
18013 | that file, not to symbols defined by other object files, | |
18014 | @item | |
18015 | every section the file's symbolic information refers to has actually | |
18016 | been loaded into the inferior, as it appears in the file, and | |
18017 | @item | |
18018 | you can determine the address at which every section was loaded, and | |
18019 | provide these to the @code{add-symbol-file} command. | |
18020 | @end itemize | |
18021 | ||
18022 | @noindent | |
18023 | Some embedded operating systems, like Sun Chorus and VxWorks, can load | |
18024 | relocatable files into an already running program; such systems | |
18025 | typically make the requirements above easy to meet. However, it's | |
18026 | important to recognize that many native systems use complex link | |
49efadf5 | 18027 | procedures (@code{.linkonce} section factoring and C@t{++} constructor table |
17d9d558 JB |
18028 | assembly, for example) that make the requirements difficult to meet. In |
18029 | general, one cannot assume that using @code{add-symbol-file} to read a | |
18030 | relocatable object file's symbolic information will have the same effect | |
18031 | as linking the relocatable object file into the program in the normal | |
18032 | way. | |
18033 | ||
c906108c SS |
18034 | @code{add-symbol-file} does not repeat if you press @key{RET} after using it. |
18035 | ||
98297bf6 NB |
18036 | @kindex remove-symbol-file |
18037 | @item remove-symbol-file @var{filename} | |
18038 | @item remove-symbol-file -a @var{address} | |
18039 | Remove a symbol file added via the @code{add-symbol-file} command. The | |
18040 | file to remove can be identified by its @var{filename} or by an @var{address} | |
18041 | that lies within the boundaries of this symbol file in memory. Example: | |
18042 | ||
18043 | @smallexample | |
18044 | (gdb) add-symbol-file /home/user/gdb/mylib.so 0x7ffff7ff9480 | |
18045 | add symbol table from file "/home/user/gdb/mylib.so" at | |
18046 | .text_addr = 0x7ffff7ff9480 | |
18047 | (y or n) y | |
18048 | Reading symbols from /home/user/gdb/mylib.so...done. | |
18049 | (gdb) remove-symbol-file -a 0x7ffff7ff9480 | |
18050 | Remove symbol table from file "/home/user/gdb/mylib.so"? (y or n) y | |
18051 | (gdb) | |
18052 | @end smallexample | |
18053 | ||
18054 | ||
18055 | @code{remove-symbol-file} does not repeat if you press @key{RET} after using it. | |
18056 | ||
c45da7e6 EZ |
18057 | @kindex add-symbol-file-from-memory |
18058 | @cindex @code{syscall DSO} | |
18059 | @cindex load symbols from memory | |
18060 | @item add-symbol-file-from-memory @var{address} | |
18061 | Load symbols from the given @var{address} in a dynamically loaded | |
18062 | object file whose image is mapped directly into the inferior's memory. | |
18063 | For example, the Linux kernel maps a @code{syscall DSO} into each | |
18064 | process's address space; this DSO provides kernel-specific code for | |
18065 | some system calls. The argument can be any expression whose | |
18066 | evaluation yields the address of the file's shared object file header. | |
18067 | For this command to work, you must have used @code{symbol-file} or | |
18068 | @code{exec-file} commands in advance. | |
18069 | ||
c906108c | 18070 | @kindex section |
09d4efe1 EZ |
18071 | @item section @var{section} @var{addr} |
18072 | The @code{section} command changes the base address of the named | |
18073 | @var{section} of the exec file to @var{addr}. This can be used if the | |
18074 | exec file does not contain section addresses, (such as in the | |
18075 | @code{a.out} format), or when the addresses specified in the file | |
18076 | itself are wrong. Each section must be changed separately. The | |
18077 | @code{info files} command, described below, lists all the sections and | |
18078 | their addresses. | |
c906108c SS |
18079 | |
18080 | @kindex info files | |
18081 | @kindex info target | |
18082 | @item info files | |
18083 | @itemx info target | |
7a292a7a SS |
18084 | @code{info files} and @code{info target} are synonymous; both print the |
18085 | current target (@pxref{Targets, ,Specifying a Debugging Target}), | |
18086 | including the names of the executable and core dump files currently in | |
18087 | use by @value{GDBN}, and the files from which symbols were loaded. The | |
18088 | command @code{help target} lists all possible targets rather than | |
18089 | current ones. | |
18090 | ||
fe95c787 MS |
18091 | @kindex maint info sections |
18092 | @item maint info sections | |
18093 | Another command that can give you extra information about program sections | |
18094 | is @code{maint info sections}. In addition to the section information | |
18095 | displayed by @code{info files}, this command displays the flags and file | |
18096 | offset of each section in the executable and core dump files. In addition, | |
18097 | @code{maint info sections} provides the following command options (which | |
18098 | may be arbitrarily combined): | |
18099 | ||
18100 | @table @code | |
18101 | @item ALLOBJ | |
18102 | Display sections for all loaded object files, including shared libraries. | |
18103 | @item @var{sections} | |
6600abed | 18104 | Display info only for named @var{sections}. |
fe95c787 MS |
18105 | @item @var{section-flags} |
18106 | Display info only for sections for which @var{section-flags} are true. | |
18107 | The section flags that @value{GDBN} currently knows about are: | |
18108 | @table @code | |
18109 | @item ALLOC | |
18110 | Section will have space allocated in the process when loaded. | |
18111 | Set for all sections except those containing debug information. | |
18112 | @item LOAD | |
18113 | Section will be loaded from the file into the child process memory. | |
18114 | Set for pre-initialized code and data, clear for @code{.bss} sections. | |
18115 | @item RELOC | |
18116 | Section needs to be relocated before loading. | |
18117 | @item READONLY | |
18118 | Section cannot be modified by the child process. | |
18119 | @item CODE | |
18120 | Section contains executable code only. | |
6600abed | 18121 | @item DATA |
fe95c787 MS |
18122 | Section contains data only (no executable code). |
18123 | @item ROM | |
18124 | Section will reside in ROM. | |
18125 | @item CONSTRUCTOR | |
18126 | Section contains data for constructor/destructor lists. | |
18127 | @item HAS_CONTENTS | |
18128 | Section is not empty. | |
18129 | @item NEVER_LOAD | |
18130 | An instruction to the linker to not output the section. | |
18131 | @item COFF_SHARED_LIBRARY | |
18132 | A notification to the linker that the section contains | |
18133 | COFF shared library information. | |
18134 | @item IS_COMMON | |
18135 | Section contains common symbols. | |
18136 | @end table | |
18137 | @end table | |
6763aef9 | 18138 | @kindex set trust-readonly-sections |
9c16f35a | 18139 | @cindex read-only sections |
6763aef9 MS |
18140 | @item set trust-readonly-sections on |
18141 | Tell @value{GDBN} that readonly sections in your object file | |
6ca652b0 | 18142 | really are read-only (i.e.@: that their contents will not change). |
6763aef9 MS |
18143 | In that case, @value{GDBN} can fetch values from these sections |
18144 | out of the object file, rather than from the target program. | |
18145 | For some targets (notably embedded ones), this can be a significant | |
18146 | enhancement to debugging performance. | |
18147 | ||
18148 | The default is off. | |
18149 | ||
18150 | @item set trust-readonly-sections off | |
15110bc3 | 18151 | Tell @value{GDBN} not to trust readonly sections. This means that |
6763aef9 MS |
18152 | the contents of the section might change while the program is running, |
18153 | and must therefore be fetched from the target when needed. | |
9c16f35a EZ |
18154 | |
18155 | @item show trust-readonly-sections | |
18156 | Show the current setting of trusting readonly sections. | |
c906108c SS |
18157 | @end table |
18158 | ||
18159 | All file-specifying commands allow both absolute and relative file names | |
18160 | as arguments. @value{GDBN} always converts the file name to an absolute file | |
18161 | name and remembers it that way. | |
18162 | ||
c906108c | 18163 | @cindex shared libraries |
9cceb671 | 18164 | @anchor{Shared Libraries} |
b1236ac3 PA |
18165 | @value{GDBN} supports @sc{gnu}/Linux, MS-Windows, SunOS, |
18166 | Darwin/Mach-O, SVr4, IBM RS/6000 AIX, QNX Neutrino, FDPIC (FR-V), and | |
18167 | DSBT (TIC6X) shared libraries. | |
53a5351d | 18168 | |
9cceb671 DJ |
18169 | On MS-Windows @value{GDBN} must be linked with the Expat library to support |
18170 | shared libraries. @xref{Expat}. | |
18171 | ||
c906108c SS |
18172 | @value{GDBN} automatically loads symbol definitions from shared libraries |
18173 | when you use the @code{run} command, or when you examine a core file. | |
18174 | (Before you issue the @code{run} command, @value{GDBN} does not understand | |
18175 | references to a function in a shared library, however---unless you are | |
18176 | debugging a core file). | |
53a5351d | 18177 | |
c906108c SS |
18178 | @c FIXME: some @value{GDBN} release may permit some refs to undef |
18179 | @c FIXME...symbols---eg in a break cmd---assuming they are from a shared | |
18180 | @c FIXME...lib; check this from time to time when updating manual | |
18181 | ||
b7209cb4 FF |
18182 | There are times, however, when you may wish to not automatically load |
18183 | symbol definitions from shared libraries, such as when they are | |
18184 | particularly large or there are many of them. | |
18185 | ||
18186 | To control the automatic loading of shared library symbols, use the | |
18187 | commands: | |
18188 | ||
18189 | @table @code | |
18190 | @kindex set auto-solib-add | |
18191 | @item set auto-solib-add @var{mode} | |
18192 | If @var{mode} is @code{on}, symbols from all shared object libraries | |
18193 | will be loaded automatically when the inferior begins execution, you | |
18194 | attach to an independently started inferior, or when the dynamic linker | |
18195 | informs @value{GDBN} that a new library has been loaded. If @var{mode} | |
18196 | is @code{off}, symbols must be loaded manually, using the | |
18197 | @code{sharedlibrary} command. The default value is @code{on}. | |
18198 | ||
dcaf7c2c EZ |
18199 | @cindex memory used for symbol tables |
18200 | If your program uses lots of shared libraries with debug info that | |
18201 | takes large amounts of memory, you can decrease the @value{GDBN} | |
18202 | memory footprint by preventing it from automatically loading the | |
18203 | symbols from shared libraries. To that end, type @kbd{set | |
18204 | auto-solib-add off} before running the inferior, then load each | |
18205 | library whose debug symbols you do need with @kbd{sharedlibrary | |
d3e8051b | 18206 | @var{regexp}}, where @var{regexp} is a regular expression that matches |
dcaf7c2c EZ |
18207 | the libraries whose symbols you want to be loaded. |
18208 | ||
b7209cb4 FF |
18209 | @kindex show auto-solib-add |
18210 | @item show auto-solib-add | |
18211 | Display the current autoloading mode. | |
18212 | @end table | |
18213 | ||
c45da7e6 | 18214 | @cindex load shared library |
b7209cb4 FF |
18215 | To explicitly load shared library symbols, use the @code{sharedlibrary} |
18216 | command: | |
18217 | ||
c906108c SS |
18218 | @table @code |
18219 | @kindex info sharedlibrary | |
18220 | @kindex info share | |
55333a84 DE |
18221 | @item info share @var{regex} |
18222 | @itemx info sharedlibrary @var{regex} | |
18223 | Print the names of the shared libraries which are currently loaded | |
18224 | that match @var{regex}. If @var{regex} is omitted then print | |
18225 | all shared libraries that are loaded. | |
c906108c | 18226 | |
b30a0bc3 JB |
18227 | @kindex info dll |
18228 | @item info dll @var{regex} | |
18229 | This is an alias of @code{info sharedlibrary}. | |
18230 | ||
c906108c SS |
18231 | @kindex sharedlibrary |
18232 | @kindex share | |
18233 | @item sharedlibrary @var{regex} | |
18234 | @itemx share @var{regex} | |
c906108c SS |
18235 | Load shared object library symbols for files matching a |
18236 | Unix regular expression. | |
18237 | As with files loaded automatically, it only loads shared libraries | |
18238 | required by your program for a core file or after typing @code{run}. If | |
18239 | @var{regex} is omitted all shared libraries required by your program are | |
18240 | loaded. | |
c45da7e6 EZ |
18241 | |
18242 | @item nosharedlibrary | |
18243 | @kindex nosharedlibrary | |
18244 | @cindex unload symbols from shared libraries | |
18245 | Unload all shared object library symbols. This discards all symbols | |
18246 | that have been loaded from all shared libraries. Symbols from shared | |
18247 | libraries that were loaded by explicit user requests are not | |
18248 | discarded. | |
c906108c SS |
18249 | @end table |
18250 | ||
721c2651 | 18251 | Sometimes you may wish that @value{GDBN} stops and gives you control |
edcc5120 TT |
18252 | when any of shared library events happen. The best way to do this is |
18253 | to use @code{catch load} and @code{catch unload} (@pxref{Set | |
18254 | Catchpoints}). | |
18255 | ||
18256 | @value{GDBN} also supports the the @code{set stop-on-solib-events} | |
18257 | command for this. This command exists for historical reasons. It is | |
18258 | less useful than setting a catchpoint, because it does not allow for | |
18259 | conditions or commands as a catchpoint does. | |
721c2651 EZ |
18260 | |
18261 | @table @code | |
18262 | @item set stop-on-solib-events | |
18263 | @kindex set stop-on-solib-events | |
18264 | This command controls whether @value{GDBN} should give you control | |
18265 | when the dynamic linker notifies it about some shared library event. | |
18266 | The most common event of interest is loading or unloading of a new | |
18267 | shared library. | |
18268 | ||
18269 | @item show stop-on-solib-events | |
18270 | @kindex show stop-on-solib-events | |
18271 | Show whether @value{GDBN} stops and gives you control when shared | |
18272 | library events happen. | |
18273 | @end table | |
18274 | ||
f5ebfba0 | 18275 | Shared libraries are also supported in many cross or remote debugging |
f1838a98 UW |
18276 | configurations. @value{GDBN} needs to have access to the target's libraries; |
18277 | this can be accomplished either by providing copies of the libraries | |
18278 | on the host system, or by asking @value{GDBN} to automatically retrieve the | |
18279 | libraries from the target. If copies of the target libraries are | |
18280 | provided, they need to be the same as the target libraries, although the | |
f5ebfba0 DJ |
18281 | copies on the target can be stripped as long as the copies on the host are |
18282 | not. | |
18283 | ||
59b7b46f EZ |
18284 | @cindex where to look for shared libraries |
18285 | For remote debugging, you need to tell @value{GDBN} where the target | |
18286 | libraries are, so that it can load the correct copies---otherwise, it | |
18287 | may try to load the host's libraries. @value{GDBN} has two variables | |
18288 | to specify the search directories for target libraries. | |
f5ebfba0 DJ |
18289 | |
18290 | @table @code | |
a9a5a3d1 | 18291 | @cindex prefix for executable and shared library file names |
f822c95b | 18292 | @cindex system root, alternate |
f5ebfba0 | 18293 | @kindex set solib-absolute-prefix |
f822c95b DJ |
18294 | @kindex set sysroot |
18295 | @item set sysroot @var{path} | |
18296 | Use @var{path} as the system root for the program being debugged. Any | |
18297 | absolute shared library paths will be prefixed with @var{path}; many | |
18298 | runtime loaders store the absolute paths to the shared library in the | |
a9a5a3d1 GB |
18299 | target program's memory. When starting processes remotely, and when |
18300 | attaching to already-running processes (local or remote), their | |
18301 | executable filenames will be prefixed with @var{path} if reported to | |
18302 | @value{GDBN} as absolute by the operating system. If you use | |
18303 | @code{set sysroot} to find executables and shared libraries, they need | |
18304 | to be laid out in the same way that they are on the target, with | |
18305 | e.g.@: a @file{/bin}, @file{/lib} and @file{/usr/lib} hierarchy under | |
18306 | @var{path}. | |
f822c95b | 18307 | |
599bd15c GB |
18308 | If @var{path} starts with the sequence @file{target:} and the target |
18309 | system is remote then @value{GDBN} will retrieve the target binaries | |
18310 | from the remote system. This is only supported when using a remote | |
18311 | target that supports the @code{remote get} command (@pxref{File | |
18312 | Transfer,,Sending files to a remote system}). The part of @var{path} | |
18313 | following the initial @file{target:} (if present) is used as system | |
18314 | root prefix on the remote file system. If @var{path} starts with the | |
18315 | sequence @file{remote:} this is converted to the sequence | |
18316 | @file{target:} by @code{set sysroot}@footnote{Historically the | |
18317 | functionality to retrieve binaries from the remote system was | |
18318 | provided by prefixing @var{path} with @file{remote:}}. If you want | |
18319 | to specify a local system root using a directory that happens to be | |
18320 | named @file{target:} or @file{remote:}, you need to use some | |
18321 | equivalent variant of the name like @file{./target:}. | |
f1838a98 | 18322 | |
ab38a727 PA |
18323 | For targets with an MS-DOS based filesystem, such as MS-Windows and |
18324 | SymbianOS, @value{GDBN} tries prefixing a few variants of the target | |
18325 | absolute file name with @var{path}. But first, on Unix hosts, | |
18326 | @value{GDBN} converts all backslash directory separators into forward | |
18327 | slashes, because the backslash is not a directory separator on Unix: | |
18328 | ||
18329 | @smallexample | |
18330 | c:\foo\bar.dll @result{} c:/foo/bar.dll | |
18331 | @end smallexample | |
18332 | ||
18333 | Then, @value{GDBN} attempts prefixing the target file name with | |
18334 | @var{path}, and looks for the resulting file name in the host file | |
18335 | system: | |
18336 | ||
18337 | @smallexample | |
18338 | c:/foo/bar.dll @result{} /path/to/sysroot/c:/foo/bar.dll | |
18339 | @end smallexample | |
18340 | ||
a9a5a3d1 | 18341 | If that does not find the binary, @value{GDBN} tries removing |
ab38a727 PA |
18342 | the @samp{:} character from the drive spec, both for convenience, and, |
18343 | for the case of the host file system not supporting file names with | |
18344 | colons: | |
18345 | ||
18346 | @smallexample | |
18347 | c:/foo/bar.dll @result{} /path/to/sysroot/c/foo/bar.dll | |
18348 | @end smallexample | |
18349 | ||
18350 | This makes it possible to have a system root that mirrors a target | |
18351 | with more than one drive. E.g., you may want to setup your local | |
18352 | copies of the target system shared libraries like so (note @samp{c} vs | |
18353 | @samp{z}): | |
18354 | ||
18355 | @smallexample | |
18356 | @file{/path/to/sysroot/c/sys/bin/foo.dll} | |
18357 | @file{/path/to/sysroot/c/sys/bin/bar.dll} | |
18358 | @file{/path/to/sysroot/z/sys/bin/bar.dll} | |
18359 | @end smallexample | |
18360 | ||
18361 | @noindent | |
18362 | and point the system root at @file{/path/to/sysroot}, so that | |
18363 | @value{GDBN} can find the correct copies of both | |
18364 | @file{c:\sys\bin\foo.dll}, and @file{z:\sys\bin\bar.dll}. | |
18365 | ||
a9a5a3d1 | 18366 | If that still does not find the binary, @value{GDBN} tries |
ab38a727 PA |
18367 | removing the whole drive spec from the target file name: |
18368 | ||
18369 | @smallexample | |
18370 | c:/foo/bar.dll @result{} /path/to/sysroot/foo/bar.dll | |
18371 | @end smallexample | |
18372 | ||
18373 | This last lookup makes it possible to not care about the drive name, | |
18374 | if you don't want or need to. | |
18375 | ||
f822c95b DJ |
18376 | The @code{set solib-absolute-prefix} command is an alias for @code{set |
18377 | sysroot}. | |
18378 | ||
18379 | @cindex default system root | |
59b7b46f | 18380 | @cindex @samp{--with-sysroot} |
f822c95b DJ |
18381 | You can set the default system root by using the configure-time |
18382 | @samp{--with-sysroot} option. If the system root is inside | |
18383 | @value{GDBN}'s configured binary prefix (set with @samp{--prefix} or | |
18384 | @samp{--exec-prefix}), then the default system root will be updated | |
18385 | automatically if the installed @value{GDBN} is moved to a new | |
18386 | location. | |
18387 | ||
18388 | @kindex show sysroot | |
18389 | @item show sysroot | |
a9a5a3d1 | 18390 | Display the current executable and shared library prefix. |
f5ebfba0 DJ |
18391 | |
18392 | @kindex set solib-search-path | |
18393 | @item set solib-search-path @var{path} | |
f822c95b DJ |
18394 | If this variable is set, @var{path} is a colon-separated list of |
18395 | directories to search for shared libraries. @samp{solib-search-path} | |
18396 | is used after @samp{sysroot} fails to locate the library, or if the | |
18397 | path to the library is relative instead of absolute. If you want to | |
18398 | use @samp{solib-search-path} instead of @samp{sysroot}, be sure to set | |
d3e8051b | 18399 | @samp{sysroot} to a nonexistent directory to prevent @value{GDBN} from |
f822c95b | 18400 | finding your host's libraries. @samp{sysroot} is preferred; setting |
d3e8051b | 18401 | it to a nonexistent directory may interfere with automatic loading |
f822c95b | 18402 | of shared library symbols. |
f5ebfba0 DJ |
18403 | |
18404 | @kindex show solib-search-path | |
18405 | @item show solib-search-path | |
18406 | Display the current shared library search path. | |
ab38a727 PA |
18407 | |
18408 | @cindex DOS file-name semantics of file names. | |
18409 | @kindex set target-file-system-kind (unix|dos-based|auto) | |
18410 | @kindex show target-file-system-kind | |
18411 | @item set target-file-system-kind @var{kind} | |
18412 | Set assumed file system kind for target reported file names. | |
18413 | ||
18414 | Shared library file names as reported by the target system may not | |
18415 | make sense as is on the system @value{GDBN} is running on. For | |
18416 | example, when remote debugging a target that has MS-DOS based file | |
18417 | system semantics, from a Unix host, the target may be reporting to | |
18418 | @value{GDBN} a list of loaded shared libraries with file names such as | |
18419 | @file{c:\Windows\kernel32.dll}. On Unix hosts, there's no concept of | |
18420 | drive letters, so the @samp{c:\} prefix is not normally understood as | |
18421 | indicating an absolute file name, and neither is the backslash | |
18422 | normally considered a directory separator character. In that case, | |
18423 | the native file system would interpret this whole absolute file name | |
18424 | as a relative file name with no directory components. This would make | |
18425 | it impossible to point @value{GDBN} at a copy of the remote target's | |
18426 | shared libraries on the host using @code{set sysroot}, and impractical | |
18427 | with @code{set solib-search-path}. Setting | |
18428 | @code{target-file-system-kind} to @code{dos-based} tells @value{GDBN} | |
18429 | to interpret such file names similarly to how the target would, and to | |
18430 | map them to file names valid on @value{GDBN}'s native file system | |
18431 | semantics. The value of @var{kind} can be @code{"auto"}, in addition | |
18432 | to one of the supported file system kinds. In that case, @value{GDBN} | |
18433 | tries to determine the appropriate file system variant based on the | |
18434 | current target's operating system (@pxref{ABI, ,Configuring the | |
18435 | Current ABI}). The supported file system settings are: | |
18436 | ||
18437 | @table @code | |
18438 | @item unix | |
18439 | Instruct @value{GDBN} to assume the target file system is of Unix | |
18440 | kind. Only file names starting the forward slash (@samp{/}) character | |
18441 | are considered absolute, and the directory separator character is also | |
18442 | the forward slash. | |
18443 | ||
18444 | @item dos-based | |
18445 | Instruct @value{GDBN} to assume the target file system is DOS based. | |
18446 | File names starting with either a forward slash, or a drive letter | |
18447 | followed by a colon (e.g., @samp{c:}), are considered absolute, and | |
18448 | both the slash (@samp{/}) and the backslash (@samp{\\}) characters are | |
18449 | considered directory separators. | |
18450 | ||
18451 | @item auto | |
18452 | Instruct @value{GDBN} to use the file system kind associated with the | |
18453 | target operating system (@pxref{ABI, ,Configuring the Current ABI}). | |
18454 | This is the default. | |
18455 | @end table | |
f5ebfba0 DJ |
18456 | @end table |
18457 | ||
c011a4f4 DE |
18458 | @cindex file name canonicalization |
18459 | @cindex base name differences | |
18460 | When processing file names provided by the user, @value{GDBN} | |
18461 | frequently needs to compare them to the file names recorded in the | |
18462 | program's debug info. Normally, @value{GDBN} compares just the | |
18463 | @dfn{base names} of the files as strings, which is reasonably fast | |
18464 | even for very large programs. (The base name of a file is the last | |
18465 | portion of its name, after stripping all the leading directories.) | |
18466 | This shortcut in comparison is based upon the assumption that files | |
18467 | cannot have more than one base name. This is usually true, but | |
18468 | references to files that use symlinks or similar filesystem | |
18469 | facilities violate that assumption. If your program records files | |
18470 | using such facilities, or if you provide file names to @value{GDBN} | |
18471 | using symlinks etc., you can set @code{basenames-may-differ} to | |
18472 | @code{true} to instruct @value{GDBN} to completely canonicalize each | |
18473 | pair of file names it needs to compare. This will make file-name | |
18474 | comparisons accurate, but at a price of a significant slowdown. | |
18475 | ||
18476 | @table @code | |
18477 | @item set basenames-may-differ | |
18478 | @kindex set basenames-may-differ | |
18479 | Set whether a source file may have multiple base names. | |
18480 | ||
18481 | @item show basenames-may-differ | |
18482 | @kindex show basenames-may-differ | |
18483 | Show whether a source file may have multiple base names. | |
18484 | @end table | |
5b5d99cf | 18485 | |
18989b3c AB |
18486 | @node File Caching |
18487 | @section File Caching | |
18488 | @cindex caching of opened files | |
18489 | @cindex caching of bfd objects | |
18490 | ||
18491 | To speed up file loading, and reduce memory usage, @value{GDBN} will | |
18492 | reuse the @code{bfd} objects used to track open files. @xref{Top, , | |
18493 | BFD, bfd, The Binary File Descriptor Library}. The following commands | |
18494 | allow visibility and control of the caching behavior. | |
18495 | ||
18496 | @table @code | |
18497 | @kindex maint info bfds | |
18498 | @item maint info bfds | |
18499 | This prints information about each @code{bfd} object that is known to | |
18500 | @value{GDBN}. | |
18501 | ||
18502 | @kindex maint set bfd-sharing | |
18503 | @kindex maint show bfd-sharing | |
18504 | @kindex bfd caching | |
18505 | @item maint set bfd-sharing | |
18506 | @item maint show bfd-sharing | |
18507 | Control whether @code{bfd} objects can be shared. When sharing is | |
18508 | enabled @value{GDBN} reuses already open @code{bfd} objects rather | |
18509 | than reopening the same file. Turning sharing off does not cause | |
18510 | already shared @code{bfd} objects to be unshared, but all future files | |
18511 | that are opened will create a new @code{bfd} object. Similarly, | |
18512 | re-enabling sharing does not cause multiple existing @code{bfd} | |
18513 | objects to be collapsed into a single shared @code{bfd} object. | |
566f5e3b AB |
18514 | |
18515 | @kindex set debug bfd-cache @var{level} | |
18516 | @kindex bfd caching | |
18517 | @item set debug bfd-cache @var{level} | |
18518 | Turns on debugging of the bfd cache, setting the level to @var{level}. | |
18519 | ||
18520 | @kindex show debug bfd-cache | |
18521 | @kindex bfd caching | |
18522 | @item show debug bfd-cache | |
18523 | Show the current debugging level of the bfd cache. | |
18989b3c AB |
18524 | @end table |
18525 | ||
5b5d99cf JB |
18526 | @node Separate Debug Files |
18527 | @section Debugging Information in Separate Files | |
18528 | @cindex separate debugging information files | |
18529 | @cindex debugging information in separate files | |
18530 | @cindex @file{.debug} subdirectories | |
18531 | @cindex debugging information directory, global | |
f307c045 | 18532 | @cindex global debugging information directories |
c7e83d54 EZ |
18533 | @cindex build ID, and separate debugging files |
18534 | @cindex @file{.build-id} directory | |
5b5d99cf JB |
18535 | |
18536 | @value{GDBN} allows you to put a program's debugging information in a | |
18537 | file separate from the executable itself, in a way that allows | |
18538 | @value{GDBN} to find and load the debugging information automatically. | |
c7e83d54 EZ |
18539 | Since debugging information can be very large---sometimes larger |
18540 | than the executable code itself---some systems distribute debugging | |
5b5d99cf JB |
18541 | information for their executables in separate files, which users can |
18542 | install only when they need to debug a problem. | |
18543 | ||
c7e83d54 EZ |
18544 | @value{GDBN} supports two ways of specifying the separate debug info |
18545 | file: | |
5b5d99cf JB |
18546 | |
18547 | @itemize @bullet | |
18548 | @item | |
c7e83d54 EZ |
18549 | The executable contains a @dfn{debug link} that specifies the name of |
18550 | the separate debug info file. The separate debug file's name is | |
18551 | usually @file{@var{executable}.debug}, where @var{executable} is the | |
18552 | name of the corresponding executable file without leading directories | |
18553 | (e.g., @file{ls.debug} for @file{/usr/bin/ls}). In addition, the | |
99e008fe EZ |
18554 | debug link specifies a 32-bit @dfn{Cyclic Redundancy Check} (CRC) |
18555 | checksum for the debug file, which @value{GDBN} uses to validate that | |
18556 | the executable and the debug file came from the same build. | |
c7e83d54 EZ |
18557 | |
18558 | @item | |
7e27a47a | 18559 | The executable contains a @dfn{build ID}, a unique bit string that is |
c7e83d54 | 18560 | also present in the corresponding debug info file. (This is supported |
c74f7d1c | 18561 | only on some operating systems, when using the ELF or PE file formats |
7e27a47a EZ |
18562 | for binary files and the @sc{gnu} Binutils.) For more details about |
18563 | this feature, see the description of the @option{--build-id} | |
18564 | command-line option in @ref{Options, , Command Line Options, ld.info, | |
18565 | The GNU Linker}. The debug info file's name is not specified | |
18566 | explicitly by the build ID, but can be computed from the build ID, see | |
18567 | below. | |
d3750b24 JK |
18568 | @end itemize |
18569 | ||
c7e83d54 EZ |
18570 | Depending on the way the debug info file is specified, @value{GDBN} |
18571 | uses two different methods of looking for the debug file: | |
d3750b24 JK |
18572 | |
18573 | @itemize @bullet | |
18574 | @item | |
c7e83d54 EZ |
18575 | For the ``debug link'' method, @value{GDBN} looks up the named file in |
18576 | the directory of the executable file, then in a subdirectory of that | |
f307c045 JK |
18577 | directory named @file{.debug}, and finally under each one of the global debug |
18578 | directories, in a subdirectory whose name is identical to the leading | |
c7e83d54 EZ |
18579 | directories of the executable's absolute file name. |
18580 | ||
18581 | @item | |
83f83d7f | 18582 | For the ``build ID'' method, @value{GDBN} looks in the |
f307c045 JK |
18583 | @file{.build-id} subdirectory of each one of the global debug directories for |
18584 | a file named @file{@var{nn}/@var{nnnnnnnn}.debug}, where @var{nn} are the | |
7e27a47a EZ |
18585 | first 2 hex characters of the build ID bit string, and @var{nnnnnnnn} |
18586 | are the rest of the bit string. (Real build ID strings are 32 or more | |
18587 | hex characters, not 10.) | |
c7e83d54 EZ |
18588 | @end itemize |
18589 | ||
18590 | So, for example, suppose you ask @value{GDBN} to debug | |
7e27a47a EZ |
18591 | @file{/usr/bin/ls}, which has a debug link that specifies the |
18592 | file @file{ls.debug}, and a build ID whose value in hex is | |
f307c045 | 18593 | @code{abcdef1234}. If the list of the global debug directories includes |
c7e83d54 EZ |
18594 | @file{/usr/lib/debug}, then @value{GDBN} will look for the following |
18595 | debug information files, in the indicated order: | |
18596 | ||
18597 | @itemize @minus | |
18598 | @item | |
18599 | @file{/usr/lib/debug/.build-id/ab/cdef1234.debug} | |
d3750b24 | 18600 | @item |
c7e83d54 | 18601 | @file{/usr/bin/ls.debug} |
5b5d99cf | 18602 | @item |
c7e83d54 | 18603 | @file{/usr/bin/.debug/ls.debug} |
5b5d99cf | 18604 | @item |
c7e83d54 | 18605 | @file{/usr/lib/debug/usr/bin/ls.debug}. |
5b5d99cf | 18606 | @end itemize |
5b5d99cf | 18607 | |
1564a261 JK |
18608 | @anchor{debug-file-directory} |
18609 | Global debugging info directories default to what is set by @value{GDBN} | |
18610 | configure option @option{--with-separate-debug-dir}. During @value{GDBN} run | |
18611 | you can also set the global debugging info directories, and view the list | |
18612 | @value{GDBN} is currently using. | |
5b5d99cf JB |
18613 | |
18614 | @table @code | |
18615 | ||
18616 | @kindex set debug-file-directory | |
24ddea62 JK |
18617 | @item set debug-file-directory @var{directories} |
18618 | Set the directories which @value{GDBN} searches for separate debugging | |
d9242c17 JK |
18619 | information files to @var{directory}. Multiple path components can be set |
18620 | concatenating them by a path separator. | |
5b5d99cf JB |
18621 | |
18622 | @kindex show debug-file-directory | |
18623 | @item show debug-file-directory | |
24ddea62 | 18624 | Show the directories @value{GDBN} searches for separate debugging |
5b5d99cf JB |
18625 | information files. |
18626 | ||
18627 | @end table | |
18628 | ||
18629 | @cindex @code{.gnu_debuglink} sections | |
c7e83d54 | 18630 | @cindex debug link sections |
5b5d99cf JB |
18631 | A debug link is a special section of the executable file named |
18632 | @code{.gnu_debuglink}. The section must contain: | |
18633 | ||
18634 | @itemize | |
18635 | @item | |
18636 | A filename, with any leading directory components removed, followed by | |
18637 | a zero byte, | |
18638 | @item | |
18639 | zero to three bytes of padding, as needed to reach the next four-byte | |
18640 | boundary within the section, and | |
18641 | @item | |
18642 | a four-byte CRC checksum, stored in the same endianness used for the | |
18643 | executable file itself. The checksum is computed on the debugging | |
18644 | information file's full contents by the function given below, passing | |
18645 | zero as the @var{crc} argument. | |
18646 | @end itemize | |
18647 | ||
18648 | Any executable file format can carry a debug link, as long as it can | |
18649 | contain a section named @code{.gnu_debuglink} with the contents | |
18650 | described above. | |
18651 | ||
d3750b24 | 18652 | @cindex @code{.note.gnu.build-id} sections |
c7e83d54 | 18653 | @cindex build ID sections |
7e27a47a EZ |
18654 | The build ID is a special section in the executable file (and in other |
18655 | ELF binary files that @value{GDBN} may consider). This section is | |
18656 | often named @code{.note.gnu.build-id}, but that name is not mandatory. | |
18657 | It contains unique identification for the built files---the ID remains | |
18658 | the same across multiple builds of the same build tree. The default | |
18659 | algorithm SHA1 produces 160 bits (40 hexadecimal characters) of the | |
18660 | content for the build ID string. The same section with an identical | |
18661 | value is present in the original built binary with symbols, in its | |
18662 | stripped variant, and in the separate debugging information file. | |
d3750b24 | 18663 | |
5b5d99cf JB |
18664 | The debugging information file itself should be an ordinary |
18665 | executable, containing a full set of linker symbols, sections, and | |
18666 | debugging information. The sections of the debugging information file | |
c7e83d54 EZ |
18667 | should have the same names, addresses, and sizes as the original file, |
18668 | but they need not contain any data---much like a @code{.bss} section | |
5b5d99cf JB |
18669 | in an ordinary executable. |
18670 | ||
7e27a47a | 18671 | The @sc{gnu} binary utilities (Binutils) package includes the |
c7e83d54 EZ |
18672 | @samp{objcopy} utility that can produce |
18673 | the separated executable / debugging information file pairs using the | |
18674 | following commands: | |
18675 | ||
18676 | @smallexample | |
18677 | @kbd{objcopy --only-keep-debug foo foo.debug} | |
18678 | @kbd{strip -g foo} | |
c7e83d54 EZ |
18679 | @end smallexample |
18680 | ||
18681 | @noindent | |
18682 | These commands remove the debugging | |
83f83d7f JK |
18683 | information from the executable file @file{foo} and place it in the file |
18684 | @file{foo.debug}. You can use the first, second or both methods to link the | |
18685 | two files: | |
18686 | ||
18687 | @itemize @bullet | |
18688 | @item | |
18689 | The debug link method needs the following additional command to also leave | |
18690 | behind a debug link in @file{foo}: | |
18691 | ||
18692 | @smallexample | |
18693 | @kbd{objcopy --add-gnu-debuglink=foo.debug foo} | |
18694 | @end smallexample | |
18695 | ||
18696 | Ulrich Drepper's @file{elfutils} package, starting with version 0.53, contains | |
d3750b24 | 18697 | a version of the @code{strip} command such that the command @kbd{strip foo -f |
83f83d7f JK |
18698 | foo.debug} has the same functionality as the two @code{objcopy} commands and |
18699 | the @code{ln -s} command above, together. | |
18700 | ||
18701 | @item | |
18702 | Build ID gets embedded into the main executable using @code{ld --build-id} or | |
18703 | the @value{NGCC} counterpart @code{gcc -Wl,--build-id}. Build ID support plus | |
18704 | compatibility fixes for debug files separation are present in @sc{gnu} binary | |
7e27a47a | 18705 | utilities (Binutils) package since version 2.18. |
83f83d7f JK |
18706 | @end itemize |
18707 | ||
18708 | @noindent | |
d3750b24 | 18709 | |
99e008fe EZ |
18710 | @cindex CRC algorithm definition |
18711 | The CRC used in @code{.gnu_debuglink} is the CRC-32 defined in | |
18712 | IEEE 802.3 using the polynomial: | |
18713 | ||
18714 | @c TexInfo requires naked braces for multi-digit exponents for Tex | |
18715 | @c output, but this causes HTML output to barf. HTML has to be set using | |
18716 | @c raw commands. So we end up having to specify this equation in 2 | |
18717 | @c different ways! | |
18718 | @ifhtml | |
18719 | @display | |
18720 | @html | |
18721 | <em>x</em><sup>32</sup> + <em>x</em><sup>26</sup> + <em>x</em><sup>23</sup> + <em>x</em><sup>22</sup> + <em>x</em><sup>16</sup> + <em>x</em><sup>12</sup> + <em>x</em><sup>11</sup> | |
18722 | + <em>x</em><sup>10</sup> + <em>x</em><sup>8</sup> + <em>x</em><sup>7</sup> + <em>x</em><sup>5</sup> + <em>x</em><sup>4</sup> + <em>x</em><sup>2</sup> + <em>x</em> + 1 | |
18723 | @end html | |
18724 | @end display | |
18725 | @end ifhtml | |
18726 | @ifnothtml | |
18727 | @display | |
18728 | @math{x^{32} + x^{26} + x^{23} + x^{22} + x^{16} + x^{12} + x^{11}} | |
18729 | @math{+ x^{10} + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1} | |
18730 | @end display | |
18731 | @end ifnothtml | |
18732 | ||
18733 | The function is computed byte at a time, taking the least | |
18734 | significant bit of each byte first. The initial pattern | |
18735 | @code{0xffffffff} is used, to ensure leading zeros affect the CRC and | |
18736 | the final result is inverted to ensure trailing zeros also affect the | |
18737 | CRC. | |
18738 | ||
18739 | @emph{Note:} This is the same CRC polynomial as used in handling the | |
936d2992 PA |
18740 | @dfn{Remote Serial Protocol} @code{qCRC} packet (@pxref{qCRC packet}). |
18741 | However in the case of the Remote Serial Protocol, the CRC is computed | |
18742 | @emph{most} significant bit first, and the result is not inverted, so | |
18743 | trailing zeros have no effect on the CRC value. | |
99e008fe EZ |
18744 | |
18745 | To complete the description, we show below the code of the function | |
18746 | which produces the CRC used in @code{.gnu_debuglink}. Inverting the | |
18747 | initially supplied @code{crc} argument means that an initial call to | |
18748 | this function passing in zero will start computing the CRC using | |
18749 | @code{0xffffffff}. | |
5b5d99cf | 18750 | |
4644b6e3 | 18751 | @kindex gnu_debuglink_crc32 |
5b5d99cf JB |
18752 | @smallexample |
18753 | unsigned long | |
18754 | gnu_debuglink_crc32 (unsigned long crc, | |
18755 | unsigned char *buf, size_t len) | |
18756 | @{ | |
18757 | static const unsigned long crc32_table[256] = | |
18758 | @{ | |
18759 | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, | |
18760 | 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, | |
18761 | 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, | |
18762 | 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, | |
18763 | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, | |
18764 | 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, | |
18765 | 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, | |
18766 | 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, | |
18767 | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, | |
18768 | 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, | |
18769 | 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, | |
18770 | 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, | |
18771 | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, | |
18772 | 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, | |
18773 | 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, | |
18774 | 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, | |
18775 | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, | |
18776 | 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, | |
18777 | 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, | |
18778 | 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, | |
18779 | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, | |
18780 | 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, | |
18781 | 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, | |
18782 | 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, | |
18783 | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, | |
18784 | 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, | |
18785 | 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, | |
18786 | 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, | |
18787 | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, | |
18788 | 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, | |
18789 | 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, | |
18790 | 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, | |
18791 | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, | |
18792 | 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, | |
18793 | 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, | |
18794 | 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, | |
18795 | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, | |
18796 | 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, | |
18797 | 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, | |
18798 | 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, | |
18799 | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, | |
18800 | 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, | |
18801 | 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, | |
18802 | 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, | |
18803 | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, | |
18804 | 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, | |
18805 | 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, | |
18806 | 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, | |
18807 | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, | |
18808 | 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, | |
18809 | 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, | |
18810 | 0x2d02ef8d | |
18811 | @}; | |
18812 | unsigned char *end; | |
18813 | ||
18814 | crc = ~crc & 0xffffffff; | |
18815 | for (end = buf + len; buf < end; ++buf) | |
18816 | crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); | |
e7a3abfc | 18817 | return ~crc & 0xffffffff; |
5b5d99cf JB |
18818 | @} |
18819 | @end smallexample | |
18820 | ||
c7e83d54 EZ |
18821 | @noindent |
18822 | This computation does not apply to the ``build ID'' method. | |
18823 | ||
608e2dbb TT |
18824 | @node MiniDebugInfo |
18825 | @section Debugging information in a special section | |
18826 | @cindex separate debug sections | |
18827 | @cindex @samp{.gnu_debugdata} section | |
18828 | ||
18829 | Some systems ship pre-built executables and libraries that have a | |
18830 | special @samp{.gnu_debugdata} section. This feature is called | |
18831 | @dfn{MiniDebugInfo}. This section holds an LZMA-compressed object and | |
18832 | is used to supply extra symbols for backtraces. | |
18833 | ||
18834 | The intent of this section is to provide extra minimal debugging | |
18835 | information for use in simple backtraces. It is not intended to be a | |
18836 | replacement for full separate debugging information (@pxref{Separate | |
18837 | Debug Files}). The example below shows the intended use; however, | |
18838 | @value{GDBN} does not currently put restrictions on what sort of | |
18839 | debugging information might be included in the section. | |
18840 | ||
18841 | @value{GDBN} has support for this extension. If the section exists, | |
18842 | then it is used provided that no other source of debugging information | |
18843 | can be found, and that @value{GDBN} was configured with LZMA support. | |
18844 | ||
18845 | This section can be easily created using @command{objcopy} and other | |
18846 | standard utilities: | |
18847 | ||
18848 | @smallexample | |
18849 | # Extract the dynamic symbols from the main binary, there is no need | |
5423b017 | 18850 | # to also have these in the normal symbol table. |
608e2dbb TT |
18851 | nm -D @var{binary} --format=posix --defined-only \ |
18852 | | awk '@{ print $1 @}' | sort > dynsyms | |
18853 | ||
5423b017 | 18854 | # Extract all the text (i.e. function) symbols from the debuginfo. |
1d236d23 JK |
18855 | # (Note that we actually also accept "D" symbols, for the benefit |
18856 | # of platforms like PowerPC64 that use function descriptors.) | |
608e2dbb | 18857 | nm @var{binary} --format=posix --defined-only \ |
1d236d23 | 18858 | | awk '@{ if ($2 == "T" || $2 == "t" || $2 == "D") print $1 @}' \ |
608e2dbb TT |
18859 | | sort > funcsyms |
18860 | ||
18861 | # Keep all the function symbols not already in the dynamic symbol | |
18862 | # table. | |
18863 | comm -13 dynsyms funcsyms > keep_symbols | |
18864 | ||
edf9f00c JK |
18865 | # Separate full debug info into debug binary. |
18866 | objcopy --only-keep-debug @var{binary} debug | |
18867 | ||
608e2dbb TT |
18868 | # Copy the full debuginfo, keeping only a minimal set of symbols and |
18869 | # removing some unnecessary sections. | |
18870 | objcopy -S --remove-section .gdb_index --remove-section .comment \ | |
edf9f00c JK |
18871 | --keep-symbols=keep_symbols debug mini_debuginfo |
18872 | ||
18873 | # Drop the full debug info from the original binary. | |
18874 | strip --strip-all -R .comment @var{binary} | |
608e2dbb TT |
18875 | |
18876 | # Inject the compressed data into the .gnu_debugdata section of the | |
18877 | # original binary. | |
18878 | xz mini_debuginfo | |
18879 | objcopy --add-section .gnu_debugdata=mini_debuginfo.xz @var{binary} | |
18880 | @end smallexample | |
5b5d99cf | 18881 | |
9291a0cd TT |
18882 | @node Index Files |
18883 | @section Index Files Speed Up @value{GDBN} | |
18884 | @cindex index files | |
18885 | @cindex @samp{.gdb_index} section | |
18886 | ||
18887 | When @value{GDBN} finds a symbol file, it scans the symbols in the | |
18888 | file in order to construct an internal symbol table. This lets most | |
18889 | @value{GDBN} operations work quickly---at the cost of a delay early | |
18890 | on. For large programs, this delay can be quite lengthy, so | |
18891 | @value{GDBN} provides a way to build an index, which speeds up | |
18892 | startup. | |
18893 | ||
18894 | The index is stored as a section in the symbol file. @value{GDBN} can | |
18895 | write the index to a file, then you can put it into the symbol file | |
18896 | using @command{objcopy}. | |
18897 | ||
18898 | To create an index file, use the @code{save gdb-index} command: | |
18899 | ||
18900 | @table @code | |
18901 | @item save gdb-index @var{directory} | |
18902 | @kindex save gdb-index | |
18903 | Create an index file for each symbol file currently known by | |
18904 | @value{GDBN}. Each file is named after its corresponding symbol file, | |
18905 | with @samp{.gdb-index} appended, and is written into the given | |
18906 | @var{directory}. | |
18907 | @end table | |
18908 | ||
18909 | Once you have created an index file you can merge it into your symbol | |
18910 | file, here named @file{symfile}, using @command{objcopy}: | |
18911 | ||
18912 | @smallexample | |
18913 | $ objcopy --add-section .gdb_index=symfile.gdb-index \ | |
18914 | --set-section-flags .gdb_index=readonly symfile symfile | |
18915 | @end smallexample | |
18916 | ||
e615022a DE |
18917 | @value{GDBN} will normally ignore older versions of @file{.gdb_index} |
18918 | sections that have been deprecated. Usually they are deprecated because | |
18919 | they are missing a new feature or have performance issues. | |
18920 | To tell @value{GDBN} to use a deprecated index section anyway | |
18921 | specify @code{set use-deprecated-index-sections on}. | |
18922 | The default is @code{off}. | |
18923 | This can speed up startup, but may result in some functionality being lost. | |
18924 | @xref{Index Section Format}. | |
18925 | ||
18926 | @emph{Warning:} Setting @code{use-deprecated-index-sections} to @code{on} | |
18927 | must be done before gdb reads the file. The following will not work: | |
18928 | ||
18929 | @smallexample | |
18930 | $ gdb -ex "set use-deprecated-index-sections on" <program> | |
18931 | @end smallexample | |
18932 | ||
18933 | Instead you must do, for example, | |
18934 | ||
18935 | @smallexample | |
18936 | $ gdb -iex "set use-deprecated-index-sections on" <program> | |
18937 | @end smallexample | |
18938 | ||
9291a0cd TT |
18939 | There are currently some limitation on indices. They only work when |
18940 | for DWARF debugging information, not stabs. And, they do not | |
18941 | currently work for programs using Ada. | |
18942 | ||
6d2ebf8b | 18943 | @node Symbol Errors |
79a6e687 | 18944 | @section Errors Reading Symbol Files |
c906108c SS |
18945 | |
18946 | While reading a symbol file, @value{GDBN} occasionally encounters problems, | |
18947 | such as symbol types it does not recognize, or known bugs in compiler | |
18948 | output. By default, @value{GDBN} does not notify you of such problems, since | |
18949 | they are relatively common and primarily of interest to people | |
18950 | debugging compilers. If you are interested in seeing information | |
18951 | about ill-constructed symbol tables, you can either ask @value{GDBN} to print | |
18952 | only one message about each such type of problem, no matter how many | |
18953 | times the problem occurs; or you can ask @value{GDBN} to print more messages, | |
18954 | to see how many times the problems occur, with the @code{set | |
79a6e687 BW |
18955 | complaints} command (@pxref{Messages/Warnings, ,Optional Warnings and |
18956 | Messages}). | |
c906108c SS |
18957 | |
18958 | The messages currently printed, and their meanings, include: | |
18959 | ||
18960 | @table @code | |
18961 | @item inner block not inside outer block in @var{symbol} | |
18962 | ||
18963 | The symbol information shows where symbol scopes begin and end | |
18964 | (such as at the start of a function or a block of statements). This | |
18965 | error indicates that an inner scope block is not fully contained | |
18966 | in its outer scope blocks. | |
18967 | ||
18968 | @value{GDBN} circumvents the problem by treating the inner block as if it had | |
18969 | the same scope as the outer block. In the error message, @var{symbol} | |
18970 | may be shown as ``@code{(don't know)}'' if the outer block is not a | |
18971 | function. | |
18972 | ||
18973 | @item block at @var{address} out of order | |
18974 | ||
18975 | The symbol information for symbol scope blocks should occur in | |
18976 | order of increasing addresses. This error indicates that it does not | |
18977 | do so. | |
18978 | ||
18979 | @value{GDBN} does not circumvent this problem, and has trouble | |
18980 | locating symbols in the source file whose symbols it is reading. (You | |
18981 | can often determine what source file is affected by specifying | |
79a6e687 BW |
18982 | @code{set verbose on}. @xref{Messages/Warnings, ,Optional Warnings and |
18983 | Messages}.) | |
c906108c SS |
18984 | |
18985 | @item bad block start address patched | |
18986 | ||
18987 | The symbol information for a symbol scope block has a start address | |
18988 | smaller than the address of the preceding source line. This is known | |
18989 | to occur in the SunOS 4.1.1 (and earlier) C compiler. | |
18990 | ||
18991 | @value{GDBN} circumvents the problem by treating the symbol scope block as | |
18992 | starting on the previous source line. | |
18993 | ||
18994 | @item bad string table offset in symbol @var{n} | |
18995 | ||
18996 | @cindex foo | |
18997 | Symbol number @var{n} contains a pointer into the string table which is | |
18998 | larger than the size of the string table. | |
18999 | ||
19000 | @value{GDBN} circumvents the problem by considering the symbol to have the | |
19001 | name @code{foo}, which may cause other problems if many symbols end up | |
19002 | with this name. | |
19003 | ||
19004 | @item unknown symbol type @code{0x@var{nn}} | |
19005 | ||
7a292a7a SS |
19006 | The symbol information contains new data types that @value{GDBN} does |
19007 | not yet know how to read. @code{0x@var{nn}} is the symbol type of the | |
d4f3574e | 19008 | uncomprehended information, in hexadecimal. |
c906108c | 19009 | |
7a292a7a SS |
19010 | @value{GDBN} circumvents the error by ignoring this symbol information. |
19011 | This usually allows you to debug your program, though certain symbols | |
c906108c | 19012 | are not accessible. If you encounter such a problem and feel like |
7a292a7a SS |
19013 | debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint |
19014 | on @code{complain}, then go up to the function @code{read_dbx_symtab} | |
19015 | and examine @code{*bufp} to see the symbol. | |
c906108c SS |
19016 | |
19017 | @item stub type has NULL name | |
c906108c | 19018 | |
7a292a7a | 19019 | @value{GDBN} could not find the full definition for a struct or class. |
c906108c | 19020 | |
7a292a7a | 19021 | @item const/volatile indicator missing (ok if using g++ v1.x), got@dots{} |
b37052ae | 19022 | The symbol information for a C@t{++} member function is missing some |
7a292a7a SS |
19023 | information that recent versions of the compiler should have output for |
19024 | it. | |
c906108c SS |
19025 | |
19026 | @item info mismatch between compiler and debugger | |
19027 | ||
19028 | @value{GDBN} could not parse a type specification output by the compiler. | |
7a292a7a | 19029 | |
c906108c SS |
19030 | @end table |
19031 | ||
b14b1491 TT |
19032 | @node Data Files |
19033 | @section GDB Data Files | |
19034 | ||
19035 | @cindex prefix for data files | |
19036 | @value{GDBN} will sometimes read an auxiliary data file. These files | |
19037 | are kept in a directory known as the @dfn{data directory}. | |
19038 | ||
19039 | You can set the data directory's name, and view the name @value{GDBN} | |
19040 | is currently using. | |
19041 | ||
19042 | @table @code | |
19043 | @kindex set data-directory | |
19044 | @item set data-directory @var{directory} | |
19045 | Set the directory which @value{GDBN} searches for auxiliary data files | |
19046 | to @var{directory}. | |
19047 | ||
19048 | @kindex show data-directory | |
19049 | @item show data-directory | |
19050 | Show the directory @value{GDBN} searches for auxiliary data files. | |
19051 | @end table | |
19052 | ||
19053 | @cindex default data directory | |
19054 | @cindex @samp{--with-gdb-datadir} | |
19055 | You can set the default data directory by using the configure-time | |
19056 | @samp{--with-gdb-datadir} option. If the data directory is inside | |
19057 | @value{GDBN}'s configured binary prefix (set with @samp{--prefix} or | |
19058 | @samp{--exec-prefix}), then the default data directory will be updated | |
19059 | automatically if the installed @value{GDBN} is moved to a new | |
19060 | location. | |
19061 | ||
aae1c79a DE |
19062 | The data directory may also be specified with the |
19063 | @code{--data-directory} command line option. | |
19064 | @xref{Mode Options}. | |
19065 | ||
6d2ebf8b | 19066 | @node Targets |
c906108c | 19067 | @chapter Specifying a Debugging Target |
7a292a7a | 19068 | |
c906108c | 19069 | @cindex debugging target |
c906108c | 19070 | A @dfn{target} is the execution environment occupied by your program. |
53a5351d JM |
19071 | |
19072 | Often, @value{GDBN} runs in the same host environment as your program; | |
19073 | in that case, the debugging target is specified as a side effect when | |
19074 | you use the @code{file} or @code{core} commands. When you need more | |
c906108c SS |
19075 | flexibility---for example, running @value{GDBN} on a physically separate |
19076 | host, or controlling a standalone system over a serial port or a | |
53a5351d JM |
19077 | realtime system over a TCP/IP connection---you can use the @code{target} |
19078 | command to specify one of the target types configured for @value{GDBN} | |
79a6e687 | 19079 | (@pxref{Target Commands, ,Commands for Managing Targets}). |
c906108c | 19080 | |
a8f24a35 EZ |
19081 | @cindex target architecture |
19082 | It is possible to build @value{GDBN} for several different @dfn{target | |
19083 | architectures}. When @value{GDBN} is built like that, you can choose | |
19084 | one of the available architectures with the @kbd{set architecture} | |
19085 | command. | |
19086 | ||
19087 | @table @code | |
19088 | @kindex set architecture | |
19089 | @kindex show architecture | |
19090 | @item set architecture @var{arch} | |
19091 | This command sets the current target architecture to @var{arch}. The | |
19092 | value of @var{arch} can be @code{"auto"}, in addition to one of the | |
19093 | supported architectures. | |
19094 | ||
19095 | @item show architecture | |
19096 | Show the current target architecture. | |
9c16f35a EZ |
19097 | |
19098 | @item set processor | |
19099 | @itemx processor | |
19100 | @kindex set processor | |
19101 | @kindex show processor | |
19102 | These are alias commands for, respectively, @code{set architecture} | |
19103 | and @code{show architecture}. | |
a8f24a35 EZ |
19104 | @end table |
19105 | ||
c906108c SS |
19106 | @menu |
19107 | * Active Targets:: Active targets | |
19108 | * Target Commands:: Commands for managing targets | |
c906108c | 19109 | * Byte Order:: Choosing target byte order |
c906108c SS |
19110 | @end menu |
19111 | ||
6d2ebf8b | 19112 | @node Active Targets |
79a6e687 | 19113 | @section Active Targets |
7a292a7a | 19114 | |
c906108c SS |
19115 | @cindex stacking targets |
19116 | @cindex active targets | |
19117 | @cindex multiple targets | |
19118 | ||
8ea5bce5 | 19119 | There are multiple classes of targets such as: processes, executable files or |
c0edd9ed JK |
19120 | recording sessions. Core files belong to the process class, making core file |
19121 | and process mutually exclusive. Otherwise, @value{GDBN} can work concurrently | |
19122 | on multiple active targets, one in each class. This allows you to (for | |
19123 | example) start a process and inspect its activity, while still having access to | |
19124 | the executable file after the process finishes. Or if you start process | |
19125 | recording (@pxref{Reverse Execution}) and @code{reverse-step} there, you are | |
19126 | presented a virtual layer of the recording target, while the process target | |
19127 | remains stopped at the chronologically last point of the process execution. | |
19128 | ||
19129 | Use the @code{core-file} and @code{exec-file} commands to select a new core | |
19130 | file or executable target (@pxref{Files, ,Commands to Specify Files}). To | |
19131 | specify as a target a process that is already running, use the @code{attach} | |
19132 | command (@pxref{Attach, ,Debugging an Already-running Process}). | |
c906108c | 19133 | |
6d2ebf8b | 19134 | @node Target Commands |
79a6e687 | 19135 | @section Commands for Managing Targets |
c906108c SS |
19136 | |
19137 | @table @code | |
19138 | @item target @var{type} @var{parameters} | |
7a292a7a SS |
19139 | Connects the @value{GDBN} host environment to a target machine or |
19140 | process. A target is typically a protocol for talking to debugging | |
19141 | facilities. You use the argument @var{type} to specify the type or | |
19142 | protocol of the target machine. | |
c906108c SS |
19143 | |
19144 | Further @var{parameters} are interpreted by the target protocol, but | |
19145 | typically include things like device names or host names to connect | |
19146 | with, process numbers, and baud rates. | |
c906108c SS |
19147 | |
19148 | The @code{target} command does not repeat if you press @key{RET} again | |
19149 | after executing the command. | |
19150 | ||
19151 | @kindex help target | |
19152 | @item help target | |
19153 | Displays the names of all targets available. To display targets | |
19154 | currently selected, use either @code{info target} or @code{info files} | |
79a6e687 | 19155 | (@pxref{Files, ,Commands to Specify Files}). |
c906108c SS |
19156 | |
19157 | @item help target @var{name} | |
19158 | Describe a particular target, including any parameters necessary to | |
19159 | select it. | |
19160 | ||
19161 | @kindex set gnutarget | |
19162 | @item set gnutarget @var{args} | |
5d161b24 | 19163 | @value{GDBN} uses its own library BFD to read your files. @value{GDBN} |
c906108c | 19164 | knows whether it is reading an @dfn{executable}, |
5d161b24 DB |
19165 | a @dfn{core}, or a @dfn{.o} file; however, you can specify the file format |
19166 | with the @code{set gnutarget} command. Unlike most @code{target} commands, | |
c906108c SS |
19167 | with @code{gnutarget} the @code{target} refers to a program, not a machine. |
19168 | ||
d4f3574e | 19169 | @quotation |
c906108c SS |
19170 | @emph{Warning:} To specify a file format with @code{set gnutarget}, |
19171 | you must know the actual BFD name. | |
d4f3574e | 19172 | @end quotation |
c906108c | 19173 | |
d4f3574e | 19174 | @noindent |
79a6e687 | 19175 | @xref{Files, , Commands to Specify Files}. |
c906108c | 19176 | |
5d161b24 | 19177 | @kindex show gnutarget |
c906108c SS |
19178 | @item show gnutarget |
19179 | Use the @code{show gnutarget} command to display what file format | |
19180 | @code{gnutarget} is set to read. If you have not set @code{gnutarget}, | |
19181 | @value{GDBN} will determine the file format for each file automatically, | |
c4957902 | 19182 | and @code{show gnutarget} displays @samp{The current BFD target is "auto"}. |
c906108c SS |
19183 | @end table |
19184 | ||
4644b6e3 | 19185 | @cindex common targets |
c906108c SS |
19186 | Here are some common targets (available, or not, depending on the GDB |
19187 | configuration): | |
c906108c SS |
19188 | |
19189 | @table @code | |
4644b6e3 | 19190 | @kindex target |
c906108c | 19191 | @item target exec @var{program} |
4644b6e3 | 19192 | @cindex executable file target |
c906108c SS |
19193 | An executable file. @samp{target exec @var{program}} is the same as |
19194 | @samp{exec-file @var{program}}. | |
19195 | ||
c906108c | 19196 | @item target core @var{filename} |
4644b6e3 | 19197 | @cindex core dump file target |
c906108c SS |
19198 | A core dump file. @samp{target core @var{filename}} is the same as |
19199 | @samp{core-file @var{filename}}. | |
c906108c | 19200 | |
1a10341b | 19201 | @item target remote @var{medium} |
4644b6e3 | 19202 | @cindex remote target |
1a10341b JB |
19203 | A remote system connected to @value{GDBN} via a serial line or network |
19204 | connection. This command tells @value{GDBN} to use its own remote | |
19205 | protocol over @var{medium} for debugging. @xref{Remote Debugging}. | |
19206 | ||
19207 | For example, if you have a board connected to @file{/dev/ttya} on the | |
19208 | machine running @value{GDBN}, you could say: | |
19209 | ||
19210 | @smallexample | |
19211 | target remote /dev/ttya | |
19212 | @end smallexample | |
19213 | ||
19214 | @code{target remote} supports the @code{load} command. This is only | |
19215 | useful if you have some other way of getting the stub to the target | |
19216 | system, and you can put it somewhere in memory where it won't get | |
19217 | clobbered by the download. | |
c906108c | 19218 | |
ee8e71d4 | 19219 | @item target sim @r{[}@var{simargs}@r{]} @dots{} |
4644b6e3 | 19220 | @cindex built-in simulator target |
2df3850c | 19221 | Builtin CPU simulator. @value{GDBN} includes simulators for most architectures. |
104c1213 | 19222 | In general, |
474c8240 | 19223 | @smallexample |
104c1213 JM |
19224 | target sim |
19225 | load | |
19226 | run | |
474c8240 | 19227 | @end smallexample |
d4f3574e | 19228 | @noindent |
104c1213 | 19229 | works; however, you cannot assume that a specific memory map, device |
d4f3574e | 19230 | drivers, or even basic I/O is available, although some simulators do |
104c1213 JM |
19231 | provide these. For info about any processor-specific simulator details, |
19232 | see the appropriate section in @ref{Embedded Processors, ,Embedded | |
19233 | Processors}. | |
19234 | ||
6a3cb8e8 PA |
19235 | @item target native |
19236 | @cindex native target | |
19237 | Setup for local/native process debugging. Useful to make the | |
19238 | @code{run} command spawn native processes (likewise @code{attach}, | |
19239 | etc.@:) even when @code{set auto-connect-native-target} is @code{off} | |
19240 | (@pxref{set auto-connect-native-target}). | |
19241 | ||
c906108c SS |
19242 | @end table |
19243 | ||
5d161b24 | 19244 | Different targets are available on different configurations of @value{GDBN}; |
c906108c | 19245 | your configuration may have more or fewer targets. |
c906108c | 19246 | |
721c2651 EZ |
19247 | Many remote targets require you to download the executable's code once |
19248 | you've successfully established a connection. You may wish to control | |
3d00d119 DJ |
19249 | various aspects of this process. |
19250 | ||
19251 | @table @code | |
721c2651 EZ |
19252 | |
19253 | @item set hash | |
19254 | @kindex set hash@r{, for remote monitors} | |
19255 | @cindex hash mark while downloading | |
19256 | This command controls whether a hash mark @samp{#} is displayed while | |
19257 | downloading a file to the remote monitor. If on, a hash mark is | |
19258 | displayed after each S-record is successfully downloaded to the | |
19259 | monitor. | |
19260 | ||
19261 | @item show hash | |
19262 | @kindex show hash@r{, for remote monitors} | |
19263 | Show the current status of displaying the hash mark. | |
19264 | ||
19265 | @item set debug monitor | |
19266 | @kindex set debug monitor | |
19267 | @cindex display remote monitor communications | |
19268 | Enable or disable display of communications messages between | |
19269 | @value{GDBN} and the remote monitor. | |
19270 | ||
19271 | @item show debug monitor | |
19272 | @kindex show debug monitor | |
19273 | Show the current status of displaying communications between | |
19274 | @value{GDBN} and the remote monitor. | |
a8f24a35 | 19275 | @end table |
c906108c SS |
19276 | |
19277 | @table @code | |
19278 | ||
19279 | @kindex load @var{filename} | |
19280 | @item load @var{filename} | |
8edfe269 | 19281 | @anchor{load} |
c906108c SS |
19282 | Depending on what remote debugging facilities are configured into |
19283 | @value{GDBN}, the @code{load} command may be available. Where it exists, it | |
19284 | is meant to make @var{filename} (an executable) available for debugging | |
19285 | on the remote system---by downloading, or dynamic linking, for example. | |
19286 | @code{load} also records the @var{filename} symbol table in @value{GDBN}, like | |
19287 | the @code{add-symbol-file} command. | |
19288 | ||
19289 | If your @value{GDBN} does not have a @code{load} command, attempting to | |
19290 | execute it gets the error message ``@code{You can't do that when your | |
19291 | target is @dots{}}'' | |
c906108c SS |
19292 | |
19293 | The file is loaded at whatever address is specified in the executable. | |
19294 | For some object file formats, you can specify the load address when you | |
19295 | link the program; for other formats, like a.out, the object file format | |
19296 | specifies a fixed address. | |
19297 | @c FIXME! This would be a good place for an xref to the GNU linker doc. | |
19298 | ||
68437a39 DJ |
19299 | Depending on the remote side capabilities, @value{GDBN} may be able to |
19300 | load programs into flash memory. | |
19301 | ||
c906108c SS |
19302 | @code{load} does not repeat if you press @key{RET} again after using it. |
19303 | @end table | |
19304 | ||
6d2ebf8b | 19305 | @node Byte Order |
79a6e687 | 19306 | @section Choosing Target Byte Order |
7a292a7a | 19307 | |
c906108c SS |
19308 | @cindex choosing target byte order |
19309 | @cindex target byte order | |
c906108c | 19310 | |
eb17f351 | 19311 | Some types of processors, such as the @acronym{MIPS}, PowerPC, and Renesas SH, |
c906108c SS |
19312 | offer the ability to run either big-endian or little-endian byte |
19313 | orders. Usually the executable or symbol will include a bit to | |
19314 | designate the endian-ness, and you will not need to worry about | |
19315 | which to use. However, you may still find it useful to adjust | |
d4f3574e | 19316 | @value{GDBN}'s idea of processor endian-ness manually. |
c906108c SS |
19317 | |
19318 | @table @code | |
4644b6e3 | 19319 | @kindex set endian |
c906108c SS |
19320 | @item set endian big |
19321 | Instruct @value{GDBN} to assume the target is big-endian. | |
19322 | ||
c906108c SS |
19323 | @item set endian little |
19324 | Instruct @value{GDBN} to assume the target is little-endian. | |
19325 | ||
c906108c SS |
19326 | @item set endian auto |
19327 | Instruct @value{GDBN} to use the byte order associated with the | |
19328 | executable. | |
19329 | ||
19330 | @item show endian | |
19331 | Display @value{GDBN}'s current idea of the target byte order. | |
19332 | ||
19333 | @end table | |
19334 | ||
19335 | Note that these commands merely adjust interpretation of symbolic | |
19336 | data on the host, and that they have absolutely no effect on the | |
19337 | target system. | |
19338 | ||
ea35711c DJ |
19339 | |
19340 | @node Remote Debugging | |
19341 | @chapter Debugging Remote Programs | |
c906108c SS |
19342 | @cindex remote debugging |
19343 | ||
19344 | If you are trying to debug a program running on a machine that cannot run | |
5d161b24 DB |
19345 | @value{GDBN} in the usual way, it is often useful to use remote debugging. |
19346 | For example, you might use remote debugging on an operating system kernel, | |
c906108c SS |
19347 | or on a small system which does not have a general purpose operating system |
19348 | powerful enough to run a full-featured debugger. | |
19349 | ||
19350 | Some configurations of @value{GDBN} have special serial or TCP/IP interfaces | |
19351 | to make this work with particular debugging targets. In addition, | |
5d161b24 | 19352 | @value{GDBN} comes with a generic serial protocol (specific to @value{GDBN}, |
c906108c SS |
19353 | but not specific to any particular target system) which you can use if you |
19354 | write the remote stubs---the code that runs on the remote system to | |
19355 | communicate with @value{GDBN}. | |
19356 | ||
19357 | Other remote targets may be available in your | |
19358 | configuration of @value{GDBN}; use @code{help target} to list them. | |
c906108c | 19359 | |
6b2f586d | 19360 | @menu |
07f31aa6 | 19361 | * Connecting:: Connecting to a remote target |
a6b151f1 | 19362 | * File Transfer:: Sending files to a remote system |
6b2f586d | 19363 | * Server:: Using the gdbserver program |
79a6e687 BW |
19364 | * Remote Configuration:: Remote configuration |
19365 | * Remote Stub:: Implementing a remote stub | |
6b2f586d AC |
19366 | @end menu |
19367 | ||
07f31aa6 | 19368 | @node Connecting |
79a6e687 | 19369 | @section Connecting to a Remote Target |
19d9d4ef DB |
19370 | @cindex remote debugging, connecting |
19371 | @cindex @code{gdbserver}, connecting | |
19372 | @cindex remote debugging, types of connections | |
19373 | @cindex @code{gdbserver}, types of connections | |
19374 | @cindex @code{gdbserver}, @code{target remote} mode | |
19375 | @cindex @code{gdbserver}, @code{target extended-remote} mode | |
19376 | ||
19377 | This section describes how to connect to a remote target, including the | |
19378 | types of connections and their differences, how to set up executable and | |
19379 | symbol files on the host and target, and the commands used for | |
19380 | connecting to and disconnecting from the remote target. | |
19381 | ||
19382 | @subsection Types of Remote Connections | |
19383 | ||
19384 | @value{GDBN} supports two types of remote connections, @code{target remote} | |
19385 | mode and @code{target extended-remote} mode. Note that many remote targets | |
19386 | support only @code{target remote} mode. There are several major | |
19387 | differences between the two types of connections, enumerated here: | |
19388 | ||
19389 | @table @asis | |
19390 | ||
19391 | @cindex remote debugging, detach and program exit | |
19392 | @item Result of detach or program exit | |
19393 | @strong{With target remote mode:} When the debugged program exits or you | |
19394 | detach from it, @value{GDBN} disconnects from the target. When using | |
19395 | @code{gdbserver}, @code{gdbserver} will exit. | |
19396 | ||
19397 | @strong{With target extended-remote mode:} When the debugged program exits or | |
19398 | you detach from it, @value{GDBN} remains connected to the target, even | |
19399 | though no program is running. You can rerun the program, attach to a | |
19400 | running program, or use @code{monitor} commands specific to the target. | |
19401 | ||
19402 | When using @code{gdbserver} in this case, it does not exit unless it was | |
19403 | invoked using the @option{--once} option. If the @option{--once} option | |
19404 | was not used, you can ask @code{gdbserver} to exit using the | |
19405 | @code{monitor exit} command (@pxref{Monitor Commands for gdbserver}). | |
19406 | ||
19407 | @item Specifying the program to debug | |
19408 | For both connection types you use the @code{file} command to specify the | |
19409 | program on the host system. If you are using @code{gdbserver} there are | |
19410 | some differences in how to specify the location of the program on the | |
19411 | target. | |
19412 | ||
19413 | @strong{With target remote mode:} You must either specify the program to debug | |
19414 | on the @code{gdbserver} command line or use the @option{--attach} option | |
19415 | (@pxref{Attaching to a program,,Attaching to a Running Program}). | |
19416 | ||
19417 | @cindex @option{--multi}, @code{gdbserver} option | |
19418 | @strong{With target extended-remote mode:} You may specify the program to debug | |
19419 | on the @code{gdbserver} command line, or you can load the program or attach | |
19420 | to it using @value{GDBN} commands after connecting to @code{gdbserver}. | |
19421 | ||
19422 | @anchor{--multi Option in Types of Remote Connnections} | |
19423 | You can start @code{gdbserver} without supplying an initial command to run | |
19424 | or process ID to attach. To do this, use the @option{--multi} command line | |
19425 | option. Then you can connect using @code{target extended-remote} and start | |
19426 | the program you want to debug (see below for details on using the | |
19427 | @code{run} command in this scenario). Note that the conditions under which | |
19428 | @code{gdbserver} terminates depend on how @value{GDBN} connects to it | |
19429 | (@code{target remote} or @code{target extended-remote}). The | |
19430 | @option{--multi} option to @code{gdbserver} has no influence on that. | |
07f31aa6 | 19431 | |
19d9d4ef DB |
19432 | @item The @code{run} command |
19433 | @strong{With target remote mode:} The @code{run} command is not | |
19434 | supported. Once a connection has been established, you can use all | |
19435 | the usual @value{GDBN} commands to examine and change data. The | |
19436 | remote program is already running, so you can use commands like | |
19437 | @kbd{step} and @kbd{continue}. | |
19438 | ||
19439 | @strong{With target extended-remote mode:} The @code{run} command is | |
19440 | supported. The @code{run} command uses the value set by | |
19441 | @code{set remote exec-file} (@pxref{set remote exec-file}) to select | |
19442 | the program to run. Command line arguments are supported, except for | |
19443 | wildcard expansion and I/O redirection (@pxref{Arguments}). | |
19444 | ||
19445 | If you specify the program to debug on the command line, then the | |
19446 | @code{run} command is not required to start execution, and you can | |
19447 | resume using commands like @kbd{step} and @kbd{continue} as with | |
19448 | @code{target remote} mode. | |
19449 | ||
19450 | @anchor{Attaching in Types of Remote Connections} | |
19451 | @item Attaching | |
19452 | @strong{With target remote mode:} The @value{GDBN} command @code{attach} is | |
19453 | not supported. To attach to a running program using @code{gdbserver}, you | |
19454 | must use the @option{--attach} option (@pxref{Running gdbserver}). | |
19455 | ||
19456 | @strong{With target extended-remote mode:} To attach to a running program, | |
19457 | you may use the @code{attach} command after the connection has been | |
19458 | established. If you are using @code{gdbserver}, you may also invoke | |
19459 | @code{gdbserver} using the @option{--attach} option | |
19460 | (@pxref{Running gdbserver}). | |
19461 | ||
19462 | @end table | |
19463 | ||
19464 | @anchor{Host and target files} | |
19465 | @subsection Host and Target Files | |
19466 | @cindex remote debugging, symbol files | |
19467 | @cindex symbol files, remote debugging | |
19468 | ||
19469 | @value{GDBN}, running on the host, needs access to symbol and debugging | |
19470 | information for your program running on the target. This requires | |
19471 | access to an unstripped copy of your program, and possibly any associated | |
19472 | symbol files. Note that this section applies equally to both @code{target | |
19473 | remote} mode and @code{target extended-remote} mode. | |
19474 | ||
19475 | Some remote targets (@pxref{qXfer executable filename read}, and | |
19476 | @pxref{Host I/O Packets}) allow @value{GDBN} to access program files over | |
19477 | the same connection used to communicate with @value{GDBN}. With such a | |
19478 | target, if the remote program is unstripped, the only command you need is | |
19479 | @code{target remote} (or @code{target extended-remote}). | |
19480 | ||
19481 | If the remote program is stripped, or the target does not support remote | |
19482 | program file access, start up @value{GDBN} using the name of the local | |
1b6e6f5c | 19483 | unstripped copy of your program as the first argument, or use the |
19d9d4ef DB |
19484 | @code{file} command. Use @code{set sysroot} to specify the location (on |
19485 | the host) of target libraries (unless your @value{GDBN} was compiled with | |
19486 | the correct sysroot using @code{--with-sysroot}). Alternatively, you | |
19487 | may use @code{set solib-search-path} to specify how @value{GDBN} locates | |
19488 | target libraries. | |
19489 | ||
19490 | The symbol file and target libraries must exactly match the executable | |
19491 | and libraries on the target, with one exception: the files on the host | |
19492 | system should not be stripped, even if the files on the target system | |
19493 | are. Mismatched or missing files will lead to confusing results | |
19494 | during debugging. On @sc{gnu}/Linux targets, mismatched or missing | |
19495 | files may also prevent @code{gdbserver} from debugging multi-threaded | |
19496 | programs. | |
07f31aa6 | 19497 | |
19d9d4ef DB |
19498 | @subsection Remote Connection Commands |
19499 | @cindex remote connection commands | |
86941c27 JB |
19500 | @value{GDBN} can communicate with the target over a serial line, or |
19501 | over an @acronym{IP} network using @acronym{TCP} or @acronym{UDP}. In | |
19502 | each case, @value{GDBN} uses the same protocol for debugging your | |
19503 | program; only the medium carrying the debugging packets varies. The | |
19d9d4ef DB |
19504 | @code{target remote} and @code{target extended-remote} commands |
19505 | establish a connection to the target. Both commands accept the same | |
19506 | arguments, which indicate the medium to use: | |
86941c27 JB |
19507 | |
19508 | @table @code | |
19509 | ||
19510 | @item target remote @var{serial-device} | |
19d9d4ef | 19511 | @itemx target extended-remote @var{serial-device} |
07f31aa6 | 19512 | @cindex serial line, @code{target remote} |
86941c27 JB |
19513 | Use @var{serial-device} to communicate with the target. For example, |
19514 | to use a serial line connected to the device named @file{/dev/ttyb}: | |
19515 | ||
19516 | @smallexample | |
19517 | target remote /dev/ttyb | |
19518 | @end smallexample | |
19519 | ||
07f31aa6 | 19520 | If you're using a serial line, you may want to give @value{GDBN} the |
2446f5ea | 19521 | @samp{--baud} option, or use the @code{set serial baud} command |
0d12017b | 19522 | (@pxref{Remote Configuration, set serial baud}) before the |
9c16f35a | 19523 | @code{target} command. |
07f31aa6 | 19524 | |
86941c27 JB |
19525 | @item target remote @code{@var{host}:@var{port}} |
19526 | @itemx target remote @code{tcp:@var{host}:@var{port}} | |
19d9d4ef DB |
19527 | @itemx target extended-remote @code{@var{host}:@var{port}} |
19528 | @itemx target extended-remote @code{tcp:@var{host}:@var{port}} | |
86941c27 JB |
19529 | @cindex @acronym{TCP} port, @code{target remote} |
19530 | Debug using a @acronym{TCP} connection to @var{port} on @var{host}. | |
19531 | The @var{host} may be either a host name or a numeric @acronym{IP} | |
19532 | address; @var{port} must be a decimal number. The @var{host} could be | |
19533 | the target machine itself, if it is directly connected to the net, or | |
19534 | it might be a terminal server which in turn has a serial line to the | |
19535 | target. | |
07f31aa6 | 19536 | |
86941c27 JB |
19537 | For example, to connect to port 2828 on a terminal server named |
19538 | @code{manyfarms}: | |
07f31aa6 DJ |
19539 | |
19540 | @smallexample | |
19541 | target remote manyfarms:2828 | |
19542 | @end smallexample | |
19543 | ||
86941c27 JB |
19544 | If your remote target is actually running on the same machine as your |
19545 | debugger session (e.g.@: a simulator for your target running on the | |
19546 | same host), you can omit the hostname. For example, to connect to | |
19547 | port 1234 on your local machine: | |
07f31aa6 DJ |
19548 | |
19549 | @smallexample | |
19550 | target remote :1234 | |
19551 | @end smallexample | |
19552 | @noindent | |
19553 | ||
19554 | Note that the colon is still required here. | |
19555 | ||
86941c27 | 19556 | @item target remote @code{udp:@var{host}:@var{port}} |
19d9d4ef | 19557 | @itemx target extended-remote @code{udp:@var{host}:@var{port}} |
86941c27 JB |
19558 | @cindex @acronym{UDP} port, @code{target remote} |
19559 | Debug using @acronym{UDP} packets to @var{port} on @var{host}. For example, to | |
19560 | connect to @acronym{UDP} port 2828 on a terminal server named @code{manyfarms}: | |
07f31aa6 DJ |
19561 | |
19562 | @smallexample | |
19563 | target remote udp:manyfarms:2828 | |
19564 | @end smallexample | |
19565 | ||
86941c27 JB |
19566 | When using a @acronym{UDP} connection for remote debugging, you should |
19567 | keep in mind that the `U' stands for ``Unreliable''. @acronym{UDP} | |
19568 | can silently drop packets on busy or unreliable networks, which will | |
19569 | cause havoc with your debugging session. | |
19570 | ||
66b8c7f6 | 19571 | @item target remote | @var{command} |
19d9d4ef | 19572 | @itemx target extended-remote | @var{command} |
66b8c7f6 JB |
19573 | @cindex pipe, @code{target remote} to |
19574 | Run @var{command} in the background and communicate with it using a | |
19575 | pipe. The @var{command} is a shell command, to be parsed and expanded | |
19576 | by the system's command shell, @code{/bin/sh}; it should expect remote | |
19577 | protocol packets on its standard input, and send replies on its | |
19578 | standard output. You could use this to run a stand-alone simulator | |
19579 | that speaks the remote debugging protocol, to make net connections | |
19580 | using programs like @code{ssh}, or for other similar tricks. | |
19581 | ||
19582 | If @var{command} closes its standard output (perhaps by exiting), | |
19583 | @value{GDBN} will try to send it a @code{SIGTERM} signal. (If the | |
19584 | program has already exited, this will have no effect.) | |
19585 | ||
86941c27 | 19586 | @end table |
07f31aa6 | 19587 | |
07f31aa6 DJ |
19588 | @cindex interrupting remote programs |
19589 | @cindex remote programs, interrupting | |
19590 | Whenever @value{GDBN} is waiting for the remote program, if you type the | |
c8aa23ab | 19591 | interrupt character (often @kbd{Ctrl-c}), @value{GDBN} attempts to stop the |
07f31aa6 DJ |
19592 | program. This may or may not succeed, depending in part on the hardware |
19593 | and the serial drivers the remote system uses. If you type the | |
19594 | interrupt character once again, @value{GDBN} displays this prompt: | |
19595 | ||
19596 | @smallexample | |
19597 | Interrupted while waiting for the program. | |
19598 | Give up (and stop debugging it)? (y or n) | |
19599 | @end smallexample | |
19600 | ||
19d9d4ef DB |
19601 | In @code{target remote} mode, if you type @kbd{y}, @value{GDBN} abandons |
19602 | the remote debugging session. (If you decide you want to try again later, | |
19603 | you can use @kbd{target remote} again to connect once more.) If you type | |
19604 | @kbd{n}, @value{GDBN} goes back to waiting. | |
19605 | ||
19606 | In @code{target extended-remote} mode, typing @kbd{n} will leave | |
19607 | @value{GDBN} connected to the target. | |
07f31aa6 DJ |
19608 | |
19609 | @table @code | |
19610 | @kindex detach (remote) | |
19611 | @item detach | |
19612 | When you have finished debugging the remote program, you can use the | |
19613 | @code{detach} command to release it from @value{GDBN} control. | |
19614 | Detaching from the target normally resumes its execution, but the results | |
19615 | will depend on your particular remote stub. After the @code{detach} | |
19d9d4ef DB |
19616 | command in @code{target remote} mode, @value{GDBN} is free to connect to |
19617 | another target. In @code{target extended-remote} mode, @value{GDBN} is | |
19618 | still connected to the target. | |
07f31aa6 DJ |
19619 | |
19620 | @kindex disconnect | |
19621 | @item disconnect | |
19d9d4ef | 19622 | The @code{disconnect} command closes the connection to the target, and |
07f31aa6 DJ |
19623 | the target is generally not resumed. It will wait for @value{GDBN} |
19624 | (this instance or another one) to connect and continue debugging. After | |
19625 | the @code{disconnect} command, @value{GDBN} is again free to connect to | |
19626 | another target. | |
09d4efe1 EZ |
19627 | |
19628 | @cindex send command to remote monitor | |
fad38dfa EZ |
19629 | @cindex extend @value{GDBN} for remote targets |
19630 | @cindex add new commands for external monitor | |
09d4efe1 EZ |
19631 | @kindex monitor |
19632 | @item monitor @var{cmd} | |
fad38dfa EZ |
19633 | This command allows you to send arbitrary commands directly to the |
19634 | remote monitor. Since @value{GDBN} doesn't care about the commands it | |
19635 | sends like this, this command is the way to extend @value{GDBN}---you | |
19636 | can add new commands that only the external monitor will understand | |
19637 | and implement. | |
07f31aa6 DJ |
19638 | @end table |
19639 | ||
a6b151f1 DJ |
19640 | @node File Transfer |
19641 | @section Sending files to a remote system | |
19642 | @cindex remote target, file transfer | |
19643 | @cindex file transfer | |
19644 | @cindex sending files to remote systems | |
19645 | ||
19646 | Some remote targets offer the ability to transfer files over the same | |
19647 | connection used to communicate with @value{GDBN}. This is convenient | |
19648 | for targets accessible through other means, e.g.@: @sc{gnu}/Linux systems | |
19649 | running @code{gdbserver} over a network interface. For other targets, | |
19650 | e.g.@: embedded devices with only a single serial port, this may be | |
19651 | the only way to upload or download files. | |
19652 | ||
19653 | Not all remote targets support these commands. | |
19654 | ||
19655 | @table @code | |
19656 | @kindex remote put | |
19657 | @item remote put @var{hostfile} @var{targetfile} | |
19658 | Copy file @var{hostfile} from the host system (the machine running | |
19659 | @value{GDBN}) to @var{targetfile} on the target system. | |
19660 | ||
19661 | @kindex remote get | |
19662 | @item remote get @var{targetfile} @var{hostfile} | |
19663 | Copy file @var{targetfile} from the target system to @var{hostfile} | |
19664 | on the host system. | |
19665 | ||
19666 | @kindex remote delete | |
19667 | @item remote delete @var{targetfile} | |
19668 | Delete @var{targetfile} from the target system. | |
19669 | ||
19670 | @end table | |
19671 | ||
6f05cf9f | 19672 | @node Server |
79a6e687 | 19673 | @section Using the @code{gdbserver} Program |
6f05cf9f AC |
19674 | |
19675 | @kindex gdbserver | |
19676 | @cindex remote connection without stubs | |
19677 | @code{gdbserver} is a control program for Unix-like systems, which | |
19678 | allows you to connect your program with a remote @value{GDBN} via | |
19d9d4ef DB |
19679 | @code{target remote} or @code{target extended-remote}---but without |
19680 | linking in the usual debugging stub. | |
6f05cf9f AC |
19681 | |
19682 | @code{gdbserver} is not a complete replacement for the debugging stubs, | |
19683 | because it requires essentially the same operating-system facilities | |
19684 | that @value{GDBN} itself does. In fact, a system that can run | |
19685 | @code{gdbserver} to connect to a remote @value{GDBN} could also run | |
19686 | @value{GDBN} locally! @code{gdbserver} is sometimes useful nevertheless, | |
19687 | because it is a much smaller program than @value{GDBN} itself. It is | |
19688 | also easier to port than all of @value{GDBN}, so you may be able to get | |
19689 | started more quickly on a new system by using @code{gdbserver}. | |
19690 | Finally, if you develop code for real-time systems, you may find that | |
19691 | the tradeoffs involved in real-time operation make it more convenient to | |
19692 | do as much development work as possible on another system, for example | |
19693 | by cross-compiling. You can use @code{gdbserver} to make a similar | |
19694 | choice for debugging. | |
19695 | ||
19696 | @value{GDBN} and @code{gdbserver} communicate via either a serial line | |
19697 | or a TCP connection, using the standard @value{GDBN} remote serial | |
19698 | protocol. | |
19699 | ||
2d717e4f DJ |
19700 | @quotation |
19701 | @emph{Warning:} @code{gdbserver} does not have any built-in security. | |
19702 | Do not run @code{gdbserver} connected to any public network; a | |
19703 | @value{GDBN} connection to @code{gdbserver} provides access to the | |
19704 | target system with the same privileges as the user running | |
19705 | @code{gdbserver}. | |
19706 | @end quotation | |
19707 | ||
19d9d4ef | 19708 | @anchor{Running gdbserver} |
2d717e4f DJ |
19709 | @subsection Running @code{gdbserver} |
19710 | @cindex arguments, to @code{gdbserver} | |
d9b1a651 | 19711 | @cindex @code{gdbserver}, command-line arguments |
2d717e4f DJ |
19712 | |
19713 | Run @code{gdbserver} on the target system. You need a copy of the | |
19714 | program you want to debug, including any libraries it requires. | |
6f05cf9f AC |
19715 | @code{gdbserver} does not need your program's symbol table, so you can |
19716 | strip the program if necessary to save space. @value{GDBN} on the host | |
19717 | system does all the symbol handling. | |
19718 | ||
19719 | To use the server, you must tell it how to communicate with @value{GDBN}; | |
56460a61 | 19720 | the name of your program; and the arguments for your program. The usual |
6f05cf9f AC |
19721 | syntax is: |
19722 | ||
19723 | @smallexample | |
19724 | target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ] | |
19725 | @end smallexample | |
19726 | ||
e0f9f062 DE |
19727 | @var{comm} is either a device name (to use a serial line), or a TCP |
19728 | hostname and portnumber, or @code{-} or @code{stdio} to use | |
19729 | stdin/stdout of @code{gdbserver}. | |
19730 | For example, to debug Emacs with the argument | |
6f05cf9f AC |
19731 | @samp{foo.txt} and communicate with @value{GDBN} over the serial port |
19732 | @file{/dev/com1}: | |
19733 | ||
19734 | @smallexample | |
19735 | target> gdbserver /dev/com1 emacs foo.txt | |
19736 | @end smallexample | |
19737 | ||
19738 | @code{gdbserver} waits passively for the host @value{GDBN} to communicate | |
19739 | with it. | |
19740 | ||
19741 | To use a TCP connection instead of a serial line: | |
19742 | ||
19743 | @smallexample | |
19744 | target> gdbserver host:2345 emacs foo.txt | |
19745 | @end smallexample | |
19746 | ||
19747 | The only difference from the previous example is the first argument, | |
19748 | specifying that you are communicating with the host @value{GDBN} via | |
19749 | TCP. The @samp{host:2345} argument means that @code{gdbserver} is to | |
19750 | expect a TCP connection from machine @samp{host} to local TCP port 2345. | |
19751 | (Currently, the @samp{host} part is ignored.) You can choose any number | |
19752 | you want for the port number as long as it does not conflict with any | |
19753 | TCP ports already in use on the target system (for example, @code{23} is | |
19754 | reserved for @code{telnet}).@footnote{If you choose a port number that | |
19755 | conflicts with another service, @code{gdbserver} prints an error message | |
19756 | and exits.} You must use the same port number with the host @value{GDBN} | |
19757 | @code{target remote} command. | |
19758 | ||
e0f9f062 DE |
19759 | The @code{stdio} connection is useful when starting @code{gdbserver} |
19760 | with ssh: | |
19761 | ||
19762 | @smallexample | |
19763 | (gdb) target remote | ssh -T hostname gdbserver - hello | |
19764 | @end smallexample | |
19765 | ||
19766 | The @samp{-T} option to ssh is provided because we don't need a remote pty, | |
19767 | and we don't want escape-character handling. Ssh does this by default when | |
19768 | a command is provided, the flag is provided to make it explicit. | |
19769 | You could elide it if you want to. | |
19770 | ||
19771 | Programs started with stdio-connected gdbserver have @file{/dev/null} for | |
19772 | @code{stdin}, and @code{stdout},@code{stderr} are sent back to gdb for | |
19773 | display through a pipe connected to gdbserver. | |
19774 | Both @code{stdout} and @code{stderr} use the same pipe. | |
19775 | ||
19d9d4ef | 19776 | @anchor{Attaching to a program} |
2d717e4f | 19777 | @subsubsection Attaching to a Running Program |
d9b1a651 EZ |
19778 | @cindex attach to a program, @code{gdbserver} |
19779 | @cindex @option{--attach}, @code{gdbserver} option | |
2d717e4f | 19780 | |
56460a61 DJ |
19781 | On some targets, @code{gdbserver} can also attach to running programs. |
19782 | This is accomplished via the @code{--attach} argument. The syntax is: | |
19783 | ||
19784 | @smallexample | |
2d717e4f | 19785 | target> gdbserver --attach @var{comm} @var{pid} |
56460a61 DJ |
19786 | @end smallexample |
19787 | ||
19d9d4ef DB |
19788 | @var{pid} is the process ID of a currently running process. It isn't |
19789 | necessary to point @code{gdbserver} at a binary for the running process. | |
19790 | ||
19791 | In @code{target extended-remote} mode, you can also attach using the | |
19792 | @value{GDBN} attach command | |
19793 | (@pxref{Attaching in Types of Remote Connections}). | |
56460a61 | 19794 | |
b1fe9455 | 19795 | @pindex pidof |
b1fe9455 DJ |
19796 | You can debug processes by name instead of process ID if your target has the |
19797 | @code{pidof} utility: | |
19798 | ||
19799 | @smallexample | |
2d717e4f | 19800 | target> gdbserver --attach @var{comm} `pidof @var{program}` |
b1fe9455 DJ |
19801 | @end smallexample |
19802 | ||
f822c95b | 19803 | In case more than one copy of @var{program} is running, or @var{program} |
b1fe9455 DJ |
19804 | has multiple threads, most versions of @code{pidof} support the |
19805 | @code{-s} option to only return the first process ID. | |
19806 | ||
03f2bd59 JK |
19807 | @subsubsection TCP port allocation lifecycle of @code{gdbserver} |
19808 | ||
19d9d4ef DB |
19809 | This section applies only when @code{gdbserver} is run to listen on a TCP |
19810 | port. | |
03f2bd59 JK |
19811 | |
19812 | @code{gdbserver} normally terminates after all of its debugged processes have | |
19813 | terminated in @kbd{target remote} mode. On the other hand, for @kbd{target | |
19814 | extended-remote}, @code{gdbserver} stays running even with no processes left. | |
19815 | @value{GDBN} normally terminates the spawned debugged process on its exit, | |
19816 | which normally also terminates @code{gdbserver} in the @kbd{target remote} | |
19817 | mode. Therefore, when the connection drops unexpectedly, and @value{GDBN} | |
19818 | cannot ask @code{gdbserver} to kill its debugged processes, @code{gdbserver} | |
19819 | stays running even in the @kbd{target remote} mode. | |
19820 | ||
19821 | When @code{gdbserver} stays running, @value{GDBN} can connect to it again later. | |
19822 | Such reconnecting is useful for features like @ref{disconnected tracing}. For | |
19823 | completeness, at most one @value{GDBN} can be connected at a time. | |
19824 | ||
19825 | @cindex @option{--once}, @code{gdbserver} option | |
19826 | By default, @code{gdbserver} keeps the listening TCP port open, so that | |
6e8c5661 | 19827 | subsequent connections are possible. However, if you start @code{gdbserver} |
03f2bd59 JK |
19828 | with the @option{--once} option, it will stop listening for any further |
19829 | connection attempts after connecting to the first @value{GDBN} session. This | |
19830 | means no further connections to @code{gdbserver} will be possible after the | |
19831 | first one. It also means @code{gdbserver} will terminate after the first | |
19832 | connection with remote @value{GDBN} has closed, even for unexpectedly closed | |
19833 | connections and even in the @kbd{target extended-remote} mode. The | |
19834 | @option{--once} option allows reusing the same port number for connecting to | |
19835 | multiple instances of @code{gdbserver} running on the same host, since each | |
19836 | instance closes its port after the first connection. | |
2d717e4f | 19837 | |
87ce2a04 | 19838 | @anchor{Other Command-Line Arguments for gdbserver} |
2d717e4f DJ |
19839 | @subsubsection Other Command-Line Arguments for @code{gdbserver} |
19840 | ||
19d9d4ef DB |
19841 | You can use the @option{--multi} option to start @code{gdbserver} without |
19842 | specifying a program to debug or a process to attach to. Then you can | |
19843 | attach in @code{target extended-remote} mode and run or attach to a | |
19844 | program. For more information, | |
19845 | @pxref{--multi Option in Types of Remote Connnections}. | |
19846 | ||
d9b1a651 | 19847 | @cindex @option{--debug}, @code{gdbserver} option |
62709adf | 19848 | The @option{--debug} option tells @code{gdbserver} to display extra |
d9b1a651 EZ |
19849 | status information about the debugging process. |
19850 | @cindex @option{--remote-debug}, @code{gdbserver} option | |
19851 | The @option{--remote-debug} option tells @code{gdbserver} to display | |
62709adf PA |
19852 | remote protocol debug output. These options are intended for |
19853 | @code{gdbserver} development and for bug reports to the developers. | |
2d717e4f | 19854 | |
87ce2a04 DE |
19855 | @cindex @option{--debug-format}, @code{gdbserver} option |
19856 | The @option{--debug-format=option1[,option2,...]} option tells | |
19857 | @code{gdbserver} to include additional information in each output. | |
19858 | Possible options are: | |
19859 | ||
19860 | @table @code | |
19861 | @item none | |
19862 | Turn off all extra information in debugging output. | |
19863 | @item all | |
19864 | Turn on all extra information in debugging output. | |
19865 | @item timestamps | |
19866 | Include a timestamp in each line of debugging output. | |
19867 | @end table | |
19868 | ||
19869 | Options are processed in order. Thus, for example, if @option{none} | |
19870 | appears last then no additional information is added to debugging output. | |
19871 | ||
d9b1a651 | 19872 | @cindex @option{--wrapper}, @code{gdbserver} option |
ccd213ac DJ |
19873 | The @option{--wrapper} option specifies a wrapper to launch programs |
19874 | for debugging. The option should be followed by the name of the | |
19875 | wrapper, then any command-line arguments to pass to the wrapper, then | |
19876 | @kbd{--} indicating the end of the wrapper arguments. | |
19877 | ||
19878 | @code{gdbserver} runs the specified wrapper program with a combined | |
19879 | command line including the wrapper arguments, then the name of the | |
19880 | program to debug, then any arguments to the program. The wrapper | |
19881 | runs until it executes your program, and then @value{GDBN} gains control. | |
19882 | ||
19883 | You can use any program that eventually calls @code{execve} with | |
19884 | its arguments as a wrapper. Several standard Unix utilities do | |
19885 | this, e.g.@: @code{env} and @code{nohup}. Any Unix shell script ending | |
19886 | with @code{exec "$@@"} will also work. | |
19887 | ||
19888 | For example, you can use @code{env} to pass an environment variable to | |
19889 | the debugged program, without setting the variable in @code{gdbserver}'s | |
19890 | environment: | |
19891 | ||
19892 | @smallexample | |
19893 | $ gdbserver --wrapper env LD_PRELOAD=libtest.so -- :2222 ./testprog | |
19894 | @end smallexample | |
19895 | ||
2d717e4f DJ |
19896 | @subsection Connecting to @code{gdbserver} |
19897 | ||
19d9d4ef DB |
19898 | The basic procedure for connecting to the remote target is: |
19899 | @itemize | |
2d717e4f | 19900 | |
19d9d4ef DB |
19901 | @item |
19902 | Run @value{GDBN} on the host system. | |
f822c95b | 19903 | |
19d9d4ef DB |
19904 | @item |
19905 | Make sure you have the necessary symbol files | |
19906 | (@pxref{Host and target files}). | |
19907 | Load symbols for your application using the @code{file} command before you | |
19908 | connect. Use @code{set sysroot} to locate target libraries (unless your | |
19909 | @value{GDBN} was compiled with the correct sysroot using | |
19910 | @code{--with-sysroot}). | |
f822c95b | 19911 | |
19d9d4ef | 19912 | @item |
79a6e687 | 19913 | Connect to your target (@pxref{Connecting,,Connecting to a Remote Target}). |
6f05cf9f | 19914 | For TCP connections, you must start up @code{gdbserver} prior to using |
19d9d4ef | 19915 | the @code{target} command. Otherwise you may get an error whose |
6f05cf9f | 19916 | text depends on the host system, but which usually looks something like |
2d717e4f | 19917 | @samp{Connection refused}. Don't use the @code{load} |
19d9d4ef DB |
19918 | command in @value{GDBN} when using @code{target remote} mode, since the |
19919 | program is already on the target. | |
19920 | ||
19921 | @end itemize | |
07f31aa6 | 19922 | |
19d9d4ef | 19923 | @anchor{Monitor Commands for gdbserver} |
79a6e687 | 19924 | @subsection Monitor Commands for @code{gdbserver} |
c74d0ad8 DJ |
19925 | @cindex monitor commands, for @code{gdbserver} |
19926 | ||
19927 | During a @value{GDBN} session using @code{gdbserver}, you can use the | |
19928 | @code{monitor} command to send special requests to @code{gdbserver}. | |
2d717e4f | 19929 | Here are the available commands. |
c74d0ad8 DJ |
19930 | |
19931 | @table @code | |
19932 | @item monitor help | |
19933 | List the available monitor commands. | |
19934 | ||
19935 | @item monitor set debug 0 | |
19936 | @itemx monitor set debug 1 | |
19937 | Disable or enable general debugging messages. | |
19938 | ||
19939 | @item monitor set remote-debug 0 | |
19940 | @itemx monitor set remote-debug 1 | |
19941 | Disable or enable specific debugging messages associated with the remote | |
19942 | protocol (@pxref{Remote Protocol}). | |
19943 | ||
87ce2a04 DE |
19944 | @item monitor set debug-format option1@r{[},option2,...@r{]} |
19945 | Specify additional text to add to debugging messages. | |
19946 | Possible options are: | |
19947 | ||
19948 | @table @code | |
19949 | @item none | |
19950 | Turn off all extra information in debugging output. | |
19951 | @item all | |
19952 | Turn on all extra information in debugging output. | |
19953 | @item timestamps | |
19954 | Include a timestamp in each line of debugging output. | |
19955 | @end table | |
19956 | ||
19957 | Options are processed in order. Thus, for example, if @option{none} | |
19958 | appears last then no additional information is added to debugging output. | |
19959 | ||
cdbfd419 PP |
19960 | @item monitor set libthread-db-search-path [PATH] |
19961 | @cindex gdbserver, search path for @code{libthread_db} | |
19962 | When this command is issued, @var{path} is a colon-separated list of | |
19963 | directories to search for @code{libthread_db} (@pxref{Threads,,set | |
19964 | libthread-db-search-path}). If you omit @var{path}, | |
84e578fb | 19965 | @samp{libthread-db-search-path} will be reset to its default value. |
cdbfd419 | 19966 | |
98a5dd13 DE |
19967 | The special entry @samp{$pdir} for @samp{libthread-db-search-path} is |
19968 | not supported in @code{gdbserver}. | |
19969 | ||
2d717e4f DJ |
19970 | @item monitor exit |
19971 | Tell gdbserver to exit immediately. This command should be followed by | |
19972 | @code{disconnect} to close the debugging session. @code{gdbserver} will | |
19973 | detach from any attached processes and kill any processes it created. | |
19974 | Use @code{monitor exit} to terminate @code{gdbserver} at the end | |
19975 | of a multi-process mode debug session. | |
19976 | ||
c74d0ad8 DJ |
19977 | @end table |
19978 | ||
fa593d66 PA |
19979 | @subsection Tracepoints support in @code{gdbserver} |
19980 | @cindex tracepoints support in @code{gdbserver} | |
19981 | ||
0fb4aa4b PA |
19982 | On some targets, @code{gdbserver} supports tracepoints, fast |
19983 | tracepoints and static tracepoints. | |
fa593d66 | 19984 | |
0fb4aa4b | 19985 | For fast or static tracepoints to work, a special library called the |
fa593d66 PA |
19986 | @dfn{in-process agent} (IPA), must be loaded in the inferior process. |
19987 | This library is built and distributed as an integral part of | |
0fb4aa4b PA |
19988 | @code{gdbserver}. In addition, support for static tracepoints |
19989 | requires building the in-process agent library with static tracepoints | |
19990 | support. At present, the UST (LTTng Userspace Tracer, | |
19991 | @url{http://lttng.org/ust}) tracing engine is supported. This support | |
19992 | is automatically available if UST development headers are found in the | |
19993 | standard include path when @code{gdbserver} is built, or if | |
19994 | @code{gdbserver} was explicitly configured using @option{--with-ust} | |
19995 | to point at such headers. You can explicitly disable the support | |
19996 | using @option{--with-ust=no}. | |
fa593d66 PA |
19997 | |
19998 | There are several ways to load the in-process agent in your program: | |
19999 | ||
20000 | @table @code | |
20001 | @item Specifying it as dependency at link time | |
20002 | ||
20003 | You can link your program dynamically with the in-process agent | |
20004 | library. On most systems, this is accomplished by adding | |
20005 | @code{-linproctrace} to the link command. | |
20006 | ||
20007 | @item Using the system's preloading mechanisms | |
20008 | ||
20009 | You can force loading the in-process agent at startup time by using | |
20010 | your system's support for preloading shared libraries. Many Unixes | |
20011 | support the concept of preloading user defined libraries. In most | |
20012 | cases, you do that by specifying @code{LD_PRELOAD=libinproctrace.so} | |
20013 | in the environment. See also the description of @code{gdbserver}'s | |
20014 | @option{--wrapper} command line option. | |
20015 | ||
20016 | @item Using @value{GDBN} to force loading the agent at run time | |
20017 | ||
20018 | On some systems, you can force the inferior to load a shared library, | |
20019 | by calling a dynamic loader function in the inferior that takes care | |
20020 | of dynamically looking up and loading a shared library. On most Unix | |
20021 | systems, the function is @code{dlopen}. You'll use the @code{call} | |
20022 | command for that. For example: | |
20023 | ||
20024 | @smallexample | |
20025 | (@value{GDBP}) call dlopen ("libinproctrace.so", ...) | |
20026 | @end smallexample | |
20027 | ||
20028 | Note that on most Unix systems, for the @code{dlopen} function to be | |
20029 | available, the program needs to be linked with @code{-ldl}. | |
20030 | @end table | |
20031 | ||
20032 | On systems that have a userspace dynamic loader, like most Unix | |
20033 | systems, when you connect to @code{gdbserver} using @code{target | |
20034 | remote}, you'll find that the program is stopped at the dynamic | |
20035 | loader's entry point, and no shared library has been loaded in the | |
20036 | program's address space yet, including the in-process agent. In that | |
0fb4aa4b PA |
20037 | case, before being able to use any of the fast or static tracepoints |
20038 | features, you need to let the loader run and load the shared | |
20039 | libraries. The simplest way to do that is to run the program to the | |
20040 | main procedure. E.g., if debugging a C or C@t{++} program, start | |
fa593d66 PA |
20041 | @code{gdbserver} like so: |
20042 | ||
20043 | @smallexample | |
20044 | $ gdbserver :9999 myprogram | |
20045 | @end smallexample | |
20046 | ||
20047 | Start GDB and connect to @code{gdbserver} like so, and run to main: | |
20048 | ||
20049 | @smallexample | |
20050 | $ gdb myprogram | |
20051 | (@value{GDBP}) target remote myhost:9999 | |
20052 | 0x00007f215893ba60 in ?? () from /lib64/ld-linux-x86-64.so.2 | |
20053 | (@value{GDBP}) b main | |
20054 | (@value{GDBP}) continue | |
20055 | @end smallexample | |
20056 | ||
20057 | The in-process tracing agent library should now be loaded into the | |
20058 | process; you can confirm it with the @code{info sharedlibrary} | |
20059 | command, which will list @file{libinproctrace.so} as loaded in the | |
0fb4aa4b PA |
20060 | process. You are now ready to install fast tracepoints, list static |
20061 | tracepoint markers, probe static tracepoints markers, and start | |
fa593d66 PA |
20062 | tracing. |
20063 | ||
79a6e687 BW |
20064 | @node Remote Configuration |
20065 | @section Remote Configuration | |
501eef12 | 20066 | |
9c16f35a EZ |
20067 | @kindex set remote |
20068 | @kindex show remote | |
20069 | This section documents the configuration options available when | |
20070 | debugging remote programs. For the options related to the File I/O | |
fc320d37 | 20071 | extensions of the remote protocol, see @ref{system, |
9c16f35a | 20072 | system-call-allowed}. |
501eef12 AC |
20073 | |
20074 | @table @code | |
9c16f35a | 20075 | @item set remoteaddresssize @var{bits} |
d3e8051b | 20076 | @cindex address size for remote targets |
9c16f35a EZ |
20077 | @cindex bits in remote address |
20078 | Set the maximum size of address in a memory packet to the specified | |
20079 | number of bits. @value{GDBN} will mask off the address bits above | |
20080 | that number, when it passes addresses to the remote target. The | |
20081 | default value is the number of bits in the target's address. | |
20082 | ||
20083 | @item show remoteaddresssize | |
20084 | Show the current value of remote address size in bits. | |
20085 | ||
0d12017b | 20086 | @item set serial baud @var{n} |
9c16f35a EZ |
20087 | @cindex baud rate for remote targets |
20088 | Set the baud rate for the remote serial I/O to @var{n} baud. The | |
20089 | value is used to set the speed of the serial port used for debugging | |
20090 | remote targets. | |
20091 | ||
0d12017b | 20092 | @item show serial baud |
9c16f35a EZ |
20093 | Show the current speed of the remote connection. |
20094 | ||
236af5e3 YG |
20095 | @item set serial parity @var{parity} |
20096 | Set the parity for the remote serial I/O. Supported values of @var{parity} are: | |
20097 | @code{even}, @code{none}, and @code{odd}. The default is @code{none}. | |
20098 | ||
20099 | @item show serial parity | |
20100 | Show the current parity of the serial port. | |
20101 | ||
9c16f35a EZ |
20102 | @item set remotebreak |
20103 | @cindex interrupt remote programs | |
20104 | @cindex BREAK signal instead of Ctrl-C | |
9a6253be | 20105 | @anchor{set remotebreak} |
9c16f35a | 20106 | If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote |
c8aa23ab | 20107 | when you type @kbd{Ctrl-c} to interrupt the program running |
9a7a1b36 | 20108 | on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C} |
9c16f35a EZ |
20109 | character instead. The default is off, since most remote systems |
20110 | expect to see @samp{Ctrl-C} as the interrupt signal. | |
20111 | ||
20112 | @item show remotebreak | |
20113 | Show whether @value{GDBN} sends @code{BREAK} or @samp{Ctrl-C} to | |
20114 | interrupt the remote program. | |
20115 | ||
23776285 MR |
20116 | @item set remoteflow on |
20117 | @itemx set remoteflow off | |
20118 | @kindex set remoteflow | |
20119 | Enable or disable hardware flow control (@code{RTS}/@code{CTS}) | |
20120 | on the serial port used to communicate to the remote target. | |
20121 | ||
20122 | @item show remoteflow | |
20123 | @kindex show remoteflow | |
20124 | Show the current setting of hardware flow control. | |
20125 | ||
9c16f35a EZ |
20126 | @item set remotelogbase @var{base} |
20127 | Set the base (a.k.a.@: radix) of logging serial protocol | |
20128 | communications to @var{base}. Supported values of @var{base} are: | |
20129 | @code{ascii}, @code{octal}, and @code{hex}. The default is | |
20130 | @code{ascii}. | |
20131 | ||
20132 | @item show remotelogbase | |
20133 | Show the current setting of the radix for logging remote serial | |
20134 | protocol. | |
20135 | ||
20136 | @item set remotelogfile @var{file} | |
20137 | @cindex record serial communications on file | |
20138 | Record remote serial communications on the named @var{file}. The | |
20139 | default is not to record at all. | |
20140 | ||
20141 | @item show remotelogfile. | |
20142 | Show the current setting of the file name on which to record the | |
20143 | serial communications. | |
20144 | ||
20145 | @item set remotetimeout @var{num} | |
20146 | @cindex timeout for serial communications | |
20147 | @cindex remote timeout | |
20148 | Set the timeout limit to wait for the remote target to respond to | |
20149 | @var{num} seconds. The default is 2 seconds. | |
20150 | ||
20151 | @item show remotetimeout | |
20152 | Show the current number of seconds to wait for the remote target | |
20153 | responses. | |
20154 | ||
20155 | @cindex limit hardware breakpoints and watchpoints | |
20156 | @cindex remote target, limit break- and watchpoints | |
501eef12 AC |
20157 | @anchor{set remote hardware-watchpoint-limit} |
20158 | @anchor{set remote hardware-breakpoint-limit} | |
20159 | @item set remote hardware-watchpoint-limit @var{limit} | |
20160 | @itemx set remote hardware-breakpoint-limit @var{limit} | |
20161 | Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or | |
20162 | watchpoints. A limit of -1, the default, is treated as unlimited. | |
2d717e4f | 20163 | |
480a3f21 PW |
20164 | @cindex limit hardware watchpoints length |
20165 | @cindex remote target, limit watchpoints length | |
20166 | @anchor{set remote hardware-watchpoint-length-limit} | |
20167 | @item set remote hardware-watchpoint-length-limit @var{limit} | |
20168 | Restrict @value{GDBN} to using @var{limit} bytes for the maximum length of | |
20169 | a remote hardware watchpoint. A limit of -1, the default, is treated | |
20170 | as unlimited. | |
20171 | ||
20172 | @item show remote hardware-watchpoint-length-limit | |
20173 | Show the current limit (in bytes) of the maximum length of | |
20174 | a remote hardware watchpoint. | |
20175 | ||
2d717e4f DJ |
20176 | @item set remote exec-file @var{filename} |
20177 | @itemx show remote exec-file | |
20178 | @anchor{set remote exec-file} | |
20179 | @cindex executable file, for remote target | |
20180 | Select the file used for @code{run} with @code{target | |
20181 | extended-remote}. This should be set to a filename valid on the | |
20182 | target system. If it is not set, the target will use a default | |
20183 | filename (e.g.@: the last program run). | |
84603566 | 20184 | |
9a7071a8 JB |
20185 | @item set remote interrupt-sequence |
20186 | @cindex interrupt remote programs | |
20187 | @cindex select Ctrl-C, BREAK or BREAK-g | |
20188 | Allow the user to select one of @samp{Ctrl-C}, a @code{BREAK} or | |
20189 | @samp{BREAK-g} as the | |
20190 | sequence to the remote target in order to interrupt the execution. | |
20191 | @samp{Ctrl-C} is a default. Some system prefers @code{BREAK} which | |
20192 | is high level of serial line for some certain time. | |
20193 | Linux kernel prefers @samp{BREAK-g}, a.k.a Magic SysRq g. | |
20194 | It is @code{BREAK} signal followed by character @code{g}. | |
20195 | ||
20196 | @item show interrupt-sequence | |
20197 | Show which of @samp{Ctrl-C}, @code{BREAK} or @code{BREAK-g} | |
20198 | is sent by @value{GDBN} to interrupt the remote program. | |
20199 | @code{BREAK-g} is BREAK signal followed by @code{g} and | |
20200 | also known as Magic SysRq g. | |
20201 | ||
20202 | @item set remote interrupt-on-connect | |
20203 | @cindex send interrupt-sequence on start | |
20204 | Specify whether interrupt-sequence is sent to remote target when | |
20205 | @value{GDBN} connects to it. This is mostly needed when you debug | |
20206 | Linux kernel. Linux kernel expects @code{BREAK} followed by @code{g} | |
20207 | which is known as Magic SysRq g in order to connect @value{GDBN}. | |
20208 | ||
20209 | @item show interrupt-on-connect | |
20210 | Show whether interrupt-sequence is sent | |
20211 | to remote target when @value{GDBN} connects to it. | |
20212 | ||
84603566 SL |
20213 | @kindex set tcp |
20214 | @kindex show tcp | |
20215 | @item set tcp auto-retry on | |
20216 | @cindex auto-retry, for remote TCP target | |
20217 | Enable auto-retry for remote TCP connections. This is useful if the remote | |
20218 | debugging agent is launched in parallel with @value{GDBN}; there is a race | |
20219 | condition because the agent may not become ready to accept the connection | |
20220 | before @value{GDBN} attempts to connect. When auto-retry is | |
20221 | enabled, if the initial attempt to connect fails, @value{GDBN} reattempts | |
20222 | to establish the connection using the timeout specified by | |
20223 | @code{set tcp connect-timeout}. | |
20224 | ||
20225 | @item set tcp auto-retry off | |
20226 | Do not auto-retry failed TCP connections. | |
20227 | ||
20228 | @item show tcp auto-retry | |
20229 | Show the current auto-retry setting. | |
20230 | ||
20231 | @item set tcp connect-timeout @var{seconds} | |
f81d1120 | 20232 | @itemx set tcp connect-timeout unlimited |
84603566 SL |
20233 | @cindex connection timeout, for remote TCP target |
20234 | @cindex timeout, for remote target connection | |
20235 | Set the timeout for establishing a TCP connection to the remote target to | |
20236 | @var{seconds}. The timeout affects both polling to retry failed connections | |
20237 | (enabled by @code{set tcp auto-retry on}) and waiting for connections | |
20238 | that are merely slow to complete, and represents an approximate cumulative | |
f81d1120 PA |
20239 | value. If @var{seconds} is @code{unlimited}, there is no timeout and |
20240 | @value{GDBN} will keep attempting to establish a connection forever, | |
20241 | unless interrupted with @kbd{Ctrl-c}. The default is 15 seconds. | |
84603566 SL |
20242 | |
20243 | @item show tcp connect-timeout | |
20244 | Show the current connection timeout setting. | |
501eef12 AC |
20245 | @end table |
20246 | ||
427c3a89 DJ |
20247 | @cindex remote packets, enabling and disabling |
20248 | The @value{GDBN} remote protocol autodetects the packets supported by | |
20249 | your debugging stub. If you need to override the autodetection, you | |
20250 | can use these commands to enable or disable individual packets. Each | |
20251 | packet can be set to @samp{on} (the remote target supports this | |
20252 | packet), @samp{off} (the remote target does not support this packet), | |
20253 | or @samp{auto} (detect remote target support for this packet). They | |
20254 | all default to @samp{auto}. For more information about each packet, | |
20255 | see @ref{Remote Protocol}. | |
20256 | ||
20257 | During normal use, you should not have to use any of these commands. | |
20258 | If you do, that may be a bug in your remote debugging stub, or a bug | |
20259 | in @value{GDBN}. You may want to report the problem to the | |
20260 | @value{GDBN} developers. | |
20261 | ||
cfa9d6d9 DJ |
20262 | For each packet @var{name}, the command to enable or disable the |
20263 | packet is @code{set remote @var{name}-packet}. The available settings | |
20264 | are: | |
427c3a89 | 20265 | |
cfa9d6d9 | 20266 | @multitable @columnfractions 0.28 0.32 0.25 |
427c3a89 DJ |
20267 | @item Command Name |
20268 | @tab Remote Packet | |
20269 | @tab Related Features | |
20270 | ||
cfa9d6d9 | 20271 | @item @code{fetch-register} |
427c3a89 DJ |
20272 | @tab @code{p} |
20273 | @tab @code{info registers} | |
20274 | ||
cfa9d6d9 | 20275 | @item @code{set-register} |
427c3a89 DJ |
20276 | @tab @code{P} |
20277 | @tab @code{set} | |
20278 | ||
cfa9d6d9 | 20279 | @item @code{binary-download} |
427c3a89 DJ |
20280 | @tab @code{X} |
20281 | @tab @code{load}, @code{set} | |
20282 | ||
cfa9d6d9 | 20283 | @item @code{read-aux-vector} |
427c3a89 DJ |
20284 | @tab @code{qXfer:auxv:read} |
20285 | @tab @code{info auxv} | |
20286 | ||
cfa9d6d9 | 20287 | @item @code{symbol-lookup} |
427c3a89 DJ |
20288 | @tab @code{qSymbol} |
20289 | @tab Detecting multiple threads | |
20290 | ||
2d717e4f DJ |
20291 | @item @code{attach} |
20292 | @tab @code{vAttach} | |
20293 | @tab @code{attach} | |
20294 | ||
cfa9d6d9 | 20295 | @item @code{verbose-resume} |
427c3a89 DJ |
20296 | @tab @code{vCont} |
20297 | @tab Stepping or resuming multiple threads | |
20298 | ||
2d717e4f DJ |
20299 | @item @code{run} |
20300 | @tab @code{vRun} | |
20301 | @tab @code{run} | |
20302 | ||
cfa9d6d9 | 20303 | @item @code{software-breakpoint} |
427c3a89 DJ |
20304 | @tab @code{Z0} |
20305 | @tab @code{break} | |
20306 | ||
cfa9d6d9 | 20307 | @item @code{hardware-breakpoint} |
427c3a89 DJ |
20308 | @tab @code{Z1} |
20309 | @tab @code{hbreak} | |
20310 | ||
cfa9d6d9 | 20311 | @item @code{write-watchpoint} |
427c3a89 DJ |
20312 | @tab @code{Z2} |
20313 | @tab @code{watch} | |
20314 | ||
cfa9d6d9 | 20315 | @item @code{read-watchpoint} |
427c3a89 DJ |
20316 | @tab @code{Z3} |
20317 | @tab @code{rwatch} | |
20318 | ||
cfa9d6d9 | 20319 | @item @code{access-watchpoint} |
427c3a89 DJ |
20320 | @tab @code{Z4} |
20321 | @tab @code{awatch} | |
20322 | ||
c78fa86a GB |
20323 | @item @code{pid-to-exec-file} |
20324 | @tab @code{qXfer:exec-file:read} | |
20325 | @tab @code{attach}, @code{run} | |
20326 | ||
cfa9d6d9 DJ |
20327 | @item @code{target-features} |
20328 | @tab @code{qXfer:features:read} | |
20329 | @tab @code{set architecture} | |
20330 | ||
20331 | @item @code{library-info} | |
20332 | @tab @code{qXfer:libraries:read} | |
20333 | @tab @code{info sharedlibrary} | |
20334 | ||
20335 | @item @code{memory-map} | |
20336 | @tab @code{qXfer:memory-map:read} | |
20337 | @tab @code{info mem} | |
20338 | ||
0fb4aa4b PA |
20339 | @item @code{read-sdata-object} |
20340 | @tab @code{qXfer:sdata:read} | |
20341 | @tab @code{print $_sdata} | |
20342 | ||
cfa9d6d9 DJ |
20343 | @item @code{read-spu-object} |
20344 | @tab @code{qXfer:spu:read} | |
20345 | @tab @code{info spu} | |
20346 | ||
20347 | @item @code{write-spu-object} | |
20348 | @tab @code{qXfer:spu:write} | |
20349 | @tab @code{info spu} | |
20350 | ||
4aa995e1 PA |
20351 | @item @code{read-siginfo-object} |
20352 | @tab @code{qXfer:siginfo:read} | |
20353 | @tab @code{print $_siginfo} | |
20354 | ||
20355 | @item @code{write-siginfo-object} | |
20356 | @tab @code{qXfer:siginfo:write} | |
20357 | @tab @code{set $_siginfo} | |
20358 | ||
dc146f7c VP |
20359 | @item @code{threads} |
20360 | @tab @code{qXfer:threads:read} | |
20361 | @tab @code{info threads} | |
20362 | ||
cfa9d6d9 | 20363 | @item @code{get-thread-local-@*storage-address} |
427c3a89 DJ |
20364 | @tab @code{qGetTLSAddr} |
20365 | @tab Displaying @code{__thread} variables | |
20366 | ||
711e434b PM |
20367 | @item @code{get-thread-information-block-address} |
20368 | @tab @code{qGetTIBAddr} | |
20369 | @tab Display MS-Windows Thread Information Block. | |
20370 | ||
08388c79 DE |
20371 | @item @code{search-memory} |
20372 | @tab @code{qSearch:memory} | |
20373 | @tab @code{find} | |
20374 | ||
427c3a89 DJ |
20375 | @item @code{supported-packets} |
20376 | @tab @code{qSupported} | |
20377 | @tab Remote communications parameters | |
20378 | ||
82075af2 JS |
20379 | @item @code{catch-syscalls} |
20380 | @tab @code{QCatchSyscalls} | |
20381 | @tab @code{catch syscall} | |
20382 | ||
cfa9d6d9 | 20383 | @item @code{pass-signals} |
89be2091 DJ |
20384 | @tab @code{QPassSignals} |
20385 | @tab @code{handle @var{signal}} | |
20386 | ||
9b224c5e PA |
20387 | @item @code{program-signals} |
20388 | @tab @code{QProgramSignals} | |
20389 | @tab @code{handle @var{signal}} | |
20390 | ||
a6b151f1 DJ |
20391 | @item @code{hostio-close-packet} |
20392 | @tab @code{vFile:close} | |
20393 | @tab @code{remote get}, @code{remote put} | |
20394 | ||
20395 | @item @code{hostio-open-packet} | |
20396 | @tab @code{vFile:open} | |
20397 | @tab @code{remote get}, @code{remote put} | |
20398 | ||
20399 | @item @code{hostio-pread-packet} | |
20400 | @tab @code{vFile:pread} | |
20401 | @tab @code{remote get}, @code{remote put} | |
20402 | ||
20403 | @item @code{hostio-pwrite-packet} | |
20404 | @tab @code{vFile:pwrite} | |
20405 | @tab @code{remote get}, @code{remote put} | |
20406 | ||
20407 | @item @code{hostio-unlink-packet} | |
20408 | @tab @code{vFile:unlink} | |
20409 | @tab @code{remote delete} | |
a6f3e723 | 20410 | |
b9e7b9c3 UW |
20411 | @item @code{hostio-readlink-packet} |
20412 | @tab @code{vFile:readlink} | |
20413 | @tab Host I/O | |
20414 | ||
0a93529c GB |
20415 | @item @code{hostio-fstat-packet} |
20416 | @tab @code{vFile:fstat} | |
20417 | @tab Host I/O | |
20418 | ||
15a201c8 GB |
20419 | @item @code{hostio-setfs-packet} |
20420 | @tab @code{vFile:setfs} | |
20421 | @tab Host I/O | |
20422 | ||
a6f3e723 SL |
20423 | @item @code{noack-packet} |
20424 | @tab @code{QStartNoAckMode} | |
20425 | @tab Packet acknowledgment | |
07e059b5 VP |
20426 | |
20427 | @item @code{osdata} | |
20428 | @tab @code{qXfer:osdata:read} | |
20429 | @tab @code{info os} | |
0b16c5cf PA |
20430 | |
20431 | @item @code{query-attached} | |
20432 | @tab @code{qAttached} | |
20433 | @tab Querying remote process attach state. | |
b3b9301e | 20434 | |
a46c1e42 PA |
20435 | @item @code{trace-buffer-size} |
20436 | @tab @code{QTBuffer:size} | |
20437 | @tab @code{set trace-buffer-size} | |
20438 | ||
bd3eecc3 PA |
20439 | @item @code{trace-status} |
20440 | @tab @code{qTStatus} | |
20441 | @tab @code{tstatus} | |
20442 | ||
b3b9301e PA |
20443 | @item @code{traceframe-info} |
20444 | @tab @code{qXfer:traceframe-info:read} | |
20445 | @tab Traceframe info | |
03583c20 | 20446 | |
1e4d1764 YQ |
20447 | @item @code{install-in-trace} |
20448 | @tab @code{InstallInTrace} | |
20449 | @tab Install tracepoint in tracing | |
20450 | ||
03583c20 UW |
20451 | @item @code{disable-randomization} |
20452 | @tab @code{QDisableRandomization} | |
20453 | @tab @code{set disable-randomization} | |
83364271 LM |
20454 | |
20455 | @item @code{conditional-breakpoints-packet} | |
20456 | @tab @code{Z0 and Z1} | |
20457 | @tab @code{Support for target-side breakpoint condition evaluation} | |
f7e6eed5 | 20458 | |
73b8c1fd PA |
20459 | @item @code{multiprocess-extensions} |
20460 | @tab @code{multiprocess extensions} | |
20461 | @tab Debug multiple processes and remote process PID awareness | |
20462 | ||
f7e6eed5 PA |
20463 | @item @code{swbreak-feature} |
20464 | @tab @code{swbreak stop reason} | |
20465 | @tab @code{break} | |
20466 | ||
20467 | @item @code{hwbreak-feature} | |
20468 | @tab @code{hwbreak stop reason} | |
20469 | @tab @code{hbreak} | |
20470 | ||
0d71eef5 DB |
20471 | @item @code{fork-event-feature} |
20472 | @tab @code{fork stop reason} | |
20473 | @tab @code{fork} | |
20474 | ||
20475 | @item @code{vfork-event-feature} | |
20476 | @tab @code{vfork stop reason} | |
20477 | @tab @code{vfork} | |
20478 | ||
b459a59b DB |
20479 | @item @code{exec-event-feature} |
20480 | @tab @code{exec stop reason} | |
20481 | @tab @code{exec} | |
20482 | ||
65706a29 PA |
20483 | @item @code{thread-events} |
20484 | @tab @code{QThreadEvents} | |
20485 | @tab Tracking thread lifetime. | |
20486 | ||
f2faf941 PA |
20487 | @item @code{no-resumed-stop-reply} |
20488 | @tab @code{no resumed thread left stop reply} | |
20489 | @tab Tracking thread lifetime. | |
20490 | ||
427c3a89 DJ |
20491 | @end multitable |
20492 | ||
79a6e687 BW |
20493 | @node Remote Stub |
20494 | @section Implementing a Remote Stub | |
7a292a7a | 20495 | |
8e04817f AC |
20496 | @cindex debugging stub, example |
20497 | @cindex remote stub, example | |
20498 | @cindex stub example, remote debugging | |
20499 | The stub files provided with @value{GDBN} implement the target side of the | |
20500 | communication protocol, and the @value{GDBN} side is implemented in the | |
20501 | @value{GDBN} source file @file{remote.c}. Normally, you can simply allow | |
20502 | these subroutines to communicate, and ignore the details. (If you're | |
20503 | implementing your own stub file, you can still ignore the details: start | |
20504 | with one of the existing stub files. @file{sparc-stub.c} is the best | |
20505 | organized, and therefore the easiest to read.) | |
20506 | ||
104c1213 JM |
20507 | @cindex remote serial debugging, overview |
20508 | To debug a program running on another machine (the debugging | |
20509 | @dfn{target} machine), you must first arrange for all the usual | |
20510 | prerequisites for the program to run by itself. For example, for a C | |
20511 | program, you need: | |
c906108c | 20512 | |
104c1213 JM |
20513 | @enumerate |
20514 | @item | |
20515 | A startup routine to set up the C runtime environment; these usually | |
20516 | have a name like @file{crt0}. The startup routine may be supplied by | |
20517 | your hardware supplier, or you may have to write your own. | |
96baa820 | 20518 | |
5d161b24 | 20519 | @item |
d4f3574e | 20520 | A C subroutine library to support your program's |
104c1213 | 20521 | subroutine calls, notably managing input and output. |
96baa820 | 20522 | |
104c1213 JM |
20523 | @item |
20524 | A way of getting your program to the other machine---for example, a | |
20525 | download program. These are often supplied by the hardware | |
20526 | manufacturer, but you may have to write your own from hardware | |
20527 | documentation. | |
20528 | @end enumerate | |
96baa820 | 20529 | |
104c1213 JM |
20530 | The next step is to arrange for your program to use a serial port to |
20531 | communicate with the machine where @value{GDBN} is running (the @dfn{host} | |
20532 | machine). In general terms, the scheme looks like this: | |
96baa820 | 20533 | |
104c1213 JM |
20534 | @table @emph |
20535 | @item On the host, | |
20536 | @value{GDBN} already understands how to use this protocol; when everything | |
20537 | else is set up, you can simply use the @samp{target remote} command | |
20538 | (@pxref{Targets,,Specifying a Debugging Target}). | |
20539 | ||
20540 | @item On the target, | |
20541 | you must link with your program a few special-purpose subroutines that | |
20542 | implement the @value{GDBN} remote serial protocol. The file containing these | |
20543 | subroutines is called a @dfn{debugging stub}. | |
20544 | ||
20545 | On certain remote targets, you can use an auxiliary program | |
20546 | @code{gdbserver} instead of linking a stub into your program. | |
79a6e687 | 20547 | @xref{Server,,Using the @code{gdbserver} Program}, for details. |
104c1213 | 20548 | @end table |
96baa820 | 20549 | |
104c1213 JM |
20550 | The debugging stub is specific to the architecture of the remote |
20551 | machine; for example, use @file{sparc-stub.c} to debug programs on | |
20552 | @sc{sparc} boards. | |
96baa820 | 20553 | |
104c1213 JM |
20554 | @cindex remote serial stub list |
20555 | These working remote stubs are distributed with @value{GDBN}: | |
96baa820 | 20556 | |
104c1213 JM |
20557 | @table @code |
20558 | ||
20559 | @item i386-stub.c | |
41afff9a | 20560 | @cindex @file{i386-stub.c} |
104c1213 JM |
20561 | @cindex Intel |
20562 | @cindex i386 | |
20563 | For Intel 386 and compatible architectures. | |
20564 | ||
20565 | @item m68k-stub.c | |
41afff9a | 20566 | @cindex @file{m68k-stub.c} |
104c1213 JM |
20567 | @cindex Motorola 680x0 |
20568 | @cindex m680x0 | |
20569 | For Motorola 680x0 architectures. | |
20570 | ||
20571 | @item sh-stub.c | |
41afff9a | 20572 | @cindex @file{sh-stub.c} |
172c2a43 | 20573 | @cindex Renesas |
104c1213 | 20574 | @cindex SH |
172c2a43 | 20575 | For Renesas SH architectures. |
104c1213 JM |
20576 | |
20577 | @item sparc-stub.c | |
41afff9a | 20578 | @cindex @file{sparc-stub.c} |
104c1213 JM |
20579 | @cindex Sparc |
20580 | For @sc{sparc} architectures. | |
20581 | ||
20582 | @item sparcl-stub.c | |
41afff9a | 20583 | @cindex @file{sparcl-stub.c} |
104c1213 JM |
20584 | @cindex Fujitsu |
20585 | @cindex SparcLite | |
20586 | For Fujitsu @sc{sparclite} architectures. | |
20587 | ||
20588 | @end table | |
20589 | ||
20590 | The @file{README} file in the @value{GDBN} distribution may list other | |
20591 | recently added stubs. | |
20592 | ||
20593 | @menu | |
20594 | * Stub Contents:: What the stub can do for you | |
20595 | * Bootstrapping:: What you must do for the stub | |
20596 | * Debug Session:: Putting it all together | |
104c1213 JM |
20597 | @end menu |
20598 | ||
6d2ebf8b | 20599 | @node Stub Contents |
79a6e687 | 20600 | @subsection What the Stub Can Do for You |
104c1213 JM |
20601 | |
20602 | @cindex remote serial stub | |
20603 | The debugging stub for your architecture supplies these three | |
20604 | subroutines: | |
20605 | ||
20606 | @table @code | |
20607 | @item set_debug_traps | |
4644b6e3 | 20608 | @findex set_debug_traps |
104c1213 JM |
20609 | @cindex remote serial stub, initialization |
20610 | This routine arranges for @code{handle_exception} to run when your | |
2fb860fc PA |
20611 | program stops. You must call this subroutine explicitly in your |
20612 | program's startup code. | |
104c1213 JM |
20613 | |
20614 | @item handle_exception | |
4644b6e3 | 20615 | @findex handle_exception |
104c1213 JM |
20616 | @cindex remote serial stub, main routine |
20617 | This is the central workhorse, but your program never calls it | |
20618 | explicitly---the setup code arranges for @code{handle_exception} to | |
20619 | run when a trap is triggered. | |
20620 | ||
20621 | @code{handle_exception} takes control when your program stops during | |
20622 | execution (for example, on a breakpoint), and mediates communications | |
20623 | with @value{GDBN} on the host machine. This is where the communications | |
20624 | protocol is implemented; @code{handle_exception} acts as the @value{GDBN} | |
d4f3574e | 20625 | representative on the target machine. It begins by sending summary |
104c1213 JM |
20626 | information on the state of your program, then continues to execute, |
20627 | retrieving and transmitting any information @value{GDBN} needs, until you | |
20628 | execute a @value{GDBN} command that makes your program resume; at that point, | |
20629 | @code{handle_exception} returns control to your own code on the target | |
5d161b24 | 20630 | machine. |
104c1213 JM |
20631 | |
20632 | @item breakpoint | |
20633 | @cindex @code{breakpoint} subroutine, remote | |
20634 | Use this auxiliary subroutine to make your program contain a | |
20635 | breakpoint. Depending on the particular situation, this may be the only | |
20636 | way for @value{GDBN} to get control. For instance, if your target | |
20637 | machine has some sort of interrupt button, you won't need to call this; | |
20638 | pressing the interrupt button transfers control to | |
20639 | @code{handle_exception}---in effect, to @value{GDBN}. On some machines, | |
20640 | simply receiving characters on the serial port may also trigger a trap; | |
20641 | again, in that situation, you don't need to call @code{breakpoint} from | |
20642 | your own program---simply running @samp{target remote} from the host | |
5d161b24 | 20643 | @value{GDBN} session gets control. |
104c1213 JM |
20644 | |
20645 | Call @code{breakpoint} if none of these is true, or if you simply want | |
20646 | to make certain your program stops at a predetermined point for the | |
20647 | start of your debugging session. | |
20648 | @end table | |
20649 | ||
6d2ebf8b | 20650 | @node Bootstrapping |
79a6e687 | 20651 | @subsection What You Must Do for the Stub |
104c1213 JM |
20652 | |
20653 | @cindex remote stub, support routines | |
20654 | The debugging stubs that come with @value{GDBN} are set up for a particular | |
20655 | chip architecture, but they have no information about the rest of your | |
20656 | debugging target machine. | |
20657 | ||
20658 | First of all you need to tell the stub how to communicate with the | |
20659 | serial port. | |
20660 | ||
20661 | @table @code | |
20662 | @item int getDebugChar() | |
4644b6e3 | 20663 | @findex getDebugChar |
104c1213 JM |
20664 | Write this subroutine to read a single character from the serial port. |
20665 | It may be identical to @code{getchar} for your target system; a | |
20666 | different name is used to allow you to distinguish the two if you wish. | |
20667 | ||
20668 | @item void putDebugChar(int) | |
4644b6e3 | 20669 | @findex putDebugChar |
104c1213 | 20670 | Write this subroutine to write a single character to the serial port. |
5d161b24 | 20671 | It may be identical to @code{putchar} for your target system; a |
104c1213 JM |
20672 | different name is used to allow you to distinguish the two if you wish. |
20673 | @end table | |
20674 | ||
20675 | @cindex control C, and remote debugging | |
20676 | @cindex interrupting remote targets | |
20677 | If you want @value{GDBN} to be able to stop your program while it is | |
20678 | running, you need to use an interrupt-driven serial driver, and arrange | |
20679 | for it to stop when it receives a @code{^C} (@samp{\003}, the control-C | |
20680 | character). That is the character which @value{GDBN} uses to tell the | |
20681 | remote system to stop. | |
20682 | ||
20683 | Getting the debugging target to return the proper status to @value{GDBN} | |
20684 | probably requires changes to the standard stub; one quick and dirty way | |
20685 | is to just execute a breakpoint instruction (the ``dirty'' part is that | |
20686 | @value{GDBN} reports a @code{SIGTRAP} instead of a @code{SIGINT}). | |
20687 | ||
20688 | Other routines you need to supply are: | |
20689 | ||
20690 | @table @code | |
20691 | @item void exceptionHandler (int @var{exception_number}, void *@var{exception_address}) | |
4644b6e3 | 20692 | @findex exceptionHandler |
104c1213 JM |
20693 | Write this function to install @var{exception_address} in the exception |
20694 | handling tables. You need to do this because the stub does not have any | |
20695 | way of knowing what the exception handling tables on your target system | |
20696 | are like (for example, the processor's table might be in @sc{rom}, | |
20697 | containing entries which point to a table in @sc{ram}). | |
697aa1b7 | 20698 | The @var{exception_number} specifies the exception which should be changed; |
104c1213 JM |
20699 | its meaning is architecture-dependent (for example, different numbers |
20700 | might represent divide by zero, misaligned access, etc). When this | |
20701 | exception occurs, control should be transferred directly to | |
20702 | @var{exception_address}, and the processor state (stack, registers, | |
20703 | and so on) should be just as it is when a processor exception occurs. So if | |
20704 | you want to use a jump instruction to reach @var{exception_address}, it | |
20705 | should be a simple jump, not a jump to subroutine. | |
20706 | ||
20707 | For the 386, @var{exception_address} should be installed as an interrupt | |
20708 | gate so that interrupts are masked while the handler runs. The gate | |
20709 | should be at privilege level 0 (the most privileged level). The | |
20710 | @sc{sparc} and 68k stubs are able to mask interrupts themselves without | |
20711 | help from @code{exceptionHandler}. | |
20712 | ||
20713 | @item void flush_i_cache() | |
4644b6e3 | 20714 | @findex flush_i_cache |
d4f3574e | 20715 | On @sc{sparc} and @sc{sparclite} only, write this subroutine to flush the |
104c1213 JM |
20716 | instruction cache, if any, on your target machine. If there is no |
20717 | instruction cache, this subroutine may be a no-op. | |
20718 | ||
20719 | On target machines that have instruction caches, @value{GDBN} requires this | |
20720 | function to make certain that the state of your program is stable. | |
20721 | @end table | |
20722 | ||
20723 | @noindent | |
20724 | You must also make sure this library routine is available: | |
20725 | ||
20726 | @table @code | |
20727 | @item void *memset(void *, int, int) | |
4644b6e3 | 20728 | @findex memset |
104c1213 JM |
20729 | This is the standard library function @code{memset} that sets an area of |
20730 | memory to a known value. If you have one of the free versions of | |
20731 | @code{libc.a}, @code{memset} can be found there; otherwise, you must | |
20732 | either obtain it from your hardware manufacturer, or write your own. | |
20733 | @end table | |
20734 | ||
20735 | If you do not use the GNU C compiler, you may need other standard | |
20736 | library subroutines as well; this varies from one stub to another, | |
20737 | but in general the stubs are likely to use any of the common library | |
e22ea452 | 20738 | subroutines which @code{@value{NGCC}} generates as inline code. |
104c1213 JM |
20739 | |
20740 | ||
6d2ebf8b | 20741 | @node Debug Session |
79a6e687 | 20742 | @subsection Putting it All Together |
104c1213 JM |
20743 | |
20744 | @cindex remote serial debugging summary | |
20745 | In summary, when your program is ready to debug, you must follow these | |
20746 | steps. | |
20747 | ||
20748 | @enumerate | |
20749 | @item | |
6d2ebf8b | 20750 | Make sure you have defined the supporting low-level routines |
79a6e687 | 20751 | (@pxref{Bootstrapping,,What You Must Do for the Stub}): |
104c1213 JM |
20752 | @display |
20753 | @code{getDebugChar}, @code{putDebugChar}, | |
20754 | @code{flush_i_cache}, @code{memset}, @code{exceptionHandler}. | |
20755 | @end display | |
20756 | ||
20757 | @item | |
2fb860fc PA |
20758 | Insert these lines in your program's startup code, before the main |
20759 | procedure is called: | |
104c1213 | 20760 | |
474c8240 | 20761 | @smallexample |
104c1213 JM |
20762 | set_debug_traps(); |
20763 | breakpoint(); | |
474c8240 | 20764 | @end smallexample |
104c1213 | 20765 | |
2fb860fc PA |
20766 | On some machines, when a breakpoint trap is raised, the hardware |
20767 | automatically makes the PC point to the instruction after the | |
20768 | breakpoint. If your machine doesn't do that, you may need to adjust | |
20769 | @code{handle_exception} to arrange for it to return to the instruction | |
20770 | after the breakpoint on this first invocation, so that your program | |
20771 | doesn't keep hitting the initial breakpoint instead of making | |
20772 | progress. | |
20773 | ||
104c1213 JM |
20774 | @item |
20775 | For the 680x0 stub only, you need to provide a variable called | |
20776 | @code{exceptionHook}. Normally you just use: | |
20777 | ||
474c8240 | 20778 | @smallexample |
104c1213 | 20779 | void (*exceptionHook)() = 0; |
474c8240 | 20780 | @end smallexample |
104c1213 | 20781 | |
d4f3574e | 20782 | @noindent |
104c1213 | 20783 | but if before calling @code{set_debug_traps}, you set it to point to a |
598ca718 | 20784 | function in your program, that function is called when |
104c1213 JM |
20785 | @code{@value{GDBN}} continues after stopping on a trap (for example, bus |
20786 | error). The function indicated by @code{exceptionHook} is called with | |
20787 | one parameter: an @code{int} which is the exception number. | |
20788 | ||
20789 | @item | |
20790 | Compile and link together: your program, the @value{GDBN} debugging stub for | |
20791 | your target architecture, and the supporting subroutines. | |
20792 | ||
20793 | @item | |
20794 | Make sure you have a serial connection between your target machine and | |
20795 | the @value{GDBN} host, and identify the serial port on the host. | |
20796 | ||
20797 | @item | |
20798 | @c The "remote" target now provides a `load' command, so we should | |
20799 | @c document that. FIXME. | |
20800 | Download your program to your target machine (or get it there by | |
20801 | whatever means the manufacturer provides), and start it. | |
20802 | ||
20803 | @item | |
07f31aa6 | 20804 | Start @value{GDBN} on the host, and connect to the target |
79a6e687 | 20805 | (@pxref{Connecting,,Connecting to a Remote Target}). |
9db8d71f | 20806 | |
104c1213 JM |
20807 | @end enumerate |
20808 | ||
8e04817f AC |
20809 | @node Configurations |
20810 | @chapter Configuration-Specific Information | |
104c1213 | 20811 | |
8e04817f AC |
20812 | While nearly all @value{GDBN} commands are available for all native and |
20813 | cross versions of the debugger, there are some exceptions. This chapter | |
20814 | describes things that are only available in certain configurations. | |
104c1213 | 20815 | |
8e04817f AC |
20816 | There are three major categories of configurations: native |
20817 | configurations, where the host and target are the same, embedded | |
20818 | operating system configurations, which are usually the same for several | |
20819 | different processor architectures, and bare embedded processors, which | |
20820 | are quite different from each other. | |
104c1213 | 20821 | |
8e04817f AC |
20822 | @menu |
20823 | * Native:: | |
20824 | * Embedded OS:: | |
20825 | * Embedded Processors:: | |
20826 | * Architectures:: | |
20827 | @end menu | |
104c1213 | 20828 | |
8e04817f AC |
20829 | @node Native |
20830 | @section Native | |
104c1213 | 20831 | |
8e04817f AC |
20832 | This section describes details specific to particular native |
20833 | configurations. | |
6cf7e474 | 20834 | |
8e04817f | 20835 | @menu |
7561d450 | 20836 | * BSD libkvm Interface:: Debugging BSD kernel memory images |
8e04817f AC |
20837 | * SVR4 Process Information:: SVR4 process information |
20838 | * DJGPP Native:: Features specific to the DJGPP port | |
78c47bea | 20839 | * Cygwin Native:: Features specific to the Cygwin port |
14d6dd68 | 20840 | * Hurd Native:: Features specific to @sc{gnu} Hurd |
a80b95ba | 20841 | * Darwin:: Features specific to Darwin |
8e04817f | 20842 | @end menu |
6cf7e474 | 20843 | |
7561d450 MK |
20844 | @node BSD libkvm Interface |
20845 | @subsection BSD libkvm Interface | |
20846 | ||
20847 | @cindex libkvm | |
20848 | @cindex kernel memory image | |
20849 | @cindex kernel crash dump | |
20850 | ||
20851 | BSD-derived systems (FreeBSD/NetBSD/OpenBSD) have a kernel memory | |
20852 | interface that provides a uniform interface for accessing kernel virtual | |
20853 | memory images, including live systems and crash dumps. @value{GDBN} | |
20854 | uses this interface to allow you to debug live kernels and kernel crash | |
20855 | dumps on many native BSD configurations. This is implemented as a | |
20856 | special @code{kvm} debugging target. For debugging a live system, load | |
20857 | the currently running kernel into @value{GDBN} and connect to the | |
20858 | @code{kvm} target: | |
20859 | ||
20860 | @smallexample | |
20861 | (@value{GDBP}) @b{target kvm} | |
20862 | @end smallexample | |
20863 | ||
20864 | For debugging crash dumps, provide the file name of the crash dump as an | |
20865 | argument: | |
20866 | ||
20867 | @smallexample | |
20868 | (@value{GDBP}) @b{target kvm /var/crash/bsd.0} | |
20869 | @end smallexample | |
20870 | ||
20871 | Once connected to the @code{kvm} target, the following commands are | |
20872 | available: | |
20873 | ||
20874 | @table @code | |
20875 | @kindex kvm | |
20876 | @item kvm pcb | |
721c2651 | 20877 | Set current context from the @dfn{Process Control Block} (PCB) address. |
7561d450 MK |
20878 | |
20879 | @item kvm proc | |
20880 | Set current context from proc address. This command isn't available on | |
20881 | modern FreeBSD systems. | |
20882 | @end table | |
20883 | ||
8e04817f | 20884 | @node SVR4 Process Information |
79a6e687 | 20885 | @subsection SVR4 Process Information |
60bf7e09 EZ |
20886 | @cindex /proc |
20887 | @cindex examine process image | |
20888 | @cindex process info via @file{/proc} | |
104c1213 | 20889 | |
60bf7e09 EZ |
20890 | Many versions of SVR4 and compatible systems provide a facility called |
20891 | @samp{/proc} that can be used to examine the image of a running | |
451b7c33 TT |
20892 | process using file-system subroutines. |
20893 | ||
20894 | If @value{GDBN} is configured for an operating system with this | |
20895 | facility, the command @code{info proc} is available to report | |
20896 | information about the process running your program, or about any | |
20897 | process running on your system. This includes, as of this writing, | |
b1236ac3 | 20898 | @sc{gnu}/Linux and Solaris, for example. |
451b7c33 TT |
20899 | |
20900 | This command may also work on core files that were created on a system | |
20901 | that has the @samp{/proc} facility. | |
104c1213 | 20902 | |
8e04817f AC |
20903 | @table @code |
20904 | @kindex info proc | |
60bf7e09 | 20905 | @cindex process ID |
8e04817f | 20906 | @item info proc |
60bf7e09 EZ |
20907 | @itemx info proc @var{process-id} |
20908 | Summarize available information about any running process. If a | |
20909 | process ID is specified by @var{process-id}, display information about | |
20910 | that process; otherwise display information about the program being | |
20911 | debugged. The summary includes the debugged process ID, the command | |
20912 | line used to invoke it, its current working directory, and its | |
20913 | executable file's absolute file name. | |
20914 | ||
20915 | On some systems, @var{process-id} can be of the form | |
20916 | @samp{[@var{pid}]/@var{tid}} which specifies a certain thread ID | |
20917 | within a process. If the optional @var{pid} part is missing, it means | |
20918 | a thread from the process being debugged (the leading @samp{/} still | |
20919 | needs to be present, or else @value{GDBN} will interpret the number as | |
20920 | a process ID rather than a thread ID). | |
6cf7e474 | 20921 | |
0c631110 TT |
20922 | @item info proc cmdline |
20923 | @cindex info proc cmdline | |
20924 | Show the original command line of the process. This command is | |
20925 | specific to @sc{gnu}/Linux. | |
20926 | ||
20927 | @item info proc cwd | |
20928 | @cindex info proc cwd | |
20929 | Show the current working directory of the process. This command is | |
20930 | specific to @sc{gnu}/Linux. | |
20931 | ||
20932 | @item info proc exe | |
20933 | @cindex info proc exe | |
20934 | Show the name of executable of the process. This command is specific | |
20935 | to @sc{gnu}/Linux. | |
20936 | ||
8e04817f | 20937 | @item info proc mappings |
60bf7e09 EZ |
20938 | @cindex memory address space mappings |
20939 | Report the memory address space ranges accessible in the program, with | |
20940 | information on whether the process has read, write, or execute access | |
20941 | rights to each range. On @sc{gnu}/Linux systems, each memory range | |
20942 | includes the object file which is mapped to that range, instead of the | |
20943 | memory access rights to that range. | |
20944 | ||
20945 | @item info proc stat | |
20946 | @itemx info proc status | |
20947 | @cindex process detailed status information | |
20948 | These subcommands are specific to @sc{gnu}/Linux systems. They show | |
20949 | the process-related information, including the user ID and group ID; | |
20950 | how many threads are there in the process; its virtual memory usage; | |
20951 | the signals that are pending, blocked, and ignored; its TTY; its | |
20952 | consumption of system and user time; its stack size; its @samp{nice} | |
2eecc4ab | 20953 | value; etc. For more information, see the @samp{proc} man page |
60bf7e09 EZ |
20954 | (type @kbd{man 5 proc} from your shell prompt). |
20955 | ||
20956 | @item info proc all | |
20957 | Show all the information about the process described under all of the | |
20958 | above @code{info proc} subcommands. | |
20959 | ||
8e04817f AC |
20960 | @ignore |
20961 | @comment These sub-options of 'info proc' were not included when | |
20962 | @comment procfs.c was re-written. Keep their descriptions around | |
20963 | @comment against the day when someone finds the time to put them back in. | |
20964 | @kindex info proc times | |
20965 | @item info proc times | |
20966 | Starting time, user CPU time, and system CPU time for your program and | |
20967 | its children. | |
6cf7e474 | 20968 | |
8e04817f AC |
20969 | @kindex info proc id |
20970 | @item info proc id | |
20971 | Report on the process IDs related to your program: its own process ID, | |
20972 | the ID of its parent, the process group ID, and the session ID. | |
8e04817f | 20973 | @end ignore |
721c2651 EZ |
20974 | |
20975 | @item set procfs-trace | |
20976 | @kindex set procfs-trace | |
20977 | @cindex @code{procfs} API calls | |
20978 | This command enables and disables tracing of @code{procfs} API calls. | |
20979 | ||
20980 | @item show procfs-trace | |
20981 | @kindex show procfs-trace | |
20982 | Show the current state of @code{procfs} API call tracing. | |
20983 | ||
20984 | @item set procfs-file @var{file} | |
20985 | @kindex set procfs-file | |
20986 | Tell @value{GDBN} to write @code{procfs} API trace to the named | |
20987 | @var{file}. @value{GDBN} appends the trace info to the previous | |
20988 | contents of the file. The default is to display the trace on the | |
20989 | standard output. | |
20990 | ||
20991 | @item show procfs-file | |
20992 | @kindex show procfs-file | |
20993 | Show the file to which @code{procfs} API trace is written. | |
20994 | ||
20995 | @item proc-trace-entry | |
20996 | @itemx proc-trace-exit | |
20997 | @itemx proc-untrace-entry | |
20998 | @itemx proc-untrace-exit | |
20999 | @kindex proc-trace-entry | |
21000 | @kindex proc-trace-exit | |
21001 | @kindex proc-untrace-entry | |
21002 | @kindex proc-untrace-exit | |
21003 | These commands enable and disable tracing of entries into and exits | |
21004 | from the @code{syscall} interface. | |
21005 | ||
21006 | @item info pidlist | |
21007 | @kindex info pidlist | |
21008 | @cindex process list, QNX Neutrino | |
21009 | For QNX Neutrino only, this command displays the list of all the | |
21010 | processes and all the threads within each process. | |
21011 | ||
21012 | @item info meminfo | |
21013 | @kindex info meminfo | |
21014 | @cindex mapinfo list, QNX Neutrino | |
21015 | For QNX Neutrino only, this command displays the list of all mapinfos. | |
8e04817f | 21016 | @end table |
104c1213 | 21017 | |
8e04817f AC |
21018 | @node DJGPP Native |
21019 | @subsection Features for Debugging @sc{djgpp} Programs | |
21020 | @cindex @sc{djgpp} debugging | |
21021 | @cindex native @sc{djgpp} debugging | |
21022 | @cindex MS-DOS-specific commands | |
104c1213 | 21023 | |
514c4d71 EZ |
21024 | @cindex DPMI |
21025 | @sc{djgpp} is a port of the @sc{gnu} development tools to MS-DOS and | |
8e04817f AC |
21026 | MS-Windows. @sc{djgpp} programs are 32-bit protected-mode programs |
21027 | that use the @dfn{DPMI} (DOS Protected-Mode Interface) API to run on | |
21028 | top of real-mode DOS systems and their emulations. | |
104c1213 | 21029 | |
8e04817f AC |
21030 | @value{GDBN} supports native debugging of @sc{djgpp} programs, and |
21031 | defines a few commands specific to the @sc{djgpp} port. This | |
21032 | subsection describes those commands. | |
104c1213 | 21033 | |
8e04817f AC |
21034 | @table @code |
21035 | @kindex info dos | |
21036 | @item info dos | |
21037 | This is a prefix of @sc{djgpp}-specific commands which print | |
21038 | information about the target system and important OS structures. | |
f1251bdd | 21039 | |
8e04817f AC |
21040 | @kindex sysinfo |
21041 | @cindex MS-DOS system info | |
21042 | @cindex free memory information (MS-DOS) | |
21043 | @item info dos sysinfo | |
21044 | This command displays assorted information about the underlying | |
21045 | platform: the CPU type and features, the OS version and flavor, the | |
21046 | DPMI version, and the available conventional and DPMI memory. | |
104c1213 | 21047 | |
8e04817f AC |
21048 | @cindex GDT |
21049 | @cindex LDT | |
21050 | @cindex IDT | |
21051 | @cindex segment descriptor tables | |
21052 | @cindex descriptor tables display | |
21053 | @item info dos gdt | |
21054 | @itemx info dos ldt | |
21055 | @itemx info dos idt | |
21056 | These 3 commands display entries from, respectively, Global, Local, | |
21057 | and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor | |
21058 | tables are data structures which store a descriptor for each segment | |
21059 | that is currently in use. The segment's selector is an index into a | |
21060 | descriptor table; the table entry for that index holds the | |
21061 | descriptor's base address and limit, and its attributes and access | |
21062 | rights. | |
104c1213 | 21063 | |
8e04817f AC |
21064 | A typical @sc{djgpp} program uses 3 segments: a code segment, a data |
21065 | segment (used for both data and the stack), and a DOS segment (which | |
21066 | allows access to DOS/BIOS data structures and absolute addresses in | |
21067 | conventional memory). However, the DPMI host will usually define | |
21068 | additional segments in order to support the DPMI environment. | |
d4f3574e | 21069 | |
8e04817f AC |
21070 | @cindex garbled pointers |
21071 | These commands allow to display entries from the descriptor tables. | |
21072 | Without an argument, all entries from the specified table are | |
21073 | displayed. An argument, which should be an integer expression, means | |
21074 | display a single entry whose index is given by the argument. For | |
21075 | example, here's a convenient way to display information about the | |
21076 | debugged program's data segment: | |
104c1213 | 21077 | |
8e04817f AC |
21078 | @smallexample |
21079 | @exdent @code{(@value{GDBP}) info dos ldt $ds} | |
21080 | @exdent @code{0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)} | |
21081 | @end smallexample | |
104c1213 | 21082 | |
8e04817f AC |
21083 | @noindent |
21084 | This comes in handy when you want to see whether a pointer is outside | |
21085 | the data segment's limit (i.e.@: @dfn{garbled}). | |
104c1213 | 21086 | |
8e04817f AC |
21087 | @cindex page tables display (MS-DOS) |
21088 | @item info dos pde | |
21089 | @itemx info dos pte | |
21090 | These two commands display entries from, respectively, the Page | |
21091 | Directory and the Page Tables. Page Directories and Page Tables are | |
21092 | data structures which control how virtual memory addresses are mapped | |
21093 | into physical addresses. A Page Table includes an entry for every | |
21094 | page of memory that is mapped into the program's address space; there | |
21095 | may be several Page Tables, each one holding up to 4096 entries. A | |
21096 | Page Directory has up to 4096 entries, one each for every Page Table | |
21097 | that is currently in use. | |
104c1213 | 21098 | |
8e04817f AC |
21099 | Without an argument, @kbd{info dos pde} displays the entire Page |
21100 | Directory, and @kbd{info dos pte} displays all the entries in all of | |
21101 | the Page Tables. An argument, an integer expression, given to the | |
21102 | @kbd{info dos pde} command means display only that entry from the Page | |
21103 | Directory table. An argument given to the @kbd{info dos pte} command | |
21104 | means display entries from a single Page Table, the one pointed to by | |
21105 | the specified entry in the Page Directory. | |
104c1213 | 21106 | |
8e04817f AC |
21107 | @cindex direct memory access (DMA) on MS-DOS |
21108 | These commands are useful when your program uses @dfn{DMA} (Direct | |
21109 | Memory Access), which needs physical addresses to program the DMA | |
21110 | controller. | |
104c1213 | 21111 | |
8e04817f | 21112 | These commands are supported only with some DPMI servers. |
104c1213 | 21113 | |
8e04817f AC |
21114 | @cindex physical address from linear address |
21115 | @item info dos address-pte @var{addr} | |
21116 | This command displays the Page Table entry for a specified linear | |
514c4d71 EZ |
21117 | address. The argument @var{addr} is a linear address which should |
21118 | already have the appropriate segment's base address added to it, | |
21119 | because this command accepts addresses which may belong to @emph{any} | |
21120 | segment. For example, here's how to display the Page Table entry for | |
21121 | the page where a variable @code{i} is stored: | |
104c1213 | 21122 | |
b383017d | 21123 | @smallexample |
8e04817f AC |
21124 | @exdent @code{(@value{GDBP}) info dos address-pte __djgpp_base_address + (char *)&i} |
21125 | @exdent @code{Page Table entry for address 0x11a00d30:} | |
b383017d | 21126 | @exdent @code{Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30} |
8e04817f | 21127 | @end smallexample |
104c1213 | 21128 | |
8e04817f AC |
21129 | @noindent |
21130 | This says that @code{i} is stored at offset @code{0xd30} from the page | |
514c4d71 | 21131 | whose physical base address is @code{0x02698000}, and shows all the |
8e04817f | 21132 | attributes of that page. |
104c1213 | 21133 | |
8e04817f AC |
21134 | Note that you must cast the addresses of variables to a @code{char *}, |
21135 | since otherwise the value of @code{__djgpp_base_address}, the base | |
21136 | address of all variables and functions in a @sc{djgpp} program, will | |
21137 | be added using the rules of C pointer arithmetics: if @code{i} is | |
21138 | declared an @code{int}, @value{GDBN} will add 4 times the value of | |
21139 | @code{__djgpp_base_address} to the address of @code{i}. | |
104c1213 | 21140 | |
8e04817f AC |
21141 | Here's another example, it displays the Page Table entry for the |
21142 | transfer buffer: | |
104c1213 | 21143 | |
8e04817f AC |
21144 | @smallexample |
21145 | @exdent @code{(@value{GDBP}) info dos address-pte *((unsigned *)&_go32_info_block + 3)} | |
21146 | @exdent @code{Page Table entry for address 0x29110:} | |
21147 | @exdent @code{Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110} | |
21148 | @end smallexample | |
104c1213 | 21149 | |
8e04817f AC |
21150 | @noindent |
21151 | (The @code{+ 3} offset is because the transfer buffer's address is the | |
514c4d71 EZ |
21152 | 3rd member of the @code{_go32_info_block} structure.) The output |
21153 | clearly shows that this DPMI server maps the addresses in conventional | |
21154 | memory 1:1, i.e.@: the physical (@code{0x00029000} + @code{0x110}) and | |
21155 | linear (@code{0x29110}) addresses are identical. | |
104c1213 | 21156 | |
8e04817f AC |
21157 | This command is supported only with some DPMI servers. |
21158 | @end table | |
104c1213 | 21159 | |
c45da7e6 | 21160 | @cindex DOS serial data link, remote debugging |
a8f24a35 EZ |
21161 | In addition to native debugging, the DJGPP port supports remote |
21162 | debugging via a serial data link. The following commands are specific | |
21163 | to remote serial debugging in the DJGPP port of @value{GDBN}. | |
21164 | ||
21165 | @table @code | |
21166 | @kindex set com1base | |
21167 | @kindex set com1irq | |
21168 | @kindex set com2base | |
21169 | @kindex set com2irq | |
21170 | @kindex set com3base | |
21171 | @kindex set com3irq | |
21172 | @kindex set com4base | |
21173 | @kindex set com4irq | |
21174 | @item set com1base @var{addr} | |
21175 | This command sets the base I/O port address of the @file{COM1} serial | |
21176 | port. | |
21177 | ||
21178 | @item set com1irq @var{irq} | |
21179 | This command sets the @dfn{Interrupt Request} (@code{IRQ}) line to use | |
21180 | for the @file{COM1} serial port. | |
21181 | ||
21182 | There are similar commands @samp{set com2base}, @samp{set com3irq}, | |
21183 | etc.@: for setting the port address and the @code{IRQ} lines for the | |
21184 | other 3 COM ports. | |
21185 | ||
21186 | @kindex show com1base | |
21187 | @kindex show com1irq | |
21188 | @kindex show com2base | |
21189 | @kindex show com2irq | |
21190 | @kindex show com3base | |
21191 | @kindex show com3irq | |
21192 | @kindex show com4base | |
21193 | @kindex show com4irq | |
21194 | The related commands @samp{show com1base}, @samp{show com1irq} etc.@: | |
21195 | display the current settings of the base address and the @code{IRQ} | |
21196 | lines used by the COM ports. | |
c45da7e6 EZ |
21197 | |
21198 | @item info serial | |
21199 | @kindex info serial | |
21200 | @cindex DOS serial port status | |
21201 | This command prints the status of the 4 DOS serial ports. For each | |
21202 | port, it prints whether it's active or not, its I/O base address and | |
21203 | IRQ number, whether it uses a 16550-style FIFO, its baudrate, and the | |
21204 | counts of various errors encountered so far. | |
a8f24a35 EZ |
21205 | @end table |
21206 | ||
21207 | ||
78c47bea | 21208 | @node Cygwin Native |
79a6e687 | 21209 | @subsection Features for Debugging MS Windows PE Executables |
78c47bea PM |
21210 | @cindex MS Windows debugging |
21211 | @cindex native Cygwin debugging | |
21212 | @cindex Cygwin-specific commands | |
21213 | ||
be448670 | 21214 | @value{GDBN} supports native debugging of MS Windows programs, including |
cbb8f428 EZ |
21215 | DLLs with and without symbolic debugging information. |
21216 | ||
21217 | @cindex Ctrl-BREAK, MS-Windows | |
21218 | @cindex interrupt debuggee on MS-Windows | |
21219 | MS-Windows programs that call @code{SetConsoleMode} to switch off the | |
21220 | special meaning of the @samp{Ctrl-C} keystroke cannot be interrupted | |
21221 | by typing @kbd{C-c}. For this reason, @value{GDBN} on MS-Windows | |
21222 | supports @kbd{C-@key{BREAK}} as an alternative interrupt key | |
21223 | sequence, which can be used to interrupt the debuggee even if it | |
21224 | ignores @kbd{C-c}. | |
21225 | ||
21226 | There are various additional Cygwin-specific commands, described in | |
21227 | this section. Working with DLLs that have no debugging symbols is | |
21228 | described in @ref{Non-debug DLL Symbols}. | |
78c47bea PM |
21229 | |
21230 | @table @code | |
21231 | @kindex info w32 | |
21232 | @item info w32 | |
db2e3e2e | 21233 | This is a prefix of MS Windows-specific commands which print |
78c47bea PM |
21234 | information about the target system and important OS structures. |
21235 | ||
21236 | @item info w32 selector | |
21237 | This command displays information returned by | |
21238 | the Win32 API @code{GetThreadSelectorEntry} function. | |
21239 | It takes an optional argument that is evaluated to | |
21240 | a long value to give the information about this given selector. | |
21241 | Without argument, this command displays information | |
d3e8051b | 21242 | about the six segment registers. |
78c47bea | 21243 | |
711e434b PM |
21244 | @item info w32 thread-information-block |
21245 | This command displays thread specific information stored in the | |
21246 | Thread Information Block (readable on the X86 CPU family using @code{$fs} | |
21247 | selector for 32-bit programs and @code{$gs} for 64-bit programs). | |
21248 | ||
be90c084 | 21249 | @kindex set cygwin-exceptions |
e16b02ee EZ |
21250 | @cindex debugging the Cygwin DLL |
21251 | @cindex Cygwin DLL, debugging | |
be90c084 | 21252 | @item set cygwin-exceptions @var{mode} |
e16b02ee EZ |
21253 | If @var{mode} is @code{on}, @value{GDBN} will break on exceptions that |
21254 | happen inside the Cygwin DLL. If @var{mode} is @code{off}, | |
21255 | @value{GDBN} will delay recognition of exceptions, and may ignore some | |
21256 | exceptions which seem to be caused by internal Cygwin DLL | |
21257 | ``bookkeeping''. This option is meant primarily for debugging the | |
21258 | Cygwin DLL itself; the default value is @code{off} to avoid annoying | |
21259 | @value{GDBN} users with false @code{SIGSEGV} signals. | |
be90c084 CF |
21260 | |
21261 | @kindex show cygwin-exceptions | |
21262 | @item show cygwin-exceptions | |
e16b02ee EZ |
21263 | Displays whether @value{GDBN} will break on exceptions that happen |
21264 | inside the Cygwin DLL itself. | |
be90c084 | 21265 | |
b383017d | 21266 | @kindex set new-console |
78c47bea | 21267 | @item set new-console @var{mode} |
b383017d | 21268 | If @var{mode} is @code{on} the debuggee will |
78c47bea | 21269 | be started in a new console on next start. |
e03e5e7b | 21270 | If @var{mode} is @code{off}, the debuggee will |
78c47bea PM |
21271 | be started in the same console as the debugger. |
21272 | ||
21273 | @kindex show new-console | |
21274 | @item show new-console | |
21275 | Displays whether a new console is used | |
21276 | when the debuggee is started. | |
21277 | ||
21278 | @kindex set new-group | |
21279 | @item set new-group @var{mode} | |
21280 | This boolean value controls whether the debuggee should | |
21281 | start a new group or stay in the same group as the debugger. | |
21282 | This affects the way the Windows OS handles | |
c8aa23ab | 21283 | @samp{Ctrl-C}. |
78c47bea PM |
21284 | |
21285 | @kindex show new-group | |
21286 | @item show new-group | |
21287 | Displays current value of new-group boolean. | |
21288 | ||
21289 | @kindex set debugevents | |
21290 | @item set debugevents | |
219eec71 EZ |
21291 | This boolean value adds debug output concerning kernel events related |
21292 | to the debuggee seen by the debugger. This includes events that | |
21293 | signal thread and process creation and exit, DLL loading and | |
21294 | unloading, console interrupts, and debugging messages produced by the | |
21295 | Windows @code{OutputDebugString} API call. | |
78c47bea PM |
21296 | |
21297 | @kindex set debugexec | |
21298 | @item set debugexec | |
b383017d | 21299 | This boolean value adds debug output concerning execute events |
219eec71 | 21300 | (such as resume thread) seen by the debugger. |
78c47bea PM |
21301 | |
21302 | @kindex set debugexceptions | |
21303 | @item set debugexceptions | |
219eec71 EZ |
21304 | This boolean value adds debug output concerning exceptions in the |
21305 | debuggee seen by the debugger. | |
78c47bea PM |
21306 | |
21307 | @kindex set debugmemory | |
21308 | @item set debugmemory | |
219eec71 EZ |
21309 | This boolean value adds debug output concerning debuggee memory reads |
21310 | and writes by the debugger. | |
78c47bea PM |
21311 | |
21312 | @kindex set shell | |
21313 | @item set shell | |
21314 | This boolean values specifies whether the debuggee is called | |
21315 | via a shell or directly (default value is on). | |
21316 | ||
21317 | @kindex show shell | |
21318 | @item show shell | |
21319 | Displays if the debuggee will be started with a shell. | |
21320 | ||
21321 | @end table | |
21322 | ||
be448670 | 21323 | @menu |
79a6e687 | 21324 | * Non-debug DLL Symbols:: Support for DLLs without debugging symbols |
be448670 CF |
21325 | @end menu |
21326 | ||
79a6e687 BW |
21327 | @node Non-debug DLL Symbols |
21328 | @subsubsection Support for DLLs without Debugging Symbols | |
be448670 CF |
21329 | @cindex DLLs with no debugging symbols |
21330 | @cindex Minimal symbols and DLLs | |
21331 | ||
21332 | Very often on windows, some of the DLLs that your program relies on do | |
21333 | not include symbolic debugging information (for example, | |
db2e3e2e | 21334 | @file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging |
be448670 | 21335 | symbols in a DLL, it relies on the minimal amount of symbolic |
db2e3e2e | 21336 | information contained in the DLL's export table. This section |
be448670 CF |
21337 | describes working with such symbols, known internally to @value{GDBN} as |
21338 | ``minimal symbols''. | |
21339 | ||
21340 | Note that before the debugged program has started execution, no DLLs | |
db2e3e2e | 21341 | will have been loaded. The easiest way around this problem is simply to |
be448670 | 21342 | start the program --- either by setting a breakpoint or letting the |
95060284 | 21343 | program run once to completion. |
be448670 | 21344 | |
79a6e687 | 21345 | @subsubsection DLL Name Prefixes |
be448670 CF |
21346 | |
21347 | In keeping with the naming conventions used by the Microsoft debugging | |
21348 | tools, DLL export symbols are made available with a prefix based on the | |
21349 | DLL name, for instance @code{KERNEL32!CreateFileA}. The plain name is | |
21350 | also entered into the symbol table, so @code{CreateFileA} is often | |
99e008fe | 21351 | sufficient. In some cases there will be name clashes within a program |
be448670 CF |
21352 | (particularly if the executable itself includes full debugging symbols) |
21353 | necessitating the use of the fully qualified name when referring to the | |
99e008fe | 21354 | contents of the DLL. Use single-quotes around the name to avoid the |
be448670 CF |
21355 | exclamation mark (``!'') being interpreted as a language operator. |
21356 | ||
21357 | Note that the internal name of the DLL may be all upper-case, even | |
99e008fe | 21358 | though the file name of the DLL is lower-case, or vice-versa. Since |
be448670 CF |
21359 | symbols within @value{GDBN} are @emph{case-sensitive} this may cause |
21360 | some confusion. If in doubt, try the @code{info functions} and | |
0869d01b NR |
21361 | @code{info variables} commands or even @code{maint print msymbols} |
21362 | (@pxref{Symbols}). Here's an example: | |
be448670 CF |
21363 | |
21364 | @smallexample | |
f7dc1244 | 21365 | (@value{GDBP}) info function CreateFileA |
be448670 CF |
21366 | All functions matching regular expression "CreateFileA": |
21367 | ||
21368 | Non-debugging symbols: | |
21369 | 0x77e885f4 CreateFileA | |
21370 | 0x77e885f4 KERNEL32!CreateFileA | |
21371 | @end smallexample | |
21372 | ||
21373 | @smallexample | |
f7dc1244 | 21374 | (@value{GDBP}) info function ! |
be448670 CF |
21375 | All functions matching regular expression "!": |
21376 | ||
21377 | Non-debugging symbols: | |
21378 | 0x6100114c cygwin1!__assert | |
21379 | 0x61004034 cygwin1!_dll_crt0@@0 | |
21380 | 0x61004240 cygwin1!dll_crt0(per_process *) | |
21381 | [etc...] | |
21382 | @end smallexample | |
21383 | ||
79a6e687 | 21384 | @subsubsection Working with Minimal Symbols |
be448670 CF |
21385 | |
21386 | Symbols extracted from a DLL's export table do not contain very much | |
21387 | type information. All that @value{GDBN} can do is guess whether a symbol | |
21388 | refers to a function or variable depending on the linker section that | |
21389 | contains the symbol. Also note that the actual contents of the memory | |
21390 | contained in a DLL are not available unless the program is running. This | |
21391 | means that you cannot examine the contents of a variable or disassemble | |
21392 | a function within a DLL without a running program. | |
21393 | ||
21394 | Variables are generally treated as pointers and dereferenced | |
21395 | automatically. For this reason, it is often necessary to prefix a | |
21396 | variable name with the address-of operator (``&'') and provide explicit | |
21397 | type information in the command. Here's an example of the type of | |
21398 | problem: | |
21399 | ||
21400 | @smallexample | |
f7dc1244 | 21401 | (@value{GDBP}) print 'cygwin1!__argv' |
be448670 CF |
21402 | $1 = 268572168 |
21403 | @end smallexample | |
21404 | ||
21405 | @smallexample | |
f7dc1244 | 21406 | (@value{GDBP}) x 'cygwin1!__argv' |
be448670 CF |
21407 | 0x10021610: "\230y\"" |
21408 | @end smallexample | |
21409 | ||
21410 | And two possible solutions: | |
21411 | ||
21412 | @smallexample | |
f7dc1244 | 21413 | (@value{GDBP}) print ((char **)'cygwin1!__argv')[0] |
be448670 CF |
21414 | $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram" |
21415 | @end smallexample | |
21416 | ||
21417 | @smallexample | |
f7dc1244 | 21418 | (@value{GDBP}) x/2x &'cygwin1!__argv' |
be448670 | 21419 | 0x610c0aa8 <cygwin1!__argv>: 0x10021608 0x00000000 |
f7dc1244 | 21420 | (@value{GDBP}) x/x 0x10021608 |
be448670 | 21421 | 0x10021608: 0x0022fd98 |
f7dc1244 | 21422 | (@value{GDBP}) x/s 0x0022fd98 |
be448670 CF |
21423 | 0x22fd98: "/cygdrive/c/mydirectory/myprogram" |
21424 | @end smallexample | |
21425 | ||
21426 | Setting a break point within a DLL is possible even before the program | |
21427 | starts execution. However, under these circumstances, @value{GDBN} can't | |
21428 | examine the initial instructions of the function in order to skip the | |
21429 | function's frame set-up code. You can work around this by using ``*&'' | |
21430 | to set the breakpoint at a raw memory address: | |
21431 | ||
21432 | @smallexample | |
f7dc1244 | 21433 | (@value{GDBP}) break *&'python22!PyOS_Readline' |
be448670 CF |
21434 | Breakpoint 1 at 0x1e04eff0 |
21435 | @end smallexample | |
21436 | ||
21437 | The author of these extensions is not entirely convinced that setting a | |
21438 | break point within a shared DLL like @file{kernel32.dll} is completely | |
21439 | safe. | |
21440 | ||
14d6dd68 | 21441 | @node Hurd Native |
79a6e687 | 21442 | @subsection Commands Specific to @sc{gnu} Hurd Systems |
14d6dd68 EZ |
21443 | @cindex @sc{gnu} Hurd debugging |
21444 | ||
21445 | This subsection describes @value{GDBN} commands specific to the | |
21446 | @sc{gnu} Hurd native debugging. | |
21447 | ||
21448 | @table @code | |
21449 | @item set signals | |
21450 | @itemx set sigs | |
21451 | @kindex set signals@r{, Hurd command} | |
21452 | @kindex set sigs@r{, Hurd command} | |
21453 | This command toggles the state of inferior signal interception by | |
21454 | @value{GDBN}. Mach exceptions, such as breakpoint traps, are not | |
21455 | affected by this command. @code{sigs} is a shorthand alias for | |
21456 | @code{signals}. | |
21457 | ||
21458 | @item show signals | |
21459 | @itemx show sigs | |
21460 | @kindex show signals@r{, Hurd command} | |
21461 | @kindex show sigs@r{, Hurd command} | |
21462 | Show the current state of intercepting inferior's signals. | |
21463 | ||
21464 | @item set signal-thread | |
21465 | @itemx set sigthread | |
21466 | @kindex set signal-thread | |
21467 | @kindex set sigthread | |
21468 | This command tells @value{GDBN} which thread is the @code{libc} signal | |
21469 | thread. That thread is run when a signal is delivered to a running | |
21470 | process. @code{set sigthread} is the shorthand alias of @code{set | |
21471 | signal-thread}. | |
21472 | ||
21473 | @item show signal-thread | |
21474 | @itemx show sigthread | |
21475 | @kindex show signal-thread | |
21476 | @kindex show sigthread | |
21477 | These two commands show which thread will run when the inferior is | |
21478 | delivered a signal. | |
21479 | ||
21480 | @item set stopped | |
21481 | @kindex set stopped@r{, Hurd command} | |
21482 | This commands tells @value{GDBN} that the inferior process is stopped, | |
21483 | as with the @code{SIGSTOP} signal. The stopped process can be | |
21484 | continued by delivering a signal to it. | |
21485 | ||
21486 | @item show stopped | |
21487 | @kindex show stopped@r{, Hurd command} | |
21488 | This command shows whether @value{GDBN} thinks the debuggee is | |
21489 | stopped. | |
21490 | ||
21491 | @item set exceptions | |
21492 | @kindex set exceptions@r{, Hurd command} | |
21493 | Use this command to turn off trapping of exceptions in the inferior. | |
21494 | When exception trapping is off, neither breakpoints nor | |
21495 | single-stepping will work. To restore the default, set exception | |
21496 | trapping on. | |
21497 | ||
21498 | @item show exceptions | |
21499 | @kindex show exceptions@r{, Hurd command} | |
21500 | Show the current state of trapping exceptions in the inferior. | |
21501 | ||
21502 | @item set task pause | |
21503 | @kindex set task@r{, Hurd commands} | |
21504 | @cindex task attributes (@sc{gnu} Hurd) | |
21505 | @cindex pause current task (@sc{gnu} Hurd) | |
21506 | This command toggles task suspension when @value{GDBN} has control. | |
21507 | Setting it to on takes effect immediately, and the task is suspended | |
21508 | whenever @value{GDBN} gets control. Setting it to off will take | |
21509 | effect the next time the inferior is continued. If this option is set | |
21510 | to off, you can use @code{set thread default pause on} or @code{set | |
21511 | thread pause on} (see below) to pause individual threads. | |
21512 | ||
21513 | @item show task pause | |
21514 | @kindex show task@r{, Hurd commands} | |
21515 | Show the current state of task suspension. | |
21516 | ||
21517 | @item set task detach-suspend-count | |
21518 | @cindex task suspend count | |
21519 | @cindex detach from task, @sc{gnu} Hurd | |
21520 | This command sets the suspend count the task will be left with when | |
21521 | @value{GDBN} detaches from it. | |
21522 | ||
21523 | @item show task detach-suspend-count | |
21524 | Show the suspend count the task will be left with when detaching. | |
21525 | ||
21526 | @item set task exception-port | |
21527 | @itemx set task excp | |
21528 | @cindex task exception port, @sc{gnu} Hurd | |
21529 | This command sets the task exception port to which @value{GDBN} will | |
21530 | forward exceptions. The argument should be the value of the @dfn{send | |
21531 | rights} of the task. @code{set task excp} is a shorthand alias. | |
21532 | ||
21533 | @item set noninvasive | |
21534 | @cindex noninvasive task options | |
21535 | This command switches @value{GDBN} to a mode that is the least | |
21536 | invasive as far as interfering with the inferior is concerned. This | |
21537 | is the same as using @code{set task pause}, @code{set exceptions}, and | |
21538 | @code{set signals} to values opposite to the defaults. | |
21539 | ||
21540 | @item info send-rights | |
21541 | @itemx info receive-rights | |
21542 | @itemx info port-rights | |
21543 | @itemx info port-sets | |
21544 | @itemx info dead-names | |
21545 | @itemx info ports | |
21546 | @itemx info psets | |
21547 | @cindex send rights, @sc{gnu} Hurd | |
21548 | @cindex receive rights, @sc{gnu} Hurd | |
21549 | @cindex port rights, @sc{gnu} Hurd | |
21550 | @cindex port sets, @sc{gnu} Hurd | |
21551 | @cindex dead names, @sc{gnu} Hurd | |
21552 | These commands display information about, respectively, send rights, | |
21553 | receive rights, port rights, port sets, and dead names of a task. | |
21554 | There are also shorthand aliases: @code{info ports} for @code{info | |
21555 | port-rights} and @code{info psets} for @code{info port-sets}. | |
21556 | ||
21557 | @item set thread pause | |
21558 | @kindex set thread@r{, Hurd command} | |
21559 | @cindex thread properties, @sc{gnu} Hurd | |
21560 | @cindex pause current thread (@sc{gnu} Hurd) | |
21561 | This command toggles current thread suspension when @value{GDBN} has | |
21562 | control. Setting it to on takes effect immediately, and the current | |
21563 | thread is suspended whenever @value{GDBN} gets control. Setting it to | |
21564 | off will take effect the next time the inferior is continued. | |
21565 | Normally, this command has no effect, since when @value{GDBN} has | |
21566 | control, the whole task is suspended. However, if you used @code{set | |
21567 | task pause off} (see above), this command comes in handy to suspend | |
21568 | only the current thread. | |
21569 | ||
21570 | @item show thread pause | |
21571 | @kindex show thread@r{, Hurd command} | |
21572 | This command shows the state of current thread suspension. | |
21573 | ||
21574 | @item set thread run | |
d3e8051b | 21575 | This command sets whether the current thread is allowed to run. |
14d6dd68 EZ |
21576 | |
21577 | @item show thread run | |
21578 | Show whether the current thread is allowed to run. | |
21579 | ||
21580 | @item set thread detach-suspend-count | |
21581 | @cindex thread suspend count, @sc{gnu} Hurd | |
21582 | @cindex detach from thread, @sc{gnu} Hurd | |
21583 | This command sets the suspend count @value{GDBN} will leave on a | |
21584 | thread when detaching. This number is relative to the suspend count | |
21585 | found by @value{GDBN} when it notices the thread; use @code{set thread | |
21586 | takeover-suspend-count} to force it to an absolute value. | |
21587 | ||
21588 | @item show thread detach-suspend-count | |
21589 | Show the suspend count @value{GDBN} will leave on the thread when | |
21590 | detaching. | |
21591 | ||
21592 | @item set thread exception-port | |
21593 | @itemx set thread excp | |
21594 | Set the thread exception port to which to forward exceptions. This | |
21595 | overrides the port set by @code{set task exception-port} (see above). | |
21596 | @code{set thread excp} is the shorthand alias. | |
21597 | ||
21598 | @item set thread takeover-suspend-count | |
21599 | Normally, @value{GDBN}'s thread suspend counts are relative to the | |
21600 | value @value{GDBN} finds when it notices each thread. This command | |
21601 | changes the suspend counts to be absolute instead. | |
21602 | ||
21603 | @item set thread default | |
21604 | @itemx show thread default | |
21605 | @cindex thread default settings, @sc{gnu} Hurd | |
21606 | Each of the above @code{set thread} commands has a @code{set thread | |
21607 | default} counterpart (e.g., @code{set thread default pause}, @code{set | |
21608 | thread default exception-port}, etc.). The @code{thread default} | |
21609 | variety of commands sets the default thread properties for all | |
21610 | threads; you can then change the properties of individual threads with | |
21611 | the non-default commands. | |
21612 | @end table | |
21613 | ||
a80b95ba TG |
21614 | @node Darwin |
21615 | @subsection Darwin | |
21616 | @cindex Darwin | |
21617 | ||
21618 | @value{GDBN} provides the following commands specific to the Darwin target: | |
21619 | ||
21620 | @table @code | |
21621 | @item set debug darwin @var{num} | |
21622 | @kindex set debug darwin | |
21623 | When set to a non zero value, enables debugging messages specific to | |
21624 | the Darwin support. Higher values produce more verbose output. | |
21625 | ||
21626 | @item show debug darwin | |
21627 | @kindex show debug darwin | |
21628 | Show the current state of Darwin messages. | |
21629 | ||
21630 | @item set debug mach-o @var{num} | |
21631 | @kindex set debug mach-o | |
21632 | When set to a non zero value, enables debugging messages while | |
21633 | @value{GDBN} is reading Darwin object files. (@dfn{Mach-O} is the | |
21634 | file format used on Darwin for object and executable files.) Higher | |
21635 | values produce more verbose output. This is a command to diagnose | |
21636 | problems internal to @value{GDBN} and should not be needed in normal | |
21637 | usage. | |
21638 | ||
21639 | @item show debug mach-o | |
21640 | @kindex show debug mach-o | |
21641 | Show the current state of Mach-O file messages. | |
21642 | ||
21643 | @item set mach-exceptions on | |
21644 | @itemx set mach-exceptions off | |
21645 | @kindex set mach-exceptions | |
21646 | On Darwin, faults are first reported as a Mach exception and are then | |
21647 | mapped to a Posix signal. Use this command to turn on trapping of | |
21648 | Mach exceptions in the inferior. This might be sometimes useful to | |
21649 | better understand the cause of a fault. The default is off. | |
21650 | ||
21651 | @item show mach-exceptions | |
21652 | @kindex show mach-exceptions | |
21653 | Show the current state of exceptions trapping. | |
21654 | @end table | |
21655 | ||
a64548ea | 21656 | |
8e04817f AC |
21657 | @node Embedded OS |
21658 | @section Embedded Operating Systems | |
104c1213 | 21659 | |
8e04817f AC |
21660 | This section describes configurations involving the debugging of |
21661 | embedded operating systems that are available for several different | |
21662 | architectures. | |
d4f3574e | 21663 | |
8e04817f AC |
21664 | @value{GDBN} includes the ability to debug programs running on |
21665 | various real-time operating systems. | |
104c1213 | 21666 | |
6d2ebf8b | 21667 | @node Embedded Processors |
104c1213 JM |
21668 | @section Embedded Processors |
21669 | ||
21670 | This section goes into details specific to particular embedded | |
21671 | configurations. | |
21672 | ||
c45da7e6 EZ |
21673 | @cindex send command to simulator |
21674 | Whenever a specific embedded processor has a simulator, @value{GDBN} | |
21675 | allows to send an arbitrary command to the simulator. | |
21676 | ||
21677 | @table @code | |
21678 | @item sim @var{command} | |
21679 | @kindex sim@r{, a command} | |
21680 | Send an arbitrary @var{command} string to the simulator. Consult the | |
21681 | documentation for the specific simulator in use for information about | |
21682 | acceptable commands. | |
21683 | @end table | |
21684 | ||
7d86b5d5 | 21685 | |
104c1213 | 21686 | @menu |
bb615428 PA |
21687 | * ARM:: ARM |
21688 | * M32R/SDI:: Renesas M32R/SDI | |
104c1213 | 21689 | * M68K:: Motorola M68K |
08be9d71 | 21690 | * MicroBlaze:: Xilinx MicroBlaze |
104c1213 | 21691 | * MIPS Embedded:: MIPS Embedded |
4acd40f3 | 21692 | * PowerPC Embedded:: PowerPC Embedded |
a64548ea EZ |
21693 | * AVR:: Atmel AVR |
21694 | * CRIS:: CRIS | |
21695 | * Super-H:: Renesas Super-H | |
104c1213 JM |
21696 | @end menu |
21697 | ||
6d2ebf8b | 21698 | @node ARM |
104c1213 | 21699 | @subsection ARM |
8e04817f | 21700 | |
e2f4edfd EZ |
21701 | @value{GDBN} provides the following ARM-specific commands: |
21702 | ||
21703 | @table @code | |
21704 | @item set arm disassembler | |
21705 | @kindex set arm | |
21706 | This commands selects from a list of disassembly styles. The | |
21707 | @code{"std"} style is the standard style. | |
21708 | ||
21709 | @item show arm disassembler | |
21710 | @kindex show arm | |
21711 | Show the current disassembly style. | |
21712 | ||
21713 | @item set arm apcs32 | |
21714 | @cindex ARM 32-bit mode | |
21715 | This command toggles ARM operation mode between 32-bit and 26-bit. | |
21716 | ||
21717 | @item show arm apcs32 | |
21718 | Display the current usage of the ARM 32-bit mode. | |
21719 | ||
21720 | @item set arm fpu @var{fputype} | |
21721 | This command sets the ARM floating-point unit (FPU) type. The | |
21722 | argument @var{fputype} can be one of these: | |
21723 | ||
21724 | @table @code | |
21725 | @item auto | |
21726 | Determine the FPU type by querying the OS ABI. | |
21727 | @item softfpa | |
21728 | Software FPU, with mixed-endian doubles on little-endian ARM | |
21729 | processors. | |
21730 | @item fpa | |
21731 | GCC-compiled FPA co-processor. | |
21732 | @item softvfp | |
21733 | Software FPU with pure-endian doubles. | |
21734 | @item vfp | |
21735 | VFP co-processor. | |
21736 | @end table | |
21737 | ||
21738 | @item show arm fpu | |
21739 | Show the current type of the FPU. | |
21740 | ||
21741 | @item set arm abi | |
21742 | This command forces @value{GDBN} to use the specified ABI. | |
21743 | ||
21744 | @item show arm abi | |
21745 | Show the currently used ABI. | |
21746 | ||
0428b8f5 DJ |
21747 | @item set arm fallback-mode (arm|thumb|auto) |
21748 | @value{GDBN} uses the symbol table, when available, to determine | |
21749 | whether instructions are ARM or Thumb. This command controls | |
21750 | @value{GDBN}'s default behavior when the symbol table is not | |
21751 | available. The default is @samp{auto}, which causes @value{GDBN} to | |
21752 | use the current execution mode (from the @code{T} bit in the @code{CPSR} | |
21753 | register). | |
21754 | ||
21755 | @item show arm fallback-mode | |
21756 | Show the current fallback instruction mode. | |
21757 | ||
21758 | @item set arm force-mode (arm|thumb|auto) | |
21759 | This command overrides use of the symbol table to determine whether | |
21760 | instructions are ARM or Thumb. The default is @samp{auto}, which | |
21761 | causes @value{GDBN} to use the symbol table and then the setting | |
21762 | of @samp{set arm fallback-mode}. | |
21763 | ||
21764 | @item show arm force-mode | |
21765 | Show the current forced instruction mode. | |
21766 | ||
e2f4edfd EZ |
21767 | @item set debug arm |
21768 | Toggle whether to display ARM-specific debugging messages from the ARM | |
21769 | target support subsystem. | |
21770 | ||
21771 | @item show debug arm | |
21772 | Show whether ARM-specific debugging messages are enabled. | |
21773 | @end table | |
21774 | ||
ee8e71d4 EZ |
21775 | @table @code |
21776 | @item target sim @r{[}@var{simargs}@r{]} @dots{} | |
21777 | The @value{GDBN} ARM simulator accepts the following optional arguments. | |
21778 | ||
21779 | @table @code | |
21780 | @item --swi-support=@var{type} | |
697aa1b7 | 21781 | Tell the simulator which SWI interfaces to support. The argument |
ee8e71d4 EZ |
21782 | @var{type} may be a comma separated list of the following values. |
21783 | The default value is @code{all}. | |
21784 | ||
21785 | @table @code | |
21786 | @item none | |
21787 | @item demon | |
21788 | @item angel | |
21789 | @item redboot | |
21790 | @item all | |
21791 | @end table | |
21792 | @end table | |
21793 | @end table | |
e2f4edfd | 21794 | |
bb615428 PA |
21795 | @node M32R/SDI |
21796 | @subsection Renesas M32R/SDI | |
8e04817f | 21797 | |
ba04e063 EZ |
21798 | The following commands are available for M32R/SDI: |
21799 | ||
21800 | @table @code | |
21801 | @item sdireset | |
21802 | @kindex sdireset | |
21803 | @cindex reset SDI connection, M32R | |
21804 | This command resets the SDI connection. | |
21805 | ||
21806 | @item sdistatus | |
21807 | @kindex sdistatus | |
21808 | This command shows the SDI connection status. | |
21809 | ||
21810 | @item debug_chaos | |
21811 | @kindex debug_chaos | |
21812 | @cindex M32R/Chaos debugging | |
21813 | Instructs the remote that M32R/Chaos debugging is to be used. | |
21814 | ||
21815 | @item use_debug_dma | |
21816 | @kindex use_debug_dma | |
21817 | Instructs the remote to use the DEBUG_DMA method of accessing memory. | |
21818 | ||
21819 | @item use_mon_code | |
21820 | @kindex use_mon_code | |
21821 | Instructs the remote to use the MON_CODE method of accessing memory. | |
21822 | ||
21823 | @item use_ib_break | |
21824 | @kindex use_ib_break | |
21825 | Instructs the remote to set breakpoints by IB break. | |
21826 | ||
21827 | @item use_dbt_break | |
21828 | @kindex use_dbt_break | |
21829 | Instructs the remote to set breakpoints by DBT. | |
21830 | @end table | |
21831 | ||
8e04817f AC |
21832 | @node M68K |
21833 | @subsection M68k | |
21834 | ||
bb615428 | 21835 | The Motorola m68k configuration includes ColdFire support. |
8e04817f | 21836 | |
08be9d71 ME |
21837 | @node MicroBlaze |
21838 | @subsection MicroBlaze | |
21839 | @cindex Xilinx MicroBlaze | |
21840 | @cindex XMD, Xilinx Microprocessor Debugger | |
21841 | ||
21842 | The MicroBlaze is a soft-core processor supported on various Xilinx | |
21843 | FPGAs, such as Spartan or Virtex series. Boards with these processors | |
21844 | usually have JTAG ports which connect to a host system running the Xilinx | |
21845 | Embedded Development Kit (EDK) or Software Development Kit (SDK). | |
21846 | This host system is used to download the configuration bitstream to | |
21847 | the target FPGA. The Xilinx Microprocessor Debugger (XMD) program | |
21848 | communicates with the target board using the JTAG interface and | |
21849 | presents a @code{gdbserver} interface to the board. By default | |
21850 | @code{xmd} uses port @code{1234}. (While it is possible to change | |
21851 | this default port, it requires the use of undocumented @code{xmd} | |
21852 | commands. Contact Xilinx support if you need to do this.) | |
21853 | ||
21854 | Use these GDB commands to connect to the MicroBlaze target processor. | |
21855 | ||
21856 | @table @code | |
21857 | @item target remote :1234 | |
21858 | Use this command to connect to the target if you are running @value{GDBN} | |
21859 | on the same system as @code{xmd}. | |
21860 | ||
21861 | @item target remote @var{xmd-host}:1234 | |
21862 | Use this command to connect to the target if it is connected to @code{xmd} | |
21863 | running on a different system named @var{xmd-host}. | |
21864 | ||
21865 | @item load | |
21866 | Use this command to download a program to the MicroBlaze target. | |
21867 | ||
21868 | @item set debug microblaze @var{n} | |
21869 | Enable MicroBlaze-specific debugging messages if non-zero. | |
21870 | ||
21871 | @item show debug microblaze @var{n} | |
21872 | Show MicroBlaze-specific debugging level. | |
21873 | @end table | |
21874 | ||
8e04817f | 21875 | @node MIPS Embedded |
eb17f351 | 21876 | @subsection @acronym{MIPS} Embedded |
8e04817f | 21877 | |
eb17f351 EZ |
21878 | @cindex @acronym{MIPS} boards |
21879 | @value{GDBN} can use the @acronym{MIPS} remote debugging protocol to talk to a | |
21880 | @acronym{MIPS} board attached to a serial line. This is available when | |
cc30c4bd | 21881 | you configure @value{GDBN} with @samp{--target=mips-elf}. |
104c1213 | 21882 | |
8e04817f AC |
21883 | @need 1000 |
21884 | Use these @value{GDBN} commands to specify the connection to your target board: | |
104c1213 | 21885 | |
8e04817f AC |
21886 | @table @code |
21887 | @item target mips @var{port} | |
21888 | @kindex target mips @var{port} | |
21889 | To run a program on the board, start up @code{@value{GDBP}} with the | |
21890 | name of your program as the argument. To connect to the board, use the | |
21891 | command @samp{target mips @var{port}}, where @var{port} is the name of | |
21892 | the serial port connected to the board. If the program has not already | |
21893 | been downloaded to the board, you may use the @code{load} command to | |
21894 | download it. You can then use all the usual @value{GDBN} commands. | |
104c1213 | 21895 | |
8e04817f AC |
21896 | For example, this sequence connects to the target board through a serial |
21897 | port, and loads and runs a program called @var{prog} through the | |
21898 | debugger: | |
104c1213 | 21899 | |
474c8240 | 21900 | @smallexample |
8e04817f AC |
21901 | host$ @value{GDBP} @var{prog} |
21902 | @value{GDBN} is free software and @dots{} | |
21903 | (@value{GDBP}) target mips /dev/ttyb | |
21904 | (@value{GDBP}) load @var{prog} | |
21905 | (@value{GDBP}) run | |
474c8240 | 21906 | @end smallexample |
104c1213 | 21907 | |
8e04817f AC |
21908 | @item target mips @var{hostname}:@var{portnumber} |
21909 | On some @value{GDBN} host configurations, you can specify a TCP | |
21910 | connection (for instance, to a serial line managed by a terminal | |
21911 | concentrator) instead of a serial port, using the syntax | |
21912 | @samp{@var{hostname}:@var{portnumber}}. | |
104c1213 | 21913 | |
8e04817f AC |
21914 | @item target pmon @var{port} |
21915 | @kindex target pmon @var{port} | |
21916 | PMON ROM monitor. | |
104c1213 | 21917 | |
8e04817f AC |
21918 | @item target ddb @var{port} |
21919 | @kindex target ddb @var{port} | |
21920 | NEC's DDB variant of PMON for Vr4300. | |
104c1213 | 21921 | |
8e04817f AC |
21922 | @item target lsi @var{port} |
21923 | @kindex target lsi @var{port} | |
21924 | LSI variant of PMON. | |
104c1213 | 21925 | |
8e04817f | 21926 | @end table |
104c1213 | 21927 | |
104c1213 | 21928 | |
8e04817f | 21929 | @noindent |
eb17f351 | 21930 | @value{GDBN} also supports these special commands for @acronym{MIPS} targets: |
104c1213 | 21931 | |
8e04817f | 21932 | @table @code |
8e04817f AC |
21933 | @item set mipsfpu double |
21934 | @itemx set mipsfpu single | |
21935 | @itemx set mipsfpu none | |
a64548ea | 21936 | @itemx set mipsfpu auto |
8e04817f AC |
21937 | @itemx show mipsfpu |
21938 | @kindex set mipsfpu | |
21939 | @kindex show mipsfpu | |
eb17f351 EZ |
21940 | @cindex @acronym{MIPS} remote floating point |
21941 | @cindex floating point, @acronym{MIPS} remote | |
21942 | If your target board does not support the @acronym{MIPS} floating point | |
8e04817f AC |
21943 | coprocessor, you should use the command @samp{set mipsfpu none} (if you |
21944 | need this, you may wish to put the command in your @value{GDBN} init | |
21945 | file). This tells @value{GDBN} how to find the return value of | |
21946 | functions which return floating point values. It also allows | |
21947 | @value{GDBN} to avoid saving the floating point registers when calling | |
21948 | functions on the board. If you are using a floating point coprocessor | |
21949 | with only single precision floating point support, as on the @sc{r4650} | |
21950 | processor, use the command @samp{set mipsfpu single}. The default | |
21951 | double precision floating point coprocessor may be selected using | |
21952 | @samp{set mipsfpu double}. | |
104c1213 | 21953 | |
8e04817f AC |
21954 | In previous versions the only choices were double precision or no |
21955 | floating point, so @samp{set mipsfpu on} will select double precision | |
21956 | and @samp{set mipsfpu off} will select no floating point. | |
104c1213 | 21957 | |
8e04817f AC |
21958 | As usual, you can inquire about the @code{mipsfpu} variable with |
21959 | @samp{show mipsfpu}. | |
104c1213 | 21960 | |
8e04817f AC |
21961 | @item set timeout @var{seconds} |
21962 | @itemx set retransmit-timeout @var{seconds} | |
21963 | @itemx show timeout | |
21964 | @itemx show retransmit-timeout | |
eb17f351 EZ |
21965 | @cindex @code{timeout}, @acronym{MIPS} protocol |
21966 | @cindex @code{retransmit-timeout}, @acronym{MIPS} protocol | |
8e04817f AC |
21967 | @kindex set timeout |
21968 | @kindex show timeout | |
21969 | @kindex set retransmit-timeout | |
21970 | @kindex show retransmit-timeout | |
eb17f351 | 21971 | You can control the timeout used while waiting for a packet, in the @acronym{MIPS} |
8e04817f AC |
21972 | remote protocol, with the @code{set timeout @var{seconds}} command. The |
21973 | default is 5 seconds. Similarly, you can control the timeout used while | |
a6f3e723 | 21974 | waiting for an acknowledgment of a packet with the @code{set |
8e04817f AC |
21975 | retransmit-timeout @var{seconds}} command. The default is 3 seconds. |
21976 | You can inspect both values with @code{show timeout} and @code{show | |
21977 | retransmit-timeout}. (These commands are @emph{only} available when | |
cc30c4bd | 21978 | @value{GDBN} is configured for @samp{--target=mips-elf}.) |
104c1213 | 21979 | |
8e04817f AC |
21980 | The timeout set by @code{set timeout} does not apply when @value{GDBN} |
21981 | is waiting for your program to stop. In that case, @value{GDBN} waits | |
21982 | forever because it has no way of knowing how long the program is going | |
21983 | to run before stopping. | |
ba04e063 EZ |
21984 | |
21985 | @item set syn-garbage-limit @var{num} | |
eb17f351 EZ |
21986 | @kindex set syn-garbage-limit@r{, @acronym{MIPS} remote} |
21987 | @cindex synchronize with remote @acronym{MIPS} target | |
ba04e063 EZ |
21988 | Limit the maximum number of characters @value{GDBN} should ignore when |
21989 | it tries to synchronize with the remote target. The default is 10 | |
21990 | characters. Setting the limit to -1 means there's no limit. | |
21991 | ||
21992 | @item show syn-garbage-limit | |
eb17f351 | 21993 | @kindex show syn-garbage-limit@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
21994 | Show the current limit on the number of characters to ignore when |
21995 | trying to synchronize with the remote system. | |
21996 | ||
21997 | @item set monitor-prompt @var{prompt} | |
eb17f351 | 21998 | @kindex set monitor-prompt@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
21999 | @cindex remote monitor prompt |
22000 | Tell @value{GDBN} to expect the specified @var{prompt} string from the | |
22001 | remote monitor. The default depends on the target: | |
22002 | @table @asis | |
22003 | @item pmon target | |
22004 | @samp{PMON} | |
22005 | @item ddb target | |
22006 | @samp{NEC010} | |
22007 | @item lsi target | |
22008 | @samp{PMON>} | |
22009 | @end table | |
22010 | ||
22011 | @item show monitor-prompt | |
eb17f351 | 22012 | @kindex show monitor-prompt@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
22013 | Show the current strings @value{GDBN} expects as the prompt from the |
22014 | remote monitor. | |
22015 | ||
22016 | @item set monitor-warnings | |
eb17f351 | 22017 | @kindex set monitor-warnings@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
22018 | Enable or disable monitor warnings about hardware breakpoints. This |
22019 | has effect only for the @code{lsi} target. When on, @value{GDBN} will | |
22020 | display warning messages whose codes are returned by the @code{lsi} | |
22021 | PMON monitor for breakpoint commands. | |
22022 | ||
22023 | @item show monitor-warnings | |
eb17f351 | 22024 | @kindex show monitor-warnings@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
22025 | Show the current setting of printing monitor warnings. |
22026 | ||
22027 | @item pmon @var{command} | |
eb17f351 | 22028 | @kindex pmon@r{, @acronym{MIPS} remote} |
ba04e063 EZ |
22029 | @cindex send PMON command |
22030 | This command allows sending an arbitrary @var{command} string to the | |
22031 | monitor. The monitor must be in debug mode for this to work. | |
8e04817f | 22032 | @end table |
104c1213 | 22033 | |
4acd40f3 TJB |
22034 | @node PowerPC Embedded |
22035 | @subsection PowerPC Embedded | |
104c1213 | 22036 | |
66b73624 TJB |
22037 | @cindex DVC register |
22038 | @value{GDBN} supports using the DVC (Data Value Compare) register to | |
22039 | implement in hardware simple hardware watchpoint conditions of the form: | |
22040 | ||
22041 | @smallexample | |
22042 | (@value{GDBP}) watch @var{ADDRESS|VARIABLE} \ | |
22043 | if @var{ADDRESS|VARIABLE} == @var{CONSTANT EXPRESSION} | |
22044 | @end smallexample | |
22045 | ||
e09342b5 TJB |
22046 | The DVC register will be automatically used when @value{GDBN} detects |
22047 | such pattern in a condition expression, and the created watchpoint uses one | |
22048 | debug register (either the @code{exact-watchpoints} option is on and the | |
22049 | variable is scalar, or the variable has a length of one byte). This feature | |
22050 | is available in native @value{GDBN} running on a Linux kernel version 2.6.34 | |
22051 | or newer. | |
22052 | ||
22053 | When running on PowerPC embedded processors, @value{GDBN} automatically uses | |
22054 | ranged hardware watchpoints, unless the @code{exact-watchpoints} option is on, | |
22055 | in which case watchpoints using only one debug register are created when | |
22056 | watching variables of scalar types. | |
22057 | ||
22058 | You can create an artificial array to watch an arbitrary memory | |
22059 | region using one of the following commands (@pxref{Expressions}): | |
22060 | ||
22061 | @smallexample | |
22062 | (@value{GDBP}) watch *((char *) @var{address})@@@var{length} | |
22063 | (@value{GDBP}) watch @{char[@var{length}]@} @var{address} | |
22064 | @end smallexample | |
66b73624 | 22065 | |
9c06b0b4 TJB |
22066 | PowerPC embedded processors support masked watchpoints. See the discussion |
22067 | about the @code{mask} argument in @ref{Set Watchpoints}. | |
22068 | ||
f1310107 TJB |
22069 | @cindex ranged breakpoint |
22070 | PowerPC embedded processors support hardware accelerated | |
22071 | @dfn{ranged breakpoints}. A ranged breakpoint stops execution of | |
22072 | the inferior whenever it executes an instruction at any address within | |
22073 | the range it specifies. To set a ranged breakpoint in @value{GDBN}, | |
22074 | use the @code{break-range} command. | |
22075 | ||
55eddb0f DJ |
22076 | @value{GDBN} provides the following PowerPC-specific commands: |
22077 | ||
104c1213 | 22078 | @table @code |
f1310107 TJB |
22079 | @kindex break-range |
22080 | @item break-range @var{start-location}, @var{end-location} | |
697aa1b7 EZ |
22081 | Set a breakpoint for an address range given by |
22082 | @var{start-location} and @var{end-location}, which can specify a function name, | |
f1310107 TJB |
22083 | a line number, an offset of lines from the current line or from the start |
22084 | location, or an address of an instruction (see @ref{Specify Location}, | |
22085 | for a list of all the possible ways to specify a @var{location}.) | |
22086 | The breakpoint will stop execution of the inferior whenever it | |
22087 | executes an instruction at any address within the specified range, | |
22088 | (including @var{start-location} and @var{end-location}.) | |
22089 | ||
55eddb0f DJ |
22090 | @kindex set powerpc |
22091 | @item set powerpc soft-float | |
22092 | @itemx show powerpc soft-float | |
22093 | Force @value{GDBN} to use (or not use) a software floating point calling | |
22094 | convention. By default, @value{GDBN} selects the calling convention based | |
22095 | on the selected architecture and the provided executable file. | |
22096 | ||
22097 | @item set powerpc vector-abi | |
22098 | @itemx show powerpc vector-abi | |
22099 | Force @value{GDBN} to use the specified calling convention for vector | |
22100 | arguments and return values. The valid options are @samp{auto}; | |
22101 | @samp{generic}, to avoid vector registers even if they are present; | |
22102 | @samp{altivec}, to use AltiVec registers; and @samp{spe} to use SPE | |
22103 | registers. By default, @value{GDBN} selects the calling convention | |
22104 | based on the selected architecture and the provided executable file. | |
22105 | ||
e09342b5 TJB |
22106 | @item set powerpc exact-watchpoints |
22107 | @itemx show powerpc exact-watchpoints | |
22108 | Allow @value{GDBN} to use only one debug register when watching a variable | |
22109 | of scalar type, thus assuming that the variable is accessed through the | |
22110 | address of its first byte. | |
22111 | ||
104c1213 JM |
22112 | @end table |
22113 | ||
a64548ea EZ |
22114 | @node AVR |
22115 | @subsection Atmel AVR | |
22116 | @cindex AVR | |
22117 | ||
22118 | When configured for debugging the Atmel AVR, @value{GDBN} supports the | |
22119 | following AVR-specific commands: | |
22120 | ||
22121 | @table @code | |
22122 | @item info io_registers | |
22123 | @kindex info io_registers@r{, AVR} | |
22124 | @cindex I/O registers (Atmel AVR) | |
22125 | This command displays information about the AVR I/O registers. For | |
22126 | each register, @value{GDBN} prints its number and value. | |
22127 | @end table | |
22128 | ||
22129 | @node CRIS | |
22130 | @subsection CRIS | |
22131 | @cindex CRIS | |
22132 | ||
22133 | When configured for debugging CRIS, @value{GDBN} provides the | |
22134 | following CRIS-specific commands: | |
22135 | ||
22136 | @table @code | |
22137 | @item set cris-version @var{ver} | |
22138 | @cindex CRIS version | |
e22e55c9 OF |
22139 | Set the current CRIS version to @var{ver}, either @samp{10} or @samp{32}. |
22140 | The CRIS version affects register names and sizes. This command is useful in | |
22141 | case autodetection of the CRIS version fails. | |
a64548ea EZ |
22142 | |
22143 | @item show cris-version | |
22144 | Show the current CRIS version. | |
22145 | ||
22146 | @item set cris-dwarf2-cfi | |
22147 | @cindex DWARF-2 CFI and CRIS | |
e22e55c9 OF |
22148 | Set the usage of DWARF-2 CFI for CRIS debugging. The default is @samp{on}. |
22149 | Change to @samp{off} when using @code{gcc-cris} whose version is below | |
22150 | @code{R59}. | |
a64548ea EZ |
22151 | |
22152 | @item show cris-dwarf2-cfi | |
22153 | Show the current state of using DWARF-2 CFI. | |
e22e55c9 OF |
22154 | |
22155 | @item set cris-mode @var{mode} | |
22156 | @cindex CRIS mode | |
22157 | Set the current CRIS mode to @var{mode}. It should only be changed when | |
22158 | debugging in guru mode, in which case it should be set to | |
22159 | @samp{guru} (the default is @samp{normal}). | |
22160 | ||
22161 | @item show cris-mode | |
22162 | Show the current CRIS mode. | |
a64548ea EZ |
22163 | @end table |
22164 | ||
22165 | @node Super-H | |
22166 | @subsection Renesas Super-H | |
22167 | @cindex Super-H | |
22168 | ||
22169 | For the Renesas Super-H processor, @value{GDBN} provides these | |
22170 | commands: | |
22171 | ||
22172 | @table @code | |
c055b101 CV |
22173 | @item set sh calling-convention @var{convention} |
22174 | @kindex set sh calling-convention | |
22175 | Set the calling-convention used when calling functions from @value{GDBN}. | |
22176 | Allowed values are @samp{gcc}, which is the default setting, and @samp{renesas}. | |
22177 | With the @samp{gcc} setting, functions are called using the @value{NGCC} calling | |
22178 | convention. If the DWARF-2 information of the called function specifies | |
22179 | that the function follows the Renesas calling convention, the function | |
22180 | is called using the Renesas calling convention. If the calling convention | |
22181 | is set to @samp{renesas}, the Renesas calling convention is always used, | |
22182 | regardless of the DWARF-2 information. This can be used to override the | |
22183 | default of @samp{gcc} if debug information is missing, or the compiler | |
22184 | does not emit the DWARF-2 calling convention entry for a function. | |
22185 | ||
22186 | @item show sh calling-convention | |
22187 | @kindex show sh calling-convention | |
22188 | Show the current calling convention setting. | |
22189 | ||
a64548ea EZ |
22190 | @end table |
22191 | ||
22192 | ||
8e04817f AC |
22193 | @node Architectures |
22194 | @section Architectures | |
104c1213 | 22195 | |
8e04817f AC |
22196 | This section describes characteristics of architectures that affect |
22197 | all uses of @value{GDBN} with the architecture, both native and cross. | |
104c1213 | 22198 | |
8e04817f | 22199 | @menu |
430ed3f0 | 22200 | * AArch64:: |
9c16f35a | 22201 | * i386:: |
8e04817f AC |
22202 | * Alpha:: |
22203 | * MIPS:: | |
a64548ea | 22204 | * HPPA:: HP PA architecture |
23d964e7 | 22205 | * SPU:: Cell Broadband Engine SPU architecture |
4acd40f3 | 22206 | * PowerPC:: |
a1217d97 | 22207 | * Nios II:: |
8e04817f | 22208 | @end menu |
104c1213 | 22209 | |
430ed3f0 MS |
22210 | @node AArch64 |
22211 | @subsection AArch64 | |
22212 | @cindex AArch64 support | |
22213 | ||
22214 | When @value{GDBN} is debugging the AArch64 architecture, it provides the | |
22215 | following special commands: | |
22216 | ||
22217 | @table @code | |
22218 | @item set debug aarch64 | |
22219 | @kindex set debug aarch64 | |
22220 | This command determines whether AArch64 architecture-specific debugging | |
22221 | messages are to be displayed. | |
22222 | ||
22223 | @item show debug aarch64 | |
22224 | Show whether AArch64 debugging messages are displayed. | |
22225 | ||
22226 | @end table | |
22227 | ||
9c16f35a | 22228 | @node i386 |
db2e3e2e | 22229 | @subsection x86 Architecture-specific Issues |
9c16f35a EZ |
22230 | |
22231 | @table @code | |
22232 | @item set struct-convention @var{mode} | |
22233 | @kindex set struct-convention | |
22234 | @cindex struct return convention | |
22235 | @cindex struct/union returned in registers | |
22236 | Set the convention used by the inferior to return @code{struct}s and | |
22237 | @code{union}s from functions to @var{mode}. Possible values of | |
22238 | @var{mode} are @code{"pcc"}, @code{"reg"}, and @code{"default"} (the | |
22239 | default). @code{"default"} or @code{"pcc"} means that @code{struct}s | |
22240 | are returned on the stack, while @code{"reg"} means that a | |
22241 | @code{struct} or a @code{union} whose size is 1, 2, 4, or 8 bytes will | |
22242 | be returned in a register. | |
22243 | ||
22244 | @item show struct-convention | |
22245 | @kindex show struct-convention | |
22246 | Show the current setting of the convention to return @code{struct}s | |
22247 | from functions. | |
966f0aef | 22248 | @end table |
29c1c244 | 22249 | |
ca8941bb | 22250 | |
bc504a31 PA |
22251 | @subsubsection Intel @dfn{Memory Protection Extensions} (MPX). |
22252 | @cindex Intel Memory Protection Extensions (MPX). | |
ca8941bb | 22253 | |
ca8941bb WT |
22254 | Memory Protection Extension (MPX) adds the bound registers @samp{BND0} |
22255 | @footnote{The register named with capital letters represent the architecture | |
22256 | registers.} through @samp{BND3}. Bound registers store a pair of 64-bit values | |
22257 | which are the lower bound and upper bound. Bounds are effective addresses or | |
22258 | memory locations. The upper bounds are architecturally represented in 1's | |
22259 | complement form. A bound having lower bound = 0, and upper bound = 0 | |
22260 | (1's complement of all bits set) will allow access to the entire address space. | |
22261 | ||
22262 | @samp{BND0} through @samp{BND3} are represented in @value{GDBN} as @samp{bnd0raw} | |
22263 | through @samp{bnd3raw}. Pseudo registers @samp{bnd0} through @samp{bnd3} | |
22264 | display the upper bound performing the complement of one operation on the | |
22265 | upper bound value, i.e.@ when upper bound in @samp{bnd0raw} is 0 in the | |
22266 | @value{GDBN} @samp{bnd0} it will be @code{0xfff@dots{}}. In this sense it | |
22267 | can also be noted that the upper bounds are inclusive. | |
22268 | ||
22269 | As an example, assume that the register BND0 holds bounds for a pointer having | |
22270 | access allowed for the range between 0x32 and 0x71. The values present on | |
22271 | bnd0raw and bnd registers are presented as follows: | |
22272 | ||
22273 | @smallexample | |
22274 | bnd0raw = @{0x32, 0xffffffff8e@} | |
22275 | bnd0 = @{lbound = 0x32, ubound = 0x71@} : size 64 | |
22276 | @end smallexample | |
22277 | ||
22f25c9d EZ |
22278 | This way the raw value can be accessed via bnd0raw@dots{}bnd3raw. Any |
22279 | change on bnd0@dots{}bnd3 or bnd0raw@dots{}bnd3raw is reflect on its | |
22280 | counterpart. When the bnd0@dots{}bnd3 registers are displayed via | |
22281 | Python, the display includes the memory size, in bits, accessible to | |
22282 | the pointer. | |
9c16f35a | 22283 | |
29c1c244 WT |
22284 | Bounds can also be stored in bounds tables, which are stored in |
22285 | application memory. These tables store bounds for pointers by specifying | |
22286 | the bounds pointer's value along with its bounds. Evaluating and changing | |
22287 | bounds located in bound tables is therefore interesting while investigating | |
22288 | bugs on MPX context. @value{GDBN} provides commands for this purpose: | |
22289 | ||
966f0aef | 22290 | @table @code |
29c1c244 WT |
22291 | @item show mpx bound @var{pointer} |
22292 | @kindex show mpx bound | |
22293 | Display bounds of the given @var{pointer}. | |
22294 | ||
22295 | @item set mpx bound @var{pointer}, @var{lbound}, @var{ubound} | |
22296 | @kindex set mpx bound | |
22297 | Set the bounds of a pointer in the bound table. | |
22298 | This command takes three parameters: @var{pointer} is the pointers | |
22299 | whose bounds are to be changed, @var{lbound} and @var{ubound} are new values | |
22300 | for lower and upper bounds respectively. | |
22301 | @end table | |
22302 | ||
8e04817f AC |
22303 | @node Alpha |
22304 | @subsection Alpha | |
104c1213 | 22305 | |
8e04817f | 22306 | See the following section. |
104c1213 | 22307 | |
8e04817f | 22308 | @node MIPS |
eb17f351 | 22309 | @subsection @acronym{MIPS} |
104c1213 | 22310 | |
8e04817f | 22311 | @cindex stack on Alpha |
eb17f351 | 22312 | @cindex stack on @acronym{MIPS} |
8e04817f | 22313 | @cindex Alpha stack |
eb17f351 EZ |
22314 | @cindex @acronym{MIPS} stack |
22315 | Alpha- and @acronym{MIPS}-based computers use an unusual stack frame, which | |
8e04817f AC |
22316 | sometimes requires @value{GDBN} to search backward in the object code to |
22317 | find the beginning of a function. | |
104c1213 | 22318 | |
eb17f351 | 22319 | @cindex response time, @acronym{MIPS} debugging |
8e04817f AC |
22320 | To improve response time (especially for embedded applications, where |
22321 | @value{GDBN} may be restricted to a slow serial line for this search) | |
22322 | you may want to limit the size of this search, using one of these | |
22323 | commands: | |
104c1213 | 22324 | |
8e04817f | 22325 | @table @code |
eb17f351 | 22326 | @cindex @code{heuristic-fence-post} (Alpha, @acronym{MIPS}) |
8e04817f AC |
22327 | @item set heuristic-fence-post @var{limit} |
22328 | Restrict @value{GDBN} to examining at most @var{limit} bytes in its | |
22329 | search for the beginning of a function. A value of @var{0} (the | |
22330 | default) means there is no limit. However, except for @var{0}, the | |
22331 | larger the limit the more bytes @code{heuristic-fence-post} must search | |
e2f4edfd EZ |
22332 | and therefore the longer it takes to run. You should only need to use |
22333 | this command when debugging a stripped executable. | |
104c1213 | 22334 | |
8e04817f AC |
22335 | @item show heuristic-fence-post |
22336 | Display the current limit. | |
22337 | @end table | |
104c1213 JM |
22338 | |
22339 | @noindent | |
8e04817f | 22340 | These commands are available @emph{only} when @value{GDBN} is configured |
eb17f351 | 22341 | for debugging programs on Alpha or @acronym{MIPS} processors. |
104c1213 | 22342 | |
eb17f351 | 22343 | Several @acronym{MIPS}-specific commands are available when debugging @acronym{MIPS} |
a64548ea EZ |
22344 | programs: |
22345 | ||
22346 | @table @code | |
a64548ea EZ |
22347 | @item set mips abi @var{arg} |
22348 | @kindex set mips abi | |
eb17f351 EZ |
22349 | @cindex set ABI for @acronym{MIPS} |
22350 | Tell @value{GDBN} which @acronym{MIPS} ABI is used by the inferior. Possible | |
a64548ea EZ |
22351 | values of @var{arg} are: |
22352 | ||
22353 | @table @samp | |
22354 | @item auto | |
22355 | The default ABI associated with the current binary (this is the | |
22356 | default). | |
22357 | @item o32 | |
22358 | @item o64 | |
22359 | @item n32 | |
22360 | @item n64 | |
22361 | @item eabi32 | |
22362 | @item eabi64 | |
a64548ea EZ |
22363 | @end table |
22364 | ||
22365 | @item show mips abi | |
22366 | @kindex show mips abi | |
eb17f351 | 22367 | Show the @acronym{MIPS} ABI used by @value{GDBN} to debug the inferior. |
a64548ea | 22368 | |
4cc0665f MR |
22369 | @item set mips compression @var{arg} |
22370 | @kindex set mips compression | |
22371 | @cindex code compression, @acronym{MIPS} | |
22372 | Tell @value{GDBN} which @acronym{MIPS} compressed | |
22373 | @acronym{ISA, Instruction Set Architecture} encoding is used by the | |
22374 | inferior. @value{GDBN} uses this for code disassembly and other | |
22375 | internal interpretation purposes. This setting is only referred to | |
22376 | when no executable has been associated with the debugging session or | |
22377 | the executable does not provide information about the encoding it uses. | |
22378 | Otherwise this setting is automatically updated from information | |
22379 | provided by the executable. | |
22380 | ||
22381 | Possible values of @var{arg} are @samp{mips16} and @samp{micromips}. | |
22382 | The default compressed @acronym{ISA} encoding is @samp{mips16}, as | |
22383 | executables containing @acronym{MIPS16} code frequently are not | |
22384 | identified as such. | |
22385 | ||
22386 | This setting is ``sticky''; that is, it retains its value across | |
22387 | debugging sessions until reset either explicitly with this command or | |
22388 | implicitly from an executable. | |
22389 | ||
22390 | The compiler and/or assembler typically add symbol table annotations to | |
22391 | identify functions compiled for the @acronym{MIPS16} or | |
22392 | @acronym{microMIPS} @acronym{ISA}s. If these function-scope annotations | |
22393 | are present, @value{GDBN} uses them in preference to the global | |
22394 | compressed @acronym{ISA} encoding setting. | |
22395 | ||
22396 | @item show mips compression | |
22397 | @kindex show mips compression | |
22398 | Show the @acronym{MIPS} compressed @acronym{ISA} encoding used by | |
22399 | @value{GDBN} to debug the inferior. | |
22400 | ||
a64548ea EZ |
22401 | @item set mipsfpu |
22402 | @itemx show mipsfpu | |
22403 | @xref{MIPS Embedded, set mipsfpu}. | |
22404 | ||
22405 | @item set mips mask-address @var{arg} | |
22406 | @kindex set mips mask-address | |
eb17f351 | 22407 | @cindex @acronym{MIPS} addresses, masking |
a64548ea | 22408 | This command determines whether the most-significant 32 bits of 64-bit |
eb17f351 | 22409 | @acronym{MIPS} addresses are masked off. The argument @var{arg} can be |
a64548ea EZ |
22410 | @samp{on}, @samp{off}, or @samp{auto}. The latter is the default |
22411 | setting, which lets @value{GDBN} determine the correct value. | |
22412 | ||
22413 | @item show mips mask-address | |
22414 | @kindex show mips mask-address | |
eb17f351 | 22415 | Show whether the upper 32 bits of @acronym{MIPS} addresses are masked off or |
a64548ea EZ |
22416 | not. |
22417 | ||
22418 | @item set remote-mips64-transfers-32bit-regs | |
22419 | @kindex set remote-mips64-transfers-32bit-regs | |
eb17f351 EZ |
22420 | This command controls compatibility with 64-bit @acronym{MIPS} targets that |
22421 | transfer data in 32-bit quantities. If you have an old @acronym{MIPS} 64 target | |
a64548ea EZ |
22422 | that transfers 32 bits for some registers, like @sc{sr} and @sc{fsr}, |
22423 | and 64 bits for other registers, set this option to @samp{on}. | |
22424 | ||
22425 | @item show remote-mips64-transfers-32bit-regs | |
22426 | @kindex show remote-mips64-transfers-32bit-regs | |
eb17f351 | 22427 | Show the current setting of compatibility with older @acronym{MIPS} 64 targets. |
a64548ea EZ |
22428 | |
22429 | @item set debug mips | |
22430 | @kindex set debug mips | |
eb17f351 | 22431 | This command turns on and off debugging messages for the @acronym{MIPS}-specific |
a64548ea EZ |
22432 | target code in @value{GDBN}. |
22433 | ||
22434 | @item show debug mips | |
22435 | @kindex show debug mips | |
eb17f351 | 22436 | Show the current setting of @acronym{MIPS} debugging messages. |
a64548ea EZ |
22437 | @end table |
22438 | ||
22439 | ||
22440 | @node HPPA | |
22441 | @subsection HPPA | |
22442 | @cindex HPPA support | |
22443 | ||
d3e8051b | 22444 | When @value{GDBN} is debugging the HP PA architecture, it provides the |
a64548ea EZ |
22445 | following special commands: |
22446 | ||
22447 | @table @code | |
22448 | @item set debug hppa | |
22449 | @kindex set debug hppa | |
db2e3e2e | 22450 | This command determines whether HPPA architecture-specific debugging |
a64548ea EZ |
22451 | messages are to be displayed. |
22452 | ||
22453 | @item show debug hppa | |
22454 | Show whether HPPA debugging messages are displayed. | |
22455 | ||
22456 | @item maint print unwind @var{address} | |
22457 | @kindex maint print unwind@r{, HPPA} | |
22458 | This command displays the contents of the unwind table entry at the | |
22459 | given @var{address}. | |
22460 | ||
22461 | @end table | |
22462 | ||
104c1213 | 22463 | |
23d964e7 UW |
22464 | @node SPU |
22465 | @subsection Cell Broadband Engine SPU architecture | |
22466 | @cindex Cell Broadband Engine | |
22467 | @cindex SPU | |
22468 | ||
22469 | When @value{GDBN} is debugging the Cell Broadband Engine SPU architecture, | |
22470 | it provides the following special commands: | |
22471 | ||
22472 | @table @code | |
22473 | @item info spu event | |
22474 | @kindex info spu | |
22475 | Display SPU event facility status. Shows current event mask | |
22476 | and pending event status. | |
22477 | ||
22478 | @item info spu signal | |
22479 | Display SPU signal notification facility status. Shows pending | |
22480 | signal-control word and signal notification mode of both signal | |
22481 | notification channels. | |
22482 | ||
22483 | @item info spu mailbox | |
22484 | Display SPU mailbox facility status. Shows all pending entries, | |
22485 | in order of processing, in each of the SPU Write Outbound, | |
22486 | SPU Write Outbound Interrupt, and SPU Read Inbound mailboxes. | |
22487 | ||
22488 | @item info spu dma | |
22489 | Display MFC DMA status. Shows all pending commands in the MFC | |
22490 | DMA queue. For each entry, opcode, tag, class IDs, effective | |
22491 | and local store addresses and transfer size are shown. | |
22492 | ||
22493 | @item info spu proxydma | |
22494 | Display MFC Proxy-DMA status. Shows all pending commands in the MFC | |
22495 | Proxy-DMA queue. For each entry, opcode, tag, class IDs, effective | |
22496 | and local store addresses and transfer size are shown. | |
22497 | ||
22498 | @end table | |
22499 | ||
3285f3fe UW |
22500 | When @value{GDBN} is debugging a combined PowerPC/SPU application |
22501 | on the Cell Broadband Engine, it provides in addition the following | |
22502 | special commands: | |
22503 | ||
22504 | @table @code | |
22505 | @item set spu stop-on-load @var{arg} | |
22506 | @kindex set spu | |
22507 | Set whether to stop for new SPE threads. When set to @code{on}, @value{GDBN} | |
22508 | will give control to the user when a new SPE thread enters its @code{main} | |
22509 | function. The default is @code{off}. | |
22510 | ||
22511 | @item show spu stop-on-load | |
22512 | @kindex show spu | |
22513 | Show whether to stop for new SPE threads. | |
22514 | ||
ff1a52c6 UW |
22515 | @item set spu auto-flush-cache @var{arg} |
22516 | Set whether to automatically flush the software-managed cache. When set to | |
22517 | @code{on}, @value{GDBN} will automatically cause the SPE software-managed | |
22518 | cache to be flushed whenever SPE execution stops. This provides a consistent | |
22519 | view of PowerPC memory that is accessed via the cache. If an application | |
22520 | does not use the software-managed cache, this option has no effect. | |
22521 | ||
22522 | @item show spu auto-flush-cache | |
22523 | Show whether to automatically flush the software-managed cache. | |
22524 | ||
3285f3fe UW |
22525 | @end table |
22526 | ||
4acd40f3 TJB |
22527 | @node PowerPC |
22528 | @subsection PowerPC | |
22529 | @cindex PowerPC architecture | |
22530 | ||
22531 | When @value{GDBN} is debugging the PowerPC architecture, it provides a set of | |
22532 | pseudo-registers to enable inspection of 128-bit wide Decimal Floating Point | |
22533 | numbers stored in the floating point registers. These values must be stored | |
22534 | in two consecutive registers, always starting at an even register like | |
22535 | @code{f0} or @code{f2}. | |
22536 | ||
22537 | The pseudo-registers go from @code{$dl0} through @code{$dl15}, and are formed | |
22538 | by joining the even/odd register pairs @code{f0} and @code{f1} for @code{$dl0}, | |
22539 | @code{f2} and @code{f3} for @code{$dl1} and so on. | |
22540 | ||
aeac0ff9 | 22541 | For POWER7 processors, @value{GDBN} provides a set of pseudo-registers, the 64-bit |
677c5bb1 LM |
22542 | wide Extended Floating Point Registers (@samp{f32} through @samp{f63}). |
22543 | ||
a1217d97 SL |
22544 | @node Nios II |
22545 | @subsection Nios II | |
22546 | @cindex Nios II architecture | |
22547 | ||
22548 | When @value{GDBN} is debugging the Nios II architecture, | |
22549 | it provides the following special commands: | |
22550 | ||
22551 | @table @code | |
22552 | ||
22553 | @item set debug nios2 | |
22554 | @kindex set debug nios2 | |
22555 | This command turns on and off debugging messages for the Nios II | |
22556 | target code in @value{GDBN}. | |
22557 | ||
22558 | @item show debug nios2 | |
22559 | @kindex show debug nios2 | |
22560 | Show the current setting of Nios II debugging messages. | |
22561 | @end table | |
23d964e7 | 22562 | |
8e04817f AC |
22563 | @node Controlling GDB |
22564 | @chapter Controlling @value{GDBN} | |
22565 | ||
22566 | You can alter the way @value{GDBN} interacts with you by using the | |
22567 | @code{set} command. For commands controlling how @value{GDBN} displays | |
79a6e687 | 22568 | data, see @ref{Print Settings, ,Print Settings}. Other settings are |
8e04817f AC |
22569 | described here. |
22570 | ||
22571 | @menu | |
22572 | * Prompt:: Prompt | |
22573 | * Editing:: Command editing | |
d620b259 | 22574 | * Command History:: Command history |
8e04817f AC |
22575 | * Screen Size:: Screen size |
22576 | * Numbers:: Numbers | |
1e698235 | 22577 | * ABI:: Configuring the current ABI |
bf88dd68 | 22578 | * Auto-loading:: Automatically loading associated files |
8e04817f AC |
22579 | * Messages/Warnings:: Optional warnings and messages |
22580 | * Debugging Output:: Optional messages about internal happenings | |
14fb1bac | 22581 | * Other Misc Settings:: Other Miscellaneous Settings |
8e04817f AC |
22582 | @end menu |
22583 | ||
22584 | @node Prompt | |
22585 | @section Prompt | |
104c1213 | 22586 | |
8e04817f | 22587 | @cindex prompt |
104c1213 | 22588 | |
8e04817f AC |
22589 | @value{GDBN} indicates its readiness to read a command by printing a string |
22590 | called the @dfn{prompt}. This string is normally @samp{(@value{GDBP})}. You | |
22591 | can change the prompt string with the @code{set prompt} command. For | |
22592 | instance, when debugging @value{GDBN} with @value{GDBN}, it is useful to change | |
22593 | the prompt in one of the @value{GDBN} sessions so that you can always tell | |
22594 | which one you are talking to. | |
104c1213 | 22595 | |
8e04817f AC |
22596 | @emph{Note:} @code{set prompt} does not add a space for you after the |
22597 | prompt you set. This allows you to set a prompt which ends in a space | |
22598 | or a prompt that does not. | |
104c1213 | 22599 | |
8e04817f AC |
22600 | @table @code |
22601 | @kindex set prompt | |
22602 | @item set prompt @var{newprompt} | |
22603 | Directs @value{GDBN} to use @var{newprompt} as its prompt string henceforth. | |
104c1213 | 22604 | |
8e04817f AC |
22605 | @kindex show prompt |
22606 | @item show prompt | |
22607 | Prints a line of the form: @samp{Gdb's prompt is: @var{your-prompt}} | |
104c1213 JM |
22608 | @end table |
22609 | ||
fa3a4f15 PM |
22610 | Versions of @value{GDBN} that ship with Python scripting enabled have |
22611 | prompt extensions. The commands for interacting with these extensions | |
22612 | are: | |
22613 | ||
22614 | @table @code | |
22615 | @kindex set extended-prompt | |
22616 | @item set extended-prompt @var{prompt} | |
22617 | Set an extended prompt that allows for substitutions. | |
22618 | @xref{gdb.prompt}, for a list of escape sequences that can be used for | |
22619 | substitution. Any escape sequences specified as part of the prompt | |
22620 | string are replaced with the corresponding strings each time the prompt | |
22621 | is displayed. | |
22622 | ||
22623 | For example: | |
22624 | ||
22625 | @smallexample | |
22626 | set extended-prompt Current working directory: \w (gdb) | |
22627 | @end smallexample | |
22628 | ||
22629 | Note that when an extended-prompt is set, it takes control of the | |
22630 | @var{prompt_hook} hook. @xref{prompt_hook}, for further information. | |
22631 | ||
22632 | @kindex show extended-prompt | |
22633 | @item show extended-prompt | |
22634 | Prints the extended prompt. Any escape sequences specified as part of | |
22635 | the prompt string with @code{set extended-prompt}, are replaced with the | |
22636 | corresponding strings each time the prompt is displayed. | |
22637 | @end table | |
22638 | ||
8e04817f | 22639 | @node Editing |
79a6e687 | 22640 | @section Command Editing |
8e04817f AC |
22641 | @cindex readline |
22642 | @cindex command line editing | |
104c1213 | 22643 | |
703663ab | 22644 | @value{GDBN} reads its input commands via the @dfn{Readline} interface. This |
8e04817f AC |
22645 | @sc{gnu} library provides consistent behavior for programs which provide a |
22646 | command line interface to the user. Advantages are @sc{gnu} Emacs-style | |
22647 | or @dfn{vi}-style inline editing of commands, @code{csh}-like history | |
22648 | substitution, and a storage and recall of command history across | |
22649 | debugging sessions. | |
104c1213 | 22650 | |
8e04817f AC |
22651 | You may control the behavior of command line editing in @value{GDBN} with the |
22652 | command @code{set}. | |
104c1213 | 22653 | |
8e04817f AC |
22654 | @table @code |
22655 | @kindex set editing | |
22656 | @cindex editing | |
22657 | @item set editing | |
22658 | @itemx set editing on | |
22659 | Enable command line editing (enabled by default). | |
104c1213 | 22660 | |
8e04817f AC |
22661 | @item set editing off |
22662 | Disable command line editing. | |
104c1213 | 22663 | |
8e04817f AC |
22664 | @kindex show editing |
22665 | @item show editing | |
22666 | Show whether command line editing is enabled. | |
104c1213 JM |
22667 | @end table |
22668 | ||
39037522 TT |
22669 | @ifset SYSTEM_READLINE |
22670 | @xref{Command Line Editing, , , rluserman, GNU Readline Library}, | |
22671 | @end ifset | |
22672 | @ifclear SYSTEM_READLINE | |
22673 | @xref{Command Line Editing}, | |
22674 | @end ifclear | |
22675 | for more details about the Readline | |
703663ab EZ |
22676 | interface. Users unfamiliar with @sc{gnu} Emacs or @code{vi} are |
22677 | encouraged to read that chapter. | |
22678 | ||
d620b259 | 22679 | @node Command History |
79a6e687 | 22680 | @section Command History |
703663ab | 22681 | @cindex command history |
8e04817f AC |
22682 | |
22683 | @value{GDBN} can keep track of the commands you type during your | |
22684 | debugging sessions, so that you can be certain of precisely what | |
22685 | happened. Use these commands to manage the @value{GDBN} command | |
22686 | history facility. | |
104c1213 | 22687 | |
703663ab | 22688 | @value{GDBN} uses the @sc{gnu} History library, a part of the Readline |
39037522 TT |
22689 | package, to provide the history facility. |
22690 | @ifset SYSTEM_READLINE | |
22691 | @xref{Using History Interactively, , , history, GNU History Library}, | |
22692 | @end ifset | |
22693 | @ifclear SYSTEM_READLINE | |
22694 | @xref{Using History Interactively}, | |
22695 | @end ifclear | |
22696 | for the detailed description of the History library. | |
703663ab | 22697 | |
d620b259 | 22698 | To issue a command to @value{GDBN} without affecting certain aspects of |
9e6c4bd5 NR |
22699 | the state which is seen by users, prefix it with @samp{server } |
22700 | (@pxref{Server Prefix}). This | |
d620b259 NR |
22701 | means that this command will not affect the command history, nor will it |
22702 | affect @value{GDBN}'s notion of which command to repeat if @key{RET} is | |
22703 | pressed on a line by itself. | |
22704 | ||
22705 | @cindex @code{server}, command prefix | |
22706 | The server prefix does not affect the recording of values into the value | |
22707 | history; to print a value without recording it into the value history, | |
22708 | use the @code{output} command instead of the @code{print} command. | |
22709 | ||
703663ab EZ |
22710 | Here is the description of @value{GDBN} commands related to command |
22711 | history. | |
22712 | ||
104c1213 | 22713 | @table @code |
8e04817f AC |
22714 | @cindex history substitution |
22715 | @cindex history file | |
22716 | @kindex set history filename | |
4644b6e3 | 22717 | @cindex @env{GDBHISTFILE}, environment variable |
8e04817f AC |
22718 | @item set history filename @var{fname} |
22719 | Set the name of the @value{GDBN} command history file to @var{fname}. | |
22720 | This is the file where @value{GDBN} reads an initial command history | |
22721 | list, and where it writes the command history from this session when it | |
22722 | exits. You can access this list through history expansion or through | |
22723 | the history command editing characters listed below. This file defaults | |
22724 | to the value of the environment variable @code{GDBHISTFILE}, or to | |
22725 | @file{./.gdb_history} (@file{./_gdb_history} on MS-DOS) if this variable | |
22726 | is not set. | |
104c1213 | 22727 | |
9c16f35a EZ |
22728 | @cindex save command history |
22729 | @kindex set history save | |
8e04817f AC |
22730 | @item set history save |
22731 | @itemx set history save on | |
22732 | Record command history in a file, whose name may be specified with the | |
22733 | @code{set history filename} command. By default, this option is disabled. | |
104c1213 | 22734 | |
8e04817f AC |
22735 | @item set history save off |
22736 | Stop recording command history in a file. | |
104c1213 | 22737 | |
8e04817f | 22738 | @cindex history size |
9c16f35a | 22739 | @kindex set history size |
b58c513b | 22740 | @cindex @env{GDBHISTSIZE}, environment variable |
8e04817f | 22741 | @item set history size @var{size} |
f81d1120 | 22742 | @itemx set history size unlimited |
8e04817f | 22743 | Set the number of commands which @value{GDBN} keeps in its history list. |
bc460514 PP |
22744 | This defaults to the value of the environment variable @env{GDBHISTSIZE}, or |
22745 | to 256 if this variable is not set. Non-numeric values of @env{GDBHISTSIZE} | |
0eacb298 PP |
22746 | are ignored. If @var{size} is @code{unlimited} or if @env{GDBHISTSIZE} is |
22747 | either a negative number or the empty string, then the number of commands | |
22748 | @value{GDBN} keeps in the history list is unlimited. | |
fc637f04 PP |
22749 | |
22750 | @cindex remove duplicate history | |
22751 | @kindex set history remove-duplicates | |
22752 | @item set history remove-duplicates @var{count} | |
22753 | @itemx set history remove-duplicates unlimited | |
22754 | Control the removal of duplicate history entries in the command history list. | |
22755 | If @var{count} is non-zero, @value{GDBN} will look back at the last @var{count} | |
22756 | history entries and remove the first entry that is a duplicate of the current | |
22757 | entry being added to the command history list. If @var{count} is | |
22758 | @code{unlimited} then this lookbehind is unbounded. If @var{count} is 0, then | |
22759 | removal of duplicate history entries is disabled. | |
22760 | ||
22761 | Only history entries added during the current session are considered for | |
22762 | removal. This option is set to 0 by default. | |
22763 | ||
104c1213 JM |
22764 | @end table |
22765 | ||
8e04817f | 22766 | History expansion assigns special meaning to the character @kbd{!}. |
39037522 TT |
22767 | @ifset SYSTEM_READLINE |
22768 | @xref{Event Designators, , , history, GNU History Library}, | |
22769 | @end ifset | |
22770 | @ifclear SYSTEM_READLINE | |
22771 | @xref{Event Designators}, | |
22772 | @end ifclear | |
22773 | for more details. | |
8e04817f | 22774 | |
703663ab | 22775 | @cindex history expansion, turn on/off |
8e04817f AC |
22776 | Since @kbd{!} is also the logical not operator in C, history expansion |
22777 | is off by default. If you decide to enable history expansion with the | |
22778 | @code{set history expansion on} command, you may sometimes need to | |
22779 | follow @kbd{!} (when it is used as logical not, in an expression) with | |
22780 | a space or a tab to prevent it from being expanded. The readline | |
22781 | history facilities do not attempt substitution on the strings | |
22782 | @kbd{!=} and @kbd{!(}, even when history expansion is enabled. | |
22783 | ||
22784 | The commands to control history expansion are: | |
104c1213 JM |
22785 | |
22786 | @table @code | |
8e04817f AC |
22787 | @item set history expansion on |
22788 | @itemx set history expansion | |
703663ab | 22789 | @kindex set history expansion |
8e04817f | 22790 | Enable history expansion. History expansion is off by default. |
104c1213 | 22791 | |
8e04817f AC |
22792 | @item set history expansion off |
22793 | Disable history expansion. | |
104c1213 | 22794 | |
8e04817f AC |
22795 | @c @group |
22796 | @kindex show history | |
22797 | @item show history | |
22798 | @itemx show history filename | |
22799 | @itemx show history save | |
22800 | @itemx show history size | |
22801 | @itemx show history expansion | |
22802 | These commands display the state of the @value{GDBN} history parameters. | |
22803 | @code{show history} by itself displays all four states. | |
22804 | @c @end group | |
22805 | @end table | |
22806 | ||
22807 | @table @code | |
9c16f35a EZ |
22808 | @kindex show commands |
22809 | @cindex show last commands | |
22810 | @cindex display command history | |
8e04817f AC |
22811 | @item show commands |
22812 | Display the last ten commands in the command history. | |
104c1213 | 22813 | |
8e04817f AC |
22814 | @item show commands @var{n} |
22815 | Print ten commands centered on command number @var{n}. | |
22816 | ||
22817 | @item show commands + | |
22818 | Print ten commands just after the commands last printed. | |
104c1213 JM |
22819 | @end table |
22820 | ||
8e04817f | 22821 | @node Screen Size |
79a6e687 | 22822 | @section Screen Size |
8e04817f | 22823 | @cindex size of screen |
f179cf97 EZ |
22824 | @cindex screen size |
22825 | @cindex pagination | |
22826 | @cindex page size | |
8e04817f | 22827 | @cindex pauses in output |
104c1213 | 22828 | |
8e04817f AC |
22829 | Certain commands to @value{GDBN} may produce large amounts of |
22830 | information output to the screen. To help you read all of it, | |
22831 | @value{GDBN} pauses and asks you for input at the end of each page of | |
22832 | output. Type @key{RET} when you want to continue the output, or @kbd{q} | |
22833 | to discard the remaining output. Also, the screen width setting | |
22834 | determines when to wrap lines of output. Depending on what is being | |
22835 | printed, @value{GDBN} tries to break the line at a readable place, | |
22836 | rather than simply letting it overflow onto the following line. | |
22837 | ||
22838 | Normally @value{GDBN} knows the size of the screen from the terminal | |
22839 | driver software. For example, on Unix @value{GDBN} uses the termcap data base | |
22840 | together with the value of the @code{TERM} environment variable and the | |
22841 | @code{stty rows} and @code{stty cols} settings. If this is not correct, | |
22842 | you can override it with the @code{set height} and @code{set | |
22843 | width} commands: | |
22844 | ||
22845 | @table @code | |
22846 | @kindex set height | |
22847 | @kindex set width | |
22848 | @kindex show width | |
22849 | @kindex show height | |
22850 | @item set height @var{lpp} | |
f81d1120 | 22851 | @itemx set height unlimited |
8e04817f AC |
22852 | @itemx show height |
22853 | @itemx set width @var{cpl} | |
f81d1120 | 22854 | @itemx set width unlimited |
8e04817f AC |
22855 | @itemx show width |
22856 | These @code{set} commands specify a screen height of @var{lpp} lines and | |
22857 | a screen width of @var{cpl} characters. The associated @code{show} | |
22858 | commands display the current settings. | |
104c1213 | 22859 | |
f81d1120 PA |
22860 | If you specify a height of either @code{unlimited} or zero lines, |
22861 | @value{GDBN} does not pause during output no matter how long the | |
22862 | output is. This is useful if output is to a file or to an editor | |
22863 | buffer. | |
104c1213 | 22864 | |
f81d1120 PA |
22865 | Likewise, you can specify @samp{set width unlimited} or @samp{set |
22866 | width 0} to prevent @value{GDBN} from wrapping its output. | |
9c16f35a EZ |
22867 | |
22868 | @item set pagination on | |
22869 | @itemx set pagination off | |
22870 | @kindex set pagination | |
22871 | Turn the output pagination on or off; the default is on. Turning | |
f81d1120 | 22872 | pagination off is the alternative to @code{set height unlimited}. Note that |
7c953934 TT |
22873 | running @value{GDBN} with the @option{--batch} option (@pxref{Mode |
22874 | Options, -batch}) also automatically disables pagination. | |
9c16f35a EZ |
22875 | |
22876 | @item show pagination | |
22877 | @kindex show pagination | |
22878 | Show the current pagination mode. | |
104c1213 JM |
22879 | @end table |
22880 | ||
8e04817f AC |
22881 | @node Numbers |
22882 | @section Numbers | |
22883 | @cindex number representation | |
22884 | @cindex entering numbers | |
104c1213 | 22885 | |
8e04817f AC |
22886 | You can always enter numbers in octal, decimal, or hexadecimal in |
22887 | @value{GDBN} by the usual conventions: octal numbers begin with | |
22888 | @samp{0}, decimal numbers end with @samp{.}, and hexadecimal numbers | |
eb2dae08 EZ |
22889 | begin with @samp{0x}. Numbers that neither begin with @samp{0} or |
22890 | @samp{0x}, nor end with a @samp{.} are, by default, entered in base | |
22891 | 10; likewise, the default display for numbers---when no particular | |
22892 | format is specified---is base 10. You can change the default base for | |
22893 | both input and output with the commands described below. | |
104c1213 | 22894 | |
8e04817f AC |
22895 | @table @code |
22896 | @kindex set input-radix | |
22897 | @item set input-radix @var{base} | |
22898 | Set the default base for numeric input. Supported choices | |
697aa1b7 | 22899 | for @var{base} are decimal 8, 10, or 16. The base must itself be |
eb2dae08 | 22900 | specified either unambiguously or using the current input radix; for |
8e04817f | 22901 | example, any of |
104c1213 | 22902 | |
8e04817f | 22903 | @smallexample |
9c16f35a EZ |
22904 | set input-radix 012 |
22905 | set input-radix 10. | |
22906 | set input-radix 0xa | |
8e04817f | 22907 | @end smallexample |
104c1213 | 22908 | |
8e04817f | 22909 | @noindent |
9c16f35a | 22910 | sets the input base to decimal. On the other hand, @samp{set input-radix 10} |
eb2dae08 EZ |
22911 | leaves the input radix unchanged, no matter what it was, since |
22912 | @samp{10}, being without any leading or trailing signs of its base, is | |
22913 | interpreted in the current radix. Thus, if the current radix is 16, | |
22914 | @samp{10} is interpreted in hex, i.e.@: as 16 decimal, which doesn't | |
22915 | change the radix. | |
104c1213 | 22916 | |
8e04817f AC |
22917 | @kindex set output-radix |
22918 | @item set output-radix @var{base} | |
22919 | Set the default base for numeric display. Supported choices | |
697aa1b7 | 22920 | for @var{base} are decimal 8, 10, or 16. The base must itself be |
eb2dae08 | 22921 | specified either unambiguously or using the current input radix. |
104c1213 | 22922 | |
8e04817f AC |
22923 | @kindex show input-radix |
22924 | @item show input-radix | |
22925 | Display the current default base for numeric input. | |
104c1213 | 22926 | |
8e04817f AC |
22927 | @kindex show output-radix |
22928 | @item show output-radix | |
22929 | Display the current default base for numeric display. | |
9c16f35a EZ |
22930 | |
22931 | @item set radix @r{[}@var{base}@r{]} | |
22932 | @itemx show radix | |
22933 | @kindex set radix | |
22934 | @kindex show radix | |
22935 | These commands set and show the default base for both input and output | |
22936 | of numbers. @code{set radix} sets the radix of input and output to | |
22937 | the same base; without an argument, it resets the radix back to its | |
22938 | default value of 10. | |
22939 | ||
8e04817f | 22940 | @end table |
104c1213 | 22941 | |
1e698235 | 22942 | @node ABI |
79a6e687 | 22943 | @section Configuring the Current ABI |
1e698235 DJ |
22944 | |
22945 | @value{GDBN} can determine the @dfn{ABI} (Application Binary Interface) of your | |
22946 | application automatically. However, sometimes you need to override its | |
22947 | conclusions. Use these commands to manage @value{GDBN}'s view of the | |
22948 | current ABI. | |
22949 | ||
98b45e30 DJ |
22950 | @cindex OS ABI |
22951 | @kindex set osabi | |
b4e9345d | 22952 | @kindex show osabi |
430ed3f0 | 22953 | @cindex Newlib OS ABI and its influence on the longjmp handling |
98b45e30 DJ |
22954 | |
22955 | One @value{GDBN} configuration can debug binaries for multiple operating | |
b383017d | 22956 | system targets, either via remote debugging or native emulation. |
98b45e30 DJ |
22957 | @value{GDBN} will autodetect the @dfn{OS ABI} (Operating System ABI) in use, |
22958 | but you can override its conclusion using the @code{set osabi} command. | |
22959 | One example where this is useful is in debugging of binaries which use | |
22960 | an alternate C library (e.g.@: @sc{uClibc} for @sc{gnu}/Linux) which does | |
22961 | not have the same identifying marks that the standard C library for your | |
22962 | platform provides. | |
22963 | ||
430ed3f0 MS |
22964 | When @value{GDBN} is debugging the AArch64 architecture, it provides a |
22965 | ``Newlib'' OS ABI. This is useful for handling @code{setjmp} and | |
22966 | @code{longjmp} when debugging binaries that use the @sc{newlib} C library. | |
22967 | The ``Newlib'' OS ABI can be selected by @code{set osabi Newlib}. | |
22968 | ||
98b45e30 DJ |
22969 | @table @code |
22970 | @item show osabi | |
22971 | Show the OS ABI currently in use. | |
22972 | ||
22973 | @item set osabi | |
22974 | With no argument, show the list of registered available OS ABI's. | |
22975 | ||
22976 | @item set osabi @var{abi} | |
22977 | Set the current OS ABI to @var{abi}. | |
22978 | @end table | |
22979 | ||
1e698235 | 22980 | @cindex float promotion |
1e698235 DJ |
22981 | |
22982 | Generally, the way that an argument of type @code{float} is passed to a | |
22983 | function depends on whether the function is prototyped. For a prototyped | |
22984 | (i.e.@: ANSI/ISO style) function, @code{float} arguments are passed unchanged, | |
22985 | according to the architecture's convention for @code{float}. For unprototyped | |
22986 | (i.e.@: K&R style) functions, @code{float} arguments are first promoted to type | |
22987 | @code{double} and then passed. | |
22988 | ||
22989 | Unfortunately, some forms of debug information do not reliably indicate whether | |
22990 | a function is prototyped. If @value{GDBN} calls a function that is not marked | |
22991 | as prototyped, it consults @kbd{set coerce-float-to-double}. | |
22992 | ||
22993 | @table @code | |
a8f24a35 | 22994 | @kindex set coerce-float-to-double |
1e698235 DJ |
22995 | @item set coerce-float-to-double |
22996 | @itemx set coerce-float-to-double on | |
22997 | Arguments of type @code{float} will be promoted to @code{double} when passed | |
22998 | to an unprototyped function. This is the default setting. | |
22999 | ||
23000 | @item set coerce-float-to-double off | |
23001 | Arguments of type @code{float} will be passed directly to unprototyped | |
23002 | functions. | |
9c16f35a EZ |
23003 | |
23004 | @kindex show coerce-float-to-double | |
23005 | @item show coerce-float-to-double | |
23006 | Show the current setting of promoting @code{float} to @code{double}. | |
1e698235 DJ |
23007 | @end table |
23008 | ||
f1212245 DJ |
23009 | @kindex set cp-abi |
23010 | @kindex show cp-abi | |
23011 | @value{GDBN} needs to know the ABI used for your program's C@t{++} | |
23012 | objects. The correct C@t{++} ABI depends on which C@t{++} compiler was | |
23013 | used to build your application. @value{GDBN} only fully supports | |
23014 | programs with a single C@t{++} ABI; if your program contains code using | |
23015 | multiple C@t{++} ABI's or if @value{GDBN} can not identify your | |
23016 | program's ABI correctly, you can tell @value{GDBN} which ABI to use. | |
23017 | Currently supported ABI's include ``gnu-v2'', for @code{g++} versions | |
23018 | before 3.0, ``gnu-v3'', for @code{g++} versions 3.0 and later, and | |
23019 | ``hpaCC'' for the HP ANSI C@t{++} compiler. Other C@t{++} compilers may | |
23020 | use the ``gnu-v2'' or ``gnu-v3'' ABI's as well. The default setting is | |
23021 | ``auto''. | |
23022 | ||
23023 | @table @code | |
23024 | @item show cp-abi | |
23025 | Show the C@t{++} ABI currently in use. | |
23026 | ||
23027 | @item set cp-abi | |
23028 | With no argument, show the list of supported C@t{++} ABI's. | |
23029 | ||
23030 | @item set cp-abi @var{abi} | |
23031 | @itemx set cp-abi auto | |
23032 | Set the current C@t{++} ABI to @var{abi}, or return to automatic detection. | |
23033 | @end table | |
23034 | ||
bf88dd68 JK |
23035 | @node Auto-loading |
23036 | @section Automatically loading associated files | |
23037 | @cindex auto-loading | |
23038 | ||
23039 | @value{GDBN} sometimes reads files with commands and settings automatically, | |
23040 | without being explicitly told so by the user. We call this feature | |
23041 | @dfn{auto-loading}. While auto-loading is useful for automatically adapting | |
23042 | @value{GDBN} to the needs of your project, it can sometimes produce unexpected | |
23043 | results or introduce security risks (e.g., if the file comes from untrusted | |
23044 | sources). | |
23045 | ||
71b8c845 DE |
23046 | @menu |
23047 | * Init File in the Current Directory:: @samp{set/show/info auto-load local-gdbinit} | |
23048 | * libthread_db.so.1 file:: @samp{set/show/info auto-load libthread-db} | |
23049 | ||
23050 | * Auto-loading safe path:: @samp{set/show/info auto-load safe-path} | |
23051 | * Auto-loading verbose mode:: @samp{set/show debug auto-load} | |
23052 | @end menu | |
23053 | ||
23054 | There are various kinds of files @value{GDBN} can automatically load. | |
23055 | In addition to these files, @value{GDBN} supports auto-loading code written | |
23056 | in various extension languages. @xref{Auto-loading extensions}. | |
23057 | ||
c1668e4e JK |
23058 | Note that loading of these associated files (including the local @file{.gdbinit} |
23059 | file) requires accordingly configured @code{auto-load safe-path} | |
23060 | (@pxref{Auto-loading safe path}). | |
23061 | ||
bf88dd68 JK |
23062 | For these reasons, @value{GDBN} includes commands and options to let you |
23063 | control when to auto-load files and which files should be auto-loaded. | |
23064 | ||
23065 | @table @code | |
23066 | @anchor{set auto-load off} | |
23067 | @kindex set auto-load off | |
23068 | @item set auto-load off | |
23069 | Globally disable loading of all auto-loaded files. | |
23070 | You may want to use this command with the @samp{-iex} option | |
23071 | (@pxref{Option -init-eval-command}) such as: | |
23072 | @smallexample | |
23073 | $ @kbd{gdb -iex "set auto-load off" untrusted-executable corefile} | |
23074 | @end smallexample | |
23075 | ||
23076 | Be aware that system init file (@pxref{System-wide configuration}) | |
23077 | and init files from your home directory (@pxref{Home Directory Init File}) | |
23078 | still get read (as they come from generally trusted directories). | |
23079 | To prevent @value{GDBN} from auto-loading even those init files, use the | |
23080 | @option{-nx} option (@pxref{Mode Options}), in addition to | |
23081 | @code{set auto-load no}. | |
23082 | ||
23083 | @anchor{show auto-load} | |
23084 | @kindex show auto-load | |
23085 | @item show auto-load | |
23086 | Show whether auto-loading of each specific @samp{auto-load} file(s) is enabled | |
23087 | or disabled. | |
23088 | ||
23089 | @smallexample | |
23090 | (gdb) show auto-load | |
23091 | gdb-scripts: Auto-loading of canned sequences of commands scripts is on. | |
23092 | libthread-db: Auto-loading of inferior specific libthread_db is on. | |
1ccacbcd JK |
23093 | local-gdbinit: Auto-loading of .gdbinit script from current directory |
23094 | is on. | |
bf88dd68 | 23095 | python-scripts: Auto-loading of Python scripts is on. |
bccbefd2 | 23096 | safe-path: List of directories from which it is safe to auto-load files |
1564a261 | 23097 | is $debugdir:$datadir/auto-load. |
7349ff92 | 23098 | scripts-directory: List of directories from which to load auto-loaded scripts |
1564a261 | 23099 | is $debugdir:$datadir/auto-load. |
bf88dd68 JK |
23100 | @end smallexample |
23101 | ||
23102 | @anchor{info auto-load} | |
23103 | @kindex info auto-load | |
23104 | @item info auto-load | |
23105 | Print whether each specific @samp{auto-load} file(s) have been auto-loaded or | |
23106 | not. | |
23107 | ||
23108 | @smallexample | |
23109 | (gdb) info auto-load | |
23110 | gdb-scripts: | |
23111 | Loaded Script | |
23112 | Yes /home/user/gdb/gdb-gdb.gdb | |
23113 | libthread-db: No auto-loaded libthread-db. | |
1ccacbcd JK |
23114 | local-gdbinit: Local .gdbinit file "/home/user/gdb/.gdbinit" has been |
23115 | loaded. | |
bf88dd68 JK |
23116 | python-scripts: |
23117 | Loaded Script | |
23118 | Yes /home/user/gdb/gdb-gdb.py | |
23119 | @end smallexample | |
23120 | @end table | |
23121 | ||
bf88dd68 JK |
23122 | These are @value{GDBN} control commands for the auto-loading: |
23123 | ||
23124 | @multitable @columnfractions .5 .5 | |
23125 | @item @xref{set auto-load off}. | |
23126 | @tab Disable auto-loading globally. | |
23127 | @item @xref{show auto-load}. | |
23128 | @tab Show setting of all kinds of files. | |
23129 | @item @xref{info auto-load}. | |
23130 | @tab Show state of all kinds of files. | |
23131 | @item @xref{set auto-load gdb-scripts}. | |
23132 | @tab Control for @value{GDBN} command scripts. | |
23133 | @item @xref{show auto-load gdb-scripts}. | |
23134 | @tab Show setting of @value{GDBN} command scripts. | |
23135 | @item @xref{info auto-load gdb-scripts}. | |
23136 | @tab Show state of @value{GDBN} command scripts. | |
23137 | @item @xref{set auto-load python-scripts}. | |
23138 | @tab Control for @value{GDBN} Python scripts. | |
23139 | @item @xref{show auto-load python-scripts}. | |
23140 | @tab Show setting of @value{GDBN} Python scripts. | |
23141 | @item @xref{info auto-load python-scripts}. | |
23142 | @tab Show state of @value{GDBN} Python scripts. | |
ed3ef339 DE |
23143 | @item @xref{set auto-load guile-scripts}. |
23144 | @tab Control for @value{GDBN} Guile scripts. | |
23145 | @item @xref{show auto-load guile-scripts}. | |
23146 | @tab Show setting of @value{GDBN} Guile scripts. | |
23147 | @item @xref{info auto-load guile-scripts}. | |
23148 | @tab Show state of @value{GDBN} Guile scripts. | |
7349ff92 JK |
23149 | @item @xref{set auto-load scripts-directory}. |
23150 | @tab Control for @value{GDBN} auto-loaded scripts location. | |
23151 | @item @xref{show auto-load scripts-directory}. | |
23152 | @tab Show @value{GDBN} auto-loaded scripts location. | |
f10c5b19 JK |
23153 | @item @xref{add-auto-load-scripts-directory}. |
23154 | @tab Add directory for auto-loaded scripts location list. | |
bf88dd68 JK |
23155 | @item @xref{set auto-load local-gdbinit}. |
23156 | @tab Control for init file in the current directory. | |
23157 | @item @xref{show auto-load local-gdbinit}. | |
23158 | @tab Show setting of init file in the current directory. | |
23159 | @item @xref{info auto-load local-gdbinit}. | |
23160 | @tab Show state of init file in the current directory. | |
23161 | @item @xref{set auto-load libthread-db}. | |
23162 | @tab Control for thread debugging library. | |
23163 | @item @xref{show auto-load libthread-db}. | |
23164 | @tab Show setting of thread debugging library. | |
23165 | @item @xref{info auto-load libthread-db}. | |
23166 | @tab Show state of thread debugging library. | |
bccbefd2 JK |
23167 | @item @xref{set auto-load safe-path}. |
23168 | @tab Control directories trusted for automatic loading. | |
23169 | @item @xref{show auto-load safe-path}. | |
23170 | @tab Show directories trusted for automatic loading. | |
23171 | @item @xref{add-auto-load-safe-path}. | |
23172 | @tab Add directory trusted for automatic loading. | |
bf88dd68 JK |
23173 | @end multitable |
23174 | ||
bf88dd68 JK |
23175 | @node Init File in the Current Directory |
23176 | @subsection Automatically loading init file in the current directory | |
23177 | @cindex auto-loading init file in the current directory | |
23178 | ||
23179 | By default, @value{GDBN} reads and executes the canned sequences of commands | |
23180 | from init file (if any) in the current working directory, | |
23181 | see @ref{Init File in the Current Directory during Startup}. | |
23182 | ||
c1668e4e JK |
23183 | Note that loading of this local @file{.gdbinit} file also requires accordingly |
23184 | configured @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
23185 | ||
bf88dd68 JK |
23186 | @table @code |
23187 | @anchor{set auto-load local-gdbinit} | |
23188 | @kindex set auto-load local-gdbinit | |
23189 | @item set auto-load local-gdbinit [on|off] | |
23190 | Enable or disable the auto-loading of canned sequences of commands | |
23191 | (@pxref{Sequences}) found in init file in the current directory. | |
23192 | ||
23193 | @anchor{show auto-load local-gdbinit} | |
23194 | @kindex show auto-load local-gdbinit | |
23195 | @item show auto-load local-gdbinit | |
23196 | Show whether auto-loading of canned sequences of commands from init file in the | |
23197 | current directory is enabled or disabled. | |
23198 | ||
23199 | @anchor{info auto-load local-gdbinit} | |
23200 | @kindex info auto-load local-gdbinit | |
23201 | @item info auto-load local-gdbinit | |
23202 | Print whether canned sequences of commands from init file in the | |
23203 | current directory have been auto-loaded. | |
23204 | @end table | |
23205 | ||
23206 | @node libthread_db.so.1 file | |
23207 | @subsection Automatically loading thread debugging library | |
23208 | @cindex auto-loading libthread_db.so.1 | |
23209 | ||
23210 | This feature is currently present only on @sc{gnu}/Linux native hosts. | |
23211 | ||
23212 | @value{GDBN} reads in some cases thread debugging library from places specific | |
23213 | to the inferior (@pxref{set libthread-db-search-path}). | |
23214 | ||
23215 | The special @samp{libthread-db-search-path} entry @samp{$sdir} is processed | |
23216 | without checking this @samp{set auto-load libthread-db} switch as system | |
23217 | libraries have to be trusted in general. In all other cases of | |
23218 | @samp{libthread-db-search-path} entries @value{GDBN} checks first if @samp{set | |
23219 | auto-load libthread-db} is enabled before trying to open such thread debugging | |
23220 | library. | |
23221 | ||
c1668e4e JK |
23222 | Note that loading of this debugging library also requires accordingly configured |
23223 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
23224 | ||
bf88dd68 JK |
23225 | @table @code |
23226 | @anchor{set auto-load libthread-db} | |
23227 | @kindex set auto-load libthread-db | |
23228 | @item set auto-load libthread-db [on|off] | |
23229 | Enable or disable the auto-loading of inferior specific thread debugging library. | |
23230 | ||
23231 | @anchor{show auto-load libthread-db} | |
23232 | @kindex show auto-load libthread-db | |
23233 | @item show auto-load libthread-db | |
23234 | Show whether auto-loading of inferior specific thread debugging library is | |
23235 | enabled or disabled. | |
23236 | ||
23237 | @anchor{info auto-load libthread-db} | |
23238 | @kindex info auto-load libthread-db | |
23239 | @item info auto-load libthread-db | |
23240 | Print the list of all loaded inferior specific thread debugging libraries and | |
23241 | for each such library print list of inferior @var{pid}s using it. | |
23242 | @end table | |
23243 | ||
bccbefd2 JK |
23244 | @node Auto-loading safe path |
23245 | @subsection Security restriction for auto-loading | |
23246 | @cindex auto-loading safe-path | |
23247 | ||
23248 | As the files of inferior can come from untrusted source (such as submitted by | |
23249 | an application user) @value{GDBN} does not always load any files automatically. | |
23250 | @value{GDBN} provides the @samp{set auto-load safe-path} setting to list | |
23251 | directories trusted for loading files not explicitly requested by user. | |
202cbf1c | 23252 | Each directory can also be a shell wildcard pattern. |
bccbefd2 JK |
23253 | |
23254 | If the path is not set properly you will see a warning and the file will not | |
23255 | get loaded: | |
23256 | ||
23257 | @smallexample | |
23258 | $ ./gdb -q ./gdb | |
23259 | Reading symbols from /home/user/gdb/gdb...done. | |
23260 | warning: File "/home/user/gdb/gdb-gdb.gdb" auto-loading has been | |
1564a261 JK |
23261 | declined by your `auto-load safe-path' set |
23262 | to "$debugdir:$datadir/auto-load". | |
bccbefd2 | 23263 | warning: File "/home/user/gdb/gdb-gdb.py" auto-loading has been |
1564a261 JK |
23264 | declined by your `auto-load safe-path' set |
23265 | to "$debugdir:$datadir/auto-load". | |
bccbefd2 JK |
23266 | @end smallexample |
23267 | ||
2c91021c JK |
23268 | @noindent |
23269 | To instruct @value{GDBN} to go ahead and use the init files anyway, | |
23270 | invoke @value{GDBN} like this: | |
23271 | ||
23272 | @smallexample | |
23273 | $ gdb -q -iex "set auto-load safe-path /home/user/gdb" ./gdb | |
23274 | @end smallexample | |
23275 | ||
bccbefd2 JK |
23276 | The list of trusted directories is controlled by the following commands: |
23277 | ||
23278 | @table @code | |
23279 | @anchor{set auto-load safe-path} | |
23280 | @kindex set auto-load safe-path | |
af2c1515 | 23281 | @item set auto-load safe-path @r{[}@var{directories}@r{]} |
bccbefd2 JK |
23282 | Set the list of directories (and their subdirectories) trusted for automatic |
23283 | loading and execution of scripts. You can also enter a specific trusted file. | |
202cbf1c JK |
23284 | Each directory can also be a shell wildcard pattern; wildcards do not match |
23285 | directory separator - see @code{FNM_PATHNAME} for system function @code{fnmatch} | |
23286 | (@pxref{Wildcard Matching, fnmatch, , libc, GNU C Library Reference Manual}). | |
af2c1515 JK |
23287 | If you omit @var{directories}, @samp{auto-load safe-path} will be reset to |
23288 | its default value as specified during @value{GDBN} compilation. | |
23289 | ||
d9242c17 | 23290 | The list of directories uses path separator (@samp{:} on GNU and Unix |
bccbefd2 JK |
23291 | systems, @samp{;} on MS-Windows and MS-DOS) to separate directories, similarly |
23292 | to the @env{PATH} environment variable. | |
23293 | ||
23294 | @anchor{show auto-load safe-path} | |
23295 | @kindex show auto-load safe-path | |
23296 | @item show auto-load safe-path | |
23297 | Show the list of directories trusted for automatic loading and execution of | |
23298 | scripts. | |
23299 | ||
23300 | @anchor{add-auto-load-safe-path} | |
23301 | @kindex add-auto-load-safe-path | |
23302 | @item add-auto-load-safe-path | |
413b59ae JK |
23303 | Add an entry (or list of entries) to the list of directories trusted for |
23304 | automatic loading and execution of scripts. Multiple entries may be delimited | |
23305 | by the host platform path separator in use. | |
bccbefd2 JK |
23306 | @end table |
23307 | ||
7349ff92 | 23308 | This variable defaults to what @code{--with-auto-load-dir} has been configured |
1564a261 JK |
23309 | to (@pxref{with-auto-load-dir}). @file{$debugdir} and @file{$datadir} |
23310 | substitution applies the same as for @ref{set auto-load scripts-directory}. | |
23311 | The default @code{set auto-load safe-path} value can be also overriden by | |
23312 | @value{GDBN} configuration option @option{--with-auto-load-safe-path}. | |
6dea1fbd | 23313 | |
6dea1fbd JK |
23314 | Setting this variable to @file{/} disables this security protection, |
23315 | corresponding @value{GDBN} configuration option is | |
23316 | @option{--without-auto-load-safe-path}. | |
bccbefd2 JK |
23317 | This variable is supposed to be set to the system directories writable by the |
23318 | system superuser only. Users can add their source directories in init files in | |
23319 | their home directories (@pxref{Home Directory Init File}). See also deprecated | |
23320 | init file in the current directory | |
23321 | (@pxref{Init File in the Current Directory during Startup}). | |
23322 | ||
23323 | To force @value{GDBN} to load the files it declined to load in the previous | |
23324 | example, you could use one of the following ways: | |
23325 | ||
0511cc75 JK |
23326 | @table @asis |
23327 | @item @file{~/.gdbinit}: @samp{add-auto-load-safe-path ~/src/gdb} | |
bccbefd2 JK |
23328 | Specify this trusted directory (or a file) as additional component of the list. |
23329 | You have to specify also any existing directories displayed by | |
23330 | by @samp{show auto-load safe-path} (such as @samp{/usr:/bin} in this example). | |
23331 | ||
174bb630 | 23332 | @item @kbd{gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" @dots{}} |
bccbefd2 JK |
23333 | Specify this directory as in the previous case but just for a single |
23334 | @value{GDBN} session. | |
23335 | ||
af2c1515 | 23336 | @item @kbd{gdb -iex "set auto-load safe-path /" @dots{}} |
bccbefd2 JK |
23337 | Disable auto-loading safety for a single @value{GDBN} session. |
23338 | This assumes all the files you debug during this @value{GDBN} session will come | |
23339 | from trusted sources. | |
23340 | ||
23341 | @item @kbd{./configure --without-auto-load-safe-path} | |
23342 | During compilation of @value{GDBN} you may disable any auto-loading safety. | |
23343 | This assumes all the files you will ever debug with this @value{GDBN} come from | |
23344 | trusted sources. | |
0511cc75 | 23345 | @end table |
bccbefd2 JK |
23346 | |
23347 | On the other hand you can also explicitly forbid automatic files loading which | |
23348 | also suppresses any such warning messages: | |
23349 | ||
0511cc75 | 23350 | @table @asis |
174bb630 | 23351 | @item @kbd{gdb -iex "set auto-load no" @dots{}} |
bccbefd2 JK |
23352 | You can use @value{GDBN} command-line option for a single @value{GDBN} session. |
23353 | ||
0511cc75 | 23354 | @item @file{~/.gdbinit}: @samp{set auto-load no} |
bccbefd2 JK |
23355 | Disable auto-loading globally for the user |
23356 | (@pxref{Home Directory Init File}). While it is improbable, you could also | |
23357 | use system init file instead (@pxref{System-wide configuration}). | |
0511cc75 | 23358 | @end table |
bccbefd2 JK |
23359 | |
23360 | This setting applies to the file names as entered by user. If no entry matches | |
23361 | @value{GDBN} tries as a last resort to also resolve all the file names into | |
23362 | their canonical form (typically resolving symbolic links) and compare the | |
23363 | entries again. @value{GDBN} already canonicalizes most of the filenames on its | |
23364 | own before starting the comparison so a canonical form of directories is | |
23365 | recommended to be entered. | |
23366 | ||
4dc84fd1 JK |
23367 | @node Auto-loading verbose mode |
23368 | @subsection Displaying files tried for auto-load | |
23369 | @cindex auto-loading verbose mode | |
23370 | ||
23371 | For better visibility of all the file locations where you can place scripts to | |
23372 | be auto-loaded with inferior --- or to protect yourself against accidental | |
23373 | execution of untrusted scripts --- @value{GDBN} provides a feature for printing | |
23374 | all the files attempted to be loaded. Both existing and non-existing files may | |
23375 | be printed. | |
23376 | ||
23377 | For example the list of directories from which it is safe to auto-load files | |
23378 | (@pxref{Auto-loading safe path}) applies also to canonicalized filenames which | |
23379 | may not be too obvious while setting it up. | |
23380 | ||
23381 | @smallexample | |
0070f25a | 23382 | (gdb) set debug auto-load on |
4dc84fd1 JK |
23383 | (gdb) file ~/src/t/true |
23384 | auto-load: Loading canned sequences of commands script "/tmp/true-gdb.gdb" | |
23385 | for objfile "/tmp/true". | |
23386 | auto-load: Updating directories of "/usr:/opt". | |
23387 | auto-load: Using directory "/usr". | |
23388 | auto-load: Using directory "/opt". | |
23389 | warning: File "/tmp/true-gdb.gdb" auto-loading has been declined | |
23390 | by your `auto-load safe-path' set to "/usr:/opt". | |
23391 | @end smallexample | |
23392 | ||
23393 | @table @code | |
23394 | @anchor{set debug auto-load} | |
23395 | @kindex set debug auto-load | |
23396 | @item set debug auto-load [on|off] | |
23397 | Set whether to print the filenames attempted to be auto-loaded. | |
23398 | ||
23399 | @anchor{show debug auto-load} | |
23400 | @kindex show debug auto-load | |
23401 | @item show debug auto-load | |
23402 | Show whether printing of the filenames attempted to be auto-loaded is turned | |
23403 | on or off. | |
23404 | @end table | |
23405 | ||
8e04817f | 23406 | @node Messages/Warnings |
79a6e687 | 23407 | @section Optional Warnings and Messages |
104c1213 | 23408 | |
9c16f35a EZ |
23409 | @cindex verbose operation |
23410 | @cindex optional warnings | |
8e04817f AC |
23411 | By default, @value{GDBN} is silent about its inner workings. If you are |
23412 | running on a slow machine, you may want to use the @code{set verbose} | |
23413 | command. This makes @value{GDBN} tell you when it does a lengthy | |
23414 | internal operation, so you will not think it has crashed. | |
104c1213 | 23415 | |
8e04817f AC |
23416 | Currently, the messages controlled by @code{set verbose} are those |
23417 | which announce that the symbol table for a source file is being read; | |
79a6e687 | 23418 | see @code{symbol-file} in @ref{Files, ,Commands to Specify Files}. |
104c1213 | 23419 | |
8e04817f AC |
23420 | @table @code |
23421 | @kindex set verbose | |
23422 | @item set verbose on | |
23423 | Enables @value{GDBN} output of certain informational messages. | |
104c1213 | 23424 | |
8e04817f AC |
23425 | @item set verbose off |
23426 | Disables @value{GDBN} output of certain informational messages. | |
104c1213 | 23427 | |
8e04817f AC |
23428 | @kindex show verbose |
23429 | @item show verbose | |
23430 | Displays whether @code{set verbose} is on or off. | |
23431 | @end table | |
104c1213 | 23432 | |
8e04817f AC |
23433 | By default, if @value{GDBN} encounters bugs in the symbol table of an |
23434 | object file, it is silent; but if you are debugging a compiler, you may | |
79a6e687 BW |
23435 | find this information useful (@pxref{Symbol Errors, ,Errors Reading |
23436 | Symbol Files}). | |
104c1213 | 23437 | |
8e04817f | 23438 | @table @code |
104c1213 | 23439 | |
8e04817f AC |
23440 | @kindex set complaints |
23441 | @item set complaints @var{limit} | |
23442 | Permits @value{GDBN} to output @var{limit} complaints about each type of | |
23443 | unusual symbols before becoming silent about the problem. Set | |
23444 | @var{limit} to zero to suppress all complaints; set it to a large number | |
23445 | to prevent complaints from being suppressed. | |
104c1213 | 23446 | |
8e04817f AC |
23447 | @kindex show complaints |
23448 | @item show complaints | |
23449 | Displays how many symbol complaints @value{GDBN} is permitted to produce. | |
104c1213 | 23450 | |
8e04817f | 23451 | @end table |
104c1213 | 23452 | |
d837706a | 23453 | @anchor{confirmation requests} |
8e04817f AC |
23454 | By default, @value{GDBN} is cautious, and asks what sometimes seems to be a |
23455 | lot of stupid questions to confirm certain commands. For example, if | |
23456 | you try to run a program which is already running: | |
104c1213 | 23457 | |
474c8240 | 23458 | @smallexample |
8e04817f AC |
23459 | (@value{GDBP}) run |
23460 | The program being debugged has been started already. | |
23461 | Start it from the beginning? (y or n) | |
474c8240 | 23462 | @end smallexample |
104c1213 | 23463 | |
8e04817f AC |
23464 | If you are willing to unflinchingly face the consequences of your own |
23465 | commands, you can disable this ``feature'': | |
104c1213 | 23466 | |
8e04817f | 23467 | @table @code |
104c1213 | 23468 | |
8e04817f AC |
23469 | @kindex set confirm |
23470 | @cindex flinching | |
23471 | @cindex confirmation | |
23472 | @cindex stupid questions | |
23473 | @item set confirm off | |
7c953934 TT |
23474 | Disables confirmation requests. Note that running @value{GDBN} with |
23475 | the @option{--batch} option (@pxref{Mode Options, -batch}) also | |
23476 | automatically disables confirmation requests. | |
104c1213 | 23477 | |
8e04817f AC |
23478 | @item set confirm on |
23479 | Enables confirmation requests (the default). | |
104c1213 | 23480 | |
8e04817f AC |
23481 | @kindex show confirm |
23482 | @item show confirm | |
23483 | Displays state of confirmation requests. | |
23484 | ||
23485 | @end table | |
104c1213 | 23486 | |
16026cd7 AS |
23487 | @cindex command tracing |
23488 | If you need to debug user-defined commands or sourced files you may find it | |
23489 | useful to enable @dfn{command tracing}. In this mode each command will be | |
23490 | printed as it is executed, prefixed with one or more @samp{+} symbols, the | |
23491 | quantity denoting the call depth of each command. | |
23492 | ||
23493 | @table @code | |
23494 | @kindex set trace-commands | |
23495 | @cindex command scripts, debugging | |
23496 | @item set trace-commands on | |
23497 | Enable command tracing. | |
23498 | @item set trace-commands off | |
23499 | Disable command tracing. | |
23500 | @item show trace-commands | |
23501 | Display the current state of command tracing. | |
23502 | @end table | |
23503 | ||
8e04817f | 23504 | @node Debugging Output |
79a6e687 | 23505 | @section Optional Messages about Internal Happenings |
4644b6e3 EZ |
23506 | @cindex optional debugging messages |
23507 | ||
da316a69 EZ |
23508 | @value{GDBN} has commands that enable optional debugging messages from |
23509 | various @value{GDBN} subsystems; normally these commands are of | |
23510 | interest to @value{GDBN} maintainers, or when reporting a bug. This | |
23511 | section documents those commands. | |
23512 | ||
104c1213 | 23513 | @table @code |
a8f24a35 EZ |
23514 | @kindex set exec-done-display |
23515 | @item set exec-done-display | |
23516 | Turns on or off the notification of asynchronous commands' | |
23517 | completion. When on, @value{GDBN} will print a message when an | |
23518 | asynchronous command finishes its execution. The default is off. | |
23519 | @kindex show exec-done-display | |
23520 | @item show exec-done-display | |
23521 | Displays the current setting of asynchronous command completion | |
23522 | notification. | |
4644b6e3 | 23523 | @kindex set debug |
be9a8770 PA |
23524 | @cindex ARM AArch64 |
23525 | @item set debug aarch64 | |
23526 | Turns on or off display of debugging messages related to ARM AArch64. | |
23527 | The default is off. | |
23528 | @kindex show debug | |
23529 | @item show debug aarch64 | |
23530 | Displays the current state of displaying debugging messages related to | |
23531 | ARM AArch64. | |
4644b6e3 | 23532 | @cindex gdbarch debugging info |
a8f24a35 | 23533 | @cindex architecture debugging info |
8e04817f | 23534 | @item set debug arch |
a8f24a35 | 23535 | Turns on or off display of gdbarch debugging info. The default is off |
8e04817f AC |
23536 | @item show debug arch |
23537 | Displays the current state of displaying gdbarch debugging info. | |
9a005eb9 JB |
23538 | @item set debug aix-solib |
23539 | @cindex AIX shared library debugging | |
23540 | Control display of debugging messages from the AIX shared library | |
23541 | support module. The default is off. | |
23542 | @item show debug aix-thread | |
23543 | Show the current state of displaying AIX shared library debugging messages. | |
721c2651 EZ |
23544 | @item set debug aix-thread |
23545 | @cindex AIX threads | |
23546 | Display debugging messages about inner workings of the AIX thread | |
23547 | module. | |
23548 | @item show debug aix-thread | |
23549 | Show the current state of AIX thread debugging info display. | |
900e11f9 JK |
23550 | @item set debug check-physname |
23551 | @cindex physname | |
23552 | Check the results of the ``physname'' computation. When reading DWARF | |
23553 | debugging information for C@t{++}, @value{GDBN} attempts to compute | |
23554 | each entity's name. @value{GDBN} can do this computation in two | |
23555 | different ways, depending on exactly what information is present. | |
23556 | When enabled, this setting causes @value{GDBN} to compute the names | |
23557 | both ways and display any discrepancies. | |
23558 | @item show debug check-physname | |
23559 | Show the current state of ``physname'' checking. | |
be9a8770 PA |
23560 | @item set debug coff-pe-read |
23561 | @cindex COFF/PE exported symbols | |
23562 | Control display of debugging messages related to reading of COFF/PE | |
23563 | exported symbols. The default is off. | |
23564 | @item show debug coff-pe-read | |
23565 | Displays the current state of displaying debugging messages related to | |
23566 | reading of COFF/PE exported symbols. | |
b4f54984 DE |
23567 | @item set debug dwarf-die |
23568 | @cindex DWARF DIEs | |
23569 | Dump DWARF DIEs after they are read in. | |
d97bc12b DE |
23570 | The value is the number of nesting levels to print. |
23571 | A value of zero turns off the display. | |
b4f54984 DE |
23572 | @item show debug dwarf-die |
23573 | Show the current state of DWARF DIE debugging. | |
27e0867f DE |
23574 | @item set debug dwarf-line |
23575 | @cindex DWARF Line Tables | |
23576 | Turns on or off display of debugging messages related to reading | |
23577 | DWARF line tables. The default is 0 (off). | |
23578 | A value of 1 provides basic information. | |
23579 | A value greater than 1 provides more verbose information. | |
23580 | @item show debug dwarf-line | |
23581 | Show the current state of DWARF line table debugging. | |
b4f54984 DE |
23582 | @item set debug dwarf-read |
23583 | @cindex DWARF Reading | |
45cfd468 | 23584 | Turns on or off display of debugging messages related to reading |
73be47f5 DE |
23585 | DWARF debug info. The default is 0 (off). |
23586 | A value of 1 provides basic information. | |
23587 | A value greater than 1 provides more verbose information. | |
b4f54984 DE |
23588 | @item show debug dwarf-read |
23589 | Show the current state of DWARF reader debugging. | |
237fc4c9 PA |
23590 | @item set debug displaced |
23591 | @cindex displaced stepping debugging info | |
23592 | Turns on or off display of @value{GDBN} debugging info for the | |
23593 | displaced stepping support. The default is off. | |
23594 | @item show debug displaced | |
23595 | Displays the current state of displaying @value{GDBN} debugging info | |
23596 | related to displaced stepping. | |
8e04817f | 23597 | @item set debug event |
4644b6e3 | 23598 | @cindex event debugging info |
a8f24a35 | 23599 | Turns on or off display of @value{GDBN} event debugging info. The |
8e04817f | 23600 | default is off. |
8e04817f AC |
23601 | @item show debug event |
23602 | Displays the current state of displaying @value{GDBN} event debugging | |
23603 | info. | |
8e04817f | 23604 | @item set debug expression |
4644b6e3 | 23605 | @cindex expression debugging info |
721c2651 EZ |
23606 | Turns on or off display of debugging info about @value{GDBN} |
23607 | expression parsing. The default is off. | |
8e04817f | 23608 | @item show debug expression |
721c2651 EZ |
23609 | Displays the current state of displaying debugging info about |
23610 | @value{GDBN} expression parsing. | |
6e9567fe JB |
23611 | @item set debug fbsd-lwp |
23612 | @cindex FreeBSD LWP debug messages | |
23613 | Turns on or off debugging messages from the FreeBSD LWP debug support. | |
23614 | @item show debug fbsd-lwp | |
23615 | Show the current state of FreeBSD LWP debugging messages. | |
7453dc06 | 23616 | @item set debug frame |
4644b6e3 | 23617 | @cindex frame debugging info |
7453dc06 AC |
23618 | Turns on or off display of @value{GDBN} frame debugging info. The |
23619 | default is off. | |
7453dc06 AC |
23620 | @item show debug frame |
23621 | Displays the current state of displaying @value{GDBN} frame debugging | |
23622 | info. | |
cbe54154 PA |
23623 | @item set debug gnu-nat |
23624 | @cindex @sc{gnu}/Hurd debug messages | |
23625 | Turns on or off debugging messages from the @sc{gnu}/Hurd debug support. | |
23626 | @item show debug gnu-nat | |
23627 | Show the current state of @sc{gnu}/Hurd debugging messages. | |
30e91e0b RC |
23628 | @item set debug infrun |
23629 | @cindex inferior debugging info | |
23630 | Turns on or off display of @value{GDBN} debugging info for running the inferior. | |
23631 | The default is off. @file{infrun.c} contains GDB's runtime state machine used | |
23632 | for implementing operations such as single-stepping the inferior. | |
23633 | @item show debug infrun | |
23634 | Displays the current state of @value{GDBN} inferior debugging. | |
a255712f PP |
23635 | @item set debug jit |
23636 | @cindex just-in-time compilation, debugging messages | |
23637 | Turns on or off debugging messages from JIT debug support. | |
23638 | @item show debug jit | |
23639 | Displays the current state of @value{GDBN} JIT debugging. | |
da316a69 EZ |
23640 | @item set debug lin-lwp |
23641 | @cindex @sc{gnu}/Linux LWP debug messages | |
23642 | @cindex Linux lightweight processes | |
721c2651 | 23643 | Turns on or off debugging messages from the Linux LWP debug support. |
da316a69 EZ |
23644 | @item show debug lin-lwp |
23645 | Show the current state of Linux LWP debugging messages. | |
7a6a1731 GB |
23646 | @item set debug linux-namespaces |
23647 | @cindex @sc{gnu}/Linux namespaces debug messages | |
23648 | Turns on or off debugging messages from the Linux namespaces debug support. | |
23649 | @item show debug linux-namespaces | |
23650 | Show the current state of Linux namespaces debugging messages. | |
be9a8770 PA |
23651 | @item set debug mach-o |
23652 | @cindex Mach-O symbols processing | |
23653 | Control display of debugging messages related to Mach-O symbols | |
23654 | processing. The default is off. | |
23655 | @item show debug mach-o | |
23656 | Displays the current state of displaying debugging messages related to | |
23657 | reading of COFF/PE exported symbols. | |
c9b6281a YQ |
23658 | @item set debug notification |
23659 | @cindex remote async notification debugging info | |
23660 | Turns on or off debugging messages about remote async notification. | |
23661 | The default is off. | |
23662 | @item show debug notification | |
23663 | Displays the current state of remote async notification debugging messages. | |
2b4855ab | 23664 | @item set debug observer |
4644b6e3 | 23665 | @cindex observer debugging info |
2b4855ab AC |
23666 | Turns on or off display of @value{GDBN} observer debugging. This |
23667 | includes info such as the notification of observable events. | |
2b4855ab AC |
23668 | @item show debug observer |
23669 | Displays the current state of observer debugging. | |
8e04817f | 23670 | @item set debug overload |
4644b6e3 | 23671 | @cindex C@t{++} overload debugging info |
8e04817f | 23672 | Turns on or off display of @value{GDBN} C@t{++} overload debugging |
359df76b | 23673 | info. This includes info such as ranking of functions, etc. The default |
8e04817f | 23674 | is off. |
8e04817f AC |
23675 | @item show debug overload |
23676 | Displays the current state of displaying @value{GDBN} C@t{++} overload | |
23677 | debugging info. | |
92981e24 TT |
23678 | @cindex expression parser, debugging info |
23679 | @cindex debug expression parser | |
23680 | @item set debug parser | |
23681 | Turns on or off the display of expression parser debugging output. | |
23682 | Internally, this sets the @code{yydebug} variable in the expression | |
23683 | parser. @xref{Tracing, , Tracing Your Parser, bison, Bison}, for | |
23684 | details. The default is off. | |
23685 | @item show debug parser | |
23686 | Show the current state of expression parser debugging. | |
8e04817f AC |
23687 | @cindex packets, reporting on stdout |
23688 | @cindex serial connections, debugging | |
605a56cb DJ |
23689 | @cindex debug remote protocol |
23690 | @cindex remote protocol debugging | |
23691 | @cindex display remote packets | |
8e04817f AC |
23692 | @item set debug remote |
23693 | Turns on or off display of reports on all packets sent back and forth across | |
23694 | the serial line to the remote machine. The info is printed on the | |
23695 | @value{GDBN} standard output stream. The default is off. | |
8e04817f AC |
23696 | @item show debug remote |
23697 | Displays the state of display of remote packets. | |
8e04817f AC |
23698 | @item set debug serial |
23699 | Turns on or off display of @value{GDBN} serial debugging info. The | |
23700 | default is off. | |
8e04817f AC |
23701 | @item show debug serial |
23702 | Displays the current state of displaying @value{GDBN} serial debugging | |
23703 | info. | |
c45da7e6 EZ |
23704 | @item set debug solib-frv |
23705 | @cindex FR-V shared-library debugging | |
23706 | Turns on or off debugging messages for FR-V shared-library code. | |
23707 | @item show debug solib-frv | |
23708 | Display the current state of FR-V shared-library code debugging | |
23709 | messages. | |
cc485e62 DE |
23710 | @item set debug symbol-lookup |
23711 | @cindex symbol lookup | |
23712 | Turns on or off display of debugging messages related to symbol lookup. | |
23713 | The default is 0 (off). | |
23714 | A value of 1 provides basic information. | |
23715 | A value greater than 1 provides more verbose information. | |
23716 | @item show debug symbol-lookup | |
23717 | Show the current state of symbol lookup debugging messages. | |
8fb8eb5c DE |
23718 | @item set debug symfile |
23719 | @cindex symbol file functions | |
23720 | Turns on or off display of debugging messages related to symbol file functions. | |
23721 | The default is off. @xref{Files}. | |
23722 | @item show debug symfile | |
23723 | Show the current state of symbol file debugging messages. | |
45cfd468 DE |
23724 | @item set debug symtab-create |
23725 | @cindex symbol table creation | |
23726 | Turns on or off display of debugging messages related to symbol table creation. | |
db0fec5c DE |
23727 | The default is 0 (off). |
23728 | A value of 1 provides basic information. | |
23729 | A value greater than 1 provides more verbose information. | |
45cfd468 DE |
23730 | @item show debug symtab-create |
23731 | Show the current state of symbol table creation debugging. | |
8e04817f | 23732 | @item set debug target |
4644b6e3 | 23733 | @cindex target debugging info |
8e04817f AC |
23734 | Turns on or off display of @value{GDBN} target debugging info. This info |
23735 | includes what is going on at the target level of GDB, as it happens. The | |
701b08bb | 23736 | default is 0. Set it to 1 to track events, and to 2 to also track the |
3cecbbbe | 23737 | value of large memory transfers. |
8e04817f AC |
23738 | @item show debug target |
23739 | Displays the current state of displaying @value{GDBN} target debugging | |
23740 | info. | |
75feb17d DJ |
23741 | @item set debug timestamp |
23742 | @cindex timestampping debugging info | |
23743 | Turns on or off display of timestamps with @value{GDBN} debugging info. | |
23744 | When enabled, seconds and microseconds are displayed before each debugging | |
23745 | message. | |
23746 | @item show debug timestamp | |
23747 | Displays the current state of displaying timestamps with @value{GDBN} | |
23748 | debugging info. | |
f989a1c8 | 23749 | @item set debug varobj |
4644b6e3 | 23750 | @cindex variable object debugging info |
8e04817f AC |
23751 | Turns on or off display of @value{GDBN} variable object debugging |
23752 | info. The default is off. | |
f989a1c8 | 23753 | @item show debug varobj |
8e04817f AC |
23754 | Displays the current state of displaying @value{GDBN} variable object |
23755 | debugging info. | |
e776119f DJ |
23756 | @item set debug xml |
23757 | @cindex XML parser debugging | |
23758 | Turns on or off debugging messages for built-in XML parsers. | |
23759 | @item show debug xml | |
23760 | Displays the current state of XML debugging messages. | |
8e04817f | 23761 | @end table |
104c1213 | 23762 | |
14fb1bac JB |
23763 | @node Other Misc Settings |
23764 | @section Other Miscellaneous Settings | |
23765 | @cindex miscellaneous settings | |
23766 | ||
23767 | @table @code | |
23768 | @kindex set interactive-mode | |
23769 | @item set interactive-mode | |
7bfc9434 JB |
23770 | If @code{on}, forces @value{GDBN} to assume that GDB was started |
23771 | in a terminal. In practice, this means that @value{GDBN} should wait | |
23772 | for the user to answer queries generated by commands entered at | |
23773 | the command prompt. If @code{off}, forces @value{GDBN} to operate | |
23774 | in the opposite mode, and it uses the default answers to all queries. | |
23775 | If @code{auto} (the default), @value{GDBN} tries to determine whether | |
23776 | its standard input is a terminal, and works in interactive-mode if it | |
23777 | is, non-interactively otherwise. | |
14fb1bac JB |
23778 | |
23779 | In the vast majority of cases, the debugger should be able to guess | |
23780 | correctly which mode should be used. But this setting can be useful | |
23781 | in certain specific cases, such as running a MinGW @value{GDBN} | |
23782 | inside a cygwin window. | |
23783 | ||
23784 | @kindex show interactive-mode | |
23785 | @item show interactive-mode | |
23786 | Displays whether the debugger is operating in interactive mode or not. | |
23787 | @end table | |
23788 | ||
d57a3c85 TJB |
23789 | @node Extending GDB |
23790 | @chapter Extending @value{GDBN} | |
23791 | @cindex extending GDB | |
23792 | ||
71b8c845 DE |
23793 | @value{GDBN} provides several mechanisms for extension. |
23794 | @value{GDBN} also provides the ability to automatically load | |
23795 | extensions when it reads a file for debugging. This allows the | |
23796 | user to automatically customize @value{GDBN} for the program | |
23797 | being debugged. | |
d57a3c85 | 23798 | |
71b8c845 DE |
23799 | @menu |
23800 | * Sequences:: Canned Sequences of @value{GDBN} Commands | |
23801 | * Python:: Extending @value{GDBN} using Python | |
ed3ef339 | 23802 | * Guile:: Extending @value{GDBN} using Guile |
71b8c845 | 23803 | * Auto-loading extensions:: Automatically loading extensions |
ed3ef339 | 23804 | * Multiple Extension Languages:: Working with multiple extension languages |
71b8c845 DE |
23805 | * Aliases:: Creating new spellings of existing commands |
23806 | @end menu | |
23807 | ||
23808 | To facilitate the use of extension languages, @value{GDBN} is capable | |
95433b34 | 23809 | of evaluating the contents of a file. When doing so, @value{GDBN} |
71b8c845 | 23810 | can recognize which extension language is being used by looking at |
95433b34 JB |
23811 | the filename extension. Files with an unrecognized filename extension |
23812 | are always treated as a @value{GDBN} Command Files. | |
23813 | @xref{Command Files,, Command files}. | |
23814 | ||
23815 | You can control how @value{GDBN} evaluates these files with the following | |
23816 | setting: | |
23817 | ||
23818 | @table @code | |
23819 | @kindex set script-extension | |
23820 | @kindex show script-extension | |
23821 | @item set script-extension off | |
23822 | All scripts are always evaluated as @value{GDBN} Command Files. | |
23823 | ||
23824 | @item set script-extension soft | |
23825 | The debugger determines the scripting language based on filename | |
23826 | extension. If this scripting language is supported, @value{GDBN} | |
23827 | evaluates the script using that language. Otherwise, it evaluates | |
23828 | the file as a @value{GDBN} Command File. | |
23829 | ||
23830 | @item set script-extension strict | |
23831 | The debugger determines the scripting language based on filename | |
23832 | extension, and evaluates the script using that language. If the | |
23833 | language is not supported, then the evaluation fails. | |
23834 | ||
23835 | @item show script-extension | |
23836 | Display the current value of the @code{script-extension} option. | |
23837 | ||
23838 | @end table | |
23839 | ||
8e04817f | 23840 | @node Sequences |
d57a3c85 | 23841 | @section Canned Sequences of Commands |
104c1213 | 23842 | |
8e04817f | 23843 | Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint |
79a6e687 | 23844 | Command Lists}), @value{GDBN} provides two ways to store sequences of |
8e04817f AC |
23845 | commands for execution as a unit: user-defined commands and command |
23846 | files. | |
104c1213 | 23847 | |
8e04817f | 23848 | @menu |
fcc73fe3 EZ |
23849 | * Define:: How to define your own commands |
23850 | * Hooks:: Hooks for user-defined commands | |
23851 | * Command Files:: How to write scripts of commands to be stored in a file | |
23852 | * Output:: Commands for controlled output | |
71b8c845 | 23853 | * Auto-loading sequences:: Controlling auto-loaded command files |
8e04817f | 23854 | @end menu |
104c1213 | 23855 | |
8e04817f | 23856 | @node Define |
d57a3c85 | 23857 | @subsection User-defined Commands |
104c1213 | 23858 | |
8e04817f | 23859 | @cindex user-defined command |
fcc73fe3 | 23860 | @cindex arguments, to user-defined commands |
8e04817f AC |
23861 | A @dfn{user-defined command} is a sequence of @value{GDBN} commands to |
23862 | which you assign a new name as a command. This is done with the | |
23863 | @code{define} command. User commands may accept up to 10 arguments | |
23864 | separated by whitespace. Arguments are accessed within the user command | |
c03c782f | 23865 | via @code{$arg0@dots{}$arg9}. A trivial example: |
104c1213 | 23866 | |
8e04817f AC |
23867 | @smallexample |
23868 | define adder | |
23869 | print $arg0 + $arg1 + $arg2 | |
c03c782f | 23870 | end |
8e04817f | 23871 | @end smallexample |
104c1213 JM |
23872 | |
23873 | @noindent | |
8e04817f | 23874 | To execute the command use: |
104c1213 | 23875 | |
8e04817f AC |
23876 | @smallexample |
23877 | adder 1 2 3 | |
23878 | @end smallexample | |
104c1213 | 23879 | |
8e04817f AC |
23880 | @noindent |
23881 | This defines the command @code{adder}, which prints the sum of | |
23882 | its three arguments. Note the arguments are text substitutions, so they may | |
23883 | reference variables, use complex expressions, or even perform inferior | |
23884 | functions calls. | |
104c1213 | 23885 | |
fcc73fe3 EZ |
23886 | @cindex argument count in user-defined commands |
23887 | @cindex how many arguments (user-defined commands) | |
c03c782f AS |
23888 | In addition, @code{$argc} may be used to find out how many arguments have |
23889 | been passed. This expands to a number in the range 0@dots{}10. | |
23890 | ||
23891 | @smallexample | |
23892 | define adder | |
23893 | if $argc == 2 | |
23894 | print $arg0 + $arg1 | |
23895 | end | |
23896 | if $argc == 3 | |
23897 | print $arg0 + $arg1 + $arg2 | |
23898 | end | |
23899 | end | |
23900 | @end smallexample | |
23901 | ||
104c1213 | 23902 | @table @code |
104c1213 | 23903 | |
8e04817f AC |
23904 | @kindex define |
23905 | @item define @var{commandname} | |
23906 | Define a command named @var{commandname}. If there is already a command | |
23907 | by that name, you are asked to confirm that you want to redefine it. | |
697aa1b7 | 23908 | The argument @var{commandname} may be a bare command name consisting of letters, |
adb483fe DJ |
23909 | numbers, dashes, and underscores. It may also start with any predefined |
23910 | prefix command. For example, @samp{define target my-target} creates | |
23911 | a user-defined @samp{target my-target} command. | |
104c1213 | 23912 | |
8e04817f AC |
23913 | The definition of the command is made up of other @value{GDBN} command lines, |
23914 | which are given following the @code{define} command. The end of these | |
23915 | commands is marked by a line containing @code{end}. | |
104c1213 | 23916 | |
8e04817f | 23917 | @kindex document |
ca91424e | 23918 | @kindex end@r{ (user-defined commands)} |
8e04817f AC |
23919 | @item document @var{commandname} |
23920 | Document the user-defined command @var{commandname}, so that it can be | |
23921 | accessed by @code{help}. The command @var{commandname} must already be | |
23922 | defined. This command reads lines of documentation just as @code{define} | |
23923 | reads the lines of the command definition, ending with @code{end}. | |
23924 | After the @code{document} command is finished, @code{help} on command | |
23925 | @var{commandname} displays the documentation you have written. | |
104c1213 | 23926 | |
8e04817f AC |
23927 | You may use the @code{document} command again to change the |
23928 | documentation of a command. Redefining the command with @code{define} | |
23929 | does not change the documentation. | |
104c1213 | 23930 | |
c45da7e6 EZ |
23931 | @kindex dont-repeat |
23932 | @cindex don't repeat command | |
23933 | @item dont-repeat | |
23934 | Used inside a user-defined command, this tells @value{GDBN} that this | |
23935 | command should not be repeated when the user hits @key{RET} | |
23936 | (@pxref{Command Syntax, repeat last command}). | |
23937 | ||
8e04817f AC |
23938 | @kindex help user-defined |
23939 | @item help user-defined | |
7d74f244 DE |
23940 | List all user-defined commands and all python commands defined in class |
23941 | COMAND_USER. The first line of the documentation or docstring is | |
23942 | included (if any). | |
104c1213 | 23943 | |
8e04817f AC |
23944 | @kindex show user |
23945 | @item show user | |
23946 | @itemx show user @var{commandname} | |
23947 | Display the @value{GDBN} commands used to define @var{commandname} (but | |
23948 | not its documentation). If no @var{commandname} is given, display the | |
23949 | definitions for all user-defined commands. | |
7d74f244 | 23950 | This does not work for user-defined python commands. |
104c1213 | 23951 | |
fcc73fe3 | 23952 | @cindex infinite recursion in user-defined commands |
20f01a46 DH |
23953 | @kindex show max-user-call-depth |
23954 | @kindex set max-user-call-depth | |
23955 | @item show max-user-call-depth | |
5ca0cb28 DH |
23956 | @itemx set max-user-call-depth |
23957 | The value of @code{max-user-call-depth} controls how many recursion | |
3f94c067 | 23958 | levels are allowed in user-defined commands before @value{GDBN} suspects an |
5ca0cb28 | 23959 | infinite recursion and aborts the command. |
7d74f244 | 23960 | This does not apply to user-defined python commands. |
104c1213 JM |
23961 | @end table |
23962 | ||
fcc73fe3 EZ |
23963 | In addition to the above commands, user-defined commands frequently |
23964 | use control flow commands, described in @ref{Command Files}. | |
23965 | ||
8e04817f AC |
23966 | When user-defined commands are executed, the |
23967 | commands of the definition are not printed. An error in any command | |
23968 | stops execution of the user-defined command. | |
104c1213 | 23969 | |
8e04817f AC |
23970 | If used interactively, commands that would ask for confirmation proceed |
23971 | without asking when used inside a user-defined command. Many @value{GDBN} | |
23972 | commands that normally print messages to say what they are doing omit the | |
23973 | messages when used in a user-defined command. | |
104c1213 | 23974 | |
8e04817f | 23975 | @node Hooks |
d57a3c85 | 23976 | @subsection User-defined Command Hooks |
8e04817f AC |
23977 | @cindex command hooks |
23978 | @cindex hooks, for commands | |
23979 | @cindex hooks, pre-command | |
104c1213 | 23980 | |
8e04817f | 23981 | @kindex hook |
8e04817f AC |
23982 | You may define @dfn{hooks}, which are a special kind of user-defined |
23983 | command. Whenever you run the command @samp{foo}, if the user-defined | |
23984 | command @samp{hook-foo} exists, it is executed (with no arguments) | |
23985 | before that command. | |
104c1213 | 23986 | |
8e04817f AC |
23987 | @cindex hooks, post-command |
23988 | @kindex hookpost | |
8e04817f AC |
23989 | A hook may also be defined which is run after the command you executed. |
23990 | Whenever you run the command @samp{foo}, if the user-defined command | |
23991 | @samp{hookpost-foo} exists, it is executed (with no arguments) after | |
23992 | that command. Post-execution hooks may exist simultaneously with | |
23993 | pre-execution hooks, for the same command. | |
104c1213 | 23994 | |
8e04817f | 23995 | It is valid for a hook to call the command which it hooks. If this |
9f1c6395 | 23996 | occurs, the hook is not re-executed, thereby avoiding infinite recursion. |
104c1213 | 23997 | |
8e04817f AC |
23998 | @c It would be nice if hookpost could be passed a parameter indicating |
23999 | @c if the command it hooks executed properly or not. FIXME! | |
104c1213 | 24000 | |
8e04817f AC |
24001 | @kindex stop@r{, a pseudo-command} |
24002 | In addition, a pseudo-command, @samp{stop} exists. Defining | |
24003 | (@samp{hook-stop}) makes the associated commands execute every time | |
24004 | execution stops in your program: before breakpoint commands are run, | |
24005 | displays are printed, or the stack frame is printed. | |
104c1213 | 24006 | |
8e04817f AC |
24007 | For example, to ignore @code{SIGALRM} signals while |
24008 | single-stepping, but treat them normally during normal execution, | |
24009 | you could define: | |
104c1213 | 24010 | |
474c8240 | 24011 | @smallexample |
8e04817f AC |
24012 | define hook-stop |
24013 | handle SIGALRM nopass | |
24014 | end | |
104c1213 | 24015 | |
8e04817f AC |
24016 | define hook-run |
24017 | handle SIGALRM pass | |
24018 | end | |
104c1213 | 24019 | |
8e04817f | 24020 | define hook-continue |
d3e8051b | 24021 | handle SIGALRM pass |
8e04817f | 24022 | end |
474c8240 | 24023 | @end smallexample |
104c1213 | 24024 | |
d3e8051b | 24025 | As a further example, to hook at the beginning and end of the @code{echo} |
b383017d | 24026 | command, and to add extra text to the beginning and end of the message, |
8e04817f | 24027 | you could define: |
104c1213 | 24028 | |
474c8240 | 24029 | @smallexample |
8e04817f AC |
24030 | define hook-echo |
24031 | echo <<<--- | |
24032 | end | |
104c1213 | 24033 | |
8e04817f AC |
24034 | define hookpost-echo |
24035 | echo --->>>\n | |
24036 | end | |
104c1213 | 24037 | |
8e04817f AC |
24038 | (@value{GDBP}) echo Hello World |
24039 | <<<---Hello World--->>> | |
24040 | (@value{GDBP}) | |
104c1213 | 24041 | |
474c8240 | 24042 | @end smallexample |
104c1213 | 24043 | |
8e04817f AC |
24044 | You can define a hook for any single-word command in @value{GDBN}, but |
24045 | not for command aliases; you should define a hook for the basic command | |
c1468174 | 24046 | name, e.g.@: @code{backtrace} rather than @code{bt}. |
8e04817f AC |
24047 | @c FIXME! So how does Joe User discover whether a command is an alias |
24048 | @c or not? | |
adb483fe DJ |
24049 | You can hook a multi-word command by adding @code{hook-} or |
24050 | @code{hookpost-} to the last word of the command, e.g.@: | |
24051 | @samp{define target hook-remote} to add a hook to @samp{target remote}. | |
24052 | ||
8e04817f AC |
24053 | If an error occurs during the execution of your hook, execution of |
24054 | @value{GDBN} commands stops and @value{GDBN} issues a prompt | |
24055 | (before the command that you actually typed had a chance to run). | |
104c1213 | 24056 | |
8e04817f AC |
24057 | If you try to define a hook which does not match any known command, you |
24058 | get a warning from the @code{define} command. | |
c906108c | 24059 | |
8e04817f | 24060 | @node Command Files |
d57a3c85 | 24061 | @subsection Command Files |
c906108c | 24062 | |
8e04817f | 24063 | @cindex command files |
fcc73fe3 | 24064 | @cindex scripting commands |
6fc08d32 EZ |
24065 | A command file for @value{GDBN} is a text file made of lines that are |
24066 | @value{GDBN} commands. Comments (lines starting with @kbd{#}) may | |
24067 | also be included. An empty line in a command file does nothing; it | |
24068 | does not mean to repeat the last command, as it would from the | |
24069 | terminal. | |
c906108c | 24070 | |
6fc08d32 | 24071 | You can request the execution of a command file with the @code{source} |
95433b34 JB |
24072 | command. Note that the @code{source} command is also used to evaluate |
24073 | scripts that are not Command Files. The exact behavior can be configured | |
24074 | using the @code{script-extension} setting. | |
24075 | @xref{Extending GDB,, Extending GDB}. | |
c906108c | 24076 | |
8e04817f AC |
24077 | @table @code |
24078 | @kindex source | |
ca91424e | 24079 | @cindex execute commands from a file |
3f7b2faa | 24080 | @item source [-s] [-v] @var{filename} |
8e04817f | 24081 | Execute the command file @var{filename}. |
c906108c SS |
24082 | @end table |
24083 | ||
fcc73fe3 EZ |
24084 | The lines in a command file are generally executed sequentially, |
24085 | unless the order of execution is changed by one of the | |
24086 | @emph{flow-control commands} described below. The commands are not | |
a71ec265 DH |
24087 | printed as they are executed. An error in any command terminates |
24088 | execution of the command file and control is returned to the console. | |
c906108c | 24089 | |
08001717 DE |
24090 | @value{GDBN} first searches for @var{filename} in the current directory. |
24091 | If the file is not found there, and @var{filename} does not specify a | |
24092 | directory, then @value{GDBN} also looks for the file on the source search path | |
24093 | (specified with the @samp{directory} command); | |
24094 | except that @file{$cdir} is not searched because the compilation directory | |
24095 | is not relevant to scripts. | |
4b505b12 | 24096 | |
3f7b2faa DE |
24097 | If @code{-s} is specified, then @value{GDBN} searches for @var{filename} |
24098 | on the search path even if @var{filename} specifies a directory. | |
24099 | The search is done by appending @var{filename} to each element of the | |
24100 | search path. So, for example, if @var{filename} is @file{mylib/myscript} | |
24101 | and the search path contains @file{/home/user} then @value{GDBN} will | |
24102 | look for the script @file{/home/user/mylib/myscript}. | |
24103 | The search is also done if @var{filename} is an absolute path. | |
24104 | For example, if @var{filename} is @file{/tmp/myscript} and | |
24105 | the search path contains @file{/home/user} then @value{GDBN} will | |
24106 | look for the script @file{/home/user/tmp/myscript}. | |
24107 | For DOS-like systems, if @var{filename} contains a drive specification, | |
24108 | it is stripped before concatenation. For example, if @var{filename} is | |
24109 | @file{d:myscript} and the search path contains @file{c:/tmp} then @value{GDBN} | |
24110 | will look for the script @file{c:/tmp/myscript}. | |
24111 | ||
16026cd7 AS |
24112 | If @code{-v}, for verbose mode, is given then @value{GDBN} displays |
24113 | each command as it is executed. The option must be given before | |
24114 | @var{filename}, and is interpreted as part of the filename anywhere else. | |
24115 | ||
8e04817f AC |
24116 | Commands that would ask for confirmation if used interactively proceed |
24117 | without asking when used in a command file. Many @value{GDBN} commands that | |
24118 | normally print messages to say what they are doing omit the messages | |
24119 | when called from command files. | |
c906108c | 24120 | |
8e04817f AC |
24121 | @value{GDBN} also accepts command input from standard input. In this |
24122 | mode, normal output goes to standard output and error output goes to | |
24123 | standard error. Errors in a command file supplied on standard input do | |
6fc08d32 | 24124 | not terminate execution of the command file---execution continues with |
8e04817f | 24125 | the next command. |
c906108c | 24126 | |
474c8240 | 24127 | @smallexample |
8e04817f | 24128 | gdb < cmds > log 2>&1 |
474c8240 | 24129 | @end smallexample |
c906108c | 24130 | |
8e04817f AC |
24131 | (The syntax above will vary depending on the shell used.) This example |
24132 | will execute commands from the file @file{cmds}. All output and errors | |
24133 | would be directed to @file{log}. | |
c906108c | 24134 | |
fcc73fe3 EZ |
24135 | Since commands stored on command files tend to be more general than |
24136 | commands typed interactively, they frequently need to deal with | |
24137 | complicated situations, such as different or unexpected values of | |
24138 | variables and symbols, changes in how the program being debugged is | |
24139 | built, etc. @value{GDBN} provides a set of flow-control commands to | |
24140 | deal with these complexities. Using these commands, you can write | |
24141 | complex scripts that loop over data structures, execute commands | |
24142 | conditionally, etc. | |
24143 | ||
24144 | @table @code | |
24145 | @kindex if | |
24146 | @kindex else | |
24147 | @item if | |
24148 | @itemx else | |
24149 | This command allows to include in your script conditionally executed | |
24150 | commands. The @code{if} command takes a single argument, which is an | |
24151 | expression to evaluate. It is followed by a series of commands that | |
24152 | are executed only if the expression is true (its value is nonzero). | |
24153 | There can then optionally be an @code{else} line, followed by a series | |
24154 | of commands that are only executed if the expression was false. The | |
24155 | end of the list is marked by a line containing @code{end}. | |
24156 | ||
24157 | @kindex while | |
24158 | @item while | |
24159 | This command allows to write loops. Its syntax is similar to | |
24160 | @code{if}: the command takes a single argument, which is an expression | |
24161 | to evaluate, and must be followed by the commands to execute, one per | |
24162 | line, terminated by an @code{end}. These commands are called the | |
24163 | @dfn{body} of the loop. The commands in the body of @code{while} are | |
24164 | executed repeatedly as long as the expression evaluates to true. | |
24165 | ||
24166 | @kindex loop_break | |
24167 | @item loop_break | |
24168 | This command exits the @code{while} loop in whose body it is included. | |
24169 | Execution of the script continues after that @code{while}s @code{end} | |
24170 | line. | |
24171 | ||
24172 | @kindex loop_continue | |
24173 | @item loop_continue | |
24174 | This command skips the execution of the rest of the body of commands | |
24175 | in the @code{while} loop in whose body it is included. Execution | |
24176 | branches to the beginning of the @code{while} loop, where it evaluates | |
24177 | the controlling expression. | |
ca91424e EZ |
24178 | |
24179 | @kindex end@r{ (if/else/while commands)} | |
24180 | @item end | |
24181 | Terminate the block of commands that are the body of @code{if}, | |
24182 | @code{else}, or @code{while} flow-control commands. | |
fcc73fe3 EZ |
24183 | @end table |
24184 | ||
24185 | ||
8e04817f | 24186 | @node Output |
d57a3c85 | 24187 | @subsection Commands for Controlled Output |
c906108c | 24188 | |
8e04817f AC |
24189 | During the execution of a command file or a user-defined command, normal |
24190 | @value{GDBN} output is suppressed; the only output that appears is what is | |
24191 | explicitly printed by the commands in the definition. This section | |
24192 | describes three commands useful for generating exactly the output you | |
24193 | want. | |
c906108c SS |
24194 | |
24195 | @table @code | |
8e04817f AC |
24196 | @kindex echo |
24197 | @item echo @var{text} | |
24198 | @c I do not consider backslash-space a standard C escape sequence | |
24199 | @c because it is not in ANSI. | |
24200 | Print @var{text}. Nonprinting characters can be included in | |
24201 | @var{text} using C escape sequences, such as @samp{\n} to print a | |
24202 | newline. @strong{No newline is printed unless you specify one.} | |
24203 | In addition to the standard C escape sequences, a backslash followed | |
24204 | by a space stands for a space. This is useful for displaying a | |
24205 | string with spaces at the beginning or the end, since leading and | |
24206 | trailing spaces are otherwise trimmed from all arguments. | |
24207 | To print @samp{@w{ }and foo =@w{ }}, use the command | |
24208 | @samp{echo \@w{ }and foo = \@w{ }}. | |
c906108c | 24209 | |
8e04817f AC |
24210 | A backslash at the end of @var{text} can be used, as in C, to continue |
24211 | the command onto subsequent lines. For example, | |
c906108c | 24212 | |
474c8240 | 24213 | @smallexample |
8e04817f AC |
24214 | echo This is some text\n\ |
24215 | which is continued\n\ | |
24216 | onto several lines.\n | |
474c8240 | 24217 | @end smallexample |
c906108c | 24218 | |
8e04817f | 24219 | produces the same output as |
c906108c | 24220 | |
474c8240 | 24221 | @smallexample |
8e04817f AC |
24222 | echo This is some text\n |
24223 | echo which is continued\n | |
24224 | echo onto several lines.\n | |
474c8240 | 24225 | @end smallexample |
c906108c | 24226 | |
8e04817f AC |
24227 | @kindex output |
24228 | @item output @var{expression} | |
24229 | Print the value of @var{expression} and nothing but that value: no | |
24230 | newlines, no @samp{$@var{nn} = }. The value is not entered in the | |
24231 | value history either. @xref{Expressions, ,Expressions}, for more information | |
24232 | on expressions. | |
c906108c | 24233 | |
8e04817f AC |
24234 | @item output/@var{fmt} @var{expression} |
24235 | Print the value of @var{expression} in format @var{fmt}. You can use | |
24236 | the same formats as for @code{print}. @xref{Output Formats,,Output | |
79a6e687 | 24237 | Formats}, for more information. |
c906108c | 24238 | |
8e04817f | 24239 | @kindex printf |
82160952 EZ |
24240 | @item printf @var{template}, @var{expressions}@dots{} |
24241 | Print the values of one or more @var{expressions} under the control of | |
24242 | the string @var{template}. To print several values, make | |
24243 | @var{expressions} be a comma-separated list of individual expressions, | |
24244 | which may be either numbers or pointers. Their values are printed as | |
24245 | specified by @var{template}, exactly as a C program would do by | |
24246 | executing the code below: | |
c906108c | 24247 | |
474c8240 | 24248 | @smallexample |
82160952 | 24249 | printf (@var{template}, @var{expressions}@dots{}); |
474c8240 | 24250 | @end smallexample |
c906108c | 24251 | |
82160952 EZ |
24252 | As in @code{C} @code{printf}, ordinary characters in @var{template} |
24253 | are printed verbatim, while @dfn{conversion specification} introduced | |
24254 | by the @samp{%} character cause subsequent @var{expressions} to be | |
24255 | evaluated, their values converted and formatted according to type and | |
24256 | style information encoded in the conversion specifications, and then | |
24257 | printed. | |
24258 | ||
8e04817f | 24259 | For example, you can print two values in hex like this: |
c906108c | 24260 | |
8e04817f AC |
24261 | @smallexample |
24262 | printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo | |
24263 | @end smallexample | |
c906108c | 24264 | |
82160952 EZ |
24265 | @code{printf} supports all the standard @code{C} conversion |
24266 | specifications, including the flags and modifiers between the @samp{%} | |
24267 | character and the conversion letter, with the following exceptions: | |
24268 | ||
24269 | @itemize @bullet | |
24270 | @item | |
24271 | The argument-ordering modifiers, such as @samp{2$}, are not supported. | |
24272 | ||
24273 | @item | |
24274 | The modifier @samp{*} is not supported for specifying precision or | |
24275 | width. | |
24276 | ||
24277 | @item | |
24278 | The @samp{'} flag (for separation of digits into groups according to | |
24279 | @code{LC_NUMERIC'}) is not supported. | |
24280 | ||
24281 | @item | |
24282 | The type modifiers @samp{hh}, @samp{j}, @samp{t}, and @samp{z} are not | |
24283 | supported. | |
24284 | ||
24285 | @item | |
24286 | The conversion letter @samp{n} (as in @samp{%n}) is not supported. | |
24287 | ||
24288 | @item | |
24289 | The conversion letters @samp{a} and @samp{A} are not supported. | |
24290 | @end itemize | |
24291 | ||
24292 | @noindent | |
24293 | Note that the @samp{ll} type modifier is supported only if the | |
24294 | underlying @code{C} implementation used to build @value{GDBN} supports | |
24295 | the @code{long long int} type, and the @samp{L} type modifier is | |
24296 | supported only if @code{long double} type is available. | |
24297 | ||
24298 | As in @code{C}, @code{printf} supports simple backslash-escape | |
24299 | sequences, such as @code{\n}, @samp{\t}, @samp{\\}, @samp{\"}, | |
24300 | @samp{\a}, and @samp{\f}, that consist of backslash followed by a | |
24301 | single character. Octal and hexadecimal escape sequences are not | |
24302 | supported. | |
1a619819 LM |
24303 | |
24304 | Additionally, @code{printf} supports conversion specifications for DFP | |
0aea4bf3 LM |
24305 | (@dfn{Decimal Floating Point}) types using the following length modifiers |
24306 | together with a floating point specifier. | |
1a619819 LM |
24307 | letters: |
24308 | ||
24309 | @itemize @bullet | |
24310 | @item | |
24311 | @samp{H} for printing @code{Decimal32} types. | |
24312 | ||
24313 | @item | |
24314 | @samp{D} for printing @code{Decimal64} types. | |
24315 | ||
24316 | @item | |
24317 | @samp{DD} for printing @code{Decimal128} types. | |
24318 | @end itemize | |
24319 | ||
24320 | If the underlying @code{C} implementation used to build @value{GDBN} has | |
0aea4bf3 | 24321 | support for the three length modifiers for DFP types, other modifiers |
3b784c4f | 24322 | such as width and precision will also be available for @value{GDBN} to use. |
1a619819 LM |
24323 | |
24324 | In case there is no such @code{C} support, no additional modifiers will be | |
24325 | available and the value will be printed in the standard way. | |
24326 | ||
24327 | Here's an example of printing DFP types using the above conversion letters: | |
24328 | @smallexample | |
0aea4bf3 | 24329 | printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl |
1a619819 LM |
24330 | @end smallexample |
24331 | ||
f1421989 HZ |
24332 | @kindex eval |
24333 | @item eval @var{template}, @var{expressions}@dots{} | |
24334 | Convert the values of one or more @var{expressions} under the control of | |
24335 | the string @var{template} to a command line, and call it. | |
24336 | ||
c906108c SS |
24337 | @end table |
24338 | ||
71b8c845 DE |
24339 | @node Auto-loading sequences |
24340 | @subsection Controlling auto-loading native @value{GDBN} scripts | |
24341 | @cindex native script auto-loading | |
24342 | ||
24343 | When a new object file is read (for example, due to the @code{file} | |
24344 | command, or because the inferior has loaded a shared library), | |
24345 | @value{GDBN} will look for the command file @file{@var{objfile}-gdb.gdb}. | |
24346 | @xref{Auto-loading extensions}. | |
24347 | ||
24348 | Auto-loading can be enabled or disabled, | |
24349 | and the list of auto-loaded scripts can be printed. | |
24350 | ||
24351 | @table @code | |
24352 | @anchor{set auto-load gdb-scripts} | |
24353 | @kindex set auto-load gdb-scripts | |
24354 | @item set auto-load gdb-scripts [on|off] | |
24355 | Enable or disable the auto-loading of canned sequences of commands scripts. | |
24356 | ||
24357 | @anchor{show auto-load gdb-scripts} | |
24358 | @kindex show auto-load gdb-scripts | |
24359 | @item show auto-load gdb-scripts | |
24360 | Show whether auto-loading of canned sequences of commands scripts is enabled or | |
24361 | disabled. | |
24362 | ||
24363 | @anchor{info auto-load gdb-scripts} | |
24364 | @kindex info auto-load gdb-scripts | |
24365 | @cindex print list of auto-loaded canned sequences of commands scripts | |
24366 | @item info auto-load gdb-scripts [@var{regexp}] | |
24367 | Print the list of all canned sequences of commands scripts that @value{GDBN} | |
24368 | auto-loaded. | |
24369 | @end table | |
24370 | ||
24371 | If @var{regexp} is supplied only canned sequences of commands scripts with | |
24372 | matching names are printed. | |
24373 | ||
329baa95 DE |
24374 | @c Python docs live in a separate file. |
24375 | @include python.texi | |
0e3509db | 24376 | |
ed3ef339 DE |
24377 | @c Guile docs live in a separate file. |
24378 | @include guile.texi | |
24379 | ||
71b8c845 DE |
24380 | @node Auto-loading extensions |
24381 | @section Auto-loading extensions | |
24382 | @cindex auto-loading extensions | |
24383 | ||
24384 | @value{GDBN} provides two mechanisms for automatically loading extensions | |
24385 | when a new object file is read (for example, due to the @code{file} | |
24386 | command, or because the inferior has loaded a shared library): | |
24387 | @file{@var{objfile}-gdb.@var{ext}} and the @code{.debug_gdb_scripts} | |
24388 | section of modern file formats like ELF. | |
24389 | ||
24390 | @menu | |
24391 | * objfile-gdb.ext file: objfile-gdbdotext file. The @file{@var{objfile}-gdb.@var{ext}} file | |
24392 | * .debug_gdb_scripts section: dotdebug_gdb_scripts section. The @code{.debug_gdb_scripts} section | |
24393 | * Which flavor to choose?:: | |
24394 | @end menu | |
24395 | ||
24396 | The auto-loading feature is useful for supplying application-specific | |
24397 | debugging commands and features. | |
24398 | ||
24399 | Auto-loading can be enabled or disabled, | |
24400 | and the list of auto-loaded scripts can be printed. | |
24401 | See the @samp{auto-loading} section of each extension language | |
24402 | for more information. | |
24403 | For @value{GDBN} command files see @ref{Auto-loading sequences}. | |
24404 | For Python files see @ref{Python Auto-loading}. | |
24405 | ||
24406 | Note that loading of this script file also requires accordingly configured | |
24407 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
24408 | ||
24409 | @node objfile-gdbdotext file | |
24410 | @subsection The @file{@var{objfile}-gdb.@var{ext}} file | |
24411 | @cindex @file{@var{objfile}-gdb.gdb} | |
24412 | @cindex @file{@var{objfile}-gdb.py} | |
24413 | @cindex @file{@var{objfile}-gdb.scm} | |
24414 | ||
24415 | When a new object file is read, @value{GDBN} looks for a file named | |
24416 | @file{@var{objfile}-gdb.@var{ext}} (we call it @var{script-name} below), | |
24417 | where @var{objfile} is the object file's name and | |
24418 | where @var{ext} is the file extension for the extension language: | |
24419 | ||
24420 | @table @code | |
24421 | @item @file{@var{objfile}-gdb.gdb} | |
24422 | GDB's own command language | |
24423 | @item @file{@var{objfile}-gdb.py} | |
24424 | Python | |
ed3ef339 DE |
24425 | @item @file{@var{objfile}-gdb.scm} |
24426 | Guile | |
71b8c845 DE |
24427 | @end table |
24428 | ||
24429 | @var{script-name} is formed by ensuring that the file name of @var{objfile} | |
24430 | is absolute, following all symlinks, and resolving @code{.} and @code{..} | |
24431 | components, and appending the @file{-gdb.@var{ext}} suffix. | |
24432 | If this file exists and is readable, @value{GDBN} will evaluate it as a | |
24433 | script in the specified extension language. | |
24434 | ||
24435 | If this file does not exist, then @value{GDBN} will look for | |
24436 | @var{script-name} file in all of the directories as specified below. | |
24437 | ||
24438 | Note that loading of these files requires an accordingly configured | |
24439 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
24440 | ||
24441 | For object files using @file{.exe} suffix @value{GDBN} tries to load first the | |
24442 | scripts normally according to its @file{.exe} filename. But if no scripts are | |
24443 | found @value{GDBN} also tries script filenames matching the object file without | |
24444 | its @file{.exe} suffix. This @file{.exe} stripping is case insensitive and it | |
24445 | is attempted on any platform. This makes the script filenames compatible | |
24446 | between Unix and MS-Windows hosts. | |
24447 | ||
24448 | @table @code | |
24449 | @anchor{set auto-load scripts-directory} | |
24450 | @kindex set auto-load scripts-directory | |
24451 | @item set auto-load scripts-directory @r{[}@var{directories}@r{]} | |
24452 | Control @value{GDBN} auto-loaded scripts location. Multiple directory entries | |
24453 | may be delimited by the host platform path separator in use | |
24454 | (@samp{:} on Unix, @samp{;} on MS-Windows and MS-DOS). | |
24455 | ||
24456 | Each entry here needs to be covered also by the security setting | |
24457 | @code{set auto-load safe-path} (@pxref{set auto-load safe-path}). | |
24458 | ||
24459 | @anchor{with-auto-load-dir} | |
24460 | This variable defaults to @file{$debugdir:$datadir/auto-load}. The default | |
24461 | @code{set auto-load safe-path} value can be also overriden by @value{GDBN} | |
24462 | configuration option @option{--with-auto-load-dir}. | |
24463 | ||
24464 | Any reference to @file{$debugdir} will get replaced by | |
24465 | @var{debug-file-directory} value (@pxref{Separate Debug Files}) and any | |
24466 | reference to @file{$datadir} will get replaced by @var{data-directory} which is | |
24467 | determined at @value{GDBN} startup (@pxref{Data Files}). @file{$debugdir} and | |
24468 | @file{$datadir} must be placed as a directory component --- either alone or | |
24469 | delimited by @file{/} or @file{\} directory separators, depending on the host | |
24470 | platform. | |
24471 | ||
24472 | The list of directories uses path separator (@samp{:} on GNU and Unix | |
24473 | systems, @samp{;} on MS-Windows and MS-DOS) to separate directories, similarly | |
24474 | to the @env{PATH} environment variable. | |
24475 | ||
24476 | @anchor{show auto-load scripts-directory} | |
24477 | @kindex show auto-load scripts-directory | |
24478 | @item show auto-load scripts-directory | |
24479 | Show @value{GDBN} auto-loaded scripts location. | |
f10c5b19 JK |
24480 | |
24481 | @anchor{add-auto-load-scripts-directory} | |
24482 | @kindex add-auto-load-scripts-directory | |
24483 | @item add-auto-load-scripts-directory @r{[}@var{directories}@dots{}@r{]} | |
24484 | Add an entry (or list of entries) to the list of auto-loaded scripts locations. | |
24485 | Multiple entries may be delimited by the host platform path separator in use. | |
71b8c845 DE |
24486 | @end table |
24487 | ||
24488 | @value{GDBN} does not track which files it has already auto-loaded this way. | |
24489 | @value{GDBN} will load the associated script every time the corresponding | |
24490 | @var{objfile} is opened. | |
24491 | So your @file{-gdb.@var{ext}} file should be careful to avoid errors if it | |
24492 | is evaluated more than once. | |
24493 | ||
24494 | @node dotdebug_gdb_scripts section | |
24495 | @subsection The @code{.debug_gdb_scripts} section | |
24496 | @cindex @code{.debug_gdb_scripts} section | |
24497 | ||
24498 | For systems using file formats like ELF and COFF, | |
24499 | when @value{GDBN} loads a new object file | |
24500 | it will look for a special section named @code{.debug_gdb_scripts}. | |
9f050062 DE |
24501 | If this section exists, its contents is a list of null-terminated entries |
24502 | specifying scripts to load. Each entry begins with a non-null prefix byte that | |
24503 | specifies the kind of entry, typically the extension language and whether the | |
24504 | script is in a file or inlined in @code{.debug_gdb_scripts}. | |
71b8c845 | 24505 | |
9f050062 DE |
24506 | The following entries are supported: |
24507 | ||
24508 | @table @code | |
24509 | @item SECTION_SCRIPT_ID_PYTHON_FILE = 1 | |
24510 | @item SECTION_SCRIPT_ID_SCHEME_FILE = 3 | |
24511 | @item SECTION_SCRIPT_ID_PYTHON_TEXT = 4 | |
24512 | @item SECTION_SCRIPT_ID_SCHEME_TEXT = 6 | |
24513 | @end table | |
24514 | ||
24515 | @subsubsection Script File Entries | |
24516 | ||
24517 | If the entry specifies a file, @value{GDBN} will look for the file first | |
24518 | in the current directory and then along the source search path | |
71b8c845 DE |
24519 | (@pxref{Source Path, ,Specifying Source Directories}), |
24520 | except that @file{$cdir} is not searched, since the compilation | |
24521 | directory is not relevant to scripts. | |
24522 | ||
9f050062 | 24523 | File entries can be placed in section @code{.debug_gdb_scripts} with, |
71b8c845 DE |
24524 | for example, this GCC macro for Python scripts. |
24525 | ||
24526 | @example | |
24527 | /* Note: The "MS" section flags are to remove duplicates. */ | |
24528 | #define DEFINE_GDB_PY_SCRIPT(script_name) \ | |
24529 | asm("\ | |
24530 | .pushsection \".debug_gdb_scripts\", \"MS\",@@progbits,1\n\ | |
24531 | .byte 1 /* Python */\n\ | |
24532 | .asciz \"" script_name "\"\n\ | |
24533 | .popsection \n\ | |
24534 | "); | |
24535 | @end example | |
24536 | ||
24537 | @noindent | |
ed3ef339 | 24538 | For Guile scripts, replace @code{.byte 1} with @code{.byte 3}. |
71b8c845 DE |
24539 | Then one can reference the macro in a header or source file like this: |
24540 | ||
24541 | @example | |
24542 | DEFINE_GDB_PY_SCRIPT ("my-app-scripts.py") | |
24543 | @end example | |
24544 | ||
24545 | The script name may include directories if desired. | |
24546 | ||
24547 | Note that loading of this script file also requires accordingly configured | |
24548 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
24549 | ||
24550 | If the macro invocation is put in a header, any application or library | |
24551 | using this header will get a reference to the specified script, | |
24552 | and with the use of @code{"MS"} attributes on the section, the linker | |
24553 | will remove duplicates. | |
24554 | ||
9f050062 DE |
24555 | @subsubsection Script Text Entries |
24556 | ||
24557 | Script text entries allow to put the executable script in the entry | |
24558 | itself instead of loading it from a file. | |
24559 | The first line of the entry, everything after the prefix byte and up to | |
24560 | the first newline (@code{0xa}) character, is the script name, and must not | |
24561 | contain any kind of space character, e.g., spaces or tabs. | |
24562 | The rest of the entry, up to the trailing null byte, is the script to | |
24563 | execute in the specified language. The name needs to be unique among | |
24564 | all script names, as @value{GDBN} executes each script only once based | |
24565 | on its name. | |
24566 | ||
24567 | Here is an example from file @file{py-section-script.c} in the @value{GDBN} | |
24568 | testsuite. | |
24569 | ||
24570 | @example | |
24571 | #include "symcat.h" | |
24572 | #include "gdb/section-scripts.h" | |
24573 | asm( | |
24574 | ".pushsection \".debug_gdb_scripts\", \"MS\",@@progbits,1\n" | |
24575 | ".byte " XSTRING (SECTION_SCRIPT_ID_PYTHON_TEXT) "\n" | |
24576 | ".ascii \"gdb.inlined-script\\n\"\n" | |
24577 | ".ascii \"class test_cmd (gdb.Command):\\n\"\n" | |
24578 | ".ascii \" def __init__ (self):\\n\"\n" | |
24579 | ".ascii \" super (test_cmd, self).__init__ (" | |
24580 | "\\\"test-cmd\\\", gdb.COMMAND_OBSCURE)\\n\"\n" | |
24581 | ".ascii \" def invoke (self, arg, from_tty):\\n\"\n" | |
24582 | ".ascii \" print (\\\"test-cmd output, arg = %s\\\" % arg)\\n\"\n" | |
24583 | ".ascii \"test_cmd ()\\n\"\n" | |
24584 | ".byte 0\n" | |
24585 | ".popsection\n" | |
24586 | ); | |
24587 | @end example | |
24588 | ||
24589 | Loading of inlined scripts requires a properly configured | |
24590 | @code{auto-load safe-path} (@pxref{Auto-loading safe path}). | |
24591 | The path to specify in @code{auto-load safe-path} is the path of the file | |
24592 | containing the @code{.debug_gdb_scripts} section. | |
24593 | ||
71b8c845 DE |
24594 | @node Which flavor to choose? |
24595 | @subsection Which flavor to choose? | |
24596 | ||
24597 | Given the multiple ways of auto-loading extensions, it might not always | |
24598 | be clear which one to choose. This section provides some guidance. | |
24599 | ||
24600 | @noindent | |
24601 | Benefits of the @file{-gdb.@var{ext}} way: | |
24602 | ||
24603 | @itemize @bullet | |
24604 | @item | |
24605 | Can be used with file formats that don't support multiple sections. | |
24606 | ||
24607 | @item | |
24608 | Ease of finding scripts for public libraries. | |
24609 | ||
24610 | Scripts specified in the @code{.debug_gdb_scripts} section are searched for | |
24611 | in the source search path. | |
24612 | For publicly installed libraries, e.g., @file{libstdc++}, there typically | |
24613 | isn't a source directory in which to find the script. | |
24614 | ||
24615 | @item | |
24616 | Doesn't require source code additions. | |
24617 | @end itemize | |
24618 | ||
24619 | @noindent | |
24620 | Benefits of the @code{.debug_gdb_scripts} way: | |
24621 | ||
24622 | @itemize @bullet | |
24623 | @item | |
24624 | Works with static linking. | |
24625 | ||
24626 | Scripts for libraries done the @file{-gdb.@var{ext}} way require an objfile to | |
24627 | trigger their loading. When an application is statically linked the only | |
24628 | objfile available is the executable, and it is cumbersome to attach all the | |
24629 | scripts from all the input libraries to the executable's | |
24630 | @file{-gdb.@var{ext}} script. | |
24631 | ||
24632 | @item | |
24633 | Works with classes that are entirely inlined. | |
24634 | ||
24635 | Some classes can be entirely inlined, and thus there may not be an associated | |
24636 | shared library to attach a @file{-gdb.@var{ext}} script to. | |
24637 | ||
24638 | @item | |
24639 | Scripts needn't be copied out of the source tree. | |
24640 | ||
24641 | In some circumstances, apps can be built out of large collections of internal | |
24642 | libraries, and the build infrastructure necessary to install the | |
24643 | @file{-gdb.@var{ext}} scripts in a place where @value{GDBN} can find them is | |
24644 | cumbersome. It may be easier to specify the scripts in the | |
24645 | @code{.debug_gdb_scripts} section as relative paths, and add a path to the | |
24646 | top of the source tree to the source search path. | |
24647 | @end itemize | |
24648 | ||
ed3ef339 DE |
24649 | @node Multiple Extension Languages |
24650 | @section Multiple Extension Languages | |
24651 | ||
24652 | The Guile and Python extension languages do not share any state, | |
24653 | and generally do not interfere with each other. | |
24654 | There are some things to be aware of, however. | |
24655 | ||
24656 | @subsection Python comes first | |
24657 | ||
24658 | Python was @value{GDBN}'s first extension language, and to avoid breaking | |
24659 | existing behaviour Python comes first. This is generally solved by the | |
24660 | ``first one wins'' principle. @value{GDBN} maintains a list of enabled | |
24661 | extension languages, and when it makes a call to an extension language, | |
24662 | (say to pretty-print a value), it tries each in turn until an extension | |
24663 | language indicates it has performed the request (e.g., has returned the | |
24664 | pretty-printed form of a value). | |
24665 | This extends to errors while performing such requests: If an error happens | |
24666 | while, for example, trying to pretty-print an object then the error is | |
24667 | reported and any following extension languages are not tried. | |
24668 | ||
5a56e9c5 DE |
24669 | @node Aliases |
24670 | @section Creating new spellings of existing commands | |
24671 | @cindex aliases for commands | |
24672 | ||
24673 | It is often useful to define alternate spellings of existing commands. | |
24674 | For example, if a new @value{GDBN} command defined in Python has | |
24675 | a long name to type, it is handy to have an abbreviated version of it | |
24676 | that involves less typing. | |
24677 | ||
24678 | @value{GDBN} itself uses aliases. For example @samp{s} is an alias | |
24679 | of the @samp{step} command even though it is otherwise an ambiguous | |
24680 | abbreviation of other commands like @samp{set} and @samp{show}. | |
24681 | ||
24682 | Aliases are also used to provide shortened or more common versions | |
24683 | of multi-word commands. For example, @value{GDBN} provides the | |
24684 | @samp{tty} alias of the @samp{set inferior-tty} command. | |
24685 | ||
24686 | You can define a new alias with the @samp{alias} command. | |
24687 | ||
24688 | @table @code | |
24689 | ||
24690 | @kindex alias | |
24691 | @item alias [-a] [--] @var{ALIAS} = @var{COMMAND} | |
24692 | ||
24693 | @end table | |
24694 | ||
24695 | @var{ALIAS} specifies the name of the new alias. | |
24696 | Each word of @var{ALIAS} must consist of letters, numbers, dashes and | |
24697 | underscores. | |
24698 | ||
24699 | @var{COMMAND} specifies the name of an existing command | |
24700 | that is being aliased. | |
24701 | ||
24702 | The @samp{-a} option specifies that the new alias is an abbreviation | |
24703 | of the command. Abbreviations are not shown in command | |
24704 | lists displayed by the @samp{help} command. | |
24705 | ||
24706 | The @samp{--} option specifies the end of options, | |
24707 | and is useful when @var{ALIAS} begins with a dash. | |
24708 | ||
24709 | Here is a simple example showing how to make an abbreviation | |
24710 | of a command so that there is less to type. | |
24711 | Suppose you were tired of typing @samp{disas}, the current | |
24712 | shortest unambiguous abbreviation of the @samp{disassemble} command | |
24713 | and you wanted an even shorter version named @samp{di}. | |
24714 | The following will accomplish this. | |
24715 | ||
24716 | @smallexample | |
24717 | (gdb) alias -a di = disas | |
24718 | @end smallexample | |
24719 | ||
24720 | Note that aliases are different from user-defined commands. | |
24721 | With a user-defined command, you also need to write documentation | |
24722 | for it with the @samp{document} command. | |
24723 | An alias automatically picks up the documentation of the existing command. | |
24724 | ||
24725 | Here is an example where we make @samp{elms} an abbreviation of | |
24726 | @samp{elements} in the @samp{set print elements} command. | |
24727 | This is to show that you can make an abbreviation of any part | |
24728 | of a command. | |
24729 | ||
24730 | @smallexample | |
24731 | (gdb) alias -a set print elms = set print elements | |
24732 | (gdb) alias -a show print elms = show print elements | |
24733 | (gdb) set p elms 20 | |
24734 | (gdb) show p elms | |
24735 | Limit on string chars or array elements to print is 200. | |
24736 | @end smallexample | |
24737 | ||
24738 | Note that if you are defining an alias of a @samp{set} command, | |
24739 | and you want to have an alias for the corresponding @samp{show} | |
24740 | command, then you need to define the latter separately. | |
24741 | ||
24742 | Unambiguously abbreviated commands are allowed in @var{COMMAND} and | |
24743 | @var{ALIAS}, just as they are normally. | |
24744 | ||
24745 | @smallexample | |
24746 | (gdb) alias -a set pr elms = set p ele | |
24747 | @end smallexample | |
24748 | ||
24749 | Finally, here is an example showing the creation of a one word | |
24750 | alias for a more complex command. | |
24751 | This creates alias @samp{spe} of the command @samp{set print elements}. | |
24752 | ||
24753 | @smallexample | |
24754 | (gdb) alias spe = set print elements | |
24755 | (gdb) spe 20 | |
24756 | @end smallexample | |
24757 | ||
21c294e6 AC |
24758 | @node Interpreters |
24759 | @chapter Command Interpreters | |
24760 | @cindex command interpreters | |
24761 | ||
24762 | @value{GDBN} supports multiple command interpreters, and some command | |
24763 | infrastructure to allow users or user interface writers to switch | |
24764 | between interpreters or run commands in other interpreters. | |
24765 | ||
24766 | @value{GDBN} currently supports two command interpreters, the console | |
24767 | interpreter (sometimes called the command-line interpreter or @sc{cli}) | |
24768 | and the machine interface interpreter (or @sc{gdb/mi}). This manual | |
24769 | describes both of these interfaces in great detail. | |
24770 | ||
24771 | By default, @value{GDBN} will start with the console interpreter. | |
24772 | However, the user may choose to start @value{GDBN} with another | |
24773 | interpreter by specifying the @option{-i} or @option{--interpreter} | |
24774 | startup options. Defined interpreters include: | |
24775 | ||
24776 | @table @code | |
24777 | @item console | |
24778 | @cindex console interpreter | |
24779 | The traditional console or command-line interpreter. This is the most often | |
24780 | used interpreter with @value{GDBN}. With no interpreter specified at runtime, | |
24781 | @value{GDBN} will use this interpreter. | |
24782 | ||
24783 | @item mi | |
24784 | @cindex mi interpreter | |
24785 | The newest @sc{gdb/mi} interface (currently @code{mi2}). Used primarily | |
24786 | by programs wishing to use @value{GDBN} as a backend for a debugger GUI | |
24787 | or an IDE. For more information, see @ref{GDB/MI, ,The @sc{gdb/mi} | |
24788 | Interface}. | |
24789 | ||
24790 | @item mi2 | |
24791 | @cindex mi2 interpreter | |
24792 | The current @sc{gdb/mi} interface. | |
24793 | ||
24794 | @item mi1 | |
24795 | @cindex mi1 interpreter | |
24796 | The @sc{gdb/mi} interface included in @value{GDBN} 5.1, 5.2, and 5.3. | |
24797 | ||
24798 | @end table | |
24799 | ||
24800 | @cindex invoke another interpreter | |
24801 | The interpreter being used by @value{GDBN} may not be dynamically | |
24802 | switched at runtime. Although possible, this could lead to a very | |
24803 | precarious situation. Consider an IDE using @sc{gdb/mi}. If a user | |
24804 | enters the command "interpreter-set console" in a console view, | |
24805 | @value{GDBN} would switch to using the console interpreter, rendering | |
24806 | the IDE inoperable! | |
24807 | ||
24808 | @kindex interpreter-exec | |
24809 | Although you may only choose a single interpreter at startup, you may execute | |
24810 | commands in any interpreter from the current interpreter using the appropriate | |
24811 | command. If you are running the console interpreter, simply use the | |
24812 | @code{interpreter-exec} command: | |
24813 | ||
24814 | @smallexample | |
24815 | interpreter-exec mi "-data-list-register-names" | |
24816 | @end smallexample | |
24817 | ||
24818 | @sc{gdb/mi} has a similar command, although it is only available in versions of | |
24819 | @value{GDBN} which support @sc{gdb/mi} version 2 (or greater). | |
24820 | ||
8e04817f AC |
24821 | @node TUI |
24822 | @chapter @value{GDBN} Text User Interface | |
24823 | @cindex TUI | |
d0d5df6f | 24824 | @cindex Text User Interface |
c906108c | 24825 | |
8e04817f AC |
24826 | @menu |
24827 | * TUI Overview:: TUI overview | |
24828 | * TUI Keys:: TUI key bindings | |
7cf36c78 | 24829 | * TUI Single Key Mode:: TUI single key mode |
db2e3e2e | 24830 | * TUI Commands:: TUI-specific commands |
8e04817f AC |
24831 | * TUI Configuration:: TUI configuration variables |
24832 | @end menu | |
c906108c | 24833 | |
46ba6afa | 24834 | The @value{GDBN} Text User Interface (TUI) is a terminal |
d0d5df6f AC |
24835 | interface which uses the @code{curses} library to show the source |
24836 | file, the assembly output, the program registers and @value{GDBN} | |
46ba6afa BW |
24837 | commands in separate text windows. The TUI mode is supported only |
24838 | on platforms where a suitable version of the @code{curses} library | |
24839 | is available. | |
d0d5df6f | 24840 | |
46ba6afa | 24841 | The TUI mode is enabled by default when you invoke @value{GDBN} as |
217bff3e | 24842 | @samp{@value{GDBP} -tui}. |
46ba6afa | 24843 | You can also switch in and out of TUI mode while @value{GDBN} runs by |
a4ea0946 | 24844 | using various TUI commands and key bindings, such as @command{tui |
bcd8537c | 24845 | enable} or @kbd{C-x C-a}. @xref{TUI Commands, ,TUI Commands}, and |
a4ea0946 | 24846 | @ref{TUI Keys, ,TUI Key Bindings}. |
c906108c | 24847 | |
8e04817f | 24848 | @node TUI Overview |
79a6e687 | 24849 | @section TUI Overview |
c906108c | 24850 | |
46ba6afa | 24851 | In TUI mode, @value{GDBN} can display several text windows: |
c906108c | 24852 | |
8e04817f AC |
24853 | @table @emph |
24854 | @item command | |
24855 | This window is the @value{GDBN} command window with the @value{GDBN} | |
46ba6afa BW |
24856 | prompt and the @value{GDBN} output. The @value{GDBN} input is still |
24857 | managed using readline. | |
c906108c | 24858 | |
8e04817f AC |
24859 | @item source |
24860 | The source window shows the source file of the program. The current | |
46ba6afa | 24861 | line and active breakpoints are displayed in this window. |
c906108c | 24862 | |
8e04817f AC |
24863 | @item assembly |
24864 | The assembly window shows the disassembly output of the program. | |
c906108c | 24865 | |
8e04817f | 24866 | @item register |
46ba6afa BW |
24867 | This window shows the processor registers. Registers are highlighted |
24868 | when their values change. | |
c906108c SS |
24869 | @end table |
24870 | ||
269c21fe | 24871 | The source and assembly windows show the current program position |
46ba6afa BW |
24872 | by highlighting the current line and marking it with a @samp{>} marker. |
24873 | Breakpoints are indicated with two markers. The first marker | |
269c21fe SC |
24874 | indicates the breakpoint type: |
24875 | ||
24876 | @table @code | |
24877 | @item B | |
24878 | Breakpoint which was hit at least once. | |
24879 | ||
24880 | @item b | |
24881 | Breakpoint which was never hit. | |
24882 | ||
24883 | @item H | |
24884 | Hardware breakpoint which was hit at least once. | |
24885 | ||
24886 | @item h | |
24887 | Hardware breakpoint which was never hit. | |
269c21fe SC |
24888 | @end table |
24889 | ||
24890 | The second marker indicates whether the breakpoint is enabled or not: | |
24891 | ||
24892 | @table @code | |
24893 | @item + | |
24894 | Breakpoint is enabled. | |
24895 | ||
24896 | @item - | |
24897 | Breakpoint is disabled. | |
269c21fe SC |
24898 | @end table |
24899 | ||
46ba6afa BW |
24900 | The source, assembly and register windows are updated when the current |
24901 | thread changes, when the frame changes, or when the program counter | |
24902 | changes. | |
24903 | ||
24904 | These windows are not all visible at the same time. The command | |
24905 | window is always visible. The others can be arranged in several | |
24906 | layouts: | |
c906108c | 24907 | |
8e04817f AC |
24908 | @itemize @bullet |
24909 | @item | |
46ba6afa | 24910 | source only, |
2df3850c | 24911 | |
8e04817f | 24912 | @item |
46ba6afa | 24913 | assembly only, |
8e04817f AC |
24914 | |
24915 | @item | |
46ba6afa | 24916 | source and assembly, |
8e04817f AC |
24917 | |
24918 | @item | |
46ba6afa | 24919 | source and registers, or |
c906108c | 24920 | |
8e04817f | 24921 | @item |
46ba6afa | 24922 | assembly and registers. |
8e04817f | 24923 | @end itemize |
c906108c | 24924 | |
46ba6afa | 24925 | A status line above the command window shows the following information: |
b7bb15bc SC |
24926 | |
24927 | @table @emph | |
24928 | @item target | |
46ba6afa | 24929 | Indicates the current @value{GDBN} target. |
b7bb15bc SC |
24930 | (@pxref{Targets, ,Specifying a Debugging Target}). |
24931 | ||
24932 | @item process | |
46ba6afa | 24933 | Gives the current process or thread number. |
b7bb15bc SC |
24934 | When no process is being debugged, this field is set to @code{No process}. |
24935 | ||
24936 | @item function | |
24937 | Gives the current function name for the selected frame. | |
24938 | The name is demangled if demangling is turned on (@pxref{Print Settings}). | |
46ba6afa | 24939 | When there is no symbol corresponding to the current program counter, |
b7bb15bc SC |
24940 | the string @code{??} is displayed. |
24941 | ||
24942 | @item line | |
24943 | Indicates the current line number for the selected frame. | |
46ba6afa | 24944 | When the current line number is not known, the string @code{??} is displayed. |
b7bb15bc SC |
24945 | |
24946 | @item pc | |
24947 | Indicates the current program counter address. | |
b7bb15bc SC |
24948 | @end table |
24949 | ||
8e04817f AC |
24950 | @node TUI Keys |
24951 | @section TUI Key Bindings | |
24952 | @cindex TUI key bindings | |
c906108c | 24953 | |
8e04817f | 24954 | The TUI installs several key bindings in the readline keymaps |
39037522 TT |
24955 | @ifset SYSTEM_READLINE |
24956 | (@pxref{Command Line Editing, , , rluserman, GNU Readline Library}). | |
24957 | @end ifset | |
24958 | @ifclear SYSTEM_READLINE | |
24959 | (@pxref{Command Line Editing}). | |
24960 | @end ifclear | |
24961 | The following key bindings are installed for both TUI mode and the | |
24962 | @value{GDBN} standard mode. | |
c906108c | 24963 | |
8e04817f AC |
24964 | @table @kbd |
24965 | @kindex C-x C-a | |
24966 | @item C-x C-a | |
24967 | @kindex C-x a | |
24968 | @itemx C-x a | |
24969 | @kindex C-x A | |
24970 | @itemx C-x A | |
46ba6afa BW |
24971 | Enter or leave the TUI mode. When leaving the TUI mode, |
24972 | the curses window management stops and @value{GDBN} operates using | |
24973 | its standard mode, writing on the terminal directly. When reentering | |
24974 | the TUI mode, control is given back to the curses windows. | |
8e04817f | 24975 | The screen is then refreshed. |
c906108c | 24976 | |
8e04817f AC |
24977 | @kindex C-x 1 |
24978 | @item C-x 1 | |
24979 | Use a TUI layout with only one window. The layout will | |
24980 | either be @samp{source} or @samp{assembly}. When the TUI mode | |
24981 | is not active, it will switch to the TUI mode. | |
2df3850c | 24982 | |
8e04817f | 24983 | Think of this key binding as the Emacs @kbd{C-x 1} binding. |
c906108c | 24984 | |
8e04817f AC |
24985 | @kindex C-x 2 |
24986 | @item C-x 2 | |
24987 | Use a TUI layout with at least two windows. When the current | |
46ba6afa | 24988 | layout already has two windows, the next layout with two windows is used. |
8e04817f AC |
24989 | When a new layout is chosen, one window will always be common to the |
24990 | previous layout and the new one. | |
c906108c | 24991 | |
8e04817f | 24992 | Think of it as the Emacs @kbd{C-x 2} binding. |
2df3850c | 24993 | |
72ffddc9 SC |
24994 | @kindex C-x o |
24995 | @item C-x o | |
24996 | Change the active window. The TUI associates several key bindings | |
46ba6afa | 24997 | (like scrolling and arrow keys) with the active window. This command |
72ffddc9 SC |
24998 | gives the focus to the next TUI window. |
24999 | ||
25000 | Think of it as the Emacs @kbd{C-x o} binding. | |
25001 | ||
7cf36c78 SC |
25002 | @kindex C-x s |
25003 | @item C-x s | |
46ba6afa BW |
25004 | Switch in and out of the TUI SingleKey mode that binds single |
25005 | keys to @value{GDBN} commands (@pxref{TUI Single Key Mode}). | |
c906108c SS |
25006 | @end table |
25007 | ||
46ba6afa | 25008 | The following key bindings only work in the TUI mode: |
5d161b24 | 25009 | |
46ba6afa | 25010 | @table @asis |
8e04817f | 25011 | @kindex PgUp |
46ba6afa | 25012 | @item @key{PgUp} |
8e04817f | 25013 | Scroll the active window one page up. |
c906108c | 25014 | |
8e04817f | 25015 | @kindex PgDn |
46ba6afa | 25016 | @item @key{PgDn} |
8e04817f | 25017 | Scroll the active window one page down. |
c906108c | 25018 | |
8e04817f | 25019 | @kindex Up |
46ba6afa | 25020 | @item @key{Up} |
8e04817f | 25021 | Scroll the active window one line up. |
c906108c | 25022 | |
8e04817f | 25023 | @kindex Down |
46ba6afa | 25024 | @item @key{Down} |
8e04817f | 25025 | Scroll the active window one line down. |
c906108c | 25026 | |
8e04817f | 25027 | @kindex Left |
46ba6afa | 25028 | @item @key{Left} |
8e04817f | 25029 | Scroll the active window one column left. |
c906108c | 25030 | |
8e04817f | 25031 | @kindex Right |
46ba6afa | 25032 | @item @key{Right} |
8e04817f | 25033 | Scroll the active window one column right. |
c906108c | 25034 | |
8e04817f | 25035 | @kindex C-L |
46ba6afa | 25036 | @item @kbd{C-L} |
8e04817f | 25037 | Refresh the screen. |
8e04817f | 25038 | @end table |
c906108c | 25039 | |
46ba6afa BW |
25040 | Because the arrow keys scroll the active window in the TUI mode, they |
25041 | are not available for their normal use by readline unless the command | |
25042 | window has the focus. When another window is active, you must use | |
25043 | other readline key bindings such as @kbd{C-p}, @kbd{C-n}, @kbd{C-b} | |
25044 | and @kbd{C-f} to control the command window. | |
8e04817f | 25045 | |
7cf36c78 SC |
25046 | @node TUI Single Key Mode |
25047 | @section TUI Single Key Mode | |
25048 | @cindex TUI single key mode | |
25049 | ||
46ba6afa BW |
25050 | The TUI also provides a @dfn{SingleKey} mode, which binds several |
25051 | frequently used @value{GDBN} commands to single keys. Type @kbd{C-x s} to | |
25052 | switch into this mode, where the following key bindings are used: | |
7cf36c78 SC |
25053 | |
25054 | @table @kbd | |
25055 | @kindex c @r{(SingleKey TUI key)} | |
25056 | @item c | |
25057 | continue | |
25058 | ||
25059 | @kindex d @r{(SingleKey TUI key)} | |
25060 | @item d | |
25061 | down | |
25062 | ||
25063 | @kindex f @r{(SingleKey TUI key)} | |
25064 | @item f | |
25065 | finish | |
25066 | ||
25067 | @kindex n @r{(SingleKey TUI key)} | |
25068 | @item n | |
25069 | next | |
25070 | ||
25071 | @kindex q @r{(SingleKey TUI key)} | |
25072 | @item q | |
46ba6afa | 25073 | exit the SingleKey mode. |
7cf36c78 SC |
25074 | |
25075 | @kindex r @r{(SingleKey TUI key)} | |
25076 | @item r | |
25077 | run | |
25078 | ||
25079 | @kindex s @r{(SingleKey TUI key)} | |
25080 | @item s | |
25081 | step | |
25082 | ||
25083 | @kindex u @r{(SingleKey TUI key)} | |
25084 | @item u | |
25085 | up | |
25086 | ||
25087 | @kindex v @r{(SingleKey TUI key)} | |
25088 | @item v | |
25089 | info locals | |
25090 | ||
25091 | @kindex w @r{(SingleKey TUI key)} | |
25092 | @item w | |
25093 | where | |
7cf36c78 SC |
25094 | @end table |
25095 | ||
25096 | Other keys temporarily switch to the @value{GDBN} command prompt. | |
25097 | The key that was pressed is inserted in the editing buffer so that | |
25098 | it is possible to type most @value{GDBN} commands without interaction | |
46ba6afa BW |
25099 | with the TUI SingleKey mode. Once the command is entered the TUI |
25100 | SingleKey mode is restored. The only way to permanently leave | |
7f9087cb | 25101 | this mode is by typing @kbd{q} or @kbd{C-x s}. |
7cf36c78 SC |
25102 | |
25103 | ||
8e04817f | 25104 | @node TUI Commands |
db2e3e2e | 25105 | @section TUI-specific Commands |
8e04817f AC |
25106 | @cindex TUI commands |
25107 | ||
25108 | The TUI has specific commands to control the text windows. | |
46ba6afa BW |
25109 | These commands are always available, even when @value{GDBN} is not in |
25110 | the TUI mode. When @value{GDBN} is in the standard mode, most | |
25111 | of these commands will automatically switch to the TUI mode. | |
c906108c | 25112 | |
ff12863f PA |
25113 | Note that if @value{GDBN}'s @code{stdout} is not connected to a |
25114 | terminal, or @value{GDBN} has been started with the machine interface | |
25115 | interpreter (@pxref{GDB/MI, ,The @sc{gdb/mi} Interface}), most of | |
25116 | these commands will fail with an error, because it would not be | |
25117 | possible or desirable to enable curses window management. | |
25118 | ||
c906108c | 25119 | @table @code |
a4ea0946 AB |
25120 | @item tui enable |
25121 | @kindex tui enable | |
25122 | Activate TUI mode. The last active TUI window layout will be used if | |
25123 | TUI mode has prevsiouly been used in the current debugging session, | |
25124 | otherwise a default layout is used. | |
25125 | ||
25126 | @item tui disable | |
25127 | @kindex tui disable | |
25128 | Disable TUI mode, returning to the console interpreter. | |
25129 | ||
3d757584 SC |
25130 | @item info win |
25131 | @kindex info win | |
25132 | List and give the size of all displayed windows. | |
25133 | ||
6008fc5f | 25134 | @item layout @var{name} |
4644b6e3 | 25135 | @kindex layout |
6008fc5f AB |
25136 | Changes which TUI windows are displayed. In each layout the command |
25137 | window is always displayed, the @var{name} parameter controls which | |
25138 | additional windows are displayed, and can be any of the following: | |
25139 | ||
25140 | @table @code | |
25141 | @item next | |
8e04817f | 25142 | Display the next layout. |
2df3850c | 25143 | |
6008fc5f | 25144 | @item prev |
8e04817f | 25145 | Display the previous layout. |
c906108c | 25146 | |
6008fc5f AB |
25147 | @item src |
25148 | Display the source and command windows. | |
c906108c | 25149 | |
6008fc5f AB |
25150 | @item asm |
25151 | Display the assembly and command windows. | |
c906108c | 25152 | |
6008fc5f AB |
25153 | @item split |
25154 | Display the source, assembly, and command windows. | |
c906108c | 25155 | |
6008fc5f AB |
25156 | @item regs |
25157 | When in @code{src} layout display the register, source, and command | |
25158 | windows. When in @code{asm} or @code{split} layout display the | |
25159 | register, assembler, and command windows. | |
25160 | @end table | |
8e04817f | 25161 | |
6008fc5f | 25162 | @item focus @var{name} |
8e04817f | 25163 | @kindex focus |
6008fc5f AB |
25164 | Changes which TUI window is currently active for scrolling. The |
25165 | @var{name} parameter can be any of the following: | |
25166 | ||
25167 | @table @code | |
25168 | @item next | |
46ba6afa BW |
25169 | Make the next window active for scrolling. |
25170 | ||
6008fc5f | 25171 | @item prev |
46ba6afa BW |
25172 | Make the previous window active for scrolling. |
25173 | ||
6008fc5f | 25174 | @item src |
46ba6afa BW |
25175 | Make the source window active for scrolling. |
25176 | ||
6008fc5f | 25177 | @item asm |
46ba6afa BW |
25178 | Make the assembly window active for scrolling. |
25179 | ||
6008fc5f | 25180 | @item regs |
46ba6afa BW |
25181 | Make the register window active for scrolling. |
25182 | ||
6008fc5f | 25183 | @item cmd |
46ba6afa | 25184 | Make the command window active for scrolling. |
6008fc5f | 25185 | @end table |
c906108c | 25186 | |
8e04817f AC |
25187 | @item refresh |
25188 | @kindex refresh | |
7f9087cb | 25189 | Refresh the screen. This is similar to typing @kbd{C-L}. |
c906108c | 25190 | |
51f0e40d | 25191 | @item tui reg @var{group} |
6a1b180d | 25192 | @kindex tui reg |
51f0e40d AB |
25193 | Changes the register group displayed in the tui register window to |
25194 | @var{group}. If the register window is not currently displayed this | |
25195 | command will cause the register window to be displayed. The list of | |
25196 | register groups, as well as their order is target specific. The | |
25197 | following groups are available on most targets: | |
25198 | @table @code | |
25199 | @item next | |
25200 | Repeatedly selecting this group will cause the display to cycle | |
25201 | through all of the available register groups. | |
25202 | ||
25203 | @item prev | |
25204 | Repeatedly selecting this group will cause the display to cycle | |
25205 | through all of the available register groups in the reverse order to | |
25206 | @var{next}. | |
25207 | ||
25208 | @item general | |
25209 | Display the general registers. | |
25210 | @item float | |
25211 | Display the floating point registers. | |
25212 | @item system | |
25213 | Display the system registers. | |
25214 | @item vector | |
25215 | Display the vector registers. | |
25216 | @item all | |
25217 | Display all registers. | |
25218 | @end table | |
6a1b180d | 25219 | |
8e04817f AC |
25220 | @item update |
25221 | @kindex update | |
25222 | Update the source window and the current execution point. | |
c906108c | 25223 | |
8e04817f AC |
25224 | @item winheight @var{name} +@var{count} |
25225 | @itemx winheight @var{name} -@var{count} | |
25226 | @kindex winheight | |
25227 | Change the height of the window @var{name} by @var{count} | |
25228 | lines. Positive counts increase the height, while negative counts | |
bf555842 EZ |
25229 | decrease it. The @var{name} parameter can be one of @code{src} (the |
25230 | source window), @code{cmd} (the command window), @code{asm} (the | |
25231 | disassembly window), or @code{regs} (the register display window). | |
2df3850c | 25232 | |
46ba6afa BW |
25233 | @item tabset @var{nchars} |
25234 | @kindex tabset | |
bf555842 EZ |
25235 | Set the width of tab stops to be @var{nchars} characters. This |
25236 | setting affects the display of TAB characters in the source and | |
25237 | assembly windows. | |
c906108c SS |
25238 | @end table |
25239 | ||
8e04817f | 25240 | @node TUI Configuration |
79a6e687 | 25241 | @section TUI Configuration Variables |
8e04817f | 25242 | @cindex TUI configuration variables |
c906108c | 25243 | |
46ba6afa | 25244 | Several configuration variables control the appearance of TUI windows. |
c906108c | 25245 | |
8e04817f AC |
25246 | @table @code |
25247 | @item set tui border-kind @var{kind} | |
25248 | @kindex set tui border-kind | |
25249 | Select the border appearance for the source, assembly and register windows. | |
25250 | The possible values are the following: | |
25251 | @table @code | |
25252 | @item space | |
25253 | Use a space character to draw the border. | |
c906108c | 25254 | |
8e04817f | 25255 | @item ascii |
46ba6afa | 25256 | Use @sc{ascii} characters @samp{+}, @samp{-} and @samp{|} to draw the border. |
c906108c | 25257 | |
8e04817f AC |
25258 | @item acs |
25259 | Use the Alternate Character Set to draw the border. The border is | |
25260 | drawn using character line graphics if the terminal supports them. | |
8e04817f | 25261 | @end table |
c78b4128 | 25262 | |
8e04817f AC |
25263 | @item set tui border-mode @var{mode} |
25264 | @kindex set tui border-mode | |
46ba6afa BW |
25265 | @itemx set tui active-border-mode @var{mode} |
25266 | @kindex set tui active-border-mode | |
25267 | Select the display attributes for the borders of the inactive windows | |
25268 | or the active window. The @var{mode} can be one of the following: | |
8e04817f AC |
25269 | @table @code |
25270 | @item normal | |
25271 | Use normal attributes to display the border. | |
c906108c | 25272 | |
8e04817f AC |
25273 | @item standout |
25274 | Use standout mode. | |
c906108c | 25275 | |
8e04817f AC |
25276 | @item reverse |
25277 | Use reverse video mode. | |
c906108c | 25278 | |
8e04817f AC |
25279 | @item half |
25280 | Use half bright mode. | |
c906108c | 25281 | |
8e04817f AC |
25282 | @item half-standout |
25283 | Use half bright and standout mode. | |
c906108c | 25284 | |
8e04817f AC |
25285 | @item bold |
25286 | Use extra bright or bold mode. | |
c78b4128 | 25287 | |
8e04817f AC |
25288 | @item bold-standout |
25289 | Use extra bright or bold and standout mode. | |
8e04817f | 25290 | @end table |
8e04817f | 25291 | @end table |
c78b4128 | 25292 | |
8e04817f AC |
25293 | @node Emacs |
25294 | @chapter Using @value{GDBN} under @sc{gnu} Emacs | |
c78b4128 | 25295 | |
8e04817f AC |
25296 | @cindex Emacs |
25297 | @cindex @sc{gnu} Emacs | |
25298 | A special interface allows you to use @sc{gnu} Emacs to view (and | |
25299 | edit) the source files for the program you are debugging with | |
25300 | @value{GDBN}. | |
c906108c | 25301 | |
8e04817f AC |
25302 | To use this interface, use the command @kbd{M-x gdb} in Emacs. Give the |
25303 | executable file you want to debug as an argument. This command starts | |
25304 | @value{GDBN} as a subprocess of Emacs, with input and output through a newly | |
25305 | created Emacs buffer. | |
25306 | @c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.) | |
c906108c | 25307 | |
5e252a2e | 25308 | Running @value{GDBN} under Emacs can be just like running @value{GDBN} normally except for two |
8e04817f | 25309 | things: |
c906108c | 25310 | |
8e04817f AC |
25311 | @itemize @bullet |
25312 | @item | |
5e252a2e NR |
25313 | All ``terminal'' input and output goes through an Emacs buffer, called |
25314 | the GUD buffer. | |
c906108c | 25315 | |
8e04817f AC |
25316 | This applies both to @value{GDBN} commands and their output, and to the input |
25317 | and output done by the program you are debugging. | |
bf0184be | 25318 | |
8e04817f AC |
25319 | This is useful because it means that you can copy the text of previous |
25320 | commands and input them again; you can even use parts of the output | |
25321 | in this way. | |
bf0184be | 25322 | |
8e04817f AC |
25323 | All the facilities of Emacs' Shell mode are available for interacting |
25324 | with your program. In particular, you can send signals the usual | |
25325 | way---for example, @kbd{C-c C-c} for an interrupt, @kbd{C-c C-z} for a | |
25326 | stop. | |
bf0184be ND |
25327 | |
25328 | @item | |
8e04817f | 25329 | @value{GDBN} displays source code through Emacs. |
bf0184be | 25330 | |
8e04817f AC |
25331 | Each time @value{GDBN} displays a stack frame, Emacs automatically finds the |
25332 | source file for that frame and puts an arrow (@samp{=>}) at the | |
25333 | left margin of the current line. Emacs uses a separate buffer for | |
25334 | source display, and splits the screen to show both your @value{GDBN} session | |
25335 | and the source. | |
bf0184be | 25336 | |
8e04817f AC |
25337 | Explicit @value{GDBN} @code{list} or search commands still produce output as |
25338 | usual, but you probably have no reason to use them from Emacs. | |
5e252a2e NR |
25339 | @end itemize |
25340 | ||
25341 | We call this @dfn{text command mode}. Emacs 22.1, and later, also uses | |
25342 | a graphical mode, enabled by default, which provides further buffers | |
25343 | that can control the execution and describe the state of your program. | |
25344 | @xref{GDB Graphical Interface,,, Emacs, The @sc{gnu} Emacs Manual}. | |
c906108c | 25345 | |
64fabec2 AC |
25346 | If you specify an absolute file name when prompted for the @kbd{M-x |
25347 | gdb} argument, then Emacs sets your current working directory to where | |
25348 | your program resides. If you only specify the file name, then Emacs | |
7a9dd1b2 | 25349 | sets your current working directory to the directory associated |
64fabec2 AC |
25350 | with the previous buffer. In this case, @value{GDBN} may find your |
25351 | program by searching your environment's @code{PATH} variable, but on | |
25352 | some operating systems it might not find the source. So, although the | |
25353 | @value{GDBN} input and output session proceeds normally, the auxiliary | |
25354 | buffer does not display the current source and line of execution. | |
25355 | ||
25356 | The initial working directory of @value{GDBN} is printed on the top | |
5e252a2e NR |
25357 | line of the GUD buffer and this serves as a default for the commands |
25358 | that specify files for @value{GDBN} to operate on. @xref{Files, | |
25359 | ,Commands to Specify Files}. | |
64fabec2 AC |
25360 | |
25361 | By default, @kbd{M-x gdb} calls the program called @file{gdb}. If you | |
25362 | need to call @value{GDBN} by a different name (for example, if you | |
25363 | keep several configurations around, with different names) you can | |
25364 | customize the Emacs variable @code{gud-gdb-command-name} to run the | |
25365 | one you want. | |
8e04817f | 25366 | |
5e252a2e | 25367 | In the GUD buffer, you can use these special Emacs commands in |
8e04817f | 25368 | addition to the standard Shell mode commands: |
c906108c | 25369 | |
8e04817f AC |
25370 | @table @kbd |
25371 | @item C-h m | |
5e252a2e | 25372 | Describe the features of Emacs' GUD Mode. |
c906108c | 25373 | |
64fabec2 | 25374 | @item C-c C-s |
8e04817f AC |
25375 | Execute to another source line, like the @value{GDBN} @code{step} command; also |
25376 | update the display window to show the current file and location. | |
c906108c | 25377 | |
64fabec2 | 25378 | @item C-c C-n |
8e04817f AC |
25379 | Execute to next source line in this function, skipping all function |
25380 | calls, like the @value{GDBN} @code{next} command. Then update the display window | |
25381 | to show the current file and location. | |
c906108c | 25382 | |
64fabec2 | 25383 | @item C-c C-i |
8e04817f AC |
25384 | Execute one instruction, like the @value{GDBN} @code{stepi} command; update |
25385 | display window accordingly. | |
c906108c | 25386 | |
8e04817f AC |
25387 | @item C-c C-f |
25388 | Execute until exit from the selected stack frame, like the @value{GDBN} | |
25389 | @code{finish} command. | |
c906108c | 25390 | |
64fabec2 | 25391 | @item C-c C-r |
8e04817f AC |
25392 | Continue execution of your program, like the @value{GDBN} @code{continue} |
25393 | command. | |
b433d00b | 25394 | |
64fabec2 | 25395 | @item C-c < |
8e04817f AC |
25396 | Go up the number of frames indicated by the numeric argument |
25397 | (@pxref{Arguments, , Numeric Arguments, Emacs, The @sc{gnu} Emacs Manual}), | |
25398 | like the @value{GDBN} @code{up} command. | |
b433d00b | 25399 | |
64fabec2 | 25400 | @item C-c > |
8e04817f AC |
25401 | Go down the number of frames indicated by the numeric argument, like the |
25402 | @value{GDBN} @code{down} command. | |
8e04817f | 25403 | @end table |
c906108c | 25404 | |
7f9087cb | 25405 | In any source file, the Emacs command @kbd{C-x @key{SPC}} (@code{gud-break}) |
8e04817f | 25406 | tells @value{GDBN} to set a breakpoint on the source line point is on. |
c906108c | 25407 | |
5e252a2e NR |
25408 | In text command mode, if you type @kbd{M-x speedbar}, Emacs displays a |
25409 | separate frame which shows a backtrace when the GUD buffer is current. | |
25410 | Move point to any frame in the stack and type @key{RET} to make it | |
25411 | become the current frame and display the associated source in the | |
25412 | source buffer. Alternatively, click @kbd{Mouse-2} to make the | |
25413 | selected frame become the current one. In graphical mode, the | |
25414 | speedbar displays watch expressions. | |
64fabec2 | 25415 | |
8e04817f AC |
25416 | If you accidentally delete the source-display buffer, an easy way to get |
25417 | it back is to type the command @code{f} in the @value{GDBN} buffer, to | |
25418 | request a frame display; when you run under Emacs, this recreates | |
25419 | the source buffer if necessary to show you the context of the current | |
25420 | frame. | |
c906108c | 25421 | |
8e04817f AC |
25422 | The source files displayed in Emacs are in ordinary Emacs buffers |
25423 | which are visiting the source files in the usual way. You can edit | |
25424 | the files with these buffers if you wish; but keep in mind that @value{GDBN} | |
25425 | communicates with Emacs in terms of line numbers. If you add or | |
25426 | delete lines from the text, the line numbers that @value{GDBN} knows cease | |
25427 | to correspond properly with the code. | |
b383017d | 25428 | |
5e252a2e NR |
25429 | A more detailed description of Emacs' interaction with @value{GDBN} is |
25430 | given in the Emacs manual (@pxref{Debuggers,,, Emacs, The @sc{gnu} | |
25431 | Emacs Manual}). | |
c906108c | 25432 | |
922fbb7b AC |
25433 | @node GDB/MI |
25434 | @chapter The @sc{gdb/mi} Interface | |
25435 | ||
25436 | @unnumberedsec Function and Purpose | |
25437 | ||
25438 | @cindex @sc{gdb/mi}, its purpose | |
6b5e8c01 NR |
25439 | @sc{gdb/mi} is a line based machine oriented text interface to |
25440 | @value{GDBN} and is activated by specifying using the | |
25441 | @option{--interpreter} command line option (@pxref{Mode Options}). It | |
25442 | is specifically intended to support the development of systems which | |
25443 | use the debugger as just one small component of a larger system. | |
922fbb7b AC |
25444 | |
25445 | This chapter is a specification of the @sc{gdb/mi} interface. It is written | |
25446 | in the form of a reference manual. | |
25447 | ||
25448 | Note that @sc{gdb/mi} is still under construction, so some of the | |
af6eff6f NR |
25449 | features described below are incomplete and subject to change |
25450 | (@pxref{GDB/MI Development and Front Ends, , @sc{gdb/mi} Development and Front Ends}). | |
922fbb7b AC |
25451 | |
25452 | @unnumberedsec Notation and Terminology | |
25453 | ||
25454 | @cindex notational conventions, for @sc{gdb/mi} | |
25455 | This chapter uses the following notation: | |
25456 | ||
25457 | @itemize @bullet | |
25458 | @item | |
25459 | @code{|} separates two alternatives. | |
25460 | ||
25461 | @item | |
25462 | @code{[ @var{something} ]} indicates that @var{something} is optional: | |
25463 | it may or may not be given. | |
25464 | ||
25465 | @item | |
25466 | @code{( @var{group} )*} means that @var{group} inside the parentheses | |
25467 | may repeat zero or more times. | |
25468 | ||
25469 | @item | |
25470 | @code{( @var{group} )+} means that @var{group} inside the parentheses | |
25471 | may repeat one or more times. | |
25472 | ||
25473 | @item | |
25474 | @code{"@var{string}"} means a literal @var{string}. | |
25475 | @end itemize | |
25476 | ||
25477 | @ignore | |
25478 | @heading Dependencies | |
25479 | @end ignore | |
25480 | ||
922fbb7b | 25481 | @menu |
c3b108f7 | 25482 | * GDB/MI General Design:: |
922fbb7b AC |
25483 | * GDB/MI Command Syntax:: |
25484 | * GDB/MI Compatibility with CLI:: | |
af6eff6f | 25485 | * GDB/MI Development and Front Ends:: |
922fbb7b | 25486 | * GDB/MI Output Records:: |
ef21caaf | 25487 | * GDB/MI Simple Examples:: |
922fbb7b | 25488 | * GDB/MI Command Description Format:: |
ef21caaf | 25489 | * GDB/MI Breakpoint Commands:: |
3fa7bf06 | 25490 | * GDB/MI Catchpoint Commands:: |
a2c02241 NR |
25491 | * GDB/MI Program Context:: |
25492 | * GDB/MI Thread Commands:: | |
5d77fe44 | 25493 | * GDB/MI Ada Tasking Commands:: |
a2c02241 NR |
25494 | * GDB/MI Program Execution:: |
25495 | * GDB/MI Stack Manipulation:: | |
25496 | * GDB/MI Variable Objects:: | |
922fbb7b | 25497 | * GDB/MI Data Manipulation:: |
a2c02241 NR |
25498 | * GDB/MI Tracepoint Commands:: |
25499 | * GDB/MI Symbol Query:: | |
351ff01a | 25500 | * GDB/MI File Commands:: |
922fbb7b AC |
25501 | @ignore |
25502 | * GDB/MI Kod Commands:: | |
25503 | * GDB/MI Memory Overlay Commands:: | |
25504 | * GDB/MI Signal Handling Commands:: | |
25505 | @end ignore | |
922fbb7b | 25506 | * GDB/MI Target Manipulation:: |
a6b151f1 | 25507 | * GDB/MI File Transfer Commands:: |
58d06528 | 25508 | * GDB/MI Ada Exceptions Commands:: |
d192b373 | 25509 | * GDB/MI Support Commands:: |
ef21caaf | 25510 | * GDB/MI Miscellaneous Commands:: |
922fbb7b AC |
25511 | @end menu |
25512 | ||
c3b108f7 VP |
25513 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25514 | @node GDB/MI General Design | |
25515 | @section @sc{gdb/mi} General Design | |
25516 | @cindex GDB/MI General Design | |
25517 | ||
25518 | Interaction of a @sc{GDB/MI} frontend with @value{GDBN} involves three | |
25519 | parts---commands sent to @value{GDBN}, responses to those commands | |
25520 | and notifications. Each command results in exactly one response, | |
25521 | indicating either successful completion of the command, or an error. | |
25522 | For the commands that do not resume the target, the response contains the | |
25523 | requested information. For the commands that resume the target, the | |
25524 | response only indicates whether the target was successfully resumed. | |
25525 | Notifications is the mechanism for reporting changes in the state of the | |
25526 | target, or in @value{GDBN} state, that cannot conveniently be associated with | |
25527 | a command and reported as part of that command response. | |
25528 | ||
25529 | The important examples of notifications are: | |
25530 | @itemize @bullet | |
25531 | ||
25532 | @item | |
25533 | Exec notifications. These are used to report changes in | |
25534 | target state---when a target is resumed, or stopped. It would not | |
25535 | be feasible to include this information in response of resuming | |
25536 | commands, because one resume commands can result in multiple events in | |
25537 | different threads. Also, quite some time may pass before any event | |
25538 | happens in the target, while a frontend needs to know whether the resuming | |
25539 | command itself was successfully executed. | |
25540 | ||
25541 | @item | |
25542 | Console output, and status notifications. Console output | |
25543 | notifications are used to report output of CLI commands, as well as | |
25544 | diagnostics for other commands. Status notifications are used to | |
25545 | report the progress of a long-running operation. Naturally, including | |
25546 | this information in command response would mean no output is produced | |
25547 | until the command is finished, which is undesirable. | |
25548 | ||
25549 | @item | |
25550 | General notifications. Commands may have various side effects on | |
25551 | the @value{GDBN} or target state beyond their official purpose. For example, | |
25552 | a command may change the selected thread. Although such changes can | |
25553 | be included in command response, using notification allows for more | |
25554 | orthogonal frontend design. | |
25555 | ||
25556 | @end itemize | |
25557 | ||
25558 | There's no guarantee that whenever an MI command reports an error, | |
25559 | @value{GDBN} or the target are in any specific state, and especially, | |
25560 | the state is not reverted to the state before the MI command was | |
25561 | processed. Therefore, whenever an MI command results in an error, | |
25562 | we recommend that the frontend refreshes all the information shown in | |
25563 | the user interface. | |
25564 | ||
508094de NR |
25565 | |
25566 | @menu | |
25567 | * Context management:: | |
25568 | * Asynchronous and non-stop modes:: | |
25569 | * Thread groups:: | |
25570 | @end menu | |
25571 | ||
25572 | @node Context management | |
c3b108f7 VP |
25573 | @subsection Context management |
25574 | ||
403cb6b1 JB |
25575 | @subsubsection Threads and Frames |
25576 | ||
c3b108f7 VP |
25577 | In most cases when @value{GDBN} accesses the target, this access is |
25578 | done in context of a specific thread and frame (@pxref{Frames}). | |
25579 | Often, even when accessing global data, the target requires that a thread | |
25580 | be specified. The CLI interface maintains the selected thread and frame, | |
25581 | and supplies them to target on each command. This is convenient, | |
25582 | because a command line user would not want to specify that information | |
25583 | explicitly on each command, and because user interacts with | |
25584 | @value{GDBN} via a single terminal, so no confusion is possible as | |
25585 | to what thread and frame are the current ones. | |
25586 | ||
25587 | In the case of MI, the concept of selected thread and frame is less | |
25588 | useful. First, a frontend can easily remember this information | |
25589 | itself. Second, a graphical frontend can have more than one window, | |
25590 | each one used for debugging a different thread, and the frontend might | |
25591 | want to access additional threads for internal purposes. This | |
25592 | increases the risk that by relying on implicitly selected thread, the | |
25593 | frontend may be operating on a wrong one. Therefore, each MI command | |
25594 | should explicitly specify which thread and frame to operate on. To | |
25595 | make it possible, each MI command accepts the @samp{--thread} and | |
5d5658a1 PA |
25596 | @samp{--frame} options, the value to each is @value{GDBN} global |
25597 | identifier for thread and frame to operate on. | |
c3b108f7 VP |
25598 | |
25599 | Usually, each top-level window in a frontend allows the user to select | |
25600 | a thread and a frame, and remembers the user selection for further | |
25601 | operations. However, in some cases @value{GDBN} may suggest that the | |
25602 | current thread be changed. For example, when stopping on a breakpoint | |
25603 | it is reasonable to switch to the thread where breakpoint is hit. For | |
25604 | another example, if the user issues the CLI @samp{thread} command via | |
25605 | the frontend, it is desirable to change the frontend's selected thread to the | |
25606 | one specified by user. @value{GDBN} communicates the suggestion to | |
25607 | change current thread using the @samp{=thread-selected} notification. | |
25608 | No such notification is available for the selected frame at the moment. | |
25609 | ||
25610 | Note that historically, MI shares the selected thread with CLI, so | |
25611 | frontends used the @code{-thread-select} to execute commands in the | |
25612 | right context. However, getting this to work right is cumbersome. The | |
25613 | simplest way is for frontend to emit @code{-thread-select} command | |
25614 | before every command. This doubles the number of commands that need | |
25615 | to be sent. The alternative approach is to suppress @code{-thread-select} | |
25616 | if the selected thread in @value{GDBN} is supposed to be identical to the | |
25617 | thread the frontend wants to operate on. However, getting this | |
25618 | optimization right can be tricky. In particular, if the frontend | |
25619 | sends several commands to @value{GDBN}, and one of the commands changes the | |
25620 | selected thread, then the behaviour of subsequent commands will | |
25621 | change. So, a frontend should either wait for response from such | |
25622 | problematic commands, or explicitly add @code{-thread-select} for | |
25623 | all subsequent commands. No frontend is known to do this exactly | |
25624 | right, so it is suggested to just always pass the @samp{--thread} and | |
25625 | @samp{--frame} options. | |
25626 | ||
403cb6b1 JB |
25627 | @subsubsection Language |
25628 | ||
25629 | The execution of several commands depends on which language is selected. | |
25630 | By default, the current language (@pxref{show language}) is used. | |
25631 | But for commands known to be language-sensitive, it is recommended | |
25632 | to use the @samp{--language} option. This option takes one argument, | |
25633 | which is the name of the language to use while executing the command. | |
25634 | For instance: | |
25635 | ||
25636 | @smallexample | |
25637 | -data-evaluate-expression --language c "sizeof (void*)" | |
25638 | ^done,value="4" | |
25639 | (gdb) | |
25640 | @end smallexample | |
25641 | ||
25642 | The valid language names are the same names accepted by the | |
25643 | @samp{set language} command (@pxref{Manually}), excluding @samp{auto}, | |
25644 | @samp{local} or @samp{unknown}. | |
25645 | ||
508094de | 25646 | @node Asynchronous and non-stop modes |
c3b108f7 VP |
25647 | @subsection Asynchronous command execution and non-stop mode |
25648 | ||
25649 | On some targets, @value{GDBN} is capable of processing MI commands | |
25650 | even while the target is running. This is called @dfn{asynchronous | |
25651 | command execution} (@pxref{Background Execution}). The frontend may | |
25652 | specify a preferrence for asynchronous execution using the | |
329ea579 | 25653 | @code{-gdb-set mi-async 1} command, which should be emitted before |
c3b108f7 VP |
25654 | either running the executable or attaching to the target. After the |
25655 | frontend has started the executable or attached to the target, it can | |
25656 | find if asynchronous execution is enabled using the | |
25657 | @code{-list-target-features} command. | |
25658 | ||
329ea579 PA |
25659 | @table @code |
25660 | @item -gdb-set mi-async on | |
25661 | @item -gdb-set mi-async off | |
25662 | Set whether MI is in asynchronous mode. | |
25663 | ||
25664 | When @code{off}, which is the default, MI execution commands (e.g., | |
25665 | @code{-exec-continue}) are foreground commands, and @value{GDBN} waits | |
25666 | for the program to stop before processing further commands. | |
25667 | ||
25668 | When @code{on}, MI execution commands are background execution | |
25669 | commands (e.g., @code{-exec-continue} becomes the equivalent of the | |
25670 | @code{c&} CLI command), and so @value{GDBN} is capable of processing | |
25671 | MI commands even while the target is running. | |
25672 | ||
25673 | @item -gdb-show mi-async | |
25674 | Show whether MI asynchronous mode is enabled. | |
25675 | @end table | |
25676 | ||
25677 | Note: In @value{GDBN} version 7.7 and earlier, this option was called | |
25678 | @code{target-async} instead of @code{mi-async}, and it had the effect | |
25679 | of both putting MI in asynchronous mode and making CLI background | |
25680 | commands possible. CLI background commands are now always possible | |
25681 | ``out of the box'' if the target supports them. The old spelling is | |
25682 | kept as a deprecated alias for backwards compatibility. | |
25683 | ||
c3b108f7 VP |
25684 | Even if @value{GDBN} can accept a command while target is running, |
25685 | many commands that access the target do not work when the target is | |
25686 | running. Therefore, asynchronous command execution is most useful | |
25687 | when combined with non-stop mode (@pxref{Non-Stop Mode}). Then, | |
25688 | it is possible to examine the state of one thread, while other threads | |
25689 | are running. | |
25690 | ||
25691 | When a given thread is running, MI commands that try to access the | |
25692 | target in the context of that thread may not work, or may work only on | |
25693 | some targets. In particular, commands that try to operate on thread's | |
25694 | stack will not work, on any target. Commands that read memory, or | |
25695 | modify breakpoints, may work or not work, depending on the target. Note | |
25696 | that even commands that operate on global state, such as @code{print}, | |
25697 | @code{set}, and breakpoint commands, still access the target in the | |
25698 | context of a specific thread, so frontend should try to find a | |
25699 | stopped thread and perform the operation on that thread (using the | |
25700 | @samp{--thread} option). | |
25701 | ||
25702 | Which commands will work in the context of a running thread is | |
25703 | highly target dependent. However, the two commands | |
25704 | @code{-exec-interrupt}, to stop a thread, and @code{-thread-info}, | |
25705 | to find the state of a thread, will always work. | |
25706 | ||
508094de | 25707 | @node Thread groups |
c3b108f7 VP |
25708 | @subsection Thread groups |
25709 | @value{GDBN} may be used to debug several processes at the same time. | |
25710 | On some platfroms, @value{GDBN} may support debugging of several | |
25711 | hardware systems, each one having several cores with several different | |
25712 | processes running on each core. This section describes the MI | |
25713 | mechanism to support such debugging scenarios. | |
25714 | ||
25715 | The key observation is that regardless of the structure of the | |
25716 | target, MI can have a global list of threads, because most commands that | |
25717 | accept the @samp{--thread} option do not need to know what process that | |
25718 | thread belongs to. Therefore, it is not necessary to introduce | |
25719 | neither additional @samp{--process} option, nor an notion of the | |
25720 | current process in the MI interface. The only strictly new feature | |
25721 | that is required is the ability to find how the threads are grouped | |
25722 | into processes. | |
25723 | ||
25724 | To allow the user to discover such grouping, and to support arbitrary | |
25725 | hierarchy of machines/cores/processes, MI introduces the concept of a | |
25726 | @dfn{thread group}. Thread group is a collection of threads and other | |
25727 | thread groups. A thread group always has a string identifier, a type, | |
25728 | and may have additional attributes specific to the type. A new | |
25729 | command, @code{-list-thread-groups}, returns the list of top-level | |
25730 | thread groups, which correspond to processes that @value{GDBN} is | |
25731 | debugging at the moment. By passing an identifier of a thread group | |
25732 | to the @code{-list-thread-groups} command, it is possible to obtain | |
25733 | the members of specific thread group. | |
25734 | ||
25735 | To allow the user to easily discover processes, and other objects, he | |
25736 | wishes to debug, a concept of @dfn{available thread group} is | |
25737 | introduced. Available thread group is an thread group that | |
25738 | @value{GDBN} is not debugging, but that can be attached to, using the | |
25739 | @code{-target-attach} command. The list of available top-level thread | |
25740 | groups can be obtained using @samp{-list-thread-groups --available}. | |
25741 | In general, the content of a thread group may be only retrieved only | |
25742 | after attaching to that thread group. | |
25743 | ||
a79b8f6e VP |
25744 | Thread groups are related to inferiors (@pxref{Inferiors and |
25745 | Programs}). Each inferior corresponds to a thread group of a special | |
25746 | type @samp{process}, and some additional operations are permitted on | |
25747 | such thread groups. | |
25748 | ||
922fbb7b AC |
25749 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25750 | @node GDB/MI Command Syntax | |
25751 | @section @sc{gdb/mi} Command Syntax | |
25752 | ||
25753 | @menu | |
25754 | * GDB/MI Input Syntax:: | |
25755 | * GDB/MI Output Syntax:: | |
922fbb7b AC |
25756 | @end menu |
25757 | ||
25758 | @node GDB/MI Input Syntax | |
25759 | @subsection @sc{gdb/mi} Input Syntax | |
25760 | ||
25761 | @cindex input syntax for @sc{gdb/mi} | |
25762 | @cindex @sc{gdb/mi}, input syntax | |
25763 | @table @code | |
25764 | @item @var{command} @expansion{} | |
25765 | @code{@var{cli-command} | @var{mi-command}} | |
25766 | ||
25767 | @item @var{cli-command} @expansion{} | |
25768 | @code{[ @var{token} ] @var{cli-command} @var{nl}}, where | |
25769 | @var{cli-command} is any existing @value{GDBN} CLI command. | |
25770 | ||
25771 | @item @var{mi-command} @expansion{} | |
25772 | @code{[ @var{token} ] "-" @var{operation} ( " " @var{option} )* | |
25773 | @code{[} " --" @code{]} ( " " @var{parameter} )* @var{nl}} | |
25774 | ||
25775 | @item @var{token} @expansion{} | |
25776 | "any sequence of digits" | |
25777 | ||
25778 | @item @var{option} @expansion{} | |
25779 | @code{"-" @var{parameter} [ " " @var{parameter} ]} | |
25780 | ||
25781 | @item @var{parameter} @expansion{} | |
25782 | @code{@var{non-blank-sequence} | @var{c-string}} | |
25783 | ||
25784 | @item @var{operation} @expansion{} | |
25785 | @emph{any of the operations described in this chapter} | |
25786 | ||
25787 | @item @var{non-blank-sequence} @expansion{} | |
25788 | @emph{anything, provided it doesn't contain special characters such as | |
25789 | "-", @var{nl}, """ and of course " "} | |
25790 | ||
25791 | @item @var{c-string} @expansion{} | |
25792 | @code{""" @var{seven-bit-iso-c-string-content} """} | |
25793 | ||
25794 | @item @var{nl} @expansion{} | |
25795 | @code{CR | CR-LF} | |
25796 | @end table | |
25797 | ||
25798 | @noindent | |
25799 | Notes: | |
25800 | ||
25801 | @itemize @bullet | |
25802 | @item | |
25803 | The CLI commands are still handled by the @sc{mi} interpreter; their | |
25804 | output is described below. | |
25805 | ||
25806 | @item | |
25807 | The @code{@var{token}}, when present, is passed back when the command | |
25808 | finishes. | |
25809 | ||
25810 | @item | |
25811 | Some @sc{mi} commands accept optional arguments as part of the parameter | |
25812 | list. Each option is identified by a leading @samp{-} (dash) and may be | |
25813 | followed by an optional argument parameter. Options occur first in the | |
25814 | parameter list and can be delimited from normal parameters using | |
25815 | @samp{--} (this is useful when some parameters begin with a dash). | |
25816 | @end itemize | |
25817 | ||
25818 | Pragmatics: | |
25819 | ||
25820 | @itemize @bullet | |
25821 | @item | |
25822 | We want easy access to the existing CLI syntax (for debugging). | |
25823 | ||
25824 | @item | |
25825 | We want it to be easy to spot a @sc{mi} operation. | |
25826 | @end itemize | |
25827 | ||
25828 | @node GDB/MI Output Syntax | |
25829 | @subsection @sc{gdb/mi} Output Syntax | |
25830 | ||
25831 | @cindex output syntax of @sc{gdb/mi} | |
25832 | @cindex @sc{gdb/mi}, output syntax | |
25833 | The output from @sc{gdb/mi} consists of zero or more out-of-band records | |
25834 | followed, optionally, by a single result record. This result record | |
25835 | is for the most recent command. The sequence of output records is | |
594fe323 | 25836 | terminated by @samp{(gdb)}. |
922fbb7b AC |
25837 | |
25838 | If an input command was prefixed with a @code{@var{token}} then the | |
25839 | corresponding output for that command will also be prefixed by that same | |
25840 | @var{token}. | |
25841 | ||
25842 | @table @code | |
25843 | @item @var{output} @expansion{} | |
594fe323 | 25844 | @code{( @var{out-of-band-record} )* [ @var{result-record} ] "(gdb)" @var{nl}} |
922fbb7b AC |
25845 | |
25846 | @item @var{result-record} @expansion{} | |
25847 | @code{ [ @var{token} ] "^" @var{result-class} ( "," @var{result} )* @var{nl}} | |
25848 | ||
25849 | @item @var{out-of-band-record} @expansion{} | |
25850 | @code{@var{async-record} | @var{stream-record}} | |
25851 | ||
25852 | @item @var{async-record} @expansion{} | |
25853 | @code{@var{exec-async-output} | @var{status-async-output} | @var{notify-async-output}} | |
25854 | ||
25855 | @item @var{exec-async-output} @expansion{} | |
dcf106f3 | 25856 | @code{[ @var{token} ] "*" @var{async-output nl}} |
922fbb7b AC |
25857 | |
25858 | @item @var{status-async-output} @expansion{} | |
dcf106f3 | 25859 | @code{[ @var{token} ] "+" @var{async-output nl}} |
922fbb7b AC |
25860 | |
25861 | @item @var{notify-async-output} @expansion{} | |
dcf106f3 | 25862 | @code{[ @var{token} ] "=" @var{async-output nl}} |
922fbb7b AC |
25863 | |
25864 | @item @var{async-output} @expansion{} | |
dcf106f3 | 25865 | @code{@var{async-class} ( "," @var{result} )*} |
922fbb7b AC |
25866 | |
25867 | @item @var{result-class} @expansion{} | |
25868 | @code{"done" | "running" | "connected" | "error" | "exit"} | |
25869 | ||
25870 | @item @var{async-class} @expansion{} | |
25871 | @code{"stopped" | @var{others}} (where @var{others} will be added | |
25872 | depending on the needs---this is still in development). | |
25873 | ||
25874 | @item @var{result} @expansion{} | |
25875 | @code{ @var{variable} "=" @var{value}} | |
25876 | ||
25877 | @item @var{variable} @expansion{} | |
25878 | @code{ @var{string} } | |
25879 | ||
25880 | @item @var{value} @expansion{} | |
25881 | @code{ @var{const} | @var{tuple} | @var{list} } | |
25882 | ||
25883 | @item @var{const} @expansion{} | |
25884 | @code{@var{c-string}} | |
25885 | ||
25886 | @item @var{tuple} @expansion{} | |
25887 | @code{ "@{@}" | "@{" @var{result} ( "," @var{result} )* "@}" } | |
25888 | ||
25889 | @item @var{list} @expansion{} | |
25890 | @code{ "[]" | "[" @var{value} ( "," @var{value} )* "]" | "[" | |
25891 | @var{result} ( "," @var{result} )* "]" } | |
25892 | ||
25893 | @item @var{stream-record} @expansion{} | |
25894 | @code{@var{console-stream-output} | @var{target-stream-output} | @var{log-stream-output}} | |
25895 | ||
25896 | @item @var{console-stream-output} @expansion{} | |
dcf106f3 | 25897 | @code{"~" @var{c-string nl}} |
922fbb7b AC |
25898 | |
25899 | @item @var{target-stream-output} @expansion{} | |
dcf106f3 | 25900 | @code{"@@" @var{c-string nl}} |
922fbb7b AC |
25901 | |
25902 | @item @var{log-stream-output} @expansion{} | |
dcf106f3 | 25903 | @code{"&" @var{c-string nl}} |
922fbb7b AC |
25904 | |
25905 | @item @var{nl} @expansion{} | |
25906 | @code{CR | CR-LF} | |
25907 | ||
25908 | @item @var{token} @expansion{} | |
25909 | @emph{any sequence of digits}. | |
25910 | @end table | |
25911 | ||
25912 | @noindent | |
25913 | Notes: | |
25914 | ||
25915 | @itemize @bullet | |
25916 | @item | |
25917 | All output sequences end in a single line containing a period. | |
25918 | ||
25919 | @item | |
721c02de VP |
25920 | The @code{@var{token}} is from the corresponding request. Note that |
25921 | for all async output, while the token is allowed by the grammar and | |
25922 | may be output by future versions of @value{GDBN} for select async | |
25923 | output messages, it is generally omitted. Frontends should treat | |
25924 | all async output as reporting general changes in the state of the | |
25925 | target and there should be no need to associate async output to any | |
25926 | prior command. | |
922fbb7b AC |
25927 | |
25928 | @item | |
25929 | @cindex status output in @sc{gdb/mi} | |
25930 | @var{status-async-output} contains on-going status information about the | |
25931 | progress of a slow operation. It can be discarded. All status output is | |
25932 | prefixed by @samp{+}. | |
25933 | ||
25934 | @item | |
25935 | @cindex async output in @sc{gdb/mi} | |
25936 | @var{exec-async-output} contains asynchronous state change on the target | |
25937 | (stopped, started, disappeared). All async output is prefixed by | |
25938 | @samp{*}. | |
25939 | ||
25940 | @item | |
25941 | @cindex notify output in @sc{gdb/mi} | |
25942 | @var{notify-async-output} contains supplementary information that the | |
25943 | client should handle (e.g., a new breakpoint information). All notify | |
25944 | output is prefixed by @samp{=}. | |
25945 | ||
25946 | @item | |
25947 | @cindex console output in @sc{gdb/mi} | |
25948 | @var{console-stream-output} is output that should be displayed as is in the | |
25949 | console. It is the textual response to a CLI command. All the console | |
25950 | output is prefixed by @samp{~}. | |
25951 | ||
25952 | @item | |
25953 | @cindex target output in @sc{gdb/mi} | |
25954 | @var{target-stream-output} is the output produced by the target program. | |
25955 | All the target output is prefixed by @samp{@@}. | |
25956 | ||
25957 | @item | |
25958 | @cindex log output in @sc{gdb/mi} | |
25959 | @var{log-stream-output} is output text coming from @value{GDBN}'s internals, for | |
25960 | instance messages that should be displayed as part of an error log. All | |
25961 | the log output is prefixed by @samp{&}. | |
25962 | ||
25963 | @item | |
25964 | @cindex list output in @sc{gdb/mi} | |
25965 | New @sc{gdb/mi} commands should only output @var{lists} containing | |
25966 | @var{values}. | |
25967 | ||
25968 | ||
25969 | @end itemize | |
25970 | ||
25971 | @xref{GDB/MI Stream Records, , @sc{gdb/mi} Stream Records}, for more | |
25972 | details about the various output records. | |
25973 | ||
922fbb7b AC |
25974 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25975 | @node GDB/MI Compatibility with CLI | |
25976 | @section @sc{gdb/mi} Compatibility with CLI | |
25977 | ||
25978 | @cindex compatibility, @sc{gdb/mi} and CLI | |
25979 | @cindex @sc{gdb/mi}, compatibility with CLI | |
922fbb7b | 25980 | |
a2c02241 NR |
25981 | For the developers convenience CLI commands can be entered directly, |
25982 | but there may be some unexpected behaviour. For example, commands | |
25983 | that query the user will behave as if the user replied yes, breakpoint | |
25984 | command lists are not executed and some CLI commands, such as | |
25985 | @code{if}, @code{when} and @code{define}, prompt for further input with | |
25986 | @samp{>}, which is not valid MI output. | |
ef21caaf NR |
25987 | |
25988 | This feature may be removed at some stage in the future and it is | |
a2c02241 NR |
25989 | recommended that front ends use the @code{-interpreter-exec} command |
25990 | (@pxref{-interpreter-exec}). | |
922fbb7b | 25991 | |
af6eff6f NR |
25992 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25993 | @node GDB/MI Development and Front Ends | |
25994 | @section @sc{gdb/mi} Development and Front Ends | |
25995 | @cindex @sc{gdb/mi} development | |
25996 | ||
25997 | The application which takes the MI output and presents the state of the | |
25998 | program being debugged to the user is called a @dfn{front end}. | |
25999 | ||
26000 | Although @sc{gdb/mi} is still incomplete, it is currently being used | |
26001 | by a variety of front ends to @value{GDBN}. This makes it difficult | |
26002 | to introduce new functionality without breaking existing usage. This | |
26003 | section tries to minimize the problems by describing how the protocol | |
26004 | might change. | |
26005 | ||
26006 | Some changes in MI need not break a carefully designed front end, and | |
26007 | for these the MI version will remain unchanged. The following is a | |
26008 | list of changes that may occur within one level, so front ends should | |
26009 | parse MI output in a way that can handle them: | |
26010 | ||
26011 | @itemize @bullet | |
26012 | @item | |
26013 | New MI commands may be added. | |
26014 | ||
26015 | @item | |
26016 | New fields may be added to the output of any MI command. | |
26017 | ||
36ece8b3 NR |
26018 | @item |
26019 | The range of values for fields with specified values, e.g., | |
9f708cb2 | 26020 | @code{in_scope} (@pxref{-var-update}) may be extended. |
36ece8b3 | 26021 | |
af6eff6f NR |
26022 | @c The format of field's content e.g type prefix, may change so parse it |
26023 | @c at your own risk. Yes, in general? | |
26024 | ||
26025 | @c The order of fields may change? Shouldn't really matter but it might | |
26026 | @c resolve inconsistencies. | |
26027 | @end itemize | |
26028 | ||
26029 | If the changes are likely to break front ends, the MI version level | |
26030 | will be increased by one. This will allow the front end to parse the | |
26031 | output according to the MI version. Apart from mi0, new versions of | |
26032 | @value{GDBN} will not support old versions of MI and it will be the | |
26033 | responsibility of the front end to work with the new one. | |
26034 | ||
26035 | @c Starting with mi3, add a new command -mi-version that prints the MI | |
26036 | @c version? | |
26037 | ||
26038 | The best way to avoid unexpected changes in MI that might break your front | |
26039 | end is to make your project known to @value{GDBN} developers and | |
7a9a6b69 | 26040 | follow development on @email{gdb@@sourceware.org} and |
fa0f268d | 26041 | @email{gdb-patches@@sourceware.org}. |
af6eff6f NR |
26042 | @cindex mailing lists |
26043 | ||
922fbb7b AC |
26044 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
26045 | @node GDB/MI Output Records | |
26046 | @section @sc{gdb/mi} Output Records | |
26047 | ||
26048 | @menu | |
26049 | * GDB/MI Result Records:: | |
26050 | * GDB/MI Stream Records:: | |
82f68b1c | 26051 | * GDB/MI Async Records:: |
54516a0b | 26052 | * GDB/MI Breakpoint Information:: |
c3b108f7 | 26053 | * GDB/MI Frame Information:: |
dc146f7c | 26054 | * GDB/MI Thread Information:: |
4368ebeb | 26055 | * GDB/MI Ada Exception Information:: |
922fbb7b AC |
26056 | @end menu |
26057 | ||
26058 | @node GDB/MI Result Records | |
26059 | @subsection @sc{gdb/mi} Result Records | |
26060 | ||
26061 | @cindex result records in @sc{gdb/mi} | |
26062 | @cindex @sc{gdb/mi}, result records | |
26063 | In addition to a number of out-of-band notifications, the response to a | |
26064 | @sc{gdb/mi} command includes one of the following result indications: | |
26065 | ||
26066 | @table @code | |
26067 | @findex ^done | |
26068 | @item "^done" [ "," @var{results} ] | |
26069 | The synchronous operation was successful, @code{@var{results}} are the return | |
26070 | values. | |
26071 | ||
26072 | @item "^running" | |
26073 | @findex ^running | |
8e9c5e02 VP |
26074 | This result record is equivalent to @samp{^done}. Historically, it |
26075 | was output instead of @samp{^done} if the command has resumed the | |
26076 | target. This behaviour is maintained for backward compatibility, but | |
26077 | all frontends should treat @samp{^done} and @samp{^running} | |
26078 | identically and rely on the @samp{*running} output record to determine | |
26079 | which threads are resumed. | |
922fbb7b | 26080 | |
ef21caaf NR |
26081 | @item "^connected" |
26082 | @findex ^connected | |
3f94c067 | 26083 | @value{GDBN} has connected to a remote target. |
ef21caaf | 26084 | |
2ea126fa | 26085 | @item "^error" "," "msg=" @var{c-string} [ "," "code=" @var{c-string} ] |
922fbb7b | 26086 | @findex ^error |
2ea126fa JB |
26087 | The operation failed. The @code{msg=@var{c-string}} variable contains |
26088 | the corresponding error message. | |
26089 | ||
26090 | If present, the @code{code=@var{c-string}} variable provides an error | |
26091 | code on which consumers can rely on to detect the corresponding | |
26092 | error condition. At present, only one error code is defined: | |
26093 | ||
26094 | @table @samp | |
26095 | @item "undefined-command" | |
26096 | Indicates that the command causing the error does not exist. | |
26097 | @end table | |
ef21caaf NR |
26098 | |
26099 | @item "^exit" | |
26100 | @findex ^exit | |
3f94c067 | 26101 | @value{GDBN} has terminated. |
ef21caaf | 26102 | |
922fbb7b AC |
26103 | @end table |
26104 | ||
26105 | @node GDB/MI Stream Records | |
26106 | @subsection @sc{gdb/mi} Stream Records | |
26107 | ||
26108 | @cindex @sc{gdb/mi}, stream records | |
26109 | @cindex stream records in @sc{gdb/mi} | |
26110 | @value{GDBN} internally maintains a number of output streams: the console, the | |
26111 | target, and the log. The output intended for each of these streams is | |
26112 | funneled through the @sc{gdb/mi} interface using @dfn{stream records}. | |
26113 | ||
26114 | Each stream record begins with a unique @dfn{prefix character} which | |
26115 | identifies its stream (@pxref{GDB/MI Output Syntax, , @sc{gdb/mi} Output | |
26116 | Syntax}). In addition to the prefix, each stream record contains a | |
26117 | @code{@var{string-output}}. This is either raw text (with an implicit new | |
26118 | line) or a quoted C string (which does not contain an implicit newline). | |
26119 | ||
26120 | @table @code | |
26121 | @item "~" @var{string-output} | |
26122 | The console output stream contains text that should be displayed in the | |
26123 | CLI console window. It contains the textual responses to CLI commands. | |
26124 | ||
26125 | @item "@@" @var{string-output} | |
26126 | The target output stream contains any textual output from the running | |
ef21caaf NR |
26127 | target. This is only present when GDB's event loop is truly |
26128 | asynchronous, which is currently only the case for remote targets. | |
922fbb7b AC |
26129 | |
26130 | @item "&" @var{string-output} | |
26131 | The log stream contains debugging messages being produced by @value{GDBN}'s | |
26132 | internals. | |
26133 | @end table | |
26134 | ||
82f68b1c VP |
26135 | @node GDB/MI Async Records |
26136 | @subsection @sc{gdb/mi} Async Records | |
922fbb7b | 26137 | |
82f68b1c VP |
26138 | @cindex async records in @sc{gdb/mi} |
26139 | @cindex @sc{gdb/mi}, async records | |
26140 | @dfn{Async} records are used to notify the @sc{gdb/mi} client of | |
922fbb7b | 26141 | additional changes that have occurred. Those changes can either be a |
82f68b1c | 26142 | consequence of @sc{gdb/mi} commands (e.g., a breakpoint modified) or a result of |
922fbb7b AC |
26143 | target activity (e.g., target stopped). |
26144 | ||
8eb41542 | 26145 | The following is the list of possible async records: |
922fbb7b AC |
26146 | |
26147 | @table @code | |
034dad6f | 26148 | |
e1ac3328 | 26149 | @item *running,thread-id="@var{thread}" |
5d5658a1 PA |
26150 | The target is now running. The @var{thread} field can be the global |
26151 | thread ID of the the thread that is now running, and it can be | |
26152 | @samp{all} if all threads are running. The frontend should assume | |
26153 | that no interaction with a running thread is possible after this | |
26154 | notification is produced. The frontend should not assume that this | |
26155 | notification is output only once for any command. @value{GDBN} may | |
26156 | emit this notification several times, either for different threads, | |
26157 | because it cannot resume all threads together, or even for a single | |
26158 | thread, if the thread must be stepped though some code before letting | |
26159 | it run freely. | |
e1ac3328 | 26160 | |
dc146f7c | 26161 | @item *stopped,reason="@var{reason}",thread-id="@var{id}",stopped-threads="@var{stopped}",core="@var{core}" |
82f68b1c VP |
26162 | The target has stopped. The @var{reason} field can have one of the |
26163 | following values: | |
034dad6f BR |
26164 | |
26165 | @table @code | |
26166 | @item breakpoint-hit | |
26167 | A breakpoint was reached. | |
26168 | @item watchpoint-trigger | |
26169 | A watchpoint was triggered. | |
26170 | @item read-watchpoint-trigger | |
26171 | A read watchpoint was triggered. | |
26172 | @item access-watchpoint-trigger | |
26173 | An access watchpoint was triggered. | |
26174 | @item function-finished | |
26175 | An -exec-finish or similar CLI command was accomplished. | |
26176 | @item location-reached | |
26177 | An -exec-until or similar CLI command was accomplished. | |
26178 | @item watchpoint-scope | |
26179 | A watchpoint has gone out of scope. | |
26180 | @item end-stepping-range | |
26181 | An -exec-next, -exec-next-instruction, -exec-step, -exec-step-instruction or | |
26182 | similar CLI command was accomplished. | |
26183 | @item exited-signalled | |
26184 | The inferior exited because of a signal. | |
26185 | @item exited | |
26186 | The inferior exited. | |
26187 | @item exited-normally | |
26188 | The inferior exited normally. | |
26189 | @item signal-received | |
26190 | A signal was received by the inferior. | |
36dfb11c TT |
26191 | @item solib-event |
26192 | The inferior has stopped due to a library being loaded or unloaded. | |
edcc5120 TT |
26193 | This can happen when @code{stop-on-solib-events} (@pxref{Files}) is |
26194 | set or when a @code{catch load} or @code{catch unload} catchpoint is | |
26195 | in use (@pxref{Set Catchpoints}). | |
36dfb11c TT |
26196 | @item fork |
26197 | The inferior has forked. This is reported when @code{catch fork} | |
26198 | (@pxref{Set Catchpoints}) has been used. | |
26199 | @item vfork | |
26200 | The inferior has vforked. This is reported in when @code{catch vfork} | |
26201 | (@pxref{Set Catchpoints}) has been used. | |
26202 | @item syscall-entry | |
26203 | The inferior entered a system call. This is reported when @code{catch | |
26204 | syscall} (@pxref{Set Catchpoints}) has been used. | |
a64c9f7b | 26205 | @item syscall-return |
36dfb11c TT |
26206 | The inferior returned from a system call. This is reported when |
26207 | @code{catch syscall} (@pxref{Set Catchpoints}) has been used. | |
26208 | @item exec | |
26209 | The inferior called @code{exec}. This is reported when @code{catch exec} | |
26210 | (@pxref{Set Catchpoints}) has been used. | |
922fbb7b AC |
26211 | @end table |
26212 | ||
5d5658a1 PA |
26213 | The @var{id} field identifies the global thread ID of the thread |
26214 | that directly caused the stop -- for example by hitting a breakpoint. | |
26215 | Depending on whether all-stop | |
c3b108f7 VP |
26216 | mode is in effect (@pxref{All-Stop Mode}), @value{GDBN} may either |
26217 | stop all threads, or only the thread that directly triggered the stop. | |
26218 | If all threads are stopped, the @var{stopped} field will have the | |
26219 | value of @code{"all"}. Otherwise, the value of the @var{stopped} | |
26220 | field will be a list of thread identifiers. Presently, this list will | |
26221 | always include a single thread, but frontend should be prepared to see | |
dc146f7c VP |
26222 | several threads in the list. The @var{core} field reports the |
26223 | processor core on which the stop event has happened. This field may be absent | |
26224 | if such information is not available. | |
c3b108f7 | 26225 | |
a79b8f6e VP |
26226 | @item =thread-group-added,id="@var{id}" |
26227 | @itemx =thread-group-removed,id="@var{id}" | |
26228 | A thread group was either added or removed. The @var{id} field | |
26229 | contains the @value{GDBN} identifier of the thread group. When a thread | |
26230 | group is added, it generally might not be associated with a running | |
26231 | process. When a thread group is removed, its id becomes invalid and | |
26232 | cannot be used in any way. | |
26233 | ||
26234 | @item =thread-group-started,id="@var{id}",pid="@var{pid}" | |
26235 | A thread group became associated with a running program, | |
26236 | either because the program was just started or the thread group | |
26237 | was attached to a program. The @var{id} field contains the | |
26238 | @value{GDBN} identifier of the thread group. The @var{pid} field | |
26239 | contains process identifier, specific to the operating system. | |
26240 | ||
8cf64490 | 26241 | @item =thread-group-exited,id="@var{id}"[,exit-code="@var{code}"] |
a79b8f6e VP |
26242 | A thread group is no longer associated with a running program, |
26243 | either because the program has exited, or because it was detached | |
c3b108f7 | 26244 | from. The @var{id} field contains the @value{GDBN} identifier of the |
697aa1b7 | 26245 | thread group. The @var{code} field is the exit code of the inferior; it exists |
8cf64490 | 26246 | only when the inferior exited with some code. |
c3b108f7 VP |
26247 | |
26248 | @item =thread-created,id="@var{id}",group-id="@var{gid}" | |
26249 | @itemx =thread-exited,id="@var{id}",group-id="@var{gid}" | |
82f68b1c | 26250 | A thread either was created, or has exited. The @var{id} field |
5d5658a1 | 26251 | contains the global @value{GDBN} identifier of the thread. The @var{gid} |
c3b108f7 | 26252 | field identifies the thread group this thread belongs to. |
66bb093b VP |
26253 | |
26254 | @item =thread-selected,id="@var{id}" | |
26255 | Informs that the selected thread was changed as result of the last | |
26256 | command. This notification is not emitted as result of @code{-thread-select} | |
26257 | command but is emitted whenever an MI command that is not documented | |
26258 | to change the selected thread actually changes it. In particular, | |
26259 | invoking, directly or indirectly (via user-defined command), the CLI | |
26260 | @code{thread} command, will generate this notification. | |
26261 | ||
26262 | We suggest that in response to this notification, front ends | |
26263 | highlight the selected thread and cause subsequent commands to apply to | |
26264 | that thread. | |
26265 | ||
c86cf029 VP |
26266 | @item =library-loaded,... |
26267 | Reports that a new library file was loaded by the program. This | |
26268 | notification has 4 fields---@var{id}, @var{target-name}, | |
134eb42c | 26269 | @var{host-name}, and @var{symbols-loaded}. The @var{id} field is an |
c86cf029 VP |
26270 | opaque identifier of the library. For remote debugging case, |
26271 | @var{target-name} and @var{host-name} fields give the name of the | |
134eb42c VP |
26272 | library file on the target, and on the host respectively. For native |
26273 | debugging, both those fields have the same value. The | |
f1cbe1d3 TT |
26274 | @var{symbols-loaded} field is emitted only for backward compatibility |
26275 | and should not be relied on to convey any useful information. The | |
26276 | @var{thread-group} field, if present, specifies the id of the thread | |
26277 | group in whose context the library was loaded. If the field is | |
26278 | absent, it means the library was loaded in the context of all present | |
26279 | thread groups. | |
c86cf029 VP |
26280 | |
26281 | @item =library-unloaded,... | |
134eb42c | 26282 | Reports that a library was unloaded by the program. This notification |
c86cf029 | 26283 | has 3 fields---@var{id}, @var{target-name} and @var{host-name} with |
a79b8f6e VP |
26284 | the same meaning as for the @code{=library-loaded} notification. |
26285 | The @var{thread-group} field, if present, specifies the id of the | |
26286 | thread group in whose context the library was unloaded. If the field is | |
26287 | absent, it means the library was unloaded in the context of all present | |
26288 | thread groups. | |
c86cf029 | 26289 | |
201b4506 YQ |
26290 | @item =traceframe-changed,num=@var{tfnum},tracepoint=@var{tpnum} |
26291 | @itemx =traceframe-changed,end | |
26292 | Reports that the trace frame was changed and its new number is | |
26293 | @var{tfnum}. The number of the tracepoint associated with this trace | |
26294 | frame is @var{tpnum}. | |
26295 | ||
134a2066 | 26296 | @item =tsv-created,name=@var{name},initial=@var{initial} |
bb25a15c | 26297 | Reports that the new trace state variable @var{name} is created with |
134a2066 | 26298 | initial value @var{initial}. |
bb25a15c YQ |
26299 | |
26300 | @item =tsv-deleted,name=@var{name} | |
26301 | @itemx =tsv-deleted | |
26302 | Reports that the trace state variable @var{name} is deleted or all | |
26303 | trace state variables are deleted. | |
26304 | ||
134a2066 YQ |
26305 | @item =tsv-modified,name=@var{name},initial=@var{initial}[,current=@var{current}] |
26306 | Reports that the trace state variable @var{name} is modified with | |
26307 | the initial value @var{initial}. The current value @var{current} of | |
26308 | trace state variable is optional and is reported if the current | |
26309 | value of trace state variable is known. | |
26310 | ||
8d3788bd VP |
26311 | @item =breakpoint-created,bkpt=@{...@} |
26312 | @itemx =breakpoint-modified,bkpt=@{...@} | |
d9f08f52 | 26313 | @itemx =breakpoint-deleted,id=@var{number} |
8d3788bd VP |
26314 | Reports that a breakpoint was created, modified, or deleted, |
26315 | respectively. Only user-visible breakpoints are reported to the MI | |
26316 | user. | |
26317 | ||
26318 | The @var{bkpt} argument is of the same form as returned by the various | |
d9f08f52 YQ |
26319 | breakpoint commands; @xref{GDB/MI Breakpoint Commands}. The |
26320 | @var{number} is the ordinal number of the breakpoint. | |
8d3788bd VP |
26321 | |
26322 | Note that if a breakpoint is emitted in the result record of a | |
26323 | command, then it will not also be emitted in an async record. | |
26324 | ||
82a90ccf YQ |
26325 | @item =record-started,thread-group="@var{id}" |
26326 | @itemx =record-stopped,thread-group="@var{id}" | |
26327 | Execution log recording was either started or stopped on an | |
26328 | inferior. The @var{id} is the @value{GDBN} identifier of the thread | |
26329 | group corresponding to the affected inferior. | |
26330 | ||
5b9afe8a YQ |
26331 | @item =cmd-param-changed,param=@var{param},value=@var{value} |
26332 | Reports that a parameter of the command @code{set @var{param}} is | |
26333 | changed to @var{value}. In the multi-word @code{set} command, | |
26334 | the @var{param} is the whole parameter list to @code{set} command. | |
26335 | For example, In command @code{set check type on}, @var{param} | |
26336 | is @code{check type} and @var{value} is @code{on}. | |
8de0566d YQ |
26337 | |
26338 | @item =memory-changed,thread-group=@var{id},addr=@var{addr},len=@var{len}[,type="code"] | |
26339 | Reports that bytes from @var{addr} to @var{data} + @var{len} were | |
26340 | written in an inferior. The @var{id} is the identifier of the | |
26341 | thread group corresponding to the affected inferior. The optional | |
26342 | @code{type="code"} part is reported if the memory written to holds | |
26343 | executable code. | |
82f68b1c VP |
26344 | @end table |
26345 | ||
54516a0b TT |
26346 | @node GDB/MI Breakpoint Information |
26347 | @subsection @sc{gdb/mi} Breakpoint Information | |
26348 | ||
26349 | When @value{GDBN} reports information about a breakpoint, a | |
26350 | tracepoint, a watchpoint, or a catchpoint, it uses a tuple with the | |
26351 | following fields: | |
26352 | ||
26353 | @table @code | |
26354 | @item number | |
26355 | The breakpoint number. For a breakpoint that represents one location | |
26356 | of a multi-location breakpoint, this will be a dotted pair, like | |
26357 | @samp{1.2}. | |
26358 | ||
26359 | @item type | |
26360 | The type of the breakpoint. For ordinary breakpoints this will be | |
26361 | @samp{breakpoint}, but many values are possible. | |
26362 | ||
8ac3646f TT |
26363 | @item catch-type |
26364 | If the type of the breakpoint is @samp{catchpoint}, then this | |
26365 | indicates the exact type of catchpoint. | |
26366 | ||
54516a0b TT |
26367 | @item disp |
26368 | This is the breakpoint disposition---either @samp{del}, meaning that | |
26369 | the breakpoint will be deleted at the next stop, or @samp{keep}, | |
26370 | meaning that the breakpoint will not be deleted. | |
26371 | ||
26372 | @item enabled | |
26373 | This indicates whether the breakpoint is enabled, in which case the | |
26374 | value is @samp{y}, or disabled, in which case the value is @samp{n}. | |
26375 | Note that this is not the same as the field @code{enable}. | |
26376 | ||
26377 | @item addr | |
26378 | The address of the breakpoint. This may be a hexidecimal number, | |
26379 | giving the address; or the string @samp{<PENDING>}, for a pending | |
26380 | breakpoint; or the string @samp{<MULTIPLE>}, for a breakpoint with | |
26381 | multiple locations. This field will not be present if no address can | |
26382 | be determined. For example, a watchpoint does not have an address. | |
26383 | ||
26384 | @item func | |
26385 | If known, the function in which the breakpoint appears. | |
26386 | If not known, this field is not present. | |
26387 | ||
26388 | @item filename | |
26389 | The name of the source file which contains this function, if known. | |
26390 | If not known, this field is not present. | |
26391 | ||
26392 | @item fullname | |
26393 | The full file name of the source file which contains this function, if | |
26394 | known. If not known, this field is not present. | |
26395 | ||
26396 | @item line | |
26397 | The line number at which this breakpoint appears, if known. | |
26398 | If not known, this field is not present. | |
26399 | ||
26400 | @item at | |
26401 | If the source file is not known, this field may be provided. If | |
26402 | provided, this holds the address of the breakpoint, possibly followed | |
26403 | by a symbol name. | |
26404 | ||
26405 | @item pending | |
26406 | If this breakpoint is pending, this field is present and holds the | |
26407 | text used to set the breakpoint, as entered by the user. | |
26408 | ||
26409 | @item evaluated-by | |
26410 | Where this breakpoint's condition is evaluated, either @samp{host} or | |
26411 | @samp{target}. | |
26412 | ||
26413 | @item thread | |
26414 | If this is a thread-specific breakpoint, then this identifies the | |
26415 | thread in which the breakpoint can trigger. | |
26416 | ||
26417 | @item task | |
26418 | If this breakpoint is restricted to a particular Ada task, then this | |
26419 | field will hold the task identifier. | |
26420 | ||
26421 | @item cond | |
26422 | If the breakpoint is conditional, this is the condition expression. | |
26423 | ||
26424 | @item ignore | |
26425 | The ignore count of the breakpoint. | |
26426 | ||
26427 | @item enable | |
26428 | The enable count of the breakpoint. | |
26429 | ||
26430 | @item traceframe-usage | |
26431 | FIXME. | |
26432 | ||
26433 | @item static-tracepoint-marker-string-id | |
26434 | For a static tracepoint, the name of the static tracepoint marker. | |
26435 | ||
26436 | @item mask | |
26437 | For a masked watchpoint, this is the mask. | |
26438 | ||
26439 | @item pass | |
26440 | A tracepoint's pass count. | |
26441 | ||
26442 | @item original-location | |
26443 | The location of the breakpoint as originally specified by the user. | |
26444 | This field is optional. | |
26445 | ||
26446 | @item times | |
26447 | The number of times the breakpoint has been hit. | |
26448 | ||
26449 | @item installed | |
26450 | This field is only given for tracepoints. This is either @samp{y}, | |
26451 | meaning that the tracepoint is installed, or @samp{n}, meaning that it | |
26452 | is not. | |
26453 | ||
26454 | @item what | |
26455 | Some extra data, the exact contents of which are type-dependent. | |
26456 | ||
26457 | @end table | |
26458 | ||
26459 | For example, here is what the output of @code{-break-insert} | |
26460 | (@pxref{GDB/MI Breakpoint Commands}) might be: | |
26461 | ||
26462 | @smallexample | |
26463 | -> -break-insert main | |
26464 | <- ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
26465 | enabled="y",addr="0x08048564",func="main",file="myprog.c", | |
998580f1 MK |
26466 | fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"], |
26467 | times="0"@} | |
54516a0b TT |
26468 | <- (gdb) |
26469 | @end smallexample | |
26470 | ||
c3b108f7 VP |
26471 | @node GDB/MI Frame Information |
26472 | @subsection @sc{gdb/mi} Frame Information | |
26473 | ||
26474 | Response from many MI commands includes an information about stack | |
26475 | frame. This information is a tuple that may have the following | |
26476 | fields: | |
26477 | ||
26478 | @table @code | |
26479 | @item level | |
26480 | The level of the stack frame. The innermost frame has the level of | |
26481 | zero. This field is always present. | |
26482 | ||
26483 | @item func | |
26484 | The name of the function corresponding to the frame. This field may | |
26485 | be absent if @value{GDBN} is unable to determine the function name. | |
26486 | ||
26487 | @item addr | |
26488 | The code address for the frame. This field is always present. | |
26489 | ||
26490 | @item file | |
26491 | The name of the source files that correspond to the frame's code | |
26492 | address. This field may be absent. | |
26493 | ||
26494 | @item line | |
26495 | The source line corresponding to the frames' code address. This field | |
26496 | may be absent. | |
26497 | ||
26498 | @item from | |
26499 | The name of the binary file (either executable or shared library) the | |
26500 | corresponds to the frame's code address. This field may be absent. | |
26501 | ||
26502 | @end table | |
82f68b1c | 26503 | |
dc146f7c VP |
26504 | @node GDB/MI Thread Information |
26505 | @subsection @sc{gdb/mi} Thread Information | |
26506 | ||
26507 | Whenever @value{GDBN} has to report an information about a thread, it | |
26508 | uses a tuple with the following fields: | |
26509 | ||
26510 | @table @code | |
26511 | @item id | |
5d5658a1 | 26512 | The global numeric id assigned to the thread by @value{GDBN}. This field is |
dc146f7c VP |
26513 | always present. |
26514 | ||
26515 | @item target-id | |
26516 | Target-specific string identifying the thread. This field is always present. | |
26517 | ||
26518 | @item details | |
26519 | Additional information about the thread provided by the target. | |
26520 | It is supposed to be human-readable and not interpreted by the | |
26521 | frontend. This field is optional. | |
26522 | ||
26523 | @item state | |
26524 | Either @samp{stopped} or @samp{running}, depending on whether the | |
26525 | thread is presently running. This field is always present. | |
26526 | ||
26527 | @item core | |
26528 | The value of this field is an integer number of the processor core the | |
26529 | thread was last seen on. This field is optional. | |
26530 | @end table | |
26531 | ||
956a9fb9 JB |
26532 | @node GDB/MI Ada Exception Information |
26533 | @subsection @sc{gdb/mi} Ada Exception Information | |
26534 | ||
26535 | Whenever a @code{*stopped} record is emitted because the program | |
26536 | stopped after hitting an exception catchpoint (@pxref{Set Catchpoints}), | |
26537 | @value{GDBN} provides the name of the exception that was raised via | |
26538 | the @code{exception-name} field. | |
922fbb7b | 26539 | |
ef21caaf NR |
26540 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
26541 | @node GDB/MI Simple Examples | |
26542 | @section Simple Examples of @sc{gdb/mi} Interaction | |
26543 | @cindex @sc{gdb/mi}, simple examples | |
26544 | ||
26545 | This subsection presents several simple examples of interaction using | |
26546 | the @sc{gdb/mi} interface. In these examples, @samp{->} means that the | |
26547 | following line is passed to @sc{gdb/mi} as input, while @samp{<-} means | |
26548 | the output received from @sc{gdb/mi}. | |
26549 | ||
d3e8051b | 26550 | Note the line breaks shown in the examples are here only for |
ef21caaf NR |
26551 | readability, they don't appear in the real output. |
26552 | ||
79a6e687 | 26553 | @subheading Setting a Breakpoint |
ef21caaf NR |
26554 | |
26555 | Setting a breakpoint generates synchronous output which contains detailed | |
26556 | information of the breakpoint. | |
26557 | ||
26558 | @smallexample | |
26559 | -> -break-insert main | |
26560 | <- ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
26561 | enabled="y",addr="0x08048564",func="main",file="myprog.c", | |
998580f1 MK |
26562 | fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"], |
26563 | times="0"@} | |
ef21caaf NR |
26564 | <- (gdb) |
26565 | @end smallexample | |
26566 | ||
26567 | @subheading Program Execution | |
26568 | ||
26569 | Program execution generates asynchronous records and MI gives the | |
26570 | reason that execution stopped. | |
26571 | ||
26572 | @smallexample | |
26573 | -> -exec-run | |
26574 | <- ^running | |
26575 | <- (gdb) | |
a47ec5fe | 26576 | <- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", |
ef21caaf NR |
26577 | frame=@{addr="0x08048564",func="main", |
26578 | args=[@{name="argc",value="1"@},@{name="argv",value="0xbfc4d4d4"@}], | |
26579 | file="myprog.c",fullname="/home/nickrob/myprog.c",line="68"@} | |
26580 | <- (gdb) | |
26581 | -> -exec-continue | |
26582 | <- ^running | |
26583 | <- (gdb) | |
26584 | <- *stopped,reason="exited-normally" | |
26585 | <- (gdb) | |
26586 | @end smallexample | |
26587 | ||
3f94c067 | 26588 | @subheading Quitting @value{GDBN} |
ef21caaf | 26589 | |
3f94c067 | 26590 | Quitting @value{GDBN} just prints the result class @samp{^exit}. |
ef21caaf NR |
26591 | |
26592 | @smallexample | |
26593 | -> (gdb) | |
26594 | <- -gdb-exit | |
26595 | <- ^exit | |
26596 | @end smallexample | |
26597 | ||
a6b29f87 VP |
26598 | Please note that @samp{^exit} is printed immediately, but it might |
26599 | take some time for @value{GDBN} to actually exit. During that time, @value{GDBN} | |
26600 | performs necessary cleanups, including killing programs being debugged | |
26601 | or disconnecting from debug hardware, so the frontend should wait till | |
26602 | @value{GDBN} exits and should only forcibly kill @value{GDBN} if it | |
26603 | fails to exit in reasonable time. | |
26604 | ||
a2c02241 | 26605 | @subheading A Bad Command |
ef21caaf NR |
26606 | |
26607 | Here's what happens if you pass a non-existent command: | |
26608 | ||
26609 | @smallexample | |
26610 | -> -rubbish | |
26611 | <- ^error,msg="Undefined MI command: rubbish" | |
594fe323 | 26612 | <- (gdb) |
ef21caaf NR |
26613 | @end smallexample |
26614 | ||
26615 | ||
922fbb7b AC |
26616 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
26617 | @node GDB/MI Command Description Format | |
26618 | @section @sc{gdb/mi} Command Description Format | |
26619 | ||
26620 | The remaining sections describe blocks of commands. Each block of | |
26621 | commands is laid out in a fashion similar to this section. | |
26622 | ||
922fbb7b AC |
26623 | @subheading Motivation |
26624 | ||
26625 | The motivation for this collection of commands. | |
26626 | ||
26627 | @subheading Introduction | |
26628 | ||
26629 | A brief introduction to this collection of commands as a whole. | |
26630 | ||
26631 | @subheading Commands | |
26632 | ||
26633 | For each command in the block, the following is described: | |
26634 | ||
26635 | @subsubheading Synopsis | |
26636 | ||
26637 | @smallexample | |
26638 | -command @var{args}@dots{} | |
26639 | @end smallexample | |
26640 | ||
922fbb7b AC |
26641 | @subsubheading Result |
26642 | ||
265eeb58 | 26643 | @subsubheading @value{GDBN} Command |
922fbb7b | 26644 | |
265eeb58 | 26645 | The corresponding @value{GDBN} CLI command(s), if any. |
922fbb7b AC |
26646 | |
26647 | @subsubheading Example | |
26648 | ||
ef21caaf NR |
26649 | Example(s) formatted for readability. Some of the described commands have |
26650 | not been implemented yet and these are labeled N.A.@: (not available). | |
26651 | ||
26652 | ||
922fbb7b | 26653 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
ef21caaf NR |
26654 | @node GDB/MI Breakpoint Commands |
26655 | @section @sc{gdb/mi} Breakpoint Commands | |
922fbb7b AC |
26656 | |
26657 | @cindex breakpoint commands for @sc{gdb/mi} | |
26658 | @cindex @sc{gdb/mi}, breakpoint commands | |
26659 | This section documents @sc{gdb/mi} commands for manipulating | |
26660 | breakpoints. | |
26661 | ||
26662 | @subheading The @code{-break-after} Command | |
26663 | @findex -break-after | |
26664 | ||
26665 | @subsubheading Synopsis | |
26666 | ||
26667 | @smallexample | |
26668 | -break-after @var{number} @var{count} | |
26669 | @end smallexample | |
26670 | ||
26671 | The breakpoint number @var{number} is not in effect until it has been | |
26672 | hit @var{count} times. To see how this is reflected in the output of | |
26673 | the @samp{-break-list} command, see the description of the | |
26674 | @samp{-break-list} command below. | |
26675 | ||
26676 | @subsubheading @value{GDBN} Command | |
26677 | ||
26678 | The corresponding @value{GDBN} command is @samp{ignore}. | |
26679 | ||
26680 | @subsubheading Example | |
26681 | ||
26682 | @smallexample | |
594fe323 | 26683 | (gdb) |
922fbb7b | 26684 | -break-insert main |
a47ec5fe AR |
26685 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep", |
26686 | enabled="y",addr="0x000100d0",func="main",file="hello.c", | |
998580f1 MK |
26687 | fullname="/home/foo/hello.c",line="5",thread-groups=["i1"], |
26688 | times="0"@} | |
594fe323 | 26689 | (gdb) |
922fbb7b AC |
26690 | -break-after 1 3 |
26691 | ~ | |
26692 | ^done | |
594fe323 | 26693 | (gdb) |
922fbb7b AC |
26694 | -break-list |
26695 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
26696 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26697 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26698 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26699 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26700 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26701 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26702 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 26703 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 26704 | line="5",thread-groups=["i1"],times="0",ignore="3"@}]@} |
594fe323 | 26705 | (gdb) |
922fbb7b AC |
26706 | @end smallexample |
26707 | ||
26708 | @ignore | |
26709 | @subheading The @code{-break-catch} Command | |
26710 | @findex -break-catch | |
48cb2d85 | 26711 | @end ignore |
922fbb7b AC |
26712 | |
26713 | @subheading The @code{-break-commands} Command | |
26714 | @findex -break-commands | |
922fbb7b | 26715 | |
48cb2d85 VP |
26716 | @subsubheading Synopsis |
26717 | ||
26718 | @smallexample | |
26719 | -break-commands @var{number} [ @var{command1} ... @var{commandN} ] | |
26720 | @end smallexample | |
26721 | ||
26722 | Specifies the CLI commands that should be executed when breakpoint | |
26723 | @var{number} is hit. The parameters @var{command1} to @var{commandN} | |
26724 | are the commands. If no command is specified, any previously-set | |
26725 | commands are cleared. @xref{Break Commands}. Typical use of this | |
26726 | functionality is tracing a program, that is, printing of values of | |
26727 | some variables whenever breakpoint is hit and then continuing. | |
26728 | ||
26729 | @subsubheading @value{GDBN} Command | |
26730 | ||
26731 | The corresponding @value{GDBN} command is @samp{commands}. | |
26732 | ||
26733 | @subsubheading Example | |
26734 | ||
26735 | @smallexample | |
26736 | (gdb) | |
26737 | -break-insert main | |
26738 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
26739 | enabled="y",addr="0x000100d0",func="main",file="hello.c", | |
998580f1 MK |
26740 | fullname="/home/foo/hello.c",line="5",thread-groups=["i1"], |
26741 | times="0"@} | |
48cb2d85 VP |
26742 | (gdb) |
26743 | -break-commands 1 "print v" "continue" | |
26744 | ^done | |
26745 | (gdb) | |
26746 | @end smallexample | |
922fbb7b AC |
26747 | |
26748 | @subheading The @code{-break-condition} Command | |
26749 | @findex -break-condition | |
26750 | ||
26751 | @subsubheading Synopsis | |
26752 | ||
26753 | @smallexample | |
26754 | -break-condition @var{number} @var{expr} | |
26755 | @end smallexample | |
26756 | ||
26757 | Breakpoint @var{number} will stop the program only if the condition in | |
26758 | @var{expr} is true. The condition becomes part of the | |
26759 | @samp{-break-list} output (see the description of the @samp{-break-list} | |
26760 | command below). | |
26761 | ||
26762 | @subsubheading @value{GDBN} Command | |
26763 | ||
26764 | The corresponding @value{GDBN} command is @samp{condition}. | |
26765 | ||
26766 | @subsubheading Example | |
26767 | ||
26768 | @smallexample | |
594fe323 | 26769 | (gdb) |
922fbb7b AC |
26770 | -break-condition 1 1 |
26771 | ^done | |
594fe323 | 26772 | (gdb) |
922fbb7b AC |
26773 | -break-list |
26774 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
26775 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26776 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26777 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26778 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26779 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26780 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26781 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 26782 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 26783 | line="5",cond="1",thread-groups=["i1"],times="0",ignore="3"@}]@} |
594fe323 | 26784 | (gdb) |
922fbb7b AC |
26785 | @end smallexample |
26786 | ||
26787 | @subheading The @code{-break-delete} Command | |
26788 | @findex -break-delete | |
26789 | ||
26790 | @subsubheading Synopsis | |
26791 | ||
26792 | @smallexample | |
26793 | -break-delete ( @var{breakpoint} )+ | |
26794 | @end smallexample | |
26795 | ||
26796 | Delete the breakpoint(s) whose number(s) are specified in the argument | |
26797 | list. This is obviously reflected in the breakpoint list. | |
26798 | ||
79a6e687 | 26799 | @subsubheading @value{GDBN} Command |
922fbb7b AC |
26800 | |
26801 | The corresponding @value{GDBN} command is @samp{delete}. | |
26802 | ||
26803 | @subsubheading Example | |
26804 | ||
26805 | @smallexample | |
594fe323 | 26806 | (gdb) |
922fbb7b AC |
26807 | -break-delete 1 |
26808 | ^done | |
594fe323 | 26809 | (gdb) |
922fbb7b AC |
26810 | -break-list |
26811 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
26812 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26813 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26814 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26815 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26816 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26817 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26818 | body=[]@} | |
594fe323 | 26819 | (gdb) |
922fbb7b AC |
26820 | @end smallexample |
26821 | ||
26822 | @subheading The @code{-break-disable} Command | |
26823 | @findex -break-disable | |
26824 | ||
26825 | @subsubheading Synopsis | |
26826 | ||
26827 | @smallexample | |
26828 | -break-disable ( @var{breakpoint} )+ | |
26829 | @end smallexample | |
26830 | ||
26831 | Disable the named @var{breakpoint}(s). The field @samp{enabled} in the | |
26832 | break list is now set to @samp{n} for the named @var{breakpoint}(s). | |
26833 | ||
26834 | @subsubheading @value{GDBN} Command | |
26835 | ||
26836 | The corresponding @value{GDBN} command is @samp{disable}. | |
26837 | ||
26838 | @subsubheading Example | |
26839 | ||
26840 | @smallexample | |
594fe323 | 26841 | (gdb) |
922fbb7b AC |
26842 | -break-disable 2 |
26843 | ^done | |
594fe323 | 26844 | (gdb) |
922fbb7b AC |
26845 | -break-list |
26846 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
26847 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26848 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26849 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26850 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26851 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26852 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26853 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="n", | |
948d5102 | 26854 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 26855 | line="5",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 26856 | (gdb) |
922fbb7b AC |
26857 | @end smallexample |
26858 | ||
26859 | @subheading The @code{-break-enable} Command | |
26860 | @findex -break-enable | |
26861 | ||
26862 | @subsubheading Synopsis | |
26863 | ||
26864 | @smallexample | |
26865 | -break-enable ( @var{breakpoint} )+ | |
26866 | @end smallexample | |
26867 | ||
26868 | Enable (previously disabled) @var{breakpoint}(s). | |
26869 | ||
26870 | @subsubheading @value{GDBN} Command | |
26871 | ||
26872 | The corresponding @value{GDBN} command is @samp{enable}. | |
26873 | ||
26874 | @subsubheading Example | |
26875 | ||
26876 | @smallexample | |
594fe323 | 26877 | (gdb) |
922fbb7b AC |
26878 | -break-enable 2 |
26879 | ^done | |
594fe323 | 26880 | (gdb) |
922fbb7b AC |
26881 | -break-list |
26882 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
26883 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
26884 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
26885 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
26886 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
26887 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
26888 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
26889 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 26890 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 26891 | line="5",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 26892 | (gdb) |
922fbb7b AC |
26893 | @end smallexample |
26894 | ||
26895 | @subheading The @code{-break-info} Command | |
26896 | @findex -break-info | |
26897 | ||
26898 | @subsubheading Synopsis | |
26899 | ||
26900 | @smallexample | |
26901 | -break-info @var{breakpoint} | |
26902 | @end smallexample | |
26903 | ||
26904 | @c REDUNDANT??? | |
26905 | Get information about a single breakpoint. | |
26906 | ||
54516a0b TT |
26907 | The result is a table of breakpoints. @xref{GDB/MI Breakpoint |
26908 | Information}, for details on the format of each breakpoint in the | |
26909 | table. | |
26910 | ||
79a6e687 | 26911 | @subsubheading @value{GDBN} Command |
922fbb7b AC |
26912 | |
26913 | The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}. | |
26914 | ||
26915 | @subsubheading Example | |
26916 | N.A. | |
26917 | ||
26918 | @subheading The @code{-break-insert} Command | |
26919 | @findex -break-insert | |
629500fa | 26920 | @anchor{-break-insert} |
922fbb7b AC |
26921 | |
26922 | @subsubheading Synopsis | |
26923 | ||
26924 | @smallexample | |
18148017 | 26925 | -break-insert [ -t ] [ -h ] [ -f ] [ -d ] [ -a ] |
922fbb7b | 26926 | [ -c @var{condition} ] [ -i @var{ignore-count} ] |
472a2379 | 26927 | [ -p @var{thread-id} ] [ @var{location} ] |
922fbb7b AC |
26928 | @end smallexample |
26929 | ||
26930 | @noindent | |
afe8ab22 | 26931 | If specified, @var{location}, can be one of: |
922fbb7b | 26932 | |
629500fa KS |
26933 | @table @var |
26934 | @item linespec location | |
26935 | A linespec location. @xref{Linespec Locations}. | |
26936 | ||
26937 | @item explicit location | |
26938 | An explicit location. @sc{gdb/mi} explicit locations are | |
26939 | analogous to the CLI's explicit locations using the option names | |
26940 | listed below. @xref{Explicit Locations}. | |
26941 | ||
26942 | @table @samp | |
26943 | @item --source @var{filename} | |
26944 | The source file name of the location. This option requires the use | |
26945 | of either @samp{--function} or @samp{--line}. | |
26946 | ||
26947 | @item --function @var{function} | |
26948 | The name of a function or method. | |
922fbb7b | 26949 | |
629500fa KS |
26950 | @item --label @var{label} |
26951 | The name of a label. | |
26952 | ||
26953 | @item --line @var{lineoffset} | |
26954 | An absolute or relative line offset from the start of the location. | |
26955 | @end table | |
26956 | ||
26957 | @item address location | |
26958 | An address location, *@var{address}. @xref{Address Locations}. | |
26959 | @end table | |
26960 | ||
26961 | @noindent | |
922fbb7b AC |
26962 | The possible optional parameters of this command are: |
26963 | ||
26964 | @table @samp | |
26965 | @item -t | |
948d5102 | 26966 | Insert a temporary breakpoint. |
922fbb7b AC |
26967 | @item -h |
26968 | Insert a hardware breakpoint. | |
afe8ab22 VP |
26969 | @item -f |
26970 | If @var{location} cannot be parsed (for example if it | |
26971 | refers to unknown files or functions), create a pending | |
26972 | breakpoint. Without this flag, @value{GDBN} will report | |
26973 | an error, and won't create a breakpoint, if @var{location} | |
26974 | cannot be parsed. | |
41447f92 VP |
26975 | @item -d |
26976 | Create a disabled breakpoint. | |
18148017 VP |
26977 | @item -a |
26978 | Create a tracepoint. @xref{Tracepoints}. When this parameter | |
26979 | is used together with @samp{-h}, a fast tracepoint is created. | |
472a2379 KS |
26980 | @item -c @var{condition} |
26981 | Make the breakpoint conditional on @var{condition}. | |
26982 | @item -i @var{ignore-count} | |
26983 | Initialize the @var{ignore-count}. | |
26984 | @item -p @var{thread-id} | |
5d5658a1 PA |
26985 | Restrict the breakpoint to the thread with the specified global |
26986 | @var{thread-id}. | |
922fbb7b AC |
26987 | @end table |
26988 | ||
26989 | @subsubheading Result | |
26990 | ||
54516a0b TT |
26991 | @xref{GDB/MI Breakpoint Information}, for details on the format of the |
26992 | resulting breakpoint. | |
922fbb7b AC |
26993 | |
26994 | Note: this format is open to change. | |
26995 | @c An out-of-band breakpoint instead of part of the result? | |
26996 | ||
26997 | @subsubheading @value{GDBN} Command | |
26998 | ||
26999 | The corresponding @value{GDBN} commands are @samp{break}, @samp{tbreak}, | |
496ee73e | 27000 | @samp{hbreak}, and @samp{thbreak}. @c and @samp{rbreak}. |
922fbb7b AC |
27001 | |
27002 | @subsubheading Example | |
27003 | ||
27004 | @smallexample | |
594fe323 | 27005 | (gdb) |
922fbb7b | 27006 | -break-insert main |
948d5102 | 27007 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c", |
998580f1 MK |
27008 | fullname="/home/foo/recursive2.c,line="4",thread-groups=["i1"], |
27009 | times="0"@} | |
594fe323 | 27010 | (gdb) |
922fbb7b | 27011 | -break-insert -t foo |
948d5102 | 27012 | ^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c", |
998580f1 MK |
27013 | fullname="/home/foo/recursive2.c,line="11",thread-groups=["i1"], |
27014 | times="0"@} | |
594fe323 | 27015 | (gdb) |
922fbb7b AC |
27016 | -break-list |
27017 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
27018 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
27019 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
27020 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
27021 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
27022 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
27023 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
27024 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 | 27025 | addr="0x0001072c", func="main",file="recursive2.c", |
998580f1 MK |
27026 | fullname="/home/foo/recursive2.c,"line="4",thread-groups=["i1"], |
27027 | times="0"@}, | |
922fbb7b | 27028 | bkpt=@{number="2",type="breakpoint",disp="del",enabled="y", |
948d5102 | 27029 | addr="0x00010774",func="foo",file="recursive2.c", |
998580f1 MK |
27030 | fullname="/home/foo/recursive2.c",line="11",thread-groups=["i1"], |
27031 | times="0"@}]@} | |
594fe323 | 27032 | (gdb) |
496ee73e KS |
27033 | @c -break-insert -r foo.* |
27034 | @c ~int foo(int, int); | |
27035 | @c ^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c, | |
998580f1 MK |
27036 | @c "fullname="/home/foo/recursive2.c",line="11",thread-groups=["i1"], |
27037 | @c times="0"@} | |
496ee73e | 27038 | @c (gdb) |
922fbb7b AC |
27039 | @end smallexample |
27040 | ||
c5867ab6 HZ |
27041 | @subheading The @code{-dprintf-insert} Command |
27042 | @findex -dprintf-insert | |
27043 | ||
27044 | @subsubheading Synopsis | |
27045 | ||
27046 | @smallexample | |
27047 | -dprintf-insert [ -t ] [ -f ] [ -d ] | |
27048 | [ -c @var{condition} ] [ -i @var{ignore-count} ] | |
27049 | [ -p @var{thread-id} ] [ @var{location} ] [ @var{format} ] | |
27050 | [ @var{argument} ] | |
27051 | @end smallexample | |
27052 | ||
27053 | @noindent | |
629500fa KS |
27054 | If supplied, @var{location} may be specified the same way as for |
27055 | the @code{-break-insert} command. @xref{-break-insert}. | |
c5867ab6 HZ |
27056 | |
27057 | The possible optional parameters of this command are: | |
27058 | ||
27059 | @table @samp | |
27060 | @item -t | |
27061 | Insert a temporary breakpoint. | |
27062 | @item -f | |
27063 | If @var{location} cannot be parsed (for example, if it | |
27064 | refers to unknown files or functions), create a pending | |
27065 | breakpoint. Without this flag, @value{GDBN} will report | |
27066 | an error, and won't create a breakpoint, if @var{location} | |
27067 | cannot be parsed. | |
27068 | @item -d | |
27069 | Create a disabled breakpoint. | |
27070 | @item -c @var{condition} | |
27071 | Make the breakpoint conditional on @var{condition}. | |
27072 | @item -i @var{ignore-count} | |
27073 | Set the ignore count of the breakpoint (@pxref{Conditions, ignore count}) | |
27074 | to @var{ignore-count}. | |
27075 | @item -p @var{thread-id} | |
5d5658a1 PA |
27076 | Restrict the breakpoint to the thread with the specified global |
27077 | @var{thread-id}. | |
c5867ab6 HZ |
27078 | @end table |
27079 | ||
27080 | @subsubheading Result | |
27081 | ||
27082 | @xref{GDB/MI Breakpoint Information}, for details on the format of the | |
27083 | resulting breakpoint. | |
27084 | ||
27085 | @c An out-of-band breakpoint instead of part of the result? | |
27086 | ||
27087 | @subsubheading @value{GDBN} Command | |
27088 | ||
27089 | The corresponding @value{GDBN} command is @samp{dprintf}. | |
27090 | ||
27091 | @subsubheading Example | |
27092 | ||
27093 | @smallexample | |
27094 | (gdb) | |
27095 | 4-dprintf-insert foo "At foo entry\n" | |
27096 | 4^done,bkpt=@{number="1",type="dprintf",disp="keep",enabled="y", | |
27097 | addr="0x000000000040061b",func="foo",file="mi-dprintf.c", | |
27098 | fullname="mi-dprintf.c",line="25",thread-groups=["i1"], | |
27099 | times="0",script=@{"printf \"At foo entry\\n\"","continue"@}, | |
27100 | original-location="foo"@} | |
27101 | (gdb) | |
27102 | 5-dprintf-insert 26 "arg=%d, g=%d\n" arg g | |
27103 | 5^done,bkpt=@{number="2",type="dprintf",disp="keep",enabled="y", | |
27104 | addr="0x000000000040062a",func="foo",file="mi-dprintf.c", | |
27105 | fullname="mi-dprintf.c",line="26",thread-groups=["i1"], | |
27106 | times="0",script=@{"printf \"arg=%d, g=%d\\n\", arg, g","continue"@}, | |
27107 | original-location="mi-dprintf.c:26"@} | |
27108 | (gdb) | |
27109 | @end smallexample | |
27110 | ||
922fbb7b AC |
27111 | @subheading The @code{-break-list} Command |
27112 | @findex -break-list | |
27113 | ||
27114 | @subsubheading Synopsis | |
27115 | ||
27116 | @smallexample | |
27117 | -break-list | |
27118 | @end smallexample | |
27119 | ||
27120 | Displays the list of inserted breakpoints, showing the following fields: | |
27121 | ||
27122 | @table @samp | |
27123 | @item Number | |
27124 | number of the breakpoint | |
27125 | @item Type | |
27126 | type of the breakpoint: @samp{breakpoint} or @samp{watchpoint} | |
27127 | @item Disposition | |
27128 | should the breakpoint be deleted or disabled when it is hit: @samp{keep} | |
27129 | or @samp{nokeep} | |
27130 | @item Enabled | |
27131 | is the breakpoint enabled or no: @samp{y} or @samp{n} | |
27132 | @item Address | |
27133 | memory location at which the breakpoint is set | |
27134 | @item What | |
27135 | logical location of the breakpoint, expressed by function name, file | |
27136 | name, line number | |
998580f1 MK |
27137 | @item Thread-groups |
27138 | list of thread groups to which this breakpoint applies | |
922fbb7b AC |
27139 | @item Times |
27140 | number of times the breakpoint has been hit | |
27141 | @end table | |
27142 | ||
27143 | If there are no breakpoints or watchpoints, the @code{BreakpointTable} | |
27144 | @code{body} field is an empty list. | |
27145 | ||
27146 | @subsubheading @value{GDBN} Command | |
27147 | ||
27148 | The corresponding @value{GDBN} command is @samp{info break}. | |
27149 | ||
27150 | @subsubheading Example | |
27151 | ||
27152 | @smallexample | |
594fe323 | 27153 | (gdb) |
922fbb7b AC |
27154 | -break-list |
27155 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
27156 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
27157 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
27158 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
27159 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
27160 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
27161 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
27162 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
998580f1 MK |
27163 | addr="0x000100d0",func="main",file="hello.c",line="5",thread-groups=["i1"], |
27164 | times="0"@}, | |
922fbb7b | 27165 | bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", |
948d5102 | 27166 | addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c", |
998580f1 | 27167 | line="13",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 27168 | (gdb) |
922fbb7b AC |
27169 | @end smallexample |
27170 | ||
27171 | Here's an example of the result when there are no breakpoints: | |
27172 | ||
27173 | @smallexample | |
594fe323 | 27174 | (gdb) |
922fbb7b AC |
27175 | -break-list |
27176 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
27177 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
27178 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
27179 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
27180 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
27181 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
27182 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
27183 | body=[]@} | |
594fe323 | 27184 | (gdb) |
922fbb7b AC |
27185 | @end smallexample |
27186 | ||
18148017 VP |
27187 | @subheading The @code{-break-passcount} Command |
27188 | @findex -break-passcount | |
27189 | ||
27190 | @subsubheading Synopsis | |
27191 | ||
27192 | @smallexample | |
27193 | -break-passcount @var{tracepoint-number} @var{passcount} | |
27194 | @end smallexample | |
27195 | ||
27196 | Set the passcount for tracepoint @var{tracepoint-number} to | |
27197 | @var{passcount}. If the breakpoint referred to by @var{tracepoint-number} | |
27198 | is not a tracepoint, error is emitted. This corresponds to CLI | |
27199 | command @samp{passcount}. | |
27200 | ||
922fbb7b AC |
27201 | @subheading The @code{-break-watch} Command |
27202 | @findex -break-watch | |
27203 | ||
27204 | @subsubheading Synopsis | |
27205 | ||
27206 | @smallexample | |
27207 | -break-watch [ -a | -r ] | |
27208 | @end smallexample | |
27209 | ||
27210 | Create a watchpoint. With the @samp{-a} option it will create an | |
d3e8051b | 27211 | @dfn{access} watchpoint, i.e., a watchpoint that triggers either on a |
922fbb7b | 27212 | read from or on a write to the memory location. With the @samp{-r} |
d3e8051b | 27213 | option, the watchpoint created is a @dfn{read} watchpoint, i.e., it will |
922fbb7b AC |
27214 | trigger only when the memory location is accessed for reading. Without |
27215 | either of the options, the watchpoint created is a regular watchpoint, | |
d3e8051b | 27216 | i.e., it will trigger when the memory location is accessed for writing. |
79a6e687 | 27217 | @xref{Set Watchpoints, , Setting Watchpoints}. |
922fbb7b AC |
27218 | |
27219 | Note that @samp{-break-list} will report a single list of watchpoints and | |
27220 | breakpoints inserted. | |
27221 | ||
27222 | @subsubheading @value{GDBN} Command | |
27223 | ||
27224 | The corresponding @value{GDBN} commands are @samp{watch}, @samp{awatch}, and | |
27225 | @samp{rwatch}. | |
27226 | ||
27227 | @subsubheading Example | |
27228 | ||
27229 | Setting a watchpoint on a variable in the @code{main} function: | |
27230 | ||
27231 | @smallexample | |
594fe323 | 27232 | (gdb) |
922fbb7b AC |
27233 | -break-watch x |
27234 | ^done,wpt=@{number="2",exp="x"@} | |
594fe323 | 27235 | (gdb) |
922fbb7b AC |
27236 | -exec-continue |
27237 | ^running | |
0869d01b NR |
27238 | (gdb) |
27239 | *stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@}, | |
922fbb7b | 27240 | value=@{old="-268439212",new="55"@}, |
76ff342d | 27241 | frame=@{func="main",args=[],file="recursive2.c", |
948d5102 | 27242 | fullname="/home/foo/bar/recursive2.c",line="5"@} |
594fe323 | 27243 | (gdb) |
922fbb7b AC |
27244 | @end smallexample |
27245 | ||
27246 | Setting a watchpoint on a variable local to a function. @value{GDBN} will stop | |
27247 | the program execution twice: first for the variable changing value, then | |
27248 | for the watchpoint going out of scope. | |
27249 | ||
27250 | @smallexample | |
594fe323 | 27251 | (gdb) |
922fbb7b AC |
27252 | -break-watch C |
27253 | ^done,wpt=@{number="5",exp="C"@} | |
594fe323 | 27254 | (gdb) |
922fbb7b AC |
27255 | -exec-continue |
27256 | ^running | |
0869d01b NR |
27257 | (gdb) |
27258 | *stopped,reason="watchpoint-trigger", | |
922fbb7b AC |
27259 | wpt=@{number="5",exp="C"@},value=@{old="-276895068",new="3"@}, |
27260 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
27261 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27262 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
594fe323 | 27263 | (gdb) |
922fbb7b AC |
27264 | -exec-continue |
27265 | ^running | |
0869d01b NR |
27266 | (gdb) |
27267 | *stopped,reason="watchpoint-scope",wpnum="5", | |
922fbb7b AC |
27268 | frame=@{func="callee3",args=[@{name="strarg", |
27269 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
27270 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27271 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 27272 | (gdb) |
922fbb7b AC |
27273 | @end smallexample |
27274 | ||
27275 | Listing breakpoints and watchpoints, at different points in the program | |
27276 | execution. Note that once the watchpoint goes out of scope, it is | |
27277 | deleted. | |
27278 | ||
27279 | @smallexample | |
594fe323 | 27280 | (gdb) |
922fbb7b AC |
27281 | -break-watch C |
27282 | ^done,wpt=@{number="2",exp="C"@} | |
594fe323 | 27283 | (gdb) |
922fbb7b AC |
27284 | -break-list |
27285 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
27286 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
27287 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
27288 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
27289 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
27290 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
27291 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
27292 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
27293 | addr="0x00010734",func="callee4", | |
948d5102 | 27294 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
998580f1 MK |
27295 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",thread-groups=["i1"], |
27296 | times="1"@}, | |
922fbb7b | 27297 | bkpt=@{number="2",type="watchpoint",disp="keep", |
998580f1 | 27298 | enabled="y",addr="",what="C",thread-groups=["i1"],times="0"@}]@} |
594fe323 | 27299 | (gdb) |
922fbb7b AC |
27300 | -exec-continue |
27301 | ^running | |
0869d01b NR |
27302 | (gdb) |
27303 | *stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@}, | |
922fbb7b AC |
27304 | value=@{old="-276895068",new="3"@}, |
27305 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
27306 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27307 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
594fe323 | 27308 | (gdb) |
922fbb7b AC |
27309 | -break-list |
27310 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
27311 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
27312 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
27313 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
27314 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
27315 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
27316 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
27317 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
27318 | addr="0x00010734",func="callee4", | |
948d5102 | 27319 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
998580f1 MK |
27320 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",thread-groups=["i1"], |
27321 | times="1"@}, | |
922fbb7b | 27322 | bkpt=@{number="2",type="watchpoint",disp="keep", |
998580f1 | 27323 | enabled="y",addr="",what="C",thread-groups=["i1"],times="-5"@}]@} |
594fe323 | 27324 | (gdb) |
922fbb7b AC |
27325 | -exec-continue |
27326 | ^running | |
27327 | ^done,reason="watchpoint-scope",wpnum="2", | |
27328 | frame=@{func="callee3",args=[@{name="strarg", | |
27329 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
27330 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27331 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 27332 | (gdb) |
922fbb7b AC |
27333 | -break-list |
27334 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
27335 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
27336 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
27337 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
27338 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
27339 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
27340 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
27341 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
27342 | addr="0x00010734",func="callee4", | |
948d5102 NR |
27343 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
27344 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8", | |
998580f1 | 27345 | thread-groups=["i1"],times="1"@}]@} |
594fe323 | 27346 | (gdb) |
922fbb7b AC |
27347 | @end smallexample |
27348 | ||
3fa7bf06 MG |
27349 | |
27350 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
27351 | @node GDB/MI Catchpoint Commands | |
27352 | @section @sc{gdb/mi} Catchpoint Commands | |
27353 | ||
27354 | This section documents @sc{gdb/mi} commands for manipulating | |
27355 | catchpoints. | |
27356 | ||
40555925 JB |
27357 | @menu |
27358 | * Shared Library GDB/MI Catchpoint Commands:: | |
27359 | * Ada Exception GDB/MI Catchpoint Commands:: | |
27360 | @end menu | |
27361 | ||
27362 | @node Shared Library GDB/MI Catchpoint Commands | |
27363 | @subsection Shared Library @sc{gdb/mi} Catchpoints | |
27364 | ||
3fa7bf06 MG |
27365 | @subheading The @code{-catch-load} Command |
27366 | @findex -catch-load | |
27367 | ||
27368 | @subsubheading Synopsis | |
27369 | ||
27370 | @smallexample | |
27371 | -catch-load [ -t ] [ -d ] @var{regexp} | |
27372 | @end smallexample | |
27373 | ||
27374 | Add a catchpoint for library load events. If the @samp{-t} option is used, | |
27375 | the catchpoint is a temporary one (@pxref{Set Breaks, ,Setting | |
27376 | Breakpoints}). If the @samp{-d} option is used, the catchpoint is created | |
27377 | in a disabled state. The @samp{regexp} argument is a regular | |
27378 | expression used to match the name of the loaded library. | |
27379 | ||
27380 | ||
27381 | @subsubheading @value{GDBN} Command | |
27382 | ||
27383 | The corresponding @value{GDBN} command is @samp{catch load}. | |
27384 | ||
27385 | @subsubheading Example | |
27386 | ||
27387 | @smallexample | |
27388 | -catch-load -t foo.so | |
27389 | ^done,bkpt=@{number="1",type="catchpoint",disp="del",enabled="y", | |
8ac3646f | 27390 | what="load of library matching foo.so",catch-type="load",times="0"@} |
3fa7bf06 MG |
27391 | (gdb) |
27392 | @end smallexample | |
27393 | ||
27394 | ||
27395 | @subheading The @code{-catch-unload} Command | |
27396 | @findex -catch-unload | |
27397 | ||
27398 | @subsubheading Synopsis | |
27399 | ||
27400 | @smallexample | |
27401 | -catch-unload [ -t ] [ -d ] @var{regexp} | |
27402 | @end smallexample | |
27403 | ||
27404 | Add a catchpoint for library unload events. If the @samp{-t} option is | |
27405 | used, the catchpoint is a temporary one (@pxref{Set Breaks, ,Setting | |
27406 | Breakpoints}). If the @samp{-d} option is used, the catchpoint is | |
27407 | created in a disabled state. The @samp{regexp} argument is a regular | |
27408 | expression used to match the name of the unloaded library. | |
27409 | ||
27410 | @subsubheading @value{GDBN} Command | |
27411 | ||
27412 | The corresponding @value{GDBN} command is @samp{catch unload}. | |
27413 | ||
27414 | @subsubheading Example | |
27415 | ||
27416 | @smallexample | |
27417 | -catch-unload -d bar.so | |
27418 | ^done,bkpt=@{number="2",type="catchpoint",disp="keep",enabled="n", | |
8ac3646f | 27419 | what="load of library matching bar.so",catch-type="unload",times="0"@} |
3fa7bf06 MG |
27420 | (gdb) |
27421 | @end smallexample | |
27422 | ||
40555925 JB |
27423 | @node Ada Exception GDB/MI Catchpoint Commands |
27424 | @subsection Ada Exception @sc{gdb/mi} Catchpoints | |
27425 | ||
27426 | The following @sc{gdb/mi} commands can be used to create catchpoints | |
27427 | that stop the execution when Ada exceptions are being raised. | |
27428 | ||
27429 | @subheading The @code{-catch-assert} Command | |
27430 | @findex -catch-assert | |
27431 | ||
27432 | @subsubheading Synopsis | |
27433 | ||
27434 | @smallexample | |
27435 | -catch-assert [ -c @var{condition}] [ -d ] [ -t ] | |
27436 | @end smallexample | |
27437 | ||
27438 | Add a catchpoint for failed Ada assertions. | |
27439 | ||
27440 | The possible optional parameters for this command are: | |
27441 | ||
27442 | @table @samp | |
27443 | @item -c @var{condition} | |
27444 | Make the catchpoint conditional on @var{condition}. | |
27445 | @item -d | |
27446 | Create a disabled catchpoint. | |
27447 | @item -t | |
27448 | Create a temporary catchpoint. | |
27449 | @end table | |
27450 | ||
27451 | @subsubheading @value{GDBN} Command | |
27452 | ||
27453 | The corresponding @value{GDBN} command is @samp{catch assert}. | |
27454 | ||
27455 | @subsubheading Example | |
27456 | ||
27457 | @smallexample | |
27458 | -catch-assert | |
27459 | ^done,bkptno="5",bkpt=@{number="5",type="breakpoint",disp="keep", | |
27460 | enabled="y",addr="0x0000000000404888",what="failed Ada assertions", | |
27461 | thread-groups=["i1"],times="0", | |
27462 | original-location="__gnat_debug_raise_assert_failure"@} | |
27463 | (gdb) | |
27464 | @end smallexample | |
27465 | ||
27466 | @subheading The @code{-catch-exception} Command | |
27467 | @findex -catch-exception | |
27468 | ||
27469 | @subsubheading Synopsis | |
27470 | ||
27471 | @smallexample | |
27472 | -catch-exception [ -c @var{condition}] [ -d ] [ -e @var{exception-name} ] | |
27473 | [ -t ] [ -u ] | |
27474 | @end smallexample | |
27475 | ||
27476 | Add a catchpoint stopping when Ada exceptions are raised. | |
27477 | By default, the command stops the program when any Ada exception | |
27478 | gets raised. But it is also possible, by using some of the | |
27479 | optional parameters described below, to create more selective | |
27480 | catchpoints. | |
27481 | ||
27482 | The possible optional parameters for this command are: | |
27483 | ||
27484 | @table @samp | |
27485 | @item -c @var{condition} | |
27486 | Make the catchpoint conditional on @var{condition}. | |
27487 | @item -d | |
27488 | Create a disabled catchpoint. | |
27489 | @item -e @var{exception-name} | |
27490 | Only stop when @var{exception-name} is raised. This option cannot | |
27491 | be used combined with @samp{-u}. | |
27492 | @item -t | |
27493 | Create a temporary catchpoint. | |
27494 | @item -u | |
27495 | Stop only when an unhandled exception gets raised. This option | |
27496 | cannot be used combined with @samp{-e}. | |
27497 | @end table | |
27498 | ||
27499 | @subsubheading @value{GDBN} Command | |
27500 | ||
27501 | The corresponding @value{GDBN} commands are @samp{catch exception} | |
27502 | and @samp{catch exception unhandled}. | |
27503 | ||
27504 | @subsubheading Example | |
27505 | ||
27506 | @smallexample | |
27507 | -catch-exception -e Program_Error | |
27508 | ^done,bkptno="4",bkpt=@{number="4",type="breakpoint",disp="keep", | |
27509 | enabled="y",addr="0x0000000000404874", | |
27510 | what="`Program_Error' Ada exception", thread-groups=["i1"], | |
27511 | times="0",original-location="__gnat_debug_raise_exception"@} | |
27512 | (gdb) | |
27513 | @end smallexample | |
3fa7bf06 | 27514 | |
922fbb7b | 27515 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
a2c02241 NR |
27516 | @node GDB/MI Program Context |
27517 | @section @sc{gdb/mi} Program Context | |
922fbb7b | 27518 | |
a2c02241 NR |
27519 | @subheading The @code{-exec-arguments} Command |
27520 | @findex -exec-arguments | |
922fbb7b | 27521 | |
922fbb7b AC |
27522 | |
27523 | @subsubheading Synopsis | |
27524 | ||
27525 | @smallexample | |
a2c02241 | 27526 | -exec-arguments @var{args} |
922fbb7b AC |
27527 | @end smallexample |
27528 | ||
a2c02241 NR |
27529 | Set the inferior program arguments, to be used in the next |
27530 | @samp{-exec-run}. | |
922fbb7b | 27531 | |
a2c02241 | 27532 | @subsubheading @value{GDBN} Command |
922fbb7b | 27533 | |
a2c02241 | 27534 | The corresponding @value{GDBN} command is @samp{set args}. |
922fbb7b | 27535 | |
a2c02241 | 27536 | @subsubheading Example |
922fbb7b | 27537 | |
fbc5282e MK |
27538 | @smallexample |
27539 | (gdb) | |
27540 | -exec-arguments -v word | |
27541 | ^done | |
27542 | (gdb) | |
27543 | @end smallexample | |
922fbb7b | 27544 | |
a2c02241 | 27545 | |
9901a55b | 27546 | @ignore |
a2c02241 NR |
27547 | @subheading The @code{-exec-show-arguments} Command |
27548 | @findex -exec-show-arguments | |
27549 | ||
27550 | @subsubheading Synopsis | |
27551 | ||
27552 | @smallexample | |
27553 | -exec-show-arguments | |
27554 | @end smallexample | |
27555 | ||
27556 | Print the arguments of the program. | |
922fbb7b AC |
27557 | |
27558 | @subsubheading @value{GDBN} Command | |
27559 | ||
a2c02241 | 27560 | The corresponding @value{GDBN} command is @samp{show args}. |
922fbb7b AC |
27561 | |
27562 | @subsubheading Example | |
a2c02241 | 27563 | N.A. |
9901a55b | 27564 | @end ignore |
922fbb7b | 27565 | |
922fbb7b | 27566 | |
a2c02241 NR |
27567 | @subheading The @code{-environment-cd} Command |
27568 | @findex -environment-cd | |
922fbb7b | 27569 | |
a2c02241 | 27570 | @subsubheading Synopsis |
922fbb7b AC |
27571 | |
27572 | @smallexample | |
a2c02241 | 27573 | -environment-cd @var{pathdir} |
922fbb7b AC |
27574 | @end smallexample |
27575 | ||
a2c02241 | 27576 | Set @value{GDBN}'s working directory. |
922fbb7b | 27577 | |
a2c02241 | 27578 | @subsubheading @value{GDBN} Command |
922fbb7b | 27579 | |
a2c02241 NR |
27580 | The corresponding @value{GDBN} command is @samp{cd}. |
27581 | ||
27582 | @subsubheading Example | |
922fbb7b AC |
27583 | |
27584 | @smallexample | |
594fe323 | 27585 | (gdb) |
a2c02241 NR |
27586 | -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb |
27587 | ^done | |
594fe323 | 27588 | (gdb) |
922fbb7b AC |
27589 | @end smallexample |
27590 | ||
27591 | ||
a2c02241 NR |
27592 | @subheading The @code{-environment-directory} Command |
27593 | @findex -environment-directory | |
922fbb7b AC |
27594 | |
27595 | @subsubheading Synopsis | |
27596 | ||
27597 | @smallexample | |
a2c02241 | 27598 | -environment-directory [ -r ] [ @var{pathdir} ]+ |
922fbb7b AC |
27599 | @end smallexample |
27600 | ||
a2c02241 NR |
27601 | Add directories @var{pathdir} to beginning of search path for source files. |
27602 | If the @samp{-r} option is used, the search path is reset to the default | |
27603 | search path. If directories @var{pathdir} are supplied in addition to the | |
27604 | @samp{-r} option, the search path is first reset and then addition | |
27605 | occurs as normal. | |
27606 | Multiple directories may be specified, separated by blanks. Specifying | |
27607 | multiple directories in a single command | |
27608 | results in the directories added to the beginning of the | |
27609 | search path in the same order they were presented in the command. | |
27610 | If blanks are needed as | |
27611 | part of a directory name, double-quotes should be used around | |
27612 | the name. In the command output, the path will show up separated | |
d3e8051b | 27613 | by the system directory-separator character. The directory-separator |
a2c02241 NR |
27614 | character must not be used |
27615 | in any directory name. | |
27616 | If no directories are specified, the current search path is displayed. | |
922fbb7b AC |
27617 | |
27618 | @subsubheading @value{GDBN} Command | |
27619 | ||
a2c02241 | 27620 | The corresponding @value{GDBN} command is @samp{dir}. |
922fbb7b AC |
27621 | |
27622 | @subsubheading Example | |
27623 | ||
922fbb7b | 27624 | @smallexample |
594fe323 | 27625 | (gdb) |
a2c02241 NR |
27626 | -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb |
27627 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
594fe323 | 27628 | (gdb) |
a2c02241 NR |
27629 | -environment-directory "" |
27630 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
594fe323 | 27631 | (gdb) |
a2c02241 NR |
27632 | -environment-directory -r /home/jjohnstn/src/gdb /usr/src |
27633 | ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" | |
594fe323 | 27634 | (gdb) |
a2c02241 NR |
27635 | -environment-directory -r |
27636 | ^done,source-path="$cdir:$cwd" | |
594fe323 | 27637 | (gdb) |
922fbb7b AC |
27638 | @end smallexample |
27639 | ||
27640 | ||
a2c02241 NR |
27641 | @subheading The @code{-environment-path} Command |
27642 | @findex -environment-path | |
922fbb7b AC |
27643 | |
27644 | @subsubheading Synopsis | |
27645 | ||
27646 | @smallexample | |
a2c02241 | 27647 | -environment-path [ -r ] [ @var{pathdir} ]+ |
922fbb7b AC |
27648 | @end smallexample |
27649 | ||
a2c02241 NR |
27650 | Add directories @var{pathdir} to beginning of search path for object files. |
27651 | If the @samp{-r} option is used, the search path is reset to the original | |
27652 | search path that existed at gdb start-up. If directories @var{pathdir} are | |
27653 | supplied in addition to the | |
27654 | @samp{-r} option, the search path is first reset and then addition | |
27655 | occurs as normal. | |
27656 | Multiple directories may be specified, separated by blanks. Specifying | |
27657 | multiple directories in a single command | |
27658 | results in the directories added to the beginning of the | |
27659 | search path in the same order they were presented in the command. | |
27660 | If blanks are needed as | |
27661 | part of a directory name, double-quotes should be used around | |
27662 | the name. In the command output, the path will show up separated | |
d3e8051b | 27663 | by the system directory-separator character. The directory-separator |
a2c02241 NR |
27664 | character must not be used |
27665 | in any directory name. | |
27666 | If no directories are specified, the current path is displayed. | |
27667 | ||
922fbb7b AC |
27668 | |
27669 | @subsubheading @value{GDBN} Command | |
27670 | ||
a2c02241 | 27671 | The corresponding @value{GDBN} command is @samp{path}. |
922fbb7b AC |
27672 | |
27673 | @subsubheading Example | |
27674 | ||
922fbb7b | 27675 | @smallexample |
594fe323 | 27676 | (gdb) |
a2c02241 NR |
27677 | -environment-path |
27678 | ^done,path="/usr/bin" | |
594fe323 | 27679 | (gdb) |
a2c02241 NR |
27680 | -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin |
27681 | ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" | |
594fe323 | 27682 | (gdb) |
a2c02241 NR |
27683 | -environment-path -r /usr/local/bin |
27684 | ^done,path="/usr/local/bin:/usr/bin" | |
594fe323 | 27685 | (gdb) |
922fbb7b AC |
27686 | @end smallexample |
27687 | ||
27688 | ||
a2c02241 NR |
27689 | @subheading The @code{-environment-pwd} Command |
27690 | @findex -environment-pwd | |
922fbb7b AC |
27691 | |
27692 | @subsubheading Synopsis | |
27693 | ||
27694 | @smallexample | |
a2c02241 | 27695 | -environment-pwd |
922fbb7b AC |
27696 | @end smallexample |
27697 | ||
a2c02241 | 27698 | Show the current working directory. |
922fbb7b | 27699 | |
79a6e687 | 27700 | @subsubheading @value{GDBN} Command |
922fbb7b | 27701 | |
a2c02241 | 27702 | The corresponding @value{GDBN} command is @samp{pwd}. |
922fbb7b AC |
27703 | |
27704 | @subsubheading Example | |
27705 | ||
922fbb7b | 27706 | @smallexample |
594fe323 | 27707 | (gdb) |
a2c02241 NR |
27708 | -environment-pwd |
27709 | ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" | |
594fe323 | 27710 | (gdb) |
922fbb7b AC |
27711 | @end smallexample |
27712 | ||
a2c02241 NR |
27713 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
27714 | @node GDB/MI Thread Commands | |
27715 | @section @sc{gdb/mi} Thread Commands | |
27716 | ||
27717 | ||
27718 | @subheading The @code{-thread-info} Command | |
27719 | @findex -thread-info | |
922fbb7b AC |
27720 | |
27721 | @subsubheading Synopsis | |
27722 | ||
27723 | @smallexample | |
8e8901c5 | 27724 | -thread-info [ @var{thread-id} ] |
922fbb7b AC |
27725 | @end smallexample |
27726 | ||
5d5658a1 PA |
27727 | Reports information about either a specific thread, if the |
27728 | @var{thread-id} parameter is present, or about all threads. | |
27729 | @var{thread-id} is the thread's global thread ID. When printing | |
27730 | information about all threads, also reports the global ID of the | |
27731 | current thread. | |
8e8901c5 | 27732 | |
79a6e687 | 27733 | @subsubheading @value{GDBN} Command |
922fbb7b | 27734 | |
8e8901c5 VP |
27735 | The @samp{info thread} command prints the same information |
27736 | about all threads. | |
922fbb7b | 27737 | |
4694da01 | 27738 | @subsubheading Result |
922fbb7b | 27739 | |
4694da01 TT |
27740 | The result is a list of threads. The following attributes are |
27741 | defined for a given thread: | |
27742 | ||
27743 | @table @samp | |
27744 | @item current | |
27745 | This field exists only for the current thread. It has the value @samp{*}. | |
27746 | ||
27747 | @item id | |
5d5658a1 | 27748 | The global identifier that @value{GDBN} uses to refer to the thread. |
4694da01 TT |
27749 | |
27750 | @item target-id | |
27751 | The identifier that the target uses to refer to the thread. | |
27752 | ||
27753 | @item details | |
27754 | Extra information about the thread, in a target-specific format. This | |
27755 | field is optional. | |
27756 | ||
27757 | @item name | |
27758 | The name of the thread. If the user specified a name using the | |
27759 | @code{thread name} command, then this name is given. Otherwise, if | |
27760 | @value{GDBN} can extract the thread name from the target, then that | |
27761 | name is given. If @value{GDBN} cannot find the thread name, then this | |
27762 | field is omitted. | |
27763 | ||
27764 | @item frame | |
27765 | The stack frame currently executing in the thread. | |
922fbb7b | 27766 | |
4694da01 TT |
27767 | @item state |
27768 | The thread's state. The @samp{state} field may have the following | |
27769 | values: | |
c3b108f7 VP |
27770 | |
27771 | @table @code | |
27772 | @item stopped | |
27773 | The thread is stopped. Frame information is available for stopped | |
27774 | threads. | |
27775 | ||
27776 | @item running | |
27777 | The thread is running. There's no frame information for running | |
27778 | threads. | |
27779 | ||
27780 | @end table | |
27781 | ||
4694da01 TT |
27782 | @item core |
27783 | If @value{GDBN} can find the CPU core on which this thread is running, | |
27784 | then this field is the core identifier. This field is optional. | |
27785 | ||
27786 | @end table | |
27787 | ||
27788 | @subsubheading Example | |
27789 | ||
27790 | @smallexample | |
27791 | -thread-info | |
27792 | ^done,threads=[ | |
27793 | @{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", | |
27794 | frame=@{level="0",addr="0xffffe410",func="__kernel_vsyscall", | |
27795 | args=[]@},state="running"@}, | |
27796 | @{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", | |
27797 | frame=@{level="0",addr="0x0804891f",func="foo", | |
27798 | args=[@{name="i",value="10"@}], | |
27799 | file="/tmp/a.c",fullname="/tmp/a.c",line="158"@}, | |
27800 | state="running"@}], | |
27801 | current-thread-id="1" | |
27802 | (gdb) | |
27803 | @end smallexample | |
27804 | ||
a2c02241 NR |
27805 | @subheading The @code{-thread-list-ids} Command |
27806 | @findex -thread-list-ids | |
922fbb7b | 27807 | |
a2c02241 | 27808 | @subsubheading Synopsis |
922fbb7b | 27809 | |
a2c02241 NR |
27810 | @smallexample |
27811 | -thread-list-ids | |
27812 | @end smallexample | |
922fbb7b | 27813 | |
5d5658a1 PA |
27814 | Produces a list of the currently known global @value{GDBN} thread ids. |
27815 | At the end of the list it also prints the total number of such | |
27816 | threads. | |
922fbb7b | 27817 | |
c3b108f7 VP |
27818 | This command is retained for historical reasons, the |
27819 | @code{-thread-info} command should be used instead. | |
27820 | ||
922fbb7b AC |
27821 | @subsubheading @value{GDBN} Command |
27822 | ||
a2c02241 | 27823 | Part of @samp{info threads} supplies the same information. |
922fbb7b AC |
27824 | |
27825 | @subsubheading Example | |
27826 | ||
922fbb7b | 27827 | @smallexample |
594fe323 | 27828 | (gdb) |
a2c02241 NR |
27829 | -thread-list-ids |
27830 | ^done,thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
592375cd | 27831 | current-thread-id="1",number-of-threads="3" |
594fe323 | 27832 | (gdb) |
922fbb7b AC |
27833 | @end smallexample |
27834 | ||
a2c02241 NR |
27835 | |
27836 | @subheading The @code{-thread-select} Command | |
27837 | @findex -thread-select | |
922fbb7b AC |
27838 | |
27839 | @subsubheading Synopsis | |
27840 | ||
27841 | @smallexample | |
5d5658a1 | 27842 | -thread-select @var{thread-id} |
922fbb7b AC |
27843 | @end smallexample |
27844 | ||
5d5658a1 PA |
27845 | Make thread with global thread number @var{thread-id} the current |
27846 | thread. It prints the number of the new current thread, and the | |
27847 | topmost frame for that thread. | |
922fbb7b | 27848 | |
c3b108f7 VP |
27849 | This command is deprecated in favor of explicitly using the |
27850 | @samp{--thread} option to each command. | |
27851 | ||
922fbb7b AC |
27852 | @subsubheading @value{GDBN} Command |
27853 | ||
a2c02241 | 27854 | The corresponding @value{GDBN} command is @samp{thread}. |
922fbb7b AC |
27855 | |
27856 | @subsubheading Example | |
922fbb7b AC |
27857 | |
27858 | @smallexample | |
594fe323 | 27859 | (gdb) |
a2c02241 NR |
27860 | -exec-next |
27861 | ^running | |
594fe323 | 27862 | (gdb) |
a2c02241 NR |
27863 | *stopped,reason="end-stepping-range",thread-id="2",line="187", |
27864 | file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c" | |
594fe323 | 27865 | (gdb) |
a2c02241 NR |
27866 | -thread-list-ids |
27867 | ^done, | |
27868 | thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
27869 | number-of-threads="3" | |
594fe323 | 27870 | (gdb) |
a2c02241 NR |
27871 | -thread-select 3 |
27872 | ^done,new-thread-id="3", | |
27873 | frame=@{level="0",func="vprintf", | |
27874 | args=[@{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""@}, | |
27875 | @{name="arg",value="0x2"@}],file="vprintf.c",line="31"@} | |
594fe323 | 27876 | (gdb) |
922fbb7b AC |
27877 | @end smallexample |
27878 | ||
5d77fe44 JB |
27879 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
27880 | @node GDB/MI Ada Tasking Commands | |
27881 | @section @sc{gdb/mi} Ada Tasking Commands | |
27882 | ||
27883 | @subheading The @code{-ada-task-info} Command | |
27884 | @findex -ada-task-info | |
27885 | ||
27886 | @subsubheading Synopsis | |
27887 | ||
27888 | @smallexample | |
27889 | -ada-task-info [ @var{task-id} ] | |
27890 | @end smallexample | |
27891 | ||
27892 | Reports information about either a specific Ada task, if the | |
27893 | @var{task-id} parameter is present, or about all Ada tasks. | |
27894 | ||
27895 | @subsubheading @value{GDBN} Command | |
27896 | ||
27897 | The @samp{info tasks} command prints the same information | |
27898 | about all Ada tasks (@pxref{Ada Tasks}). | |
27899 | ||
27900 | @subsubheading Result | |
27901 | ||
27902 | The result is a table of Ada tasks. The following columns are | |
27903 | defined for each Ada task: | |
27904 | ||
27905 | @table @samp | |
27906 | @item current | |
27907 | This field exists only for the current thread. It has the value @samp{*}. | |
27908 | ||
27909 | @item id | |
27910 | The identifier that @value{GDBN} uses to refer to the Ada task. | |
27911 | ||
27912 | @item task-id | |
27913 | The identifier that the target uses to refer to the Ada task. | |
27914 | ||
27915 | @item thread-id | |
5d5658a1 PA |
27916 | The global thread identifier of the thread corresponding to the Ada |
27917 | task. | |
5d77fe44 JB |
27918 | |
27919 | This field should always exist, as Ada tasks are always implemented | |
27920 | on top of a thread. But if @value{GDBN} cannot find this corresponding | |
27921 | thread for any reason, the field is omitted. | |
27922 | ||
27923 | @item parent-id | |
27924 | This field exists only when the task was created by another task. | |
27925 | In this case, it provides the ID of the parent task. | |
27926 | ||
27927 | @item priority | |
27928 | The base priority of the task. | |
27929 | ||
27930 | @item state | |
27931 | The current state of the task. For a detailed description of the | |
27932 | possible states, see @ref{Ada Tasks}. | |
27933 | ||
27934 | @item name | |
27935 | The name of the task. | |
27936 | ||
27937 | @end table | |
27938 | ||
27939 | @subsubheading Example | |
27940 | ||
27941 | @smallexample | |
27942 | -ada-task-info | |
27943 | ^done,tasks=@{nr_rows="3",nr_cols="8", | |
27944 | hdr=[@{width="1",alignment="-1",col_name="current",colhdr=""@}, | |
27945 | @{width="3",alignment="1",col_name="id",colhdr="ID"@}, | |
27946 | @{width="9",alignment="1",col_name="task-id",colhdr="TID"@}, | |
27947 | @{width="4",alignment="1",col_name="thread-id",colhdr=""@}, | |
27948 | @{width="4",alignment="1",col_name="parent-id",colhdr="P-ID"@}, | |
27949 | @{width="3",alignment="1",col_name="priority",colhdr="Pri"@}, | |
27950 | @{width="22",alignment="-1",col_name="state",colhdr="State"@}, | |
27951 | @{width="1",alignment="2",col_name="name",colhdr="Name"@}], | |
27952 | body=[@{current="*",id="1",task-id=" 644010",thread-id="1",priority="48", | |
27953 | state="Child Termination Wait",name="main_task"@}]@} | |
27954 | (gdb) | |
27955 | @end smallexample | |
27956 | ||
a2c02241 NR |
27957 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
27958 | @node GDB/MI Program Execution | |
27959 | @section @sc{gdb/mi} Program Execution | |
922fbb7b | 27960 | |
ef21caaf | 27961 | These are the asynchronous commands which generate the out-of-band |
3f94c067 | 27962 | record @samp{*stopped}. Currently @value{GDBN} only really executes |
ef21caaf NR |
27963 | asynchronously with remote targets and this interaction is mimicked in |
27964 | other cases. | |
922fbb7b | 27965 | |
922fbb7b AC |
27966 | @subheading The @code{-exec-continue} Command |
27967 | @findex -exec-continue | |
27968 | ||
27969 | @subsubheading Synopsis | |
27970 | ||
27971 | @smallexample | |
540aa8e7 | 27972 | -exec-continue [--reverse] [--all|--thread-group N] |
922fbb7b AC |
27973 | @end smallexample |
27974 | ||
540aa8e7 MS |
27975 | Resumes the execution of the inferior program, which will continue |
27976 | to execute until it reaches a debugger stop event. If the | |
27977 | @samp{--reverse} option is specified, execution resumes in reverse until | |
27978 | it reaches a stop event. Stop events may include | |
27979 | @itemize @bullet | |
27980 | @item | |
27981 | breakpoints or watchpoints | |
27982 | @item | |
27983 | signals or exceptions | |
27984 | @item | |
27985 | the end of the process (or its beginning under @samp{--reverse}) | |
27986 | @item | |
27987 | the end or beginning of a replay log if one is being used. | |
27988 | @end itemize | |
27989 | In all-stop mode (@pxref{All-Stop | |
27990 | Mode}), may resume only one thread, or all threads, depending on the | |
27991 | value of the @samp{scheduler-locking} variable. If @samp{--all} is | |
a79b8f6e | 27992 | specified, all threads (in all inferiors) will be resumed. The @samp{--all} option is |
540aa8e7 MS |
27993 | ignored in all-stop mode. If the @samp{--thread-group} options is |
27994 | specified, then all threads in that thread group are resumed. | |
922fbb7b AC |
27995 | |
27996 | @subsubheading @value{GDBN} Command | |
27997 | ||
27998 | The corresponding @value{GDBN} corresponding is @samp{continue}. | |
27999 | ||
28000 | @subsubheading Example | |
28001 | ||
28002 | @smallexample | |
28003 | -exec-continue | |
28004 | ^running | |
594fe323 | 28005 | (gdb) |
922fbb7b | 28006 | @@Hello world |
a47ec5fe AR |
28007 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",frame=@{ |
28008 | func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c", | |
28009 | line="13"@} | |
594fe323 | 28010 | (gdb) |
922fbb7b AC |
28011 | @end smallexample |
28012 | ||
28013 | ||
28014 | @subheading The @code{-exec-finish} Command | |
28015 | @findex -exec-finish | |
28016 | ||
28017 | @subsubheading Synopsis | |
28018 | ||
28019 | @smallexample | |
540aa8e7 | 28020 | -exec-finish [--reverse] |
922fbb7b AC |
28021 | @end smallexample |
28022 | ||
ef21caaf NR |
28023 | Resumes the execution of the inferior program until the current |
28024 | function is exited. Displays the results returned by the function. | |
540aa8e7 MS |
28025 | If the @samp{--reverse} option is specified, resumes the reverse |
28026 | execution of the inferior program until the point where current | |
28027 | function was called. | |
922fbb7b AC |
28028 | |
28029 | @subsubheading @value{GDBN} Command | |
28030 | ||
28031 | The corresponding @value{GDBN} command is @samp{finish}. | |
28032 | ||
28033 | @subsubheading Example | |
28034 | ||
28035 | Function returning @code{void}. | |
28036 | ||
28037 | @smallexample | |
28038 | -exec-finish | |
28039 | ^running | |
594fe323 | 28040 | (gdb) |
922fbb7b AC |
28041 | @@hello from foo |
28042 | *stopped,reason="function-finished",frame=@{func="main",args=[], | |
948d5102 | 28043 | file="hello.c",fullname="/home/foo/bar/hello.c",line="7"@} |
594fe323 | 28044 | (gdb) |
922fbb7b AC |
28045 | @end smallexample |
28046 | ||
28047 | Function returning other than @code{void}. The name of the internal | |
28048 | @value{GDBN} variable storing the result is printed, together with the | |
28049 | value itself. | |
28050 | ||
28051 | @smallexample | |
28052 | -exec-finish | |
28053 | ^running | |
594fe323 | 28054 | (gdb) |
922fbb7b AC |
28055 | *stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo", |
28056 | args=[@{name="a",value="1"],@{name="b",value="9"@}@}, | |
948d5102 | 28057 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, |
922fbb7b | 28058 | gdb-result-var="$1",return-value="0" |
594fe323 | 28059 | (gdb) |
922fbb7b AC |
28060 | @end smallexample |
28061 | ||
28062 | ||
28063 | @subheading The @code{-exec-interrupt} Command | |
28064 | @findex -exec-interrupt | |
28065 | ||
28066 | @subsubheading Synopsis | |
28067 | ||
28068 | @smallexample | |
c3b108f7 | 28069 | -exec-interrupt [--all|--thread-group N] |
922fbb7b AC |
28070 | @end smallexample |
28071 | ||
ef21caaf NR |
28072 | Interrupts the background execution of the target. Note how the token |
28073 | associated with the stop message is the one for the execution command | |
28074 | that has been interrupted. The token for the interrupt itself only | |
28075 | appears in the @samp{^done} output. If the user is trying to | |
922fbb7b AC |
28076 | interrupt a non-running program, an error message will be printed. |
28077 | ||
c3b108f7 VP |
28078 | Note that when asynchronous execution is enabled, this command is |
28079 | asynchronous just like other execution commands. That is, first the | |
28080 | @samp{^done} response will be printed, and the target stop will be | |
28081 | reported after that using the @samp{*stopped} notification. | |
28082 | ||
28083 | In non-stop mode, only the context thread is interrupted by default. | |
a79b8f6e VP |
28084 | All threads (in all inferiors) will be interrupted if the |
28085 | @samp{--all} option is specified. If the @samp{--thread-group} | |
28086 | option is specified, all threads in that group will be interrupted. | |
c3b108f7 | 28087 | |
922fbb7b AC |
28088 | @subsubheading @value{GDBN} Command |
28089 | ||
28090 | The corresponding @value{GDBN} command is @samp{interrupt}. | |
28091 | ||
28092 | @subsubheading Example | |
28093 | ||
28094 | @smallexample | |
594fe323 | 28095 | (gdb) |
922fbb7b AC |
28096 | 111-exec-continue |
28097 | 111^running | |
28098 | ||
594fe323 | 28099 | (gdb) |
922fbb7b AC |
28100 | 222-exec-interrupt |
28101 | 222^done | |
594fe323 | 28102 | (gdb) |
922fbb7b | 28103 | 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt", |
76ff342d | 28104 | frame=@{addr="0x00010140",func="foo",args=[],file="try.c", |
948d5102 | 28105 | fullname="/home/foo/bar/try.c",line="13"@} |
594fe323 | 28106 | (gdb) |
922fbb7b | 28107 | |
594fe323 | 28108 | (gdb) |
922fbb7b AC |
28109 | -exec-interrupt |
28110 | ^error,msg="mi_cmd_exec_interrupt: Inferior not executing." | |
594fe323 | 28111 | (gdb) |
922fbb7b AC |
28112 | @end smallexample |
28113 | ||
83eba9b7 VP |
28114 | @subheading The @code{-exec-jump} Command |
28115 | @findex -exec-jump | |
28116 | ||
28117 | @subsubheading Synopsis | |
28118 | ||
28119 | @smallexample | |
28120 | -exec-jump @var{location} | |
28121 | @end smallexample | |
28122 | ||
28123 | Resumes execution of the inferior program at the location specified by | |
28124 | parameter. @xref{Specify Location}, for a description of the | |
28125 | different forms of @var{location}. | |
28126 | ||
28127 | @subsubheading @value{GDBN} Command | |
28128 | ||
28129 | The corresponding @value{GDBN} command is @samp{jump}. | |
28130 | ||
28131 | @subsubheading Example | |
28132 | ||
28133 | @smallexample | |
28134 | -exec-jump foo.c:10 | |
28135 | *running,thread-id="all" | |
28136 | ^running | |
28137 | @end smallexample | |
28138 | ||
922fbb7b AC |
28139 | |
28140 | @subheading The @code{-exec-next} Command | |
28141 | @findex -exec-next | |
28142 | ||
28143 | @subsubheading Synopsis | |
28144 | ||
28145 | @smallexample | |
540aa8e7 | 28146 | -exec-next [--reverse] |
922fbb7b AC |
28147 | @end smallexample |
28148 | ||
ef21caaf NR |
28149 | Resumes execution of the inferior program, stopping when the beginning |
28150 | of the next source line is reached. | |
922fbb7b | 28151 | |
540aa8e7 MS |
28152 | If the @samp{--reverse} option is specified, resumes reverse execution |
28153 | of the inferior program, stopping at the beginning of the previous | |
28154 | source line. If you issue this command on the first line of a | |
28155 | function, it will take you back to the caller of that function, to the | |
28156 | source line where the function was called. | |
28157 | ||
28158 | ||
922fbb7b AC |
28159 | @subsubheading @value{GDBN} Command |
28160 | ||
28161 | The corresponding @value{GDBN} command is @samp{next}. | |
28162 | ||
28163 | @subsubheading Example | |
28164 | ||
28165 | @smallexample | |
28166 | -exec-next | |
28167 | ^running | |
594fe323 | 28168 | (gdb) |
922fbb7b | 28169 | *stopped,reason="end-stepping-range",line="8",file="hello.c" |
594fe323 | 28170 | (gdb) |
922fbb7b AC |
28171 | @end smallexample |
28172 | ||
28173 | ||
28174 | @subheading The @code{-exec-next-instruction} Command | |
28175 | @findex -exec-next-instruction | |
28176 | ||
28177 | @subsubheading Synopsis | |
28178 | ||
28179 | @smallexample | |
540aa8e7 | 28180 | -exec-next-instruction [--reverse] |
922fbb7b AC |
28181 | @end smallexample |
28182 | ||
ef21caaf NR |
28183 | Executes one machine instruction. If the instruction is a function |
28184 | call, continues until the function returns. If the program stops at an | |
28185 | instruction in the middle of a source line, the address will be | |
28186 | printed as well. | |
922fbb7b | 28187 | |
540aa8e7 MS |
28188 | If the @samp{--reverse} option is specified, resumes reverse execution |
28189 | of the inferior program, stopping at the previous instruction. If the | |
28190 | previously executed instruction was a return from another function, | |
28191 | it will continue to execute in reverse until the call to that function | |
28192 | (from the current stack frame) is reached. | |
28193 | ||
922fbb7b AC |
28194 | @subsubheading @value{GDBN} Command |
28195 | ||
28196 | The corresponding @value{GDBN} command is @samp{nexti}. | |
28197 | ||
28198 | @subsubheading Example | |
28199 | ||
28200 | @smallexample | |
594fe323 | 28201 | (gdb) |
922fbb7b AC |
28202 | -exec-next-instruction |
28203 | ^running | |
28204 | ||
594fe323 | 28205 | (gdb) |
922fbb7b AC |
28206 | *stopped,reason="end-stepping-range", |
28207 | addr="0x000100d4",line="5",file="hello.c" | |
594fe323 | 28208 | (gdb) |
922fbb7b AC |
28209 | @end smallexample |
28210 | ||
28211 | ||
28212 | @subheading The @code{-exec-return} Command | |
28213 | @findex -exec-return | |
28214 | ||
28215 | @subsubheading Synopsis | |
28216 | ||
28217 | @smallexample | |
28218 | -exec-return | |
28219 | @end smallexample | |
28220 | ||
28221 | Makes current function return immediately. Doesn't execute the inferior. | |
28222 | Displays the new current frame. | |
28223 | ||
28224 | @subsubheading @value{GDBN} Command | |
28225 | ||
28226 | The corresponding @value{GDBN} command is @samp{return}. | |
28227 | ||
28228 | @subsubheading Example | |
28229 | ||
28230 | @smallexample | |
594fe323 | 28231 | (gdb) |
922fbb7b AC |
28232 | 200-break-insert callee4 |
28233 | 200^done,bkpt=@{number="1",addr="0x00010734", | |
28234 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
594fe323 | 28235 | (gdb) |
922fbb7b AC |
28236 | 000-exec-run |
28237 | 000^running | |
594fe323 | 28238 | (gdb) |
a47ec5fe | 28239 | 000*stopped,reason="breakpoint-hit",disp="keep",bkptno="1", |
922fbb7b | 28240 | frame=@{func="callee4",args=[], |
76ff342d DJ |
28241 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
28242 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
594fe323 | 28243 | (gdb) |
922fbb7b AC |
28244 | 205-break-delete |
28245 | 205^done | |
594fe323 | 28246 | (gdb) |
922fbb7b AC |
28247 | 111-exec-return |
28248 | 111^done,frame=@{level="0",func="callee3", | |
28249 | args=[@{name="strarg", | |
28250 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
28251 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
28252 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 28253 | (gdb) |
922fbb7b AC |
28254 | @end smallexample |
28255 | ||
28256 | ||
28257 | @subheading The @code{-exec-run} Command | |
28258 | @findex -exec-run | |
28259 | ||
28260 | @subsubheading Synopsis | |
28261 | ||
28262 | @smallexample | |
5713b9b5 | 28263 | -exec-run [ --all | --thread-group N ] [ --start ] |
922fbb7b AC |
28264 | @end smallexample |
28265 | ||
ef21caaf NR |
28266 | Starts execution of the inferior from the beginning. The inferior |
28267 | executes until either a breakpoint is encountered or the program | |
28268 | exits. In the latter case the output will include an exit code, if | |
28269 | the program has exited exceptionally. | |
922fbb7b | 28270 | |
5713b9b5 JB |
28271 | When neither the @samp{--all} nor the @samp{--thread-group} option |
28272 | is specified, the current inferior is started. If the | |
a79b8f6e VP |
28273 | @samp{--thread-group} option is specified, it should refer to a thread |
28274 | group of type @samp{process}, and that thread group will be started. | |
28275 | If the @samp{--all} option is specified, then all inferiors will be started. | |
28276 | ||
5713b9b5 JB |
28277 | Using the @samp{--start} option instructs the debugger to stop |
28278 | the execution at the start of the inferior's main subprogram, | |
28279 | following the same behavior as the @code{start} command | |
28280 | (@pxref{Starting}). | |
28281 | ||
922fbb7b AC |
28282 | @subsubheading @value{GDBN} Command |
28283 | ||
28284 | The corresponding @value{GDBN} command is @samp{run}. | |
28285 | ||
ef21caaf | 28286 | @subsubheading Examples |
922fbb7b AC |
28287 | |
28288 | @smallexample | |
594fe323 | 28289 | (gdb) |
922fbb7b AC |
28290 | -break-insert main |
28291 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
594fe323 | 28292 | (gdb) |
922fbb7b AC |
28293 | -exec-run |
28294 | ^running | |
594fe323 | 28295 | (gdb) |
a47ec5fe | 28296 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1", |
76ff342d | 28297 | frame=@{func="main",args=[],file="recursive2.c", |
948d5102 | 28298 | fullname="/home/foo/bar/recursive2.c",line="4"@} |
594fe323 | 28299 | (gdb) |
922fbb7b AC |
28300 | @end smallexample |
28301 | ||
ef21caaf NR |
28302 | @noindent |
28303 | Program exited normally: | |
28304 | ||
28305 | @smallexample | |
594fe323 | 28306 | (gdb) |
ef21caaf NR |
28307 | -exec-run |
28308 | ^running | |
594fe323 | 28309 | (gdb) |
ef21caaf NR |
28310 | x = 55 |
28311 | *stopped,reason="exited-normally" | |
594fe323 | 28312 | (gdb) |
ef21caaf NR |
28313 | @end smallexample |
28314 | ||
28315 | @noindent | |
28316 | Program exited exceptionally: | |
28317 | ||
28318 | @smallexample | |
594fe323 | 28319 | (gdb) |
ef21caaf NR |
28320 | -exec-run |
28321 | ^running | |
594fe323 | 28322 | (gdb) |
ef21caaf NR |
28323 | x = 55 |
28324 | *stopped,reason="exited",exit-code="01" | |
594fe323 | 28325 | (gdb) |
ef21caaf NR |
28326 | @end smallexample |
28327 | ||
28328 | Another way the program can terminate is if it receives a signal such as | |
28329 | @code{SIGINT}. In this case, @sc{gdb/mi} displays this: | |
28330 | ||
28331 | @smallexample | |
594fe323 | 28332 | (gdb) |
ef21caaf NR |
28333 | *stopped,reason="exited-signalled",signal-name="SIGINT", |
28334 | signal-meaning="Interrupt" | |
28335 | @end smallexample | |
28336 | ||
922fbb7b | 28337 | |
a2c02241 NR |
28338 | @c @subheading -exec-signal |
28339 | ||
28340 | ||
28341 | @subheading The @code{-exec-step} Command | |
28342 | @findex -exec-step | |
922fbb7b AC |
28343 | |
28344 | @subsubheading Synopsis | |
28345 | ||
28346 | @smallexample | |
540aa8e7 | 28347 | -exec-step [--reverse] |
922fbb7b AC |
28348 | @end smallexample |
28349 | ||
a2c02241 NR |
28350 | Resumes execution of the inferior program, stopping when the beginning |
28351 | of the next source line is reached, if the next source line is not a | |
28352 | function call. If it is, stop at the first instruction of the called | |
540aa8e7 MS |
28353 | function. If the @samp{--reverse} option is specified, resumes reverse |
28354 | execution of the inferior program, stopping at the beginning of the | |
28355 | previously executed source line. | |
922fbb7b AC |
28356 | |
28357 | @subsubheading @value{GDBN} Command | |
28358 | ||
a2c02241 | 28359 | The corresponding @value{GDBN} command is @samp{step}. |
922fbb7b AC |
28360 | |
28361 | @subsubheading Example | |
28362 | ||
28363 | Stepping into a function: | |
28364 | ||
28365 | @smallexample | |
28366 | -exec-step | |
28367 | ^running | |
594fe323 | 28368 | (gdb) |
922fbb7b AC |
28369 | *stopped,reason="end-stepping-range", |
28370 | frame=@{func="foo",args=[@{name="a",value="10"@}, | |
76ff342d | 28371 | @{name="b",value="0"@}],file="recursive2.c", |
948d5102 | 28372 | fullname="/home/foo/bar/recursive2.c",line="11"@} |
594fe323 | 28373 | (gdb) |
922fbb7b AC |
28374 | @end smallexample |
28375 | ||
28376 | Regular stepping: | |
28377 | ||
28378 | @smallexample | |
28379 | -exec-step | |
28380 | ^running | |
594fe323 | 28381 | (gdb) |
922fbb7b | 28382 | *stopped,reason="end-stepping-range",line="14",file="recursive2.c" |
594fe323 | 28383 | (gdb) |
922fbb7b AC |
28384 | @end smallexample |
28385 | ||
28386 | ||
28387 | @subheading The @code{-exec-step-instruction} Command | |
28388 | @findex -exec-step-instruction | |
28389 | ||
28390 | @subsubheading Synopsis | |
28391 | ||
28392 | @smallexample | |
540aa8e7 | 28393 | -exec-step-instruction [--reverse] |
922fbb7b AC |
28394 | @end smallexample |
28395 | ||
540aa8e7 MS |
28396 | Resumes the inferior which executes one machine instruction. If the |
28397 | @samp{--reverse} option is specified, resumes reverse execution of the | |
28398 | inferior program, stopping at the previously executed instruction. | |
28399 | The output, once @value{GDBN} has stopped, will vary depending on | |
28400 | whether we have stopped in the middle of a source line or not. In the | |
28401 | former case, the address at which the program stopped will be printed | |
28402 | as well. | |
922fbb7b AC |
28403 | |
28404 | @subsubheading @value{GDBN} Command | |
28405 | ||
28406 | The corresponding @value{GDBN} command is @samp{stepi}. | |
28407 | ||
28408 | @subsubheading Example | |
28409 | ||
28410 | @smallexample | |
594fe323 | 28411 | (gdb) |
922fbb7b AC |
28412 | -exec-step-instruction |
28413 | ^running | |
28414 | ||
594fe323 | 28415 | (gdb) |
922fbb7b | 28416 | *stopped,reason="end-stepping-range", |
76ff342d | 28417 | frame=@{func="foo",args=[],file="try.c", |
948d5102 | 28418 | fullname="/home/foo/bar/try.c",line="10"@} |
594fe323 | 28419 | (gdb) |
922fbb7b AC |
28420 | -exec-step-instruction |
28421 | ^running | |
28422 | ||
594fe323 | 28423 | (gdb) |
922fbb7b | 28424 | *stopped,reason="end-stepping-range", |
76ff342d | 28425 | frame=@{addr="0x000100f4",func="foo",args=[],file="try.c", |
948d5102 | 28426 | fullname="/home/foo/bar/try.c",line="10"@} |
594fe323 | 28427 | (gdb) |
922fbb7b AC |
28428 | @end smallexample |
28429 | ||
28430 | ||
28431 | @subheading The @code{-exec-until} Command | |
28432 | @findex -exec-until | |
28433 | ||
28434 | @subsubheading Synopsis | |
28435 | ||
28436 | @smallexample | |
28437 | -exec-until [ @var{location} ] | |
28438 | @end smallexample | |
28439 | ||
ef21caaf NR |
28440 | Executes the inferior until the @var{location} specified in the |
28441 | argument is reached. If there is no argument, the inferior executes | |
28442 | until a source line greater than the current one is reached. The | |
28443 | reason for stopping in this case will be @samp{location-reached}. | |
922fbb7b AC |
28444 | |
28445 | @subsubheading @value{GDBN} Command | |
28446 | ||
28447 | The corresponding @value{GDBN} command is @samp{until}. | |
28448 | ||
28449 | @subsubheading Example | |
28450 | ||
28451 | @smallexample | |
594fe323 | 28452 | (gdb) |
922fbb7b AC |
28453 | -exec-until recursive2.c:6 |
28454 | ^running | |
594fe323 | 28455 | (gdb) |
922fbb7b AC |
28456 | x = 55 |
28457 | *stopped,reason="location-reached",frame=@{func="main",args=[], | |
948d5102 | 28458 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6"@} |
594fe323 | 28459 | (gdb) |
922fbb7b AC |
28460 | @end smallexample |
28461 | ||
28462 | @ignore | |
28463 | @subheading -file-clear | |
28464 | Is this going away???? | |
28465 | @end ignore | |
28466 | ||
351ff01a | 28467 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
a2c02241 NR |
28468 | @node GDB/MI Stack Manipulation |
28469 | @section @sc{gdb/mi} Stack Manipulation Commands | |
351ff01a | 28470 | |
1e611234 PM |
28471 | @subheading The @code{-enable-frame-filters} Command |
28472 | @findex -enable-frame-filters | |
28473 | ||
28474 | @smallexample | |
28475 | -enable-frame-filters | |
28476 | @end smallexample | |
28477 | ||
28478 | @value{GDBN} allows Python-based frame filters to affect the output of | |
28479 | the MI commands relating to stack traces. As there is no way to | |
28480 | implement this in a fully backward-compatible way, a front end must | |
28481 | request that this functionality be enabled. | |
28482 | ||
28483 | Once enabled, this feature cannot be disabled. | |
28484 | ||
28485 | Note that if Python support has not been compiled into @value{GDBN}, | |
28486 | this command will still succeed (and do nothing). | |
922fbb7b | 28487 | |
a2c02241 NR |
28488 | @subheading The @code{-stack-info-frame} Command |
28489 | @findex -stack-info-frame | |
922fbb7b AC |
28490 | |
28491 | @subsubheading Synopsis | |
28492 | ||
28493 | @smallexample | |
a2c02241 | 28494 | -stack-info-frame |
922fbb7b AC |
28495 | @end smallexample |
28496 | ||
a2c02241 | 28497 | Get info on the selected frame. |
922fbb7b AC |
28498 | |
28499 | @subsubheading @value{GDBN} Command | |
28500 | ||
a2c02241 NR |
28501 | The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame} |
28502 | (without arguments). | |
922fbb7b AC |
28503 | |
28504 | @subsubheading Example | |
28505 | ||
28506 | @smallexample | |
594fe323 | 28507 | (gdb) |
a2c02241 NR |
28508 | -stack-info-frame |
28509 | ^done,frame=@{level="1",addr="0x0001076c",func="callee3", | |
28510 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
28511 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@} | |
594fe323 | 28512 | (gdb) |
922fbb7b AC |
28513 | @end smallexample |
28514 | ||
a2c02241 NR |
28515 | @subheading The @code{-stack-info-depth} Command |
28516 | @findex -stack-info-depth | |
922fbb7b AC |
28517 | |
28518 | @subsubheading Synopsis | |
28519 | ||
28520 | @smallexample | |
a2c02241 | 28521 | -stack-info-depth [ @var{max-depth} ] |
922fbb7b AC |
28522 | @end smallexample |
28523 | ||
a2c02241 NR |
28524 | Return the depth of the stack. If the integer argument @var{max-depth} |
28525 | is specified, do not count beyond @var{max-depth} frames. | |
922fbb7b AC |
28526 | |
28527 | @subsubheading @value{GDBN} Command | |
28528 | ||
a2c02241 | 28529 | There's no equivalent @value{GDBN} command. |
922fbb7b AC |
28530 | |
28531 | @subsubheading Example | |
28532 | ||
a2c02241 NR |
28533 | For a stack with frame levels 0 through 11: |
28534 | ||
922fbb7b | 28535 | @smallexample |
594fe323 | 28536 | (gdb) |
a2c02241 NR |
28537 | -stack-info-depth |
28538 | ^done,depth="12" | |
594fe323 | 28539 | (gdb) |
a2c02241 NR |
28540 | -stack-info-depth 4 |
28541 | ^done,depth="4" | |
594fe323 | 28542 | (gdb) |
a2c02241 NR |
28543 | -stack-info-depth 12 |
28544 | ^done,depth="12" | |
594fe323 | 28545 | (gdb) |
a2c02241 NR |
28546 | -stack-info-depth 11 |
28547 | ^done,depth="11" | |
594fe323 | 28548 | (gdb) |
a2c02241 NR |
28549 | -stack-info-depth 13 |
28550 | ^done,depth="12" | |
594fe323 | 28551 | (gdb) |
922fbb7b AC |
28552 | @end smallexample |
28553 | ||
1e611234 | 28554 | @anchor{-stack-list-arguments} |
a2c02241 NR |
28555 | @subheading The @code{-stack-list-arguments} Command |
28556 | @findex -stack-list-arguments | |
922fbb7b AC |
28557 | |
28558 | @subsubheading Synopsis | |
28559 | ||
28560 | @smallexample | |
6211c335 | 28561 | -stack-list-arguments [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values} |
a2c02241 | 28562 | [ @var{low-frame} @var{high-frame} ] |
922fbb7b AC |
28563 | @end smallexample |
28564 | ||
a2c02241 NR |
28565 | Display a list of the arguments for the frames between @var{low-frame} |
28566 | and @var{high-frame} (inclusive). If @var{low-frame} and | |
2f1acb09 VP |
28567 | @var{high-frame} are not provided, list the arguments for the whole |
28568 | call stack. If the two arguments are equal, show the single frame | |
28569 | at the corresponding level. It is an error if @var{low-frame} is | |
28570 | larger than the actual number of frames. On the other hand, | |
28571 | @var{high-frame} may be larger than the actual number of frames, in | |
28572 | which case only existing frames will be returned. | |
a2c02241 | 28573 | |
3afae151 VP |
28574 | If @var{print-values} is 0 or @code{--no-values}, print only the names of |
28575 | the variables; if it is 1 or @code{--all-values}, print also their | |
28576 | values; and if it is 2 or @code{--simple-values}, print the name, | |
28577 | type and value for simple data types, and the name and type for arrays, | |
1e611234 PM |
28578 | structures and unions. If the option @code{--no-frame-filters} is |
28579 | supplied, then Python frame filters will not be executed. | |
28580 | ||
6211c335 YQ |
28581 | If the @code{--skip-unavailable} option is specified, arguments that |
28582 | are not available are not listed. Partially available arguments | |
28583 | are still displayed, however. | |
922fbb7b | 28584 | |
b3372f91 VP |
28585 | Use of this command to obtain arguments in a single frame is |
28586 | deprecated in favor of the @samp{-stack-list-variables} command. | |
28587 | ||
922fbb7b AC |
28588 | @subsubheading @value{GDBN} Command |
28589 | ||
a2c02241 NR |
28590 | @value{GDBN} does not have an equivalent command. @code{gdbtk} has a |
28591 | @samp{gdb_get_args} command which partially overlaps with the | |
28592 | functionality of @samp{-stack-list-arguments}. | |
922fbb7b AC |
28593 | |
28594 | @subsubheading Example | |
922fbb7b | 28595 | |
a2c02241 | 28596 | @smallexample |
594fe323 | 28597 | (gdb) |
a2c02241 NR |
28598 | -stack-list-frames |
28599 | ^done, | |
28600 | stack=[ | |
28601 | frame=@{level="0",addr="0x00010734",func="callee4", | |
28602 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
28603 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}, | |
28604 | frame=@{level="1",addr="0x0001076c",func="callee3", | |
28605 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
28606 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@}, | |
28607 | frame=@{level="2",addr="0x0001078c",func="callee2", | |
28608 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
28609 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22"@}, | |
28610 | frame=@{level="3",addr="0x000107b4",func="callee1", | |
28611 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
28612 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27"@}, | |
28613 | frame=@{level="4",addr="0x000107e0",func="main", | |
28614 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
28615 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32"@}] | |
594fe323 | 28616 | (gdb) |
a2c02241 NR |
28617 | -stack-list-arguments 0 |
28618 | ^done, | |
28619 | stack-args=[ | |
28620 | frame=@{level="0",args=[]@}, | |
28621 | frame=@{level="1",args=[name="strarg"]@}, | |
28622 | frame=@{level="2",args=[name="intarg",name="strarg"]@}, | |
28623 | frame=@{level="3",args=[name="intarg",name="strarg",name="fltarg"]@}, | |
28624 | frame=@{level="4",args=[]@}] | |
594fe323 | 28625 | (gdb) |
a2c02241 NR |
28626 | -stack-list-arguments 1 |
28627 | ^done, | |
28628 | stack-args=[ | |
28629 | frame=@{level="0",args=[]@}, | |
28630 | frame=@{level="1", | |
28631 | args=[@{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
28632 | frame=@{level="2",args=[ | |
28633 | @{name="intarg",value="2"@}, | |
28634 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
28635 | @{frame=@{level="3",args=[ | |
28636 | @{name="intarg",value="2"@}, | |
28637 | @{name="strarg",value="0x11940 \"A string argument.\""@}, | |
28638 | @{name="fltarg",value="3.5"@}]@}, | |
28639 | frame=@{level="4",args=[]@}] | |
594fe323 | 28640 | (gdb) |
a2c02241 NR |
28641 | -stack-list-arguments 0 2 2 |
28642 | ^done,stack-args=[frame=@{level="2",args=[name="intarg",name="strarg"]@}] | |
594fe323 | 28643 | (gdb) |
a2c02241 NR |
28644 | -stack-list-arguments 1 2 2 |
28645 | ^done,stack-args=[frame=@{level="2", | |
28646 | args=[@{name="intarg",value="2"@}, | |
28647 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}] | |
594fe323 | 28648 | (gdb) |
a2c02241 NR |
28649 | @end smallexample |
28650 | ||
28651 | @c @subheading -stack-list-exception-handlers | |
922fbb7b | 28652 | |
a2c02241 | 28653 | |
1e611234 | 28654 | @anchor{-stack-list-frames} |
a2c02241 NR |
28655 | @subheading The @code{-stack-list-frames} Command |
28656 | @findex -stack-list-frames | |
1abaf70c BR |
28657 | |
28658 | @subsubheading Synopsis | |
28659 | ||
28660 | @smallexample | |
1e611234 | 28661 | -stack-list-frames [ --no-frame-filters @var{low-frame} @var{high-frame} ] |
1abaf70c BR |
28662 | @end smallexample |
28663 | ||
a2c02241 NR |
28664 | List the frames currently on the stack. For each frame it displays the |
28665 | following info: | |
28666 | ||
28667 | @table @samp | |
28668 | @item @var{level} | |
d3e8051b | 28669 | The frame number, 0 being the topmost frame, i.e., the innermost function. |
a2c02241 NR |
28670 | @item @var{addr} |
28671 | The @code{$pc} value for that frame. | |
28672 | @item @var{func} | |
28673 | Function name. | |
28674 | @item @var{file} | |
28675 | File name of the source file where the function lives. | |
7d288aaa TT |
28676 | @item @var{fullname} |
28677 | The full file name of the source file where the function lives. | |
a2c02241 NR |
28678 | @item @var{line} |
28679 | Line number corresponding to the @code{$pc}. | |
7d288aaa TT |
28680 | @item @var{from} |
28681 | The shared library where this function is defined. This is only given | |
28682 | if the frame's function is not known. | |
a2c02241 NR |
28683 | @end table |
28684 | ||
28685 | If invoked without arguments, this command prints a backtrace for the | |
28686 | whole stack. If given two integer arguments, it shows the frames whose | |
28687 | levels are between the two arguments (inclusive). If the two arguments | |
2ab1eb7a VP |
28688 | are equal, it shows the single frame at the corresponding level. It is |
28689 | an error if @var{low-frame} is larger than the actual number of | |
a5451f4e | 28690 | frames. On the other hand, @var{high-frame} may be larger than the |
1e611234 PM |
28691 | actual number of frames, in which case only existing frames will be |
28692 | returned. If the option @code{--no-frame-filters} is supplied, then | |
28693 | Python frame filters will not be executed. | |
1abaf70c BR |
28694 | |
28695 | @subsubheading @value{GDBN} Command | |
28696 | ||
a2c02241 | 28697 | The corresponding @value{GDBN} commands are @samp{backtrace} and @samp{where}. |
1abaf70c BR |
28698 | |
28699 | @subsubheading Example | |
28700 | ||
a2c02241 NR |
28701 | Full stack backtrace: |
28702 | ||
1abaf70c | 28703 | @smallexample |
594fe323 | 28704 | (gdb) |
a2c02241 NR |
28705 | -stack-list-frames |
28706 | ^done,stack= | |
28707 | [frame=@{level="0",addr="0x0001076c",func="foo", | |
28708 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11"@}, | |
28709 | frame=@{level="1",addr="0x000107a4",func="foo", | |
28710 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28711 | frame=@{level="2",addr="0x000107a4",func="foo", | |
28712 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28713 | frame=@{level="3",addr="0x000107a4",func="foo", | |
28714 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28715 | frame=@{level="4",addr="0x000107a4",func="foo", | |
28716 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28717 | frame=@{level="5",addr="0x000107a4",func="foo", | |
28718 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28719 | frame=@{level="6",addr="0x000107a4",func="foo", | |
28720 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28721 | frame=@{level="7",addr="0x000107a4",func="foo", | |
28722 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28723 | frame=@{level="8",addr="0x000107a4",func="foo", | |
28724 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28725 | frame=@{level="9",addr="0x000107a4",func="foo", | |
28726 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28727 | frame=@{level="10",addr="0x000107a4",func="foo", | |
28728 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28729 | frame=@{level="11",addr="0x00010738",func="main", | |
28730 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4"@}] | |
594fe323 | 28731 | (gdb) |
1abaf70c BR |
28732 | @end smallexample |
28733 | ||
a2c02241 | 28734 | Show frames between @var{low_frame} and @var{high_frame}: |
1abaf70c | 28735 | |
a2c02241 | 28736 | @smallexample |
594fe323 | 28737 | (gdb) |
a2c02241 NR |
28738 | -stack-list-frames 3 5 |
28739 | ^done,stack= | |
28740 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
28741 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28742 | frame=@{level="4",addr="0x000107a4",func="foo", | |
28743 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
28744 | frame=@{level="5",addr="0x000107a4",func="foo", | |
28745 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}] | |
594fe323 | 28746 | (gdb) |
a2c02241 | 28747 | @end smallexample |
922fbb7b | 28748 | |
a2c02241 | 28749 | Show a single frame: |
922fbb7b AC |
28750 | |
28751 | @smallexample | |
594fe323 | 28752 | (gdb) |
a2c02241 NR |
28753 | -stack-list-frames 3 3 |
28754 | ^done,stack= | |
28755 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
28756 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}] | |
594fe323 | 28757 | (gdb) |
922fbb7b AC |
28758 | @end smallexample |
28759 | ||
922fbb7b | 28760 | |
a2c02241 NR |
28761 | @subheading The @code{-stack-list-locals} Command |
28762 | @findex -stack-list-locals | |
1e611234 | 28763 | @anchor{-stack-list-locals} |
57c22c6c | 28764 | |
a2c02241 | 28765 | @subsubheading Synopsis |
922fbb7b AC |
28766 | |
28767 | @smallexample | |
6211c335 | 28768 | -stack-list-locals [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values} |
922fbb7b AC |
28769 | @end smallexample |
28770 | ||
a2c02241 NR |
28771 | Display the local variable names for the selected frame. If |
28772 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
28773 | the variables; if it is 1 or @code{--all-values}, print also their | |
28774 | values; and if it is 2 or @code{--simple-values}, print the name, | |
3afae151 | 28775 | type and value for simple data types, and the name and type for arrays, |
a2c02241 NR |
28776 | structures and unions. In this last case, a frontend can immediately |
28777 | display the value of simple data types and create variable objects for | |
d3e8051b | 28778 | other data types when the user wishes to explore their values in |
1e611234 PM |
28779 | more detail. If the option @code{--no-frame-filters} is supplied, then |
28780 | Python frame filters will not be executed. | |
922fbb7b | 28781 | |
6211c335 YQ |
28782 | If the @code{--skip-unavailable} option is specified, local variables |
28783 | that are not available are not listed. Partially available local | |
28784 | variables are still displayed, however. | |
28785 | ||
b3372f91 VP |
28786 | This command is deprecated in favor of the |
28787 | @samp{-stack-list-variables} command. | |
28788 | ||
922fbb7b AC |
28789 | @subsubheading @value{GDBN} Command |
28790 | ||
a2c02241 | 28791 | @samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}. |
922fbb7b AC |
28792 | |
28793 | @subsubheading Example | |
922fbb7b AC |
28794 | |
28795 | @smallexample | |
594fe323 | 28796 | (gdb) |
a2c02241 NR |
28797 | -stack-list-locals 0 |
28798 | ^done,locals=[name="A",name="B",name="C"] | |
594fe323 | 28799 | (gdb) |
a2c02241 NR |
28800 | -stack-list-locals --all-values |
28801 | ^done,locals=[@{name="A",value="1"@},@{name="B",value="2"@}, | |
28802 | @{name="C",value="@{1, 2, 3@}"@}] | |
28803 | -stack-list-locals --simple-values | |
28804 | ^done,locals=[@{name="A",type="int",value="1"@}, | |
28805 | @{name="B",type="int",value="2"@},@{name="C",type="int [3]"@}] | |
594fe323 | 28806 | (gdb) |
922fbb7b AC |
28807 | @end smallexample |
28808 | ||
1e611234 | 28809 | @anchor{-stack-list-variables} |
b3372f91 VP |
28810 | @subheading The @code{-stack-list-variables} Command |
28811 | @findex -stack-list-variables | |
28812 | ||
28813 | @subsubheading Synopsis | |
28814 | ||
28815 | @smallexample | |
6211c335 | 28816 | -stack-list-variables [ --no-frame-filters ] [ --skip-unavailable ] @var{print-values} |
b3372f91 VP |
28817 | @end smallexample |
28818 | ||
28819 | Display the names of local variables and function arguments for the selected frame. If | |
28820 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
28821 | the variables; if it is 1 or @code{--all-values}, print also their | |
28822 | values; and if it is 2 or @code{--simple-values}, print the name, | |
3afae151 | 28823 | type and value for simple data types, and the name and type for arrays, |
1e611234 PM |
28824 | structures and unions. If the option @code{--no-frame-filters} is |
28825 | supplied, then Python frame filters will not be executed. | |
b3372f91 | 28826 | |
6211c335 YQ |
28827 | If the @code{--skip-unavailable} option is specified, local variables |
28828 | and arguments that are not available are not listed. Partially | |
28829 | available arguments and local variables are still displayed, however. | |
28830 | ||
b3372f91 VP |
28831 | @subsubheading Example |
28832 | ||
28833 | @smallexample | |
28834 | (gdb) | |
28835 | -stack-list-variables --thread 1 --frame 0 --all-values | |
4f412fd0 | 28836 | ^done,variables=[@{name="x",value="11"@},@{name="s",value="@{a = 1, b = 2@}"@}] |
b3372f91 VP |
28837 | (gdb) |
28838 | @end smallexample | |
28839 | ||
922fbb7b | 28840 | |
a2c02241 NR |
28841 | @subheading The @code{-stack-select-frame} Command |
28842 | @findex -stack-select-frame | |
922fbb7b AC |
28843 | |
28844 | @subsubheading Synopsis | |
28845 | ||
28846 | @smallexample | |
a2c02241 | 28847 | -stack-select-frame @var{framenum} |
922fbb7b AC |
28848 | @end smallexample |
28849 | ||
a2c02241 NR |
28850 | Change the selected frame. Select a different frame @var{framenum} on |
28851 | the stack. | |
922fbb7b | 28852 | |
c3b108f7 VP |
28853 | This command in deprecated in favor of passing the @samp{--frame} |
28854 | option to every command. | |
28855 | ||
922fbb7b AC |
28856 | @subsubheading @value{GDBN} Command |
28857 | ||
a2c02241 NR |
28858 | The corresponding @value{GDBN} commands are @samp{frame}, @samp{up}, |
28859 | @samp{down}, @samp{select-frame}, @samp{up-silent}, and @samp{down-silent}. | |
922fbb7b AC |
28860 | |
28861 | @subsubheading Example | |
28862 | ||
28863 | @smallexample | |
594fe323 | 28864 | (gdb) |
a2c02241 | 28865 | -stack-select-frame 2 |
922fbb7b | 28866 | ^done |
594fe323 | 28867 | (gdb) |
922fbb7b AC |
28868 | @end smallexample |
28869 | ||
28870 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
a2c02241 NR |
28871 | @node GDB/MI Variable Objects |
28872 | @section @sc{gdb/mi} Variable Objects | |
922fbb7b | 28873 | |
a1b5960f | 28874 | @ignore |
922fbb7b | 28875 | |
a2c02241 | 28876 | @subheading Motivation for Variable Objects in @sc{gdb/mi} |
922fbb7b | 28877 | |
a2c02241 NR |
28878 | For the implementation of a variable debugger window (locals, watched |
28879 | expressions, etc.), we are proposing the adaptation of the existing code | |
28880 | used by @code{Insight}. | |
922fbb7b | 28881 | |
a2c02241 | 28882 | The two main reasons for that are: |
922fbb7b | 28883 | |
a2c02241 NR |
28884 | @enumerate 1 |
28885 | @item | |
28886 | It has been proven in practice (it is already on its second generation). | |
922fbb7b | 28887 | |
a2c02241 NR |
28888 | @item |
28889 | It will shorten development time (needless to say how important it is | |
28890 | now). | |
28891 | @end enumerate | |
922fbb7b | 28892 | |
a2c02241 NR |
28893 | The original interface was designed to be used by Tcl code, so it was |
28894 | slightly changed so it could be used through @sc{gdb/mi}. This section | |
28895 | describes the @sc{gdb/mi} operations that will be available and gives some | |
28896 | hints about their use. | |
922fbb7b | 28897 | |
a2c02241 NR |
28898 | @emph{Note}: In addition to the set of operations described here, we |
28899 | expect the @sc{gui} implementation of a variable window to require, at | |
28900 | least, the following operations: | |
922fbb7b | 28901 | |
a2c02241 NR |
28902 | @itemize @bullet |
28903 | @item @code{-gdb-show} @code{output-radix} | |
28904 | @item @code{-stack-list-arguments} | |
28905 | @item @code{-stack-list-locals} | |
28906 | @item @code{-stack-select-frame} | |
28907 | @end itemize | |
922fbb7b | 28908 | |
a1b5960f VP |
28909 | @end ignore |
28910 | ||
c8b2f53c | 28911 | @subheading Introduction to Variable Objects |
922fbb7b | 28912 | |
a2c02241 | 28913 | @cindex variable objects in @sc{gdb/mi} |
c8b2f53c VP |
28914 | |
28915 | Variable objects are "object-oriented" MI interface for examining and | |
28916 | changing values of expressions. Unlike some other MI interfaces that | |
28917 | work with expressions, variable objects are specifically designed for | |
28918 | simple and efficient presentation in the frontend. A variable object | |
28919 | is identified by string name. When a variable object is created, the | |
28920 | frontend specifies the expression for that variable object. The | |
28921 | expression can be a simple variable, or it can be an arbitrary complex | |
28922 | expression, and can even involve CPU registers. After creating a | |
28923 | variable object, the frontend can invoke other variable object | |
28924 | operations---for example to obtain or change the value of a variable | |
28925 | object, or to change display format. | |
28926 | ||
28927 | Variable objects have hierarchical tree structure. Any variable object | |
28928 | that corresponds to a composite type, such as structure in C, has | |
28929 | a number of child variable objects, for example corresponding to each | |
28930 | element of a structure. A child variable object can itself have | |
28931 | children, recursively. Recursion ends when we reach | |
25d5ea92 VP |
28932 | leaf variable objects, which always have built-in types. Child variable |
28933 | objects are created only by explicit request, so if a frontend | |
28934 | is not interested in the children of a particular variable object, no | |
28935 | child will be created. | |
c8b2f53c VP |
28936 | |
28937 | For a leaf variable object it is possible to obtain its value as a | |
28938 | string, or set the value from a string. String value can be also | |
28939 | obtained for a non-leaf variable object, but it's generally a string | |
28940 | that only indicates the type of the object, and does not list its | |
28941 | contents. Assignment to a non-leaf variable object is not allowed. | |
28942 | ||
28943 | A frontend does not need to read the values of all variable objects each time | |
28944 | the program stops. Instead, MI provides an update command that lists all | |
28945 | variable objects whose values has changed since the last update | |
28946 | operation. This considerably reduces the amount of data that must | |
25d5ea92 VP |
28947 | be transferred to the frontend. As noted above, children variable |
28948 | objects are created on demand, and only leaf variable objects have a | |
28949 | real value. As result, gdb will read target memory only for leaf | |
28950 | variables that frontend has created. | |
28951 | ||
28952 | The automatic update is not always desirable. For example, a frontend | |
28953 | might want to keep a value of some expression for future reference, | |
28954 | and never update it. For another example, fetching memory is | |
28955 | relatively slow for embedded targets, so a frontend might want | |
28956 | to disable automatic update for the variables that are either not | |
28957 | visible on the screen, or ``closed''. This is possible using so | |
28958 | called ``frozen variable objects''. Such variable objects are never | |
28959 | implicitly updated. | |
922fbb7b | 28960 | |
c3b108f7 VP |
28961 | Variable objects can be either @dfn{fixed} or @dfn{floating}. For the |
28962 | fixed variable object, the expression is parsed when the variable | |
28963 | object is created, including associating identifiers to specific | |
28964 | variables. The meaning of expression never changes. For a floating | |
28965 | variable object the values of variables whose names appear in the | |
28966 | expressions are re-evaluated every time in the context of the current | |
28967 | frame. Consider this example: | |
28968 | ||
28969 | @smallexample | |
28970 | void do_work(...) | |
28971 | @{ | |
28972 | struct work_state state; | |
28973 | ||
28974 | if (...) | |
28975 | do_work(...); | |
28976 | @} | |
28977 | @end smallexample | |
28978 | ||
28979 | If a fixed variable object for the @code{state} variable is created in | |
7a9dd1b2 | 28980 | this function, and we enter the recursive call, the variable |
c3b108f7 VP |
28981 | object will report the value of @code{state} in the top-level |
28982 | @code{do_work} invocation. On the other hand, a floating variable | |
28983 | object will report the value of @code{state} in the current frame. | |
28984 | ||
28985 | If an expression specified when creating a fixed variable object | |
28986 | refers to a local variable, the variable object becomes bound to the | |
28987 | thread and frame in which the variable object is created. When such | |
28988 | variable object is updated, @value{GDBN} makes sure that the | |
28989 | thread/frame combination the variable object is bound to still exists, | |
28990 | and re-evaluates the variable object in context of that thread/frame. | |
28991 | ||
a2c02241 NR |
28992 | The following is the complete set of @sc{gdb/mi} operations defined to |
28993 | access this functionality: | |
922fbb7b | 28994 | |
a2c02241 NR |
28995 | @multitable @columnfractions .4 .6 |
28996 | @item @strong{Operation} | |
28997 | @tab @strong{Description} | |
922fbb7b | 28998 | |
0cc7d26f TT |
28999 | @item @code{-enable-pretty-printing} |
29000 | @tab enable Python-based pretty-printing | |
a2c02241 NR |
29001 | @item @code{-var-create} |
29002 | @tab create a variable object | |
29003 | @item @code{-var-delete} | |
22d8a470 | 29004 | @tab delete the variable object and/or its children |
a2c02241 NR |
29005 | @item @code{-var-set-format} |
29006 | @tab set the display format of this variable | |
29007 | @item @code{-var-show-format} | |
29008 | @tab show the display format of this variable | |
29009 | @item @code{-var-info-num-children} | |
29010 | @tab tells how many children this object has | |
29011 | @item @code{-var-list-children} | |
29012 | @tab return a list of the object's children | |
29013 | @item @code{-var-info-type} | |
29014 | @tab show the type of this variable object | |
29015 | @item @code{-var-info-expression} | |
02142340 VP |
29016 | @tab print parent-relative expression that this variable object represents |
29017 | @item @code{-var-info-path-expression} | |
29018 | @tab print full expression that this variable object represents | |
a2c02241 NR |
29019 | @item @code{-var-show-attributes} |
29020 | @tab is this variable editable? does it exist here? | |
29021 | @item @code{-var-evaluate-expression} | |
29022 | @tab get the value of this variable | |
29023 | @item @code{-var-assign} | |
29024 | @tab set the value of this variable | |
29025 | @item @code{-var-update} | |
29026 | @tab update the variable and its children | |
25d5ea92 VP |
29027 | @item @code{-var-set-frozen} |
29028 | @tab set frozeness attribute | |
0cc7d26f TT |
29029 | @item @code{-var-set-update-range} |
29030 | @tab set range of children to display on update | |
a2c02241 | 29031 | @end multitable |
922fbb7b | 29032 | |
a2c02241 NR |
29033 | In the next subsection we describe each operation in detail and suggest |
29034 | how it can be used. | |
922fbb7b | 29035 | |
a2c02241 | 29036 | @subheading Description And Use of Operations on Variable Objects |
922fbb7b | 29037 | |
0cc7d26f TT |
29038 | @subheading The @code{-enable-pretty-printing} Command |
29039 | @findex -enable-pretty-printing | |
29040 | ||
29041 | @smallexample | |
29042 | -enable-pretty-printing | |
29043 | @end smallexample | |
29044 | ||
29045 | @value{GDBN} allows Python-based visualizers to affect the output of the | |
29046 | MI variable object commands. However, because there was no way to | |
29047 | implement this in a fully backward-compatible way, a front end must | |
29048 | request that this functionality be enabled. | |
29049 | ||
29050 | Once enabled, this feature cannot be disabled. | |
29051 | ||
29052 | Note that if Python support has not been compiled into @value{GDBN}, | |
29053 | this command will still succeed (and do nothing). | |
29054 | ||
f43030c4 TT |
29055 | This feature is currently (as of @value{GDBN} 7.0) experimental, and |
29056 | may work differently in future versions of @value{GDBN}. | |
29057 | ||
a2c02241 NR |
29058 | @subheading The @code{-var-create} Command |
29059 | @findex -var-create | |
ef21caaf | 29060 | |
a2c02241 | 29061 | @subsubheading Synopsis |
ef21caaf | 29062 | |
a2c02241 NR |
29063 | @smallexample |
29064 | -var-create @{@var{name} | "-"@} | |
c3b108f7 | 29065 | @{@var{frame-addr} | "*" | "@@"@} @var{expression} |
a2c02241 NR |
29066 | @end smallexample |
29067 | ||
29068 | This operation creates a variable object, which allows the monitoring of | |
29069 | a variable, the result of an expression, a memory cell or a CPU | |
29070 | register. | |
ef21caaf | 29071 | |
a2c02241 NR |
29072 | The @var{name} parameter is the string by which the object can be |
29073 | referenced. It must be unique. If @samp{-} is specified, the varobj | |
29074 | system will generate a string ``varNNNNNN'' automatically. It will be | |
c3b108f7 | 29075 | unique provided that one does not specify @var{name} of that format. |
a2c02241 | 29076 | The command fails if a duplicate name is found. |
ef21caaf | 29077 | |
a2c02241 NR |
29078 | The frame under which the expression should be evaluated can be |
29079 | specified by @var{frame-addr}. A @samp{*} indicates that the current | |
c3b108f7 VP |
29080 | frame should be used. A @samp{@@} indicates that a floating variable |
29081 | object must be created. | |
922fbb7b | 29082 | |
a2c02241 NR |
29083 | @var{expression} is any expression valid on the current language set (must not |
29084 | begin with a @samp{*}), or one of the following: | |
922fbb7b | 29085 | |
a2c02241 NR |
29086 | @itemize @bullet |
29087 | @item | |
29088 | @samp{*@var{addr}}, where @var{addr} is the address of a memory cell | |
922fbb7b | 29089 | |
a2c02241 NR |
29090 | @item |
29091 | @samp{*@var{addr}-@var{addr}} --- a memory address range (TBD) | |
922fbb7b | 29092 | |
a2c02241 NR |
29093 | @item |
29094 | @samp{$@var{regname}} --- a CPU register name | |
29095 | @end itemize | |
922fbb7b | 29096 | |
0cc7d26f TT |
29097 | @cindex dynamic varobj |
29098 | A varobj's contents may be provided by a Python-based pretty-printer. In this | |
29099 | case the varobj is known as a @dfn{dynamic varobj}. Dynamic varobjs | |
29100 | have slightly different semantics in some cases. If the | |
29101 | @code{-enable-pretty-printing} command is not sent, then @value{GDBN} | |
29102 | will never create a dynamic varobj. This ensures backward | |
29103 | compatibility for existing clients. | |
29104 | ||
a2c02241 | 29105 | @subsubheading Result |
922fbb7b | 29106 | |
0cc7d26f TT |
29107 | This operation returns attributes of the newly-created varobj. These |
29108 | are: | |
29109 | ||
29110 | @table @samp | |
29111 | @item name | |
29112 | The name of the varobj. | |
29113 | ||
29114 | @item numchild | |
29115 | The number of children of the varobj. This number is not necessarily | |
29116 | reliable for a dynamic varobj. Instead, you must examine the | |
29117 | @samp{has_more} attribute. | |
29118 | ||
29119 | @item value | |
29120 | The varobj's scalar value. For a varobj whose type is some sort of | |
29121 | aggregate (e.g., a @code{struct}), or for a dynamic varobj, this value | |
29122 | will not be interesting. | |
29123 | ||
29124 | @item type | |
29125 | The varobj's type. This is a string representation of the type, as | |
8264ba82 AG |
29126 | would be printed by the @value{GDBN} CLI. If @samp{print object} |
29127 | (@pxref{Print Settings, set print object}) is set to @code{on}, the | |
29128 | @emph{actual} (derived) type of the object is shown rather than the | |
29129 | @emph{declared} one. | |
0cc7d26f TT |
29130 | |
29131 | @item thread-id | |
29132 | If a variable object is bound to a specific thread, then this is the | |
5d5658a1 | 29133 | thread's global identifier. |
0cc7d26f TT |
29134 | |
29135 | @item has_more | |
29136 | For a dynamic varobj, this indicates whether there appear to be any | |
29137 | children available. For a non-dynamic varobj, this will be 0. | |
29138 | ||
29139 | @item dynamic | |
29140 | This attribute will be present and have the value @samp{1} if the | |
29141 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
29142 | then this attribute will not be present. | |
29143 | ||
29144 | @item displayhint | |
29145 | A dynamic varobj can supply a display hint to the front end. The | |
29146 | value comes directly from the Python pretty-printer object's | |
4c374409 | 29147 | @code{display_hint} method. @xref{Pretty Printing API}. |
0cc7d26f TT |
29148 | @end table |
29149 | ||
29150 | Typical output will look like this: | |
922fbb7b AC |
29151 | |
29152 | @smallexample | |
0cc7d26f TT |
29153 | name="@var{name}",numchild="@var{N}",type="@var{type}",thread-id="@var{M}", |
29154 | has_more="@var{has_more}" | |
dcaaae04 NR |
29155 | @end smallexample |
29156 | ||
a2c02241 NR |
29157 | |
29158 | @subheading The @code{-var-delete} Command | |
29159 | @findex -var-delete | |
922fbb7b AC |
29160 | |
29161 | @subsubheading Synopsis | |
29162 | ||
29163 | @smallexample | |
22d8a470 | 29164 | -var-delete [ -c ] @var{name} |
922fbb7b AC |
29165 | @end smallexample |
29166 | ||
a2c02241 | 29167 | Deletes a previously created variable object and all of its children. |
22d8a470 | 29168 | With the @samp{-c} option, just deletes the children. |
922fbb7b | 29169 | |
a2c02241 | 29170 | Returns an error if the object @var{name} is not found. |
922fbb7b | 29171 | |
922fbb7b | 29172 | |
a2c02241 NR |
29173 | @subheading The @code{-var-set-format} Command |
29174 | @findex -var-set-format | |
922fbb7b | 29175 | |
a2c02241 | 29176 | @subsubheading Synopsis |
922fbb7b AC |
29177 | |
29178 | @smallexample | |
a2c02241 | 29179 | -var-set-format @var{name} @var{format-spec} |
922fbb7b AC |
29180 | @end smallexample |
29181 | ||
a2c02241 NR |
29182 | Sets the output format for the value of the object @var{name} to be |
29183 | @var{format-spec}. | |
29184 | ||
de051565 | 29185 | @anchor{-var-set-format} |
a2c02241 NR |
29186 | The syntax for the @var{format-spec} is as follows: |
29187 | ||
29188 | @smallexample | |
29189 | @var{format-spec} @expansion{} | |
1c35a88f | 29190 | @{binary | decimal | hexadecimal | octal | natural | zero-hexadecimal@} |
a2c02241 NR |
29191 | @end smallexample |
29192 | ||
c8b2f53c VP |
29193 | The natural format is the default format choosen automatically |
29194 | based on the variable type (like decimal for an @code{int}, hex | |
29195 | for pointers, etc.). | |
29196 | ||
1c35a88f LM |
29197 | The zero-hexadecimal format has a representation similar to hexadecimal |
29198 | but with padding zeroes to the left of the value. For example, a 32-bit | |
29199 | hexadecimal value of 0x1234 would be represented as 0x00001234 in the | |
29200 | zero-hexadecimal format. | |
29201 | ||
c8b2f53c VP |
29202 | For a variable with children, the format is set only on the |
29203 | variable itself, and the children are not affected. | |
a2c02241 NR |
29204 | |
29205 | @subheading The @code{-var-show-format} Command | |
29206 | @findex -var-show-format | |
922fbb7b AC |
29207 | |
29208 | @subsubheading Synopsis | |
29209 | ||
29210 | @smallexample | |
a2c02241 | 29211 | -var-show-format @var{name} |
922fbb7b AC |
29212 | @end smallexample |
29213 | ||
a2c02241 | 29214 | Returns the format used to display the value of the object @var{name}. |
922fbb7b | 29215 | |
a2c02241 NR |
29216 | @smallexample |
29217 | @var{format} @expansion{} | |
29218 | @var{format-spec} | |
29219 | @end smallexample | |
922fbb7b | 29220 | |
922fbb7b | 29221 | |
a2c02241 NR |
29222 | @subheading The @code{-var-info-num-children} Command |
29223 | @findex -var-info-num-children | |
29224 | ||
29225 | @subsubheading Synopsis | |
29226 | ||
29227 | @smallexample | |
29228 | -var-info-num-children @var{name} | |
29229 | @end smallexample | |
29230 | ||
29231 | Returns the number of children of a variable object @var{name}: | |
29232 | ||
29233 | @smallexample | |
29234 | numchild=@var{n} | |
29235 | @end smallexample | |
29236 | ||
0cc7d26f TT |
29237 | Note that this number is not completely reliable for a dynamic varobj. |
29238 | It will return the current number of children, but more children may | |
29239 | be available. | |
29240 | ||
a2c02241 NR |
29241 | |
29242 | @subheading The @code{-var-list-children} Command | |
29243 | @findex -var-list-children | |
29244 | ||
29245 | @subsubheading Synopsis | |
29246 | ||
29247 | @smallexample | |
0cc7d26f | 29248 | -var-list-children [@var{print-values}] @var{name} [@var{from} @var{to}] |
a2c02241 | 29249 | @end smallexample |
b569d230 | 29250 | @anchor{-var-list-children} |
a2c02241 NR |
29251 | |
29252 | Return a list of the children of the specified variable object and | |
29253 | create variable objects for them, if they do not already exist. With | |
f5011d11 | 29254 | a single argument or if @var{print-values} has a value of 0 or |
a2c02241 NR |
29255 | @code{--no-values}, print only the names of the variables; if |
29256 | @var{print-values} is 1 or @code{--all-values}, also print their | |
29257 | values; and if it is 2 or @code{--simple-values} print the name and | |
29258 | value for simple data types and just the name for arrays, structures | |
29259 | and unions. | |
922fbb7b | 29260 | |
0cc7d26f TT |
29261 | @var{from} and @var{to}, if specified, indicate the range of children |
29262 | to report. If @var{from} or @var{to} is less than zero, the range is | |
29263 | reset and all children will be reported. Otherwise, children starting | |
29264 | at @var{from} (zero-based) and up to and excluding @var{to} will be | |
29265 | reported. | |
29266 | ||
29267 | If a child range is requested, it will only affect the current call to | |
29268 | @code{-var-list-children}, but not future calls to @code{-var-update}. | |
29269 | For this, you must instead use @code{-var-set-update-range}. The | |
29270 | intent of this approach is to enable a front end to implement any | |
29271 | update approach it likes; for example, scrolling a view may cause the | |
29272 | front end to request more children with @code{-var-list-children}, and | |
29273 | then the front end could call @code{-var-set-update-range} with a | |
29274 | different range to ensure that future updates are restricted to just | |
29275 | the visible items. | |
29276 | ||
b569d230 EZ |
29277 | For each child the following results are returned: |
29278 | ||
29279 | @table @var | |
29280 | ||
29281 | @item name | |
29282 | Name of the variable object created for this child. | |
29283 | ||
29284 | @item exp | |
29285 | The expression to be shown to the user by the front end to designate this child. | |
29286 | For example this may be the name of a structure member. | |
29287 | ||
0cc7d26f TT |
29288 | For a dynamic varobj, this value cannot be used to form an |
29289 | expression. There is no way to do this at all with a dynamic varobj. | |
29290 | ||
b569d230 EZ |
29291 | For C/C@t{++} structures there are several pseudo children returned to |
29292 | designate access qualifiers. For these pseudo children @var{exp} is | |
29293 | @samp{public}, @samp{private}, or @samp{protected}. In this case the | |
29294 | type and value are not present. | |
29295 | ||
0cc7d26f TT |
29296 | A dynamic varobj will not report the access qualifying |
29297 | pseudo-children, regardless of the language. This information is not | |
29298 | available at all with a dynamic varobj. | |
29299 | ||
b569d230 | 29300 | @item numchild |
0cc7d26f TT |
29301 | Number of children this child has. For a dynamic varobj, this will be |
29302 | 0. | |
b569d230 EZ |
29303 | |
29304 | @item type | |
8264ba82 AG |
29305 | The type of the child. If @samp{print object} |
29306 | (@pxref{Print Settings, set print object}) is set to @code{on}, the | |
29307 | @emph{actual} (derived) type of the object is shown rather than the | |
29308 | @emph{declared} one. | |
b569d230 EZ |
29309 | |
29310 | @item value | |
29311 | If values were requested, this is the value. | |
29312 | ||
29313 | @item thread-id | |
5d5658a1 PA |
29314 | If this variable object is associated with a thread, this is the |
29315 | thread's global thread id. Otherwise this result is not present. | |
b569d230 EZ |
29316 | |
29317 | @item frozen | |
29318 | If the variable object is frozen, this variable will be present with a value of 1. | |
c78feb39 | 29319 | |
9df9dbe0 YQ |
29320 | @item displayhint |
29321 | A dynamic varobj can supply a display hint to the front end. The | |
29322 | value comes directly from the Python pretty-printer object's | |
29323 | @code{display_hint} method. @xref{Pretty Printing API}. | |
29324 | ||
c78feb39 YQ |
29325 | @item dynamic |
29326 | This attribute will be present and have the value @samp{1} if the | |
29327 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
29328 | then this attribute will not be present. | |
29329 | ||
b569d230 EZ |
29330 | @end table |
29331 | ||
0cc7d26f TT |
29332 | The result may have its own attributes: |
29333 | ||
29334 | @table @samp | |
29335 | @item displayhint | |
29336 | A dynamic varobj can supply a display hint to the front end. The | |
29337 | value comes directly from the Python pretty-printer object's | |
4c374409 | 29338 | @code{display_hint} method. @xref{Pretty Printing API}. |
0cc7d26f TT |
29339 | |
29340 | @item has_more | |
29341 | This is an integer attribute which is nonzero if there are children | |
29342 | remaining after the end of the selected range. | |
29343 | @end table | |
29344 | ||
922fbb7b AC |
29345 | @subsubheading Example |
29346 | ||
29347 | @smallexample | |
594fe323 | 29348 | (gdb) |
a2c02241 | 29349 | -var-list-children n |
b569d230 | 29350 | ^done,numchild=@var{n},children=[child=@{name=@var{name},exp=@var{exp}, |
a2c02241 | 29351 | numchild=@var{n},type=@var{type}@},@r{(repeats N times)}] |
594fe323 | 29352 | (gdb) |
a2c02241 | 29353 | -var-list-children --all-values n |
b569d230 | 29354 | ^done,numchild=@var{n},children=[child=@{name=@var{name},exp=@var{exp}, |
a2c02241 | 29355 | numchild=@var{n},value=@var{value},type=@var{type}@},@r{(repeats N times)}] |
922fbb7b AC |
29356 | @end smallexample |
29357 | ||
922fbb7b | 29358 | |
a2c02241 NR |
29359 | @subheading The @code{-var-info-type} Command |
29360 | @findex -var-info-type | |
922fbb7b | 29361 | |
a2c02241 NR |
29362 | @subsubheading Synopsis |
29363 | ||
29364 | @smallexample | |
29365 | -var-info-type @var{name} | |
29366 | @end smallexample | |
29367 | ||
29368 | Returns the type of the specified variable @var{name}. The type is | |
29369 | returned as a string in the same format as it is output by the | |
29370 | @value{GDBN} CLI: | |
29371 | ||
29372 | @smallexample | |
29373 | type=@var{typename} | |
29374 | @end smallexample | |
29375 | ||
29376 | ||
29377 | @subheading The @code{-var-info-expression} Command | |
29378 | @findex -var-info-expression | |
922fbb7b AC |
29379 | |
29380 | @subsubheading Synopsis | |
29381 | ||
29382 | @smallexample | |
a2c02241 | 29383 | -var-info-expression @var{name} |
922fbb7b AC |
29384 | @end smallexample |
29385 | ||
02142340 VP |
29386 | Returns a string that is suitable for presenting this |
29387 | variable object in user interface. The string is generally | |
29388 | not valid expression in the current language, and cannot be evaluated. | |
29389 | ||
29390 | For example, if @code{a} is an array, and variable object | |
29391 | @code{A} was created for @code{a}, then we'll get this output: | |
922fbb7b | 29392 | |
a2c02241 | 29393 | @smallexample |
02142340 VP |
29394 | (gdb) -var-info-expression A.1 |
29395 | ^done,lang="C",exp="1" | |
a2c02241 | 29396 | @end smallexample |
922fbb7b | 29397 | |
a2c02241 | 29398 | @noindent |
fa4d0c40 YQ |
29399 | Here, the value of @code{lang} is the language name, which can be |
29400 | found in @ref{Supported Languages}. | |
02142340 VP |
29401 | |
29402 | Note that the output of the @code{-var-list-children} command also | |
29403 | includes those expressions, so the @code{-var-info-expression} command | |
29404 | is of limited use. | |
29405 | ||
29406 | @subheading The @code{-var-info-path-expression} Command | |
29407 | @findex -var-info-path-expression | |
29408 | ||
29409 | @subsubheading Synopsis | |
29410 | ||
29411 | @smallexample | |
29412 | -var-info-path-expression @var{name} | |
29413 | @end smallexample | |
29414 | ||
29415 | Returns an expression that can be evaluated in the current | |
29416 | context and will yield the same value that a variable object has. | |
29417 | Compare this with the @code{-var-info-expression} command, which | |
29418 | result can be used only for UI presentation. Typical use of | |
29419 | the @code{-var-info-path-expression} command is creating a | |
29420 | watchpoint from a variable object. | |
29421 | ||
0cc7d26f TT |
29422 | This command is currently not valid for children of a dynamic varobj, |
29423 | and will give an error when invoked on one. | |
29424 | ||
02142340 VP |
29425 | For example, suppose @code{C} is a C@t{++} class, derived from class |
29426 | @code{Base}, and that the @code{Base} class has a member called | |
29427 | @code{m_size}. Assume a variable @code{c} is has the type of | |
29428 | @code{C} and a variable object @code{C} was created for variable | |
29429 | @code{c}. Then, we'll get this output: | |
29430 | @smallexample | |
29431 | (gdb) -var-info-path-expression C.Base.public.m_size | |
29432 | ^done,path_expr=((Base)c).m_size) | |
29433 | @end smallexample | |
922fbb7b | 29434 | |
a2c02241 NR |
29435 | @subheading The @code{-var-show-attributes} Command |
29436 | @findex -var-show-attributes | |
922fbb7b | 29437 | |
a2c02241 | 29438 | @subsubheading Synopsis |
922fbb7b | 29439 | |
a2c02241 NR |
29440 | @smallexample |
29441 | -var-show-attributes @var{name} | |
29442 | @end smallexample | |
922fbb7b | 29443 | |
a2c02241 | 29444 | List attributes of the specified variable object @var{name}: |
922fbb7b AC |
29445 | |
29446 | @smallexample | |
a2c02241 | 29447 | status=@var{attr} [ ( ,@var{attr} )* ] |
922fbb7b AC |
29448 | @end smallexample |
29449 | ||
a2c02241 NR |
29450 | @noindent |
29451 | where @var{attr} is @code{@{ @{ editable | noneditable @} | TBD @}}. | |
29452 | ||
29453 | @subheading The @code{-var-evaluate-expression} Command | |
29454 | @findex -var-evaluate-expression | |
29455 | ||
29456 | @subsubheading Synopsis | |
29457 | ||
29458 | @smallexample | |
de051565 | 29459 | -var-evaluate-expression [-f @var{format-spec}] @var{name} |
a2c02241 NR |
29460 | @end smallexample |
29461 | ||
29462 | Evaluates the expression that is represented by the specified variable | |
de051565 MK |
29463 | object and returns its value as a string. The format of the string |
29464 | can be specified with the @samp{-f} option. The possible values of | |
29465 | this option are the same as for @code{-var-set-format} | |
29466 | (@pxref{-var-set-format}). If the @samp{-f} option is not specified, | |
29467 | the current display format will be used. The current display format | |
29468 | can be changed using the @code{-var-set-format} command. | |
a2c02241 NR |
29469 | |
29470 | @smallexample | |
29471 | value=@var{value} | |
29472 | @end smallexample | |
29473 | ||
29474 | Note that one must invoke @code{-var-list-children} for a variable | |
29475 | before the value of a child variable can be evaluated. | |
29476 | ||
29477 | @subheading The @code{-var-assign} Command | |
29478 | @findex -var-assign | |
29479 | ||
29480 | @subsubheading Synopsis | |
29481 | ||
29482 | @smallexample | |
29483 | -var-assign @var{name} @var{expression} | |
29484 | @end smallexample | |
29485 | ||
29486 | Assigns the value of @var{expression} to the variable object specified | |
29487 | by @var{name}. The object must be @samp{editable}. If the variable's | |
29488 | value is altered by the assign, the variable will show up in any | |
29489 | subsequent @code{-var-update} list. | |
29490 | ||
29491 | @subsubheading Example | |
922fbb7b AC |
29492 | |
29493 | @smallexample | |
594fe323 | 29494 | (gdb) |
a2c02241 NR |
29495 | -var-assign var1 3 |
29496 | ^done,value="3" | |
594fe323 | 29497 | (gdb) |
a2c02241 NR |
29498 | -var-update * |
29499 | ^done,changelist=[@{name="var1",in_scope="true",type_changed="false"@}] | |
594fe323 | 29500 | (gdb) |
922fbb7b AC |
29501 | @end smallexample |
29502 | ||
a2c02241 NR |
29503 | @subheading The @code{-var-update} Command |
29504 | @findex -var-update | |
29505 | ||
29506 | @subsubheading Synopsis | |
29507 | ||
29508 | @smallexample | |
29509 | -var-update [@var{print-values}] @{@var{name} | "*"@} | |
29510 | @end smallexample | |
29511 | ||
c8b2f53c VP |
29512 | Reevaluate the expressions corresponding to the variable object |
29513 | @var{name} and all its direct and indirect children, and return the | |
36ece8b3 NR |
29514 | list of variable objects whose values have changed; @var{name} must |
29515 | be a root variable object. Here, ``changed'' means that the result of | |
29516 | @code{-var-evaluate-expression} before and after the | |
29517 | @code{-var-update} is different. If @samp{*} is used as the variable | |
9f708cb2 VP |
29518 | object names, all existing variable objects are updated, except |
29519 | for frozen ones (@pxref{-var-set-frozen}). The option | |
36ece8b3 | 29520 | @var{print-values} determines whether both names and values, or just |
de051565 | 29521 | names are printed. The possible values of this option are the same |
36ece8b3 NR |
29522 | as for @code{-var-list-children} (@pxref{-var-list-children}). It is |
29523 | recommended to use the @samp{--all-values} option, to reduce the | |
29524 | number of MI commands needed on each program stop. | |
c8b2f53c | 29525 | |
c3b108f7 VP |
29526 | With the @samp{*} parameter, if a variable object is bound to a |
29527 | currently running thread, it will not be updated, without any | |
29528 | diagnostic. | |
a2c02241 | 29529 | |
0cc7d26f TT |
29530 | If @code{-var-set-update-range} was previously used on a varobj, then |
29531 | only the selected range of children will be reported. | |
922fbb7b | 29532 | |
0cc7d26f TT |
29533 | @code{-var-update} reports all the changed varobjs in a tuple named |
29534 | @samp{changelist}. | |
29535 | ||
29536 | Each item in the change list is itself a tuple holding: | |
29537 | ||
29538 | @table @samp | |
29539 | @item name | |
29540 | The name of the varobj. | |
29541 | ||
29542 | @item value | |
29543 | If values were requested for this update, then this field will be | |
29544 | present and will hold the value of the varobj. | |
922fbb7b | 29545 | |
0cc7d26f | 29546 | @item in_scope |
9f708cb2 | 29547 | @anchor{-var-update} |
0cc7d26f | 29548 | This field is a string which may take one of three values: |
36ece8b3 NR |
29549 | |
29550 | @table @code | |
29551 | @item "true" | |
29552 | The variable object's current value is valid. | |
29553 | ||
29554 | @item "false" | |
29555 | The variable object does not currently hold a valid value but it may | |
29556 | hold one in the future if its associated expression comes back into | |
29557 | scope. | |
29558 | ||
29559 | @item "invalid" | |
29560 | The variable object no longer holds a valid value. | |
29561 | This can occur when the executable file being debugged has changed, | |
29562 | either through recompilation or by using the @value{GDBN} @code{file} | |
29563 | command. The front end should normally choose to delete these variable | |
29564 | objects. | |
29565 | @end table | |
29566 | ||
29567 | In the future new values may be added to this list so the front should | |
29568 | be prepared for this possibility. @xref{GDB/MI Development and Front Ends, ,@sc{GDB/MI} Development and Front Ends}. | |
29569 | ||
0cc7d26f TT |
29570 | @item type_changed |
29571 | This is only present if the varobj is still valid. If the type | |
29572 | changed, then this will be the string @samp{true}; otherwise it will | |
29573 | be @samp{false}. | |
29574 | ||
7191c139 JB |
29575 | When a varobj's type changes, its children are also likely to have |
29576 | become incorrect. Therefore, the varobj's children are automatically | |
29577 | deleted when this attribute is @samp{true}. Also, the varobj's update | |
29578 | range, when set using the @code{-var-set-update-range} command, is | |
29579 | unset. | |
29580 | ||
0cc7d26f TT |
29581 | @item new_type |
29582 | If the varobj's type changed, then this field will be present and will | |
29583 | hold the new type. | |
29584 | ||
29585 | @item new_num_children | |
29586 | For a dynamic varobj, if the number of children changed, or if the | |
29587 | type changed, this will be the new number of children. | |
29588 | ||
29589 | The @samp{numchild} field in other varobj responses is generally not | |
29590 | valid for a dynamic varobj -- it will show the number of children that | |
29591 | @value{GDBN} knows about, but because dynamic varobjs lazily | |
29592 | instantiate their children, this will not reflect the number of | |
29593 | children which may be available. | |
29594 | ||
29595 | The @samp{new_num_children} attribute only reports changes to the | |
29596 | number of children known by @value{GDBN}. This is the only way to | |
29597 | detect whether an update has removed children (which necessarily can | |
29598 | only happen at the end of the update range). | |
29599 | ||
29600 | @item displayhint | |
29601 | The display hint, if any. | |
29602 | ||
29603 | @item has_more | |
29604 | This is an integer value, which will be 1 if there are more children | |
29605 | available outside the varobj's update range. | |
29606 | ||
29607 | @item dynamic | |
29608 | This attribute will be present and have the value @samp{1} if the | |
29609 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
29610 | then this attribute will not be present. | |
29611 | ||
29612 | @item new_children | |
29613 | If new children were added to a dynamic varobj within the selected | |
29614 | update range (as set by @code{-var-set-update-range}), then they will | |
29615 | be listed in this attribute. | |
29616 | @end table | |
29617 | ||
29618 | @subsubheading Example | |
29619 | ||
29620 | @smallexample | |
29621 | (gdb) | |
29622 | -var-assign var1 3 | |
29623 | ^done,value="3" | |
29624 | (gdb) | |
29625 | -var-update --all-values var1 | |
29626 | ^done,changelist=[@{name="var1",value="3",in_scope="true", | |
29627 | type_changed="false"@}] | |
29628 | (gdb) | |
29629 | @end smallexample | |
29630 | ||
25d5ea92 VP |
29631 | @subheading The @code{-var-set-frozen} Command |
29632 | @findex -var-set-frozen | |
9f708cb2 | 29633 | @anchor{-var-set-frozen} |
25d5ea92 VP |
29634 | |
29635 | @subsubheading Synopsis | |
29636 | ||
29637 | @smallexample | |
9f708cb2 | 29638 | -var-set-frozen @var{name} @var{flag} |
25d5ea92 VP |
29639 | @end smallexample |
29640 | ||
9f708cb2 | 29641 | Set the frozenness flag on the variable object @var{name}. The |
25d5ea92 | 29642 | @var{flag} parameter should be either @samp{1} to make the variable |
9f708cb2 | 29643 | frozen or @samp{0} to make it unfrozen. If a variable object is |
25d5ea92 | 29644 | frozen, then neither itself, nor any of its children, are |
9f708cb2 | 29645 | implicitly updated by @code{-var-update} of |
25d5ea92 VP |
29646 | a parent variable or by @code{-var-update *}. Only |
29647 | @code{-var-update} of the variable itself will update its value and | |
29648 | values of its children. After a variable object is unfrozen, it is | |
29649 | implicitly updated by all subsequent @code{-var-update} operations. | |
29650 | Unfreezing a variable does not update it, only subsequent | |
29651 | @code{-var-update} does. | |
29652 | ||
29653 | @subsubheading Example | |
29654 | ||
29655 | @smallexample | |
29656 | (gdb) | |
29657 | -var-set-frozen V 1 | |
29658 | ^done | |
29659 | (gdb) | |
29660 | @end smallexample | |
29661 | ||
0cc7d26f TT |
29662 | @subheading The @code{-var-set-update-range} command |
29663 | @findex -var-set-update-range | |
29664 | @anchor{-var-set-update-range} | |
29665 | ||
29666 | @subsubheading Synopsis | |
29667 | ||
29668 | @smallexample | |
29669 | -var-set-update-range @var{name} @var{from} @var{to} | |
29670 | @end smallexample | |
29671 | ||
29672 | Set the range of children to be returned by future invocations of | |
29673 | @code{-var-update}. | |
29674 | ||
29675 | @var{from} and @var{to} indicate the range of children to report. If | |
29676 | @var{from} or @var{to} is less than zero, the range is reset and all | |
29677 | children will be reported. Otherwise, children starting at @var{from} | |
29678 | (zero-based) and up to and excluding @var{to} will be reported. | |
29679 | ||
29680 | @subsubheading Example | |
29681 | ||
29682 | @smallexample | |
29683 | (gdb) | |
29684 | -var-set-update-range V 1 2 | |
29685 | ^done | |
29686 | @end smallexample | |
29687 | ||
b6313243 TT |
29688 | @subheading The @code{-var-set-visualizer} command |
29689 | @findex -var-set-visualizer | |
29690 | @anchor{-var-set-visualizer} | |
29691 | ||
29692 | @subsubheading Synopsis | |
29693 | ||
29694 | @smallexample | |
29695 | -var-set-visualizer @var{name} @var{visualizer} | |
29696 | @end smallexample | |
29697 | ||
29698 | Set a visualizer for the variable object @var{name}. | |
29699 | ||
29700 | @var{visualizer} is the visualizer to use. The special value | |
29701 | @samp{None} means to disable any visualizer in use. | |
29702 | ||
29703 | If not @samp{None}, @var{visualizer} must be a Python expression. | |
29704 | This expression must evaluate to a callable object which accepts a | |
29705 | single argument. @value{GDBN} will call this object with the value of | |
29706 | the varobj @var{name} as an argument (this is done so that the same | |
29707 | Python pretty-printing code can be used for both the CLI and MI). | |
29708 | When called, this object must return an object which conforms to the | |
4c374409 | 29709 | pretty-printing interface (@pxref{Pretty Printing API}). |
b6313243 TT |
29710 | |
29711 | The pre-defined function @code{gdb.default_visualizer} may be used to | |
29712 | select a visualizer by following the built-in process | |
29713 | (@pxref{Selecting Pretty-Printers}). This is done automatically when | |
29714 | a varobj is created, and so ordinarily is not needed. | |
29715 | ||
29716 | This feature is only available if Python support is enabled. The MI | |
d192b373 | 29717 | command @code{-list-features} (@pxref{GDB/MI Support Commands}) |
b6313243 TT |
29718 | can be used to check this. |
29719 | ||
29720 | @subsubheading Example | |
29721 | ||
29722 | Resetting the visualizer: | |
29723 | ||
29724 | @smallexample | |
29725 | (gdb) | |
29726 | -var-set-visualizer V None | |
29727 | ^done | |
29728 | @end smallexample | |
29729 | ||
29730 | Reselecting the default (type-based) visualizer: | |
29731 | ||
29732 | @smallexample | |
29733 | (gdb) | |
29734 | -var-set-visualizer V gdb.default_visualizer | |
29735 | ^done | |
29736 | @end smallexample | |
29737 | ||
29738 | Suppose @code{SomeClass} is a visualizer class. A lambda expression | |
29739 | can be used to instantiate this class for a varobj: | |
29740 | ||
29741 | @smallexample | |
29742 | (gdb) | |
29743 | -var-set-visualizer V "lambda val: SomeClass()" | |
29744 | ^done | |
29745 | @end smallexample | |
25d5ea92 | 29746 | |
a2c02241 NR |
29747 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
29748 | @node GDB/MI Data Manipulation | |
29749 | @section @sc{gdb/mi} Data Manipulation | |
922fbb7b | 29750 | |
a2c02241 NR |
29751 | @cindex data manipulation, in @sc{gdb/mi} |
29752 | @cindex @sc{gdb/mi}, data manipulation | |
29753 | This section describes the @sc{gdb/mi} commands that manipulate data: | |
29754 | examine memory and registers, evaluate expressions, etc. | |
29755 | ||
a86c90e6 SM |
29756 | For details about what an addressable memory unit is, |
29757 | @pxref{addressable memory unit}. | |
29758 | ||
a2c02241 NR |
29759 | @c REMOVED FROM THE INTERFACE. |
29760 | @c @subheading -data-assign | |
29761 | @c Change the value of a program variable. Plenty of side effects. | |
79a6e687 | 29762 | @c @subsubheading GDB Command |
a2c02241 NR |
29763 | @c set variable |
29764 | @c @subsubheading Example | |
29765 | @c N.A. | |
29766 | ||
29767 | @subheading The @code{-data-disassemble} Command | |
29768 | @findex -data-disassemble | |
922fbb7b AC |
29769 | |
29770 | @subsubheading Synopsis | |
29771 | ||
29772 | @smallexample | |
a2c02241 NR |
29773 | -data-disassemble |
29774 | [ -s @var{start-addr} -e @var{end-addr} ] | |
29775 | | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ] | |
29776 | -- @var{mode} | |
922fbb7b AC |
29777 | @end smallexample |
29778 | ||
a2c02241 NR |
29779 | @noindent |
29780 | Where: | |
29781 | ||
29782 | @table @samp | |
29783 | @item @var{start-addr} | |
29784 | is the beginning address (or @code{$pc}) | |
29785 | @item @var{end-addr} | |
29786 | is the end address | |
29787 | @item @var{filename} | |
29788 | is the name of the file to disassemble | |
29789 | @item @var{linenum} | |
29790 | is the line number to disassemble around | |
29791 | @item @var{lines} | |
d3e8051b | 29792 | is the number of disassembly lines to be produced. If it is -1, |
a2c02241 NR |
29793 | the whole function will be disassembled, in case no @var{end-addr} is |
29794 | specified. If @var{end-addr} is specified as a non-zero value, and | |
29795 | @var{lines} is lower than the number of disassembly lines between | |
29796 | @var{start-addr} and @var{end-addr}, only @var{lines} lines are | |
29797 | displayed; if @var{lines} is higher than the number of lines between | |
29798 | @var{start-addr} and @var{end-addr}, only the lines up to @var{end-addr} | |
29799 | are displayed. | |
29800 | @item @var{mode} | |
6ff0ba5f DE |
29801 | is one of: |
29802 | @itemize @bullet | |
29803 | @item 0 disassembly only | |
29804 | @item 1 mixed source and disassembly (deprecated) | |
29805 | @item 2 disassembly with raw opcodes | |
29806 | @item 3 mixed source and disassembly with raw opcodes (deprecated) | |
29807 | @item 4 mixed source and disassembly | |
29808 | @item 5 mixed source and disassembly with raw opcodes | |
29809 | @end itemize | |
29810 | ||
29811 | Modes 1 and 3 are deprecated. The output is ``source centric'' | |
29812 | which hasn't proved useful in practice. | |
29813 | @xref{Machine Code}, for a discussion of the difference between | |
29814 | @code{/m} and @code{/s} output of the @code{disassemble} command. | |
a2c02241 NR |
29815 | @end table |
29816 | ||
29817 | @subsubheading Result | |
29818 | ||
ed8a1c2d AB |
29819 | The result of the @code{-data-disassemble} command will be a list named |
29820 | @samp{asm_insns}, the contents of this list depend on the @var{mode} | |
29821 | used with the @code{-data-disassemble} command. | |
a2c02241 | 29822 | |
ed8a1c2d AB |
29823 | For modes 0 and 2 the @samp{asm_insns} list contains tuples with the |
29824 | following fields: | |
29825 | ||
29826 | @table @code | |
29827 | @item address | |
29828 | The address at which this instruction was disassembled. | |
29829 | ||
29830 | @item func-name | |
29831 | The name of the function this instruction is within. | |
29832 | ||
29833 | @item offset | |
29834 | The decimal offset in bytes from the start of @samp{func-name}. | |
29835 | ||
29836 | @item inst | |
29837 | The text disassembly for this @samp{address}. | |
29838 | ||
29839 | @item opcodes | |
6ff0ba5f | 29840 | This field is only present for modes 2, 3 and 5. This contains the raw opcode |
ed8a1c2d AB |
29841 | bytes for the @samp{inst} field. |
29842 | ||
29843 | @end table | |
29844 | ||
6ff0ba5f | 29845 | For modes 1, 3, 4 and 5 the @samp{asm_insns} list contains tuples named |
ed8a1c2d | 29846 | @samp{src_and_asm_line}, each of which has the following fields: |
a2c02241 | 29847 | |
ed8a1c2d AB |
29848 | @table @code |
29849 | @item line | |
29850 | The line number within @samp{file}. | |
29851 | ||
29852 | @item file | |
29853 | The file name from the compilation unit. This might be an absolute | |
29854 | file name or a relative file name depending on the compile command | |
29855 | used. | |
29856 | ||
29857 | @item fullname | |
f35a17b5 JK |
29858 | Absolute file name of @samp{file}. It is converted to a canonical form |
29859 | using the source file search path | |
29860 | (@pxref{Source Path, ,Specifying Source Directories}) | |
29861 | and after resolving all the symbolic links. | |
29862 | ||
29863 | If the source file is not found this field will contain the path as | |
29864 | present in the debug information. | |
ed8a1c2d AB |
29865 | |
29866 | @item line_asm_insn | |
29867 | This is a list of tuples containing the disassembly for @samp{line} in | |
29868 | @samp{file}. The fields of each tuple are the same as for | |
29869 | @code{-data-disassemble} in @var{mode} 0 and 2, so @samp{address}, | |
29870 | @samp{func-name}, @samp{offset}, @samp{inst}, and optionally | |
29871 | @samp{opcodes}. | |
29872 | ||
29873 | @end table | |
29874 | ||
29875 | Note that whatever included in the @samp{inst} field, is not | |
29876 | manipulated directly by @sc{gdb/mi}, i.e., it is not possible to | |
29877 | adjust its format. | |
922fbb7b AC |
29878 | |
29879 | @subsubheading @value{GDBN} Command | |
29880 | ||
ed8a1c2d | 29881 | The corresponding @value{GDBN} command is @samp{disassemble}. |
922fbb7b AC |
29882 | |
29883 | @subsubheading Example | |
29884 | ||
a2c02241 NR |
29885 | Disassemble from the current value of @code{$pc} to @code{$pc + 20}: |
29886 | ||
922fbb7b | 29887 | @smallexample |
594fe323 | 29888 | (gdb) |
a2c02241 NR |
29889 | -data-disassemble -s $pc -e "$pc + 20" -- 0 |
29890 | ^done, | |
29891 | asm_insns=[ | |
29892 | @{address="0x000107c0",func-name="main",offset="4", | |
29893 | inst="mov 2, %o0"@}, | |
29894 | @{address="0x000107c4",func-name="main",offset="8", | |
29895 | inst="sethi %hi(0x11800), %o2"@}, | |
29896 | @{address="0x000107c8",func-name="main",offset="12", | |
29897 | inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"@}, | |
29898 | @{address="0x000107cc",func-name="main",offset="16", | |
29899 | inst="sethi %hi(0x11800), %o2"@}, | |
29900 | @{address="0x000107d0",func-name="main",offset="20", | |
29901 | inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"@}] | |
594fe323 | 29902 | (gdb) |
a2c02241 NR |
29903 | @end smallexample |
29904 | ||
29905 | Disassemble the whole @code{main} function. Line 32 is part of | |
29906 | @code{main}. | |
29907 | ||
29908 | @smallexample | |
29909 | -data-disassemble -f basics.c -l 32 -- 0 | |
29910 | ^done,asm_insns=[ | |
29911 | @{address="0x000107bc",func-name="main",offset="0", | |
29912 | inst="save %sp, -112, %sp"@}, | |
29913 | @{address="0x000107c0",func-name="main",offset="4", | |
29914 | inst="mov 2, %o0"@}, | |
29915 | @{address="0x000107c4",func-name="main",offset="8", | |
29916 | inst="sethi %hi(0x11800), %o2"@}, | |
29917 | [@dots{}] | |
29918 | @{address="0x0001081c",func-name="main",offset="96",inst="ret "@}, | |
29919 | @{address="0x00010820",func-name="main",offset="100",inst="restore "@}] | |
594fe323 | 29920 | (gdb) |
922fbb7b AC |
29921 | @end smallexample |
29922 | ||
a2c02241 | 29923 | Disassemble 3 instructions from the start of @code{main}: |
922fbb7b | 29924 | |
a2c02241 | 29925 | @smallexample |
594fe323 | 29926 | (gdb) |
a2c02241 NR |
29927 | -data-disassemble -f basics.c -l 32 -n 3 -- 0 |
29928 | ^done,asm_insns=[ | |
29929 | @{address="0x000107bc",func-name="main",offset="0", | |
29930 | inst="save %sp, -112, %sp"@}, | |
29931 | @{address="0x000107c0",func-name="main",offset="4", | |
29932 | inst="mov 2, %o0"@}, | |
29933 | @{address="0x000107c4",func-name="main",offset="8", | |
29934 | inst="sethi %hi(0x11800), %o2"@}] | |
594fe323 | 29935 | (gdb) |
a2c02241 NR |
29936 | @end smallexample |
29937 | ||
29938 | Disassemble 3 instructions from the start of @code{main} in mixed mode: | |
29939 | ||
29940 | @smallexample | |
594fe323 | 29941 | (gdb) |
a2c02241 NR |
29942 | -data-disassemble -f basics.c -l 32 -n 3 -- 1 |
29943 | ^done,asm_insns=[ | |
29944 | src_and_asm_line=@{line="31", | |
ed8a1c2d AB |
29945 | file="../../../src/gdb/testsuite/gdb.mi/basics.c", |
29946 | fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c", | |
29947 | line_asm_insn=[@{address="0x000107bc", | |
29948 | func-name="main",offset="0",inst="save %sp, -112, %sp"@}]@}, | |
a2c02241 | 29949 | src_and_asm_line=@{line="32", |
ed8a1c2d AB |
29950 | file="../../../src/gdb/testsuite/gdb.mi/basics.c", |
29951 | fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c", | |
29952 | line_asm_insn=[@{address="0x000107c0", | |
29953 | func-name="main",offset="4",inst="mov 2, %o0"@}, | |
a2c02241 NR |
29954 | @{address="0x000107c4",func-name="main",offset="8", |
29955 | inst="sethi %hi(0x11800), %o2"@}]@}] | |
594fe323 | 29956 | (gdb) |
a2c02241 NR |
29957 | @end smallexample |
29958 | ||
29959 | ||
29960 | @subheading The @code{-data-evaluate-expression} Command | |
29961 | @findex -data-evaluate-expression | |
922fbb7b AC |
29962 | |
29963 | @subsubheading Synopsis | |
29964 | ||
29965 | @smallexample | |
a2c02241 | 29966 | -data-evaluate-expression @var{expr} |
922fbb7b AC |
29967 | @end smallexample |
29968 | ||
a2c02241 NR |
29969 | Evaluate @var{expr} as an expression. The expression could contain an |
29970 | inferior function call. The function call will execute synchronously. | |
29971 | If the expression contains spaces, it must be enclosed in double quotes. | |
922fbb7b AC |
29972 | |
29973 | @subsubheading @value{GDBN} Command | |
29974 | ||
a2c02241 NR |
29975 | The corresponding @value{GDBN} commands are @samp{print}, @samp{output}, and |
29976 | @samp{call}. In @code{gdbtk} only, there's a corresponding | |
29977 | @samp{gdb_eval} command. | |
922fbb7b AC |
29978 | |
29979 | @subsubheading Example | |
29980 | ||
a2c02241 NR |
29981 | In the following example, the numbers that precede the commands are the |
29982 | @dfn{tokens} described in @ref{GDB/MI Command Syntax, ,@sc{gdb/mi} | |
29983 | Command Syntax}. Notice how @sc{gdb/mi} returns the same tokens in its | |
29984 | output. | |
29985 | ||
922fbb7b | 29986 | @smallexample |
a2c02241 NR |
29987 | 211-data-evaluate-expression A |
29988 | 211^done,value="1" | |
594fe323 | 29989 | (gdb) |
a2c02241 NR |
29990 | 311-data-evaluate-expression &A |
29991 | 311^done,value="0xefffeb7c" | |
594fe323 | 29992 | (gdb) |
a2c02241 NR |
29993 | 411-data-evaluate-expression A+3 |
29994 | 411^done,value="4" | |
594fe323 | 29995 | (gdb) |
a2c02241 NR |
29996 | 511-data-evaluate-expression "A + 3" |
29997 | 511^done,value="4" | |
594fe323 | 29998 | (gdb) |
a2c02241 | 29999 | @end smallexample |
922fbb7b AC |
30000 | |
30001 | ||
a2c02241 NR |
30002 | @subheading The @code{-data-list-changed-registers} Command |
30003 | @findex -data-list-changed-registers | |
922fbb7b AC |
30004 | |
30005 | @subsubheading Synopsis | |
30006 | ||
30007 | @smallexample | |
a2c02241 | 30008 | -data-list-changed-registers |
922fbb7b AC |
30009 | @end smallexample |
30010 | ||
a2c02241 | 30011 | Display a list of the registers that have changed. |
922fbb7b AC |
30012 | |
30013 | @subsubheading @value{GDBN} Command | |
30014 | ||
a2c02241 NR |
30015 | @value{GDBN} doesn't have a direct analog for this command; @code{gdbtk} |
30016 | has the corresponding command @samp{gdb_changed_register_list}. | |
922fbb7b AC |
30017 | |
30018 | @subsubheading Example | |
922fbb7b | 30019 | |
a2c02241 | 30020 | On a PPC MBX board: |
922fbb7b AC |
30021 | |
30022 | @smallexample | |
594fe323 | 30023 | (gdb) |
a2c02241 NR |
30024 | -exec-continue |
30025 | ^running | |
922fbb7b | 30026 | |
594fe323 | 30027 | (gdb) |
a47ec5fe AR |
30028 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame=@{ |
30029 | func="main",args=[],file="try.c",fullname="/home/foo/bar/try.c", | |
30030 | line="5"@} | |
594fe323 | 30031 | (gdb) |
a2c02241 NR |
30032 | -data-list-changed-registers |
30033 | ^done,changed-registers=["0","1","2","4","5","6","7","8","9", | |
30034 | "10","11","13","14","15","16","17","18","19","20","21","22","23", | |
30035 | "24","25","26","27","28","30","31","64","65","66","67","69"] | |
594fe323 | 30036 | (gdb) |
a2c02241 | 30037 | @end smallexample |
922fbb7b AC |
30038 | |
30039 | ||
a2c02241 NR |
30040 | @subheading The @code{-data-list-register-names} Command |
30041 | @findex -data-list-register-names | |
922fbb7b AC |
30042 | |
30043 | @subsubheading Synopsis | |
30044 | ||
30045 | @smallexample | |
a2c02241 | 30046 | -data-list-register-names [ ( @var{regno} )+ ] |
922fbb7b AC |
30047 | @end smallexample |
30048 | ||
a2c02241 NR |
30049 | Show a list of register names for the current target. If no arguments |
30050 | are given, it shows a list of the names of all the registers. If | |
30051 | integer numbers are given as arguments, it will print a list of the | |
30052 | names of the registers corresponding to the arguments. To ensure | |
30053 | consistency between a register name and its number, the output list may | |
30054 | include empty register names. | |
922fbb7b AC |
30055 | |
30056 | @subsubheading @value{GDBN} Command | |
30057 | ||
a2c02241 NR |
30058 | @value{GDBN} does not have a command which corresponds to |
30059 | @samp{-data-list-register-names}. In @code{gdbtk} there is a | |
30060 | corresponding command @samp{gdb_regnames}. | |
922fbb7b AC |
30061 | |
30062 | @subsubheading Example | |
922fbb7b | 30063 | |
a2c02241 NR |
30064 | For the PPC MBX board: |
30065 | @smallexample | |
594fe323 | 30066 | (gdb) |
a2c02241 NR |
30067 | -data-list-register-names |
30068 | ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7", | |
30069 | "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18", | |
30070 | "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29", | |
30071 | "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9", | |
30072 | "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20", | |
30073 | "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31", | |
30074 | "", "pc","ps","cr","lr","ctr","xer"] | |
594fe323 | 30075 | (gdb) |
a2c02241 NR |
30076 | -data-list-register-names 1 2 3 |
30077 | ^done,register-names=["r1","r2","r3"] | |
594fe323 | 30078 | (gdb) |
a2c02241 | 30079 | @end smallexample |
922fbb7b | 30080 | |
a2c02241 NR |
30081 | @subheading The @code{-data-list-register-values} Command |
30082 | @findex -data-list-register-values | |
922fbb7b AC |
30083 | |
30084 | @subsubheading Synopsis | |
30085 | ||
30086 | @smallexample | |
c898adb7 YQ |
30087 | -data-list-register-values |
30088 | [ @code{--skip-unavailable} ] @var{fmt} [ ( @var{regno} )*] | |
922fbb7b AC |
30089 | @end smallexample |
30090 | ||
697aa1b7 EZ |
30091 | Display the registers' contents. The format according to which the |
30092 | registers' contents are to be returned is given by @var{fmt}, followed | |
30093 | by an optional list of numbers specifying the registers to display. A | |
30094 | missing list of numbers indicates that the contents of all the | |
30095 | registers must be returned. The @code{--skip-unavailable} option | |
30096 | indicates that only the available registers are to be returned. | |
a2c02241 NR |
30097 | |
30098 | Allowed formats for @var{fmt} are: | |
30099 | ||
30100 | @table @code | |
30101 | @item x | |
30102 | Hexadecimal | |
30103 | @item o | |
30104 | Octal | |
30105 | @item t | |
30106 | Binary | |
30107 | @item d | |
30108 | Decimal | |
30109 | @item r | |
30110 | Raw | |
30111 | @item N | |
30112 | Natural | |
30113 | @end table | |
922fbb7b AC |
30114 | |
30115 | @subsubheading @value{GDBN} Command | |
30116 | ||
a2c02241 NR |
30117 | The corresponding @value{GDBN} commands are @samp{info reg}, @samp{info |
30118 | all-reg}, and (in @code{gdbtk}) @samp{gdb_fetch_registers}. | |
922fbb7b AC |
30119 | |
30120 | @subsubheading Example | |
922fbb7b | 30121 | |
a2c02241 NR |
30122 | For a PPC MBX board (note: line breaks are for readability only, they |
30123 | don't appear in the actual output): | |
30124 | ||
30125 | @smallexample | |
594fe323 | 30126 | (gdb) |
a2c02241 NR |
30127 | -data-list-register-values r 64 65 |
30128 | ^done,register-values=[@{number="64",value="0xfe00a300"@}, | |
30129 | @{number="65",value="0x00029002"@}] | |
594fe323 | 30130 | (gdb) |
a2c02241 NR |
30131 | -data-list-register-values x |
30132 | ^done,register-values=[@{number="0",value="0xfe0043c8"@}, | |
30133 | @{number="1",value="0x3fff88"@},@{number="2",value="0xfffffffe"@}, | |
30134 | @{number="3",value="0x0"@},@{number="4",value="0xa"@}, | |
30135 | @{number="5",value="0x3fff68"@},@{number="6",value="0x3fff58"@}, | |
30136 | @{number="7",value="0xfe011e98"@},@{number="8",value="0x2"@}, | |
30137 | @{number="9",value="0xfa202820"@},@{number="10",value="0xfa202808"@}, | |
30138 | @{number="11",value="0x1"@},@{number="12",value="0x0"@}, | |
30139 | @{number="13",value="0x4544"@},@{number="14",value="0xffdfffff"@}, | |
30140 | @{number="15",value="0xffffffff"@},@{number="16",value="0xfffffeff"@}, | |
30141 | @{number="17",value="0xefffffed"@},@{number="18",value="0xfffffffe"@}, | |
30142 | @{number="19",value="0xffffffff"@},@{number="20",value="0xffffffff"@}, | |
30143 | @{number="21",value="0xffffffff"@},@{number="22",value="0xfffffff7"@}, | |
30144 | @{number="23",value="0xffffffff"@},@{number="24",value="0xffffffff"@}, | |
30145 | @{number="25",value="0xffffffff"@},@{number="26",value="0xfffffffb"@}, | |
30146 | @{number="27",value="0xffffffff"@},@{number="28",value="0xf7bfffff"@}, | |
30147 | @{number="29",value="0x0"@},@{number="30",value="0xfe010000"@}, | |
30148 | @{number="31",value="0x0"@},@{number="32",value="0x0"@}, | |
30149 | @{number="33",value="0x0"@},@{number="34",value="0x0"@}, | |
30150 | @{number="35",value="0x0"@},@{number="36",value="0x0"@}, | |
30151 | @{number="37",value="0x0"@},@{number="38",value="0x0"@}, | |
30152 | @{number="39",value="0x0"@},@{number="40",value="0x0"@}, | |
30153 | @{number="41",value="0x0"@},@{number="42",value="0x0"@}, | |
30154 | @{number="43",value="0x0"@},@{number="44",value="0x0"@}, | |
30155 | @{number="45",value="0x0"@},@{number="46",value="0x0"@}, | |
30156 | @{number="47",value="0x0"@},@{number="48",value="0x0"@}, | |
30157 | @{number="49",value="0x0"@},@{number="50",value="0x0"@}, | |
30158 | @{number="51",value="0x0"@},@{number="52",value="0x0"@}, | |
30159 | @{number="53",value="0x0"@},@{number="54",value="0x0"@}, | |
30160 | @{number="55",value="0x0"@},@{number="56",value="0x0"@}, | |
30161 | @{number="57",value="0x0"@},@{number="58",value="0x0"@}, | |
30162 | @{number="59",value="0x0"@},@{number="60",value="0x0"@}, | |
30163 | @{number="61",value="0x0"@},@{number="62",value="0x0"@}, | |
30164 | @{number="63",value="0x0"@},@{number="64",value="0xfe00a300"@}, | |
30165 | @{number="65",value="0x29002"@},@{number="66",value="0x202f04b5"@}, | |
30166 | @{number="67",value="0xfe0043b0"@},@{number="68",value="0xfe00b3e4"@}, | |
30167 | @{number="69",value="0x20002b03"@}] | |
594fe323 | 30168 | (gdb) |
a2c02241 | 30169 | @end smallexample |
922fbb7b | 30170 | |
a2c02241 NR |
30171 | |
30172 | @subheading The @code{-data-read-memory} Command | |
30173 | @findex -data-read-memory | |
922fbb7b | 30174 | |
8dedea02 VP |
30175 | This command is deprecated, use @code{-data-read-memory-bytes} instead. |
30176 | ||
922fbb7b AC |
30177 | @subsubheading Synopsis |
30178 | ||
30179 | @smallexample | |
a2c02241 NR |
30180 | -data-read-memory [ -o @var{byte-offset} ] |
30181 | @var{address} @var{word-format} @var{word-size} | |
30182 | @var{nr-rows} @var{nr-cols} [ @var{aschar} ] | |
922fbb7b AC |
30183 | @end smallexample |
30184 | ||
a2c02241 NR |
30185 | @noindent |
30186 | where: | |
922fbb7b | 30187 | |
a2c02241 NR |
30188 | @table @samp |
30189 | @item @var{address} | |
30190 | An expression specifying the address of the first memory word to be | |
30191 | read. Complex expressions containing embedded white space should be | |
30192 | quoted using the C convention. | |
922fbb7b | 30193 | |
a2c02241 NR |
30194 | @item @var{word-format} |
30195 | The format to be used to print the memory words. The notation is the | |
30196 | same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats, | |
79a6e687 | 30197 | ,Output Formats}). |
922fbb7b | 30198 | |
a2c02241 NR |
30199 | @item @var{word-size} |
30200 | The size of each memory word in bytes. | |
922fbb7b | 30201 | |
a2c02241 NR |
30202 | @item @var{nr-rows} |
30203 | The number of rows in the output table. | |
922fbb7b | 30204 | |
a2c02241 NR |
30205 | @item @var{nr-cols} |
30206 | The number of columns in the output table. | |
922fbb7b | 30207 | |
a2c02241 NR |
30208 | @item @var{aschar} |
30209 | If present, indicates that each row should include an @sc{ascii} dump. The | |
30210 | value of @var{aschar} is used as a padding character when a byte is not a | |
30211 | member of the printable @sc{ascii} character set (printable @sc{ascii} | |
30212 | characters are those whose code is between 32 and 126, inclusively). | |
922fbb7b | 30213 | |
a2c02241 NR |
30214 | @item @var{byte-offset} |
30215 | An offset to add to the @var{address} before fetching memory. | |
30216 | @end table | |
922fbb7b | 30217 | |
a2c02241 NR |
30218 | This command displays memory contents as a table of @var{nr-rows} by |
30219 | @var{nr-cols} words, each word being @var{word-size} bytes. In total, | |
30220 | @code{@var{nr-rows} * @var{nr-cols} * @var{word-size}} bytes are read | |
30221 | (returned as @samp{total-bytes}). Should less than the requested number | |
30222 | of bytes be returned by the target, the missing words are identified | |
30223 | using @samp{N/A}. The number of bytes read from the target is returned | |
30224 | in @samp{nr-bytes} and the starting address used to read memory in | |
30225 | @samp{addr}. | |
30226 | ||
30227 | The address of the next/previous row or page is available in | |
30228 | @samp{next-row} and @samp{prev-row}, @samp{next-page} and | |
30229 | @samp{prev-page}. | |
922fbb7b AC |
30230 | |
30231 | @subsubheading @value{GDBN} Command | |
30232 | ||
a2c02241 NR |
30233 | The corresponding @value{GDBN} command is @samp{x}. @code{gdbtk} has |
30234 | @samp{gdb_get_mem} memory read command. | |
922fbb7b AC |
30235 | |
30236 | @subsubheading Example | |
32e7087d | 30237 | |
a2c02241 NR |
30238 | Read six bytes of memory starting at @code{bytes+6} but then offset by |
30239 | @code{-6} bytes. Format as three rows of two columns. One byte per | |
30240 | word. Display each word in hex. | |
32e7087d JB |
30241 | |
30242 | @smallexample | |
594fe323 | 30243 | (gdb) |
a2c02241 NR |
30244 | 9-data-read-memory -o -6 -- bytes+6 x 1 3 2 |
30245 | 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6", | |
30246 | next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396", | |
30247 | prev-page="0x0000138a",memory=[ | |
30248 | @{addr="0x00001390",data=["0x00","0x01"]@}, | |
30249 | @{addr="0x00001392",data=["0x02","0x03"]@}, | |
30250 | @{addr="0x00001394",data=["0x04","0x05"]@}] | |
594fe323 | 30251 | (gdb) |
32e7087d JB |
30252 | @end smallexample |
30253 | ||
a2c02241 NR |
30254 | Read two bytes of memory starting at address @code{shorts + 64} and |
30255 | display as a single word formatted in decimal. | |
32e7087d | 30256 | |
32e7087d | 30257 | @smallexample |
594fe323 | 30258 | (gdb) |
a2c02241 NR |
30259 | 5-data-read-memory shorts+64 d 2 1 1 |
30260 | 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2", | |
30261 | next-row="0x00001512",prev-row="0x0000150e", | |
30262 | next-page="0x00001512",prev-page="0x0000150e",memory=[ | |
30263 | @{addr="0x00001510",data=["128"]@}] | |
594fe323 | 30264 | (gdb) |
32e7087d JB |
30265 | @end smallexample |
30266 | ||
a2c02241 NR |
30267 | Read thirty two bytes of memory starting at @code{bytes+16} and format |
30268 | as eight rows of four columns. Include a string encoding with @samp{x} | |
30269 | used as the non-printable character. | |
922fbb7b AC |
30270 | |
30271 | @smallexample | |
594fe323 | 30272 | (gdb) |
a2c02241 NR |
30273 | 4-data-read-memory bytes+16 x 1 8 4 x |
30274 | 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32", | |
30275 | next-row="0x000013c0",prev-row="0x0000139c", | |
30276 | next-page="0x000013c0",prev-page="0x00001380",memory=[ | |
30277 | @{addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"@}, | |
30278 | @{addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"@}, | |
30279 | @{addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"@}, | |
30280 | @{addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"@}, | |
30281 | @{addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"@}, | |
30282 | @{addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"@}, | |
30283 | @{addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"@}, | |
30284 | @{addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"@}] | |
594fe323 | 30285 | (gdb) |
922fbb7b AC |
30286 | @end smallexample |
30287 | ||
8dedea02 VP |
30288 | @subheading The @code{-data-read-memory-bytes} Command |
30289 | @findex -data-read-memory-bytes | |
30290 | ||
30291 | @subsubheading Synopsis | |
30292 | ||
30293 | @smallexample | |
a86c90e6 | 30294 | -data-read-memory-bytes [ -o @var{offset} ] |
8dedea02 VP |
30295 | @var{address} @var{count} |
30296 | @end smallexample | |
30297 | ||
30298 | @noindent | |
30299 | where: | |
30300 | ||
30301 | @table @samp | |
30302 | @item @var{address} | |
a86c90e6 SM |
30303 | An expression specifying the address of the first addressable memory unit |
30304 | to be read. Complex expressions containing embedded white space should be | |
8dedea02 VP |
30305 | quoted using the C convention. |
30306 | ||
30307 | @item @var{count} | |
a86c90e6 SM |
30308 | The number of addressable memory units to read. This should be an integer |
30309 | literal. | |
8dedea02 | 30310 | |
a86c90e6 SM |
30311 | @item @var{offset} |
30312 | The offset relative to @var{address} at which to start reading. This | |
30313 | should be an integer literal. This option is provided so that a frontend | |
30314 | is not required to first evaluate address and then perform address | |
30315 | arithmetics itself. | |
8dedea02 VP |
30316 | |
30317 | @end table | |
30318 | ||
30319 | This command attempts to read all accessible memory regions in the | |
30320 | specified range. First, all regions marked as unreadable in the memory | |
30321 | map (if one is defined) will be skipped. @xref{Memory Region | |
30322 | Attributes}. Second, @value{GDBN} will attempt to read the remaining | |
30323 | regions. For each one, if reading full region results in an errors, | |
30324 | @value{GDBN} will try to read a subset of the region. | |
30325 | ||
a86c90e6 SM |
30326 | In general, every single memory unit in the region may be readable or not, |
30327 | and the only way to read every readable unit is to try a read at | |
8dedea02 | 30328 | every address, which is not practical. Therefore, @value{GDBN} will |
a86c90e6 | 30329 | attempt to read all accessible memory units at either beginning or the end |
8dedea02 VP |
30330 | of the region, using a binary division scheme. This heuristic works |
30331 | well for reading accross a memory map boundary. Note that if a region | |
30332 | has a readable range that is neither at the beginning or the end, | |
30333 | @value{GDBN} will not read it. | |
30334 | ||
30335 | The result record (@pxref{GDB/MI Result Records}) that is output of | |
30336 | the command includes a field named @samp{memory} whose content is a | |
30337 | list of tuples. Each tuple represent a successfully read memory block | |
30338 | and has the following fields: | |
30339 | ||
30340 | @table @code | |
30341 | @item begin | |
30342 | The start address of the memory block, as hexadecimal literal. | |
30343 | ||
30344 | @item end | |
30345 | The end address of the memory block, as hexadecimal literal. | |
30346 | ||
30347 | @item offset | |
30348 | The offset of the memory block, as hexadecimal literal, relative to | |
30349 | the start address passed to @code{-data-read-memory-bytes}. | |
30350 | ||
30351 | @item contents | |
30352 | The contents of the memory block, in hex. | |
30353 | ||
30354 | @end table | |
30355 | ||
30356 | ||
30357 | ||
30358 | @subsubheading @value{GDBN} Command | |
30359 | ||
30360 | The corresponding @value{GDBN} command is @samp{x}. | |
30361 | ||
30362 | @subsubheading Example | |
30363 | ||
30364 | @smallexample | |
30365 | (gdb) | |
30366 | -data-read-memory-bytes &a 10 | |
30367 | ^done,memory=[@{begin="0xbffff154",offset="0x00000000", | |
30368 | end="0xbffff15e", | |
30369 | contents="01000000020000000300"@}] | |
30370 | (gdb) | |
30371 | @end smallexample | |
30372 | ||
30373 | ||
30374 | @subheading The @code{-data-write-memory-bytes} Command | |
30375 | @findex -data-write-memory-bytes | |
30376 | ||
30377 | @subsubheading Synopsis | |
30378 | ||
30379 | @smallexample | |
30380 | -data-write-memory-bytes @var{address} @var{contents} | |
62747a60 | 30381 | -data-write-memory-bytes @var{address} @var{contents} @r{[}@var{count}@r{]} |
8dedea02 VP |
30382 | @end smallexample |
30383 | ||
30384 | @noindent | |
30385 | where: | |
30386 | ||
30387 | @table @samp | |
30388 | @item @var{address} | |
a86c90e6 SM |
30389 | An expression specifying the address of the first addressable memory unit |
30390 | to be written. Complex expressions containing embedded white space should | |
30391 | be quoted using the C convention. | |
8dedea02 VP |
30392 | |
30393 | @item @var{contents} | |
a86c90e6 SM |
30394 | The hex-encoded data to write. It is an error if @var{contents} does |
30395 | not represent an integral number of addressable memory units. | |
8dedea02 | 30396 | |
62747a60 | 30397 | @item @var{count} |
a86c90e6 SM |
30398 | Optional argument indicating the number of addressable memory units to be |
30399 | written. If @var{count} is greater than @var{contents}' length, | |
30400 | @value{GDBN} will repeatedly write @var{contents} until it fills | |
30401 | @var{count} memory units. | |
62747a60 | 30402 | |
8dedea02 VP |
30403 | @end table |
30404 | ||
30405 | @subsubheading @value{GDBN} Command | |
30406 | ||
30407 | There's no corresponding @value{GDBN} command. | |
30408 | ||
30409 | @subsubheading Example | |
30410 | ||
30411 | @smallexample | |
30412 | (gdb) | |
30413 | -data-write-memory-bytes &a "aabbccdd" | |
30414 | ^done | |
30415 | (gdb) | |
30416 | @end smallexample | |
30417 | ||
62747a60 TT |
30418 | @smallexample |
30419 | (gdb) | |
30420 | -data-write-memory-bytes &a "aabbccdd" 16e | |
30421 | ^done | |
30422 | (gdb) | |
30423 | @end smallexample | |
8dedea02 | 30424 | |
a2c02241 NR |
30425 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30426 | @node GDB/MI Tracepoint Commands | |
30427 | @section @sc{gdb/mi} Tracepoint Commands | |
922fbb7b | 30428 | |
18148017 VP |
30429 | The commands defined in this section implement MI support for |
30430 | tracepoints. For detailed introduction, see @ref{Tracepoints}. | |
30431 | ||
30432 | @subheading The @code{-trace-find} Command | |
30433 | @findex -trace-find | |
30434 | ||
30435 | @subsubheading Synopsis | |
30436 | ||
30437 | @smallexample | |
30438 | -trace-find @var{mode} [@var{parameters}@dots{}] | |
30439 | @end smallexample | |
30440 | ||
30441 | Find a trace frame using criteria defined by @var{mode} and | |
30442 | @var{parameters}. The following table lists permissible | |
30443 | modes and their parameters. For details of operation, see @ref{tfind}. | |
30444 | ||
30445 | @table @samp | |
30446 | ||
30447 | @item none | |
30448 | No parameters are required. Stops examining trace frames. | |
30449 | ||
30450 | @item frame-number | |
30451 | An integer is required as parameter. Selects tracepoint frame with | |
30452 | that index. | |
30453 | ||
30454 | @item tracepoint-number | |
30455 | An integer is required as parameter. Finds next | |
30456 | trace frame that corresponds to tracepoint with the specified number. | |
30457 | ||
30458 | @item pc | |
30459 | An address is required as parameter. Finds | |
30460 | next trace frame that corresponds to any tracepoint at the specified | |
30461 | address. | |
30462 | ||
30463 | @item pc-inside-range | |
30464 | Two addresses are required as parameters. Finds next trace | |
30465 | frame that corresponds to a tracepoint at an address inside the | |
30466 | specified range. Both bounds are considered to be inside the range. | |
30467 | ||
30468 | @item pc-outside-range | |
30469 | Two addresses are required as parameters. Finds | |
30470 | next trace frame that corresponds to a tracepoint at an address outside | |
30471 | the specified range. Both bounds are considered to be inside the range. | |
30472 | ||
30473 | @item line | |
30474 | Line specification is required as parameter. @xref{Specify Location}. | |
30475 | Finds next trace frame that corresponds to a tracepoint at | |
30476 | the specified location. | |
30477 | ||
30478 | @end table | |
30479 | ||
30480 | If @samp{none} was passed as @var{mode}, the response does not | |
30481 | have fields. Otherwise, the response may have the following fields: | |
30482 | ||
30483 | @table @samp | |
30484 | @item found | |
30485 | This field has either @samp{0} or @samp{1} as the value, depending | |
30486 | on whether a matching tracepoint was found. | |
30487 | ||
30488 | @item traceframe | |
30489 | The index of the found traceframe. This field is present iff | |
30490 | the @samp{found} field has value of @samp{1}. | |
30491 | ||
30492 | @item tracepoint | |
30493 | The index of the found tracepoint. This field is present iff | |
30494 | the @samp{found} field has value of @samp{1}. | |
30495 | ||
30496 | @item frame | |
30497 | The information about the frame corresponding to the found trace | |
30498 | frame. This field is present only if a trace frame was found. | |
cd64ee31 | 30499 | @xref{GDB/MI Frame Information}, for description of this field. |
18148017 VP |
30500 | |
30501 | @end table | |
30502 | ||
7d13fe92 SS |
30503 | @subsubheading @value{GDBN} Command |
30504 | ||
30505 | The corresponding @value{GDBN} command is @samp{tfind}. | |
30506 | ||
18148017 VP |
30507 | @subheading -trace-define-variable |
30508 | @findex -trace-define-variable | |
30509 | ||
30510 | @subsubheading Synopsis | |
30511 | ||
30512 | @smallexample | |
30513 | -trace-define-variable @var{name} [ @var{value} ] | |
30514 | @end smallexample | |
30515 | ||
30516 | Create trace variable @var{name} if it does not exist. If | |
30517 | @var{value} is specified, sets the initial value of the specified | |
30518 | trace variable to that value. Note that the @var{name} should start | |
30519 | with the @samp{$} character. | |
30520 | ||
7d13fe92 SS |
30521 | @subsubheading @value{GDBN} Command |
30522 | ||
30523 | The corresponding @value{GDBN} command is @samp{tvariable}. | |
30524 | ||
dc673c81 YQ |
30525 | @subheading The @code{-trace-frame-collected} Command |
30526 | @findex -trace-frame-collected | |
30527 | ||
30528 | @subsubheading Synopsis | |
30529 | ||
30530 | @smallexample | |
30531 | -trace-frame-collected | |
30532 | [--var-print-values @var{var_pval}] | |
30533 | [--comp-print-values @var{comp_pval}] | |
30534 | [--registers-format @var{regformat}] | |
30535 | [--memory-contents] | |
30536 | @end smallexample | |
30537 | ||
30538 | This command returns the set of collected objects, register names, | |
30539 | trace state variable names, memory ranges and computed expressions | |
30540 | that have been collected at a particular trace frame. The optional | |
30541 | parameters to the command affect the output format in different ways. | |
30542 | See the output description table below for more details. | |
30543 | ||
30544 | The reported names can be used in the normal manner to create | |
30545 | varobjs and inspect the objects themselves. The items returned by | |
30546 | this command are categorized so that it is clear which is a variable, | |
30547 | which is a register, which is a trace state variable, which is a | |
30548 | memory range and which is a computed expression. | |
30549 | ||
30550 | For instance, if the actions were | |
30551 | @smallexample | |
30552 | collect myVar, myArray[myIndex], myObj.field, myPtr->field, myCount + 2 | |
30553 | collect *(int*)0xaf02bef0@@40 | |
30554 | @end smallexample | |
30555 | ||
30556 | @noindent | |
30557 | the object collected in its entirety would be @code{myVar}. The | |
30558 | object @code{myArray} would be partially collected, because only the | |
30559 | element at index @code{myIndex} would be collected. The remaining | |
30560 | objects would be computed expressions. | |
30561 | ||
30562 | An example output would be: | |
30563 | ||
30564 | @smallexample | |
30565 | (gdb) | |
30566 | -trace-frame-collected | |
30567 | ^done, | |
30568 | explicit-variables=[@{name="myVar",value="1"@}], | |
30569 | computed-expressions=[@{name="myArray[myIndex]",value="0"@}, | |
30570 | @{name="myObj.field",value="0"@}, | |
30571 | @{name="myPtr->field",value="1"@}, | |
30572 | @{name="myCount + 2",value="3"@}, | |
30573 | @{name="$tvar1 + 1",value="43970027"@}], | |
30574 | registers=[@{number="0",value="0x7fe2c6e79ec8"@}, | |
30575 | @{number="1",value="0x0"@}, | |
30576 | @{number="2",value="0x4"@}, | |
30577 | ... | |
30578 | @{number="125",value="0x0"@}], | |
30579 | tvars=[@{name="$tvar1",current="43970026"@}], | |
30580 | memory=[@{address="0x0000000000602264",length="4"@}, | |
30581 | @{address="0x0000000000615bc0",length="4"@}] | |
30582 | (gdb) | |
30583 | @end smallexample | |
30584 | ||
30585 | Where: | |
30586 | ||
30587 | @table @code | |
30588 | @item explicit-variables | |
30589 | The set of objects that have been collected in their entirety (as | |
30590 | opposed to collecting just a few elements of an array or a few struct | |
30591 | members). For each object, its name and value are printed. | |
30592 | The @code{--var-print-values} option affects how or whether the value | |
30593 | field is output. If @var{var_pval} is 0, then print only the names; | |
30594 | if it is 1, print also their values; and if it is 2, print the name, | |
30595 | type and value for simple data types, and the name and type for | |
30596 | arrays, structures and unions. | |
30597 | ||
30598 | @item computed-expressions | |
30599 | The set of computed expressions that have been collected at the | |
30600 | current trace frame. The @code{--comp-print-values} option affects | |
30601 | this set like the @code{--var-print-values} option affects the | |
30602 | @code{explicit-variables} set. See above. | |
30603 | ||
30604 | @item registers | |
30605 | The registers that have been collected at the current trace frame. | |
30606 | For each register collected, the name and current value are returned. | |
30607 | The value is formatted according to the @code{--registers-format} | |
30608 | option. See the @command{-data-list-register-values} command for a | |
30609 | list of the allowed formats. The default is @samp{x}. | |
30610 | ||
30611 | @item tvars | |
30612 | The trace state variables that have been collected at the current | |
30613 | trace frame. For each trace state variable collected, the name and | |
30614 | current value are returned. | |
30615 | ||
30616 | @item memory | |
30617 | The set of memory ranges that have been collected at the current trace | |
30618 | frame. Its content is a list of tuples. Each tuple represents a | |
30619 | collected memory range and has the following fields: | |
30620 | ||
30621 | @table @code | |
30622 | @item address | |
30623 | The start address of the memory range, as hexadecimal literal. | |
30624 | ||
30625 | @item length | |
30626 | The length of the memory range, as decimal literal. | |
30627 | ||
30628 | @item contents | |
30629 | The contents of the memory block, in hex. This field is only present | |
30630 | if the @code{--memory-contents} option is specified. | |
30631 | ||
30632 | @end table | |
30633 | ||
30634 | @end table | |
30635 | ||
30636 | @subsubheading @value{GDBN} Command | |
30637 | ||
30638 | There is no corresponding @value{GDBN} command. | |
30639 | ||
30640 | @subsubheading Example | |
30641 | ||
18148017 VP |
30642 | @subheading -trace-list-variables |
30643 | @findex -trace-list-variables | |
922fbb7b | 30644 | |
18148017 | 30645 | @subsubheading Synopsis |
922fbb7b | 30646 | |
18148017 VP |
30647 | @smallexample |
30648 | -trace-list-variables | |
30649 | @end smallexample | |
922fbb7b | 30650 | |
18148017 VP |
30651 | Return a table of all defined trace variables. Each element of the |
30652 | table has the following fields: | |
922fbb7b | 30653 | |
18148017 VP |
30654 | @table @samp |
30655 | @item name | |
30656 | The name of the trace variable. This field is always present. | |
922fbb7b | 30657 | |
18148017 VP |
30658 | @item initial |
30659 | The initial value. This is a 64-bit signed integer. This | |
30660 | field is always present. | |
922fbb7b | 30661 | |
18148017 VP |
30662 | @item current |
30663 | The value the trace variable has at the moment. This is a 64-bit | |
30664 | signed integer. This field is absent iff current value is | |
30665 | not defined, for example if the trace was never run, or is | |
30666 | presently running. | |
922fbb7b | 30667 | |
18148017 | 30668 | @end table |
922fbb7b | 30669 | |
7d13fe92 SS |
30670 | @subsubheading @value{GDBN} Command |
30671 | ||
30672 | The corresponding @value{GDBN} command is @samp{tvariables}. | |
30673 | ||
18148017 | 30674 | @subsubheading Example |
922fbb7b | 30675 | |
18148017 VP |
30676 | @smallexample |
30677 | (gdb) | |
30678 | -trace-list-variables | |
30679 | ^done,trace-variables=@{nr_rows="1",nr_cols="3", | |
30680 | hdr=[@{width="15",alignment="-1",col_name="name",colhdr="Name"@}, | |
30681 | @{width="11",alignment="-1",col_name="initial",colhdr="Initial"@}, | |
30682 | @{width="11",alignment="-1",col_name="current",colhdr="Current"@}], | |
30683 | body=[variable=@{name="$trace_timestamp",initial="0"@} | |
30684 | variable=@{name="$foo",initial="10",current="15"@}]@} | |
30685 | (gdb) | |
30686 | @end smallexample | |
922fbb7b | 30687 | |
18148017 VP |
30688 | @subheading -trace-save |
30689 | @findex -trace-save | |
922fbb7b | 30690 | |
18148017 VP |
30691 | @subsubheading Synopsis |
30692 | ||
30693 | @smallexample | |
30694 | -trace-save [-r ] @var{filename} | |
30695 | @end smallexample | |
30696 | ||
30697 | Saves the collected trace data to @var{filename}. Without the | |
30698 | @samp{-r} option, the data is downloaded from the target and saved | |
30699 | in a local file. With the @samp{-r} option the target is asked | |
30700 | to perform the save. | |
30701 | ||
7d13fe92 SS |
30702 | @subsubheading @value{GDBN} Command |
30703 | ||
30704 | The corresponding @value{GDBN} command is @samp{tsave}. | |
30705 | ||
18148017 VP |
30706 | |
30707 | @subheading -trace-start | |
30708 | @findex -trace-start | |
30709 | ||
30710 | @subsubheading Synopsis | |
30711 | ||
30712 | @smallexample | |
30713 | -trace-start | |
30714 | @end smallexample | |
922fbb7b | 30715 | |
18148017 VP |
30716 | Starts a tracing experiments. The result of this command does not |
30717 | have any fields. | |
922fbb7b | 30718 | |
7d13fe92 SS |
30719 | @subsubheading @value{GDBN} Command |
30720 | ||
30721 | The corresponding @value{GDBN} command is @samp{tstart}. | |
30722 | ||
18148017 VP |
30723 | @subheading -trace-status |
30724 | @findex -trace-status | |
922fbb7b | 30725 | |
18148017 VP |
30726 | @subsubheading Synopsis |
30727 | ||
30728 | @smallexample | |
30729 | -trace-status | |
30730 | @end smallexample | |
30731 | ||
a97153c7 | 30732 | Obtains the status of a tracing experiment. The result may include |
18148017 VP |
30733 | the following fields: |
30734 | ||
30735 | @table @samp | |
30736 | ||
30737 | @item supported | |
30738 | May have a value of either @samp{0}, when no tracing operations are | |
30739 | supported, @samp{1}, when all tracing operations are supported, or | |
30740 | @samp{file} when examining trace file. In the latter case, examining | |
30741 | of trace frame is possible but new tracing experiement cannot be | |
30742 | started. This field is always present. | |
30743 | ||
30744 | @item running | |
30745 | May have a value of either @samp{0} or @samp{1} depending on whether | |
30746 | tracing experiement is in progress on target. This field is present | |
30747 | if @samp{supported} field is not @samp{0}. | |
30748 | ||
30749 | @item stop-reason | |
30750 | Report the reason why the tracing was stopped last time. This field | |
30751 | may be absent iff tracing was never stopped on target yet. The | |
30752 | value of @samp{request} means the tracing was stopped as result of | |
30753 | the @code{-trace-stop} command. The value of @samp{overflow} means | |
30754 | the tracing buffer is full. The value of @samp{disconnection} means | |
30755 | tracing was automatically stopped when @value{GDBN} has disconnected. | |
30756 | The value of @samp{passcount} means tracing was stopped when a | |
30757 | tracepoint was passed a maximal number of times for that tracepoint. | |
30758 | This field is present if @samp{supported} field is not @samp{0}. | |
30759 | ||
30760 | @item stopping-tracepoint | |
30761 | The number of tracepoint whose passcount as exceeded. This field is | |
30762 | present iff the @samp{stop-reason} field has the value of | |
30763 | @samp{passcount}. | |
30764 | ||
30765 | @item frames | |
87290684 SS |
30766 | @itemx frames-created |
30767 | The @samp{frames} field is a count of the total number of trace frames | |
30768 | in the trace buffer, while @samp{frames-created} is the total created | |
30769 | during the run, including ones that were discarded, such as when a | |
30770 | circular trace buffer filled up. Both fields are optional. | |
18148017 VP |
30771 | |
30772 | @item buffer-size | |
30773 | @itemx buffer-free | |
30774 | These fields tell the current size of the tracing buffer and the | |
87290684 | 30775 | remaining space. These fields are optional. |
18148017 | 30776 | |
a97153c7 PA |
30777 | @item circular |
30778 | The value of the circular trace buffer flag. @code{1} means that the | |
30779 | trace buffer is circular and old trace frames will be discarded if | |
30780 | necessary to make room, @code{0} means that the trace buffer is linear | |
30781 | and may fill up. | |
30782 | ||
30783 | @item disconnected | |
30784 | The value of the disconnected tracing flag. @code{1} means that | |
30785 | tracing will continue after @value{GDBN} disconnects, @code{0} means | |
30786 | that the trace run will stop. | |
30787 | ||
f5911ea1 HAQ |
30788 | @item trace-file |
30789 | The filename of the trace file being examined. This field is | |
30790 | optional, and only present when examining a trace file. | |
30791 | ||
18148017 VP |
30792 | @end table |
30793 | ||
7d13fe92 SS |
30794 | @subsubheading @value{GDBN} Command |
30795 | ||
30796 | The corresponding @value{GDBN} command is @samp{tstatus}. | |
30797 | ||
18148017 VP |
30798 | @subheading -trace-stop |
30799 | @findex -trace-stop | |
30800 | ||
30801 | @subsubheading Synopsis | |
30802 | ||
30803 | @smallexample | |
30804 | -trace-stop | |
30805 | @end smallexample | |
922fbb7b | 30806 | |
18148017 VP |
30807 | Stops a tracing experiment. The result of this command has the same |
30808 | fields as @code{-trace-status}, except that the @samp{supported} and | |
30809 | @samp{running} fields are not output. | |
922fbb7b | 30810 | |
7d13fe92 SS |
30811 | @subsubheading @value{GDBN} Command |
30812 | ||
30813 | The corresponding @value{GDBN} command is @samp{tstop}. | |
30814 | ||
922fbb7b | 30815 | |
a2c02241 NR |
30816 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
30817 | @node GDB/MI Symbol Query | |
30818 | @section @sc{gdb/mi} Symbol Query Commands | |
922fbb7b AC |
30819 | |
30820 | ||
9901a55b | 30821 | @ignore |
a2c02241 NR |
30822 | @subheading The @code{-symbol-info-address} Command |
30823 | @findex -symbol-info-address | |
922fbb7b AC |
30824 | |
30825 | @subsubheading Synopsis | |
30826 | ||
30827 | @smallexample | |
a2c02241 | 30828 | -symbol-info-address @var{symbol} |
922fbb7b AC |
30829 | @end smallexample |
30830 | ||
a2c02241 | 30831 | Describe where @var{symbol} is stored. |
922fbb7b AC |
30832 | |
30833 | @subsubheading @value{GDBN} Command | |
30834 | ||
a2c02241 | 30835 | The corresponding @value{GDBN} command is @samp{info address}. |
922fbb7b AC |
30836 | |
30837 | @subsubheading Example | |
30838 | N.A. | |
30839 | ||
30840 | ||
a2c02241 NR |
30841 | @subheading The @code{-symbol-info-file} Command |
30842 | @findex -symbol-info-file | |
922fbb7b AC |
30843 | |
30844 | @subsubheading Synopsis | |
30845 | ||
30846 | @smallexample | |
a2c02241 | 30847 | -symbol-info-file |
922fbb7b AC |
30848 | @end smallexample |
30849 | ||
a2c02241 | 30850 | Show the file for the symbol. |
922fbb7b | 30851 | |
a2c02241 | 30852 | @subsubheading @value{GDBN} Command |
922fbb7b | 30853 | |
a2c02241 NR |
30854 | There's no equivalent @value{GDBN} command. @code{gdbtk} has |
30855 | @samp{gdb_find_file}. | |
922fbb7b AC |
30856 | |
30857 | @subsubheading Example | |
30858 | N.A. | |
30859 | ||
30860 | ||
a2c02241 NR |
30861 | @subheading The @code{-symbol-info-function} Command |
30862 | @findex -symbol-info-function | |
922fbb7b AC |
30863 | |
30864 | @subsubheading Synopsis | |
30865 | ||
30866 | @smallexample | |
a2c02241 | 30867 | -symbol-info-function |
922fbb7b AC |
30868 | @end smallexample |
30869 | ||
a2c02241 | 30870 | Show which function the symbol lives in. |
922fbb7b AC |
30871 | |
30872 | @subsubheading @value{GDBN} Command | |
30873 | ||
a2c02241 | 30874 | @samp{gdb_get_function} in @code{gdbtk}. |
922fbb7b AC |
30875 | |
30876 | @subsubheading Example | |
30877 | N.A. | |
30878 | ||
30879 | ||
a2c02241 NR |
30880 | @subheading The @code{-symbol-info-line} Command |
30881 | @findex -symbol-info-line | |
922fbb7b AC |
30882 | |
30883 | @subsubheading Synopsis | |
30884 | ||
30885 | @smallexample | |
a2c02241 | 30886 | -symbol-info-line |
922fbb7b AC |
30887 | @end smallexample |
30888 | ||
a2c02241 | 30889 | Show the core addresses of the code for a source line. |
922fbb7b | 30890 | |
a2c02241 | 30891 | @subsubheading @value{GDBN} Command |
922fbb7b | 30892 | |
a2c02241 NR |
30893 | The corresponding @value{GDBN} command is @samp{info line}. |
30894 | @code{gdbtk} has the @samp{gdb_get_line} and @samp{gdb_get_file} commands. | |
922fbb7b AC |
30895 | |
30896 | @subsubheading Example | |
a2c02241 | 30897 | N.A. |
922fbb7b AC |
30898 | |
30899 | ||
a2c02241 NR |
30900 | @subheading The @code{-symbol-info-symbol} Command |
30901 | @findex -symbol-info-symbol | |
07f31aa6 DJ |
30902 | |
30903 | @subsubheading Synopsis | |
30904 | ||
a2c02241 NR |
30905 | @smallexample |
30906 | -symbol-info-symbol @var{addr} | |
30907 | @end smallexample | |
07f31aa6 | 30908 | |
a2c02241 | 30909 | Describe what symbol is at location @var{addr}. |
07f31aa6 | 30910 | |
a2c02241 | 30911 | @subsubheading @value{GDBN} Command |
07f31aa6 | 30912 | |
a2c02241 | 30913 | The corresponding @value{GDBN} command is @samp{info symbol}. |
07f31aa6 DJ |
30914 | |
30915 | @subsubheading Example | |
a2c02241 | 30916 | N.A. |
07f31aa6 DJ |
30917 | |
30918 | ||
a2c02241 NR |
30919 | @subheading The @code{-symbol-list-functions} Command |
30920 | @findex -symbol-list-functions | |
922fbb7b AC |
30921 | |
30922 | @subsubheading Synopsis | |
30923 | ||
30924 | @smallexample | |
a2c02241 | 30925 | -symbol-list-functions |
922fbb7b AC |
30926 | @end smallexample |
30927 | ||
a2c02241 | 30928 | List the functions in the executable. |
922fbb7b AC |
30929 | |
30930 | @subsubheading @value{GDBN} Command | |
30931 | ||
a2c02241 NR |
30932 | @samp{info functions} in @value{GDBN}, @samp{gdb_listfunc} and |
30933 | @samp{gdb_search} in @code{gdbtk}. | |
922fbb7b AC |
30934 | |
30935 | @subsubheading Example | |
a2c02241 | 30936 | N.A. |
9901a55b | 30937 | @end ignore |
922fbb7b AC |
30938 | |
30939 | ||
a2c02241 NR |
30940 | @subheading The @code{-symbol-list-lines} Command |
30941 | @findex -symbol-list-lines | |
922fbb7b AC |
30942 | |
30943 | @subsubheading Synopsis | |
30944 | ||
30945 | @smallexample | |
a2c02241 | 30946 | -symbol-list-lines @var{filename} |
922fbb7b AC |
30947 | @end smallexample |
30948 | ||
a2c02241 NR |
30949 | Print the list of lines that contain code and their associated program |
30950 | addresses for the given source filename. The entries are sorted in | |
30951 | ascending PC order. | |
922fbb7b AC |
30952 | |
30953 | @subsubheading @value{GDBN} Command | |
30954 | ||
a2c02241 | 30955 | There is no corresponding @value{GDBN} command. |
922fbb7b AC |
30956 | |
30957 | @subsubheading Example | |
a2c02241 | 30958 | @smallexample |
594fe323 | 30959 | (gdb) |
a2c02241 NR |
30960 | -symbol-list-lines basics.c |
30961 | ^done,lines=[@{pc="0x08048554",line="7"@},@{pc="0x0804855a",line="8"@}] | |
594fe323 | 30962 | (gdb) |
a2c02241 | 30963 | @end smallexample |
922fbb7b AC |
30964 | |
30965 | ||
9901a55b | 30966 | @ignore |
a2c02241 NR |
30967 | @subheading The @code{-symbol-list-types} Command |
30968 | @findex -symbol-list-types | |
922fbb7b AC |
30969 | |
30970 | @subsubheading Synopsis | |
30971 | ||
30972 | @smallexample | |
a2c02241 | 30973 | -symbol-list-types |
922fbb7b AC |
30974 | @end smallexample |
30975 | ||
a2c02241 | 30976 | List all the type names. |
922fbb7b AC |
30977 | |
30978 | @subsubheading @value{GDBN} Command | |
30979 | ||
a2c02241 NR |
30980 | The corresponding commands are @samp{info types} in @value{GDBN}, |
30981 | @samp{gdb_search} in @code{gdbtk}. | |
922fbb7b AC |
30982 | |
30983 | @subsubheading Example | |
30984 | N.A. | |
30985 | ||
30986 | ||
a2c02241 NR |
30987 | @subheading The @code{-symbol-list-variables} Command |
30988 | @findex -symbol-list-variables | |
922fbb7b AC |
30989 | |
30990 | @subsubheading Synopsis | |
30991 | ||
30992 | @smallexample | |
a2c02241 | 30993 | -symbol-list-variables |
922fbb7b AC |
30994 | @end smallexample |
30995 | ||
a2c02241 | 30996 | List all the global and static variable names. |
922fbb7b AC |
30997 | |
30998 | @subsubheading @value{GDBN} Command | |
30999 | ||
a2c02241 | 31000 | @samp{info variables} in @value{GDBN}, @samp{gdb_search} in @code{gdbtk}. |
922fbb7b AC |
31001 | |
31002 | @subsubheading Example | |
31003 | N.A. | |
31004 | ||
31005 | ||
a2c02241 NR |
31006 | @subheading The @code{-symbol-locate} Command |
31007 | @findex -symbol-locate | |
922fbb7b AC |
31008 | |
31009 | @subsubheading Synopsis | |
31010 | ||
31011 | @smallexample | |
a2c02241 | 31012 | -symbol-locate |
922fbb7b AC |
31013 | @end smallexample |
31014 | ||
922fbb7b AC |
31015 | @subsubheading @value{GDBN} Command |
31016 | ||
a2c02241 | 31017 | @samp{gdb_loc} in @code{gdbtk}. |
922fbb7b AC |
31018 | |
31019 | @subsubheading Example | |
31020 | N.A. | |
31021 | ||
31022 | ||
a2c02241 NR |
31023 | @subheading The @code{-symbol-type} Command |
31024 | @findex -symbol-type | |
922fbb7b AC |
31025 | |
31026 | @subsubheading Synopsis | |
31027 | ||
31028 | @smallexample | |
a2c02241 | 31029 | -symbol-type @var{variable} |
922fbb7b AC |
31030 | @end smallexample |
31031 | ||
a2c02241 | 31032 | Show type of @var{variable}. |
922fbb7b | 31033 | |
a2c02241 | 31034 | @subsubheading @value{GDBN} Command |
922fbb7b | 31035 | |
a2c02241 NR |
31036 | The corresponding @value{GDBN} command is @samp{ptype}, @code{gdbtk} has |
31037 | @samp{gdb_obj_variable}. | |
31038 | ||
31039 | @subsubheading Example | |
31040 | N.A. | |
9901a55b | 31041 | @end ignore |
a2c02241 NR |
31042 | |
31043 | ||
31044 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
31045 | @node GDB/MI File Commands | |
31046 | @section @sc{gdb/mi} File Commands | |
31047 | ||
31048 | This section describes the GDB/MI commands to specify executable file names | |
31049 | and to read in and obtain symbol table information. | |
31050 | ||
31051 | @subheading The @code{-file-exec-and-symbols} Command | |
31052 | @findex -file-exec-and-symbols | |
31053 | ||
31054 | @subsubheading Synopsis | |
922fbb7b AC |
31055 | |
31056 | @smallexample | |
a2c02241 | 31057 | -file-exec-and-symbols @var{file} |
922fbb7b AC |
31058 | @end smallexample |
31059 | ||
a2c02241 NR |
31060 | Specify the executable file to be debugged. This file is the one from |
31061 | which the symbol table is also read. If no file is specified, the | |
31062 | command clears the executable and symbol information. If breakpoints | |
31063 | are set when using this command with no arguments, @value{GDBN} will produce | |
31064 | error messages. Otherwise, no output is produced, except a completion | |
31065 | notification. | |
31066 | ||
922fbb7b AC |
31067 | @subsubheading @value{GDBN} Command |
31068 | ||
a2c02241 | 31069 | The corresponding @value{GDBN} command is @samp{file}. |
922fbb7b AC |
31070 | |
31071 | @subsubheading Example | |
31072 | ||
31073 | @smallexample | |
594fe323 | 31074 | (gdb) |
a2c02241 NR |
31075 | -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
31076 | ^done | |
594fe323 | 31077 | (gdb) |
922fbb7b AC |
31078 | @end smallexample |
31079 | ||
922fbb7b | 31080 | |
a2c02241 NR |
31081 | @subheading The @code{-file-exec-file} Command |
31082 | @findex -file-exec-file | |
922fbb7b AC |
31083 | |
31084 | @subsubheading Synopsis | |
31085 | ||
31086 | @smallexample | |
a2c02241 | 31087 | -file-exec-file @var{file} |
922fbb7b AC |
31088 | @end smallexample |
31089 | ||
a2c02241 NR |
31090 | Specify the executable file to be debugged. Unlike |
31091 | @samp{-file-exec-and-symbols}, the symbol table is @emph{not} read | |
31092 | from this file. If used without argument, @value{GDBN} clears the information | |
31093 | about the executable file. No output is produced, except a completion | |
31094 | notification. | |
922fbb7b | 31095 | |
a2c02241 NR |
31096 | @subsubheading @value{GDBN} Command |
31097 | ||
31098 | The corresponding @value{GDBN} command is @samp{exec-file}. | |
922fbb7b AC |
31099 | |
31100 | @subsubheading Example | |
a2c02241 NR |
31101 | |
31102 | @smallexample | |
594fe323 | 31103 | (gdb) |
a2c02241 NR |
31104 | -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
31105 | ^done | |
594fe323 | 31106 | (gdb) |
a2c02241 | 31107 | @end smallexample |
922fbb7b AC |
31108 | |
31109 | ||
9901a55b | 31110 | @ignore |
a2c02241 NR |
31111 | @subheading The @code{-file-list-exec-sections} Command |
31112 | @findex -file-list-exec-sections | |
922fbb7b AC |
31113 | |
31114 | @subsubheading Synopsis | |
31115 | ||
31116 | @smallexample | |
a2c02241 | 31117 | -file-list-exec-sections |
922fbb7b AC |
31118 | @end smallexample |
31119 | ||
a2c02241 NR |
31120 | List the sections of the current executable file. |
31121 | ||
922fbb7b AC |
31122 | @subsubheading @value{GDBN} Command |
31123 | ||
a2c02241 NR |
31124 | The @value{GDBN} command @samp{info file} shows, among the rest, the same |
31125 | information as this command. @code{gdbtk} has a corresponding command | |
31126 | @samp{gdb_load_info}. | |
922fbb7b AC |
31127 | |
31128 | @subsubheading Example | |
31129 | N.A. | |
9901a55b | 31130 | @end ignore |
922fbb7b AC |
31131 | |
31132 | ||
a2c02241 NR |
31133 | @subheading The @code{-file-list-exec-source-file} Command |
31134 | @findex -file-list-exec-source-file | |
922fbb7b AC |
31135 | |
31136 | @subsubheading Synopsis | |
31137 | ||
31138 | @smallexample | |
a2c02241 | 31139 | -file-list-exec-source-file |
922fbb7b AC |
31140 | @end smallexample |
31141 | ||
a2c02241 | 31142 | List the line number, the current source file, and the absolute path |
44288b44 NR |
31143 | to the current source file for the current executable. The macro |
31144 | information field has a value of @samp{1} or @samp{0} depending on | |
31145 | whether or not the file includes preprocessor macro information. | |
922fbb7b AC |
31146 | |
31147 | @subsubheading @value{GDBN} Command | |
31148 | ||
a2c02241 | 31149 | The @value{GDBN} equivalent is @samp{info source} |
922fbb7b AC |
31150 | |
31151 | @subsubheading Example | |
31152 | ||
922fbb7b | 31153 | @smallexample |
594fe323 | 31154 | (gdb) |
a2c02241 | 31155 | 123-file-list-exec-source-file |
44288b44 | 31156 | 123^done,line="1",file="foo.c",fullname="/home/bar/foo.c,macro-info="1" |
594fe323 | 31157 | (gdb) |
922fbb7b AC |
31158 | @end smallexample |
31159 | ||
31160 | ||
a2c02241 NR |
31161 | @subheading The @code{-file-list-exec-source-files} Command |
31162 | @findex -file-list-exec-source-files | |
922fbb7b AC |
31163 | |
31164 | @subsubheading Synopsis | |
31165 | ||
31166 | @smallexample | |
a2c02241 | 31167 | -file-list-exec-source-files |
922fbb7b AC |
31168 | @end smallexample |
31169 | ||
a2c02241 NR |
31170 | List the source files for the current executable. |
31171 | ||
f35a17b5 JK |
31172 | It will always output both the filename and fullname (absolute file |
31173 | name) of a source file. | |
922fbb7b AC |
31174 | |
31175 | @subsubheading @value{GDBN} Command | |
31176 | ||
a2c02241 NR |
31177 | The @value{GDBN} equivalent is @samp{info sources}. |
31178 | @code{gdbtk} has an analogous command @samp{gdb_listfiles}. | |
922fbb7b AC |
31179 | |
31180 | @subsubheading Example | |
922fbb7b | 31181 | @smallexample |
594fe323 | 31182 | (gdb) |
a2c02241 NR |
31183 | -file-list-exec-source-files |
31184 | ^done,files=[ | |
31185 | @{file=foo.c,fullname=/home/foo.c@}, | |
31186 | @{file=/home/bar.c,fullname=/home/bar.c@}, | |
31187 | @{file=gdb_could_not_find_fullpath.c@}] | |
594fe323 | 31188 | (gdb) |
922fbb7b AC |
31189 | @end smallexample |
31190 | ||
9901a55b | 31191 | @ignore |
a2c02241 NR |
31192 | @subheading The @code{-file-list-shared-libraries} Command |
31193 | @findex -file-list-shared-libraries | |
922fbb7b | 31194 | |
a2c02241 | 31195 | @subsubheading Synopsis |
922fbb7b | 31196 | |
a2c02241 NR |
31197 | @smallexample |
31198 | -file-list-shared-libraries | |
31199 | @end smallexample | |
922fbb7b | 31200 | |
a2c02241 | 31201 | List the shared libraries in the program. |
922fbb7b | 31202 | |
a2c02241 | 31203 | @subsubheading @value{GDBN} Command |
922fbb7b | 31204 | |
a2c02241 | 31205 | The corresponding @value{GDBN} command is @samp{info shared}. |
922fbb7b | 31206 | |
a2c02241 NR |
31207 | @subsubheading Example |
31208 | N.A. | |
922fbb7b AC |
31209 | |
31210 | ||
a2c02241 NR |
31211 | @subheading The @code{-file-list-symbol-files} Command |
31212 | @findex -file-list-symbol-files | |
922fbb7b | 31213 | |
a2c02241 | 31214 | @subsubheading Synopsis |
922fbb7b | 31215 | |
a2c02241 NR |
31216 | @smallexample |
31217 | -file-list-symbol-files | |
31218 | @end smallexample | |
922fbb7b | 31219 | |
a2c02241 | 31220 | List symbol files. |
922fbb7b | 31221 | |
a2c02241 | 31222 | @subsubheading @value{GDBN} Command |
922fbb7b | 31223 | |
a2c02241 | 31224 | The corresponding @value{GDBN} command is @samp{info file} (part of it). |
922fbb7b | 31225 | |
a2c02241 NR |
31226 | @subsubheading Example |
31227 | N.A. | |
9901a55b | 31228 | @end ignore |
922fbb7b | 31229 | |
922fbb7b | 31230 | |
a2c02241 NR |
31231 | @subheading The @code{-file-symbol-file} Command |
31232 | @findex -file-symbol-file | |
922fbb7b | 31233 | |
a2c02241 | 31234 | @subsubheading Synopsis |
922fbb7b | 31235 | |
a2c02241 NR |
31236 | @smallexample |
31237 | -file-symbol-file @var{file} | |
31238 | @end smallexample | |
922fbb7b | 31239 | |
a2c02241 NR |
31240 | Read symbol table info from the specified @var{file} argument. When |
31241 | used without arguments, clears @value{GDBN}'s symbol table info. No output is | |
31242 | produced, except for a completion notification. | |
922fbb7b | 31243 | |
a2c02241 | 31244 | @subsubheading @value{GDBN} Command |
922fbb7b | 31245 | |
a2c02241 | 31246 | The corresponding @value{GDBN} command is @samp{symbol-file}. |
922fbb7b | 31247 | |
a2c02241 | 31248 | @subsubheading Example |
922fbb7b | 31249 | |
a2c02241 | 31250 | @smallexample |
594fe323 | 31251 | (gdb) |
a2c02241 NR |
31252 | -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
31253 | ^done | |
594fe323 | 31254 | (gdb) |
a2c02241 | 31255 | @end smallexample |
922fbb7b | 31256 | |
a2c02241 | 31257 | @ignore |
a2c02241 NR |
31258 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
31259 | @node GDB/MI Memory Overlay Commands | |
31260 | @section @sc{gdb/mi} Memory Overlay Commands | |
922fbb7b | 31261 | |
a2c02241 | 31262 | The memory overlay commands are not implemented. |
922fbb7b | 31263 | |
a2c02241 | 31264 | @c @subheading -overlay-auto |
922fbb7b | 31265 | |
a2c02241 | 31266 | @c @subheading -overlay-list-mapping-state |
922fbb7b | 31267 | |
a2c02241 | 31268 | @c @subheading -overlay-list-overlays |
922fbb7b | 31269 | |
a2c02241 | 31270 | @c @subheading -overlay-map |
922fbb7b | 31271 | |
a2c02241 | 31272 | @c @subheading -overlay-off |
922fbb7b | 31273 | |
a2c02241 | 31274 | @c @subheading -overlay-on |
922fbb7b | 31275 | |
a2c02241 | 31276 | @c @subheading -overlay-unmap |
922fbb7b | 31277 | |
a2c02241 NR |
31278 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
31279 | @node GDB/MI Signal Handling Commands | |
31280 | @section @sc{gdb/mi} Signal Handling Commands | |
922fbb7b | 31281 | |
a2c02241 | 31282 | Signal handling commands are not implemented. |
922fbb7b | 31283 | |
a2c02241 | 31284 | @c @subheading -signal-handle |
922fbb7b | 31285 | |
a2c02241 | 31286 | @c @subheading -signal-list-handle-actions |
922fbb7b | 31287 | |
a2c02241 NR |
31288 | @c @subheading -signal-list-signal-types |
31289 | @end ignore | |
922fbb7b | 31290 | |
922fbb7b | 31291 | |
a2c02241 NR |
31292 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
31293 | @node GDB/MI Target Manipulation | |
31294 | @section @sc{gdb/mi} Target Manipulation Commands | |
922fbb7b AC |
31295 | |
31296 | ||
a2c02241 NR |
31297 | @subheading The @code{-target-attach} Command |
31298 | @findex -target-attach | |
922fbb7b AC |
31299 | |
31300 | @subsubheading Synopsis | |
31301 | ||
31302 | @smallexample | |
c3b108f7 | 31303 | -target-attach @var{pid} | @var{gid} | @var{file} |
922fbb7b AC |
31304 | @end smallexample |
31305 | ||
c3b108f7 VP |
31306 | Attach to a process @var{pid} or a file @var{file} outside of |
31307 | @value{GDBN}, or a thread group @var{gid}. If attaching to a thread | |
31308 | group, the id previously returned by | |
31309 | @samp{-list-thread-groups --available} must be used. | |
922fbb7b | 31310 | |
79a6e687 | 31311 | @subsubheading @value{GDBN} Command |
922fbb7b | 31312 | |
a2c02241 | 31313 | The corresponding @value{GDBN} command is @samp{attach}. |
922fbb7b | 31314 | |
a2c02241 | 31315 | @subsubheading Example |
b56e7235 VP |
31316 | @smallexample |
31317 | (gdb) | |
31318 | -target-attach 34 | |
31319 | =thread-created,id="1" | |
5ae4183a | 31320 | *stopped,thread-id="1",frame=@{addr="0xb7f7e410",func="bar",args=[]@} |
b56e7235 VP |
31321 | ^done |
31322 | (gdb) | |
31323 | @end smallexample | |
a2c02241 | 31324 | |
9901a55b | 31325 | @ignore |
a2c02241 NR |
31326 | @subheading The @code{-target-compare-sections} Command |
31327 | @findex -target-compare-sections | |
922fbb7b AC |
31328 | |
31329 | @subsubheading Synopsis | |
31330 | ||
31331 | @smallexample | |
a2c02241 | 31332 | -target-compare-sections [ @var{section} ] |
922fbb7b AC |
31333 | @end smallexample |
31334 | ||
a2c02241 NR |
31335 | Compare data of section @var{section} on target to the exec file. |
31336 | Without the argument, all sections are compared. | |
922fbb7b | 31337 | |
a2c02241 | 31338 | @subsubheading @value{GDBN} Command |
922fbb7b | 31339 | |
a2c02241 | 31340 | The @value{GDBN} equivalent is @samp{compare-sections}. |
922fbb7b | 31341 | |
a2c02241 NR |
31342 | @subsubheading Example |
31343 | N.A. | |
9901a55b | 31344 | @end ignore |
a2c02241 NR |
31345 | |
31346 | ||
31347 | @subheading The @code{-target-detach} Command | |
31348 | @findex -target-detach | |
922fbb7b AC |
31349 | |
31350 | @subsubheading Synopsis | |
31351 | ||
31352 | @smallexample | |
c3b108f7 | 31353 | -target-detach [ @var{pid} | @var{gid} ] |
922fbb7b AC |
31354 | @end smallexample |
31355 | ||
a2c02241 | 31356 | Detach from the remote target which normally resumes its execution. |
c3b108f7 VP |
31357 | If either @var{pid} or @var{gid} is specified, detaches from either |
31358 | the specified process, or specified thread group. There's no output. | |
a2c02241 | 31359 | |
79a6e687 | 31360 | @subsubheading @value{GDBN} Command |
a2c02241 NR |
31361 | |
31362 | The corresponding @value{GDBN} command is @samp{detach}. | |
31363 | ||
31364 | @subsubheading Example | |
922fbb7b AC |
31365 | |
31366 | @smallexample | |
594fe323 | 31367 | (gdb) |
a2c02241 NR |
31368 | -target-detach |
31369 | ^done | |
594fe323 | 31370 | (gdb) |
922fbb7b AC |
31371 | @end smallexample |
31372 | ||
31373 | ||
a2c02241 NR |
31374 | @subheading The @code{-target-disconnect} Command |
31375 | @findex -target-disconnect | |
922fbb7b AC |
31376 | |
31377 | @subsubheading Synopsis | |
31378 | ||
123dc839 | 31379 | @smallexample |
a2c02241 | 31380 | -target-disconnect |
123dc839 | 31381 | @end smallexample |
922fbb7b | 31382 | |
a2c02241 NR |
31383 | Disconnect from the remote target. There's no output and the target is |
31384 | generally not resumed. | |
31385 | ||
79a6e687 | 31386 | @subsubheading @value{GDBN} Command |
a2c02241 NR |
31387 | |
31388 | The corresponding @value{GDBN} command is @samp{disconnect}. | |
bc8ced35 NR |
31389 | |
31390 | @subsubheading Example | |
922fbb7b AC |
31391 | |
31392 | @smallexample | |
594fe323 | 31393 | (gdb) |
a2c02241 NR |
31394 | -target-disconnect |
31395 | ^done | |
594fe323 | 31396 | (gdb) |
922fbb7b AC |
31397 | @end smallexample |
31398 | ||
31399 | ||
a2c02241 NR |
31400 | @subheading The @code{-target-download} Command |
31401 | @findex -target-download | |
922fbb7b AC |
31402 | |
31403 | @subsubheading Synopsis | |
31404 | ||
31405 | @smallexample | |
a2c02241 | 31406 | -target-download |
922fbb7b AC |
31407 | @end smallexample |
31408 | ||
a2c02241 NR |
31409 | Loads the executable onto the remote target. |
31410 | It prints out an update message every half second, which includes the fields: | |
31411 | ||
31412 | @table @samp | |
31413 | @item section | |
31414 | The name of the section. | |
31415 | @item section-sent | |
31416 | The size of what has been sent so far for that section. | |
31417 | @item section-size | |
31418 | The size of the section. | |
31419 | @item total-sent | |
31420 | The total size of what was sent so far (the current and the previous sections). | |
31421 | @item total-size | |
31422 | The size of the overall executable to download. | |
31423 | @end table | |
31424 | ||
31425 | @noindent | |
31426 | Each message is sent as status record (@pxref{GDB/MI Output Syntax, , | |
31427 | @sc{gdb/mi} Output Syntax}). | |
31428 | ||
31429 | In addition, it prints the name and size of the sections, as they are | |
31430 | downloaded. These messages include the following fields: | |
31431 | ||
31432 | @table @samp | |
31433 | @item section | |
31434 | The name of the section. | |
31435 | @item section-size | |
31436 | The size of the section. | |
31437 | @item total-size | |
31438 | The size of the overall executable to download. | |
31439 | @end table | |
31440 | ||
31441 | @noindent | |
31442 | At the end, a summary is printed. | |
31443 | ||
31444 | @subsubheading @value{GDBN} Command | |
31445 | ||
31446 | The corresponding @value{GDBN} command is @samp{load}. | |
31447 | ||
31448 | @subsubheading Example | |
31449 | ||
31450 | Note: each status message appears on a single line. Here the messages | |
31451 | have been broken down so that they can fit onto a page. | |
922fbb7b AC |
31452 | |
31453 | @smallexample | |
594fe323 | 31454 | (gdb) |
a2c02241 NR |
31455 | -target-download |
31456 | +download,@{section=".text",section-size="6668",total-size="9880"@} | |
31457 | +download,@{section=".text",section-sent="512",section-size="6668", | |
31458 | total-sent="512",total-size="9880"@} | |
31459 | +download,@{section=".text",section-sent="1024",section-size="6668", | |
31460 | total-sent="1024",total-size="9880"@} | |
31461 | +download,@{section=".text",section-sent="1536",section-size="6668", | |
31462 | total-sent="1536",total-size="9880"@} | |
31463 | +download,@{section=".text",section-sent="2048",section-size="6668", | |
31464 | total-sent="2048",total-size="9880"@} | |
31465 | +download,@{section=".text",section-sent="2560",section-size="6668", | |
31466 | total-sent="2560",total-size="9880"@} | |
31467 | +download,@{section=".text",section-sent="3072",section-size="6668", | |
31468 | total-sent="3072",total-size="9880"@} | |
31469 | +download,@{section=".text",section-sent="3584",section-size="6668", | |
31470 | total-sent="3584",total-size="9880"@} | |
31471 | +download,@{section=".text",section-sent="4096",section-size="6668", | |
31472 | total-sent="4096",total-size="9880"@} | |
31473 | +download,@{section=".text",section-sent="4608",section-size="6668", | |
31474 | total-sent="4608",total-size="9880"@} | |
31475 | +download,@{section=".text",section-sent="5120",section-size="6668", | |
31476 | total-sent="5120",total-size="9880"@} | |
31477 | +download,@{section=".text",section-sent="5632",section-size="6668", | |
31478 | total-sent="5632",total-size="9880"@} | |
31479 | +download,@{section=".text",section-sent="6144",section-size="6668", | |
31480 | total-sent="6144",total-size="9880"@} | |
31481 | +download,@{section=".text",section-sent="6656",section-size="6668", | |
31482 | total-sent="6656",total-size="9880"@} | |
31483 | +download,@{section=".init",section-size="28",total-size="9880"@} | |
31484 | +download,@{section=".fini",section-size="28",total-size="9880"@} | |
31485 | +download,@{section=".data",section-size="3156",total-size="9880"@} | |
31486 | +download,@{section=".data",section-sent="512",section-size="3156", | |
31487 | total-sent="7236",total-size="9880"@} | |
31488 | +download,@{section=".data",section-sent="1024",section-size="3156", | |
31489 | total-sent="7748",total-size="9880"@} | |
31490 | +download,@{section=".data",section-sent="1536",section-size="3156", | |
31491 | total-sent="8260",total-size="9880"@} | |
31492 | +download,@{section=".data",section-sent="2048",section-size="3156", | |
31493 | total-sent="8772",total-size="9880"@} | |
31494 | +download,@{section=".data",section-sent="2560",section-size="3156", | |
31495 | total-sent="9284",total-size="9880"@} | |
31496 | +download,@{section=".data",section-sent="3072",section-size="3156", | |
31497 | total-sent="9796",total-size="9880"@} | |
31498 | ^done,address="0x10004",load-size="9880",transfer-rate="6586", | |
31499 | write-rate="429" | |
594fe323 | 31500 | (gdb) |
922fbb7b AC |
31501 | @end smallexample |
31502 | ||
31503 | ||
9901a55b | 31504 | @ignore |
a2c02241 NR |
31505 | @subheading The @code{-target-exec-status} Command |
31506 | @findex -target-exec-status | |
922fbb7b AC |
31507 | |
31508 | @subsubheading Synopsis | |
31509 | ||
31510 | @smallexample | |
a2c02241 | 31511 | -target-exec-status |
922fbb7b AC |
31512 | @end smallexample |
31513 | ||
a2c02241 NR |
31514 | Provide information on the state of the target (whether it is running or |
31515 | not, for instance). | |
922fbb7b | 31516 | |
a2c02241 | 31517 | @subsubheading @value{GDBN} Command |
922fbb7b | 31518 | |
a2c02241 NR |
31519 | There's no equivalent @value{GDBN} command. |
31520 | ||
31521 | @subsubheading Example | |
31522 | N.A. | |
922fbb7b | 31523 | |
a2c02241 NR |
31524 | |
31525 | @subheading The @code{-target-list-available-targets} Command | |
31526 | @findex -target-list-available-targets | |
922fbb7b AC |
31527 | |
31528 | @subsubheading Synopsis | |
31529 | ||
31530 | @smallexample | |
a2c02241 | 31531 | -target-list-available-targets |
922fbb7b AC |
31532 | @end smallexample |
31533 | ||
a2c02241 | 31534 | List the possible targets to connect to. |
922fbb7b | 31535 | |
a2c02241 | 31536 | @subsubheading @value{GDBN} Command |
922fbb7b | 31537 | |
a2c02241 | 31538 | The corresponding @value{GDBN} command is @samp{help target}. |
922fbb7b | 31539 | |
a2c02241 NR |
31540 | @subsubheading Example |
31541 | N.A. | |
31542 | ||
31543 | ||
31544 | @subheading The @code{-target-list-current-targets} Command | |
31545 | @findex -target-list-current-targets | |
922fbb7b AC |
31546 | |
31547 | @subsubheading Synopsis | |
31548 | ||
31549 | @smallexample | |
a2c02241 | 31550 | -target-list-current-targets |
922fbb7b AC |
31551 | @end smallexample |
31552 | ||
a2c02241 | 31553 | Describe the current target. |
922fbb7b | 31554 | |
a2c02241 | 31555 | @subsubheading @value{GDBN} Command |
922fbb7b | 31556 | |
a2c02241 NR |
31557 | The corresponding information is printed by @samp{info file} (among |
31558 | other things). | |
922fbb7b | 31559 | |
a2c02241 NR |
31560 | @subsubheading Example |
31561 | N.A. | |
31562 | ||
31563 | ||
31564 | @subheading The @code{-target-list-parameters} Command | |
31565 | @findex -target-list-parameters | |
922fbb7b AC |
31566 | |
31567 | @subsubheading Synopsis | |
31568 | ||
31569 | @smallexample | |
a2c02241 | 31570 | -target-list-parameters |
922fbb7b AC |
31571 | @end smallexample |
31572 | ||
a2c02241 | 31573 | @c ???? |
9901a55b | 31574 | @end ignore |
a2c02241 NR |
31575 | |
31576 | @subsubheading @value{GDBN} Command | |
31577 | ||
31578 | No equivalent. | |
922fbb7b AC |
31579 | |
31580 | @subsubheading Example | |
a2c02241 NR |
31581 | N.A. |
31582 | ||
31583 | ||
31584 | @subheading The @code{-target-select} Command | |
31585 | @findex -target-select | |
31586 | ||
31587 | @subsubheading Synopsis | |
922fbb7b AC |
31588 | |
31589 | @smallexample | |
a2c02241 | 31590 | -target-select @var{type} @var{parameters @dots{}} |
922fbb7b AC |
31591 | @end smallexample |
31592 | ||
a2c02241 | 31593 | Connect @value{GDBN} to the remote target. This command takes two args: |
922fbb7b | 31594 | |
a2c02241 NR |
31595 | @table @samp |
31596 | @item @var{type} | |
75c99385 | 31597 | The type of target, for instance @samp{remote}, etc. |
a2c02241 NR |
31598 | @item @var{parameters} |
31599 | Device names, host names and the like. @xref{Target Commands, , | |
79a6e687 | 31600 | Commands for Managing Targets}, for more details. |
a2c02241 NR |
31601 | @end table |
31602 | ||
31603 | The output is a connection notification, followed by the address at | |
31604 | which the target program is, in the following form: | |
922fbb7b AC |
31605 | |
31606 | @smallexample | |
a2c02241 NR |
31607 | ^connected,addr="@var{address}",func="@var{function name}", |
31608 | args=[@var{arg list}] | |
922fbb7b AC |
31609 | @end smallexample |
31610 | ||
a2c02241 NR |
31611 | @subsubheading @value{GDBN} Command |
31612 | ||
31613 | The corresponding @value{GDBN} command is @samp{target}. | |
265eeb58 NR |
31614 | |
31615 | @subsubheading Example | |
922fbb7b | 31616 | |
265eeb58 | 31617 | @smallexample |
594fe323 | 31618 | (gdb) |
75c99385 | 31619 | -target-select remote /dev/ttya |
a2c02241 | 31620 | ^connected,addr="0xfe00a300",func="??",args=[] |
594fe323 | 31621 | (gdb) |
265eeb58 | 31622 | @end smallexample |
ef21caaf | 31623 | |
a6b151f1 DJ |
31624 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
31625 | @node GDB/MI File Transfer Commands | |
31626 | @section @sc{gdb/mi} File Transfer Commands | |
31627 | ||
31628 | ||
31629 | @subheading The @code{-target-file-put} Command | |
31630 | @findex -target-file-put | |
31631 | ||
31632 | @subsubheading Synopsis | |
31633 | ||
31634 | @smallexample | |
31635 | -target-file-put @var{hostfile} @var{targetfile} | |
31636 | @end smallexample | |
31637 | ||
31638 | Copy file @var{hostfile} from the host system (the machine running | |
31639 | @value{GDBN}) to @var{targetfile} on the target system. | |
31640 | ||
31641 | @subsubheading @value{GDBN} Command | |
31642 | ||
31643 | The corresponding @value{GDBN} command is @samp{remote put}. | |
31644 | ||
31645 | @subsubheading Example | |
31646 | ||
31647 | @smallexample | |
31648 | (gdb) | |
31649 | -target-file-put localfile remotefile | |
31650 | ^done | |
31651 | (gdb) | |
31652 | @end smallexample | |
31653 | ||
31654 | ||
1763a388 | 31655 | @subheading The @code{-target-file-get} Command |
a6b151f1 DJ |
31656 | @findex -target-file-get |
31657 | ||
31658 | @subsubheading Synopsis | |
31659 | ||
31660 | @smallexample | |
31661 | -target-file-get @var{targetfile} @var{hostfile} | |
31662 | @end smallexample | |
31663 | ||
31664 | Copy file @var{targetfile} from the target system to @var{hostfile} | |
31665 | on the host system. | |
31666 | ||
31667 | @subsubheading @value{GDBN} Command | |
31668 | ||
31669 | The corresponding @value{GDBN} command is @samp{remote get}. | |
31670 | ||
31671 | @subsubheading Example | |
31672 | ||
31673 | @smallexample | |
31674 | (gdb) | |
31675 | -target-file-get remotefile localfile | |
31676 | ^done | |
31677 | (gdb) | |
31678 | @end smallexample | |
31679 | ||
31680 | ||
31681 | @subheading The @code{-target-file-delete} Command | |
31682 | @findex -target-file-delete | |
31683 | ||
31684 | @subsubheading Synopsis | |
31685 | ||
31686 | @smallexample | |
31687 | -target-file-delete @var{targetfile} | |
31688 | @end smallexample | |
31689 | ||
31690 | Delete @var{targetfile} from the target system. | |
31691 | ||
31692 | @subsubheading @value{GDBN} Command | |
31693 | ||
31694 | The corresponding @value{GDBN} command is @samp{remote delete}. | |
31695 | ||
31696 | @subsubheading Example | |
31697 | ||
31698 | @smallexample | |
31699 | (gdb) | |
31700 | -target-file-delete remotefile | |
31701 | ^done | |
31702 | (gdb) | |
31703 | @end smallexample | |
31704 | ||
31705 | ||
58d06528 JB |
31706 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
31707 | @node GDB/MI Ada Exceptions Commands | |
31708 | @section Ada Exceptions @sc{gdb/mi} Commands | |
31709 | ||
31710 | @subheading The @code{-info-ada-exceptions} Command | |
31711 | @findex -info-ada-exceptions | |
31712 | ||
31713 | @subsubheading Synopsis | |
31714 | ||
31715 | @smallexample | |
31716 | -info-ada-exceptions [ @var{regexp}] | |
31717 | @end smallexample | |
31718 | ||
31719 | List all Ada exceptions defined within the program being debugged. | |
31720 | With a regular expression @var{regexp}, only those exceptions whose | |
31721 | names match @var{regexp} are listed. | |
31722 | ||
31723 | @subsubheading @value{GDBN} Command | |
31724 | ||
31725 | The corresponding @value{GDBN} command is @samp{info exceptions}. | |
31726 | ||
31727 | @subsubheading Result | |
31728 | ||
31729 | The result is a table of Ada exceptions. The following columns are | |
31730 | defined for each exception: | |
31731 | ||
31732 | @table @samp | |
31733 | @item name | |
31734 | The name of the exception. | |
31735 | ||
31736 | @item address | |
31737 | The address of the exception. | |
31738 | ||
31739 | @end table | |
31740 | ||
31741 | @subsubheading Example | |
31742 | ||
31743 | @smallexample | |
31744 | -info-ada-exceptions aint | |
31745 | ^done,ada-exceptions=@{nr_rows="2",nr_cols="2", | |
31746 | hdr=[@{width="1",alignment="-1",col_name="name",colhdr="Name"@}, | |
31747 | @{width="1",alignment="-1",col_name="address",colhdr="Address"@}], | |
31748 | body=[@{name="constraint_error",address="0x0000000000613da0"@}, | |
31749 | @{name="const.aint_global_e",address="0x0000000000613b00"@}]@} | |
31750 | @end smallexample | |
31751 | ||
31752 | @subheading Catching Ada Exceptions | |
31753 | ||
31754 | The commands describing how to ask @value{GDBN} to stop when a program | |
31755 | raises an exception are described at @ref{Ada Exception GDB/MI | |
31756 | Catchpoint Commands}. | |
31757 | ||
31758 | ||
ef21caaf | 31759 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
d192b373 JB |
31760 | @node GDB/MI Support Commands |
31761 | @section @sc{gdb/mi} Support Commands | |
ef21caaf | 31762 | |
d192b373 JB |
31763 | Since new commands and features get regularly added to @sc{gdb/mi}, |
31764 | some commands are available to help front-ends query the debugger | |
31765 | about support for these capabilities. Similarly, it is also possible | |
31766 | to query @value{GDBN} about target support of certain features. | |
ef21caaf | 31767 | |
6b7cbff1 JB |
31768 | @subheading The @code{-info-gdb-mi-command} Command |
31769 | @cindex @code{-info-gdb-mi-command} | |
31770 | @findex -info-gdb-mi-command | |
31771 | ||
31772 | @subsubheading Synopsis | |
31773 | ||
31774 | @smallexample | |
31775 | -info-gdb-mi-command @var{cmd_name} | |
31776 | @end smallexample | |
31777 | ||
31778 | Query support for the @sc{gdb/mi} command named @var{cmd_name}. | |
31779 | ||
31780 | Note that the dash (@code{-}) starting all @sc{gdb/mi} commands | |
31781 | is technically not part of the command name (@pxref{GDB/MI Input | |
31782 | Syntax}), and thus should be omitted in @var{cmd_name}. However, | |
31783 | for ease of use, this command also accepts the form with the leading | |
31784 | dash. | |
31785 | ||
31786 | @subsubheading @value{GDBN} Command | |
31787 | ||
31788 | There is no corresponding @value{GDBN} command. | |
31789 | ||
31790 | @subsubheading Result | |
31791 | ||
31792 | The result is a tuple. There is currently only one field: | |
31793 | ||
31794 | @table @samp | |
31795 | @item exists | |
31796 | This field is equal to @code{"true"} if the @sc{gdb/mi} command exists, | |
31797 | @code{"false"} otherwise. | |
31798 | ||
31799 | @end table | |
31800 | ||
31801 | @subsubheading Example | |
31802 | ||
31803 | Here is an example where the @sc{gdb/mi} command does not exist: | |
31804 | ||
31805 | @smallexample | |
31806 | -info-gdb-mi-command unsupported-command | |
31807 | ^done,command=@{exists="false"@} | |
31808 | @end smallexample | |
31809 | ||
31810 | @noindent | |
31811 | And here is an example where the @sc{gdb/mi} command is known | |
31812 | to the debugger: | |
31813 | ||
31814 | @smallexample | |
31815 | -info-gdb-mi-command symbol-list-lines | |
31816 | ^done,command=@{exists="true"@} | |
31817 | @end smallexample | |
31818 | ||
084344da VP |
31819 | @subheading The @code{-list-features} Command |
31820 | @findex -list-features | |
9b26f0fb | 31821 | @cindex supported @sc{gdb/mi} features, list |
084344da VP |
31822 | |
31823 | Returns a list of particular features of the MI protocol that | |
31824 | this version of gdb implements. A feature can be a command, | |
31825 | or a new field in an output of some command, or even an | |
31826 | important bugfix. While a frontend can sometimes detect presence | |
31827 | of a feature at runtime, it is easier to perform detection at debugger | |
d192b373 | 31828 | startup. |
084344da VP |
31829 | |
31830 | The command returns a list of strings, with each string naming an | |
31831 | available feature. Each returned string is just a name, it does not | |
d192b373 | 31832 | have any internal structure. The list of possible feature names |
084344da VP |
31833 | is given below. |
31834 | ||
31835 | Example output: | |
31836 | ||
31837 | @smallexample | |
31838 | (gdb) -list-features | |
31839 | ^done,result=["feature1","feature2"] | |
31840 | @end smallexample | |
31841 | ||
31842 | The current list of features is: | |
31843 | ||
edef6000 | 31844 | @ftable @samp |
30e026bb | 31845 | @item frozen-varobjs |
a05336a1 JB |
31846 | Indicates support for the @code{-var-set-frozen} command, as well |
31847 | as possible presense of the @code{frozen} field in the output | |
30e026bb VP |
31848 | of @code{-varobj-create}. |
31849 | @item pending-breakpoints | |
a05336a1 JB |
31850 | Indicates support for the @option{-f} option to the @code{-break-insert} |
31851 | command. | |
b6313243 | 31852 | @item python |
a05336a1 | 31853 | Indicates Python scripting support, Python-based |
b6313243 TT |
31854 | pretty-printing commands, and possible presence of the |
31855 | @samp{display_hint} field in the output of @code{-var-list-children} | |
30e026bb | 31856 | @item thread-info |
a05336a1 | 31857 | Indicates support for the @code{-thread-info} command. |
8dedea02 | 31858 | @item data-read-memory-bytes |
a05336a1 | 31859 | Indicates support for the @code{-data-read-memory-bytes} and the |
8dedea02 | 31860 | @code{-data-write-memory-bytes} commands. |
39c4d40a TT |
31861 | @item breakpoint-notifications |
31862 | Indicates that changes to breakpoints and breakpoints created via the | |
31863 | CLI will be announced via async records. | |
5d77fe44 | 31864 | @item ada-task-info |
6adcee18 | 31865 | Indicates support for the @code{-ada-task-info} command. |
422ad5c2 JB |
31866 | @item language-option |
31867 | Indicates that all @sc{gdb/mi} commands accept the @option{--language} | |
31868 | option (@pxref{Context management}). | |
6b7cbff1 JB |
31869 | @item info-gdb-mi-command |
31870 | Indicates support for the @code{-info-gdb-mi-command} command. | |
2ea126fa JB |
31871 | @item undefined-command-error-code |
31872 | Indicates support for the "undefined-command" error code in error result | |
31873 | records, produced when trying to execute an undefined @sc{gdb/mi} command | |
31874 | (@pxref{GDB/MI Result Records}). | |
72bfa06c JB |
31875 | @item exec-run-start-option |
31876 | Indicates that the @code{-exec-run} command supports the @option{--start} | |
31877 | option (@pxref{GDB/MI Program Execution}). | |
edef6000 | 31878 | @end ftable |
084344da | 31879 | |
c6ebd6cf VP |
31880 | @subheading The @code{-list-target-features} Command |
31881 | @findex -list-target-features | |
31882 | ||
31883 | Returns a list of particular features that are supported by the | |
31884 | target. Those features affect the permitted MI commands, but | |
31885 | unlike the features reported by the @code{-list-features} command, the | |
31886 | features depend on which target GDB is using at the moment. Whenever | |
31887 | a target can change, due to commands such as @code{-target-select}, | |
31888 | @code{-target-attach} or @code{-exec-run}, the list of target features | |
31889 | may change, and the frontend should obtain it again. | |
31890 | Example output: | |
31891 | ||
31892 | @smallexample | |
b3d3b4bd | 31893 | (gdb) -list-target-features |
c6ebd6cf VP |
31894 | ^done,result=["async"] |
31895 | @end smallexample | |
31896 | ||
31897 | The current list of features is: | |
31898 | ||
31899 | @table @samp | |
31900 | @item async | |
31901 | Indicates that the target is capable of asynchronous command | |
31902 | execution, which means that @value{GDBN} will accept further commands | |
31903 | while the target is running. | |
31904 | ||
f75d858b MK |
31905 | @item reverse |
31906 | Indicates that the target is capable of reverse execution. | |
31907 | @xref{Reverse Execution}, for more information. | |
31908 | ||
c6ebd6cf VP |
31909 | @end table |
31910 | ||
d192b373 JB |
31911 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
31912 | @node GDB/MI Miscellaneous Commands | |
31913 | @section Miscellaneous @sc{gdb/mi} Commands | |
31914 | ||
31915 | @c @subheading -gdb-complete | |
31916 | ||
31917 | @subheading The @code{-gdb-exit} Command | |
31918 | @findex -gdb-exit | |
31919 | ||
31920 | @subsubheading Synopsis | |
31921 | ||
31922 | @smallexample | |
31923 | -gdb-exit | |
31924 | @end smallexample | |
31925 | ||
31926 | Exit @value{GDBN} immediately. | |
31927 | ||
31928 | @subsubheading @value{GDBN} Command | |
31929 | ||
31930 | Approximately corresponds to @samp{quit}. | |
31931 | ||
31932 | @subsubheading Example | |
31933 | ||
31934 | @smallexample | |
31935 | (gdb) | |
31936 | -gdb-exit | |
31937 | ^exit | |
31938 | @end smallexample | |
31939 | ||
31940 | ||
31941 | @ignore | |
31942 | @subheading The @code{-exec-abort} Command | |
31943 | @findex -exec-abort | |
31944 | ||
31945 | @subsubheading Synopsis | |
31946 | ||
31947 | @smallexample | |
31948 | -exec-abort | |
31949 | @end smallexample | |
31950 | ||
31951 | Kill the inferior running program. | |
31952 | ||
31953 | @subsubheading @value{GDBN} Command | |
31954 | ||
31955 | The corresponding @value{GDBN} command is @samp{kill}. | |
31956 | ||
31957 | @subsubheading Example | |
31958 | N.A. | |
31959 | @end ignore | |
31960 | ||
31961 | ||
31962 | @subheading The @code{-gdb-set} Command | |
31963 | @findex -gdb-set | |
31964 | ||
31965 | @subsubheading Synopsis | |
31966 | ||
31967 | @smallexample | |
31968 | -gdb-set | |
31969 | @end smallexample | |
31970 | ||
31971 | Set an internal @value{GDBN} variable. | |
31972 | @c IS THIS A DOLLAR VARIABLE? OR SOMETHING LIKE ANNOTATE ????? | |
31973 | ||
31974 | @subsubheading @value{GDBN} Command | |
31975 | ||
31976 | The corresponding @value{GDBN} command is @samp{set}. | |
31977 | ||
31978 | @subsubheading Example | |
31979 | ||
31980 | @smallexample | |
31981 | (gdb) | |
31982 | -gdb-set $foo=3 | |
31983 | ^done | |
31984 | (gdb) | |
31985 | @end smallexample | |
31986 | ||
31987 | ||
31988 | @subheading The @code{-gdb-show} Command | |
31989 | @findex -gdb-show | |
31990 | ||
31991 | @subsubheading Synopsis | |
31992 | ||
31993 | @smallexample | |
31994 | -gdb-show | |
31995 | @end smallexample | |
31996 | ||
31997 | Show the current value of a @value{GDBN} variable. | |
31998 | ||
31999 | @subsubheading @value{GDBN} Command | |
32000 | ||
32001 | The corresponding @value{GDBN} command is @samp{show}. | |
32002 | ||
32003 | @subsubheading Example | |
32004 | ||
32005 | @smallexample | |
32006 | (gdb) | |
32007 | -gdb-show annotate | |
32008 | ^done,value="0" | |
32009 | (gdb) | |
32010 | @end smallexample | |
32011 | ||
32012 | @c @subheading -gdb-source | |
32013 | ||
32014 | ||
32015 | @subheading The @code{-gdb-version} Command | |
32016 | @findex -gdb-version | |
32017 | ||
32018 | @subsubheading Synopsis | |
32019 | ||
32020 | @smallexample | |
32021 | -gdb-version | |
32022 | @end smallexample | |
32023 | ||
32024 | Show version information for @value{GDBN}. Used mostly in testing. | |
32025 | ||
32026 | @subsubheading @value{GDBN} Command | |
32027 | ||
32028 | The @value{GDBN} equivalent is @samp{show version}. @value{GDBN} by | |
32029 | default shows this information when you start an interactive session. | |
32030 | ||
32031 | @subsubheading Example | |
32032 | ||
32033 | @c This example modifies the actual output from GDB to avoid overfull | |
32034 | @c box in TeX. | |
32035 | @smallexample | |
32036 | (gdb) | |
32037 | -gdb-version | |
32038 | ~GNU gdb 5.2.1 | |
32039 | ~Copyright 2000 Free Software Foundation, Inc. | |
32040 | ~GDB is free software, covered by the GNU General Public License, and | |
32041 | ~you are welcome to change it and/or distribute copies of it under | |
32042 | ~ certain conditions. | |
32043 | ~Type "show copying" to see the conditions. | |
32044 | ~There is absolutely no warranty for GDB. Type "show warranty" for | |
32045 | ~ details. | |
32046 | ~This GDB was configured as | |
32047 | "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". | |
32048 | ^done | |
32049 | (gdb) | |
32050 | @end smallexample | |
32051 | ||
c3b108f7 VP |
32052 | @subheading The @code{-list-thread-groups} Command |
32053 | @findex -list-thread-groups | |
32054 | ||
32055 | @subheading Synopsis | |
32056 | ||
32057 | @smallexample | |
dc146f7c | 32058 | -list-thread-groups [ --available ] [ --recurse 1 ] [ @var{group} ... ] |
c3b108f7 VP |
32059 | @end smallexample |
32060 | ||
dc146f7c VP |
32061 | Lists thread groups (@pxref{Thread groups}). When a single thread |
32062 | group is passed as the argument, lists the children of that group. | |
32063 | When several thread group are passed, lists information about those | |
32064 | thread groups. Without any parameters, lists information about all | |
32065 | top-level thread groups. | |
32066 | ||
32067 | Normally, thread groups that are being debugged are reported. | |
32068 | With the @samp{--available} option, @value{GDBN} reports thread groups | |
32069 | available on the target. | |
32070 | ||
32071 | The output of this command may have either a @samp{threads} result or | |
32072 | a @samp{groups} result. The @samp{thread} result has a list of tuples | |
32073 | as value, with each tuple describing a thread (@pxref{GDB/MI Thread | |
32074 | Information}). The @samp{groups} result has a list of tuples as value, | |
32075 | each tuple describing a thread group. If top-level groups are | |
32076 | requested (that is, no parameter is passed), or when several groups | |
32077 | are passed, the output always has a @samp{groups} result. The format | |
32078 | of the @samp{group} result is described below. | |
32079 | ||
32080 | To reduce the number of roundtrips it's possible to list thread groups | |
32081 | together with their children, by passing the @samp{--recurse} option | |
32082 | and the recursion depth. Presently, only recursion depth of 1 is | |
32083 | permitted. If this option is present, then every reported thread group | |
32084 | will also include its children, either as @samp{group} or | |
32085 | @samp{threads} field. | |
32086 | ||
32087 | In general, any combination of option and parameters is permitted, with | |
32088 | the following caveats: | |
32089 | ||
32090 | @itemize @bullet | |
32091 | @item | |
32092 | When a single thread group is passed, the output will typically | |
32093 | be the @samp{threads} result. Because threads may not contain | |
32094 | anything, the @samp{recurse} option will be ignored. | |
32095 | ||
32096 | @item | |
32097 | When the @samp{--available} option is passed, limited information may | |
32098 | be available. In particular, the list of threads of a process might | |
32099 | be inaccessible. Further, specifying specific thread groups might | |
32100 | not give any performance advantage over listing all thread groups. | |
32101 | The frontend should assume that @samp{-list-thread-groups --available} | |
32102 | is always an expensive operation and cache the results. | |
32103 | ||
32104 | @end itemize | |
32105 | ||
32106 | The @samp{groups} result is a list of tuples, where each tuple may | |
32107 | have the following fields: | |
32108 | ||
32109 | @table @code | |
32110 | @item id | |
32111 | Identifier of the thread group. This field is always present. | |
a79b8f6e VP |
32112 | The identifier is an opaque string; frontends should not try to |
32113 | convert it to an integer, even though it might look like one. | |
dc146f7c VP |
32114 | |
32115 | @item type | |
32116 | The type of the thread group. At present, only @samp{process} is a | |
32117 | valid type. | |
32118 | ||
32119 | @item pid | |
32120 | The target-specific process identifier. This field is only present | |
a79b8f6e | 32121 | for thread groups of type @samp{process} and only if the process exists. |
c3b108f7 | 32122 | |
2ddf4301 SM |
32123 | @item exit-code |
32124 | The exit code of this group's last exited thread, formatted in octal. | |
32125 | This field is only present for thread groups of type @samp{process} and | |
32126 | only if the process is not running. | |
32127 | ||
dc146f7c VP |
32128 | @item num_children |
32129 | The number of children this thread group has. This field may be | |
32130 | absent for an available thread group. | |
32131 | ||
32132 | @item threads | |
32133 | This field has a list of tuples as value, each tuple describing a | |
32134 | thread. It may be present if the @samp{--recurse} option is | |
32135 | specified, and it's actually possible to obtain the threads. | |
32136 | ||
32137 | @item cores | |
32138 | This field is a list of integers, each identifying a core that one | |
32139 | thread of the group is running on. This field may be absent if | |
32140 | such information is not available. | |
32141 | ||
a79b8f6e VP |
32142 | @item executable |
32143 | The name of the executable file that corresponds to this thread group. | |
32144 | The field is only present for thread groups of type @samp{process}, | |
32145 | and only if there is a corresponding executable file. | |
32146 | ||
dc146f7c | 32147 | @end table |
c3b108f7 VP |
32148 | |
32149 | @subheading Example | |
32150 | ||
32151 | @smallexample | |
32152 | @value{GDBP} | |
32153 | -list-thread-groups | |
32154 | ^done,groups=[@{id="17",type="process",pid="yyy",num_children="2"@}] | |
32155 | -list-thread-groups 17 | |
32156 | ^done,threads=[@{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", | |
32157 | frame=@{level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]@},state="running"@}, | |
32158 | @{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", | |
32159 | frame=@{level="0",addr="0x0804891f",func="foo",args=[@{name="i",value="10"@}], | |
32160 | file="/tmp/a.c",fullname="/tmp/a.c",line="158"@},state="running"@}]] | |
dc146f7c VP |
32161 | -list-thread-groups --available |
32162 | ^done,groups=[@{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]@}] | |
32163 | -list-thread-groups --available --recurse 1 | |
32164 | ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], | |
32165 | threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@}, | |
32166 | @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},..] | |
32167 | -list-thread-groups --available --recurse 1 17 18 | |
32168 | ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], | |
32169 | threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@}, | |
32170 | @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},...] | |
c3b108f7 | 32171 | @end smallexample |
c6ebd6cf | 32172 | |
f3e0e960 SS |
32173 | @subheading The @code{-info-os} Command |
32174 | @findex -info-os | |
32175 | ||
32176 | @subsubheading Synopsis | |
32177 | ||
32178 | @smallexample | |
32179 | -info-os [ @var{type} ] | |
32180 | @end smallexample | |
32181 | ||
32182 | If no argument is supplied, the command returns a table of available | |
32183 | operating-system-specific information types. If one of these types is | |
32184 | supplied as an argument @var{type}, then the command returns a table | |
32185 | of data of that type. | |
32186 | ||
32187 | The types of information available depend on the target operating | |
32188 | system. | |
32189 | ||
32190 | @subsubheading @value{GDBN} Command | |
32191 | ||
32192 | The corresponding @value{GDBN} command is @samp{info os}. | |
32193 | ||
32194 | @subsubheading Example | |
32195 | ||
32196 | When run on a @sc{gnu}/Linux system, the output will look something | |
32197 | like this: | |
32198 | ||
32199 | @smallexample | |
32200 | @value{GDBP} | |
32201 | -info-os | |
d33279b3 | 32202 | ^done,OSDataTable=@{nr_rows="10",nr_cols="3", |
f3e0e960 | 32203 | hdr=[@{width="10",alignment="-1",col_name="col0",colhdr="Type"@}, |
71caed83 SS |
32204 | @{width="10",alignment="-1",col_name="col1",colhdr="Description"@}, |
32205 | @{width="10",alignment="-1",col_name="col2",colhdr="Title"@}], | |
d33279b3 AT |
32206 | body=[item=@{col0="cpus",col1="Listing of all cpus/cores on the system", |
32207 | col2="CPUs"@}, | |
32208 | item=@{col0="files",col1="Listing of all file descriptors", | |
32209 | col2="File descriptors"@}, | |
32210 | item=@{col0="modules",col1="Listing of all loaded kernel modules", | |
32211 | col2="Kernel modules"@}, | |
32212 | item=@{col0="msg",col1="Listing of all message queues", | |
32213 | col2="Message queues"@}, | |
32214 | item=@{col0="processes",col1="Listing of all processes", | |
71caed83 SS |
32215 | col2="Processes"@}, |
32216 | item=@{col0="procgroups",col1="Listing of all process groups", | |
32217 | col2="Process groups"@}, | |
71caed83 SS |
32218 | item=@{col0="semaphores",col1="Listing of all semaphores", |
32219 | col2="Semaphores"@}, | |
d33279b3 AT |
32220 | item=@{col0="shm",col1="Listing of all shared-memory regions", |
32221 | col2="Shared-memory regions"@}, | |
32222 | item=@{col0="sockets",col1="Listing of all internet-domain sockets", | |
32223 | col2="Sockets"@}, | |
32224 | item=@{col0="threads",col1="Listing of all threads", | |
32225 | col2="Threads"@}] | |
f3e0e960 SS |
32226 | @value{GDBP} |
32227 | -info-os processes | |
32228 | ^done,OSDataTable=@{nr_rows="190",nr_cols="4", | |
32229 | hdr=[@{width="10",alignment="-1",col_name="col0",colhdr="pid"@}, | |
32230 | @{width="10",alignment="-1",col_name="col1",colhdr="user"@}, | |
32231 | @{width="10",alignment="-1",col_name="col2",colhdr="command"@}, | |
32232 | @{width="10",alignment="-1",col_name="col3",colhdr="cores"@}], | |
32233 | body=[item=@{col0="1",col1="root",col2="/sbin/init",col3="0"@}, | |
32234 | item=@{col0="2",col1="root",col2="[kthreadd]",col3="1"@}, | |
32235 | item=@{col0="3",col1="root",col2="[ksoftirqd/0]",col3="0"@}, | |
32236 | ... | |
32237 | item=@{col0="26446",col1="stan",col2="bash",col3="0"@}, | |
32238 | item=@{col0="28152",col1="stan",col2="bash",col3="1"@}]@} | |
32239 | (gdb) | |
32240 | @end smallexample | |
a79b8f6e | 32241 | |
71caed83 SS |
32242 | (Note that the MI output here includes a @code{"Title"} column that |
32243 | does not appear in command-line @code{info os}; this column is useful | |
32244 | for MI clients that want to enumerate the types of data, such as in a | |
32245 | popup menu, but is needless clutter on the command line, and | |
32246 | @code{info os} omits it.) | |
32247 | ||
a79b8f6e VP |
32248 | @subheading The @code{-add-inferior} Command |
32249 | @findex -add-inferior | |
32250 | ||
32251 | @subheading Synopsis | |
32252 | ||
32253 | @smallexample | |
32254 | -add-inferior | |
32255 | @end smallexample | |
32256 | ||
32257 | Creates a new inferior (@pxref{Inferiors and Programs}). The created | |
32258 | inferior is not associated with any executable. Such association may | |
32259 | be established with the @samp{-file-exec-and-symbols} command | |
32260 | (@pxref{GDB/MI File Commands}). The command response has a single | |
b7742092 | 32261 | field, @samp{inferior}, whose value is the identifier of the |
a79b8f6e VP |
32262 | thread group corresponding to the new inferior. |
32263 | ||
32264 | @subheading Example | |
32265 | ||
32266 | @smallexample | |
32267 | @value{GDBP} | |
32268 | -add-inferior | |
b7742092 | 32269 | ^done,inferior="i3" |
a79b8f6e VP |
32270 | @end smallexample |
32271 | ||
ef21caaf NR |
32272 | @subheading The @code{-interpreter-exec} Command |
32273 | @findex -interpreter-exec | |
32274 | ||
32275 | @subheading Synopsis | |
32276 | ||
32277 | @smallexample | |
32278 | -interpreter-exec @var{interpreter} @var{command} | |
32279 | @end smallexample | |
a2c02241 | 32280 | @anchor{-interpreter-exec} |
ef21caaf NR |
32281 | |
32282 | Execute the specified @var{command} in the given @var{interpreter}. | |
32283 | ||
32284 | @subheading @value{GDBN} Command | |
32285 | ||
32286 | The corresponding @value{GDBN} command is @samp{interpreter-exec}. | |
32287 | ||
32288 | @subheading Example | |
32289 | ||
32290 | @smallexample | |
594fe323 | 32291 | (gdb) |
ef21caaf NR |
32292 | -interpreter-exec console "break main" |
32293 | &"During symbol reading, couldn't parse type; debugger out of date?.\n" | |
32294 | &"During symbol reading, bad structure-type format.\n" | |
32295 | ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n" | |
32296 | ^done | |
594fe323 | 32297 | (gdb) |
ef21caaf NR |
32298 | @end smallexample |
32299 | ||
32300 | @subheading The @code{-inferior-tty-set} Command | |
32301 | @findex -inferior-tty-set | |
32302 | ||
32303 | @subheading Synopsis | |
32304 | ||
32305 | @smallexample | |
32306 | -inferior-tty-set /dev/pts/1 | |
32307 | @end smallexample | |
32308 | ||
32309 | Set terminal for future runs of the program being debugged. | |
32310 | ||
32311 | @subheading @value{GDBN} Command | |
32312 | ||
32313 | The corresponding @value{GDBN} command is @samp{set inferior-tty} /dev/pts/1. | |
32314 | ||
32315 | @subheading Example | |
32316 | ||
32317 | @smallexample | |
594fe323 | 32318 | (gdb) |
ef21caaf NR |
32319 | -inferior-tty-set /dev/pts/1 |
32320 | ^done | |
594fe323 | 32321 | (gdb) |
ef21caaf NR |
32322 | @end smallexample |
32323 | ||
32324 | @subheading The @code{-inferior-tty-show} Command | |
32325 | @findex -inferior-tty-show | |
32326 | ||
32327 | @subheading Synopsis | |
32328 | ||
32329 | @smallexample | |
32330 | -inferior-tty-show | |
32331 | @end smallexample | |
32332 | ||
32333 | Show terminal for future runs of program being debugged. | |
32334 | ||
32335 | @subheading @value{GDBN} Command | |
32336 | ||
32337 | The corresponding @value{GDBN} command is @samp{show inferior-tty}. | |
32338 | ||
32339 | @subheading Example | |
32340 | ||
32341 | @smallexample | |
594fe323 | 32342 | (gdb) |
ef21caaf NR |
32343 | -inferior-tty-set /dev/pts/1 |
32344 | ^done | |
594fe323 | 32345 | (gdb) |
ef21caaf NR |
32346 | -inferior-tty-show |
32347 | ^done,inferior_tty_terminal="/dev/pts/1" | |
594fe323 | 32348 | (gdb) |
ef21caaf | 32349 | @end smallexample |
922fbb7b | 32350 | |
a4eefcd8 NR |
32351 | @subheading The @code{-enable-timings} Command |
32352 | @findex -enable-timings | |
32353 | ||
32354 | @subheading Synopsis | |
32355 | ||
32356 | @smallexample | |
32357 | -enable-timings [yes | no] | |
32358 | @end smallexample | |
32359 | ||
32360 | Toggle the printing of the wallclock, user and system times for an MI | |
32361 | command as a field in its output. This command is to help frontend | |
32362 | developers optimize the performance of their code. No argument is | |
32363 | equivalent to @samp{yes}. | |
32364 | ||
32365 | @subheading @value{GDBN} Command | |
32366 | ||
32367 | No equivalent. | |
32368 | ||
32369 | @subheading Example | |
32370 | ||
32371 | @smallexample | |
32372 | (gdb) | |
32373 | -enable-timings | |
32374 | ^done | |
32375 | (gdb) | |
32376 | -break-insert main | |
32377 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
32378 | addr="0x080484ed",func="main",file="myprog.c", | |
998580f1 MK |
32379 | fullname="/home/nickrob/myprog.c",line="73",thread-groups=["i1"], |
32380 | times="0"@}, | |
a4eefcd8 NR |
32381 | time=@{wallclock="0.05185",user="0.00800",system="0.00000"@} |
32382 | (gdb) | |
32383 | -enable-timings no | |
32384 | ^done | |
32385 | (gdb) | |
32386 | -exec-run | |
32387 | ^running | |
32388 | (gdb) | |
a47ec5fe | 32389 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", |
a4eefcd8 NR |
32390 | frame=@{addr="0x080484ed",func="main",args=[@{name="argc",value="1"@}, |
32391 | @{name="argv",value="0xbfb60364"@}],file="myprog.c", | |
32392 | fullname="/home/nickrob/myprog.c",line="73"@} | |
32393 | (gdb) | |
32394 | @end smallexample | |
32395 | ||
922fbb7b AC |
32396 | @node Annotations |
32397 | @chapter @value{GDBN} Annotations | |
32398 | ||
086432e2 AC |
32399 | This chapter describes annotations in @value{GDBN}. Annotations were |
32400 | designed to interface @value{GDBN} to graphical user interfaces or other | |
32401 | similar programs which want to interact with @value{GDBN} at a | |
922fbb7b AC |
32402 | relatively high level. |
32403 | ||
d3e8051b | 32404 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 AC |
32405 | (@pxref{GDB/MI}). |
32406 | ||
922fbb7b AC |
32407 | @ignore |
32408 | This is Edition @value{EDITION}, @value{DATE}. | |
32409 | @end ignore | |
32410 | ||
32411 | @menu | |
32412 | * Annotations Overview:: What annotations are; the general syntax. | |
9e6c4bd5 | 32413 | * Server Prefix:: Issuing a command without affecting user state. |
922fbb7b AC |
32414 | * Prompting:: Annotations marking @value{GDBN}'s need for input. |
32415 | * Errors:: Annotations for error messages. | |
922fbb7b AC |
32416 | * Invalidation:: Some annotations describe things now invalid. |
32417 | * Annotations for Running:: | |
32418 | Whether the program is running, how it stopped, etc. | |
32419 | * Source Annotations:: Annotations describing source code. | |
922fbb7b AC |
32420 | @end menu |
32421 | ||
32422 | @node Annotations Overview | |
32423 | @section What is an Annotation? | |
32424 | @cindex annotations | |
32425 | ||
922fbb7b AC |
32426 | Annotations start with a newline character, two @samp{control-z} |
32427 | characters, and the name of the annotation. If there is no additional | |
32428 | information associated with this annotation, the name of the annotation | |
32429 | is followed immediately by a newline. If there is additional | |
32430 | information, the name of the annotation is followed by a space, the | |
32431 | additional information, and a newline. The additional information | |
32432 | cannot contain newline characters. | |
32433 | ||
32434 | Any output not beginning with a newline and two @samp{control-z} | |
32435 | characters denotes literal output from @value{GDBN}. Currently there is | |
32436 | no need for @value{GDBN} to output a newline followed by two | |
32437 | @samp{control-z} characters, but if there was such a need, the | |
32438 | annotations could be extended with an @samp{escape} annotation which | |
32439 | means those three characters as output. | |
32440 | ||
086432e2 AC |
32441 | The annotation @var{level}, which is specified using the |
32442 | @option{--annotate} command line option (@pxref{Mode Options}), controls | |
32443 | how much information @value{GDBN} prints together with its prompt, | |
32444 | values of expressions, source lines, and other types of output. Level 0 | |
d3e8051b | 32445 | is for no annotations, level 1 is for use when @value{GDBN} is run as a |
086432e2 AC |
32446 | subprocess of @sc{gnu} Emacs, level 3 is the maximum annotation suitable |
32447 | for programs that control @value{GDBN}, and level 2 annotations have | |
32448 | been made obsolete (@pxref{Limitations, , Limitations of the Annotation | |
09d4efe1 EZ |
32449 | Interface, annotate, GDB's Obsolete Annotations}). |
32450 | ||
32451 | @table @code | |
32452 | @kindex set annotate | |
32453 | @item set annotate @var{level} | |
e09f16f9 | 32454 | The @value{GDBN} command @code{set annotate} sets the level of |
09d4efe1 | 32455 | annotations to the specified @var{level}. |
9c16f35a EZ |
32456 | |
32457 | @item show annotate | |
32458 | @kindex show annotate | |
32459 | Show the current annotation level. | |
09d4efe1 EZ |
32460 | @end table |
32461 | ||
32462 | This chapter describes level 3 annotations. | |
086432e2 | 32463 | |
922fbb7b AC |
32464 | A simple example of starting up @value{GDBN} with annotations is: |
32465 | ||
32466 | @smallexample | |
086432e2 AC |
32467 | $ @kbd{gdb --annotate=3} |
32468 | GNU gdb 6.0 | |
32469 | Copyright 2003 Free Software Foundation, Inc. | |
922fbb7b AC |
32470 | GDB is free software, covered by the GNU General Public License, |
32471 | and you are welcome to change it and/or distribute copies of it | |
32472 | under certain conditions. | |
32473 | Type "show copying" to see the conditions. | |
32474 | There is absolutely no warranty for GDB. Type "show warranty" | |
32475 | for details. | |
086432e2 | 32476 | This GDB was configured as "i386-pc-linux-gnu" |
922fbb7b AC |
32477 | |
32478 | ^Z^Zpre-prompt | |
f7dc1244 | 32479 | (@value{GDBP}) |
922fbb7b | 32480 | ^Z^Zprompt |
086432e2 | 32481 | @kbd{quit} |
922fbb7b AC |
32482 | |
32483 | ^Z^Zpost-prompt | |
b383017d | 32484 | $ |
922fbb7b AC |
32485 | @end smallexample |
32486 | ||
32487 | Here @samp{quit} is input to @value{GDBN}; the rest is output from | |
32488 | @value{GDBN}. The three lines beginning @samp{^Z^Z} (where @samp{^Z} | |
32489 | denotes a @samp{control-z} character) are annotations; the rest is | |
32490 | output from @value{GDBN}. | |
32491 | ||
9e6c4bd5 NR |
32492 | @node Server Prefix |
32493 | @section The Server Prefix | |
32494 | @cindex server prefix | |
32495 | ||
32496 | If you prefix a command with @samp{server } then it will not affect | |
32497 | the command history, nor will it affect @value{GDBN}'s notion of which | |
32498 | command to repeat if @key{RET} is pressed on a line by itself. This | |
32499 | means that commands can be run behind a user's back by a front-end in | |
32500 | a transparent manner. | |
32501 | ||
d837706a NR |
32502 | The @code{server } prefix does not affect the recording of values into |
32503 | the value history; to print a value without recording it into the | |
32504 | value history, use the @code{output} command instead of the | |
32505 | @code{print} command. | |
32506 | ||
32507 | Using this prefix also disables confirmation requests | |
32508 | (@pxref{confirmation requests}). | |
9e6c4bd5 | 32509 | |
922fbb7b AC |
32510 | @node Prompting |
32511 | @section Annotation for @value{GDBN} Input | |
32512 | ||
32513 | @cindex annotations for prompts | |
32514 | When @value{GDBN} prompts for input, it annotates this fact so it is possible | |
32515 | to know when to send output, when the output from a given command is | |
32516 | over, etc. | |
32517 | ||
32518 | Different kinds of input each have a different @dfn{input type}. Each | |
32519 | input type has three annotations: a @code{pre-} annotation, which | |
32520 | denotes the beginning of any prompt which is being output, a plain | |
32521 | annotation, which denotes the end of the prompt, and then a @code{post-} | |
32522 | annotation which denotes the end of any echo which may (or may not) be | |
32523 | associated with the input. For example, the @code{prompt} input type | |
32524 | features the following annotations: | |
32525 | ||
32526 | @smallexample | |
32527 | ^Z^Zpre-prompt | |
32528 | ^Z^Zprompt | |
32529 | ^Z^Zpost-prompt | |
32530 | @end smallexample | |
32531 | ||
32532 | The input types are | |
32533 | ||
32534 | @table @code | |
e5ac9b53 EZ |
32535 | @findex pre-prompt annotation |
32536 | @findex prompt annotation | |
32537 | @findex post-prompt annotation | |
922fbb7b AC |
32538 | @item prompt |
32539 | When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt). | |
32540 | ||
e5ac9b53 EZ |
32541 | @findex pre-commands annotation |
32542 | @findex commands annotation | |
32543 | @findex post-commands annotation | |
922fbb7b AC |
32544 | @item commands |
32545 | When @value{GDBN} prompts for a set of commands, like in the @code{commands} | |
32546 | command. The annotations are repeated for each command which is input. | |
32547 | ||
e5ac9b53 EZ |
32548 | @findex pre-overload-choice annotation |
32549 | @findex overload-choice annotation | |
32550 | @findex post-overload-choice annotation | |
922fbb7b AC |
32551 | @item overload-choice |
32552 | When @value{GDBN} wants the user to select between various overloaded functions. | |
32553 | ||
e5ac9b53 EZ |
32554 | @findex pre-query annotation |
32555 | @findex query annotation | |
32556 | @findex post-query annotation | |
922fbb7b AC |
32557 | @item query |
32558 | When @value{GDBN} wants the user to confirm a potentially dangerous operation. | |
32559 | ||
e5ac9b53 EZ |
32560 | @findex pre-prompt-for-continue annotation |
32561 | @findex prompt-for-continue annotation | |
32562 | @findex post-prompt-for-continue annotation | |
922fbb7b AC |
32563 | @item prompt-for-continue |
32564 | When @value{GDBN} is asking the user to press return to continue. Note: Don't | |
32565 | expect this to work well; instead use @code{set height 0} to disable | |
32566 | prompting. This is because the counting of lines is buggy in the | |
32567 | presence of annotations. | |
32568 | @end table | |
32569 | ||
32570 | @node Errors | |
32571 | @section Errors | |
32572 | @cindex annotations for errors, warnings and interrupts | |
32573 | ||
e5ac9b53 | 32574 | @findex quit annotation |
922fbb7b AC |
32575 | @smallexample |
32576 | ^Z^Zquit | |
32577 | @end smallexample | |
32578 | ||
32579 | This annotation occurs right before @value{GDBN} responds to an interrupt. | |
32580 | ||
e5ac9b53 | 32581 | @findex error annotation |
922fbb7b AC |
32582 | @smallexample |
32583 | ^Z^Zerror | |
32584 | @end smallexample | |
32585 | ||
32586 | This annotation occurs right before @value{GDBN} responds to an error. | |
32587 | ||
32588 | Quit and error annotations indicate that any annotations which @value{GDBN} was | |
32589 | in the middle of may end abruptly. For example, if a | |
32590 | @code{value-history-begin} annotation is followed by a @code{error}, one | |
32591 | cannot expect to receive the matching @code{value-history-end}. One | |
32592 | cannot expect not to receive it either, however; an error annotation | |
32593 | does not necessarily mean that @value{GDBN} is immediately returning all the way | |
32594 | to the top level. | |
32595 | ||
e5ac9b53 | 32596 | @findex error-begin annotation |
922fbb7b AC |
32597 | A quit or error annotation may be preceded by |
32598 | ||
32599 | @smallexample | |
32600 | ^Z^Zerror-begin | |
32601 | @end smallexample | |
32602 | ||
32603 | Any output between that and the quit or error annotation is the error | |
32604 | message. | |
32605 | ||
32606 | Warning messages are not yet annotated. | |
32607 | @c If we want to change that, need to fix warning(), type_error(), | |
32608 | @c range_error(), and possibly other places. | |
32609 | ||
922fbb7b AC |
32610 | @node Invalidation |
32611 | @section Invalidation Notices | |
32612 | ||
32613 | @cindex annotations for invalidation messages | |
32614 | The following annotations say that certain pieces of state may have | |
32615 | changed. | |
32616 | ||
32617 | @table @code | |
e5ac9b53 | 32618 | @findex frames-invalid annotation |
922fbb7b AC |
32619 | @item ^Z^Zframes-invalid |
32620 | ||
32621 | The frames (for example, output from the @code{backtrace} command) may | |
32622 | have changed. | |
32623 | ||
e5ac9b53 | 32624 | @findex breakpoints-invalid annotation |
922fbb7b AC |
32625 | @item ^Z^Zbreakpoints-invalid |
32626 | ||
32627 | The breakpoints may have changed. For example, the user just added or | |
32628 | deleted a breakpoint. | |
32629 | @end table | |
32630 | ||
32631 | @node Annotations for Running | |
32632 | @section Running the Program | |
32633 | @cindex annotations for running programs | |
32634 | ||
e5ac9b53 EZ |
32635 | @findex starting annotation |
32636 | @findex stopping annotation | |
922fbb7b | 32637 | When the program starts executing due to a @value{GDBN} command such as |
b383017d | 32638 | @code{step} or @code{continue}, |
922fbb7b AC |
32639 | |
32640 | @smallexample | |
32641 | ^Z^Zstarting | |
32642 | @end smallexample | |
32643 | ||
b383017d | 32644 | is output. When the program stops, |
922fbb7b AC |
32645 | |
32646 | @smallexample | |
32647 | ^Z^Zstopped | |
32648 | @end smallexample | |
32649 | ||
32650 | is output. Before the @code{stopped} annotation, a variety of | |
32651 | annotations describe how the program stopped. | |
32652 | ||
32653 | @table @code | |
e5ac9b53 | 32654 | @findex exited annotation |
922fbb7b AC |
32655 | @item ^Z^Zexited @var{exit-status} |
32656 | The program exited, and @var{exit-status} is the exit status (zero for | |
32657 | successful exit, otherwise nonzero). | |
32658 | ||
e5ac9b53 EZ |
32659 | @findex signalled annotation |
32660 | @findex signal-name annotation | |
32661 | @findex signal-name-end annotation | |
32662 | @findex signal-string annotation | |
32663 | @findex signal-string-end annotation | |
922fbb7b AC |
32664 | @item ^Z^Zsignalled |
32665 | The program exited with a signal. After the @code{^Z^Zsignalled}, the | |
32666 | annotation continues: | |
32667 | ||
32668 | @smallexample | |
32669 | @var{intro-text} | |
32670 | ^Z^Zsignal-name | |
32671 | @var{name} | |
32672 | ^Z^Zsignal-name-end | |
32673 | @var{middle-text} | |
32674 | ^Z^Zsignal-string | |
32675 | @var{string} | |
32676 | ^Z^Zsignal-string-end | |
32677 | @var{end-text} | |
32678 | @end smallexample | |
32679 | ||
32680 | @noindent | |
32681 | where @var{name} is the name of the signal, such as @code{SIGILL} or | |
32682 | @code{SIGSEGV}, and @var{string} is the explanation of the signal, such | |
697aa1b7 | 32683 | as @code{Illegal Instruction} or @code{Segmentation fault}. The arguments |
922fbb7b AC |
32684 | @var{intro-text}, @var{middle-text}, and @var{end-text} are for the |
32685 | user's benefit and have no particular format. | |
32686 | ||
e5ac9b53 | 32687 | @findex signal annotation |
922fbb7b AC |
32688 | @item ^Z^Zsignal |
32689 | The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is | |
32690 | just saying that the program received the signal, not that it was | |
32691 | terminated with it. | |
32692 | ||
e5ac9b53 | 32693 | @findex breakpoint annotation |
922fbb7b AC |
32694 | @item ^Z^Zbreakpoint @var{number} |
32695 | The program hit breakpoint number @var{number}. | |
32696 | ||
e5ac9b53 | 32697 | @findex watchpoint annotation |
922fbb7b AC |
32698 | @item ^Z^Zwatchpoint @var{number} |
32699 | The program hit watchpoint number @var{number}. | |
32700 | @end table | |
32701 | ||
32702 | @node Source Annotations | |
32703 | @section Displaying Source | |
32704 | @cindex annotations for source display | |
32705 | ||
e5ac9b53 | 32706 | @findex source annotation |
922fbb7b AC |
32707 | The following annotation is used instead of displaying source code: |
32708 | ||
32709 | @smallexample | |
32710 | ^Z^Zsource @var{filename}:@var{line}:@var{character}:@var{middle}:@var{addr} | |
32711 | @end smallexample | |
32712 | ||
32713 | where @var{filename} is an absolute file name indicating which source | |
32714 | file, @var{line} is the line number within that file (where 1 is the | |
32715 | first line in the file), @var{character} is the character position | |
32716 | within the file (where 0 is the first character in the file) (for most | |
32717 | debug formats this will necessarily point to the beginning of a line), | |
32718 | @var{middle} is @samp{middle} if @var{addr} is in the middle of the | |
32719 | line, or @samp{beg} if @var{addr} is at the beginning of the line, and | |
32720 | @var{addr} is the address in the target program associated with the | |
697aa1b7 | 32721 | source which is being displayed. The @var{addr} is in the form @samp{0x} |
922fbb7b AC |
32722 | followed by one or more lowercase hex digits (note that this does not |
32723 | depend on the language). | |
32724 | ||
4efc6507 DE |
32725 | @node JIT Interface |
32726 | @chapter JIT Compilation Interface | |
32727 | @cindex just-in-time compilation | |
32728 | @cindex JIT compilation interface | |
32729 | ||
32730 | This chapter documents @value{GDBN}'s @dfn{just-in-time} (JIT) compilation | |
32731 | interface. A JIT compiler is a program or library that generates native | |
32732 | executable code at runtime and executes it, usually in order to achieve good | |
32733 | performance while maintaining platform independence. | |
32734 | ||
32735 | Programs that use JIT compilation are normally difficult to debug because | |
32736 | portions of their code are generated at runtime, instead of being loaded from | |
32737 | object files, which is where @value{GDBN} normally finds the program's symbols | |
32738 | and debug information. In order to debug programs that use JIT compilation, | |
32739 | @value{GDBN} has an interface that allows the program to register in-memory | |
32740 | symbol files with @value{GDBN} at runtime. | |
32741 | ||
32742 | If you are using @value{GDBN} to debug a program that uses this interface, then | |
32743 | it should work transparently so long as you have not stripped the binary. If | |
32744 | you are developing a JIT compiler, then the interface is documented in the rest | |
32745 | of this chapter. At this time, the only known client of this interface is the | |
32746 | LLVM JIT. | |
32747 | ||
32748 | Broadly speaking, the JIT interface mirrors the dynamic loader interface. The | |
32749 | JIT compiler communicates with @value{GDBN} by writing data into a global | |
32750 | variable and calling a fuction at a well-known symbol. When @value{GDBN} | |
32751 | attaches, it reads a linked list of symbol files from the global variable to | |
32752 | find existing code, and puts a breakpoint in the function so that it can find | |
32753 | out about additional code. | |
32754 | ||
32755 | @menu | |
32756 | * Declarations:: Relevant C struct declarations | |
32757 | * Registering Code:: Steps to register code | |
32758 | * Unregistering Code:: Steps to unregister code | |
f85b53f8 | 32759 | * Custom Debug Info:: Emit debug information in a custom format |
4efc6507 DE |
32760 | @end menu |
32761 | ||
32762 | @node Declarations | |
32763 | @section JIT Declarations | |
32764 | ||
32765 | These are the relevant struct declarations that a C program should include to | |
32766 | implement the interface: | |
32767 | ||
32768 | @smallexample | |
32769 | typedef enum | |
32770 | @{ | |
32771 | JIT_NOACTION = 0, | |
32772 | JIT_REGISTER_FN, | |
32773 | JIT_UNREGISTER_FN | |
32774 | @} jit_actions_t; | |
32775 | ||
32776 | struct jit_code_entry | |
32777 | @{ | |
32778 | struct jit_code_entry *next_entry; | |
32779 | struct jit_code_entry *prev_entry; | |
32780 | const char *symfile_addr; | |
32781 | uint64_t symfile_size; | |
32782 | @}; | |
32783 | ||
32784 | struct jit_descriptor | |
32785 | @{ | |
32786 | uint32_t version; | |
32787 | /* This type should be jit_actions_t, but we use uint32_t | |
32788 | to be explicit about the bitwidth. */ | |
32789 | uint32_t action_flag; | |
32790 | struct jit_code_entry *relevant_entry; | |
32791 | struct jit_code_entry *first_entry; | |
32792 | @}; | |
32793 | ||
32794 | /* GDB puts a breakpoint in this function. */ | |
32795 | void __attribute__((noinline)) __jit_debug_register_code() @{ @}; | |
32796 | ||
32797 | /* Make sure to specify the version statically, because the | |
32798 | debugger may check the version before we can set it. */ | |
32799 | struct jit_descriptor __jit_debug_descriptor = @{ 1, 0, 0, 0 @}; | |
32800 | @end smallexample | |
32801 | ||
32802 | If the JIT is multi-threaded, then it is important that the JIT synchronize any | |
32803 | modifications to this global data properly, which can easily be done by putting | |
32804 | a global mutex around modifications to these structures. | |
32805 | ||
32806 | @node Registering Code | |
32807 | @section Registering Code | |
32808 | ||
32809 | To register code with @value{GDBN}, the JIT should follow this protocol: | |
32810 | ||
32811 | @itemize @bullet | |
32812 | @item | |
32813 | Generate an object file in memory with symbols and other desired debug | |
32814 | information. The file must include the virtual addresses of the sections. | |
32815 | ||
32816 | @item | |
32817 | Create a code entry for the file, which gives the start and size of the symbol | |
32818 | file. | |
32819 | ||
32820 | @item | |
32821 | Add it to the linked list in the JIT descriptor. | |
32822 | ||
32823 | @item | |
32824 | Point the relevant_entry field of the descriptor at the entry. | |
32825 | ||
32826 | @item | |
32827 | Set @code{action_flag} to @code{JIT_REGISTER} and call | |
32828 | @code{__jit_debug_register_code}. | |
32829 | @end itemize | |
32830 | ||
32831 | When @value{GDBN} is attached and the breakpoint fires, @value{GDBN} uses the | |
32832 | @code{relevant_entry} pointer so it doesn't have to walk the list looking for | |
32833 | new code. However, the linked list must still be maintained in order to allow | |
32834 | @value{GDBN} to attach to a running process and still find the symbol files. | |
32835 | ||
32836 | @node Unregistering Code | |
32837 | @section Unregistering Code | |
32838 | ||
32839 | If code is freed, then the JIT should use the following protocol: | |
32840 | ||
32841 | @itemize @bullet | |
32842 | @item | |
32843 | Remove the code entry corresponding to the code from the linked list. | |
32844 | ||
32845 | @item | |
32846 | Point the @code{relevant_entry} field of the descriptor at the code entry. | |
32847 | ||
32848 | @item | |
32849 | Set @code{action_flag} to @code{JIT_UNREGISTER} and call | |
32850 | @code{__jit_debug_register_code}. | |
32851 | @end itemize | |
32852 | ||
32853 | If the JIT frees or recompiles code without unregistering it, then @value{GDBN} | |
32854 | and the JIT will leak the memory used for the associated symbol files. | |
32855 | ||
f85b53f8 SD |
32856 | @node Custom Debug Info |
32857 | @section Custom Debug Info | |
32858 | @cindex custom JIT debug info | |
32859 | @cindex JIT debug info reader | |
32860 | ||
32861 | Generating debug information in platform-native file formats (like ELF | |
32862 | or COFF) may be an overkill for JIT compilers; especially if all the | |
32863 | debug info is used for is displaying a meaningful backtrace. The | |
32864 | issue can be resolved by having the JIT writers decide on a debug info | |
32865 | format and also provide a reader that parses the debug info generated | |
32866 | by the JIT compiler. This section gives a brief overview on writing | |
32867 | such a parser. More specific details can be found in the source file | |
32868 | @file{gdb/jit-reader.in}, which is also installed as a header at | |
32869 | @file{@var{includedir}/gdb/jit-reader.h} for easy inclusion. | |
32870 | ||
32871 | The reader is implemented as a shared object (so this functionality is | |
32872 | not available on platforms which don't allow loading shared objects at | |
32873 | runtime). Two @value{GDBN} commands, @code{jit-reader-load} and | |
32874 | @code{jit-reader-unload} are provided, to be used to load and unload | |
32875 | the readers from a preconfigured directory. Once loaded, the shared | |
32876 | object is used the parse the debug information emitted by the JIT | |
32877 | compiler. | |
32878 | ||
32879 | @menu | |
32880 | * Using JIT Debug Info Readers:: How to use supplied readers correctly | |
32881 | * Writing JIT Debug Info Readers:: Creating a debug-info reader | |
32882 | @end menu | |
32883 | ||
32884 | @node Using JIT Debug Info Readers | |
32885 | @subsection Using JIT Debug Info Readers | |
32886 | @kindex jit-reader-load | |
32887 | @kindex jit-reader-unload | |
32888 | ||
32889 | Readers can be loaded and unloaded using the @code{jit-reader-load} | |
32890 | and @code{jit-reader-unload} commands. | |
32891 | ||
32892 | @table @code | |
c9fb1240 | 32893 | @item jit-reader-load @var{reader} |
697aa1b7 | 32894 | Load the JIT reader named @var{reader}, which is a shared |
c9fb1240 SD |
32895 | object specified as either an absolute or a relative file name. In |
32896 | the latter case, @value{GDBN} will try to load the reader from a | |
32897 | pre-configured directory, usually @file{@var{libdir}/gdb/} on a UNIX | |
32898 | system (here @var{libdir} is the system library directory, often | |
32899 | @file{/usr/local/lib}). | |
32900 | ||
32901 | Only one reader can be active at a time; trying to load a second | |
32902 | reader when one is already loaded will result in @value{GDBN} | |
32903 | reporting an error. A new JIT reader can be loaded by first unloading | |
32904 | the current one using @code{jit-reader-unload} and then invoking | |
32905 | @code{jit-reader-load}. | |
f85b53f8 SD |
32906 | |
32907 | @item jit-reader-unload | |
32908 | Unload the currently loaded JIT reader. | |
32909 | ||
32910 | @end table | |
32911 | ||
32912 | @node Writing JIT Debug Info Readers | |
32913 | @subsection Writing JIT Debug Info Readers | |
32914 | @cindex writing JIT debug info readers | |
32915 | ||
32916 | As mentioned, a reader is essentially a shared object conforming to a | |
32917 | certain ABI. This ABI is described in @file{jit-reader.h}. | |
32918 | ||
32919 | @file{jit-reader.h} defines the structures, macros and functions | |
32920 | required to write a reader. It is installed (along with | |
32921 | @value{GDBN}), in @file{@var{includedir}/gdb} where @var{includedir} is | |
32922 | the system include directory. | |
32923 | ||
32924 | Readers need to be released under a GPL compatible license. A reader | |
32925 | can be declared as released under such a license by placing the macro | |
32926 | @code{GDB_DECLARE_GPL_COMPATIBLE_READER} in a source file. | |
32927 | ||
32928 | The entry point for readers is the symbol @code{gdb_init_reader}, | |
32929 | which is expected to be a function with the prototype | |
32930 | ||
32931 | @findex gdb_init_reader | |
32932 | @smallexample | |
32933 | extern struct gdb_reader_funcs *gdb_init_reader (void); | |
32934 | @end smallexample | |
32935 | ||
32936 | @cindex @code{struct gdb_reader_funcs} | |
32937 | ||
32938 | @code{struct gdb_reader_funcs} contains a set of pointers to callback | |
32939 | functions. These functions are executed to read the debug info | |
32940 | generated by the JIT compiler (@code{read}), to unwind stack frames | |
32941 | (@code{unwind}) and to create canonical frame IDs | |
32942 | (@code{get_Frame_id}). It also has a callback that is called when the | |
32943 | reader is being unloaded (@code{destroy}). The struct looks like this | |
32944 | ||
32945 | @smallexample | |
32946 | struct gdb_reader_funcs | |
32947 | @{ | |
32948 | /* Must be set to GDB_READER_INTERFACE_VERSION. */ | |
32949 | int reader_version; | |
32950 | ||
32951 | /* For use by the reader. */ | |
32952 | void *priv_data; | |
32953 | ||
32954 | gdb_read_debug_info *read; | |
32955 | gdb_unwind_frame *unwind; | |
32956 | gdb_get_frame_id *get_frame_id; | |
32957 | gdb_destroy_reader *destroy; | |
32958 | @}; | |
32959 | @end smallexample | |
32960 | ||
32961 | @cindex @code{struct gdb_symbol_callbacks} | |
32962 | @cindex @code{struct gdb_unwind_callbacks} | |
32963 | ||
32964 | The callbacks are provided with another set of callbacks by | |
32965 | @value{GDBN} to do their job. For @code{read}, these callbacks are | |
32966 | passed in a @code{struct gdb_symbol_callbacks} and for @code{unwind} | |
32967 | and @code{get_frame_id}, in a @code{struct gdb_unwind_callbacks}. | |
32968 | @code{struct gdb_symbol_callbacks} has callbacks to create new object | |
32969 | files and new symbol tables inside those object files. @code{struct | |
32970 | gdb_unwind_callbacks} has callbacks to read registers off the current | |
32971 | frame and to write out the values of the registers in the previous | |
32972 | frame. Both have a callback (@code{target_read}) to read bytes off the | |
32973 | target's address space. | |
32974 | ||
d1feda86 YQ |
32975 | @node In-Process Agent |
32976 | @chapter In-Process Agent | |
32977 | @cindex debugging agent | |
32978 | The traditional debugging model is conceptually low-speed, but works fine, | |
32979 | because most bugs can be reproduced in debugging-mode execution. However, | |
32980 | as multi-core or many-core processors are becoming mainstream, and | |
32981 | multi-threaded programs become more and more popular, there should be more | |
32982 | and more bugs that only manifest themselves at normal-mode execution, for | |
32983 | example, thread races, because debugger's interference with the program's | |
32984 | timing may conceal the bugs. On the other hand, in some applications, | |
32985 | it is not feasible for the debugger to interrupt the program's execution | |
32986 | long enough for the developer to learn anything helpful about its behavior. | |
32987 | If the program's correctness depends on its real-time behavior, delays | |
32988 | introduced by a debugger might cause the program to fail, even when the | |
32989 | code itself is correct. It is useful to be able to observe the program's | |
32990 | behavior without interrupting it. | |
32991 | ||
32992 | Therefore, traditional debugging model is too intrusive to reproduce | |
32993 | some bugs. In order to reduce the interference with the program, we can | |
32994 | reduce the number of operations performed by debugger. The | |
32995 | @dfn{In-Process Agent}, a shared library, is running within the same | |
32996 | process with inferior, and is able to perform some debugging operations | |
32997 | itself. As a result, debugger is only involved when necessary, and | |
32998 | performance of debugging can be improved accordingly. Note that | |
32999 | interference with program can be reduced but can't be removed completely, | |
33000 | because the in-process agent will still stop or slow down the program. | |
33001 | ||
33002 | The in-process agent can interpret and execute Agent Expressions | |
33003 | (@pxref{Agent Expressions}) during performing debugging operations. The | |
33004 | agent expressions can be used for different purposes, such as collecting | |
33005 | data in tracepoints, and condition evaluation in breakpoints. | |
33006 | ||
33007 | @anchor{Control Agent} | |
33008 | You can control whether the in-process agent is used as an aid for | |
33009 | debugging with the following commands: | |
33010 | ||
33011 | @table @code | |
33012 | @kindex set agent on | |
33013 | @item set agent on | |
33014 | Causes the in-process agent to perform some operations on behalf of the | |
33015 | debugger. Just which operations requested by the user will be done | |
33016 | by the in-process agent depends on the its capabilities. For example, | |
33017 | if you request to evaluate breakpoint conditions in the in-process agent, | |
33018 | and the in-process agent has such capability as well, then breakpoint | |
33019 | conditions will be evaluated in the in-process agent. | |
33020 | ||
33021 | @kindex set agent off | |
33022 | @item set agent off | |
33023 | Disables execution of debugging operations by the in-process agent. All | |
33024 | of the operations will be performed by @value{GDBN}. | |
33025 | ||
33026 | @kindex show agent | |
33027 | @item show agent | |
33028 | Display the current setting of execution of debugging operations by | |
33029 | the in-process agent. | |
33030 | @end table | |
33031 | ||
16bdd41f YQ |
33032 | @menu |
33033 | * In-Process Agent Protocol:: | |
33034 | @end menu | |
33035 | ||
33036 | @node In-Process Agent Protocol | |
33037 | @section In-Process Agent Protocol | |
33038 | @cindex in-process agent protocol | |
33039 | ||
33040 | The in-process agent is able to communicate with both @value{GDBN} and | |
33041 | GDBserver (@pxref{In-Process Agent}). This section documents the protocol | |
33042 | used for communications between @value{GDBN} or GDBserver and the IPA. | |
33043 | In general, @value{GDBN} or GDBserver sends commands | |
33044 | (@pxref{IPA Protocol Commands}) and data to in-process agent, and then | |
33045 | in-process agent replies back with the return result of the command, or | |
33046 | some other information. The data sent to in-process agent is composed | |
33047 | of primitive data types, such as 4-byte or 8-byte type, and composite | |
33048 | types, which are called objects (@pxref{IPA Protocol Objects}). | |
33049 | ||
33050 | @menu | |
33051 | * IPA Protocol Objects:: | |
33052 | * IPA Protocol Commands:: | |
33053 | @end menu | |
33054 | ||
33055 | @node IPA Protocol Objects | |
33056 | @subsection IPA Protocol Objects | |
33057 | @cindex ipa protocol objects | |
33058 | ||
33059 | The commands sent to and results received from agent may contain some | |
33060 | complex data types called @dfn{objects}. | |
33061 | ||
33062 | The in-process agent is running on the same machine with @value{GDBN} | |
33063 | or GDBserver, so it doesn't have to handle as much differences between | |
33064 | two ends as remote protocol (@pxref{Remote Protocol}) tries to handle. | |
33065 | However, there are still some differences of two ends in two processes: | |
33066 | ||
33067 | @enumerate | |
33068 | @item | |
33069 | word size. On some 64-bit machines, @value{GDBN} or GDBserver can be | |
33070 | compiled as a 64-bit executable, while in-process agent is a 32-bit one. | |
33071 | @item | |
33072 | ABI. Some machines may have multiple types of ABI, @value{GDBN} or | |
33073 | GDBserver is compiled with one, and in-process agent is compiled with | |
33074 | the other one. | |
33075 | @end enumerate | |
33076 | ||
33077 | Here are the IPA Protocol Objects: | |
33078 | ||
33079 | @enumerate | |
33080 | @item | |
33081 | agent expression object. It represents an agent expression | |
33082 | (@pxref{Agent Expressions}). | |
33083 | @anchor{agent expression object} | |
33084 | @item | |
33085 | tracepoint action object. It represents a tracepoint action | |
33086 | (@pxref{Tracepoint Actions,,Tracepoint Action Lists}) to collect registers, | |
33087 | memory, static trace data and to evaluate expression. | |
33088 | @anchor{tracepoint action object} | |
33089 | @item | |
33090 | tracepoint object. It represents a tracepoint (@pxref{Tracepoints}). | |
33091 | @anchor{tracepoint object} | |
33092 | ||
33093 | @end enumerate | |
33094 | ||
33095 | The following table describes important attributes of each IPA protocol | |
33096 | object: | |
33097 | ||
33098 | @multitable @columnfractions .30 .20 .50 | |
33099 | @headitem Name @tab Size @tab Description | |
33100 | @item @emph{agent expression object} @tab @tab | |
33101 | @item length @tab 4 @tab length of bytes code | |
33102 | @item byte code @tab @var{length} @tab contents of byte code | |
33103 | @item @emph{tracepoint action for collecting memory} @tab @tab | |
33104 | @item 'M' @tab 1 @tab type of tracepoint action | |
33105 | @item addr @tab 8 @tab if @var{basereg} is @samp{-1}, @var{addr} is the | |
33106 | address of the lowest byte to collect, otherwise @var{addr} is the offset | |
33107 | of @var{basereg} for memory collecting. | |
33108 | @item len @tab 8 @tab length of memory for collecting | |
33109 | @item basereg @tab 4 @tab the register number containing the starting | |
33110 | memory address for collecting. | |
33111 | @item @emph{tracepoint action for collecting registers} @tab @tab | |
33112 | @item 'R' @tab 1 @tab type of tracepoint action | |
33113 | @item @emph{tracepoint action for collecting static trace data} @tab @tab | |
33114 | @item 'L' @tab 1 @tab type of tracepoint action | |
33115 | @item @emph{tracepoint action for expression evaluation} @tab @tab | |
33116 | @item 'X' @tab 1 @tab type of tracepoint action | |
33117 | @item agent expression @tab length of @tab @ref{agent expression object} | |
33118 | @item @emph{tracepoint object} @tab @tab | |
33119 | @item number @tab 4 @tab number of tracepoint | |
33120 | @item address @tab 8 @tab address of tracepoint inserted on | |
33121 | @item type @tab 4 @tab type of tracepoint | |
33122 | @item enabled @tab 1 @tab enable or disable of tracepoint | |
33123 | @item step_count @tab 8 @tab step | |
33124 | @item pass_count @tab 8 @tab pass | |
33125 | @item numactions @tab 4 @tab number of tracepoint actions | |
33126 | @item hit count @tab 8 @tab hit count | |
33127 | @item trace frame usage @tab 8 @tab trace frame usage | |
33128 | @item compiled_cond @tab 8 @tab compiled condition | |
33129 | @item orig_size @tab 8 @tab orig size | |
33130 | @item condition @tab 4 if condition is NULL otherwise length of | |
33131 | @ref{agent expression object} | |
33132 | @tab zero if condition is NULL, otherwise is | |
33133 | @ref{agent expression object} | |
33134 | @item actions @tab variable | |
33135 | @tab numactions number of @ref{tracepoint action object} | |
33136 | @end multitable | |
33137 | ||
33138 | @node IPA Protocol Commands | |
33139 | @subsection IPA Protocol Commands | |
33140 | @cindex ipa protocol commands | |
33141 | ||
33142 | The spaces in each command are delimiters to ease reading this commands | |
33143 | specification. They don't exist in real commands. | |
33144 | ||
33145 | @table @samp | |
33146 | ||
33147 | @item FastTrace:@var{tracepoint_object} @var{gdb_jump_pad_head} | |
33148 | Installs a new fast tracepoint described by @var{tracepoint_object} | |
697aa1b7 | 33149 | (@pxref{tracepoint object}). The @var{gdb_jump_pad_head}, 8-byte long, is the |
16bdd41f YQ |
33150 | head of @dfn{jumppad}, which is used to jump to data collection routine |
33151 | in IPA finally. | |
33152 | ||
33153 | Replies: | |
33154 | @table @samp | |
33155 | @item OK @var{target_address} @var{gdb_jump_pad_head} @var{fjump_size} @var{fjump} | |
33156 | @var{target_address} is address of tracepoint in the inferior. | |
697aa1b7 | 33157 | The @var{gdb_jump_pad_head} is updated head of jumppad. Both of |
16bdd41f | 33158 | @var{target_address} and @var{gdb_jump_pad_head} are 8-byte long. |
697aa1b7 EZ |
33159 | The @var{fjump} contains a sequence of instructions jump to jumppad entry. |
33160 | The @var{fjump_size}, 4-byte long, is the size of @var{fjump}. | |
16bdd41f YQ |
33161 | @item E @var{NN} |
33162 | for an error | |
33163 | ||
33164 | @end table | |
33165 | ||
7255706c YQ |
33166 | @item close |
33167 | Closes the in-process agent. This command is sent when @value{GDBN} or GDBserver | |
33168 | is about to kill inferiors. | |
33169 | ||
16bdd41f YQ |
33170 | @item qTfSTM |
33171 | @xref{qTfSTM}. | |
33172 | @item qTsSTM | |
33173 | @xref{qTsSTM}. | |
33174 | @item qTSTMat | |
33175 | @xref{qTSTMat}. | |
33176 | @item probe_marker_at:@var{address} | |
33177 | Asks in-process agent to probe the marker at @var{address}. | |
33178 | ||
33179 | Replies: | |
33180 | @table @samp | |
33181 | @item E @var{NN} | |
33182 | for an error | |
33183 | @end table | |
33184 | @item unprobe_marker_at:@var{address} | |
33185 | Asks in-process agent to unprobe the marker at @var{address}. | |
33186 | @end table | |
33187 | ||
8e04817f AC |
33188 | @node GDB Bugs |
33189 | @chapter Reporting Bugs in @value{GDBN} | |
33190 | @cindex bugs in @value{GDBN} | |
33191 | @cindex reporting bugs in @value{GDBN} | |
c906108c | 33192 | |
8e04817f | 33193 | Your bug reports play an essential role in making @value{GDBN} reliable. |
c906108c | 33194 | |
8e04817f AC |
33195 | Reporting a bug may help you by bringing a solution to your problem, or it |
33196 | may not. But in any case the principal function of a bug report is to help | |
33197 | the entire community by making the next version of @value{GDBN} work better. Bug | |
33198 | reports are your contribution to the maintenance of @value{GDBN}. | |
c906108c | 33199 | |
8e04817f AC |
33200 | In order for a bug report to serve its purpose, you must include the |
33201 | information that enables us to fix the bug. | |
c4555f82 SC |
33202 | |
33203 | @menu | |
8e04817f AC |
33204 | * Bug Criteria:: Have you found a bug? |
33205 | * Bug Reporting:: How to report bugs | |
c4555f82 SC |
33206 | @end menu |
33207 | ||
8e04817f | 33208 | @node Bug Criteria |
79a6e687 | 33209 | @section Have You Found a Bug? |
8e04817f | 33210 | @cindex bug criteria |
c4555f82 | 33211 | |
8e04817f | 33212 | If you are not sure whether you have found a bug, here are some guidelines: |
c4555f82 SC |
33213 | |
33214 | @itemize @bullet | |
8e04817f AC |
33215 | @cindex fatal signal |
33216 | @cindex debugger crash | |
33217 | @cindex crash of debugger | |
c4555f82 | 33218 | @item |
8e04817f AC |
33219 | If the debugger gets a fatal signal, for any input whatever, that is a |
33220 | @value{GDBN} bug. Reliable debuggers never crash. | |
33221 | ||
33222 | @cindex error on valid input | |
33223 | @item | |
33224 | If @value{GDBN} produces an error message for valid input, that is a | |
33225 | bug. (Note that if you're cross debugging, the problem may also be | |
33226 | somewhere in the connection to the target.) | |
c4555f82 | 33227 | |
8e04817f | 33228 | @cindex invalid input |
c4555f82 | 33229 | @item |
8e04817f AC |
33230 | If @value{GDBN} does not produce an error message for invalid input, |
33231 | that is a bug. However, you should note that your idea of | |
33232 | ``invalid input'' might be our idea of ``an extension'' or ``support | |
33233 | for traditional practice''. | |
33234 | ||
33235 | @item | |
33236 | If you are an experienced user of debugging tools, your suggestions | |
33237 | for improvement of @value{GDBN} are welcome in any case. | |
c4555f82 SC |
33238 | @end itemize |
33239 | ||
8e04817f | 33240 | @node Bug Reporting |
79a6e687 | 33241 | @section How to Report Bugs |
8e04817f AC |
33242 | @cindex bug reports |
33243 | @cindex @value{GDBN} bugs, reporting | |
33244 | ||
33245 | A number of companies and individuals offer support for @sc{gnu} products. | |
33246 | If you obtained @value{GDBN} from a support organization, we recommend you | |
33247 | contact that organization first. | |
33248 | ||
33249 | You can find contact information for many support companies and | |
33250 | individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs | |
33251 | distribution. | |
33252 | @c should add a web page ref... | |
33253 | ||
c16158bc JM |
33254 | @ifset BUGURL |
33255 | @ifset BUGURL_DEFAULT | |
129188f6 | 33256 | In any event, we also recommend that you submit bug reports for |
d3e8051b | 33257 | @value{GDBN}. The preferred method is to submit them directly using |
129188f6 AC |
33258 | @uref{http://www.gnu.org/software/gdb/bugs/, @value{GDBN}'s Bugs web |
33259 | page}. Alternatively, the @email{bug-gdb@@gnu.org, e-mail gateway} can | |
33260 | be used. | |
8e04817f AC |
33261 | |
33262 | @strong{Do not send bug reports to @samp{info-gdb}, or to | |
33263 | @samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do | |
33264 | not want to receive bug reports. Those that do have arranged to receive | |
33265 | @samp{bug-gdb}. | |
33266 | ||
33267 | The mailing list @samp{bug-gdb} has a newsgroup @samp{gnu.gdb.bug} which | |
33268 | serves as a repeater. The mailing list and the newsgroup carry exactly | |
33269 | the same messages. Often people think of posting bug reports to the | |
33270 | newsgroup instead of mailing them. This appears to work, but it has one | |
33271 | problem which can be crucial: a newsgroup posting often lacks a mail | |
33272 | path back to the sender. Thus, if we need to ask for more information, | |
33273 | we may be unable to reach you. For this reason, it is better to send | |
33274 | bug reports to the mailing list. | |
c16158bc JM |
33275 | @end ifset |
33276 | @ifclear BUGURL_DEFAULT | |
33277 | In any event, we also recommend that you submit bug reports for | |
33278 | @value{GDBN} to @value{BUGURL}. | |
33279 | @end ifclear | |
33280 | @end ifset | |
c4555f82 | 33281 | |
8e04817f AC |
33282 | The fundamental principle of reporting bugs usefully is this: |
33283 | @strong{report all the facts}. If you are not sure whether to state a | |
33284 | fact or leave it out, state it! | |
c4555f82 | 33285 | |
8e04817f AC |
33286 | Often people omit facts because they think they know what causes the |
33287 | problem and assume that some details do not matter. Thus, you might | |
33288 | assume that the name of the variable you use in an example does not matter. | |
33289 | Well, probably it does not, but one cannot be sure. Perhaps the bug is a | |
33290 | stray memory reference which happens to fetch from the location where that | |
33291 | name is stored in memory; perhaps, if the name were different, the contents | |
33292 | of that location would fool the debugger into doing the right thing despite | |
33293 | the bug. Play it safe and give a specific, complete example. That is the | |
33294 | easiest thing for you to do, and the most helpful. | |
c4555f82 | 33295 | |
8e04817f AC |
33296 | Keep in mind that the purpose of a bug report is to enable us to fix the |
33297 | bug. It may be that the bug has been reported previously, but neither | |
33298 | you nor we can know that unless your bug report is complete and | |
33299 | self-contained. | |
c4555f82 | 33300 | |
8e04817f AC |
33301 | Sometimes people give a few sketchy facts and ask, ``Does this ring a |
33302 | bell?'' Those bug reports are useless, and we urge everyone to | |
33303 | @emph{refuse to respond to them} except to chide the sender to report | |
33304 | bugs properly. | |
33305 | ||
33306 | To enable us to fix the bug, you should include all these things: | |
c4555f82 SC |
33307 | |
33308 | @itemize @bullet | |
33309 | @item | |
8e04817f AC |
33310 | The version of @value{GDBN}. @value{GDBN} announces it if you start |
33311 | with no arguments; you can also print it at any time using @code{show | |
33312 | version}. | |
c4555f82 | 33313 | |
8e04817f AC |
33314 | Without this, we will not know whether there is any point in looking for |
33315 | the bug in the current version of @value{GDBN}. | |
c4555f82 SC |
33316 | |
33317 | @item | |
8e04817f AC |
33318 | The type of machine you are using, and the operating system name and |
33319 | version number. | |
c4555f82 | 33320 | |
6eaaf48b EZ |
33321 | @item |
33322 | The details of the @value{GDBN} build-time configuration. | |
33323 | @value{GDBN} shows these details if you invoke it with the | |
33324 | @option{--configuration} command-line option, or if you type | |
33325 | @code{show configuration} at @value{GDBN}'s prompt. | |
33326 | ||
c4555f82 | 33327 | @item |
c1468174 | 33328 | What compiler (and its version) was used to compile @value{GDBN}---e.g.@: |
8e04817f | 33329 | ``@value{GCC}--2.8.1''. |
c4555f82 SC |
33330 | |
33331 | @item | |
8e04817f | 33332 | What compiler (and its version) was used to compile the program you are |
c1468174 | 33333 | debugging---e.g.@: ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP |
3f94c067 BW |
33334 | C Compiler''. For @value{NGCC}, you can say @kbd{@value{GCC} --version} |
33335 | to get this information; for other compilers, see the documentation for | |
33336 | those compilers. | |
c4555f82 | 33337 | |
8e04817f AC |
33338 | @item |
33339 | The command arguments you gave the compiler to compile your example and | |
33340 | observe the bug. For example, did you use @samp{-O}? To guarantee | |
33341 | you will not omit something important, list them all. A copy of the | |
33342 | Makefile (or the output from make) is sufficient. | |
c4555f82 | 33343 | |
8e04817f AC |
33344 | If we were to try to guess the arguments, we would probably guess wrong |
33345 | and then we might not encounter the bug. | |
c4555f82 | 33346 | |
8e04817f AC |
33347 | @item |
33348 | A complete input script, and all necessary source files, that will | |
33349 | reproduce the bug. | |
c4555f82 | 33350 | |
8e04817f AC |
33351 | @item |
33352 | A description of what behavior you observe that you believe is | |
33353 | incorrect. For example, ``It gets a fatal signal.'' | |
c4555f82 | 33354 | |
8e04817f AC |
33355 | Of course, if the bug is that @value{GDBN} gets a fatal signal, then we |
33356 | will certainly notice it. But if the bug is incorrect output, we might | |
33357 | not notice unless it is glaringly wrong. You might as well not give us | |
33358 | a chance to make a mistake. | |
c4555f82 | 33359 | |
8e04817f AC |
33360 | Even if the problem you experience is a fatal signal, you should still |
33361 | say so explicitly. Suppose something strange is going on, such as, your | |
33362 | copy of @value{GDBN} is out of synch, or you have encountered a bug in | |
33363 | the C library on your system. (This has happened!) Your copy might | |
33364 | crash and ours would not. If you told us to expect a crash, then when | |
33365 | ours fails to crash, we would know that the bug was not happening for | |
33366 | us. If you had not told us to expect a crash, then we would not be able | |
33367 | to draw any conclusion from our observations. | |
c4555f82 | 33368 | |
e0c07bf0 MC |
33369 | @pindex script |
33370 | @cindex recording a session script | |
33371 | To collect all this information, you can use a session recording program | |
33372 | such as @command{script}, which is available on many Unix systems. | |
33373 | Just run your @value{GDBN} session inside @command{script} and then | |
33374 | include the @file{typescript} file with your bug report. | |
33375 | ||
33376 | Another way to record a @value{GDBN} session is to run @value{GDBN} | |
33377 | inside Emacs and then save the entire buffer to a file. | |
33378 | ||
8e04817f AC |
33379 | @item |
33380 | If you wish to suggest changes to the @value{GDBN} source, send us context | |
33381 | diffs. If you even discuss something in the @value{GDBN} source, refer to | |
33382 | it by context, not by line number. | |
c4555f82 | 33383 | |
8e04817f AC |
33384 | The line numbers in our development sources will not match those in your |
33385 | sources. Your line numbers would convey no useful information to us. | |
c4555f82 | 33386 | |
8e04817f | 33387 | @end itemize |
c4555f82 | 33388 | |
8e04817f | 33389 | Here are some things that are not necessary: |
c4555f82 | 33390 | |
8e04817f AC |
33391 | @itemize @bullet |
33392 | @item | |
33393 | A description of the envelope of the bug. | |
c4555f82 | 33394 | |
8e04817f AC |
33395 | Often people who encounter a bug spend a lot of time investigating |
33396 | which changes to the input file will make the bug go away and which | |
33397 | changes will not affect it. | |
c4555f82 | 33398 | |
8e04817f AC |
33399 | This is often time consuming and not very useful, because the way we |
33400 | will find the bug is by running a single example under the debugger | |
33401 | with breakpoints, not by pure deduction from a series of examples. | |
33402 | We recommend that you save your time for something else. | |
c4555f82 | 33403 | |
8e04817f AC |
33404 | Of course, if you can find a simpler example to report @emph{instead} |
33405 | of the original one, that is a convenience for us. Errors in the | |
33406 | output will be easier to spot, running under the debugger will take | |
33407 | less time, and so on. | |
c4555f82 | 33408 | |
8e04817f AC |
33409 | However, simplification is not vital; if you do not want to do this, |
33410 | report the bug anyway and send us the entire test case you used. | |
c4555f82 | 33411 | |
8e04817f AC |
33412 | @item |
33413 | A patch for the bug. | |
c4555f82 | 33414 | |
8e04817f AC |
33415 | A patch for the bug does help us if it is a good one. But do not omit |
33416 | the necessary information, such as the test case, on the assumption that | |
33417 | a patch is all we need. We might see problems with your patch and decide | |
33418 | to fix the problem another way, or we might not understand it at all. | |
c4555f82 | 33419 | |
8e04817f AC |
33420 | Sometimes with a program as complicated as @value{GDBN} it is very hard to |
33421 | construct an example that will make the program follow a certain path | |
33422 | through the code. If you do not send us the example, we will not be able | |
33423 | to construct one, so we will not be able to verify that the bug is fixed. | |
c4555f82 | 33424 | |
8e04817f AC |
33425 | And if we cannot understand what bug you are trying to fix, or why your |
33426 | patch should be an improvement, we will not install it. A test case will | |
33427 | help us to understand. | |
c4555f82 | 33428 | |
8e04817f AC |
33429 | @item |
33430 | A guess about what the bug is or what it depends on. | |
c4555f82 | 33431 | |
8e04817f AC |
33432 | Such guesses are usually wrong. Even we cannot guess right about such |
33433 | things without first using the debugger to find the facts. | |
33434 | @end itemize | |
c4555f82 | 33435 | |
8e04817f AC |
33436 | @c The readline documentation is distributed with the readline code |
33437 | @c and consists of the two following files: | |
cc88a640 JK |
33438 | @c rluser.texi |
33439 | @c hsuser.texi | |
8e04817f AC |
33440 | @c Use -I with makeinfo to point to the appropriate directory, |
33441 | @c environment var TEXINPUTS with TeX. | |
39037522 | 33442 | @ifclear SYSTEM_READLINE |
5bdf8622 | 33443 | @include rluser.texi |
cc88a640 | 33444 | @include hsuser.texi |
39037522 | 33445 | @end ifclear |
c4555f82 | 33446 | |
4ceed123 JB |
33447 | @node In Memoriam |
33448 | @appendix In Memoriam | |
33449 | ||
9ed350ad JB |
33450 | The @value{GDBN} project mourns the loss of the following long-time |
33451 | contributors: | |
4ceed123 JB |
33452 | |
33453 | @table @code | |
33454 | @item Fred Fish | |
9ed350ad JB |
33455 | Fred was a long-standing contributor to @value{GDBN} (1991-2006), and |
33456 | to Free Software in general. Outside of @value{GDBN}, he was known in | |
33457 | the Amiga world for his series of Fish Disks, and the GeekGadget project. | |
4ceed123 JB |
33458 | |
33459 | @item Michael Snyder | |
9ed350ad JB |
33460 | Michael was one of the Global Maintainers of the @value{GDBN} project, |
33461 | with contributions recorded as early as 1996, until 2011. In addition | |
33462 | to his day to day participation, he was a large driving force behind | |
33463 | adding Reverse Debugging to @value{GDBN}. | |
4ceed123 JB |
33464 | @end table |
33465 | ||
33466 | Beyond their technical contributions to the project, they were also | |
33467 | enjoyable members of the Free Software Community. We will miss them. | |
c4555f82 | 33468 | |
8e04817f AC |
33469 | @node Formatting Documentation |
33470 | @appendix Formatting Documentation | |
c4555f82 | 33471 | |
8e04817f AC |
33472 | @cindex @value{GDBN} reference card |
33473 | @cindex reference card | |
33474 | The @value{GDBN} 4 release includes an already-formatted reference card, ready | |
33475 | for printing with PostScript or Ghostscript, in the @file{gdb} | |
33476 | subdirectory of the main source directory@footnote{In | |
33477 | @file{gdb-@value{GDBVN}/gdb/refcard.ps} of the version @value{GDBVN} | |
33478 | release.}. If you can use PostScript or Ghostscript with your printer, | |
33479 | you can print the reference card immediately with @file{refcard.ps}. | |
c4555f82 | 33480 | |
8e04817f AC |
33481 | The release also includes the source for the reference card. You |
33482 | can format it, using @TeX{}, by typing: | |
c4555f82 | 33483 | |
474c8240 | 33484 | @smallexample |
8e04817f | 33485 | make refcard.dvi |
474c8240 | 33486 | @end smallexample |
c4555f82 | 33487 | |
8e04817f AC |
33488 | The @value{GDBN} reference card is designed to print in @dfn{landscape} |
33489 | mode on US ``letter'' size paper; | |
33490 | that is, on a sheet 11 inches wide by 8.5 inches | |
33491 | high. You will need to specify this form of printing as an option to | |
33492 | your @sc{dvi} output program. | |
c4555f82 | 33493 | |
8e04817f | 33494 | @cindex documentation |
c4555f82 | 33495 | |
8e04817f AC |
33496 | All the documentation for @value{GDBN} comes as part of the machine-readable |
33497 | distribution. The documentation is written in Texinfo format, which is | |
33498 | a documentation system that uses a single source file to produce both | |
33499 | on-line information and a printed manual. You can use one of the Info | |
33500 | formatting commands to create the on-line version of the documentation | |
33501 | and @TeX{} (or @code{texi2roff}) to typeset the printed version. | |
c4555f82 | 33502 | |
8e04817f AC |
33503 | @value{GDBN} includes an already formatted copy of the on-line Info |
33504 | version of this manual in the @file{gdb} subdirectory. The main Info | |
33505 | file is @file{gdb-@value{GDBVN}/gdb/gdb.info}, and it refers to | |
33506 | subordinate files matching @samp{gdb.info*} in the same directory. If | |
33507 | necessary, you can print out these files, or read them with any editor; | |
33508 | but they are easier to read using the @code{info} subsystem in @sc{gnu} | |
33509 | Emacs or the standalone @code{info} program, available as part of the | |
33510 | @sc{gnu} Texinfo distribution. | |
c4555f82 | 33511 | |
8e04817f AC |
33512 | If you want to format these Info files yourself, you need one of the |
33513 | Info formatting programs, such as @code{texinfo-format-buffer} or | |
33514 | @code{makeinfo}. | |
c4555f82 | 33515 | |
8e04817f AC |
33516 | If you have @code{makeinfo} installed, and are in the top level |
33517 | @value{GDBN} source directory (@file{gdb-@value{GDBVN}}, in the case of | |
33518 | version @value{GDBVN}), you can make the Info file by typing: | |
c4555f82 | 33519 | |
474c8240 | 33520 | @smallexample |
8e04817f AC |
33521 | cd gdb |
33522 | make gdb.info | |
474c8240 | 33523 | @end smallexample |
c4555f82 | 33524 | |
8e04817f AC |
33525 | If you want to typeset and print copies of this manual, you need @TeX{}, |
33526 | a program to print its @sc{dvi} output files, and @file{texinfo.tex}, the | |
33527 | Texinfo definitions file. | |
c4555f82 | 33528 | |
8e04817f AC |
33529 | @TeX{} is a typesetting program; it does not print files directly, but |
33530 | produces output files called @sc{dvi} files. To print a typeset | |
33531 | document, you need a program to print @sc{dvi} files. If your system | |
33532 | has @TeX{} installed, chances are it has such a program. The precise | |
33533 | command to use depends on your system; @kbd{lpr -d} is common; another | |
33534 | (for PostScript devices) is @kbd{dvips}. The @sc{dvi} print command may | |
33535 | require a file name without any extension or a @samp{.dvi} extension. | |
c4555f82 | 33536 | |
8e04817f AC |
33537 | @TeX{} also requires a macro definitions file called |
33538 | @file{texinfo.tex}. This file tells @TeX{} how to typeset a document | |
33539 | written in Texinfo format. On its own, @TeX{} cannot either read or | |
33540 | typeset a Texinfo file. @file{texinfo.tex} is distributed with GDB | |
33541 | and is located in the @file{gdb-@var{version-number}/texinfo} | |
33542 | directory. | |
c4555f82 | 33543 | |
8e04817f | 33544 | If you have @TeX{} and a @sc{dvi} printer program installed, you can |
d3e8051b | 33545 | typeset and print this manual. First switch to the @file{gdb} |
8e04817f AC |
33546 | subdirectory of the main source directory (for example, to |
33547 | @file{gdb-@value{GDBVN}/gdb}) and type: | |
c4555f82 | 33548 | |
474c8240 | 33549 | @smallexample |
8e04817f | 33550 | make gdb.dvi |
474c8240 | 33551 | @end smallexample |
c4555f82 | 33552 | |
8e04817f | 33553 | Then give @file{gdb.dvi} to your @sc{dvi} printing program. |
c4555f82 | 33554 | |
8e04817f AC |
33555 | @node Installing GDB |
33556 | @appendix Installing @value{GDBN} | |
8e04817f | 33557 | @cindex installation |
c4555f82 | 33558 | |
7fa2210b DJ |
33559 | @menu |
33560 | * Requirements:: Requirements for building @value{GDBN} | |
db2e3e2e | 33561 | * Running Configure:: Invoking the @value{GDBN} @file{configure} script |
7fa2210b DJ |
33562 | * Separate Objdir:: Compiling @value{GDBN} in another directory |
33563 | * Config Names:: Specifying names for hosts and targets | |
33564 | * Configure Options:: Summary of options for configure | |
098b41a6 | 33565 | * System-wide configuration:: Having a system-wide init file |
7fa2210b DJ |
33566 | @end menu |
33567 | ||
33568 | @node Requirements | |
79a6e687 | 33569 | @section Requirements for Building @value{GDBN} |
7fa2210b DJ |
33570 | @cindex building @value{GDBN}, requirements for |
33571 | ||
33572 | Building @value{GDBN} requires various tools and packages to be available. | |
33573 | Other packages will be used only if they are found. | |
33574 | ||
79a6e687 | 33575 | @heading Tools/Packages Necessary for Building @value{GDBN} |
7fa2210b DJ |
33576 | @table @asis |
33577 | @item ISO C90 compiler | |
33578 | @value{GDBN} is written in ISO C90. It should be buildable with any | |
33579 | working C90 compiler, e.g.@: GCC. | |
33580 | ||
33581 | @end table | |
33582 | ||
79a6e687 | 33583 | @heading Tools/Packages Optional for Building @value{GDBN} |
7fa2210b DJ |
33584 | @table @asis |
33585 | @item Expat | |
123dc839 | 33586 | @anchor{Expat} |
7fa2210b DJ |
33587 | @value{GDBN} can use the Expat XML parsing library. This library may be |
33588 | included with your operating system distribution; if it is not, you | |
33589 | can get the latest version from @url{http://expat.sourceforge.net}. | |
db2e3e2e | 33590 | The @file{configure} script will search for this library in several |
7fa2210b DJ |
33591 | standard locations; if it is installed in an unusual path, you can |
33592 | use the @option{--with-libexpat-prefix} option to specify its location. | |
33593 | ||
9cceb671 DJ |
33594 | Expat is used for: |
33595 | ||
33596 | @itemize @bullet | |
33597 | @item | |
33598 | Remote protocol memory maps (@pxref{Memory Map Format}) | |
33599 | @item | |
33600 | Target descriptions (@pxref{Target Descriptions}) | |
33601 | @item | |
2268b414 JK |
33602 | Remote shared library lists (@xref{Library List Format}, |
33603 | or alternatively @pxref{Library List Format for SVR4 Targets}) | |
9cceb671 DJ |
33604 | @item |
33605 | MS-Windows shared libraries (@pxref{Shared Libraries}) | |
b3b9301e PA |
33606 | @item |
33607 | Traceframe info (@pxref{Traceframe Info Format}) | |
2ae8c8e7 | 33608 | @item |
f4abbc16 MM |
33609 | Branch trace (@pxref{Branch Trace Format}, |
33610 | @pxref{Branch Trace Configuration Format}) | |
9cceb671 | 33611 | @end itemize |
7fa2210b | 33612 | |
31fffb02 CS |
33613 | @item zlib |
33614 | @cindex compressed debug sections | |
33615 | @value{GDBN} will use the @samp{zlib} library, if available, to read | |
33616 | compressed debug sections. Some linkers, such as GNU gold, are capable | |
33617 | of producing binaries with compressed debug sections. If @value{GDBN} | |
33618 | is compiled with @samp{zlib}, it will be able to read the debug | |
33619 | information in such binaries. | |
33620 | ||
33621 | The @samp{zlib} library is likely included with your operating system | |
33622 | distribution; if it is not, you can get the latest version from | |
33623 | @url{http://zlib.net}. | |
33624 | ||
6c7a06a3 TT |
33625 | @item iconv |
33626 | @value{GDBN}'s features related to character sets (@pxref{Character | |
33627 | Sets}) require a functioning @code{iconv} implementation. If you are | |
33628 | on a GNU system, then this is provided by the GNU C Library. Some | |
33629 | other systems also provide a working @code{iconv}. | |
33630 | ||
478aac75 DE |
33631 | If @value{GDBN} is using the @code{iconv} program which is installed |
33632 | in a non-standard place, you will need to tell @value{GDBN} where to find it. | |
33633 | This is done with @option{--with-iconv-bin} which specifies the | |
33634 | directory that contains the @code{iconv} program. | |
33635 | ||
33636 | On systems without @code{iconv}, you can install GNU Libiconv. If you | |
6c7a06a3 TT |
33637 | have previously installed Libiconv, you can use the |
33638 | @option{--with-libiconv-prefix} option to configure. | |
33639 | ||
33640 | @value{GDBN}'s top-level @file{configure} and @file{Makefile} will | |
33641 | arrange to build Libiconv if a directory named @file{libiconv} appears | |
33642 | in the top-most source directory. If Libiconv is built this way, and | |
33643 | if the operating system does not provide a suitable @code{iconv} | |
33644 | implementation, then the just-built library will automatically be used | |
33645 | by @value{GDBN}. One easy way to set this up is to download GNU | |
33646 | Libiconv, unpack it, and then rename the directory holding the | |
33647 | Libiconv source code to @samp{libiconv}. | |
7fa2210b DJ |
33648 | @end table |
33649 | ||
33650 | @node Running Configure | |
db2e3e2e | 33651 | @section Invoking the @value{GDBN} @file{configure} Script |
7fa2210b | 33652 | @cindex configuring @value{GDBN} |
db2e3e2e | 33653 | @value{GDBN} comes with a @file{configure} script that automates the process |
8e04817f AC |
33654 | of preparing @value{GDBN} for installation; you can then use @code{make} to |
33655 | build the @code{gdb} program. | |
33656 | @iftex | |
33657 | @c irrelevant in info file; it's as current as the code it lives with. | |
33658 | @footnote{If you have a more recent version of @value{GDBN} than @value{GDBVN}, | |
33659 | look at the @file{README} file in the sources; we may have improved the | |
33660 | installation procedures since publishing this manual.} | |
33661 | @end iftex | |
c4555f82 | 33662 | |
8e04817f AC |
33663 | The @value{GDBN} distribution includes all the source code you need for |
33664 | @value{GDBN} in a single directory, whose name is usually composed by | |
33665 | appending the version number to @samp{gdb}. | |
c4555f82 | 33666 | |
8e04817f AC |
33667 | For example, the @value{GDBN} version @value{GDBVN} distribution is in the |
33668 | @file{gdb-@value{GDBVN}} directory. That directory contains: | |
c4555f82 | 33669 | |
8e04817f AC |
33670 | @table @code |
33671 | @item gdb-@value{GDBVN}/configure @r{(and supporting files)} | |
33672 | script for configuring @value{GDBN} and all its supporting libraries | |
c4555f82 | 33673 | |
8e04817f AC |
33674 | @item gdb-@value{GDBVN}/gdb |
33675 | the source specific to @value{GDBN} itself | |
c4555f82 | 33676 | |
8e04817f AC |
33677 | @item gdb-@value{GDBVN}/bfd |
33678 | source for the Binary File Descriptor library | |
c906108c | 33679 | |
8e04817f AC |
33680 | @item gdb-@value{GDBVN}/include |
33681 | @sc{gnu} include files | |
c906108c | 33682 | |
8e04817f AC |
33683 | @item gdb-@value{GDBVN}/libiberty |
33684 | source for the @samp{-liberty} free software library | |
c906108c | 33685 | |
8e04817f AC |
33686 | @item gdb-@value{GDBVN}/opcodes |
33687 | source for the library of opcode tables and disassemblers | |
c906108c | 33688 | |
8e04817f AC |
33689 | @item gdb-@value{GDBVN}/readline |
33690 | source for the @sc{gnu} command-line interface | |
c906108c | 33691 | |
8e04817f AC |
33692 | @item gdb-@value{GDBVN}/glob |
33693 | source for the @sc{gnu} filename pattern-matching subroutine | |
c906108c | 33694 | |
8e04817f AC |
33695 | @item gdb-@value{GDBVN}/mmalloc |
33696 | source for the @sc{gnu} memory-mapped malloc package | |
33697 | @end table | |
c906108c | 33698 | |
db2e3e2e | 33699 | The simplest way to configure and build @value{GDBN} is to run @file{configure} |
8e04817f AC |
33700 | from the @file{gdb-@var{version-number}} source directory, which in |
33701 | this example is the @file{gdb-@value{GDBVN}} directory. | |
c906108c | 33702 | |
8e04817f | 33703 | First switch to the @file{gdb-@var{version-number}} source directory |
db2e3e2e | 33704 | if you are not already in it; then run @file{configure}. Pass the |
8e04817f AC |
33705 | identifier for the platform on which @value{GDBN} will run as an |
33706 | argument. | |
c906108c | 33707 | |
8e04817f | 33708 | For example: |
c906108c | 33709 | |
474c8240 | 33710 | @smallexample |
8e04817f AC |
33711 | cd gdb-@value{GDBVN} |
33712 | ./configure @var{host} | |
33713 | make | |
474c8240 | 33714 | @end smallexample |
c906108c | 33715 | |
8e04817f AC |
33716 | @noindent |
33717 | where @var{host} is an identifier such as @samp{sun4} or | |
33718 | @samp{decstation}, that identifies the platform where @value{GDBN} will run. | |
db2e3e2e | 33719 | (You can often leave off @var{host}; @file{configure} tries to guess the |
8e04817f | 33720 | correct value by examining your system.) |
c906108c | 33721 | |
8e04817f AC |
33722 | Running @samp{configure @var{host}} and then running @code{make} builds the |
33723 | @file{bfd}, @file{readline}, @file{mmalloc}, and @file{libiberty} | |
33724 | libraries, then @code{gdb} itself. The configured source files, and the | |
33725 | binaries, are left in the corresponding source directories. | |
c906108c | 33726 | |
8e04817f | 33727 | @need 750 |
db2e3e2e | 33728 | @file{configure} is a Bourne-shell (@code{/bin/sh}) script; if your |
8e04817f AC |
33729 | system does not recognize this automatically when you run a different |
33730 | shell, you may need to run @code{sh} on it explicitly: | |
c906108c | 33731 | |
474c8240 | 33732 | @smallexample |
8e04817f | 33733 | sh configure @var{host} |
474c8240 | 33734 | @end smallexample |
c906108c | 33735 | |
db2e3e2e | 33736 | If you run @file{configure} from a directory that contains source |
8e04817f | 33737 | directories for multiple libraries or programs, such as the |
db2e3e2e BW |
33738 | @file{gdb-@value{GDBVN}} source directory for version @value{GDBVN}, |
33739 | @file{configure} | |
8e04817f AC |
33740 | creates configuration files for every directory level underneath (unless |
33741 | you tell it not to, with the @samp{--norecursion} option). | |
33742 | ||
db2e3e2e | 33743 | You should run the @file{configure} script from the top directory in the |
94e91d6d | 33744 | source tree, the @file{gdb-@var{version-number}} directory. If you run |
db2e3e2e | 33745 | @file{configure} from one of the subdirectories, you will configure only |
94e91d6d | 33746 | that subdirectory. That is usually not what you want. In particular, |
db2e3e2e | 33747 | if you run the first @file{configure} from the @file{gdb} subdirectory |
94e91d6d MC |
33748 | of the @file{gdb-@var{version-number}} directory, you will omit the |
33749 | configuration of @file{bfd}, @file{readline}, and other sibling | |
33750 | directories of the @file{gdb} subdirectory. This leads to build errors | |
33751 | about missing include files such as @file{bfd/bfd.h}. | |
c906108c | 33752 | |
8e04817f AC |
33753 | You can install @code{@value{GDBP}} anywhere; it has no hardwired paths. |
33754 | However, you should make sure that the shell on your path (named by | |
33755 | the @samp{SHELL} environment variable) is publicly readable. Remember | |
33756 | that @value{GDBN} uses the shell to start your program---some systems refuse to | |
33757 | let @value{GDBN} debug child processes whose programs are not readable. | |
c906108c | 33758 | |
8e04817f | 33759 | @node Separate Objdir |
79a6e687 | 33760 | @section Compiling @value{GDBN} in Another Directory |
c906108c | 33761 | |
8e04817f AC |
33762 | If you want to run @value{GDBN} versions for several host or target machines, |
33763 | you need a different @code{gdb} compiled for each combination of | |
db2e3e2e | 33764 | host and target. @file{configure} is designed to make this easy by |
8e04817f AC |
33765 | allowing you to generate each configuration in a separate subdirectory, |
33766 | rather than in the source directory. If your @code{make} program | |
33767 | handles the @samp{VPATH} feature (@sc{gnu} @code{make} does), running | |
33768 | @code{make} in each of these directories builds the @code{gdb} | |
33769 | program specified there. | |
c906108c | 33770 | |
db2e3e2e | 33771 | To build @code{gdb} in a separate directory, run @file{configure} |
8e04817f | 33772 | with the @samp{--srcdir} option to specify where to find the source. |
db2e3e2e BW |
33773 | (You also need to specify a path to find @file{configure} |
33774 | itself from your working directory. If the path to @file{configure} | |
8e04817f AC |
33775 | would be the same as the argument to @samp{--srcdir}, you can leave out |
33776 | the @samp{--srcdir} option; it is assumed.) | |
c906108c | 33777 | |
8e04817f AC |
33778 | For example, with version @value{GDBVN}, you can build @value{GDBN} in a |
33779 | separate directory for a Sun 4 like this: | |
c906108c | 33780 | |
474c8240 | 33781 | @smallexample |
8e04817f AC |
33782 | @group |
33783 | cd gdb-@value{GDBVN} | |
33784 | mkdir ../gdb-sun4 | |
33785 | cd ../gdb-sun4 | |
33786 | ../gdb-@value{GDBVN}/configure sun4 | |
33787 | make | |
33788 | @end group | |
474c8240 | 33789 | @end smallexample |
c906108c | 33790 | |
db2e3e2e | 33791 | When @file{configure} builds a configuration using a remote source |
8e04817f AC |
33792 | directory, it creates a tree for the binaries with the same structure |
33793 | (and using the same names) as the tree under the source directory. In | |
33794 | the example, you'd find the Sun 4 library @file{libiberty.a} in the | |
33795 | directory @file{gdb-sun4/libiberty}, and @value{GDBN} itself in | |
33796 | @file{gdb-sun4/gdb}. | |
c906108c | 33797 | |
94e91d6d MC |
33798 | Make sure that your path to the @file{configure} script has just one |
33799 | instance of @file{gdb} in it. If your path to @file{configure} looks | |
33800 | like @file{../gdb-@value{GDBVN}/gdb/configure}, you are configuring only | |
33801 | one subdirectory of @value{GDBN}, not the whole package. This leads to | |
33802 | build errors about missing include files such as @file{bfd/bfd.h}. | |
33803 | ||
8e04817f AC |
33804 | One popular reason to build several @value{GDBN} configurations in separate |
33805 | directories is to configure @value{GDBN} for cross-compiling (where | |
33806 | @value{GDBN} runs on one machine---the @dfn{host}---while debugging | |
33807 | programs that run on another machine---the @dfn{target}). | |
33808 | You specify a cross-debugging target by | |
db2e3e2e | 33809 | giving the @samp{--target=@var{target}} option to @file{configure}. |
c906108c | 33810 | |
8e04817f AC |
33811 | When you run @code{make} to build a program or library, you must run |
33812 | it in a configured directory---whatever directory you were in when you | |
db2e3e2e | 33813 | called @file{configure} (or one of its subdirectories). |
c906108c | 33814 | |
db2e3e2e | 33815 | The @code{Makefile} that @file{configure} generates in each source |
8e04817f AC |
33816 | directory also runs recursively. If you type @code{make} in a source |
33817 | directory such as @file{gdb-@value{GDBVN}} (or in a separate configured | |
33818 | directory configured with @samp{--srcdir=@var{dirname}/gdb-@value{GDBVN}}), you | |
33819 | will build all the required libraries, and then build GDB. | |
c906108c | 33820 | |
8e04817f AC |
33821 | When you have multiple hosts or targets configured in separate |
33822 | directories, you can run @code{make} on them in parallel (for example, | |
33823 | if they are NFS-mounted on each of the hosts); they will not interfere | |
33824 | with each other. | |
c906108c | 33825 | |
8e04817f | 33826 | @node Config Names |
79a6e687 | 33827 | @section Specifying Names for Hosts and Targets |
c906108c | 33828 | |
db2e3e2e | 33829 | The specifications used for hosts and targets in the @file{configure} |
8e04817f AC |
33830 | script are based on a three-part naming scheme, but some short predefined |
33831 | aliases are also supported. The full naming scheme encodes three pieces | |
33832 | of information in the following pattern: | |
c906108c | 33833 | |
474c8240 | 33834 | @smallexample |
8e04817f | 33835 | @var{architecture}-@var{vendor}-@var{os} |
474c8240 | 33836 | @end smallexample |
c906108c | 33837 | |
8e04817f AC |
33838 | For example, you can use the alias @code{sun4} as a @var{host} argument, |
33839 | or as the value for @var{target} in a @code{--target=@var{target}} | |
33840 | option. The equivalent full name is @samp{sparc-sun-sunos4}. | |
c906108c | 33841 | |
db2e3e2e | 33842 | The @file{configure} script accompanying @value{GDBN} does not provide |
8e04817f | 33843 | any query facility to list all supported host and target names or |
db2e3e2e | 33844 | aliases. @file{configure} calls the Bourne shell script |
8e04817f AC |
33845 | @code{config.sub} to map abbreviations to full names; you can read the |
33846 | script, if you wish, or you can use it to test your guesses on | |
33847 | abbreviations---for example: | |
c906108c | 33848 | |
8e04817f AC |
33849 | @smallexample |
33850 | % sh config.sub i386-linux | |
33851 | i386-pc-linux-gnu | |
33852 | % sh config.sub alpha-linux | |
33853 | alpha-unknown-linux-gnu | |
33854 | % sh config.sub hp9k700 | |
33855 | hppa1.1-hp-hpux | |
33856 | % sh config.sub sun4 | |
33857 | sparc-sun-sunos4.1.1 | |
33858 | % sh config.sub sun3 | |
33859 | m68k-sun-sunos4.1.1 | |
33860 | % sh config.sub i986v | |
33861 | Invalid configuration `i986v': machine `i986v' not recognized | |
33862 | @end smallexample | |
c906108c | 33863 | |
8e04817f AC |
33864 | @noindent |
33865 | @code{config.sub} is also distributed in the @value{GDBN} source | |
33866 | directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}). | |
d700128c | 33867 | |
8e04817f | 33868 | @node Configure Options |
db2e3e2e | 33869 | @section @file{configure} Options |
c906108c | 33870 | |
db2e3e2e BW |
33871 | Here is a summary of the @file{configure} options and arguments that |
33872 | are most often useful for building @value{GDBN}. @file{configure} also has | |
8e04817f | 33873 | several other options not listed here. @inforef{What Configure |
db2e3e2e | 33874 | Does,,configure.info}, for a full explanation of @file{configure}. |
c906108c | 33875 | |
474c8240 | 33876 | @smallexample |
8e04817f AC |
33877 | configure @r{[}--help@r{]} |
33878 | @r{[}--prefix=@var{dir}@r{]} | |
33879 | @r{[}--exec-prefix=@var{dir}@r{]} | |
33880 | @r{[}--srcdir=@var{dirname}@r{]} | |
33881 | @r{[}--norecursion@r{]} @r{[}--rm@r{]} | |
33882 | @r{[}--target=@var{target}@r{]} | |
33883 | @var{host} | |
474c8240 | 33884 | @end smallexample |
c906108c | 33885 | |
8e04817f AC |
33886 | @noindent |
33887 | You may introduce options with a single @samp{-} rather than | |
33888 | @samp{--} if you prefer; but you may abbreviate option names if you use | |
33889 | @samp{--}. | |
c906108c | 33890 | |
8e04817f AC |
33891 | @table @code |
33892 | @item --help | |
db2e3e2e | 33893 | Display a quick summary of how to invoke @file{configure}. |
c906108c | 33894 | |
8e04817f AC |
33895 | @item --prefix=@var{dir} |
33896 | Configure the source to install programs and files under directory | |
33897 | @file{@var{dir}}. | |
c906108c | 33898 | |
8e04817f AC |
33899 | @item --exec-prefix=@var{dir} |
33900 | Configure the source to install programs under directory | |
33901 | @file{@var{dir}}. | |
c906108c | 33902 | |
8e04817f AC |
33903 | @c avoid splitting the warning from the explanation: |
33904 | @need 2000 | |
33905 | @item --srcdir=@var{dirname} | |
33906 | @strong{Warning: using this option requires @sc{gnu} @code{make}, or another | |
33907 | @code{make} that implements the @code{VPATH} feature.}@* | |
33908 | Use this option to make configurations in directories separate from the | |
33909 | @value{GDBN} source directories. Among other things, you can use this to | |
33910 | build (or maintain) several configurations simultaneously, in separate | |
db2e3e2e | 33911 | directories. @file{configure} writes configuration-specific files in |
8e04817f | 33912 | the current directory, but arranges for them to use the source in the |
db2e3e2e | 33913 | directory @var{dirname}. @file{configure} creates directories under |
8e04817f AC |
33914 | the working directory in parallel to the source directories below |
33915 | @var{dirname}. | |
c906108c | 33916 | |
8e04817f | 33917 | @item --norecursion |
db2e3e2e | 33918 | Configure only the directory level where @file{configure} is executed; do not |
8e04817f | 33919 | propagate configuration to subdirectories. |
c906108c | 33920 | |
8e04817f AC |
33921 | @item --target=@var{target} |
33922 | Configure @value{GDBN} for cross-debugging programs running on the specified | |
33923 | @var{target}. Without this option, @value{GDBN} is configured to debug | |
33924 | programs that run on the same machine (@var{host}) as @value{GDBN} itself. | |
c906108c | 33925 | |
8e04817f | 33926 | There is no convenient way to generate a list of all available targets. |
c906108c | 33927 | |
8e04817f AC |
33928 | @item @var{host} @dots{} |
33929 | Configure @value{GDBN} to run on the specified @var{host}. | |
c906108c | 33930 | |
8e04817f AC |
33931 | There is no convenient way to generate a list of all available hosts. |
33932 | @end table | |
c906108c | 33933 | |
8e04817f AC |
33934 | There are many other options available as well, but they are generally |
33935 | needed for special purposes only. | |
c906108c | 33936 | |
098b41a6 JG |
33937 | @node System-wide configuration |
33938 | @section System-wide configuration and settings | |
33939 | @cindex system-wide init file | |
33940 | ||
33941 | @value{GDBN} can be configured to have a system-wide init file; | |
33942 | this file will be read and executed at startup (@pxref{Startup, , What | |
33943 | @value{GDBN} does during startup}). | |
33944 | ||
33945 | Here is the corresponding configure option: | |
33946 | ||
33947 | @table @code | |
33948 | @item --with-system-gdbinit=@var{file} | |
33949 | Specify that the default location of the system-wide init file is | |
33950 | @var{file}. | |
33951 | @end table | |
33952 | ||
33953 | If @value{GDBN} has been configured with the option @option{--prefix=$prefix}, | |
33954 | it may be subject to relocation. Two possible cases: | |
33955 | ||
33956 | @itemize @bullet | |
33957 | @item | |
33958 | If the default location of this init file contains @file{$prefix}, | |
33959 | it will be subject to relocation. Suppose that the configure options | |
33960 | are @option{--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit}; | |
33961 | if @value{GDBN} is moved from @file{$prefix} to @file{$install}, the system | |
33962 | init file is looked for as @file{$install/etc/gdbinit} instead of | |
33963 | @file{$prefix/etc/gdbinit}. | |
33964 | ||
33965 | @item | |
33966 | By contrast, if the default location does not contain the prefix, | |
33967 | it will not be relocated. E.g.@: if @value{GDBN} has been configured with | |
33968 | @option{--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit}, | |
33969 | then @value{GDBN} will always look for @file{/usr/share/gdb/gdbinit}, | |
33970 | wherever @value{GDBN} is installed. | |
33971 | @end itemize | |
33972 | ||
e64e0392 DE |
33973 | If the configured location of the system-wide init file (as given by the |
33974 | @option{--with-system-gdbinit} option at configure time) is in the | |
33975 | data-directory (as specified by @option{--with-gdb-datadir} at configure | |
33976 | time) or in one of its subdirectories, then @value{GDBN} will look for the | |
33977 | system-wide init file in the directory specified by the | |
33978 | @option{--data-directory} command-line option. | |
33979 | Note that the system-wide init file is only read once, during @value{GDBN} | |
33980 | initialization. If the data-directory is changed after @value{GDBN} has | |
33981 | started with the @code{set data-directory} command, the file will not be | |
33982 | reread. | |
33983 | ||
5901af59 JB |
33984 | @menu |
33985 | * System-wide Configuration Scripts:: Installed System-wide Configuration Scripts | |
33986 | @end menu | |
33987 | ||
33988 | @node System-wide Configuration Scripts | |
0201faac JB |
33989 | @subsection Installed System-wide Configuration Scripts |
33990 | @cindex system-wide configuration scripts | |
33991 | ||
33992 | The @file{system-gdbinit} directory, located inside the data-directory | |
33993 | (as specified by @option{--with-gdb-datadir} at configure time) contains | |
33994 | a number of scripts which can be used as system-wide init files. To | |
33995 | automatically source those scripts at startup, @value{GDBN} should be | |
33996 | configured with @option{--with-system-gdbinit}. Otherwise, any user | |
33997 | should be able to source them by hand as needed. | |
33998 | ||
33999 | The following scripts are currently available: | |
34000 | @itemize @bullet | |
34001 | ||
34002 | @item @file{elinos.py} | |
34003 | @pindex elinos.py | |
34004 | @cindex ELinOS system-wide configuration script | |
34005 | This script is useful when debugging a program on an ELinOS target. | |
34006 | It takes advantage of the environment variables defined in a standard | |
34007 | ELinOS environment in order to determine the location of the system | |
34008 | shared libraries, and then sets the @samp{solib-absolute-prefix} | |
34009 | and @samp{solib-search-path} variables appropriately. | |
34010 | ||
34011 | @item @file{wrs-linux.py} | |
34012 | @pindex wrs-linux.py | |
34013 | @cindex Wind River Linux system-wide configuration script | |
34014 | This script is useful when debugging a program on a target running | |
34015 | Wind River Linux. It expects the @env{ENV_PREFIX} to be set to | |
34016 | the host-side sysroot used by the target system. | |
34017 | ||
34018 | @end itemize | |
34019 | ||
8e04817f AC |
34020 | @node Maintenance Commands |
34021 | @appendix Maintenance Commands | |
34022 | @cindex maintenance commands | |
34023 | @cindex internal commands | |
c906108c | 34024 | |
8e04817f | 34025 | In addition to commands intended for @value{GDBN} users, @value{GDBN} |
09d4efe1 EZ |
34026 | includes a number of commands intended for @value{GDBN} developers, |
34027 | that are not documented elsewhere in this manual. These commands are | |
da316a69 EZ |
34028 | provided here for reference. (For commands that turn on debugging |
34029 | messages, see @ref{Debugging Output}.) | |
c906108c | 34030 | |
8e04817f | 34031 | @table @code |
09d4efe1 | 34032 | @kindex maint agent |
782b2b07 | 34033 | @kindex maint agent-eval |
f77cc5f0 HZ |
34034 | @item maint agent @r{[}-at @var{location}@r{,}@r{]} @var{expression} |
34035 | @itemx maint agent-eval @r{[}-at @var{location}@r{,}@r{]} @var{expression} | |
09d4efe1 EZ |
34036 | Translate the given @var{expression} into remote agent bytecodes. |
34037 | This command is useful for debugging the Agent Expression mechanism | |
782b2b07 SS |
34038 | (@pxref{Agent Expressions}). The @samp{agent} version produces an |
34039 | expression useful for data collection, such as by tracepoints, while | |
34040 | @samp{maint agent-eval} produces an expression that evaluates directly | |
34041 | to a result. For instance, a collection expression for @code{globa + | |
34042 | globb} will include bytecodes to record four bytes of memory at each | |
34043 | of the addresses of @code{globa} and @code{globb}, while discarding | |
34044 | the result of the addition, while an evaluation expression will do the | |
34045 | addition and return the sum. | |
f77cc5f0 HZ |
34046 | If @code{-at} is given, generate remote agent bytecode for @var{location}. |
34047 | If not, generate remote agent bytecode for current frame PC address. | |
09d4efe1 | 34048 | |
d3ce09f5 SS |
34049 | @kindex maint agent-printf |
34050 | @item maint agent-printf @var{format},@var{expr},... | |
34051 | Translate the given format string and list of argument expressions | |
34052 | into remote agent bytecodes and display them as a disassembled list. | |
34053 | This command is useful for debugging the agent version of dynamic | |
6dd24dfa | 34054 | printf (@pxref{Dynamic Printf}). |
d3ce09f5 | 34055 | |
8e04817f AC |
34056 | @kindex maint info breakpoints |
34057 | @item @anchor{maint info breakpoints}maint info breakpoints | |
34058 | Using the same format as @samp{info breakpoints}, display both the | |
34059 | breakpoints you've set explicitly, and those @value{GDBN} is using for | |
34060 | internal purposes. Internal breakpoints are shown with negative | |
34061 | breakpoint numbers. The type column identifies what kind of breakpoint | |
34062 | is shown: | |
c906108c | 34063 | |
8e04817f AC |
34064 | @table @code |
34065 | @item breakpoint | |
34066 | Normal, explicitly set breakpoint. | |
c906108c | 34067 | |
8e04817f AC |
34068 | @item watchpoint |
34069 | Normal, explicitly set watchpoint. | |
c906108c | 34070 | |
8e04817f AC |
34071 | @item longjmp |
34072 | Internal breakpoint, used to handle correctly stepping through | |
34073 | @code{longjmp} calls. | |
c906108c | 34074 | |
8e04817f AC |
34075 | @item longjmp resume |
34076 | Internal breakpoint at the target of a @code{longjmp}. | |
c906108c | 34077 | |
8e04817f AC |
34078 | @item until |
34079 | Temporary internal breakpoint used by the @value{GDBN} @code{until} command. | |
c906108c | 34080 | |
8e04817f AC |
34081 | @item finish |
34082 | Temporary internal breakpoint used by the @value{GDBN} @code{finish} command. | |
c906108c | 34083 | |
8e04817f AC |
34084 | @item shlib events |
34085 | Shared library events. | |
c906108c | 34086 | |
8e04817f | 34087 | @end table |
c906108c | 34088 | |
b0627500 MM |
34089 | @kindex maint info btrace |
34090 | @item maint info btrace | |
34091 | Pint information about raw branch tracing data. | |
34092 | ||
34093 | @kindex maint btrace packet-history | |
34094 | @item maint btrace packet-history | |
34095 | Print the raw branch trace packets that are used to compute the | |
34096 | execution history for the @samp{record btrace} command. Both the | |
34097 | information and the format in which it is printed depend on the btrace | |
34098 | recording format. | |
34099 | ||
34100 | @table @code | |
34101 | @item bts | |
34102 | For the BTS recording format, print a list of blocks of sequential | |
34103 | code. For each block, the following information is printed: | |
34104 | ||
34105 | @table @asis | |
34106 | @item Block number | |
34107 | Newer blocks have higher numbers. The oldest block has number zero. | |
34108 | @item Lowest @samp{PC} | |
34109 | @item Highest @samp{PC} | |
34110 | @end table | |
34111 | ||
34112 | @item pt | |
bc504a31 PA |
34113 | For the Intel Processor Trace recording format, print a list of |
34114 | Intel Processor Trace packets. For each packet, the following | |
b0627500 MM |
34115 | information is printed: |
34116 | ||
34117 | @table @asis | |
34118 | @item Packet number | |
34119 | Newer packets have higher numbers. The oldest packet has number zero. | |
34120 | @item Trace offset | |
34121 | The packet's offset in the trace stream. | |
34122 | @item Packet opcode and payload | |
34123 | @end table | |
34124 | @end table | |
34125 | ||
34126 | @kindex maint btrace clear-packet-history | |
34127 | @item maint btrace clear-packet-history | |
34128 | Discards the cached packet history printed by the @samp{maint btrace | |
34129 | packet-history} command. The history will be computed again when | |
34130 | needed. | |
34131 | ||
34132 | @kindex maint btrace clear | |
34133 | @item maint btrace clear | |
34134 | Discard the branch trace data. The data will be fetched anew and the | |
34135 | branch trace will be recomputed when needed. | |
34136 | ||
34137 | This implicitly truncates the branch trace to a single branch trace | |
34138 | buffer. When updating branch trace incrementally, the branch trace | |
34139 | available to @value{GDBN} may be bigger than a single branch trace | |
34140 | buffer. | |
34141 | ||
34142 | @kindex maint set btrace pt skip-pad | |
34143 | @item maint set btrace pt skip-pad | |
34144 | @kindex maint show btrace pt skip-pad | |
34145 | @item maint show btrace pt skip-pad | |
34146 | Control whether @value{GDBN} will skip PAD packets when computing the | |
34147 | packet history. | |
34148 | ||
fff08868 HZ |
34149 | @kindex set displaced-stepping |
34150 | @kindex show displaced-stepping | |
237fc4c9 PA |
34151 | @cindex displaced stepping support |
34152 | @cindex out-of-line single-stepping | |
fff08868 HZ |
34153 | @item set displaced-stepping |
34154 | @itemx show displaced-stepping | |
237fc4c9 | 34155 | Control whether or not @value{GDBN} will do @dfn{displaced stepping} |
fff08868 HZ |
34156 | if the target supports it. Displaced stepping is a way to single-step |
34157 | over breakpoints without removing them from the inferior, by executing | |
34158 | an out-of-line copy of the instruction that was originally at the | |
34159 | breakpoint location. It is also known as out-of-line single-stepping. | |
34160 | ||
34161 | @table @code | |
34162 | @item set displaced-stepping on | |
34163 | If the target architecture supports it, @value{GDBN} will use | |
34164 | displaced stepping to step over breakpoints. | |
34165 | ||
34166 | @item set displaced-stepping off | |
34167 | @value{GDBN} will not use displaced stepping to step over breakpoints, | |
34168 | even if such is supported by the target architecture. | |
34169 | ||
34170 | @cindex non-stop mode, and @samp{set displaced-stepping} | |
34171 | @item set displaced-stepping auto | |
34172 | This is the default mode. @value{GDBN} will use displaced stepping | |
34173 | only if non-stop mode is active (@pxref{Non-Stop Mode}) and the target | |
34174 | architecture supports displaced stepping. | |
34175 | @end table | |
237fc4c9 | 34176 | |
7d0c9981 DE |
34177 | @kindex maint check-psymtabs |
34178 | @item maint check-psymtabs | |
34179 | Check the consistency of currently expanded psymtabs versus symtabs. | |
34180 | Use this to check, for example, whether a symbol is in one but not the other. | |
34181 | ||
09d4efe1 EZ |
34182 | @kindex maint check-symtabs |
34183 | @item maint check-symtabs | |
7d0c9981 DE |
34184 | Check the consistency of currently expanded symtabs. |
34185 | ||
34186 | @kindex maint expand-symtabs | |
34187 | @item maint expand-symtabs [@var{regexp}] | |
34188 | Expand symbol tables. | |
34189 | If @var{regexp} is specified, only expand symbol tables for file | |
34190 | names matching @var{regexp}. | |
09d4efe1 | 34191 | |
992c7d70 GB |
34192 | @kindex maint set catch-demangler-crashes |
34193 | @kindex maint show catch-demangler-crashes | |
34194 | @cindex demangler crashes | |
34195 | @item maint set catch-demangler-crashes [on|off] | |
34196 | @itemx maint show catch-demangler-crashes | |
34197 | Control whether @value{GDBN} should attempt to catch crashes in the | |
34198 | symbol name demangler. The default is to attempt to catch crashes. | |
34199 | If enabled, the first time a crash is caught, a core file is created, | |
34200 | the offending symbol is displayed and the user is presented with the | |
34201 | option to terminate the current session. | |
34202 | ||
09d4efe1 EZ |
34203 | @kindex maint cplus first_component |
34204 | @item maint cplus first_component @var{name} | |
34205 | Print the first C@t{++} class/namespace component of @var{name}. | |
34206 | ||
34207 | @kindex maint cplus namespace | |
34208 | @item maint cplus namespace | |
34209 | Print the list of possible C@t{++} namespaces. | |
34210 | ||
09d4efe1 EZ |
34211 | @kindex maint deprecate |
34212 | @kindex maint undeprecate | |
34213 | @cindex deprecated commands | |
34214 | @item maint deprecate @var{command} @r{[}@var{replacement}@r{]} | |
34215 | @itemx maint undeprecate @var{command} | |
34216 | Deprecate or undeprecate the named @var{command}. Deprecated commands | |
34217 | cause @value{GDBN} to issue a warning when you use them. The optional | |
34218 | argument @var{replacement} says which newer command should be used in | |
34219 | favor of the deprecated one; if it is given, @value{GDBN} will mention | |
34220 | the replacement as part of the warning. | |
34221 | ||
34222 | @kindex maint dump-me | |
34223 | @item maint dump-me | |
721c2651 | 34224 | @cindex @code{SIGQUIT} signal, dump core of @value{GDBN} |
09d4efe1 | 34225 | Cause a fatal signal in the debugger and force it to dump its core. |
721c2651 EZ |
34226 | This is supported only on systems which support aborting a program |
34227 | with the @code{SIGQUIT} signal. | |
09d4efe1 | 34228 | |
8d30a00d AC |
34229 | @kindex maint internal-error |
34230 | @kindex maint internal-warning | |
57fcfb1b GB |
34231 | @kindex maint demangler-warning |
34232 | @cindex demangler crashes | |
09d4efe1 EZ |
34233 | @item maint internal-error @r{[}@var{message-text}@r{]} |
34234 | @itemx maint internal-warning @r{[}@var{message-text}@r{]} | |
57fcfb1b GB |
34235 | @itemx maint demangler-warning @r{[}@var{message-text}@r{]} |
34236 | ||
34237 | Cause @value{GDBN} to call the internal function @code{internal_error}, | |
34238 | @code{internal_warning} or @code{demangler_warning} and hence behave | |
7ee67ee4 | 34239 | as though an internal problem has been detected. In addition to |
57fcfb1b GB |
34240 | reporting the internal problem, these functions give the user the |
34241 | opportunity to either quit @value{GDBN} or (for @code{internal_error} | |
34242 | and @code{internal_warning}) create a core file of the current | |
8d30a00d AC |
34243 | @value{GDBN} session. |
34244 | ||
09d4efe1 EZ |
34245 | These commands take an optional parameter @var{message-text} that is |
34246 | used as the text of the error or warning message. | |
34247 | ||
d3e8051b | 34248 | Here's an example of using @code{internal-error}: |
09d4efe1 | 34249 | |
8d30a00d | 34250 | @smallexample |
f7dc1244 | 34251 | (@value{GDBP}) @kbd{maint internal-error testing, 1, 2} |
8d30a00d AC |
34252 | @dots{}/maint.c:121: internal-error: testing, 1, 2 |
34253 | A problem internal to GDB has been detected. Further | |
34254 | debugging may prove unreliable. | |
34255 | Quit this debugging session? (y or n) @kbd{n} | |
34256 | Create a core file? (y or n) @kbd{n} | |
f7dc1244 | 34257 | (@value{GDBP}) |
8d30a00d AC |
34258 | @end smallexample |
34259 | ||
3c16cced PA |
34260 | @cindex @value{GDBN} internal error |
34261 | @cindex internal errors, control of @value{GDBN} behavior | |
57fcfb1b | 34262 | @cindex demangler crashes |
3c16cced PA |
34263 | |
34264 | @kindex maint set internal-error | |
34265 | @kindex maint show internal-error | |
34266 | @kindex maint set internal-warning | |
34267 | @kindex maint show internal-warning | |
57fcfb1b GB |
34268 | @kindex maint set demangler-warning |
34269 | @kindex maint show demangler-warning | |
3c16cced PA |
34270 | @item maint set internal-error @var{action} [ask|yes|no] |
34271 | @itemx maint show internal-error @var{action} | |
34272 | @itemx maint set internal-warning @var{action} [ask|yes|no] | |
34273 | @itemx maint show internal-warning @var{action} | |
57fcfb1b GB |
34274 | @itemx maint set demangler-warning @var{action} [ask|yes|no] |
34275 | @itemx maint show demangler-warning @var{action} | |
3c16cced PA |
34276 | When @value{GDBN} reports an internal problem (error or warning) it |
34277 | gives the user the opportunity to both quit @value{GDBN} and create a | |
34278 | core file of the current @value{GDBN} session. These commands let you | |
34279 | override the default behaviour for each particular @var{action}, | |
34280 | described in the table below. | |
34281 | ||
34282 | @table @samp | |
34283 | @item quit | |
34284 | You can specify that @value{GDBN} should always (yes) or never (no) | |
34285 | quit. The default is to ask the user what to do. | |
34286 | ||
34287 | @item corefile | |
34288 | You can specify that @value{GDBN} should always (yes) or never (no) | |
57fcfb1b GB |
34289 | create a core file. The default is to ask the user what to do. Note |
34290 | that there is no @code{corefile} option for @code{demangler-warning}: | |
34291 | demangler warnings always create a core file and this cannot be | |
34292 | disabled. | |
3c16cced PA |
34293 | @end table |
34294 | ||
09d4efe1 EZ |
34295 | @kindex maint packet |
34296 | @item maint packet @var{text} | |
34297 | If @value{GDBN} is talking to an inferior via the serial protocol, | |
34298 | then this command sends the string @var{text} to the inferior, and | |
34299 | displays the response packet. @value{GDBN} supplies the initial | |
34300 | @samp{$} character, the terminating @samp{#} character, and the | |
34301 | checksum. | |
34302 | ||
34303 | @kindex maint print architecture | |
34304 | @item maint print architecture @r{[}@var{file}@r{]} | |
34305 | Print the entire architecture configuration. The optional argument | |
34306 | @var{file} names the file where the output goes. | |
8d30a00d | 34307 | |
81adfced DJ |
34308 | @kindex maint print c-tdesc |
34309 | @item maint print c-tdesc | |
34310 | Print the current target description (@pxref{Target Descriptions}) as | |
34311 | a C source file. The created source file can be used in @value{GDBN} | |
34312 | when an XML parser is not available to parse the description. | |
34313 | ||
00905d52 AC |
34314 | @kindex maint print dummy-frames |
34315 | @item maint print dummy-frames | |
00905d52 AC |
34316 | Prints the contents of @value{GDBN}'s internal dummy-frame stack. |
34317 | ||
34318 | @smallexample | |
f7dc1244 | 34319 | (@value{GDBP}) @kbd{b add} |
00905d52 | 34320 | @dots{} |
f7dc1244 | 34321 | (@value{GDBP}) @kbd{print add(2,3)} |
00905d52 AC |
34322 | Breakpoint 2, add (a=2, b=3) at @dots{} |
34323 | 58 return (a + b); | |
34324 | The program being debugged stopped while in a function called from GDB. | |
34325 | @dots{} | |
f7dc1244 | 34326 | (@value{GDBP}) @kbd{maint print dummy-frames} |
b67a2c6f | 34327 | 0xa8206d8: id=@{stack=0xbfffe734,code=0xbfffe73f,!special@}, ptid=process 9353 |
f7dc1244 | 34328 | (@value{GDBP}) |
00905d52 AC |
34329 | @end smallexample |
34330 | ||
34331 | Takes an optional file parameter. | |
34332 | ||
0680b120 AC |
34333 | @kindex maint print registers |
34334 | @kindex maint print raw-registers | |
34335 | @kindex maint print cooked-registers | |
617073a9 | 34336 | @kindex maint print register-groups |
c21236dc | 34337 | @kindex maint print remote-registers |
09d4efe1 EZ |
34338 | @item maint print registers @r{[}@var{file}@r{]} |
34339 | @itemx maint print raw-registers @r{[}@var{file}@r{]} | |
34340 | @itemx maint print cooked-registers @r{[}@var{file}@r{]} | |
34341 | @itemx maint print register-groups @r{[}@var{file}@r{]} | |
c21236dc | 34342 | @itemx maint print remote-registers @r{[}@var{file}@r{]} |
0680b120 AC |
34343 | Print @value{GDBN}'s internal register data structures. |
34344 | ||
617073a9 | 34345 | The command @code{maint print raw-registers} includes the contents of |
c21236dc PA |
34346 | the raw register cache; the command @code{maint print |
34347 | cooked-registers} includes the (cooked) value of all registers, | |
34348 | including registers which aren't available on the target nor visible | |
34349 | to user; the command @code{maint print register-groups} includes the | |
34350 | groups that each register is a member of; and the command @code{maint | |
34351 | print remote-registers} includes the remote target's register numbers | |
0a7cfe2c | 34352 | and offsets in the `G' packets. |
0680b120 | 34353 | |
09d4efe1 EZ |
34354 | These commands take an optional parameter, a file name to which to |
34355 | write the information. | |
0680b120 | 34356 | |
617073a9 | 34357 | @kindex maint print reggroups |
09d4efe1 EZ |
34358 | @item maint print reggroups @r{[}@var{file}@r{]} |
34359 | Print @value{GDBN}'s internal register group data structures. The | |
34360 | optional argument @var{file} tells to what file to write the | |
34361 | information. | |
617073a9 | 34362 | |
09d4efe1 | 34363 | The register groups info looks like this: |
617073a9 AC |
34364 | |
34365 | @smallexample | |
f7dc1244 | 34366 | (@value{GDBP}) @kbd{maint print reggroups} |
b383017d RM |
34367 | Group Type |
34368 | general user | |
34369 | float user | |
34370 | all user | |
34371 | vector user | |
34372 | system user | |
34373 | save internal | |
34374 | restore internal | |
617073a9 AC |
34375 | @end smallexample |
34376 | ||
09d4efe1 EZ |
34377 | @kindex flushregs |
34378 | @item flushregs | |
34379 | This command forces @value{GDBN} to flush its internal register cache. | |
34380 | ||
34381 | @kindex maint print objfiles | |
34382 | @cindex info for known object files | |
52e260a3 DE |
34383 | @item maint print objfiles @r{[}@var{regexp}@r{]} |
34384 | Print a dump of all known object files. | |
34385 | If @var{regexp} is specified, only print object files whose names | |
34386 | match @var{regexp}. For each object file, this command prints its name, | |
34387 | address in memory, and all of its psymtabs and symtabs. | |
09d4efe1 | 34388 | |
f5b95c01 AA |
34389 | @kindex maint print user-registers |
34390 | @cindex user registers | |
34391 | @item maint print user-registers | |
34392 | List all currently available @dfn{user registers}. User registers | |
34393 | typically provide alternate names for actual hardware registers. They | |
34394 | include the four ``standard'' registers @code{$fp}, @code{$pc}, | |
34395 | @code{$sp}, and @code{$ps}. @xref{standard registers}. User | |
34396 | registers can be used in expressions in the same way as the canonical | |
34397 | register names, but only the latter are listed by the @code{info | |
34398 | registers} and @code{maint print registers} commands. | |
34399 | ||
8a1ea21f DE |
34400 | @kindex maint print section-scripts |
34401 | @cindex info for known .debug_gdb_scripts-loaded scripts | |
34402 | @item maint print section-scripts [@var{regexp}] | |
34403 | Print a dump of scripts specified in the @code{.debug_gdb_section} section. | |
34404 | If @var{regexp} is specified, only print scripts loaded by object files | |
34405 | matching @var{regexp}. | |
34406 | For each script, this command prints its name as specified in the objfile, | |
34407 | and the full path if known. | |
8e0583c8 | 34408 | @xref{dotdebug_gdb_scripts section}. |
8a1ea21f | 34409 | |
09d4efe1 EZ |
34410 | @kindex maint print statistics |
34411 | @cindex bcache statistics | |
34412 | @item maint print statistics | |
34413 | This command prints, for each object file in the program, various data | |
34414 | about that object file followed by the byte cache (@dfn{bcache}) | |
34415 | statistics for the object file. The objfile data includes the number | |
d3e8051b | 34416 | of minimal, partial, full, and stabs symbols, the number of types |
09d4efe1 EZ |
34417 | defined by the objfile, the number of as yet unexpanded psym tables, |
34418 | the number of line tables and string tables, and the amount of memory | |
34419 | used by the various tables. The bcache statistics include the counts, | |
34420 | sizes, and counts of duplicates of all and unique objects, max, | |
34421 | average, and median entry size, total memory used and its overhead and | |
34422 | savings, and various measures of the hash table size and chain | |
34423 | lengths. | |
34424 | ||
c7ba131e JB |
34425 | @kindex maint print target-stack |
34426 | @cindex target stack description | |
34427 | @item maint print target-stack | |
34428 | A @dfn{target} is an interface between the debugger and a particular | |
34429 | kind of file or process. Targets can be stacked in @dfn{strata}, | |
34430 | so that more than one target can potentially respond to a request. | |
34431 | In particular, memory accesses will walk down the stack of targets | |
34432 | until they find a target that is interested in handling that particular | |
34433 | address. | |
34434 | ||
34435 | This command prints a short description of each layer that was pushed on | |
34436 | the @dfn{target stack}, starting from the top layer down to the bottom one. | |
34437 | ||
09d4efe1 EZ |
34438 | @kindex maint print type |
34439 | @cindex type chain of a data type | |
34440 | @item maint print type @var{expr} | |
34441 | Print the type chain for a type specified by @var{expr}. The argument | |
34442 | can be either a type name or a symbol. If it is a symbol, the type of | |
34443 | that symbol is described. The type chain produced by this command is | |
34444 | a recursive definition of the data type as stored in @value{GDBN}'s | |
34445 | data structures, including its flags and contained types. | |
34446 | ||
b4f54984 DE |
34447 | @kindex maint set dwarf always-disassemble |
34448 | @kindex maint show dwarf always-disassemble | |
34449 | @item maint set dwarf always-disassemble | |
34450 | @item maint show dwarf always-disassemble | |
9eae7c52 TT |
34451 | Control the behavior of @code{info address} when using DWARF debugging |
34452 | information. | |
34453 | ||
34454 | The default is @code{off}, which means that @value{GDBN} should try to | |
34455 | describe a variable's location in an easily readable format. When | |
34456 | @code{on}, @value{GDBN} will instead display the DWARF location | |
34457 | expression in an assembly-like format. Note that some locations are | |
34458 | too complex for @value{GDBN} to describe simply; in this case you will | |
34459 | always see the disassembly form. | |
34460 | ||
34461 | Here is an example of the resulting disassembly: | |
34462 | ||
34463 | @smallexample | |
34464 | (gdb) info addr argc | |
34465 | Symbol "argc" is a complex DWARF expression: | |
34466 | 1: DW_OP_fbreg 0 | |
34467 | @end smallexample | |
34468 | ||
34469 | For more information on these expressions, see | |
34470 | @uref{http://www.dwarfstd.org/, the DWARF standard}. | |
34471 | ||
b4f54984 DE |
34472 | @kindex maint set dwarf max-cache-age |
34473 | @kindex maint show dwarf max-cache-age | |
34474 | @item maint set dwarf max-cache-age | |
34475 | @itemx maint show dwarf max-cache-age | |
34476 | Control the DWARF compilation unit cache. | |
09d4efe1 | 34477 | |
b4f54984 | 34478 | @cindex DWARF compilation units cache |
09d4efe1 | 34479 | In object files with inter-compilation-unit references, such as those |
b4f54984 | 34480 | produced by the GCC option @samp{-feliminate-dwarf2-dups}, the DWARF |
09d4efe1 EZ |
34481 | reader needs to frequently refer to previously read compilation units. |
34482 | This setting controls how long a compilation unit will remain in the | |
34483 | cache if it is not referenced. A higher limit means that cached | |
34484 | compilation units will be stored in memory longer, and more total | |
34485 | memory will be used. Setting it to zero disables caching, which will | |
34486 | slow down @value{GDBN} startup, but reduce memory consumption. | |
34487 | ||
e7ba9c65 DJ |
34488 | @kindex maint set profile |
34489 | @kindex maint show profile | |
34490 | @cindex profiling GDB | |
34491 | @item maint set profile | |
34492 | @itemx maint show profile | |
34493 | Control profiling of @value{GDBN}. | |
34494 | ||
34495 | Profiling will be disabled until you use the @samp{maint set profile} | |
34496 | command to enable it. When you enable profiling, the system will begin | |
34497 | collecting timing and execution count data; when you disable profiling or | |
34498 | exit @value{GDBN}, the results will be written to a log file. Remember that | |
34499 | if you use profiling, @value{GDBN} will overwrite the profiling log file | |
34500 | (often called @file{gmon.out}). If you have a record of important profiling | |
34501 | data in a @file{gmon.out} file, be sure to move it to a safe location. | |
34502 | ||
34503 | Configuring with @samp{--enable-profiling} arranges for @value{GDBN} to be | |
b383017d | 34504 | compiled with the @samp{-pg} compiler option. |
e7ba9c65 | 34505 | |
cbe54154 PA |
34506 | @kindex maint set show-debug-regs |
34507 | @kindex maint show show-debug-regs | |
eac35c4e | 34508 | @cindex hardware debug registers |
cbe54154 PA |
34509 | @item maint set show-debug-regs |
34510 | @itemx maint show show-debug-regs | |
eac35c4e | 34511 | Control whether to show variables that mirror the hardware debug |
6dd315ba | 34512 | registers. Use @code{on} to enable, @code{off} to disable. If |
3f94c067 | 34513 | enabled, the debug registers values are shown when @value{GDBN} inserts or |
09d4efe1 EZ |
34514 | removes a hardware breakpoint or watchpoint, and when the inferior |
34515 | triggers a hardware-assisted breakpoint or watchpoint. | |
34516 | ||
711e434b PM |
34517 | @kindex maint set show-all-tib |
34518 | @kindex maint show show-all-tib | |
34519 | @item maint set show-all-tib | |
34520 | @itemx maint show show-all-tib | |
34521 | Control whether to show all non zero areas within a 1k block starting | |
34522 | at thread local base, when using the @samp{info w32 thread-information-block} | |
34523 | command. | |
34524 | ||
329ea579 PA |
34525 | @kindex maint set target-async |
34526 | @kindex maint show target-async | |
34527 | @item maint set target-async | |
34528 | @itemx maint show target-async | |
34529 | This controls whether @value{GDBN} targets operate in synchronous or | |
34530 | asynchronous mode (@pxref{Background Execution}). Normally the | |
34531 | default is asynchronous, if it is available; but this can be changed | |
34532 | to more easily debug problems occurring only in synchronous mode. | |
34533 | ||
fbea99ea PA |
34534 | @kindex maint set target-non-stop @var{mode} [on|off|auto] |
34535 | @kindex maint show target-non-stop | |
34536 | @item maint set target-non-stop | |
34537 | @itemx maint show target-non-stop | |
34538 | ||
34539 | This controls whether @value{GDBN} targets always operate in non-stop | |
34540 | mode even if @code{set non-stop} is @code{off} (@pxref{Non-Stop | |
34541 | Mode}). The default is @code{auto}, meaning non-stop mode is enabled | |
34542 | if supported by the target. | |
34543 | ||
34544 | @table @code | |
34545 | @item maint set target-non-stop auto | |
34546 | This is the default mode. @value{GDBN} controls the target in | |
34547 | non-stop mode if the target supports it. | |
34548 | ||
34549 | @item maint set target-non-stop on | |
34550 | @value{GDBN} controls the target in non-stop mode even if the target | |
34551 | does not indicate support. | |
34552 | ||
34553 | @item maint set target-non-stop off | |
34554 | @value{GDBN} does not control the target in non-stop mode even if the | |
34555 | target supports it. | |
34556 | @end table | |
34557 | ||
bd712aed DE |
34558 | @kindex maint set per-command |
34559 | @kindex maint show per-command | |
34560 | @item maint set per-command | |
34561 | @itemx maint show per-command | |
34562 | @cindex resources used by commands | |
09d4efe1 | 34563 | |
bd712aed DE |
34564 | @value{GDBN} can display the resources used by each command. |
34565 | This is useful in debugging performance problems. | |
34566 | ||
34567 | @table @code | |
34568 | @item maint set per-command space [on|off] | |
34569 | @itemx maint show per-command space | |
34570 | Enable or disable the printing of the memory used by GDB for each command. | |
34571 | If enabled, @value{GDBN} will display how much memory each command | |
34572 | took, following the command's own output. | |
34573 | This can also be requested by invoking @value{GDBN} with the | |
34574 | @option{--statistics} command-line switch (@pxref{Mode Options}). | |
34575 | ||
34576 | @item maint set per-command time [on|off] | |
34577 | @itemx maint show per-command time | |
34578 | Enable or disable the printing of the execution time of @value{GDBN} | |
34579 | for each command. | |
34580 | If enabled, @value{GDBN} will display how much time it | |
09d4efe1 | 34581 | took to execute each command, following the command's own output. |
0a1c4d10 DE |
34582 | Both CPU time and wallclock time are printed. |
34583 | Printing both is useful when trying to determine whether the cost is | |
bd712aed | 34584 | CPU or, e.g., disk/network latency. |
0a1c4d10 DE |
34585 | Note that the CPU time printed is for @value{GDBN} only, it does not include |
34586 | the execution time of the inferior because there's no mechanism currently | |
34587 | to compute how much time was spent by @value{GDBN} and how much time was | |
34588 | spent by the program been debugged. | |
09d4efe1 EZ |
34589 | This can also be requested by invoking @value{GDBN} with the |
34590 | @option{--statistics} command-line switch (@pxref{Mode Options}). | |
34591 | ||
bd712aed DE |
34592 | @item maint set per-command symtab [on|off] |
34593 | @itemx maint show per-command symtab | |
34594 | Enable or disable the printing of basic symbol table statistics | |
34595 | for each command. | |
34596 | If enabled, @value{GDBN} will display the following information: | |
34597 | ||
215b9f98 EZ |
34598 | @enumerate a |
34599 | @item | |
34600 | number of symbol tables | |
34601 | @item | |
34602 | number of primary symbol tables | |
34603 | @item | |
34604 | number of blocks in the blockvector | |
34605 | @end enumerate | |
bd712aed DE |
34606 | @end table |
34607 | ||
34608 | @kindex maint space | |
34609 | @cindex memory used by commands | |
34610 | @item maint space @var{value} | |
34611 | An alias for @code{maint set per-command space}. | |
34612 | A non-zero value enables it, zero disables it. | |
34613 | ||
34614 | @kindex maint time | |
34615 | @cindex time of command execution | |
34616 | @item maint time @var{value} | |
34617 | An alias for @code{maint set per-command time}. | |
34618 | A non-zero value enables it, zero disables it. | |
34619 | ||
09d4efe1 EZ |
34620 | @kindex maint translate-address |
34621 | @item maint translate-address @r{[}@var{section}@r{]} @var{addr} | |
34622 | Find the symbol stored at the location specified by the address | |
34623 | @var{addr} and an optional section name @var{section}. If found, | |
34624 | @value{GDBN} prints the name of the closest symbol and an offset from | |
34625 | the symbol's location to the specified address. This is similar to | |
34626 | the @code{info address} command (@pxref{Symbols}), except that this | |
34627 | command also allows to find symbols in other sections. | |
ae038cb0 | 34628 | |
c14c28ba PP |
34629 | If section was not specified, the section in which the symbol was found |
34630 | is also printed. For dynamically linked executables, the name of | |
34631 | executable or shared library containing the symbol is printed as well. | |
34632 | ||
8e04817f | 34633 | @end table |
c906108c | 34634 | |
9c16f35a EZ |
34635 | The following command is useful for non-interactive invocations of |
34636 | @value{GDBN}, such as in the test suite. | |
34637 | ||
34638 | @table @code | |
34639 | @item set watchdog @var{nsec} | |
34640 | @kindex set watchdog | |
34641 | @cindex watchdog timer | |
34642 | @cindex timeout for commands | |
34643 | Set the maximum number of seconds @value{GDBN} will wait for the | |
34644 | target operation to finish. If this time expires, @value{GDBN} | |
34645 | reports and error and the command is aborted. | |
34646 | ||
34647 | @item show watchdog | |
34648 | Show the current setting of the target wait timeout. | |
34649 | @end table | |
c906108c | 34650 | |
e0ce93ac | 34651 | @node Remote Protocol |
8e04817f | 34652 | @appendix @value{GDBN} Remote Serial Protocol |
c906108c | 34653 | |
ee2d5c50 AC |
34654 | @menu |
34655 | * Overview:: | |
34656 | * Packets:: | |
34657 | * Stop Reply Packets:: | |
34658 | * General Query Packets:: | |
a1dcb23a | 34659 | * Architecture-Specific Protocol Details:: |
9d29849a | 34660 | * Tracepoint Packets:: |
a6b151f1 | 34661 | * Host I/O Packets:: |
9a6253be | 34662 | * Interrupts:: |
8b23ecc4 SL |
34663 | * Notification Packets:: |
34664 | * Remote Non-Stop:: | |
a6f3e723 | 34665 | * Packet Acknowledgment:: |
ee2d5c50 | 34666 | * Examples:: |
79a6e687 | 34667 | * File-I/O Remote Protocol Extension:: |
cfa9d6d9 | 34668 | * Library List Format:: |
2268b414 | 34669 | * Library List Format for SVR4 Targets:: |
79a6e687 | 34670 | * Memory Map Format:: |
dc146f7c | 34671 | * Thread List Format:: |
b3b9301e | 34672 | * Traceframe Info Format:: |
2ae8c8e7 | 34673 | * Branch Trace Format:: |
f4abbc16 | 34674 | * Branch Trace Configuration Format:: |
ee2d5c50 AC |
34675 | @end menu |
34676 | ||
34677 | @node Overview | |
34678 | @section Overview | |
34679 | ||
8e04817f AC |
34680 | There may be occasions when you need to know something about the |
34681 | protocol---for example, if there is only one serial port to your target | |
34682 | machine, you might want your program to do something special if it | |
34683 | recognizes a packet meant for @value{GDBN}. | |
c906108c | 34684 | |
d2c6833e | 34685 | In the examples below, @samp{->} and @samp{<-} are used to indicate |
bf06d120 | 34686 | transmitted and received data, respectively. |
c906108c | 34687 | |
8e04817f AC |
34688 | @cindex protocol, @value{GDBN} remote serial |
34689 | @cindex serial protocol, @value{GDBN} remote | |
34690 | @cindex remote serial protocol | |
8b23ecc4 SL |
34691 | All @value{GDBN} commands and responses (other than acknowledgments |
34692 | and notifications, see @ref{Notification Packets}) are sent as a | |
34693 | @var{packet}. A @var{packet} is introduced with the character | |
8e04817f AC |
34694 | @samp{$}, the actual @var{packet-data}, and the terminating character |
34695 | @samp{#} followed by a two-digit @var{checksum}: | |
c906108c | 34696 | |
474c8240 | 34697 | @smallexample |
8e04817f | 34698 | @code{$}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 34699 | @end smallexample |
8e04817f | 34700 | @noindent |
c906108c | 34701 | |
8e04817f AC |
34702 | @cindex checksum, for @value{GDBN} remote |
34703 | @noindent | |
34704 | The two-digit @var{checksum} is computed as the modulo 256 sum of all | |
34705 | characters between the leading @samp{$} and the trailing @samp{#} (an | |
34706 | eight bit unsigned checksum). | |
c906108c | 34707 | |
8e04817f AC |
34708 | Implementors should note that prior to @value{GDBN} 5.0 the protocol |
34709 | specification also included an optional two-digit @var{sequence-id}: | |
c906108c | 34710 | |
474c8240 | 34711 | @smallexample |
8e04817f | 34712 | @code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 34713 | @end smallexample |
c906108c | 34714 | |
8e04817f AC |
34715 | @cindex sequence-id, for @value{GDBN} remote |
34716 | @noindent | |
34717 | That @var{sequence-id} was appended to the acknowledgment. @value{GDBN} | |
34718 | has never output @var{sequence-id}s. Stubs that handle packets added | |
34719 | since @value{GDBN} 5.0 must not accept @var{sequence-id}. | |
c906108c | 34720 | |
8e04817f AC |
34721 | When either the host or the target machine receives a packet, the first |
34722 | response expected is an acknowledgment: either @samp{+} (to indicate | |
34723 | the package was received correctly) or @samp{-} (to request | |
34724 | retransmission): | |
c906108c | 34725 | |
474c8240 | 34726 | @smallexample |
d2c6833e AC |
34727 | -> @code{$}@var{packet-data}@code{#}@var{checksum} |
34728 | <- @code{+} | |
474c8240 | 34729 | @end smallexample |
8e04817f | 34730 | @noindent |
53a5351d | 34731 | |
a6f3e723 SL |
34732 | The @samp{+}/@samp{-} acknowledgments can be disabled |
34733 | once a connection is established. | |
34734 | @xref{Packet Acknowledgment}, for details. | |
34735 | ||
8e04817f AC |
34736 | The host (@value{GDBN}) sends @var{command}s, and the target (the |
34737 | debugging stub incorporated in your program) sends a @var{response}. In | |
34738 | the case of step and continue @var{command}s, the response is only sent | |
8b23ecc4 SL |
34739 | when the operation has completed, and the target has again stopped all |
34740 | threads in all attached processes. This is the default all-stop mode | |
34741 | behavior, but the remote protocol also supports @value{GDBN}'s non-stop | |
34742 | execution mode; see @ref{Remote Non-Stop}, for details. | |
c906108c | 34743 | |
8e04817f AC |
34744 | @var{packet-data} consists of a sequence of characters with the |
34745 | exception of @samp{#} and @samp{$} (see @samp{X} packet for additional | |
34746 | exceptions). | |
c906108c | 34747 | |
ee2d5c50 | 34748 | @cindex remote protocol, field separator |
0876f84a | 34749 | Fields within the packet should be separated using @samp{,} @samp{;} or |
8e04817f | 34750 | @samp{:}. Except where otherwise noted all numbers are represented in |
ee2d5c50 | 34751 | @sc{hex} with leading zeros suppressed. |
c906108c | 34752 | |
8e04817f AC |
34753 | Implementors should note that prior to @value{GDBN} 5.0, the character |
34754 | @samp{:} could not appear as the third character in a packet (as it | |
34755 | would potentially conflict with the @var{sequence-id}). | |
c906108c | 34756 | |
0876f84a DJ |
34757 | @cindex remote protocol, binary data |
34758 | @anchor{Binary Data} | |
34759 | Binary data in most packets is encoded either as two hexadecimal | |
34760 | digits per byte of binary data. This allowed the traditional remote | |
34761 | protocol to work over connections which were only seven-bit clean. | |
34762 | Some packets designed more recently assume an eight-bit clean | |
34763 | connection, and use a more efficient encoding to send and receive | |
34764 | binary data. | |
34765 | ||
34766 | The binary data representation uses @code{7d} (@sc{ascii} @samp{@}}) | |
34767 | as an escape character. Any escaped byte is transmitted as the escape | |
34768 | character followed by the original character XORed with @code{0x20}. | |
34769 | For example, the byte @code{0x7d} would be transmitted as the two | |
34770 | bytes @code{0x7d 0x5d}. The bytes @code{0x23} (@sc{ascii} @samp{#}), | |
34771 | @code{0x24} (@sc{ascii} @samp{$}), and @code{0x7d} (@sc{ascii} | |
34772 | @samp{@}}) must always be escaped. Responses sent by the stub | |
34773 | must also escape @code{0x2a} (@sc{ascii} @samp{*}), so that it | |
34774 | is not interpreted as the start of a run-length encoded sequence | |
34775 | (described next). | |
34776 | ||
1d3811f6 DJ |
34777 | Response @var{data} can be run-length encoded to save space. |
34778 | Run-length encoding replaces runs of identical characters with one | |
34779 | instance of the repeated character, followed by a @samp{*} and a | |
34780 | repeat count. The repeat count is itself sent encoded, to avoid | |
34781 | binary characters in @var{data}: a value of @var{n} is sent as | |
34782 | @code{@var{n}+29}. For a repeat count greater or equal to 3, this | |
34783 | produces a printable @sc{ascii} character, e.g.@: a space (@sc{ascii} | |
34784 | code 32) for a repeat count of 3. (This is because run-length | |
34785 | encoding starts to win for counts 3 or more.) Thus, for example, | |
34786 | @samp{0* } is a run-length encoding of ``0000'': the space character | |
34787 | after @samp{*} means repeat the leading @code{0} @w{@code{32 - 29 = | |
34788 | 3}} more times. | |
34789 | ||
34790 | The printable characters @samp{#} and @samp{$} or with a numeric value | |
34791 | greater than 126 must not be used. Runs of six repeats (@samp{#}) or | |
34792 | seven repeats (@samp{$}) can be expanded using a repeat count of only | |
34793 | five (@samp{"}). For example, @samp{00000000} can be encoded as | |
34794 | @samp{0*"00}. | |
c906108c | 34795 | |
8e04817f AC |
34796 | The error response returned for some packets includes a two character |
34797 | error number. That number is not well defined. | |
c906108c | 34798 | |
f8da2bff | 34799 | @cindex empty response, for unsupported packets |
8e04817f AC |
34800 | For any @var{command} not supported by the stub, an empty response |
34801 | (@samp{$#00}) should be returned. That way it is possible to extend the | |
34802 | protocol. A newer @value{GDBN} can tell if a packet is supported based | |
34803 | on that response. | |
c906108c | 34804 | |
393eab54 PA |
34805 | At a minimum, a stub is required to support the @samp{g} and @samp{G} |
34806 | commands for register access, and the @samp{m} and @samp{M} commands | |
34807 | for memory access. Stubs that only control single-threaded targets | |
34808 | can implement run control with the @samp{c} (continue), and @samp{s} | |
34809 | (step) commands. Stubs that support multi-threading targets should | |
34810 | support the @samp{vCont} command. All other commands are optional. | |
c906108c | 34811 | |
ee2d5c50 AC |
34812 | @node Packets |
34813 | @section Packets | |
34814 | ||
34815 | The following table provides a complete list of all currently defined | |
34816 | @var{command}s and their corresponding response @var{data}. | |
79a6e687 | 34817 | @xref{File-I/O Remote Protocol Extension}, for details about the File |
9c16f35a | 34818 | I/O extension of the remote protocol. |
ee2d5c50 | 34819 | |
b8ff78ce JB |
34820 | Each packet's description has a template showing the packet's overall |
34821 | syntax, followed by an explanation of the packet's meaning. We | |
34822 | include spaces in some of the templates for clarity; these are not | |
34823 | part of the packet's syntax. No @value{GDBN} packet uses spaces to | |
34824 | separate its components. For example, a template like @samp{foo | |
34825 | @var{bar} @var{baz}} describes a packet beginning with the three ASCII | |
34826 | bytes @samp{foo}, followed by a @var{bar}, followed directly by a | |
3f94c067 | 34827 | @var{baz}. @value{GDBN} does not transmit a space character between the |
b8ff78ce JB |
34828 | @samp{foo} and the @var{bar}, or between the @var{bar} and the |
34829 | @var{baz}. | |
34830 | ||
b90a069a SL |
34831 | @cindex @var{thread-id}, in remote protocol |
34832 | @anchor{thread-id syntax} | |
34833 | Several packets and replies include a @var{thread-id} field to identify | |
34834 | a thread. Normally these are positive numbers with a target-specific | |
34835 | interpretation, formatted as big-endian hex strings. A @var{thread-id} | |
34836 | can also be a literal @samp{-1} to indicate all threads, or @samp{0} to | |
34837 | pick any thread. | |
34838 | ||
34839 | In addition, the remote protocol supports a multiprocess feature in | |
34840 | which the @var{thread-id} syntax is extended to optionally include both | |
34841 | process and thread ID fields, as @samp{p@var{pid}.@var{tid}}. | |
34842 | The @var{pid} (process) and @var{tid} (thread) components each have the | |
34843 | format described above: a positive number with target-specific | |
34844 | interpretation formatted as a big-endian hex string, literal @samp{-1} | |
34845 | to indicate all processes or threads (respectively), or @samp{0} to | |
34846 | indicate an arbitrary process or thread. Specifying just a process, as | |
34847 | @samp{p@var{pid}}, is equivalent to @samp{p@var{pid}.-1}. It is an | |
34848 | error to specify all processes but a specific thread, such as | |
34849 | @samp{p-1.@var{tid}}. Note that the @samp{p} prefix is @emph{not} used | |
34850 | for those packets and replies explicitly documented to include a process | |
34851 | ID, rather than a @var{thread-id}. | |
34852 | ||
34853 | The multiprocess @var{thread-id} syntax extensions are only used if both | |
34854 | @value{GDBN} and the stub report support for the @samp{multiprocess} | |
34855 | feature using @samp{qSupported}. @xref{multiprocess extensions}, for | |
34856 | more information. | |
34857 | ||
8ffe2530 JB |
34858 | Note that all packet forms beginning with an upper- or lower-case |
34859 | letter, other than those described here, are reserved for future use. | |
34860 | ||
b8ff78ce | 34861 | Here are the packet descriptions. |
ee2d5c50 | 34862 | |
b8ff78ce | 34863 | @table @samp |
ee2d5c50 | 34864 | |
b8ff78ce JB |
34865 | @item ! |
34866 | @cindex @samp{!} packet | |
2d717e4f | 34867 | @anchor{extended mode} |
8e04817f AC |
34868 | Enable extended mode. In extended mode, the remote server is made |
34869 | persistent. The @samp{R} packet is used to restart the program being | |
34870 | debugged. | |
ee2d5c50 AC |
34871 | |
34872 | Reply: | |
34873 | @table @samp | |
34874 | @item OK | |
8e04817f | 34875 | The remote target both supports and has enabled extended mode. |
ee2d5c50 | 34876 | @end table |
c906108c | 34877 | |
b8ff78ce JB |
34878 | @item ? |
34879 | @cindex @samp{?} packet | |
36cb1214 | 34880 | @anchor{? packet} |
ee2d5c50 | 34881 | Indicate the reason the target halted. The reply is the same as for |
8b23ecc4 SL |
34882 | step and continue. This packet has a special interpretation when the |
34883 | target is in non-stop mode; see @ref{Remote Non-Stop}. | |
c906108c | 34884 | |
ee2d5c50 AC |
34885 | Reply: |
34886 | @xref{Stop Reply Packets}, for the reply specifications. | |
34887 | ||
b8ff78ce JB |
34888 | @item A @var{arglen},@var{argnum},@var{arg},@dots{} |
34889 | @cindex @samp{A} packet | |
34890 | Initialized @code{argv[]} array passed into program. @var{arglen} | |
34891 | specifies the number of bytes in the hex encoded byte stream | |
34892 | @var{arg}. See @code{gdbserver} for more details. | |
ee2d5c50 AC |
34893 | |
34894 | Reply: | |
34895 | @table @samp | |
34896 | @item OK | |
b8ff78ce JB |
34897 | The arguments were set. |
34898 | @item E @var{NN} | |
34899 | An error occurred. | |
ee2d5c50 AC |
34900 | @end table |
34901 | ||
b8ff78ce JB |
34902 | @item b @var{baud} |
34903 | @cindex @samp{b} packet | |
34904 | (Don't use this packet; its behavior is not well-defined.) | |
ee2d5c50 AC |
34905 | Change the serial line speed to @var{baud}. |
34906 | ||
34907 | JTC: @emph{When does the transport layer state change? When it's | |
34908 | received, or after the ACK is transmitted. In either case, there are | |
34909 | problems if the command or the acknowledgment packet is dropped.} | |
34910 | ||
34911 | Stan: @emph{If people really wanted to add something like this, and get | |
34912 | it working for the first time, they ought to modify ser-unix.c to send | |
34913 | some kind of out-of-band message to a specially-setup stub and have the | |
34914 | switch happen "in between" packets, so that from remote protocol's point | |
34915 | of view, nothing actually happened.} | |
34916 | ||
b8ff78ce JB |
34917 | @item B @var{addr},@var{mode} |
34918 | @cindex @samp{B} packet | |
8e04817f | 34919 | Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a |
2f870471 AC |
34920 | breakpoint at @var{addr}. |
34921 | ||
b8ff78ce | 34922 | Don't use this packet. Use the @samp{Z} and @samp{z} packets instead |
2f870471 | 34923 | (@pxref{insert breakpoint or watchpoint packet}). |
c906108c | 34924 | |
bacec72f | 34925 | @cindex @samp{bc} packet |
0d772ac9 MS |
34926 | @anchor{bc} |
34927 | @item bc | |
bacec72f MS |
34928 | Backward continue. Execute the target system in reverse. No parameter. |
34929 | @xref{Reverse Execution}, for more information. | |
34930 | ||
34931 | Reply: | |
34932 | @xref{Stop Reply Packets}, for the reply specifications. | |
34933 | ||
bacec72f | 34934 | @cindex @samp{bs} packet |
0d772ac9 MS |
34935 | @anchor{bs} |
34936 | @item bs | |
bacec72f MS |
34937 | Backward single step. Execute one instruction in reverse. No parameter. |
34938 | @xref{Reverse Execution}, for more information. | |
34939 | ||
34940 | Reply: | |
34941 | @xref{Stop Reply Packets}, for the reply specifications. | |
34942 | ||
4f553f88 | 34943 | @item c @r{[}@var{addr}@r{]} |
b8ff78ce | 34944 | @cindex @samp{c} packet |
697aa1b7 EZ |
34945 | Continue at @var{addr}, which is the address to resume. If @var{addr} |
34946 | is omitted, resume at current address. | |
c906108c | 34947 | |
393eab54 PA |
34948 | This packet is deprecated for multi-threading support. @xref{vCont |
34949 | packet}. | |
34950 | ||
ee2d5c50 AC |
34951 | Reply: |
34952 | @xref{Stop Reply Packets}, for the reply specifications. | |
34953 | ||
4f553f88 | 34954 | @item C @var{sig}@r{[};@var{addr}@r{]} |
b8ff78ce | 34955 | @cindex @samp{C} packet |
8e04817f | 34956 | Continue with signal @var{sig} (hex signal number). If |
b8ff78ce | 34957 | @samp{;@var{addr}} is omitted, resume at same address. |
c906108c | 34958 | |
393eab54 PA |
34959 | This packet is deprecated for multi-threading support. @xref{vCont |
34960 | packet}. | |
34961 | ||
ee2d5c50 AC |
34962 | Reply: |
34963 | @xref{Stop Reply Packets}, for the reply specifications. | |
c906108c | 34964 | |
b8ff78ce JB |
34965 | @item d |
34966 | @cindex @samp{d} packet | |
ee2d5c50 AC |
34967 | Toggle debug flag. |
34968 | ||
b8ff78ce JB |
34969 | Don't use this packet; instead, define a general set packet |
34970 | (@pxref{General Query Packets}). | |
ee2d5c50 | 34971 | |
b8ff78ce | 34972 | @item D |
b90a069a | 34973 | @itemx D;@var{pid} |
b8ff78ce | 34974 | @cindex @samp{D} packet |
b90a069a SL |
34975 | The first form of the packet is used to detach @value{GDBN} from the |
34976 | remote system. It is sent to the remote target | |
07f31aa6 | 34977 | before @value{GDBN} disconnects via the @code{detach} command. |
ee2d5c50 | 34978 | |
b90a069a SL |
34979 | The second form, including a process ID, is used when multiprocess |
34980 | protocol extensions are enabled (@pxref{multiprocess extensions}), to | |
34981 | detach only a specific process. The @var{pid} is specified as a | |
34982 | big-endian hex string. | |
34983 | ||
ee2d5c50 AC |
34984 | Reply: |
34985 | @table @samp | |
10fac096 NW |
34986 | @item OK |
34987 | for success | |
b8ff78ce | 34988 | @item E @var{NN} |
10fac096 | 34989 | for an error |
ee2d5c50 | 34990 | @end table |
c906108c | 34991 | |
b8ff78ce JB |
34992 | @item F @var{RC},@var{EE},@var{CF};@var{XX} |
34993 | @cindex @samp{F} packet | |
34994 | A reply from @value{GDBN} to an @samp{F} packet sent by the target. | |
34995 | This is part of the File-I/O protocol extension. @xref{File-I/O | |
79a6e687 | 34996 | Remote Protocol Extension}, for the specification. |
ee2d5c50 | 34997 | |
b8ff78ce | 34998 | @item g |
ee2d5c50 | 34999 | @anchor{read registers packet} |
b8ff78ce | 35000 | @cindex @samp{g} packet |
ee2d5c50 AC |
35001 | Read general registers. |
35002 | ||
35003 | Reply: | |
35004 | @table @samp | |
35005 | @item @var{XX@dots{}} | |
8e04817f AC |
35006 | Each byte of register data is described by two hex digits. The bytes |
35007 | with the register are transmitted in target byte order. The size of | |
b8ff78ce | 35008 | each register and their position within the @samp{g} packet are |
4a9bb1df UW |
35009 | determined by the @value{GDBN} internal gdbarch functions |
35010 | @code{DEPRECATED_REGISTER_RAW_SIZE} and @code{gdbarch_register_name}. The | |
b8ff78ce | 35011 | specification of several standard @samp{g} packets is specified below. |
ad196637 PA |
35012 | |
35013 | When reading registers from a trace frame (@pxref{Analyze Collected | |
35014 | Data,,Using the Collected Data}), the stub may also return a string of | |
35015 | literal @samp{x}'s in place of the register data digits, to indicate | |
35016 | that the corresponding register has not been collected, thus its value | |
35017 | is unavailable. For example, for an architecture with 4 registers of | |
35018 | 4 bytes each, the following reply indicates to @value{GDBN} that | |
35019 | registers 0 and 2 have not been collected, while registers 1 and 3 | |
35020 | have been collected, and both have zero value: | |
35021 | ||
35022 | @smallexample | |
35023 | -> @code{g} | |
35024 | <- @code{xxxxxxxx00000000xxxxxxxx00000000} | |
35025 | @end smallexample | |
35026 | ||
b8ff78ce | 35027 | @item E @var{NN} |
ee2d5c50 AC |
35028 | for an error. |
35029 | @end table | |
c906108c | 35030 | |
b8ff78ce JB |
35031 | @item G @var{XX@dots{}} |
35032 | @cindex @samp{G} packet | |
35033 | Write general registers. @xref{read registers packet}, for a | |
35034 | description of the @var{XX@dots{}} data. | |
ee2d5c50 AC |
35035 | |
35036 | Reply: | |
35037 | @table @samp | |
35038 | @item OK | |
35039 | for success | |
b8ff78ce | 35040 | @item E @var{NN} |
ee2d5c50 AC |
35041 | for an error |
35042 | @end table | |
35043 | ||
393eab54 | 35044 | @item H @var{op} @var{thread-id} |
b8ff78ce | 35045 | @cindex @samp{H} packet |
8e04817f | 35046 | Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g}, |
697aa1b7 EZ |
35047 | @samp{G}, et.al.). Depending on the operation to be performed, @var{op} |
35048 | should be @samp{c} for step and continue operations (note that this | |
393eab54 | 35049 | is deprecated, supporting the @samp{vCont} command is a better |
697aa1b7 | 35050 | option), and @samp{g} for other operations. The thread designator |
393eab54 PA |
35051 | @var{thread-id} has the format and interpretation described in |
35052 | @ref{thread-id syntax}. | |
ee2d5c50 AC |
35053 | |
35054 | Reply: | |
35055 | @table @samp | |
35056 | @item OK | |
35057 | for success | |
b8ff78ce | 35058 | @item E @var{NN} |
ee2d5c50 AC |
35059 | for an error |
35060 | @end table | |
c906108c | 35061 | |
8e04817f AC |
35062 | @c FIXME: JTC: |
35063 | @c 'H': How restrictive (or permissive) is the thread model. If a | |
35064 | @c thread is selected and stopped, are other threads allowed | |
35065 | @c to continue to execute? As I mentioned above, I think the | |
35066 | @c semantics of each command when a thread is selected must be | |
35067 | @c described. For example: | |
35068 | @c | |
35069 | @c 'g': If the stub supports threads and a specific thread is | |
35070 | @c selected, returns the register block from that thread; | |
35071 | @c otherwise returns current registers. | |
35072 | @c | |
35073 | @c 'G' If the stub supports threads and a specific thread is | |
35074 | @c selected, sets the registers of the register block of | |
35075 | @c that thread; otherwise sets current registers. | |
c906108c | 35076 | |
b8ff78ce | 35077 | @item i @r{[}@var{addr}@r{[},@var{nnn}@r{]]} |
ee2d5c50 | 35078 | @anchor{cycle step packet} |
b8ff78ce JB |
35079 | @cindex @samp{i} packet |
35080 | Step the remote target by a single clock cycle. If @samp{,@var{nnn}} is | |
8e04817f AC |
35081 | present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle |
35082 | step starting at that address. | |
c906108c | 35083 | |
b8ff78ce JB |
35084 | @item I |
35085 | @cindex @samp{I} packet | |
35086 | Signal, then cycle step. @xref{step with signal packet}. @xref{cycle | |
35087 | step packet}. | |
ee2d5c50 | 35088 | |
b8ff78ce JB |
35089 | @item k |
35090 | @cindex @samp{k} packet | |
35091 | Kill request. | |
c906108c | 35092 | |
36cb1214 HZ |
35093 | The exact effect of this packet is not specified. |
35094 | ||
35095 | For a bare-metal target, it may power cycle or reset the target | |
35096 | system. For that reason, the @samp{k} packet has no reply. | |
35097 | ||
35098 | For a single-process target, it may kill that process if possible. | |
35099 | ||
35100 | A multiple-process target may choose to kill just one process, or all | |
35101 | that are under @value{GDBN}'s control. For more precise control, use | |
35102 | the vKill packet (@pxref{vKill packet}). | |
35103 | ||
35104 | If the target system immediately closes the connection in response to | |
35105 | @samp{k}, @value{GDBN} does not consider the lack of packet | |
35106 | acknowledgment to be an error, and assumes the kill was successful. | |
35107 | ||
35108 | If connected using @kbd{target extended-remote}, and the target does | |
35109 | not close the connection in response to a kill request, @value{GDBN} | |
35110 | probes the target state as if a new connection was opened | |
35111 | (@pxref{? packet}). | |
c906108c | 35112 | |
b8ff78ce JB |
35113 | @item m @var{addr},@var{length} |
35114 | @cindex @samp{m} packet | |
a86c90e6 SM |
35115 | Read @var{length} addressable memory units starting at address @var{addr} |
35116 | (@pxref{addressable memory unit}). Note that @var{addr} may not be aligned to | |
35117 | any particular boundary. | |
fb031cdf JB |
35118 | |
35119 | The stub need not use any particular size or alignment when gathering | |
35120 | data from memory for the response; even if @var{addr} is word-aligned | |
35121 | and @var{length} is a multiple of the word size, the stub is free to | |
35122 | use byte accesses, or not. For this reason, this packet may not be | |
35123 | suitable for accessing memory-mapped I/O devices. | |
c43c5473 JB |
35124 | @cindex alignment of remote memory accesses |
35125 | @cindex size of remote memory accesses | |
35126 | @cindex memory, alignment and size of remote accesses | |
c906108c | 35127 | |
ee2d5c50 AC |
35128 | Reply: |
35129 | @table @samp | |
35130 | @item @var{XX@dots{}} | |
a86c90e6 SM |
35131 | Memory contents; each byte is transmitted as a two-digit hexadecimal number. |
35132 | The reply may contain fewer addressable memory units than requested if the | |
b8ff78ce JB |
35133 | server was able to read only part of the region of memory. |
35134 | @item E @var{NN} | |
ee2d5c50 AC |
35135 | @var{NN} is errno |
35136 | @end table | |
35137 | ||
b8ff78ce JB |
35138 | @item M @var{addr},@var{length}:@var{XX@dots{}} |
35139 | @cindex @samp{M} packet | |
a86c90e6 SM |
35140 | Write @var{length} addressable memory units starting at address @var{addr} |
35141 | (@pxref{addressable memory unit}). The data is given by @var{XX@dots{}}; each | |
35142 | byte is transmitted as a two-digit hexadecimal number. | |
ee2d5c50 AC |
35143 | |
35144 | Reply: | |
35145 | @table @samp | |
35146 | @item OK | |
35147 | for success | |
b8ff78ce | 35148 | @item E @var{NN} |
8e04817f AC |
35149 | for an error (this includes the case where only part of the data was |
35150 | written). | |
ee2d5c50 | 35151 | @end table |
c906108c | 35152 | |
b8ff78ce JB |
35153 | @item p @var{n} |
35154 | @cindex @samp{p} packet | |
35155 | Read the value of register @var{n}; @var{n} is in hex. | |
2e868123 AC |
35156 | @xref{read registers packet}, for a description of how the returned |
35157 | register value is encoded. | |
ee2d5c50 AC |
35158 | |
35159 | Reply: | |
35160 | @table @samp | |
2e868123 AC |
35161 | @item @var{XX@dots{}} |
35162 | the register's value | |
b8ff78ce | 35163 | @item E @var{NN} |
2e868123 | 35164 | for an error |
d57350ea | 35165 | @item @w{} |
2e868123 | 35166 | Indicating an unrecognized @var{query}. |
ee2d5c50 AC |
35167 | @end table |
35168 | ||
b8ff78ce | 35169 | @item P @var{n@dots{}}=@var{r@dots{}} |
ee2d5c50 | 35170 | @anchor{write register packet} |
b8ff78ce JB |
35171 | @cindex @samp{P} packet |
35172 | Write register @var{n@dots{}} with value @var{r@dots{}}. The register | |
599b237a | 35173 | number @var{n} is in hexadecimal, and @var{r@dots{}} contains two hex |
8e04817f | 35174 | digits for each byte in the register (target byte order). |
c906108c | 35175 | |
ee2d5c50 AC |
35176 | Reply: |
35177 | @table @samp | |
35178 | @item OK | |
35179 | for success | |
b8ff78ce | 35180 | @item E @var{NN} |
ee2d5c50 AC |
35181 | for an error |
35182 | @end table | |
35183 | ||
5f3bebba JB |
35184 | @item q @var{name} @var{params}@dots{} |
35185 | @itemx Q @var{name} @var{params}@dots{} | |
b8ff78ce | 35186 | @cindex @samp{q} packet |
b8ff78ce | 35187 | @cindex @samp{Q} packet |
5f3bebba JB |
35188 | General query (@samp{q}) and set (@samp{Q}). These packets are |
35189 | described fully in @ref{General Query Packets}. | |
c906108c | 35190 | |
b8ff78ce JB |
35191 | @item r |
35192 | @cindex @samp{r} packet | |
8e04817f | 35193 | Reset the entire system. |
c906108c | 35194 | |
b8ff78ce | 35195 | Don't use this packet; use the @samp{R} packet instead. |
ee2d5c50 | 35196 | |
b8ff78ce JB |
35197 | @item R @var{XX} |
35198 | @cindex @samp{R} packet | |
697aa1b7 | 35199 | Restart the program being debugged. The @var{XX}, while needed, is ignored. |
2d717e4f | 35200 | This packet is only available in extended mode (@pxref{extended mode}). |
ee2d5c50 | 35201 | |
8e04817f | 35202 | The @samp{R} packet has no reply. |
ee2d5c50 | 35203 | |
4f553f88 | 35204 | @item s @r{[}@var{addr}@r{]} |
b8ff78ce | 35205 | @cindex @samp{s} packet |
697aa1b7 | 35206 | Single step, resuming at @var{addr}. If |
b8ff78ce | 35207 | @var{addr} is omitted, resume at same address. |
c906108c | 35208 | |
393eab54 PA |
35209 | This packet is deprecated for multi-threading support. @xref{vCont |
35210 | packet}. | |
35211 | ||
ee2d5c50 AC |
35212 | Reply: |
35213 | @xref{Stop Reply Packets}, for the reply specifications. | |
35214 | ||
4f553f88 | 35215 | @item S @var{sig}@r{[};@var{addr}@r{]} |
ee2d5c50 | 35216 | @anchor{step with signal packet} |
b8ff78ce JB |
35217 | @cindex @samp{S} packet |
35218 | Step with signal. This is analogous to the @samp{C} packet, but | |
35219 | requests a single-step, rather than a normal resumption of execution. | |
c906108c | 35220 | |
393eab54 PA |
35221 | This packet is deprecated for multi-threading support. @xref{vCont |
35222 | packet}. | |
35223 | ||
ee2d5c50 AC |
35224 | Reply: |
35225 | @xref{Stop Reply Packets}, for the reply specifications. | |
35226 | ||
b8ff78ce JB |
35227 | @item t @var{addr}:@var{PP},@var{MM} |
35228 | @cindex @samp{t} packet | |
8e04817f | 35229 | Search backwards starting at address @var{addr} for a match with pattern |
697aa1b7 EZ |
35230 | @var{PP} and mask @var{MM}, both of which are are 4 byte long. |
35231 | There must be at least 3 digits in @var{addr}. | |
c906108c | 35232 | |
b90a069a | 35233 | @item T @var{thread-id} |
b8ff78ce | 35234 | @cindex @samp{T} packet |
b90a069a | 35235 | Find out if the thread @var{thread-id} is alive. @xref{thread-id syntax}. |
c906108c | 35236 | |
ee2d5c50 AC |
35237 | Reply: |
35238 | @table @samp | |
35239 | @item OK | |
35240 | thread is still alive | |
b8ff78ce | 35241 | @item E @var{NN} |
ee2d5c50 AC |
35242 | thread is dead |
35243 | @end table | |
35244 | ||
b8ff78ce JB |
35245 | @item v |
35246 | Packets starting with @samp{v} are identified by a multi-letter name, | |
35247 | up to the first @samp{;} or @samp{?} (or the end of the packet). | |
86d30acc | 35248 | |
2d717e4f DJ |
35249 | @item vAttach;@var{pid} |
35250 | @cindex @samp{vAttach} packet | |
8b23ecc4 SL |
35251 | Attach to a new process with the specified process ID @var{pid}. |
35252 | The process ID is a | |
35253 | hexadecimal integer identifying the process. In all-stop mode, all | |
35254 | threads in the attached process are stopped; in non-stop mode, it may be | |
35255 | attached without being stopped if that is supported by the target. | |
35256 | ||
35257 | @c In non-stop mode, on a successful vAttach, the stub should set the | |
35258 | @c current thread to a thread of the newly-attached process. After | |
35259 | @c attaching, GDB queries for the attached process's thread ID with qC. | |
35260 | @c Also note that, from a user perspective, whether or not the | |
35261 | @c target is stopped on attach in non-stop mode depends on whether you | |
35262 | @c use the foreground or background version of the attach command, not | |
35263 | @c on what vAttach does; GDB does the right thing with respect to either | |
35264 | @c stopping or restarting threads. | |
2d717e4f DJ |
35265 | |
35266 | This packet is only available in extended mode (@pxref{extended mode}). | |
35267 | ||
35268 | Reply: | |
35269 | @table @samp | |
35270 | @item E @var{nn} | |
35271 | for an error | |
35272 | @item @r{Any stop packet} | |
8b23ecc4 SL |
35273 | for success in all-stop mode (@pxref{Stop Reply Packets}) |
35274 | @item OK | |
35275 | for success in non-stop mode (@pxref{Remote Non-Stop}) | |
2d717e4f DJ |
35276 | @end table |
35277 | ||
b90a069a | 35278 | @item vCont@r{[};@var{action}@r{[}:@var{thread-id}@r{]]}@dots{} |
b8ff78ce | 35279 | @cindex @samp{vCont} packet |
393eab54 | 35280 | @anchor{vCont packet} |
b8ff78ce | 35281 | Resume the inferior, specifying different actions for each thread. |
b90a069a | 35282 | If an action is specified with no @var{thread-id}, then it is applied to any |
86d30acc | 35283 | threads that don't have a specific action specified; if no default action is |
8b23ecc4 SL |
35284 | specified then other threads should remain stopped in all-stop mode and |
35285 | in their current state in non-stop mode. | |
35286 | Specifying multiple | |
86d30acc | 35287 | default actions is an error; specifying no actions is also an error. |
b90a069a SL |
35288 | Thread IDs are specified using the syntax described in @ref{thread-id syntax}. |
35289 | ||
35290 | Currently supported actions are: | |
86d30acc | 35291 | |
b8ff78ce | 35292 | @table @samp |
86d30acc DJ |
35293 | @item c |
35294 | Continue. | |
b8ff78ce | 35295 | @item C @var{sig} |
8b23ecc4 | 35296 | Continue with signal @var{sig}. The signal @var{sig} should be two hex digits. |
86d30acc DJ |
35297 | @item s |
35298 | Step. | |
b8ff78ce | 35299 | @item S @var{sig} |
8b23ecc4 SL |
35300 | Step with signal @var{sig}. The signal @var{sig} should be two hex digits. |
35301 | @item t | |
35302 | Stop. | |
c1e36e3e PA |
35303 | @item r @var{start},@var{end} |
35304 | Step once, and then keep stepping as long as the thread stops at | |
35305 | addresses between @var{start} (inclusive) and @var{end} (exclusive). | |
35306 | The remote stub reports a stop reply when either the thread goes out | |
35307 | of the range or is stopped due to an unrelated reason, such as hitting | |
35308 | a breakpoint. @xref{range stepping}. | |
35309 | ||
35310 | If the range is empty (@var{start} == @var{end}), then the action | |
35311 | becomes equivalent to the @samp{s} action. In other words, | |
35312 | single-step once, and report the stop (even if the stepped instruction | |
35313 | jumps to @var{start}). | |
35314 | ||
35315 | (A stop reply may be sent at any point even if the PC is still within | |
35316 | the stepping range; for example, it is valid to implement this packet | |
35317 | in a degenerate way as a single instruction step operation.) | |
35318 | ||
86d30acc DJ |
35319 | @end table |
35320 | ||
8b23ecc4 SL |
35321 | The optional argument @var{addr} normally associated with the |
35322 | @samp{c}, @samp{C}, @samp{s}, and @samp{S} packets is | |
b8ff78ce | 35323 | not supported in @samp{vCont}. |
86d30acc | 35324 | |
08a0efd0 PA |
35325 | The @samp{t} action is only relevant in non-stop mode |
35326 | (@pxref{Remote Non-Stop}) and may be ignored by the stub otherwise. | |
8b23ecc4 SL |
35327 | A stop reply should be generated for any affected thread not already stopped. |
35328 | When a thread is stopped by means of a @samp{t} action, | |
35329 | the corresponding stop reply should indicate that the thread has stopped with | |
35330 | signal @samp{0}, regardless of whether the target uses some other signal | |
35331 | as an implementation detail. | |
35332 | ||
4220b2f8 TS |
35333 | The stub must support @samp{vCont} if it reports support for |
35334 | multiprocess extensions (@pxref{multiprocess extensions}). Note that in | |
35335 | this case @samp{vCont} actions can be specified to apply to all threads | |
35336 | in a process by using the @samp{p@var{pid}.-1} form of the | |
35337 | @var{thread-id}. | |
35338 | ||
86d30acc DJ |
35339 | Reply: |
35340 | @xref{Stop Reply Packets}, for the reply specifications. | |
35341 | ||
b8ff78ce JB |
35342 | @item vCont? |
35343 | @cindex @samp{vCont?} packet | |
d3e8051b | 35344 | Request a list of actions supported by the @samp{vCont} packet. |
86d30acc DJ |
35345 | |
35346 | Reply: | |
35347 | @table @samp | |
b8ff78ce JB |
35348 | @item vCont@r{[};@var{action}@dots{}@r{]} |
35349 | The @samp{vCont} packet is supported. Each @var{action} is a supported | |
35350 | command in the @samp{vCont} packet. | |
d57350ea | 35351 | @item @w{} |
b8ff78ce | 35352 | The @samp{vCont} packet is not supported. |
86d30acc | 35353 | @end table |
ee2d5c50 | 35354 | |
de979965 PA |
35355 | @anchor{vCtrlC packet} |
35356 | @item vCtrlC | |
35357 | @cindex @samp{vCtrlC} packet | |
35358 | Interrupt remote target as if a control-C was pressed on the remote | |
35359 | terminal. This is the equivalent to reacting to the @code{^C} | |
35360 | (@samp{\003}, the control-C character) character in all-stop mode | |
35361 | while the target is running, except this works in non-stop mode. | |
35362 | @xref{interrupting remote targets}, for more info on the all-stop | |
35363 | variant. | |
35364 | ||
35365 | Reply: | |
35366 | @table @samp | |
35367 | @item E @var{nn} | |
35368 | for an error | |
35369 | @item OK | |
35370 | for success | |
35371 | @end table | |
35372 | ||
a6b151f1 DJ |
35373 | @item vFile:@var{operation}:@var{parameter}@dots{} |
35374 | @cindex @samp{vFile} packet | |
35375 | Perform a file operation on the target system. For details, | |
35376 | see @ref{Host I/O Packets}. | |
35377 | ||
68437a39 DJ |
35378 | @item vFlashErase:@var{addr},@var{length} |
35379 | @cindex @samp{vFlashErase} packet | |
35380 | Direct the stub to erase @var{length} bytes of flash starting at | |
35381 | @var{addr}. The region may enclose any number of flash blocks, but | |
35382 | its start and end must fall on block boundaries, as indicated by the | |
79a6e687 BW |
35383 | flash block size appearing in the memory map (@pxref{Memory Map |
35384 | Format}). @value{GDBN} groups flash memory programming operations | |
68437a39 DJ |
35385 | together, and sends a @samp{vFlashDone} request after each group; the |
35386 | stub is allowed to delay erase operation until the @samp{vFlashDone} | |
35387 | packet is received. | |
35388 | ||
35389 | Reply: | |
35390 | @table @samp | |
35391 | @item OK | |
35392 | for success | |
35393 | @item E @var{NN} | |
35394 | for an error | |
35395 | @end table | |
35396 | ||
35397 | @item vFlashWrite:@var{addr}:@var{XX@dots{}} | |
35398 | @cindex @samp{vFlashWrite} packet | |
35399 | Direct the stub to write data to flash address @var{addr}. The data | |
35400 | is passed in binary form using the same encoding as for the @samp{X} | |
35401 | packet (@pxref{Binary Data}). The memory ranges specified by | |
35402 | @samp{vFlashWrite} packets preceding a @samp{vFlashDone} packet must | |
35403 | not overlap, and must appear in order of increasing addresses | |
35404 | (although @samp{vFlashErase} packets for higher addresses may already | |
35405 | have been received; the ordering is guaranteed only between | |
35406 | @samp{vFlashWrite} packets). If a packet writes to an address that was | |
35407 | neither erased by a preceding @samp{vFlashErase} packet nor by some other | |
35408 | target-specific method, the results are unpredictable. | |
35409 | ||
35410 | ||
35411 | Reply: | |
35412 | @table @samp | |
35413 | @item OK | |
35414 | for success | |
35415 | @item E.memtype | |
35416 | for vFlashWrite addressing non-flash memory | |
35417 | @item E @var{NN} | |
35418 | for an error | |
35419 | @end table | |
35420 | ||
35421 | @item vFlashDone | |
35422 | @cindex @samp{vFlashDone} packet | |
35423 | Indicate to the stub that flash programming operation is finished. | |
35424 | The stub is permitted to delay or batch the effects of a group of | |
35425 | @samp{vFlashErase} and @samp{vFlashWrite} packets until a | |
35426 | @samp{vFlashDone} packet is received. The contents of the affected | |
35427 | regions of flash memory are unpredictable until the @samp{vFlashDone} | |
35428 | request is completed. | |
35429 | ||
b90a069a SL |
35430 | @item vKill;@var{pid} |
35431 | @cindex @samp{vKill} packet | |
36cb1214 | 35432 | @anchor{vKill packet} |
697aa1b7 | 35433 | Kill the process with the specified process ID @var{pid}, which is a |
b90a069a SL |
35434 | hexadecimal integer identifying the process. This packet is used in |
35435 | preference to @samp{k} when multiprocess protocol extensions are | |
35436 | supported; see @ref{multiprocess extensions}. | |
35437 | ||
35438 | Reply: | |
35439 | @table @samp | |
35440 | @item E @var{nn} | |
35441 | for an error | |
35442 | @item OK | |
35443 | for success | |
35444 | @end table | |
35445 | ||
2d717e4f DJ |
35446 | @item vRun;@var{filename}@r{[};@var{argument}@r{]}@dots{} |
35447 | @cindex @samp{vRun} packet | |
35448 | Run the program @var{filename}, passing it each @var{argument} on its | |
35449 | command line. The file and arguments are hex-encoded strings. If | |
35450 | @var{filename} is an empty string, the stub may use a default program | |
35451 | (e.g.@: the last program run). The program is created in the stopped | |
9b562ab8 | 35452 | state. |
2d717e4f | 35453 | |
8b23ecc4 SL |
35454 | @c FIXME: What about non-stop mode? |
35455 | ||
2d717e4f DJ |
35456 | This packet is only available in extended mode (@pxref{extended mode}). |
35457 | ||
35458 | Reply: | |
35459 | @table @samp | |
35460 | @item E @var{nn} | |
35461 | for an error | |
35462 | @item @r{Any stop packet} | |
35463 | for success (@pxref{Stop Reply Packets}) | |
35464 | @end table | |
35465 | ||
8b23ecc4 | 35466 | @item vStopped |
8b23ecc4 | 35467 | @cindex @samp{vStopped} packet |
8dbe8ece | 35468 | @xref{Notification Packets}. |
8b23ecc4 | 35469 | |
b8ff78ce | 35470 | @item X @var{addr},@var{length}:@var{XX@dots{}} |
9a6253be | 35471 | @anchor{X packet} |
b8ff78ce JB |
35472 | @cindex @samp{X} packet |
35473 | Write data to memory, where the data is transmitted in binary. | |
a86c90e6 SM |
35474 | Memory is specified by its address @var{addr} and number of addressable memory |
35475 | units @var{length} (@pxref{addressable memory unit}); | |
0876f84a | 35476 | @samp{@var{XX}@dots{}} is binary data (@pxref{Binary Data}). |
c906108c | 35477 | |
ee2d5c50 AC |
35478 | Reply: |
35479 | @table @samp | |
35480 | @item OK | |
35481 | for success | |
b8ff78ce | 35482 | @item E @var{NN} |
ee2d5c50 AC |
35483 | for an error |
35484 | @end table | |
35485 | ||
a1dcb23a DJ |
35486 | @item z @var{type},@var{addr},@var{kind} |
35487 | @itemx Z @var{type},@var{addr},@var{kind} | |
2f870471 | 35488 | @anchor{insert breakpoint or watchpoint packet} |
b8ff78ce JB |
35489 | @cindex @samp{z} packet |
35490 | @cindex @samp{Z} packets | |
35491 | Insert (@samp{Z}) or remove (@samp{z}) a @var{type} breakpoint or | |
a1dcb23a | 35492 | watchpoint starting at address @var{address} of kind @var{kind}. |
ee2d5c50 | 35493 | |
2f870471 AC |
35494 | Each breakpoint and watchpoint packet @var{type} is documented |
35495 | separately. | |
35496 | ||
512217c7 AC |
35497 | @emph{Implementation notes: A remote target shall return an empty string |
35498 | for an unrecognized breakpoint or watchpoint packet @var{type}. A | |
35499 | remote target shall support either both or neither of a given | |
b8ff78ce | 35500 | @samp{Z@var{type}@dots{}} and @samp{z@var{type}@dots{}} packet pair. To |
2f870471 AC |
35501 | avoid potential problems with duplicate packets, the operations should |
35502 | be implemented in an idempotent way.} | |
35503 | ||
a1dcb23a | 35504 | @item z0,@var{addr},@var{kind} |
d3ce09f5 | 35505 | @itemx Z0,@var{addr},@var{kind}@r{[};@var{cond_list}@dots{}@r{]}@r{[};cmds:@var{persist},@var{cmd_list}@dots{}@r{]} |
b8ff78ce JB |
35506 | @cindex @samp{z0} packet |
35507 | @cindex @samp{Z0} packet | |
35508 | Insert (@samp{Z0}) or remove (@samp{z0}) a memory breakpoint at address | |
a1dcb23a | 35509 | @var{addr} of type @var{kind}. |
2f870471 AC |
35510 | |
35511 | A memory breakpoint is implemented by replacing the instruction at | |
35512 | @var{addr} with a software breakpoint or trap instruction. The | |
a1dcb23a DJ |
35513 | @var{kind} is target-specific and typically indicates the size of |
35514 | the breakpoint in bytes that should be inserted. E.g., the @sc{arm} | |
35515 | and @sc{mips} can insert either a 2 or 4 byte breakpoint. Some | |
35516 | architectures have additional meanings for @var{kind}; | |
83364271 LM |
35517 | @var{cond_list} is an optional list of conditional expressions in bytecode |
35518 | form that should be evaluated on the target's side. These are the | |
35519 | conditions that should be taken into consideration when deciding if | |
35520 | the breakpoint trigger should be reported back to @var{GDBN}. | |
35521 | ||
f7e6eed5 PA |
35522 | See also the @samp{swbreak} stop reason (@pxref{swbreak stop reason}) |
35523 | for how to best report a memory breakpoint event to @value{GDBN}. | |
35524 | ||
83364271 LM |
35525 | The @var{cond_list} parameter is comprised of a series of expressions, |
35526 | concatenated without separators. Each expression has the following form: | |
35527 | ||
35528 | @table @samp | |
35529 | ||
35530 | @item X @var{len},@var{expr} | |
35531 | @var{len} is the length of the bytecode expression and @var{expr} is the | |
35532 | actual conditional expression in bytecode form. | |
35533 | ||
35534 | @end table | |
35535 | ||
d3ce09f5 SS |
35536 | The optional @var{cmd_list} parameter introduces commands that may be |
35537 | run on the target, rather than being reported back to @value{GDBN}. | |
35538 | The parameter starts with a numeric flag @var{persist}; if the flag is | |
35539 | nonzero, then the breakpoint may remain active and the commands | |
35540 | continue to be run even when @value{GDBN} disconnects from the target. | |
35541 | Following this flag is a series of expressions concatenated with no | |
35542 | separators. Each expression has the following form: | |
35543 | ||
35544 | @table @samp | |
35545 | ||
35546 | @item X @var{len},@var{expr} | |
35547 | @var{len} is the length of the bytecode expression and @var{expr} is the | |
35548 | actual conditional expression in bytecode form. | |
35549 | ||
35550 | @end table | |
35551 | ||
a1dcb23a | 35552 | see @ref{Architecture-Specific Protocol Details}. |
c906108c | 35553 | |
2f870471 AC |
35554 | @emph{Implementation note: It is possible for a target to copy or move |
35555 | code that contains memory breakpoints (e.g., when implementing | |
35556 | overlays). The behavior of this packet, in the presence of such a | |
35557 | target, is not defined.} | |
c906108c | 35558 | |
ee2d5c50 AC |
35559 | Reply: |
35560 | @table @samp | |
2f870471 AC |
35561 | @item OK |
35562 | success | |
d57350ea | 35563 | @item @w{} |
2f870471 | 35564 | not supported |
b8ff78ce | 35565 | @item E @var{NN} |
ee2d5c50 | 35566 | for an error |
2f870471 AC |
35567 | @end table |
35568 | ||
a1dcb23a | 35569 | @item z1,@var{addr},@var{kind} |
83364271 | 35570 | @itemx Z1,@var{addr},@var{kind}@r{[};@var{cond_list}@dots{}@r{]} |
b8ff78ce JB |
35571 | @cindex @samp{z1} packet |
35572 | @cindex @samp{Z1} packet | |
35573 | Insert (@samp{Z1}) or remove (@samp{z1}) a hardware breakpoint at | |
a1dcb23a | 35574 | address @var{addr}. |
2f870471 AC |
35575 | |
35576 | A hardware breakpoint is implemented using a mechanism that is not | |
697aa1b7 | 35577 | dependant on being able to modify the target's memory. The @var{kind} |
83364271 | 35578 | and @var{cond_list} have the same meaning as in @samp{Z0} packets. |
2f870471 AC |
35579 | |
35580 | @emph{Implementation note: A hardware breakpoint is not affected by code | |
35581 | movement.} | |
35582 | ||
35583 | Reply: | |
35584 | @table @samp | |
ee2d5c50 | 35585 | @item OK |
2f870471 | 35586 | success |
d57350ea | 35587 | @item @w{} |
2f870471 | 35588 | not supported |
b8ff78ce | 35589 | @item E @var{NN} |
2f870471 AC |
35590 | for an error |
35591 | @end table | |
35592 | ||
a1dcb23a DJ |
35593 | @item z2,@var{addr},@var{kind} |
35594 | @itemx Z2,@var{addr},@var{kind} | |
b8ff78ce JB |
35595 | @cindex @samp{z2} packet |
35596 | @cindex @samp{Z2} packet | |
a1dcb23a | 35597 | Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint at @var{addr}. |
697aa1b7 | 35598 | The number of bytes to watch is specified by @var{kind}. |
2f870471 AC |
35599 | |
35600 | Reply: | |
35601 | @table @samp | |
35602 | @item OK | |
35603 | success | |
d57350ea | 35604 | @item @w{} |
2f870471 | 35605 | not supported |
b8ff78ce | 35606 | @item E @var{NN} |
2f870471 AC |
35607 | for an error |
35608 | @end table | |
35609 | ||
a1dcb23a DJ |
35610 | @item z3,@var{addr},@var{kind} |
35611 | @itemx Z3,@var{addr},@var{kind} | |
b8ff78ce JB |
35612 | @cindex @samp{z3} packet |
35613 | @cindex @samp{Z3} packet | |
a1dcb23a | 35614 | Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint at @var{addr}. |
697aa1b7 | 35615 | The number of bytes to watch is specified by @var{kind}. |
2f870471 AC |
35616 | |
35617 | Reply: | |
35618 | @table @samp | |
35619 | @item OK | |
35620 | success | |
d57350ea | 35621 | @item @w{} |
2f870471 | 35622 | not supported |
b8ff78ce | 35623 | @item E @var{NN} |
2f870471 AC |
35624 | for an error |
35625 | @end table | |
35626 | ||
a1dcb23a DJ |
35627 | @item z4,@var{addr},@var{kind} |
35628 | @itemx Z4,@var{addr},@var{kind} | |
b8ff78ce JB |
35629 | @cindex @samp{z4} packet |
35630 | @cindex @samp{Z4} packet | |
a1dcb23a | 35631 | Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint at @var{addr}. |
697aa1b7 | 35632 | The number of bytes to watch is specified by @var{kind}. |
2f870471 AC |
35633 | |
35634 | Reply: | |
35635 | @table @samp | |
35636 | @item OK | |
35637 | success | |
d57350ea | 35638 | @item @w{} |
2f870471 | 35639 | not supported |
b8ff78ce | 35640 | @item E @var{NN} |
2f870471 | 35641 | for an error |
ee2d5c50 AC |
35642 | @end table |
35643 | ||
35644 | @end table | |
c906108c | 35645 | |
ee2d5c50 AC |
35646 | @node Stop Reply Packets |
35647 | @section Stop Reply Packets | |
35648 | @cindex stop reply packets | |
c906108c | 35649 | |
8b23ecc4 SL |
35650 | The @samp{C}, @samp{c}, @samp{S}, @samp{s}, @samp{vCont}, |
35651 | @samp{vAttach}, @samp{vRun}, @samp{vStopped}, and @samp{?} packets can | |
35652 | receive any of the below as a reply. Except for @samp{?} | |
35653 | and @samp{vStopped}, that reply is only returned | |
b8ff78ce | 35654 | when the target halts. In the below the exact meaning of @dfn{signal |
89be2091 DJ |
35655 | number} is defined by the header @file{include/gdb/signals.h} in the |
35656 | @value{GDBN} source code. | |
c906108c | 35657 | |
b8ff78ce JB |
35658 | As in the description of request packets, we include spaces in the |
35659 | reply templates for clarity; these are not part of the reply packet's | |
35660 | syntax. No @value{GDBN} stop reply packet uses spaces to separate its | |
35661 | components. | |
c906108c | 35662 | |
b8ff78ce | 35663 | @table @samp |
ee2d5c50 | 35664 | |
b8ff78ce | 35665 | @item S @var{AA} |
599b237a | 35666 | The program received signal number @var{AA} (a two-digit hexadecimal |
940178d3 JB |
35667 | number). This is equivalent to a @samp{T} response with no |
35668 | @var{n}:@var{r} pairs. | |
c906108c | 35669 | |
b8ff78ce JB |
35670 | @item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{} |
35671 | @cindex @samp{T} packet reply | |
599b237a | 35672 | The program received signal number @var{AA} (a two-digit hexadecimal |
940178d3 JB |
35673 | number). This is equivalent to an @samp{S} response, except that the |
35674 | @samp{@var{n}:@var{r}} pairs can carry values of important registers | |
35675 | and other information directly in the stop reply packet, reducing | |
35676 | round-trip latency. Single-step and breakpoint traps are reported | |
35677 | this way. Each @samp{@var{n}:@var{r}} pair is interpreted as follows: | |
cfa9d6d9 DJ |
35678 | |
35679 | @itemize @bullet | |
b8ff78ce | 35680 | @item |
599b237a | 35681 | If @var{n} is a hexadecimal number, it is a register number, and the |
697aa1b7 | 35682 | corresponding @var{r} gives that register's value. The data @var{r} is a |
b8ff78ce JB |
35683 | series of bytes in target byte order, with each byte given by a |
35684 | two-digit hex number. | |
cfa9d6d9 | 35685 | |
b8ff78ce | 35686 | @item |
b90a069a SL |
35687 | If @var{n} is @samp{thread}, then @var{r} is the @var{thread-id} of |
35688 | the stopped thread, as specified in @ref{thread-id syntax}. | |
cfa9d6d9 | 35689 | |
dc146f7c VP |
35690 | @item |
35691 | If @var{n} is @samp{core}, then @var{r} is the hexadecimal number of | |
35692 | the core on which the stop event was detected. | |
35693 | ||
b8ff78ce | 35694 | @item |
cfa9d6d9 DJ |
35695 | If @var{n} is a recognized @dfn{stop reason}, it describes a more |
35696 | specific event that stopped the target. The currently defined stop | |
697aa1b7 | 35697 | reasons are listed below. The @var{aa} should be @samp{05}, the trap |
cfa9d6d9 DJ |
35698 | signal. At most one stop reason should be present. |
35699 | ||
b8ff78ce JB |
35700 | @item |
35701 | Otherwise, @value{GDBN} should ignore this @samp{@var{n}:@var{r}} pair | |
35702 | and go on to the next; this allows us to extend the protocol in the | |
35703 | future. | |
cfa9d6d9 DJ |
35704 | @end itemize |
35705 | ||
35706 | The currently defined stop reasons are: | |
35707 | ||
35708 | @table @samp | |
35709 | @item watch | |
35710 | @itemx rwatch | |
35711 | @itemx awatch | |
35712 | The packet indicates a watchpoint hit, and @var{r} is the data address, in | |
35713 | hex. | |
35714 | ||
82075af2 JS |
35715 | @item syscall_entry |
35716 | @itemx syscall_return | |
35717 | The packet indicates a syscall entry or return, and @var{r} is the | |
35718 | syscall number, in hex. | |
35719 | ||
cfa9d6d9 DJ |
35720 | @cindex shared library events, remote reply |
35721 | @item library | |
35722 | The packet indicates that the loaded libraries have changed. | |
35723 | @value{GDBN} should use @samp{qXfer:libraries:read} to fetch a new | |
697aa1b7 | 35724 | list of loaded libraries. The @var{r} part is ignored. |
bacec72f MS |
35725 | |
35726 | @cindex replay log events, remote reply | |
35727 | @item replaylog | |
35728 | The packet indicates that the target cannot continue replaying | |
35729 | logged execution events, because it has reached the end (or the | |
35730 | beginning when executing backward) of the log. The value of @var{r} | |
35731 | will be either @samp{begin} or @samp{end}. @xref{Reverse Execution}, | |
35732 | for more information. | |
f7e6eed5 PA |
35733 | |
35734 | @item swbreak | |
35735 | @anchor{swbreak stop reason} | |
35736 | The packet indicates a memory breakpoint instruction was executed, | |
35737 | irrespective of whether it was @value{GDBN} that planted the | |
35738 | breakpoint or the breakpoint is hardcoded in the program. The @var{r} | |
35739 | part must be left empty. | |
35740 | ||
35741 | On some architectures, such as x86, at the architecture level, when a | |
35742 | breakpoint instruction executes the program counter points at the | |
35743 | breakpoint address plus an offset. On such targets, the stub is | |
35744 | responsible for adjusting the PC to point back at the breakpoint | |
35745 | address. | |
35746 | ||
35747 | This packet should not be sent by default; older @value{GDBN} versions | |
35748 | did not support it. @value{GDBN} requests it, by supplying an | |
35749 | appropriate @samp{qSupported} feature (@pxref{qSupported}). The | |
35750 | remote stub must also supply the appropriate @samp{qSupported} feature | |
35751 | indicating support. | |
35752 | ||
35753 | This packet is required for correct non-stop mode operation. | |
35754 | ||
35755 | @item hwbreak | |
35756 | The packet indicates the target stopped for a hardware breakpoint. | |
35757 | The @var{r} part must be left empty. | |
35758 | ||
35759 | The same remarks about @samp{qSupported} and non-stop mode above | |
35760 | apply. | |
0d71eef5 DB |
35761 | |
35762 | @cindex fork events, remote reply | |
35763 | @item fork | |
35764 | The packet indicates that @code{fork} was called, and @var{r} | |
35765 | is the thread ID of the new child process. Refer to | |
35766 | @ref{thread-id syntax} for the format of the @var{thread-id} | |
35767 | field. This packet is only applicable to targets that support | |
35768 | fork events. | |
35769 | ||
35770 | This packet should not be sent by default; older @value{GDBN} versions | |
35771 | did not support it. @value{GDBN} requests it, by supplying an | |
35772 | appropriate @samp{qSupported} feature (@pxref{qSupported}). The | |
35773 | remote stub must also supply the appropriate @samp{qSupported} feature | |
35774 | indicating support. | |
35775 | ||
35776 | @cindex vfork events, remote reply | |
35777 | @item vfork | |
35778 | The packet indicates that @code{vfork} was called, and @var{r} | |
35779 | is the thread ID of the new child process. Refer to | |
35780 | @ref{thread-id syntax} for the format of the @var{thread-id} | |
35781 | field. This packet is only applicable to targets that support | |
35782 | vfork events. | |
35783 | ||
35784 | This packet should not be sent by default; older @value{GDBN} versions | |
35785 | did not support it. @value{GDBN} requests it, by supplying an | |
35786 | appropriate @samp{qSupported} feature (@pxref{qSupported}). The | |
35787 | remote stub must also supply the appropriate @samp{qSupported} feature | |
35788 | indicating support. | |
35789 | ||
35790 | @cindex vforkdone events, remote reply | |
35791 | @item vforkdone | |
e68fa6f0 PA |
35792 | The packet indicates that a child process created by a vfork |
35793 | has either called @code{exec} or terminated, so that the | |
35794 | address spaces of the parent and child process are no longer | |
35795 | shared. The @var{r} part is ignored. This packet is only | |
35796 | applicable to targets that support vforkdone events. | |
0d71eef5 DB |
35797 | |
35798 | This packet should not be sent by default; older @value{GDBN} versions | |
35799 | did not support it. @value{GDBN} requests it, by supplying an | |
35800 | appropriate @samp{qSupported} feature (@pxref{qSupported}). The | |
35801 | remote stub must also supply the appropriate @samp{qSupported} feature | |
35802 | indicating support. | |
35803 | ||
b459a59b DB |
35804 | @cindex exec events, remote reply |
35805 | @item exec | |
35806 | The packet indicates that @code{execve} was called, and @var{r} | |
35807 | is the absolute pathname of the file that was executed, in hex. | |
35808 | This packet is only applicable to targets that support exec events. | |
35809 | ||
35810 | This packet should not be sent by default; older @value{GDBN} versions | |
35811 | did not support it. @value{GDBN} requests it, by supplying an | |
35812 | appropriate @samp{qSupported} feature (@pxref{qSupported}). The | |
35813 | remote stub must also supply the appropriate @samp{qSupported} feature | |
35814 | indicating support. | |
35815 | ||
65706a29 PA |
35816 | @cindex thread create event, remote reply |
35817 | @anchor{thread create event} | |
35818 | @item create | |
35819 | The packet indicates that the thread was just created. The new thread | |
35820 | is stopped until @value{GDBN} sets it running with a resumption packet | |
35821 | (@pxref{vCont packet}). This packet should not be sent by default; | |
35822 | @value{GDBN} requests it with the @ref{QThreadEvents} packet. See | |
35823 | also the @samp{w} (@ref{thread exit event}) remote reply below. | |
35824 | ||
cfa9d6d9 | 35825 | @end table |
ee2d5c50 | 35826 | |
b8ff78ce | 35827 | @item W @var{AA} |
b90a069a | 35828 | @itemx W @var{AA} ; process:@var{pid} |
8e04817f | 35829 | The process exited, and @var{AA} is the exit status. This is only |
ee2d5c50 AC |
35830 | applicable to certain targets. |
35831 | ||
b90a069a SL |
35832 | The second form of the response, including the process ID of the exited |
35833 | process, can be used only when @value{GDBN} has reported support for | |
35834 | multiprocess protocol extensions; see @ref{multiprocess extensions}. | |
35835 | The @var{pid} is formatted as a big-endian hex string. | |
35836 | ||
b8ff78ce | 35837 | @item X @var{AA} |
b90a069a | 35838 | @itemx X @var{AA} ; process:@var{pid} |
8e04817f | 35839 | The process terminated with signal @var{AA}. |
c906108c | 35840 | |
b90a069a SL |
35841 | The second form of the response, including the process ID of the |
35842 | terminated process, can be used only when @value{GDBN} has reported | |
35843 | support for multiprocess protocol extensions; see @ref{multiprocess | |
35844 | extensions}. The @var{pid} is formatted as a big-endian hex string. | |
35845 | ||
65706a29 PA |
35846 | @anchor{thread exit event} |
35847 | @cindex thread exit event, remote reply | |
35848 | @item w @var{AA} ; @var{tid} | |
35849 | ||
35850 | The thread exited, and @var{AA} is the exit status. This response | |
35851 | should not be sent by default; @value{GDBN} requests it with the | |
35852 | @ref{QThreadEvents} packet. See also @ref{thread create event} above. | |
35853 | ||
f2faf941 PA |
35854 | @item N |
35855 | There are no resumed threads left in the target. In other words, even | |
35856 | though the process is alive, the last resumed thread has exited. For | |
35857 | example, say the target process has two threads: thread 1 and thread | |
35858 | 2. The client leaves thread 1 stopped, and resumes thread 2, which | |
35859 | subsequently exits. At this point, even though the process is still | |
35860 | alive, and thus no @samp{W} stop reply is sent, no thread is actually | |
35861 | executing either. The @samp{N} stop reply thus informs the client | |
35862 | that it can stop waiting for stop replies. This packet should not be | |
35863 | sent by default; older @value{GDBN} versions did not support it. | |
35864 | @value{GDBN} requests it, by supplying an appropriate | |
35865 | @samp{qSupported} feature (@pxref{qSupported}). The remote stub must | |
35866 | also supply the appropriate @samp{qSupported} feature indicating | |
35867 | support. | |
35868 | ||
b8ff78ce JB |
35869 | @item O @var{XX}@dots{} |
35870 | @samp{@var{XX}@dots{}} is hex encoding of @sc{ascii} data, to be | |
35871 | written as the program's console output. This can happen at any time | |
35872 | while the program is running and the debugger should continue to wait | |
8b23ecc4 | 35873 | for @samp{W}, @samp{T}, etc. This reply is not permitted in non-stop mode. |
0ce1b118 | 35874 | |
b8ff78ce | 35875 | @item F @var{call-id},@var{parameter}@dots{} |
0ce1b118 CV |
35876 | @var{call-id} is the identifier which says which host system call should |
35877 | be called. This is just the name of the function. Translation into the | |
35878 | correct system call is only applicable as it's defined in @value{GDBN}. | |
79a6e687 | 35879 | @xref{File-I/O Remote Protocol Extension}, for a list of implemented |
0ce1b118 CV |
35880 | system calls. |
35881 | ||
b8ff78ce JB |
35882 | @samp{@var{parameter}@dots{}} is a list of parameters as defined for |
35883 | this very system call. | |
0ce1b118 | 35884 | |
b8ff78ce JB |
35885 | The target replies with this packet when it expects @value{GDBN} to |
35886 | call a host system call on behalf of the target. @value{GDBN} replies | |
35887 | with an appropriate @samp{F} packet and keeps up waiting for the next | |
35888 | reply packet from the target. The latest @samp{C}, @samp{c}, @samp{S} | |
79a6e687 BW |
35889 | or @samp{s} action is expected to be continued. @xref{File-I/O Remote |
35890 | Protocol Extension}, for more details. | |
0ce1b118 | 35891 | |
ee2d5c50 AC |
35892 | @end table |
35893 | ||
35894 | @node General Query Packets | |
35895 | @section General Query Packets | |
9c16f35a | 35896 | @cindex remote query requests |
c906108c | 35897 | |
5f3bebba JB |
35898 | Packets starting with @samp{q} are @dfn{general query packets}; |
35899 | packets starting with @samp{Q} are @dfn{general set packets}. General | |
35900 | query and set packets are a semi-unified form for retrieving and | |
35901 | sending information to and from the stub. | |
35902 | ||
35903 | The initial letter of a query or set packet is followed by a name | |
35904 | indicating what sort of thing the packet applies to. For example, | |
35905 | @value{GDBN} may use a @samp{qSymbol} packet to exchange symbol | |
35906 | definitions with the stub. These packet names follow some | |
35907 | conventions: | |
35908 | ||
35909 | @itemize @bullet | |
35910 | @item | |
35911 | The name must not contain commas, colons or semicolons. | |
35912 | @item | |
35913 | Most @value{GDBN} query and set packets have a leading upper case | |
35914 | letter. | |
35915 | @item | |
35916 | The names of custom vendor packets should use a company prefix, in | |
35917 | lower case, followed by a period. For example, packets designed at | |
35918 | the Acme Corporation might begin with @samp{qacme.foo} (for querying | |
35919 | foos) or @samp{Qacme.bar} (for setting bars). | |
35920 | @end itemize | |
35921 | ||
aa56d27a JB |
35922 | The name of a query or set packet should be separated from any |
35923 | parameters by a @samp{:}; the parameters themselves should be | |
35924 | separated by @samp{,} or @samp{;}. Stubs must be careful to match the | |
369af7bd DJ |
35925 | full packet name, and check for a separator or the end of the packet, |
35926 | in case two packet names share a common prefix. New packets should not begin | |
35927 | with @samp{qC}, @samp{qP}, or @samp{qL}@footnote{The @samp{qP} and @samp{qL} | |
35928 | packets predate these conventions, and have arguments without any terminator | |
35929 | for the packet name; we suspect they are in widespread use in places that | |
35930 | are difficult to upgrade. The @samp{qC} packet has no arguments, but some | |
35931 | existing stubs (e.g.@: RedBoot) are known to not check for the end of the | |
35932 | packet.}. | |
c906108c | 35933 | |
b8ff78ce JB |
35934 | Like the descriptions of the other packets, each description here |
35935 | has a template showing the packet's overall syntax, followed by an | |
35936 | explanation of the packet's meaning. We include spaces in some of the | |
35937 | templates for clarity; these are not part of the packet's syntax. No | |
35938 | @value{GDBN} packet uses spaces to separate its components. | |
35939 | ||
5f3bebba JB |
35940 | Here are the currently defined query and set packets: |
35941 | ||
b8ff78ce | 35942 | @table @samp |
c906108c | 35943 | |
d1feda86 | 35944 | @item QAgent:1 |
af4238e5 | 35945 | @itemx QAgent:0 |
d1feda86 YQ |
35946 | Turn on or off the agent as a helper to perform some debugging operations |
35947 | delegated from @value{GDBN} (@pxref{Control Agent}). | |
35948 | ||
d914c394 SS |
35949 | @item QAllow:@var{op}:@var{val}@dots{} |
35950 | @cindex @samp{QAllow} packet | |
35951 | Specify which operations @value{GDBN} expects to request of the | |
35952 | target, as a semicolon-separated list of operation name and value | |
35953 | pairs. Possible values for @var{op} include @samp{WriteReg}, | |
35954 | @samp{WriteMem}, @samp{InsertBreak}, @samp{InsertTrace}, | |
35955 | @samp{InsertFastTrace}, and @samp{Stop}. @var{val} is either 0, | |
35956 | indicating that @value{GDBN} will not request the operation, or 1, | |
35957 | indicating that it may. (The target can then use this to set up its | |
35958 | own internals optimally, for instance if the debugger never expects to | |
35959 | insert breakpoints, it may not need to install its own trap handler.) | |
35960 | ||
b8ff78ce | 35961 | @item qC |
9c16f35a | 35962 | @cindex current thread, remote request |
b8ff78ce | 35963 | @cindex @samp{qC} packet |
b90a069a | 35964 | Return the current thread ID. |
ee2d5c50 AC |
35965 | |
35966 | Reply: | |
35967 | @table @samp | |
b90a069a SL |
35968 | @item QC @var{thread-id} |
35969 | Where @var{thread-id} is a thread ID as documented in | |
35970 | @ref{thread-id syntax}. | |
b8ff78ce | 35971 | @item @r{(anything else)} |
b90a069a | 35972 | Any other reply implies the old thread ID. |
ee2d5c50 AC |
35973 | @end table |
35974 | ||
b8ff78ce | 35975 | @item qCRC:@var{addr},@var{length} |
ff2587ec | 35976 | @cindex CRC of memory block, remote request |
b8ff78ce | 35977 | @cindex @samp{qCRC} packet |
936d2992 | 35978 | @anchor{qCRC packet} |
99e008fe EZ |
35979 | Compute the CRC checksum of a block of memory using CRC-32 defined in |
35980 | IEEE 802.3. The CRC is computed byte at a time, taking the most | |
35981 | significant bit of each byte first. The initial pattern code | |
35982 | @code{0xffffffff} is used to ensure leading zeros affect the CRC. | |
35983 | ||
35984 | @emph{Note:} This is the same CRC used in validating separate debug | |
35985 | files (@pxref{Separate Debug Files, , Debugging Information in Separate | |
35986 | Files}). However the algorithm is slightly different. When validating | |
35987 | separate debug files, the CRC is computed taking the @emph{least} | |
35988 | significant bit of each byte first, and the final result is inverted to | |
35989 | detect trailing zeros. | |
35990 | ||
ff2587ec WZ |
35991 | Reply: |
35992 | @table @samp | |
b8ff78ce | 35993 | @item E @var{NN} |
ff2587ec | 35994 | An error (such as memory fault) |
b8ff78ce JB |
35995 | @item C @var{crc32} |
35996 | The specified memory region's checksum is @var{crc32}. | |
ff2587ec WZ |
35997 | @end table |
35998 | ||
03583c20 UW |
35999 | @item QDisableRandomization:@var{value} |
36000 | @cindex disable address space randomization, remote request | |
36001 | @cindex @samp{QDisableRandomization} packet | |
36002 | Some target operating systems will randomize the virtual address space | |
36003 | of the inferior process as a security feature, but provide a feature | |
36004 | to disable such randomization, e.g.@: to allow for a more deterministic | |
36005 | debugging experience. On such systems, this packet with a @var{value} | |
36006 | of 1 directs the target to disable address space randomization for | |
36007 | processes subsequently started via @samp{vRun} packets, while a packet | |
36008 | with a @var{value} of 0 tells the target to enable address space | |
36009 | randomization. | |
36010 | ||
36011 | This packet is only available in extended mode (@pxref{extended mode}). | |
36012 | ||
36013 | Reply: | |
36014 | @table @samp | |
36015 | @item OK | |
36016 | The request succeeded. | |
36017 | ||
36018 | @item E @var{nn} | |
697aa1b7 | 36019 | An error occurred. The error number @var{nn} is given as hex digits. |
03583c20 | 36020 | |
d57350ea | 36021 | @item @w{} |
03583c20 UW |
36022 | An empty reply indicates that @samp{QDisableRandomization} is not supported |
36023 | by the stub. | |
36024 | @end table | |
36025 | ||
36026 | This packet is not probed by default; the remote stub must request it, | |
36027 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
36028 | This should only be done on targets that actually support disabling | |
36029 | address space randomization. | |
36030 | ||
b8ff78ce JB |
36031 | @item qfThreadInfo |
36032 | @itemx qsThreadInfo | |
9c16f35a | 36033 | @cindex list active threads, remote request |
b8ff78ce JB |
36034 | @cindex @samp{qfThreadInfo} packet |
36035 | @cindex @samp{qsThreadInfo} packet | |
b90a069a | 36036 | Obtain a list of all active thread IDs from the target (OS). Since there |
8e04817f AC |
36037 | may be too many active threads to fit into one reply packet, this query |
36038 | works iteratively: it may require more than one query/reply sequence to | |
36039 | obtain the entire list of threads. The first query of the sequence will | |
b8ff78ce JB |
36040 | be the @samp{qfThreadInfo} query; subsequent queries in the |
36041 | sequence will be the @samp{qsThreadInfo} query. | |
ee2d5c50 | 36042 | |
b8ff78ce | 36043 | NOTE: This packet replaces the @samp{qL} query (see below). |
ee2d5c50 AC |
36044 | |
36045 | Reply: | |
36046 | @table @samp | |
b90a069a SL |
36047 | @item m @var{thread-id} |
36048 | A single thread ID | |
36049 | @item m @var{thread-id},@var{thread-id}@dots{} | |
36050 | a comma-separated list of thread IDs | |
b8ff78ce JB |
36051 | @item l |
36052 | (lower case letter @samp{L}) denotes end of list. | |
ee2d5c50 AC |
36053 | @end table |
36054 | ||
36055 | In response to each query, the target will reply with a list of one or | |
b90a069a | 36056 | more thread IDs, separated by commas. |
e1aac25b | 36057 | @value{GDBN} will respond to each reply with a request for more thread |
b8ff78ce | 36058 | ids (using the @samp{qs} form of the query), until the target responds |
501994c0 | 36059 | with @samp{l} (lower-case ell, for @dfn{last}). |
b90a069a SL |
36060 | Refer to @ref{thread-id syntax}, for the format of the @var{thread-id} |
36061 | fields. | |
c906108c | 36062 | |
8dfcab11 DT |
36063 | @emph{Note: @value{GDBN} will send the @code{qfThreadInfo} query during the |
36064 | initial connection with the remote target, and the very first thread ID | |
36065 | mentioned in the reply will be stopped by @value{GDBN} in a subsequent | |
36066 | message. Therefore, the stub should ensure that the first thread ID in | |
36067 | the @code{qfThreadInfo} reply is suitable for being stopped by @value{GDBN}.} | |
36068 | ||
b8ff78ce | 36069 | @item qGetTLSAddr:@var{thread-id},@var{offset},@var{lm} |
ff2587ec | 36070 | @cindex get thread-local storage address, remote request |
b8ff78ce | 36071 | @cindex @samp{qGetTLSAddr} packet |
ff2587ec WZ |
36072 | Fetch the address associated with thread local storage specified |
36073 | by @var{thread-id}, @var{offset}, and @var{lm}. | |
36074 | ||
b90a069a SL |
36075 | @var{thread-id} is the thread ID associated with the |
36076 | thread for which to fetch the TLS address. @xref{thread-id syntax}. | |
ff2587ec WZ |
36077 | |
36078 | @var{offset} is the (big endian, hex encoded) offset associated with the | |
36079 | thread local variable. (This offset is obtained from the debug | |
36080 | information associated with the variable.) | |
36081 | ||
db2e3e2e | 36082 | @var{lm} is the (big endian, hex encoded) OS/ABI-specific encoding of the |
7a9dd1b2 | 36083 | load module associated with the thread local storage. For example, |
ff2587ec WZ |
36084 | a @sc{gnu}/Linux system will pass the link map address of the shared |
36085 | object associated with the thread local storage under consideration. | |
36086 | Other operating environments may choose to represent the load module | |
36087 | differently, so the precise meaning of this parameter will vary. | |
ee2d5c50 AC |
36088 | |
36089 | Reply: | |
b8ff78ce JB |
36090 | @table @samp |
36091 | @item @var{XX}@dots{} | |
ff2587ec WZ |
36092 | Hex encoded (big endian) bytes representing the address of the thread |
36093 | local storage requested. | |
36094 | ||
b8ff78ce | 36095 | @item E @var{nn} |
697aa1b7 | 36096 | An error occurred. The error number @var{nn} is given as hex digits. |
ff2587ec | 36097 | |
d57350ea | 36098 | @item @w{} |
b8ff78ce | 36099 | An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub. |
ee2d5c50 AC |
36100 | @end table |
36101 | ||
711e434b PM |
36102 | @item qGetTIBAddr:@var{thread-id} |
36103 | @cindex get thread information block address | |
36104 | @cindex @samp{qGetTIBAddr} packet | |
36105 | Fetch address of the Windows OS specific Thread Information Block. | |
36106 | ||
36107 | @var{thread-id} is the thread ID associated with the thread. | |
36108 | ||
36109 | Reply: | |
36110 | @table @samp | |
36111 | @item @var{XX}@dots{} | |
36112 | Hex encoded (big endian) bytes representing the linear address of the | |
36113 | thread information block. | |
36114 | ||
36115 | @item E @var{nn} | |
36116 | An error occured. This means that either the thread was not found, or the | |
36117 | address could not be retrieved. | |
36118 | ||
d57350ea | 36119 | @item @w{} |
711e434b PM |
36120 | An empty reply indicates that @samp{qGetTIBAddr} is not supported by the stub. |
36121 | @end table | |
36122 | ||
b8ff78ce | 36123 | @item qL @var{startflag} @var{threadcount} @var{nextthread} |
8e04817f AC |
36124 | Obtain thread information from RTOS. Where: @var{startflag} (one hex |
36125 | digit) is one to indicate the first query and zero to indicate a | |
36126 | subsequent query; @var{threadcount} (two hex digits) is the maximum | |
36127 | number of threads the response packet can contain; and @var{nextthread} | |
36128 | (eight hex digits), for subsequent queries (@var{startflag} is zero), is | |
36129 | returned in the response as @var{argthread}. | |
ee2d5c50 | 36130 | |
b8ff78ce | 36131 | Don't use this packet; use the @samp{qfThreadInfo} query instead (see above). |
ee2d5c50 AC |
36132 | |
36133 | Reply: | |
36134 | @table @samp | |
b8ff78ce | 36135 | @item qM @var{count} @var{done} @var{argthread} @var{thread}@dots{} |
8e04817f AC |
36136 | Where: @var{count} (two hex digits) is the number of threads being |
36137 | returned; @var{done} (one hex digit) is zero to indicate more threads | |
36138 | and one indicates no further threads; @var{argthreadid} (eight hex | |
b8ff78ce | 36139 | digits) is @var{nextthread} from the request packet; @var{thread}@dots{} |
697aa1b7 EZ |
36140 | is a sequence of thread IDs, @var{threadid} (eight hex |
36141 | digits), from the target. See @code{remote.c:parse_threadlist_response()}. | |
ee2d5c50 | 36142 | @end table |
c906108c | 36143 | |
b8ff78ce | 36144 | @item qOffsets |
9c16f35a | 36145 | @cindex section offsets, remote request |
b8ff78ce | 36146 | @cindex @samp{qOffsets} packet |
31d99776 DJ |
36147 | Get section offsets that the target used when relocating the downloaded |
36148 | image. | |
c906108c | 36149 | |
ee2d5c50 AC |
36150 | Reply: |
36151 | @table @samp | |
31d99776 DJ |
36152 | @item Text=@var{xxx};Data=@var{yyy}@r{[};Bss=@var{zzz}@r{]} |
36153 | Relocate the @code{Text} section by @var{xxx} from its original address. | |
36154 | Relocate the @code{Data} section by @var{yyy} from its original address. | |
36155 | If the object file format provides segment information (e.g.@: @sc{elf} | |
36156 | @samp{PT_LOAD} program headers), @value{GDBN} will relocate entire | |
36157 | segments by the supplied offsets. | |
36158 | ||
36159 | @emph{Note: while a @code{Bss} offset may be included in the response, | |
36160 | @value{GDBN} ignores this and instead applies the @code{Data} offset | |
36161 | to the @code{Bss} section.} | |
36162 | ||
36163 | @item TextSeg=@var{xxx}@r{[};DataSeg=@var{yyy}@r{]} | |
36164 | Relocate the first segment of the object file, which conventionally | |
36165 | contains program code, to a starting address of @var{xxx}. If | |
36166 | @samp{DataSeg} is specified, relocate the second segment, which | |
36167 | conventionally contains modifiable data, to a starting address of | |
36168 | @var{yyy}. @value{GDBN} will report an error if the object file | |
36169 | does not contain segment information, or does not contain at least | |
36170 | as many segments as mentioned in the reply. Extra segments are | |
36171 | kept at fixed offsets relative to the last relocated segment. | |
ee2d5c50 AC |
36172 | @end table |
36173 | ||
b90a069a | 36174 | @item qP @var{mode} @var{thread-id} |
9c16f35a | 36175 | @cindex thread information, remote request |
b8ff78ce | 36176 | @cindex @samp{qP} packet |
b90a069a SL |
36177 | Returns information on @var{thread-id}. Where: @var{mode} is a hex |
36178 | encoded 32 bit mode; @var{thread-id} is a thread ID | |
36179 | (@pxref{thread-id syntax}). | |
ee2d5c50 | 36180 | |
aa56d27a JB |
36181 | Don't use this packet; use the @samp{qThreadExtraInfo} query instead |
36182 | (see below). | |
36183 | ||
b8ff78ce | 36184 | Reply: see @code{remote.c:remote_unpack_thread_info_response()}. |
c906108c | 36185 | |
8b23ecc4 | 36186 | @item QNonStop:1 |
687e43a4 | 36187 | @itemx QNonStop:0 |
8b23ecc4 SL |
36188 | @cindex non-stop mode, remote request |
36189 | @cindex @samp{QNonStop} packet | |
36190 | @anchor{QNonStop} | |
36191 | Enter non-stop (@samp{QNonStop:1}) or all-stop (@samp{QNonStop:0}) mode. | |
36192 | @xref{Remote Non-Stop}, for more information. | |
36193 | ||
36194 | Reply: | |
36195 | @table @samp | |
36196 | @item OK | |
36197 | The request succeeded. | |
36198 | ||
36199 | @item E @var{nn} | |
697aa1b7 | 36200 | An error occurred. The error number @var{nn} is given as hex digits. |
8b23ecc4 | 36201 | |
d57350ea | 36202 | @item @w{} |
8b23ecc4 SL |
36203 | An empty reply indicates that @samp{QNonStop} is not supported by |
36204 | the stub. | |
36205 | @end table | |
36206 | ||
36207 | This packet is not probed by default; the remote stub must request it, | |
36208 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
36209 | Use of this packet is controlled by the @code{set non-stop} command; | |
36210 | @pxref{Non-Stop Mode}. | |
36211 | ||
82075af2 JS |
36212 | @item QCatchSyscalls:1 @r{[};@var{sysno}@r{]}@dots{} |
36213 | @itemx QCatchSyscalls:0 | |
36214 | @cindex catch syscalls from inferior, remote request | |
36215 | @cindex @samp{QCatchSyscalls} packet | |
36216 | @anchor{QCatchSyscalls} | |
36217 | Enable (@samp{QCatchSyscalls:1}) or disable (@samp{QCatchSyscalls:0}) | |
36218 | catching syscalls from the inferior process. | |
36219 | ||
36220 | For @samp{QCatchSyscalls:1}, each listed syscall @var{sysno} (encoded | |
36221 | in hex) should be reported to @value{GDBN}. If no syscall @var{sysno} | |
36222 | is listed, every system call should be reported. | |
36223 | ||
36224 | Note that if a syscall not in the list is reported, @value{GDBN} will | |
36225 | still filter the event according to its own list from all corresponding | |
36226 | @code{catch syscall} commands. However, it is more efficient to only | |
36227 | report the requested syscalls. | |
36228 | ||
36229 | Multiple @samp{QCatchSyscalls:1} packets do not combine; any earlier | |
36230 | @samp{QCatchSyscalls:1} list is completely replaced by the new list. | |
36231 | ||
36232 | If the inferior process execs, the state of @samp{QCatchSyscalls} is | |
36233 | kept for the new process too. On targets where exec may affect syscall | |
36234 | numbers, for example with exec between 32 and 64-bit processes, the | |
36235 | client should send a new packet with the new syscall list. | |
36236 | ||
36237 | Reply: | |
36238 | @table @samp | |
36239 | @item OK | |
36240 | The request succeeded. | |
36241 | ||
36242 | @item E @var{nn} | |
36243 | An error occurred. @var{nn} are hex digits. | |
36244 | ||
36245 | @item @w{} | |
36246 | An empty reply indicates that @samp{QCatchSyscalls} is not supported by | |
36247 | the stub. | |
36248 | @end table | |
36249 | ||
36250 | Use of this packet is controlled by the @code{set remote catch-syscalls} | |
36251 | command (@pxref{Remote Configuration, set remote catch-syscalls}). | |
36252 | This packet is not probed by default; the remote stub must request it, | |
36253 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
36254 | ||
89be2091 DJ |
36255 | @item QPassSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{} |
36256 | @cindex pass signals to inferior, remote request | |
36257 | @cindex @samp{QPassSignals} packet | |
23181151 | 36258 | @anchor{QPassSignals} |
89be2091 DJ |
36259 | Each listed @var{signal} should be passed directly to the inferior process. |
36260 | Signals are numbered identically to continue packets and stop replies | |
36261 | (@pxref{Stop Reply Packets}). Each @var{signal} list item should be | |
36262 | strictly greater than the previous item. These signals do not need to stop | |
36263 | the inferior, or be reported to @value{GDBN}. All other signals should be | |
36264 | reported to @value{GDBN}. Multiple @samp{QPassSignals} packets do not | |
36265 | combine; any earlier @samp{QPassSignals} list is completely replaced by the | |
36266 | new list. This packet improves performance when using @samp{handle | |
36267 | @var{signal} nostop noprint pass}. | |
36268 | ||
36269 | Reply: | |
36270 | @table @samp | |
36271 | @item OK | |
36272 | The request succeeded. | |
36273 | ||
36274 | @item E @var{nn} | |
697aa1b7 | 36275 | An error occurred. The error number @var{nn} is given as hex digits. |
89be2091 | 36276 | |
d57350ea | 36277 | @item @w{} |
89be2091 DJ |
36278 | An empty reply indicates that @samp{QPassSignals} is not supported by |
36279 | the stub. | |
36280 | @end table | |
36281 | ||
36282 | Use of this packet is controlled by the @code{set remote pass-signals} | |
79a6e687 | 36283 | command (@pxref{Remote Configuration, set remote pass-signals}). |
89be2091 DJ |
36284 | This packet is not probed by default; the remote stub must request it, |
36285 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
36286 | ||
9b224c5e PA |
36287 | @item QProgramSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{} |
36288 | @cindex signals the inferior may see, remote request | |
36289 | @cindex @samp{QProgramSignals} packet | |
36290 | @anchor{QProgramSignals} | |
36291 | Each listed @var{signal} may be delivered to the inferior process. | |
36292 | Others should be silently discarded. | |
36293 | ||
36294 | In some cases, the remote stub may need to decide whether to deliver a | |
36295 | signal to the program or not without @value{GDBN} involvement. One | |
36296 | example of that is while detaching --- the program's threads may have | |
36297 | stopped for signals that haven't yet had a chance of being reported to | |
36298 | @value{GDBN}, and so the remote stub can use the signal list specified | |
36299 | by this packet to know whether to deliver or ignore those pending | |
36300 | signals. | |
36301 | ||
36302 | This does not influence whether to deliver a signal as requested by a | |
36303 | resumption packet (@pxref{vCont packet}). | |
36304 | ||
36305 | Signals are numbered identically to continue packets and stop replies | |
36306 | (@pxref{Stop Reply Packets}). Each @var{signal} list item should be | |
36307 | strictly greater than the previous item. Multiple | |
36308 | @samp{QProgramSignals} packets do not combine; any earlier | |
36309 | @samp{QProgramSignals} list is completely replaced by the new list. | |
36310 | ||
36311 | Reply: | |
36312 | @table @samp | |
36313 | @item OK | |
36314 | The request succeeded. | |
36315 | ||
36316 | @item E @var{nn} | |
697aa1b7 | 36317 | An error occurred. The error number @var{nn} is given as hex digits. |
9b224c5e | 36318 | |
d57350ea | 36319 | @item @w{} |
9b224c5e PA |
36320 | An empty reply indicates that @samp{QProgramSignals} is not supported |
36321 | by the stub. | |
36322 | @end table | |
36323 | ||
36324 | Use of this packet is controlled by the @code{set remote program-signals} | |
36325 | command (@pxref{Remote Configuration, set remote program-signals}). | |
36326 | This packet is not probed by default; the remote stub must request it, | |
36327 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
36328 | ||
65706a29 PA |
36329 | @anchor{QThreadEvents} |
36330 | @item QThreadEvents:1 | |
36331 | @itemx QThreadEvents:0 | |
36332 | @cindex thread create/exit events, remote request | |
36333 | @cindex @samp{QThreadEvents} packet | |
36334 | ||
36335 | Enable (@samp{QThreadEvents:1}) or disable (@samp{QThreadEvents:0}) | |
36336 | reporting of thread create and exit events. @xref{thread create | |
36337 | event}, for the reply specifications. For example, this is used in | |
36338 | non-stop mode when @value{GDBN} stops a set of threads and | |
36339 | synchronously waits for the their corresponding stop replies. Without | |
36340 | exit events, if one of the threads exits, @value{GDBN} would hang | |
36341 | forever not knowing that it should no longer expect a stop for that | |
36342 | same thread. @value{GDBN} does not enable this feature unless the | |
36343 | stub reports that it supports it by including @samp{QThreadEvents+} in | |
36344 | its @samp{qSupported} reply. | |
36345 | ||
36346 | Reply: | |
36347 | @table @samp | |
36348 | @item OK | |
36349 | The request succeeded. | |
36350 | ||
36351 | @item E @var{nn} | |
36352 | An error occurred. The error number @var{nn} is given as hex digits. | |
36353 | ||
36354 | @item @w{} | |
36355 | An empty reply indicates that @samp{QThreadEvents} is not supported by | |
36356 | the stub. | |
36357 | @end table | |
36358 | ||
36359 | Use of this packet is controlled by the @code{set remote thread-events} | |
36360 | command (@pxref{Remote Configuration, set remote thread-events}). | |
36361 | ||
b8ff78ce | 36362 | @item qRcmd,@var{command} |
ff2587ec | 36363 | @cindex execute remote command, remote request |
b8ff78ce | 36364 | @cindex @samp{qRcmd} packet |
ff2587ec | 36365 | @var{command} (hex encoded) is passed to the local interpreter for |
b8ff78ce JB |
36366 | execution. Invalid commands should be reported using the output |
36367 | string. Before the final result packet, the target may also respond | |
36368 | with a number of intermediate @samp{O@var{output}} console output | |
36369 | packets. @emph{Implementors should note that providing access to a | |
36370 | stubs's interpreter may have security implications}. | |
fa93a9d8 | 36371 | |
ff2587ec WZ |
36372 | Reply: |
36373 | @table @samp | |
36374 | @item OK | |
36375 | A command response with no output. | |
36376 | @item @var{OUTPUT} | |
36377 | A command response with the hex encoded output string @var{OUTPUT}. | |
b8ff78ce | 36378 | @item E @var{NN} |
ff2587ec | 36379 | Indicate a badly formed request. |
d57350ea | 36380 | @item @w{} |
b8ff78ce | 36381 | An empty reply indicates that @samp{qRcmd} is not recognized. |
ff2587ec | 36382 | @end table |
fa93a9d8 | 36383 | |
aa56d27a JB |
36384 | (Note that the @code{qRcmd} packet's name is separated from the |
36385 | command by a @samp{,}, not a @samp{:}, contrary to the naming | |
36386 | conventions above. Please don't use this packet as a model for new | |
36387 | packets.) | |
36388 | ||
08388c79 DE |
36389 | @item qSearch:memory:@var{address};@var{length};@var{search-pattern} |
36390 | @cindex searching memory, in remote debugging | |
5c4808ca | 36391 | @ifnotinfo |
08388c79 | 36392 | @cindex @samp{qSearch:memory} packet |
5c4808ca EZ |
36393 | @end ifnotinfo |
36394 | @cindex @samp{qSearch memory} packet | |
08388c79 DE |
36395 | @anchor{qSearch memory} |
36396 | Search @var{length} bytes at @var{address} for @var{search-pattern}. | |
697aa1b7 EZ |
36397 | Both @var{address} and @var{length} are encoded in hex; |
36398 | @var{search-pattern} is a sequence of bytes, also hex encoded. | |
08388c79 DE |
36399 | |
36400 | Reply: | |
36401 | @table @samp | |
36402 | @item 0 | |
36403 | The pattern was not found. | |
36404 | @item 1,address | |
36405 | The pattern was found at @var{address}. | |
36406 | @item E @var{NN} | |
36407 | A badly formed request or an error was encountered while searching memory. | |
d57350ea | 36408 | @item @w{} |
08388c79 DE |
36409 | An empty reply indicates that @samp{qSearch:memory} is not recognized. |
36410 | @end table | |
36411 | ||
a6f3e723 SL |
36412 | @item QStartNoAckMode |
36413 | @cindex @samp{QStartNoAckMode} packet | |
36414 | @anchor{QStartNoAckMode} | |
36415 | Request that the remote stub disable the normal @samp{+}/@samp{-} | |
36416 | protocol acknowledgments (@pxref{Packet Acknowledgment}). | |
36417 | ||
36418 | Reply: | |
36419 | @table @samp | |
36420 | @item OK | |
36421 | The stub has switched to no-acknowledgment mode. | |
36422 | @value{GDBN} acknowledges this reponse, | |
36423 | but neither the stub nor @value{GDBN} shall send or expect further | |
36424 | @samp{+}/@samp{-} acknowledgments in the current connection. | |
d57350ea | 36425 | @item @w{} |
a6f3e723 SL |
36426 | An empty reply indicates that the stub does not support no-acknowledgment mode. |
36427 | @end table | |
36428 | ||
be2a5f71 DJ |
36429 | @item qSupported @r{[}:@var{gdbfeature} @r{[};@var{gdbfeature}@r{]}@dots{} @r{]} |
36430 | @cindex supported packets, remote query | |
36431 | @cindex features of the remote protocol | |
36432 | @cindex @samp{qSupported} packet | |
0876f84a | 36433 | @anchor{qSupported} |
be2a5f71 DJ |
36434 | Tell the remote stub about features supported by @value{GDBN}, and |
36435 | query the stub for features it supports. This packet allows | |
36436 | @value{GDBN} and the remote stub to take advantage of each others' | |
36437 | features. @samp{qSupported} also consolidates multiple feature probes | |
36438 | at startup, to improve @value{GDBN} performance---a single larger | |
36439 | packet performs better than multiple smaller probe packets on | |
36440 | high-latency links. Some features may enable behavior which must not | |
36441 | be on by default, e.g.@: because it would confuse older clients or | |
36442 | stubs. Other features may describe packets which could be | |
36443 | automatically probed for, but are not. These features must be | |
36444 | reported before @value{GDBN} will use them. This ``default | |
36445 | unsupported'' behavior is not appropriate for all packets, but it | |
36446 | helps to keep the initial connection time under control with new | |
36447 | versions of @value{GDBN} which support increasing numbers of packets. | |
36448 | ||
36449 | Reply: | |
36450 | @table @samp | |
36451 | @item @var{stubfeature} @r{[};@var{stubfeature}@r{]}@dots{} | |
36452 | The stub supports or does not support each returned @var{stubfeature}, | |
36453 | depending on the form of each @var{stubfeature} (see below for the | |
36454 | possible forms). | |
d57350ea | 36455 | @item @w{} |
be2a5f71 DJ |
36456 | An empty reply indicates that @samp{qSupported} is not recognized, |
36457 | or that no features needed to be reported to @value{GDBN}. | |
36458 | @end table | |
36459 | ||
36460 | The allowed forms for each feature (either a @var{gdbfeature} in the | |
36461 | @samp{qSupported} packet, or a @var{stubfeature} in the response) | |
36462 | are: | |
36463 | ||
36464 | @table @samp | |
36465 | @item @var{name}=@var{value} | |
36466 | The remote protocol feature @var{name} is supported, and associated | |
36467 | with the specified @var{value}. The format of @var{value} depends | |
36468 | on the feature, but it must not include a semicolon. | |
36469 | @item @var{name}+ | |
36470 | The remote protocol feature @var{name} is supported, and does not | |
36471 | need an associated value. | |
36472 | @item @var{name}- | |
36473 | The remote protocol feature @var{name} is not supported. | |
36474 | @item @var{name}? | |
36475 | The remote protocol feature @var{name} may be supported, and | |
36476 | @value{GDBN} should auto-detect support in some other way when it is | |
36477 | needed. This form will not be used for @var{gdbfeature} notifications, | |
36478 | but may be used for @var{stubfeature} responses. | |
36479 | @end table | |
36480 | ||
36481 | Whenever the stub receives a @samp{qSupported} request, the | |
36482 | supplied set of @value{GDBN} features should override any previous | |
36483 | request. This allows @value{GDBN} to put the stub in a known | |
36484 | state, even if the stub had previously been communicating with | |
36485 | a different version of @value{GDBN}. | |
36486 | ||
b90a069a SL |
36487 | The following values of @var{gdbfeature} (for the packet sent by @value{GDBN}) |
36488 | are defined: | |
36489 | ||
36490 | @table @samp | |
36491 | @item multiprocess | |
36492 | This feature indicates whether @value{GDBN} supports multiprocess | |
36493 | extensions to the remote protocol. @value{GDBN} does not use such | |
36494 | extensions unless the stub also reports that it supports them by | |
36495 | including @samp{multiprocess+} in its @samp{qSupported} reply. | |
36496 | @xref{multiprocess extensions}, for details. | |
c8d5aac9 L |
36497 | |
36498 | @item xmlRegisters | |
36499 | This feature indicates that @value{GDBN} supports the XML target | |
36500 | description. If the stub sees @samp{xmlRegisters=} with target | |
36501 | specific strings separated by a comma, it will report register | |
36502 | description. | |
dde08ee1 PA |
36503 | |
36504 | @item qRelocInsn | |
36505 | This feature indicates whether @value{GDBN} supports the | |
36506 | @samp{qRelocInsn} packet (@pxref{Tracepoint Packets,,Relocate | |
36507 | instruction reply packet}). | |
f7e6eed5 PA |
36508 | |
36509 | @item swbreak | |
36510 | This feature indicates whether @value{GDBN} supports the swbreak stop | |
36511 | reason in stop replies. @xref{swbreak stop reason}, for details. | |
36512 | ||
36513 | @item hwbreak | |
36514 | This feature indicates whether @value{GDBN} supports the hwbreak stop | |
36515 | reason in stop replies. @xref{swbreak stop reason}, for details. | |
0d71eef5 DB |
36516 | |
36517 | @item fork-events | |
36518 | This feature indicates whether @value{GDBN} supports fork event | |
36519 | extensions to the remote protocol. @value{GDBN} does not use such | |
36520 | extensions unless the stub also reports that it supports them by | |
36521 | including @samp{fork-events+} in its @samp{qSupported} reply. | |
36522 | ||
36523 | @item vfork-events | |
36524 | This feature indicates whether @value{GDBN} supports vfork event | |
36525 | extensions to the remote protocol. @value{GDBN} does not use such | |
36526 | extensions unless the stub also reports that it supports them by | |
36527 | including @samp{vfork-events+} in its @samp{qSupported} reply. | |
b459a59b DB |
36528 | |
36529 | @item exec-events | |
36530 | This feature indicates whether @value{GDBN} supports exec event | |
36531 | extensions to the remote protocol. @value{GDBN} does not use such | |
36532 | extensions unless the stub also reports that it supports them by | |
36533 | including @samp{exec-events+} in its @samp{qSupported} reply. | |
750ce8d1 YQ |
36534 | |
36535 | @item vContSupported | |
36536 | This feature indicates whether @value{GDBN} wants to know the | |
36537 | supported actions in the reply to @samp{vCont?} packet. | |
b90a069a SL |
36538 | @end table |
36539 | ||
36540 | Stubs should ignore any unknown values for | |
be2a5f71 DJ |
36541 | @var{gdbfeature}. Any @value{GDBN} which sends a @samp{qSupported} |
36542 | packet supports receiving packets of unlimited length (earlier | |
b90a069a | 36543 | versions of @value{GDBN} may reject overly long responses). Additional values |
be2a5f71 DJ |
36544 | for @var{gdbfeature} may be defined in the future to let the stub take |
36545 | advantage of new features in @value{GDBN}, e.g.@: incompatible | |
b90a069a SL |
36546 | improvements in the remote protocol---the @samp{multiprocess} feature is |
36547 | an example of such a feature. The stub's reply should be independent | |
be2a5f71 DJ |
36548 | of the @var{gdbfeature} entries sent by @value{GDBN}; first @value{GDBN} |
36549 | describes all the features it supports, and then the stub replies with | |
36550 | all the features it supports. | |
36551 | ||
36552 | Similarly, @value{GDBN} will silently ignore unrecognized stub feature | |
36553 | responses, as long as each response uses one of the standard forms. | |
36554 | ||
36555 | Some features are flags. A stub which supports a flag feature | |
36556 | should respond with a @samp{+} form response. Other features | |
36557 | require values, and the stub should respond with an @samp{=} | |
36558 | form response. | |
36559 | ||
36560 | Each feature has a default value, which @value{GDBN} will use if | |
36561 | @samp{qSupported} is not available or if the feature is not mentioned | |
36562 | in the @samp{qSupported} response. The default values are fixed; a | |
36563 | stub is free to omit any feature responses that match the defaults. | |
36564 | ||
36565 | Not all features can be probed, but for those which can, the probing | |
36566 | mechanism is useful: in some cases, a stub's internal | |
36567 | architecture may not allow the protocol layer to know some information | |
36568 | about the underlying target in advance. This is especially common in | |
36569 | stubs which may be configured for multiple targets. | |
36570 | ||
36571 | These are the currently defined stub features and their properties: | |
36572 | ||
cfa9d6d9 | 36573 | @multitable @columnfractions 0.35 0.2 0.12 0.2 |
be2a5f71 DJ |
36574 | @c NOTE: The first row should be @headitem, but we do not yet require |
36575 | @c a new enough version of Texinfo (4.7) to use @headitem. | |
0876f84a | 36576 | @item Feature Name |
be2a5f71 DJ |
36577 | @tab Value Required |
36578 | @tab Default | |
36579 | @tab Probe Allowed | |
36580 | ||
36581 | @item @samp{PacketSize} | |
36582 | @tab Yes | |
36583 | @tab @samp{-} | |
36584 | @tab No | |
36585 | ||
0876f84a DJ |
36586 | @item @samp{qXfer:auxv:read} |
36587 | @tab No | |
36588 | @tab @samp{-} | |
36589 | @tab Yes | |
36590 | ||
2ae8c8e7 MM |
36591 | @item @samp{qXfer:btrace:read} |
36592 | @tab No | |
36593 | @tab @samp{-} | |
36594 | @tab Yes | |
36595 | ||
f4abbc16 MM |
36596 | @item @samp{qXfer:btrace-conf:read} |
36597 | @tab No | |
36598 | @tab @samp{-} | |
36599 | @tab Yes | |
36600 | ||
c78fa86a GB |
36601 | @item @samp{qXfer:exec-file:read} |
36602 | @tab No | |
36603 | @tab @samp{-} | |
36604 | @tab Yes | |
36605 | ||
23181151 DJ |
36606 | @item @samp{qXfer:features:read} |
36607 | @tab No | |
36608 | @tab @samp{-} | |
36609 | @tab Yes | |
36610 | ||
cfa9d6d9 DJ |
36611 | @item @samp{qXfer:libraries:read} |
36612 | @tab No | |
36613 | @tab @samp{-} | |
36614 | @tab Yes | |
36615 | ||
85dc5a12 GB |
36616 | @item @samp{qXfer:libraries-svr4:read} |
36617 | @tab No | |
36618 | @tab @samp{-} | |
36619 | @tab Yes | |
36620 | ||
36621 | @item @samp{augmented-libraries-svr4-read} | |
36622 | @tab No | |
36623 | @tab @samp{-} | |
36624 | @tab No | |
36625 | ||
68437a39 DJ |
36626 | @item @samp{qXfer:memory-map:read} |
36627 | @tab No | |
36628 | @tab @samp{-} | |
36629 | @tab Yes | |
36630 | ||
0fb4aa4b PA |
36631 | @item @samp{qXfer:sdata:read} |
36632 | @tab No | |
36633 | @tab @samp{-} | |
36634 | @tab Yes | |
36635 | ||
0e7f50da UW |
36636 | @item @samp{qXfer:spu:read} |
36637 | @tab No | |
36638 | @tab @samp{-} | |
36639 | @tab Yes | |
36640 | ||
36641 | @item @samp{qXfer:spu:write} | |
36642 | @tab No | |
36643 | @tab @samp{-} | |
36644 | @tab Yes | |
36645 | ||
4aa995e1 PA |
36646 | @item @samp{qXfer:siginfo:read} |
36647 | @tab No | |
36648 | @tab @samp{-} | |
36649 | @tab Yes | |
36650 | ||
36651 | @item @samp{qXfer:siginfo:write} | |
36652 | @tab No | |
36653 | @tab @samp{-} | |
36654 | @tab Yes | |
36655 | ||
dc146f7c VP |
36656 | @item @samp{qXfer:threads:read} |
36657 | @tab No | |
36658 | @tab @samp{-} | |
36659 | @tab Yes | |
36660 | ||
b3b9301e PA |
36661 | @item @samp{qXfer:traceframe-info:read} |
36662 | @tab No | |
36663 | @tab @samp{-} | |
36664 | @tab Yes | |
36665 | ||
169081d0 TG |
36666 | @item @samp{qXfer:uib:read} |
36667 | @tab No | |
36668 | @tab @samp{-} | |
36669 | @tab Yes | |
36670 | ||
78d85199 YQ |
36671 | @item @samp{qXfer:fdpic:read} |
36672 | @tab No | |
36673 | @tab @samp{-} | |
36674 | @tab Yes | |
dc146f7c | 36675 | |
2ae8c8e7 MM |
36676 | @item @samp{Qbtrace:off} |
36677 | @tab Yes | |
36678 | @tab @samp{-} | |
36679 | @tab Yes | |
36680 | ||
36681 | @item @samp{Qbtrace:bts} | |
36682 | @tab Yes | |
36683 | @tab @samp{-} | |
36684 | @tab Yes | |
36685 | ||
b20a6524 MM |
36686 | @item @samp{Qbtrace:pt} |
36687 | @tab Yes | |
36688 | @tab @samp{-} | |
36689 | @tab Yes | |
36690 | ||
d33501a5 MM |
36691 | @item @samp{Qbtrace-conf:bts:size} |
36692 | @tab Yes | |
36693 | @tab @samp{-} | |
36694 | @tab Yes | |
36695 | ||
b20a6524 MM |
36696 | @item @samp{Qbtrace-conf:pt:size} |
36697 | @tab Yes | |
36698 | @tab @samp{-} | |
36699 | @tab Yes | |
36700 | ||
8b23ecc4 SL |
36701 | @item @samp{QNonStop} |
36702 | @tab No | |
36703 | @tab @samp{-} | |
36704 | @tab Yes | |
36705 | ||
82075af2 JS |
36706 | @item @samp{QCatchSyscalls} |
36707 | @tab No | |
36708 | @tab @samp{-} | |
36709 | @tab Yes | |
36710 | ||
89be2091 DJ |
36711 | @item @samp{QPassSignals} |
36712 | @tab No | |
36713 | @tab @samp{-} | |
36714 | @tab Yes | |
36715 | ||
a6f3e723 SL |
36716 | @item @samp{QStartNoAckMode} |
36717 | @tab No | |
36718 | @tab @samp{-} | |
36719 | @tab Yes | |
36720 | ||
b90a069a SL |
36721 | @item @samp{multiprocess} |
36722 | @tab No | |
36723 | @tab @samp{-} | |
36724 | @tab No | |
36725 | ||
83364271 LM |
36726 | @item @samp{ConditionalBreakpoints} |
36727 | @tab No | |
36728 | @tab @samp{-} | |
36729 | @tab No | |
36730 | ||
782b2b07 SS |
36731 | @item @samp{ConditionalTracepoints} |
36732 | @tab No | |
36733 | @tab @samp{-} | |
36734 | @tab No | |
36735 | ||
0d772ac9 MS |
36736 | @item @samp{ReverseContinue} |
36737 | @tab No | |
2f8132f3 | 36738 | @tab @samp{-} |
0d772ac9 MS |
36739 | @tab No |
36740 | ||
36741 | @item @samp{ReverseStep} | |
36742 | @tab No | |
2f8132f3 | 36743 | @tab @samp{-} |
0d772ac9 MS |
36744 | @tab No |
36745 | ||
409873ef SS |
36746 | @item @samp{TracepointSource} |
36747 | @tab No | |
36748 | @tab @samp{-} | |
36749 | @tab No | |
36750 | ||
d1feda86 YQ |
36751 | @item @samp{QAgent} |
36752 | @tab No | |
36753 | @tab @samp{-} | |
36754 | @tab No | |
36755 | ||
d914c394 SS |
36756 | @item @samp{QAllow} |
36757 | @tab No | |
36758 | @tab @samp{-} | |
36759 | @tab No | |
36760 | ||
03583c20 UW |
36761 | @item @samp{QDisableRandomization} |
36762 | @tab No | |
36763 | @tab @samp{-} | |
36764 | @tab No | |
36765 | ||
d248b706 KY |
36766 | @item @samp{EnableDisableTracepoints} |
36767 | @tab No | |
36768 | @tab @samp{-} | |
36769 | @tab No | |
36770 | ||
f6f899bf HAQ |
36771 | @item @samp{QTBuffer:size} |
36772 | @tab No | |
36773 | @tab @samp{-} | |
36774 | @tab No | |
36775 | ||
3065dfb6 SS |
36776 | @item @samp{tracenz} |
36777 | @tab No | |
36778 | @tab @samp{-} | |
36779 | @tab No | |
36780 | ||
d3ce09f5 SS |
36781 | @item @samp{BreakpointCommands} |
36782 | @tab No | |
36783 | @tab @samp{-} | |
36784 | @tab No | |
36785 | ||
f7e6eed5 PA |
36786 | @item @samp{swbreak} |
36787 | @tab No | |
36788 | @tab @samp{-} | |
36789 | @tab No | |
36790 | ||
36791 | @item @samp{hwbreak} | |
36792 | @tab No | |
36793 | @tab @samp{-} | |
36794 | @tab No | |
36795 | ||
0d71eef5 DB |
36796 | @item @samp{fork-events} |
36797 | @tab No | |
36798 | @tab @samp{-} | |
36799 | @tab No | |
36800 | ||
36801 | @item @samp{vfork-events} | |
36802 | @tab No | |
36803 | @tab @samp{-} | |
36804 | @tab No | |
36805 | ||
b459a59b DB |
36806 | @item @samp{exec-events} |
36807 | @tab No | |
36808 | @tab @samp{-} | |
36809 | @tab No | |
36810 | ||
65706a29 PA |
36811 | @item @samp{QThreadEvents} |
36812 | @tab No | |
36813 | @tab @samp{-} | |
36814 | @tab No | |
36815 | ||
f2faf941 PA |
36816 | @item @samp{no-resumed} |
36817 | @tab No | |
36818 | @tab @samp{-} | |
36819 | @tab No | |
36820 | ||
be2a5f71 DJ |
36821 | @end multitable |
36822 | ||
36823 | These are the currently defined stub features, in more detail: | |
36824 | ||
36825 | @table @samp | |
36826 | @cindex packet size, remote protocol | |
36827 | @item PacketSize=@var{bytes} | |
36828 | The remote stub can accept packets up to at least @var{bytes} in | |
36829 | length. @value{GDBN} will send packets up to this size for bulk | |
36830 | transfers, and will never send larger packets. This is a limit on the | |
36831 | data characters in the packet, including the frame and checksum. | |
36832 | There is no trailing NUL byte in a remote protocol packet; if the stub | |
36833 | stores packets in a NUL-terminated format, it should allow an extra | |
36834 | byte in its buffer for the NUL. If this stub feature is not supported, | |
36835 | @value{GDBN} guesses based on the size of the @samp{g} packet response. | |
36836 | ||
0876f84a DJ |
36837 | @item qXfer:auxv:read |
36838 | The remote stub understands the @samp{qXfer:auxv:read} packet | |
36839 | (@pxref{qXfer auxiliary vector read}). | |
36840 | ||
2ae8c8e7 MM |
36841 | @item qXfer:btrace:read |
36842 | The remote stub understands the @samp{qXfer:btrace:read} | |
36843 | packet (@pxref{qXfer btrace read}). | |
36844 | ||
f4abbc16 MM |
36845 | @item qXfer:btrace-conf:read |
36846 | The remote stub understands the @samp{qXfer:btrace-conf:read} | |
36847 | packet (@pxref{qXfer btrace-conf read}). | |
36848 | ||
c78fa86a GB |
36849 | @item qXfer:exec-file:read |
36850 | The remote stub understands the @samp{qXfer:exec-file:read} packet | |
36851 | (@pxref{qXfer executable filename read}). | |
36852 | ||
23181151 DJ |
36853 | @item qXfer:features:read |
36854 | The remote stub understands the @samp{qXfer:features:read} packet | |
36855 | (@pxref{qXfer target description read}). | |
36856 | ||
cfa9d6d9 DJ |
36857 | @item qXfer:libraries:read |
36858 | The remote stub understands the @samp{qXfer:libraries:read} packet | |
36859 | (@pxref{qXfer library list read}). | |
36860 | ||
2268b414 JK |
36861 | @item qXfer:libraries-svr4:read |
36862 | The remote stub understands the @samp{qXfer:libraries-svr4:read} packet | |
36863 | (@pxref{qXfer svr4 library list read}). | |
36864 | ||
85dc5a12 GB |
36865 | @item augmented-libraries-svr4-read |
36866 | The remote stub understands the augmented form of the | |
36867 | @samp{qXfer:libraries-svr4:read} packet | |
36868 | (@pxref{qXfer svr4 library list read}). | |
36869 | ||
23181151 DJ |
36870 | @item qXfer:memory-map:read |
36871 | The remote stub understands the @samp{qXfer:memory-map:read} packet | |
36872 | (@pxref{qXfer memory map read}). | |
36873 | ||
0fb4aa4b PA |
36874 | @item qXfer:sdata:read |
36875 | The remote stub understands the @samp{qXfer:sdata:read} packet | |
36876 | (@pxref{qXfer sdata read}). | |
36877 | ||
0e7f50da UW |
36878 | @item qXfer:spu:read |
36879 | The remote stub understands the @samp{qXfer:spu:read} packet | |
36880 | (@pxref{qXfer spu read}). | |
36881 | ||
36882 | @item qXfer:spu:write | |
36883 | The remote stub understands the @samp{qXfer:spu:write} packet | |
36884 | (@pxref{qXfer spu write}). | |
36885 | ||
4aa995e1 PA |
36886 | @item qXfer:siginfo:read |
36887 | The remote stub understands the @samp{qXfer:siginfo:read} packet | |
36888 | (@pxref{qXfer siginfo read}). | |
36889 | ||
36890 | @item qXfer:siginfo:write | |
36891 | The remote stub understands the @samp{qXfer:siginfo:write} packet | |
36892 | (@pxref{qXfer siginfo write}). | |
36893 | ||
dc146f7c VP |
36894 | @item qXfer:threads:read |
36895 | The remote stub understands the @samp{qXfer:threads:read} packet | |
36896 | (@pxref{qXfer threads read}). | |
36897 | ||
b3b9301e PA |
36898 | @item qXfer:traceframe-info:read |
36899 | The remote stub understands the @samp{qXfer:traceframe-info:read} | |
36900 | packet (@pxref{qXfer traceframe info read}). | |
36901 | ||
169081d0 TG |
36902 | @item qXfer:uib:read |
36903 | The remote stub understands the @samp{qXfer:uib:read} | |
36904 | packet (@pxref{qXfer unwind info block}). | |
36905 | ||
78d85199 YQ |
36906 | @item qXfer:fdpic:read |
36907 | The remote stub understands the @samp{qXfer:fdpic:read} | |
36908 | packet (@pxref{qXfer fdpic loadmap read}). | |
36909 | ||
8b23ecc4 SL |
36910 | @item QNonStop |
36911 | The remote stub understands the @samp{QNonStop} packet | |
36912 | (@pxref{QNonStop}). | |
36913 | ||
82075af2 JS |
36914 | @item QCatchSyscalls |
36915 | The remote stub understands the @samp{QCatchSyscalls} packet | |
36916 | (@pxref{QCatchSyscalls}). | |
36917 | ||
23181151 DJ |
36918 | @item QPassSignals |
36919 | The remote stub understands the @samp{QPassSignals} packet | |
36920 | (@pxref{QPassSignals}). | |
36921 | ||
a6f3e723 SL |
36922 | @item QStartNoAckMode |
36923 | The remote stub understands the @samp{QStartNoAckMode} packet and | |
36924 | prefers to operate in no-acknowledgment mode. @xref{Packet Acknowledgment}. | |
36925 | ||
b90a069a SL |
36926 | @item multiprocess |
36927 | @anchor{multiprocess extensions} | |
36928 | @cindex multiprocess extensions, in remote protocol | |
36929 | The remote stub understands the multiprocess extensions to the remote | |
36930 | protocol syntax. The multiprocess extensions affect the syntax of | |
36931 | thread IDs in both packets and replies (@pxref{thread-id syntax}), and | |
36932 | add process IDs to the @samp{D} packet and @samp{W} and @samp{X} | |
36933 | replies. Note that reporting this feature indicates support for the | |
36934 | syntactic extensions only, not that the stub necessarily supports | |
36935 | debugging of more than one process at a time. The stub must not use | |
36936 | multiprocess extensions in packet replies unless @value{GDBN} has also | |
36937 | indicated it supports them in its @samp{qSupported} request. | |
36938 | ||
07e059b5 VP |
36939 | @item qXfer:osdata:read |
36940 | The remote stub understands the @samp{qXfer:osdata:read} packet | |
36941 | ((@pxref{qXfer osdata read}). | |
36942 | ||
83364271 LM |
36943 | @item ConditionalBreakpoints |
36944 | The target accepts and implements evaluation of conditional expressions | |
36945 | defined for breakpoints. The target will only report breakpoint triggers | |
36946 | when such conditions are true (@pxref{Conditions, ,Break Conditions}). | |
36947 | ||
782b2b07 SS |
36948 | @item ConditionalTracepoints |
36949 | The remote stub accepts and implements conditional expressions defined | |
36950 | for tracepoints (@pxref{Tracepoint Conditions}). | |
36951 | ||
0d772ac9 MS |
36952 | @item ReverseContinue |
36953 | The remote stub accepts and implements the reverse continue packet | |
36954 | (@pxref{bc}). | |
36955 | ||
36956 | @item ReverseStep | |
36957 | The remote stub accepts and implements the reverse step packet | |
36958 | (@pxref{bs}). | |
36959 | ||
409873ef SS |
36960 | @item TracepointSource |
36961 | The remote stub understands the @samp{QTDPsrc} packet that supplies | |
36962 | the source form of tracepoint definitions. | |
36963 | ||
d1feda86 YQ |
36964 | @item QAgent |
36965 | The remote stub understands the @samp{QAgent} packet. | |
36966 | ||
d914c394 SS |
36967 | @item QAllow |
36968 | The remote stub understands the @samp{QAllow} packet. | |
36969 | ||
03583c20 UW |
36970 | @item QDisableRandomization |
36971 | The remote stub understands the @samp{QDisableRandomization} packet. | |
36972 | ||
0fb4aa4b PA |
36973 | @item StaticTracepoint |
36974 | @cindex static tracepoints, in remote protocol | |
36975 | The remote stub supports static tracepoints. | |
36976 | ||
1e4d1764 YQ |
36977 | @item InstallInTrace |
36978 | @anchor{install tracepoint in tracing} | |
36979 | The remote stub supports installing tracepoint in tracing. | |
36980 | ||
d248b706 KY |
36981 | @item EnableDisableTracepoints |
36982 | The remote stub supports the @samp{QTEnable} (@pxref{QTEnable}) and | |
36983 | @samp{QTDisable} (@pxref{QTDisable}) packets that allow tracepoints | |
36984 | to be enabled and disabled while a trace experiment is running. | |
36985 | ||
f6f899bf | 36986 | @item QTBuffer:size |
28abe188 | 36987 | The remote stub supports the @samp{QTBuffer:size} (@pxref{QTBuffer-size}) |
f6f899bf HAQ |
36988 | packet that allows to change the size of the trace buffer. |
36989 | ||
3065dfb6 SS |
36990 | @item tracenz |
36991 | @cindex string tracing, in remote protocol | |
36992 | The remote stub supports the @samp{tracenz} bytecode for collecting strings. | |
36993 | See @ref{Bytecode Descriptions} for details about the bytecode. | |
36994 | ||
d3ce09f5 SS |
36995 | @item BreakpointCommands |
36996 | @cindex breakpoint commands, in remote protocol | |
36997 | The remote stub supports running a breakpoint's command list itself, | |
36998 | rather than reporting the hit to @value{GDBN}. | |
36999 | ||
2ae8c8e7 MM |
37000 | @item Qbtrace:off |
37001 | The remote stub understands the @samp{Qbtrace:off} packet. | |
37002 | ||
37003 | @item Qbtrace:bts | |
37004 | The remote stub understands the @samp{Qbtrace:bts} packet. | |
37005 | ||
b20a6524 MM |
37006 | @item Qbtrace:pt |
37007 | The remote stub understands the @samp{Qbtrace:pt} packet. | |
37008 | ||
d33501a5 MM |
37009 | @item Qbtrace-conf:bts:size |
37010 | The remote stub understands the @samp{Qbtrace-conf:bts:size} packet. | |
37011 | ||
b20a6524 MM |
37012 | @item Qbtrace-conf:pt:size |
37013 | The remote stub understands the @samp{Qbtrace-conf:pt:size} packet. | |
37014 | ||
f7e6eed5 PA |
37015 | @item swbreak |
37016 | The remote stub reports the @samp{swbreak} stop reason for memory | |
37017 | breakpoints. | |
37018 | ||
37019 | @item hwbreak | |
37020 | The remote stub reports the @samp{hwbreak} stop reason for hardware | |
37021 | breakpoints. | |
37022 | ||
0d71eef5 DB |
37023 | @item fork-events |
37024 | The remote stub reports the @samp{fork} stop reason for fork events. | |
37025 | ||
37026 | @item vfork-events | |
37027 | The remote stub reports the @samp{vfork} stop reason for vfork events | |
37028 | and vforkdone events. | |
37029 | ||
b459a59b DB |
37030 | @item exec-events |
37031 | The remote stub reports the @samp{exec} stop reason for exec events. | |
37032 | ||
750ce8d1 YQ |
37033 | @item vContSupported |
37034 | The remote stub reports the supported actions in the reply to | |
37035 | @samp{vCont?} packet. | |
37036 | ||
65706a29 PA |
37037 | @item QThreadEvents |
37038 | The remote stub understands the @samp{QThreadEvents} packet. | |
37039 | ||
f2faf941 PA |
37040 | @item no-resumed |
37041 | The remote stub reports the @samp{N} stop reply. | |
37042 | ||
be2a5f71 DJ |
37043 | @end table |
37044 | ||
b8ff78ce | 37045 | @item qSymbol:: |
ff2587ec | 37046 | @cindex symbol lookup, remote request |
b8ff78ce | 37047 | @cindex @samp{qSymbol} packet |
ff2587ec WZ |
37048 | Notify the target that @value{GDBN} is prepared to serve symbol lookup |
37049 | requests. Accept requests from the target for the values of symbols. | |
fa93a9d8 JB |
37050 | |
37051 | Reply: | |
ff2587ec | 37052 | @table @samp |
b8ff78ce | 37053 | @item OK |
ff2587ec | 37054 | The target does not need to look up any (more) symbols. |
b8ff78ce | 37055 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
37056 | The target requests the value of symbol @var{sym_name} (hex encoded). |
37057 | @value{GDBN} may provide the value by using the | |
b8ff78ce JB |
37058 | @samp{qSymbol:@var{sym_value}:@var{sym_name}} message, described |
37059 | below. | |
ff2587ec | 37060 | @end table |
83761cbd | 37061 | |
b8ff78ce | 37062 | @item qSymbol:@var{sym_value}:@var{sym_name} |
ff2587ec WZ |
37063 | Set the value of @var{sym_name} to @var{sym_value}. |
37064 | ||
37065 | @var{sym_name} (hex encoded) is the name of a symbol whose value the | |
37066 | target has previously requested. | |
37067 | ||
37068 | @var{sym_value} (hex) is the value for symbol @var{sym_name}. If | |
37069 | @value{GDBN} cannot supply a value for @var{sym_name}, then this field | |
37070 | will be empty. | |
37071 | ||
37072 | Reply: | |
37073 | @table @samp | |
b8ff78ce | 37074 | @item OK |
ff2587ec | 37075 | The target does not need to look up any (more) symbols. |
b8ff78ce | 37076 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
37077 | The target requests the value of a new symbol @var{sym_name} (hex |
37078 | encoded). @value{GDBN} will continue to supply the values of symbols | |
37079 | (if available), until the target ceases to request them. | |
fa93a9d8 | 37080 | @end table |
0abb7bc7 | 37081 | |
00bf0b85 | 37082 | @item qTBuffer |
687e43a4 TT |
37083 | @itemx QTBuffer |
37084 | @itemx QTDisconnected | |
d5551862 | 37085 | @itemx QTDP |
409873ef | 37086 | @itemx QTDPsrc |
d5551862 | 37087 | @itemx QTDV |
00bf0b85 SS |
37088 | @itemx qTfP |
37089 | @itemx qTfV | |
9d29849a | 37090 | @itemx QTFrame |
405f8e94 SS |
37091 | @itemx qTMinFTPILen |
37092 | ||
9d29849a JB |
37093 | @xref{Tracepoint Packets}. |
37094 | ||
b90a069a | 37095 | @item qThreadExtraInfo,@var{thread-id} |
ff2587ec | 37096 | @cindex thread attributes info, remote request |
b8ff78ce | 37097 | @cindex @samp{qThreadExtraInfo} packet |
697aa1b7 EZ |
37098 | Obtain from the target OS a printable string description of thread |
37099 | attributes for the thread @var{thread-id}; see @ref{thread-id syntax}, | |
37100 | for the forms of @var{thread-id}. This | |
b8ff78ce JB |
37101 | string may contain anything that the target OS thinks is interesting |
37102 | for @value{GDBN} to tell the user about the thread. The string is | |
37103 | displayed in @value{GDBN}'s @code{info threads} display. Some | |
37104 | examples of possible thread extra info strings are @samp{Runnable}, or | |
37105 | @samp{Blocked on Mutex}. | |
ff2587ec WZ |
37106 | |
37107 | Reply: | |
37108 | @table @samp | |
b8ff78ce JB |
37109 | @item @var{XX}@dots{} |
37110 | Where @samp{@var{XX}@dots{}} is a hex encoding of @sc{ascii} data, | |
37111 | comprising the printable string containing the extra information about | |
37112 | the thread's attributes. | |
ff2587ec | 37113 | @end table |
814e32d7 | 37114 | |
aa56d27a JB |
37115 | (Note that the @code{qThreadExtraInfo} packet's name is separated from |
37116 | the command by a @samp{,}, not a @samp{:}, contrary to the naming | |
37117 | conventions above. Please don't use this packet as a model for new | |
37118 | packets.) | |
37119 | ||
f196051f | 37120 | @item QTNotes |
687e43a4 TT |
37121 | @itemx qTP |
37122 | @itemx QTSave | |
37123 | @itemx qTsP | |
37124 | @itemx qTsV | |
d5551862 | 37125 | @itemx QTStart |
9d29849a | 37126 | @itemx QTStop |
d248b706 KY |
37127 | @itemx QTEnable |
37128 | @itemx QTDisable | |
9d29849a JB |
37129 | @itemx QTinit |
37130 | @itemx QTro | |
37131 | @itemx qTStatus | |
d5551862 | 37132 | @itemx qTV |
0fb4aa4b PA |
37133 | @itemx qTfSTM |
37134 | @itemx qTsSTM | |
37135 | @itemx qTSTMat | |
9d29849a JB |
37136 | @xref{Tracepoint Packets}. |
37137 | ||
0876f84a DJ |
37138 | @item qXfer:@var{object}:read:@var{annex}:@var{offset},@var{length} |
37139 | @cindex read special object, remote request | |
37140 | @cindex @samp{qXfer} packet | |
68437a39 | 37141 | @anchor{qXfer read} |
0876f84a DJ |
37142 | Read uninterpreted bytes from the target's special data area |
37143 | identified by the keyword @var{object}. Request @var{length} bytes | |
37144 | starting at @var{offset} bytes into the data. The content and | |
0e7f50da | 37145 | encoding of @var{annex} is specific to @var{object}; it can supply |
0876f84a DJ |
37146 | additional details about what data to access. |
37147 | ||
37148 | Here are the specific requests of this form defined so far. All | |
37149 | @samp{qXfer:@var{object}:read:@dots{}} requests use the same reply | |
37150 | formats, listed below. | |
37151 | ||
37152 | @table @samp | |
37153 | @item qXfer:auxv:read::@var{offset},@var{length} | |
37154 | @anchor{qXfer auxiliary vector read} | |
37155 | Access the target's @dfn{auxiliary vector}. @xref{OS Information, | |
427c3a89 | 37156 | auxiliary vector}. Note @var{annex} must be empty. |
0876f84a DJ |
37157 | |
37158 | This packet is not probed by default; the remote stub must request it, | |
89be2091 | 37159 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). |
0876f84a | 37160 | |
2ae8c8e7 MM |
37161 | @item qXfer:btrace:read:@var{annex}:@var{offset},@var{length} |
37162 | @anchor{qXfer btrace read} | |
37163 | ||
37164 | Return a description of the current branch trace. | |
37165 | @xref{Branch Trace Format}. The annex part of the generic @samp{qXfer} | |
37166 | packet may have one of the following values: | |
37167 | ||
37168 | @table @code | |
37169 | @item all | |
37170 | Returns all available branch trace. | |
37171 | ||
37172 | @item new | |
37173 | Returns all available branch trace if the branch trace changed since | |
37174 | the last read request. | |
969c39fb MM |
37175 | |
37176 | @item delta | |
37177 | Returns the new branch trace since the last read request. Adds a new | |
37178 | block to the end of the trace that begins at zero and ends at the source | |
37179 | location of the first branch in the trace buffer. This extra block is | |
37180 | used to stitch traces together. | |
37181 | ||
37182 | If the trace buffer overflowed, returns an error indicating the overflow. | |
2ae8c8e7 MM |
37183 | @end table |
37184 | ||
37185 | This packet is not probed by default; the remote stub must request it | |
37186 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37187 | ||
f4abbc16 MM |
37188 | @item qXfer:btrace-conf:read::@var{offset},@var{length} |
37189 | @anchor{qXfer btrace-conf read} | |
37190 | ||
37191 | Return a description of the current branch trace configuration. | |
37192 | @xref{Branch Trace Configuration Format}. | |
37193 | ||
37194 | This packet is not probed by default; the remote stub must request it | |
37195 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
c78fa86a GB |
37196 | |
37197 | @item qXfer:exec-file:read:@var{annex}:@var{offset},@var{length} | |
37198 | @anchor{qXfer executable filename read} | |
37199 | Return the full absolute name of the file that was executed to create | |
37200 | a process running on the remote system. The annex specifies the | |
37201 | numeric process ID of the process to query, encoded as a hexadecimal | |
835205d0 GB |
37202 | number. If the annex part is empty the remote stub should return the |
37203 | filename corresponding to the currently executing process. | |
c78fa86a GB |
37204 | |
37205 | This packet is not probed by default; the remote stub must request it, | |
37206 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
f4abbc16 | 37207 | |
23181151 DJ |
37208 | @item qXfer:features:read:@var{annex}:@var{offset},@var{length} |
37209 | @anchor{qXfer target description read} | |
37210 | Access the @dfn{target description}. @xref{Target Descriptions}. The | |
37211 | annex specifies which XML document to access. The main description is | |
37212 | always loaded from the @samp{target.xml} annex. | |
37213 | ||
37214 | This packet is not probed by default; the remote stub must request it, | |
37215 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37216 | ||
cfa9d6d9 DJ |
37217 | @item qXfer:libraries:read:@var{annex}:@var{offset},@var{length} |
37218 | @anchor{qXfer library list read} | |
37219 | Access the target's list of loaded libraries. @xref{Library List Format}. | |
37220 | The annex part of the generic @samp{qXfer} packet must be empty | |
37221 | (@pxref{qXfer read}). | |
37222 | ||
37223 | Targets which maintain a list of libraries in the program's memory do | |
37224 | not need to implement this packet; it is designed for platforms where | |
37225 | the operating system manages the list of loaded libraries. | |
37226 | ||
37227 | This packet is not probed by default; the remote stub must request it, | |
37228 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37229 | ||
2268b414 JK |
37230 | @item qXfer:libraries-svr4:read:@var{annex}:@var{offset},@var{length} |
37231 | @anchor{qXfer svr4 library list read} | |
37232 | Access the target's list of loaded libraries when the target is an SVR4 | |
37233 | platform. @xref{Library List Format for SVR4 Targets}. The annex part | |
85dc5a12 GB |
37234 | of the generic @samp{qXfer} packet must be empty unless the remote |
37235 | stub indicated it supports the augmented form of this packet | |
37236 | by supplying an appropriate @samp{qSupported} response | |
37237 | (@pxref{qXfer read}, @ref{qSupported}). | |
2268b414 JK |
37238 | |
37239 | This packet is optional for better performance on SVR4 targets. | |
37240 | @value{GDBN} uses memory read packets to read the SVR4 library list otherwise. | |
37241 | ||
37242 | This packet is not probed by default; the remote stub must request it, | |
37243 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37244 | ||
85dc5a12 GB |
37245 | If the remote stub indicates it supports the augmented form of this |
37246 | packet then the annex part of the generic @samp{qXfer} packet may | |
37247 | contain a semicolon-separated list of @samp{@var{name}=@var{value}} | |
37248 | arguments. The currently supported arguments are: | |
37249 | ||
37250 | @table @code | |
37251 | @item start=@var{address} | |
37252 | A hexadecimal number specifying the address of the @samp{struct | |
37253 | link_map} to start reading the library list from. If unset or zero | |
37254 | then the first @samp{struct link_map} in the library list will be | |
37255 | chosen as the starting point. | |
37256 | ||
37257 | @item prev=@var{address} | |
37258 | A hexadecimal number specifying the address of the @samp{struct | |
37259 | link_map} immediately preceding the @samp{struct link_map} | |
37260 | specified by the @samp{start} argument. If unset or zero then | |
37261 | the remote stub will expect that no @samp{struct link_map} | |
37262 | exists prior to the starting point. | |
37263 | ||
37264 | @end table | |
37265 | ||
37266 | Arguments that are not understood by the remote stub will be silently | |
37267 | ignored. | |
37268 | ||
68437a39 DJ |
37269 | @item qXfer:memory-map:read::@var{offset},@var{length} |
37270 | @anchor{qXfer memory map read} | |
79a6e687 | 37271 | Access the target's @dfn{memory-map}. @xref{Memory Map Format}. The |
68437a39 DJ |
37272 | annex part of the generic @samp{qXfer} packet must be empty |
37273 | (@pxref{qXfer read}). | |
37274 | ||
0e7f50da UW |
37275 | This packet is not probed by default; the remote stub must request it, |
37276 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37277 | ||
0fb4aa4b PA |
37278 | @item qXfer:sdata:read::@var{offset},@var{length} |
37279 | @anchor{qXfer sdata read} | |
37280 | ||
37281 | Read contents of the extra collected static tracepoint marker | |
37282 | information. The annex part of the generic @samp{qXfer} packet must | |
37283 | be empty (@pxref{qXfer read}). @xref{Tracepoint Actions,,Tracepoint | |
37284 | Action Lists}. | |
37285 | ||
37286 | This packet is not probed by default; the remote stub must request it, | |
37287 | by supplying an appropriate @samp{qSupported} response | |
37288 | (@pxref{qSupported}). | |
37289 | ||
4aa995e1 PA |
37290 | @item qXfer:siginfo:read::@var{offset},@var{length} |
37291 | @anchor{qXfer siginfo read} | |
37292 | Read contents of the extra signal information on the target | |
37293 | system. The annex part of the generic @samp{qXfer} packet must be | |
37294 | empty (@pxref{qXfer read}). | |
37295 | ||
37296 | This packet is not probed by default; the remote stub must request it, | |
37297 | by supplying an appropriate @samp{qSupported} response | |
37298 | (@pxref{qSupported}). | |
37299 | ||
0e7f50da UW |
37300 | @item qXfer:spu:read:@var{annex}:@var{offset},@var{length} |
37301 | @anchor{qXfer spu read} | |
37302 | Read contents of an @code{spufs} file on the target system. The | |
37303 | annex specifies which file to read; it must be of the form | |
37304 | @file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID | |
37305 | in the target process, and @var{name} identifes the @code{spufs} file | |
37306 | in that context to be accessed. | |
37307 | ||
68437a39 | 37308 | This packet is not probed by default; the remote stub must request it, |
07e059b5 VP |
37309 | by supplying an appropriate @samp{qSupported} response |
37310 | (@pxref{qSupported}). | |
37311 | ||
dc146f7c VP |
37312 | @item qXfer:threads:read::@var{offset},@var{length} |
37313 | @anchor{qXfer threads read} | |
37314 | Access the list of threads on target. @xref{Thread List Format}. The | |
37315 | annex part of the generic @samp{qXfer} packet must be empty | |
37316 | (@pxref{qXfer read}). | |
37317 | ||
37318 | This packet is not probed by default; the remote stub must request it, | |
37319 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37320 | ||
b3b9301e PA |
37321 | @item qXfer:traceframe-info:read::@var{offset},@var{length} |
37322 | @anchor{qXfer traceframe info read} | |
37323 | ||
37324 | Return a description of the current traceframe's contents. | |
37325 | @xref{Traceframe Info Format}. The annex part of the generic | |
37326 | @samp{qXfer} packet must be empty (@pxref{qXfer read}). | |
37327 | ||
37328 | This packet is not probed by default; the remote stub must request it, | |
37329 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37330 | ||
169081d0 TG |
37331 | @item qXfer:uib:read:@var{pc}:@var{offset},@var{length} |
37332 | @anchor{qXfer unwind info block} | |
37333 | ||
37334 | Return the unwind information block for @var{pc}. This packet is used | |
37335 | on OpenVMS/ia64 to ask the kernel unwind information. | |
37336 | ||
37337 | This packet is not probed by default. | |
37338 | ||
78d85199 YQ |
37339 | @item qXfer:fdpic:read:@var{annex}:@var{offset},@var{length} |
37340 | @anchor{qXfer fdpic loadmap read} | |
37341 | Read contents of @code{loadmap}s on the target system. The | |
37342 | annex, either @samp{exec} or @samp{interp}, specifies which @code{loadmap}, | |
37343 | executable @code{loadmap} or interpreter @code{loadmap} to read. | |
37344 | ||
37345 | This packet is not probed by default; the remote stub must request it, | |
37346 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37347 | ||
07e059b5 VP |
37348 | @item qXfer:osdata:read::@var{offset},@var{length} |
37349 | @anchor{qXfer osdata read} | |
697aa1b7 | 37350 | Access the target's @dfn{operating system information}. |
07e059b5 VP |
37351 | @xref{Operating System Information}. |
37352 | ||
68437a39 DJ |
37353 | @end table |
37354 | ||
0876f84a DJ |
37355 | Reply: |
37356 | @table @samp | |
37357 | @item m @var{data} | |
37358 | Data @var{data} (@pxref{Binary Data}) has been read from the | |
37359 | target. There may be more data at a higher address (although | |
37360 | it is permitted to return @samp{m} even for the last valid | |
37361 | block of data, as long as at least one byte of data was read). | |
697aa1b7 | 37362 | It is possible for @var{data} to have fewer bytes than the @var{length} in the |
0876f84a DJ |
37363 | request. |
37364 | ||
37365 | @item l @var{data} | |
37366 | Data @var{data} (@pxref{Binary Data}) has been read from the target. | |
697aa1b7 EZ |
37367 | There is no more data to be read. It is possible for @var{data} to |
37368 | have fewer bytes than the @var{length} in the request. | |
0876f84a DJ |
37369 | |
37370 | @item l | |
37371 | The @var{offset} in the request is at the end of the data. | |
37372 | There is no more data to be read. | |
37373 | ||
37374 | @item E00 | |
37375 | The request was malformed, or @var{annex} was invalid. | |
37376 | ||
37377 | @item E @var{nn} | |
37378 | The offset was invalid, or there was an error encountered reading the data. | |
697aa1b7 | 37379 | The @var{nn} part is a hex-encoded @code{errno} value. |
0876f84a | 37380 | |
d57350ea | 37381 | @item @w{} |
0876f84a DJ |
37382 | An empty reply indicates the @var{object} string was not recognized by |
37383 | the stub, or that the object does not support reading. | |
37384 | @end table | |
37385 | ||
37386 | @item qXfer:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{} | |
37387 | @cindex write data into object, remote request | |
4aa995e1 | 37388 | @anchor{qXfer write} |
0876f84a DJ |
37389 | Write uninterpreted bytes into the target's special data area |
37390 | identified by the keyword @var{object}, starting at @var{offset} bytes | |
697aa1b7 EZ |
37391 | into the data. The binary-encoded data (@pxref{Binary Data}) to be |
37392 | written is given by @var{data}@dots{}. The content and encoding of @var{annex} | |
0e7f50da | 37393 | is specific to @var{object}; it can supply additional details about what data |
0876f84a DJ |
37394 | to access. |
37395 | ||
0e7f50da UW |
37396 | Here are the specific requests of this form defined so far. All |
37397 | @samp{qXfer:@var{object}:write:@dots{}} requests use the same reply | |
37398 | formats, listed below. | |
37399 | ||
37400 | @table @samp | |
4aa995e1 PA |
37401 | @item qXfer:siginfo:write::@var{offset}:@var{data}@dots{} |
37402 | @anchor{qXfer siginfo write} | |
37403 | Write @var{data} to the extra signal information on the target system. | |
37404 | The annex part of the generic @samp{qXfer} packet must be | |
37405 | empty (@pxref{qXfer write}). | |
37406 | ||
37407 | This packet is not probed by default; the remote stub must request it, | |
37408 | by supplying an appropriate @samp{qSupported} response | |
37409 | (@pxref{qSupported}). | |
37410 | ||
84fcdf95 | 37411 | @item qXfer:spu:write:@var{annex}:@var{offset}:@var{data}@dots{} |
0e7f50da UW |
37412 | @anchor{qXfer spu write} |
37413 | Write @var{data} to an @code{spufs} file on the target system. The | |
37414 | annex specifies which file to write; it must be of the form | |
37415 | @file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID | |
37416 | in the target process, and @var{name} identifes the @code{spufs} file | |
37417 | in that context to be accessed. | |
37418 | ||
37419 | This packet is not probed by default; the remote stub must request it, | |
37420 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
37421 | @end table | |
0876f84a DJ |
37422 | |
37423 | Reply: | |
37424 | @table @samp | |
37425 | @item @var{nn} | |
37426 | @var{nn} (hex encoded) is the number of bytes written. | |
37427 | This may be fewer bytes than supplied in the request. | |
37428 | ||
37429 | @item E00 | |
37430 | The request was malformed, or @var{annex} was invalid. | |
37431 | ||
37432 | @item E @var{nn} | |
37433 | The offset was invalid, or there was an error encountered writing the data. | |
697aa1b7 | 37434 | The @var{nn} part is a hex-encoded @code{errno} value. |
0876f84a | 37435 | |
d57350ea | 37436 | @item @w{} |
0876f84a DJ |
37437 | An empty reply indicates the @var{object} string was not |
37438 | recognized by the stub, or that the object does not support writing. | |
37439 | @end table | |
37440 | ||
37441 | @item qXfer:@var{object}:@var{operation}:@dots{} | |
37442 | Requests of this form may be added in the future. When a stub does | |
37443 | not recognize the @var{object} keyword, or its support for | |
37444 | @var{object} does not recognize the @var{operation} keyword, the stub | |
37445 | must respond with an empty packet. | |
37446 | ||
0b16c5cf PA |
37447 | @item qAttached:@var{pid} |
37448 | @cindex query attached, remote request | |
37449 | @cindex @samp{qAttached} packet | |
37450 | Return an indication of whether the remote server attached to an | |
37451 | existing process or created a new process. When the multiprocess | |
37452 | protocol extensions are supported (@pxref{multiprocess extensions}), | |
37453 | @var{pid} is an integer in hexadecimal format identifying the target | |
37454 | process. Otherwise, @value{GDBN} will omit the @var{pid} field and | |
37455 | the query packet will be simplified as @samp{qAttached}. | |
37456 | ||
37457 | This query is used, for example, to know whether the remote process | |
37458 | should be detached or killed when a @value{GDBN} session is ended with | |
37459 | the @code{quit} command. | |
37460 | ||
37461 | Reply: | |
37462 | @table @samp | |
37463 | @item 1 | |
37464 | The remote server attached to an existing process. | |
37465 | @item 0 | |
37466 | The remote server created a new process. | |
37467 | @item E @var{NN} | |
37468 | A badly formed request or an error was encountered. | |
37469 | @end table | |
37470 | ||
2ae8c8e7 | 37471 | @item Qbtrace:bts |
b20a6524 MM |
37472 | Enable branch tracing for the current thread using Branch Trace Store. |
37473 | ||
37474 | Reply: | |
37475 | @table @samp | |
37476 | @item OK | |
37477 | Branch tracing has been enabled. | |
37478 | @item E.errtext | |
37479 | A badly formed request or an error was encountered. | |
37480 | @end table | |
37481 | ||
37482 | @item Qbtrace:pt | |
bc504a31 | 37483 | Enable branch tracing for the current thread using Intel Processor Trace. |
2ae8c8e7 MM |
37484 | |
37485 | Reply: | |
37486 | @table @samp | |
37487 | @item OK | |
37488 | Branch tracing has been enabled. | |
37489 | @item E.errtext | |
37490 | A badly formed request or an error was encountered. | |
37491 | @end table | |
37492 | ||
37493 | @item Qbtrace:off | |
37494 | Disable branch tracing for the current thread. | |
37495 | ||
37496 | Reply: | |
37497 | @table @samp | |
37498 | @item OK | |
37499 | Branch tracing has been disabled. | |
37500 | @item E.errtext | |
37501 | A badly formed request or an error was encountered. | |
37502 | @end table | |
37503 | ||
d33501a5 MM |
37504 | @item Qbtrace-conf:bts:size=@var{value} |
37505 | Set the requested ring buffer size for new threads that use the | |
37506 | btrace recording method in bts format. | |
37507 | ||
37508 | Reply: | |
37509 | @table @samp | |
37510 | @item OK | |
37511 | The ring buffer size has been set. | |
37512 | @item E.errtext | |
37513 | A badly formed request or an error was encountered. | |
37514 | @end table | |
37515 | ||
b20a6524 MM |
37516 | @item Qbtrace-conf:pt:size=@var{value} |
37517 | Set the requested ring buffer size for new threads that use the | |
37518 | btrace recording method in pt format. | |
37519 | ||
37520 | Reply: | |
37521 | @table @samp | |
37522 | @item OK | |
37523 | The ring buffer size has been set. | |
37524 | @item E.errtext | |
37525 | A badly formed request or an error was encountered. | |
37526 | @end table | |
37527 | ||
ee2d5c50 AC |
37528 | @end table |
37529 | ||
a1dcb23a DJ |
37530 | @node Architecture-Specific Protocol Details |
37531 | @section Architecture-Specific Protocol Details | |
37532 | ||
37533 | This section describes how the remote protocol is applied to specific | |
37534 | target architectures. Also see @ref{Standard Target Features}, for | |
37535 | details of XML target descriptions for each architecture. | |
37536 | ||
02b67415 MR |
37537 | @menu |
37538 | * ARM-Specific Protocol Details:: | |
37539 | * MIPS-Specific Protocol Details:: | |
37540 | @end menu | |
37541 | ||
37542 | @node ARM-Specific Protocol Details | |
37543 | @subsection @acronym{ARM}-specific Protocol Details | |
37544 | ||
37545 | @menu | |
37546 | * ARM Breakpoint Kinds:: | |
37547 | @end menu | |
a1dcb23a | 37548 | |
02b67415 MR |
37549 | @node ARM Breakpoint Kinds |
37550 | @subsubsection @acronym{ARM} Breakpoint Kinds | |
37551 | @cindex breakpoint kinds, @acronym{ARM} | |
a1dcb23a DJ |
37552 | |
37553 | These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets. | |
37554 | ||
37555 | @table @r | |
37556 | ||
37557 | @item 2 | |
37558 | 16-bit Thumb mode breakpoint. | |
37559 | ||
37560 | @item 3 | |
37561 | 32-bit Thumb mode (Thumb-2) breakpoint. | |
37562 | ||
37563 | @item 4 | |
02b67415 | 37564 | 32-bit @acronym{ARM} mode breakpoint. |
a1dcb23a DJ |
37565 | |
37566 | @end table | |
37567 | ||
02b67415 MR |
37568 | @node MIPS-Specific Protocol Details |
37569 | @subsection @acronym{MIPS}-specific Protocol Details | |
37570 | ||
37571 | @menu | |
37572 | * MIPS Register packet Format:: | |
4cc0665f | 37573 | * MIPS Breakpoint Kinds:: |
02b67415 | 37574 | @end menu |
a1dcb23a | 37575 | |
02b67415 MR |
37576 | @node MIPS Register packet Format |
37577 | @subsubsection @acronym{MIPS} Register Packet Format | |
eb17f351 | 37578 | @cindex register packet format, @acronym{MIPS} |
eb12ee30 | 37579 | |
b8ff78ce | 37580 | The following @code{g}/@code{G} packets have previously been defined. |
ee2d5c50 AC |
37581 | In the below, some thirty-two bit registers are transferred as |
37582 | sixty-four bits. Those registers should be zero/sign extended (which?) | |
599b237a BW |
37583 | to fill the space allocated. Register bytes are transferred in target |
37584 | byte order. The two nibbles within a register byte are transferred | |
02b67415 | 37585 | most-significant -- least-significant. |
eb12ee30 | 37586 | |
ee2d5c50 | 37587 | @table @r |
eb12ee30 | 37588 | |
8e04817f | 37589 | @item MIPS32 |
599b237a | 37590 | All registers are transferred as thirty-two bit quantities in the order: |
8e04817f AC |
37591 | 32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point |
37592 | registers; fsr; fir; fp. | |
eb12ee30 | 37593 | |
8e04817f | 37594 | @item MIPS64 |
599b237a | 37595 | All registers are transferred as sixty-four bit quantities (including |
8e04817f AC |
37596 | thirty-two bit registers such as @code{sr}). The ordering is the same |
37597 | as @code{MIPS32}. | |
eb12ee30 | 37598 | |
ee2d5c50 AC |
37599 | @end table |
37600 | ||
4cc0665f MR |
37601 | @node MIPS Breakpoint Kinds |
37602 | @subsubsection @acronym{MIPS} Breakpoint Kinds | |
37603 | @cindex breakpoint kinds, @acronym{MIPS} | |
37604 | ||
37605 | These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets. | |
37606 | ||
37607 | @table @r | |
37608 | ||
37609 | @item 2 | |
37610 | 16-bit @acronym{MIPS16} mode breakpoint. | |
37611 | ||
37612 | @item 3 | |
37613 | 16-bit @acronym{microMIPS} mode breakpoint. | |
37614 | ||
37615 | @item 4 | |
37616 | 32-bit standard @acronym{MIPS} mode breakpoint. | |
37617 | ||
37618 | @item 5 | |
37619 | 32-bit @acronym{microMIPS} mode breakpoint. | |
37620 | ||
37621 | @end table | |
37622 | ||
9d29849a JB |
37623 | @node Tracepoint Packets |
37624 | @section Tracepoint Packets | |
37625 | @cindex tracepoint packets | |
37626 | @cindex packets, tracepoint | |
37627 | ||
37628 | Here we describe the packets @value{GDBN} uses to implement | |
37629 | tracepoints (@pxref{Tracepoints}). | |
37630 | ||
37631 | @table @samp | |
37632 | ||
7a697b8d | 37633 | @item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}[:F@var{flen}][:X@var{len},@var{bytes}]@r{[}-@r{]} |
c614397c | 37634 | @cindex @samp{QTDP} packet |
9d29849a JB |
37635 | Create a new tracepoint, number @var{n}, at @var{addr}. If @var{ena} |
37636 | is @samp{E}, then the tracepoint is enabled; if it is @samp{D}, then | |
697aa1b7 EZ |
37637 | the tracepoint is disabled. The @var{step} gives the tracepoint's step |
37638 | count, and @var{pass} gives its pass count. If an @samp{F} is present, | |
7a697b8d SS |
37639 | then the tracepoint is to be a fast tracepoint, and the @var{flen} is |
37640 | the number of bytes that the target should copy elsewhere to make room | |
37641 | for the tracepoint. If an @samp{X} is present, it introduces a | |
37642 | tracepoint condition, which consists of a hexadecimal length, followed | |
37643 | by a comma and hex-encoded bytes, in a manner similar to action | |
37644 | encodings as described below. If the trailing @samp{-} is present, | |
37645 | further @samp{QTDP} packets will follow to specify this tracepoint's | |
37646 | actions. | |
9d29849a JB |
37647 | |
37648 | Replies: | |
37649 | @table @samp | |
37650 | @item OK | |
37651 | The packet was understood and carried out. | |
dde08ee1 PA |
37652 | @item qRelocInsn |
37653 | @xref{Tracepoint Packets,,Relocate instruction reply packet}. | |
d57350ea | 37654 | @item @w{} |
9d29849a JB |
37655 | The packet was not recognized. |
37656 | @end table | |
37657 | ||
37658 | @item QTDP:-@var{n}:@var{addr}:@r{[}S@r{]}@var{action}@dots{}@r{[}-@r{]} | |
697aa1b7 | 37659 | Define actions to be taken when a tracepoint is hit. The @var{n} and |
9d29849a JB |
37660 | @var{addr} must be the same as in the initial @samp{QTDP} packet for |
37661 | this tracepoint. This packet may only be sent immediately after | |
37662 | another @samp{QTDP} packet that ended with a @samp{-}. If the | |
37663 | trailing @samp{-} is present, further @samp{QTDP} packets will follow, | |
37664 | specifying more actions for this tracepoint. | |
37665 | ||
37666 | In the series of action packets for a given tracepoint, at most one | |
37667 | can have an @samp{S} before its first @var{action}. If such a packet | |
37668 | is sent, it and the following packets define ``while-stepping'' | |
37669 | actions. Any prior packets define ordinary actions --- that is, those | |
37670 | taken when the tracepoint is first hit. If no action packet has an | |
37671 | @samp{S}, then all the packets in the series specify ordinary | |
37672 | tracepoint actions. | |
37673 | ||
37674 | The @samp{@var{action}@dots{}} portion of the packet is a series of | |
37675 | actions, concatenated without separators. Each action has one of the | |
37676 | following forms: | |
37677 | ||
37678 | @table @samp | |
37679 | ||
37680 | @item R @var{mask} | |
697aa1b7 | 37681 | Collect the registers whose bits are set in @var{mask}, |
599b237a | 37682 | a hexadecimal number whose @var{i}'th bit is set if register number |
9d29849a JB |
37683 | @var{i} should be collected. (The least significant bit is numbered |
37684 | zero.) Note that @var{mask} may be any number of digits long; it may | |
37685 | not fit in a 32-bit word. | |
37686 | ||
37687 | @item M @var{basereg},@var{offset},@var{len} | |
37688 | Collect @var{len} bytes of memory starting at the address in register | |
37689 | number @var{basereg}, plus @var{offset}. If @var{basereg} is | |
37690 | @samp{-1}, then the range has a fixed address: @var{offset} is the | |
37691 | address of the lowest byte to collect. The @var{basereg}, | |
599b237a | 37692 | @var{offset}, and @var{len} parameters are all unsigned hexadecimal |
9d29849a JB |
37693 | values (the @samp{-1} value for @var{basereg} is a special case). |
37694 | ||
37695 | @item X @var{len},@var{expr} | |
37696 | Evaluate @var{expr}, whose length is @var{len}, and collect memory as | |
697aa1b7 | 37697 | it directs. The agent expression @var{expr} is as described in |
9d29849a JB |
37698 | @ref{Agent Expressions}. Each byte of the expression is encoded as a |
37699 | two-digit hex number in the packet; @var{len} is the number of bytes | |
37700 | in the expression (and thus one-half the number of hex digits in the | |
37701 | packet). | |
37702 | ||
37703 | @end table | |
37704 | ||
37705 | Any number of actions may be packed together in a single @samp{QTDP} | |
37706 | packet, as long as the packet does not exceed the maximum packet | |
c1947b85 JB |
37707 | length (400 bytes, for many stubs). There may be only one @samp{R} |
37708 | action per tracepoint, and it must precede any @samp{M} or @samp{X} | |
37709 | actions. Any registers referred to by @samp{M} and @samp{X} actions | |
37710 | must be collected by a preceding @samp{R} action. (The | |
37711 | ``while-stepping'' actions are treated as if they were attached to a | |
37712 | separate tracepoint, as far as these restrictions are concerned.) | |
9d29849a JB |
37713 | |
37714 | Replies: | |
37715 | @table @samp | |
37716 | @item OK | |
37717 | The packet was understood and carried out. | |
dde08ee1 PA |
37718 | @item qRelocInsn |
37719 | @xref{Tracepoint Packets,,Relocate instruction reply packet}. | |
d57350ea | 37720 | @item @w{} |
9d29849a JB |
37721 | The packet was not recognized. |
37722 | @end table | |
37723 | ||
409873ef SS |
37724 | @item QTDPsrc:@var{n}:@var{addr}:@var{type}:@var{start}:@var{slen}:@var{bytes} |
37725 | @cindex @samp{QTDPsrc} packet | |
37726 | Specify a source string of tracepoint @var{n} at address @var{addr}. | |
37727 | This is useful to get accurate reproduction of the tracepoints | |
697aa1b7 | 37728 | originally downloaded at the beginning of the trace run. The @var{type} |
409873ef SS |
37729 | is the name of the tracepoint part, such as @samp{cond} for the |
37730 | tracepoint's conditional expression (see below for a list of types), while | |
37731 | @var{bytes} is the string, encoded in hexadecimal. | |
37732 | ||
37733 | @var{start} is the offset of the @var{bytes} within the overall source | |
37734 | string, while @var{slen} is the total length of the source string. | |
37735 | This is intended for handling source strings that are longer than will | |
37736 | fit in a single packet. | |
37737 | @c Add detailed example when this info is moved into a dedicated | |
37738 | @c tracepoint descriptions section. | |
37739 | ||
37740 | The available string types are @samp{at} for the location, | |
37741 | @samp{cond} for the conditional, and @samp{cmd} for an action command. | |
37742 | @value{GDBN} sends a separate packet for each command in the action | |
37743 | list, in the same order in which the commands are stored in the list. | |
37744 | ||
37745 | The target does not need to do anything with source strings except | |
37746 | report them back as part of the replies to the @samp{qTfP}/@samp{qTsP} | |
37747 | query packets. | |
37748 | ||
37749 | Although this packet is optional, and @value{GDBN} will only send it | |
37750 | if the target replies with @samp{TracepointSource} @xref{General | |
37751 | Query Packets}, it makes both disconnected tracing and trace files | |
37752 | much easier to use. Otherwise the user must be careful that the | |
37753 | tracepoints in effect while looking at trace frames are identical to | |
37754 | the ones in effect during the trace run; even a small discrepancy | |
37755 | could cause @samp{tdump} not to work, or a particular trace frame not | |
37756 | be found. | |
37757 | ||
fa3f8d5a | 37758 | @item QTDV:@var{n}:@var{value}:@var{builtin}:@var{name} |
f61e138d SS |
37759 | @cindex define trace state variable, remote request |
37760 | @cindex @samp{QTDV} packet | |
37761 | Create a new trace state variable, number @var{n}, with an initial | |
37762 | value of @var{value}, which is a 64-bit signed integer. Both @var{n} | |
37763 | and @var{value} are encoded as hexadecimal values. @value{GDBN} has | |
37764 | the option of not using this packet for initial values of zero; the | |
37765 | target should simply create the trace state variables as they are | |
fa3f8d5a DT |
37766 | mentioned in expressions. The value @var{builtin} should be 1 (one) |
37767 | if the trace state variable is builtin and 0 (zero) if it is not builtin. | |
37768 | @value{GDBN} only sets @var{builtin} to 1 if a previous @samp{qTfV} or | |
37769 | @samp{qTsV} packet had it set. The contents of @var{name} is the | |
37770 | hex-encoded name (without the leading @samp{$}) of the trace state | |
37771 | variable. | |
f61e138d | 37772 | |
9d29849a | 37773 | @item QTFrame:@var{n} |
c614397c | 37774 | @cindex @samp{QTFrame} packet |
9d29849a JB |
37775 | Select the @var{n}'th tracepoint frame from the buffer, and use the |
37776 | register and memory contents recorded there to answer subsequent | |
37777 | request packets from @value{GDBN}. | |
37778 | ||
37779 | A successful reply from the stub indicates that the stub has found the | |
37780 | requested frame. The response is a series of parts, concatenated | |
37781 | without separators, describing the frame we selected. Each part has | |
37782 | one of the following forms: | |
37783 | ||
37784 | @table @samp | |
37785 | @item F @var{f} | |
37786 | The selected frame is number @var{n} in the trace frame buffer; | |
599b237a | 37787 | @var{f} is a hexadecimal number. If @var{f} is @samp{-1}, then there |
9d29849a JB |
37788 | was no frame matching the criteria in the request packet. |
37789 | ||
37790 | @item T @var{t} | |
37791 | The selected trace frame records a hit of tracepoint number @var{t}; | |
599b237a | 37792 | @var{t} is a hexadecimal number. |
9d29849a JB |
37793 | |
37794 | @end table | |
37795 | ||
37796 | @item QTFrame:pc:@var{addr} | |
37797 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
37798 | currently selected frame whose PC is @var{addr}; | |
599b237a | 37799 | @var{addr} is a hexadecimal number. |
9d29849a JB |
37800 | |
37801 | @item QTFrame:tdp:@var{t} | |
37802 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
37803 | currently selected frame that is a hit of tracepoint @var{t}; @var{t} | |
599b237a | 37804 | is a hexadecimal number. |
9d29849a JB |
37805 | |
37806 | @item QTFrame:range:@var{start}:@var{end} | |
37807 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
37808 | currently selected frame whose PC is between @var{start} (inclusive) | |
081dfbf7 | 37809 | and @var{end} (inclusive); @var{start} and @var{end} are hexadecimal |
9d29849a JB |
37810 | numbers. |
37811 | ||
37812 | @item QTFrame:outside:@var{start}:@var{end} | |
37813 | Like @samp{QTFrame:range:@var{start}:@var{end}}, but select the first | |
081dfbf7 | 37814 | frame @emph{outside} the given range of addresses (exclusive). |
9d29849a | 37815 | |
405f8e94 | 37816 | @item qTMinFTPILen |
c614397c | 37817 | @cindex @samp{qTMinFTPILen} packet |
405f8e94 SS |
37818 | This packet requests the minimum length of instruction at which a fast |
37819 | tracepoint (@pxref{Set Tracepoints}) may be placed. For instance, on | |
37820 | the 32-bit x86 architecture, it is possible to use a 4-byte jump, but | |
37821 | it depends on the target system being able to create trampolines in | |
37822 | the first 64K of memory, which might or might not be possible for that | |
37823 | system. So the reply to this packet will be 4 if it is able to | |
37824 | arrange for that. | |
37825 | ||
37826 | Replies: | |
37827 | ||
37828 | @table @samp | |
37829 | @item 0 | |
37830 | The minimum instruction length is currently unknown. | |
37831 | @item @var{length} | |
697aa1b7 EZ |
37832 | The minimum instruction length is @var{length}, where @var{length} |
37833 | is a hexadecimal number greater or equal to 1. A reply | |
37834 | of 1 means that a fast tracepoint may be placed on any instruction | |
37835 | regardless of size. | |
405f8e94 SS |
37836 | @item E |
37837 | An error has occurred. | |
d57350ea | 37838 | @item @w{} |
405f8e94 SS |
37839 | An empty reply indicates that the request is not supported by the stub. |
37840 | @end table | |
37841 | ||
9d29849a | 37842 | @item QTStart |
c614397c | 37843 | @cindex @samp{QTStart} packet |
dde08ee1 PA |
37844 | Begin the tracepoint experiment. Begin collecting data from |
37845 | tracepoint hits in the trace frame buffer. This packet supports the | |
37846 | @samp{qRelocInsn} reply (@pxref{Tracepoint Packets,,Relocate | |
37847 | instruction reply packet}). | |
9d29849a JB |
37848 | |
37849 | @item QTStop | |
c614397c | 37850 | @cindex @samp{QTStop} packet |
9d29849a JB |
37851 | End the tracepoint experiment. Stop collecting trace frames. |
37852 | ||
d248b706 KY |
37853 | @item QTEnable:@var{n}:@var{addr} |
37854 | @anchor{QTEnable} | |
c614397c | 37855 | @cindex @samp{QTEnable} packet |
d248b706 KY |
37856 | Enable tracepoint @var{n} at address @var{addr} in a started tracepoint |
37857 | experiment. If the tracepoint was previously disabled, then collection | |
37858 | of data from it will resume. | |
37859 | ||
37860 | @item QTDisable:@var{n}:@var{addr} | |
37861 | @anchor{QTDisable} | |
c614397c | 37862 | @cindex @samp{QTDisable} packet |
d248b706 KY |
37863 | Disable tracepoint @var{n} at address @var{addr} in a started tracepoint |
37864 | experiment. No more data will be collected from the tracepoint unless | |
37865 | @samp{QTEnable:@var{n}:@var{addr}} is subsequently issued. | |
37866 | ||
9d29849a | 37867 | @item QTinit |
c614397c | 37868 | @cindex @samp{QTinit} packet |
9d29849a JB |
37869 | Clear the table of tracepoints, and empty the trace frame buffer. |
37870 | ||
37871 | @item QTro:@var{start1},@var{end1}:@var{start2},@var{end2}:@dots{} | |
c614397c | 37872 | @cindex @samp{QTro} packet |
9d29849a JB |
37873 | Establish the given ranges of memory as ``transparent''. The stub |
37874 | will answer requests for these ranges from memory's current contents, | |
37875 | if they were not collected as part of the tracepoint hit. | |
37876 | ||
37877 | @value{GDBN} uses this to mark read-only regions of memory, like those | |
37878 | containing program code. Since these areas never change, they should | |
37879 | still have the same contents they did when the tracepoint was hit, so | |
37880 | there's no reason for the stub to refuse to provide their contents. | |
37881 | ||
d5551862 | 37882 | @item QTDisconnected:@var{value} |
c614397c | 37883 | @cindex @samp{QTDisconnected} packet |
d5551862 SS |
37884 | Set the choice to what to do with the tracing run when @value{GDBN} |
37885 | disconnects from the target. A @var{value} of 1 directs the target to | |
37886 | continue the tracing run, while 0 tells the target to stop tracing if | |
37887 | @value{GDBN} is no longer in the picture. | |
37888 | ||
9d29849a | 37889 | @item qTStatus |
c614397c | 37890 | @cindex @samp{qTStatus} packet |
9d29849a JB |
37891 | Ask the stub if there is a trace experiment running right now. |
37892 | ||
4daf5ac0 SS |
37893 | The reply has the form: |
37894 | ||
37895 | @table @samp | |
37896 | ||
37897 | @item T@var{running}@r{[};@var{field}@r{]}@dots{} | |
37898 | @var{running} is a single digit @code{1} if the trace is presently | |
37899 | running, or @code{0} if not. It is followed by semicolon-separated | |
37900 | optional fields that an agent may use to report additional status. | |
37901 | ||
37902 | @end table | |
37903 | ||
37904 | If the trace is not running, the agent may report any of several | |
37905 | explanations as one of the optional fields: | |
37906 | ||
37907 | @table @samp | |
37908 | ||
37909 | @item tnotrun:0 | |
37910 | No trace has been run yet. | |
37911 | ||
f196051f SS |
37912 | @item tstop[:@var{text}]:0 |
37913 | The trace was stopped by a user-originated stop command. The optional | |
37914 | @var{text} field is a user-supplied string supplied as part of the | |
37915 | stop command (for instance, an explanation of why the trace was | |
37916 | stopped manually). It is hex-encoded. | |
4daf5ac0 SS |
37917 | |
37918 | @item tfull:0 | |
37919 | The trace stopped because the trace buffer filled up. | |
37920 | ||
37921 | @item tdisconnected:0 | |
37922 | The trace stopped because @value{GDBN} disconnected from the target. | |
37923 | ||
37924 | @item tpasscount:@var{tpnum} | |
37925 | The trace stopped because tracepoint @var{tpnum} exceeded its pass count. | |
37926 | ||
6c28cbf2 SS |
37927 | @item terror:@var{text}:@var{tpnum} |
37928 | The trace stopped because tracepoint @var{tpnum} had an error. The | |
37929 | string @var{text} is available to describe the nature of the error | |
697aa1b7 EZ |
37930 | (for instance, a divide by zero in the condition expression); it |
37931 | is hex encoded. | |
6c28cbf2 | 37932 | |
4daf5ac0 SS |
37933 | @item tunknown:0 |
37934 | The trace stopped for some other reason. | |
37935 | ||
37936 | @end table | |
37937 | ||
33da3f1c SS |
37938 | Additional optional fields supply statistical and other information. |
37939 | Although not required, they are extremely useful for users monitoring | |
37940 | the progress of a trace run. If a trace has stopped, and these | |
37941 | numbers are reported, they must reflect the state of the just-stopped | |
37942 | trace. | |
4daf5ac0 | 37943 | |
9d29849a | 37944 | @table @samp |
4daf5ac0 SS |
37945 | |
37946 | @item tframes:@var{n} | |
37947 | The number of trace frames in the buffer. | |
37948 | ||
37949 | @item tcreated:@var{n} | |
37950 | The total number of trace frames created during the run. This may | |
37951 | be larger than the trace frame count, if the buffer is circular. | |
37952 | ||
37953 | @item tsize:@var{n} | |
37954 | The total size of the trace buffer, in bytes. | |
37955 | ||
37956 | @item tfree:@var{n} | |
37957 | The number of bytes still unused in the buffer. | |
37958 | ||
33da3f1c SS |
37959 | @item circular:@var{n} |
37960 | The value of the circular trace buffer flag. @code{1} means that the | |
37961 | trace buffer is circular and old trace frames will be discarded if | |
37962 | necessary to make room, @code{0} means that the trace buffer is linear | |
37963 | and may fill up. | |
37964 | ||
37965 | @item disconn:@var{n} | |
37966 | The value of the disconnected tracing flag. @code{1} means that | |
37967 | tracing will continue after @value{GDBN} disconnects, @code{0} means | |
37968 | that the trace run will stop. | |
37969 | ||
9d29849a JB |
37970 | @end table |
37971 | ||
f196051f SS |
37972 | @item qTP:@var{tp}:@var{addr} |
37973 | @cindex tracepoint status, remote request | |
37974 | @cindex @samp{qTP} packet | |
37975 | Ask the stub for the current state of tracepoint number @var{tp} at | |
37976 | address @var{addr}. | |
37977 | ||
37978 | Replies: | |
37979 | @table @samp | |
37980 | @item V@var{hits}:@var{usage} | |
37981 | The tracepoint has been hit @var{hits} times so far during the trace | |
37982 | run, and accounts for @var{usage} in the trace buffer. Note that | |
37983 | @code{while-stepping} steps are not counted as separate hits, but the | |
37984 | steps' space consumption is added into the usage number. | |
37985 | ||
37986 | @end table | |
37987 | ||
f61e138d SS |
37988 | @item qTV:@var{var} |
37989 | @cindex trace state variable value, remote request | |
37990 | @cindex @samp{qTV} packet | |
37991 | Ask the stub for the value of the trace state variable number @var{var}. | |
37992 | ||
37993 | Replies: | |
37994 | @table @samp | |
37995 | @item V@var{value} | |
37996 | The value of the variable is @var{value}. This will be the current | |
37997 | value of the variable if the user is examining a running target, or a | |
37998 | saved value if the variable was collected in the trace frame that the | |
37999 | user is looking at. Note that multiple requests may result in | |
38000 | different reply values, such as when requesting values while the | |
38001 | program is running. | |
38002 | ||
38003 | @item U | |
38004 | The value of the variable is unknown. This would occur, for example, | |
38005 | if the user is examining a trace frame in which the requested variable | |
38006 | was not collected. | |
9d29849a JB |
38007 | @end table |
38008 | ||
d5551862 | 38009 | @item qTfP |
c614397c | 38010 | @cindex @samp{qTfP} packet |
d5551862 | 38011 | @itemx qTsP |
c614397c | 38012 | @cindex @samp{qTsP} packet |
d5551862 SS |
38013 | These packets request data about tracepoints that are being used by |
38014 | the target. @value{GDBN} sends @code{qTfP} to get the first piece | |
38015 | of data, and multiple @code{qTsP} to get additional pieces. Replies | |
38016 | to these packets generally take the form of the @code{QTDP} packets | |
38017 | that define tracepoints. (FIXME add detailed syntax) | |
38018 | ||
00bf0b85 | 38019 | @item qTfV |
c614397c | 38020 | @cindex @samp{qTfV} packet |
00bf0b85 | 38021 | @itemx qTsV |
c614397c | 38022 | @cindex @samp{qTsV} packet |
00bf0b85 SS |
38023 | These packets request data about trace state variables that are on the |
38024 | target. @value{GDBN} sends @code{qTfV} to get the first vari of data, | |
38025 | and multiple @code{qTsV} to get additional variables. Replies to | |
38026 | these packets follow the syntax of the @code{QTDV} packets that define | |
38027 | trace state variables. | |
38028 | ||
0fb4aa4b PA |
38029 | @item qTfSTM |
38030 | @itemx qTsSTM | |
16bdd41f YQ |
38031 | @anchor{qTfSTM} |
38032 | @anchor{qTsSTM} | |
c614397c YQ |
38033 | @cindex @samp{qTfSTM} packet |
38034 | @cindex @samp{qTsSTM} packet | |
0fb4aa4b PA |
38035 | These packets request data about static tracepoint markers that exist |
38036 | in the target program. @value{GDBN} sends @code{qTfSTM} to get the | |
38037 | first piece of data, and multiple @code{qTsSTM} to get additional | |
38038 | pieces. Replies to these packets take the following form: | |
38039 | ||
38040 | Reply: | |
38041 | @table @samp | |
38042 | @item m @var{address}:@var{id}:@var{extra} | |
38043 | A single marker | |
38044 | @item m @var{address}:@var{id}:@var{extra},@var{address}:@var{id}:@var{extra}@dots{} | |
38045 | a comma-separated list of markers | |
38046 | @item l | |
38047 | (lower case letter @samp{L}) denotes end of list. | |
38048 | @item E @var{nn} | |
697aa1b7 | 38049 | An error occurred. The error number @var{nn} is given as hex digits. |
d57350ea | 38050 | @item @w{} |
0fb4aa4b PA |
38051 | An empty reply indicates that the request is not supported by the |
38052 | stub. | |
38053 | @end table | |
38054 | ||
697aa1b7 | 38055 | The @var{address} is encoded in hex; |
0fb4aa4b PA |
38056 | @var{id} and @var{extra} are strings encoded in hex. |
38057 | ||
38058 | In response to each query, the target will reply with a list of one or | |
38059 | more markers, separated by commas. @value{GDBN} will respond to each | |
38060 | reply with a request for more markers (using the @samp{qs} form of the | |
38061 | query), until the target responds with @samp{l} (lower-case ell, for | |
38062 | @dfn{last}). | |
38063 | ||
38064 | @item qTSTMat:@var{address} | |
16bdd41f | 38065 | @anchor{qTSTMat} |
c614397c | 38066 | @cindex @samp{qTSTMat} packet |
0fb4aa4b PA |
38067 | This packets requests data about static tracepoint markers in the |
38068 | target program at @var{address}. Replies to this packet follow the | |
38069 | syntax of the @samp{qTfSTM} and @code{qTsSTM} packets that list static | |
38070 | tracepoint markers. | |
38071 | ||
00bf0b85 | 38072 | @item QTSave:@var{filename} |
c614397c | 38073 | @cindex @samp{QTSave} packet |
00bf0b85 | 38074 | This packet directs the target to save trace data to the file name |
697aa1b7 | 38075 | @var{filename} in the target's filesystem. The @var{filename} is encoded |
00bf0b85 SS |
38076 | as a hex string; the interpretation of the file name (relative vs |
38077 | absolute, wild cards, etc) is up to the target. | |
38078 | ||
38079 | @item qTBuffer:@var{offset},@var{len} | |
c614397c | 38080 | @cindex @samp{qTBuffer} packet |
00bf0b85 SS |
38081 | Return up to @var{len} bytes of the current contents of trace buffer, |
38082 | starting at @var{offset}. The trace buffer is treated as if it were | |
38083 | a contiguous collection of traceframes, as per the trace file format. | |
38084 | The reply consists as many hex-encoded bytes as the target can deliver | |
38085 | in a packet; it is not an error to return fewer than were asked for. | |
38086 | A reply consisting of just @code{l} indicates that no bytes are | |
38087 | available. | |
38088 | ||
4daf5ac0 SS |
38089 | @item QTBuffer:circular:@var{value} |
38090 | This packet directs the target to use a circular trace buffer if | |
38091 | @var{value} is 1, or a linear buffer if the value is 0. | |
38092 | ||
f6f899bf | 38093 | @item QTBuffer:size:@var{size} |
28abe188 EZ |
38094 | @anchor{QTBuffer-size} |
38095 | @cindex @samp{QTBuffer size} packet | |
f6f899bf HAQ |
38096 | This packet directs the target to make the trace buffer be of size |
38097 | @var{size} if possible. A value of @code{-1} tells the target to | |
38098 | use whatever size it prefers. | |
38099 | ||
f196051f | 38100 | @item QTNotes:@r{[}@var{type}:@var{text}@r{]}@r{[};@var{type}:@var{text}@r{]}@dots{} |
c614397c | 38101 | @cindex @samp{QTNotes} packet |
f196051f SS |
38102 | This packet adds optional textual notes to the trace run. Allowable |
38103 | types include @code{user}, @code{notes}, and @code{tstop}, the | |
38104 | @var{text} fields are arbitrary strings, hex-encoded. | |
38105 | ||
f61e138d | 38106 | @end table |
9d29849a | 38107 | |
dde08ee1 PA |
38108 | @subsection Relocate instruction reply packet |
38109 | When installing fast tracepoints in memory, the target may need to | |
38110 | relocate the instruction currently at the tracepoint address to a | |
38111 | different address in memory. For most instructions, a simple copy is | |
38112 | enough, but, for example, call instructions that implicitly push the | |
38113 | return address on the stack, and relative branches or other | |
38114 | PC-relative instructions require offset adjustment, so that the effect | |
38115 | of executing the instruction at a different address is the same as if | |
38116 | it had executed in the original location. | |
38117 | ||
38118 | In response to several of the tracepoint packets, the target may also | |
38119 | respond with a number of intermediate @samp{qRelocInsn} request | |
38120 | packets before the final result packet, to have @value{GDBN} handle | |
38121 | this relocation operation. If a packet supports this mechanism, its | |
38122 | documentation will explicitly say so. See for example the above | |
38123 | descriptions for the @samp{QTStart} and @samp{QTDP} packets. The | |
38124 | format of the request is: | |
38125 | ||
38126 | @table @samp | |
38127 | @item qRelocInsn:@var{from};@var{to} | |
38128 | ||
38129 | This requests @value{GDBN} to copy instruction at address @var{from} | |
38130 | to address @var{to}, possibly adjusted so that executing the | |
38131 | instruction at @var{to} has the same effect as executing it at | |
38132 | @var{from}. @value{GDBN} writes the adjusted instruction to target | |
38133 | memory starting at @var{to}. | |
38134 | @end table | |
38135 | ||
38136 | Replies: | |
38137 | @table @samp | |
38138 | @item qRelocInsn:@var{adjusted_size} | |
697aa1b7 | 38139 | Informs the stub the relocation is complete. The @var{adjusted_size} is |
dde08ee1 PA |
38140 | the length in bytes of resulting relocated instruction sequence. |
38141 | @item E @var{NN} | |
38142 | A badly formed request was detected, or an error was encountered while | |
38143 | relocating the instruction. | |
38144 | @end table | |
38145 | ||
a6b151f1 DJ |
38146 | @node Host I/O Packets |
38147 | @section Host I/O Packets | |
38148 | @cindex Host I/O, remote protocol | |
38149 | @cindex file transfer, remote protocol | |
38150 | ||
38151 | The @dfn{Host I/O} packets allow @value{GDBN} to perform I/O | |
38152 | operations on the far side of a remote link. For example, Host I/O is | |
38153 | used to upload and download files to a remote target with its own | |
38154 | filesystem. Host I/O uses the same constant values and data structure | |
38155 | layout as the target-initiated File-I/O protocol. However, the | |
38156 | Host I/O packets are structured differently. The target-initiated | |
38157 | protocol relies on target memory to store parameters and buffers. | |
38158 | Host I/O requests are initiated by @value{GDBN}, and the | |
38159 | target's memory is not involved. @xref{File-I/O Remote Protocol | |
38160 | Extension}, for more details on the target-initiated protocol. | |
38161 | ||
38162 | The Host I/O request packets all encode a single operation along with | |
38163 | its arguments. They have this format: | |
38164 | ||
38165 | @table @samp | |
38166 | ||
38167 | @item vFile:@var{operation}: @var{parameter}@dots{} | |
38168 | @var{operation} is the name of the particular request; the target | |
38169 | should compare the entire packet name up to the second colon when checking | |
38170 | for a supported operation. The format of @var{parameter} depends on | |
38171 | the operation. Numbers are always passed in hexadecimal. Negative | |
38172 | numbers have an explicit minus sign (i.e.@: two's complement is not | |
38173 | used). Strings (e.g.@: filenames) are encoded as a series of | |
38174 | hexadecimal bytes. The last argument to a system call may be a | |
38175 | buffer of escaped binary data (@pxref{Binary Data}). | |
38176 | ||
38177 | @end table | |
38178 | ||
38179 | The valid responses to Host I/O packets are: | |
38180 | ||
38181 | @table @samp | |
38182 | ||
38183 | @item F @var{result} [, @var{errno}] [; @var{attachment}] | |
38184 | @var{result} is the integer value returned by this operation, usually | |
38185 | non-negative for success and -1 for errors. If an error has occured, | |
697aa1b7 | 38186 | @var{errno} will be included in the result specifying a |
a6b151f1 DJ |
38187 | value defined by the File-I/O protocol (@pxref{Errno Values}). For |
38188 | operations which return data, @var{attachment} supplies the data as a | |
38189 | binary buffer. Binary buffers in response packets are escaped in the | |
38190 | normal way (@pxref{Binary Data}). See the individual packet | |
38191 | documentation for the interpretation of @var{result} and | |
38192 | @var{attachment}. | |
38193 | ||
d57350ea | 38194 | @item @w{} |
a6b151f1 DJ |
38195 | An empty response indicates that this operation is not recognized. |
38196 | ||
38197 | @end table | |
38198 | ||
38199 | These are the supported Host I/O operations: | |
38200 | ||
38201 | @table @samp | |
697aa1b7 EZ |
38202 | @item vFile:open: @var{filename}, @var{flags}, @var{mode} |
38203 | Open a file at @var{filename} and return a file descriptor for it, or | |
38204 | return -1 if an error occurs. The @var{filename} is a string, | |
a6b151f1 DJ |
38205 | @var{flags} is an integer indicating a mask of open flags |
38206 | (@pxref{Open Flags}), and @var{mode} is an integer indicating a mask | |
38207 | of mode bits to use if the file is created (@pxref{mode_t Values}). | |
c1c25a1a | 38208 | @xref{open}, for details of the open flags and mode values. |
a6b151f1 DJ |
38209 | |
38210 | @item vFile:close: @var{fd} | |
38211 | Close the open file corresponding to @var{fd} and return 0, or | |
38212 | -1 if an error occurs. | |
38213 | ||
38214 | @item vFile:pread: @var{fd}, @var{count}, @var{offset} | |
38215 | Read data from the open file corresponding to @var{fd}. Up to | |
38216 | @var{count} bytes will be read from the file, starting at @var{offset} | |
38217 | relative to the start of the file. The target may read fewer bytes; | |
38218 | common reasons include packet size limits and an end-of-file | |
38219 | condition. The number of bytes read is returned. Zero should only be | |
38220 | returned for a successful read at the end of the file, or if | |
38221 | @var{count} was zero. | |
38222 | ||
38223 | The data read should be returned as a binary attachment on success. | |
38224 | If zero bytes were read, the response should include an empty binary | |
38225 | attachment (i.e.@: a trailing semicolon). The return value is the | |
38226 | number of target bytes read; the binary attachment may be longer if | |
38227 | some characters were escaped. | |
38228 | ||
38229 | @item vFile:pwrite: @var{fd}, @var{offset}, @var{data} | |
38230 | Write @var{data} (a binary buffer) to the open file corresponding | |
38231 | to @var{fd}. Start the write at @var{offset} from the start of the | |
38232 | file. Unlike many @code{write} system calls, there is no | |
38233 | separate @var{count} argument; the length of @var{data} in the | |
38234 | packet is used. @samp{vFile:write} returns the number of bytes written, | |
38235 | which may be shorter than the length of @var{data}, or -1 if an | |
38236 | error occurred. | |
38237 | ||
0a93529c GB |
38238 | @item vFile:fstat: @var{fd} |
38239 | Get information about the open file corresponding to @var{fd}. | |
38240 | On success the information is returned as a binary attachment | |
38241 | and the return value is the size of this attachment in bytes. | |
38242 | If an error occurs the return value is -1. The format of the | |
38243 | returned binary attachment is as described in @ref{struct stat}. | |
38244 | ||
697aa1b7 EZ |
38245 | @item vFile:unlink: @var{filename} |
38246 | Delete the file at @var{filename} on the target. Return 0, | |
38247 | or -1 if an error occurs. The @var{filename} is a string. | |
a6b151f1 | 38248 | |
b9e7b9c3 UW |
38249 | @item vFile:readlink: @var{filename} |
38250 | Read value of symbolic link @var{filename} on the target. Return | |
38251 | the number of bytes read, or -1 if an error occurs. | |
38252 | ||
38253 | The data read should be returned as a binary attachment on success. | |
38254 | If zero bytes were read, the response should include an empty binary | |
38255 | attachment (i.e.@: a trailing semicolon). The return value is the | |
38256 | number of target bytes read; the binary attachment may be longer if | |
38257 | some characters were escaped. | |
38258 | ||
15a201c8 GB |
38259 | @item vFile:setfs: @var{pid} |
38260 | Select the filesystem on which @code{vFile} operations with | |
38261 | @var{filename} arguments will operate. This is required for | |
38262 | @value{GDBN} to be able to access files on remote targets where | |
38263 | the remote stub does not share a common filesystem with the | |
38264 | inferior(s). | |
38265 | ||
38266 | If @var{pid} is nonzero, select the filesystem as seen by process | |
38267 | @var{pid}. If @var{pid} is zero, select the filesystem as seen by | |
38268 | the remote stub. Return 0 on success, or -1 if an error occurs. | |
38269 | If @code{vFile:setfs:} indicates success, the selected filesystem | |
38270 | remains selected until the next successful @code{vFile:setfs:} | |
38271 | operation. | |
38272 | ||
a6b151f1 DJ |
38273 | @end table |
38274 | ||
9a6253be KB |
38275 | @node Interrupts |
38276 | @section Interrupts | |
38277 | @cindex interrupts (remote protocol) | |
de979965 | 38278 | @anchor{interrupting remote targets} |
9a6253be | 38279 | |
de979965 PA |
38280 | In all-stop mode, when a program on the remote target is running, |
38281 | @value{GDBN} may attempt to interrupt it by sending a @samp{Ctrl-C}, | |
38282 | @code{BREAK} or a @code{BREAK} followed by @code{g}, control of which | |
38283 | is specified via @value{GDBN}'s @samp{interrupt-sequence}. | |
9a6253be KB |
38284 | |
38285 | The precise meaning of @code{BREAK} is defined by the transport | |
8775bb90 MS |
38286 | mechanism and may, in fact, be undefined. @value{GDBN} does not |
38287 | currently define a @code{BREAK} mechanism for any of the network | |
38288 | interfaces except for TCP, in which case @value{GDBN} sends the | |
38289 | @code{telnet} BREAK sequence. | |
9a6253be KB |
38290 | |
38291 | @samp{Ctrl-C}, on the other hand, is defined and implemented for all | |
38292 | transport mechanisms. It is represented by sending the single byte | |
38293 | @code{0x03} without any of the usual packet overhead described in | |
38294 | the Overview section (@pxref{Overview}). When a @code{0x03} byte is | |
38295 | transmitted as part of a packet, it is considered to be packet data | |
38296 | and does @emph{not} represent an interrupt. E.g., an @samp{X} packet | |
0876f84a | 38297 | (@pxref{X packet}), used for binary downloads, may include an unescaped |
9a6253be KB |
38298 | @code{0x03} as part of its packet. |
38299 | ||
9a7071a8 JB |
38300 | @code{BREAK} followed by @code{g} is also known as Magic SysRq g. |
38301 | When Linux kernel receives this sequence from serial port, | |
38302 | it stops execution and connects to gdb. | |
38303 | ||
de979965 PA |
38304 | In non-stop mode, because packet resumptions are asynchronous |
38305 | (@pxref{vCont packet}), @value{GDBN} is always free to send a remote | |
38306 | command to the remote stub, even when the target is running. For that | |
38307 | reason, @value{GDBN} instead sends a regular packet (@pxref{vCtrlC | |
38308 | packet}) with the usual packet framing instead of the single byte | |
38309 | @code{0x03}. | |
38310 | ||
9a6253be KB |
38311 | Stubs are not required to recognize these interrupt mechanisms and the |
38312 | precise meaning associated with receipt of the interrupt is | |
8b23ecc4 SL |
38313 | implementation defined. If the target supports debugging of multiple |
38314 | threads and/or processes, it should attempt to interrupt all | |
38315 | currently-executing threads and processes. | |
38316 | If the stub is successful at interrupting the | |
38317 | running program, it should send one of the stop | |
38318 | reply packets (@pxref{Stop Reply Packets}) to @value{GDBN} as a result | |
38319 | of successfully stopping the program in all-stop mode, and a stop reply | |
38320 | for each stopped thread in non-stop mode. | |
38321 | Interrupts received while the | |
cde67b27 YQ |
38322 | program is stopped are queued and the program will be interrupted when |
38323 | it is resumed next time. | |
8b23ecc4 SL |
38324 | |
38325 | @node Notification Packets | |
38326 | @section Notification Packets | |
38327 | @cindex notification packets | |
38328 | @cindex packets, notification | |
38329 | ||
38330 | The @value{GDBN} remote serial protocol includes @dfn{notifications}, | |
38331 | packets that require no acknowledgment. Both the GDB and the stub | |
38332 | may send notifications (although the only notifications defined at | |
38333 | present are sent by the stub). Notifications carry information | |
38334 | without incurring the round-trip latency of an acknowledgment, and so | |
38335 | are useful for low-impact communications where occasional packet loss | |
38336 | is not a problem. | |
38337 | ||
38338 | A notification packet has the form @samp{% @var{data} # | |
38339 | @var{checksum}}, where @var{data} is the content of the notification, | |
38340 | and @var{checksum} is a checksum of @var{data}, computed and formatted | |
38341 | as for ordinary @value{GDBN} packets. A notification's @var{data} | |
38342 | never contains @samp{$}, @samp{%} or @samp{#} characters. Upon | |
38343 | receiving a notification, the recipient sends no @samp{+} or @samp{-} | |
38344 | to acknowledge the notification's receipt or to report its corruption. | |
38345 | ||
38346 | Every notification's @var{data} begins with a name, which contains no | |
38347 | colon characters, followed by a colon character. | |
38348 | ||
38349 | Recipients should silently ignore corrupted notifications and | |
38350 | notifications they do not understand. Recipients should restart | |
38351 | timeout periods on receipt of a well-formed notification, whether or | |
38352 | not they understand it. | |
38353 | ||
38354 | Senders should only send the notifications described here when this | |
38355 | protocol description specifies that they are permitted. In the | |
38356 | future, we may extend the protocol to permit existing notifications in | |
38357 | new contexts; this rule helps older senders avoid confusing newer | |
38358 | recipients. | |
38359 | ||
38360 | (Older versions of @value{GDBN} ignore bytes received until they see | |
38361 | the @samp{$} byte that begins an ordinary packet, so new stubs may | |
38362 | transmit notifications without fear of confusing older clients. There | |
38363 | are no notifications defined for @value{GDBN} to send at the moment, but we | |
38364 | assume that most older stubs would ignore them, as well.) | |
38365 | ||
8dbe8ece | 38366 | Each notification is comprised of three parts: |
8b23ecc4 | 38367 | @table @samp |
8dbe8ece YQ |
38368 | @item @var{name}:@var{event} |
38369 | The notification packet is sent by the side that initiates the | |
38370 | exchange (currently, only the stub does that), with @var{event} | |
697aa1b7 EZ |
38371 | carrying the specific information about the notification, and |
38372 | @var{name} specifying the name of the notification. | |
8dbe8ece YQ |
38373 | @item @var{ack} |
38374 | The acknowledge sent by the other side, usually @value{GDBN}, to | |
38375 | acknowledge the exchange and request the event. | |
38376 | @end table | |
38377 | ||
38378 | The purpose of an asynchronous notification mechanism is to report to | |
38379 | @value{GDBN} that something interesting happened in the remote stub. | |
38380 | ||
38381 | The remote stub may send notification @var{name}:@var{event} | |
38382 | at any time, but @value{GDBN} acknowledges the notification when | |
38383 | appropriate. The notification event is pending before @value{GDBN} | |
38384 | acknowledges. Only one notification at a time may be pending; if | |
38385 | additional events occur before @value{GDBN} has acknowledged the | |
38386 | previous notification, they must be queued by the stub for later | |
38387 | synchronous transmission in response to @var{ack} packets from | |
38388 | @value{GDBN}. Because the notification mechanism is unreliable, | |
38389 | the stub is permitted to resend a notification if it believes | |
38390 | @value{GDBN} may not have received it. | |
38391 | ||
38392 | Specifically, notifications may appear when @value{GDBN} is not | |
38393 | otherwise reading input from the stub, or when @value{GDBN} is | |
38394 | expecting to read a normal synchronous response or a | |
38395 | @samp{+}/@samp{-} acknowledgment to a packet it has sent. | |
38396 | Notification packets are distinct from any other communication from | |
38397 | the stub so there is no ambiguity. | |
38398 | ||
38399 | After receiving a notification, @value{GDBN} shall acknowledge it by | |
38400 | sending a @var{ack} packet as a regular, synchronous request to the | |
38401 | stub. Such acknowledgment is not required to happen immediately, as | |
38402 | @value{GDBN} is permitted to send other, unrelated packets to the | |
38403 | stub first, which the stub should process normally. | |
38404 | ||
38405 | Upon receiving a @var{ack} packet, if the stub has other queued | |
38406 | events to report to @value{GDBN}, it shall respond by sending a | |
38407 | normal @var{event}. @value{GDBN} shall then send another @var{ack} | |
38408 | packet to solicit further responses; again, it is permitted to send | |
38409 | other, unrelated packets as well which the stub should process | |
38410 | normally. | |
38411 | ||
38412 | If the stub receives a @var{ack} packet and there are no additional | |
38413 | @var{event} to report, the stub shall return an @samp{OK} response. | |
38414 | At this point, @value{GDBN} has finished processing a notification | |
38415 | and the stub has completed sending any queued events. @value{GDBN} | |
38416 | won't accept any new notifications until the final @samp{OK} is | |
38417 | received . If further notification events occur, the stub shall send | |
38418 | a new notification, @value{GDBN} shall accept the notification, and | |
38419 | the process shall be repeated. | |
38420 | ||
38421 | The process of asynchronous notification can be illustrated by the | |
38422 | following example: | |
38423 | @smallexample | |
38424 | <- @code{%%Stop:T0505:98e7ffbf;04:4ce6ffbf;08:b1b6e54c;thread:p7526.7526;core:0;} | |
38425 | @code{...} | |
38426 | -> @code{vStopped} | |
38427 | <- @code{T0505:68f37db7;04:40f37db7;08:63850408;thread:p7526.7528;core:0;} | |
38428 | -> @code{vStopped} | |
38429 | <- @code{T0505:68e3fdb6;04:40e3fdb6;08:63850408;thread:p7526.7529;core:0;} | |
38430 | -> @code{vStopped} | |
38431 | <- @code{OK} | |
38432 | @end smallexample | |
38433 | ||
38434 | The following notifications are defined: | |
38435 | @multitable @columnfractions 0.12 0.12 0.38 0.38 | |
38436 | ||
38437 | @item Notification | |
38438 | @tab Ack | |
38439 | @tab Event | |
38440 | @tab Description | |
38441 | ||
38442 | @item Stop | |
38443 | @tab vStopped | |
38444 | @tab @var{reply}. The @var{reply} has the form of a stop reply, as | |
8b23ecc4 SL |
38445 | described in @ref{Stop Reply Packets}. Refer to @ref{Remote Non-Stop}, |
38446 | for information on how these notifications are acknowledged by | |
38447 | @value{GDBN}. | |
8dbe8ece YQ |
38448 | @tab Report an asynchronous stop event in non-stop mode. |
38449 | ||
38450 | @end multitable | |
8b23ecc4 SL |
38451 | |
38452 | @node Remote Non-Stop | |
38453 | @section Remote Protocol Support for Non-Stop Mode | |
38454 | ||
38455 | @value{GDBN}'s remote protocol supports non-stop debugging of | |
38456 | multi-threaded programs, as described in @ref{Non-Stop Mode}. If the stub | |
38457 | supports non-stop mode, it should report that to @value{GDBN} by including | |
38458 | @samp{QNonStop+} in its @samp{qSupported} response (@pxref{qSupported}). | |
38459 | ||
38460 | @value{GDBN} typically sends a @samp{QNonStop} packet only when | |
38461 | establishing a new connection with the stub. Entering non-stop mode | |
38462 | does not alter the state of any currently-running threads, but targets | |
38463 | must stop all threads in any already-attached processes when entering | |
38464 | all-stop mode. @value{GDBN} uses the @samp{?} packet as necessary to | |
38465 | probe the target state after a mode change. | |
38466 | ||
38467 | In non-stop mode, when an attached process encounters an event that | |
38468 | would otherwise be reported with a stop reply, it uses the | |
38469 | asynchronous notification mechanism (@pxref{Notification Packets}) to | |
38470 | inform @value{GDBN}. In contrast to all-stop mode, where all threads | |
38471 | in all processes are stopped when a stop reply is sent, in non-stop | |
38472 | mode only the thread reporting the stop event is stopped. That is, | |
38473 | when reporting a @samp{S} or @samp{T} response to indicate completion | |
38474 | of a step operation, hitting a breakpoint, or a fault, only the | |
38475 | affected thread is stopped; any other still-running threads continue | |
38476 | to run. When reporting a @samp{W} or @samp{X} response, all running | |
38477 | threads belonging to other attached processes continue to run. | |
38478 | ||
8b23ecc4 SL |
38479 | In non-stop mode, the target shall respond to the @samp{?} packet as |
38480 | follows. First, any incomplete stop reply notification/@samp{vStopped} | |
38481 | sequence in progress is abandoned. The target must begin a new | |
38482 | sequence reporting stop events for all stopped threads, whether or not | |
38483 | it has previously reported those events to @value{GDBN}. The first | |
38484 | stop reply is sent as a synchronous reply to the @samp{?} packet, and | |
38485 | subsequent stop replies are sent as responses to @samp{vStopped} packets | |
38486 | using the mechanism described above. The target must not send | |
38487 | asynchronous stop reply notifications until the sequence is complete. | |
38488 | If all threads are running when the target receives the @samp{?} packet, | |
38489 | or if the target is not attached to any process, it shall respond | |
38490 | @samp{OK}. | |
9a6253be | 38491 | |
f7e6eed5 PA |
38492 | If the stub supports non-stop mode, it should also support the |
38493 | @samp{swbreak} stop reason if software breakpoints are supported, and | |
38494 | the @samp{hwbreak} stop reason if hardware breakpoints are supported | |
38495 | (@pxref{swbreak stop reason}). This is because given the asynchronous | |
38496 | nature of non-stop mode, between the time a thread hits a breakpoint | |
38497 | and the time the event is finally processed by @value{GDBN}, the | |
38498 | breakpoint may have already been removed from the target. Due to | |
38499 | this, @value{GDBN} needs to be able to tell whether a trap stop was | |
38500 | caused by a delayed breakpoint event, which should be ignored, as | |
38501 | opposed to a random trap signal, which should be reported to the user. | |
38502 | Note the @samp{swbreak} feature implies that the target is responsible | |
38503 | for adjusting the PC when a software breakpoint triggers, if | |
38504 | necessary, such as on the x86 architecture. | |
38505 | ||
a6f3e723 SL |
38506 | @node Packet Acknowledgment |
38507 | @section Packet Acknowledgment | |
38508 | ||
38509 | @cindex acknowledgment, for @value{GDBN} remote | |
38510 | @cindex packet acknowledgment, for @value{GDBN} remote | |
38511 | By default, when either the host or the target machine receives a packet, | |
38512 | the first response expected is an acknowledgment: either @samp{+} (to indicate | |
38513 | the package was received correctly) or @samp{-} (to request retransmission). | |
38514 | This mechanism allows the @value{GDBN} remote protocol to operate over | |
38515 | unreliable transport mechanisms, such as a serial line. | |
38516 | ||
38517 | In cases where the transport mechanism is itself reliable (such as a pipe or | |
38518 | TCP connection), the @samp{+}/@samp{-} acknowledgments are redundant. | |
38519 | It may be desirable to disable them in that case to reduce communication | |
38520 | overhead, or for other reasons. This can be accomplished by means of the | |
38521 | @samp{QStartNoAckMode} packet; @pxref{QStartNoAckMode}. | |
38522 | ||
38523 | When in no-acknowledgment mode, neither the stub nor @value{GDBN} shall send or | |
38524 | expect @samp{+}/@samp{-} protocol acknowledgments. The packet | |
38525 | and response format still includes the normal checksum, as described in | |
38526 | @ref{Overview}, but the checksum may be ignored by the receiver. | |
38527 | ||
38528 | If the stub supports @samp{QStartNoAckMode} and prefers to operate in | |
38529 | no-acknowledgment mode, it should report that to @value{GDBN} | |
38530 | by including @samp{QStartNoAckMode+} in its response to @samp{qSupported}; | |
38531 | @pxref{qSupported}. | |
38532 | If @value{GDBN} also supports @samp{QStartNoAckMode} and it has not been | |
38533 | disabled via the @code{set remote noack-packet off} command | |
38534 | (@pxref{Remote Configuration}), | |
38535 | @value{GDBN} may then send a @samp{QStartNoAckMode} packet to the stub. | |
38536 | Only then may the stub actually turn off packet acknowledgments. | |
38537 | @value{GDBN} sends a final @samp{+} acknowledgment of the stub's @samp{OK} | |
38538 | response, which can be safely ignored by the stub. | |
38539 | ||
38540 | Note that @code{set remote noack-packet} command only affects negotiation | |
38541 | between @value{GDBN} and the stub when subsequent connections are made; | |
38542 | it does not affect the protocol acknowledgment state for any current | |
38543 | connection. | |
38544 | Since @samp{+}/@samp{-} acknowledgments are enabled by default when a | |
38545 | new connection is established, | |
38546 | there is also no protocol request to re-enable the acknowledgments | |
38547 | for the current connection, once disabled. | |
38548 | ||
ee2d5c50 AC |
38549 | @node Examples |
38550 | @section Examples | |
eb12ee30 | 38551 | |
8e04817f AC |
38552 | Example sequence of a target being re-started. Notice how the restart |
38553 | does not get any direct output: | |
eb12ee30 | 38554 | |
474c8240 | 38555 | @smallexample |
d2c6833e AC |
38556 | -> @code{R00} |
38557 | <- @code{+} | |
8e04817f | 38558 | @emph{target restarts} |
d2c6833e | 38559 | -> @code{?} |
8e04817f | 38560 | <- @code{+} |
d2c6833e AC |
38561 | <- @code{T001:1234123412341234} |
38562 | -> @code{+} | |
474c8240 | 38563 | @end smallexample |
eb12ee30 | 38564 | |
8e04817f | 38565 | Example sequence of a target being stepped by a single instruction: |
eb12ee30 | 38566 | |
474c8240 | 38567 | @smallexample |
d2c6833e | 38568 | -> @code{G1445@dots{}} |
8e04817f | 38569 | <- @code{+} |
d2c6833e AC |
38570 | -> @code{s} |
38571 | <- @code{+} | |
38572 | @emph{time passes} | |
38573 | <- @code{T001:1234123412341234} | |
8e04817f | 38574 | -> @code{+} |
d2c6833e | 38575 | -> @code{g} |
8e04817f | 38576 | <- @code{+} |
d2c6833e AC |
38577 | <- @code{1455@dots{}} |
38578 | -> @code{+} | |
474c8240 | 38579 | @end smallexample |
eb12ee30 | 38580 | |
79a6e687 BW |
38581 | @node File-I/O Remote Protocol Extension |
38582 | @section File-I/O Remote Protocol Extension | |
0ce1b118 CV |
38583 | @cindex File-I/O remote protocol extension |
38584 | ||
38585 | @menu | |
38586 | * File-I/O Overview:: | |
79a6e687 BW |
38587 | * Protocol Basics:: |
38588 | * The F Request Packet:: | |
38589 | * The F Reply Packet:: | |
38590 | * The Ctrl-C Message:: | |
0ce1b118 | 38591 | * Console I/O:: |
79a6e687 | 38592 | * List of Supported Calls:: |
db2e3e2e | 38593 | * Protocol-specific Representation of Datatypes:: |
0ce1b118 CV |
38594 | * Constants:: |
38595 | * File-I/O Examples:: | |
38596 | @end menu | |
38597 | ||
38598 | @node File-I/O Overview | |
38599 | @subsection File-I/O Overview | |
38600 | @cindex file-i/o overview | |
38601 | ||
9c16f35a | 38602 | The @dfn{File I/O remote protocol extension} (short: File-I/O) allows the |
fc320d37 | 38603 | target to use the host's file system and console I/O to perform various |
0ce1b118 | 38604 | system calls. System calls on the target system are translated into a |
fc320d37 SL |
38605 | remote protocol packet to the host system, which then performs the needed |
38606 | actions and returns a response packet to the target system. | |
0ce1b118 CV |
38607 | This simulates file system operations even on targets that lack file systems. |
38608 | ||
fc320d37 SL |
38609 | The protocol is defined to be independent of both the host and target systems. |
38610 | It uses its own internal representation of datatypes and values. Both | |
0ce1b118 | 38611 | @value{GDBN} and the target's @value{GDBN} stub are responsible for |
fc320d37 SL |
38612 | translating the system-dependent value representations into the internal |
38613 | protocol representations when data is transmitted. | |
0ce1b118 | 38614 | |
fc320d37 SL |
38615 | The communication is synchronous. A system call is possible only when |
38616 | @value{GDBN} is waiting for a response from the @samp{C}, @samp{c}, @samp{S} | |
38617 | or @samp{s} packets. While @value{GDBN} handles the request for a system call, | |
0ce1b118 | 38618 | the target is stopped to allow deterministic access to the target's |
fc320d37 SL |
38619 | memory. Therefore File-I/O is not interruptible by target signals. On |
38620 | the other hand, it is possible to interrupt File-I/O by a user interrupt | |
c8aa23ab | 38621 | (@samp{Ctrl-C}) within @value{GDBN}. |
0ce1b118 CV |
38622 | |
38623 | The target's request to perform a host system call does not finish | |
38624 | the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means, | |
38625 | after finishing the system call, the target returns to continuing the | |
38626 | previous activity (continue, step). No additional continue or step | |
38627 | request from @value{GDBN} is required. | |
38628 | ||
38629 | @smallexample | |
f7dc1244 | 38630 | (@value{GDBP}) continue |
0ce1b118 CV |
38631 | <- target requests 'system call X' |
38632 | target is stopped, @value{GDBN} executes system call | |
3f94c067 BW |
38633 | -> @value{GDBN} returns result |
38634 | ... target continues, @value{GDBN} returns to wait for the target | |
0ce1b118 CV |
38635 | <- target hits breakpoint and sends a Txx packet |
38636 | @end smallexample | |
38637 | ||
fc320d37 SL |
38638 | The protocol only supports I/O on the console and to regular files on |
38639 | the host file system. Character or block special devices, pipes, | |
38640 | named pipes, sockets or any other communication method on the host | |
0ce1b118 CV |
38641 | system are not supported by this protocol. |
38642 | ||
8b23ecc4 SL |
38643 | File I/O is not supported in non-stop mode. |
38644 | ||
79a6e687 BW |
38645 | @node Protocol Basics |
38646 | @subsection Protocol Basics | |
0ce1b118 CV |
38647 | @cindex protocol basics, file-i/o |
38648 | ||
fc320d37 SL |
38649 | The File-I/O protocol uses the @code{F} packet as the request as well |
38650 | as reply packet. Since a File-I/O system call can only occur when | |
38651 | @value{GDBN} is waiting for a response from the continuing or stepping target, | |
38652 | the File-I/O request is a reply that @value{GDBN} has to expect as a result | |
38653 | of a previous @samp{C}, @samp{c}, @samp{S} or @samp{s} packet. | |
0ce1b118 CV |
38654 | This @code{F} packet contains all information needed to allow @value{GDBN} |
38655 | to call the appropriate host system call: | |
38656 | ||
38657 | @itemize @bullet | |
b383017d | 38658 | @item |
0ce1b118 CV |
38659 | A unique identifier for the requested system call. |
38660 | ||
38661 | @item | |
38662 | All parameters to the system call. Pointers are given as addresses | |
38663 | in the target memory address space. Pointers to strings are given as | |
b383017d | 38664 | pointer/length pair. Numerical values are given as they are. |
db2e3e2e | 38665 | Numerical control flags are given in a protocol-specific representation. |
0ce1b118 CV |
38666 | |
38667 | @end itemize | |
38668 | ||
fc320d37 | 38669 | At this point, @value{GDBN} has to perform the following actions. |
0ce1b118 CV |
38670 | |
38671 | @itemize @bullet | |
b383017d | 38672 | @item |
fc320d37 SL |
38673 | If the parameters include pointer values to data needed as input to a |
38674 | system call, @value{GDBN} requests this data from the target with a | |
0ce1b118 CV |
38675 | standard @code{m} packet request. This additional communication has to be |
38676 | expected by the target implementation and is handled as any other @code{m} | |
38677 | packet. | |
38678 | ||
38679 | @item | |
38680 | @value{GDBN} translates all value from protocol representation to host | |
38681 | representation as needed. Datatypes are coerced into the host types. | |
38682 | ||
38683 | @item | |
fc320d37 | 38684 | @value{GDBN} calls the system call. |
0ce1b118 CV |
38685 | |
38686 | @item | |
38687 | It then coerces datatypes back to protocol representation. | |
38688 | ||
38689 | @item | |
fc320d37 SL |
38690 | If the system call is expected to return data in buffer space specified |
38691 | by pointer parameters to the call, the data is transmitted to the | |
0ce1b118 CV |
38692 | target using a @code{M} or @code{X} packet. This packet has to be expected |
38693 | by the target implementation and is handled as any other @code{M} or @code{X} | |
38694 | packet. | |
38695 | ||
38696 | @end itemize | |
38697 | ||
38698 | Eventually @value{GDBN} replies with another @code{F} packet which contains all | |
38699 | necessary information for the target to continue. This at least contains | |
38700 | ||
38701 | @itemize @bullet | |
38702 | @item | |
38703 | Return value. | |
38704 | ||
38705 | @item | |
38706 | @code{errno}, if has been changed by the system call. | |
38707 | ||
38708 | @item | |
38709 | ``Ctrl-C'' flag. | |
38710 | ||
38711 | @end itemize | |
38712 | ||
38713 | After having done the needed type and value coercion, the target continues | |
38714 | the latest continue or step action. | |
38715 | ||
79a6e687 BW |
38716 | @node The F Request Packet |
38717 | @subsection The @code{F} Request Packet | |
0ce1b118 CV |
38718 | @cindex file-i/o request packet |
38719 | @cindex @code{F} request packet | |
38720 | ||
38721 | The @code{F} request packet has the following format: | |
38722 | ||
38723 | @table @samp | |
fc320d37 | 38724 | @item F@var{call-id},@var{parameter@dots{}} |
0ce1b118 CV |
38725 | |
38726 | @var{call-id} is the identifier to indicate the host system call to be called. | |
38727 | This is just the name of the function. | |
38728 | ||
fc320d37 SL |
38729 | @var{parameter@dots{}} are the parameters to the system call. |
38730 | Parameters are hexadecimal integer values, either the actual values in case | |
38731 | of scalar datatypes, pointers to target buffer space in case of compound | |
38732 | datatypes and unspecified memory areas, or pointer/length pairs in case | |
38733 | of string parameters. These are appended to the @var{call-id} as a | |
38734 | comma-delimited list. All values are transmitted in ASCII | |
38735 | string representation, pointer/length pairs separated by a slash. | |
0ce1b118 | 38736 | |
b383017d | 38737 | @end table |
0ce1b118 | 38738 | |
fc320d37 | 38739 | |
0ce1b118 | 38740 | |
79a6e687 BW |
38741 | @node The F Reply Packet |
38742 | @subsection The @code{F} Reply Packet | |
0ce1b118 CV |
38743 | @cindex file-i/o reply packet |
38744 | @cindex @code{F} reply packet | |
38745 | ||
38746 | The @code{F} reply packet has the following format: | |
38747 | ||
38748 | @table @samp | |
38749 | ||
d3bdde98 | 38750 | @item F@var{retcode},@var{errno},@var{Ctrl-C flag};@var{call-specific attachment} |
0ce1b118 CV |
38751 | |
38752 | @var{retcode} is the return code of the system call as hexadecimal value. | |
38753 | ||
db2e3e2e BW |
38754 | @var{errno} is the @code{errno} set by the call, in protocol-specific |
38755 | representation. | |
0ce1b118 CV |
38756 | This parameter can be omitted if the call was successful. |
38757 | ||
fc320d37 SL |
38758 | @var{Ctrl-C flag} is only sent if the user requested a break. In this |
38759 | case, @var{errno} must be sent as well, even if the call was successful. | |
38760 | The @var{Ctrl-C flag} itself consists of the character @samp{C}: | |
0ce1b118 CV |
38761 | |
38762 | @smallexample | |
38763 | F0,0,C | |
38764 | @end smallexample | |
38765 | ||
38766 | @noindent | |
fc320d37 | 38767 | or, if the call was interrupted before the host call has been performed: |
0ce1b118 CV |
38768 | |
38769 | @smallexample | |
38770 | F-1,4,C | |
38771 | @end smallexample | |
38772 | ||
38773 | @noindent | |
db2e3e2e | 38774 | assuming 4 is the protocol-specific representation of @code{EINTR}. |
0ce1b118 CV |
38775 | |
38776 | @end table | |
38777 | ||
0ce1b118 | 38778 | |
79a6e687 BW |
38779 | @node The Ctrl-C Message |
38780 | @subsection The @samp{Ctrl-C} Message | |
0ce1b118 CV |
38781 | @cindex ctrl-c message, in file-i/o protocol |
38782 | ||
c8aa23ab | 38783 | If the @samp{Ctrl-C} flag is set in the @value{GDBN} |
79a6e687 | 38784 | reply packet (@pxref{The F Reply Packet}), |
fc320d37 | 38785 | the target should behave as if it had |
0ce1b118 | 38786 | gotten a break message. The meaning for the target is ``system call |
fc320d37 | 38787 | interrupted by @code{SIGINT}''. Consequentially, the target should actually stop |
0ce1b118 | 38788 | (as with a break message) and return to @value{GDBN} with a @code{T02} |
c8aa23ab | 38789 | packet. |
fc320d37 SL |
38790 | |
38791 | It's important for the target to know in which | |
38792 | state the system call was interrupted. There are two possible cases: | |
0ce1b118 CV |
38793 | |
38794 | @itemize @bullet | |
38795 | @item | |
38796 | The system call hasn't been performed on the host yet. | |
38797 | ||
38798 | @item | |
38799 | The system call on the host has been finished. | |
38800 | ||
38801 | @end itemize | |
38802 | ||
38803 | These two states can be distinguished by the target by the value of the | |
38804 | returned @code{errno}. If it's the protocol representation of @code{EINTR}, the system | |
38805 | call hasn't been performed. This is equivalent to the @code{EINTR} handling | |
38806 | on POSIX systems. In any other case, the target may presume that the | |
fc320d37 | 38807 | system call has been finished --- successfully or not --- and should behave |
0ce1b118 CV |
38808 | as if the break message arrived right after the system call. |
38809 | ||
fc320d37 | 38810 | @value{GDBN} must behave reliably. If the system call has not been called |
0ce1b118 CV |
38811 | yet, @value{GDBN} may send the @code{F} reply immediately, setting @code{EINTR} as |
38812 | @code{errno} in the packet. If the system call on the host has been finished | |
fc320d37 SL |
38813 | before the user requests a break, the full action must be finished by |
38814 | @value{GDBN}. This requires sending @code{M} or @code{X} packets as necessary. | |
38815 | The @code{F} packet may only be sent when either nothing has happened | |
0ce1b118 CV |
38816 | or the full action has been completed. |
38817 | ||
38818 | @node Console I/O | |
38819 | @subsection Console I/O | |
38820 | @cindex console i/o as part of file-i/o | |
38821 | ||
d3e8051b | 38822 | By default and if not explicitly closed by the target system, the file |
0ce1b118 CV |
38823 | descriptors 0, 1 and 2 are connected to the @value{GDBN} console. Output |
38824 | on the @value{GDBN} console is handled as any other file output operation | |
38825 | (@code{write(1, @dots{})} or @code{write(2, @dots{})}). Console input is handled | |
38826 | by @value{GDBN} so that after the target read request from file descriptor | |
38827 | 0 all following typing is buffered until either one of the following | |
38828 | conditions is met: | |
38829 | ||
38830 | @itemize @bullet | |
38831 | @item | |
c8aa23ab | 38832 | The user types @kbd{Ctrl-c}. The behaviour is as explained above, and the |
0ce1b118 CV |
38833 | @code{read} |
38834 | system call is treated as finished. | |
38835 | ||
38836 | @item | |
7f9087cb | 38837 | The user presses @key{RET}. This is treated as end of input with a trailing |
fc320d37 | 38838 | newline. |
0ce1b118 CV |
38839 | |
38840 | @item | |
c8aa23ab EZ |
38841 | The user types @kbd{Ctrl-d}. This is treated as end of input. No trailing |
38842 | character (neither newline nor @samp{Ctrl-D}) is appended to the input. | |
0ce1b118 CV |
38843 | |
38844 | @end itemize | |
38845 | ||
fc320d37 SL |
38846 | If the user has typed more characters than fit in the buffer given to |
38847 | the @code{read} call, the trailing characters are buffered in @value{GDBN} until | |
38848 | either another @code{read(0, @dots{})} is requested by the target, or debugging | |
38849 | is stopped at the user's request. | |
0ce1b118 | 38850 | |
0ce1b118 | 38851 | |
79a6e687 BW |
38852 | @node List of Supported Calls |
38853 | @subsection List of Supported Calls | |
0ce1b118 CV |
38854 | @cindex list of supported file-i/o calls |
38855 | ||
38856 | @menu | |
38857 | * open:: | |
38858 | * close:: | |
38859 | * read:: | |
38860 | * write:: | |
38861 | * lseek:: | |
38862 | * rename:: | |
38863 | * unlink:: | |
38864 | * stat/fstat:: | |
38865 | * gettimeofday:: | |
38866 | * isatty:: | |
38867 | * system:: | |
38868 | @end menu | |
38869 | ||
38870 | @node open | |
38871 | @unnumberedsubsubsec open | |
38872 | @cindex open, file-i/o system call | |
38873 | ||
fc320d37 SL |
38874 | @table @asis |
38875 | @item Synopsis: | |
0ce1b118 | 38876 | @smallexample |
0ce1b118 CV |
38877 | int open(const char *pathname, int flags); |
38878 | int open(const char *pathname, int flags, mode_t mode); | |
0ce1b118 CV |
38879 | @end smallexample |
38880 | ||
fc320d37 SL |
38881 | @item Request: |
38882 | @samp{Fopen,@var{pathptr}/@var{len},@var{flags},@var{mode}} | |
38883 | ||
0ce1b118 | 38884 | @noindent |
fc320d37 | 38885 | @var{flags} is the bitwise @code{OR} of the following values: |
0ce1b118 CV |
38886 | |
38887 | @table @code | |
b383017d | 38888 | @item O_CREAT |
0ce1b118 CV |
38889 | If the file does not exist it will be created. The host |
38890 | rules apply as far as file ownership and time stamps | |
38891 | are concerned. | |
38892 | ||
b383017d | 38893 | @item O_EXCL |
fc320d37 | 38894 | When used with @code{O_CREAT}, if the file already exists it is |
0ce1b118 CV |
38895 | an error and open() fails. |
38896 | ||
b383017d | 38897 | @item O_TRUNC |
0ce1b118 | 38898 | If the file already exists and the open mode allows |
fc320d37 SL |
38899 | writing (@code{O_RDWR} or @code{O_WRONLY} is given) it will be |
38900 | truncated to zero length. | |
0ce1b118 | 38901 | |
b383017d | 38902 | @item O_APPEND |
0ce1b118 CV |
38903 | The file is opened in append mode. |
38904 | ||
b383017d | 38905 | @item O_RDONLY |
0ce1b118 CV |
38906 | The file is opened for reading only. |
38907 | ||
b383017d | 38908 | @item O_WRONLY |
0ce1b118 CV |
38909 | The file is opened for writing only. |
38910 | ||
b383017d | 38911 | @item O_RDWR |
0ce1b118 | 38912 | The file is opened for reading and writing. |
fc320d37 | 38913 | @end table |
0ce1b118 CV |
38914 | |
38915 | @noindent | |
fc320d37 | 38916 | Other bits are silently ignored. |
0ce1b118 | 38917 | |
0ce1b118 CV |
38918 | |
38919 | @noindent | |
fc320d37 | 38920 | @var{mode} is the bitwise @code{OR} of the following values: |
0ce1b118 CV |
38921 | |
38922 | @table @code | |
b383017d | 38923 | @item S_IRUSR |
0ce1b118 CV |
38924 | User has read permission. |
38925 | ||
b383017d | 38926 | @item S_IWUSR |
0ce1b118 CV |
38927 | User has write permission. |
38928 | ||
b383017d | 38929 | @item S_IRGRP |
0ce1b118 CV |
38930 | Group has read permission. |
38931 | ||
b383017d | 38932 | @item S_IWGRP |
0ce1b118 CV |
38933 | Group has write permission. |
38934 | ||
b383017d | 38935 | @item S_IROTH |
0ce1b118 CV |
38936 | Others have read permission. |
38937 | ||
b383017d | 38938 | @item S_IWOTH |
0ce1b118 | 38939 | Others have write permission. |
fc320d37 | 38940 | @end table |
0ce1b118 CV |
38941 | |
38942 | @noindent | |
fc320d37 | 38943 | Other bits are silently ignored. |
0ce1b118 | 38944 | |
0ce1b118 | 38945 | |
fc320d37 SL |
38946 | @item Return value: |
38947 | @code{open} returns the new file descriptor or -1 if an error | |
38948 | occurred. | |
0ce1b118 | 38949 | |
fc320d37 | 38950 | @item Errors: |
0ce1b118 CV |
38951 | |
38952 | @table @code | |
b383017d | 38953 | @item EEXIST |
fc320d37 | 38954 | @var{pathname} already exists and @code{O_CREAT} and @code{O_EXCL} were used. |
0ce1b118 | 38955 | |
b383017d | 38956 | @item EISDIR |
fc320d37 | 38957 | @var{pathname} refers to a directory. |
0ce1b118 | 38958 | |
b383017d | 38959 | @item EACCES |
0ce1b118 CV |
38960 | The requested access is not allowed. |
38961 | ||
38962 | @item ENAMETOOLONG | |
fc320d37 | 38963 | @var{pathname} was too long. |
0ce1b118 | 38964 | |
b383017d | 38965 | @item ENOENT |
fc320d37 | 38966 | A directory component in @var{pathname} does not exist. |
0ce1b118 | 38967 | |
b383017d | 38968 | @item ENODEV |
fc320d37 | 38969 | @var{pathname} refers to a device, pipe, named pipe or socket. |
0ce1b118 | 38970 | |
b383017d | 38971 | @item EROFS |
fc320d37 | 38972 | @var{pathname} refers to a file on a read-only filesystem and |
0ce1b118 CV |
38973 | write access was requested. |
38974 | ||
b383017d | 38975 | @item EFAULT |
fc320d37 | 38976 | @var{pathname} is an invalid pointer value. |
0ce1b118 | 38977 | |
b383017d | 38978 | @item ENOSPC |
0ce1b118 CV |
38979 | No space on device to create the file. |
38980 | ||
b383017d | 38981 | @item EMFILE |
0ce1b118 CV |
38982 | The process already has the maximum number of files open. |
38983 | ||
b383017d | 38984 | @item ENFILE |
0ce1b118 CV |
38985 | The limit on the total number of files open on the system |
38986 | has been reached. | |
38987 | ||
b383017d | 38988 | @item EINTR |
0ce1b118 CV |
38989 | The call was interrupted by the user. |
38990 | @end table | |
38991 | ||
fc320d37 SL |
38992 | @end table |
38993 | ||
0ce1b118 CV |
38994 | @node close |
38995 | @unnumberedsubsubsec close | |
38996 | @cindex close, file-i/o system call | |
38997 | ||
fc320d37 SL |
38998 | @table @asis |
38999 | @item Synopsis: | |
0ce1b118 | 39000 | @smallexample |
0ce1b118 | 39001 | int close(int fd); |
fc320d37 | 39002 | @end smallexample |
0ce1b118 | 39003 | |
fc320d37 SL |
39004 | @item Request: |
39005 | @samp{Fclose,@var{fd}} | |
0ce1b118 | 39006 | |
fc320d37 SL |
39007 | @item Return value: |
39008 | @code{close} returns zero on success, or -1 if an error occurred. | |
0ce1b118 | 39009 | |
fc320d37 | 39010 | @item Errors: |
0ce1b118 CV |
39011 | |
39012 | @table @code | |
b383017d | 39013 | @item EBADF |
fc320d37 | 39014 | @var{fd} isn't a valid open file descriptor. |
0ce1b118 | 39015 | |
b383017d | 39016 | @item EINTR |
0ce1b118 CV |
39017 | The call was interrupted by the user. |
39018 | @end table | |
39019 | ||
fc320d37 SL |
39020 | @end table |
39021 | ||
0ce1b118 CV |
39022 | @node read |
39023 | @unnumberedsubsubsec read | |
39024 | @cindex read, file-i/o system call | |
39025 | ||
fc320d37 SL |
39026 | @table @asis |
39027 | @item Synopsis: | |
0ce1b118 | 39028 | @smallexample |
0ce1b118 | 39029 | int read(int fd, void *buf, unsigned int count); |
fc320d37 | 39030 | @end smallexample |
0ce1b118 | 39031 | |
fc320d37 SL |
39032 | @item Request: |
39033 | @samp{Fread,@var{fd},@var{bufptr},@var{count}} | |
0ce1b118 | 39034 | |
fc320d37 | 39035 | @item Return value: |
0ce1b118 CV |
39036 | On success, the number of bytes read is returned. |
39037 | Zero indicates end of file. If count is zero, read | |
b383017d | 39038 | returns zero as well. On error, -1 is returned. |
0ce1b118 | 39039 | |
fc320d37 | 39040 | @item Errors: |
0ce1b118 CV |
39041 | |
39042 | @table @code | |
b383017d | 39043 | @item EBADF |
fc320d37 | 39044 | @var{fd} is not a valid file descriptor or is not open for |
0ce1b118 CV |
39045 | reading. |
39046 | ||
b383017d | 39047 | @item EFAULT |
fc320d37 | 39048 | @var{bufptr} is an invalid pointer value. |
0ce1b118 | 39049 | |
b383017d | 39050 | @item EINTR |
0ce1b118 CV |
39051 | The call was interrupted by the user. |
39052 | @end table | |
39053 | ||
fc320d37 SL |
39054 | @end table |
39055 | ||
0ce1b118 CV |
39056 | @node write |
39057 | @unnumberedsubsubsec write | |
39058 | @cindex write, file-i/o system call | |
39059 | ||
fc320d37 SL |
39060 | @table @asis |
39061 | @item Synopsis: | |
0ce1b118 | 39062 | @smallexample |
0ce1b118 | 39063 | int write(int fd, const void *buf, unsigned int count); |
fc320d37 | 39064 | @end smallexample |
0ce1b118 | 39065 | |
fc320d37 SL |
39066 | @item Request: |
39067 | @samp{Fwrite,@var{fd},@var{bufptr},@var{count}} | |
0ce1b118 | 39068 | |
fc320d37 | 39069 | @item Return value: |
0ce1b118 CV |
39070 | On success, the number of bytes written are returned. |
39071 | Zero indicates nothing was written. On error, -1 | |
39072 | is returned. | |
39073 | ||
fc320d37 | 39074 | @item Errors: |
0ce1b118 CV |
39075 | |
39076 | @table @code | |
b383017d | 39077 | @item EBADF |
fc320d37 | 39078 | @var{fd} is not a valid file descriptor or is not open for |
0ce1b118 CV |
39079 | writing. |
39080 | ||
b383017d | 39081 | @item EFAULT |
fc320d37 | 39082 | @var{bufptr} is an invalid pointer value. |
0ce1b118 | 39083 | |
b383017d | 39084 | @item EFBIG |
0ce1b118 | 39085 | An attempt was made to write a file that exceeds the |
db2e3e2e | 39086 | host-specific maximum file size allowed. |
0ce1b118 | 39087 | |
b383017d | 39088 | @item ENOSPC |
0ce1b118 CV |
39089 | No space on device to write the data. |
39090 | ||
b383017d | 39091 | @item EINTR |
0ce1b118 CV |
39092 | The call was interrupted by the user. |
39093 | @end table | |
39094 | ||
fc320d37 SL |
39095 | @end table |
39096 | ||
0ce1b118 CV |
39097 | @node lseek |
39098 | @unnumberedsubsubsec lseek | |
39099 | @cindex lseek, file-i/o system call | |
39100 | ||
fc320d37 SL |
39101 | @table @asis |
39102 | @item Synopsis: | |
0ce1b118 | 39103 | @smallexample |
0ce1b118 | 39104 | long lseek (int fd, long offset, int flag); |
0ce1b118 CV |
39105 | @end smallexample |
39106 | ||
fc320d37 SL |
39107 | @item Request: |
39108 | @samp{Flseek,@var{fd},@var{offset},@var{flag}} | |
39109 | ||
39110 | @var{flag} is one of: | |
0ce1b118 CV |
39111 | |
39112 | @table @code | |
b383017d | 39113 | @item SEEK_SET |
fc320d37 | 39114 | The offset is set to @var{offset} bytes. |
0ce1b118 | 39115 | |
b383017d | 39116 | @item SEEK_CUR |
fc320d37 | 39117 | The offset is set to its current location plus @var{offset} |
0ce1b118 CV |
39118 | bytes. |
39119 | ||
b383017d | 39120 | @item SEEK_END |
fc320d37 | 39121 | The offset is set to the size of the file plus @var{offset} |
0ce1b118 CV |
39122 | bytes. |
39123 | @end table | |
39124 | ||
fc320d37 | 39125 | @item Return value: |
0ce1b118 CV |
39126 | On success, the resulting unsigned offset in bytes from |
39127 | the beginning of the file is returned. Otherwise, a | |
39128 | value of -1 is returned. | |
39129 | ||
fc320d37 | 39130 | @item Errors: |
0ce1b118 CV |
39131 | |
39132 | @table @code | |
b383017d | 39133 | @item EBADF |
fc320d37 | 39134 | @var{fd} is not a valid open file descriptor. |
0ce1b118 | 39135 | |
b383017d | 39136 | @item ESPIPE |
fc320d37 | 39137 | @var{fd} is associated with the @value{GDBN} console. |
0ce1b118 | 39138 | |
b383017d | 39139 | @item EINVAL |
fc320d37 | 39140 | @var{flag} is not a proper value. |
0ce1b118 | 39141 | |
b383017d | 39142 | @item EINTR |
0ce1b118 CV |
39143 | The call was interrupted by the user. |
39144 | @end table | |
39145 | ||
fc320d37 SL |
39146 | @end table |
39147 | ||
0ce1b118 CV |
39148 | @node rename |
39149 | @unnumberedsubsubsec rename | |
39150 | @cindex rename, file-i/o system call | |
39151 | ||
fc320d37 SL |
39152 | @table @asis |
39153 | @item Synopsis: | |
0ce1b118 | 39154 | @smallexample |
0ce1b118 | 39155 | int rename(const char *oldpath, const char *newpath); |
fc320d37 | 39156 | @end smallexample |
0ce1b118 | 39157 | |
fc320d37 SL |
39158 | @item Request: |
39159 | @samp{Frename,@var{oldpathptr}/@var{len},@var{newpathptr}/@var{len}} | |
0ce1b118 | 39160 | |
fc320d37 | 39161 | @item Return value: |
0ce1b118 CV |
39162 | On success, zero is returned. On error, -1 is returned. |
39163 | ||
fc320d37 | 39164 | @item Errors: |
0ce1b118 CV |
39165 | |
39166 | @table @code | |
b383017d | 39167 | @item EISDIR |
fc320d37 | 39168 | @var{newpath} is an existing directory, but @var{oldpath} is not a |
0ce1b118 CV |
39169 | directory. |
39170 | ||
b383017d | 39171 | @item EEXIST |
fc320d37 | 39172 | @var{newpath} is a non-empty directory. |
0ce1b118 | 39173 | |
b383017d | 39174 | @item EBUSY |
fc320d37 | 39175 | @var{oldpath} or @var{newpath} is a directory that is in use by some |
0ce1b118 CV |
39176 | process. |
39177 | ||
b383017d | 39178 | @item EINVAL |
0ce1b118 CV |
39179 | An attempt was made to make a directory a subdirectory |
39180 | of itself. | |
39181 | ||
b383017d | 39182 | @item ENOTDIR |
fc320d37 SL |
39183 | A component used as a directory in @var{oldpath} or new |
39184 | path is not a directory. Or @var{oldpath} is a directory | |
39185 | and @var{newpath} exists but is not a directory. | |
0ce1b118 | 39186 | |
b383017d | 39187 | @item EFAULT |
fc320d37 | 39188 | @var{oldpathptr} or @var{newpathptr} are invalid pointer values. |
0ce1b118 | 39189 | |
b383017d | 39190 | @item EACCES |
0ce1b118 CV |
39191 | No access to the file or the path of the file. |
39192 | ||
39193 | @item ENAMETOOLONG | |
b383017d | 39194 | |
fc320d37 | 39195 | @var{oldpath} or @var{newpath} was too long. |
0ce1b118 | 39196 | |
b383017d | 39197 | @item ENOENT |
fc320d37 | 39198 | A directory component in @var{oldpath} or @var{newpath} does not exist. |
0ce1b118 | 39199 | |
b383017d | 39200 | @item EROFS |
0ce1b118 CV |
39201 | The file is on a read-only filesystem. |
39202 | ||
b383017d | 39203 | @item ENOSPC |
0ce1b118 CV |
39204 | The device containing the file has no room for the new |
39205 | directory entry. | |
39206 | ||
b383017d | 39207 | @item EINTR |
0ce1b118 CV |
39208 | The call was interrupted by the user. |
39209 | @end table | |
39210 | ||
fc320d37 SL |
39211 | @end table |
39212 | ||
0ce1b118 CV |
39213 | @node unlink |
39214 | @unnumberedsubsubsec unlink | |
39215 | @cindex unlink, file-i/o system call | |
39216 | ||
fc320d37 SL |
39217 | @table @asis |
39218 | @item Synopsis: | |
0ce1b118 | 39219 | @smallexample |
0ce1b118 | 39220 | int unlink(const char *pathname); |
fc320d37 | 39221 | @end smallexample |
0ce1b118 | 39222 | |
fc320d37 SL |
39223 | @item Request: |
39224 | @samp{Funlink,@var{pathnameptr}/@var{len}} | |
0ce1b118 | 39225 | |
fc320d37 | 39226 | @item Return value: |
0ce1b118 CV |
39227 | On success, zero is returned. On error, -1 is returned. |
39228 | ||
fc320d37 | 39229 | @item Errors: |
0ce1b118 CV |
39230 | |
39231 | @table @code | |
b383017d | 39232 | @item EACCES |
0ce1b118 CV |
39233 | No access to the file or the path of the file. |
39234 | ||
b383017d | 39235 | @item EPERM |
0ce1b118 CV |
39236 | The system does not allow unlinking of directories. |
39237 | ||
b383017d | 39238 | @item EBUSY |
fc320d37 | 39239 | The file @var{pathname} cannot be unlinked because it's |
0ce1b118 CV |
39240 | being used by another process. |
39241 | ||
b383017d | 39242 | @item EFAULT |
fc320d37 | 39243 | @var{pathnameptr} is an invalid pointer value. |
0ce1b118 CV |
39244 | |
39245 | @item ENAMETOOLONG | |
fc320d37 | 39246 | @var{pathname} was too long. |
0ce1b118 | 39247 | |
b383017d | 39248 | @item ENOENT |
fc320d37 | 39249 | A directory component in @var{pathname} does not exist. |
0ce1b118 | 39250 | |
b383017d | 39251 | @item ENOTDIR |
0ce1b118 CV |
39252 | A component of the path is not a directory. |
39253 | ||
b383017d | 39254 | @item EROFS |
0ce1b118 CV |
39255 | The file is on a read-only filesystem. |
39256 | ||
b383017d | 39257 | @item EINTR |
0ce1b118 CV |
39258 | The call was interrupted by the user. |
39259 | @end table | |
39260 | ||
fc320d37 SL |
39261 | @end table |
39262 | ||
0ce1b118 CV |
39263 | @node stat/fstat |
39264 | @unnumberedsubsubsec stat/fstat | |
39265 | @cindex fstat, file-i/o system call | |
39266 | @cindex stat, file-i/o system call | |
39267 | ||
fc320d37 SL |
39268 | @table @asis |
39269 | @item Synopsis: | |
0ce1b118 | 39270 | @smallexample |
0ce1b118 CV |
39271 | int stat(const char *pathname, struct stat *buf); |
39272 | int fstat(int fd, struct stat *buf); | |
fc320d37 | 39273 | @end smallexample |
0ce1b118 | 39274 | |
fc320d37 SL |
39275 | @item Request: |
39276 | @samp{Fstat,@var{pathnameptr}/@var{len},@var{bufptr}}@* | |
39277 | @samp{Ffstat,@var{fd},@var{bufptr}} | |
0ce1b118 | 39278 | |
fc320d37 | 39279 | @item Return value: |
0ce1b118 CV |
39280 | On success, zero is returned. On error, -1 is returned. |
39281 | ||
fc320d37 | 39282 | @item Errors: |
0ce1b118 CV |
39283 | |
39284 | @table @code | |
b383017d | 39285 | @item EBADF |
fc320d37 | 39286 | @var{fd} is not a valid open file. |
0ce1b118 | 39287 | |
b383017d | 39288 | @item ENOENT |
fc320d37 | 39289 | A directory component in @var{pathname} does not exist or the |
0ce1b118 CV |
39290 | path is an empty string. |
39291 | ||
b383017d | 39292 | @item ENOTDIR |
0ce1b118 CV |
39293 | A component of the path is not a directory. |
39294 | ||
b383017d | 39295 | @item EFAULT |
fc320d37 | 39296 | @var{pathnameptr} is an invalid pointer value. |
0ce1b118 | 39297 | |
b383017d | 39298 | @item EACCES |
0ce1b118 CV |
39299 | No access to the file or the path of the file. |
39300 | ||
39301 | @item ENAMETOOLONG | |
fc320d37 | 39302 | @var{pathname} was too long. |
0ce1b118 | 39303 | |
b383017d | 39304 | @item EINTR |
0ce1b118 CV |
39305 | The call was interrupted by the user. |
39306 | @end table | |
39307 | ||
fc320d37 SL |
39308 | @end table |
39309 | ||
0ce1b118 CV |
39310 | @node gettimeofday |
39311 | @unnumberedsubsubsec gettimeofday | |
39312 | @cindex gettimeofday, file-i/o system call | |
39313 | ||
fc320d37 SL |
39314 | @table @asis |
39315 | @item Synopsis: | |
0ce1b118 | 39316 | @smallexample |
0ce1b118 | 39317 | int gettimeofday(struct timeval *tv, void *tz); |
fc320d37 | 39318 | @end smallexample |
0ce1b118 | 39319 | |
fc320d37 SL |
39320 | @item Request: |
39321 | @samp{Fgettimeofday,@var{tvptr},@var{tzptr}} | |
0ce1b118 | 39322 | |
fc320d37 | 39323 | @item Return value: |
0ce1b118 CV |
39324 | On success, 0 is returned, -1 otherwise. |
39325 | ||
fc320d37 | 39326 | @item Errors: |
0ce1b118 CV |
39327 | |
39328 | @table @code | |
b383017d | 39329 | @item EINVAL |
fc320d37 | 39330 | @var{tz} is a non-NULL pointer. |
0ce1b118 | 39331 | |
b383017d | 39332 | @item EFAULT |
fc320d37 SL |
39333 | @var{tvptr} and/or @var{tzptr} is an invalid pointer value. |
39334 | @end table | |
39335 | ||
0ce1b118 CV |
39336 | @end table |
39337 | ||
39338 | @node isatty | |
39339 | @unnumberedsubsubsec isatty | |
39340 | @cindex isatty, file-i/o system call | |
39341 | ||
fc320d37 SL |
39342 | @table @asis |
39343 | @item Synopsis: | |
0ce1b118 | 39344 | @smallexample |
0ce1b118 | 39345 | int isatty(int fd); |
fc320d37 | 39346 | @end smallexample |
0ce1b118 | 39347 | |
fc320d37 SL |
39348 | @item Request: |
39349 | @samp{Fisatty,@var{fd}} | |
0ce1b118 | 39350 | |
fc320d37 SL |
39351 | @item Return value: |
39352 | Returns 1 if @var{fd} refers to the @value{GDBN} console, 0 otherwise. | |
0ce1b118 | 39353 | |
fc320d37 | 39354 | @item Errors: |
0ce1b118 CV |
39355 | |
39356 | @table @code | |
b383017d | 39357 | @item EINTR |
0ce1b118 CV |
39358 | The call was interrupted by the user. |
39359 | @end table | |
39360 | ||
fc320d37 SL |
39361 | @end table |
39362 | ||
39363 | Note that the @code{isatty} call is treated as a special case: it returns | |
39364 | 1 to the target if the file descriptor is attached | |
39365 | to the @value{GDBN} console, 0 otherwise. Implementing through system calls | |
39366 | would require implementing @code{ioctl} and would be more complex than | |
39367 | needed. | |
39368 | ||
39369 | ||
0ce1b118 CV |
39370 | @node system |
39371 | @unnumberedsubsubsec system | |
39372 | @cindex system, file-i/o system call | |
39373 | ||
fc320d37 SL |
39374 | @table @asis |
39375 | @item Synopsis: | |
0ce1b118 | 39376 | @smallexample |
0ce1b118 | 39377 | int system(const char *command); |
fc320d37 | 39378 | @end smallexample |
0ce1b118 | 39379 | |
fc320d37 SL |
39380 | @item Request: |
39381 | @samp{Fsystem,@var{commandptr}/@var{len}} | |
0ce1b118 | 39382 | |
fc320d37 | 39383 | @item Return value: |
5600ea19 NS |
39384 | If @var{len} is zero, the return value indicates whether a shell is |
39385 | available. A zero return value indicates a shell is not available. | |
39386 | For non-zero @var{len}, the value returned is -1 on error and the | |
39387 | return status of the command otherwise. Only the exit status of the | |
39388 | command is returned, which is extracted from the host's @code{system} | |
39389 | return value by calling @code{WEXITSTATUS(retval)}. In case | |
39390 | @file{/bin/sh} could not be executed, 127 is returned. | |
0ce1b118 | 39391 | |
fc320d37 | 39392 | @item Errors: |
0ce1b118 CV |
39393 | |
39394 | @table @code | |
b383017d | 39395 | @item EINTR |
0ce1b118 CV |
39396 | The call was interrupted by the user. |
39397 | @end table | |
39398 | ||
fc320d37 SL |
39399 | @end table |
39400 | ||
39401 | @value{GDBN} takes over the full task of calling the necessary host calls | |
39402 | to perform the @code{system} call. The return value of @code{system} on | |
39403 | the host is simplified before it's returned | |
39404 | to the target. Any termination signal information from the child process | |
39405 | is discarded, and the return value consists | |
39406 | entirely of the exit status of the called command. | |
39407 | ||
39408 | Due to security concerns, the @code{system} call is by default refused | |
39409 | by @value{GDBN}. The user has to allow this call explicitly with the | |
39410 | @code{set remote system-call-allowed 1} command. | |
39411 | ||
39412 | @table @code | |
39413 | @item set remote system-call-allowed | |
39414 | @kindex set remote system-call-allowed | |
39415 | Control whether to allow the @code{system} calls in the File I/O | |
39416 | protocol for the remote target. The default is zero (disabled). | |
39417 | ||
39418 | @item show remote system-call-allowed | |
39419 | @kindex show remote system-call-allowed | |
39420 | Show whether the @code{system} calls are allowed in the File I/O | |
39421 | protocol. | |
39422 | @end table | |
39423 | ||
db2e3e2e BW |
39424 | @node Protocol-specific Representation of Datatypes |
39425 | @subsection Protocol-specific Representation of Datatypes | |
39426 | @cindex protocol-specific representation of datatypes, in file-i/o protocol | |
0ce1b118 CV |
39427 | |
39428 | @menu | |
79a6e687 BW |
39429 | * Integral Datatypes:: |
39430 | * Pointer Values:: | |
39431 | * Memory Transfer:: | |
0ce1b118 CV |
39432 | * struct stat:: |
39433 | * struct timeval:: | |
39434 | @end menu | |
39435 | ||
79a6e687 BW |
39436 | @node Integral Datatypes |
39437 | @unnumberedsubsubsec Integral Datatypes | |
0ce1b118 CV |
39438 | @cindex integral datatypes, in file-i/o protocol |
39439 | ||
fc320d37 SL |
39440 | The integral datatypes used in the system calls are @code{int}, |
39441 | @code{unsigned int}, @code{long}, @code{unsigned long}, | |
39442 | @code{mode_t}, and @code{time_t}. | |
0ce1b118 | 39443 | |
fc320d37 | 39444 | @code{int}, @code{unsigned int}, @code{mode_t} and @code{time_t} are |
0ce1b118 CV |
39445 | implemented as 32 bit values in this protocol. |
39446 | ||
fc320d37 | 39447 | @code{long} and @code{unsigned long} are implemented as 64 bit types. |
b383017d | 39448 | |
0ce1b118 CV |
39449 | @xref{Limits}, for corresponding MIN and MAX values (similar to those |
39450 | in @file{limits.h}) to allow range checking on host and target. | |
39451 | ||
39452 | @code{time_t} datatypes are defined as seconds since the Epoch. | |
39453 | ||
39454 | All integral datatypes transferred as part of a memory read or write of a | |
39455 | structured datatype e.g.@: a @code{struct stat} have to be given in big endian | |
39456 | byte order. | |
39457 | ||
79a6e687 BW |
39458 | @node Pointer Values |
39459 | @unnumberedsubsubsec Pointer Values | |
0ce1b118 CV |
39460 | @cindex pointer values, in file-i/o protocol |
39461 | ||
39462 | Pointers to target data are transmitted as they are. An exception | |
39463 | is made for pointers to buffers for which the length isn't | |
39464 | transmitted as part of the function call, namely strings. Strings | |
39465 | are transmitted as a pointer/length pair, both as hex values, e.g.@: | |
39466 | ||
39467 | @smallexample | |
39468 | @code{1aaf/12} | |
39469 | @end smallexample | |
39470 | ||
39471 | @noindent | |
39472 | which is a pointer to data of length 18 bytes at position 0x1aaf. | |
39473 | The length is defined as the full string length in bytes, including | |
fc320d37 SL |
39474 | the trailing null byte. For example, the string @code{"hello world"} |
39475 | at address 0x123456 is transmitted as | |
0ce1b118 CV |
39476 | |
39477 | @smallexample | |
fc320d37 | 39478 | @code{123456/d} |
0ce1b118 CV |
39479 | @end smallexample |
39480 | ||
79a6e687 BW |
39481 | @node Memory Transfer |
39482 | @unnumberedsubsubsec Memory Transfer | |
fc320d37 SL |
39483 | @cindex memory transfer, in file-i/o protocol |
39484 | ||
39485 | Structured data which is transferred using a memory read or write (for | |
db2e3e2e | 39486 | example, a @code{struct stat}) is expected to be in a protocol-specific format |
fc320d37 SL |
39487 | with all scalar multibyte datatypes being big endian. Translation to |
39488 | this representation needs to be done both by the target before the @code{F} | |
39489 | packet is sent, and by @value{GDBN} before | |
39490 | it transfers memory to the target. Transferred pointers to structured | |
39491 | data should point to the already-coerced data at any time. | |
0ce1b118 | 39492 | |
0ce1b118 CV |
39493 | |
39494 | @node struct stat | |
39495 | @unnumberedsubsubsec struct stat | |
39496 | @cindex struct stat, in file-i/o protocol | |
39497 | ||
fc320d37 SL |
39498 | The buffer of type @code{struct stat} used by the target and @value{GDBN} |
39499 | is defined as follows: | |
0ce1b118 CV |
39500 | |
39501 | @smallexample | |
39502 | struct stat @{ | |
39503 | unsigned int st_dev; /* device */ | |
39504 | unsigned int st_ino; /* inode */ | |
39505 | mode_t st_mode; /* protection */ | |
39506 | unsigned int st_nlink; /* number of hard links */ | |
39507 | unsigned int st_uid; /* user ID of owner */ | |
39508 | unsigned int st_gid; /* group ID of owner */ | |
39509 | unsigned int st_rdev; /* device type (if inode device) */ | |
39510 | unsigned long st_size; /* total size, in bytes */ | |
39511 | unsigned long st_blksize; /* blocksize for filesystem I/O */ | |
39512 | unsigned long st_blocks; /* number of blocks allocated */ | |
39513 | time_t st_atime; /* time of last access */ | |
39514 | time_t st_mtime; /* time of last modification */ | |
39515 | time_t st_ctime; /* time of last change */ | |
39516 | @}; | |
39517 | @end smallexample | |
39518 | ||
fc320d37 | 39519 | The integral datatypes conform to the definitions given in the |
79a6e687 | 39520 | appropriate section (see @ref{Integral Datatypes}, for details) so this |
0ce1b118 CV |
39521 | structure is of size 64 bytes. |
39522 | ||
39523 | The values of several fields have a restricted meaning and/or | |
39524 | range of values. | |
39525 | ||
fc320d37 | 39526 | @table @code |
0ce1b118 | 39527 | |
fc320d37 SL |
39528 | @item st_dev |
39529 | A value of 0 represents a file, 1 the console. | |
0ce1b118 | 39530 | |
fc320d37 SL |
39531 | @item st_ino |
39532 | No valid meaning for the target. Transmitted unchanged. | |
0ce1b118 | 39533 | |
fc320d37 SL |
39534 | @item st_mode |
39535 | Valid mode bits are described in @ref{Constants}. Any other | |
39536 | bits have currently no meaning for the target. | |
0ce1b118 | 39537 | |
fc320d37 SL |
39538 | @item st_uid |
39539 | @itemx st_gid | |
39540 | @itemx st_rdev | |
39541 | No valid meaning for the target. Transmitted unchanged. | |
0ce1b118 | 39542 | |
fc320d37 SL |
39543 | @item st_atime |
39544 | @itemx st_mtime | |
39545 | @itemx st_ctime | |
39546 | These values have a host and file system dependent | |
39547 | accuracy. Especially on Windows hosts, the file system may not | |
39548 | support exact timing values. | |
39549 | @end table | |
0ce1b118 | 39550 | |
fc320d37 SL |
39551 | The target gets a @code{struct stat} of the above representation and is |
39552 | responsible for coercing it to the target representation before | |
0ce1b118 CV |
39553 | continuing. |
39554 | ||
fc320d37 SL |
39555 | Note that due to size differences between the host, target, and protocol |
39556 | representations of @code{struct stat} members, these members could eventually | |
0ce1b118 CV |
39557 | get truncated on the target. |
39558 | ||
39559 | @node struct timeval | |
39560 | @unnumberedsubsubsec struct timeval | |
39561 | @cindex struct timeval, in file-i/o protocol | |
39562 | ||
fc320d37 | 39563 | The buffer of type @code{struct timeval} used by the File-I/O protocol |
0ce1b118 CV |
39564 | is defined as follows: |
39565 | ||
39566 | @smallexample | |
b383017d | 39567 | struct timeval @{ |
0ce1b118 CV |
39568 | time_t tv_sec; /* second */ |
39569 | long tv_usec; /* microsecond */ | |
39570 | @}; | |
39571 | @end smallexample | |
39572 | ||
fc320d37 | 39573 | The integral datatypes conform to the definitions given in the |
79a6e687 | 39574 | appropriate section (see @ref{Integral Datatypes}, for details) so this |
0ce1b118 CV |
39575 | structure is of size 8 bytes. |
39576 | ||
39577 | @node Constants | |
39578 | @subsection Constants | |
39579 | @cindex constants, in file-i/o protocol | |
39580 | ||
39581 | The following values are used for the constants inside of the | |
fc320d37 | 39582 | protocol. @value{GDBN} and target are responsible for translating these |
0ce1b118 CV |
39583 | values before and after the call as needed. |
39584 | ||
39585 | @menu | |
79a6e687 BW |
39586 | * Open Flags:: |
39587 | * mode_t Values:: | |
39588 | * Errno Values:: | |
39589 | * Lseek Flags:: | |
0ce1b118 CV |
39590 | * Limits:: |
39591 | @end menu | |
39592 | ||
79a6e687 BW |
39593 | @node Open Flags |
39594 | @unnumberedsubsubsec Open Flags | |
0ce1b118 CV |
39595 | @cindex open flags, in file-i/o protocol |
39596 | ||
39597 | All values are given in hexadecimal representation. | |
39598 | ||
39599 | @smallexample | |
39600 | O_RDONLY 0x0 | |
39601 | O_WRONLY 0x1 | |
39602 | O_RDWR 0x2 | |
39603 | O_APPEND 0x8 | |
39604 | O_CREAT 0x200 | |
39605 | O_TRUNC 0x400 | |
39606 | O_EXCL 0x800 | |
39607 | @end smallexample | |
39608 | ||
79a6e687 BW |
39609 | @node mode_t Values |
39610 | @unnumberedsubsubsec mode_t Values | |
0ce1b118 CV |
39611 | @cindex mode_t values, in file-i/o protocol |
39612 | ||
39613 | All values are given in octal representation. | |
39614 | ||
39615 | @smallexample | |
39616 | S_IFREG 0100000 | |
39617 | S_IFDIR 040000 | |
39618 | S_IRUSR 0400 | |
39619 | S_IWUSR 0200 | |
39620 | S_IXUSR 0100 | |
39621 | S_IRGRP 040 | |
39622 | S_IWGRP 020 | |
39623 | S_IXGRP 010 | |
39624 | S_IROTH 04 | |
39625 | S_IWOTH 02 | |
39626 | S_IXOTH 01 | |
39627 | @end smallexample | |
39628 | ||
79a6e687 BW |
39629 | @node Errno Values |
39630 | @unnumberedsubsubsec Errno Values | |
0ce1b118 CV |
39631 | @cindex errno values, in file-i/o protocol |
39632 | ||
39633 | All values are given in decimal representation. | |
39634 | ||
39635 | @smallexample | |
39636 | EPERM 1 | |
39637 | ENOENT 2 | |
39638 | EINTR 4 | |
39639 | EBADF 9 | |
39640 | EACCES 13 | |
39641 | EFAULT 14 | |
39642 | EBUSY 16 | |
39643 | EEXIST 17 | |
39644 | ENODEV 19 | |
39645 | ENOTDIR 20 | |
39646 | EISDIR 21 | |
39647 | EINVAL 22 | |
39648 | ENFILE 23 | |
39649 | EMFILE 24 | |
39650 | EFBIG 27 | |
39651 | ENOSPC 28 | |
39652 | ESPIPE 29 | |
39653 | EROFS 30 | |
39654 | ENAMETOOLONG 91 | |
39655 | EUNKNOWN 9999 | |
39656 | @end smallexample | |
39657 | ||
fc320d37 | 39658 | @code{EUNKNOWN} is used as a fallback error value if a host system returns |
0ce1b118 CV |
39659 | any error value not in the list of supported error numbers. |
39660 | ||
79a6e687 BW |
39661 | @node Lseek Flags |
39662 | @unnumberedsubsubsec Lseek Flags | |
0ce1b118 CV |
39663 | @cindex lseek flags, in file-i/o protocol |
39664 | ||
39665 | @smallexample | |
39666 | SEEK_SET 0 | |
39667 | SEEK_CUR 1 | |
39668 | SEEK_END 2 | |
39669 | @end smallexample | |
39670 | ||
39671 | @node Limits | |
39672 | @unnumberedsubsubsec Limits | |
39673 | @cindex limits, in file-i/o protocol | |
39674 | ||
39675 | All values are given in decimal representation. | |
39676 | ||
39677 | @smallexample | |
39678 | INT_MIN -2147483648 | |
39679 | INT_MAX 2147483647 | |
39680 | UINT_MAX 4294967295 | |
39681 | LONG_MIN -9223372036854775808 | |
39682 | LONG_MAX 9223372036854775807 | |
39683 | ULONG_MAX 18446744073709551615 | |
39684 | @end smallexample | |
39685 | ||
39686 | @node File-I/O Examples | |
39687 | @subsection File-I/O Examples | |
39688 | @cindex file-i/o examples | |
39689 | ||
39690 | Example sequence of a write call, file descriptor 3, buffer is at target | |
39691 | address 0x1234, 6 bytes should be written: | |
39692 | ||
39693 | @smallexample | |
39694 | <- @code{Fwrite,3,1234,6} | |
39695 | @emph{request memory read from target} | |
39696 | -> @code{m1234,6} | |
39697 | <- XXXXXX | |
39698 | @emph{return "6 bytes written"} | |
39699 | -> @code{F6} | |
39700 | @end smallexample | |
39701 | ||
39702 | Example sequence of a read call, file descriptor 3, buffer is at target | |
39703 | address 0x1234, 6 bytes should be read: | |
39704 | ||
39705 | @smallexample | |
39706 | <- @code{Fread,3,1234,6} | |
39707 | @emph{request memory write to target} | |
39708 | -> @code{X1234,6:XXXXXX} | |
39709 | @emph{return "6 bytes read"} | |
39710 | -> @code{F6} | |
39711 | @end smallexample | |
39712 | ||
39713 | Example sequence of a read call, call fails on the host due to invalid | |
fc320d37 | 39714 | file descriptor (@code{EBADF}): |
0ce1b118 CV |
39715 | |
39716 | @smallexample | |
39717 | <- @code{Fread,3,1234,6} | |
39718 | -> @code{F-1,9} | |
39719 | @end smallexample | |
39720 | ||
c8aa23ab | 39721 | Example sequence of a read call, user presses @kbd{Ctrl-c} before syscall on |
0ce1b118 CV |
39722 | host is called: |
39723 | ||
39724 | @smallexample | |
39725 | <- @code{Fread,3,1234,6} | |
39726 | -> @code{F-1,4,C} | |
39727 | <- @code{T02} | |
39728 | @end smallexample | |
39729 | ||
c8aa23ab | 39730 | Example sequence of a read call, user presses @kbd{Ctrl-c} after syscall on |
0ce1b118 CV |
39731 | host is called: |
39732 | ||
39733 | @smallexample | |
39734 | <- @code{Fread,3,1234,6} | |
39735 | -> @code{X1234,6:XXXXXX} | |
39736 | <- @code{T02} | |
39737 | @end smallexample | |
39738 | ||
cfa9d6d9 DJ |
39739 | @node Library List Format |
39740 | @section Library List Format | |
39741 | @cindex library list format, remote protocol | |
39742 | ||
39743 | On some platforms, a dynamic loader (e.g.@: @file{ld.so}) runs in the | |
39744 | same process as your application to manage libraries. In this case, | |
39745 | @value{GDBN} can use the loader's symbol table and normal memory | |
39746 | operations to maintain a list of shared libraries. On other | |
39747 | platforms, the operating system manages loaded libraries. | |
39748 | @value{GDBN} can not retrieve the list of currently loaded libraries | |
39749 | through memory operations, so it uses the @samp{qXfer:libraries:read} | |
39750 | packet (@pxref{qXfer library list read}) instead. The remote stub | |
39751 | queries the target's operating system and reports which libraries | |
39752 | are loaded. | |
39753 | ||
39754 | The @samp{qXfer:libraries:read} packet returns an XML document which | |
39755 | lists loaded libraries and their offsets. Each library has an | |
1fddbabb PA |
39756 | associated name and one or more segment or section base addresses, |
39757 | which report where the library was loaded in memory. | |
39758 | ||
39759 | For the common case of libraries that are fully linked binaries, the | |
39760 | library should have a list of segments. If the target supports | |
39761 | dynamic linking of a relocatable object file, its library XML element | |
39762 | should instead include a list of allocated sections. The segment or | |
39763 | section bases are start addresses, not relocation offsets; they do not | |
39764 | depend on the library's link-time base addresses. | |
cfa9d6d9 | 39765 | |
9cceb671 DJ |
39766 | @value{GDBN} must be linked with the Expat library to support XML |
39767 | library lists. @xref{Expat}. | |
39768 | ||
cfa9d6d9 DJ |
39769 | A simple memory map, with one loaded library relocated by a single |
39770 | offset, looks like this: | |
39771 | ||
39772 | @smallexample | |
39773 | <library-list> | |
39774 | <library name="/lib/libc.so.6"> | |
39775 | <segment address="0x10000000"/> | |
39776 | </library> | |
39777 | </library-list> | |
39778 | @end smallexample | |
39779 | ||
1fddbabb PA |
39780 | Another simple memory map, with one loaded library with three |
39781 | allocated sections (.text, .data, .bss), looks like this: | |
39782 | ||
39783 | @smallexample | |
39784 | <library-list> | |
39785 | <library name="sharedlib.o"> | |
39786 | <section address="0x10000000"/> | |
39787 | <section address="0x20000000"/> | |
39788 | <section address="0x30000000"/> | |
39789 | </library> | |
39790 | </library-list> | |
39791 | @end smallexample | |
39792 | ||
cfa9d6d9 DJ |
39793 | The format of a library list is described by this DTD: |
39794 | ||
39795 | @smallexample | |
39796 | <!-- library-list: Root element with versioning --> | |
39797 | <!ELEMENT library-list (library)*> | |
39798 | <!ATTLIST library-list version CDATA #FIXED "1.0"> | |
1fddbabb | 39799 | <!ELEMENT library (segment*, section*)> |
cfa9d6d9 DJ |
39800 | <!ATTLIST library name CDATA #REQUIRED> |
39801 | <!ELEMENT segment EMPTY> | |
39802 | <!ATTLIST segment address CDATA #REQUIRED> | |
1fddbabb PA |
39803 | <!ELEMENT section EMPTY> |
39804 | <!ATTLIST section address CDATA #REQUIRED> | |
cfa9d6d9 DJ |
39805 | @end smallexample |
39806 | ||
1fddbabb PA |
39807 | In addition, segments and section descriptors cannot be mixed within a |
39808 | single library element, and you must supply at least one segment or | |
39809 | section for each library. | |
39810 | ||
2268b414 JK |
39811 | @node Library List Format for SVR4 Targets |
39812 | @section Library List Format for SVR4 Targets | |
39813 | @cindex library list format, remote protocol | |
39814 | ||
39815 | On SVR4 platforms @value{GDBN} can use the symbol table of a dynamic loader | |
39816 | (e.g.@: @file{ld.so}) and normal memory operations to maintain a list of | |
39817 | shared libraries. Still a special library list provided by this packet is | |
39818 | more efficient for the @value{GDBN} remote protocol. | |
39819 | ||
39820 | The @samp{qXfer:libraries-svr4:read} packet returns an XML document which lists | |
39821 | loaded libraries and their SVR4 linker parameters. For each library on SVR4 | |
39822 | target, the following parameters are reported: | |
39823 | ||
39824 | @itemize @minus | |
39825 | @item | |
39826 | @code{name}, the absolute file name from the @code{l_name} field of | |
39827 | @code{struct link_map}. | |
39828 | @item | |
39829 | @code{lm} with address of @code{struct link_map} used for TLS | |
39830 | (Thread Local Storage) access. | |
39831 | @item | |
39832 | @code{l_addr}, the displacement as read from the field @code{l_addr} of | |
39833 | @code{struct link_map}. For prelinked libraries this is not an absolute | |
39834 | memory address. It is a displacement of absolute memory address against | |
39835 | address the file was prelinked to during the library load. | |
39836 | @item | |
39837 | @code{l_ld}, which is memory address of the @code{PT_DYNAMIC} segment | |
39838 | @end itemize | |
39839 | ||
39840 | Additionally the single @code{main-lm} attribute specifies address of | |
39841 | @code{struct link_map} used for the main executable. This parameter is used | |
39842 | for TLS access and its presence is optional. | |
39843 | ||
39844 | @value{GDBN} must be linked with the Expat library to support XML | |
39845 | SVR4 library lists. @xref{Expat}. | |
39846 | ||
39847 | A simple memory map, with two loaded libraries (which do not use prelink), | |
39848 | looks like this: | |
39849 | ||
39850 | @smallexample | |
39851 | <library-list-svr4 version="1.0" main-lm="0xe4f8f8"> | |
39852 | <library name="/lib/ld-linux.so.2" lm="0xe4f51c" l_addr="0xe2d000" | |
39853 | l_ld="0xe4eefc"/> | |
39854 | <library name="/lib/libc.so.6" lm="0xe4fbe8" l_addr="0x154000" | |
db1ff28b | 39855 | l_ld="0x152350"/> |
2268b414 JK |
39856 | </library-list-svr> |
39857 | @end smallexample | |
39858 | ||
39859 | The format of an SVR4 library list is described by this DTD: | |
39860 | ||
39861 | @smallexample | |
39862 | <!-- library-list-svr4: Root element with versioning --> | |
39863 | <!ELEMENT library-list-svr4 (library)*> | |
db1ff28b JK |
39864 | <!ATTLIST library-list-svr4 version CDATA #FIXED "1.0"> |
39865 | <!ATTLIST library-list-svr4 main-lm CDATA #IMPLIED> | |
2268b414 | 39866 | <!ELEMENT library EMPTY> |
db1ff28b JK |
39867 | <!ATTLIST library name CDATA #REQUIRED> |
39868 | <!ATTLIST library lm CDATA #REQUIRED> | |
39869 | <!ATTLIST library l_addr CDATA #REQUIRED> | |
39870 | <!ATTLIST library l_ld CDATA #REQUIRED> | |
2268b414 JK |
39871 | @end smallexample |
39872 | ||
79a6e687 BW |
39873 | @node Memory Map Format |
39874 | @section Memory Map Format | |
68437a39 DJ |
39875 | @cindex memory map format |
39876 | ||
39877 | To be able to write into flash memory, @value{GDBN} needs to obtain a | |
39878 | memory map from the target. This section describes the format of the | |
39879 | memory map. | |
39880 | ||
39881 | The memory map is obtained using the @samp{qXfer:memory-map:read} | |
39882 | (@pxref{qXfer memory map read}) packet and is an XML document that | |
9cceb671 DJ |
39883 | lists memory regions. |
39884 | ||
39885 | @value{GDBN} must be linked with the Expat library to support XML | |
39886 | memory maps. @xref{Expat}. | |
39887 | ||
39888 | The top-level structure of the document is shown below: | |
68437a39 DJ |
39889 | |
39890 | @smallexample | |
39891 | <?xml version="1.0"?> | |
39892 | <!DOCTYPE memory-map | |
39893 | PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN" | |
39894 | "http://sourceware.org/gdb/gdb-memory-map.dtd"> | |
39895 | <memory-map> | |
39896 | region... | |
39897 | </memory-map> | |
39898 | @end smallexample | |
39899 | ||
39900 | Each region can be either: | |
39901 | ||
39902 | @itemize | |
39903 | ||
39904 | @item | |
39905 | A region of RAM starting at @var{addr} and extending for @var{length} | |
39906 | bytes from there: | |
39907 | ||
39908 | @smallexample | |
39909 | <memory type="ram" start="@var{addr}" length="@var{length}"/> | |
39910 | @end smallexample | |
39911 | ||
39912 | ||
39913 | @item | |
39914 | A region of read-only memory: | |
39915 | ||
39916 | @smallexample | |
39917 | <memory type="rom" start="@var{addr}" length="@var{length}"/> | |
39918 | @end smallexample | |
39919 | ||
39920 | ||
39921 | @item | |
39922 | A region of flash memory, with erasure blocks @var{blocksize} | |
39923 | bytes in length: | |
39924 | ||
39925 | @smallexample | |
39926 | <memory type="flash" start="@var{addr}" length="@var{length}"> | |
39927 | <property name="blocksize">@var{blocksize}</property> | |
39928 | </memory> | |
39929 | @end smallexample | |
39930 | ||
39931 | @end itemize | |
39932 | ||
39933 | Regions must not overlap. @value{GDBN} assumes that areas of memory not covered | |
39934 | by the memory map are RAM, and uses the ordinary @samp{M} and @samp{X} | |
39935 | packets to write to addresses in such ranges. | |
39936 | ||
39937 | The formal DTD for memory map format is given below: | |
39938 | ||
39939 | @smallexample | |
39940 | <!-- ................................................... --> | |
39941 | <!-- Memory Map XML DTD ................................ --> | |
39942 | <!-- File: memory-map.dtd .............................. --> | |
39943 | <!-- .................................... .............. --> | |
39944 | <!-- memory-map.dtd --> | |
39945 | <!-- memory-map: Root element with versioning --> | |
39946 | <!ELEMENT memory-map (memory | property)> | |
39947 | <!ATTLIST memory-map version CDATA #FIXED "1.0.0"> | |
39948 | <!ELEMENT memory (property)> | |
39949 | <!-- memory: Specifies a memory region, | |
39950 | and its type, or device. --> | |
39951 | <!ATTLIST memory type CDATA #REQUIRED | |
39952 | start CDATA #REQUIRED | |
39953 | length CDATA #REQUIRED | |
39954 | device CDATA #IMPLIED> | |
39955 | <!-- property: Generic attribute tag --> | |
39956 | <!ELEMENT property (#PCDATA | property)*> | |
39957 | <!ATTLIST property name CDATA #REQUIRED> | |
39958 | @end smallexample | |
39959 | ||
dc146f7c VP |
39960 | @node Thread List Format |
39961 | @section Thread List Format | |
39962 | @cindex thread list format | |
39963 | ||
39964 | To efficiently update the list of threads and their attributes, | |
39965 | @value{GDBN} issues the @samp{qXfer:threads:read} packet | |
39966 | (@pxref{qXfer threads read}) and obtains the XML document with | |
39967 | the following structure: | |
39968 | ||
39969 | @smallexample | |
39970 | <?xml version="1.0"?> | |
39971 | <threads> | |
79efa585 | 39972 | <thread id="id" core="0" name="name"> |
dc146f7c VP |
39973 | ... description ... |
39974 | </thread> | |
39975 | </threads> | |
39976 | @end smallexample | |
39977 | ||
39978 | Each @samp{thread} element must have the @samp{id} attribute that | |
39979 | identifies the thread (@pxref{thread-id syntax}). The | |
39980 | @samp{core} attribute, if present, specifies which processor core | |
79efa585 SM |
39981 | the thread was last executing on. The @samp{name} attribute, if |
39982 | present, specifies the human-readable name of the thread. The content | |
39983 | of the of @samp{thread} element is interpreted as human-readable | |
39984 | auxiliary information. | |
dc146f7c | 39985 | |
b3b9301e PA |
39986 | @node Traceframe Info Format |
39987 | @section Traceframe Info Format | |
39988 | @cindex traceframe info format | |
39989 | ||
39990 | To be able to know which objects in the inferior can be examined when | |
39991 | inspecting a tracepoint hit, @value{GDBN} needs to obtain the list of | |
39992 | memory ranges, registers and trace state variables that have been | |
39993 | collected in a traceframe. | |
39994 | ||
39995 | This list is obtained using the @samp{qXfer:traceframe-info:read} | |
39996 | (@pxref{qXfer traceframe info read}) packet and is an XML document. | |
39997 | ||
39998 | @value{GDBN} must be linked with the Expat library to support XML | |
39999 | traceframe info discovery. @xref{Expat}. | |
40000 | ||
40001 | The top-level structure of the document is shown below: | |
40002 | ||
40003 | @smallexample | |
40004 | <?xml version="1.0"?> | |
40005 | <!DOCTYPE traceframe-info | |
40006 | PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN" | |
40007 | "http://sourceware.org/gdb/gdb-traceframe-info.dtd"> | |
40008 | <traceframe-info> | |
40009 | block... | |
40010 | </traceframe-info> | |
40011 | @end smallexample | |
40012 | ||
40013 | Each traceframe block can be either: | |
40014 | ||
40015 | @itemize | |
40016 | ||
40017 | @item | |
40018 | A region of collected memory starting at @var{addr} and extending for | |
40019 | @var{length} bytes from there: | |
40020 | ||
40021 | @smallexample | |
40022 | <memory start="@var{addr}" length="@var{length}"/> | |
40023 | @end smallexample | |
40024 | ||
28a93511 YQ |
40025 | @item |
40026 | A block indicating trace state variable numbered @var{number} has been | |
40027 | collected: | |
40028 | ||
40029 | @smallexample | |
40030 | <tvar id="@var{number}"/> | |
40031 | @end smallexample | |
40032 | ||
b3b9301e PA |
40033 | @end itemize |
40034 | ||
40035 | The formal DTD for the traceframe info format is given below: | |
40036 | ||
40037 | @smallexample | |
28a93511 | 40038 | <!ELEMENT traceframe-info (memory | tvar)* > |
b3b9301e PA |
40039 | <!ATTLIST traceframe-info version CDATA #FIXED "1.0"> |
40040 | ||
40041 | <!ELEMENT memory EMPTY> | |
40042 | <!ATTLIST memory start CDATA #REQUIRED | |
40043 | length CDATA #REQUIRED> | |
28a93511 YQ |
40044 | <!ELEMENT tvar> |
40045 | <!ATTLIST tvar id CDATA #REQUIRED> | |
b3b9301e PA |
40046 | @end smallexample |
40047 | ||
2ae8c8e7 MM |
40048 | @node Branch Trace Format |
40049 | @section Branch Trace Format | |
40050 | @cindex branch trace format | |
40051 | ||
40052 | In order to display the branch trace of an inferior thread, | |
40053 | @value{GDBN} needs to obtain the list of branches. This list is | |
40054 | represented as list of sequential code blocks that are connected via | |
40055 | branches. The code in each block has been executed sequentially. | |
40056 | ||
40057 | This list is obtained using the @samp{qXfer:btrace:read} | |
40058 | (@pxref{qXfer btrace read}) packet and is an XML document. | |
40059 | ||
40060 | @value{GDBN} must be linked with the Expat library to support XML | |
40061 | traceframe info discovery. @xref{Expat}. | |
40062 | ||
40063 | The top-level structure of the document is shown below: | |
40064 | ||
40065 | @smallexample | |
40066 | <?xml version="1.0"?> | |
40067 | <!DOCTYPE btrace | |
40068 | PUBLIC "+//IDN gnu.org//DTD GDB Branch Trace V1.0//EN" | |
40069 | "http://sourceware.org/gdb/gdb-btrace.dtd"> | |
40070 | <btrace> | |
40071 | block... | |
40072 | </btrace> | |
40073 | @end smallexample | |
40074 | ||
40075 | @itemize | |
40076 | ||
40077 | @item | |
40078 | A block of sequentially executed instructions starting at @var{begin} | |
40079 | and ending at @var{end}: | |
40080 | ||
40081 | @smallexample | |
40082 | <block begin="@var{begin}" end="@var{end}"/> | |
40083 | @end smallexample | |
40084 | ||
40085 | @end itemize | |
40086 | ||
40087 | The formal DTD for the branch trace format is given below: | |
40088 | ||
40089 | @smallexample | |
b20a6524 | 40090 | <!ELEMENT btrace (block* | pt) > |
2ae8c8e7 MM |
40091 | <!ATTLIST btrace version CDATA #FIXED "1.0"> |
40092 | ||
40093 | <!ELEMENT block EMPTY> | |
40094 | <!ATTLIST block begin CDATA #REQUIRED | |
40095 | end CDATA #REQUIRED> | |
b20a6524 MM |
40096 | |
40097 | <!ELEMENT pt (pt-config?, raw?)> | |
40098 | ||
40099 | <!ELEMENT pt-config (cpu?)> | |
40100 | ||
40101 | <!ELEMENT cpu EMPTY> | |
40102 | <!ATTLIST cpu vendor CDATA #REQUIRED | |
40103 | family CDATA #REQUIRED | |
40104 | model CDATA #REQUIRED | |
40105 | stepping CDATA #REQUIRED> | |
40106 | ||
40107 | <!ELEMENT raw (#PCDATA)> | |
2ae8c8e7 MM |
40108 | @end smallexample |
40109 | ||
f4abbc16 MM |
40110 | @node Branch Trace Configuration Format |
40111 | @section Branch Trace Configuration Format | |
40112 | @cindex branch trace configuration format | |
40113 | ||
40114 | For each inferior thread, @value{GDBN} can obtain the branch trace | |
40115 | configuration using the @samp{qXfer:btrace-conf:read} | |
40116 | (@pxref{qXfer btrace-conf read}) packet. | |
40117 | ||
40118 | The configuration describes the branch trace format and configuration | |
d33501a5 MM |
40119 | settings for that format. The following information is described: |
40120 | ||
40121 | @table @code | |
40122 | @item bts | |
40123 | This thread uses the @dfn{Branch Trace Store} (@acronym{BTS}) format. | |
40124 | @table @code | |
40125 | @item size | |
40126 | The size of the @acronym{BTS} ring buffer in bytes. | |
40127 | @end table | |
b20a6524 | 40128 | @item pt |
bc504a31 | 40129 | This thread uses the @dfn{Intel Processor Trace} (@acronym{Intel |
b20a6524 MM |
40130 | PT}) format. |
40131 | @table @code | |
40132 | @item size | |
bc504a31 | 40133 | The size of the @acronym{Intel PT} ring buffer in bytes. |
b20a6524 | 40134 | @end table |
d33501a5 | 40135 | @end table |
f4abbc16 MM |
40136 | |
40137 | @value{GDBN} must be linked with the Expat library to support XML | |
40138 | branch trace configuration discovery. @xref{Expat}. | |
40139 | ||
40140 | The formal DTD for the branch trace configuration format is given below: | |
40141 | ||
40142 | @smallexample | |
b20a6524 | 40143 | <!ELEMENT btrace-conf (bts?, pt?)> |
f4abbc16 MM |
40144 | <!ATTLIST btrace-conf version CDATA #FIXED "1.0"> |
40145 | ||
40146 | <!ELEMENT bts EMPTY> | |
d33501a5 | 40147 | <!ATTLIST bts size CDATA #IMPLIED> |
b20a6524 MM |
40148 | |
40149 | <!ELEMENT pt EMPTY> | |
40150 | <!ATTLIST pt size CDATA #IMPLIED> | |
f4abbc16 MM |
40151 | @end smallexample |
40152 | ||
f418dd93 DJ |
40153 | @include agentexpr.texi |
40154 | ||
23181151 DJ |
40155 | @node Target Descriptions |
40156 | @appendix Target Descriptions | |
40157 | @cindex target descriptions | |
40158 | ||
23181151 DJ |
40159 | One of the challenges of using @value{GDBN} to debug embedded systems |
40160 | is that there are so many minor variants of each processor | |
40161 | architecture in use. It is common practice for vendors to start with | |
eb17f351 | 40162 | a standard processor core --- ARM, PowerPC, or @acronym{MIPS}, for example --- |
23181151 DJ |
40163 | and then make changes to adapt it to a particular market niche. Some |
40164 | architectures have hundreds of variants, available from dozens of | |
40165 | vendors. This leads to a number of problems: | |
40166 | ||
40167 | @itemize @bullet | |
40168 | @item | |
40169 | With so many different customized processors, it is difficult for | |
40170 | the @value{GDBN} maintainers to keep up with the changes. | |
40171 | @item | |
40172 | Since individual variants may have short lifetimes or limited | |
40173 | audiences, it may not be worthwhile to carry information about every | |
40174 | variant in the @value{GDBN} source tree. | |
40175 | @item | |
40176 | When @value{GDBN} does support the architecture of the embedded system | |
40177 | at hand, the task of finding the correct architecture name to give the | |
40178 | @command{set architecture} command can be error-prone. | |
40179 | @end itemize | |
40180 | ||
40181 | To address these problems, the @value{GDBN} remote protocol allows a | |
40182 | target system to not only identify itself to @value{GDBN}, but to | |
40183 | actually describe its own features. This lets @value{GDBN} support | |
40184 | processor variants it has never seen before --- to the extent that the | |
40185 | descriptions are accurate, and that @value{GDBN} understands them. | |
40186 | ||
9cceb671 DJ |
40187 | @value{GDBN} must be linked with the Expat library to support XML |
40188 | target descriptions. @xref{Expat}. | |
123dc839 | 40189 | |
23181151 DJ |
40190 | @menu |
40191 | * Retrieving Descriptions:: How descriptions are fetched from a target. | |
40192 | * Target Description Format:: The contents of a target description. | |
123dc839 DJ |
40193 | * Predefined Target Types:: Standard types available for target |
40194 | descriptions. | |
40195 | * Standard Target Features:: Features @value{GDBN} knows about. | |
23181151 DJ |
40196 | @end menu |
40197 | ||
40198 | @node Retrieving Descriptions | |
40199 | @section Retrieving Descriptions | |
40200 | ||
40201 | Target descriptions can be read from the target automatically, or | |
40202 | specified by the user manually. The default behavior is to read the | |
40203 | description from the target. @value{GDBN} retrieves it via the remote | |
40204 | protocol using @samp{qXfer} requests (@pxref{General Query Packets, | |
40205 | qXfer}). The @var{annex} in the @samp{qXfer} packet will be | |
40206 | @samp{target.xml}. The contents of the @samp{target.xml} annex are an | |
40207 | XML document, of the form described in @ref{Target Description | |
40208 | Format}. | |
40209 | ||
40210 | Alternatively, you can specify a file to read for the target description. | |
40211 | If a file is set, the target will not be queried. The commands to | |
40212 | specify a file are: | |
40213 | ||
40214 | @table @code | |
40215 | @cindex set tdesc filename | |
40216 | @item set tdesc filename @var{path} | |
40217 | Read the target description from @var{path}. | |
40218 | ||
40219 | @cindex unset tdesc filename | |
40220 | @item unset tdesc filename | |
40221 | Do not read the XML target description from a file. @value{GDBN} | |
40222 | will use the description supplied by the current target. | |
40223 | ||
40224 | @cindex show tdesc filename | |
40225 | @item show tdesc filename | |
40226 | Show the filename to read for a target description, if any. | |
40227 | @end table | |
40228 | ||
40229 | ||
40230 | @node Target Description Format | |
40231 | @section Target Description Format | |
40232 | @cindex target descriptions, XML format | |
40233 | ||
40234 | A target description annex is an @uref{http://www.w3.org/XML/, XML} | |
40235 | document which complies with the Document Type Definition provided in | |
40236 | the @value{GDBN} sources in @file{gdb/features/gdb-target.dtd}. This | |
40237 | means you can use generally available tools like @command{xmllint} to | |
40238 | check that your feature descriptions are well-formed and valid. | |
40239 | However, to help people unfamiliar with XML write descriptions for | |
40240 | their targets, we also describe the grammar here. | |
40241 | ||
123dc839 DJ |
40242 | Target descriptions can identify the architecture of the remote target |
40243 | and (for some architectures) provide information about custom register | |
08d16641 PA |
40244 | sets. They can also identify the OS ABI of the remote target. |
40245 | @value{GDBN} can use this information to autoconfigure for your | |
123dc839 | 40246 | target, or to warn you if you connect to an unsupported target. |
23181151 DJ |
40247 | |
40248 | Here is a simple target description: | |
40249 | ||
123dc839 | 40250 | @smallexample |
1780a0ed | 40251 | <target version="1.0"> |
23181151 DJ |
40252 | <architecture>i386:x86-64</architecture> |
40253 | </target> | |
123dc839 | 40254 | @end smallexample |
23181151 DJ |
40255 | |
40256 | @noindent | |
40257 | This minimal description only says that the target uses | |
40258 | the x86-64 architecture. | |
40259 | ||
123dc839 DJ |
40260 | A target description has the following overall form, with [ ] marking |
40261 | optional elements and @dots{} marking repeatable elements. The elements | |
40262 | are explained further below. | |
23181151 | 40263 | |
123dc839 | 40264 | @smallexample |
23181151 DJ |
40265 | <?xml version="1.0"?> |
40266 | <!DOCTYPE target SYSTEM "gdb-target.dtd"> | |
1780a0ed | 40267 | <target version="1.0"> |
123dc839 | 40268 | @r{[}@var{architecture}@r{]} |
08d16641 | 40269 | @r{[}@var{osabi}@r{]} |
e35359c5 | 40270 | @r{[}@var{compatible}@r{]} |
123dc839 | 40271 | @r{[}@var{feature}@dots{}@r{]} |
23181151 | 40272 | </target> |
123dc839 | 40273 | @end smallexample |
23181151 DJ |
40274 | |
40275 | @noindent | |
40276 | The description is generally insensitive to whitespace and line | |
40277 | breaks, under the usual common-sense rules. The XML version | |
40278 | declaration and document type declaration can generally be omitted | |
40279 | (@value{GDBN} does not require them), but specifying them may be | |
1780a0ed DJ |
40280 | useful for XML validation tools. The @samp{version} attribute for |
40281 | @samp{<target>} may also be omitted, but we recommend | |
40282 | including it; if future versions of @value{GDBN} use an incompatible | |
40283 | revision of @file{gdb-target.dtd}, they will detect and report | |
40284 | the version mismatch. | |
23181151 | 40285 | |
108546a0 DJ |
40286 | @subsection Inclusion |
40287 | @cindex target descriptions, inclusion | |
40288 | @cindex XInclude | |
40289 | @ifnotinfo | |
40290 | @cindex <xi:include> | |
40291 | @end ifnotinfo | |
40292 | ||
40293 | It can sometimes be valuable to split a target description up into | |
40294 | several different annexes, either for organizational purposes, or to | |
40295 | share files between different possible target descriptions. You can | |
40296 | divide a description into multiple files by replacing any element of | |
40297 | the target description with an inclusion directive of the form: | |
40298 | ||
123dc839 | 40299 | @smallexample |
108546a0 | 40300 | <xi:include href="@var{document}"/> |
123dc839 | 40301 | @end smallexample |
108546a0 DJ |
40302 | |
40303 | @noindent | |
40304 | When @value{GDBN} encounters an element of this form, it will retrieve | |
40305 | the named XML @var{document}, and replace the inclusion directive with | |
40306 | the contents of that document. If the current description was read | |
40307 | using @samp{qXfer}, then so will be the included document; | |
40308 | @var{document} will be interpreted as the name of an annex. If the | |
40309 | current description was read from a file, @value{GDBN} will look for | |
40310 | @var{document} as a file in the same directory where it found the | |
40311 | original description. | |
40312 | ||
123dc839 DJ |
40313 | @subsection Architecture |
40314 | @cindex <architecture> | |
40315 | ||
40316 | An @samp{<architecture>} element has this form: | |
40317 | ||
40318 | @smallexample | |
40319 | <architecture>@var{arch}</architecture> | |
40320 | @end smallexample | |
40321 | ||
e35359c5 UW |
40322 | @var{arch} is one of the architectures from the set accepted by |
40323 | @code{set architecture} (@pxref{Targets, ,Specifying a Debugging Target}). | |
123dc839 | 40324 | |
08d16641 PA |
40325 | @subsection OS ABI |
40326 | @cindex @code{<osabi>} | |
40327 | ||
40328 | This optional field was introduced in @value{GDBN} version 7.0. | |
40329 | Previous versions of @value{GDBN} ignore it. | |
40330 | ||
40331 | An @samp{<osabi>} element has this form: | |
40332 | ||
40333 | @smallexample | |
40334 | <osabi>@var{abi-name}</osabi> | |
40335 | @end smallexample | |
40336 | ||
40337 | @var{abi-name} is an OS ABI name from the same selection accepted by | |
40338 | @w{@code{set osabi}} (@pxref{ABI, ,Configuring the Current ABI}). | |
40339 | ||
e35359c5 UW |
40340 | @subsection Compatible Architecture |
40341 | @cindex @code{<compatible>} | |
40342 | ||
40343 | This optional field was introduced in @value{GDBN} version 7.0. | |
40344 | Previous versions of @value{GDBN} ignore it. | |
40345 | ||
40346 | A @samp{<compatible>} element has this form: | |
40347 | ||
40348 | @smallexample | |
40349 | <compatible>@var{arch}</compatible> | |
40350 | @end smallexample | |
40351 | ||
40352 | @var{arch} is one of the architectures from the set accepted by | |
40353 | @code{set architecture} (@pxref{Targets, ,Specifying a Debugging Target}). | |
40354 | ||
40355 | A @samp{<compatible>} element is used to specify that the target | |
40356 | is able to run binaries in some other than the main target architecture | |
40357 | given by the @samp{<architecture>} element. For example, on the | |
40358 | Cell Broadband Engine, the main architecture is @code{powerpc:common} | |
40359 | or @code{powerpc:common64}, but the system is able to run binaries | |
40360 | in the @code{spu} architecture as well. The way to describe this | |
40361 | capability with @samp{<compatible>} is as follows: | |
40362 | ||
40363 | @smallexample | |
40364 | <architecture>powerpc:common</architecture> | |
40365 | <compatible>spu</compatible> | |
40366 | @end smallexample | |
40367 | ||
123dc839 DJ |
40368 | @subsection Features |
40369 | @cindex <feature> | |
40370 | ||
40371 | Each @samp{<feature>} describes some logical portion of the target | |
40372 | system. Features are currently used to describe available CPU | |
40373 | registers and the types of their contents. A @samp{<feature>} element | |
40374 | has this form: | |
40375 | ||
40376 | @smallexample | |
40377 | <feature name="@var{name}"> | |
40378 | @r{[}@var{type}@dots{}@r{]} | |
40379 | @var{reg}@dots{} | |
40380 | </feature> | |
40381 | @end smallexample | |
40382 | ||
40383 | @noindent | |
40384 | Each feature's name should be unique within the description. The name | |
40385 | of a feature does not matter unless @value{GDBN} has some special | |
40386 | knowledge of the contents of that feature; if it does, the feature | |
40387 | should have its standard name. @xref{Standard Target Features}. | |
40388 | ||
40389 | @subsection Types | |
40390 | ||
40391 | Any register's value is a collection of bits which @value{GDBN} must | |
40392 | interpret. The default interpretation is a two's complement integer, | |
40393 | but other types can be requested by name in the register description. | |
40394 | Some predefined types are provided by @value{GDBN} (@pxref{Predefined | |
40395 | Target Types}), and the description can define additional composite types. | |
40396 | ||
40397 | Each type element must have an @samp{id} attribute, which gives | |
40398 | a unique (within the containing @samp{<feature>}) name to the type. | |
40399 | Types must be defined before they are used. | |
40400 | ||
40401 | @cindex <vector> | |
40402 | Some targets offer vector registers, which can be treated as arrays | |
40403 | of scalar elements. These types are written as @samp{<vector>} elements, | |
40404 | specifying the array element type, @var{type}, and the number of elements, | |
40405 | @var{count}: | |
40406 | ||
40407 | @smallexample | |
40408 | <vector id="@var{id}" type="@var{type}" count="@var{count}"/> | |
40409 | @end smallexample | |
40410 | ||
40411 | @cindex <union> | |
40412 | If a register's value is usefully viewed in multiple ways, define it | |
40413 | with a union type containing the useful representations. The | |
40414 | @samp{<union>} element contains one or more @samp{<field>} elements, | |
40415 | each of which has a @var{name} and a @var{type}: | |
40416 | ||
40417 | @smallexample | |
40418 | <union id="@var{id}"> | |
40419 | <field name="@var{name}" type="@var{type}"/> | |
40420 | @dots{} | |
40421 | </union> | |
40422 | @end smallexample | |
40423 | ||
f5dff777 DJ |
40424 | @cindex <struct> |
40425 | If a register's value is composed from several separate values, define | |
40426 | it with a structure type. There are two forms of the @samp{<struct>} | |
40427 | element; a @samp{<struct>} element must either contain only bitfields | |
40428 | or contain no bitfields. If the structure contains only bitfields, | |
40429 | its total size in bytes must be specified, each bitfield must have an | |
40430 | explicit start and end, and bitfields are automatically assigned an | |
40431 | integer type. The field's @var{start} should be less than or | |
40432 | equal to its @var{end}, and zero represents the least significant bit. | |
40433 | ||
40434 | @smallexample | |
40435 | <struct id="@var{id}" size="@var{size}"> | |
40436 | <field name="@var{name}" start="@var{start}" end="@var{end}"/> | |
40437 | @dots{} | |
40438 | </struct> | |
40439 | @end smallexample | |
40440 | ||
40441 | If the structure contains no bitfields, then each field has an | |
40442 | explicit type, and no implicit padding is added. | |
40443 | ||
40444 | @smallexample | |
40445 | <struct id="@var{id}"> | |
40446 | <field name="@var{name}" type="@var{type}"/> | |
40447 | @dots{} | |
40448 | </struct> | |
40449 | @end smallexample | |
40450 | ||
40451 | @cindex <flags> | |
40452 | If a register's value is a series of single-bit flags, define it with | |
40453 | a flags type. The @samp{<flags>} element has an explicit @var{size} | |
40454 | and contains one or more @samp{<field>} elements. Each field has a | |
40455 | @var{name}, a @var{start}, and an @var{end}. Only single-bit flags | |
40456 | are supported. | |
40457 | ||
40458 | @smallexample | |
40459 | <flags id="@var{id}" size="@var{size}"> | |
40460 | <field name="@var{name}" start="@var{start}" end="@var{end}"/> | |
40461 | @dots{} | |
40462 | </flags> | |
40463 | @end smallexample | |
40464 | ||
123dc839 DJ |
40465 | @subsection Registers |
40466 | @cindex <reg> | |
40467 | ||
40468 | Each register is represented as an element with this form: | |
40469 | ||
40470 | @smallexample | |
40471 | <reg name="@var{name}" | |
40472 | bitsize="@var{size}" | |
40473 | @r{[}regnum="@var{num}"@r{]} | |
40474 | @r{[}save-restore="@var{save-restore}"@r{]} | |
40475 | @r{[}type="@var{type}"@r{]} | |
40476 | @r{[}group="@var{group}"@r{]}/> | |
40477 | @end smallexample | |
40478 | ||
40479 | @noindent | |
40480 | The components are as follows: | |
40481 | ||
40482 | @table @var | |
40483 | ||
40484 | @item name | |
40485 | The register's name; it must be unique within the target description. | |
40486 | ||
40487 | @item bitsize | |
40488 | The register's size, in bits. | |
40489 | ||
40490 | @item regnum | |
40491 | The register's number. If omitted, a register's number is one greater | |
40492 | than that of the previous register (either in the current feature or in | |
177b42fe | 40493 | a preceding feature); the first register in the target description |
123dc839 DJ |
40494 | defaults to zero. This register number is used to read or write |
40495 | the register; e.g.@: it is used in the remote @code{p} and @code{P} | |
40496 | packets, and registers appear in the @code{g} and @code{G} packets | |
40497 | in order of increasing register number. | |
40498 | ||
40499 | @item save-restore | |
40500 | Whether the register should be preserved across inferior function | |
40501 | calls; this must be either @code{yes} or @code{no}. The default is | |
40502 | @code{yes}, which is appropriate for most registers except for | |
40503 | some system control registers; this is not related to the target's | |
40504 | ABI. | |
40505 | ||
40506 | @item type | |
697aa1b7 | 40507 | The type of the register. It may be a predefined type, a type |
123dc839 DJ |
40508 | defined in the current feature, or one of the special types @code{int} |
40509 | and @code{float}. @code{int} is an integer type of the correct size | |
40510 | for @var{bitsize}, and @code{float} is a floating point type (in the | |
40511 | architecture's normal floating point format) of the correct size for | |
40512 | @var{bitsize}. The default is @code{int}. | |
40513 | ||
40514 | @item group | |
697aa1b7 | 40515 | The register group to which this register belongs. It must |
123dc839 DJ |
40516 | be either @code{general}, @code{float}, or @code{vector}. If no |
40517 | @var{group} is specified, @value{GDBN} will not display the register | |
40518 | in @code{info registers}. | |
40519 | ||
40520 | @end table | |
40521 | ||
40522 | @node Predefined Target Types | |
40523 | @section Predefined Target Types | |
40524 | @cindex target descriptions, predefined types | |
40525 | ||
40526 | Type definitions in the self-description can build up composite types | |
40527 | from basic building blocks, but can not define fundamental types. Instead, | |
40528 | standard identifiers are provided by @value{GDBN} for the fundamental | |
40529 | types. The currently supported types are: | |
40530 | ||
40531 | @table @code | |
40532 | ||
40533 | @item int8 | |
40534 | @itemx int16 | |
40535 | @itemx int32 | |
40536 | @itemx int64 | |
7cc46491 | 40537 | @itemx int128 |
123dc839 DJ |
40538 | Signed integer types holding the specified number of bits. |
40539 | ||
40540 | @item uint8 | |
40541 | @itemx uint16 | |
40542 | @itemx uint32 | |
40543 | @itemx uint64 | |
7cc46491 | 40544 | @itemx uint128 |
123dc839 DJ |
40545 | Unsigned integer types holding the specified number of bits. |
40546 | ||
40547 | @item code_ptr | |
40548 | @itemx data_ptr | |
40549 | Pointers to unspecified code and data. The program counter and | |
40550 | any dedicated return address register may be marked as code | |
40551 | pointers; printing a code pointer converts it into a symbolic | |
40552 | address. The stack pointer and any dedicated address registers | |
40553 | may be marked as data pointers. | |
40554 | ||
6e3bbd1a PB |
40555 | @item ieee_single |
40556 | Single precision IEEE floating point. | |
40557 | ||
40558 | @item ieee_double | |
40559 | Double precision IEEE floating point. | |
40560 | ||
123dc839 DJ |
40561 | @item arm_fpa_ext |
40562 | The 12-byte extended precision format used by ARM FPA registers. | |
40563 | ||
075b51b7 L |
40564 | @item i387_ext |
40565 | The 10-byte extended precision format used by x87 registers. | |
40566 | ||
40567 | @item i386_eflags | |
40568 | 32bit @sc{eflags} register used by x86. | |
40569 | ||
40570 | @item i386_mxcsr | |
40571 | 32bit @sc{mxcsr} register used by x86. | |
40572 | ||
123dc839 DJ |
40573 | @end table |
40574 | ||
40575 | @node Standard Target Features | |
40576 | @section Standard Target Features | |
40577 | @cindex target descriptions, standard features | |
40578 | ||
40579 | A target description must contain either no registers or all the | |
40580 | target's registers. If the description contains no registers, then | |
40581 | @value{GDBN} will assume a default register layout, selected based on | |
40582 | the architecture. If the description contains any registers, the | |
40583 | default layout will not be used; the standard registers must be | |
40584 | described in the target description, in such a way that @value{GDBN} | |
40585 | can recognize them. | |
40586 | ||
40587 | This is accomplished by giving specific names to feature elements | |
40588 | which contain standard registers. @value{GDBN} will look for features | |
40589 | with those names and verify that they contain the expected registers; | |
40590 | if any known feature is missing required registers, or if any required | |
40591 | feature is missing, @value{GDBN} will reject the target | |
40592 | description. You can add additional registers to any of the | |
40593 | standard features --- @value{GDBN} will display them just as if | |
40594 | they were added to an unrecognized feature. | |
40595 | ||
40596 | This section lists the known features and their expected contents. | |
40597 | Sample XML documents for these features are included in the | |
40598 | @value{GDBN} source tree, in the directory @file{gdb/features}. | |
40599 | ||
40600 | Names recognized by @value{GDBN} should include the name of the | |
40601 | company or organization which selected the name, and the overall | |
40602 | architecture to which the feature applies; so e.g.@: the feature | |
40603 | containing ARM core registers is named @samp{org.gnu.gdb.arm.core}. | |
40604 | ||
ff6f572f DJ |
40605 | The names of registers are not case sensitive for the purpose |
40606 | of recognizing standard features, but @value{GDBN} will only display | |
40607 | registers using the capitalization used in the description. | |
40608 | ||
e9c17194 | 40609 | @menu |
430ed3f0 | 40610 | * AArch64 Features:: |
e9c17194 | 40611 | * ARM Features:: |
3bb8d5c3 | 40612 | * i386 Features:: |
164224e9 | 40613 | * MicroBlaze Features:: |
1e26b4f8 | 40614 | * MIPS Features:: |
e9c17194 | 40615 | * M68K Features:: |
a1217d97 | 40616 | * Nios II Features:: |
1e26b4f8 | 40617 | * PowerPC Features:: |
4ac33720 | 40618 | * S/390 and System z Features:: |
224bbe49 | 40619 | * TIC6x Features:: |
e9c17194 VP |
40620 | @end menu |
40621 | ||
40622 | ||
430ed3f0 MS |
40623 | @node AArch64 Features |
40624 | @subsection AArch64 Features | |
40625 | @cindex target descriptions, AArch64 features | |
40626 | ||
40627 | The @samp{org.gnu.gdb.aarch64.core} feature is required for AArch64 | |
40628 | targets. It should contain registers @samp{x0} through @samp{x30}, | |
40629 | @samp{sp}, @samp{pc}, and @samp{cpsr}. | |
40630 | ||
40631 | The @samp{org.gnu.gdb.aarch64.fpu} feature is optional. If present, | |
40632 | it should contain registers @samp{v0} through @samp{v31}, @samp{fpsr}, | |
40633 | and @samp{fpcr}. | |
40634 | ||
e9c17194 | 40635 | @node ARM Features |
123dc839 DJ |
40636 | @subsection ARM Features |
40637 | @cindex target descriptions, ARM features | |
40638 | ||
9779414d DJ |
40639 | The @samp{org.gnu.gdb.arm.core} feature is required for non-M-profile |
40640 | ARM targets. | |
123dc839 DJ |
40641 | It should contain registers @samp{r0} through @samp{r13}, @samp{sp}, |
40642 | @samp{lr}, @samp{pc}, and @samp{cpsr}. | |
40643 | ||
9779414d DJ |
40644 | For M-profile targets (e.g. Cortex-M3), the @samp{org.gnu.gdb.arm.core} |
40645 | feature is replaced by @samp{org.gnu.gdb.arm.m-profile}. It should contain | |
40646 | registers @samp{r0} through @samp{r13}, @samp{sp}, @samp{lr}, @samp{pc}, | |
40647 | and @samp{xpsr}. | |
40648 | ||
123dc839 DJ |
40649 | The @samp{org.gnu.gdb.arm.fpa} feature is optional. If present, it |
40650 | should contain registers @samp{f0} through @samp{f7} and @samp{fps}. | |
40651 | ||
ff6f572f DJ |
40652 | The @samp{org.gnu.gdb.xscale.iwmmxt} feature is optional. If present, |
40653 | it should contain at least registers @samp{wR0} through @samp{wR15} and | |
40654 | @samp{wCGR0} through @samp{wCGR3}. The @samp{wCID}, @samp{wCon}, | |
40655 | @samp{wCSSF}, and @samp{wCASF} registers are optional. | |
23181151 | 40656 | |
58d6951d DJ |
40657 | The @samp{org.gnu.gdb.arm.vfp} feature is optional. If present, it |
40658 | should contain at least registers @samp{d0} through @samp{d15}. If | |
40659 | they are present, @samp{d16} through @samp{d31} should also be included. | |
40660 | @value{GDBN} will synthesize the single-precision registers from | |
40661 | halves of the double-precision registers. | |
40662 | ||
40663 | The @samp{org.gnu.gdb.arm.neon} feature is optional. It does not | |
40664 | need to contain registers; it instructs @value{GDBN} to display the | |
40665 | VFP double-precision registers as vectors and to synthesize the | |
40666 | quad-precision registers from pairs of double-precision registers. | |
40667 | If this feature is present, @samp{org.gnu.gdb.arm.vfp} must also | |
40668 | be present and include 32 double-precision registers. | |
40669 | ||
3bb8d5c3 L |
40670 | @node i386 Features |
40671 | @subsection i386 Features | |
40672 | @cindex target descriptions, i386 features | |
40673 | ||
40674 | The @samp{org.gnu.gdb.i386.core} feature is required for i386/amd64 | |
40675 | targets. It should describe the following registers: | |
40676 | ||
40677 | @itemize @minus | |
40678 | @item | |
40679 | @samp{eax} through @samp{edi} plus @samp{eip} for i386 | |
40680 | @item | |
40681 | @samp{rax} through @samp{r15} plus @samp{rip} for amd64 | |
40682 | @item | |
40683 | @samp{eflags}, @samp{cs}, @samp{ss}, @samp{ds}, @samp{es}, | |
40684 | @samp{fs}, @samp{gs} | |
40685 | @item | |
40686 | @samp{st0} through @samp{st7} | |
40687 | @item | |
40688 | @samp{fctrl}, @samp{fstat}, @samp{ftag}, @samp{fiseg}, @samp{fioff}, | |
40689 | @samp{foseg}, @samp{fooff} and @samp{fop} | |
40690 | @end itemize | |
40691 | ||
40692 | The register sets may be different, depending on the target. | |
40693 | ||
3a13a53b | 40694 | The @samp{org.gnu.gdb.i386.sse} feature is optional. It should |
3bb8d5c3 L |
40695 | describe registers: |
40696 | ||
40697 | @itemize @minus | |
40698 | @item | |
40699 | @samp{xmm0} through @samp{xmm7} for i386 | |
40700 | @item | |
40701 | @samp{xmm0} through @samp{xmm15} for amd64 | |
40702 | @item | |
40703 | @samp{mxcsr} | |
40704 | @end itemize | |
40705 | ||
3a13a53b L |
40706 | The @samp{org.gnu.gdb.i386.avx} feature is optional and requires the |
40707 | @samp{org.gnu.gdb.i386.sse} feature. It should | |
f68eb612 L |
40708 | describe the upper 128 bits of @sc{ymm} registers: |
40709 | ||
40710 | @itemize @minus | |
40711 | @item | |
40712 | @samp{ymm0h} through @samp{ymm7h} for i386 | |
40713 | @item | |
40714 | @samp{ymm0h} through @samp{ymm15h} for amd64 | |
f68eb612 L |
40715 | @end itemize |
40716 | ||
bc504a31 | 40717 | The @samp{org.gnu.gdb.i386.mpx} is an optional feature representing Intel |
ca8941bb WT |
40718 | Memory Protection Extension (MPX). It should describe the following registers: |
40719 | ||
40720 | @itemize @minus | |
40721 | @item | |
40722 | @samp{bnd0raw} through @samp{bnd3raw} for i386 and amd64. | |
40723 | @item | |
40724 | @samp{bndcfgu} and @samp{bndstatus} for i386 and amd64. | |
40725 | @end itemize | |
40726 | ||
3bb8d5c3 L |
40727 | The @samp{org.gnu.gdb.i386.linux} feature is optional. It should |
40728 | describe a single register, @samp{orig_eax}. | |
40729 | ||
01f9f808 MS |
40730 | The @samp{org.gnu.gdb.i386.avx512} feature is optional and requires the |
40731 | @samp{org.gnu.gdb.i386.avx} feature. It should | |
40732 | describe additional @sc{xmm} registers: | |
40733 | ||
40734 | @itemize @minus | |
40735 | @item | |
40736 | @samp{xmm16h} through @samp{xmm31h}, only valid for amd64. | |
40737 | @end itemize | |
40738 | ||
40739 | It should describe the upper 128 bits of additional @sc{ymm} registers: | |
40740 | ||
40741 | @itemize @minus | |
40742 | @item | |
40743 | @samp{ymm16h} through @samp{ymm31h}, only valid for amd64. | |
40744 | @end itemize | |
40745 | ||
40746 | It should | |
40747 | describe the upper 256 bits of @sc{zmm} registers: | |
40748 | ||
40749 | @itemize @minus | |
40750 | @item | |
40751 | @samp{zmm0h} through @samp{zmm7h} for i386. | |
40752 | @item | |
40753 | @samp{zmm0h} through @samp{zmm15h} for amd64. | |
40754 | @end itemize | |
40755 | ||
40756 | It should | |
40757 | describe the additional @sc{zmm} registers: | |
40758 | ||
40759 | @itemize @minus | |
40760 | @item | |
40761 | @samp{zmm16h} through @samp{zmm31h}, only valid for amd64. | |
40762 | @end itemize | |
40763 | ||
164224e9 ME |
40764 | @node MicroBlaze Features |
40765 | @subsection MicroBlaze Features | |
40766 | @cindex target descriptions, MicroBlaze features | |
40767 | ||
40768 | The @samp{org.gnu.gdb.microblaze.core} feature is required for MicroBlaze | |
40769 | targets. It should contain registers @samp{r0} through @samp{r31}, | |
40770 | @samp{rpc}, @samp{rmsr}, @samp{rear}, @samp{resr}, @samp{rfsr}, @samp{rbtr}, | |
40771 | @samp{rpvr}, @samp{rpvr1} through @samp{rpvr11}, @samp{redr}, @samp{rpid}, | |
40772 | @samp{rzpr}, @samp{rtlbx}, @samp{rtlbsx}, @samp{rtlblo}, and @samp{rtlbhi}. | |
40773 | ||
40774 | The @samp{org.gnu.gdb.microblaze.stack-protect} feature is optional. | |
40775 | If present, it should contain registers @samp{rshr} and @samp{rslr} | |
40776 | ||
1e26b4f8 | 40777 | @node MIPS Features |
eb17f351 EZ |
40778 | @subsection @acronym{MIPS} Features |
40779 | @cindex target descriptions, @acronym{MIPS} features | |
f8b73d13 | 40780 | |
eb17f351 | 40781 | The @samp{org.gnu.gdb.mips.cpu} feature is required for @acronym{MIPS} targets. |
f8b73d13 DJ |
40782 | It should contain registers @samp{r0} through @samp{r31}, @samp{lo}, |
40783 | @samp{hi}, and @samp{pc}. They may be 32-bit or 64-bit depending | |
40784 | on the target. | |
40785 | ||
40786 | The @samp{org.gnu.gdb.mips.cp0} feature is also required. It should | |
40787 | contain at least the @samp{status}, @samp{badvaddr}, and @samp{cause} | |
40788 | registers. They may be 32-bit or 64-bit depending on the target. | |
40789 | ||
40790 | The @samp{org.gnu.gdb.mips.fpu} feature is currently required, though | |
40791 | it may be optional in a future version of @value{GDBN}. It should | |
40792 | contain registers @samp{f0} through @samp{f31}, @samp{fcsr}, and | |
40793 | @samp{fir}. They may be 32-bit or 64-bit depending on the target. | |
40794 | ||
1faeff08 MR |
40795 | The @samp{org.gnu.gdb.mips.dsp} feature is optional. It should |
40796 | contain registers @samp{hi1} through @samp{hi3}, @samp{lo1} through | |
40797 | @samp{lo3}, and @samp{dspctl}. The @samp{dspctl} register should | |
40798 | be 32-bit and the rest may be 32-bit or 64-bit depending on the target. | |
40799 | ||
822b6570 DJ |
40800 | The @samp{org.gnu.gdb.mips.linux} feature is optional. It should |
40801 | contain a single register, @samp{restart}, which is used by the | |
40802 | Linux kernel to control restartable syscalls. | |
40803 | ||
e9c17194 VP |
40804 | @node M68K Features |
40805 | @subsection M68K Features | |
40806 | @cindex target descriptions, M68K features | |
40807 | ||
40808 | @table @code | |
40809 | @item @samp{org.gnu.gdb.m68k.core} | |
40810 | @itemx @samp{org.gnu.gdb.coldfire.core} | |
40811 | @itemx @samp{org.gnu.gdb.fido.core} | |
40812 | One of those features must be always present. | |
249e1128 | 40813 | The feature that is present determines which flavor of m68k is |
e9c17194 VP |
40814 | used. The feature that is present should contain registers |
40815 | @samp{d0} through @samp{d7}, @samp{a0} through @samp{a5}, @samp{fp}, | |
40816 | @samp{sp}, @samp{ps} and @samp{pc}. | |
40817 | ||
40818 | @item @samp{org.gnu.gdb.coldfire.fp} | |
40819 | This feature is optional. If present, it should contain registers | |
40820 | @samp{fp0} through @samp{fp7}, @samp{fpcontrol}, @samp{fpstatus} and | |
40821 | @samp{fpiaddr}. | |
40822 | @end table | |
40823 | ||
a1217d97 SL |
40824 | @node Nios II Features |
40825 | @subsection Nios II Features | |
40826 | @cindex target descriptions, Nios II features | |
40827 | ||
40828 | The @samp{org.gnu.gdb.nios2.cpu} feature is required for Nios II | |
40829 | targets. It should contain the 32 core registers (@samp{zero}, | |
40830 | @samp{at}, @samp{r2} through @samp{r23}, @samp{et} through @samp{ra}), | |
40831 | @samp{pc}, and the 16 control registers (@samp{status} through | |
40832 | @samp{mpuacc}). | |
40833 | ||
1e26b4f8 | 40834 | @node PowerPC Features |
7cc46491 DJ |
40835 | @subsection PowerPC Features |
40836 | @cindex target descriptions, PowerPC features | |
40837 | ||
40838 | The @samp{org.gnu.gdb.power.core} feature is required for PowerPC | |
40839 | targets. It should contain registers @samp{r0} through @samp{r31}, | |
40840 | @samp{pc}, @samp{msr}, @samp{cr}, @samp{lr}, @samp{ctr}, and | |
40841 | @samp{xer}. They may be 32-bit or 64-bit depending on the target. | |
40842 | ||
40843 | The @samp{org.gnu.gdb.power.fpu} feature is optional. It should | |
40844 | contain registers @samp{f0} through @samp{f31} and @samp{fpscr}. | |
40845 | ||
40846 | The @samp{org.gnu.gdb.power.altivec} feature is optional. It should | |
40847 | contain registers @samp{vr0} through @samp{vr31}, @samp{vscr}, | |
40848 | and @samp{vrsave}. | |
40849 | ||
677c5bb1 LM |
40850 | The @samp{org.gnu.gdb.power.vsx} feature is optional. It should |
40851 | contain registers @samp{vs0h} through @samp{vs31h}. @value{GDBN} | |
40852 | will combine these registers with the floating point registers | |
40853 | (@samp{f0} through @samp{f31}) and the altivec registers (@samp{vr0} | |
aeac0ff9 | 40854 | through @samp{vr31}) to present the 128-bit wide registers @samp{vs0} |
677c5bb1 LM |
40855 | through @samp{vs63}, the set of vector registers for POWER7. |
40856 | ||
7cc46491 DJ |
40857 | The @samp{org.gnu.gdb.power.spe} feature is optional. It should |
40858 | contain registers @samp{ev0h} through @samp{ev31h}, @samp{acc}, and | |
40859 | @samp{spefscr}. SPE targets should provide 32-bit registers in | |
40860 | @samp{org.gnu.gdb.power.core} and provide the upper halves in | |
40861 | @samp{ev0h} through @samp{ev31h}. @value{GDBN} will combine | |
40862 | these to present registers @samp{ev0} through @samp{ev31} to the | |
40863 | user. | |
40864 | ||
4ac33720 UW |
40865 | @node S/390 and System z Features |
40866 | @subsection S/390 and System z Features | |
40867 | @cindex target descriptions, S/390 features | |
40868 | @cindex target descriptions, System z features | |
40869 | ||
40870 | The @samp{org.gnu.gdb.s390.core} feature is required for S/390 and | |
40871 | System z targets. It should contain the PSW and the 16 general | |
40872 | registers. In particular, System z targets should provide the 64-bit | |
40873 | registers @samp{pswm}, @samp{pswa}, and @samp{r0} through @samp{r15}. | |
40874 | S/390 targets should provide the 32-bit versions of these registers. | |
40875 | A System z target that runs in 31-bit addressing mode should provide | |
40876 | 32-bit versions of @samp{pswm} and @samp{pswa}, as well as the general | |
40877 | register's upper halves @samp{r0h} through @samp{r15h}, and their | |
40878 | lower halves @samp{r0l} through @samp{r15l}. | |
40879 | ||
40880 | The @samp{org.gnu.gdb.s390.fpr} feature is required. It should | |
40881 | contain the 64-bit registers @samp{f0} through @samp{f15}, and | |
40882 | @samp{fpc}. | |
40883 | ||
40884 | The @samp{org.gnu.gdb.s390.acr} feature is required. It should | |
40885 | contain the 32-bit registers @samp{acr0} through @samp{acr15}. | |
40886 | ||
40887 | The @samp{org.gnu.gdb.s390.linux} feature is optional. It should | |
40888 | contain the register @samp{orig_r2}, which is 64-bit wide on System z | |
40889 | targets and 32-bit otherwise. In addition, the feature may contain | |
40890 | the @samp{last_break} register, whose width depends on the addressing | |
40891 | mode, as well as the @samp{system_call} register, which is always | |
40892 | 32-bit wide. | |
40893 | ||
40894 | The @samp{org.gnu.gdb.s390.tdb} feature is optional. It should | |
40895 | contain the 64-bit registers @samp{tdb0}, @samp{tac}, @samp{tct}, | |
40896 | @samp{atia}, and @samp{tr0} through @samp{tr15}. | |
40897 | ||
446899e4 AA |
40898 | The @samp{org.gnu.gdb.s390.vx} feature is optional. It should contain |
40899 | 64-bit wide registers @samp{v0l} through @samp{v15l}, which will be | |
40900 | combined by @value{GDBN} with the floating point registers @samp{f0} | |
40901 | through @samp{f15} to present the 128-bit wide vector registers | |
40902 | @samp{v0} through @samp{v15}. In addition, this feature should | |
40903 | contain the 128-bit wide vector registers @samp{v16} through | |
40904 | @samp{v31}. | |
40905 | ||
224bbe49 YQ |
40906 | @node TIC6x Features |
40907 | @subsection TMS320C6x Features | |
40908 | @cindex target descriptions, TIC6x features | |
40909 | @cindex target descriptions, TMS320C6x features | |
40910 | The @samp{org.gnu.gdb.tic6x.core} feature is required for TMS320C6x | |
40911 | targets. It should contain registers @samp{A0} through @samp{A15}, | |
40912 | registers @samp{B0} through @samp{B15}, @samp{CSR} and @samp{PC}. | |
40913 | ||
40914 | The @samp{org.gnu.gdb.tic6x.gp} feature is optional. It should | |
40915 | contain registers @samp{A16} through @samp{A31} and @samp{B16} | |
40916 | through @samp{B31}. | |
40917 | ||
40918 | The @samp{org.gnu.gdb.tic6x.c6xp} feature is optional. It should | |
40919 | contain registers @samp{TSR}, @samp{ILC} and @samp{RILC}. | |
40920 | ||
07e059b5 VP |
40921 | @node Operating System Information |
40922 | @appendix Operating System Information | |
40923 | @cindex operating system information | |
40924 | ||
40925 | @menu | |
40926 | * Process list:: | |
40927 | @end menu | |
40928 | ||
40929 | Users of @value{GDBN} often wish to obtain information about the state of | |
40930 | the operating system running on the target---for example the list of | |
40931 | processes, or the list of open files. This section describes the | |
40932 | mechanism that makes it possible. This mechanism is similar to the | |
40933 | target features mechanism (@pxref{Target Descriptions}), but focuses | |
40934 | on a different aspect of target. | |
40935 | ||
40936 | Operating system information is retrived from the target via the | |
40937 | remote protocol, using @samp{qXfer} requests (@pxref{qXfer osdata | |
40938 | read}). The object name in the request should be @samp{osdata}, and | |
40939 | the @var{annex} identifies the data to be fetched. | |
40940 | ||
40941 | @node Process list | |
40942 | @appendixsection Process list | |
40943 | @cindex operating system information, process list | |
40944 | ||
40945 | When requesting the process list, the @var{annex} field in the | |
40946 | @samp{qXfer} request should be @samp{processes}. The returned data is | |
40947 | an XML document. The formal syntax of this document is defined in | |
40948 | @file{gdb/features/osdata.dtd}. | |
40949 | ||
40950 | An example document is: | |
40951 | ||
40952 | @smallexample | |
40953 | <?xml version="1.0"?> | |
40954 | <!DOCTYPE target SYSTEM "osdata.dtd"> | |
40955 | <osdata type="processes"> | |
40956 | <item> | |
40957 | <column name="pid">1</column> | |
40958 | <column name="user">root</column> | |
40959 | <column name="command">/sbin/init</column> | |
dc146f7c | 40960 | <column name="cores">1,2,3</column> |
07e059b5 VP |
40961 | </item> |
40962 | </osdata> | |
40963 | @end smallexample | |
40964 | ||
40965 | Each item should include a column whose name is @samp{pid}. The value | |
40966 | of that column should identify the process on the target. The | |
40967 | @samp{user} and @samp{command} columns are optional, and will be | |
dc146f7c VP |
40968 | displayed by @value{GDBN}. The @samp{cores} column, if present, |
40969 | should contain a comma-separated list of cores that this process | |
40970 | is running on. Target may provide additional columns, | |
07e059b5 VP |
40971 | which @value{GDBN} currently ignores. |
40972 | ||
05c8c3f5 TT |
40973 | @node Trace File Format |
40974 | @appendix Trace File Format | |
40975 | @cindex trace file format | |
40976 | ||
40977 | The trace file comes in three parts: a header, a textual description | |
40978 | section, and a trace frame section with binary data. | |
40979 | ||
40980 | The header has the form @code{\x7fTRACE0\n}. The first byte is | |
40981 | @code{0x7f} so as to indicate that the file contains binary data, | |
40982 | while the @code{0} is a version number that may have different values | |
40983 | in the future. | |
40984 | ||
40985 | The description section consists of multiple lines of @sc{ascii} text | |
40986 | separated by newline characters (@code{0xa}). The lines may include a | |
40987 | variety of optional descriptive or context-setting information, such | |
40988 | as tracepoint definitions or register set size. @value{GDBN} will | |
40989 | ignore any line that it does not recognize. An empty line marks the end | |
40990 | of this section. | |
40991 | ||
40992 | @c FIXME add some specific types of data | |
40993 | ||
40994 | The trace frame section consists of a number of consecutive frames. | |
40995 | Each frame begins with a two-byte tracepoint number, followed by a | |
40996 | four-byte size giving the amount of data in the frame. The data in | |
40997 | the frame consists of a number of blocks, each introduced by a | |
40998 | character indicating its type (at least register, memory, and trace | |
40999 | state variable). The data in this section is raw binary, not a | |
41000 | hexadecimal or other encoding; its endianness matches the target's | |
41001 | endianness. | |
41002 | ||
41003 | @c FIXME bi-arch may require endianness/arch info in description section | |
41004 | ||
41005 | @table @code | |
41006 | @item R @var{bytes} | |
41007 | Register block. The number and ordering of bytes matches that of a | |
41008 | @code{g} packet in the remote protocol. Note that these are the | |
41009 | actual bytes, in target order and @value{GDBN} register order, not a | |
41010 | hexadecimal encoding. | |
41011 | ||
41012 | @item M @var{address} @var{length} @var{bytes}... | |
41013 | Memory block. This is a contiguous block of memory, at the 8-byte | |
41014 | address @var{address}, with a 2-byte length @var{length}, followed by | |
41015 | @var{length} bytes. | |
41016 | ||
41017 | @item V @var{number} @var{value} | |
41018 | Trace state variable block. This records the 8-byte signed value | |
41019 | @var{value} of trace state variable numbered @var{number}. | |
41020 | ||
41021 | @end table | |
41022 | ||
41023 | Future enhancements of the trace file format may include additional types | |
41024 | of blocks. | |
41025 | ||
90476074 TT |
41026 | @node Index Section Format |
41027 | @appendix @code{.gdb_index} section format | |
41028 | @cindex .gdb_index section format | |
41029 | @cindex index section format | |
41030 | ||
41031 | This section documents the index section that is created by @code{save | |
41032 | gdb-index} (@pxref{Index Files}). The index section is | |
41033 | DWARF-specific; some knowledge of DWARF is assumed in this | |
41034 | description. | |
41035 | ||
41036 | The mapped index file format is designed to be directly | |
41037 | @code{mmap}able on any architecture. In most cases, a datum is | |
41038 | represented using a little-endian 32-bit integer value, called an | |
41039 | @code{offset_type}. Big endian machines must byte-swap the values | |
41040 | before using them. Exceptions to this rule are noted. The data is | |
41041 | laid out such that alignment is always respected. | |
41042 | ||
41043 | A mapped index consists of several areas, laid out in order. | |
41044 | ||
41045 | @enumerate | |
41046 | @item | |
41047 | The file header. This is a sequence of values, of @code{offset_type} | |
41048 | unless otherwise noted: | |
41049 | ||
41050 | @enumerate | |
41051 | @item | |
796a7ff8 | 41052 | The version number, currently 8. Versions 1, 2 and 3 are obsolete. |
481860b3 | 41053 | Version 4 uses a different hashing function from versions 5 and 6. |
b6ba681c TT |
41054 | Version 6 includes symbols for inlined functions, whereas versions 4 |
41055 | and 5 do not. Version 7 adds attributes to the CU indices in the | |
796a7ff8 DE |
41056 | symbol table. Version 8 specifies that symbols from DWARF type units |
41057 | (@samp{DW_TAG_type_unit}) refer to the type unit's symbol table and not the | |
41058 | compilation unit (@samp{DW_TAG_comp_unit}) using the type. | |
41059 | ||
41060 | @value{GDBN} will only read version 4, 5, or 6 indices | |
e615022a | 41061 | by specifying @code{set use-deprecated-index-sections on}. |
796a7ff8 DE |
41062 | GDB has a workaround for potentially broken version 7 indices so it is |
41063 | currently not flagged as deprecated. | |
90476074 TT |
41064 | |
41065 | @item | |
41066 | The offset, from the start of the file, of the CU list. | |
41067 | ||
41068 | @item | |
41069 | The offset, from the start of the file, of the types CU list. Note | |
41070 | that this area can be empty, in which case this offset will be equal | |
41071 | to the next offset. | |
41072 | ||
41073 | @item | |
41074 | The offset, from the start of the file, of the address area. | |
41075 | ||
41076 | @item | |
41077 | The offset, from the start of the file, of the symbol table. | |
41078 | ||
41079 | @item | |
41080 | The offset, from the start of the file, of the constant pool. | |
41081 | @end enumerate | |
41082 | ||
41083 | @item | |
41084 | The CU list. This is a sequence of pairs of 64-bit little-endian | |
41085 | values, sorted by the CU offset. The first element in each pair is | |
41086 | the offset of a CU in the @code{.debug_info} section. The second | |
41087 | element in each pair is the length of that CU. References to a CU | |
41088 | elsewhere in the map are done using a CU index, which is just the | |
41089 | 0-based index into this table. Note that if there are type CUs, then | |
41090 | conceptually CUs and type CUs form a single list for the purposes of | |
41091 | CU indices. | |
41092 | ||
41093 | @item | |
41094 | The types CU list. This is a sequence of triplets of 64-bit | |
41095 | little-endian values. In a triplet, the first value is the CU offset, | |
41096 | the second value is the type offset in the CU, and the third value is | |
41097 | the type signature. The types CU list is not sorted. | |
41098 | ||
41099 | @item | |
41100 | The address area. The address area consists of a sequence of address | |
41101 | entries. Each address entry has three elements: | |
41102 | ||
41103 | @enumerate | |
41104 | @item | |
41105 | The low address. This is a 64-bit little-endian value. | |
41106 | ||
41107 | @item | |
41108 | The high address. This is a 64-bit little-endian value. Like | |
41109 | @code{DW_AT_high_pc}, the value is one byte beyond the end. | |
41110 | ||
41111 | @item | |
41112 | The CU index. This is an @code{offset_type} value. | |
41113 | @end enumerate | |
41114 | ||
41115 | @item | |
41116 | The symbol table. This is an open-addressed hash table. The size of | |
41117 | the hash table is always a power of 2. | |
41118 | ||
41119 | Each slot in the hash table consists of a pair of @code{offset_type} | |
41120 | values. The first value is the offset of the symbol's name in the | |
41121 | constant pool. The second value is the offset of the CU vector in the | |
41122 | constant pool. | |
41123 | ||
41124 | If both values are 0, then this slot in the hash table is empty. This | |
41125 | is ok because while 0 is a valid constant pool index, it cannot be a | |
41126 | valid index for both a string and a CU vector. | |
41127 | ||
41128 | The hash value for a table entry is computed by applying an | |
41129 | iterative hash function to the symbol's name. Starting with an | |
41130 | initial value of @code{r = 0}, each (unsigned) character @samp{c} in | |
559a7a62 JK |
41131 | the string is incorporated into the hash using the formula depending on the |
41132 | index version: | |
41133 | ||
41134 | @table @asis | |
41135 | @item Version 4 | |
41136 | The formula is @code{r = r * 67 + c - 113}. | |
41137 | ||
156942c7 | 41138 | @item Versions 5 to 7 |
559a7a62 JK |
41139 | The formula is @code{r = r * 67 + tolower (c) - 113}. |
41140 | @end table | |
41141 | ||
41142 | The terminating @samp{\0} is not incorporated into the hash. | |
90476074 TT |
41143 | |
41144 | The step size used in the hash table is computed via | |
41145 | @code{((hash * 17) & (size - 1)) | 1}, where @samp{hash} is the hash | |
41146 | value, and @samp{size} is the size of the hash table. The step size | |
41147 | is used to find the next candidate slot when handling a hash | |
41148 | collision. | |
41149 | ||
41150 | The names of C@t{++} symbols in the hash table are canonicalized. We | |
41151 | don't currently have a simple description of the canonicalization | |
41152 | algorithm; if you intend to create new index sections, you must read | |
41153 | the code. | |
41154 | ||
41155 | @item | |
41156 | The constant pool. This is simply a bunch of bytes. It is organized | |
41157 | so that alignment is correct: CU vectors are stored first, followed by | |
41158 | strings. | |
41159 | ||
41160 | A CU vector in the constant pool is a sequence of @code{offset_type} | |
41161 | values. The first value is the number of CU indices in the vector. | |
156942c7 DE |
41162 | Each subsequent value is the index and symbol attributes of a CU in |
41163 | the CU list. This element in the hash table is used to indicate which | |
41164 | CUs define the symbol and how the symbol is used. | |
41165 | See below for the format of each CU index+attributes entry. | |
90476074 TT |
41166 | |
41167 | A string in the constant pool is zero-terminated. | |
41168 | @end enumerate | |
41169 | ||
156942c7 DE |
41170 | Attributes were added to CU index values in @code{.gdb_index} version 7. |
41171 | If a symbol has multiple uses within a CU then there is one | |
41172 | CU index+attributes value for each use. | |
41173 | ||
41174 | The format of each CU index+attributes entry is as follows | |
41175 | (bit 0 = LSB): | |
41176 | ||
41177 | @table @asis | |
41178 | ||
41179 | @item Bits 0-23 | |
41180 | This is the index of the CU in the CU list. | |
41181 | @item Bits 24-27 | |
41182 | These bits are reserved for future purposes and must be zero. | |
41183 | @item Bits 28-30 | |
41184 | The kind of the symbol in the CU. | |
41185 | ||
41186 | @table @asis | |
41187 | @item 0 | |
41188 | This value is reserved and should not be used. | |
41189 | By reserving zero the full @code{offset_type} value is backwards compatible | |
41190 | with previous versions of the index. | |
41191 | @item 1 | |
41192 | The symbol is a type. | |
41193 | @item 2 | |
41194 | The symbol is a variable or an enum value. | |
41195 | @item 3 | |
41196 | The symbol is a function. | |
41197 | @item 4 | |
41198 | Any other kind of symbol. | |
41199 | @item 5,6,7 | |
41200 | These values are reserved. | |
41201 | @end table | |
41202 | ||
41203 | @item Bit 31 | |
41204 | This bit is zero if the value is global and one if it is static. | |
41205 | ||
41206 | The determination of whether a symbol is global or static is complicated. | |
41207 | The authorative reference is the file @file{dwarf2read.c} in | |
41208 | @value{GDBN} sources. | |
41209 | ||
41210 | @end table | |
41211 | ||
41212 | This pseudo-code describes the computation of a symbol's kind and | |
41213 | global/static attributes in the index. | |
41214 | ||
41215 | @smallexample | |
41216 | is_external = get_attribute (die, DW_AT_external); | |
41217 | language = get_attribute (cu_die, DW_AT_language); | |
41218 | switch (die->tag) | |
41219 | @{ | |
41220 | case DW_TAG_typedef: | |
41221 | case DW_TAG_base_type: | |
41222 | case DW_TAG_subrange_type: | |
41223 | kind = TYPE; | |
41224 | is_static = 1; | |
41225 | break; | |
41226 | case DW_TAG_enumerator: | |
41227 | kind = VARIABLE; | |
41228 | is_static = (language != CPLUS && language != JAVA); | |
41229 | break; | |
41230 | case DW_TAG_subprogram: | |
41231 | kind = FUNCTION; | |
41232 | is_static = ! (is_external || language == ADA); | |
41233 | break; | |
41234 | case DW_TAG_constant: | |
41235 | kind = VARIABLE; | |
41236 | is_static = ! is_external; | |
41237 | break; | |
41238 | case DW_TAG_variable: | |
41239 | kind = VARIABLE; | |
41240 | is_static = ! is_external; | |
41241 | break; | |
41242 | case DW_TAG_namespace: | |
41243 | kind = TYPE; | |
41244 | is_static = 0; | |
41245 | break; | |
41246 | case DW_TAG_class_type: | |
41247 | case DW_TAG_interface_type: | |
41248 | case DW_TAG_structure_type: | |
41249 | case DW_TAG_union_type: | |
41250 | case DW_TAG_enumeration_type: | |
41251 | kind = TYPE; | |
41252 | is_static = (language != CPLUS && language != JAVA); | |
41253 | break; | |
41254 | default: | |
41255 | assert (0); | |
41256 | @} | |
41257 | @end smallexample | |
41258 | ||
43662968 JK |
41259 | @node Man Pages |
41260 | @appendix Manual pages | |
41261 | @cindex Man pages | |
41262 | ||
41263 | @menu | |
41264 | * gdb man:: The GNU Debugger man page | |
41265 | * gdbserver man:: Remote Server for the GNU Debugger man page | |
b292c783 | 41266 | * gcore man:: Generate a core file of a running program |
43662968 JK |
41267 | * gdbinit man:: gdbinit scripts |
41268 | @end menu | |
41269 | ||
41270 | @node gdb man | |
41271 | @heading gdb man | |
41272 | ||
41273 | @c man title gdb The GNU Debugger | |
41274 | ||
41275 | @c man begin SYNOPSIS gdb | |
41276 | gdb [@option{-help}] [@option{-nh}] [@option{-nx}] [@option{-q}] | |
41277 | [@option{-batch}] [@option{-cd=}@var{dir}] [@option{-f}] | |
41278 | [@option{-b}@w{ }@var{bps}] | |
41279 | [@option{-tty=}@var{dev}] [@option{-s} @var{symfile}] | |
41280 | [@option{-e}@w{ }@var{prog}] [@option{-se}@w{ }@var{prog}] | |
906ccdf0 JK |
41281 | [@option{-c}@w{ }@var{core}] [@option{-p}@w{ }@var{procID}] |
41282 | [@option{-x}@w{ }@var{cmds}] [@option{-d}@w{ }@var{dir}] | |
41283 | [@var{prog}|@var{prog} @var{procID}|@var{prog} @var{core}] | |
43662968 JK |
41284 | @c man end |
41285 | ||
41286 | @c man begin DESCRIPTION gdb | |
41287 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
41288 | going on ``inside'' another program while it executes -- or what another | |
41289 | program was doing at the moment it crashed. | |
41290 | ||
41291 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
41292 | these) to help you catch bugs in the act: | |
41293 | ||
41294 | @itemize @bullet | |
41295 | @item | |
41296 | Start your program, specifying anything that might affect its behavior. | |
41297 | ||
41298 | @item | |
41299 | Make your program stop on specified conditions. | |
41300 | ||
41301 | @item | |
41302 | Examine what has happened, when your program has stopped. | |
41303 | ||
41304 | @item | |
41305 | Change things in your program, so you can experiment with correcting the | |
41306 | effects of one bug and go on to learn about another. | |
41307 | @end itemize | |
41308 | ||
906ccdf0 JK |
41309 | You can use @value{GDBN} to debug programs written in C, C@t{++}, Fortran and |
41310 | Modula-2. | |
43662968 JK |
41311 | |
41312 | @value{GDBN} is invoked with the shell command @code{gdb}. Once started, it reads | |
41313 | commands from the terminal until you tell it to exit with the @value{GDBN} | |
41314 | command @code{quit}. You can get online help from @value{GDBN} itself | |
41315 | by using the command @code{help}. | |
41316 | ||
41317 | You can run @code{gdb} with no arguments or options; but the most | |
41318 | usual way to start @value{GDBN} is with one argument or two, specifying an | |
41319 | executable program as the argument: | |
41320 | ||
41321 | @smallexample | |
41322 | gdb program | |
41323 | @end smallexample | |
41324 | ||
41325 | You can also start with both an executable program and a core file specified: | |
41326 | ||
41327 | @smallexample | |
41328 | gdb program core | |
41329 | @end smallexample | |
41330 | ||
41331 | You can, instead, specify a process ID as a second argument, if you want | |
41332 | to debug a running process: | |
41333 | ||
41334 | @smallexample | |
41335 | gdb program 1234 | |
906ccdf0 | 41336 | gdb -p 1234 |
43662968 JK |
41337 | @end smallexample |
41338 | ||
41339 | @noindent | |
41340 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
41341 | named @file{1234}; @value{GDBN} does check for a core file first). | |
906ccdf0 | 41342 | With option @option{-p} you can omit the @var{program} filename. |
43662968 JK |
41343 | |
41344 | Here are some of the most frequently needed @value{GDBN} commands: | |
41345 | ||
41346 | @c pod2man highlights the right hand side of the @item lines. | |
41347 | @table @env | |
41348 | @item break [@var{file}:]@var{functiop} | |
41349 | Set a breakpoint at @var{function} (in @var{file}). | |
41350 | ||
41351 | @item run [@var{arglist}] | |
41352 | Start your program (with @var{arglist}, if specified). | |
41353 | ||
41354 | @item bt | |
41355 | Backtrace: display the program stack. | |
41356 | ||
41357 | @item print @var{expr} | |
41358 | Display the value of an expression. | |
41359 | ||
41360 | @item c | |
41361 | Continue running your program (after stopping, e.g. at a breakpoint). | |
41362 | ||
41363 | @item next | |
41364 | Execute next program line (after stopping); step @emph{over} any | |
41365 | function calls in the line. | |
41366 | ||
41367 | @item edit [@var{file}:]@var{function} | |
41368 | look at the program line where it is presently stopped. | |
41369 | ||
41370 | @item list [@var{file}:]@var{function} | |
41371 | type the text of the program in the vicinity of where it is presently stopped. | |
41372 | ||
41373 | @item step | |
41374 | Execute next program line (after stopping); step @emph{into} any | |
41375 | function calls in the line. | |
41376 | ||
41377 | @item help [@var{name}] | |
41378 | Show information about @value{GDBN} command @var{name}, or general information | |
41379 | about using @value{GDBN}. | |
41380 | ||
41381 | @item quit | |
41382 | Exit from @value{GDBN}. | |
41383 | @end table | |
41384 | ||
41385 | @ifset man | |
41386 | For full details on @value{GDBN}, | |
41387 | see @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
41388 | by Richard M. Stallman and Roland H. Pesch. The same text is available online | |
41389 | as the @code{gdb} entry in the @code{info} program. | |
41390 | @end ifset | |
41391 | @c man end | |
41392 | ||
41393 | @c man begin OPTIONS gdb | |
41394 | Any arguments other than options specify an executable | |
41395 | file and core file (or process ID); that is, the first argument | |
41396 | encountered with no | |
41397 | associated option flag is equivalent to a @option{-se} option, and the second, | |
41398 | if any, is equivalent to a @option{-c} option if it's the name of a file. | |
41399 | Many options have | |
41400 | both long and short forms; both are shown here. The long forms are also | |
41401 | recognized if you truncate them, so long as enough of the option is | |
41402 | present to be unambiguous. (If you prefer, you can flag option | |
41403 | arguments with @option{+} rather than @option{-}, though we illustrate the | |
41404 | more usual convention.) | |
41405 | ||
41406 | All the options and command line arguments you give are processed | |
41407 | in sequential order. The order makes a difference when the @option{-x} | |
41408 | option is used. | |
41409 | ||
41410 | @table @env | |
41411 | @item -help | |
41412 | @itemx -h | |
41413 | List all options, with brief explanations. | |
41414 | ||
41415 | @item -symbols=@var{file} | |
41416 | @itemx -s @var{file} | |
41417 | Read symbol table from file @var{file}. | |
41418 | ||
41419 | @item -write | |
41420 | Enable writing into executable and core files. | |
41421 | ||
41422 | @item -exec=@var{file} | |
41423 | @itemx -e @var{file} | |
41424 | Use file @var{file} as the executable file to execute when | |
41425 | appropriate, and for examining pure data in conjunction with a core | |
41426 | dump. | |
41427 | ||
41428 | @item -se=@var{file} | |
41429 | Read symbol table from file @var{file} and use it as the executable | |
41430 | file. | |
41431 | ||
41432 | @item -core=@var{file} | |
41433 | @itemx -c @var{file} | |
41434 | Use file @var{file} as a core dump to examine. | |
41435 | ||
41436 | @item -command=@var{file} | |
41437 | @itemx -x @var{file} | |
41438 | Execute @value{GDBN} commands from file @var{file}. | |
41439 | ||
41440 | @item -ex @var{command} | |
41441 | Execute given @value{GDBN} @var{command}. | |
41442 | ||
41443 | @item -directory=@var{directory} | |
41444 | @itemx -d @var{directory} | |
41445 | Add @var{directory} to the path to search for source files. | |
41446 | ||
41447 | @item -nh | |
41448 | Do not execute commands from @file{~/.gdbinit}. | |
41449 | ||
41450 | @item -nx | |
41451 | @itemx -n | |
41452 | Do not execute commands from any @file{.gdbinit} initialization files. | |
41453 | ||
41454 | @item -quiet | |
41455 | @itemx -q | |
41456 | ``Quiet''. Do not print the introductory and copyright messages. These | |
41457 | messages are also suppressed in batch mode. | |
41458 | ||
41459 | @item -batch | |
41460 | Run in batch mode. Exit with status @code{0} after processing all the command | |
41461 | files specified with @option{-x} (and @file{.gdbinit}, if not inhibited). | |
41462 | Exit with nonzero status if an error occurs in executing the @value{GDBN} | |
41463 | commands in the command files. | |
41464 | ||
41465 | Batch mode may be useful for running @value{GDBN} as a filter, for example to | |
41466 | download and run a program on another computer; in order to make this | |
41467 | more useful, the message | |
41468 | ||
41469 | @smallexample | |
41470 | Program exited normally. | |
41471 | @end smallexample | |
41472 | ||
41473 | @noindent | |
41474 | (which is ordinarily issued whenever a program running under @value{GDBN} control | |
41475 | terminates) is not issued when running in batch mode. | |
41476 | ||
41477 | @item -cd=@var{directory} | |
41478 | Run @value{GDBN} using @var{directory} as its working directory, | |
41479 | instead of the current directory. | |
41480 | ||
41481 | @item -fullname | |
41482 | @itemx -f | |
41483 | Emacs sets this option when it runs @value{GDBN} as a subprocess. It tells | |
41484 | @value{GDBN} to output the full file name and line number in a standard, | |
41485 | recognizable fashion each time a stack frame is displayed (which | |
41486 | includes each time the program stops). This recognizable format looks | |
41487 | like two @samp{\032} characters, followed by the file name, line number | |
41488 | and character position separated by colons, and a newline. The | |
41489 | Emacs-to-@value{GDBN} interface program uses the two @samp{\032} | |
41490 | characters as a signal to display the source code for the frame. | |
41491 | ||
41492 | @item -b @var{bps} | |
41493 | Set the line speed (baud rate or bits per second) of any serial | |
41494 | interface used by @value{GDBN} for remote debugging. | |
41495 | ||
41496 | @item -tty=@var{device} | |
41497 | Run using @var{device} for your program's standard input and output. | |
41498 | @end table | |
41499 | @c man end | |
41500 | ||
41501 | @c man begin SEEALSO gdb | |
41502 | @ifset man | |
41503 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
41504 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
41505 | documentation are properly installed at your site, the command | |
41506 | ||
41507 | @smallexample | |
41508 | info gdb | |
41509 | @end smallexample | |
41510 | ||
41511 | @noindent | |
41512 | should give you access to the complete manual. | |
41513 | ||
41514 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
41515 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
41516 | @end ifset | |
41517 | @c man end | |
41518 | ||
41519 | @node gdbserver man | |
41520 | @heading gdbserver man | |
41521 | ||
41522 | @c man title gdbserver Remote Server for the GNU Debugger | |
41523 | @format | |
41524 | @c man begin SYNOPSIS gdbserver | |
5b8b6385 | 41525 | gdbserver @var{comm} @var{prog} [@var{args}@dots{}] |
43662968 | 41526 | |
5b8b6385 JK |
41527 | gdbserver --attach @var{comm} @var{pid} |
41528 | ||
41529 | gdbserver --multi @var{comm} | |
43662968 JK |
41530 | @c man end |
41531 | @end format | |
41532 | ||
41533 | @c man begin DESCRIPTION gdbserver | |
41534 | @command{gdbserver} is a program that allows you to run @value{GDBN} on a different machine | |
41535 | than the one which is running the program being debugged. | |
41536 | ||
41537 | @ifclear man | |
41538 | @subheading Usage (server (target) side) | |
41539 | @end ifclear | |
41540 | @ifset man | |
41541 | Usage (server (target) side): | |
41542 | @end ifset | |
41543 | ||
41544 | First, you need to have a copy of the program you want to debug put onto | |
41545 | the target system. The program can be stripped to save space if needed, as | |
41546 | @command{gdbserver} doesn't care about symbols. All symbol handling is taken care of by | |
41547 | the @value{GDBN} running on the host system. | |
41548 | ||
41549 | To use the server, you log on to the target system, and run the @command{gdbserver} | |
41550 | program. You must tell it (a) how to communicate with @value{GDBN}, (b) the name of | |
41551 | your program, and (c) its arguments. The general syntax is: | |
41552 | ||
41553 | @smallexample | |
41554 | target> gdbserver @var{comm} @var{program} [@var{args} ...] | |
41555 | @end smallexample | |
41556 | ||
41557 | For example, using a serial port, you might say: | |
41558 | ||
41559 | @smallexample | |
41560 | @ifset man | |
41561 | @c @file would wrap it as F</dev/com1>. | |
41562 | target> gdbserver /dev/com1 emacs foo.txt | |
41563 | @end ifset | |
41564 | @ifclear man | |
41565 | target> gdbserver @file{/dev/com1} emacs foo.txt | |
41566 | @end ifclear | |
41567 | @end smallexample | |
41568 | ||
41569 | This tells @command{gdbserver} to debug emacs with an argument of foo.txt, and | |
41570 | to communicate with @value{GDBN} via @file{/dev/com1}. @command{gdbserver} now | |
41571 | waits patiently for the host @value{GDBN} to communicate with it. | |
41572 | ||
41573 | To use a TCP connection, you could say: | |
41574 | ||
41575 | @smallexample | |
41576 | target> gdbserver host:2345 emacs foo.txt | |
41577 | @end smallexample | |
41578 | ||
41579 | This says pretty much the same thing as the last example, except that we are | |
41580 | going to communicate with the @code{host} @value{GDBN} via TCP. The @code{host:2345} argument means | |
41581 | that we are expecting to see a TCP connection from @code{host} to local TCP port | |
41582 | 2345. (Currently, the @code{host} part is ignored.) You can choose any number you | |
41583 | want for the port number as long as it does not conflict with any existing TCP | |
41584 | ports on the target system. This same port number must be used in the host | |
41585 | @value{GDBN}s @code{target remote} command, which will be described shortly. Note that if | |
41586 | you chose a port number that conflicts with another service, @command{gdbserver} will | |
41587 | print an error message and exit. | |
41588 | ||
5b8b6385 | 41589 | @command{gdbserver} can also attach to running programs. |
43662968 JK |
41590 | This is accomplished via the @option{--attach} argument. The syntax is: |
41591 | ||
41592 | @smallexample | |
5b8b6385 | 41593 | target> gdbserver --attach @var{comm} @var{pid} |
43662968 JK |
41594 | @end smallexample |
41595 | ||
41596 | @var{pid} is the process ID of a currently running process. It isn't | |
41597 | necessary to point @command{gdbserver} at a binary for the running process. | |
41598 | ||
5b8b6385 JK |
41599 | To start @code{gdbserver} without supplying an initial command to run |
41600 | or process ID to attach, use the @option{--multi} command line option. | |
41601 | In such case you should connect using @kbd{target extended-remote} to start | |
41602 | the program you want to debug. | |
41603 | ||
41604 | @smallexample | |
41605 | target> gdbserver --multi @var{comm} | |
41606 | @end smallexample | |
41607 | ||
43662968 JK |
41608 | @ifclear man |
41609 | @subheading Usage (host side) | |
41610 | @end ifclear | |
41611 | @ifset man | |
41612 | Usage (host side): | |
41613 | @end ifset | |
41614 | ||
41615 | You need an unstripped copy of the target program on your host system, since | |
41616 | @value{GDBN} needs to examine it's symbol tables and such. Start up @value{GDBN} as you normally | |
41617 | would, with the target program as the first argument. (You may need to use the | |
41618 | @option{--baud} option if the serial line is running at anything except 9600 baud.) | |
41619 | That is @code{gdb TARGET-PROG}, or @code{gdb --baud BAUD TARGET-PROG}. After that, the only | |
5b8b6385 JK |
41620 | new command you need to know about is @code{target remote} |
41621 | (or @code{target extended-remote}). Its argument is either | |
43662968 JK |
41622 | a device name (usually a serial device, like @file{/dev/ttyb}), or a @code{HOST:PORT} |
41623 | descriptor. For example: | |
41624 | ||
41625 | @smallexample | |
41626 | @ifset man | |
41627 | @c @file would wrap it as F</dev/ttyb>. | |
41628 | (gdb) target remote /dev/ttyb | |
41629 | @end ifset | |
41630 | @ifclear man | |
41631 | (gdb) target remote @file{/dev/ttyb} | |
41632 | @end ifclear | |
41633 | @end smallexample | |
41634 | ||
41635 | @noindent | |
41636 | communicates with the server via serial line @file{/dev/ttyb}, and: | |
41637 | ||
41638 | @smallexample | |
41639 | (gdb) target remote the-target:2345 | |
41640 | @end smallexample | |
41641 | ||
41642 | @noindent | |
41643 | communicates via a TCP connection to port 2345 on host `the-target', where | |
41644 | you previously started up @command{gdbserver} with the same port number. Note that for | |
41645 | TCP connections, you must start up @command{gdbserver} prior to using the `target remote' | |
41646 | command, otherwise you may get an error that looks something like | |
41647 | `Connection refused'. | |
5b8b6385 JK |
41648 | |
41649 | @command{gdbserver} can also debug multiple inferiors at once, | |
41650 | described in | |
41651 | @ifset man | |
41652 | the @value{GDBN} manual in node @code{Inferiors and Programs} | |
41653 | -- shell command @code{info -f gdb -n 'Inferiors and Programs'}. | |
41654 | @end ifset | |
41655 | @ifclear man | |
41656 | @ref{Inferiors and Programs}. | |
41657 | @end ifclear | |
41658 | In such case use the @code{extended-remote} @value{GDBN} command variant: | |
41659 | ||
41660 | @smallexample | |
41661 | (gdb) target extended-remote the-target:2345 | |
41662 | @end smallexample | |
41663 | ||
41664 | The @command{gdbserver} option @option{--multi} may or may not be used in such | |
41665 | case. | |
43662968 JK |
41666 | @c man end |
41667 | ||
41668 | @c man begin OPTIONS gdbserver | |
5b8b6385 JK |
41669 | There are three different modes for invoking @command{gdbserver}: |
41670 | ||
41671 | @itemize @bullet | |
41672 | ||
41673 | @item | |
41674 | Debug a specific program specified by its program name: | |
41675 | ||
41676 | @smallexample | |
41677 | gdbserver @var{comm} @var{prog} [@var{args}@dots{}] | |
41678 | @end smallexample | |
41679 | ||
41680 | The @var{comm} parameter specifies how should the server communicate | |
41681 | with @value{GDBN}; it is either a device name (to use a serial line), | |
41682 | a TCP port number (@code{:1234}), or @code{-} or @code{stdio} to use | |
41683 | stdin/stdout of @code{gdbserver}. Specify the name of the program to | |
41684 | debug in @var{prog}. Any remaining arguments will be passed to the | |
41685 | program verbatim. When the program exits, @value{GDBN} will close the | |
41686 | connection, and @code{gdbserver} will exit. | |
41687 | ||
41688 | @item | |
41689 | Debug a specific program by specifying the process ID of a running | |
41690 | program: | |
41691 | ||
41692 | @smallexample | |
41693 | gdbserver --attach @var{comm} @var{pid} | |
41694 | @end smallexample | |
41695 | ||
41696 | The @var{comm} parameter is as described above. Supply the process ID | |
41697 | of a running program in @var{pid}; @value{GDBN} will do everything | |
41698 | else. Like with the previous mode, when the process @var{pid} exits, | |
41699 | @value{GDBN} will close the connection, and @code{gdbserver} will exit. | |
41700 | ||
41701 | @item | |
41702 | Multi-process mode -- debug more than one program/process: | |
41703 | ||
41704 | @smallexample | |
41705 | gdbserver --multi @var{comm} | |
41706 | @end smallexample | |
41707 | ||
41708 | In this mode, @value{GDBN} can instruct @command{gdbserver} which | |
41709 | command(s) to run. Unlike the other 2 modes, @value{GDBN} will not | |
41710 | close the connection when a process being debugged exits, so you can | |
41711 | debug several processes in the same session. | |
41712 | @end itemize | |
41713 | ||
41714 | In each of the modes you may specify these options: | |
41715 | ||
41716 | @table @env | |
41717 | ||
41718 | @item --help | |
41719 | List all options, with brief explanations. | |
41720 | ||
41721 | @item --version | |
41722 | This option causes @command{gdbserver} to print its version number and exit. | |
41723 | ||
41724 | @item --attach | |
41725 | @command{gdbserver} will attach to a running program. The syntax is: | |
41726 | ||
41727 | @smallexample | |
41728 | target> gdbserver --attach @var{comm} @var{pid} | |
41729 | @end smallexample | |
41730 | ||
41731 | @var{pid} is the process ID of a currently running process. It isn't | |
41732 | necessary to point @command{gdbserver} at a binary for the running process. | |
41733 | ||
41734 | @item --multi | |
41735 | To start @code{gdbserver} without supplying an initial command to run | |
41736 | or process ID to attach, use this command line option. | |
41737 | Then you can connect using @kbd{target extended-remote} and start | |
41738 | the program you want to debug. The syntax is: | |
41739 | ||
41740 | @smallexample | |
41741 | target> gdbserver --multi @var{comm} | |
41742 | @end smallexample | |
41743 | ||
41744 | @item --debug | |
41745 | Instruct @code{gdbserver} to display extra status information about the debugging | |
41746 | process. | |
41747 | This option is intended for @code{gdbserver} development and for bug reports to | |
41748 | the developers. | |
41749 | ||
41750 | @item --remote-debug | |
41751 | Instruct @code{gdbserver} to display remote protocol debug output. | |
41752 | This option is intended for @code{gdbserver} development and for bug reports to | |
41753 | the developers. | |
41754 | ||
87ce2a04 DE |
41755 | @item --debug-format=option1@r{[},option2,...@r{]} |
41756 | Instruct @code{gdbserver} to include extra information in each line | |
41757 | of debugging output. | |
41758 | @xref{Other Command-Line Arguments for gdbserver}. | |
41759 | ||
5b8b6385 JK |
41760 | @item --wrapper |
41761 | Specify a wrapper to launch programs | |
41762 | for debugging. The option should be followed by the name of the | |
41763 | wrapper, then any command-line arguments to pass to the wrapper, then | |
41764 | @kbd{--} indicating the end of the wrapper arguments. | |
41765 | ||
41766 | @item --once | |
41767 | By default, @command{gdbserver} keeps the listening TCP port open, so that | |
41768 | additional connections are possible. However, if you start @code{gdbserver} | |
41769 | with the @option{--once} option, it will stop listening for any further | |
41770 | connection attempts after connecting to the first @value{GDBN} session. | |
41771 | ||
41772 | @c --disable-packet is not documented for users. | |
41773 | ||
41774 | @c --disable-randomization and --no-disable-randomization are superseded by | |
41775 | @c QDisableRandomization. | |
41776 | ||
41777 | @end table | |
43662968 JK |
41778 | @c man end |
41779 | ||
41780 | @c man begin SEEALSO gdbserver | |
41781 | @ifset man | |
41782 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
41783 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
41784 | documentation are properly installed at your site, the command | |
41785 | ||
41786 | @smallexample | |
41787 | info gdb | |
41788 | @end smallexample | |
41789 | ||
41790 | should give you access to the complete manual. | |
41791 | ||
41792 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
41793 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
41794 | @end ifset | |
41795 | @c man end | |
41796 | ||
b292c783 JK |
41797 | @node gcore man |
41798 | @heading gcore | |
41799 | ||
41800 | @c man title gcore Generate a core file of a running program | |
41801 | ||
41802 | @format | |
41803 | @c man begin SYNOPSIS gcore | |
41804 | gcore [-o @var{filename}] @var{pid} | |
41805 | @c man end | |
41806 | @end format | |
41807 | ||
41808 | @c man begin DESCRIPTION gcore | |
41809 | Generate a core dump of a running program with process ID @var{pid}. | |
41810 | Produced file is equivalent to a kernel produced core file as if the process | |
41811 | crashed (and if @kbd{ulimit -c} were used to set up an appropriate core dump | |
41812 | limit). Unlike after a crash, after @command{gcore} the program remains | |
41813 | running without any change. | |
41814 | @c man end | |
41815 | ||
41816 | @c man begin OPTIONS gcore | |
41817 | @table @env | |
41818 | @item -o @var{filename} | |
41819 | The optional argument | |
41820 | @var{filename} specifies the file name where to put the core dump. | |
41821 | If not specified, the file name defaults to @file{core.@var{pid}}, | |
41822 | where @var{pid} is the running program process ID. | |
41823 | @end table | |
41824 | @c man end | |
41825 | ||
41826 | @c man begin SEEALSO gcore | |
41827 | @ifset man | |
41828 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
41829 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
41830 | documentation are properly installed at your site, the command | |
41831 | ||
41832 | @smallexample | |
41833 | info gdb | |
41834 | @end smallexample | |
41835 | ||
41836 | @noindent | |
41837 | should give you access to the complete manual. | |
41838 | ||
41839 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
41840 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
41841 | @end ifset | |
41842 | @c man end | |
41843 | ||
43662968 JK |
41844 | @node gdbinit man |
41845 | @heading gdbinit | |
41846 | ||
41847 | @c man title gdbinit GDB initialization scripts | |
41848 | ||
41849 | @format | |
41850 | @c man begin SYNOPSIS gdbinit | |
41851 | @ifset SYSTEM_GDBINIT | |
41852 | @value{SYSTEM_GDBINIT} | |
41853 | @end ifset | |
41854 | ||
41855 | ~/.gdbinit | |
41856 | ||
41857 | ./.gdbinit | |
41858 | @c man end | |
41859 | @end format | |
41860 | ||
41861 | @c man begin DESCRIPTION gdbinit | |
41862 | These files contain @value{GDBN} commands to automatically execute during | |
41863 | @value{GDBN} startup. The lines of contents are canned sequences of commands, | |
41864 | described in | |
41865 | @ifset man | |
41866 | the @value{GDBN} manual in node @code{Sequences} | |
41867 | -- shell command @code{info -f gdb -n Sequences}. | |
41868 | @end ifset | |
41869 | @ifclear man | |
41870 | @ref{Sequences}. | |
41871 | @end ifclear | |
41872 | ||
41873 | Please read more in | |
41874 | @ifset man | |
41875 | the @value{GDBN} manual in node @code{Startup} | |
41876 | -- shell command @code{info -f gdb -n Startup}. | |
41877 | @end ifset | |
41878 | @ifclear man | |
41879 | @ref{Startup}. | |
41880 | @end ifclear | |
41881 | ||
41882 | @table @env | |
41883 | @ifset SYSTEM_GDBINIT | |
41884 | @item @value{SYSTEM_GDBINIT} | |
41885 | @end ifset | |
41886 | @ifclear SYSTEM_GDBINIT | |
41887 | @item (not enabled with @code{--with-system-gdbinit} during compilation) | |
41888 | @end ifclear | |
41889 | System-wide initialization file. It is executed unless user specified | |
41890 | @value{GDBN} option @code{-nx} or @code{-n}. | |
41891 | See more in | |
41892 | @ifset man | |
41893 | the @value{GDBN} manual in node @code{System-wide configuration} | |
41894 | -- shell command @code{info -f gdb -n 'System-wide configuration'}. | |
41895 | @end ifset | |
41896 | @ifclear man | |
41897 | @ref{System-wide configuration}. | |
41898 | @end ifclear | |
41899 | ||
41900 | @item ~/.gdbinit | |
41901 | User initialization file. It is executed unless user specified | |
41902 | @value{GDBN} options @code{-nx}, @code{-n} or @code{-nh}. | |
41903 | ||
41904 | @item ./.gdbinit | |
41905 | Initialization file for current directory. It may need to be enabled with | |
41906 | @value{GDBN} security command @code{set auto-load local-gdbinit}. | |
41907 | See more in | |
41908 | @ifset man | |
41909 | the @value{GDBN} manual in node @code{Init File in the Current Directory} | |
41910 | -- shell command @code{info -f gdb -n 'Init File in the Current Directory'}. | |
41911 | @end ifset | |
41912 | @ifclear man | |
41913 | @ref{Init File in the Current Directory}. | |
41914 | @end ifclear | |
41915 | @end table | |
41916 | @c man end | |
41917 | ||
41918 | @c man begin SEEALSO gdbinit | |
41919 | @ifset man | |
41920 | gdb(1), @code{info -f gdb -n Startup} | |
41921 | ||
41922 | The full documentation for @value{GDBN} is maintained as a Texinfo manual. | |
41923 | If the @code{info} and @code{gdb} programs and @value{GDBN}'s Texinfo | |
41924 | documentation are properly installed at your site, the command | |
41925 | ||
41926 | @smallexample | |
41927 | info gdb | |
41928 | @end smallexample | |
41929 | ||
41930 | should give you access to the complete manual. | |
41931 | ||
41932 | @cite{Using GDB: A Guide to the GNU Source-Level Debugger}, | |
41933 | Richard M. Stallman and Roland H. Pesch, July 1991. | |
41934 | @end ifset | |
41935 | @c man end | |
41936 | ||
aab4e0ec | 41937 | @include gpl.texi |
eb12ee30 | 41938 | |
e4c0cfae SS |
41939 | @node GNU Free Documentation License |
41940 | @appendix GNU Free Documentation License | |
6826cf00 EZ |
41941 | @include fdl.texi |
41942 | ||
00595b5e EZ |
41943 | @node Concept Index |
41944 | @unnumbered Concept Index | |
c906108c SS |
41945 | |
41946 | @printindex cp | |
41947 | ||
00595b5e EZ |
41948 | @node Command and Variable Index |
41949 | @unnumbered Command, Variable, and Function Index | |
41950 | ||
41951 | @printindex fn | |
41952 | ||
c906108c | 41953 | @tex |
984359d2 | 41954 | % I think something like @@colophon should be in texinfo. In the |
c906108c SS |
41955 | % meantime: |
41956 | \long\def\colophon{\hbox to0pt{}\vfill | |
41957 | \centerline{The body of this manual is set in} | |
41958 | \centerline{\fontname\tenrm,} | |
41959 | \centerline{with headings in {\bf\fontname\tenbf}} | |
41960 | \centerline{and examples in {\tt\fontname\tentt}.} | |
41961 | \centerline{{\it\fontname\tenit\/},} | |
41962 | \centerline{{\bf\fontname\tenbf}, and} | |
41963 | \centerline{{\sl\fontname\tensl\/}} | |
41964 | \centerline{are used for emphasis.}\vfill} | |
41965 | \page\colophon | |
984359d2 | 41966 | % Blame: doc@@cygnus.com, 1991. |
c906108c SS |
41967 | @end tex |
41968 | ||
c906108c | 41969 | @bye |