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c906108c | 1 | \input texinfo @c -*-texinfo-*- |
c02a867d | 2 | @c Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, |
9d2897ad | 3 | @c 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
c906108c SS |
4 | @c Free Software Foundation, Inc. |
5 | @c | |
5d161b24 | 6 | @c %**start of header |
c906108c SS |
7 | @c makeinfo ignores cmds prev to setfilename, so its arg cannot make use |
8 | @c of @set vars. However, you can override filename with makeinfo -o. | |
9 | @setfilename gdb.info | |
10 | @c | |
11 | @include gdb-cfg.texi | |
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 | |
23 | @syncodeindex ky cp | |
89c73ade | 24 | @syncodeindex tp cp |
c906108c | 25 | |
41afff9a | 26 | @c readline appendices use @vindex, @findex and @ftable, |
48e934c6 | 27 | @c annotate.texi and gdbmi use @findex. |
c906108c | 28 | @syncodeindex vr cp |
41afff9a | 29 | @syncodeindex fn cp |
c906108c SS |
30 | |
31 | @c !!set GDB manual's edition---not the same as GDB version! | |
9fe8321b | 32 | @c This is updated by GNU Press. |
e9c75b65 | 33 | @set EDITION Ninth |
c906108c | 34 | |
87885426 FN |
35 | @c !!set GDB edit command default editor |
36 | @set EDITOR /bin/ex | |
c906108c | 37 | |
6c0e9fb3 | 38 | @c THIS MANUAL REQUIRES TEXINFO 4.0 OR LATER. |
c906108c | 39 | |
c906108c | 40 | @c This is a dir.info fragment to support semi-automated addition of |
6d2ebf8b | 41 | @c manuals to an info tree. |
03727ca6 | 42 | @dircategory Software development |
96a2c332 | 43 | @direntry |
03727ca6 | 44 | * Gdb: (gdb). The GNU debugger. |
96a2c332 SS |
45 | @end direntry |
46 | ||
a67ec3f4 JM |
47 | @copying |
48 | Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, | |
9d2897ad | 49 | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
a67ec3f4 | 50 | Free Software Foundation, Inc. |
c906108c | 51 | |
e9c75b65 | 52 | Permission is granted to copy, distribute and/or modify this document |
4f5d9f07 | 53 | under the terms of the GNU Free Documentation License, Version 1.3 or |
e9c75b65 | 54 | any later version published by the Free Software Foundation; with the |
959acfd1 EZ |
55 | Invariant Sections being ``Free Software'' and ``Free Software Needs |
56 | Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' | |
57 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 58 | |
b8533aec DJ |
59 | (a) The FSF's Back-Cover Text is: ``You are free to copy and modify |
60 | this GNU Manual. Buying copies from GNU Press supports the FSF in | |
61 | developing GNU and promoting software freedom.'' | |
a67ec3f4 JM |
62 | @end copying |
63 | ||
64 | @ifnottex | |
65 | This file documents the @sc{gnu} debugger @value{GDBN}. | |
66 | ||
67 | This is the @value{EDITION} Edition, of @cite{Debugging with | |
68 | @value{GDBN}: the @sc{gnu} Source-Level Debugger} for @value{GDBN} | |
69 | @ifset VERSION_PACKAGE | |
70 | @value{VERSION_PACKAGE} | |
71 | @end ifset | |
72 | Version @value{GDBVN}. | |
73 | ||
74 | @insertcopying | |
75 | @end ifnottex | |
c906108c SS |
76 | |
77 | @titlepage | |
78 | @title Debugging with @value{GDBN} | |
79 | @subtitle The @sc{gnu} Source-Level Debugger | |
c906108c | 80 | @sp 1 |
c906108c | 81 | @subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN} |
c16158bc JM |
82 | @ifset VERSION_PACKAGE |
83 | @sp 1 | |
84 | @subtitle @value{VERSION_PACKAGE} | |
85 | @end ifset | |
9e9c5ae7 | 86 | @author Richard Stallman, Roland Pesch, Stan Shebs, et al. |
c906108c | 87 | @page |
c906108c SS |
88 | @tex |
89 | {\parskip=0pt | |
c16158bc | 90 | \hfill (Send bugs and comments on @value{GDBN} to @value{BUGURL}.)\par |
c906108c SS |
91 | \hfill {\it Debugging with @value{GDBN}}\par |
92 | \hfill \TeX{}info \texinfoversion\par | |
93 | } | |
94 | @end tex | |
53a5351d | 95 | |
c906108c | 96 | @vskip 0pt plus 1filll |
c906108c | 97 | Published by the Free Software Foundation @* |
c02a867d EZ |
98 | 51 Franklin Street, Fifth Floor, |
99 | Boston, MA 02110-1301, USA@* | |
6d2ebf8b | 100 | ISBN 1-882114-77-9 @* |
e9c75b65 | 101 | |
a67ec3f4 | 102 | @insertcopying |
3fb6a982 JB |
103 | @page |
104 | This edition of the GDB manual is dedicated to the memory of Fred | |
105 | Fish. Fred was a long-standing contributor to GDB and to Free | |
106 | software in general. We will miss him. | |
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 | |
9d2897ad | 123 | Copyright (C) 1988-2010 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. |
6d2ebf8b SS |
163 | |
164 | * GDB Bugs:: Reporting bugs in @value{GDBN} | |
6d2ebf8b | 165 | |
39037522 TT |
166 | @ifset SYSTEM_READLINE |
167 | * Command Line Editing: (rluserman). Command Line Editing | |
168 | * Using History Interactively: (history). Using History Interactively | |
169 | @end ifset | |
170 | @ifclear SYSTEM_READLINE | |
6d2ebf8b SS |
171 | * Command Line Editing:: Command Line Editing |
172 | * Using History Interactively:: Using History Interactively | |
39037522 | 173 | @end ifclear |
0869d01b | 174 | * Formatting Documentation:: How to format and print @value{GDBN} documentation |
6d2ebf8b | 175 | * Installing GDB:: Installing GDB |
eb12ee30 | 176 | * Maintenance Commands:: Maintenance Commands |
e0ce93ac | 177 | * Remote Protocol:: GDB Remote Serial Protocol |
f418dd93 | 178 | * Agent Expressions:: The GDB Agent Expression Mechanism |
23181151 DJ |
179 | * Target Descriptions:: How targets can describe themselves to |
180 | @value{GDBN} | |
07e059b5 VP |
181 | * Operating System Information:: Getting additional information from |
182 | the operating system | |
00bf0b85 | 183 | * Trace File Format:: GDB trace file format |
aab4e0ec AC |
184 | * Copying:: GNU General Public License says |
185 | how you can copy and share GDB | |
6826cf00 | 186 | * GNU Free Documentation License:: The license for this documentation |
6d2ebf8b SS |
187 | * Index:: Index |
188 | @end menu | |
189 | ||
6c0e9fb3 | 190 | @end ifnottex |
c906108c | 191 | |
449f3b6c | 192 | @contents |
449f3b6c | 193 | |
6d2ebf8b | 194 | @node Summary |
c906108c SS |
195 | @unnumbered Summary of @value{GDBN} |
196 | ||
197 | The purpose of a debugger such as @value{GDBN} is to allow you to see what is | |
198 | going on ``inside'' another program while it executes---or what another | |
199 | program was doing at the moment it crashed. | |
200 | ||
201 | @value{GDBN} can do four main kinds of things (plus other things in support of | |
202 | these) to help you catch bugs in the act: | |
203 | ||
204 | @itemize @bullet | |
205 | @item | |
206 | Start your program, specifying anything that might affect its behavior. | |
207 | ||
208 | @item | |
209 | Make your program stop on specified conditions. | |
210 | ||
211 | @item | |
212 | Examine what has happened, when your program has stopped. | |
213 | ||
214 | @item | |
215 | Change things in your program, so you can experiment with correcting the | |
216 | effects of one bug and go on to learn about another. | |
217 | @end itemize | |
218 | ||
49efadf5 | 219 | You can use @value{GDBN} to debug programs written in C and C@t{++}. |
79a6e687 | 220 | For more information, see @ref{Supported Languages,,Supported Languages}. |
c906108c SS |
221 | For more information, see @ref{C,,C and C++}. |
222 | ||
6aecb9c2 JB |
223 | Support for D is partial. For information on D, see |
224 | @ref{D,,D}. | |
225 | ||
cce74817 | 226 | @cindex Modula-2 |
e632838e AC |
227 | Support for Modula-2 is partial. For information on Modula-2, see |
228 | @ref{Modula-2,,Modula-2}. | |
c906108c | 229 | |
f4b8a18d KW |
230 | Support for OpenCL C is partial. For information on OpenCL C, see |
231 | @ref{OpenCL C,,OpenCL C}. | |
232 | ||
cce74817 JM |
233 | @cindex Pascal |
234 | Debugging Pascal programs which use sets, subranges, file variables, or | |
235 | nested functions does not currently work. @value{GDBN} does not support | |
236 | entering expressions, printing values, or similar features using Pascal | |
237 | syntax. | |
c906108c | 238 | |
c906108c SS |
239 | @cindex Fortran |
240 | @value{GDBN} can be used to debug programs written in Fortran, although | |
53a5351d | 241 | it may be necessary to refer to some variables with a trailing |
cce74817 | 242 | underscore. |
c906108c | 243 | |
b37303ee AF |
244 | @value{GDBN} can be used to debug programs written in Objective-C, |
245 | using either the Apple/NeXT or the GNU Objective-C runtime. | |
246 | ||
c906108c SS |
247 | @menu |
248 | * Free Software:: Freely redistributable software | |
249 | * Contributors:: Contributors to GDB | |
250 | @end menu | |
251 | ||
6d2ebf8b | 252 | @node Free Software |
79a6e687 | 253 | @unnumberedsec Free Software |
c906108c | 254 | |
5d161b24 | 255 | @value{GDBN} is @dfn{free software}, protected by the @sc{gnu} |
c906108c SS |
256 | General Public License |
257 | (GPL). The GPL gives you the freedom to copy or adapt a licensed | |
258 | program---but every person getting a copy also gets with it the | |
259 | freedom to modify that copy (which means that they must get access to | |
260 | the source code), and the freedom to distribute further copies. | |
261 | Typical software companies use copyrights to limit your freedoms; the | |
262 | Free Software Foundation uses the GPL to preserve these freedoms. | |
263 | ||
264 | Fundamentally, the General Public License is a license which says that | |
265 | you have these freedoms and that you cannot take these freedoms away | |
266 | from anyone else. | |
267 | ||
2666264b | 268 | @unnumberedsec Free Software Needs Free Documentation |
959acfd1 EZ |
269 | |
270 | The biggest deficiency in the free software community today is not in | |
271 | the software---it is the lack of good free documentation that we can | |
272 | include with the free software. Many of our most important | |
273 | programs do not come with free reference manuals and free introductory | |
274 | texts. Documentation is an essential part of any software package; | |
275 | when an important free software package does not come with a free | |
276 | manual and a free tutorial, that is a major gap. We have many such | |
277 | gaps today. | |
278 | ||
279 | Consider Perl, for instance. The tutorial manuals that people | |
280 | normally use are non-free. How did this come about? Because the | |
281 | authors of those manuals published them with restrictive terms---no | |
282 | copying, no modification, source files not available---which exclude | |
283 | them from the free software world. | |
284 | ||
285 | That wasn't the first time this sort of thing happened, and it was far | |
286 | from the last. Many times we have heard a GNU user eagerly describe a | |
287 | manual that he is writing, his intended contribution to the community, | |
288 | only to learn that he had ruined everything by signing a publication | |
289 | contract to make it non-free. | |
290 | ||
291 | Free documentation, like free software, is a matter of freedom, not | |
292 | price. The problem with the non-free manual is not that publishers | |
293 | charge a price for printed copies---that in itself is fine. (The Free | |
294 | Software Foundation sells printed copies of manuals, too.) The | |
295 | problem is the restrictions on the use of the manual. Free manuals | |
296 | are available in source code form, and give you permission to copy and | |
297 | modify. Non-free manuals do not allow this. | |
298 | ||
299 | The criteria of freedom for a free manual are roughly the same as for | |
300 | free software. Redistribution (including the normal kinds of | |
301 | commercial redistribution) must be permitted, so that the manual can | |
302 | accompany every copy of the program, both on-line and on paper. | |
303 | ||
304 | Permission for modification of the technical content is crucial too. | |
305 | When people modify the software, adding or changing features, if they | |
306 | are conscientious they will change the manual too---so they can | |
307 | provide accurate and clear documentation for the modified program. A | |
308 | manual that leaves you no choice but to write a new manual to document | |
309 | a changed version of the program is not really available to our | |
310 | community. | |
311 | ||
312 | Some kinds of limits on the way modification is handled are | |
313 | acceptable. For example, requirements to preserve the original | |
314 | author's copyright notice, the distribution terms, or the list of | |
315 | authors, are ok. It is also no problem to require modified versions | |
316 | to include notice that they were modified. Even entire sections that | |
317 | may not be deleted or changed are acceptable, as long as they deal | |
318 | with nontechnical topics (like this one). These kinds of restrictions | |
319 | are acceptable because they don't obstruct the community's normal use | |
320 | of the manual. | |
321 | ||
322 | However, it must be possible to modify all the @emph{technical} | |
323 | content of the manual, and then distribute the result in all the usual | |
324 | media, through all the usual channels. Otherwise, the restrictions | |
325 | obstruct the use of the manual, it is not free, and we need another | |
326 | manual to replace it. | |
327 | ||
328 | Please spread the word about this issue. Our community continues to | |
329 | lose manuals to proprietary publishing. If we spread the word that | |
330 | free software needs free reference manuals and free tutorials, perhaps | |
331 | the next person who wants to contribute by writing documentation will | |
332 | realize, before it is too late, that only free manuals contribute to | |
333 | the free software community. | |
334 | ||
335 | If you are writing documentation, please insist on publishing it under | |
336 | the GNU Free Documentation License or another free documentation | |
337 | license. Remember that this decision requires your approval---you | |
338 | don't have to let the publisher decide. Some commercial publishers | |
339 | will use a free license if you insist, but they will not propose the | |
340 | option; it is up to you to raise the issue and say firmly that this is | |
341 | what you want. If the publisher you are dealing with refuses, please | |
342 | try other publishers. If you're not sure whether a proposed license | |
42584a72 | 343 | is free, write to @email{licensing@@gnu.org}. |
959acfd1 EZ |
344 | |
345 | You can encourage commercial publishers to sell more free, copylefted | |
346 | manuals and tutorials by buying them, and particularly by buying | |
347 | copies from the publishers that paid for their writing or for major | |
348 | improvements. Meanwhile, try to avoid buying non-free documentation | |
349 | at all. Check the distribution terms of a manual before you buy it, | |
350 | and insist that whoever seeks your business must respect your freedom. | |
72c9928d EZ |
351 | Check the history of the book, and try to reward the publishers that |
352 | have paid or pay the authors to work on it. | |
959acfd1 EZ |
353 | |
354 | The Free Software Foundation maintains a list of free documentation | |
355 | published by other publishers, at | |
356 | @url{http://www.fsf.org/doc/other-free-books.html}. | |
357 | ||
6d2ebf8b | 358 | @node Contributors |
96a2c332 SS |
359 | @unnumberedsec Contributors to @value{GDBN} |
360 | ||
361 | Richard Stallman was the original author of @value{GDBN}, and of many | |
362 | other @sc{gnu} programs. Many others have contributed to its | |
363 | development. This section attempts to credit major contributors. One | |
364 | of the virtues of free software is that everyone is free to contribute | |
365 | to it; with regret, we cannot actually acknowledge everyone here. The | |
366 | file @file{ChangeLog} in the @value{GDBN} distribution approximates a | |
c906108c SS |
367 | blow-by-blow account. |
368 | ||
369 | Changes much prior to version 2.0 are lost in the mists of time. | |
370 | ||
371 | @quotation | |
372 | @emph{Plea:} Additions to this section are particularly welcome. If you | |
373 | or your friends (or enemies, to be evenhanded) have been unfairly | |
374 | omitted from this list, we would like to add your names! | |
375 | @end quotation | |
376 | ||
377 | So that they may not regard their many labors as thankless, we | |
378 | particularly thank those who shepherded @value{GDBN} through major | |
379 | releases: | |
7ba3cf9c | 380 | Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0); |
c906108c SS |
381 | Jim Blandy (release 4.18); |
382 | Jason Molenda (release 4.17); | |
383 | Stan Shebs (release 4.14); | |
384 | Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); | |
385 | Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); | |
386 | John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); | |
387 | Jim Kingdon (releases 3.5, 3.4, and 3.3); | |
388 | and Randy Smith (releases 3.2, 3.1, and 3.0). | |
389 | ||
390 | Richard Stallman, assisted at various times by Peter TerMaat, Chris | |
391 | Hanson, and Richard Mlynarik, handled releases through 2.8. | |
392 | ||
b37052ae EZ |
393 | Michael Tiemann is the author of most of the @sc{gnu} C@t{++} support |
394 | in @value{GDBN}, with significant additional contributions from Per | |
395 | Bothner and Daniel Berlin. James Clark wrote the @sc{gnu} C@t{++} | |
396 | demangler. Early work on C@t{++} was by Peter TerMaat (who also did | |
397 | much general update work leading to release 3.0). | |
c906108c | 398 | |
b37052ae | 399 | @value{GDBN} uses the BFD subroutine library to examine multiple |
c906108c SS |
400 | object-file formats; BFD was a joint project of David V. |
401 | Henkel-Wallace, Rich Pixley, Steve Chamberlain, and John Gilmore. | |
402 | ||
403 | David Johnson wrote the original COFF support; Pace Willison did | |
404 | the original support for encapsulated COFF. | |
405 | ||
0179ffac | 406 | Brent Benson of Harris Computer Systems contributed DWARF 2 support. |
c906108c SS |
407 | |
408 | Adam de Boor and Bradley Davis contributed the ISI Optimum V support. | |
409 | Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS | |
410 | support. | |
411 | Jean-Daniel Fekete contributed Sun 386i support. | |
412 | Chris Hanson improved the HP9000 support. | |
413 | Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. | |
414 | David Johnson contributed Encore Umax support. | |
415 | Jyrki Kuoppala contributed Altos 3068 support. | |
416 | Jeff Law contributed HP PA and SOM support. | |
417 | Keith Packard contributed NS32K support. | |
418 | Doug Rabson contributed Acorn Risc Machine support. | |
419 | Bob Rusk contributed Harris Nighthawk CX-UX support. | |
420 | Chris Smith contributed Convex support (and Fortran debugging). | |
421 | Jonathan Stone contributed Pyramid support. | |
422 | Michael Tiemann contributed SPARC support. | |
423 | Tim Tucker contributed support for the Gould NP1 and Gould Powernode. | |
424 | Pace Willison contributed Intel 386 support. | |
425 | Jay Vosburgh contributed Symmetry support. | |
a37295f9 | 426 | Marko Mlinar contributed OpenRISC 1000 support. |
c906108c | 427 | |
1104b9e7 | 428 | Andreas Schwab contributed M68K @sc{gnu}/Linux support. |
c906108c SS |
429 | |
430 | Rich Schaefer and Peter Schauer helped with support of SunOS shared | |
431 | libraries. | |
432 | ||
433 | Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree | |
434 | about several machine instruction sets. | |
435 | ||
436 | Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop | |
437 | remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM | |
438 | contributed remote debugging modules for the i960, VxWorks, A29K UDI, | |
439 | and RDI targets, respectively. | |
440 | ||
441 | Brian Fox is the author of the readline libraries providing | |
442 | command-line editing and command history. | |
443 | ||
7a292a7a SS |
444 | Andrew Beers of SUNY Buffalo wrote the language-switching code, the |
445 | Modula-2 support, and contributed the Languages chapter of this manual. | |
c906108c | 446 | |
5d161b24 | 447 | Fred Fish wrote most of the support for Unix System Vr4. |
b37052ae | 448 | He also enhanced the command-completion support to cover C@t{++} overloaded |
c906108c | 449 | symbols. |
c906108c | 450 | |
f24c5e49 KI |
451 | Hitachi America (now Renesas America), Ltd. sponsored the support for |
452 | H8/300, H8/500, and Super-H processors. | |
c906108c SS |
453 | |
454 | NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors. | |
455 | ||
f24c5e49 KI |
456 | Mitsubishi (now Renesas) sponsored the support for D10V, D30V, and M32R/D |
457 | processors. | |
c906108c SS |
458 | |
459 | Toshiba sponsored the support for the TX39 Mips processor. | |
460 | ||
461 | Matsushita sponsored the support for the MN10200 and MN10300 processors. | |
462 | ||
96a2c332 | 463 | Fujitsu sponsored the support for SPARClite and FR30 processors. |
c906108c SS |
464 | |
465 | Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware | |
466 | watchpoints. | |
467 | ||
468 | Michael Snyder added support for tracepoints. | |
469 | ||
470 | Stu Grossman wrote gdbserver. | |
471 | ||
472 | Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made | |
96a2c332 | 473 | nearly innumerable bug fixes and cleanups throughout @value{GDBN}. |
c906108c SS |
474 | |
475 | The following people at the Hewlett-Packard Company contributed | |
476 | support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0 | |
b37052ae | 477 | (narrow mode), HP's implementation of kernel threads, HP's aC@t{++} |
d0d5df6f AC |
478 | compiler, and the Text User Interface (nee Terminal User Interface): |
479 | Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann, | |
480 | Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase | |
481 | provided HP-specific information in this manual. | |
c906108c | 482 | |
b37052ae EZ |
483 | DJ Delorie ported @value{GDBN} to MS-DOS, for the DJGPP project. |
484 | Robert Hoehne made significant contributions to the DJGPP port. | |
485 | ||
96a2c332 SS |
486 | Cygnus Solutions has sponsored @value{GDBN} maintenance and much of its |
487 | development since 1991. Cygnus engineers who have worked on @value{GDBN} | |
2df3850c JM |
488 | fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin |
489 | Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim | |
490 | Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler, | |
491 | Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek | |
492 | Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In | |
493 | addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton, | |
494 | JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug | |
495 | Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff | |
496 | Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner, | |
497 | Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin | |
498 | Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela | |
499 | Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David | |
500 | Zuhn have made contributions both large and small. | |
c906108c | 501 | |
ffed4509 AC |
502 | Andrew Cagney, Fernando Nasser, and Elena Zannoni, while working for |
503 | Cygnus Solutions, implemented the original @sc{gdb/mi} interface. | |
504 | ||
e2e0bcd1 JB |
505 | Jim Blandy added support for preprocessor macros, while working for Red |
506 | Hat. | |
c906108c | 507 | |
a9967aef AC |
508 | Andrew Cagney designed @value{GDBN}'s architecture vector. Many |
509 | people including Andrew Cagney, Stephane Carrez, Randolph Chung, Nick | |
510 | Duffek, Richard Henderson, Mark Kettenis, Grace Sainsbury, Kei | |
511 | Sakamoto, Yoshinori Sato, Michael Snyder, Andreas Schwab, Jason | |
512 | Thorpe, Corinna Vinschen, Ulrich Weigand, and Elena Zannoni, helped | |
513 | with the migration of old architectures to this new framework. | |
514 | ||
c5e30d01 AC |
515 | Andrew Cagney completely re-designed and re-implemented @value{GDBN}'s |
516 | unwinder framework, this consisting of a fresh new design featuring | |
517 | frame IDs, independent frame sniffers, and the sentinel frame. Mark | |
518 | Kettenis implemented the @sc{dwarf 2} unwinder, Jeff Johnston the | |
519 | libunwind unwinder, and Andrew Cagney the dummy, sentinel, tramp, and | |
db2e3e2e | 520 | trad unwinders. The architecture-specific changes, each involving a |
c5e30d01 AC |
521 | complete rewrite of the architecture's frame code, were carried out by |
522 | Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane | |
523 | Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel | |
524 | Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei | |
525 | Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich | |
526 | Weigand. | |
527 | ||
ca3bf3bd DJ |
528 | Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from |
529 | Tensilica, Inc.@: contributed support for Xtensa processors. Others | |
530 | who have worked on the Xtensa port of @value{GDBN} in the past include | |
531 | Steve Tjiang, John Newlin, and Scott Foehner. | |
532 | ||
08be9d71 ME |
533 | Michael Eager and staff of Xilinx, Inc., contributed support for the |
534 | Xilinx MicroBlaze architecture. | |
535 | ||
6d2ebf8b | 536 | @node Sample Session |
c906108c SS |
537 | @chapter A Sample @value{GDBN} Session |
538 | ||
539 | You can use this manual at your leisure to read all about @value{GDBN}. | |
540 | However, a handful of commands are enough to get started using the | |
541 | debugger. This chapter illustrates those commands. | |
542 | ||
543 | @iftex | |
544 | In this sample session, we emphasize user input like this: @b{input}, | |
545 | to make it easier to pick out from the surrounding output. | |
546 | @end iftex | |
547 | ||
548 | @c FIXME: this example may not be appropriate for some configs, where | |
549 | @c FIXME...primary interest is in remote use. | |
550 | ||
551 | One of the preliminary versions of @sc{gnu} @code{m4} (a generic macro | |
552 | processor) exhibits the following bug: sometimes, when we change its | |
553 | quote strings from the default, the commands used to capture one macro | |
554 | definition within another stop working. In the following short @code{m4} | |
555 | session, we define a macro @code{foo} which expands to @code{0000}; we | |
556 | then use the @code{m4} built-in @code{defn} to define @code{bar} as the | |
557 | same thing. However, when we change the open quote string to | |
558 | @code{<QUOTE>} and the close quote string to @code{<UNQUOTE>}, the same | |
559 | procedure fails to define a new synonym @code{baz}: | |
560 | ||
561 | @smallexample | |
562 | $ @b{cd gnu/m4} | |
563 | $ @b{./m4} | |
564 | @b{define(foo,0000)} | |
565 | ||
566 | @b{foo} | |
567 | 0000 | |
568 | @b{define(bar,defn(`foo'))} | |
569 | ||
570 | @b{bar} | |
571 | 0000 | |
572 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
573 | ||
574 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
575 | @b{baz} | |
c8aa23ab | 576 | @b{Ctrl-d} |
c906108c SS |
577 | m4: End of input: 0: fatal error: EOF in string |
578 | @end smallexample | |
579 | ||
580 | @noindent | |
581 | Let us use @value{GDBN} to try to see what is going on. | |
582 | ||
c906108c SS |
583 | @smallexample |
584 | $ @b{@value{GDBP} m4} | |
585 | @c FIXME: this falsifies the exact text played out, to permit smallbook | |
586 | @c FIXME... format to come out better. | |
587 | @value{GDBN} is free software and you are welcome to distribute copies | |
5d161b24 | 588 | of it under certain conditions; type "show copying" to see |
c906108c | 589 | the conditions. |
5d161b24 | 590 | There is absolutely no warranty for @value{GDBN}; type "show warranty" |
c906108c SS |
591 | for details. |
592 | ||
593 | @value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc... | |
594 | (@value{GDBP}) | |
595 | @end smallexample | |
c906108c SS |
596 | |
597 | @noindent | |
598 | @value{GDBN} reads only enough symbol data to know where to find the | |
599 | rest when needed; as a result, the first prompt comes up very quickly. | |
600 | We now tell @value{GDBN} to use a narrower display width than usual, so | |
601 | that examples fit in this manual. | |
602 | ||
603 | @smallexample | |
604 | (@value{GDBP}) @b{set width 70} | |
605 | @end smallexample | |
606 | ||
607 | @noindent | |
608 | We need to see how the @code{m4} built-in @code{changequote} works. | |
609 | Having looked at the source, we know the relevant subroutine is | |
610 | @code{m4_changequote}, so we set a breakpoint there with the @value{GDBN} | |
611 | @code{break} command. | |
612 | ||
613 | @smallexample | |
614 | (@value{GDBP}) @b{break m4_changequote} | |
615 | Breakpoint 1 at 0x62f4: file builtin.c, line 879. | |
616 | @end smallexample | |
617 | ||
618 | @noindent | |
619 | Using the @code{run} command, we start @code{m4} running under @value{GDBN} | |
620 | control; as long as control does not reach the @code{m4_changequote} | |
621 | subroutine, the program runs as usual: | |
622 | ||
623 | @smallexample | |
624 | (@value{GDBP}) @b{run} | |
625 | Starting program: /work/Editorial/gdb/gnu/m4/m4 | |
626 | @b{define(foo,0000)} | |
627 | ||
628 | @b{foo} | |
629 | 0000 | |
630 | @end smallexample | |
631 | ||
632 | @noindent | |
633 | To trigger the breakpoint, we call @code{changequote}. @value{GDBN} | |
634 | suspends execution of @code{m4}, displaying information about the | |
635 | context where it stops. | |
636 | ||
637 | @smallexample | |
638 | @b{changequote(<QUOTE>,<UNQUOTE>)} | |
639 | ||
5d161b24 | 640 | Breakpoint 1, m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
641 | at builtin.c:879 |
642 | 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3)) | |
643 | @end smallexample | |
644 | ||
645 | @noindent | |
646 | Now we use the command @code{n} (@code{next}) to advance execution to | |
647 | the next line of the current function. | |
648 | ||
649 | @smallexample | |
650 | (@value{GDBP}) @b{n} | |
651 | 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\ | |
652 | : nil, | |
653 | @end smallexample | |
654 | ||
655 | @noindent | |
656 | @code{set_quotes} looks like a promising subroutine. We can go into it | |
657 | by using the command @code{s} (@code{step}) instead of @code{next}. | |
658 | @code{step} goes to the next line to be executed in @emph{any} | |
659 | subroutine, so it steps into @code{set_quotes}. | |
660 | ||
661 | @smallexample | |
662 | (@value{GDBP}) @b{s} | |
663 | set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
664 | at input.c:530 | |
665 | 530 if (lquote != def_lquote) | |
666 | @end smallexample | |
667 | ||
668 | @noindent | |
669 | The display that shows the subroutine where @code{m4} is now | |
670 | suspended (and its arguments) is called a stack frame display. It | |
671 | shows a summary of the stack. We can use the @code{backtrace} | |
672 | command (which can also be spelled @code{bt}), to see where we are | |
673 | in the stack as a whole: the @code{backtrace} command displays a | |
674 | stack frame for each active subroutine. | |
675 | ||
676 | @smallexample | |
677 | (@value{GDBP}) @b{bt} | |
678 | #0 set_quotes (lq=0x34c78 "<QUOTE>", rq=0x34c88 "<UNQUOTE>") | |
679 | at input.c:530 | |
5d161b24 | 680 | #1 0x6344 in m4_changequote (argc=3, argv=0x33c70) |
c906108c SS |
681 | at builtin.c:882 |
682 | #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242 | |
683 | #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30) | |
684 | at macro.c:71 | |
685 | #4 0x79dc in expand_input () at macro.c:40 | |
686 | #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195 | |
687 | @end smallexample | |
688 | ||
689 | @noindent | |
690 | We step through a few more lines to see what happens. The first two | |
691 | times, we can use @samp{s}; the next two times we use @code{n} to avoid | |
692 | falling into the @code{xstrdup} subroutine. | |
693 | ||
694 | @smallexample | |
695 | (@value{GDBP}) @b{s} | |
696 | 0x3b5c 532 if (rquote != def_rquote) | |
697 | (@value{GDBP}) @b{s} | |
698 | 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \ | |
699 | def_lquote : xstrdup(lq); | |
700 | (@value{GDBP}) @b{n} | |
701 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
702 | : xstrdup(rq); | |
703 | (@value{GDBP}) @b{n} | |
704 | 538 len_lquote = strlen(rquote); | |
705 | @end smallexample | |
706 | ||
707 | @noindent | |
708 | The last line displayed looks a little odd; we can examine the variables | |
709 | @code{lquote} and @code{rquote} to see if they are in fact the new left | |
710 | and right quotes we specified. We use the command @code{p} | |
711 | (@code{print}) to see their values. | |
712 | ||
713 | @smallexample | |
714 | (@value{GDBP}) @b{p lquote} | |
715 | $1 = 0x35d40 "<QUOTE>" | |
716 | (@value{GDBP}) @b{p rquote} | |
717 | $2 = 0x35d50 "<UNQUOTE>" | |
718 | @end smallexample | |
719 | ||
720 | @noindent | |
721 | @code{lquote} and @code{rquote} are indeed the new left and right quotes. | |
722 | To look at some context, we can display ten lines of source | |
723 | surrounding the current line with the @code{l} (@code{list}) command. | |
724 | ||
725 | @smallexample | |
726 | (@value{GDBP}) @b{l} | |
727 | 533 xfree(rquote); | |
728 | 534 | |
729 | 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\ | |
730 | : xstrdup (lq); | |
731 | 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ | |
732 | : xstrdup (rq); | |
733 | 537 | |
734 | 538 len_lquote = strlen(rquote); | |
735 | 539 len_rquote = strlen(lquote); | |
736 | 540 @} | |
737 | 541 | |
738 | 542 void | |
739 | @end smallexample | |
740 | ||
741 | @noindent | |
742 | Let us step past the two lines that set @code{len_lquote} and | |
743 | @code{len_rquote}, and then examine the values of those variables. | |
744 | ||
745 | @smallexample | |
746 | (@value{GDBP}) @b{n} | |
747 | 539 len_rquote = strlen(lquote); | |
748 | (@value{GDBP}) @b{n} | |
749 | 540 @} | |
750 | (@value{GDBP}) @b{p len_lquote} | |
751 | $3 = 9 | |
752 | (@value{GDBP}) @b{p len_rquote} | |
753 | $4 = 7 | |
754 | @end smallexample | |
755 | ||
756 | @noindent | |
757 | That certainly looks wrong, assuming @code{len_lquote} and | |
758 | @code{len_rquote} are meant to be the lengths of @code{lquote} and | |
759 | @code{rquote} respectively. We can set them to better values using | |
760 | the @code{p} command, since it can print the value of | |
761 | any expression---and that expression can include subroutine calls and | |
762 | assignments. | |
763 | ||
764 | @smallexample | |
765 | (@value{GDBP}) @b{p len_lquote=strlen(lquote)} | |
766 | $5 = 7 | |
767 | (@value{GDBP}) @b{p len_rquote=strlen(rquote)} | |
768 | $6 = 9 | |
769 | @end smallexample | |
770 | ||
771 | @noindent | |
772 | Is that enough to fix the problem of using the new quotes with the | |
773 | @code{m4} built-in @code{defn}? We can allow @code{m4} to continue | |
774 | executing with the @code{c} (@code{continue}) command, and then try the | |
775 | example that caused trouble initially: | |
776 | ||
777 | @smallexample | |
778 | (@value{GDBP}) @b{c} | |
779 | Continuing. | |
780 | ||
781 | @b{define(baz,defn(<QUOTE>foo<UNQUOTE>))} | |
782 | ||
783 | baz | |
784 | 0000 | |
785 | @end smallexample | |
786 | ||
787 | @noindent | |
788 | Success! The new quotes now work just as well as the default ones. The | |
789 | problem seems to have been just the two typos defining the wrong | |
790 | lengths. We allow @code{m4} exit by giving it an EOF as input: | |
791 | ||
792 | @smallexample | |
c8aa23ab | 793 | @b{Ctrl-d} |
c906108c SS |
794 | Program exited normally. |
795 | @end smallexample | |
796 | ||
797 | @noindent | |
798 | The message @samp{Program exited normally.} is from @value{GDBN}; it | |
799 | indicates @code{m4} has finished executing. We can end our @value{GDBN} | |
800 | session with the @value{GDBN} @code{quit} command. | |
801 | ||
802 | @smallexample | |
803 | (@value{GDBP}) @b{quit} | |
804 | @end smallexample | |
c906108c | 805 | |
6d2ebf8b | 806 | @node Invocation |
c906108c SS |
807 | @chapter Getting In and Out of @value{GDBN} |
808 | ||
809 | This chapter discusses how to start @value{GDBN}, and how to get out of it. | |
5d161b24 | 810 | The essentials are: |
c906108c | 811 | @itemize @bullet |
5d161b24 | 812 | @item |
53a5351d | 813 | type @samp{@value{GDBP}} to start @value{GDBN}. |
5d161b24 | 814 | @item |
c8aa23ab | 815 | type @kbd{quit} or @kbd{Ctrl-d} to exit. |
c906108c SS |
816 | @end itemize |
817 | ||
818 | @menu | |
819 | * Invoking GDB:: How to start @value{GDBN} | |
820 | * Quitting GDB:: How to quit @value{GDBN} | |
821 | * Shell Commands:: How to use shell commands inside @value{GDBN} | |
79a6e687 | 822 | * Logging Output:: How to log @value{GDBN}'s output to a file |
c906108c SS |
823 | @end menu |
824 | ||
6d2ebf8b | 825 | @node Invoking GDB |
c906108c SS |
826 | @section Invoking @value{GDBN} |
827 | ||
c906108c SS |
828 | Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started, |
829 | @value{GDBN} reads commands from the terminal until you tell it to exit. | |
830 | ||
831 | You can also run @code{@value{GDBP}} with a variety of arguments and options, | |
832 | to specify more of your debugging environment at the outset. | |
833 | ||
c906108c SS |
834 | The command-line options described here are designed |
835 | to cover a variety of situations; in some environments, some of these | |
5d161b24 | 836 | options may effectively be unavailable. |
c906108c SS |
837 | |
838 | The most usual way to start @value{GDBN} is with one argument, | |
839 | specifying an executable program: | |
840 | ||
474c8240 | 841 | @smallexample |
c906108c | 842 | @value{GDBP} @var{program} |
474c8240 | 843 | @end smallexample |
c906108c | 844 | |
c906108c SS |
845 | @noindent |
846 | You can also start with both an executable program and a core file | |
847 | specified: | |
848 | ||
474c8240 | 849 | @smallexample |
c906108c | 850 | @value{GDBP} @var{program} @var{core} |
474c8240 | 851 | @end smallexample |
c906108c SS |
852 | |
853 | You can, instead, specify a process ID as a second argument, if you want | |
854 | to debug a running process: | |
855 | ||
474c8240 | 856 | @smallexample |
c906108c | 857 | @value{GDBP} @var{program} 1234 |
474c8240 | 858 | @end smallexample |
c906108c SS |
859 | |
860 | @noindent | |
861 | would attach @value{GDBN} to process @code{1234} (unless you also have a file | |
862 | named @file{1234}; @value{GDBN} does check for a core file first). | |
863 | ||
c906108c | 864 | Taking advantage of the second command-line argument requires a fairly |
2df3850c JM |
865 | complete operating system; when you use @value{GDBN} as a remote |
866 | debugger attached to a bare board, there may not be any notion of | |
867 | ``process'', and there is often no way to get a core dump. @value{GDBN} | |
868 | will warn you if it is unable to attach or to read core dumps. | |
c906108c | 869 | |
aa26fa3a TT |
870 | You can optionally have @code{@value{GDBP}} pass any arguments after the |
871 | executable file to the inferior using @code{--args}. This option stops | |
872 | option processing. | |
474c8240 | 873 | @smallexample |
3f94c067 | 874 | @value{GDBP} --args gcc -O2 -c foo.c |
474c8240 | 875 | @end smallexample |
aa26fa3a TT |
876 | This will cause @code{@value{GDBP}} to debug @code{gcc}, and to set |
877 | @code{gcc}'s command-line arguments (@pxref{Arguments}) to @samp{-O2 -c foo.c}. | |
878 | ||
96a2c332 | 879 | You can run @code{@value{GDBP}} without printing the front material, which describes |
c906108c SS |
880 | @value{GDBN}'s non-warranty, by specifying @code{-silent}: |
881 | ||
882 | @smallexample | |
883 | @value{GDBP} -silent | |
884 | @end smallexample | |
885 | ||
886 | @noindent | |
887 | You can further control how @value{GDBN} starts up by using command-line | |
888 | options. @value{GDBN} itself can remind you of the options available. | |
889 | ||
890 | @noindent | |
891 | Type | |
892 | ||
474c8240 | 893 | @smallexample |
c906108c | 894 | @value{GDBP} -help |
474c8240 | 895 | @end smallexample |
c906108c SS |
896 | |
897 | @noindent | |
898 | to display all available options and briefly describe their use | |
899 | (@samp{@value{GDBP} -h} is a shorter equivalent). | |
900 | ||
901 | All options and command line arguments you give are processed | |
902 | in sequential order. The order makes a difference when the | |
903 | @samp{-x} option is used. | |
904 | ||
905 | ||
906 | @menu | |
c906108c SS |
907 | * File Options:: Choosing files |
908 | * Mode Options:: Choosing modes | |
6fc08d32 | 909 | * Startup:: What @value{GDBN} does during startup |
c906108c SS |
910 | @end menu |
911 | ||
6d2ebf8b | 912 | @node File Options |
79a6e687 | 913 | @subsection Choosing Files |
c906108c | 914 | |
2df3850c | 915 | When @value{GDBN} starts, it reads any arguments other than options as |
c906108c SS |
916 | specifying an executable file and core file (or process ID). This is |
917 | the same as if the arguments were specified by the @samp{-se} and | |
d52fb0e9 | 918 | @samp{-c} (or @samp{-p}) options respectively. (@value{GDBN} reads the |
19837790 MS |
919 | first argument that does not have an associated option flag as |
920 | equivalent to the @samp{-se} option followed by that argument; and the | |
921 | second argument that does not have an associated option flag, if any, as | |
922 | equivalent to the @samp{-c}/@samp{-p} option followed by that argument.) | |
923 | If the second argument begins with a decimal digit, @value{GDBN} will | |
924 | first attempt to attach to it as a process, and if that fails, attempt | |
925 | to open it as a corefile. If you have a corefile whose name begins with | |
b383017d | 926 | a digit, you can prevent @value{GDBN} from treating it as a pid by |
c1468174 | 927 | prefixing it with @file{./}, e.g.@: @file{./12345}. |
7a292a7a SS |
928 | |
929 | If @value{GDBN} has not been configured to included core file support, | |
930 | such as for most embedded targets, then it will complain about a second | |
931 | argument and ignore it. | |
c906108c SS |
932 | |
933 | Many options have both long and short forms; both are shown in the | |
934 | following list. @value{GDBN} also recognizes the long forms if you truncate | |
935 | them, so long as enough of the option is present to be unambiguous. | |
936 | (If you prefer, you can flag option arguments with @samp{--} rather | |
937 | than @samp{-}, though we illustrate the more usual convention.) | |
938 | ||
d700128c EZ |
939 | @c NOTE: the @cindex entries here use double dashes ON PURPOSE. This |
940 | @c way, both those who look for -foo and --foo in the index, will find | |
941 | @c it. | |
942 | ||
c906108c SS |
943 | @table @code |
944 | @item -symbols @var{file} | |
945 | @itemx -s @var{file} | |
d700128c EZ |
946 | @cindex @code{--symbols} |
947 | @cindex @code{-s} | |
c906108c SS |
948 | Read symbol table from file @var{file}. |
949 | ||
950 | @item -exec @var{file} | |
951 | @itemx -e @var{file} | |
d700128c EZ |
952 | @cindex @code{--exec} |
953 | @cindex @code{-e} | |
7a292a7a SS |
954 | Use file @var{file} as the executable file to execute when appropriate, |
955 | and for examining pure data in conjunction with a core dump. | |
c906108c SS |
956 | |
957 | @item -se @var{file} | |
d700128c | 958 | @cindex @code{--se} |
c906108c SS |
959 | Read symbol table from file @var{file} and use it as the executable |
960 | file. | |
961 | ||
c906108c SS |
962 | @item -core @var{file} |
963 | @itemx -c @var{file} | |
d700128c EZ |
964 | @cindex @code{--core} |
965 | @cindex @code{-c} | |
b383017d | 966 | Use file @var{file} as a core dump to examine. |
c906108c | 967 | |
19837790 MS |
968 | @item -pid @var{number} |
969 | @itemx -p @var{number} | |
970 | @cindex @code{--pid} | |
971 | @cindex @code{-p} | |
972 | Connect to process ID @var{number}, as with the @code{attach} command. | |
c906108c SS |
973 | |
974 | @item -command @var{file} | |
975 | @itemx -x @var{file} | |
d700128c EZ |
976 | @cindex @code{--command} |
977 | @cindex @code{-x} | |
95433b34 JB |
978 | Execute commands from file @var{file}. The contents of this file is |
979 | evaluated exactly as the @code{source} command would. | |
8150ff9c | 980 | @xref{Command Files,, Command files}. |
c906108c | 981 | |
8a5a3c82 AS |
982 | @item -eval-command @var{command} |
983 | @itemx -ex @var{command} | |
984 | @cindex @code{--eval-command} | |
985 | @cindex @code{-ex} | |
986 | Execute a single @value{GDBN} command. | |
987 | ||
988 | This option may be used multiple times to call multiple commands. It may | |
989 | also be interleaved with @samp{-command} as required. | |
990 | ||
991 | @smallexample | |
992 | @value{GDBP} -ex 'target sim' -ex 'load' \ | |
993 | -x setbreakpoints -ex 'run' a.out | |
994 | @end smallexample | |
995 | ||
c906108c SS |
996 | @item -directory @var{directory} |
997 | @itemx -d @var{directory} | |
d700128c EZ |
998 | @cindex @code{--directory} |
999 | @cindex @code{-d} | |
4b505b12 | 1000 | Add @var{directory} to the path to search for source and script files. |
c906108c | 1001 | |
c906108c SS |
1002 | @item -r |
1003 | @itemx -readnow | |
d700128c EZ |
1004 | @cindex @code{--readnow} |
1005 | @cindex @code{-r} | |
c906108c SS |
1006 | Read each symbol file's entire symbol table immediately, rather than |
1007 | the default, which is to read it incrementally as it is needed. | |
1008 | This makes startup slower, but makes future operations faster. | |
53a5351d | 1009 | |
c906108c SS |
1010 | @end table |
1011 | ||
6d2ebf8b | 1012 | @node Mode Options |
79a6e687 | 1013 | @subsection Choosing Modes |
c906108c SS |
1014 | |
1015 | You can run @value{GDBN} in various alternative modes---for example, in | |
1016 | batch mode or quiet mode. | |
1017 | ||
1018 | @table @code | |
1019 | @item -nx | |
1020 | @itemx -n | |
d700128c EZ |
1021 | @cindex @code{--nx} |
1022 | @cindex @code{-n} | |
96565e91 | 1023 | Do not execute commands found in any initialization files. Normally, |
2df3850c JM |
1024 | @value{GDBN} executes the commands in these files after all the command |
1025 | options and arguments have been processed. @xref{Command Files,,Command | |
79a6e687 | 1026 | Files}. |
c906108c SS |
1027 | |
1028 | @item -quiet | |
d700128c | 1029 | @itemx -silent |
c906108c | 1030 | @itemx -q |
d700128c EZ |
1031 | @cindex @code{--quiet} |
1032 | @cindex @code{--silent} | |
1033 | @cindex @code{-q} | |
c906108c SS |
1034 | ``Quiet''. Do not print the introductory and copyright messages. These |
1035 | messages are also suppressed in batch mode. | |
1036 | ||
1037 | @item -batch | |
d700128c | 1038 | @cindex @code{--batch} |
c906108c SS |
1039 | Run in batch mode. Exit with status @code{0} after processing all the |
1040 | command files specified with @samp{-x} (and all commands from | |
1041 | initialization files, if not inhibited with @samp{-n}). Exit with | |
1042 | nonzero status if an error occurs in executing the @value{GDBN} commands | |
5da1313b JK |
1043 | in the command files. Batch mode also disables pagination, sets unlimited |
1044 | terminal width and height @pxref{Screen Size}, and acts as if @kbd{set confirm | |
1045 | off} were in effect (@pxref{Messages/Warnings}). | |
c906108c | 1046 | |
2df3850c JM |
1047 | Batch mode may be useful for running @value{GDBN} as a filter, for |
1048 | example to download and run a program on another computer; in order to | |
1049 | make this more useful, the message | |
c906108c | 1050 | |
474c8240 | 1051 | @smallexample |
c906108c | 1052 | Program exited normally. |
474c8240 | 1053 | @end smallexample |
c906108c SS |
1054 | |
1055 | @noindent | |
2df3850c JM |
1056 | (which is ordinarily issued whenever a program running under |
1057 | @value{GDBN} control terminates) is not issued when running in batch | |
1058 | mode. | |
1059 | ||
1a088d06 AS |
1060 | @item -batch-silent |
1061 | @cindex @code{--batch-silent} | |
1062 | Run in batch mode exactly like @samp{-batch}, but totally silently. All | |
1063 | @value{GDBN} output to @code{stdout} is prevented (@code{stderr} is | |
1064 | unaffected). This is much quieter than @samp{-silent} and would be useless | |
1065 | for an interactive session. | |
1066 | ||
1067 | This is particularly useful when using targets that give @samp{Loading section} | |
1068 | messages, for example. | |
1069 | ||
1070 | Note that targets that give their output via @value{GDBN}, as opposed to | |
1071 | writing directly to @code{stdout}, will also be made silent. | |
1072 | ||
4b0ad762 AS |
1073 | @item -return-child-result |
1074 | @cindex @code{--return-child-result} | |
1075 | The return code from @value{GDBN} will be the return code from the child | |
1076 | process (the process being debugged), with the following exceptions: | |
1077 | ||
1078 | @itemize @bullet | |
1079 | @item | |
1080 | @value{GDBN} exits abnormally. E.g., due to an incorrect argument or an | |
1081 | internal error. In this case the exit code is the same as it would have been | |
1082 | without @samp{-return-child-result}. | |
1083 | @item | |
1084 | The user quits with an explicit value. E.g., @samp{quit 1}. | |
1085 | @item | |
1086 | The child process never runs, or is not allowed to terminate, in which case | |
1087 | the exit code will be -1. | |
1088 | @end itemize | |
1089 | ||
1090 | This option is useful in conjunction with @samp{-batch} or @samp{-batch-silent}, | |
1091 | when @value{GDBN} is being used as a remote program loader or simulator | |
1092 | interface. | |
1093 | ||
2df3850c JM |
1094 | @item -nowindows |
1095 | @itemx -nw | |
d700128c EZ |
1096 | @cindex @code{--nowindows} |
1097 | @cindex @code{-nw} | |
2df3850c | 1098 | ``No windows''. If @value{GDBN} comes with a graphical user interface |
96a2c332 | 1099 | (GUI) built in, then this option tells @value{GDBN} to only use the command-line |
2df3850c JM |
1100 | interface. If no GUI is available, this option has no effect. |
1101 | ||
1102 | @item -windows | |
1103 | @itemx -w | |
d700128c EZ |
1104 | @cindex @code{--windows} |
1105 | @cindex @code{-w} | |
2df3850c JM |
1106 | If @value{GDBN} includes a GUI, then this option requires it to be |
1107 | used if possible. | |
c906108c SS |
1108 | |
1109 | @item -cd @var{directory} | |
d700128c | 1110 | @cindex @code{--cd} |
c906108c SS |
1111 | Run @value{GDBN} using @var{directory} as its working directory, |
1112 | instead of the current directory. | |
1113 | ||
aae1c79a DE |
1114 | @item -data-directory @var{directory} |
1115 | @cindex @code{--data-directory} | |
1116 | Run @value{GDBN} using @var{directory} as its data directory. | |
1117 | The data directory is where @value{GDBN} searches for its | |
1118 | auxiliary files. @xref{Data Files}. | |
1119 | ||
c906108c SS |
1120 | @item -fullname |
1121 | @itemx -f | |
d700128c EZ |
1122 | @cindex @code{--fullname} |
1123 | @cindex @code{-f} | |
7a292a7a SS |
1124 | @sc{gnu} Emacs sets this option when it runs @value{GDBN} as a |
1125 | subprocess. It tells @value{GDBN} to output the full file name and line | |
1126 | number in a standard, recognizable fashion each time a stack frame is | |
1127 | displayed (which includes each time your program stops). This | |
1128 | recognizable format looks like two @samp{\032} characters, followed by | |
1129 | the file name, line number and character position separated by colons, | |
1130 | and a newline. The Emacs-to-@value{GDBN} interface program uses the two | |
1131 | @samp{\032} characters as a signal to display the source code for the | |
1132 | frame. | |
c906108c | 1133 | |
d700128c EZ |
1134 | @item -epoch |
1135 | @cindex @code{--epoch} | |
1136 | The Epoch Emacs-@value{GDBN} interface sets this option when it runs | |
1137 | @value{GDBN} as a subprocess. It tells @value{GDBN} to modify its print | |
1138 | routines so as to allow Epoch to display values of expressions in a | |
1139 | separate window. | |
1140 | ||
1141 | @item -annotate @var{level} | |
1142 | @cindex @code{--annotate} | |
1143 | This option sets the @dfn{annotation level} inside @value{GDBN}. Its | |
1144 | effect is identical to using @samp{set annotate @var{level}} | |
086432e2 AC |
1145 | (@pxref{Annotations}). The annotation @var{level} controls how much |
1146 | information @value{GDBN} prints together with its prompt, values of | |
1147 | expressions, source lines, and other types of output. Level 0 is the | |
1148 | normal, level 1 is for use when @value{GDBN} is run as a subprocess of | |
1149 | @sc{gnu} Emacs, level 3 is the maximum annotation suitable for programs | |
1150 | that control @value{GDBN}, and level 2 has been deprecated. | |
1151 | ||
265eeb58 | 1152 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 | 1153 | (@pxref{GDB/MI}). |
d700128c | 1154 | |
aa26fa3a TT |
1155 | @item --args |
1156 | @cindex @code{--args} | |
1157 | Change interpretation of command line so that arguments following the | |
1158 | executable file are passed as command line arguments to the inferior. | |
1159 | This option stops option processing. | |
1160 | ||
2df3850c JM |
1161 | @item -baud @var{bps} |
1162 | @itemx -b @var{bps} | |
d700128c EZ |
1163 | @cindex @code{--baud} |
1164 | @cindex @code{-b} | |
c906108c SS |
1165 | Set the line speed (baud rate or bits per second) of any serial |
1166 | interface used by @value{GDBN} for remote debugging. | |
c906108c | 1167 | |
f47b1503 AS |
1168 | @item -l @var{timeout} |
1169 | @cindex @code{-l} | |
1170 | Set the timeout (in seconds) of any communication used by @value{GDBN} | |
1171 | for remote debugging. | |
1172 | ||
c906108c | 1173 | @item -tty @var{device} |
d700128c EZ |
1174 | @itemx -t @var{device} |
1175 | @cindex @code{--tty} | |
1176 | @cindex @code{-t} | |
c906108c SS |
1177 | Run using @var{device} for your program's standard input and output. |
1178 | @c FIXME: kingdon thinks there is more to -tty. Investigate. | |
c906108c | 1179 | |
53a5351d | 1180 | @c resolve the situation of these eventually |
c4555f82 SC |
1181 | @item -tui |
1182 | @cindex @code{--tui} | |
d0d5df6f AC |
1183 | Activate the @dfn{Text User Interface} when starting. The Text User |
1184 | Interface manages several text windows on the terminal, showing | |
1185 | source, assembly, registers and @value{GDBN} command outputs | |
1186 | (@pxref{TUI, ,@value{GDBN} Text User Interface}). Alternatively, the | |
1187 | Text User Interface can be enabled by invoking the program | |
46ba6afa | 1188 | @samp{@value{GDBTUI}}. Do not use this option if you run @value{GDBN} from |
d0d5df6f | 1189 | Emacs (@pxref{Emacs, ,Using @value{GDBN} under @sc{gnu} Emacs}). |
53a5351d JM |
1190 | |
1191 | @c @item -xdb | |
d700128c | 1192 | @c @cindex @code{--xdb} |
53a5351d JM |
1193 | @c Run in XDB compatibility mode, allowing the use of certain XDB commands. |
1194 | @c For information, see the file @file{xdb_trans.html}, which is usually | |
1195 | @c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX | |
1196 | @c systems. | |
1197 | ||
d700128c EZ |
1198 | @item -interpreter @var{interp} |
1199 | @cindex @code{--interpreter} | |
1200 | Use the interpreter @var{interp} for interface with the controlling | |
1201 | program or device. This option is meant to be set by programs which | |
94bbb2c0 | 1202 | communicate with @value{GDBN} using it as a back end. |
21c294e6 | 1203 | @xref{Interpreters, , Command Interpreters}. |
94bbb2c0 | 1204 | |
da0f9dcd | 1205 | @samp{--interpreter=mi} (or @samp{--interpreter=mi2}) causes |
2fcf52f0 | 1206 | @value{GDBN} to use the @dfn{@sc{gdb/mi} interface} (@pxref{GDB/MI, , |
6b5e8c01 | 1207 | The @sc{gdb/mi} Interface}) included since @value{GDBN} version 6.0. The |
6c74ac8b AC |
1208 | previous @sc{gdb/mi} interface, included in @value{GDBN} version 5.3 and |
1209 | selected with @samp{--interpreter=mi1}, is deprecated. Earlier | |
1210 | @sc{gdb/mi} interfaces are no longer supported. | |
d700128c EZ |
1211 | |
1212 | @item -write | |
1213 | @cindex @code{--write} | |
1214 | Open the executable and core files for both reading and writing. This | |
1215 | is equivalent to the @samp{set write on} command inside @value{GDBN} | |
1216 | (@pxref{Patching}). | |
1217 | ||
1218 | @item -statistics | |
1219 | @cindex @code{--statistics} | |
1220 | This option causes @value{GDBN} to print statistics about time and | |
1221 | memory usage after it completes each command and returns to the prompt. | |
1222 | ||
1223 | @item -version | |
1224 | @cindex @code{--version} | |
1225 | This option causes @value{GDBN} to print its version number and | |
1226 | no-warranty blurb, and exit. | |
1227 | ||
c906108c SS |
1228 | @end table |
1229 | ||
6fc08d32 | 1230 | @node Startup |
79a6e687 | 1231 | @subsection What @value{GDBN} Does During Startup |
6fc08d32 EZ |
1232 | @cindex @value{GDBN} startup |
1233 | ||
1234 | Here's the description of what @value{GDBN} does during session startup: | |
1235 | ||
1236 | @enumerate | |
1237 | @item | |
1238 | Sets up the command interpreter as specified by the command line | |
1239 | (@pxref{Mode Options, interpreter}). | |
1240 | ||
1241 | @item | |
1242 | @cindex init file | |
098b41a6 JG |
1243 | Reads the system-wide @dfn{init file} (if @option{--with-system-gdbinit} was |
1244 | used when building @value{GDBN}; @pxref{System-wide configuration, | |
1245 | ,System-wide configuration and settings}) and executes all the commands in | |
1246 | that file. | |
1247 | ||
1248 | @item | |
1249 | Reads the init file (if any) in your home directory@footnote{On | |
6fc08d32 EZ |
1250 | DOS/Windows systems, the home directory is the one pointed to by the |
1251 | @code{HOME} environment variable.} and executes all the commands in | |
1252 | that file. | |
1253 | ||
1254 | @item | |
1255 | Processes command line options and operands. | |
1256 | ||
1257 | @item | |
1258 | Reads and executes the commands from init file (if any) in the current | |
119b882a EZ |
1259 | working directory. This is only done if the current directory is |
1260 | different from your home directory. Thus, you can have more than one | |
1261 | init file, one generic in your home directory, and another, specific | |
1262 | to the program you are debugging, in the directory where you invoke | |
6fc08d32 EZ |
1263 | @value{GDBN}. |
1264 | ||
a86caf66 DE |
1265 | @item |
1266 | If the command line specified a program to debug, or a process to | |
1267 | attach to, or a core file, @value{GDBN} loads any auto-loaded | |
1268 | scripts provided for the program or for its loaded shared libraries. | |
1269 | @xref{Auto-loading}. | |
1270 | ||
1271 | If you wish to disable the auto-loading during startup, | |
1272 | you must do something like the following: | |
1273 | ||
1274 | @smallexample | |
1275 | $ gdb -ex "set auto-load-scripts off" -ex "file myprogram" | |
1276 | @end smallexample | |
1277 | ||
1278 | The following does not work because the auto-loading is turned off too late: | |
1279 | ||
1280 | @smallexample | |
1281 | $ gdb -ex "set auto-load-scripts off" myprogram | |
1282 | @end smallexample | |
1283 | ||
6fc08d32 EZ |
1284 | @item |
1285 | Reads command files specified by the @samp{-x} option. @xref{Command | |
1286 | Files}, for more details about @value{GDBN} command files. | |
1287 | ||
1288 | @item | |
1289 | Reads the command history recorded in the @dfn{history file}. | |
d620b259 | 1290 | @xref{Command History}, for more details about the command history and the |
6fc08d32 EZ |
1291 | files where @value{GDBN} records it. |
1292 | @end enumerate | |
1293 | ||
1294 | Init files use the same syntax as @dfn{command files} (@pxref{Command | |
1295 | Files}) and are processed by @value{GDBN} in the same way. The init | |
1296 | file in your home directory can set options (such as @samp{set | |
1297 | complaints}) that affect subsequent processing of command line options | |
1298 | and operands. Init files are not executed if you use the @samp{-nx} | |
79a6e687 | 1299 | option (@pxref{Mode Options, ,Choosing Modes}). |
6fc08d32 | 1300 | |
098b41a6 JG |
1301 | To display the list of init files loaded by gdb at startup, you |
1302 | can use @kbd{gdb --help}. | |
1303 | ||
6fc08d32 EZ |
1304 | @cindex init file name |
1305 | @cindex @file{.gdbinit} | |
119b882a | 1306 | @cindex @file{gdb.ini} |
8807d78b | 1307 | The @value{GDBN} init files are normally called @file{.gdbinit}. |
119b882a EZ |
1308 | The DJGPP port of @value{GDBN} uses the name @file{gdb.ini}, due to |
1309 | the limitations of file names imposed by DOS filesystems. The Windows | |
1310 | ports of @value{GDBN} use the standard name, but if they find a | |
1311 | @file{gdb.ini} file, they warn you about that and suggest to rename | |
1312 | the file to the standard name. | |
1313 | ||
6fc08d32 | 1314 | |
6d2ebf8b | 1315 | @node Quitting GDB |
c906108c SS |
1316 | @section Quitting @value{GDBN} |
1317 | @cindex exiting @value{GDBN} | |
1318 | @cindex leaving @value{GDBN} | |
1319 | ||
1320 | @table @code | |
1321 | @kindex quit @r{[}@var{expression}@r{]} | |
41afff9a | 1322 | @kindex q @r{(@code{quit})} |
96a2c332 SS |
1323 | @item quit @r{[}@var{expression}@r{]} |
1324 | @itemx q | |
1325 | To exit @value{GDBN}, use the @code{quit} command (abbreviated | |
c8aa23ab | 1326 | @code{q}), or type an end-of-file character (usually @kbd{Ctrl-d}). If you |
96a2c332 SS |
1327 | do not supply @var{expression}, @value{GDBN} will terminate normally; |
1328 | otherwise it will terminate using the result of @var{expression} as the | |
1329 | error code. | |
c906108c SS |
1330 | @end table |
1331 | ||
1332 | @cindex interrupt | |
c8aa23ab | 1333 | An interrupt (often @kbd{Ctrl-c}) does not exit from @value{GDBN}, but rather |
c906108c SS |
1334 | terminates the action of any @value{GDBN} command that is in progress and |
1335 | returns to @value{GDBN} command level. It is safe to type the interrupt | |
1336 | character at any time because @value{GDBN} does not allow it to take effect | |
1337 | until a time when it is safe. | |
1338 | ||
c906108c SS |
1339 | If you have been using @value{GDBN} to control an attached process or |
1340 | device, you can release it with the @code{detach} command | |
79a6e687 | 1341 | (@pxref{Attach, ,Debugging an Already-running Process}). |
c906108c | 1342 | |
6d2ebf8b | 1343 | @node Shell Commands |
79a6e687 | 1344 | @section Shell Commands |
c906108c SS |
1345 | |
1346 | If you need to execute occasional shell commands during your | |
1347 | debugging session, there is no need to leave or suspend @value{GDBN}; you can | |
1348 | just use the @code{shell} command. | |
1349 | ||
1350 | @table @code | |
1351 | @kindex shell | |
1352 | @cindex shell escape | |
1353 | @item shell @var{command string} | |
1354 | Invoke a standard shell to execute @var{command string}. | |
c906108c | 1355 | If it exists, the environment variable @code{SHELL} determines which |
d4f3574e SS |
1356 | shell to run. Otherwise @value{GDBN} uses the default shell |
1357 | (@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.). | |
c906108c SS |
1358 | @end table |
1359 | ||
1360 | The utility @code{make} is often needed in development environments. | |
1361 | You do not have to use the @code{shell} command for this purpose in | |
1362 | @value{GDBN}: | |
1363 | ||
1364 | @table @code | |
1365 | @kindex make | |
1366 | @cindex calling make | |
1367 | @item make @var{make-args} | |
1368 | Execute the @code{make} program with the specified | |
1369 | arguments. This is equivalent to @samp{shell make @var{make-args}}. | |
1370 | @end table | |
1371 | ||
79a6e687 BW |
1372 | @node Logging Output |
1373 | @section Logging Output | |
0fac0b41 | 1374 | @cindex logging @value{GDBN} output |
9c16f35a | 1375 | @cindex save @value{GDBN} output to a file |
0fac0b41 DJ |
1376 | |
1377 | You may want to save the output of @value{GDBN} commands to a file. | |
1378 | There are several commands to control @value{GDBN}'s logging. | |
1379 | ||
1380 | @table @code | |
1381 | @kindex set logging | |
1382 | @item set logging on | |
1383 | Enable logging. | |
1384 | @item set logging off | |
1385 | Disable logging. | |
9c16f35a | 1386 | @cindex logging file name |
0fac0b41 DJ |
1387 | @item set logging file @var{file} |
1388 | Change the name of the current logfile. The default logfile is @file{gdb.txt}. | |
1389 | @item set logging overwrite [on|off] | |
1390 | By default, @value{GDBN} will append to the logfile. Set @code{overwrite} if | |
1391 | you want @code{set logging on} to overwrite the logfile instead. | |
1392 | @item set logging redirect [on|off] | |
1393 | By default, @value{GDBN} output will go to both the terminal and the logfile. | |
1394 | Set @code{redirect} if you want output to go only to the log file. | |
1395 | @kindex show logging | |
1396 | @item show logging | |
1397 | Show the current values of the logging settings. | |
1398 | @end table | |
1399 | ||
6d2ebf8b | 1400 | @node Commands |
c906108c SS |
1401 | @chapter @value{GDBN} Commands |
1402 | ||
1403 | You can abbreviate a @value{GDBN} command to the first few letters of the command | |
1404 | name, if that abbreviation is unambiguous; and you can repeat certain | |
1405 | @value{GDBN} commands by typing just @key{RET}. You can also use the @key{TAB} | |
1406 | key to get @value{GDBN} to fill out the rest of a word in a command (or to | |
1407 | show you the alternatives available, if there is more than one possibility). | |
1408 | ||
1409 | @menu | |
1410 | * Command Syntax:: How to give commands to @value{GDBN} | |
1411 | * Completion:: Command completion | |
1412 | * Help:: How to ask @value{GDBN} for help | |
1413 | @end menu | |
1414 | ||
6d2ebf8b | 1415 | @node Command Syntax |
79a6e687 | 1416 | @section Command Syntax |
c906108c SS |
1417 | |
1418 | A @value{GDBN} command is a single line of input. There is no limit on | |
1419 | how long it can be. It starts with a command name, which is followed by | |
1420 | arguments whose meaning depends on the command name. For example, the | |
1421 | command @code{step} accepts an argument which is the number of times to | |
1422 | step, as in @samp{step 5}. You can also use the @code{step} command | |
96a2c332 | 1423 | with no arguments. Some commands do not allow any arguments. |
c906108c SS |
1424 | |
1425 | @cindex abbreviation | |
1426 | @value{GDBN} command names may always be truncated if that abbreviation is | |
1427 | unambiguous. Other possible command abbreviations are listed in the | |
1428 | documentation for individual commands. In some cases, even ambiguous | |
1429 | abbreviations are allowed; for example, @code{s} is specially defined as | |
1430 | equivalent to @code{step} even though there are other commands whose | |
1431 | names start with @code{s}. You can test abbreviations by using them as | |
1432 | arguments to the @code{help} command. | |
1433 | ||
1434 | @cindex repeating commands | |
41afff9a | 1435 | @kindex RET @r{(repeat last command)} |
c906108c | 1436 | A blank line as input to @value{GDBN} (typing just @key{RET}) means to |
96a2c332 | 1437 | repeat the previous command. Certain commands (for example, @code{run}) |
c906108c SS |
1438 | will not repeat this way; these are commands whose unintentional |
1439 | repetition might cause trouble and which you are unlikely to want to | |
c45da7e6 EZ |
1440 | repeat. User-defined commands can disable this feature; see |
1441 | @ref{Define, dont-repeat}. | |
c906108c SS |
1442 | |
1443 | The @code{list} and @code{x} commands, when you repeat them with | |
1444 | @key{RET}, construct new arguments rather than repeating | |
1445 | exactly as typed. This permits easy scanning of source or memory. | |
1446 | ||
1447 | @value{GDBN} can also use @key{RET} in another way: to partition lengthy | |
1448 | output, in a way similar to the common utility @code{more} | |
79a6e687 | 1449 | (@pxref{Screen Size,,Screen Size}). Since it is easy to press one |
c906108c SS |
1450 | @key{RET} too many in this situation, @value{GDBN} disables command |
1451 | repetition after any command that generates this sort of display. | |
1452 | ||
41afff9a | 1453 | @kindex # @r{(a comment)} |
c906108c SS |
1454 | @cindex comment |
1455 | Any text from a @kbd{#} to the end of the line is a comment; it does | |
1456 | nothing. This is useful mainly in command files (@pxref{Command | |
79a6e687 | 1457 | Files,,Command Files}). |
c906108c | 1458 | |
88118b3a | 1459 | @cindex repeating command sequences |
c8aa23ab EZ |
1460 | @kindex Ctrl-o @r{(operate-and-get-next)} |
1461 | The @kbd{Ctrl-o} binding is useful for repeating a complex sequence of | |
7f9087cb | 1462 | commands. This command accepts the current line, like @key{RET}, and |
88118b3a TT |
1463 | then fetches the next line relative to the current line from the history |
1464 | for editing. | |
1465 | ||
6d2ebf8b | 1466 | @node Completion |
79a6e687 | 1467 | @section Command Completion |
c906108c SS |
1468 | |
1469 | @cindex completion | |
1470 | @cindex word completion | |
1471 | @value{GDBN} can fill in the rest of a word in a command for you, if there is | |
1472 | only one possibility; it can also show you what the valid possibilities | |
1473 | are for the next word in a command, at any time. This works for @value{GDBN} | |
1474 | commands, @value{GDBN} subcommands, and the names of symbols in your program. | |
1475 | ||
1476 | Press the @key{TAB} key whenever you want @value{GDBN} to fill out the rest | |
1477 | of a word. If there is only one possibility, @value{GDBN} fills in the | |
1478 | word, and waits for you to finish the command (or press @key{RET} to | |
1479 | enter it). For example, if you type | |
1480 | ||
1481 | @c FIXME "@key" does not distinguish its argument sufficiently to permit | |
1482 | @c complete accuracy in these examples; space introduced for clarity. | |
1483 | @c If texinfo enhancements make it unnecessary, it would be nice to | |
1484 | @c replace " @key" by "@key" in the following... | |
474c8240 | 1485 | @smallexample |
c906108c | 1486 | (@value{GDBP}) info bre @key{TAB} |
474c8240 | 1487 | @end smallexample |
c906108c SS |
1488 | |
1489 | @noindent | |
1490 | @value{GDBN} fills in the rest of the word @samp{breakpoints}, since that is | |
1491 | the only @code{info} subcommand beginning with @samp{bre}: | |
1492 | ||
474c8240 | 1493 | @smallexample |
c906108c | 1494 | (@value{GDBP}) info breakpoints |
474c8240 | 1495 | @end smallexample |
c906108c SS |
1496 | |
1497 | @noindent | |
1498 | You can either press @key{RET} at this point, to run the @code{info | |
1499 | breakpoints} command, or backspace and enter something else, if | |
1500 | @samp{breakpoints} does not look like the command you expected. (If you | |
1501 | were sure you wanted @code{info breakpoints} in the first place, you | |
1502 | might as well just type @key{RET} immediately after @samp{info bre}, | |
1503 | to exploit command abbreviations rather than command completion). | |
1504 | ||
1505 | If there is more than one possibility for the next word when you press | |
1506 | @key{TAB}, @value{GDBN} sounds a bell. You can either supply more | |
1507 | characters and try again, or just press @key{TAB} a second time; | |
1508 | @value{GDBN} displays all the possible completions for that word. For | |
1509 | example, you might want to set a breakpoint on a subroutine whose name | |
1510 | begins with @samp{make_}, but when you type @kbd{b make_@key{TAB}} @value{GDBN} | |
1511 | just sounds the bell. Typing @key{TAB} again displays all the | |
1512 | function names in your program that begin with those characters, for | |
1513 | example: | |
1514 | ||
474c8240 | 1515 | @smallexample |
c906108c SS |
1516 | (@value{GDBP}) b make_ @key{TAB} |
1517 | @exdent @value{GDBN} sounds bell; press @key{TAB} again, to see: | |
5d161b24 DB |
1518 | make_a_section_from_file make_environ |
1519 | make_abs_section make_function_type | |
1520 | make_blockvector make_pointer_type | |
1521 | make_cleanup make_reference_type | |
c906108c SS |
1522 | make_command make_symbol_completion_list |
1523 | (@value{GDBP}) b make_ | |
474c8240 | 1524 | @end smallexample |
c906108c SS |
1525 | |
1526 | @noindent | |
1527 | After displaying the available possibilities, @value{GDBN} copies your | |
1528 | partial input (@samp{b make_} in the example) so you can finish the | |
1529 | command. | |
1530 | ||
1531 | If you just want to see the list of alternatives in the first place, you | |
b37052ae | 1532 | can press @kbd{M-?} rather than pressing @key{TAB} twice. @kbd{M-?} |
7a292a7a | 1533 | means @kbd{@key{META} ?}. You can type this either by holding down a |
c906108c | 1534 | key designated as the @key{META} shift on your keyboard (if there is |
7a292a7a | 1535 | one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}. |
c906108c SS |
1536 | |
1537 | @cindex quotes in commands | |
1538 | @cindex completion of quoted strings | |
1539 | Sometimes the string you need, while logically a ``word'', may contain | |
7a292a7a SS |
1540 | parentheses or other characters that @value{GDBN} normally excludes from |
1541 | its notion of a word. To permit word completion to work in this | |
1542 | situation, you may enclose words in @code{'} (single quote marks) in | |
1543 | @value{GDBN} commands. | |
c906108c | 1544 | |
c906108c | 1545 | The most likely situation where you might need this is in typing the |
b37052ae EZ |
1546 | name of a C@t{++} function. This is because C@t{++} allows function |
1547 | overloading (multiple definitions of the same function, distinguished | |
1548 | by argument type). For example, when you want to set a breakpoint you | |
1549 | may need to distinguish whether you mean the version of @code{name} | |
1550 | that takes an @code{int} parameter, @code{name(int)}, or the version | |
1551 | that takes a @code{float} parameter, @code{name(float)}. To use the | |
1552 | word-completion facilities in this situation, type a single quote | |
1553 | @code{'} at the beginning of the function name. This alerts | |
1554 | @value{GDBN} that it may need to consider more information than usual | |
1555 | when you press @key{TAB} or @kbd{M-?} to request word completion: | |
c906108c | 1556 | |
474c8240 | 1557 | @smallexample |
96a2c332 | 1558 | (@value{GDBP}) b 'bubble( @kbd{M-?} |
c906108c SS |
1559 | bubble(double,double) bubble(int,int) |
1560 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1561 | @end smallexample |
c906108c SS |
1562 | |
1563 | In some cases, @value{GDBN} can tell that completing a name requires using | |
1564 | quotes. When this happens, @value{GDBN} inserts the quote for you (while | |
1565 | completing as much as it can) if you do not type the quote in the first | |
1566 | place: | |
1567 | ||
474c8240 | 1568 | @smallexample |
c906108c SS |
1569 | (@value{GDBP}) b bub @key{TAB} |
1570 | @exdent @value{GDBN} alters your input line to the following, and rings a bell: | |
1571 | (@value{GDBP}) b 'bubble( | |
474c8240 | 1572 | @end smallexample |
c906108c SS |
1573 | |
1574 | @noindent | |
1575 | In general, @value{GDBN} can tell that a quote is needed (and inserts it) if | |
1576 | you have not yet started typing the argument list when you ask for | |
1577 | completion on an overloaded symbol. | |
1578 | ||
79a6e687 BW |
1579 | For more information about overloaded functions, see @ref{C Plus Plus |
1580 | Expressions, ,C@t{++} Expressions}. You can use the command @code{set | |
c906108c | 1581 | overload-resolution off} to disable overload resolution; |
79a6e687 | 1582 | see @ref{Debugging C Plus Plus, ,@value{GDBN} Features for C@t{++}}. |
c906108c | 1583 | |
65d12d83 TT |
1584 | @cindex completion of structure field names |
1585 | @cindex structure field name completion | |
1586 | @cindex completion of union field names | |
1587 | @cindex union field name completion | |
1588 | When completing in an expression which looks up a field in a | |
1589 | structure, @value{GDBN} also tries@footnote{The completer can be | |
1590 | confused by certain kinds of invalid expressions. Also, it only | |
1591 | examines the static type of the expression, not the dynamic type.} to | |
1592 | limit completions to the field names available in the type of the | |
1593 | left-hand-side: | |
1594 | ||
1595 | @smallexample | |
1596 | (@value{GDBP}) p gdb_stdout.@kbd{M-?} | |
1597 | magic to_delete to_fputs to_put to_rewind | |
1598 | to_data to_flush to_isatty to_read to_write | |
1599 | @end smallexample | |
1600 | ||
1601 | @noindent | |
1602 | This is because the @code{gdb_stdout} is a variable of the type | |
1603 | @code{struct ui_file} that is defined in @value{GDBN} sources as | |
1604 | follows: | |
1605 | ||
1606 | @smallexample | |
1607 | struct ui_file | |
1608 | @{ | |
1609 | int *magic; | |
1610 | ui_file_flush_ftype *to_flush; | |
1611 | ui_file_write_ftype *to_write; | |
1612 | ui_file_fputs_ftype *to_fputs; | |
1613 | ui_file_read_ftype *to_read; | |
1614 | ui_file_delete_ftype *to_delete; | |
1615 | ui_file_isatty_ftype *to_isatty; | |
1616 | ui_file_rewind_ftype *to_rewind; | |
1617 | ui_file_put_ftype *to_put; | |
1618 | void *to_data; | |
1619 | @} | |
1620 | @end smallexample | |
1621 | ||
c906108c | 1622 | |
6d2ebf8b | 1623 | @node Help |
79a6e687 | 1624 | @section Getting Help |
c906108c SS |
1625 | @cindex online documentation |
1626 | @kindex help | |
1627 | ||
5d161b24 | 1628 | You can always ask @value{GDBN} itself for information on its commands, |
c906108c SS |
1629 | using the command @code{help}. |
1630 | ||
1631 | @table @code | |
41afff9a | 1632 | @kindex h @r{(@code{help})} |
c906108c SS |
1633 | @item help |
1634 | @itemx h | |
1635 | You can use @code{help} (abbreviated @code{h}) with no arguments to | |
1636 | display a short list of named classes of commands: | |
1637 | ||
1638 | @smallexample | |
1639 | (@value{GDBP}) help | |
1640 | List of classes of commands: | |
1641 | ||
2df3850c | 1642 | aliases -- Aliases of other commands |
c906108c | 1643 | breakpoints -- Making program stop at certain points |
2df3850c | 1644 | data -- Examining data |
c906108c | 1645 | files -- Specifying and examining files |
2df3850c JM |
1646 | internals -- Maintenance commands |
1647 | obscure -- Obscure features | |
1648 | running -- Running the program | |
1649 | stack -- Examining the stack | |
c906108c SS |
1650 | status -- Status inquiries |
1651 | support -- Support facilities | |
12c27660 | 1652 | tracepoints -- Tracing of program execution without |
96a2c332 | 1653 | stopping the program |
c906108c | 1654 | user-defined -- User-defined commands |
c906108c | 1655 | |
5d161b24 | 1656 | Type "help" followed by a class name for a list of |
c906108c | 1657 | commands in that class. |
5d161b24 | 1658 | Type "help" followed by command name for full |
c906108c SS |
1659 | documentation. |
1660 | Command name abbreviations are allowed if unambiguous. | |
1661 | (@value{GDBP}) | |
1662 | @end smallexample | |
96a2c332 | 1663 | @c the above line break eliminates huge line overfull... |
c906108c SS |
1664 | |
1665 | @item help @var{class} | |
1666 | Using one of the general help classes as an argument, you can get a | |
1667 | list of the individual commands in that class. For example, here is the | |
1668 | help display for the class @code{status}: | |
1669 | ||
1670 | @smallexample | |
1671 | (@value{GDBP}) help status | |
1672 | Status inquiries. | |
1673 | ||
1674 | List of commands: | |
1675 | ||
1676 | @c Line break in "show" line falsifies real output, but needed | |
1677 | @c to fit in smallbook page size. | |
2df3850c | 1678 | info -- Generic command for showing things |
12c27660 | 1679 | about the program being debugged |
2df3850c | 1680 | show -- Generic command for showing things |
12c27660 | 1681 | about the debugger |
c906108c | 1682 | |
5d161b24 | 1683 | Type "help" followed by command name for full |
c906108c SS |
1684 | documentation. |
1685 | Command name abbreviations are allowed if unambiguous. | |
1686 | (@value{GDBP}) | |
1687 | @end smallexample | |
1688 | ||
1689 | @item help @var{command} | |
1690 | With a command name as @code{help} argument, @value{GDBN} displays a | |
1691 | short paragraph on how to use that command. | |
1692 | ||
6837a0a2 DB |
1693 | @kindex apropos |
1694 | @item apropos @var{args} | |
09d4efe1 | 1695 | The @code{apropos} command searches through all of the @value{GDBN} |
6837a0a2 | 1696 | commands, and their documentation, for the regular expression specified in |
99e008fe | 1697 | @var{args}. It prints out all matches found. For example: |
6837a0a2 DB |
1698 | |
1699 | @smallexample | |
1700 | apropos reload | |
1701 | @end smallexample | |
1702 | ||
b37052ae EZ |
1703 | @noindent |
1704 | results in: | |
6837a0a2 DB |
1705 | |
1706 | @smallexample | |
6d2ebf8b SS |
1707 | @c @group |
1708 | set symbol-reloading -- Set dynamic symbol table reloading | |
12c27660 | 1709 | multiple times in one run |
6d2ebf8b | 1710 | show symbol-reloading -- Show dynamic symbol table reloading |
12c27660 | 1711 | multiple times in one run |
6d2ebf8b | 1712 | @c @end group |
6837a0a2 DB |
1713 | @end smallexample |
1714 | ||
c906108c SS |
1715 | @kindex complete |
1716 | @item complete @var{args} | |
1717 | The @code{complete @var{args}} command lists all the possible completions | |
1718 | for the beginning of a command. Use @var{args} to specify the beginning of the | |
1719 | command you want completed. For example: | |
1720 | ||
1721 | @smallexample | |
1722 | complete i | |
1723 | @end smallexample | |
1724 | ||
1725 | @noindent results in: | |
1726 | ||
1727 | @smallexample | |
1728 | @group | |
2df3850c JM |
1729 | if |
1730 | ignore | |
c906108c SS |
1731 | info |
1732 | inspect | |
c906108c SS |
1733 | @end group |
1734 | @end smallexample | |
1735 | ||
1736 | @noindent This is intended for use by @sc{gnu} Emacs. | |
1737 | @end table | |
1738 | ||
1739 | In addition to @code{help}, you can use the @value{GDBN} commands @code{info} | |
1740 | and @code{show} to inquire about the state of your program, or the state | |
1741 | of @value{GDBN} itself. Each command supports many topics of inquiry; this | |
1742 | manual introduces each of them in the appropriate context. The listings | |
1743 | under @code{info} and under @code{show} in the Index point to | |
1744 | all the sub-commands. @xref{Index}. | |
1745 | ||
1746 | @c @group | |
1747 | @table @code | |
1748 | @kindex info | |
41afff9a | 1749 | @kindex i @r{(@code{info})} |
c906108c SS |
1750 | @item info |
1751 | This command (abbreviated @code{i}) is for describing the state of your | |
cda4ce5a | 1752 | program. For example, you can show the arguments passed to a function |
c906108c SS |
1753 | with @code{info args}, list the registers currently in use with @code{info |
1754 | registers}, or list the breakpoints you have set with @code{info breakpoints}. | |
1755 | You can get a complete list of the @code{info} sub-commands with | |
1756 | @w{@code{help info}}. | |
1757 | ||
1758 | @kindex set | |
1759 | @item set | |
5d161b24 | 1760 | You can assign the result of an expression to an environment variable with |
c906108c SS |
1761 | @code{set}. For example, you can set the @value{GDBN} prompt to a $-sign with |
1762 | @code{set prompt $}. | |
1763 | ||
1764 | @kindex show | |
1765 | @item show | |
5d161b24 | 1766 | In contrast to @code{info}, @code{show} is for describing the state of |
c906108c SS |
1767 | @value{GDBN} itself. |
1768 | You can change most of the things you can @code{show}, by using the | |
1769 | related command @code{set}; for example, you can control what number | |
1770 | system is used for displays with @code{set radix}, or simply inquire | |
1771 | which is currently in use with @code{show radix}. | |
1772 | ||
1773 | @kindex info set | |
1774 | To display all the settable parameters and their current | |
1775 | values, you can use @code{show} with no arguments; you may also use | |
1776 | @code{info set}. Both commands produce the same display. | |
1777 | @c FIXME: "info set" violates the rule that "info" is for state of | |
1778 | @c FIXME...program. Ck w/ GNU: "info set" to be called something else, | |
1779 | @c FIXME...or change desc of rule---eg "state of prog and debugging session"? | |
1780 | @end table | |
1781 | @c @end group | |
1782 | ||
1783 | Here are three miscellaneous @code{show} subcommands, all of which are | |
1784 | exceptional in lacking corresponding @code{set} commands: | |
1785 | ||
1786 | @table @code | |
1787 | @kindex show version | |
9c16f35a | 1788 | @cindex @value{GDBN} version number |
c906108c SS |
1789 | @item show version |
1790 | Show what version of @value{GDBN} is running. You should include this | |
2df3850c JM |
1791 | information in @value{GDBN} bug-reports. If multiple versions of |
1792 | @value{GDBN} are in use at your site, you may need to determine which | |
1793 | version of @value{GDBN} you are running; as @value{GDBN} evolves, new | |
1794 | commands are introduced, and old ones may wither away. Also, many | |
1795 | system vendors ship variant versions of @value{GDBN}, and there are | |
96a2c332 | 1796 | variant versions of @value{GDBN} in @sc{gnu}/Linux distributions as well. |
2df3850c JM |
1797 | The version number is the same as the one announced when you start |
1798 | @value{GDBN}. | |
c906108c SS |
1799 | |
1800 | @kindex show copying | |
09d4efe1 | 1801 | @kindex info copying |
9c16f35a | 1802 | @cindex display @value{GDBN} copyright |
c906108c | 1803 | @item show copying |
09d4efe1 | 1804 | @itemx info copying |
c906108c SS |
1805 | Display information about permission for copying @value{GDBN}. |
1806 | ||
1807 | @kindex show warranty | |
09d4efe1 | 1808 | @kindex info warranty |
c906108c | 1809 | @item show warranty |
09d4efe1 | 1810 | @itemx info warranty |
2df3850c | 1811 | Display the @sc{gnu} ``NO WARRANTY'' statement, or a warranty, |
96a2c332 | 1812 | if your version of @value{GDBN} comes with one. |
2df3850c | 1813 | |
c906108c SS |
1814 | @end table |
1815 | ||
6d2ebf8b | 1816 | @node Running |
c906108c SS |
1817 | @chapter Running Programs Under @value{GDBN} |
1818 | ||
1819 | When you run a program under @value{GDBN}, you must first generate | |
1820 | debugging information when you compile it. | |
7a292a7a SS |
1821 | |
1822 | You may start @value{GDBN} with its arguments, if any, in an environment | |
1823 | of your choice. If you are doing native debugging, you may redirect | |
1824 | your program's input and output, debug an already running process, or | |
1825 | kill a child process. | |
c906108c SS |
1826 | |
1827 | @menu | |
1828 | * Compilation:: Compiling for debugging | |
1829 | * Starting:: Starting your program | |
c906108c SS |
1830 | * Arguments:: Your program's arguments |
1831 | * Environment:: Your program's environment | |
c906108c SS |
1832 | |
1833 | * Working Directory:: Your program's working directory | |
1834 | * Input/Output:: Your program's input and output | |
1835 | * Attach:: Debugging an already-running process | |
1836 | * Kill Process:: Killing the child process | |
c906108c | 1837 | |
6c95b8df | 1838 | * Inferiors and Programs:: Debugging multiple inferiors and programs |
c906108c | 1839 | * Threads:: Debugging programs with multiple threads |
6c95b8df | 1840 | * Forks:: Debugging forks |
5c95884b | 1841 | * Checkpoint/Restart:: Setting a @emph{bookmark} to return to later |
c906108c SS |
1842 | @end menu |
1843 | ||
6d2ebf8b | 1844 | @node Compilation |
79a6e687 | 1845 | @section Compiling for Debugging |
c906108c SS |
1846 | |
1847 | In order to debug a program effectively, you need to generate | |
1848 | debugging information when you compile it. This debugging information | |
1849 | is stored in the object file; it describes the data type of each | |
1850 | variable or function and the correspondence between source line numbers | |
1851 | and addresses in the executable code. | |
1852 | ||
1853 | To request debugging information, specify the @samp{-g} option when you run | |
1854 | the compiler. | |
1855 | ||
514c4d71 | 1856 | Programs that are to be shipped to your customers are compiled with |
edb3359d | 1857 | optimizations, using the @samp{-O} compiler option. However, some |
514c4d71 EZ |
1858 | compilers are unable to handle the @samp{-g} and @samp{-O} options |
1859 | together. Using those compilers, you cannot generate optimized | |
c906108c SS |
1860 | executables containing debugging information. |
1861 | ||
514c4d71 | 1862 | @value{NGCC}, the @sc{gnu} C/C@t{++} compiler, supports @samp{-g} with or |
53a5351d JM |
1863 | without @samp{-O}, making it possible to debug optimized code. We |
1864 | recommend that you @emph{always} use @samp{-g} whenever you compile a | |
1865 | program. You may think your program is correct, but there is no sense | |
edb3359d | 1866 | in pushing your luck. For more information, see @ref{Optimized Code}. |
c906108c SS |
1867 | |
1868 | Older versions of the @sc{gnu} C compiler permitted a variant option | |
1869 | @w{@samp{-gg}} for debugging information. @value{GDBN} no longer supports this | |
1870 | format; if your @sc{gnu} C compiler has this option, do not use it. | |
1871 | ||
514c4d71 EZ |
1872 | @value{GDBN} knows about preprocessor macros and can show you their |
1873 | expansion (@pxref{Macros}). Most compilers do not include information | |
1874 | about preprocessor macros in the debugging information if you specify | |
1875 | the @option{-g} flag alone, because this information is rather large. | |
1876 | Version 3.1 and later of @value{NGCC}, the @sc{gnu} C compiler, | |
1877 | provides macro information if you specify the options | |
1878 | @option{-gdwarf-2} and @option{-g3}; the former option requests | |
1879 | debugging information in the Dwarf 2 format, and the latter requests | |
1880 | ``extra information''. In the future, we hope to find more compact | |
1881 | ways to represent macro information, so that it can be included with | |
1882 | @option{-g} alone. | |
1883 | ||
c906108c | 1884 | @need 2000 |
6d2ebf8b | 1885 | @node Starting |
79a6e687 | 1886 | @section Starting your Program |
c906108c SS |
1887 | @cindex starting |
1888 | @cindex running | |
1889 | ||
1890 | @table @code | |
1891 | @kindex run | |
41afff9a | 1892 | @kindex r @r{(@code{run})} |
c906108c SS |
1893 | @item run |
1894 | @itemx r | |
7a292a7a SS |
1895 | Use the @code{run} command to start your program under @value{GDBN}. |
1896 | You must first specify the program name (except on VxWorks) with an | |
1897 | argument to @value{GDBN} (@pxref{Invocation, ,Getting In and Out of | |
1898 | @value{GDBN}}), or by using the @code{file} or @code{exec-file} command | |
79a6e687 | 1899 | (@pxref{Files, ,Commands to Specify Files}). |
c906108c SS |
1900 | |
1901 | @end table | |
1902 | ||
c906108c SS |
1903 | If you are running your program in an execution environment that |
1904 | supports processes, @code{run} creates an inferior process and makes | |
8edfe269 DJ |
1905 | that process run your program. In some environments without processes, |
1906 | @code{run} jumps to the start of your program. Other targets, | |
1907 | like @samp{remote}, are always running. If you get an error | |
1908 | message like this one: | |
1909 | ||
1910 | @smallexample | |
1911 | The "remote" target does not support "run". | |
1912 | Try "help target" or "continue". | |
1913 | @end smallexample | |
1914 | ||
1915 | @noindent | |
1916 | then use @code{continue} to run your program. You may need @code{load} | |
1917 | first (@pxref{load}). | |
c906108c SS |
1918 | |
1919 | The execution of a program is affected by certain information it | |
1920 | receives from its superior. @value{GDBN} provides ways to specify this | |
1921 | information, which you must do @emph{before} starting your program. (You | |
1922 | can change it after starting your program, but such changes only affect | |
1923 | your program the next time you start it.) This information may be | |
1924 | divided into four categories: | |
1925 | ||
1926 | @table @asis | |
1927 | @item The @emph{arguments.} | |
1928 | Specify the arguments to give your program as the arguments of the | |
1929 | @code{run} command. If a shell is available on your target, the shell | |
1930 | is used to pass the arguments, so that you may use normal conventions | |
1931 | (such as wildcard expansion or variable substitution) in describing | |
1932 | the arguments. | |
1933 | In Unix systems, you can control which shell is used with the | |
1934 | @code{SHELL} environment variable. | |
79a6e687 | 1935 | @xref{Arguments, ,Your Program's Arguments}. |
c906108c SS |
1936 | |
1937 | @item The @emph{environment.} | |
1938 | Your program normally inherits its environment from @value{GDBN}, but you can | |
1939 | use the @value{GDBN} commands @code{set environment} and @code{unset | |
1940 | environment} to change parts of the environment that affect | |
79a6e687 | 1941 | your program. @xref{Environment, ,Your Program's Environment}. |
c906108c SS |
1942 | |
1943 | @item The @emph{working directory.} | |
1944 | Your program inherits its working directory from @value{GDBN}. You can set | |
1945 | the @value{GDBN} working directory with the @code{cd} command in @value{GDBN}. | |
79a6e687 | 1946 | @xref{Working Directory, ,Your Program's Working Directory}. |
c906108c SS |
1947 | |
1948 | @item The @emph{standard input and output.} | |
1949 | Your program normally uses the same device for standard input and | |
1950 | standard output as @value{GDBN} is using. You can redirect input and output | |
1951 | in the @code{run} command line, or you can use the @code{tty} command to | |
1952 | set a different device for your program. | |
79a6e687 | 1953 | @xref{Input/Output, ,Your Program's Input and Output}. |
c906108c SS |
1954 | |
1955 | @cindex pipes | |
1956 | @emph{Warning:} While input and output redirection work, you cannot use | |
1957 | pipes to pass the output of the program you are debugging to another | |
1958 | program; if you attempt this, @value{GDBN} is likely to wind up debugging the | |
1959 | wrong program. | |
1960 | @end table | |
c906108c SS |
1961 | |
1962 | When you issue the @code{run} command, your program begins to execute | |
79a6e687 | 1963 | immediately. @xref{Stopping, ,Stopping and Continuing}, for discussion |
c906108c SS |
1964 | of how to arrange for your program to stop. Once your program has |
1965 | stopped, you may call functions in your program, using the @code{print} | |
1966 | or @code{call} commands. @xref{Data, ,Examining Data}. | |
1967 | ||
1968 | If the modification time of your symbol file has changed since the last | |
1969 | time @value{GDBN} read its symbols, @value{GDBN} discards its symbol | |
1970 | table, and reads it again. When it does this, @value{GDBN} tries to retain | |
1971 | your current breakpoints. | |
1972 | ||
4e8b0763 JB |
1973 | @table @code |
1974 | @kindex start | |
1975 | @item start | |
1976 | @cindex run to main procedure | |
1977 | The name of the main procedure can vary from language to language. | |
1978 | With C or C@t{++}, the main procedure name is always @code{main}, but | |
1979 | other languages such as Ada do not require a specific name for their | |
1980 | main procedure. The debugger provides a convenient way to start the | |
1981 | execution of the program and to stop at the beginning of the main | |
1982 | procedure, depending on the language used. | |
1983 | ||
1984 | The @samp{start} command does the equivalent of setting a temporary | |
1985 | breakpoint at the beginning of the main procedure and then invoking | |
1986 | the @samp{run} command. | |
1987 | ||
f018e82f EZ |
1988 | @cindex elaboration phase |
1989 | Some programs contain an @dfn{elaboration} phase where some startup code is | |
1990 | executed before the main procedure is called. This depends on the | |
1991 | languages used to write your program. In C@t{++}, for instance, | |
4e8b0763 JB |
1992 | constructors for static and global objects are executed before |
1993 | @code{main} is called. It is therefore possible that the debugger stops | |
1994 | before reaching the main procedure. However, the temporary breakpoint | |
1995 | will remain to halt execution. | |
1996 | ||
1997 | Specify the arguments to give to your program as arguments to the | |
1998 | @samp{start} command. These arguments will be given verbatim to the | |
1999 | underlying @samp{run} command. Note that the same arguments will be | |
2000 | reused if no argument is provided during subsequent calls to | |
2001 | @samp{start} or @samp{run}. | |
2002 | ||
2003 | It is sometimes necessary to debug the program during elaboration. In | |
2004 | these cases, using the @code{start} command would stop the execution of | |
2005 | your program too late, as the program would have already completed the | |
2006 | elaboration phase. Under these circumstances, insert breakpoints in your | |
2007 | elaboration code before running your program. | |
ccd213ac DJ |
2008 | |
2009 | @kindex set exec-wrapper | |
2010 | @item set exec-wrapper @var{wrapper} | |
2011 | @itemx show exec-wrapper | |
2012 | @itemx unset exec-wrapper | |
2013 | When @samp{exec-wrapper} is set, the specified wrapper is used to | |
2014 | launch programs for debugging. @value{GDBN} starts your program | |
2015 | with a shell command of the form @kbd{exec @var{wrapper} | |
2016 | @var{program}}. Quoting is added to @var{program} and its | |
2017 | arguments, but not to @var{wrapper}, so you should add quotes if | |
2018 | appropriate for your shell. The wrapper runs until it executes | |
2019 | your program, and then @value{GDBN} takes control. | |
2020 | ||
2021 | You can use any program that eventually calls @code{execve} with | |
2022 | its arguments as a wrapper. Several standard Unix utilities do | |
2023 | this, e.g.@: @code{env} and @code{nohup}. Any Unix shell script ending | |
2024 | with @code{exec "$@@"} will also work. | |
2025 | ||
2026 | For example, you can use @code{env} to pass an environment variable to | |
2027 | the debugged program, without setting the variable in your shell's | |
2028 | environment: | |
2029 | ||
2030 | @smallexample | |
2031 | (@value{GDBP}) set exec-wrapper env 'LD_PRELOAD=libtest.so' | |
2032 | (@value{GDBP}) run | |
2033 | @end smallexample | |
2034 | ||
2035 | This command is available when debugging locally on most targets, excluding | |
2036 | @sc{djgpp}, Cygwin, MS Windows, and QNX Neutrino. | |
2037 | ||
10568435 JK |
2038 | @kindex set disable-randomization |
2039 | @item set disable-randomization | |
2040 | @itemx set disable-randomization on | |
2041 | This option (enabled by default in @value{GDBN}) will turn off the native | |
2042 | randomization of the virtual address space of the started program. This option | |
2043 | is useful for multiple debugging sessions to make the execution better | |
2044 | reproducible and memory addresses reusable across debugging sessions. | |
2045 | ||
2046 | This feature is implemented only on @sc{gnu}/Linux. You can get the same | |
2047 | behavior using | |
2048 | ||
2049 | @smallexample | |
2050 | (@value{GDBP}) set exec-wrapper setarch `uname -m` -R | |
2051 | @end smallexample | |
2052 | ||
2053 | @item set disable-randomization off | |
2054 | Leave the behavior of the started executable unchanged. Some bugs rear their | |
2055 | ugly heads only when the program is loaded at certain addresses. If your bug | |
2056 | disappears when you run the program under @value{GDBN}, that might be because | |
2057 | @value{GDBN} by default disables the address randomization on platforms, such | |
2058 | as @sc{gnu}/Linux, which do that for stand-alone programs. Use @kbd{set | |
2059 | disable-randomization off} to try to reproduce such elusive bugs. | |
2060 | ||
2061 | The virtual address space randomization is implemented only on @sc{gnu}/Linux. | |
2062 | It protects the programs against some kinds of security attacks. In these | |
2063 | cases the attacker needs to know the exact location of a concrete executable | |
2064 | code. Randomizing its location makes it impossible to inject jumps misusing | |
2065 | a code at its expected addresses. | |
2066 | ||
2067 | Prelinking shared libraries provides a startup performance advantage but it | |
2068 | makes addresses in these libraries predictable for privileged processes by | |
2069 | having just unprivileged access at the target system. Reading the shared | |
2070 | library binary gives enough information for assembling the malicious code | |
2071 | misusing it. Still even a prelinked shared library can get loaded at a new | |
2072 | random address just requiring the regular relocation process during the | |
2073 | startup. Shared libraries not already prelinked are always loaded at | |
2074 | a randomly chosen address. | |
2075 | ||
2076 | Position independent executables (PIE) contain position independent code | |
2077 | similar to the shared libraries and therefore such executables get loaded at | |
2078 | a randomly chosen address upon startup. PIE executables always load even | |
2079 | already prelinked shared libraries at a random address. You can build such | |
2080 | executable using @command{gcc -fPIE -pie}. | |
2081 | ||
2082 | Heap (malloc storage), stack and custom mmap areas are always placed randomly | |
2083 | (as long as the randomization is enabled). | |
2084 | ||
2085 | @item show disable-randomization | |
2086 | Show the current setting of the explicit disable of the native randomization of | |
2087 | the virtual address space of the started program. | |
2088 | ||
4e8b0763 JB |
2089 | @end table |
2090 | ||
6d2ebf8b | 2091 | @node Arguments |
79a6e687 | 2092 | @section Your Program's Arguments |
c906108c SS |
2093 | |
2094 | @cindex arguments (to your program) | |
2095 | The arguments to your program can be specified by the arguments of the | |
5d161b24 | 2096 | @code{run} command. |
c906108c SS |
2097 | They are passed to a shell, which expands wildcard characters and |
2098 | performs redirection of I/O, and thence to your program. Your | |
2099 | @code{SHELL} environment variable (if it exists) specifies what shell | |
2100 | @value{GDBN} uses. If you do not define @code{SHELL}, @value{GDBN} uses | |
d4f3574e SS |
2101 | the default shell (@file{/bin/sh} on Unix). |
2102 | ||
2103 | On non-Unix systems, the program is usually invoked directly by | |
2104 | @value{GDBN}, which emulates I/O redirection via the appropriate system | |
2105 | calls, and the wildcard characters are expanded by the startup code of | |
2106 | the program, not by the shell. | |
c906108c SS |
2107 | |
2108 | @code{run} with no arguments uses the same arguments used by the previous | |
2109 | @code{run}, or those set by the @code{set args} command. | |
2110 | ||
c906108c | 2111 | @table @code |
41afff9a | 2112 | @kindex set args |
c906108c SS |
2113 | @item set args |
2114 | Specify the arguments to be used the next time your program is run. If | |
2115 | @code{set args} has no arguments, @code{run} executes your program | |
2116 | with no arguments. Once you have run your program with arguments, | |
2117 | using @code{set args} before the next @code{run} is the only way to run | |
2118 | it again without arguments. | |
2119 | ||
2120 | @kindex show args | |
2121 | @item show args | |
2122 | Show the arguments to give your program when it is started. | |
2123 | @end table | |
2124 | ||
6d2ebf8b | 2125 | @node Environment |
79a6e687 | 2126 | @section Your Program's Environment |
c906108c SS |
2127 | |
2128 | @cindex environment (of your program) | |
2129 | The @dfn{environment} consists of a set of environment variables and | |
2130 | their values. Environment variables conventionally record such things as | |
2131 | your user name, your home directory, your terminal type, and your search | |
2132 | path for programs to run. Usually you set up environment variables with | |
2133 | the shell and they are inherited by all the other programs you run. When | |
2134 | debugging, it can be useful to try running your program with a modified | |
2135 | environment without having to start @value{GDBN} over again. | |
2136 | ||
2137 | @table @code | |
2138 | @kindex path | |
2139 | @item path @var{directory} | |
2140 | Add @var{directory} to the front of the @code{PATH} environment variable | |
17cc6a06 EZ |
2141 | (the search path for executables) that will be passed to your program. |
2142 | The value of @code{PATH} used by @value{GDBN} does not change. | |
d4f3574e SS |
2143 | You may specify several directory names, separated by whitespace or by a |
2144 | system-dependent separator character (@samp{:} on Unix, @samp{;} on | |
2145 | MS-DOS and MS-Windows). If @var{directory} is already in the path, it | |
2146 | is moved to the front, so it is searched sooner. | |
c906108c SS |
2147 | |
2148 | You can use the string @samp{$cwd} to refer to whatever is the current | |
2149 | working directory at the time @value{GDBN} searches the path. If you | |
2150 | use @samp{.} instead, it refers to the directory where you executed the | |
2151 | @code{path} command. @value{GDBN} replaces @samp{.} in the | |
2152 | @var{directory} argument (with the current path) before adding | |
2153 | @var{directory} to the search path. | |
2154 | @c 'path' is explicitly nonrepeatable, but RMS points out it is silly to | |
2155 | @c document that, since repeating it would be a no-op. | |
2156 | ||
2157 | @kindex show paths | |
2158 | @item show paths | |
2159 | Display the list of search paths for executables (the @code{PATH} | |
2160 | environment variable). | |
2161 | ||
2162 | @kindex show environment | |
2163 | @item show environment @r{[}@var{varname}@r{]} | |
2164 | Print the value of environment variable @var{varname} to be given to | |
2165 | your program when it starts. If you do not supply @var{varname}, | |
2166 | print the names and values of all environment variables to be given to | |
2167 | your program. You can abbreviate @code{environment} as @code{env}. | |
2168 | ||
2169 | @kindex set environment | |
53a5351d | 2170 | @item set environment @var{varname} @r{[}=@var{value}@r{]} |
c906108c SS |
2171 | Set environment variable @var{varname} to @var{value}. The value |
2172 | changes for your program only, not for @value{GDBN} itself. @var{value} may | |
2173 | be any string; the values of environment variables are just strings, and | |
2174 | any interpretation is supplied by your program itself. The @var{value} | |
2175 | parameter is optional; if it is eliminated, the variable is set to a | |
2176 | null value. | |
2177 | @c "any string" here does not include leading, trailing | |
2178 | @c blanks. Gnu asks: does anyone care? | |
2179 | ||
2180 | For example, this command: | |
2181 | ||
474c8240 | 2182 | @smallexample |
c906108c | 2183 | set env USER = foo |
474c8240 | 2184 | @end smallexample |
c906108c SS |
2185 | |
2186 | @noindent | |
d4f3574e | 2187 | tells the debugged program, when subsequently run, that its user is named |
c906108c SS |
2188 | @samp{foo}. (The spaces around @samp{=} are used for clarity here; they |
2189 | are not actually required.) | |
2190 | ||
2191 | @kindex unset environment | |
2192 | @item unset environment @var{varname} | |
2193 | Remove variable @var{varname} from the environment to be passed to your | |
2194 | program. This is different from @samp{set env @var{varname} =}; | |
2195 | @code{unset environment} removes the variable from the environment, | |
2196 | rather than assigning it an empty value. | |
2197 | @end table | |
2198 | ||
d4f3574e SS |
2199 | @emph{Warning:} On Unix systems, @value{GDBN} runs your program using |
2200 | the shell indicated | |
c906108c SS |
2201 | by your @code{SHELL} environment variable if it exists (or |
2202 | @code{/bin/sh} if not). If your @code{SHELL} variable names a shell | |
2203 | that runs an initialization file---such as @file{.cshrc} for C-shell, or | |
2204 | @file{.bashrc} for BASH---any variables you set in that file affect | |
2205 | your program. You may wish to move setting of environment variables to | |
2206 | files that are only run when you sign on, such as @file{.login} or | |
2207 | @file{.profile}. | |
2208 | ||
6d2ebf8b | 2209 | @node Working Directory |
79a6e687 | 2210 | @section Your Program's Working Directory |
c906108c SS |
2211 | |
2212 | @cindex working directory (of your program) | |
2213 | Each time you start your program with @code{run}, it inherits its | |
2214 | working directory from the current working directory of @value{GDBN}. | |
2215 | The @value{GDBN} working directory is initially whatever it inherited | |
2216 | from its parent process (typically the shell), but you can specify a new | |
2217 | working directory in @value{GDBN} with the @code{cd} command. | |
2218 | ||
2219 | The @value{GDBN} working directory also serves as a default for the commands | |
2220 | that specify files for @value{GDBN} to operate on. @xref{Files, ,Commands to | |
79a6e687 | 2221 | Specify Files}. |
c906108c SS |
2222 | |
2223 | @table @code | |
2224 | @kindex cd | |
721c2651 | 2225 | @cindex change working directory |
c906108c SS |
2226 | @item cd @var{directory} |
2227 | Set the @value{GDBN} working directory to @var{directory}. | |
2228 | ||
2229 | @kindex pwd | |
2230 | @item pwd | |
2231 | Print the @value{GDBN} working directory. | |
2232 | @end table | |
2233 | ||
60bf7e09 EZ |
2234 | It is generally impossible to find the current working directory of |
2235 | the process being debugged (since a program can change its directory | |
2236 | during its run). If you work on a system where @value{GDBN} is | |
2237 | configured with the @file{/proc} support, you can use the @code{info | |
2238 | proc} command (@pxref{SVR4 Process Information}) to find out the | |
2239 | current working directory of the debuggee. | |
2240 | ||
6d2ebf8b | 2241 | @node Input/Output |
79a6e687 | 2242 | @section Your Program's Input and Output |
c906108c SS |
2243 | |
2244 | @cindex redirection | |
2245 | @cindex i/o | |
2246 | @cindex terminal | |
2247 | By default, the program you run under @value{GDBN} does input and output to | |
5d161b24 | 2248 | the same terminal that @value{GDBN} uses. @value{GDBN} switches the terminal |
c906108c SS |
2249 | to its own terminal modes to interact with you, but it records the terminal |
2250 | modes your program was using and switches back to them when you continue | |
2251 | running your program. | |
2252 | ||
2253 | @table @code | |
2254 | @kindex info terminal | |
2255 | @item info terminal | |
2256 | Displays information recorded by @value{GDBN} about the terminal modes your | |
2257 | program is using. | |
2258 | @end table | |
2259 | ||
2260 | You can redirect your program's input and/or output using shell | |
2261 | redirection with the @code{run} command. For example, | |
2262 | ||
474c8240 | 2263 | @smallexample |
c906108c | 2264 | run > outfile |
474c8240 | 2265 | @end smallexample |
c906108c SS |
2266 | |
2267 | @noindent | |
2268 | starts your program, diverting its output to the file @file{outfile}. | |
2269 | ||
2270 | @kindex tty | |
2271 | @cindex controlling terminal | |
2272 | Another way to specify where your program should do input and output is | |
2273 | with the @code{tty} command. This command accepts a file name as | |
2274 | argument, and causes this file to be the default for future @code{run} | |
2275 | commands. It also resets the controlling terminal for the child | |
2276 | process, for future @code{run} commands. For example, | |
2277 | ||
474c8240 | 2278 | @smallexample |
c906108c | 2279 | tty /dev/ttyb |
474c8240 | 2280 | @end smallexample |
c906108c SS |
2281 | |
2282 | @noindent | |
2283 | directs that processes started with subsequent @code{run} commands | |
2284 | default to do input and output on the terminal @file{/dev/ttyb} and have | |
2285 | that as their controlling terminal. | |
2286 | ||
2287 | An explicit redirection in @code{run} overrides the @code{tty} command's | |
2288 | effect on the input/output device, but not its effect on the controlling | |
2289 | terminal. | |
2290 | ||
2291 | When you use the @code{tty} command or redirect input in the @code{run} | |
2292 | command, only the input @emph{for your program} is affected. The input | |
3cb3b8df BR |
2293 | for @value{GDBN} still comes from your terminal. @code{tty} is an alias |
2294 | for @code{set inferior-tty}. | |
2295 | ||
2296 | @cindex inferior tty | |
2297 | @cindex set inferior controlling terminal | |
2298 | You can use the @code{show inferior-tty} command to tell @value{GDBN} to | |
2299 | display the name of the terminal that will be used for future runs of your | |
2300 | program. | |
2301 | ||
2302 | @table @code | |
2303 | @item set inferior-tty /dev/ttyb | |
2304 | @kindex set inferior-tty | |
2305 | Set the tty for the program being debugged to /dev/ttyb. | |
2306 | ||
2307 | @item show inferior-tty | |
2308 | @kindex show inferior-tty | |
2309 | Show the current tty for the program being debugged. | |
2310 | @end table | |
c906108c | 2311 | |
6d2ebf8b | 2312 | @node Attach |
79a6e687 | 2313 | @section Debugging an Already-running Process |
c906108c SS |
2314 | @kindex attach |
2315 | @cindex attach | |
2316 | ||
2317 | @table @code | |
2318 | @item attach @var{process-id} | |
2319 | This command attaches to a running process---one that was started | |
2320 | outside @value{GDBN}. (@code{info files} shows your active | |
2321 | targets.) The command takes as argument a process ID. The usual way to | |
09d4efe1 | 2322 | find out the @var{process-id} of a Unix process is with the @code{ps} utility, |
c906108c SS |
2323 | or with the @samp{jobs -l} shell command. |
2324 | ||
2325 | @code{attach} does not repeat if you press @key{RET} a second time after | |
2326 | executing the command. | |
2327 | @end table | |
2328 | ||
2329 | To use @code{attach}, your program must be running in an environment | |
2330 | which supports processes; for example, @code{attach} does not work for | |
2331 | programs on bare-board targets that lack an operating system. You must | |
2332 | also have permission to send the process a signal. | |
2333 | ||
2334 | When you use @code{attach}, the debugger finds the program running in | |
2335 | the process first by looking in the current working directory, then (if | |
2336 | the program is not found) by using the source file search path | |
79a6e687 | 2337 | (@pxref{Source Path, ,Specifying Source Directories}). You can also use |
c906108c SS |
2338 | the @code{file} command to load the program. @xref{Files, ,Commands to |
2339 | Specify Files}. | |
2340 | ||
2341 | The first thing @value{GDBN} does after arranging to debug the specified | |
2342 | process is to stop it. You can examine and modify an attached process | |
53a5351d JM |
2343 | with all the @value{GDBN} commands that are ordinarily available when |
2344 | you start processes with @code{run}. You can insert breakpoints; you | |
2345 | can step and continue; you can modify storage. If you would rather the | |
2346 | process continue running, you may use the @code{continue} command after | |
c906108c SS |
2347 | attaching @value{GDBN} to the process. |
2348 | ||
2349 | @table @code | |
2350 | @kindex detach | |
2351 | @item detach | |
2352 | When you have finished debugging the attached process, you can use the | |
2353 | @code{detach} command to release it from @value{GDBN} control. Detaching | |
2354 | the process continues its execution. After the @code{detach} command, | |
2355 | that process and @value{GDBN} become completely independent once more, and you | |
2356 | are ready to @code{attach} another process or start one with @code{run}. | |
2357 | @code{detach} does not repeat if you press @key{RET} again after | |
2358 | executing the command. | |
2359 | @end table | |
2360 | ||
159fcc13 JK |
2361 | If you exit @value{GDBN} while you have an attached process, you detach |
2362 | that process. If you use the @code{run} command, you kill that process. | |
2363 | By default, @value{GDBN} asks for confirmation if you try to do either of these | |
2364 | things; you can control whether or not you need to confirm by using the | |
2365 | @code{set confirm} command (@pxref{Messages/Warnings, ,Optional Warnings and | |
79a6e687 | 2366 | Messages}). |
c906108c | 2367 | |
6d2ebf8b | 2368 | @node Kill Process |
79a6e687 | 2369 | @section Killing the Child Process |
c906108c SS |
2370 | |
2371 | @table @code | |
2372 | @kindex kill | |
2373 | @item kill | |
2374 | Kill the child process in which your program is running under @value{GDBN}. | |
2375 | @end table | |
2376 | ||
2377 | This command is useful if you wish to debug a core dump instead of a | |
2378 | running process. @value{GDBN} ignores any core dump file while your program | |
2379 | is running. | |
2380 | ||
2381 | On some operating systems, a program cannot be executed outside @value{GDBN} | |
2382 | while you have breakpoints set on it inside @value{GDBN}. You can use the | |
2383 | @code{kill} command in this situation to permit running your program | |
2384 | outside the debugger. | |
2385 | ||
2386 | The @code{kill} command is also useful if you wish to recompile and | |
2387 | relink your program, since on many systems it is impossible to modify an | |
2388 | executable file while it is running in a process. In this case, when you | |
2389 | next type @code{run}, @value{GDBN} notices that the file has changed, and | |
2390 | reads the symbol table again (while trying to preserve your current | |
2391 | breakpoint settings). | |
2392 | ||
6c95b8df PA |
2393 | @node Inferiors and Programs |
2394 | @section Debugging Multiple Inferiors and Programs | |
b77209e0 | 2395 | |
6c95b8df PA |
2396 | @value{GDBN} lets you run and debug multiple programs in a single |
2397 | session. In addition, @value{GDBN} on some systems may let you run | |
2398 | several programs simultaneously (otherwise you have to exit from one | |
2399 | before starting another). In the most general case, you can have | |
2400 | multiple threads of execution in each of multiple processes, launched | |
2401 | from multiple executables. | |
b77209e0 PA |
2402 | |
2403 | @cindex inferior | |
2404 | @value{GDBN} represents the state of each program execution with an | |
2405 | object called an @dfn{inferior}. An inferior typically corresponds to | |
2406 | a process, but is more general and applies also to targets that do not | |
2407 | have processes. Inferiors may be created before a process runs, and | |
6c95b8df PA |
2408 | may be retained after a process exits. Inferiors have unique |
2409 | identifiers that are different from process ids. Usually each | |
2410 | inferior will also have its own distinct address space, although some | |
2411 | embedded targets may have several inferiors running in different parts | |
2412 | of a single address space. Each inferior may in turn have multiple | |
2413 | threads running in it. | |
b77209e0 | 2414 | |
6c95b8df PA |
2415 | To find out what inferiors exist at any moment, use @w{@code{info |
2416 | inferiors}}: | |
b77209e0 PA |
2417 | |
2418 | @table @code | |
2419 | @kindex info inferiors | |
2420 | @item info inferiors | |
2421 | Print a list of all inferiors currently being managed by @value{GDBN}. | |
3a1ff0b6 PA |
2422 | |
2423 | @value{GDBN} displays for each inferior (in this order): | |
2424 | ||
2425 | @enumerate | |
2426 | @item | |
2427 | the inferior number assigned by @value{GDBN} | |
2428 | ||
2429 | @item | |
2430 | the target system's inferior identifier | |
6c95b8df PA |
2431 | |
2432 | @item | |
2433 | the name of the executable the inferior is running. | |
2434 | ||
3a1ff0b6 PA |
2435 | @end enumerate |
2436 | ||
2437 | @noindent | |
2438 | An asterisk @samp{*} preceding the @value{GDBN} inferior number | |
2439 | indicates the current inferior. | |
2440 | ||
2441 | For example, | |
2277426b | 2442 | @end table |
3a1ff0b6 PA |
2443 | @c end table here to get a little more width for example |
2444 | ||
2445 | @smallexample | |
2446 | (@value{GDBP}) info inferiors | |
6c95b8df PA |
2447 | Num Description Executable |
2448 | 2 process 2307 hello | |
2449 | * 1 process 3401 goodbye | |
3a1ff0b6 | 2450 | @end smallexample |
2277426b PA |
2451 | |
2452 | To switch focus between inferiors, use the @code{inferior} command: | |
2453 | ||
2454 | @table @code | |
3a1ff0b6 PA |
2455 | @kindex inferior @var{infno} |
2456 | @item inferior @var{infno} | |
2457 | Make inferior number @var{infno} the current inferior. The argument | |
2458 | @var{infno} is the inferior number assigned by @value{GDBN}, as shown | |
2459 | in the first field of the @samp{info inferiors} display. | |
2277426b PA |
2460 | @end table |
2461 | ||
6c95b8df PA |
2462 | |
2463 | You can get multiple executables into a debugging session via the | |
2464 | @code{add-inferior} and @w{@code{clone-inferior}} commands. On some | |
2465 | systems @value{GDBN} can add inferiors to the debug session | |
2466 | automatically by following calls to @code{fork} and @code{exec}. To | |
2467 | remove inferiors from the debugging session use the | |
2468 | @w{@code{remove-inferior}} command. | |
2469 | ||
2470 | @table @code | |
2471 | @kindex add-inferior | |
2472 | @item add-inferior [ -copies @var{n} ] [ -exec @var{executable} ] | |
2473 | Adds @var{n} inferiors to be run using @var{executable} as the | |
2474 | executable. @var{n} defaults to 1. If no executable is specified, | |
2475 | the inferiors begins empty, with no program. You can still assign or | |
2476 | change the program assigned to the inferior at any time by using the | |
2477 | @code{file} command with the executable name as its argument. | |
2478 | ||
2479 | @kindex clone-inferior | |
2480 | @item clone-inferior [ -copies @var{n} ] [ @var{infno} ] | |
2481 | Adds @var{n} inferiors ready to execute the same program as inferior | |
2482 | @var{infno}. @var{n} defaults to 1. @var{infno} defaults to the | |
2483 | number of the current inferior. This is a convenient command when you | |
2484 | want to run another instance of the inferior you are debugging. | |
2485 | ||
2486 | @smallexample | |
2487 | (@value{GDBP}) info inferiors | |
2488 | Num Description Executable | |
2489 | * 1 process 29964 helloworld | |
2490 | (@value{GDBP}) clone-inferior | |
2491 | Added inferior 2. | |
2492 | 1 inferiors added. | |
2493 | (@value{GDBP}) info inferiors | |
2494 | Num Description Executable | |
2495 | 2 <null> helloworld | |
2496 | * 1 process 29964 helloworld | |
2497 | @end smallexample | |
2498 | ||
2499 | You can now simply switch focus to inferior 2 and run it. | |
2500 | ||
2501 | @kindex remove-inferior | |
2502 | @item remove-inferior @var{infno} | |
2503 | Removes the inferior @var{infno}. It is not possible to remove an | |
2504 | inferior that is running with this command. For those, use the | |
2505 | @code{kill} or @code{detach} command first. | |
2506 | ||
2507 | @end table | |
2508 | ||
2509 | To quit debugging one of the running inferiors that is not the current | |
2510 | inferior, you can either detach from it by using the @w{@code{detach | |
2511 | inferior}} command (allowing it to run independently), or kill it | |
2512 | using the @w{@code{kill inferior}} command: | |
2277426b PA |
2513 | |
2514 | @table @code | |
3a1ff0b6 PA |
2515 | @kindex detach inferior @var{infno} |
2516 | @item detach inferior @var{infno} | |
2277426b | 2517 | Detach from the inferior identified by @value{GDBN} inferior number |
6c13bbe1 HZ |
2518 | @var{infno}. Note that the inferior's entry still stays on the list |
2519 | of inferiors shown by @code{info inferiors}, but its Description will | |
2520 | show @samp{<null>}. | |
2277426b | 2521 | |
3a1ff0b6 PA |
2522 | @kindex kill inferior @var{infno} |
2523 | @item kill inferior @var{infno} | |
2277426b | 2524 | Kill the inferior identified by @value{GDBN} inferior number |
6c13bbe1 HZ |
2525 | @var{infno}. Note that the inferior's entry still stays on the list |
2526 | of inferiors shown by @code{info inferiors}, but its Description will | |
2527 | show @samp{<null>}. | |
2277426b PA |
2528 | @end table |
2529 | ||
6c95b8df PA |
2530 | After the successful completion of a command such as @code{detach}, |
2531 | @code{detach inferior}, @code{kill} or @code{kill inferior}, or after | |
2532 | a normal process exit, the inferior is still valid and listed with | |
2533 | @code{info inferiors}, ready to be restarted. | |
2534 | ||
2535 | ||
2277426b PA |
2536 | To be notified when inferiors are started or exit under @value{GDBN}'s |
2537 | control use @w{@code{set print inferior-events}}: | |
b77209e0 | 2538 | |
2277426b | 2539 | @table @code |
b77209e0 PA |
2540 | @kindex set print inferior-events |
2541 | @cindex print messages on inferior start and exit | |
2542 | @item set print inferior-events | |
2543 | @itemx set print inferior-events on | |
2544 | @itemx set print inferior-events off | |
2545 | The @code{set print inferior-events} command allows you to enable or | |
2546 | disable printing of messages when @value{GDBN} notices that new | |
2547 | inferiors have started or that inferiors have exited or have been | |
2548 | detached. By default, these messages will not be printed. | |
2549 | ||
2550 | @kindex show print inferior-events | |
2551 | @item show print inferior-events | |
2552 | Show whether messages will be printed when @value{GDBN} detects that | |
2553 | inferiors have started, exited or have been detached. | |
2554 | @end table | |
2555 | ||
6c95b8df PA |
2556 | Many commands will work the same with multiple programs as with a |
2557 | single program: e.g., @code{print myglobal} will simply display the | |
2558 | value of @code{myglobal} in the current inferior. | |
2559 | ||
2560 | ||
2561 | Occasionaly, when debugging @value{GDBN} itself, it may be useful to | |
2562 | get more info about the relationship of inferiors, programs, address | |
2563 | spaces in a debug session. You can do that with the @w{@code{maint | |
2564 | info program-spaces}} command. | |
2565 | ||
2566 | @table @code | |
2567 | @kindex maint info program-spaces | |
2568 | @item maint info program-spaces | |
2569 | Print a list of all program spaces currently being managed by | |
2570 | @value{GDBN}. | |
2571 | ||
2572 | @value{GDBN} displays for each program space (in this order): | |
2573 | ||
2574 | @enumerate | |
2575 | @item | |
2576 | the program space number assigned by @value{GDBN} | |
2577 | ||
2578 | @item | |
2579 | the name of the executable loaded into the program space, with e.g., | |
2580 | the @code{file} command. | |
2581 | ||
2582 | @end enumerate | |
2583 | ||
2584 | @noindent | |
2585 | An asterisk @samp{*} preceding the @value{GDBN} program space number | |
2586 | indicates the current program space. | |
2587 | ||
2588 | In addition, below each program space line, @value{GDBN} prints extra | |
2589 | information that isn't suitable to display in tabular form. For | |
2590 | example, the list of inferiors bound to the program space. | |
2591 | ||
2592 | @smallexample | |
2593 | (@value{GDBP}) maint info program-spaces | |
2594 | Id Executable | |
2595 | 2 goodbye | |
2596 | Bound inferiors: ID 1 (process 21561) | |
2597 | * 1 hello | |
2598 | @end smallexample | |
2599 | ||
2600 | Here we can see that no inferior is running the program @code{hello}, | |
2601 | while @code{process 21561} is running the program @code{goodbye}. On | |
2602 | some targets, it is possible that multiple inferiors are bound to the | |
2603 | same program space. The most common example is that of debugging both | |
2604 | the parent and child processes of a @code{vfork} call. For example, | |
2605 | ||
2606 | @smallexample | |
2607 | (@value{GDBP}) maint info program-spaces | |
2608 | Id Executable | |
2609 | * 1 vfork-test | |
2610 | Bound inferiors: ID 2 (process 18050), ID 1 (process 18045) | |
2611 | @end smallexample | |
2612 | ||
2613 | Here, both inferior 2 and inferior 1 are running in the same program | |
2614 | space as a result of inferior 1 having executed a @code{vfork} call. | |
2615 | @end table | |
2616 | ||
6d2ebf8b | 2617 | @node Threads |
79a6e687 | 2618 | @section Debugging Programs with Multiple Threads |
c906108c SS |
2619 | |
2620 | @cindex threads of execution | |
2621 | @cindex multiple threads | |
2622 | @cindex switching threads | |
2623 | In some operating systems, such as HP-UX and Solaris, a single program | |
2624 | may have more than one @dfn{thread} of execution. The precise semantics | |
2625 | of threads differ from one operating system to another, but in general | |
2626 | the threads of a single program are akin to multiple processes---except | |
2627 | that they share one address space (that is, they can all examine and | |
2628 | modify the same variables). On the other hand, each thread has its own | |
2629 | registers and execution stack, and perhaps private memory. | |
2630 | ||
2631 | @value{GDBN} provides these facilities for debugging multi-thread | |
2632 | programs: | |
2633 | ||
2634 | @itemize @bullet | |
2635 | @item automatic notification of new threads | |
2636 | @item @samp{thread @var{threadno}}, a command to switch among threads | |
2637 | @item @samp{info threads}, a command to inquire about existing threads | |
5d161b24 | 2638 | @item @samp{thread apply [@var{threadno}] [@var{all}] @var{args}}, |
c906108c SS |
2639 | a command to apply a command to a list of threads |
2640 | @item thread-specific breakpoints | |
93815fbf VP |
2641 | @item @samp{set print thread-events}, which controls printing of |
2642 | messages on thread start and exit. | |
17a37d48 PP |
2643 | @item @samp{set libthread-db-search-path @var{path}}, which lets |
2644 | the user specify which @code{libthread_db} to use if the default choice | |
2645 | isn't compatible with the program. | |
c906108c SS |
2646 | @end itemize |
2647 | ||
c906108c SS |
2648 | @quotation |
2649 | @emph{Warning:} These facilities are not yet available on every | |
2650 | @value{GDBN} configuration where the operating system supports threads. | |
2651 | If your @value{GDBN} does not support threads, these commands have no | |
2652 | effect. For example, a system without thread support shows no output | |
2653 | from @samp{info threads}, and always rejects the @code{thread} command, | |
2654 | like this: | |
2655 | ||
2656 | @smallexample | |
2657 | (@value{GDBP}) info threads | |
2658 | (@value{GDBP}) thread 1 | |
2659 | Thread ID 1 not known. Use the "info threads" command to | |
2660 | see the IDs of currently known threads. | |
2661 | @end smallexample | |
2662 | @c FIXME to implementors: how hard would it be to say "sorry, this GDB | |
2663 | @c doesn't support threads"? | |
2664 | @end quotation | |
c906108c SS |
2665 | |
2666 | @cindex focus of debugging | |
2667 | @cindex current thread | |
2668 | The @value{GDBN} thread debugging facility allows you to observe all | |
2669 | threads while your program runs---but whenever @value{GDBN} takes | |
2670 | control, one thread in particular is always the focus of debugging. | |
2671 | This thread is called the @dfn{current thread}. Debugging commands show | |
2672 | program information from the perspective of the current thread. | |
2673 | ||
41afff9a | 2674 | @cindex @code{New} @var{systag} message |
c906108c SS |
2675 | @cindex thread identifier (system) |
2676 | @c FIXME-implementors!! It would be more helpful if the [New...] message | |
2677 | @c included GDB's numeric thread handle, so you could just go to that | |
2678 | @c thread without first checking `info threads'. | |
2679 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2680 | the target system's identification for the thread with a message in the | |
2681 | form @samp{[New @var{systag}]}. @var{systag} is a thread identifier | |
2682 | whose form varies depending on the particular system. For example, on | |
8807d78b | 2683 | @sc{gnu}/Linux, you might see |
c906108c | 2684 | |
474c8240 | 2685 | @smallexample |
8807d78b | 2686 | [New Thread 46912507313328 (LWP 25582)] |
474c8240 | 2687 | @end smallexample |
c906108c SS |
2688 | |
2689 | @noindent | |
2690 | when @value{GDBN} notices a new thread. In contrast, on an SGI system, | |
2691 | the @var{systag} is simply something like @samp{process 368}, with no | |
2692 | further qualifier. | |
2693 | ||
2694 | @c FIXME!! (1) Does the [New...] message appear even for the very first | |
2695 | @c thread of a program, or does it only appear for the | |
6ca652b0 | 2696 | @c second---i.e.@: when it becomes obvious we have a multithread |
c906108c SS |
2697 | @c program? |
2698 | @c (2) *Is* there necessarily a first thread always? Or do some | |
2699 | @c multithread systems permit starting a program with multiple | |
5d161b24 | 2700 | @c threads ab initio? |
c906108c SS |
2701 | |
2702 | @cindex thread number | |
2703 | @cindex thread identifier (GDB) | |
2704 | For debugging purposes, @value{GDBN} associates its own thread | |
2705 | number---always a single integer---with each thread in your program. | |
2706 | ||
2707 | @table @code | |
2708 | @kindex info threads | |
2709 | @item info threads | |
2710 | Display a summary of all threads currently in your | |
2711 | program. @value{GDBN} displays for each thread (in this order): | |
2712 | ||
2713 | @enumerate | |
09d4efe1 EZ |
2714 | @item |
2715 | the thread number assigned by @value{GDBN} | |
c906108c | 2716 | |
09d4efe1 EZ |
2717 | @item |
2718 | the target system's thread identifier (@var{systag}) | |
c906108c | 2719 | |
09d4efe1 EZ |
2720 | @item |
2721 | the current stack frame summary for that thread | |
c906108c SS |
2722 | @end enumerate |
2723 | ||
2724 | @noindent | |
2725 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2726 | indicates the current thread. | |
2727 | ||
5d161b24 | 2728 | For example, |
c906108c SS |
2729 | @end table |
2730 | @c end table here to get a little more width for example | |
2731 | ||
2732 | @smallexample | |
2733 | (@value{GDBP}) info threads | |
2734 | 3 process 35 thread 27 0x34e5 in sigpause () | |
2735 | 2 process 35 thread 23 0x34e5 in sigpause () | |
2736 | * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) | |
2737 | at threadtest.c:68 | |
2738 | @end smallexample | |
53a5351d JM |
2739 | |
2740 | On HP-UX systems: | |
c906108c | 2741 | |
4644b6e3 EZ |
2742 | @cindex debugging multithreaded programs (on HP-UX) |
2743 | @cindex thread identifier (GDB), on HP-UX | |
c906108c SS |
2744 | For debugging purposes, @value{GDBN} associates its own thread |
2745 | number---a small integer assigned in thread-creation order---with each | |
2746 | thread in your program. | |
2747 | ||
41afff9a EZ |
2748 | @cindex @code{New} @var{systag} message, on HP-UX |
2749 | @cindex thread identifier (system), on HP-UX | |
c906108c SS |
2750 | @c FIXME-implementors!! It would be more helpful if the [New...] message |
2751 | @c included GDB's numeric thread handle, so you could just go to that | |
2752 | @c thread without first checking `info threads'. | |
2753 | Whenever @value{GDBN} detects a new thread in your program, it displays | |
2754 | both @value{GDBN}'s thread number and the target system's identification for the thread with a message in the | |
2755 | form @samp{[New @var{systag}]}. @var{systag} is a thread identifier | |
2756 | whose form varies depending on the particular system. For example, on | |
2757 | HP-UX, you see | |
2758 | ||
474c8240 | 2759 | @smallexample |
c906108c | 2760 | [New thread 2 (system thread 26594)] |
474c8240 | 2761 | @end smallexample |
c906108c SS |
2762 | |
2763 | @noindent | |
5d161b24 | 2764 | when @value{GDBN} notices a new thread. |
c906108c SS |
2765 | |
2766 | @table @code | |
4644b6e3 | 2767 | @kindex info threads (HP-UX) |
c906108c SS |
2768 | @item info threads |
2769 | Display a summary of all threads currently in your | |
2770 | program. @value{GDBN} displays for each thread (in this order): | |
2771 | ||
2772 | @enumerate | |
2773 | @item the thread number assigned by @value{GDBN} | |
2774 | ||
2775 | @item the target system's thread identifier (@var{systag}) | |
2776 | ||
2777 | @item the current stack frame summary for that thread | |
2778 | @end enumerate | |
2779 | ||
2780 | @noindent | |
2781 | An asterisk @samp{*} to the left of the @value{GDBN} thread number | |
2782 | indicates the current thread. | |
2783 | ||
5d161b24 | 2784 | For example, |
c906108c SS |
2785 | @end table |
2786 | @c end table here to get a little more width for example | |
2787 | ||
474c8240 | 2788 | @smallexample |
c906108c | 2789 | (@value{GDBP}) info threads |
6d2ebf8b SS |
2790 | * 3 system thread 26607 worker (wptr=0x7b09c318 "@@") \@* |
2791 | at quicksort.c:137 | |
2792 | 2 system thread 26606 0x7b0030d8 in __ksleep () \@* | |
2793 | from /usr/lib/libc.2 | |
2794 | 1 system thread 27905 0x7b003498 in _brk () \@* | |
2795 | from /usr/lib/libc.2 | |
474c8240 | 2796 | @end smallexample |
c906108c | 2797 | |
c45da7e6 EZ |
2798 | On Solaris, you can display more information about user threads with a |
2799 | Solaris-specific command: | |
2800 | ||
2801 | @table @code | |
2802 | @item maint info sol-threads | |
2803 | @kindex maint info sol-threads | |
2804 | @cindex thread info (Solaris) | |
2805 | Display info on Solaris user threads. | |
2806 | @end table | |
2807 | ||
c906108c SS |
2808 | @table @code |
2809 | @kindex thread @var{threadno} | |
2810 | @item thread @var{threadno} | |
2811 | Make thread number @var{threadno} the current thread. The command | |
2812 | argument @var{threadno} is the internal @value{GDBN} thread number, as | |
2813 | shown in the first field of the @samp{info threads} display. | |
2814 | @value{GDBN} responds by displaying the system identifier of the thread | |
2815 | you selected, and its current stack frame summary: | |
2816 | ||
2817 | @smallexample | |
2818 | @c FIXME!! This example made up; find a @value{GDBN} w/threads and get real one | |
2819 | (@value{GDBP}) thread 2 | |
c906108c | 2820 | [Switching to process 35 thread 23] |
c906108c SS |
2821 | 0x34e5 in sigpause () |
2822 | @end smallexample | |
2823 | ||
2824 | @noindent | |
2825 | As with the @samp{[New @dots{}]} message, the form of the text after | |
2826 | @samp{Switching to} depends on your system's conventions for identifying | |
5d161b24 | 2827 | threads. |
c906108c | 2828 | |
6aed2dbc SS |
2829 | @vindex $_thread@r{, convenience variable} |
2830 | The debugger convenience variable @samp{$_thread} contains the number | |
2831 | of the current thread. You may find this useful in writing breakpoint | |
2832 | conditional expressions, command scripts, and so forth. See | |
2833 | @xref{Convenience Vars,, Convenience Variables}, for general | |
2834 | information on convenience variables. | |
2835 | ||
9c16f35a | 2836 | @kindex thread apply |
638ac427 | 2837 | @cindex apply command to several threads |
839c27b7 EZ |
2838 | @item thread apply [@var{threadno}] [@var{all}] @var{command} |
2839 | The @code{thread apply} command allows you to apply the named | |
2840 | @var{command} to one or more threads. Specify the numbers of the | |
2841 | threads that you want affected with the command argument | |
2842 | @var{threadno}. It can be a single thread number, one of the numbers | |
2843 | shown in the first field of the @samp{info threads} display; or it | |
2844 | could be a range of thread numbers, as in @code{2-4}. To apply a | |
2845 | command to all threads, type @kbd{thread apply all @var{command}}. | |
93815fbf VP |
2846 | |
2847 | @kindex set print thread-events | |
2848 | @cindex print messages on thread start and exit | |
2849 | @item set print thread-events | |
2850 | @itemx set print thread-events on | |
2851 | @itemx set print thread-events off | |
2852 | The @code{set print thread-events} command allows you to enable or | |
2853 | disable printing of messages when @value{GDBN} notices that new threads have | |
2854 | started or that threads have exited. By default, these messages will | |
2855 | be printed if detection of these events is supported by the target. | |
2856 | Note that these messages cannot be disabled on all targets. | |
2857 | ||
2858 | @kindex show print thread-events | |
2859 | @item show print thread-events | |
2860 | Show whether messages will be printed when @value{GDBN} detects that threads | |
2861 | have started and exited. | |
c906108c SS |
2862 | @end table |
2863 | ||
79a6e687 | 2864 | @xref{Thread Stops,,Stopping and Starting Multi-thread Programs}, for |
c906108c SS |
2865 | more information about how @value{GDBN} behaves when you stop and start |
2866 | programs with multiple threads. | |
2867 | ||
79a6e687 | 2868 | @xref{Set Watchpoints,,Setting Watchpoints}, for information about |
c906108c | 2869 | watchpoints in programs with multiple threads. |
c906108c | 2870 | |
17a37d48 PP |
2871 | @table @code |
2872 | @kindex set libthread-db-search-path | |
2873 | @cindex search path for @code{libthread_db} | |
2874 | @item set libthread-db-search-path @r{[}@var{path}@r{]} | |
2875 | If this variable is set, @var{path} is a colon-separated list of | |
2876 | directories @value{GDBN} will use to search for @code{libthread_db}. | |
2877 | If you omit @var{path}, @samp{libthread-db-search-path} will be reset to | |
2878 | an empty list. | |
2879 | ||
2880 | On @sc{gnu}/Linux and Solaris systems, @value{GDBN} uses a ``helper'' | |
2881 | @code{libthread_db} library to obtain information about threads in the | |
2882 | inferior process. @value{GDBN} will use @samp{libthread-db-search-path} | |
2883 | to find @code{libthread_db}. If that fails, @value{GDBN} will continue | |
2884 | with default system shared library directories, and finally the directory | |
2885 | from which @code{libpthread} was loaded in the inferior process. | |
2886 | ||
2887 | For any @code{libthread_db} library @value{GDBN} finds in above directories, | |
2888 | @value{GDBN} attempts to initialize it with the current inferior process. | |
2889 | If this initialization fails (which could happen because of a version | |
2890 | mismatch between @code{libthread_db} and @code{libpthread}), @value{GDBN} | |
2891 | will unload @code{libthread_db}, and continue with the next directory. | |
2892 | If none of @code{libthread_db} libraries initialize successfully, | |
2893 | @value{GDBN} will issue a warning and thread debugging will be disabled. | |
2894 | ||
2895 | Setting @code{libthread-db-search-path} is currently implemented | |
2896 | only on some platforms. | |
2897 | ||
2898 | @kindex show libthread-db-search-path | |
2899 | @item show libthread-db-search-path | |
2900 | Display current libthread_db search path. | |
02d868e8 PP |
2901 | |
2902 | @kindex set debug libthread-db | |
2903 | @kindex show debug libthread-db | |
2904 | @cindex debugging @code{libthread_db} | |
2905 | @item set debug libthread-db | |
2906 | @itemx show debug libthread-db | |
2907 | Turns on or off display of @code{libthread_db}-related events. | |
2908 | Use @code{1} to enable, @code{0} to disable. | |
17a37d48 PP |
2909 | @end table |
2910 | ||
6c95b8df PA |
2911 | @node Forks |
2912 | @section Debugging Forks | |
c906108c SS |
2913 | |
2914 | @cindex fork, debugging programs which call | |
2915 | @cindex multiple processes | |
2916 | @cindex processes, multiple | |
53a5351d JM |
2917 | On most systems, @value{GDBN} has no special support for debugging |
2918 | programs which create additional processes using the @code{fork} | |
2919 | function. When a program forks, @value{GDBN} will continue to debug the | |
2920 | parent process and the child process will run unimpeded. If you have | |
2921 | set a breakpoint in any code which the child then executes, the child | |
2922 | will get a @code{SIGTRAP} signal which (unless it catches the signal) | |
2923 | will cause it to terminate. | |
c906108c SS |
2924 | |
2925 | However, if you want to debug the child process there is a workaround | |
2926 | which isn't too painful. Put a call to @code{sleep} in the code which | |
2927 | the child process executes after the fork. It may be useful to sleep | |
2928 | only if a certain environment variable is set, or a certain file exists, | |
2929 | so that the delay need not occur when you don't want to run @value{GDBN} | |
2930 | on the child. While the child is sleeping, use the @code{ps} program to | |
2931 | get its process ID. Then tell @value{GDBN} (a new invocation of | |
2932 | @value{GDBN} if you are also debugging the parent process) to attach to | |
d4f3574e | 2933 | the child process (@pxref{Attach}). From that point on you can debug |
c906108c | 2934 | the child process just like any other process which you attached to. |
c906108c | 2935 | |
b51970ac DJ |
2936 | On some systems, @value{GDBN} provides support for debugging programs that |
2937 | create additional processes using the @code{fork} or @code{vfork} functions. | |
2938 | Currently, the only platforms with this feature are HP-UX (11.x and later | |
a6b151f1 | 2939 | only?) and @sc{gnu}/Linux (kernel version 2.5.60 and later). |
c906108c SS |
2940 | |
2941 | By default, when a program forks, @value{GDBN} will continue to debug | |
2942 | the parent process and the child process will run unimpeded. | |
2943 | ||
2944 | If you want to follow the child process instead of the parent process, | |
2945 | use the command @w{@code{set follow-fork-mode}}. | |
2946 | ||
2947 | @table @code | |
2948 | @kindex set follow-fork-mode | |
2949 | @item set follow-fork-mode @var{mode} | |
2950 | Set the debugger response to a program call of @code{fork} or | |
2951 | @code{vfork}. A call to @code{fork} or @code{vfork} creates a new | |
9c16f35a | 2952 | process. The @var{mode} argument can be: |
c906108c SS |
2953 | |
2954 | @table @code | |
2955 | @item parent | |
2956 | The original process is debugged after a fork. The child process runs | |
2df3850c | 2957 | unimpeded. This is the default. |
c906108c SS |
2958 | |
2959 | @item child | |
2960 | The new process is debugged after a fork. The parent process runs | |
2961 | unimpeded. | |
2962 | ||
c906108c SS |
2963 | @end table |
2964 | ||
9c16f35a | 2965 | @kindex show follow-fork-mode |
c906108c | 2966 | @item show follow-fork-mode |
2df3850c | 2967 | Display the current debugger response to a @code{fork} or @code{vfork} call. |
c906108c SS |
2968 | @end table |
2969 | ||
5c95884b MS |
2970 | @cindex debugging multiple processes |
2971 | On Linux, if you want to debug both the parent and child processes, use the | |
2972 | command @w{@code{set detach-on-fork}}. | |
2973 | ||
2974 | @table @code | |
2975 | @kindex set detach-on-fork | |
2976 | @item set detach-on-fork @var{mode} | |
2977 | Tells gdb whether to detach one of the processes after a fork, or | |
2978 | retain debugger control over them both. | |
2979 | ||
2980 | @table @code | |
2981 | @item on | |
2982 | The child process (or parent process, depending on the value of | |
2983 | @code{follow-fork-mode}) will be detached and allowed to run | |
2984 | independently. This is the default. | |
2985 | ||
2986 | @item off | |
2987 | Both processes will be held under the control of @value{GDBN}. | |
2988 | One process (child or parent, depending on the value of | |
2989 | @code{follow-fork-mode}) is debugged as usual, while the other | |
2990 | is held suspended. | |
2991 | ||
2992 | @end table | |
2993 | ||
11310833 NR |
2994 | @kindex show detach-on-fork |
2995 | @item show detach-on-fork | |
2996 | Show whether detach-on-fork mode is on/off. | |
5c95884b MS |
2997 | @end table |
2998 | ||
2277426b PA |
2999 | If you choose to set @samp{detach-on-fork} mode off, then @value{GDBN} |
3000 | will retain control of all forked processes (including nested forks). | |
3001 | You can list the forked processes under the control of @value{GDBN} by | |
3002 | using the @w{@code{info inferiors}} command, and switch from one fork | |
6c95b8df PA |
3003 | to another by using the @code{inferior} command (@pxref{Inferiors and |
3004 | Programs, ,Debugging Multiple Inferiors and Programs}). | |
5c95884b MS |
3005 | |
3006 | To quit debugging one of the forked processes, you can either detach | |
2277426b PA |
3007 | from it by using the @w{@code{detach inferior}} command (allowing it |
3008 | to run independently), or kill it using the @w{@code{kill inferior}} | |
6c95b8df PA |
3009 | command. @xref{Inferiors and Programs, ,Debugging Multiple Inferiors |
3010 | and Programs}. | |
5c95884b | 3011 | |
c906108c SS |
3012 | If you ask to debug a child process and a @code{vfork} is followed by an |
3013 | @code{exec}, @value{GDBN} executes the new target up to the first | |
3014 | breakpoint in the new target. If you have a breakpoint set on | |
3015 | @code{main} in your original program, the breakpoint will also be set on | |
3016 | the child process's @code{main}. | |
3017 | ||
2277426b PA |
3018 | On some systems, when a child process is spawned by @code{vfork}, you |
3019 | cannot debug the child or parent until an @code{exec} call completes. | |
c906108c SS |
3020 | |
3021 | If you issue a @code{run} command to @value{GDBN} after an @code{exec} | |
6c95b8df PA |
3022 | call executes, the new target restarts. To restart the parent |
3023 | process, use the @code{file} command with the parent executable name | |
3024 | as its argument. By default, after an @code{exec} call executes, | |
3025 | @value{GDBN} discards the symbols of the previous executable image. | |
3026 | You can change this behaviour with the @w{@code{set follow-exec-mode}} | |
3027 | command. | |
3028 | ||
3029 | @table @code | |
3030 | @kindex set follow-exec-mode | |
3031 | @item set follow-exec-mode @var{mode} | |
3032 | ||
3033 | Set debugger response to a program call of @code{exec}. An | |
3034 | @code{exec} call replaces the program image of a process. | |
3035 | ||
3036 | @code{follow-exec-mode} can be: | |
3037 | ||
3038 | @table @code | |
3039 | @item new | |
3040 | @value{GDBN} creates a new inferior and rebinds the process to this | |
3041 | new inferior. The program the process was running before the | |
3042 | @code{exec} call can be restarted afterwards by restarting the | |
3043 | original inferior. | |
3044 | ||
3045 | For example: | |
3046 | ||
3047 | @smallexample | |
3048 | (@value{GDBP}) info inferiors | |
3049 | (gdb) info inferior | |
3050 | Id Description Executable | |
3051 | * 1 <null> prog1 | |
3052 | (@value{GDBP}) run | |
3053 | process 12020 is executing new program: prog2 | |
3054 | Program exited normally. | |
3055 | (@value{GDBP}) info inferiors | |
3056 | Id Description Executable | |
3057 | * 2 <null> prog2 | |
3058 | 1 <null> prog1 | |
3059 | @end smallexample | |
3060 | ||
3061 | @item same | |
3062 | @value{GDBN} keeps the process bound to the same inferior. The new | |
3063 | executable image replaces the previous executable loaded in the | |
3064 | inferior. Restarting the inferior after the @code{exec} call, with | |
3065 | e.g., the @code{run} command, restarts the executable the process was | |
3066 | running after the @code{exec} call. This is the default mode. | |
3067 | ||
3068 | For example: | |
3069 | ||
3070 | @smallexample | |
3071 | (@value{GDBP}) info inferiors | |
3072 | Id Description Executable | |
3073 | * 1 <null> prog1 | |
3074 | (@value{GDBP}) run | |
3075 | process 12020 is executing new program: prog2 | |
3076 | Program exited normally. | |
3077 | (@value{GDBP}) info inferiors | |
3078 | Id Description Executable | |
3079 | * 1 <null> prog2 | |
3080 | @end smallexample | |
3081 | ||
3082 | @end table | |
3083 | @end table | |
c906108c SS |
3084 | |
3085 | You can use the @code{catch} command to make @value{GDBN} stop whenever | |
3086 | a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set | |
79a6e687 | 3087 | Catchpoints, ,Setting Catchpoints}. |
c906108c | 3088 | |
5c95884b | 3089 | @node Checkpoint/Restart |
79a6e687 | 3090 | @section Setting a @emph{Bookmark} to Return to Later |
5c95884b MS |
3091 | |
3092 | @cindex checkpoint | |
3093 | @cindex restart | |
3094 | @cindex bookmark | |
3095 | @cindex snapshot of a process | |
3096 | @cindex rewind program state | |
3097 | ||
3098 | On certain operating systems@footnote{Currently, only | |
3099 | @sc{gnu}/Linux.}, @value{GDBN} is able to save a @dfn{snapshot} of a | |
3100 | program's state, called a @dfn{checkpoint}, and come back to it | |
3101 | later. | |
3102 | ||
3103 | Returning to a checkpoint effectively undoes everything that has | |
3104 | happened in the program since the @code{checkpoint} was saved. This | |
3105 | includes changes in memory, registers, and even (within some limits) | |
3106 | system state. Effectively, it is like going back in time to the | |
3107 | moment when the checkpoint was saved. | |
3108 | ||
3109 | Thus, if you're stepping thru a program and you think you're | |
3110 | getting close to the point where things go wrong, you can save | |
3111 | a checkpoint. Then, if you accidentally go too far and miss | |
3112 | the critical statement, instead of having to restart your program | |
3113 | from the beginning, you can just go back to the checkpoint and | |
3114 | start again from there. | |
3115 | ||
3116 | This can be especially useful if it takes a lot of time or | |
3117 | steps to reach the point where you think the bug occurs. | |
3118 | ||
3119 | To use the @code{checkpoint}/@code{restart} method of debugging: | |
3120 | ||
3121 | @table @code | |
3122 | @kindex checkpoint | |
3123 | @item checkpoint | |
3124 | Save a snapshot of the debugged program's current execution state. | |
3125 | The @code{checkpoint} command takes no arguments, but each checkpoint | |
3126 | is assigned a small integer id, similar to a breakpoint id. | |
3127 | ||
3128 | @kindex info checkpoints | |
3129 | @item info checkpoints | |
3130 | List the checkpoints that have been saved in the current debugging | |
3131 | session. For each checkpoint, the following information will be | |
3132 | listed: | |
3133 | ||
3134 | @table @code | |
3135 | @item Checkpoint ID | |
3136 | @item Process ID | |
3137 | @item Code Address | |
3138 | @item Source line, or label | |
3139 | @end table | |
3140 | ||
3141 | @kindex restart @var{checkpoint-id} | |
3142 | @item restart @var{checkpoint-id} | |
3143 | Restore the program state that was saved as checkpoint number | |
3144 | @var{checkpoint-id}. All program variables, registers, stack frames | |
3145 | etc.@: will be returned to the values that they had when the checkpoint | |
3146 | was saved. In essence, gdb will ``wind back the clock'' to the point | |
3147 | in time when the checkpoint was saved. | |
3148 | ||
3149 | Note that breakpoints, @value{GDBN} variables, command history etc. | |
3150 | are not affected by restoring a checkpoint. In general, a checkpoint | |
3151 | only restores things that reside in the program being debugged, not in | |
3152 | the debugger. | |
3153 | ||
b8db102d MS |
3154 | @kindex delete checkpoint @var{checkpoint-id} |
3155 | @item delete checkpoint @var{checkpoint-id} | |
5c95884b MS |
3156 | Delete the previously-saved checkpoint identified by @var{checkpoint-id}. |
3157 | ||
3158 | @end table | |
3159 | ||
3160 | Returning to a previously saved checkpoint will restore the user state | |
3161 | of the program being debugged, plus a significant subset of the system | |
3162 | (OS) state, including file pointers. It won't ``un-write'' data from | |
3163 | a file, but it will rewind the file pointer to the previous location, | |
3164 | so that the previously written data can be overwritten. For files | |
3165 | opened in read mode, the pointer will also be restored so that the | |
3166 | previously read data can be read again. | |
3167 | ||
3168 | Of course, characters that have been sent to a printer (or other | |
3169 | external device) cannot be ``snatched back'', and characters received | |
3170 | from eg.@: a serial device can be removed from internal program buffers, | |
3171 | but they cannot be ``pushed back'' into the serial pipeline, ready to | |
3172 | be received again. Similarly, the actual contents of files that have | |
3173 | been changed cannot be restored (at this time). | |
3174 | ||
3175 | However, within those constraints, you actually can ``rewind'' your | |
3176 | program to a previously saved point in time, and begin debugging it | |
3177 | again --- and you can change the course of events so as to debug a | |
3178 | different execution path this time. | |
3179 | ||
3180 | @cindex checkpoints and process id | |
3181 | Finally, there is one bit of internal program state that will be | |
3182 | different when you return to a checkpoint --- the program's process | |
3183 | id. Each checkpoint will have a unique process id (or @var{pid}), | |
3184 | and each will be different from the program's original @var{pid}. | |
3185 | If your program has saved a local copy of its process id, this could | |
3186 | potentially pose a problem. | |
3187 | ||
79a6e687 | 3188 | @subsection A Non-obvious Benefit of Using Checkpoints |
5c95884b MS |
3189 | |
3190 | On some systems such as @sc{gnu}/Linux, address space randomization | |
3191 | is performed on new processes for security reasons. This makes it | |
3192 | difficult or impossible to set a breakpoint, or watchpoint, on an | |
3193 | absolute address if you have to restart the program, since the | |
3194 | absolute location of a symbol will change from one execution to the | |
3195 | next. | |
3196 | ||
3197 | A checkpoint, however, is an @emph{identical} copy of a process. | |
3198 | Therefore if you create a checkpoint at (eg.@:) the start of main, | |
3199 | and simply return to that checkpoint instead of restarting the | |
3200 | process, you can avoid the effects of address randomization and | |
3201 | your symbols will all stay in the same place. | |
3202 | ||
6d2ebf8b | 3203 | @node Stopping |
c906108c SS |
3204 | @chapter Stopping and Continuing |
3205 | ||
3206 | The principal purposes of using a debugger are so that you can stop your | |
3207 | program before it terminates; or so that, if your program runs into | |
3208 | trouble, you can investigate and find out why. | |
3209 | ||
7a292a7a SS |
3210 | Inside @value{GDBN}, your program may stop for any of several reasons, |
3211 | such as a signal, a breakpoint, or reaching a new line after a | |
3212 | @value{GDBN} command such as @code{step}. You may then examine and | |
3213 | change variables, set new breakpoints or remove old ones, and then | |
3214 | continue execution. Usually, the messages shown by @value{GDBN} provide | |
3215 | ample explanation of the status of your program---but you can also | |
3216 | explicitly request this information at any time. | |
c906108c SS |
3217 | |
3218 | @table @code | |
3219 | @kindex info program | |
3220 | @item info program | |
3221 | Display information about the status of your program: whether it is | |
7a292a7a | 3222 | running or not, what process it is, and why it stopped. |
c906108c SS |
3223 | @end table |
3224 | ||
3225 | @menu | |
3226 | * Breakpoints:: Breakpoints, watchpoints, and catchpoints | |
3227 | * Continuing and Stepping:: Resuming execution | |
c906108c | 3228 | * Signals:: Signals |
c906108c | 3229 | * Thread Stops:: Stopping and starting multi-thread programs |
c906108c SS |
3230 | @end menu |
3231 | ||
6d2ebf8b | 3232 | @node Breakpoints |
79a6e687 | 3233 | @section Breakpoints, Watchpoints, and Catchpoints |
c906108c SS |
3234 | |
3235 | @cindex breakpoints | |
3236 | A @dfn{breakpoint} makes your program stop whenever a certain point in | |
3237 | the program is reached. For each breakpoint, you can add conditions to | |
3238 | control in finer detail whether your program stops. You can set | |
3239 | breakpoints with the @code{break} command and its variants (@pxref{Set | |
79a6e687 | 3240 | Breaks, ,Setting Breakpoints}), to specify the place where your program |
c906108c SS |
3241 | should stop by line number, function name or exact address in the |
3242 | program. | |
3243 | ||
09d4efe1 EZ |
3244 | On some systems, you can set breakpoints in shared libraries before |
3245 | the executable is run. There is a minor limitation on HP-UX systems: | |
3246 | you must wait until the executable is run in order to set breakpoints | |
3247 | in shared library routines that are not called directly by the program | |
3248 | (for example, routines that are arguments in a @code{pthread_create} | |
3249 | call). | |
c906108c SS |
3250 | |
3251 | @cindex watchpoints | |
fd60e0df | 3252 | @cindex data breakpoints |
c906108c SS |
3253 | @cindex memory tracing |
3254 | @cindex breakpoint on memory address | |
3255 | @cindex breakpoint on variable modification | |
3256 | A @dfn{watchpoint} is a special breakpoint that stops your program | |
fd60e0df | 3257 | when the value of an expression changes. The expression may be a value |
0ced0c34 | 3258 | of a variable, or it could involve values of one or more variables |
fd60e0df EZ |
3259 | combined by operators, such as @samp{a + b}. This is sometimes called |
3260 | @dfn{data breakpoints}. You must use a different command to set | |
79a6e687 | 3261 | watchpoints (@pxref{Set Watchpoints, ,Setting Watchpoints}), but aside |
fd60e0df EZ |
3262 | from that, you can manage a watchpoint like any other breakpoint: you |
3263 | enable, disable, and delete both breakpoints and watchpoints using the | |
3264 | same commands. | |
c906108c SS |
3265 | |
3266 | You can arrange to have values from your program displayed automatically | |
3267 | whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,, | |
79a6e687 | 3268 | Automatic Display}. |
c906108c SS |
3269 | |
3270 | @cindex catchpoints | |
3271 | @cindex breakpoint on events | |
3272 | A @dfn{catchpoint} is another special breakpoint that stops your program | |
b37052ae | 3273 | when a certain kind of event occurs, such as the throwing of a C@t{++} |
c906108c SS |
3274 | exception or the loading of a library. As with watchpoints, you use a |
3275 | different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting | |
79a6e687 | 3276 | Catchpoints}), but aside from that, you can manage a catchpoint like any |
c906108c | 3277 | other breakpoint. (To stop when your program receives a signal, use the |
d4f3574e | 3278 | @code{handle} command; see @ref{Signals, ,Signals}.) |
c906108c SS |
3279 | |
3280 | @cindex breakpoint numbers | |
3281 | @cindex numbers for breakpoints | |
3282 | @value{GDBN} assigns a number to each breakpoint, watchpoint, or | |
3283 | catchpoint when you create it; these numbers are successive integers | |
3284 | starting with one. In many of the commands for controlling various | |
3285 | features of breakpoints you use the breakpoint number to say which | |
3286 | breakpoint you want to change. Each breakpoint may be @dfn{enabled} or | |
3287 | @dfn{disabled}; if disabled, it has no effect on your program until you | |
3288 | enable it again. | |
3289 | ||
c5394b80 JM |
3290 | @cindex breakpoint ranges |
3291 | @cindex ranges of breakpoints | |
3292 | Some @value{GDBN} commands accept a range of breakpoints on which to | |
3293 | operate. A breakpoint range is either a single breakpoint number, like | |
3294 | @samp{5}, or two such numbers, in increasing order, separated by a | |
3295 | hyphen, like @samp{5-7}. When a breakpoint range is given to a command, | |
d52fb0e9 | 3296 | all breakpoints in that range are operated on. |
c5394b80 | 3297 | |
c906108c SS |
3298 | @menu |
3299 | * Set Breaks:: Setting breakpoints | |
3300 | * Set Watchpoints:: Setting watchpoints | |
3301 | * Set Catchpoints:: Setting catchpoints | |
3302 | * Delete Breaks:: Deleting breakpoints | |
3303 | * Disabling:: Disabling breakpoints | |
3304 | * Conditions:: Break conditions | |
3305 | * Break Commands:: Breakpoint command lists | |
6149aea9 | 3306 | * Save Breakpoints:: How to save breakpoints in a file |
d4f3574e | 3307 | * Error in Breakpoints:: ``Cannot insert breakpoints'' |
79a6e687 | 3308 | * Breakpoint-related Warnings:: ``Breakpoint address adjusted...'' |
c906108c SS |
3309 | @end menu |
3310 | ||
6d2ebf8b | 3311 | @node Set Breaks |
79a6e687 | 3312 | @subsection Setting Breakpoints |
c906108c | 3313 | |
5d161b24 | 3314 | @c FIXME LMB what does GDB do if no code on line of breakpt? |
c906108c SS |
3315 | @c consider in particular declaration with/without initialization. |
3316 | @c | |
3317 | @c FIXME 2 is there stuff on this already? break at fun start, already init? | |
3318 | ||
3319 | @kindex break | |
41afff9a EZ |
3320 | @kindex b @r{(@code{break})} |
3321 | @vindex $bpnum@r{, convenience variable} | |
c906108c SS |
3322 | @cindex latest breakpoint |
3323 | Breakpoints are set with the @code{break} command (abbreviated | |
5d161b24 | 3324 | @code{b}). The debugger convenience variable @samp{$bpnum} records the |
f3b28801 | 3325 | number of the breakpoint you've set most recently; see @ref{Convenience |
79a6e687 | 3326 | Vars,, Convenience Variables}, for a discussion of what you can do with |
c906108c SS |
3327 | convenience variables. |
3328 | ||
c906108c | 3329 | @table @code |
2a25a5ba EZ |
3330 | @item break @var{location} |
3331 | Set a breakpoint at the given @var{location}, which can specify a | |
3332 | function name, a line number, or an address of an instruction. | |
3333 | (@xref{Specify Location}, for a list of all the possible ways to | |
3334 | specify a @var{location}.) The breakpoint will stop your program just | |
3335 | before it executes any of the code in the specified @var{location}. | |
3336 | ||
c906108c | 3337 | When using source languages that permit overloading of symbols, such as |
2a25a5ba | 3338 | C@t{++}, a function name may refer to more than one possible place to break. |
6ba66d6a JB |
3339 | @xref{Ambiguous Expressions,,Ambiguous Expressions}, for a discussion of |
3340 | that situation. | |
c906108c | 3341 | |
45ac276d | 3342 | It is also possible to insert a breakpoint that will stop the program |
2c88c651 JB |
3343 | only if a specific thread (@pxref{Thread-Specific Breakpoints}) |
3344 | or a specific task (@pxref{Ada Tasks}) hits that breakpoint. | |
45ac276d | 3345 | |
c906108c SS |
3346 | @item break |
3347 | When called without any arguments, @code{break} sets a breakpoint at | |
3348 | the next instruction to be executed in the selected stack frame | |
3349 | (@pxref{Stack, ,Examining the Stack}). In any selected frame but the | |
3350 | innermost, this makes your program stop as soon as control | |
3351 | returns to that frame. This is similar to the effect of a | |
3352 | @code{finish} command in the frame inside the selected frame---except | |
3353 | that @code{finish} does not leave an active breakpoint. If you use | |
3354 | @code{break} without an argument in the innermost frame, @value{GDBN} stops | |
3355 | the next time it reaches the current location; this may be useful | |
3356 | inside loops. | |
3357 | ||
3358 | @value{GDBN} normally ignores breakpoints when it resumes execution, until at | |
3359 | least one instruction has been executed. If it did not do this, you | |
3360 | would be unable to proceed past a breakpoint without first disabling the | |
3361 | breakpoint. This rule applies whether or not the breakpoint already | |
3362 | existed when your program stopped. | |
3363 | ||
3364 | @item break @dots{} if @var{cond} | |
3365 | Set a breakpoint with condition @var{cond}; evaluate the expression | |
3366 | @var{cond} each time the breakpoint is reached, and stop only if the | |
3367 | value is nonzero---that is, if @var{cond} evaluates as true. | |
3368 | @samp{@dots{}} stands for one of the possible arguments described | |
3369 | above (or no argument) specifying where to break. @xref{Conditions, | |
79a6e687 | 3370 | ,Break Conditions}, for more information on breakpoint conditions. |
c906108c SS |
3371 | |
3372 | @kindex tbreak | |
3373 | @item tbreak @var{args} | |
3374 | Set a breakpoint enabled only for one stop. @var{args} are the | |
3375 | same as for the @code{break} command, and the breakpoint is set in the same | |
3376 | way, but the breakpoint is automatically deleted after the first time your | |
79a6e687 | 3377 | program stops there. @xref{Disabling, ,Disabling Breakpoints}. |
c906108c | 3378 | |
c906108c | 3379 | @kindex hbreak |
ba04e063 | 3380 | @cindex hardware breakpoints |
c906108c | 3381 | @item hbreak @var{args} |
d4f3574e SS |
3382 | Set a hardware-assisted breakpoint. @var{args} are the same as for the |
3383 | @code{break} command and the breakpoint is set in the same way, but the | |
c906108c SS |
3384 | breakpoint requires hardware support and some target hardware may not |
3385 | have this support. The main purpose of this is EPROM/ROM code | |
d4f3574e SS |
3386 | debugging, so you can set a breakpoint at an instruction without |
3387 | changing the instruction. This can be used with the new trap-generation | |
09d4efe1 | 3388 | provided by SPARClite DSU and most x86-based targets. These targets |
d4f3574e SS |
3389 | will generate traps when a program accesses some data or instruction |
3390 | address that is assigned to the debug registers. However the hardware | |
3391 | breakpoint registers can take a limited number of breakpoints. For | |
3392 | example, on the DSU, only two data breakpoints can be set at a time, and | |
3393 | @value{GDBN} will reject this command if more than two are used. Delete | |
3394 | or disable unused hardware breakpoints before setting new ones | |
79a6e687 BW |
3395 | (@pxref{Disabling, ,Disabling Breakpoints}). |
3396 | @xref{Conditions, ,Break Conditions}. | |
9c16f35a EZ |
3397 | For remote targets, you can restrict the number of hardware |
3398 | breakpoints @value{GDBN} will use, see @ref{set remote | |
3399 | hardware-breakpoint-limit}. | |
501eef12 | 3400 | |
c906108c SS |
3401 | @kindex thbreak |
3402 | @item thbreak @var{args} | |
3403 | Set a hardware-assisted breakpoint enabled only for one stop. @var{args} | |
3404 | are the same as for the @code{hbreak} command and the breakpoint is set in | |
5d161b24 | 3405 | the same way. However, like the @code{tbreak} command, |
c906108c SS |
3406 | the breakpoint is automatically deleted after the |
3407 | first time your program stops there. Also, like the @code{hbreak} | |
5d161b24 | 3408 | command, the breakpoint requires hardware support and some target hardware |
79a6e687 BW |
3409 | may not have this support. @xref{Disabling, ,Disabling Breakpoints}. |
3410 | See also @ref{Conditions, ,Break Conditions}. | |
c906108c SS |
3411 | |
3412 | @kindex rbreak | |
3413 | @cindex regular expression | |
8bd10a10 | 3414 | @cindex breakpoints at functions matching a regexp |
c45da7e6 | 3415 | @cindex set breakpoints in many functions |
c906108c | 3416 | @item rbreak @var{regex} |
c906108c | 3417 | Set breakpoints on all functions matching the regular expression |
11cf8741 JM |
3418 | @var{regex}. This command sets an unconditional breakpoint on all |
3419 | matches, printing a list of all breakpoints it set. Once these | |
3420 | breakpoints are set, they are treated just like the breakpoints set with | |
3421 | the @code{break} command. You can delete them, disable them, or make | |
3422 | them conditional the same way as any other breakpoint. | |
3423 | ||
3424 | The syntax of the regular expression is the standard one used with tools | |
3425 | like @file{grep}. Note that this is different from the syntax used by | |
3426 | shells, so for instance @code{foo*} matches all functions that include | |
3427 | an @code{fo} followed by zero or more @code{o}s. There is an implicit | |
3428 | @code{.*} leading and trailing the regular expression you supply, so to | |
3429 | match only functions that begin with @code{foo}, use @code{^foo}. | |
c906108c | 3430 | |
f7dc1244 | 3431 | @cindex non-member C@t{++} functions, set breakpoint in |
b37052ae | 3432 | When debugging C@t{++} programs, @code{rbreak} is useful for setting |
c906108c SS |
3433 | breakpoints on overloaded functions that are not members of any special |
3434 | classes. | |
c906108c | 3435 | |
f7dc1244 EZ |
3436 | @cindex set breakpoints on all functions |
3437 | The @code{rbreak} command can be used to set breakpoints in | |
3438 | @strong{all} the functions in a program, like this: | |
3439 | ||
3440 | @smallexample | |
3441 | (@value{GDBP}) rbreak . | |
3442 | @end smallexample | |
3443 | ||
8bd10a10 CM |
3444 | @item rbreak @var{file}:@var{regex} |
3445 | If @code{rbreak} is called with a filename qualification, it limits | |
3446 | the search for functions matching the given regular expression to the | |
3447 | specified @var{file}. This can be used, for example, to set breakpoints on | |
3448 | every function in a given file: | |
3449 | ||
3450 | @smallexample | |
3451 | (@value{GDBP}) rbreak file.c:. | |
3452 | @end smallexample | |
3453 | ||
3454 | The colon separating the filename qualifier from the regex may | |
3455 | optionally be surrounded by spaces. | |
3456 | ||
c906108c SS |
3457 | @kindex info breakpoints |
3458 | @cindex @code{$_} and @code{info breakpoints} | |
3459 | @item info breakpoints @r{[}@var{n}@r{]} | |
3460 | @itemx info break @r{[}@var{n}@r{]} | |
c906108c | 3461 | Print a table of all breakpoints, watchpoints, and catchpoints set and |
45ac1734 EZ |
3462 | not deleted. Optional argument @var{n} means print information only |
3463 | about the specified breakpoint (or watchpoint or catchpoint). For | |
3464 | each breakpoint, following columns are printed: | |
c906108c SS |
3465 | |
3466 | @table @emph | |
3467 | @item Breakpoint Numbers | |
3468 | @item Type | |
3469 | Breakpoint, watchpoint, or catchpoint. | |
3470 | @item Disposition | |
3471 | Whether the breakpoint is marked to be disabled or deleted when hit. | |
3472 | @item Enabled or Disabled | |
3473 | Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints | |
b3db7447 | 3474 | that are not enabled. |
c906108c | 3475 | @item Address |
fe6fbf8b | 3476 | Where the breakpoint is in your program, as a memory address. For a |
b3db7447 NR |
3477 | pending breakpoint whose address is not yet known, this field will |
3478 | contain @samp{<PENDING>}. Such breakpoint won't fire until a shared | |
3479 | library that has the symbol or line referred by breakpoint is loaded. | |
3480 | See below for details. A breakpoint with several locations will | |
3b784c4f | 3481 | have @samp{<MULTIPLE>} in this field---see below for details. |
c906108c SS |
3482 | @item What |
3483 | Where the breakpoint is in the source for your program, as a file and | |
2650777c JJ |
3484 | line number. For a pending breakpoint, the original string passed to |
3485 | the breakpoint command will be listed as it cannot be resolved until | |
3486 | the appropriate shared library is loaded in the future. | |
c906108c SS |
3487 | @end table |
3488 | ||
3489 | @noindent | |
3490 | If a breakpoint is conditional, @code{info break} shows the condition on | |
3491 | the line following the affected breakpoint; breakpoint commands, if any, | |
2650777c JJ |
3492 | are listed after that. A pending breakpoint is allowed to have a condition |
3493 | specified for it. The condition is not parsed for validity until a shared | |
3494 | library is loaded that allows the pending breakpoint to resolve to a | |
3495 | valid location. | |
c906108c SS |
3496 | |
3497 | @noindent | |
3498 | @code{info break} with a breakpoint | |
3499 | number @var{n} as argument lists only that breakpoint. The | |
3500 | convenience variable @code{$_} and the default examining-address for | |
3501 | the @code{x} command are set to the address of the last breakpoint | |
79a6e687 | 3502 | listed (@pxref{Memory, ,Examining Memory}). |
c906108c SS |
3503 | |
3504 | @noindent | |
3505 | @code{info break} displays a count of the number of times the breakpoint | |
3506 | has been hit. This is especially useful in conjunction with the | |
3507 | @code{ignore} command. You can ignore a large number of breakpoint | |
3508 | hits, look at the breakpoint info to see how many times the breakpoint | |
3509 | was hit, and then run again, ignoring one less than that number. This | |
3510 | will get you quickly to the last hit of that breakpoint. | |
3511 | @end table | |
3512 | ||
3513 | @value{GDBN} allows you to set any number of breakpoints at the same place in | |
3514 | your program. There is nothing silly or meaningless about this. When | |
3515 | the breakpoints are conditional, this is even useful | |
79a6e687 | 3516 | (@pxref{Conditions, ,Break Conditions}). |
c906108c | 3517 | |
2e9132cc EZ |
3518 | @cindex multiple locations, breakpoints |
3519 | @cindex breakpoints, multiple locations | |
fcda367b | 3520 | It is possible that a breakpoint corresponds to several locations |
fe6fbf8b VP |
3521 | in your program. Examples of this situation are: |
3522 | ||
3523 | @itemize @bullet | |
fe6fbf8b VP |
3524 | @item |
3525 | For a C@t{++} constructor, the @value{NGCC} compiler generates several | |
3526 | instances of the function body, used in different cases. | |
3527 | ||
3528 | @item | |
3529 | For a C@t{++} template function, a given line in the function can | |
3530 | correspond to any number of instantiations. | |
3531 | ||
3532 | @item | |
3533 | For an inlined function, a given source line can correspond to | |
3534 | several places where that function is inlined. | |
fe6fbf8b VP |
3535 | @end itemize |
3536 | ||
3537 | In all those cases, @value{GDBN} will insert a breakpoint at all | |
2e9132cc EZ |
3538 | the relevant locations@footnote{ |
3539 | As of this writing, multiple-location breakpoints work only if there's | |
3540 | line number information for all the locations. This means that they | |
3541 | will generally not work in system libraries, unless you have debug | |
3542 | info with line numbers for them.}. | |
fe6fbf8b | 3543 | |
3b784c4f EZ |
3544 | A breakpoint with multiple locations is displayed in the breakpoint |
3545 | table using several rows---one header row, followed by one row for | |
3546 | each breakpoint location. The header row has @samp{<MULTIPLE>} in the | |
3547 | address column. The rows for individual locations contain the actual | |
3548 | addresses for locations, and show the functions to which those | |
3549 | locations belong. The number column for a location is of the form | |
fe6fbf8b VP |
3550 | @var{breakpoint-number}.@var{location-number}. |
3551 | ||
3552 | For example: | |
3b784c4f | 3553 | |
fe6fbf8b VP |
3554 | @smallexample |
3555 | Num Type Disp Enb Address What | |
3556 | 1 breakpoint keep y <MULTIPLE> | |
3557 | stop only if i==1 | |
3558 | breakpoint already hit 1 time | |
3559 | 1.1 y 0x080486a2 in void foo<int>() at t.cc:8 | |
3560 | 1.2 y 0x080486ca in void foo<double>() at t.cc:8 | |
3561 | @end smallexample | |
3562 | ||
3563 | Each location can be individually enabled or disabled by passing | |
3564 | @var{breakpoint-number}.@var{location-number} as argument to the | |
3b784c4f EZ |
3565 | @code{enable} and @code{disable} commands. Note that you cannot |
3566 | delete the individual locations from the list, you can only delete the | |
16bfc218 | 3567 | entire list of locations that belong to their parent breakpoint (with |
3b784c4f EZ |
3568 | the @kbd{delete @var{num}} command, where @var{num} is the number of |
3569 | the parent breakpoint, 1 in the above example). Disabling or enabling | |
3570 | the parent breakpoint (@pxref{Disabling}) affects all of the locations | |
3571 | that belong to that breakpoint. | |
fe6fbf8b | 3572 | |
2650777c | 3573 | @cindex pending breakpoints |
fe6fbf8b | 3574 | It's quite common to have a breakpoint inside a shared library. |
3b784c4f | 3575 | Shared libraries can be loaded and unloaded explicitly, |
fe6fbf8b VP |
3576 | and possibly repeatedly, as the program is executed. To support |
3577 | this use case, @value{GDBN} updates breakpoint locations whenever | |
3578 | any shared library is loaded or unloaded. Typically, you would | |
fcda367b | 3579 | set a breakpoint in a shared library at the beginning of your |
fe6fbf8b VP |
3580 | debugging session, when the library is not loaded, and when the |
3581 | symbols from the library are not available. When you try to set | |
3582 | breakpoint, @value{GDBN} will ask you if you want to set | |
3b784c4f | 3583 | a so called @dfn{pending breakpoint}---breakpoint whose address |
fe6fbf8b VP |
3584 | is not yet resolved. |
3585 | ||
3586 | After the program is run, whenever a new shared library is loaded, | |
3587 | @value{GDBN} reevaluates all the breakpoints. When a newly loaded | |
3588 | shared library contains the symbol or line referred to by some | |
3589 | pending breakpoint, that breakpoint is resolved and becomes an | |
3590 | ordinary breakpoint. When a library is unloaded, all breakpoints | |
3591 | that refer to its symbols or source lines become pending again. | |
3592 | ||
3593 | This logic works for breakpoints with multiple locations, too. For | |
3594 | example, if you have a breakpoint in a C@t{++} template function, and | |
3595 | a newly loaded shared library has an instantiation of that template, | |
3596 | a new location is added to the list of locations for the breakpoint. | |
3597 | ||
3598 | Except for having unresolved address, pending breakpoints do not | |
3599 | differ from regular breakpoints. You can set conditions or commands, | |
3600 | enable and disable them and perform other breakpoint operations. | |
3601 | ||
3602 | @value{GDBN} provides some additional commands for controlling what | |
3603 | happens when the @samp{break} command cannot resolve breakpoint | |
3604 | address specification to an address: | |
dd79a6cf JJ |
3605 | |
3606 | @kindex set breakpoint pending | |
3607 | @kindex show breakpoint pending | |
3608 | @table @code | |
3609 | @item set breakpoint pending auto | |
3610 | This is the default behavior. When @value{GDBN} cannot find the breakpoint | |
3611 | location, it queries you whether a pending breakpoint should be created. | |
3612 | ||
3613 | @item set breakpoint pending on | |
3614 | This indicates that an unrecognized breakpoint location should automatically | |
3615 | result in a pending breakpoint being created. | |
3616 | ||
3617 | @item set breakpoint pending off | |
3618 | This indicates that pending breakpoints are not to be created. Any | |
3619 | unrecognized breakpoint location results in an error. This setting does | |
3620 | not affect any pending breakpoints previously created. | |
3621 | ||
3622 | @item show breakpoint pending | |
3623 | Show the current behavior setting for creating pending breakpoints. | |
3624 | @end table | |
2650777c | 3625 | |
fe6fbf8b VP |
3626 | The settings above only affect the @code{break} command and its |
3627 | variants. Once breakpoint is set, it will be automatically updated | |
3628 | as shared libraries are loaded and unloaded. | |
2650777c | 3629 | |
765dc015 VP |
3630 | @cindex automatic hardware breakpoints |
3631 | For some targets, @value{GDBN} can automatically decide if hardware or | |
3632 | software breakpoints should be used, depending on whether the | |
3633 | breakpoint address is read-only or read-write. This applies to | |
3634 | breakpoints set with the @code{break} command as well as to internal | |
3635 | breakpoints set by commands like @code{next} and @code{finish}. For | |
fcda367b | 3636 | breakpoints set with @code{hbreak}, @value{GDBN} will always use hardware |
765dc015 VP |
3637 | breakpoints. |
3638 | ||
3639 | You can control this automatic behaviour with the following commands:: | |
3640 | ||
3641 | @kindex set breakpoint auto-hw | |
3642 | @kindex show breakpoint auto-hw | |
3643 | @table @code | |
3644 | @item set breakpoint auto-hw on | |
3645 | This is the default behavior. When @value{GDBN} sets a breakpoint, it | |
3646 | will try to use the target memory map to decide if software or hardware | |
3647 | breakpoint must be used. | |
3648 | ||
3649 | @item set breakpoint auto-hw off | |
3650 | This indicates @value{GDBN} should not automatically select breakpoint | |
3651 | type. If the target provides a memory map, @value{GDBN} will warn when | |
3652 | trying to set software breakpoint at a read-only address. | |
3653 | @end table | |
3654 | ||
74960c60 VP |
3655 | @value{GDBN} normally implements breakpoints by replacing the program code |
3656 | at the breakpoint address with a special instruction, which, when | |
3657 | executed, given control to the debugger. By default, the program | |
3658 | code is so modified only when the program is resumed. As soon as | |
3659 | the program stops, @value{GDBN} restores the original instructions. This | |
3660 | behaviour guards against leaving breakpoints inserted in the | |
3661 | target should gdb abrubptly disconnect. However, with slow remote | |
3662 | targets, inserting and removing breakpoint can reduce the performance. | |
3663 | This behavior can be controlled with the following commands:: | |
3664 | ||
3665 | @kindex set breakpoint always-inserted | |
3666 | @kindex show breakpoint always-inserted | |
3667 | @table @code | |
3668 | @item set breakpoint always-inserted off | |
33e5cbd6 PA |
3669 | All breakpoints, including newly added by the user, are inserted in |
3670 | the target only when the target is resumed. All breakpoints are | |
3671 | removed from the target when it stops. | |
74960c60 VP |
3672 | |
3673 | @item set breakpoint always-inserted on | |
3674 | Causes all breakpoints to be inserted in the target at all times. If | |
3675 | the user adds a new breakpoint, or changes an existing breakpoint, the | |
3676 | breakpoints in the target are updated immediately. A breakpoint is | |
3677 | removed from the target only when breakpoint itself is removed. | |
33e5cbd6 PA |
3678 | |
3679 | @cindex non-stop mode, and @code{breakpoint always-inserted} | |
3680 | @item set breakpoint always-inserted auto | |
3681 | This is the default mode. If @value{GDBN} is controlling the inferior | |
3682 | in non-stop mode (@pxref{Non-Stop Mode}), gdb behaves as if | |
3683 | @code{breakpoint always-inserted} mode is on. If @value{GDBN} is | |
3684 | controlling the inferior in all-stop mode, @value{GDBN} behaves as if | |
3685 | @code{breakpoint always-inserted} mode is off. | |
74960c60 | 3686 | @end table |
765dc015 | 3687 | |
c906108c SS |
3688 | @cindex negative breakpoint numbers |
3689 | @cindex internal @value{GDBN} breakpoints | |
eb12ee30 AC |
3690 | @value{GDBN} itself sometimes sets breakpoints in your program for |
3691 | special purposes, such as proper handling of @code{longjmp} (in C | |
3692 | programs). These internal breakpoints are assigned negative numbers, | |
3693 | starting with @code{-1}; @samp{info breakpoints} does not display them. | |
c906108c | 3694 | You can see these breakpoints with the @value{GDBN} maintenance command |
eb12ee30 | 3695 | @samp{maint info breakpoints} (@pxref{maint info breakpoints}). |
c906108c SS |
3696 | |
3697 | ||
6d2ebf8b | 3698 | @node Set Watchpoints |
79a6e687 | 3699 | @subsection Setting Watchpoints |
c906108c SS |
3700 | |
3701 | @cindex setting watchpoints | |
c906108c SS |
3702 | You can use a watchpoint to stop execution whenever the value of an |
3703 | expression changes, without having to predict a particular place where | |
fd60e0df EZ |
3704 | this may happen. (This is sometimes called a @dfn{data breakpoint}.) |
3705 | The expression may be as simple as the value of a single variable, or | |
3706 | as complex as many variables combined by operators. Examples include: | |
3707 | ||
3708 | @itemize @bullet | |
3709 | @item | |
3710 | A reference to the value of a single variable. | |
3711 | ||
3712 | @item | |
3713 | An address cast to an appropriate data type. For example, | |
3714 | @samp{*(int *)0x12345678} will watch a 4-byte region at the specified | |
3715 | address (assuming an @code{int} occupies 4 bytes). | |
3716 | ||
3717 | @item | |
3718 | An arbitrarily complex expression, such as @samp{a*b + c/d}. The | |
3719 | expression can use any operators valid in the program's native | |
3720 | language (@pxref{Languages}). | |
3721 | @end itemize | |
c906108c | 3722 | |
fa4727a6 DJ |
3723 | You can set a watchpoint on an expression even if the expression can |
3724 | not be evaluated yet. For instance, you can set a watchpoint on | |
3725 | @samp{*global_ptr} before @samp{global_ptr} is initialized. | |
3726 | @value{GDBN} will stop when your program sets @samp{global_ptr} and | |
3727 | the expression produces a valid value. If the expression becomes | |
3728 | valid in some other way than changing a variable (e.g.@: if the memory | |
3729 | pointed to by @samp{*global_ptr} becomes readable as the result of a | |
3730 | @code{malloc} call), @value{GDBN} may not stop until the next time | |
3731 | the expression changes. | |
3732 | ||
82f2d802 EZ |
3733 | @cindex software watchpoints |
3734 | @cindex hardware watchpoints | |
c906108c | 3735 | Depending on your system, watchpoints may be implemented in software or |
2df3850c | 3736 | hardware. @value{GDBN} does software watchpointing by single-stepping your |
c906108c SS |
3737 | program and testing the variable's value each time, which is hundreds of |
3738 | times slower than normal execution. (But this may still be worth it, to | |
3739 | catch errors where you have no clue what part of your program is the | |
3740 | culprit.) | |
3741 | ||
37e4754d | 3742 | On some systems, such as HP-UX, PowerPC, @sc{gnu}/Linux and most other |
82f2d802 EZ |
3743 | x86-based targets, @value{GDBN} includes support for hardware |
3744 | watchpoints, which do not slow down the running of your program. | |
c906108c SS |
3745 | |
3746 | @table @code | |
3747 | @kindex watch | |
06a64a0b | 3748 | @item watch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} |
fd60e0df EZ |
3749 | Set a watchpoint for an expression. @value{GDBN} will break when the |
3750 | expression @var{expr} is written into by the program and its value | |
3751 | changes. The simplest (and the most popular) use of this command is | |
3752 | to watch the value of a single variable: | |
3753 | ||
3754 | @smallexample | |
3755 | (@value{GDBP}) watch foo | |
3756 | @end smallexample | |
c906108c | 3757 | |
d8b2a693 JB |
3758 | If the command includes a @code{@r{[}thread @var{threadnum}@r{]}} |
3759 | clause, @value{GDBN} breaks only when the thread identified by | |
3760 | @var{threadnum} changes the value of @var{expr}. If any other threads | |
3761 | change the value of @var{expr}, @value{GDBN} will not break. Note | |
3762 | that watchpoints restricted to a single thread in this way only work | |
3763 | with Hardware Watchpoints. | |
3764 | ||
06a64a0b TT |
3765 | Ordinarily a watchpoint respects the scope of variables in @var{expr} |
3766 | (see below). The @code{-location} argument tells @value{GDBN} to | |
3767 | instead watch the memory referred to by @var{expr}. In this case, | |
3768 | @value{GDBN} will evaluate @var{expr}, take the address of the result, | |
3769 | and watch the memory at that address. The type of the result is used | |
3770 | to determine the size of the watched memory. If the expression's | |
3771 | result does not have an address, then @value{GDBN} will print an | |
3772 | error. | |
3773 | ||
c906108c | 3774 | @kindex rwatch |
06a64a0b | 3775 | @item rwatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} |
09d4efe1 EZ |
3776 | Set a watchpoint that will break when the value of @var{expr} is read |
3777 | by the program. | |
c906108c SS |
3778 | |
3779 | @kindex awatch | |
06a64a0b | 3780 | @item awatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} |
09d4efe1 EZ |
3781 | Set a watchpoint that will break when @var{expr} is either read from |
3782 | or written into by the program. | |
c906108c | 3783 | |
45ac1734 | 3784 | @kindex info watchpoints @r{[}@var{n}@r{]} |
c906108c | 3785 | @item info watchpoints |
d77f58be SS |
3786 | This command prints a list of watchpoints, using the same format as |
3787 | @code{info break} (@pxref{Set Breaks}). | |
c906108c SS |
3788 | @end table |
3789 | ||
65d79d4b SDJ |
3790 | If you watch for a change in a numerically entered address you need to |
3791 | dereference it, as the address itself is just a constant number which will | |
3792 | never change. @value{GDBN} refuses to create a watchpoint that watches | |
3793 | a never-changing value: | |
3794 | ||
3795 | @smallexample | |
3796 | (@value{GDBP}) watch 0x600850 | |
3797 | Cannot watch constant value 0x600850. | |
3798 | (@value{GDBP}) watch *(int *) 0x600850 | |
3799 | Watchpoint 1: *(int *) 6293584 | |
3800 | @end smallexample | |
3801 | ||
c906108c SS |
3802 | @value{GDBN} sets a @dfn{hardware watchpoint} if possible. Hardware |
3803 | watchpoints execute very quickly, and the debugger reports a change in | |
3804 | value at the exact instruction where the change occurs. If @value{GDBN} | |
3805 | cannot set a hardware watchpoint, it sets a software watchpoint, which | |
3806 | executes more slowly and reports the change in value at the next | |
82f2d802 EZ |
3807 | @emph{statement}, not the instruction, after the change occurs. |
3808 | ||
82f2d802 EZ |
3809 | @cindex use only software watchpoints |
3810 | You can force @value{GDBN} to use only software watchpoints with the | |
3811 | @kbd{set can-use-hw-watchpoints 0} command. With this variable set to | |
3812 | zero, @value{GDBN} will never try to use hardware watchpoints, even if | |
3813 | the underlying system supports them. (Note that hardware-assisted | |
3814 | watchpoints that were set @emph{before} setting | |
3815 | @code{can-use-hw-watchpoints} to zero will still use the hardware | |
d3e8051b | 3816 | mechanism of watching expression values.) |
c906108c | 3817 | |
9c16f35a EZ |
3818 | @table @code |
3819 | @item set can-use-hw-watchpoints | |
3820 | @kindex set can-use-hw-watchpoints | |
3821 | Set whether or not to use hardware watchpoints. | |
3822 | ||
3823 | @item show can-use-hw-watchpoints | |
3824 | @kindex show can-use-hw-watchpoints | |
3825 | Show the current mode of using hardware watchpoints. | |
3826 | @end table | |
3827 | ||
3828 | For remote targets, you can restrict the number of hardware | |
3829 | watchpoints @value{GDBN} will use, see @ref{set remote | |
3830 | hardware-breakpoint-limit}. | |
3831 | ||
c906108c SS |
3832 | When you issue the @code{watch} command, @value{GDBN} reports |
3833 | ||
474c8240 | 3834 | @smallexample |
c906108c | 3835 | Hardware watchpoint @var{num}: @var{expr} |
474c8240 | 3836 | @end smallexample |
c906108c SS |
3837 | |
3838 | @noindent | |
3839 | if it was able to set a hardware watchpoint. | |
3840 | ||
7be570e7 JM |
3841 | Currently, the @code{awatch} and @code{rwatch} commands can only set |
3842 | hardware watchpoints, because accesses to data that don't change the | |
3843 | value of the watched expression cannot be detected without examining | |
3844 | every instruction as it is being executed, and @value{GDBN} does not do | |
3845 | that currently. If @value{GDBN} finds that it is unable to set a | |
3846 | hardware breakpoint with the @code{awatch} or @code{rwatch} command, it | |
3847 | will print a message like this: | |
3848 | ||
3849 | @smallexample | |
3850 | Expression cannot be implemented with read/access watchpoint. | |
3851 | @end smallexample | |
3852 | ||
3853 | Sometimes, @value{GDBN} cannot set a hardware watchpoint because the | |
3854 | data type of the watched expression is wider than what a hardware | |
3855 | watchpoint on the target machine can handle. For example, some systems | |
3856 | can only watch regions that are up to 4 bytes wide; on such systems you | |
3857 | cannot set hardware watchpoints for an expression that yields a | |
3858 | double-precision floating-point number (which is typically 8 bytes | |
3859 | wide). As a work-around, it might be possible to break the large region | |
3860 | into a series of smaller ones and watch them with separate watchpoints. | |
3861 | ||
3862 | If you set too many hardware watchpoints, @value{GDBN} might be unable | |
3863 | to insert all of them when you resume the execution of your program. | |
3864 | Since the precise number of active watchpoints is unknown until such | |
3865 | time as the program is about to be resumed, @value{GDBN} might not be | |
3866 | able to warn you about this when you set the watchpoints, and the | |
3867 | warning will be printed only when the program is resumed: | |
3868 | ||
3869 | @smallexample | |
3870 | Hardware watchpoint @var{num}: Could not insert watchpoint | |
3871 | @end smallexample | |
3872 | ||
3873 | @noindent | |
3874 | If this happens, delete or disable some of the watchpoints. | |
3875 | ||
fd60e0df EZ |
3876 | Watching complex expressions that reference many variables can also |
3877 | exhaust the resources available for hardware-assisted watchpoints. | |
3878 | That's because @value{GDBN} needs to watch every variable in the | |
3879 | expression with separately allocated resources. | |
3880 | ||
c906108c | 3881 | If you call a function interactively using @code{print} or @code{call}, |
2df3850c | 3882 | any watchpoints you have set will be inactive until @value{GDBN} reaches another |
c906108c SS |
3883 | kind of breakpoint or the call completes. |
3884 | ||
7be570e7 JM |
3885 | @value{GDBN} automatically deletes watchpoints that watch local |
3886 | (automatic) variables, or expressions that involve such variables, when | |
3887 | they go out of scope, that is, when the execution leaves the block in | |
3888 | which these variables were defined. In particular, when the program | |
3889 | being debugged terminates, @emph{all} local variables go out of scope, | |
3890 | and so only watchpoints that watch global variables remain set. If you | |
3891 | rerun the program, you will need to set all such watchpoints again. One | |
3892 | way of doing that would be to set a code breakpoint at the entry to the | |
3893 | @code{main} function and when it breaks, set all the watchpoints. | |
3894 | ||
c906108c SS |
3895 | @cindex watchpoints and threads |
3896 | @cindex threads and watchpoints | |
d983da9c DJ |
3897 | In multi-threaded programs, watchpoints will detect changes to the |
3898 | watched expression from every thread. | |
3899 | ||
3900 | @quotation | |
3901 | @emph{Warning:} In multi-threaded programs, software watchpoints | |
53a5351d JM |
3902 | have only limited usefulness. If @value{GDBN} creates a software |
3903 | watchpoint, it can only watch the value of an expression @emph{in a | |
3904 | single thread}. If you are confident that the expression can only | |
3905 | change due to the current thread's activity (and if you are also | |
3906 | confident that no other thread can become current), then you can use | |
3907 | software watchpoints as usual. However, @value{GDBN} may not notice | |
3908 | when a non-current thread's activity changes the expression. (Hardware | |
3909 | watchpoints, in contrast, watch an expression in all threads.) | |
c906108c | 3910 | @end quotation |
c906108c | 3911 | |
501eef12 AC |
3912 | @xref{set remote hardware-watchpoint-limit}. |
3913 | ||
6d2ebf8b | 3914 | @node Set Catchpoints |
79a6e687 | 3915 | @subsection Setting Catchpoints |
d4f3574e | 3916 | @cindex catchpoints, setting |
c906108c SS |
3917 | @cindex exception handlers |
3918 | @cindex event handling | |
3919 | ||
3920 | You can use @dfn{catchpoints} to cause the debugger to stop for certain | |
b37052ae | 3921 | kinds of program events, such as C@t{++} exceptions or the loading of a |
c906108c SS |
3922 | shared library. Use the @code{catch} command to set a catchpoint. |
3923 | ||
3924 | @table @code | |
3925 | @kindex catch | |
3926 | @item catch @var{event} | |
3927 | Stop when @var{event} occurs. @var{event} can be any of the following: | |
3928 | @table @code | |
3929 | @item throw | |
4644b6e3 | 3930 | @cindex stop on C@t{++} exceptions |
b37052ae | 3931 | The throwing of a C@t{++} exception. |
c906108c SS |
3932 | |
3933 | @item catch | |
b37052ae | 3934 | The catching of a C@t{++} exception. |
c906108c | 3935 | |
8936fcda JB |
3936 | @item exception |
3937 | @cindex Ada exception catching | |
3938 | @cindex catch Ada exceptions | |
3939 | An Ada exception being raised. If an exception name is specified | |
3940 | at the end of the command (eg @code{catch exception Program_Error}), | |
3941 | the debugger will stop only when this specific exception is raised. | |
3942 | Otherwise, the debugger stops execution when any Ada exception is raised. | |
3943 | ||
87f67dba JB |
3944 | When inserting an exception catchpoint on a user-defined exception whose |
3945 | name is identical to one of the exceptions defined by the language, the | |
3946 | fully qualified name must be used as the exception name. Otherwise, | |
3947 | @value{GDBN} will assume that it should stop on the pre-defined exception | |
3948 | rather than the user-defined one. For instance, assuming an exception | |
3949 | called @code{Constraint_Error} is defined in package @code{Pck}, then | |
3950 | the command to use to catch such exceptions is @kbd{catch exception | |
3951 | Pck.Constraint_Error}. | |
3952 | ||
8936fcda JB |
3953 | @item exception unhandled |
3954 | An exception that was raised but is not handled by the program. | |
3955 | ||
3956 | @item assert | |
3957 | A failed Ada assertion. | |
3958 | ||
c906108c | 3959 | @item exec |
4644b6e3 | 3960 | @cindex break on fork/exec |
5ee187d7 DJ |
3961 | A call to @code{exec}. This is currently only available for HP-UX |
3962 | and @sc{gnu}/Linux. | |
c906108c | 3963 | |
a96d9b2e | 3964 | @item syscall |
ee8e71d4 | 3965 | @itemx syscall @r{[}@var{name} @r{|} @var{number}@r{]} @dots{} |
a96d9b2e SDJ |
3966 | @cindex break on a system call. |
3967 | A call to or return from a system call, a.k.a.@: @dfn{syscall}. A | |
3968 | syscall is a mechanism for application programs to request a service | |
3969 | from the operating system (OS) or one of the OS system services. | |
3970 | @value{GDBN} can catch some or all of the syscalls issued by the | |
3971 | debuggee, and show the related information for each syscall. If no | |
3972 | argument is specified, calls to and returns from all system calls | |
3973 | will be caught. | |
3974 | ||
3975 | @var{name} can be any system call name that is valid for the | |
3976 | underlying OS. Just what syscalls are valid depends on the OS. On | |
3977 | GNU and Unix systems, you can find the full list of valid syscall | |
3978 | names on @file{/usr/include/asm/unistd.h}. | |
3979 | ||
3980 | @c For MS-Windows, the syscall names and the corresponding numbers | |
3981 | @c can be found, e.g., on this URL: | |
3982 | @c http://www.metasploit.com/users/opcode/syscalls.html | |
3983 | @c but we don't support Windows syscalls yet. | |
3984 | ||
3985 | Normally, @value{GDBN} knows in advance which syscalls are valid for | |
3986 | each OS, so you can use the @value{GDBN} command-line completion | |
3987 | facilities (@pxref{Completion,, command completion}) to list the | |
3988 | available choices. | |
3989 | ||
3990 | You may also specify the system call numerically. A syscall's | |
3991 | number is the value passed to the OS's syscall dispatcher to | |
3992 | identify the requested service. When you specify the syscall by its | |
3993 | name, @value{GDBN} uses its database of syscalls to convert the name | |
3994 | into the corresponding numeric code, but using the number directly | |
3995 | may be useful if @value{GDBN}'s database does not have the complete | |
3996 | list of syscalls on your system (e.g., because @value{GDBN} lags | |
3997 | behind the OS upgrades). | |
3998 | ||
3999 | The example below illustrates how this command works if you don't provide | |
4000 | arguments to it: | |
4001 | ||
4002 | @smallexample | |
4003 | (@value{GDBP}) catch syscall | |
4004 | Catchpoint 1 (syscall) | |
4005 | (@value{GDBP}) r | |
4006 | Starting program: /tmp/catch-syscall | |
4007 | ||
4008 | Catchpoint 1 (call to syscall 'close'), \ | |
4009 | 0xffffe424 in __kernel_vsyscall () | |
4010 | (@value{GDBP}) c | |
4011 | Continuing. | |
4012 | ||
4013 | Catchpoint 1 (returned from syscall 'close'), \ | |
4014 | 0xffffe424 in __kernel_vsyscall () | |
4015 | (@value{GDBP}) | |
4016 | @end smallexample | |
4017 | ||
4018 | Here is an example of catching a system call by name: | |
4019 | ||
4020 | @smallexample | |
4021 | (@value{GDBP}) catch syscall chroot | |
4022 | Catchpoint 1 (syscall 'chroot' [61]) | |
4023 | (@value{GDBP}) r | |
4024 | Starting program: /tmp/catch-syscall | |
4025 | ||
4026 | Catchpoint 1 (call to syscall 'chroot'), \ | |
4027 | 0xffffe424 in __kernel_vsyscall () | |
4028 | (@value{GDBP}) c | |
4029 | Continuing. | |
4030 | ||
4031 | Catchpoint 1 (returned from syscall 'chroot'), \ | |
4032 | 0xffffe424 in __kernel_vsyscall () | |
4033 | (@value{GDBP}) | |
4034 | @end smallexample | |
4035 | ||
4036 | An example of specifying a system call numerically. In the case | |
4037 | below, the syscall number has a corresponding entry in the XML | |
4038 | file, so @value{GDBN} finds its name and prints it: | |
4039 | ||
4040 | @smallexample | |
4041 | (@value{GDBP}) catch syscall 252 | |
4042 | Catchpoint 1 (syscall(s) 'exit_group') | |
4043 | (@value{GDBP}) r | |
4044 | Starting program: /tmp/catch-syscall | |
4045 | ||
4046 | Catchpoint 1 (call to syscall 'exit_group'), \ | |
4047 | 0xffffe424 in __kernel_vsyscall () | |
4048 | (@value{GDBP}) c | |
4049 | Continuing. | |
4050 | ||
4051 | Program exited normally. | |
4052 | (@value{GDBP}) | |
4053 | @end smallexample | |
4054 | ||
4055 | However, there can be situations when there is no corresponding name | |
4056 | in XML file for that syscall number. In this case, @value{GDBN} prints | |
4057 | a warning message saying that it was not able to find the syscall name, | |
4058 | but the catchpoint will be set anyway. See the example below: | |
4059 | ||
4060 | @smallexample | |
4061 | (@value{GDBP}) catch syscall 764 | |
4062 | warning: The number '764' does not represent a known syscall. | |
4063 | Catchpoint 2 (syscall 764) | |
4064 | (@value{GDBP}) | |
4065 | @end smallexample | |
4066 | ||
4067 | If you configure @value{GDBN} using the @samp{--without-expat} option, | |
4068 | it will not be able to display syscall names. Also, if your | |
4069 | architecture does not have an XML file describing its system calls, | |
4070 | you will not be able to see the syscall names. It is important to | |
4071 | notice that these two features are used for accessing the syscall | |
4072 | name database. In either case, you will see a warning like this: | |
4073 | ||
4074 | @smallexample | |
4075 | (@value{GDBP}) catch syscall | |
4076 | warning: Could not open "syscalls/i386-linux.xml" | |
4077 | warning: Could not load the syscall XML file 'syscalls/i386-linux.xml'. | |
4078 | GDB will not be able to display syscall names. | |
4079 | Catchpoint 1 (syscall) | |
4080 | (@value{GDBP}) | |
4081 | @end smallexample | |
4082 | ||
4083 | Of course, the file name will change depending on your architecture and system. | |
4084 | ||
4085 | Still using the example above, you can also try to catch a syscall by its | |
4086 | number. In this case, you would see something like: | |
4087 | ||
4088 | @smallexample | |
4089 | (@value{GDBP}) catch syscall 252 | |
4090 | Catchpoint 1 (syscall(s) 252) | |
4091 | @end smallexample | |
4092 | ||
4093 | Again, in this case @value{GDBN} would not be able to display syscall's names. | |
4094 | ||
c906108c | 4095 | @item fork |
5ee187d7 DJ |
4096 | A call to @code{fork}. This is currently only available for HP-UX |
4097 | and @sc{gnu}/Linux. | |
c906108c SS |
4098 | |
4099 | @item vfork | |
5ee187d7 DJ |
4100 | A call to @code{vfork}. This is currently only available for HP-UX |
4101 | and @sc{gnu}/Linux. | |
c906108c | 4102 | |
c906108c SS |
4103 | @end table |
4104 | ||
4105 | @item tcatch @var{event} | |
4106 | Set a catchpoint that is enabled only for one stop. The catchpoint is | |
4107 | automatically deleted after the first time the event is caught. | |
4108 | ||
4109 | @end table | |
4110 | ||
4111 | Use the @code{info break} command to list the current catchpoints. | |
4112 | ||
b37052ae | 4113 | There are currently some limitations to C@t{++} exception handling |
c906108c SS |
4114 | (@code{catch throw} and @code{catch catch}) in @value{GDBN}: |
4115 | ||
4116 | @itemize @bullet | |
4117 | @item | |
4118 | If you call a function interactively, @value{GDBN} normally returns | |
4119 | control to you when the function has finished executing. If the call | |
4120 | raises an exception, however, the call may bypass the mechanism that | |
4121 | returns control to you and cause your program either to abort or to | |
4122 | simply continue running until it hits a breakpoint, catches a signal | |
4123 | that @value{GDBN} is listening for, or exits. This is the case even if | |
4124 | you set a catchpoint for the exception; catchpoints on exceptions are | |
4125 | disabled within interactive calls. | |
4126 | ||
4127 | @item | |
4128 | You cannot raise an exception interactively. | |
4129 | ||
4130 | @item | |
4131 | You cannot install an exception handler interactively. | |
4132 | @end itemize | |
4133 | ||
4134 | @cindex raise exceptions | |
4135 | Sometimes @code{catch} is not the best way to debug exception handling: | |
4136 | if you need to know exactly where an exception is raised, it is better to | |
4137 | stop @emph{before} the exception handler is called, since that way you | |
4138 | can see the stack before any unwinding takes place. If you set a | |
4139 | breakpoint in an exception handler instead, it may not be easy to find | |
4140 | out where the exception was raised. | |
4141 | ||
4142 | To stop just before an exception handler is called, you need some | |
b37052ae | 4143 | knowledge of the implementation. In the case of @sc{gnu} C@t{++}, exceptions are |
c906108c SS |
4144 | raised by calling a library function named @code{__raise_exception} |
4145 | which has the following ANSI C interface: | |
4146 | ||
474c8240 | 4147 | @smallexample |
c906108c | 4148 | /* @var{addr} is where the exception identifier is stored. |
d4f3574e SS |
4149 | @var{id} is the exception identifier. */ |
4150 | void __raise_exception (void **addr, void *id); | |
474c8240 | 4151 | @end smallexample |
c906108c SS |
4152 | |
4153 | @noindent | |
4154 | To make the debugger catch all exceptions before any stack | |
4155 | unwinding takes place, set a breakpoint on @code{__raise_exception} | |
79a6e687 | 4156 | (@pxref{Breakpoints, ,Breakpoints; Watchpoints; and Exceptions}). |
c906108c | 4157 | |
79a6e687 | 4158 | With a conditional breakpoint (@pxref{Conditions, ,Break Conditions}) |
c906108c SS |
4159 | that depends on the value of @var{id}, you can stop your program when |
4160 | a specific exception is raised. You can use multiple conditional | |
4161 | breakpoints to stop your program when any of a number of exceptions are | |
4162 | raised. | |
4163 | ||
4164 | ||
6d2ebf8b | 4165 | @node Delete Breaks |
79a6e687 | 4166 | @subsection Deleting Breakpoints |
c906108c SS |
4167 | |
4168 | @cindex clearing breakpoints, watchpoints, catchpoints | |
4169 | @cindex deleting breakpoints, watchpoints, catchpoints | |
4170 | It is often necessary to eliminate a breakpoint, watchpoint, or | |
4171 | catchpoint once it has done its job and you no longer want your program | |
4172 | to stop there. This is called @dfn{deleting} the breakpoint. A | |
4173 | breakpoint that has been deleted no longer exists; it is forgotten. | |
4174 | ||
4175 | With the @code{clear} command you can delete breakpoints according to | |
4176 | where they are in your program. With the @code{delete} command you can | |
4177 | delete individual breakpoints, watchpoints, or catchpoints by specifying | |
4178 | their breakpoint numbers. | |
4179 | ||
4180 | It is not necessary to delete a breakpoint to proceed past it. @value{GDBN} | |
4181 | automatically ignores breakpoints on the first instruction to be executed | |
4182 | when you continue execution without changing the execution address. | |
4183 | ||
4184 | @table @code | |
4185 | @kindex clear | |
4186 | @item clear | |
4187 | Delete any breakpoints at the next instruction to be executed in the | |
79a6e687 | 4188 | selected stack frame (@pxref{Selection, ,Selecting a Frame}). When |
c906108c SS |
4189 | the innermost frame is selected, this is a good way to delete a |
4190 | breakpoint where your program just stopped. | |
4191 | ||
2a25a5ba EZ |
4192 | @item clear @var{location} |
4193 | Delete any breakpoints set at the specified @var{location}. | |
4194 | @xref{Specify Location}, for the various forms of @var{location}; the | |
4195 | most useful ones are listed below: | |
4196 | ||
4197 | @table @code | |
c906108c SS |
4198 | @item clear @var{function} |
4199 | @itemx clear @var{filename}:@var{function} | |
09d4efe1 | 4200 | Delete any breakpoints set at entry to the named @var{function}. |
c906108c SS |
4201 | |
4202 | @item clear @var{linenum} | |
4203 | @itemx clear @var{filename}:@var{linenum} | |
09d4efe1 EZ |
4204 | Delete any breakpoints set at or within the code of the specified |
4205 | @var{linenum} of the specified @var{filename}. | |
2a25a5ba | 4206 | @end table |
c906108c SS |
4207 | |
4208 | @cindex delete breakpoints | |
4209 | @kindex delete | |
41afff9a | 4210 | @kindex d @r{(@code{delete})} |
c5394b80 JM |
4211 | @item delete @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
4212 | Delete the breakpoints, watchpoints, or catchpoints of the breakpoint | |
4213 | ranges specified as arguments. If no argument is specified, delete all | |
c906108c SS |
4214 | breakpoints (@value{GDBN} asks confirmation, unless you have @code{set |
4215 | confirm off}). You can abbreviate this command as @code{d}. | |
4216 | @end table | |
4217 | ||
6d2ebf8b | 4218 | @node Disabling |
79a6e687 | 4219 | @subsection Disabling Breakpoints |
c906108c | 4220 | |
4644b6e3 | 4221 | @cindex enable/disable a breakpoint |
c906108c SS |
4222 | Rather than deleting a breakpoint, watchpoint, or catchpoint, you might |
4223 | prefer to @dfn{disable} it. This makes the breakpoint inoperative as if | |
4224 | it had been deleted, but remembers the information on the breakpoint so | |
4225 | that you can @dfn{enable} it again later. | |
4226 | ||
4227 | You disable and enable breakpoints, watchpoints, and catchpoints with | |
d77f58be SS |
4228 | the @code{enable} and @code{disable} commands, optionally specifying |
4229 | one or more breakpoint numbers as arguments. Use @code{info break} to | |
4230 | print a list of all breakpoints, watchpoints, and catchpoints if you | |
4231 | do not know which numbers to use. | |
c906108c | 4232 | |
3b784c4f EZ |
4233 | Disabling and enabling a breakpoint that has multiple locations |
4234 | affects all of its locations. | |
4235 | ||
c906108c SS |
4236 | A breakpoint, watchpoint, or catchpoint can have any of four different |
4237 | states of enablement: | |
4238 | ||
4239 | @itemize @bullet | |
4240 | @item | |
4241 | Enabled. The breakpoint stops your program. A breakpoint set | |
4242 | with the @code{break} command starts out in this state. | |
4243 | @item | |
4244 | Disabled. The breakpoint has no effect on your program. | |
4245 | @item | |
4246 | Enabled once. The breakpoint stops your program, but then becomes | |
d4f3574e | 4247 | disabled. |
c906108c SS |
4248 | @item |
4249 | Enabled for deletion. The breakpoint stops your program, but | |
d4f3574e SS |
4250 | immediately after it does so it is deleted permanently. A breakpoint |
4251 | set with the @code{tbreak} command starts out in this state. | |
c906108c SS |
4252 | @end itemize |
4253 | ||
4254 | You can use the following commands to enable or disable breakpoints, | |
4255 | watchpoints, and catchpoints: | |
4256 | ||
4257 | @table @code | |
c906108c | 4258 | @kindex disable |
41afff9a | 4259 | @kindex dis @r{(@code{disable})} |
c5394b80 | 4260 | @item disable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4261 | Disable the specified breakpoints---or all breakpoints, if none are |
4262 | listed. A disabled breakpoint has no effect but is not forgotten. All | |
4263 | options such as ignore-counts, conditions and commands are remembered in | |
4264 | case the breakpoint is enabled again later. You may abbreviate | |
4265 | @code{disable} as @code{dis}. | |
4266 | ||
c906108c | 4267 | @kindex enable |
c5394b80 | 4268 | @item enable @r{[}breakpoints@r{]} @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4269 | Enable the specified breakpoints (or all defined breakpoints). They |
4270 | become effective once again in stopping your program. | |
4271 | ||
c5394b80 | 4272 | @item enable @r{[}breakpoints@r{]} once @var{range}@dots{} |
c906108c SS |
4273 | Enable the specified breakpoints temporarily. @value{GDBN} disables any |
4274 | of these breakpoints immediately after stopping your program. | |
4275 | ||
c5394b80 | 4276 | @item enable @r{[}breakpoints@r{]} delete @var{range}@dots{} |
c906108c SS |
4277 | Enable the specified breakpoints to work once, then die. @value{GDBN} |
4278 | deletes any of these breakpoints as soon as your program stops there. | |
09d4efe1 | 4279 | Breakpoints set by the @code{tbreak} command start out in this state. |
c906108c SS |
4280 | @end table |
4281 | ||
d4f3574e SS |
4282 | @c FIXME: I think the following ``Except for [...] @code{tbreak}'' is |
4283 | @c confusing: tbreak is also initially enabled. | |
c906108c | 4284 | Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks, |
79a6e687 | 4285 | ,Setting Breakpoints}), breakpoints that you set are initially enabled; |
c906108c SS |
4286 | subsequently, they become disabled or enabled only when you use one of |
4287 | the commands above. (The command @code{until} can set and delete a | |
4288 | breakpoint of its own, but it does not change the state of your other | |
4289 | breakpoints; see @ref{Continuing and Stepping, ,Continuing and | |
79a6e687 | 4290 | Stepping}.) |
c906108c | 4291 | |
6d2ebf8b | 4292 | @node Conditions |
79a6e687 | 4293 | @subsection Break Conditions |
c906108c SS |
4294 | @cindex conditional breakpoints |
4295 | @cindex breakpoint conditions | |
4296 | ||
4297 | @c FIXME what is scope of break condition expr? Context where wanted? | |
5d161b24 | 4298 | @c in particular for a watchpoint? |
c906108c SS |
4299 | The simplest sort of breakpoint breaks every time your program reaches a |
4300 | specified place. You can also specify a @dfn{condition} for a | |
4301 | breakpoint. A condition is just a Boolean expression in your | |
4302 | programming language (@pxref{Expressions, ,Expressions}). A breakpoint with | |
4303 | a condition evaluates the expression each time your program reaches it, | |
4304 | and your program stops only if the condition is @emph{true}. | |
4305 | ||
4306 | This is the converse of using assertions for program validation; in that | |
4307 | situation, you want to stop when the assertion is violated---that is, | |
4308 | when the condition is false. In C, if you want to test an assertion expressed | |
4309 | by the condition @var{assert}, you should set the condition | |
4310 | @samp{! @var{assert}} on the appropriate breakpoint. | |
4311 | ||
4312 | Conditions are also accepted for watchpoints; you may not need them, | |
4313 | since a watchpoint is inspecting the value of an expression anyhow---but | |
4314 | it might be simpler, say, to just set a watchpoint on a variable name, | |
4315 | and specify a condition that tests whether the new value is an interesting | |
4316 | one. | |
4317 | ||
4318 | Break conditions can have side effects, and may even call functions in | |
4319 | your program. This can be useful, for example, to activate functions | |
4320 | that log program progress, or to use your own print functions to | |
99e008fe | 4321 | format special data structures. The effects are completely predictable |
c906108c SS |
4322 | unless there is another enabled breakpoint at the same address. (In |
4323 | that case, @value{GDBN} might see the other breakpoint first and stop your | |
4324 | program without checking the condition of this one.) Note that | |
d4f3574e SS |
4325 | breakpoint commands are usually more convenient and flexible than break |
4326 | conditions for the | |
c906108c | 4327 | purpose of performing side effects when a breakpoint is reached |
79a6e687 | 4328 | (@pxref{Break Commands, ,Breakpoint Command Lists}). |
c906108c SS |
4329 | |
4330 | Break conditions can be specified when a breakpoint is set, by using | |
4331 | @samp{if} in the arguments to the @code{break} command. @xref{Set | |
79a6e687 | 4332 | Breaks, ,Setting Breakpoints}. They can also be changed at any time |
c906108c | 4333 | with the @code{condition} command. |
53a5351d | 4334 | |
c906108c SS |
4335 | You can also use the @code{if} keyword with the @code{watch} command. |
4336 | The @code{catch} command does not recognize the @code{if} keyword; | |
4337 | @code{condition} is the only way to impose a further condition on a | |
4338 | catchpoint. | |
c906108c SS |
4339 | |
4340 | @table @code | |
4341 | @kindex condition | |
4342 | @item condition @var{bnum} @var{expression} | |
4343 | Specify @var{expression} as the break condition for breakpoint, | |
4344 | watchpoint, or catchpoint number @var{bnum}. After you set a condition, | |
4345 | breakpoint @var{bnum} stops your program only if the value of | |
4346 | @var{expression} is true (nonzero, in C). When you use | |
4347 | @code{condition}, @value{GDBN} checks @var{expression} immediately for | |
4348 | syntactic correctness, and to determine whether symbols in it have | |
d4f3574e SS |
4349 | referents in the context of your breakpoint. If @var{expression} uses |
4350 | symbols not referenced in the context of the breakpoint, @value{GDBN} | |
4351 | prints an error message: | |
4352 | ||
474c8240 | 4353 | @smallexample |
d4f3574e | 4354 | No symbol "foo" in current context. |
474c8240 | 4355 | @end smallexample |
d4f3574e SS |
4356 | |
4357 | @noindent | |
c906108c SS |
4358 | @value{GDBN} does |
4359 | not actually evaluate @var{expression} at the time the @code{condition} | |
d4f3574e SS |
4360 | command (or a command that sets a breakpoint with a condition, like |
4361 | @code{break if @dots{}}) is given, however. @xref{Expressions, ,Expressions}. | |
c906108c SS |
4362 | |
4363 | @item condition @var{bnum} | |
4364 | Remove the condition from breakpoint number @var{bnum}. It becomes | |
4365 | an ordinary unconditional breakpoint. | |
4366 | @end table | |
4367 | ||
4368 | @cindex ignore count (of breakpoint) | |
4369 | A special case of a breakpoint condition is to stop only when the | |
4370 | breakpoint has been reached a certain number of times. This is so | |
4371 | useful that there is a special way to do it, using the @dfn{ignore | |
4372 | count} of the breakpoint. Every breakpoint has an ignore count, which | |
4373 | is an integer. Most of the time, the ignore count is zero, and | |
4374 | therefore has no effect. But if your program reaches a breakpoint whose | |
4375 | ignore count is positive, then instead of stopping, it just decrements | |
4376 | the ignore count by one and continues. As a result, if the ignore count | |
4377 | value is @var{n}, the breakpoint does not stop the next @var{n} times | |
4378 | your program reaches it. | |
4379 | ||
4380 | @table @code | |
4381 | @kindex ignore | |
4382 | @item ignore @var{bnum} @var{count} | |
4383 | Set the ignore count of breakpoint number @var{bnum} to @var{count}. | |
4384 | The next @var{count} times the breakpoint is reached, your program's | |
4385 | execution does not stop; other than to decrement the ignore count, @value{GDBN} | |
4386 | takes no action. | |
4387 | ||
4388 | To make the breakpoint stop the next time it is reached, specify | |
4389 | a count of zero. | |
4390 | ||
4391 | When you use @code{continue} to resume execution of your program from a | |
4392 | breakpoint, you can specify an ignore count directly as an argument to | |
4393 | @code{continue}, rather than using @code{ignore}. @xref{Continuing and | |
79a6e687 | 4394 | Stepping,,Continuing and Stepping}. |
c906108c SS |
4395 | |
4396 | If a breakpoint has a positive ignore count and a condition, the | |
4397 | condition is not checked. Once the ignore count reaches zero, | |
4398 | @value{GDBN} resumes checking the condition. | |
4399 | ||
4400 | You could achieve the effect of the ignore count with a condition such | |
4401 | as @w{@samp{$foo-- <= 0}} using a debugger convenience variable that | |
4402 | is decremented each time. @xref{Convenience Vars, ,Convenience | |
79a6e687 | 4403 | Variables}. |
c906108c SS |
4404 | @end table |
4405 | ||
4406 | Ignore counts apply to breakpoints, watchpoints, and catchpoints. | |
4407 | ||
4408 | ||
6d2ebf8b | 4409 | @node Break Commands |
79a6e687 | 4410 | @subsection Breakpoint Command Lists |
c906108c SS |
4411 | |
4412 | @cindex breakpoint commands | |
4413 | You can give any breakpoint (or watchpoint or catchpoint) a series of | |
4414 | commands to execute when your program stops due to that breakpoint. For | |
4415 | example, you might want to print the values of certain expressions, or | |
4416 | enable other breakpoints. | |
4417 | ||
4418 | @table @code | |
4419 | @kindex commands | |
ca91424e | 4420 | @kindex end@r{ (breakpoint commands)} |
95a42b64 | 4421 | @item commands @r{[}@var{range}@dots{}@r{]} |
c906108c SS |
4422 | @itemx @dots{} @var{command-list} @dots{} |
4423 | @itemx end | |
95a42b64 | 4424 | Specify a list of commands for the given breakpoints. The commands |
c906108c SS |
4425 | themselves appear on the following lines. Type a line containing just |
4426 | @code{end} to terminate the commands. | |
4427 | ||
4428 | To remove all commands from a breakpoint, type @code{commands} and | |
4429 | follow it immediately with @code{end}; that is, give no commands. | |
4430 | ||
95a42b64 TT |
4431 | With no argument, @code{commands} refers to the last breakpoint, |
4432 | watchpoint, or catchpoint set (not to the breakpoint most recently | |
4433 | encountered). If the most recent breakpoints were set with a single | |
4434 | command, then the @code{commands} will apply to all the breakpoints | |
4435 | set by that command. This applies to breakpoints set by | |
86b17b60 PA |
4436 | @code{rbreak}, and also applies when a single @code{break} command |
4437 | creates multiple breakpoints (@pxref{Ambiguous Expressions,,Ambiguous | |
4438 | Expressions}). | |
c906108c SS |
4439 | @end table |
4440 | ||
4441 | Pressing @key{RET} as a means of repeating the last @value{GDBN} command is | |
4442 | disabled within a @var{command-list}. | |
4443 | ||
4444 | You can use breakpoint commands to start your program up again. Simply | |
4445 | use the @code{continue} command, or @code{step}, or any other command | |
4446 | that resumes execution. | |
4447 | ||
4448 | Any other commands in the command list, after a command that resumes | |
4449 | execution, are ignored. This is because any time you resume execution | |
4450 | (even with a simple @code{next} or @code{step}), you may encounter | |
4451 | another breakpoint---which could have its own command list, leading to | |
4452 | ambiguities about which list to execute. | |
4453 | ||
4454 | @kindex silent | |
4455 | If the first command you specify in a command list is @code{silent}, the | |
4456 | usual message about stopping at a breakpoint is not printed. This may | |
4457 | be desirable for breakpoints that are to print a specific message and | |
4458 | then continue. If none of the remaining commands print anything, you | |
4459 | see no sign that the breakpoint was reached. @code{silent} is | |
4460 | meaningful only at the beginning of a breakpoint command list. | |
4461 | ||
4462 | The commands @code{echo}, @code{output}, and @code{printf} allow you to | |
4463 | print precisely controlled output, and are often useful in silent | |
79a6e687 | 4464 | breakpoints. @xref{Output, ,Commands for Controlled Output}. |
c906108c SS |
4465 | |
4466 | For example, here is how you could use breakpoint commands to print the | |
4467 | value of @code{x} at entry to @code{foo} whenever @code{x} is positive. | |
4468 | ||
474c8240 | 4469 | @smallexample |
c906108c SS |
4470 | break foo if x>0 |
4471 | commands | |
4472 | silent | |
4473 | printf "x is %d\n",x | |
4474 | cont | |
4475 | end | |
474c8240 | 4476 | @end smallexample |
c906108c SS |
4477 | |
4478 | One application for breakpoint commands is to compensate for one bug so | |
4479 | you can test for another. Put a breakpoint just after the erroneous line | |
4480 | of code, give it a condition to detect the case in which something | |
4481 | erroneous has been done, and give it commands to assign correct values | |
4482 | to any variables that need them. End with the @code{continue} command | |
4483 | so that your program does not stop, and start with the @code{silent} | |
4484 | command so that no output is produced. Here is an example: | |
4485 | ||
474c8240 | 4486 | @smallexample |
c906108c SS |
4487 | break 403 |
4488 | commands | |
4489 | silent | |
4490 | set x = y + 4 | |
4491 | cont | |
4492 | end | |
474c8240 | 4493 | @end smallexample |
c906108c | 4494 | |
6149aea9 PA |
4495 | @node Save Breakpoints |
4496 | @subsection How to save breakpoints to a file | |
4497 | ||
4498 | To save breakpoint definitions to a file use the @w{@code{save | |
4499 | breakpoints}} command. | |
4500 | ||
4501 | @table @code | |
4502 | @kindex save breakpoints | |
4503 | @cindex save breakpoints to a file for future sessions | |
4504 | @item save breakpoints [@var{filename}] | |
4505 | This command saves all current breakpoint definitions together with | |
4506 | their commands and ignore counts, into a file @file{@var{filename}} | |
4507 | suitable for use in a later debugging session. This includes all | |
4508 | types of breakpoints (breakpoints, watchpoints, catchpoints, | |
4509 | tracepoints). To read the saved breakpoint definitions, use the | |
4510 | @code{source} command (@pxref{Command Files}). Note that watchpoints | |
4511 | with expressions involving local variables may fail to be recreated | |
4512 | because it may not be possible to access the context where the | |
4513 | watchpoint is valid anymore. Because the saved breakpoint definitions | |
4514 | are simply a sequence of @value{GDBN} commands that recreate the | |
4515 | breakpoints, you can edit the file in your favorite editing program, | |
4516 | and remove the breakpoint definitions you're not interested in, or | |
4517 | that can no longer be recreated. | |
4518 | @end table | |
4519 | ||
c906108c | 4520 | @c @ifclear BARETARGET |
6d2ebf8b | 4521 | @node Error in Breakpoints |
d4f3574e | 4522 | @subsection ``Cannot insert breakpoints'' |
c906108c | 4523 | |
fa3a767f PA |
4524 | If you request too many active hardware-assisted breakpoints and |
4525 | watchpoints, you will see this error message: | |
d4f3574e SS |
4526 | |
4527 | @c FIXME: the precise wording of this message may change; the relevant | |
4528 | @c source change is not committed yet (Sep 3, 1999). | |
4529 | @smallexample | |
4530 | Stopped; cannot insert breakpoints. | |
4531 | You may have requested too many hardware breakpoints and watchpoints. | |
4532 | @end smallexample | |
4533 | ||
4534 | @noindent | |
4535 | This message is printed when you attempt to resume the program, since | |
4536 | only then @value{GDBN} knows exactly how many hardware breakpoints and | |
4537 | watchpoints it needs to insert. | |
4538 | ||
4539 | When this message is printed, you need to disable or remove some of the | |
4540 | hardware-assisted breakpoints and watchpoints, and then continue. | |
4541 | ||
79a6e687 | 4542 | @node Breakpoint-related Warnings |
1485d690 KB |
4543 | @subsection ``Breakpoint address adjusted...'' |
4544 | @cindex breakpoint address adjusted | |
4545 | ||
4546 | Some processor architectures place constraints on the addresses at | |
4547 | which breakpoints may be placed. For architectures thus constrained, | |
4548 | @value{GDBN} will attempt to adjust the breakpoint's address to comply | |
4549 | with the constraints dictated by the architecture. | |
4550 | ||
4551 | One example of such an architecture is the Fujitsu FR-V. The FR-V is | |
4552 | a VLIW architecture in which a number of RISC-like instructions may be | |
4553 | bundled together for parallel execution. The FR-V architecture | |
4554 | constrains the location of a breakpoint instruction within such a | |
4555 | bundle to the instruction with the lowest address. @value{GDBN} | |
4556 | honors this constraint by adjusting a breakpoint's address to the | |
4557 | first in the bundle. | |
4558 | ||
4559 | It is not uncommon for optimized code to have bundles which contain | |
4560 | instructions from different source statements, thus it may happen that | |
4561 | a breakpoint's address will be adjusted from one source statement to | |
4562 | another. Since this adjustment may significantly alter @value{GDBN}'s | |
4563 | breakpoint related behavior from what the user expects, a warning is | |
4564 | printed when the breakpoint is first set and also when the breakpoint | |
4565 | is hit. | |
4566 | ||
4567 | A warning like the one below is printed when setting a breakpoint | |
4568 | that's been subject to address adjustment: | |
4569 | ||
4570 | @smallexample | |
4571 | warning: Breakpoint address adjusted from 0x00010414 to 0x00010410. | |
4572 | @end smallexample | |
4573 | ||
4574 | Such warnings are printed both for user settable and @value{GDBN}'s | |
4575 | internal breakpoints. If you see one of these warnings, you should | |
4576 | verify that a breakpoint set at the adjusted address will have the | |
4577 | desired affect. If not, the breakpoint in question may be removed and | |
b383017d | 4578 | other breakpoints may be set which will have the desired behavior. |
1485d690 KB |
4579 | E.g., it may be sufficient to place the breakpoint at a later |
4580 | instruction. A conditional breakpoint may also be useful in some | |
4581 | cases to prevent the breakpoint from triggering too often. | |
4582 | ||
4583 | @value{GDBN} will also issue a warning when stopping at one of these | |
4584 | adjusted breakpoints: | |
4585 | ||
4586 | @smallexample | |
4587 | warning: Breakpoint 1 address previously adjusted from 0x00010414 | |
4588 | to 0x00010410. | |
4589 | @end smallexample | |
4590 | ||
4591 | When this warning is encountered, it may be too late to take remedial | |
4592 | action except in cases where the breakpoint is hit earlier or more | |
4593 | frequently than expected. | |
d4f3574e | 4594 | |
6d2ebf8b | 4595 | @node Continuing and Stepping |
79a6e687 | 4596 | @section Continuing and Stepping |
c906108c SS |
4597 | |
4598 | @cindex stepping | |
4599 | @cindex continuing | |
4600 | @cindex resuming execution | |
4601 | @dfn{Continuing} means resuming program execution until your program | |
4602 | completes normally. In contrast, @dfn{stepping} means executing just | |
4603 | one more ``step'' of your program, where ``step'' may mean either one | |
4604 | line of source code, or one machine instruction (depending on what | |
7a292a7a SS |
4605 | particular command you use). Either when continuing or when stepping, |
4606 | your program may stop even sooner, due to a breakpoint or a signal. (If | |
d4f3574e SS |
4607 | it stops due to a signal, you may want to use @code{handle}, or use |
4608 | @samp{signal 0} to resume execution. @xref{Signals, ,Signals}.) | |
c906108c SS |
4609 | |
4610 | @table @code | |
4611 | @kindex continue | |
41afff9a EZ |
4612 | @kindex c @r{(@code{continue})} |
4613 | @kindex fg @r{(resume foreground execution)} | |
c906108c SS |
4614 | @item continue @r{[}@var{ignore-count}@r{]} |
4615 | @itemx c @r{[}@var{ignore-count}@r{]} | |
4616 | @itemx fg @r{[}@var{ignore-count}@r{]} | |
4617 | Resume program execution, at the address where your program last stopped; | |
4618 | any breakpoints set at that address are bypassed. The optional argument | |
4619 | @var{ignore-count} allows you to specify a further number of times to | |
4620 | ignore a breakpoint at this location; its effect is like that of | |
79a6e687 | 4621 | @code{ignore} (@pxref{Conditions, ,Break Conditions}). |
c906108c SS |
4622 | |
4623 | The argument @var{ignore-count} is meaningful only when your program | |
4624 | stopped due to a breakpoint. At other times, the argument to | |
4625 | @code{continue} is ignored. | |
4626 | ||
d4f3574e SS |
4627 | The synonyms @code{c} and @code{fg} (for @dfn{foreground}, as the |
4628 | debugged program is deemed to be the foreground program) are provided | |
4629 | purely for convenience, and have exactly the same behavior as | |
4630 | @code{continue}. | |
c906108c SS |
4631 | @end table |
4632 | ||
4633 | To resume execution at a different place, you can use @code{return} | |
79a6e687 | 4634 | (@pxref{Returning, ,Returning from a Function}) to go back to the |
c906108c | 4635 | calling function; or @code{jump} (@pxref{Jumping, ,Continuing at a |
79a6e687 | 4636 | Different Address}) to go to an arbitrary location in your program. |
c906108c SS |
4637 | |
4638 | A typical technique for using stepping is to set a breakpoint | |
79a6e687 | 4639 | (@pxref{Breakpoints, ,Breakpoints; Watchpoints; and Catchpoints}) at the |
c906108c SS |
4640 | beginning of the function or the section of your program where a problem |
4641 | is believed to lie, run your program until it stops at that breakpoint, | |
4642 | and then step through the suspect area, examining the variables that are | |
4643 | interesting, until you see the problem happen. | |
4644 | ||
4645 | @table @code | |
4646 | @kindex step | |
41afff9a | 4647 | @kindex s @r{(@code{step})} |
c906108c SS |
4648 | @item step |
4649 | Continue running your program until control reaches a different source | |
4650 | line, then stop it and return control to @value{GDBN}. This command is | |
4651 | abbreviated @code{s}. | |
4652 | ||
4653 | @quotation | |
4654 | @c "without debugging information" is imprecise; actually "without line | |
4655 | @c numbers in the debugging information". (gcc -g1 has debugging info but | |
4656 | @c not line numbers). But it seems complex to try to make that | |
4657 | @c distinction here. | |
4658 | @emph{Warning:} If you use the @code{step} command while control is | |
4659 | within a function that was compiled without debugging information, | |
4660 | execution proceeds until control reaches a function that does have | |
4661 | debugging information. Likewise, it will not step into a function which | |
4662 | is compiled without debugging information. To step through functions | |
4663 | without debugging information, use the @code{stepi} command, described | |
4664 | below. | |
4665 | @end quotation | |
4666 | ||
4a92d011 EZ |
4667 | The @code{step} command only stops at the first instruction of a source |
4668 | line. This prevents the multiple stops that could otherwise occur in | |
4669 | @code{switch} statements, @code{for} loops, etc. @code{step} continues | |
4670 | to stop if a function that has debugging information is called within | |
4671 | the line. In other words, @code{step} @emph{steps inside} any functions | |
4672 | called within the line. | |
c906108c | 4673 | |
d4f3574e SS |
4674 | Also, the @code{step} command only enters a function if there is line |
4675 | number information for the function. Otherwise it acts like the | |
5d161b24 | 4676 | @code{next} command. This avoids problems when using @code{cc -gl} |
c906108c | 4677 | on MIPS machines. Previously, @code{step} entered subroutines if there |
5d161b24 | 4678 | was any debugging information about the routine. |
c906108c SS |
4679 | |
4680 | @item step @var{count} | |
4681 | Continue running as in @code{step}, but do so @var{count} times. If a | |
7a292a7a SS |
4682 | breakpoint is reached, or a signal not related to stepping occurs before |
4683 | @var{count} steps, stepping stops right away. | |
c906108c SS |
4684 | |
4685 | @kindex next | |
41afff9a | 4686 | @kindex n @r{(@code{next})} |
c906108c SS |
4687 | @item next @r{[}@var{count}@r{]} |
4688 | Continue to the next source line in the current (innermost) stack frame. | |
7a292a7a SS |
4689 | This is similar to @code{step}, but function calls that appear within |
4690 | the line of code are executed without stopping. Execution stops when | |
4691 | control reaches a different line of code at the original stack level | |
4692 | that was executing when you gave the @code{next} command. This command | |
4693 | is abbreviated @code{n}. | |
c906108c SS |
4694 | |
4695 | An argument @var{count} is a repeat count, as for @code{step}. | |
4696 | ||
4697 | ||
4698 | @c FIX ME!! Do we delete this, or is there a way it fits in with | |
4699 | @c the following paragraph? --- Vctoria | |
4700 | @c | |
4701 | @c @code{next} within a function that lacks debugging information acts like | |
4702 | @c @code{step}, but any function calls appearing within the code of the | |
4703 | @c function are executed without stopping. | |
4704 | ||
d4f3574e SS |
4705 | The @code{next} command only stops at the first instruction of a |
4706 | source line. This prevents multiple stops that could otherwise occur in | |
4a92d011 | 4707 | @code{switch} statements, @code{for} loops, etc. |
c906108c | 4708 | |
b90a5f51 CF |
4709 | @kindex set step-mode |
4710 | @item set step-mode | |
4711 | @cindex functions without line info, and stepping | |
4712 | @cindex stepping into functions with no line info | |
4713 | @itemx set step-mode on | |
4a92d011 | 4714 | The @code{set step-mode on} command causes the @code{step} command to |
b90a5f51 CF |
4715 | stop at the first instruction of a function which contains no debug line |
4716 | information rather than stepping over it. | |
4717 | ||
4a92d011 EZ |
4718 | This is useful in cases where you may be interested in inspecting the |
4719 | machine instructions of a function which has no symbolic info and do not | |
4720 | want @value{GDBN} to automatically skip over this function. | |
b90a5f51 CF |
4721 | |
4722 | @item set step-mode off | |
4a92d011 | 4723 | Causes the @code{step} command to step over any functions which contains no |
b90a5f51 CF |
4724 | debug information. This is the default. |
4725 | ||
9c16f35a EZ |
4726 | @item show step-mode |
4727 | Show whether @value{GDBN} will stop in or step over functions without | |
4728 | source line debug information. | |
4729 | ||
c906108c | 4730 | @kindex finish |
8dfa32fc | 4731 | @kindex fin @r{(@code{finish})} |
c906108c SS |
4732 | @item finish |
4733 | Continue running until just after function in the selected stack frame | |
8dfa32fc JB |
4734 | returns. Print the returned value (if any). This command can be |
4735 | abbreviated as @code{fin}. | |
c906108c SS |
4736 | |
4737 | Contrast this with the @code{return} command (@pxref{Returning, | |
79a6e687 | 4738 | ,Returning from a Function}). |
c906108c SS |
4739 | |
4740 | @kindex until | |
41afff9a | 4741 | @kindex u @r{(@code{until})} |
09d4efe1 | 4742 | @cindex run until specified location |
c906108c SS |
4743 | @item until |
4744 | @itemx u | |
4745 | Continue running until a source line past the current line, in the | |
4746 | current stack frame, is reached. This command is used to avoid single | |
4747 | stepping through a loop more than once. It is like the @code{next} | |
4748 | command, except that when @code{until} encounters a jump, it | |
4749 | automatically continues execution until the program counter is greater | |
4750 | than the address of the jump. | |
4751 | ||
4752 | This means that when you reach the end of a loop after single stepping | |
4753 | though it, @code{until} makes your program continue execution until it | |
4754 | exits the loop. In contrast, a @code{next} command at the end of a loop | |
4755 | simply steps back to the beginning of the loop, which forces you to step | |
4756 | through the next iteration. | |
4757 | ||
4758 | @code{until} always stops your program if it attempts to exit the current | |
4759 | stack frame. | |
4760 | ||
4761 | @code{until} may produce somewhat counterintuitive results if the order | |
4762 | of machine code does not match the order of the source lines. For | |
4763 | example, in the following excerpt from a debugging session, the @code{f} | |
4764 | (@code{frame}) command shows that execution is stopped at line | |
4765 | @code{206}; yet when we use @code{until}, we get to line @code{195}: | |
4766 | ||
474c8240 | 4767 | @smallexample |
c906108c SS |
4768 | (@value{GDBP}) f |
4769 | #0 main (argc=4, argv=0xf7fffae8) at m4.c:206 | |
4770 | 206 expand_input(); | |
4771 | (@value{GDBP}) until | |
4772 | 195 for ( ; argc > 0; NEXTARG) @{ | |
474c8240 | 4773 | @end smallexample |
c906108c SS |
4774 | |
4775 | This happened because, for execution efficiency, the compiler had | |
4776 | generated code for the loop closure test at the end, rather than the | |
4777 | start, of the loop---even though the test in a C @code{for}-loop is | |
4778 | written before the body of the loop. The @code{until} command appeared | |
4779 | to step back to the beginning of the loop when it advanced to this | |
4780 | expression; however, it has not really gone to an earlier | |
4781 | statement---not in terms of the actual machine code. | |
4782 | ||
4783 | @code{until} with no argument works by means of single | |
4784 | instruction stepping, and hence is slower than @code{until} with an | |
4785 | argument. | |
4786 | ||
4787 | @item until @var{location} | |
4788 | @itemx u @var{location} | |
4789 | Continue running your program until either the specified location is | |
4790 | reached, or the current stack frame returns. @var{location} is any of | |
2a25a5ba EZ |
4791 | the forms described in @ref{Specify Location}. |
4792 | This form of the command uses temporary breakpoints, and | |
c60eb6f1 EZ |
4793 | hence is quicker than @code{until} without an argument. The specified |
4794 | location is actually reached only if it is in the current frame. This | |
4795 | implies that @code{until} can be used to skip over recursive function | |
4796 | invocations. For instance in the code below, if the current location is | |
4797 | line @code{96}, issuing @code{until 99} will execute the program up to | |
db2e3e2e | 4798 | line @code{99} in the same invocation of factorial, i.e., after the inner |
c60eb6f1 EZ |
4799 | invocations have returned. |
4800 | ||
4801 | @smallexample | |
4802 | 94 int factorial (int value) | |
4803 | 95 @{ | |
4804 | 96 if (value > 1) @{ | |
4805 | 97 value *= factorial (value - 1); | |
4806 | 98 @} | |
4807 | 99 return (value); | |
4808 | 100 @} | |
4809 | @end smallexample | |
4810 | ||
4811 | ||
4812 | @kindex advance @var{location} | |
4813 | @itemx advance @var{location} | |
09d4efe1 | 4814 | Continue running the program up to the given @var{location}. An argument is |
2a25a5ba EZ |
4815 | required, which should be of one of the forms described in |
4816 | @ref{Specify Location}. | |
4817 | Execution will also stop upon exit from the current stack | |
c60eb6f1 EZ |
4818 | frame. This command is similar to @code{until}, but @code{advance} will |
4819 | not skip over recursive function calls, and the target location doesn't | |
4820 | have to be in the same frame as the current one. | |
4821 | ||
c906108c SS |
4822 | |
4823 | @kindex stepi | |
41afff9a | 4824 | @kindex si @r{(@code{stepi})} |
c906108c | 4825 | @item stepi |
96a2c332 | 4826 | @itemx stepi @var{arg} |
c906108c SS |
4827 | @itemx si |
4828 | Execute one machine instruction, then stop and return to the debugger. | |
4829 | ||
4830 | It is often useful to do @samp{display/i $pc} when stepping by machine | |
4831 | instructions. This makes @value{GDBN} automatically display the next | |
4832 | instruction to be executed, each time your program stops. @xref{Auto | |
79a6e687 | 4833 | Display,, Automatic Display}. |
c906108c SS |
4834 | |
4835 | An argument is a repeat count, as in @code{step}. | |
4836 | ||
4837 | @need 750 | |
4838 | @kindex nexti | |
41afff9a | 4839 | @kindex ni @r{(@code{nexti})} |
c906108c | 4840 | @item nexti |
96a2c332 | 4841 | @itemx nexti @var{arg} |
c906108c SS |
4842 | @itemx ni |
4843 | Execute one machine instruction, but if it is a function call, | |
4844 | proceed until the function returns. | |
4845 | ||
4846 | An argument is a repeat count, as in @code{next}. | |
4847 | @end table | |
4848 | ||
6d2ebf8b | 4849 | @node Signals |
c906108c SS |
4850 | @section Signals |
4851 | @cindex signals | |
4852 | ||
4853 | A signal is an asynchronous event that can happen in a program. The | |
4854 | operating system defines the possible kinds of signals, and gives each | |
4855 | kind a name and a number. For example, in Unix @code{SIGINT} is the | |
c8aa23ab | 4856 | signal a program gets when you type an interrupt character (often @kbd{Ctrl-c}); |
c906108c SS |
4857 | @code{SIGSEGV} is the signal a program gets from referencing a place in |
4858 | memory far away from all the areas in use; @code{SIGALRM} occurs when | |
4859 | the alarm clock timer goes off (which happens only if your program has | |
4860 | requested an alarm). | |
4861 | ||
4862 | @cindex fatal signals | |
4863 | Some signals, including @code{SIGALRM}, are a normal part of the | |
4864 | functioning of your program. Others, such as @code{SIGSEGV}, indicate | |
d4f3574e | 4865 | errors; these signals are @dfn{fatal} (they kill your program immediately) if the |
c906108c SS |
4866 | program has not specified in advance some other way to handle the signal. |
4867 | @code{SIGINT} does not indicate an error in your program, but it is normally | |
4868 | fatal so it can carry out the purpose of the interrupt: to kill the program. | |
4869 | ||
4870 | @value{GDBN} has the ability to detect any occurrence of a signal in your | |
4871 | program. You can tell @value{GDBN} in advance what to do for each kind of | |
4872 | signal. | |
4873 | ||
4874 | @cindex handling signals | |
24f93129 EZ |
4875 | Normally, @value{GDBN} is set up to let the non-erroneous signals like |
4876 | @code{SIGALRM} be silently passed to your program | |
4877 | (so as not to interfere with their role in the program's functioning) | |
c906108c SS |
4878 | but to stop your program immediately whenever an error signal happens. |
4879 | You can change these settings with the @code{handle} command. | |
4880 | ||
4881 | @table @code | |
4882 | @kindex info signals | |
09d4efe1 | 4883 | @kindex info handle |
c906108c | 4884 | @item info signals |
96a2c332 | 4885 | @itemx info handle |
c906108c SS |
4886 | Print a table of all the kinds of signals and how @value{GDBN} has been told to |
4887 | handle each one. You can use this to see the signal numbers of all | |
4888 | the defined types of signals. | |
4889 | ||
45ac1734 EZ |
4890 | @item info signals @var{sig} |
4891 | Similar, but print information only about the specified signal number. | |
4892 | ||
d4f3574e | 4893 | @code{info handle} is an alias for @code{info signals}. |
c906108c SS |
4894 | |
4895 | @kindex handle | |
45ac1734 | 4896 | @item handle @var{signal} @r{[}@var{keywords}@dots{}@r{]} |
5ece1a18 EZ |
4897 | Change the way @value{GDBN} handles signal @var{signal}. @var{signal} |
4898 | can be the number of a signal or its name (with or without the | |
24f93129 | 4899 | @samp{SIG} at the beginning); a list of signal numbers of the form |
5ece1a18 | 4900 | @samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the |
45ac1734 EZ |
4901 | known signals. Optional arguments @var{keywords}, described below, |
4902 | say what change to make. | |
c906108c SS |
4903 | @end table |
4904 | ||
4905 | @c @group | |
4906 | The keywords allowed by the @code{handle} command can be abbreviated. | |
4907 | Their full names are: | |
4908 | ||
4909 | @table @code | |
4910 | @item nostop | |
4911 | @value{GDBN} should not stop your program when this signal happens. It may | |
4912 | still print a message telling you that the signal has come in. | |
4913 | ||
4914 | @item stop | |
4915 | @value{GDBN} should stop your program when this signal happens. This implies | |
4916 | the @code{print} keyword as well. | |
4917 | ||
4918 | @item print | |
4919 | @value{GDBN} should print a message when this signal happens. | |
4920 | ||
4921 | @item noprint | |
4922 | @value{GDBN} should not mention the occurrence of the signal at all. This | |
4923 | implies the @code{nostop} keyword as well. | |
4924 | ||
4925 | @item pass | |
5ece1a18 | 4926 | @itemx noignore |
c906108c SS |
4927 | @value{GDBN} should allow your program to see this signal; your program |
4928 | can handle the signal, or else it may terminate if the signal is fatal | |
5ece1a18 | 4929 | and not handled. @code{pass} and @code{noignore} are synonyms. |
c906108c SS |
4930 | |
4931 | @item nopass | |
5ece1a18 | 4932 | @itemx ignore |
c906108c | 4933 | @value{GDBN} should not allow your program to see this signal. |
5ece1a18 | 4934 | @code{nopass} and @code{ignore} are synonyms. |
c906108c SS |
4935 | @end table |
4936 | @c @end group | |
4937 | ||
d4f3574e SS |
4938 | When a signal stops your program, the signal is not visible to the |
4939 | program until you | |
c906108c SS |
4940 | continue. Your program sees the signal then, if @code{pass} is in |
4941 | effect for the signal in question @emph{at that time}. In other words, | |
4942 | after @value{GDBN} reports a signal, you can use the @code{handle} | |
4943 | command with @code{pass} or @code{nopass} to control whether your | |
4944 | program sees that signal when you continue. | |
4945 | ||
24f93129 EZ |
4946 | The default is set to @code{nostop}, @code{noprint}, @code{pass} for |
4947 | non-erroneous signals such as @code{SIGALRM}, @code{SIGWINCH} and | |
4948 | @code{SIGCHLD}, and to @code{stop}, @code{print}, @code{pass} for the | |
4949 | erroneous signals. | |
4950 | ||
c906108c SS |
4951 | You can also use the @code{signal} command to prevent your program from |
4952 | seeing a signal, or cause it to see a signal it normally would not see, | |
4953 | or to give it any signal at any time. For example, if your program stopped | |
4954 | due to some sort of memory reference error, you might store correct | |
4955 | values into the erroneous variables and continue, hoping to see more | |
4956 | execution; but your program would probably terminate immediately as | |
4957 | a result of the fatal signal once it saw the signal. To prevent this, | |
4958 | you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your | |
79a6e687 | 4959 | Program a Signal}. |
c906108c | 4960 | |
4aa995e1 PA |
4961 | @cindex extra signal information |
4962 | @anchor{extra signal information} | |
4963 | ||
4964 | On some targets, @value{GDBN} can inspect extra signal information | |
4965 | associated with the intercepted signal, before it is actually | |
4966 | delivered to the program being debugged. This information is exported | |
4967 | by the convenience variable @code{$_siginfo}, and consists of data | |
4968 | that is passed by the kernel to the signal handler at the time of the | |
4969 | receipt of a signal. The data type of the information itself is | |
4970 | target dependent. You can see the data type using the @code{ptype | |
4971 | $_siginfo} command. On Unix systems, it typically corresponds to the | |
4972 | standard @code{siginfo_t} type, as defined in the @file{signal.h} | |
4973 | system header. | |
4974 | ||
4975 | Here's an example, on a @sc{gnu}/Linux system, printing the stray | |
4976 | referenced address that raised a segmentation fault. | |
4977 | ||
4978 | @smallexample | |
4979 | @group | |
4980 | (@value{GDBP}) continue | |
4981 | Program received signal SIGSEGV, Segmentation fault. | |
4982 | 0x0000000000400766 in main () | |
4983 | 69 *(int *)p = 0; | |
4984 | (@value{GDBP}) ptype $_siginfo | |
4985 | type = struct @{ | |
4986 | int si_signo; | |
4987 | int si_errno; | |
4988 | int si_code; | |
4989 | union @{ | |
4990 | int _pad[28]; | |
4991 | struct @{...@} _kill; | |
4992 | struct @{...@} _timer; | |
4993 | struct @{...@} _rt; | |
4994 | struct @{...@} _sigchld; | |
4995 | struct @{...@} _sigfault; | |
4996 | struct @{...@} _sigpoll; | |
4997 | @} _sifields; | |
4998 | @} | |
4999 | (@value{GDBP}) ptype $_siginfo._sifields._sigfault | |
5000 | type = struct @{ | |
5001 | void *si_addr; | |
5002 | @} | |
5003 | (@value{GDBP}) p $_siginfo._sifields._sigfault.si_addr | |
5004 | $1 = (void *) 0x7ffff7ff7000 | |
5005 | @end group | |
5006 | @end smallexample | |
5007 | ||
5008 | Depending on target support, @code{$_siginfo} may also be writable. | |
5009 | ||
6d2ebf8b | 5010 | @node Thread Stops |
79a6e687 | 5011 | @section Stopping and Starting Multi-thread Programs |
c906108c | 5012 | |
0606b73b SL |
5013 | @cindex stopped threads |
5014 | @cindex threads, stopped | |
5015 | ||
5016 | @cindex continuing threads | |
5017 | @cindex threads, continuing | |
5018 | ||
5019 | @value{GDBN} supports debugging programs with multiple threads | |
5020 | (@pxref{Threads,, Debugging Programs with Multiple Threads}). There | |
5021 | are two modes of controlling execution of your program within the | |
5022 | debugger. In the default mode, referred to as @dfn{all-stop mode}, | |
5023 | when any thread in your program stops (for example, at a breakpoint | |
5024 | or while being stepped), all other threads in the program are also stopped by | |
5025 | @value{GDBN}. On some targets, @value{GDBN} also supports | |
5026 | @dfn{non-stop mode}, in which other threads can continue to run freely while | |
5027 | you examine the stopped thread in the debugger. | |
5028 | ||
5029 | @menu | |
5030 | * All-Stop Mode:: All threads stop when GDB takes control | |
5031 | * Non-Stop Mode:: Other threads continue to execute | |
5032 | * Background Execution:: Running your program asynchronously | |
5033 | * Thread-Specific Breakpoints:: Controlling breakpoints | |
5034 | * Interrupted System Calls:: GDB may interfere with system calls | |
d914c394 | 5035 | * Observer Mode:: GDB does not alter program behavior |
0606b73b SL |
5036 | @end menu |
5037 | ||
5038 | @node All-Stop Mode | |
5039 | @subsection All-Stop Mode | |
5040 | ||
5041 | @cindex all-stop mode | |
5042 | ||
5043 | In all-stop mode, whenever your program stops under @value{GDBN} for any reason, | |
5044 | @emph{all} threads of execution stop, not just the current thread. This | |
5045 | allows you to examine the overall state of the program, including | |
5046 | switching between threads, without worrying that things may change | |
5047 | underfoot. | |
5048 | ||
5049 | Conversely, whenever you restart the program, @emph{all} threads start | |
5050 | executing. @emph{This is true even when single-stepping} with commands | |
5051 | like @code{step} or @code{next}. | |
5052 | ||
5053 | In particular, @value{GDBN} cannot single-step all threads in lockstep. | |
5054 | Since thread scheduling is up to your debugging target's operating | |
5055 | system (not controlled by @value{GDBN}), other threads may | |
5056 | execute more than one statement while the current thread completes a | |
5057 | single step. Moreover, in general other threads stop in the middle of a | |
5058 | statement, rather than at a clean statement boundary, when the program | |
5059 | stops. | |
5060 | ||
5061 | You might even find your program stopped in another thread after | |
5062 | continuing or even single-stepping. This happens whenever some other | |
5063 | thread runs into a breakpoint, a signal, or an exception before the | |
5064 | first thread completes whatever you requested. | |
5065 | ||
5066 | @cindex automatic thread selection | |
5067 | @cindex switching threads automatically | |
5068 | @cindex threads, automatic switching | |
5069 | Whenever @value{GDBN} stops your program, due to a breakpoint or a | |
5070 | signal, it automatically selects the thread where that breakpoint or | |
5071 | signal happened. @value{GDBN} alerts you to the context switch with a | |
5072 | message such as @samp{[Switching to Thread @var{n}]} to identify the | |
5073 | thread. | |
5074 | ||
5075 | On some OSes, you can modify @value{GDBN}'s default behavior by | |
5076 | locking the OS scheduler to allow only a single thread to run. | |
5077 | ||
5078 | @table @code | |
5079 | @item set scheduler-locking @var{mode} | |
5080 | @cindex scheduler locking mode | |
5081 | @cindex lock scheduler | |
5082 | Set the scheduler locking mode. If it is @code{off}, then there is no | |
5083 | locking and any thread may run at any time. If @code{on}, then only the | |
5084 | current thread may run when the inferior is resumed. The @code{step} | |
5085 | mode optimizes for single-stepping; it prevents other threads | |
5086 | from preempting the current thread while you are stepping, so that | |
5087 | the focus of debugging does not change unexpectedly. | |
5088 | Other threads only rarely (or never) get a chance to run | |
5089 | when you step. They are more likely to run when you @samp{next} over a | |
5090 | function call, and they are completely free to run when you use commands | |
5091 | like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another | |
5092 | thread hits a breakpoint during its timeslice, @value{GDBN} does not change | |
5093 | the current thread away from the thread that you are debugging. | |
5094 | ||
5095 | @item show scheduler-locking | |
5096 | Display the current scheduler locking mode. | |
5097 | @end table | |
5098 | ||
d4db2f36 PA |
5099 | @cindex resume threads of multiple processes simultaneously |
5100 | By default, when you issue one of the execution commands such as | |
5101 | @code{continue}, @code{next} or @code{step}, @value{GDBN} allows only | |
5102 | threads of the current inferior to run. For example, if @value{GDBN} | |
5103 | is attached to two inferiors, each with two threads, the | |
5104 | @code{continue} command resumes only the two threads of the current | |
5105 | inferior. This is useful, for example, when you debug a program that | |
5106 | forks and you want to hold the parent stopped (so that, for instance, | |
5107 | it doesn't run to exit), while you debug the child. In other | |
5108 | situations, you may not be interested in inspecting the current state | |
5109 | of any of the processes @value{GDBN} is attached to, and you may want | |
5110 | to resume them all until some breakpoint is hit. In the latter case, | |
5111 | you can instruct @value{GDBN} to allow all threads of all the | |
5112 | inferiors to run with the @w{@code{set schedule-multiple}} command. | |
5113 | ||
5114 | @table @code | |
5115 | @kindex set schedule-multiple | |
5116 | @item set schedule-multiple | |
5117 | Set the mode for allowing threads of multiple processes to be resumed | |
5118 | when an execution command is issued. When @code{on}, all threads of | |
5119 | all processes are allowed to run. When @code{off}, only the threads | |
5120 | of the current process are resumed. The default is @code{off}. The | |
5121 | @code{scheduler-locking} mode takes precedence when set to @code{on}, | |
5122 | or while you are stepping and set to @code{step}. | |
5123 | ||
5124 | @item show schedule-multiple | |
5125 | Display the current mode for resuming the execution of threads of | |
5126 | multiple processes. | |
5127 | @end table | |
5128 | ||
0606b73b SL |
5129 | @node Non-Stop Mode |
5130 | @subsection Non-Stop Mode | |
5131 | ||
5132 | @cindex non-stop mode | |
5133 | ||
5134 | @c This section is really only a place-holder, and needs to be expanded | |
5135 | @c with more details. | |
5136 | ||
5137 | For some multi-threaded targets, @value{GDBN} supports an optional | |
5138 | mode of operation in which you can examine stopped program threads in | |
5139 | the debugger while other threads continue to execute freely. This | |
5140 | minimizes intrusion when debugging live systems, such as programs | |
5141 | where some threads have real-time constraints or must continue to | |
5142 | respond to external events. This is referred to as @dfn{non-stop} mode. | |
5143 | ||
5144 | In non-stop mode, when a thread stops to report a debugging event, | |
5145 | @emph{only} that thread is stopped; @value{GDBN} does not stop other | |
5146 | threads as well, in contrast to the all-stop mode behavior. Additionally, | |
5147 | execution commands such as @code{continue} and @code{step} apply by default | |
5148 | only to the current thread in non-stop mode, rather than all threads as | |
5149 | in all-stop mode. This allows you to control threads explicitly in | |
5150 | ways that are not possible in all-stop mode --- for example, stepping | |
5151 | one thread while allowing others to run freely, stepping | |
5152 | one thread while holding all others stopped, or stepping several threads | |
5153 | independently and simultaneously. | |
5154 | ||
5155 | To enter non-stop mode, use this sequence of commands before you run | |
5156 | or attach to your program: | |
5157 | ||
0606b73b SL |
5158 | @smallexample |
5159 | # Enable the async interface. | |
c6ebd6cf | 5160 | set target-async 1 |
0606b73b | 5161 | |
0606b73b SL |
5162 | # If using the CLI, pagination breaks non-stop. |
5163 | set pagination off | |
5164 | ||
5165 | # Finally, turn it on! | |
5166 | set non-stop on | |
5167 | @end smallexample | |
5168 | ||
5169 | You can use these commands to manipulate the non-stop mode setting: | |
5170 | ||
5171 | @table @code | |
5172 | @kindex set non-stop | |
5173 | @item set non-stop on | |
5174 | Enable selection of non-stop mode. | |
5175 | @item set non-stop off | |
5176 | Disable selection of non-stop mode. | |
5177 | @kindex show non-stop | |
5178 | @item show non-stop | |
5179 | Show the current non-stop enablement setting. | |
5180 | @end table | |
5181 | ||
5182 | Note these commands only reflect whether non-stop mode is enabled, | |
5183 | not whether the currently-executing program is being run in non-stop mode. | |
5184 | In particular, the @code{set non-stop} preference is only consulted when | |
5185 | @value{GDBN} starts or connects to the target program, and it is generally | |
5186 | not possible to switch modes once debugging has started. Furthermore, | |
5187 | since not all targets support non-stop mode, even when you have enabled | |
5188 | non-stop mode, @value{GDBN} may still fall back to all-stop operation by | |
5189 | default. | |
5190 | ||
5191 | In non-stop mode, all execution commands apply only to the current thread | |
5192 | by default. That is, @code{continue} only continues one thread. | |
5193 | To continue all threads, issue @code{continue -a} or @code{c -a}. | |
5194 | ||
5195 | You can use @value{GDBN}'s background execution commands | |
5196 | (@pxref{Background Execution}) to run some threads in the background | |
5197 | while you continue to examine or step others from @value{GDBN}. | |
5198 | The MI execution commands (@pxref{GDB/MI Program Execution}) are | |
5199 | always executed asynchronously in non-stop mode. | |
5200 | ||
5201 | Suspending execution is done with the @code{interrupt} command when | |
5202 | running in the background, or @kbd{Ctrl-c} during foreground execution. | |
5203 | In all-stop mode, this stops the whole process; | |
5204 | but in non-stop mode the interrupt applies only to the current thread. | |
5205 | To stop the whole program, use @code{interrupt -a}. | |
5206 | ||
5207 | Other execution commands do not currently support the @code{-a} option. | |
5208 | ||
5209 | In non-stop mode, when a thread stops, @value{GDBN} doesn't automatically make | |
5210 | that thread current, as it does in all-stop mode. This is because the | |
5211 | thread stop notifications are asynchronous with respect to @value{GDBN}'s | |
5212 | command interpreter, and it would be confusing if @value{GDBN} unexpectedly | |
5213 | changed to a different thread just as you entered a command to operate on the | |
5214 | previously current thread. | |
5215 | ||
5216 | @node Background Execution | |
5217 | @subsection Background Execution | |
5218 | ||
5219 | @cindex foreground execution | |
5220 | @cindex background execution | |
5221 | @cindex asynchronous execution | |
5222 | @cindex execution, foreground, background and asynchronous | |
5223 | ||
5224 | @value{GDBN}'s execution commands have two variants: the normal | |
5225 | foreground (synchronous) behavior, and a background | |
5226 | (asynchronous) behavior. In foreground execution, @value{GDBN} waits for | |
5227 | the program to report that some thread has stopped before prompting for | |
5228 | another command. In background execution, @value{GDBN} immediately gives | |
5229 | a command prompt so that you can issue other commands while your program runs. | |
5230 | ||
32fc0df9 PA |
5231 | You need to explicitly enable asynchronous mode before you can use |
5232 | background execution commands. You can use these commands to | |
5233 | manipulate the asynchronous mode setting: | |
5234 | ||
5235 | @table @code | |
5236 | @kindex set target-async | |
5237 | @item set target-async on | |
5238 | Enable asynchronous mode. | |
5239 | @item set target-async off | |
5240 | Disable asynchronous mode. | |
5241 | @kindex show target-async | |
5242 | @item show target-async | |
5243 | Show the current target-async setting. | |
5244 | @end table | |
5245 | ||
5246 | If the target doesn't support async mode, @value{GDBN} issues an error | |
5247 | message if you attempt to use the background execution commands. | |
5248 | ||
0606b73b SL |
5249 | To specify background execution, add a @code{&} to the command. For example, |
5250 | the background form of the @code{continue} command is @code{continue&}, or | |
5251 | just @code{c&}. The execution commands that accept background execution | |
5252 | are: | |
5253 | ||
5254 | @table @code | |
5255 | @kindex run& | |
5256 | @item run | |
5257 | @xref{Starting, , Starting your Program}. | |
5258 | ||
5259 | @item attach | |
5260 | @kindex attach& | |
5261 | @xref{Attach, , Debugging an Already-running Process}. | |
5262 | ||
5263 | @item step | |
5264 | @kindex step& | |
5265 | @xref{Continuing and Stepping, step}. | |
5266 | ||
5267 | @item stepi | |
5268 | @kindex stepi& | |
5269 | @xref{Continuing and Stepping, stepi}. | |
5270 | ||
5271 | @item next | |
5272 | @kindex next& | |
5273 | @xref{Continuing and Stepping, next}. | |
5274 | ||
7ce58dd2 DE |
5275 | @item nexti |
5276 | @kindex nexti& | |
5277 | @xref{Continuing and Stepping, nexti}. | |
5278 | ||
0606b73b SL |
5279 | @item continue |
5280 | @kindex continue& | |
5281 | @xref{Continuing and Stepping, continue}. | |
5282 | ||
5283 | @item finish | |
5284 | @kindex finish& | |
5285 | @xref{Continuing and Stepping, finish}. | |
5286 | ||
5287 | @item until | |
5288 | @kindex until& | |
5289 | @xref{Continuing and Stepping, until}. | |
5290 | ||
5291 | @end table | |
5292 | ||
5293 | Background execution is especially useful in conjunction with non-stop | |
5294 | mode for debugging programs with multiple threads; see @ref{Non-Stop Mode}. | |
5295 | However, you can also use these commands in the normal all-stop mode with | |
5296 | the restriction that you cannot issue another execution command until the | |
5297 | previous one finishes. Examples of commands that are valid in all-stop | |
5298 | mode while the program is running include @code{help} and @code{info break}. | |
5299 | ||
5300 | You can interrupt your program while it is running in the background by | |
5301 | using the @code{interrupt} command. | |
5302 | ||
5303 | @table @code | |
5304 | @kindex interrupt | |
5305 | @item interrupt | |
5306 | @itemx interrupt -a | |
5307 | ||
5308 | Suspend execution of the running program. In all-stop mode, | |
5309 | @code{interrupt} stops the whole process, but in non-stop mode, it stops | |
5310 | only the current thread. To stop the whole program in non-stop mode, | |
5311 | use @code{interrupt -a}. | |
5312 | @end table | |
5313 | ||
0606b73b SL |
5314 | @node Thread-Specific Breakpoints |
5315 | @subsection Thread-Specific Breakpoints | |
5316 | ||
c906108c | 5317 | When your program has multiple threads (@pxref{Threads,, Debugging |
79a6e687 | 5318 | Programs with Multiple Threads}), you can choose whether to set |
c906108c SS |
5319 | breakpoints on all threads, or on a particular thread. |
5320 | ||
5321 | @table @code | |
5322 | @cindex breakpoints and threads | |
5323 | @cindex thread breakpoints | |
5324 | @kindex break @dots{} thread @var{threadno} | |
5325 | @item break @var{linespec} thread @var{threadno} | |
5326 | @itemx break @var{linespec} thread @var{threadno} if @dots{} | |
5327 | @var{linespec} specifies source lines; there are several ways of | |
2a25a5ba EZ |
5328 | writing them (@pxref{Specify Location}), but the effect is always to |
5329 | specify some source line. | |
c906108c SS |
5330 | |
5331 | Use the qualifier @samp{thread @var{threadno}} with a breakpoint command | |
5332 | to specify that you only want @value{GDBN} to stop the program when a | |
5333 | particular thread reaches this breakpoint. @var{threadno} is one of the | |
5334 | numeric thread identifiers assigned by @value{GDBN}, shown in the first | |
5335 | column of the @samp{info threads} display. | |
5336 | ||
5337 | If you do not specify @samp{thread @var{threadno}} when you set a | |
5338 | breakpoint, the breakpoint applies to @emph{all} threads of your | |
5339 | program. | |
5340 | ||
5341 | You can use the @code{thread} qualifier on conditional breakpoints as | |
b6199126 DJ |
5342 | well; in this case, place @samp{thread @var{threadno}} before or |
5343 | after the breakpoint condition, like this: | |
c906108c SS |
5344 | |
5345 | @smallexample | |
2df3850c | 5346 | (@value{GDBP}) break frik.c:13 thread 28 if bartab > lim |
c906108c SS |
5347 | @end smallexample |
5348 | ||
5349 | @end table | |
5350 | ||
0606b73b SL |
5351 | @node Interrupted System Calls |
5352 | @subsection Interrupted System Calls | |
c906108c | 5353 | |
36d86913 MC |
5354 | @cindex thread breakpoints and system calls |
5355 | @cindex system calls and thread breakpoints | |
5356 | @cindex premature return from system calls | |
0606b73b SL |
5357 | There is an unfortunate side effect when using @value{GDBN} to debug |
5358 | multi-threaded programs. If one thread stops for a | |
36d86913 MC |
5359 | breakpoint, or for some other reason, and another thread is blocked in a |
5360 | system call, then the system call may return prematurely. This is a | |
5361 | consequence of the interaction between multiple threads and the signals | |
5362 | that @value{GDBN} uses to implement breakpoints and other events that | |
5363 | stop execution. | |
5364 | ||
5365 | To handle this problem, your program should check the return value of | |
5366 | each system call and react appropriately. This is good programming | |
5367 | style anyways. | |
5368 | ||
5369 | For example, do not write code like this: | |
5370 | ||
5371 | @smallexample | |
5372 | sleep (10); | |
5373 | @end smallexample | |
5374 | ||
5375 | The call to @code{sleep} will return early if a different thread stops | |
5376 | at a breakpoint or for some other reason. | |
5377 | ||
5378 | Instead, write this: | |
5379 | ||
5380 | @smallexample | |
5381 | int unslept = 10; | |
5382 | while (unslept > 0) | |
5383 | unslept = sleep (unslept); | |
5384 | @end smallexample | |
5385 | ||
5386 | A system call is allowed to return early, so the system is still | |
5387 | conforming to its specification. But @value{GDBN} does cause your | |
5388 | multi-threaded program to behave differently than it would without | |
5389 | @value{GDBN}. | |
5390 | ||
5391 | Also, @value{GDBN} uses internal breakpoints in the thread library to | |
5392 | monitor certain events such as thread creation and thread destruction. | |
5393 | When such an event happens, a system call in another thread may return | |
5394 | prematurely, even though your program does not appear to stop. | |
5395 | ||
d914c394 SS |
5396 | @node Observer Mode |
5397 | @subsection Observer Mode | |
5398 | ||
5399 | If you want to build on non-stop mode and observe program behavior | |
5400 | without any chance of disruption by @value{GDBN}, you can set | |
5401 | variables to disable all of the debugger's attempts to modify state, | |
5402 | whether by writing memory, inserting breakpoints, etc. These operate | |
5403 | at a low level, intercepting operations from all commands. | |
5404 | ||
5405 | When all of these are set to @code{off}, then @value{GDBN} is said to | |
5406 | be @dfn{observer mode}. As a convenience, the variable | |
5407 | @code{observer} can be set to disable these, plus enable non-stop | |
5408 | mode. | |
5409 | ||
5410 | Note that @value{GDBN} will not prevent you from making nonsensical | |
5411 | combinations of these settings. For instance, if you have enabled | |
5412 | @code{may-insert-breakpoints} but disabled @code{may-write-memory}, | |
5413 | then breakpoints that work by writing trap instructions into the code | |
5414 | stream will still not be able to be placed. | |
5415 | ||
5416 | @table @code | |
5417 | ||
5418 | @kindex observer | |
5419 | @item set observer on | |
5420 | @itemx set observer off | |
5421 | When set to @code{on}, this disables all the permission variables | |
5422 | below (except for @code{insert-fast-tracepoints}), plus enables | |
5423 | non-stop debugging. Setting this to @code{off} switches back to | |
5424 | normal debugging, though remaining in non-stop mode. | |
5425 | ||
5426 | @item show observer | |
5427 | Show whether observer mode is on or off. | |
5428 | ||
5429 | @kindex may-write-registers | |
5430 | @item set may-write-registers on | |
5431 | @itemx set may-write-registers off | |
5432 | This controls whether @value{GDBN} will attempt to alter the values of | |
5433 | registers, such as with assignment expressions in @code{print}, or the | |
5434 | @code{jump} command. It defaults to @code{on}. | |
5435 | ||
5436 | @item show may-write-registers | |
5437 | Show the current permission to write registers. | |
5438 | ||
5439 | @kindex may-write-memory | |
5440 | @item set may-write-memory on | |
5441 | @itemx set may-write-memory off | |
5442 | This controls whether @value{GDBN} will attempt to alter the contents | |
5443 | of memory, such as with assignment expressions in @code{print}. It | |
5444 | defaults to @code{on}. | |
5445 | ||
5446 | @item show may-write-memory | |
5447 | Show the current permission to write memory. | |
5448 | ||
5449 | @kindex may-insert-breakpoints | |
5450 | @item set may-insert-breakpoints on | |
5451 | @itemx set may-insert-breakpoints off | |
5452 | This controls whether @value{GDBN} will attempt to insert breakpoints. | |
5453 | This affects all breakpoints, including internal breakpoints defined | |
5454 | by @value{GDBN}. It defaults to @code{on}. | |
5455 | ||
5456 | @item show may-insert-breakpoints | |
5457 | Show the current permission to insert breakpoints. | |
5458 | ||
5459 | @kindex may-insert-tracepoints | |
5460 | @item set may-insert-tracepoints on | |
5461 | @itemx set may-insert-tracepoints off | |
5462 | This controls whether @value{GDBN} will attempt to insert (regular) | |
5463 | tracepoints at the beginning of a tracing experiment. It affects only | |
5464 | non-fast tracepoints, fast tracepoints being under the control of | |
5465 | @code{may-insert-fast-tracepoints}. It defaults to @code{on}. | |
5466 | ||
5467 | @item show may-insert-tracepoints | |
5468 | Show the current permission to insert tracepoints. | |
5469 | ||
5470 | @kindex may-insert-fast-tracepoints | |
5471 | @item set may-insert-fast-tracepoints on | |
5472 | @itemx set may-insert-fast-tracepoints off | |
5473 | This controls whether @value{GDBN} will attempt to insert fast | |
5474 | tracepoints at the beginning of a tracing experiment. It affects only | |
5475 | fast tracepoints, regular (non-fast) tracepoints being under the | |
5476 | control of @code{may-insert-tracepoints}. It defaults to @code{on}. | |
5477 | ||
5478 | @item show may-insert-fast-tracepoints | |
5479 | Show the current permission to insert fast tracepoints. | |
5480 | ||
5481 | @kindex may-interrupt | |
5482 | @item set may-interrupt on | |
5483 | @itemx set may-interrupt off | |
5484 | This controls whether @value{GDBN} will attempt to interrupt or stop | |
5485 | program execution. When this variable is @code{off}, the | |
5486 | @code{interrupt} command will have no effect, nor will | |
5487 | @kbd{Ctrl-c}. It defaults to @code{on}. | |
5488 | ||
5489 | @item show may-interrupt | |
5490 | Show the current permission to interrupt or stop the program. | |
5491 | ||
5492 | @end table | |
c906108c | 5493 | |
bacec72f MS |
5494 | @node Reverse Execution |
5495 | @chapter Running programs backward | |
5496 | @cindex reverse execution | |
5497 | @cindex running programs backward | |
5498 | ||
5499 | When you are debugging a program, it is not unusual to realize that | |
5500 | you have gone too far, and some event of interest has already happened. | |
5501 | If the target environment supports it, @value{GDBN} can allow you to | |
5502 | ``rewind'' the program by running it backward. | |
5503 | ||
5504 | A target environment that supports reverse execution should be able | |
5505 | to ``undo'' the changes in machine state that have taken place as the | |
5506 | program was executing normally. Variables, registers etc.@: should | |
5507 | revert to their previous values. Obviously this requires a great | |
5508 | deal of sophistication on the part of the target environment; not | |
5509 | all target environments can support reverse execution. | |
5510 | ||
5511 | When a program is executed in reverse, the instructions that | |
5512 | have most recently been executed are ``un-executed'', in reverse | |
5513 | order. The program counter runs backward, following the previous | |
5514 | thread of execution in reverse. As each instruction is ``un-executed'', | |
5515 | the values of memory and/or registers that were changed by that | |
5516 | instruction are reverted to their previous states. After executing | |
5517 | a piece of source code in reverse, all side effects of that code | |
5518 | should be ``undone'', and all variables should be returned to their | |
5519 | prior values@footnote{ | |
5520 | Note that some side effects are easier to undo than others. For instance, | |
5521 | memory and registers are relatively easy, but device I/O is hard. Some | |
5522 | targets may be able undo things like device I/O, and some may not. | |
5523 | ||
5524 | The contract between @value{GDBN} and the reverse executing target | |
5525 | requires only that the target do something reasonable when | |
5526 | @value{GDBN} tells it to execute backwards, and then report the | |
5527 | results back to @value{GDBN}. Whatever the target reports back to | |
5528 | @value{GDBN}, @value{GDBN} will report back to the user. @value{GDBN} | |
5529 | assumes that the memory and registers that the target reports are in a | |
5530 | consistant state, but @value{GDBN} accepts whatever it is given. | |
5531 | }. | |
5532 | ||
5533 | If you are debugging in a target environment that supports | |
5534 | reverse execution, @value{GDBN} provides the following commands. | |
5535 | ||
5536 | @table @code | |
5537 | @kindex reverse-continue | |
5538 | @kindex rc @r{(@code{reverse-continue})} | |
5539 | @item reverse-continue @r{[}@var{ignore-count}@r{]} | |
5540 | @itemx rc @r{[}@var{ignore-count}@r{]} | |
5541 | Beginning at the point where your program last stopped, start executing | |
5542 | in reverse. Reverse execution will stop for breakpoints and synchronous | |
5543 | exceptions (signals), just like normal execution. Behavior of | |
5544 | asynchronous signals depends on the target environment. | |
5545 | ||
5546 | @kindex reverse-step | |
5547 | @kindex rs @r{(@code{step})} | |
5548 | @item reverse-step @r{[}@var{count}@r{]} | |
5549 | Run the program backward until control reaches the start of a | |
5550 | different source line; then stop it, and return control to @value{GDBN}. | |
5551 | ||
5552 | Like the @code{step} command, @code{reverse-step} will only stop | |
5553 | at the beginning of a source line. It ``un-executes'' the previously | |
5554 | executed source line. If the previous source line included calls to | |
5555 | debuggable functions, @code{reverse-step} will step (backward) into | |
5556 | the called function, stopping at the beginning of the @emph{last} | |
5557 | statement in the called function (typically a return statement). | |
5558 | ||
5559 | Also, as with the @code{step} command, if non-debuggable functions are | |
5560 | called, @code{reverse-step} will run thru them backward without stopping. | |
5561 | ||
5562 | @kindex reverse-stepi | |
5563 | @kindex rsi @r{(@code{reverse-stepi})} | |
5564 | @item reverse-stepi @r{[}@var{count}@r{]} | |
5565 | Reverse-execute one machine instruction. Note that the instruction | |
5566 | to be reverse-executed is @emph{not} the one pointed to by the program | |
5567 | counter, but the instruction executed prior to that one. For instance, | |
5568 | if the last instruction was a jump, @code{reverse-stepi} will take you | |
5569 | back from the destination of the jump to the jump instruction itself. | |
5570 | ||
5571 | @kindex reverse-next | |
5572 | @kindex rn @r{(@code{reverse-next})} | |
5573 | @item reverse-next @r{[}@var{count}@r{]} | |
5574 | Run backward to the beginning of the previous line executed in | |
5575 | the current (innermost) stack frame. If the line contains function | |
5576 | calls, they will be ``un-executed'' without stopping. Starting from | |
5577 | the first line of a function, @code{reverse-next} will take you back | |
5578 | to the caller of that function, @emph{before} the function was called, | |
5579 | just as the normal @code{next} command would take you from the last | |
5580 | line of a function back to its return to its caller | |
16af530a | 5581 | @footnote{Unless the code is too heavily optimized.}. |
bacec72f MS |
5582 | |
5583 | @kindex reverse-nexti | |
5584 | @kindex rni @r{(@code{reverse-nexti})} | |
5585 | @item reverse-nexti @r{[}@var{count}@r{]} | |
5586 | Like @code{nexti}, @code{reverse-nexti} executes a single instruction | |
5587 | in reverse, except that called functions are ``un-executed'' atomically. | |
5588 | That is, if the previously executed instruction was a return from | |
540aa8e7 | 5589 | another function, @code{reverse-nexti} will continue to execute |
bacec72f MS |
5590 | in reverse until the call to that function (from the current stack |
5591 | frame) is reached. | |
5592 | ||
5593 | @kindex reverse-finish | |
5594 | @item reverse-finish | |
5595 | Just as the @code{finish} command takes you to the point where the | |
5596 | current function returns, @code{reverse-finish} takes you to the point | |
5597 | where it was called. Instead of ending up at the end of the current | |
5598 | function invocation, you end up at the beginning. | |
5599 | ||
5600 | @kindex set exec-direction | |
5601 | @item set exec-direction | |
5602 | Set the direction of target execution. | |
5603 | @itemx set exec-direction reverse | |
5604 | @cindex execute forward or backward in time | |
5605 | @value{GDBN} will perform all execution commands in reverse, until the | |
5606 | exec-direction mode is changed to ``forward''. Affected commands include | |
5607 | @code{step, stepi, next, nexti, continue, and finish}. The @code{return} | |
5608 | command cannot be used in reverse mode. | |
5609 | @item set exec-direction forward | |
5610 | @value{GDBN} will perform all execution commands in the normal fashion. | |
5611 | This is the default. | |
5612 | @end table | |
5613 | ||
c906108c | 5614 | |
a2311334 EZ |
5615 | @node Process Record and Replay |
5616 | @chapter Recording Inferior's Execution and Replaying It | |
53cc454a HZ |
5617 | @cindex process record and replay |
5618 | @cindex recording inferior's execution and replaying it | |
5619 | ||
8e05493c EZ |
5620 | On some platforms, @value{GDBN} provides a special @dfn{process record |
5621 | and replay} target that can record a log of the process execution, and | |
5622 | replay it later with both forward and reverse execution commands. | |
a2311334 EZ |
5623 | |
5624 | @cindex replay mode | |
5625 | When this target is in use, if the execution log includes the record | |
5626 | for the next instruction, @value{GDBN} will debug in @dfn{replay | |
5627 | mode}. In the replay mode, the inferior does not really execute code | |
5628 | instructions. Instead, all the events that normally happen during | |
5629 | code execution are taken from the execution log. While code is not | |
5630 | really executed in replay mode, the values of registers (including the | |
5631 | program counter register) and the memory of the inferior are still | |
8e05493c EZ |
5632 | changed as they normally would. Their contents are taken from the |
5633 | execution log. | |
a2311334 EZ |
5634 | |
5635 | @cindex record mode | |
5636 | If the record for the next instruction is not in the execution log, | |
5637 | @value{GDBN} will debug in @dfn{record mode}. In this mode, the | |
5638 | inferior executes normally, and @value{GDBN} records the execution log | |
5639 | for future replay. | |
5640 | ||
8e05493c EZ |
5641 | The process record and replay target supports reverse execution |
5642 | (@pxref{Reverse Execution}), even if the platform on which the | |
5643 | inferior runs does not. However, the reverse execution is limited in | |
5644 | this case by the range of the instructions recorded in the execution | |
5645 | log. In other words, reverse execution on platforms that don't | |
5646 | support it directly can only be done in the replay mode. | |
5647 | ||
5648 | When debugging in the reverse direction, @value{GDBN} will work in | |
5649 | replay mode as long as the execution log includes the record for the | |
5650 | previous instruction; otherwise, it will work in record mode, if the | |
5651 | platform supports reverse execution, or stop if not. | |
5652 | ||
a2311334 EZ |
5653 | For architecture environments that support process record and replay, |
5654 | @value{GDBN} provides the following commands: | |
53cc454a HZ |
5655 | |
5656 | @table @code | |
5657 | @kindex target record | |
5658 | @kindex record | |
5659 | @kindex rec | |
5660 | @item target record | |
a2311334 EZ |
5661 | This command starts the process record and replay target. The process |
5662 | record and replay target can only debug a process that is already | |
5663 | running. Therefore, you need first to start the process with the | |
5664 | @kbd{run} or @kbd{start} commands, and then start the recording with | |
5665 | the @kbd{target record} command. | |
5666 | ||
5667 | Both @code{record} and @code{rec} are aliases of @code{target record}. | |
5668 | ||
5669 | @cindex displaced stepping, and process record and replay | |
5670 | Displaced stepping (@pxref{Maintenance Commands,, displaced stepping}) | |
5671 | will be automatically disabled when process record and replay target | |
5672 | is started. That's because the process record and replay target | |
5673 | doesn't support displaced stepping. | |
5674 | ||
5675 | @cindex non-stop mode, and process record and replay | |
5676 | @cindex asynchronous execution, and process record and replay | |
5677 | If the inferior is in the non-stop mode (@pxref{Non-Stop Mode}) or in | |
5678 | the asynchronous execution mode (@pxref{Background Execution}), the | |
5679 | process record and replay target cannot be started because it doesn't | |
5680 | support these two modes. | |
53cc454a HZ |
5681 | |
5682 | @kindex record stop | |
5683 | @kindex rec s | |
5684 | @item record stop | |
a2311334 EZ |
5685 | Stop the process record and replay target. When process record and |
5686 | replay target stops, the entire execution log will be deleted and the | |
5687 | inferior will either be terminated, or will remain in its final state. | |
53cc454a | 5688 | |
a2311334 EZ |
5689 | When you stop the process record and replay target in record mode (at |
5690 | the end of the execution log), the inferior will be stopped at the | |
5691 | next instruction that would have been recorded. In other words, if | |
5692 | you record for a while and then stop recording, the inferior process | |
5693 | will be left in the same state as if the recording never happened. | |
53cc454a | 5694 | |
a2311334 EZ |
5695 | On the other hand, if the process record and replay target is stopped |
5696 | while in replay mode (that is, not at the end of the execution log, | |
5697 | but at some earlier point), the inferior process will become ``live'' | |
5698 | at that earlier state, and it will then be possible to continue the | |
5699 | usual ``live'' debugging of the process from that state. | |
53cc454a | 5700 | |
a2311334 EZ |
5701 | When the inferior process exits, or @value{GDBN} detaches from it, |
5702 | process record and replay target will automatically stop itself. | |
53cc454a | 5703 | |
24e933df HZ |
5704 | @kindex record save |
5705 | @item record save @var{filename} | |
5706 | Save the execution log to a file @file{@var{filename}}. | |
5707 | Default filename is @file{gdb_record.@var{process_id}}, where | |
5708 | @var{process_id} is the process ID of the inferior. | |
5709 | ||
5710 | @kindex record restore | |
5711 | @item record restore @var{filename} | |
5712 | Restore the execution log from a file @file{@var{filename}}. | |
5713 | File must have been created with @code{record save}. | |
5714 | ||
53cc454a HZ |
5715 | @kindex set record insn-number-max |
5716 | @item set record insn-number-max @var{limit} | |
5717 | Set the limit of instructions to be recorded. Default value is 200000. | |
5718 | ||
a2311334 EZ |
5719 | If @var{limit} is a positive number, then @value{GDBN} will start |
5720 | deleting instructions from the log once the number of the record | |
5721 | instructions becomes greater than @var{limit}. For every new recorded | |
5722 | instruction, @value{GDBN} will delete the earliest recorded | |
5723 | instruction to keep the number of recorded instructions at the limit. | |
5724 | (Since deleting recorded instructions loses information, @value{GDBN} | |
5725 | lets you control what happens when the limit is reached, by means of | |
5726 | the @code{stop-at-limit} option, described below.) | |
53cc454a | 5727 | |
a2311334 EZ |
5728 | If @var{limit} is zero, @value{GDBN} will never delete recorded |
5729 | instructions from the execution log. The number of recorded | |
5730 | instructions is unlimited in this case. | |
53cc454a HZ |
5731 | |
5732 | @kindex show record insn-number-max | |
5733 | @item show record insn-number-max | |
a2311334 | 5734 | Show the limit of instructions to be recorded. |
53cc454a HZ |
5735 | |
5736 | @kindex set record stop-at-limit | |
a2311334 EZ |
5737 | @item set record stop-at-limit |
5738 | Control the behavior when the number of recorded instructions reaches | |
5739 | the limit. If ON (the default), @value{GDBN} will stop when the limit | |
5740 | is reached for the first time and ask you whether you want to stop the | |
5741 | inferior or continue running it and recording the execution log. If | |
5742 | you decide to continue recording, each new recorded instruction will | |
5743 | cause the oldest one to be deleted. | |
53cc454a | 5744 | |
a2311334 EZ |
5745 | If this option is OFF, @value{GDBN} will automatically delete the |
5746 | oldest record to make room for each new one, without asking. | |
53cc454a HZ |
5747 | |
5748 | @kindex show record stop-at-limit | |
5749 | @item show record stop-at-limit | |
a2311334 | 5750 | Show the current setting of @code{stop-at-limit}. |
53cc454a | 5751 | |
bb08c432 HZ |
5752 | @kindex set record memory-query |
5753 | @item set record memory-query | |
5754 | Control the behavior when @value{GDBN} is unable to record memory | |
5755 | changes caused by an instruction. If ON, @value{GDBN} will query | |
5756 | whether to stop the inferior in that case. | |
5757 | ||
5758 | If this option is OFF (the default), @value{GDBN} will automatically | |
5759 | ignore the effect of such instructions on memory. Later, when | |
5760 | @value{GDBN} replays this execution log, it will mark the log of this | |
5761 | instruction as not accessible, and it will not affect the replay | |
5762 | results. | |
5763 | ||
5764 | @kindex show record memory-query | |
5765 | @item show record memory-query | |
5766 | Show the current setting of @code{memory-query}. | |
5767 | ||
29153c24 MS |
5768 | @kindex info record |
5769 | @item info record | |
5770 | Show various statistics about the state of process record and its | |
5771 | in-memory execution log buffer, including: | |
5772 | ||
5773 | @itemize @bullet | |
5774 | @item | |
5775 | Whether in record mode or replay mode. | |
5776 | @item | |
5777 | Lowest recorded instruction number (counting from when the current execution log started recording instructions). | |
5778 | @item | |
5779 | Highest recorded instruction number. | |
5780 | @item | |
5781 | Current instruction about to be replayed (if in replay mode). | |
5782 | @item | |
5783 | Number of instructions contained in the execution log. | |
5784 | @item | |
5785 | Maximum number of instructions that may be contained in the execution log. | |
5786 | @end itemize | |
53cc454a HZ |
5787 | |
5788 | @kindex record delete | |
5789 | @kindex rec del | |
5790 | @item record delete | |
a2311334 | 5791 | When record target runs in replay mode (``in the past''), delete the |
53cc454a | 5792 | subsequent execution log and begin to record a new execution log starting |
a2311334 | 5793 | from the current address. This means you will abandon the previously |
53cc454a HZ |
5794 | recorded ``future'' and begin recording a new ``future''. |
5795 | @end table | |
5796 | ||
5797 | ||
6d2ebf8b | 5798 | @node Stack |
c906108c SS |
5799 | @chapter Examining the Stack |
5800 | ||
5801 | When your program has stopped, the first thing you need to know is where it | |
5802 | stopped and how it got there. | |
5803 | ||
5804 | @cindex call stack | |
5d161b24 DB |
5805 | Each time your program performs a function call, information about the call |
5806 | is generated. | |
5807 | That information includes the location of the call in your program, | |
5808 | the arguments of the call, | |
c906108c | 5809 | and the local variables of the function being called. |
5d161b24 | 5810 | The information is saved in a block of data called a @dfn{stack frame}. |
c906108c SS |
5811 | The stack frames are allocated in a region of memory called the @dfn{call |
5812 | stack}. | |
5813 | ||
5814 | When your program stops, the @value{GDBN} commands for examining the | |
5815 | stack allow you to see all of this information. | |
5816 | ||
5817 | @cindex selected frame | |
5818 | One of the stack frames is @dfn{selected} by @value{GDBN} and many | |
5819 | @value{GDBN} commands refer implicitly to the selected frame. In | |
5820 | particular, whenever you ask @value{GDBN} for the value of a variable in | |
5821 | your program, the value is found in the selected frame. There are | |
5822 | special @value{GDBN} commands to select whichever frame you are | |
79a6e687 | 5823 | interested in. @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
5824 | |
5825 | When your program stops, @value{GDBN} automatically selects the | |
5d161b24 | 5826 | currently executing frame and describes it briefly, similar to the |
79a6e687 | 5827 | @code{frame} command (@pxref{Frame Info, ,Information about a Frame}). |
c906108c SS |
5828 | |
5829 | @menu | |
5830 | * Frames:: Stack frames | |
5831 | * Backtrace:: Backtraces | |
5832 | * Selection:: Selecting a frame | |
5833 | * Frame Info:: Information on a frame | |
c906108c SS |
5834 | |
5835 | @end menu | |
5836 | ||
6d2ebf8b | 5837 | @node Frames |
79a6e687 | 5838 | @section Stack Frames |
c906108c | 5839 | |
d4f3574e | 5840 | @cindex frame, definition |
c906108c SS |
5841 | @cindex stack frame |
5842 | The call stack is divided up into contiguous pieces called @dfn{stack | |
5843 | frames}, or @dfn{frames} for short; each frame is the data associated | |
5844 | with one call to one function. The frame contains the arguments given | |
5845 | to the function, the function's local variables, and the address at | |
5846 | which the function is executing. | |
5847 | ||
5848 | @cindex initial frame | |
5849 | @cindex outermost frame | |
5850 | @cindex innermost frame | |
5851 | When your program is started, the stack has only one frame, that of the | |
5852 | function @code{main}. This is called the @dfn{initial} frame or the | |
5853 | @dfn{outermost} frame. Each time a function is called, a new frame is | |
5854 | made. Each time a function returns, the frame for that function invocation | |
5855 | is eliminated. If a function is recursive, there can be many frames for | |
5856 | the same function. The frame for the function in which execution is | |
5857 | actually occurring is called the @dfn{innermost} frame. This is the most | |
5858 | recently created of all the stack frames that still exist. | |
5859 | ||
5860 | @cindex frame pointer | |
5861 | Inside your program, stack frames are identified by their addresses. A | |
5862 | stack frame consists of many bytes, each of which has its own address; each | |
5863 | kind of computer has a convention for choosing one byte whose | |
5864 | address serves as the address of the frame. Usually this address is kept | |
e09f16f9 EZ |
5865 | in a register called the @dfn{frame pointer register} |
5866 | (@pxref{Registers, $fp}) while execution is going on in that frame. | |
c906108c SS |
5867 | |
5868 | @cindex frame number | |
5869 | @value{GDBN} assigns numbers to all existing stack frames, starting with | |
5870 | zero for the innermost frame, one for the frame that called it, | |
5871 | and so on upward. These numbers do not really exist in your program; | |
5872 | they are assigned by @value{GDBN} to give you a way of designating stack | |
5873 | frames in @value{GDBN} commands. | |
5874 | ||
6d2ebf8b SS |
5875 | @c The -fomit-frame-pointer below perennially causes hbox overflow |
5876 | @c underflow problems. | |
c906108c SS |
5877 | @cindex frameless execution |
5878 | Some compilers provide a way to compile functions so that they operate | |
e22ea452 | 5879 | without stack frames. (For example, the @value{NGCC} option |
474c8240 | 5880 | @smallexample |
6d2ebf8b | 5881 | @samp{-fomit-frame-pointer} |
474c8240 | 5882 | @end smallexample |
6d2ebf8b | 5883 | generates functions without a frame.) |
c906108c SS |
5884 | This is occasionally done with heavily used library functions to save |
5885 | the frame setup time. @value{GDBN} has limited facilities for dealing | |
5886 | with these function invocations. If the innermost function invocation | |
5887 | has no stack frame, @value{GDBN} nevertheless regards it as though | |
5888 | it had a separate frame, which is numbered zero as usual, allowing | |
5889 | correct tracing of the function call chain. However, @value{GDBN} has | |
5890 | no provision for frameless functions elsewhere in the stack. | |
5891 | ||
5892 | @table @code | |
d4f3574e | 5893 | @kindex frame@r{, command} |
41afff9a | 5894 | @cindex current stack frame |
c906108c | 5895 | @item frame @var{args} |
5d161b24 | 5896 | The @code{frame} command allows you to move from one stack frame to another, |
c906108c | 5897 | and to print the stack frame you select. @var{args} may be either the |
5d161b24 DB |
5898 | address of the frame or the stack frame number. Without an argument, |
5899 | @code{frame} prints the current stack frame. | |
c906108c SS |
5900 | |
5901 | @kindex select-frame | |
41afff9a | 5902 | @cindex selecting frame silently |
c906108c SS |
5903 | @item select-frame |
5904 | The @code{select-frame} command allows you to move from one stack frame | |
5905 | to another without printing the frame. This is the silent version of | |
5906 | @code{frame}. | |
5907 | @end table | |
5908 | ||
6d2ebf8b | 5909 | @node Backtrace |
c906108c SS |
5910 | @section Backtraces |
5911 | ||
09d4efe1 EZ |
5912 | @cindex traceback |
5913 | @cindex call stack traces | |
c906108c SS |
5914 | A backtrace is a summary of how your program got where it is. It shows one |
5915 | line per frame, for many frames, starting with the currently executing | |
5916 | frame (frame zero), followed by its caller (frame one), and on up the | |
5917 | stack. | |
5918 | ||
5919 | @table @code | |
5920 | @kindex backtrace | |
41afff9a | 5921 | @kindex bt @r{(@code{backtrace})} |
c906108c SS |
5922 | @item backtrace |
5923 | @itemx bt | |
5924 | Print a backtrace of the entire stack: one line per frame for all | |
5925 | frames in the stack. | |
5926 | ||
5927 | You can stop the backtrace at any time by typing the system interrupt | |
c8aa23ab | 5928 | character, normally @kbd{Ctrl-c}. |
c906108c SS |
5929 | |
5930 | @item backtrace @var{n} | |
5931 | @itemx bt @var{n} | |
5932 | Similar, but print only the innermost @var{n} frames. | |
5933 | ||
5934 | @item backtrace -@var{n} | |
5935 | @itemx bt -@var{n} | |
5936 | Similar, but print only the outermost @var{n} frames. | |
0f061b69 NR |
5937 | |
5938 | @item backtrace full | |
0f061b69 | 5939 | @itemx bt full |
dd74f6ae NR |
5940 | @itemx bt full @var{n} |
5941 | @itemx bt full -@var{n} | |
e7109c7e | 5942 | Print the values of the local variables also. @var{n} specifies the |
286ba84d | 5943 | number of frames to print, as described above. |
c906108c SS |
5944 | @end table |
5945 | ||
5946 | @kindex where | |
5947 | @kindex info stack | |
c906108c SS |
5948 | The names @code{where} and @code{info stack} (abbreviated @code{info s}) |
5949 | are additional aliases for @code{backtrace}. | |
5950 | ||
839c27b7 EZ |
5951 | @cindex multiple threads, backtrace |
5952 | In a multi-threaded program, @value{GDBN} by default shows the | |
5953 | backtrace only for the current thread. To display the backtrace for | |
5954 | several or all of the threads, use the command @code{thread apply} | |
5955 | (@pxref{Threads, thread apply}). For example, if you type @kbd{thread | |
5956 | apply all backtrace}, @value{GDBN} will display the backtrace for all | |
5957 | the threads; this is handy when you debug a core dump of a | |
5958 | multi-threaded program. | |
5959 | ||
c906108c SS |
5960 | Each line in the backtrace shows the frame number and the function name. |
5961 | The program counter value is also shown---unless you use @code{set | |
5962 | print address off}. The backtrace also shows the source file name and | |
5963 | line number, as well as the arguments to the function. The program | |
5964 | counter value is omitted if it is at the beginning of the code for that | |
5965 | line number. | |
5966 | ||
5967 | Here is an example of a backtrace. It was made with the command | |
5968 | @samp{bt 3}, so it shows the innermost three frames. | |
5969 | ||
5970 | @smallexample | |
5971 | @group | |
5d161b24 | 5972 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) |
c906108c | 5973 | at builtin.c:993 |
4f5376b2 | 5974 | #1 0x6e38 in expand_macro (sym=0x2b600, data=...) at macro.c:242 |
c906108c SS |
5975 | #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08) |
5976 | at macro.c:71 | |
5977 | (More stack frames follow...) | |
5978 | @end group | |
5979 | @end smallexample | |
5980 | ||
5981 | @noindent | |
5982 | The display for frame zero does not begin with a program counter | |
5983 | value, indicating that your program has stopped at the beginning of the | |
5984 | code for line @code{993} of @code{builtin.c}. | |
5985 | ||
4f5376b2 JB |
5986 | @noindent |
5987 | The value of parameter @code{data} in frame 1 has been replaced by | |
5988 | @code{@dots{}}. By default, @value{GDBN} prints the value of a parameter | |
5989 | only if it is a scalar (integer, pointer, enumeration, etc). See command | |
5990 | @kbd{set print frame-arguments} in @ref{Print Settings} for more details | |
5991 | on how to configure the way function parameter values are printed. | |
5992 | ||
18999be5 EZ |
5993 | @cindex value optimized out, in backtrace |
5994 | @cindex function call arguments, optimized out | |
5995 | If your program was compiled with optimizations, some compilers will | |
5996 | optimize away arguments passed to functions if those arguments are | |
5997 | never used after the call. Such optimizations generate code that | |
5998 | passes arguments through registers, but doesn't store those arguments | |
5999 | in the stack frame. @value{GDBN} has no way of displaying such | |
6000 | arguments in stack frames other than the innermost one. Here's what | |
6001 | such a backtrace might look like: | |
6002 | ||
6003 | @smallexample | |
6004 | @group | |
6005 | #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) | |
6006 | at builtin.c:993 | |
6007 | #1 0x6e38 in expand_macro (sym=<value optimized out>) at macro.c:242 | |
6008 | #2 0x6840 in expand_token (obs=0x0, t=<value optimized out>, td=0xf7fffb08) | |
6009 | at macro.c:71 | |
6010 | (More stack frames follow...) | |
6011 | @end group | |
6012 | @end smallexample | |
6013 | ||
6014 | @noindent | |
6015 | The values of arguments that were not saved in their stack frames are | |
6016 | shown as @samp{<value optimized out>}. | |
6017 | ||
6018 | If you need to display the values of such optimized-out arguments, | |
6019 | either deduce that from other variables whose values depend on the one | |
6020 | you are interested in, or recompile without optimizations. | |
6021 | ||
a8f24a35 EZ |
6022 | @cindex backtrace beyond @code{main} function |
6023 | @cindex program entry point | |
6024 | @cindex startup code, and backtrace | |
25d29d70 AC |
6025 | Most programs have a standard user entry point---a place where system |
6026 | libraries and startup code transition into user code. For C this is | |
d416eeec EZ |
6027 | @code{main}@footnote{ |
6028 | Note that embedded programs (the so-called ``free-standing'' | |
6029 | environment) are not required to have a @code{main} function as the | |
6030 | entry point. They could even have multiple entry points.}. | |
6031 | When @value{GDBN} finds the entry function in a backtrace | |
25d29d70 AC |
6032 | it will terminate the backtrace, to avoid tracing into highly |
6033 | system-specific (and generally uninteresting) code. | |
6034 | ||
6035 | If you need to examine the startup code, or limit the number of levels | |
6036 | in a backtrace, you can change this behavior: | |
95f90d25 DJ |
6037 | |
6038 | @table @code | |
25d29d70 AC |
6039 | @item set backtrace past-main |
6040 | @itemx set backtrace past-main on | |
4644b6e3 | 6041 | @kindex set backtrace |
25d29d70 AC |
6042 | Backtraces will continue past the user entry point. |
6043 | ||
6044 | @item set backtrace past-main off | |
95f90d25 DJ |
6045 | Backtraces will stop when they encounter the user entry point. This is the |
6046 | default. | |
6047 | ||
25d29d70 | 6048 | @item show backtrace past-main |
4644b6e3 | 6049 | @kindex show backtrace |
25d29d70 AC |
6050 | Display the current user entry point backtrace policy. |
6051 | ||
2315ffec RC |
6052 | @item set backtrace past-entry |
6053 | @itemx set backtrace past-entry on | |
a8f24a35 | 6054 | Backtraces will continue past the internal entry point of an application. |
2315ffec RC |
6055 | This entry point is encoded by the linker when the application is built, |
6056 | and is likely before the user entry point @code{main} (or equivalent) is called. | |
6057 | ||
6058 | @item set backtrace past-entry off | |
d3e8051b | 6059 | Backtraces will stop when they encounter the internal entry point of an |
2315ffec RC |
6060 | application. This is the default. |
6061 | ||
6062 | @item show backtrace past-entry | |
6063 | Display the current internal entry point backtrace policy. | |
6064 | ||
25d29d70 AC |
6065 | @item set backtrace limit @var{n} |
6066 | @itemx set backtrace limit 0 | |
6067 | @cindex backtrace limit | |
6068 | Limit the backtrace to @var{n} levels. A value of zero means | |
6069 | unlimited. | |
95f90d25 | 6070 | |
25d29d70 AC |
6071 | @item show backtrace limit |
6072 | Display the current limit on backtrace levels. | |
95f90d25 DJ |
6073 | @end table |
6074 | ||
6d2ebf8b | 6075 | @node Selection |
79a6e687 | 6076 | @section Selecting a Frame |
c906108c SS |
6077 | |
6078 | Most commands for examining the stack and other data in your program work on | |
6079 | whichever stack frame is selected at the moment. Here are the commands for | |
6080 | selecting a stack frame; all of them finish by printing a brief description | |
6081 | of the stack frame just selected. | |
6082 | ||
6083 | @table @code | |
d4f3574e | 6084 | @kindex frame@r{, selecting} |
41afff9a | 6085 | @kindex f @r{(@code{frame})} |
c906108c SS |
6086 | @item frame @var{n} |
6087 | @itemx f @var{n} | |
6088 | Select frame number @var{n}. Recall that frame zero is the innermost | |
6089 | (currently executing) frame, frame one is the frame that called the | |
6090 | innermost one, and so on. The highest-numbered frame is the one for | |
6091 | @code{main}. | |
6092 | ||
6093 | @item frame @var{addr} | |
6094 | @itemx f @var{addr} | |
6095 | Select the frame at address @var{addr}. This is useful mainly if the | |
6096 | chaining of stack frames has been damaged by a bug, making it | |
6097 | impossible for @value{GDBN} to assign numbers properly to all frames. In | |
6098 | addition, this can be useful when your program has multiple stacks and | |
6099 | switches between them. | |
6100 | ||
c906108c SS |
6101 | On the SPARC architecture, @code{frame} needs two addresses to |
6102 | select an arbitrary frame: a frame pointer and a stack pointer. | |
6103 | ||
6104 | On the MIPS and Alpha architecture, it needs two addresses: a stack | |
6105 | pointer and a program counter. | |
6106 | ||
6107 | On the 29k architecture, it needs three addresses: a register stack | |
6108 | pointer, a program counter, and a memory stack pointer. | |
c906108c SS |
6109 | |
6110 | @kindex up | |
6111 | @item up @var{n} | |
6112 | Move @var{n} frames up the stack. For positive numbers @var{n}, this | |
6113 | advances toward the outermost frame, to higher frame numbers, to frames | |
6114 | that have existed longer. @var{n} defaults to one. | |
6115 | ||
6116 | @kindex down | |
41afff9a | 6117 | @kindex do @r{(@code{down})} |
c906108c SS |
6118 | @item down @var{n} |
6119 | Move @var{n} frames down the stack. For positive numbers @var{n}, this | |
6120 | advances toward the innermost frame, to lower frame numbers, to frames | |
6121 | that were created more recently. @var{n} defaults to one. You may | |
6122 | abbreviate @code{down} as @code{do}. | |
6123 | @end table | |
6124 | ||
6125 | All of these commands end by printing two lines of output describing the | |
6126 | frame. The first line shows the frame number, the function name, the | |
6127 | arguments, and the source file and line number of execution in that | |
5d161b24 | 6128 | frame. The second line shows the text of that source line. |
c906108c SS |
6129 | |
6130 | @need 1000 | |
6131 | For example: | |
6132 | ||
6133 | @smallexample | |
6134 | @group | |
6135 | (@value{GDBP}) up | |
6136 | #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc) | |
6137 | at env.c:10 | |
6138 | 10 read_input_file (argv[i]); | |
6139 | @end group | |
6140 | @end smallexample | |
6141 | ||
6142 | After such a printout, the @code{list} command with no arguments | |
6143 | prints ten lines centered on the point of execution in the frame. | |
87885426 FN |
6144 | You can also edit the program at the point of execution with your favorite |
6145 | editing program by typing @code{edit}. | |
79a6e687 | 6146 | @xref{List, ,Printing Source Lines}, |
87885426 | 6147 | for details. |
c906108c SS |
6148 | |
6149 | @table @code | |
6150 | @kindex down-silently | |
6151 | @kindex up-silently | |
6152 | @item up-silently @var{n} | |
6153 | @itemx down-silently @var{n} | |
6154 | These two commands are variants of @code{up} and @code{down}, | |
6155 | respectively; they differ in that they do their work silently, without | |
6156 | causing display of the new frame. They are intended primarily for use | |
6157 | in @value{GDBN} command scripts, where the output might be unnecessary and | |
6158 | distracting. | |
6159 | @end table | |
6160 | ||
6d2ebf8b | 6161 | @node Frame Info |
79a6e687 | 6162 | @section Information About a Frame |
c906108c SS |
6163 | |
6164 | There are several other commands to print information about the selected | |
6165 | stack frame. | |
6166 | ||
6167 | @table @code | |
6168 | @item frame | |
6169 | @itemx f | |
6170 | When used without any argument, this command does not change which | |
6171 | frame is selected, but prints a brief description of the currently | |
6172 | selected stack frame. It can be abbreviated @code{f}. With an | |
6173 | argument, this command is used to select a stack frame. | |
79a6e687 | 6174 | @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
6175 | |
6176 | @kindex info frame | |
41afff9a | 6177 | @kindex info f @r{(@code{info frame})} |
c906108c SS |
6178 | @item info frame |
6179 | @itemx info f | |
6180 | This command prints a verbose description of the selected stack frame, | |
6181 | including: | |
6182 | ||
6183 | @itemize @bullet | |
5d161b24 DB |
6184 | @item |
6185 | the address of the frame | |
c906108c SS |
6186 | @item |
6187 | the address of the next frame down (called by this frame) | |
6188 | @item | |
6189 | the address of the next frame up (caller of this frame) | |
6190 | @item | |
6191 | the language in which the source code corresponding to this frame is written | |
6192 | @item | |
6193 | the address of the frame's arguments | |
6194 | @item | |
d4f3574e SS |
6195 | the address of the frame's local variables |
6196 | @item | |
c906108c SS |
6197 | the program counter saved in it (the address of execution in the caller frame) |
6198 | @item | |
6199 | which registers were saved in the frame | |
6200 | @end itemize | |
6201 | ||
6202 | @noindent The verbose description is useful when | |
6203 | something has gone wrong that has made the stack format fail to fit | |
6204 | the usual conventions. | |
6205 | ||
6206 | @item info frame @var{addr} | |
6207 | @itemx info f @var{addr} | |
6208 | Print a verbose description of the frame at address @var{addr}, without | |
6209 | selecting that frame. The selected frame remains unchanged by this | |
6210 | command. This requires the same kind of address (more than one for some | |
6211 | architectures) that you specify in the @code{frame} command. | |
79a6e687 | 6212 | @xref{Selection, ,Selecting a Frame}. |
c906108c SS |
6213 | |
6214 | @kindex info args | |
6215 | @item info args | |
6216 | Print the arguments of the selected frame, each on a separate line. | |
6217 | ||
6218 | @item info locals | |
6219 | @kindex info locals | |
6220 | Print the local variables of the selected frame, each on a separate | |
6221 | line. These are all variables (declared either static or automatic) | |
6222 | accessible at the point of execution of the selected frame. | |
6223 | ||
c906108c | 6224 | @kindex info catch |
d4f3574e SS |
6225 | @cindex catch exceptions, list active handlers |
6226 | @cindex exception handlers, how to list | |
c906108c SS |
6227 | @item info catch |
6228 | Print a list of all the exception handlers that are active in the | |
6229 | current stack frame at the current point of execution. To see other | |
6230 | exception handlers, visit the associated frame (using the @code{up}, | |
6231 | @code{down}, or @code{frame} commands); then type @code{info catch}. | |
79a6e687 | 6232 | @xref{Set Catchpoints, , Setting Catchpoints}. |
53a5351d | 6233 | |
c906108c SS |
6234 | @end table |
6235 | ||
c906108c | 6236 | |
6d2ebf8b | 6237 | @node Source |
c906108c SS |
6238 | @chapter Examining Source Files |
6239 | ||
6240 | @value{GDBN} can print parts of your program's source, since the debugging | |
6241 | information recorded in the program tells @value{GDBN} what source files were | |
6242 | used to build it. When your program stops, @value{GDBN} spontaneously prints | |
6243 | the line where it stopped. Likewise, when you select a stack frame | |
79a6e687 | 6244 | (@pxref{Selection, ,Selecting a Frame}), @value{GDBN} prints the line where |
c906108c SS |
6245 | execution in that frame has stopped. You can print other portions of |
6246 | source files by explicit command. | |
6247 | ||
7a292a7a | 6248 | If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may |
d4f3574e | 6249 | prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using |
7a292a7a | 6250 | @value{GDBN} under @sc{gnu} Emacs}. |
c906108c SS |
6251 | |
6252 | @menu | |
6253 | * List:: Printing source lines | |
2a25a5ba | 6254 | * Specify Location:: How to specify code locations |
87885426 | 6255 | * Edit:: Editing source files |
c906108c | 6256 | * Search:: Searching source files |
c906108c SS |
6257 | * Source Path:: Specifying source directories |
6258 | * Machine Code:: Source and machine code | |
6259 | @end menu | |
6260 | ||
6d2ebf8b | 6261 | @node List |
79a6e687 | 6262 | @section Printing Source Lines |
c906108c SS |
6263 | |
6264 | @kindex list | |
41afff9a | 6265 | @kindex l @r{(@code{list})} |
c906108c | 6266 | To print lines from a source file, use the @code{list} command |
5d161b24 | 6267 | (abbreviated @code{l}). By default, ten lines are printed. |
2a25a5ba EZ |
6268 | There are several ways to specify what part of the file you want to |
6269 | print; see @ref{Specify Location}, for the full list. | |
c906108c SS |
6270 | |
6271 | Here are the forms of the @code{list} command most commonly used: | |
6272 | ||
6273 | @table @code | |
6274 | @item list @var{linenum} | |
6275 | Print lines centered around line number @var{linenum} in the | |
6276 | current source file. | |
6277 | ||
6278 | @item list @var{function} | |
6279 | Print lines centered around the beginning of function | |
6280 | @var{function}. | |
6281 | ||
6282 | @item list | |
6283 | Print more lines. If the last lines printed were printed with a | |
6284 | @code{list} command, this prints lines following the last lines | |
6285 | printed; however, if the last line printed was a solitary line printed | |
6286 | as part of displaying a stack frame (@pxref{Stack, ,Examining the | |
6287 | Stack}), this prints lines centered around that line. | |
6288 | ||
6289 | @item list - | |
6290 | Print lines just before the lines last printed. | |
6291 | @end table | |
6292 | ||
9c16f35a | 6293 | @cindex @code{list}, how many lines to display |
c906108c SS |
6294 | By default, @value{GDBN} prints ten source lines with any of these forms of |
6295 | the @code{list} command. You can change this using @code{set listsize}: | |
6296 | ||
6297 | @table @code | |
6298 | @kindex set listsize | |
6299 | @item set listsize @var{count} | |
6300 | Make the @code{list} command display @var{count} source lines (unless | |
6301 | the @code{list} argument explicitly specifies some other number). | |
6302 | ||
6303 | @kindex show listsize | |
6304 | @item show listsize | |
6305 | Display the number of lines that @code{list} prints. | |
6306 | @end table | |
6307 | ||
6308 | Repeating a @code{list} command with @key{RET} discards the argument, | |
6309 | so it is equivalent to typing just @code{list}. This is more useful | |
6310 | than listing the same lines again. An exception is made for an | |
6311 | argument of @samp{-}; that argument is preserved in repetition so that | |
6312 | each repetition moves up in the source file. | |
6313 | ||
c906108c SS |
6314 | In general, the @code{list} command expects you to supply zero, one or two |
6315 | @dfn{linespecs}. Linespecs specify source lines; there are several ways | |
2a25a5ba EZ |
6316 | of writing them (@pxref{Specify Location}), but the effect is always |
6317 | to specify some source line. | |
6318 | ||
c906108c SS |
6319 | Here is a complete description of the possible arguments for @code{list}: |
6320 | ||
6321 | @table @code | |
6322 | @item list @var{linespec} | |
6323 | Print lines centered around the line specified by @var{linespec}. | |
6324 | ||
6325 | @item list @var{first},@var{last} | |
6326 | Print lines from @var{first} to @var{last}. Both arguments are | |
2a25a5ba EZ |
6327 | linespecs. When a @code{list} command has two linespecs, and the |
6328 | source file of the second linespec is omitted, this refers to | |
6329 | the same source file as the first linespec. | |
c906108c SS |
6330 | |
6331 | @item list ,@var{last} | |
6332 | Print lines ending with @var{last}. | |
6333 | ||
6334 | @item list @var{first}, | |
6335 | Print lines starting with @var{first}. | |
6336 | ||
6337 | @item list + | |
6338 | Print lines just after the lines last printed. | |
6339 | ||
6340 | @item list - | |
6341 | Print lines just before the lines last printed. | |
6342 | ||
6343 | @item list | |
6344 | As described in the preceding table. | |
6345 | @end table | |
6346 | ||
2a25a5ba EZ |
6347 | @node Specify Location |
6348 | @section Specifying a Location | |
6349 | @cindex specifying location | |
6350 | @cindex linespec | |
c906108c | 6351 | |
2a25a5ba EZ |
6352 | Several @value{GDBN} commands accept arguments that specify a location |
6353 | of your program's code. Since @value{GDBN} is a source-level | |
6354 | debugger, a location usually specifies some line in the source code; | |
6355 | for that reason, locations are also known as @dfn{linespecs}. | |
c906108c | 6356 | |
2a25a5ba EZ |
6357 | Here are all the different ways of specifying a code location that |
6358 | @value{GDBN} understands: | |
c906108c | 6359 | |
2a25a5ba EZ |
6360 | @table @code |
6361 | @item @var{linenum} | |
6362 | Specifies the line number @var{linenum} of the current source file. | |
c906108c | 6363 | |
2a25a5ba EZ |
6364 | @item -@var{offset} |
6365 | @itemx +@var{offset} | |
6366 | Specifies the line @var{offset} lines before or after the @dfn{current | |
6367 | line}. For the @code{list} command, the current line is the last one | |
6368 | printed; for the breakpoint commands, this is the line at which | |
6369 | execution stopped in the currently selected @dfn{stack frame} | |
6370 | (@pxref{Frames, ,Frames}, for a description of stack frames.) When | |
6371 | used as the second of the two linespecs in a @code{list} command, | |
6372 | this specifies the line @var{offset} lines up or down from the first | |
6373 | linespec. | |
6374 | ||
6375 | @item @var{filename}:@var{linenum} | |
6376 | Specifies the line @var{linenum} in the source file @var{filename}. | |
c906108c SS |
6377 | |
6378 | @item @var{function} | |
6379 | Specifies the line that begins the body of the function @var{function}. | |
2a25a5ba | 6380 | For example, in C, this is the line with the open brace. |
c906108c SS |
6381 | |
6382 | @item @var{filename}:@var{function} | |
2a25a5ba EZ |
6383 | Specifies the line that begins the body of the function @var{function} |
6384 | in the file @var{filename}. You only need the file name with a | |
6385 | function name to avoid ambiguity when there are identically named | |
6386 | functions in different source files. | |
c906108c | 6387 | |
0f5238ed TT |
6388 | @item @var{label} |
6389 | Specifies the line at which the label named @var{label} appears. | |
6390 | @value{GDBN} searches for the label in the function corresponding to | |
6391 | the currently selected stack frame. If there is no current selected | |
6392 | stack frame (for instance, if the inferior is not running), then | |
6393 | @value{GDBN} will not search for a label. | |
6394 | ||
c906108c | 6395 | @item *@var{address} |
2a25a5ba EZ |
6396 | Specifies the program address @var{address}. For line-oriented |
6397 | commands, such as @code{list} and @code{edit}, this specifies a source | |
6398 | line that contains @var{address}. For @code{break} and other | |
6399 | breakpoint oriented commands, this can be used to set breakpoints in | |
6400 | parts of your program which do not have debugging information or | |
6401 | source files. | |
6402 | ||
6403 | Here @var{address} may be any expression valid in the current working | |
6404 | language (@pxref{Languages, working language}) that specifies a code | |
5fa54e5d EZ |
6405 | address. In addition, as a convenience, @value{GDBN} extends the |
6406 | semantics of expressions used in locations to cover the situations | |
6407 | that frequently happen during debugging. Here are the various forms | |
6408 | of @var{address}: | |
2a25a5ba EZ |
6409 | |
6410 | @table @code | |
6411 | @item @var{expression} | |
6412 | Any expression valid in the current working language. | |
6413 | ||
6414 | @item @var{funcaddr} | |
6415 | An address of a function or procedure derived from its name. In C, | |
6416 | C@t{++}, Java, Objective-C, Fortran, minimal, and assembly, this is | |
6417 | simply the function's name @var{function} (and actually a special case | |
6418 | of a valid expression). In Pascal and Modula-2, this is | |
6419 | @code{&@var{function}}. In Ada, this is @code{@var{function}'Address} | |
6420 | (although the Pascal form also works). | |
6421 | ||
6422 | This form specifies the address of the function's first instruction, | |
6423 | before the stack frame and arguments have been set up. | |
6424 | ||
6425 | @item '@var{filename}'::@var{funcaddr} | |
6426 | Like @var{funcaddr} above, but also specifies the name of the source | |
6427 | file explicitly. This is useful if the name of the function does not | |
6428 | specify the function unambiguously, e.g., if there are several | |
6429 | functions with identical names in different source files. | |
c906108c SS |
6430 | @end table |
6431 | ||
2a25a5ba EZ |
6432 | @end table |
6433 | ||
6434 | ||
87885426 | 6435 | @node Edit |
79a6e687 | 6436 | @section Editing Source Files |
87885426 FN |
6437 | @cindex editing source files |
6438 | ||
6439 | @kindex edit | |
6440 | @kindex e @r{(@code{edit})} | |
6441 | To edit the lines in a source file, use the @code{edit} command. | |
6442 | The editing program of your choice | |
6443 | is invoked with the current line set to | |
6444 | the active line in the program. | |
6445 | Alternatively, there are several ways to specify what part of the file you | |
2a25a5ba | 6446 | want to print if you want to see other parts of the program: |
87885426 FN |
6447 | |
6448 | @table @code | |
2a25a5ba EZ |
6449 | @item edit @var{location} |
6450 | Edit the source file specified by @code{location}. Editing starts at | |
6451 | that @var{location}, e.g., at the specified source line of the | |
6452 | specified file. @xref{Specify Location}, for all the possible forms | |
6453 | of the @var{location} argument; here are the forms of the @code{edit} | |
6454 | command most commonly used: | |
87885426 | 6455 | |
2a25a5ba | 6456 | @table @code |
87885426 FN |
6457 | @item edit @var{number} |
6458 | Edit the current source file with @var{number} as the active line number. | |
6459 | ||
6460 | @item edit @var{function} | |
6461 | Edit the file containing @var{function} at the beginning of its definition. | |
2a25a5ba | 6462 | @end table |
87885426 | 6463 | |
87885426 FN |
6464 | @end table |
6465 | ||
79a6e687 | 6466 | @subsection Choosing your Editor |
87885426 FN |
6467 | You can customize @value{GDBN} to use any editor you want |
6468 | @footnote{ | |
6469 | The only restriction is that your editor (say @code{ex}), recognizes the | |
6470 | following command-line syntax: | |
10998722 | 6471 | @smallexample |
87885426 | 6472 | ex +@var{number} file |
10998722 | 6473 | @end smallexample |
15387254 EZ |
6474 | The optional numeric value +@var{number} specifies the number of the line in |
6475 | the file where to start editing.}. | |
6476 | By default, it is @file{@value{EDITOR}}, but you can change this | |
10998722 AC |
6477 | by setting the environment variable @code{EDITOR} before using |
6478 | @value{GDBN}. For example, to configure @value{GDBN} to use the | |
6479 | @code{vi} editor, you could use these commands with the @code{sh} shell: | |
6480 | @smallexample | |
87885426 FN |
6481 | EDITOR=/usr/bin/vi |
6482 | export EDITOR | |
15387254 | 6483 | gdb @dots{} |
10998722 | 6484 | @end smallexample |
87885426 | 6485 | or in the @code{csh} shell, |
10998722 | 6486 | @smallexample |
87885426 | 6487 | setenv EDITOR /usr/bin/vi |
15387254 | 6488 | gdb @dots{} |
10998722 | 6489 | @end smallexample |
87885426 | 6490 | |
6d2ebf8b | 6491 | @node Search |
79a6e687 | 6492 | @section Searching Source Files |
15387254 | 6493 | @cindex searching source files |
c906108c SS |
6494 | |
6495 | There are two commands for searching through the current source file for a | |
6496 | regular expression. | |
6497 | ||
6498 | @table @code | |
6499 | @kindex search | |
6500 | @kindex forward-search | |
6501 | @item forward-search @var{regexp} | |
6502 | @itemx search @var{regexp} | |
6503 | The command @samp{forward-search @var{regexp}} checks each line, | |
6504 | starting with the one following the last line listed, for a match for | |
5d161b24 | 6505 | @var{regexp}. It lists the line that is found. You can use the |
c906108c SS |
6506 | synonym @samp{search @var{regexp}} or abbreviate the command name as |
6507 | @code{fo}. | |
6508 | ||
09d4efe1 | 6509 | @kindex reverse-search |
c906108c SS |
6510 | @item reverse-search @var{regexp} |
6511 | The command @samp{reverse-search @var{regexp}} checks each line, starting | |
6512 | with the one before the last line listed and going backward, for a match | |
6513 | for @var{regexp}. It lists the line that is found. You can abbreviate | |
6514 | this command as @code{rev}. | |
6515 | @end table | |
c906108c | 6516 | |
6d2ebf8b | 6517 | @node Source Path |
79a6e687 | 6518 | @section Specifying Source Directories |
c906108c SS |
6519 | |
6520 | @cindex source path | |
6521 | @cindex directories for source files | |
6522 | Executable programs sometimes do not record the directories of the source | |
6523 | files from which they were compiled, just the names. Even when they do, | |
6524 | the directories could be moved between the compilation and your debugging | |
6525 | session. @value{GDBN} has a list of directories to search for source files; | |
6526 | this is called the @dfn{source path}. Each time @value{GDBN} wants a source file, | |
6527 | it tries all the directories in the list, in the order they are present | |
0b66e38c EZ |
6528 | in the list, until it finds a file with the desired name. |
6529 | ||
6530 | For example, suppose an executable references the file | |
6531 | @file{/usr/src/foo-1.0/lib/foo.c}, and our source path is | |
6532 | @file{/mnt/cross}. The file is first looked up literally; if this | |
6533 | fails, @file{/mnt/cross/usr/src/foo-1.0/lib/foo.c} is tried; if this | |
6534 | fails, @file{/mnt/cross/foo.c} is opened; if this fails, an error | |
6535 | message is printed. @value{GDBN} does not look up the parts of the | |
6536 | source file name, such as @file{/mnt/cross/src/foo-1.0/lib/foo.c}. | |
6537 | Likewise, the subdirectories of the source path are not searched: if | |
6538 | the source path is @file{/mnt/cross}, and the binary refers to | |
6539 | @file{foo.c}, @value{GDBN} would not find it under | |
6540 | @file{/mnt/cross/usr/src/foo-1.0/lib}. | |
6541 | ||
6542 | Plain file names, relative file names with leading directories, file | |
6543 | names containing dots, etc.@: are all treated as described above; for | |
6544 | instance, if the source path is @file{/mnt/cross}, and the source file | |
6545 | is recorded as @file{../lib/foo.c}, @value{GDBN} would first try | |
6546 | @file{../lib/foo.c}, then @file{/mnt/cross/../lib/foo.c}, and after | |
6547 | that---@file{/mnt/cross/foo.c}. | |
6548 | ||
6549 | Note that the executable search path is @emph{not} used to locate the | |
cd852561 | 6550 | source files. |
c906108c SS |
6551 | |
6552 | Whenever you reset or rearrange the source path, @value{GDBN} clears out | |
6553 | any information it has cached about where source files are found and where | |
6554 | each line is in the file. | |
6555 | ||
6556 | @kindex directory | |
6557 | @kindex dir | |
d4f3574e SS |
6558 | When you start @value{GDBN}, its source path includes only @samp{cdir} |
6559 | and @samp{cwd}, in that order. | |
c906108c SS |
6560 | To add other directories, use the @code{directory} command. |
6561 | ||
4b505b12 AS |
6562 | The search path is used to find both program source files and @value{GDBN} |
6563 | script files (read using the @samp{-command} option and @samp{source} command). | |
6564 | ||
30daae6c JB |
6565 | In addition to the source path, @value{GDBN} provides a set of commands |
6566 | that manage a list of source path substitution rules. A @dfn{substitution | |
6567 | rule} specifies how to rewrite source directories stored in the program's | |
6568 | debug information in case the sources were moved to a different | |
6569 | directory between compilation and debugging. A rule is made of | |
6570 | two strings, the first specifying what needs to be rewritten in | |
6571 | the path, and the second specifying how it should be rewritten. | |
6572 | In @ref{set substitute-path}, we name these two parts @var{from} and | |
6573 | @var{to} respectively. @value{GDBN} does a simple string replacement | |
6574 | of @var{from} with @var{to} at the start of the directory part of the | |
6575 | source file name, and uses that result instead of the original file | |
6576 | name to look up the sources. | |
6577 | ||
6578 | Using the previous example, suppose the @file{foo-1.0} tree has been | |
6579 | moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell | |
3f94c067 | 6580 | @value{GDBN} to replace @file{/usr/src} in all source path names with |
30daae6c JB |
6581 | @file{/mnt/cross}. The first lookup will then be |
6582 | @file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location | |
6583 | of @file{/usr/src/foo-1.0/lib/foo.c}. To define a source path | |
6584 | substitution rule, use the @code{set substitute-path} command | |
6585 | (@pxref{set substitute-path}). | |
6586 | ||
6587 | To avoid unexpected substitution results, a rule is applied only if the | |
6588 | @var{from} part of the directory name ends at a directory separator. | |
6589 | For instance, a rule substituting @file{/usr/source} into | |
6590 | @file{/mnt/cross} will be applied to @file{/usr/source/foo-1.0} but | |
6591 | not to @file{/usr/sourceware/foo-2.0}. And because the substitution | |
d3e8051b | 6592 | is applied only at the beginning of the directory name, this rule will |
30daae6c JB |
6593 | not be applied to @file{/root/usr/source/baz.c} either. |
6594 | ||
6595 | In many cases, you can achieve the same result using the @code{directory} | |
6596 | command. However, @code{set substitute-path} can be more efficient in | |
6597 | the case where the sources are organized in a complex tree with multiple | |
6598 | subdirectories. With the @code{directory} command, you need to add each | |
6599 | subdirectory of your project. If you moved the entire tree while | |
6600 | preserving its internal organization, then @code{set substitute-path} | |
6601 | allows you to direct the debugger to all the sources with one single | |
6602 | command. | |
6603 | ||
6604 | @code{set substitute-path} is also more than just a shortcut command. | |
6605 | The source path is only used if the file at the original location no | |
6606 | longer exists. On the other hand, @code{set substitute-path} modifies | |
6607 | the debugger behavior to look at the rewritten location instead. So, if | |
6608 | for any reason a source file that is not relevant to your executable is | |
6609 | located at the original location, a substitution rule is the only | |
3f94c067 | 6610 | method available to point @value{GDBN} at the new location. |
30daae6c | 6611 | |
29b0e8a2 JM |
6612 | @cindex @samp{--with-relocated-sources} |
6613 | @cindex default source path substitution | |
6614 | You can configure a default source path substitution rule by | |
6615 | configuring @value{GDBN} with the | |
6616 | @samp{--with-relocated-sources=@var{dir}} option. The @var{dir} | |
6617 | should be the name of a directory under @value{GDBN}'s configured | |
6618 | prefix (set with @samp{--prefix} or @samp{--exec-prefix}), and | |
6619 | directory names in debug information under @var{dir} will be adjusted | |
6620 | automatically if the installed @value{GDBN} is moved to a new | |
6621 | location. This is useful if @value{GDBN}, libraries or executables | |
6622 | with debug information and corresponding source code are being moved | |
6623 | together. | |
6624 | ||
c906108c SS |
6625 | @table @code |
6626 | @item directory @var{dirname} @dots{} | |
6627 | @item dir @var{dirname} @dots{} | |
6628 | Add directory @var{dirname} to the front of the source path. Several | |
d4f3574e SS |
6629 | directory names may be given to this command, separated by @samp{:} |
6630 | (@samp{;} on MS-DOS and MS-Windows, where @samp{:} usually appears as | |
6631 | part of absolute file names) or | |
c906108c SS |
6632 | whitespace. You may specify a directory that is already in the source |
6633 | path; this moves it forward, so @value{GDBN} searches it sooner. | |
6634 | ||
6635 | @kindex cdir | |
6636 | @kindex cwd | |
41afff9a | 6637 | @vindex $cdir@r{, convenience variable} |
d3e8051b | 6638 | @vindex $cwd@r{, convenience variable} |
c906108c SS |
6639 | @cindex compilation directory |
6640 | @cindex current directory | |
6641 | @cindex working directory | |
6642 | @cindex directory, current | |
6643 | @cindex directory, compilation | |
6644 | You can use the string @samp{$cdir} to refer to the compilation | |
6645 | directory (if one is recorded), and @samp{$cwd} to refer to the current | |
6646 | working directory. @samp{$cwd} is not the same as @samp{.}---the former | |
6647 | tracks the current working directory as it changes during your @value{GDBN} | |
6648 | session, while the latter is immediately expanded to the current | |
6649 | directory at the time you add an entry to the source path. | |
6650 | ||
6651 | @item directory | |
cd852561 | 6652 | Reset the source path to its default value (@samp{$cdir:$cwd} on Unix systems). This requires confirmation. |
c906108c SS |
6653 | |
6654 | @c RET-repeat for @code{directory} is explicitly disabled, but since | |
6655 | @c repeating it would be a no-op we do not say that. (thanks to RMS) | |
6656 | ||
99e7ae30 DE |
6657 | @item set directories @var{path-list} |
6658 | @kindex set directories | |
6659 | Set the source path to @var{path-list}. | |
6660 | @samp{$cdir:$cwd} are added if missing. | |
6661 | ||
c906108c SS |
6662 | @item show directories |
6663 | @kindex show directories | |
6664 | Print the source path: show which directories it contains. | |
30daae6c JB |
6665 | |
6666 | @anchor{set substitute-path} | |
6667 | @item set substitute-path @var{from} @var{to} | |
6668 | @kindex set substitute-path | |
6669 | Define a source path substitution rule, and add it at the end of the | |
6670 | current list of existing substitution rules. If a rule with the same | |
6671 | @var{from} was already defined, then the old rule is also deleted. | |
6672 | ||
6673 | For example, if the file @file{/foo/bar/baz.c} was moved to | |
6674 | @file{/mnt/cross/baz.c}, then the command | |
6675 | ||
6676 | @smallexample | |
6677 | (@value{GDBP}) set substitute-path /usr/src /mnt/cross | |
6678 | @end smallexample | |
6679 | ||
6680 | @noindent | |
6681 | will tell @value{GDBN} to replace @samp{/usr/src} with | |
6682 | @samp{/mnt/cross}, which will allow @value{GDBN} to find the file | |
6683 | @file{baz.c} even though it was moved. | |
6684 | ||
6685 | In the case when more than one substitution rule have been defined, | |
6686 | the rules are evaluated one by one in the order where they have been | |
6687 | defined. The first one matching, if any, is selected to perform | |
6688 | the substitution. | |
6689 | ||
6690 | For instance, if we had entered the following commands: | |
6691 | ||
6692 | @smallexample | |
6693 | (@value{GDBP}) set substitute-path /usr/src/include /mnt/include | |
6694 | (@value{GDBP}) set substitute-path /usr/src /mnt/src | |
6695 | @end smallexample | |
6696 | ||
6697 | @noindent | |
6698 | @value{GDBN} would then rewrite @file{/usr/src/include/defs.h} into | |
6699 | @file{/mnt/include/defs.h} by using the first rule. However, it would | |
6700 | use the second rule to rewrite @file{/usr/src/lib/foo.c} into | |
6701 | @file{/mnt/src/lib/foo.c}. | |
6702 | ||
6703 | ||
6704 | @item unset substitute-path [path] | |
6705 | @kindex unset substitute-path | |
6706 | If a path is specified, search the current list of substitution rules | |
6707 | for a rule that would rewrite that path. Delete that rule if found. | |
6708 | A warning is emitted by the debugger if no rule could be found. | |
6709 | ||
6710 | If no path is specified, then all substitution rules are deleted. | |
6711 | ||
6712 | @item show substitute-path [path] | |
6713 | @kindex show substitute-path | |
6714 | If a path is specified, then print the source path substitution rule | |
6715 | which would rewrite that path, if any. | |
6716 | ||
6717 | If no path is specified, then print all existing source path substitution | |
6718 | rules. | |
6719 | ||
c906108c SS |
6720 | @end table |
6721 | ||
6722 | If your source path is cluttered with directories that are no longer of | |
6723 | interest, @value{GDBN} may sometimes cause confusion by finding the wrong | |
6724 | versions of source. You can correct the situation as follows: | |
6725 | ||
6726 | @enumerate | |
6727 | @item | |
cd852561 | 6728 | Use @code{directory} with no argument to reset the source path to its default value. |
c906108c SS |
6729 | |
6730 | @item | |
6731 | Use @code{directory} with suitable arguments to reinstall the | |
6732 | directories you want in the source path. You can add all the | |
6733 | directories in one command. | |
6734 | @end enumerate | |
6735 | ||
6d2ebf8b | 6736 | @node Machine Code |
79a6e687 | 6737 | @section Source and Machine Code |
15387254 | 6738 | @cindex source line and its code address |
c906108c SS |
6739 | |
6740 | You can use the command @code{info line} to map source lines to program | |
6741 | addresses (and vice versa), and the command @code{disassemble} to display | |
91440f57 HZ |
6742 | a range of addresses as machine instructions. You can use the command |
6743 | @code{set disassemble-next-line} to set whether to disassemble next | |
6744 | source line when execution stops. When run under @sc{gnu} Emacs | |
d4f3574e | 6745 | mode, the @code{info line} command causes the arrow to point to the |
5d161b24 | 6746 | line specified. Also, @code{info line} prints addresses in symbolic form as |
c906108c SS |
6747 | well as hex. |
6748 | ||
6749 | @table @code | |
6750 | @kindex info line | |
6751 | @item info line @var{linespec} | |
6752 | Print the starting and ending addresses of the compiled code for | |
6753 | source line @var{linespec}. You can specify source lines in any of | |
2a25a5ba | 6754 | the ways documented in @ref{Specify Location}. |
c906108c SS |
6755 | @end table |
6756 | ||
6757 | For example, we can use @code{info line} to discover the location of | |
6758 | the object code for the first line of function | |
6759 | @code{m4_changequote}: | |
6760 | ||
d4f3574e SS |
6761 | @c FIXME: I think this example should also show the addresses in |
6762 | @c symbolic form, as they usually would be displayed. | |
c906108c | 6763 | @smallexample |
96a2c332 | 6764 | (@value{GDBP}) info line m4_changequote |
c906108c SS |
6765 | Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350. |
6766 | @end smallexample | |
6767 | ||
6768 | @noindent | |
15387254 | 6769 | @cindex code address and its source line |
c906108c SS |
6770 | We can also inquire (using @code{*@var{addr}} as the form for |
6771 | @var{linespec}) what source line covers a particular address: | |
6772 | @smallexample | |
6773 | (@value{GDBP}) info line *0x63ff | |
6774 | Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404. | |
6775 | @end smallexample | |
6776 | ||
6777 | @cindex @code{$_} and @code{info line} | |
15387254 | 6778 | @cindex @code{x} command, default address |
41afff9a | 6779 | @kindex x@r{(examine), and} info line |
c906108c SS |
6780 | After @code{info line}, the default address for the @code{x} command |
6781 | is changed to the starting address of the line, so that @samp{x/i} is | |
6782 | sufficient to begin examining the machine code (@pxref{Memory, | |
79a6e687 | 6783 | ,Examining Memory}). Also, this address is saved as the value of the |
c906108c | 6784 | convenience variable @code{$_} (@pxref{Convenience Vars, ,Convenience |
79a6e687 | 6785 | Variables}). |
c906108c SS |
6786 | |
6787 | @table @code | |
6788 | @kindex disassemble | |
6789 | @cindex assembly instructions | |
6790 | @cindex instructions, assembly | |
6791 | @cindex machine instructions | |
6792 | @cindex listing machine instructions | |
6793 | @item disassemble | |
d14508fe | 6794 | @itemx disassemble /m |
9b117ef3 | 6795 | @itemx disassemble /r |
c906108c | 6796 | This specialized command dumps a range of memory as machine |
d14508fe | 6797 | instructions. It can also print mixed source+disassembly by specifying |
9b117ef3 HZ |
6798 | the @code{/m} modifier and print the raw instructions in hex as well as |
6799 | in symbolic form by specifying the @code{/r}. | |
d14508fe | 6800 | The default memory range is the function surrounding the |
c906108c SS |
6801 | program counter of the selected frame. A single argument to this |
6802 | command is a program counter value; @value{GDBN} dumps the function | |
21a0512e PP |
6803 | surrounding this value. When two arguments are given, they should |
6804 | be separated by a comma, possibly surrounded by whitespace. The | |
53a71c06 CR |
6805 | arguments specify a range of addresses to dump, in one of two forms: |
6806 | ||
6807 | @table @code | |
6808 | @item @var{start},@var{end} | |
6809 | the addresses from @var{start} (inclusive) to @var{end} (exclusive) | |
6810 | @item @var{start},+@var{length} | |
6811 | the addresses from @var{start} (inclusive) to | |
6812 | @code{@var{start}+@var{length}} (exclusive). | |
6813 | @end table | |
6814 | ||
6815 | @noindent | |
6816 | When 2 arguments are specified, the name of the function is also | |
6817 | printed (since there could be several functions in the given range). | |
21a0512e PP |
6818 | |
6819 | The argument(s) can be any expression yielding a numeric value, such as | |
6820 | @samp{0x32c4}, @samp{&main+10} or @samp{$pc - 8}. | |
2b28d209 PP |
6821 | |
6822 | If the range of memory being disassembled contains current program counter, | |
6823 | the instruction at that location is shown with a @code{=>} marker. | |
c906108c SS |
6824 | @end table |
6825 | ||
c906108c SS |
6826 | The following example shows the disassembly of a range of addresses of |
6827 | HP PA-RISC 2.0 code: | |
6828 | ||
6829 | @smallexample | |
21a0512e | 6830 | (@value{GDBP}) disas 0x32c4, 0x32e4 |
c906108c | 6831 | Dump of assembler code from 0x32c4 to 0x32e4: |
2b28d209 PP |
6832 | 0x32c4 <main+204>: addil 0,dp |
6833 | 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26 | |
6834 | 0x32cc <main+212>: ldil 0x3000,r31 | |
6835 | 0x32d0 <main+216>: ble 0x3f8(sr4,r31) | |
6836 | 0x32d4 <main+220>: ldo 0(r31),rp | |
6837 | 0x32d8 <main+224>: addil -0x800,dp | |
6838 | 0x32dc <main+228>: ldo 0x588(r1),r26 | |
6839 | 0x32e0 <main+232>: ldil 0x3000,r31 | |
c906108c SS |
6840 | End of assembler dump. |
6841 | @end smallexample | |
c906108c | 6842 | |
2b28d209 PP |
6843 | Here is an example showing mixed source+assembly for Intel x86, when the |
6844 | program is stopped just after function prologue: | |
d14508fe DE |
6845 | |
6846 | @smallexample | |
6847 | (@value{GDBP}) disas /m main | |
6848 | Dump of assembler code for function main: | |
6849 | 5 @{ | |
9c419145 PP |
6850 | 0x08048330 <+0>: push %ebp |
6851 | 0x08048331 <+1>: mov %esp,%ebp | |
6852 | 0x08048333 <+3>: sub $0x8,%esp | |
6853 | 0x08048336 <+6>: and $0xfffffff0,%esp | |
6854 | 0x08048339 <+9>: sub $0x10,%esp | |
d14508fe DE |
6855 | |
6856 | 6 printf ("Hello.\n"); | |
9c419145 PP |
6857 | => 0x0804833c <+12>: movl $0x8048440,(%esp) |
6858 | 0x08048343 <+19>: call 0x8048284 <puts@@plt> | |
d14508fe DE |
6859 | |
6860 | 7 return 0; | |
6861 | 8 @} | |
9c419145 PP |
6862 | 0x08048348 <+24>: mov $0x0,%eax |
6863 | 0x0804834d <+29>: leave | |
6864 | 0x0804834e <+30>: ret | |
d14508fe DE |
6865 | |
6866 | End of assembler dump. | |
6867 | @end smallexample | |
6868 | ||
53a71c06 CR |
6869 | Here is another example showing raw instructions in hex for AMD x86-64, |
6870 | ||
6871 | @smallexample | |
6872 | (gdb) disas /r 0x400281,+10 | |
6873 | Dump of assembler code from 0x400281 to 0x40028b: | |
6874 | 0x0000000000400281: 38 36 cmp %dh,(%rsi) | |
6875 | 0x0000000000400283: 2d 36 34 2e 73 sub $0x732e3436,%eax | |
6876 | 0x0000000000400288: 6f outsl %ds:(%rsi),(%dx) | |
6877 | 0x0000000000400289: 2e 32 00 xor %cs:(%rax),%al | |
6878 | End of assembler dump. | |
6879 | @end smallexample | |
6880 | ||
c906108c SS |
6881 | Some architectures have more than one commonly-used set of instruction |
6882 | mnemonics or other syntax. | |
6883 | ||
76d17f34 EZ |
6884 | For programs that were dynamically linked and use shared libraries, |
6885 | instructions that call functions or branch to locations in the shared | |
6886 | libraries might show a seemingly bogus location---it's actually a | |
6887 | location of the relocation table. On some architectures, @value{GDBN} | |
6888 | might be able to resolve these to actual function names. | |
6889 | ||
c906108c | 6890 | @table @code |
d4f3574e | 6891 | @kindex set disassembly-flavor |
d4f3574e SS |
6892 | @cindex Intel disassembly flavor |
6893 | @cindex AT&T disassembly flavor | |
6894 | @item set disassembly-flavor @var{instruction-set} | |
c906108c SS |
6895 | Select the instruction set to use when disassembling the |
6896 | program via the @code{disassemble} or @code{x/i} commands. | |
6897 | ||
6898 | Currently this command is only defined for the Intel x86 family. You | |
d4f3574e SS |
6899 | can set @var{instruction-set} to either @code{intel} or @code{att}. |
6900 | The default is @code{att}, the AT&T flavor used by default by Unix | |
6901 | assemblers for x86-based targets. | |
9c16f35a EZ |
6902 | |
6903 | @kindex show disassembly-flavor | |
6904 | @item show disassembly-flavor | |
6905 | Show the current setting of the disassembly flavor. | |
c906108c SS |
6906 | @end table |
6907 | ||
91440f57 HZ |
6908 | @table @code |
6909 | @kindex set disassemble-next-line | |
6910 | @kindex show disassemble-next-line | |
6911 | @item set disassemble-next-line | |
6912 | @itemx show disassemble-next-line | |
32ae1842 EZ |
6913 | Control whether or not @value{GDBN} will disassemble the next source |
6914 | line or instruction when execution stops. If ON, @value{GDBN} will | |
6915 | display disassembly of the next source line when execution of the | |
6916 | program being debugged stops. This is @emph{in addition} to | |
6917 | displaying the source line itself, which @value{GDBN} always does if | |
6918 | possible. If the next source line cannot be displayed for some reason | |
6919 | (e.g., if @value{GDBN} cannot find the source file, or there's no line | |
6920 | info in the debug info), @value{GDBN} will display disassembly of the | |
6921 | next @emph{instruction} instead of showing the next source line. If | |
6922 | AUTO, @value{GDBN} will display disassembly of next instruction only | |
6923 | if the source line cannot be displayed. This setting causes | |
6924 | @value{GDBN} to display some feedback when you step through a function | |
6925 | with no line info or whose source file is unavailable. The default is | |
6926 | OFF, which means never display the disassembly of the next line or | |
6927 | instruction. | |
91440f57 HZ |
6928 | @end table |
6929 | ||
c906108c | 6930 | |
6d2ebf8b | 6931 | @node Data |
c906108c SS |
6932 | @chapter Examining Data |
6933 | ||
6934 | @cindex printing data | |
6935 | @cindex examining data | |
6936 | @kindex print | |
6937 | @kindex inspect | |
6938 | @c "inspect" is not quite a synonym if you are using Epoch, which we do not | |
6939 | @c document because it is nonstandard... Under Epoch it displays in a | |
6940 | @c different window or something like that. | |
6941 | The usual way to examine data in your program is with the @code{print} | |
7a292a7a SS |
6942 | command (abbreviated @code{p}), or its synonym @code{inspect}. It |
6943 | evaluates and prints the value of an expression of the language your | |
6944 | program is written in (@pxref{Languages, ,Using @value{GDBN} with | |
78e2826b TT |
6945 | Different Languages}). It may also print the expression using a |
6946 | Python-based pretty-printer (@pxref{Pretty Printing}). | |
c906108c SS |
6947 | |
6948 | @table @code | |
d4f3574e SS |
6949 | @item print @var{expr} |
6950 | @itemx print /@var{f} @var{expr} | |
6951 | @var{expr} is an expression (in the source language). By default the | |
6952 | value of @var{expr} is printed in a format appropriate to its data type; | |
c906108c | 6953 | you can choose a different format by specifying @samp{/@var{f}}, where |
d4f3574e | 6954 | @var{f} is a letter specifying the format; see @ref{Output Formats,,Output |
79a6e687 | 6955 | Formats}. |
c906108c SS |
6956 | |
6957 | @item print | |
6958 | @itemx print /@var{f} | |
15387254 | 6959 | @cindex reprint the last value |
d4f3574e | 6960 | If you omit @var{expr}, @value{GDBN} displays the last value again (from the |
79a6e687 | 6961 | @dfn{value history}; @pxref{Value History, ,Value History}). This allows you to |
c906108c SS |
6962 | conveniently inspect the same value in an alternative format. |
6963 | @end table | |
6964 | ||
6965 | A more low-level way of examining data is with the @code{x} command. | |
6966 | It examines data in memory at a specified address and prints it in a | |
79a6e687 | 6967 | specified format. @xref{Memory, ,Examining Memory}. |
c906108c | 6968 | |
7a292a7a | 6969 | If you are interested in information about types, or about how the |
d4f3574e SS |
6970 | fields of a struct or a class are declared, use the @code{ptype @var{exp}} |
6971 | command rather than @code{print}. @xref{Symbols, ,Examining the Symbol | |
7a292a7a | 6972 | Table}. |
c906108c SS |
6973 | |
6974 | @menu | |
6975 | * Expressions:: Expressions | |
6ba66d6a | 6976 | * Ambiguous Expressions:: Ambiguous Expressions |
c906108c SS |
6977 | * Variables:: Program variables |
6978 | * Arrays:: Artificial arrays | |
6979 | * Output Formats:: Output formats | |
6980 | * Memory:: Examining memory | |
6981 | * Auto Display:: Automatic display | |
6982 | * Print Settings:: Print settings | |
4c374409 | 6983 | * Pretty Printing:: Python pretty printing |
c906108c SS |
6984 | * Value History:: Value history |
6985 | * Convenience Vars:: Convenience variables | |
6986 | * Registers:: Registers | |
c906108c | 6987 | * Floating Point Hardware:: Floating point hardware |
53c69bd7 | 6988 | * Vector Unit:: Vector Unit |
721c2651 | 6989 | * OS Information:: Auxiliary data provided by operating system |
29e57380 | 6990 | * Memory Region Attributes:: Memory region attributes |
16d9dec6 | 6991 | * Dump/Restore Files:: Copy between memory and a file |
384ee23f | 6992 | * Core File Generation:: Cause a program dump its core |
a0eb71c5 KB |
6993 | * Character Sets:: Debugging programs that use a different |
6994 | character set than GDB does | |
09d4efe1 | 6995 | * Caching Remote Data:: Data caching for remote targets |
08388c79 | 6996 | * Searching Memory:: Searching memory for a sequence of bytes |
c906108c SS |
6997 | @end menu |
6998 | ||
6d2ebf8b | 6999 | @node Expressions |
c906108c SS |
7000 | @section Expressions |
7001 | ||
7002 | @cindex expressions | |
7003 | @code{print} and many other @value{GDBN} commands accept an expression and | |
7004 | compute its value. Any kind of constant, variable or operator defined | |
7005 | by the programming language you are using is valid in an expression in | |
e2e0bcd1 JB |
7006 | @value{GDBN}. This includes conditional expressions, function calls, |
7007 | casts, and string constants. It also includes preprocessor macros, if | |
7008 | you compiled your program to include this information; see | |
7009 | @ref{Compilation}. | |
c906108c | 7010 | |
15387254 | 7011 | @cindex arrays in expressions |
d4f3574e SS |
7012 | @value{GDBN} supports array constants in expressions input by |
7013 | the user. The syntax is @{@var{element}, @var{element}@dots{}@}. For example, | |
63092375 DJ |
7014 | you can use the command @code{print @{1, 2, 3@}} to create an array |
7015 | of three integers. If you pass an array to a function or assign it | |
7016 | to a program variable, @value{GDBN} copies the array to memory that | |
7017 | is @code{malloc}ed in the target program. | |
c906108c | 7018 | |
c906108c SS |
7019 | Because C is so widespread, most of the expressions shown in examples in |
7020 | this manual are in C. @xref{Languages, , Using @value{GDBN} with Different | |
7021 | Languages}, for information on how to use expressions in other | |
7022 | languages. | |
7023 | ||
7024 | In this section, we discuss operators that you can use in @value{GDBN} | |
7025 | expressions regardless of your programming language. | |
7026 | ||
15387254 | 7027 | @cindex casts, in expressions |
c906108c SS |
7028 | Casts are supported in all languages, not just in C, because it is so |
7029 | useful to cast a number into a pointer in order to examine a structure | |
7030 | at that address in memory. | |
7031 | @c FIXME: casts supported---Mod2 true? | |
c906108c SS |
7032 | |
7033 | @value{GDBN} supports these operators, in addition to those common | |
7034 | to programming languages: | |
7035 | ||
7036 | @table @code | |
7037 | @item @@ | |
7038 | @samp{@@} is a binary operator for treating parts of memory as arrays. | |
79a6e687 | 7039 | @xref{Arrays, ,Artificial Arrays}, for more information. |
c906108c SS |
7040 | |
7041 | @item :: | |
7042 | @samp{::} allows you to specify a variable in terms of the file or | |
79a6e687 | 7043 | function where it is defined. @xref{Variables, ,Program Variables}. |
c906108c SS |
7044 | |
7045 | @cindex @{@var{type}@} | |
7046 | @cindex type casting memory | |
7047 | @cindex memory, viewing as typed object | |
7048 | @cindex casts, to view memory | |
7049 | @item @{@var{type}@} @var{addr} | |
7050 | Refers to an object of type @var{type} stored at address @var{addr} in | |
7051 | memory. @var{addr} may be any expression whose value is an integer or | |
7052 | pointer (but parentheses are required around binary operators, just as in | |
7053 | a cast). This construct is allowed regardless of what kind of data is | |
7054 | normally supposed to reside at @var{addr}. | |
7055 | @end table | |
7056 | ||
6ba66d6a JB |
7057 | @node Ambiguous Expressions |
7058 | @section Ambiguous Expressions | |
7059 | @cindex ambiguous expressions | |
7060 | ||
7061 | Expressions can sometimes contain some ambiguous elements. For instance, | |
7062 | some programming languages (notably Ada, C@t{++} and Objective-C) permit | |
7063 | a single function name to be defined several times, for application in | |
7064 | different contexts. This is called @dfn{overloading}. Another example | |
7065 | involving Ada is generics. A @dfn{generic package} is similar to C@t{++} | |
7066 | templates and is typically instantiated several times, resulting in | |
7067 | the same function name being defined in different contexts. | |
7068 | ||
7069 | In some cases and depending on the language, it is possible to adjust | |
7070 | the expression to remove the ambiguity. For instance in C@t{++}, you | |
7071 | can specify the signature of the function you want to break on, as in | |
7072 | @kbd{break @var{function}(@var{types})}. In Ada, using the fully | |
7073 | qualified name of your function often makes the expression unambiguous | |
7074 | as well. | |
7075 | ||
7076 | When an ambiguity that needs to be resolved is detected, the debugger | |
7077 | has the capability to display a menu of numbered choices for each | |
7078 | possibility, and then waits for the selection with the prompt @samp{>}. | |
7079 | The first option is always @samp{[0] cancel}, and typing @kbd{0 @key{RET}} | |
7080 | aborts the current command. If the command in which the expression was | |
7081 | used allows more than one choice to be selected, the next option in the | |
7082 | menu is @samp{[1] all}, and typing @kbd{1 @key{RET}} selects all possible | |
7083 | choices. | |
7084 | ||
7085 | For example, the following session excerpt shows an attempt to set a | |
7086 | breakpoint at the overloaded symbol @code{String::after}. | |
7087 | We choose three particular definitions of that function name: | |
7088 | ||
7089 | @c FIXME! This is likely to change to show arg type lists, at least | |
7090 | @smallexample | |
7091 | @group | |
7092 | (@value{GDBP}) b String::after | |
7093 | [0] cancel | |
7094 | [1] all | |
7095 | [2] file:String.cc; line number:867 | |
7096 | [3] file:String.cc; line number:860 | |
7097 | [4] file:String.cc; line number:875 | |
7098 | [5] file:String.cc; line number:853 | |
7099 | [6] file:String.cc; line number:846 | |
7100 | [7] file:String.cc; line number:735 | |
7101 | > 2 4 6 | |
7102 | Breakpoint 1 at 0xb26c: file String.cc, line 867. | |
7103 | Breakpoint 2 at 0xb344: file String.cc, line 875. | |
7104 | Breakpoint 3 at 0xafcc: file String.cc, line 846. | |
7105 | Multiple breakpoints were set. | |
7106 | Use the "delete" command to delete unwanted | |
7107 | breakpoints. | |
7108 | (@value{GDBP}) | |
7109 | @end group | |
7110 | @end smallexample | |
7111 | ||
7112 | @table @code | |
7113 | @kindex set multiple-symbols | |
7114 | @item set multiple-symbols @var{mode} | |
7115 | @cindex multiple-symbols menu | |
7116 | ||
7117 | This option allows you to adjust the debugger behavior when an expression | |
7118 | is ambiguous. | |
7119 | ||
7120 | By default, @var{mode} is set to @code{all}. If the command with which | |
7121 | the expression is used allows more than one choice, then @value{GDBN} | |
7122 | automatically selects all possible choices. For instance, inserting | |
7123 | a breakpoint on a function using an ambiguous name results in a breakpoint | |
7124 | inserted on each possible match. However, if a unique choice must be made, | |
7125 | then @value{GDBN} uses the menu to help you disambiguate the expression. | |
7126 | For instance, printing the address of an overloaded function will result | |
7127 | in the use of the menu. | |
7128 | ||
7129 | When @var{mode} is set to @code{ask}, the debugger always uses the menu | |
7130 | when an ambiguity is detected. | |
7131 | ||
7132 | Finally, when @var{mode} is set to @code{cancel}, the debugger reports | |
7133 | an error due to the ambiguity and the command is aborted. | |
7134 | ||
7135 | @kindex show multiple-symbols | |
7136 | @item show multiple-symbols | |
7137 | Show the current value of the @code{multiple-symbols} setting. | |
7138 | @end table | |
7139 | ||
6d2ebf8b | 7140 | @node Variables |
79a6e687 | 7141 | @section Program Variables |
c906108c SS |
7142 | |
7143 | The most common kind of expression to use is the name of a variable | |
7144 | in your program. | |
7145 | ||
7146 | Variables in expressions are understood in the selected stack frame | |
79a6e687 | 7147 | (@pxref{Selection, ,Selecting a Frame}); they must be either: |
c906108c SS |
7148 | |
7149 | @itemize @bullet | |
7150 | @item | |
7151 | global (or file-static) | |
7152 | @end itemize | |
7153 | ||
5d161b24 | 7154 | @noindent or |
c906108c SS |
7155 | |
7156 | @itemize @bullet | |
7157 | @item | |
7158 | visible according to the scope rules of the | |
7159 | programming language from the point of execution in that frame | |
5d161b24 | 7160 | @end itemize |
c906108c SS |
7161 | |
7162 | @noindent This means that in the function | |
7163 | ||
474c8240 | 7164 | @smallexample |
c906108c SS |
7165 | foo (a) |
7166 | int a; | |
7167 | @{ | |
7168 | bar (a); | |
7169 | @{ | |
7170 | int b = test (); | |
7171 | bar (b); | |
7172 | @} | |
7173 | @} | |
474c8240 | 7174 | @end smallexample |
c906108c SS |
7175 | |
7176 | @noindent | |
7177 | you can examine and use the variable @code{a} whenever your program is | |
7178 | executing within the function @code{foo}, but you can only use or | |
7179 | examine the variable @code{b} while your program is executing inside | |
7180 | the block where @code{b} is declared. | |
7181 | ||
7182 | @cindex variable name conflict | |
7183 | There is an exception: you can refer to a variable or function whose | |
7184 | scope is a single source file even if the current execution point is not | |
7185 | in this file. But it is possible to have more than one such variable or | |
7186 | function with the same name (in different source files). If that | |
7187 | happens, referring to that name has unpredictable effects. If you wish, | |
7188 | you can specify a static variable in a particular function or file, | |
15387254 | 7189 | using the colon-colon (@code{::}) notation: |
c906108c | 7190 | |
d4f3574e | 7191 | @cindex colon-colon, context for variables/functions |
12c27660 | 7192 | @ifnotinfo |
c906108c | 7193 | @c info cannot cope with a :: index entry, but why deprive hard copy readers? |
41afff9a | 7194 | @cindex @code{::}, context for variables/functions |
12c27660 | 7195 | @end ifnotinfo |
474c8240 | 7196 | @smallexample |
c906108c SS |
7197 | @var{file}::@var{variable} |
7198 | @var{function}::@var{variable} | |
474c8240 | 7199 | @end smallexample |
c906108c SS |
7200 | |
7201 | @noindent | |
7202 | Here @var{file} or @var{function} is the name of the context for the | |
7203 | static @var{variable}. In the case of file names, you can use quotes to | |
7204 | make sure @value{GDBN} parses the file name as a single word---for example, | |
7205 | to print a global value of @code{x} defined in @file{f2.c}: | |
7206 | ||
474c8240 | 7207 | @smallexample |
c906108c | 7208 | (@value{GDBP}) p 'f2.c'::x |
474c8240 | 7209 | @end smallexample |
c906108c | 7210 | |
b37052ae | 7211 | @cindex C@t{++} scope resolution |
c906108c | 7212 | This use of @samp{::} is very rarely in conflict with the very similar |
b37052ae | 7213 | use of the same notation in C@t{++}. @value{GDBN} also supports use of the C@t{++} |
c906108c SS |
7214 | scope resolution operator in @value{GDBN} expressions. |
7215 | @c FIXME: Um, so what happens in one of those rare cases where it's in | |
7216 | @c conflict?? --mew | |
c906108c SS |
7217 | |
7218 | @cindex wrong values | |
7219 | @cindex variable values, wrong | |
15387254 EZ |
7220 | @cindex function entry/exit, wrong values of variables |
7221 | @cindex optimized code, wrong values of variables | |
c906108c SS |
7222 | @quotation |
7223 | @emph{Warning:} Occasionally, a local variable may appear to have the | |
7224 | wrong value at certain points in a function---just after entry to a new | |
7225 | scope, and just before exit. | |
7226 | @end quotation | |
7227 | You may see this problem when you are stepping by machine instructions. | |
7228 | This is because, on most machines, it takes more than one instruction to | |
7229 | set up a stack frame (including local variable definitions); if you are | |
7230 | stepping by machine instructions, variables may appear to have the wrong | |
7231 | values until the stack frame is completely built. On exit, it usually | |
7232 | also takes more than one machine instruction to destroy a stack frame; | |
7233 | after you begin stepping through that group of instructions, local | |
7234 | variable definitions may be gone. | |
7235 | ||
7236 | This may also happen when the compiler does significant optimizations. | |
7237 | To be sure of always seeing accurate values, turn off all optimization | |
7238 | when compiling. | |
7239 | ||
d4f3574e SS |
7240 | @cindex ``No symbol "foo" in current context'' |
7241 | Another possible effect of compiler optimizations is to optimize | |
7242 | unused variables out of existence, or assign variables to registers (as | |
7243 | opposed to memory addresses). Depending on the support for such cases | |
7244 | offered by the debug info format used by the compiler, @value{GDBN} | |
7245 | might not be able to display values for such local variables. If that | |
7246 | happens, @value{GDBN} will print a message like this: | |
7247 | ||
474c8240 | 7248 | @smallexample |
d4f3574e | 7249 | No symbol "foo" in current context. |
474c8240 | 7250 | @end smallexample |
d4f3574e SS |
7251 | |
7252 | To solve such problems, either recompile without optimizations, or use a | |
7253 | different debug info format, if the compiler supports several such | |
15387254 | 7254 | formats. For example, @value{NGCC}, the @sc{gnu} C/C@t{++} compiler, |
0179ffac DC |
7255 | usually supports the @option{-gstabs+} option. @option{-gstabs+} |
7256 | produces debug info in a format that is superior to formats such as | |
7257 | COFF. You may be able to use DWARF 2 (@option{-gdwarf-2}), which is also | |
7258 | an effective form for debug info. @xref{Debugging Options,,Options | |
ce9341a1 BW |
7259 | for Debugging Your Program or GCC, gcc.info, Using the @sc{gnu} |
7260 | Compiler Collection (GCC)}. | |
79a6e687 | 7261 | @xref{C, ,C and C@t{++}}, for more information about debug info formats |
15387254 | 7262 | that are best suited to C@t{++} programs. |
d4f3574e | 7263 | |
ab1adacd EZ |
7264 | If you ask to print an object whose contents are unknown to |
7265 | @value{GDBN}, e.g., because its data type is not completely specified | |
7266 | by the debug information, @value{GDBN} will say @samp{<incomplete | |
7267 | type>}. @xref{Symbols, incomplete type}, for more about this. | |
7268 | ||
3a60f64e JK |
7269 | Strings are identified as arrays of @code{char} values without specified |
7270 | signedness. Arrays of either @code{signed char} or @code{unsigned char} get | |
7271 | printed as arrays of 1 byte sized integers. @code{-fsigned-char} or | |
7272 | @code{-funsigned-char} @value{NGCC} options have no effect as @value{GDBN} | |
7273 | defines literal string type @code{"char"} as @code{char} without a sign. | |
7274 | For program code | |
7275 | ||
7276 | @smallexample | |
7277 | char var0[] = "A"; | |
7278 | signed char var1[] = "A"; | |
7279 | @end smallexample | |
7280 | ||
7281 | You get during debugging | |
7282 | @smallexample | |
7283 | (gdb) print var0 | |
7284 | $1 = "A" | |
7285 | (gdb) print var1 | |
7286 | $2 = @{65 'A', 0 '\0'@} | |
7287 | @end smallexample | |
7288 | ||
6d2ebf8b | 7289 | @node Arrays |
79a6e687 | 7290 | @section Artificial Arrays |
c906108c SS |
7291 | |
7292 | @cindex artificial array | |
15387254 | 7293 | @cindex arrays |
41afff9a | 7294 | @kindex @@@r{, referencing memory as an array} |
c906108c SS |
7295 | It is often useful to print out several successive objects of the |
7296 | same type in memory; a section of an array, or an array of | |
7297 | dynamically determined size for which only a pointer exists in the | |
7298 | program. | |
7299 | ||
7300 | You can do this by referring to a contiguous span of memory as an | |
7301 | @dfn{artificial array}, using the binary operator @samp{@@}. The left | |
7302 | operand of @samp{@@} should be the first element of the desired array | |
7303 | and be an individual object. The right operand should be the desired length | |
7304 | of the array. The result is an array value whose elements are all of | |
7305 | the type of the left argument. The first element is actually the left | |
7306 | argument; the second element comes from bytes of memory immediately | |
7307 | following those that hold the first element, and so on. Here is an | |
7308 | example. If a program says | |
7309 | ||
474c8240 | 7310 | @smallexample |
c906108c | 7311 | int *array = (int *) malloc (len * sizeof (int)); |
474c8240 | 7312 | @end smallexample |
c906108c SS |
7313 | |
7314 | @noindent | |
7315 | you can print the contents of @code{array} with | |
7316 | ||
474c8240 | 7317 | @smallexample |
c906108c | 7318 | p *array@@len |
474c8240 | 7319 | @end smallexample |
c906108c SS |
7320 | |
7321 | The left operand of @samp{@@} must reside in memory. Array values made | |
7322 | with @samp{@@} in this way behave just like other arrays in terms of | |
7323 | subscripting, and are coerced to pointers when used in expressions. | |
7324 | Artificial arrays most often appear in expressions via the value history | |
79a6e687 | 7325 | (@pxref{Value History, ,Value History}), after printing one out. |
c906108c SS |
7326 | |
7327 | Another way to create an artificial array is to use a cast. | |
7328 | This re-interprets a value as if it were an array. | |
7329 | The value need not be in memory: | |
474c8240 | 7330 | @smallexample |
c906108c SS |
7331 | (@value{GDBP}) p/x (short[2])0x12345678 |
7332 | $1 = @{0x1234, 0x5678@} | |
474c8240 | 7333 | @end smallexample |
c906108c SS |
7334 | |
7335 | As a convenience, if you leave the array length out (as in | |
c3f6f71d | 7336 | @samp{(@var{type}[])@var{value}}) @value{GDBN} calculates the size to fill |
c906108c | 7337 | the value (as @samp{sizeof(@var{value})/sizeof(@var{type})}: |
474c8240 | 7338 | @smallexample |
c906108c SS |
7339 | (@value{GDBP}) p/x (short[])0x12345678 |
7340 | $2 = @{0x1234, 0x5678@} | |
474c8240 | 7341 | @end smallexample |
c906108c SS |
7342 | |
7343 | Sometimes the artificial array mechanism is not quite enough; in | |
7344 | moderately complex data structures, the elements of interest may not | |
7345 | actually be adjacent---for example, if you are interested in the values | |
7346 | of pointers in an array. One useful work-around in this situation is | |
7347 | to use a convenience variable (@pxref{Convenience Vars, ,Convenience | |
79a6e687 | 7348 | Variables}) as a counter in an expression that prints the first |
c906108c SS |
7349 | interesting value, and then repeat that expression via @key{RET}. For |
7350 | instance, suppose you have an array @code{dtab} of pointers to | |
7351 | structures, and you are interested in the values of a field @code{fv} | |
7352 | in each structure. Here is an example of what you might type: | |
7353 | ||
474c8240 | 7354 | @smallexample |
c906108c SS |
7355 | set $i = 0 |
7356 | p dtab[$i++]->fv | |
7357 | @key{RET} | |
7358 | @key{RET} | |
7359 | @dots{} | |
474c8240 | 7360 | @end smallexample |
c906108c | 7361 | |
6d2ebf8b | 7362 | @node Output Formats |
79a6e687 | 7363 | @section Output Formats |
c906108c SS |
7364 | |
7365 | @cindex formatted output | |
7366 | @cindex output formats | |
7367 | By default, @value{GDBN} prints a value according to its data type. Sometimes | |
7368 | this is not what you want. For example, you might want to print a number | |
7369 | in hex, or a pointer in decimal. Or you might want to view data in memory | |
7370 | at a certain address as a character string or as an instruction. To do | |
7371 | these things, specify an @dfn{output format} when you print a value. | |
7372 | ||
7373 | The simplest use of output formats is to say how to print a value | |
7374 | already computed. This is done by starting the arguments of the | |
7375 | @code{print} command with a slash and a format letter. The format | |
7376 | letters supported are: | |
7377 | ||
7378 | @table @code | |
7379 | @item x | |
7380 | Regard the bits of the value as an integer, and print the integer in | |
7381 | hexadecimal. | |
7382 | ||
7383 | @item d | |
7384 | Print as integer in signed decimal. | |
7385 | ||
7386 | @item u | |
7387 | Print as integer in unsigned decimal. | |
7388 | ||
7389 | @item o | |
7390 | Print as integer in octal. | |
7391 | ||
7392 | @item t | |
7393 | Print as integer in binary. The letter @samp{t} stands for ``two''. | |
7394 | @footnote{@samp{b} cannot be used because these format letters are also | |
7395 | used with the @code{x} command, where @samp{b} stands for ``byte''; | |
79a6e687 | 7396 | see @ref{Memory,,Examining Memory}.} |
c906108c SS |
7397 | |
7398 | @item a | |
7399 | @cindex unknown address, locating | |
3d67e040 | 7400 | @cindex locate address |
c906108c SS |
7401 | Print as an address, both absolute in hexadecimal and as an offset from |
7402 | the nearest preceding symbol. You can use this format used to discover | |
7403 | where (in what function) an unknown address is located: | |
7404 | ||
474c8240 | 7405 | @smallexample |
c906108c SS |
7406 | (@value{GDBP}) p/a 0x54320 |
7407 | $3 = 0x54320 <_initialize_vx+396> | |
474c8240 | 7408 | @end smallexample |
c906108c | 7409 | |
3d67e040 EZ |
7410 | @noindent |
7411 | The command @code{info symbol 0x54320} yields similar results. | |
7412 | @xref{Symbols, info symbol}. | |
7413 | ||
c906108c | 7414 | @item c |
51274035 EZ |
7415 | Regard as an integer and print it as a character constant. This |
7416 | prints both the numerical value and its character representation. The | |
7417 | character representation is replaced with the octal escape @samp{\nnn} | |
7418 | for characters outside the 7-bit @sc{ascii} range. | |
c906108c | 7419 | |
ea37ba09 DJ |
7420 | Without this format, @value{GDBN} displays @code{char}, |
7421 | @w{@code{unsigned char}}, and @w{@code{signed char}} data as character | |
7422 | constants. Single-byte members of vectors are displayed as integer | |
7423 | data. | |
7424 | ||
c906108c SS |
7425 | @item f |
7426 | Regard the bits of the value as a floating point number and print | |
7427 | using typical floating point syntax. | |
ea37ba09 DJ |
7428 | |
7429 | @item s | |
7430 | @cindex printing strings | |
7431 | @cindex printing byte arrays | |
7432 | Regard as a string, if possible. With this format, pointers to single-byte | |
7433 | data are displayed as null-terminated strings and arrays of single-byte data | |
7434 | are displayed as fixed-length strings. Other values are displayed in their | |
7435 | natural types. | |
7436 | ||
7437 | Without this format, @value{GDBN} displays pointers to and arrays of | |
7438 | @code{char}, @w{@code{unsigned char}}, and @w{@code{signed char}} as | |
7439 | strings. Single-byte members of a vector are displayed as an integer | |
7440 | array. | |
a6bac58e TT |
7441 | |
7442 | @item r | |
7443 | @cindex raw printing | |
7444 | Print using the @samp{raw} formatting. By default, @value{GDBN} will | |
78e2826b TT |
7445 | use a Python-based pretty-printer, if one is available (@pxref{Pretty |
7446 | Printing}). This typically results in a higher-level display of the | |
7447 | value's contents. The @samp{r} format bypasses any Python | |
7448 | pretty-printer which might exist. | |
c906108c SS |
7449 | @end table |
7450 | ||
7451 | For example, to print the program counter in hex (@pxref{Registers}), type | |
7452 | ||
474c8240 | 7453 | @smallexample |
c906108c | 7454 | p/x $pc |
474c8240 | 7455 | @end smallexample |
c906108c SS |
7456 | |
7457 | @noindent | |
7458 | Note that no space is required before the slash; this is because command | |
7459 | names in @value{GDBN} cannot contain a slash. | |
7460 | ||
7461 | To reprint the last value in the value history with a different format, | |
7462 | you can use the @code{print} command with just a format and no | |
7463 | expression. For example, @samp{p/x} reprints the last value in hex. | |
7464 | ||
6d2ebf8b | 7465 | @node Memory |
79a6e687 | 7466 | @section Examining Memory |
c906108c SS |
7467 | |
7468 | You can use the command @code{x} (for ``examine'') to examine memory in | |
7469 | any of several formats, independently of your program's data types. | |
7470 | ||
7471 | @cindex examining memory | |
7472 | @table @code | |
41afff9a | 7473 | @kindex x @r{(examine memory)} |
c906108c SS |
7474 | @item x/@var{nfu} @var{addr} |
7475 | @itemx x @var{addr} | |
7476 | @itemx x | |
7477 | Use the @code{x} command to examine memory. | |
7478 | @end table | |
7479 | ||
7480 | @var{n}, @var{f}, and @var{u} are all optional parameters that specify how | |
7481 | much memory to display and how to format it; @var{addr} is an | |
7482 | expression giving the address where you want to start displaying memory. | |
7483 | If you use defaults for @var{nfu}, you need not type the slash @samp{/}. | |
7484 | Several commands set convenient defaults for @var{addr}. | |
7485 | ||
7486 | @table @r | |
7487 | @item @var{n}, the repeat count | |
7488 | The repeat count is a decimal integer; the default is 1. It specifies | |
7489 | how much memory (counting by units @var{u}) to display. | |
7490 | @c This really is **decimal**; unaffected by 'set radix' as of GDB | |
7491 | @c 4.1.2. | |
7492 | ||
7493 | @item @var{f}, the display format | |
51274035 EZ |
7494 | The display format is one of the formats used by @code{print} |
7495 | (@samp{x}, @samp{d}, @samp{u}, @samp{o}, @samp{t}, @samp{a}, @samp{c}, | |
ea37ba09 DJ |
7496 | @samp{f}, @samp{s}), and in addition @samp{i} (for machine instructions). |
7497 | The default is @samp{x} (hexadecimal) initially. The default changes | |
7498 | each time you use either @code{x} or @code{print}. | |
c906108c SS |
7499 | |
7500 | @item @var{u}, the unit size | |
7501 | The unit size is any of | |
7502 | ||
7503 | @table @code | |
7504 | @item b | |
7505 | Bytes. | |
7506 | @item h | |
7507 | Halfwords (two bytes). | |
7508 | @item w | |
7509 | Words (four bytes). This is the initial default. | |
7510 | @item g | |
7511 | Giant words (eight bytes). | |
7512 | @end table | |
7513 | ||
7514 | Each time you specify a unit size with @code{x}, that size becomes the | |
9a22f0d0 PM |
7515 | default unit the next time you use @code{x}. For the @samp{i} format, |
7516 | the unit size is ignored and is normally not written. For the @samp{s} format, | |
7517 | the unit size defaults to @samp{b}, unless it is explicitly given. | |
7518 | Use @kbd{x /hs} to display 16-bit char strings and @kbd{x /ws} to display | |
7519 | 32-bit strings. The next use of @kbd{x /s} will again display 8-bit strings. | |
7520 | Note that the results depend on the programming language of the | |
7521 | current compilation unit. If the language is C, the @samp{s} | |
7522 | modifier will use the UTF-16 encoding while @samp{w} will use | |
7523 | UTF-32. The encoding is set by the programming language and cannot | |
7524 | be altered. | |
c906108c SS |
7525 | |
7526 | @item @var{addr}, starting display address | |
7527 | @var{addr} is the address where you want @value{GDBN} to begin displaying | |
7528 | memory. The expression need not have a pointer value (though it may); | |
7529 | it is always interpreted as an integer address of a byte of memory. | |
7530 | @xref{Expressions, ,Expressions}, for more information on expressions. The default for | |
7531 | @var{addr} is usually just after the last address examined---but several | |
7532 | other commands also set the default address: @code{info breakpoints} (to | |
7533 | the address of the last breakpoint listed), @code{info line} (to the | |
7534 | starting address of a line), and @code{print} (if you use it to display | |
7535 | a value from memory). | |
7536 | @end table | |
7537 | ||
7538 | For example, @samp{x/3uh 0x54320} is a request to display three halfwords | |
7539 | (@code{h}) of memory, formatted as unsigned decimal integers (@samp{u}), | |
7540 | starting at address @code{0x54320}. @samp{x/4xw $sp} prints the four | |
7541 | words (@samp{w}) of memory above the stack pointer (here, @samp{$sp}; | |
d4f3574e | 7542 | @pxref{Registers, ,Registers}) in hexadecimal (@samp{x}). |
c906108c SS |
7543 | |
7544 | Since the letters indicating unit sizes are all distinct from the | |
7545 | letters specifying output formats, you do not have to remember whether | |
7546 | unit size or format comes first; either order works. The output | |
7547 | specifications @samp{4xw} and @samp{4wx} mean exactly the same thing. | |
7548 | (However, the count @var{n} must come first; @samp{wx4} does not work.) | |
7549 | ||
7550 | Even though the unit size @var{u} is ignored for the formats @samp{s} | |
7551 | and @samp{i}, you might still want to use a count @var{n}; for example, | |
7552 | @samp{3i} specifies that you want to see three machine instructions, | |
a4642986 MR |
7553 | including any operands. For convenience, especially when used with |
7554 | the @code{display} command, the @samp{i} format also prints branch delay | |
7555 | slot instructions, if any, beyond the count specified, which immediately | |
7556 | follow the last instruction that is within the count. The command | |
7557 | @code{disassemble} gives an alternative way of inspecting machine | |
7558 | instructions; see @ref{Machine Code,,Source and Machine Code}. | |
c906108c SS |
7559 | |
7560 | All the defaults for the arguments to @code{x} are designed to make it | |
7561 | easy to continue scanning memory with minimal specifications each time | |
7562 | you use @code{x}. For example, after you have inspected three machine | |
7563 | instructions with @samp{x/3i @var{addr}}, you can inspect the next seven | |
7564 | with just @samp{x/7}. If you use @key{RET} to repeat the @code{x} command, | |
7565 | the repeat count @var{n} is used again; the other arguments default as | |
7566 | for successive uses of @code{x}. | |
7567 | ||
2b28d209 PP |
7568 | When examining machine instructions, the instruction at current program |
7569 | counter is shown with a @code{=>} marker. For example: | |
7570 | ||
7571 | @smallexample | |
7572 | (@value{GDBP}) x/5i $pc-6 | |
7573 | 0x804837f <main+11>: mov %esp,%ebp | |
7574 | 0x8048381 <main+13>: push %ecx | |
7575 | 0x8048382 <main+14>: sub $0x4,%esp | |
7576 | => 0x8048385 <main+17>: movl $0x8048460,(%esp) | |
7577 | 0x804838c <main+24>: call 0x80482d4 <puts@@plt> | |
7578 | @end smallexample | |
7579 | ||
c906108c SS |
7580 | @cindex @code{$_}, @code{$__}, and value history |
7581 | The addresses and contents printed by the @code{x} command are not saved | |
7582 | in the value history because there is often too much of them and they | |
7583 | would get in the way. Instead, @value{GDBN} makes these values available for | |
7584 | subsequent use in expressions as values of the convenience variables | |
7585 | @code{$_} and @code{$__}. After an @code{x} command, the last address | |
7586 | examined is available for use in expressions in the convenience variable | |
7587 | @code{$_}. The contents of that address, as examined, are available in | |
7588 | the convenience variable @code{$__}. | |
7589 | ||
7590 | If the @code{x} command has a repeat count, the address and contents saved | |
7591 | are from the last memory unit printed; this is not the same as the last | |
7592 | address printed if several units were printed on the last line of output. | |
7593 | ||
09d4efe1 EZ |
7594 | @cindex remote memory comparison |
7595 | @cindex verify remote memory image | |
7596 | When you are debugging a program running on a remote target machine | |
ea35711c | 7597 | (@pxref{Remote Debugging}), you may wish to verify the program's image in the |
09d4efe1 EZ |
7598 | remote machine's memory against the executable file you downloaded to |
7599 | the target. The @code{compare-sections} command is provided for such | |
7600 | situations. | |
7601 | ||
7602 | @table @code | |
7603 | @kindex compare-sections | |
7604 | @item compare-sections @r{[}@var{section-name}@r{]} | |
7605 | Compare the data of a loadable section @var{section-name} in the | |
7606 | executable file of the program being debugged with the same section in | |
7607 | the remote machine's memory, and report any mismatches. With no | |
7608 | arguments, compares all loadable sections. This command's | |
7609 | availability depends on the target's support for the @code{"qCRC"} | |
7610 | remote request. | |
7611 | @end table | |
7612 | ||
6d2ebf8b | 7613 | @node Auto Display |
79a6e687 | 7614 | @section Automatic Display |
c906108c SS |
7615 | @cindex automatic display |
7616 | @cindex display of expressions | |
7617 | ||
7618 | If you find that you want to print the value of an expression frequently | |
7619 | (to see how it changes), you might want to add it to the @dfn{automatic | |
7620 | display list} so that @value{GDBN} prints its value each time your program stops. | |
7621 | Each expression added to the list is given a number to identify it; | |
7622 | to remove an expression from the list, you specify that number. | |
7623 | The automatic display looks like this: | |
7624 | ||
474c8240 | 7625 | @smallexample |
c906108c SS |
7626 | 2: foo = 38 |
7627 | 3: bar[5] = (struct hack *) 0x3804 | |
474c8240 | 7628 | @end smallexample |
c906108c SS |
7629 | |
7630 | @noindent | |
7631 | This display shows item numbers, expressions and their current values. As with | |
7632 | displays you request manually using @code{x} or @code{print}, you can | |
7633 | specify the output format you prefer; in fact, @code{display} decides | |
ea37ba09 DJ |
7634 | whether to use @code{print} or @code{x} depending your format |
7635 | specification---it uses @code{x} if you specify either the @samp{i} | |
7636 | or @samp{s} format, or a unit size; otherwise it uses @code{print}. | |
c906108c SS |
7637 | |
7638 | @table @code | |
7639 | @kindex display | |
d4f3574e SS |
7640 | @item display @var{expr} |
7641 | Add the expression @var{expr} to the list of expressions to display | |
c906108c SS |
7642 | each time your program stops. @xref{Expressions, ,Expressions}. |
7643 | ||
7644 | @code{display} does not repeat if you press @key{RET} again after using it. | |
7645 | ||
d4f3574e | 7646 | @item display/@var{fmt} @var{expr} |
c906108c | 7647 | For @var{fmt} specifying only a display format and not a size or |
d4f3574e | 7648 | count, add the expression @var{expr} to the auto-display list but |
c906108c | 7649 | arrange to display it each time in the specified format @var{fmt}. |
79a6e687 | 7650 | @xref{Output Formats,,Output Formats}. |
c906108c SS |
7651 | |
7652 | @item display/@var{fmt} @var{addr} | |
7653 | For @var{fmt} @samp{i} or @samp{s}, or including a unit-size or a | |
7654 | number of units, add the expression @var{addr} as a memory address to | |
7655 | be examined each time your program stops. Examining means in effect | |
79a6e687 | 7656 | doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining Memory}. |
c906108c SS |
7657 | @end table |
7658 | ||
7659 | For example, @samp{display/i $pc} can be helpful, to see the machine | |
7660 | instruction about to be executed each time execution stops (@samp{$pc} | |
d4f3574e | 7661 | is a common name for the program counter; @pxref{Registers, ,Registers}). |
c906108c SS |
7662 | |
7663 | @table @code | |
7664 | @kindex delete display | |
7665 | @kindex undisplay | |
7666 | @item undisplay @var{dnums}@dots{} | |
7667 | @itemx delete display @var{dnums}@dots{} | |
7668 | Remove item numbers @var{dnums} from the list of expressions to display. | |
7669 | ||
7670 | @code{undisplay} does not repeat if you press @key{RET} after using it. | |
7671 | (Otherwise you would just get the error @samp{No display number @dots{}}.) | |
7672 | ||
7673 | @kindex disable display | |
7674 | @item disable display @var{dnums}@dots{} | |
7675 | Disable the display of item numbers @var{dnums}. A disabled display | |
7676 | item is not printed automatically, but is not forgotten. It may be | |
7677 | enabled again later. | |
7678 | ||
7679 | @kindex enable display | |
7680 | @item enable display @var{dnums}@dots{} | |
7681 | Enable display of item numbers @var{dnums}. It becomes effective once | |
7682 | again in auto display of its expression, until you specify otherwise. | |
7683 | ||
7684 | @item display | |
7685 | Display the current values of the expressions on the list, just as is | |
7686 | done when your program stops. | |
7687 | ||
7688 | @kindex info display | |
7689 | @item info display | |
7690 | Print the list of expressions previously set up to display | |
7691 | automatically, each one with its item number, but without showing the | |
7692 | values. This includes disabled expressions, which are marked as such. | |
7693 | It also includes expressions which would not be displayed right now | |
7694 | because they refer to automatic variables not currently available. | |
7695 | @end table | |
7696 | ||
15387254 | 7697 | @cindex display disabled out of scope |
c906108c SS |
7698 | If a display expression refers to local variables, then it does not make |
7699 | sense outside the lexical context for which it was set up. Such an | |
7700 | expression is disabled when execution enters a context where one of its | |
7701 | variables is not defined. For example, if you give the command | |
7702 | @code{display last_char} while inside a function with an argument | |
7703 | @code{last_char}, @value{GDBN} displays this argument while your program | |
7704 | continues to stop inside that function. When it stops elsewhere---where | |
7705 | there is no variable @code{last_char}---the display is disabled | |
7706 | automatically. The next time your program stops where @code{last_char} | |
7707 | is meaningful, you can enable the display expression once again. | |
7708 | ||
6d2ebf8b | 7709 | @node Print Settings |
79a6e687 | 7710 | @section Print Settings |
c906108c SS |
7711 | |
7712 | @cindex format options | |
7713 | @cindex print settings | |
7714 | @value{GDBN} provides the following ways to control how arrays, structures, | |
7715 | and symbols are printed. | |
7716 | ||
7717 | @noindent | |
7718 | These settings are useful for debugging programs in any language: | |
7719 | ||
7720 | @table @code | |
4644b6e3 | 7721 | @kindex set print |
c906108c SS |
7722 | @item set print address |
7723 | @itemx set print address on | |
4644b6e3 | 7724 | @cindex print/don't print memory addresses |
c906108c SS |
7725 | @value{GDBN} prints memory addresses showing the location of stack |
7726 | traces, structure values, pointer values, breakpoints, and so forth, | |
7727 | even when it also displays the contents of those addresses. The default | |
7728 | is @code{on}. For example, this is what a stack frame display looks like with | |
7729 | @code{set print address on}: | |
7730 | ||
7731 | @smallexample | |
7732 | @group | |
7733 | (@value{GDBP}) f | |
7734 | #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>") | |
7735 | at input.c:530 | |
7736 | 530 if (lquote != def_lquote) | |
7737 | @end group | |
7738 | @end smallexample | |
7739 | ||
7740 | @item set print address off | |
7741 | Do not print addresses when displaying their contents. For example, | |
7742 | this is the same stack frame displayed with @code{set print address off}: | |
7743 | ||
7744 | @smallexample | |
7745 | @group | |
7746 | (@value{GDBP}) set print addr off | |
7747 | (@value{GDBP}) f | |
7748 | #0 set_quotes (lq="<<", rq=">>") at input.c:530 | |
7749 | 530 if (lquote != def_lquote) | |
7750 | @end group | |
7751 | @end smallexample | |
7752 | ||
7753 | You can use @samp{set print address off} to eliminate all machine | |
7754 | dependent displays from the @value{GDBN} interface. For example, with | |
7755 | @code{print address off}, you should get the same text for backtraces on | |
7756 | all machines---whether or not they involve pointer arguments. | |
7757 | ||
4644b6e3 | 7758 | @kindex show print |
c906108c SS |
7759 | @item show print address |
7760 | Show whether or not addresses are to be printed. | |
7761 | @end table | |
7762 | ||
7763 | When @value{GDBN} prints a symbolic address, it normally prints the | |
7764 | closest earlier symbol plus an offset. If that symbol does not uniquely | |
7765 | identify the address (for example, it is a name whose scope is a single | |
7766 | source file), you may need to clarify. One way to do this is with | |
7767 | @code{info line}, for example @samp{info line *0x4537}. Alternately, | |
7768 | you can set @value{GDBN} to print the source file and line number when | |
7769 | it prints a symbolic address: | |
7770 | ||
7771 | @table @code | |
c906108c | 7772 | @item set print symbol-filename on |
9c16f35a EZ |
7773 | @cindex source file and line of a symbol |
7774 | @cindex symbol, source file and line | |
c906108c SS |
7775 | Tell @value{GDBN} to print the source file name and line number of a |
7776 | symbol in the symbolic form of an address. | |
7777 | ||
7778 | @item set print symbol-filename off | |
7779 | Do not print source file name and line number of a symbol. This is the | |
7780 | default. | |
7781 | ||
c906108c SS |
7782 | @item show print symbol-filename |
7783 | Show whether or not @value{GDBN} will print the source file name and | |
7784 | line number of a symbol in the symbolic form of an address. | |
7785 | @end table | |
7786 | ||
7787 | Another situation where it is helpful to show symbol filenames and line | |
7788 | numbers is when disassembling code; @value{GDBN} shows you the line | |
7789 | number and source file that corresponds to each instruction. | |
7790 | ||
7791 | Also, you may wish to see the symbolic form only if the address being | |
7792 | printed is reasonably close to the closest earlier symbol: | |
7793 | ||
7794 | @table @code | |
c906108c | 7795 | @item set print max-symbolic-offset @var{max-offset} |
4644b6e3 | 7796 | @cindex maximum value for offset of closest symbol |
c906108c SS |
7797 | Tell @value{GDBN} to only display the symbolic form of an address if the |
7798 | offset between the closest earlier symbol and the address is less than | |
5d161b24 | 7799 | @var{max-offset}. The default is 0, which tells @value{GDBN} |
c906108c SS |
7800 | to always print the symbolic form of an address if any symbol precedes it. |
7801 | ||
c906108c SS |
7802 | @item show print max-symbolic-offset |
7803 | Ask how large the maximum offset is that @value{GDBN} prints in a | |
7804 | symbolic address. | |
7805 | @end table | |
7806 | ||
7807 | @cindex wild pointer, interpreting | |
7808 | @cindex pointer, finding referent | |
7809 | If you have a pointer and you are not sure where it points, try | |
7810 | @samp{set print symbol-filename on}. Then you can determine the name | |
7811 | and source file location of the variable where it points, using | |
7812 | @samp{p/a @var{pointer}}. This interprets the address in symbolic form. | |
7813 | For example, here @value{GDBN} shows that a variable @code{ptt} points | |
7814 | at another variable @code{t}, defined in @file{hi2.c}: | |
7815 | ||
474c8240 | 7816 | @smallexample |
c906108c SS |
7817 | (@value{GDBP}) set print symbol-filename on |
7818 | (@value{GDBP}) p/a ptt | |
7819 | $4 = 0xe008 <t in hi2.c> | |
474c8240 | 7820 | @end smallexample |
c906108c SS |
7821 | |
7822 | @quotation | |
7823 | @emph{Warning:} For pointers that point to a local variable, @samp{p/a} | |
7824 | does not show the symbol name and filename of the referent, even with | |
7825 | the appropriate @code{set print} options turned on. | |
7826 | @end quotation | |
7827 | ||
7828 | Other settings control how different kinds of objects are printed: | |
7829 | ||
7830 | @table @code | |
c906108c SS |
7831 | @item set print array |
7832 | @itemx set print array on | |
4644b6e3 | 7833 | @cindex pretty print arrays |
c906108c SS |
7834 | Pretty print arrays. This format is more convenient to read, |
7835 | but uses more space. The default is off. | |
7836 | ||
7837 | @item set print array off | |
7838 | Return to compressed format for arrays. | |
7839 | ||
c906108c SS |
7840 | @item show print array |
7841 | Show whether compressed or pretty format is selected for displaying | |
7842 | arrays. | |
7843 | ||
3c9c013a JB |
7844 | @cindex print array indexes |
7845 | @item set print array-indexes | |
7846 | @itemx set print array-indexes on | |
7847 | Print the index of each element when displaying arrays. May be more | |
7848 | convenient to locate a given element in the array or quickly find the | |
7849 | index of a given element in that printed array. The default is off. | |
7850 | ||
7851 | @item set print array-indexes off | |
7852 | Stop printing element indexes when displaying arrays. | |
7853 | ||
7854 | @item show print array-indexes | |
7855 | Show whether the index of each element is printed when displaying | |
7856 | arrays. | |
7857 | ||
c906108c | 7858 | @item set print elements @var{number-of-elements} |
4644b6e3 | 7859 | @cindex number of array elements to print |
9c16f35a | 7860 | @cindex limit on number of printed array elements |
c906108c SS |
7861 | Set a limit on how many elements of an array @value{GDBN} will print. |
7862 | If @value{GDBN} is printing a large array, it stops printing after it has | |
7863 | printed the number of elements set by the @code{set print elements} command. | |
7864 | This limit also applies to the display of strings. | |
d4f3574e | 7865 | When @value{GDBN} starts, this limit is set to 200. |
c906108c SS |
7866 | Setting @var{number-of-elements} to zero means that the printing is unlimited. |
7867 | ||
c906108c SS |
7868 | @item show print elements |
7869 | Display the number of elements of a large array that @value{GDBN} will print. | |
7870 | If the number is 0, then the printing is unlimited. | |
7871 | ||
b4740add | 7872 | @item set print frame-arguments @var{value} |
a0381d3a | 7873 | @kindex set print frame-arguments |
b4740add JB |
7874 | @cindex printing frame argument values |
7875 | @cindex print all frame argument values | |
7876 | @cindex print frame argument values for scalars only | |
7877 | @cindex do not print frame argument values | |
7878 | This command allows to control how the values of arguments are printed | |
7879 | when the debugger prints a frame (@pxref{Frames}). The possible | |
7880 | values are: | |
7881 | ||
7882 | @table @code | |
7883 | @item all | |
4f5376b2 | 7884 | The values of all arguments are printed. |
b4740add JB |
7885 | |
7886 | @item scalars | |
7887 | Print the value of an argument only if it is a scalar. The value of more | |
7888 | complex arguments such as arrays, structures, unions, etc, is replaced | |
4f5376b2 JB |
7889 | by @code{@dots{}}. This is the default. Here is an example where |
7890 | only scalar arguments are shown: | |
b4740add JB |
7891 | |
7892 | @smallexample | |
7893 | #1 0x08048361 in call_me (i=3, s=@dots{}, ss=0xbf8d508c, u=@dots{}, e=green) | |
7894 | at frame-args.c:23 | |
7895 | @end smallexample | |
7896 | ||
7897 | @item none | |
7898 | None of the argument values are printed. Instead, the value of each argument | |
7899 | is replaced by @code{@dots{}}. In this case, the example above now becomes: | |
7900 | ||
7901 | @smallexample | |
7902 | #1 0x08048361 in call_me (i=@dots{}, s=@dots{}, ss=@dots{}, u=@dots{}, e=@dots{}) | |
7903 | at frame-args.c:23 | |
7904 | @end smallexample | |
7905 | @end table | |
7906 | ||
4f5376b2 JB |
7907 | By default, only scalar arguments are printed. This command can be used |
7908 | to configure the debugger to print the value of all arguments, regardless | |
7909 | of their type. However, it is often advantageous to not print the value | |
7910 | of more complex parameters. For instance, it reduces the amount of | |
7911 | information printed in each frame, making the backtrace more readable. | |
7912 | Also, it improves performance when displaying Ada frames, because | |
7913 | the computation of large arguments can sometimes be CPU-intensive, | |
7914 | especially in large applications. Setting @code{print frame-arguments} | |
7915 | to @code{scalars} (the default) or @code{none} avoids this computation, | |
7916 | thus speeding up the display of each Ada frame. | |
b4740add JB |
7917 | |
7918 | @item show print frame-arguments | |
7919 | Show how the value of arguments should be displayed when printing a frame. | |
7920 | ||
9c16f35a EZ |
7921 | @item set print repeats |
7922 | @cindex repeated array elements | |
7923 | Set the threshold for suppressing display of repeated array | |
d3e8051b | 7924 | elements. When the number of consecutive identical elements of an |
9c16f35a EZ |
7925 | array exceeds the threshold, @value{GDBN} prints the string |
7926 | @code{"<repeats @var{n} times>"}, where @var{n} is the number of | |
7927 | identical repetitions, instead of displaying the identical elements | |
7928 | themselves. Setting the threshold to zero will cause all elements to | |
7929 | be individually printed. The default threshold is 10. | |
7930 | ||
7931 | @item show print repeats | |
7932 | Display the current threshold for printing repeated identical | |
7933 | elements. | |
7934 | ||
c906108c | 7935 | @item set print null-stop |
4644b6e3 | 7936 | @cindex @sc{null} elements in arrays |
c906108c | 7937 | Cause @value{GDBN} to stop printing the characters of an array when the first |
d4f3574e | 7938 | @sc{null} is encountered. This is useful when large arrays actually |
c906108c | 7939 | contain only short strings. |
d4f3574e | 7940 | The default is off. |
c906108c | 7941 | |
9c16f35a EZ |
7942 | @item show print null-stop |
7943 | Show whether @value{GDBN} stops printing an array on the first | |
7944 | @sc{null} character. | |
7945 | ||
c906108c | 7946 | @item set print pretty on |
9c16f35a EZ |
7947 | @cindex print structures in indented form |
7948 | @cindex indentation in structure display | |
5d161b24 | 7949 | Cause @value{GDBN} to print structures in an indented format with one member |
c906108c SS |
7950 | per line, like this: |
7951 | ||
7952 | @smallexample | |
7953 | @group | |
7954 | $1 = @{ | |
7955 | next = 0x0, | |
7956 | flags = @{ | |
7957 | sweet = 1, | |
7958 | sour = 1 | |
7959 | @}, | |
7960 | meat = 0x54 "Pork" | |
7961 | @} | |
7962 | @end group | |
7963 | @end smallexample | |
7964 | ||
7965 | @item set print pretty off | |
7966 | Cause @value{GDBN} to print structures in a compact format, like this: | |
7967 | ||
7968 | @smallexample | |
7969 | @group | |
7970 | $1 = @{next = 0x0, flags = @{sweet = 1, sour = 1@}, \ | |
7971 | meat = 0x54 "Pork"@} | |
7972 | @end group | |
7973 | @end smallexample | |
7974 | ||
7975 | @noindent | |
7976 | This is the default format. | |
7977 | ||
c906108c SS |
7978 | @item show print pretty |
7979 | Show which format @value{GDBN} is using to print structures. | |
7980 | ||
c906108c | 7981 | @item set print sevenbit-strings on |
4644b6e3 EZ |
7982 | @cindex eight-bit characters in strings |
7983 | @cindex octal escapes in strings | |
c906108c SS |
7984 | Print using only seven-bit characters; if this option is set, |
7985 | @value{GDBN} displays any eight-bit characters (in strings or | |
7986 | character values) using the notation @code{\}@var{nnn}. This setting is | |
7987 | best if you are working in English (@sc{ascii}) and you use the | |
7988 | high-order bit of characters as a marker or ``meta'' bit. | |
7989 | ||
7990 | @item set print sevenbit-strings off | |
7991 | Print full eight-bit characters. This allows the use of more | |
7992 | international character sets, and is the default. | |
7993 | ||
c906108c SS |
7994 | @item show print sevenbit-strings |
7995 | Show whether or not @value{GDBN} is printing only seven-bit characters. | |
7996 | ||
c906108c | 7997 | @item set print union on |
4644b6e3 | 7998 | @cindex unions in structures, printing |
9c16f35a EZ |
7999 | Tell @value{GDBN} to print unions which are contained in structures |
8000 | and other unions. This is the default setting. | |
c906108c SS |
8001 | |
8002 | @item set print union off | |
9c16f35a EZ |
8003 | Tell @value{GDBN} not to print unions which are contained in |
8004 | structures and other unions. @value{GDBN} will print @code{"@{...@}"} | |
8005 | instead. | |
c906108c | 8006 | |
c906108c SS |
8007 | @item show print union |
8008 | Ask @value{GDBN} whether or not it will print unions which are contained in | |
9c16f35a | 8009 | structures and other unions. |
c906108c SS |
8010 | |
8011 | For example, given the declarations | |
8012 | ||
8013 | @smallexample | |
8014 | typedef enum @{Tree, Bug@} Species; | |
8015 | typedef enum @{Big_tree, Acorn, Seedling@} Tree_forms; | |
5d161b24 | 8016 | typedef enum @{Caterpillar, Cocoon, Butterfly@} |
c906108c SS |
8017 | Bug_forms; |
8018 | ||
8019 | struct thing @{ | |
8020 | Species it; | |
8021 | union @{ | |
8022 | Tree_forms tree; | |
8023 | Bug_forms bug; | |
8024 | @} form; | |
8025 | @}; | |
8026 | ||
8027 | struct thing foo = @{Tree, @{Acorn@}@}; | |
8028 | @end smallexample | |
8029 | ||
8030 | @noindent | |
8031 | with @code{set print union on} in effect @samp{p foo} would print | |
8032 | ||
8033 | @smallexample | |
8034 | $1 = @{it = Tree, form = @{tree = Acorn, bug = Cocoon@}@} | |
8035 | @end smallexample | |
8036 | ||
8037 | @noindent | |
8038 | and with @code{set print union off} in effect it would print | |
8039 | ||
8040 | @smallexample | |
8041 | $1 = @{it = Tree, form = @{...@}@} | |
8042 | @end smallexample | |
9c16f35a EZ |
8043 | |
8044 | @noindent | |
8045 | @code{set print union} affects programs written in C-like languages | |
8046 | and in Pascal. | |
c906108c SS |
8047 | @end table |
8048 | ||
c906108c SS |
8049 | @need 1000 |
8050 | @noindent | |
b37052ae | 8051 | These settings are of interest when debugging C@t{++} programs: |
c906108c SS |
8052 | |
8053 | @table @code | |
4644b6e3 | 8054 | @cindex demangling C@t{++} names |
c906108c SS |
8055 | @item set print demangle |
8056 | @itemx set print demangle on | |
b37052ae | 8057 | Print C@t{++} names in their source form rather than in the encoded |
c906108c | 8058 | (``mangled'') form passed to the assembler and linker for type-safe |
d4f3574e | 8059 | linkage. The default is on. |
c906108c | 8060 | |
c906108c | 8061 | @item show print demangle |
b37052ae | 8062 | Show whether C@t{++} names are printed in mangled or demangled form. |
c906108c | 8063 | |
c906108c SS |
8064 | @item set print asm-demangle |
8065 | @itemx set print asm-demangle on | |
b37052ae | 8066 | Print C@t{++} names in their source form rather than their mangled form, even |
c906108c SS |
8067 | in assembler code printouts such as instruction disassemblies. |
8068 | The default is off. | |
8069 | ||
c906108c | 8070 | @item show print asm-demangle |
b37052ae | 8071 | Show whether C@t{++} names in assembly listings are printed in mangled |
c906108c SS |
8072 | or demangled form. |
8073 | ||
b37052ae EZ |
8074 | @cindex C@t{++} symbol decoding style |
8075 | @cindex symbol decoding style, C@t{++} | |
a8f24a35 | 8076 | @kindex set demangle-style |
c906108c SS |
8077 | @item set demangle-style @var{style} |
8078 | Choose among several encoding schemes used by different compilers to | |
b37052ae | 8079 | represent C@t{++} names. The choices for @var{style} are currently: |
c906108c SS |
8080 | |
8081 | @table @code | |
8082 | @item auto | |
8083 | Allow @value{GDBN} to choose a decoding style by inspecting your program. | |
8084 | ||
8085 | @item gnu | |
b37052ae | 8086 | Decode based on the @sc{gnu} C@t{++} compiler (@code{g++}) encoding algorithm. |
c906108c | 8087 | This is the default. |
c906108c SS |
8088 | |
8089 | @item hp | |
b37052ae | 8090 | Decode based on the HP ANSI C@t{++} (@code{aCC}) encoding algorithm. |
c906108c SS |
8091 | |
8092 | @item lucid | |
b37052ae | 8093 | Decode based on the Lucid C@t{++} compiler (@code{lcc}) encoding algorithm. |
c906108c SS |
8094 | |
8095 | @item arm | |
b37052ae | 8096 | Decode using the algorithm in the @cite{C@t{++} Annotated Reference Manual}. |
c906108c SS |
8097 | @strong{Warning:} this setting alone is not sufficient to allow |
8098 | debugging @code{cfront}-generated executables. @value{GDBN} would | |
8099 | require further enhancement to permit that. | |
8100 | ||
8101 | @end table | |
8102 | If you omit @var{style}, you will see a list of possible formats. | |
8103 | ||
c906108c | 8104 | @item show demangle-style |
b37052ae | 8105 | Display the encoding style currently in use for decoding C@t{++} symbols. |
c906108c | 8106 | |
c906108c SS |
8107 | @item set print object |
8108 | @itemx set print object on | |
4644b6e3 | 8109 | @cindex derived type of an object, printing |
9c16f35a | 8110 | @cindex display derived types |
c906108c SS |
8111 | When displaying a pointer to an object, identify the @emph{actual} |
8112 | (derived) type of the object rather than the @emph{declared} type, using | |
8113 | the virtual function table. | |
8114 | ||
8115 | @item set print object off | |
8116 | Display only the declared type of objects, without reference to the | |
8117 | virtual function table. This is the default setting. | |
8118 | ||
c906108c SS |
8119 | @item show print object |
8120 | Show whether actual, or declared, object types are displayed. | |
8121 | ||
c906108c SS |
8122 | @item set print static-members |
8123 | @itemx set print static-members on | |
4644b6e3 | 8124 | @cindex static members of C@t{++} objects |
b37052ae | 8125 | Print static members when displaying a C@t{++} object. The default is on. |
c906108c SS |
8126 | |
8127 | @item set print static-members off | |
b37052ae | 8128 | Do not print static members when displaying a C@t{++} object. |
c906108c | 8129 | |
c906108c | 8130 | @item show print static-members |
9c16f35a EZ |
8131 | Show whether C@t{++} static members are printed or not. |
8132 | ||
8133 | @item set print pascal_static-members | |
8134 | @itemx set print pascal_static-members on | |
d3e8051b EZ |
8135 | @cindex static members of Pascal objects |
8136 | @cindex Pascal objects, static members display | |
9c16f35a EZ |
8137 | Print static members when displaying a Pascal object. The default is on. |
8138 | ||
8139 | @item set print pascal_static-members off | |
8140 | Do not print static members when displaying a Pascal object. | |
8141 | ||
8142 | @item show print pascal_static-members | |
8143 | Show whether Pascal static members are printed or not. | |
c906108c SS |
8144 | |
8145 | @c These don't work with HP ANSI C++ yet. | |
c906108c SS |
8146 | @item set print vtbl |
8147 | @itemx set print vtbl on | |
4644b6e3 | 8148 | @cindex pretty print C@t{++} virtual function tables |
9c16f35a EZ |
8149 | @cindex virtual functions (C@t{++}) display |
8150 | @cindex VTBL display | |
b37052ae | 8151 | Pretty print C@t{++} virtual function tables. The default is off. |
c906108c | 8152 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 8153 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
8154 | |
8155 | @item set print vtbl off | |
b37052ae | 8156 | Do not pretty print C@t{++} virtual function tables. |
c906108c | 8157 | |
c906108c | 8158 | @item show print vtbl |
b37052ae | 8159 | Show whether C@t{++} virtual function tables are pretty printed, or not. |
c906108c | 8160 | @end table |
c906108c | 8161 | |
4c374409 JK |
8162 | @node Pretty Printing |
8163 | @section Pretty Printing | |
8164 | ||
8165 | @value{GDBN} provides a mechanism to allow pretty-printing of values using | |
8166 | Python code. It greatly simplifies the display of complex objects. This | |
8167 | mechanism works for both MI and the CLI. | |
8168 | ||
7b51bc51 DE |
8169 | @menu |
8170 | * Pretty-Printer Introduction:: Introduction to pretty-printers | |
8171 | * Pretty-Printer Example:: An example pretty-printer | |
8172 | * Pretty-Printer Commands:: Pretty-printer commands | |
8173 | @end menu | |
8174 | ||
8175 | @node Pretty-Printer Introduction | |
8176 | @subsection Pretty-Printer Introduction | |
8177 | ||
8178 | When @value{GDBN} prints a value, it first sees if there is a pretty-printer | |
8179 | registered for the value. If there is then @value{GDBN} invokes the | |
8180 | pretty-printer to print the value. Otherwise the value is printed normally. | |
8181 | ||
8182 | Pretty-printers are normally named. This makes them easy to manage. | |
8183 | The @samp{info pretty-printer} command will list all the installed | |
8184 | pretty-printers with their names. | |
8185 | If a pretty-printer can handle multiple data types, then its | |
8186 | @dfn{subprinters} are the printers for the individual data types. | |
8187 | Each such subprinter has its own name. | |
4e04c971 | 8188 | The format of the name is @var{printer-name};@var{subprinter-name}. |
7b51bc51 DE |
8189 | |
8190 | Pretty-printers are installed by @dfn{registering} them with @value{GDBN}. | |
8191 | Typically they are automatically loaded and registered when the corresponding | |
8192 | debug information is loaded, thus making them available without having to | |
8193 | do anything special. | |
8194 | ||
8195 | There are three places where a pretty-printer can be registered. | |
8196 | ||
8197 | @itemize @bullet | |
8198 | @item | |
8199 | Pretty-printers registered globally are available when debugging | |
8200 | all inferiors. | |
8201 | ||
8202 | @item | |
8203 | Pretty-printers registered with a program space are available only | |
8204 | when debugging that program. | |
8205 | @xref{Progspaces In Python}, for more details on program spaces in Python. | |
8206 | ||
8207 | @item | |
8208 | Pretty-printers registered with an objfile are loaded and unloaded | |
8209 | with the corresponding objfile (e.g., shared library). | |
8210 | @xref{Objfiles In Python}, for more details on objfiles in Python. | |
8211 | @end itemize | |
8212 | ||
8213 | @xref{Selecting Pretty-Printers}, for further information on how | |
8214 | pretty-printers are selected, | |
8215 | ||
8216 | @xref{Writing a Pretty-Printer}, for implementing pretty printers | |
8217 | for new types. | |
8218 | ||
8219 | @node Pretty-Printer Example | |
8220 | @subsection Pretty-Printer Example | |
8221 | ||
8222 | Here is how a C@t{++} @code{std::string} looks without a pretty-printer: | |
4c374409 JK |
8223 | |
8224 | @smallexample | |
8225 | (@value{GDBP}) print s | |
8226 | $1 = @{ | |
8227 | static npos = 4294967295, | |
8228 | _M_dataplus = @{ | |
8229 | <std::allocator<char>> = @{ | |
8230 | <__gnu_cxx::new_allocator<char>> = @{ | |
8231 | <No data fields>@}, <No data fields> | |
8232 | @}, | |
8233 | members of std::basic_string<char, std::char_traits<char>, | |
8234 | std::allocator<char> >::_Alloc_hider: | |
8235 | _M_p = 0x804a014 "abcd" | |
8236 | @} | |
8237 | @} | |
8238 | @end smallexample | |
8239 | ||
8240 | With a pretty-printer for @code{std::string} only the contents are printed: | |
8241 | ||
8242 | @smallexample | |
8243 | (@value{GDBP}) print s | |
8244 | $2 = "abcd" | |
8245 | @end smallexample | |
8246 | ||
7b51bc51 DE |
8247 | @node Pretty-Printer Commands |
8248 | @subsection Pretty-Printer Commands | |
8249 | @cindex pretty-printer commands | |
8250 | ||
8251 | @table @code | |
8252 | @kindex info pretty-printer | |
8253 | @item info pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
8254 | Print the list of installed pretty-printers. | |
8255 | This includes disabled pretty-printers, which are marked as such. | |
8256 | ||
8257 | @var{object-regexp} is a regular expression matching the objects | |
8258 | whose pretty-printers to list. | |
8259 | Objects can be @code{global}, the program space's file | |
8260 | (@pxref{Progspaces In Python}), | |
8261 | and the object files within that program space (@pxref{Objfiles In Python}). | |
8262 | @xref{Selecting Pretty-Printers}, for details on how @value{GDBN} | |
8263 | looks up a printer from these three objects. | |
8264 | ||
8265 | @var{name-regexp} is a regular expression matching the name of the printers | |
8266 | to list. | |
8267 | ||
8268 | @kindex disable pretty-printer | |
8269 | @item disable pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
8270 | Disable pretty-printers matching @var{object-regexp} and @var{name-regexp}. | |
8271 | A disabled pretty-printer is not forgotten, it may be enabled again later. | |
8272 | ||
8273 | @kindex enable pretty-printer | |
8274 | @item enable pretty-printer [@var{object-regexp} [@var{name-regexp}]] | |
8275 | Enable pretty-printers matching @var{object-regexp} and @var{name-regexp}. | |
8276 | @end table | |
8277 | ||
8278 | Example: | |
8279 | ||
8280 | Suppose we have three pretty-printers installed: one from library1.so | |
8281 | named @code{foo} that prints objects of type @code{foo}, and | |
8282 | another from library2.so named @code{bar} that prints two types of objects, | |
8283 | @code{bar1} and @code{bar2}. | |
8284 | ||
8285 | @smallexample | |
8286 | (gdb) info pretty-printer | |
8287 | library1.so: | |
8288 | foo | |
8289 | library2.so: | |
8290 | bar | |
8291 | bar1 | |
8292 | bar2 | |
8293 | (gdb) info pretty-printer library2 | |
8294 | library2.so: | |
8295 | bar | |
8296 | bar1 | |
8297 | bar2 | |
8298 | (gdb) disable pretty-printer library1 | |
8299 | 1 printer disabled | |
8300 | 2 of 3 printers enabled | |
8301 | (gdb) info pretty-printer | |
8302 | library1.so: | |
8303 | foo [disabled] | |
8304 | library2.so: | |
8305 | bar | |
8306 | bar1 | |
8307 | bar2 | |
8308 | (gdb) disable pretty-printer library2 bar:bar1 | |
8309 | 1 printer disabled | |
8310 | 1 of 3 printers enabled | |
8311 | (gdb) info pretty-printer library2 | |
8312 | library1.so: | |
8313 | foo [disabled] | |
8314 | library2.so: | |
8315 | bar | |
8316 | bar1 [disabled] | |
8317 | bar2 | |
8318 | (gdb) disable pretty-printer library2 bar | |
8319 | 1 printer disabled | |
8320 | 0 of 3 printers enabled | |
8321 | (gdb) info pretty-printer library2 | |
8322 | library1.so: | |
8323 | foo [disabled] | |
8324 | library2.so: | |
8325 | bar [disabled] | |
8326 | bar1 [disabled] | |
8327 | bar2 | |
8328 | @end smallexample | |
8329 | ||
8330 | Note that for @code{bar} the entire printer can be disabled, | |
8331 | as can each individual subprinter. | |
4c374409 | 8332 | |
6d2ebf8b | 8333 | @node Value History |
79a6e687 | 8334 | @section Value History |
c906108c SS |
8335 | |
8336 | @cindex value history | |
9c16f35a | 8337 | @cindex history of values printed by @value{GDBN} |
5d161b24 DB |
8338 | Values printed by the @code{print} command are saved in the @value{GDBN} |
8339 | @dfn{value history}. This allows you to refer to them in other expressions. | |
8340 | Values are kept until the symbol table is re-read or discarded | |
8341 | (for example with the @code{file} or @code{symbol-file} commands). | |
8342 | When the symbol table changes, the value history is discarded, | |
8343 | since the values may contain pointers back to the types defined in the | |
c906108c SS |
8344 | symbol table. |
8345 | ||
8346 | @cindex @code{$} | |
8347 | @cindex @code{$$} | |
8348 | @cindex history number | |
8349 | The values printed are given @dfn{history numbers} by which you can | |
8350 | refer to them. These are successive integers starting with one. | |
8351 | @code{print} shows you the history number assigned to a value by | |
8352 | printing @samp{$@var{num} = } before the value; here @var{num} is the | |
8353 | history number. | |
8354 | ||
8355 | To refer to any previous value, use @samp{$} followed by the value's | |
8356 | history number. The way @code{print} labels its output is designed to | |
8357 | remind you of this. Just @code{$} refers to the most recent value in | |
8358 | the history, and @code{$$} refers to the value before that. | |
8359 | @code{$$@var{n}} refers to the @var{n}th value from the end; @code{$$2} | |
8360 | is the value just prior to @code{$$}, @code{$$1} is equivalent to | |
8361 | @code{$$}, and @code{$$0} is equivalent to @code{$}. | |
8362 | ||
8363 | For example, suppose you have just printed a pointer to a structure and | |
8364 | want to see the contents of the structure. It suffices to type | |
8365 | ||
474c8240 | 8366 | @smallexample |
c906108c | 8367 | p *$ |
474c8240 | 8368 | @end smallexample |
c906108c SS |
8369 | |
8370 | If you have a chain of structures where the component @code{next} points | |
8371 | to the next one, you can print the contents of the next one with this: | |
8372 | ||
474c8240 | 8373 | @smallexample |
c906108c | 8374 | p *$.next |
474c8240 | 8375 | @end smallexample |
c906108c SS |
8376 | |
8377 | @noindent | |
8378 | You can print successive links in the chain by repeating this | |
8379 | command---which you can do by just typing @key{RET}. | |
8380 | ||
8381 | Note that the history records values, not expressions. If the value of | |
8382 | @code{x} is 4 and you type these commands: | |
8383 | ||
474c8240 | 8384 | @smallexample |
c906108c SS |
8385 | print x |
8386 | set x=5 | |
474c8240 | 8387 | @end smallexample |
c906108c SS |
8388 | |
8389 | @noindent | |
8390 | then the value recorded in the value history by the @code{print} command | |
8391 | remains 4 even though the value of @code{x} has changed. | |
8392 | ||
8393 | @table @code | |
8394 | @kindex show values | |
8395 | @item show values | |
8396 | Print the last ten values in the value history, with their item numbers. | |
8397 | This is like @samp{p@ $$9} repeated ten times, except that @code{show | |
8398 | values} does not change the history. | |
8399 | ||
8400 | @item show values @var{n} | |
8401 | Print ten history values centered on history item number @var{n}. | |
8402 | ||
8403 | @item show values + | |
8404 | Print ten history values just after the values last printed. If no more | |
8405 | values are available, @code{show values +} produces no display. | |
8406 | @end table | |
8407 | ||
8408 | Pressing @key{RET} to repeat @code{show values @var{n}} has exactly the | |
8409 | same effect as @samp{show values +}. | |
8410 | ||
6d2ebf8b | 8411 | @node Convenience Vars |
79a6e687 | 8412 | @section Convenience Variables |
c906108c SS |
8413 | |
8414 | @cindex convenience variables | |
9c16f35a | 8415 | @cindex user-defined variables |
c906108c SS |
8416 | @value{GDBN} provides @dfn{convenience variables} that you can use within |
8417 | @value{GDBN} to hold on to a value and refer to it later. These variables | |
8418 | exist entirely within @value{GDBN}; they are not part of your program, and | |
8419 | setting a convenience variable has no direct effect on further execution | |
8420 | of your program. That is why you can use them freely. | |
8421 | ||
8422 | Convenience variables are prefixed with @samp{$}. Any name preceded by | |
8423 | @samp{$} can be used for a convenience variable, unless it is one of | |
d4f3574e | 8424 | the predefined machine-specific register names (@pxref{Registers, ,Registers}). |
c906108c | 8425 | (Value history references, in contrast, are @emph{numbers} preceded |
79a6e687 | 8426 | by @samp{$}. @xref{Value History, ,Value History}.) |
c906108c SS |
8427 | |
8428 | You can save a value in a convenience variable with an assignment | |
8429 | expression, just as you would set a variable in your program. | |
8430 | For example: | |
8431 | ||
474c8240 | 8432 | @smallexample |
c906108c | 8433 | set $foo = *object_ptr |
474c8240 | 8434 | @end smallexample |
c906108c SS |
8435 | |
8436 | @noindent | |
8437 | would save in @code{$foo} the value contained in the object pointed to by | |
8438 | @code{object_ptr}. | |
8439 | ||
8440 | Using a convenience variable for the first time creates it, but its | |
8441 | value is @code{void} until you assign a new value. You can alter the | |
8442 | value with another assignment at any time. | |
8443 | ||
8444 | Convenience variables have no fixed types. You can assign a convenience | |
8445 | variable any type of value, including structures and arrays, even if | |
8446 | that variable already has a value of a different type. The convenience | |
8447 | variable, when used as an expression, has the type of its current value. | |
8448 | ||
8449 | @table @code | |
8450 | @kindex show convenience | |
9c16f35a | 8451 | @cindex show all user variables |
c906108c SS |
8452 | @item show convenience |
8453 | Print a list of convenience variables used so far, and their values. | |
d4f3574e | 8454 | Abbreviated @code{show conv}. |
53e5f3cf AS |
8455 | |
8456 | @kindex init-if-undefined | |
8457 | @cindex convenience variables, initializing | |
8458 | @item init-if-undefined $@var{variable} = @var{expression} | |
8459 | Set a convenience variable if it has not already been set. This is useful | |
8460 | for user-defined commands that keep some state. It is similar, in concept, | |
8461 | to using local static variables with initializers in C (except that | |
8462 | convenience variables are global). It can also be used to allow users to | |
8463 | override default values used in a command script. | |
8464 | ||
8465 | If the variable is already defined then the expression is not evaluated so | |
8466 | any side-effects do not occur. | |
c906108c SS |
8467 | @end table |
8468 | ||
8469 | One of the ways to use a convenience variable is as a counter to be | |
8470 | incremented or a pointer to be advanced. For example, to print | |
8471 | a field from successive elements of an array of structures: | |
8472 | ||
474c8240 | 8473 | @smallexample |
c906108c SS |
8474 | set $i = 0 |
8475 | print bar[$i++]->contents | |
474c8240 | 8476 | @end smallexample |
c906108c | 8477 | |
d4f3574e SS |
8478 | @noindent |
8479 | Repeat that command by typing @key{RET}. | |
c906108c SS |
8480 | |
8481 | Some convenience variables are created automatically by @value{GDBN} and given | |
8482 | values likely to be useful. | |
8483 | ||
8484 | @table @code | |
41afff9a | 8485 | @vindex $_@r{, convenience variable} |
c906108c SS |
8486 | @item $_ |
8487 | The variable @code{$_} is automatically set by the @code{x} command to | |
79a6e687 | 8488 | the last address examined (@pxref{Memory, ,Examining Memory}). Other |
c906108c SS |
8489 | commands which provide a default address for @code{x} to examine also |
8490 | set @code{$_} to that address; these commands include @code{info line} | |
8491 | and @code{info breakpoint}. The type of @code{$_} is @code{void *} | |
8492 | except when set by the @code{x} command, in which case it is a pointer | |
8493 | to the type of @code{$__}. | |
8494 | ||
41afff9a | 8495 | @vindex $__@r{, convenience variable} |
c906108c SS |
8496 | @item $__ |
8497 | The variable @code{$__} is automatically set by the @code{x} command | |
8498 | to the value found in the last address examined. Its type is chosen | |
8499 | to match the format in which the data was printed. | |
8500 | ||
8501 | @item $_exitcode | |
41afff9a | 8502 | @vindex $_exitcode@r{, convenience variable} |
c906108c SS |
8503 | The variable @code{$_exitcode} is automatically set to the exit code when |
8504 | the program being debugged terminates. | |
4aa995e1 | 8505 | |
0fb4aa4b PA |
8506 | @item $_sdata |
8507 | @vindex $_sdata@r{, inspect, convenience variable} | |
8508 | The variable @code{$_sdata} contains extra collected static tracepoint | |
8509 | data. @xref{Tracepoint Actions,,Tracepoint Action Lists}. Note that | |
8510 | @code{$_sdata} could be empty, if not inspecting a trace buffer, or | |
8511 | if extra static tracepoint data has not been collected. | |
8512 | ||
4aa995e1 PA |
8513 | @item $_siginfo |
8514 | @vindex $_siginfo@r{, convenience variable} | |
ec7e75e7 PP |
8515 | The variable @code{$_siginfo} contains extra signal information |
8516 | (@pxref{extra signal information}). Note that @code{$_siginfo} | |
8517 | could be empty, if the application has not yet received any signals. | |
8518 | For example, it will be empty before you execute the @code{run} command. | |
711e434b PM |
8519 | |
8520 | @item $_tlb | |
8521 | @vindex $_tlb@r{, convenience variable} | |
8522 | The variable @code{$_tlb} is automatically set when debugging | |
8523 | applications running on MS-Windows in native mode or connected to | |
8524 | gdbserver that supports the @code{qGetTIBAddr} request. | |
8525 | @xref{General Query Packets}. | |
8526 | This variable contains the address of the thread information block. | |
8527 | ||
c906108c SS |
8528 | @end table |
8529 | ||
53a5351d JM |
8530 | On HP-UX systems, if you refer to a function or variable name that |
8531 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
8532 | name first, before it searches for a convenience variable. | |
c906108c | 8533 | |
bc3b79fd TJB |
8534 | @cindex convenience functions |
8535 | @value{GDBN} also supplies some @dfn{convenience functions}. These | |
8536 | have a syntax similar to convenience variables. A convenience | |
8537 | function can be used in an expression just like an ordinary function; | |
8538 | however, a convenience function is implemented internally to | |
8539 | @value{GDBN}. | |
8540 | ||
8541 | @table @code | |
8542 | @item help function | |
8543 | @kindex help function | |
8544 | @cindex show all convenience functions | |
8545 | Print a list of all convenience functions. | |
8546 | @end table | |
8547 | ||
6d2ebf8b | 8548 | @node Registers |
c906108c SS |
8549 | @section Registers |
8550 | ||
8551 | @cindex registers | |
8552 | You can refer to machine register contents, in expressions, as variables | |
8553 | with names starting with @samp{$}. The names of registers are different | |
8554 | for each machine; use @code{info registers} to see the names used on | |
8555 | your machine. | |
8556 | ||
8557 | @table @code | |
8558 | @kindex info registers | |
8559 | @item info registers | |
8560 | Print the names and values of all registers except floating-point | |
c85508ee | 8561 | and vector registers (in the selected stack frame). |
c906108c SS |
8562 | |
8563 | @kindex info all-registers | |
8564 | @cindex floating point registers | |
8565 | @item info all-registers | |
8566 | Print the names and values of all registers, including floating-point | |
c85508ee | 8567 | and vector registers (in the selected stack frame). |
c906108c SS |
8568 | |
8569 | @item info registers @var{regname} @dots{} | |
8570 | Print the @dfn{relativized} value of each specified register @var{regname}. | |
5d161b24 DB |
8571 | As discussed in detail below, register values are normally relative to |
8572 | the selected stack frame. @var{regname} may be any register name valid on | |
c906108c SS |
8573 | the machine you are using, with or without the initial @samp{$}. |
8574 | @end table | |
8575 | ||
e09f16f9 EZ |
8576 | @cindex stack pointer register |
8577 | @cindex program counter register | |
8578 | @cindex process status register | |
8579 | @cindex frame pointer register | |
8580 | @cindex standard registers | |
c906108c SS |
8581 | @value{GDBN} has four ``standard'' register names that are available (in |
8582 | expressions) on most machines---whenever they do not conflict with an | |
8583 | architecture's canonical mnemonics for registers. The register names | |
8584 | @code{$pc} and @code{$sp} are used for the program counter register and | |
8585 | the stack pointer. @code{$fp} is used for a register that contains a | |
8586 | pointer to the current stack frame, and @code{$ps} is used for a | |
8587 | register that contains the processor status. For example, | |
8588 | you could print the program counter in hex with | |
8589 | ||
474c8240 | 8590 | @smallexample |
c906108c | 8591 | p/x $pc |
474c8240 | 8592 | @end smallexample |
c906108c SS |
8593 | |
8594 | @noindent | |
8595 | or print the instruction to be executed next with | |
8596 | ||
474c8240 | 8597 | @smallexample |
c906108c | 8598 | x/i $pc |
474c8240 | 8599 | @end smallexample |
c906108c SS |
8600 | |
8601 | @noindent | |
8602 | or add four to the stack pointer@footnote{This is a way of removing | |
8603 | one word from the stack, on machines where stacks grow downward in | |
8604 | memory (most machines, nowadays). This assumes that the innermost | |
8605 | stack frame is selected; setting @code{$sp} is not allowed when other | |
8606 | stack frames are selected. To pop entire frames off the stack, | |
8607 | regardless of machine architecture, use @code{return}; | |
79a6e687 | 8608 | see @ref{Returning, ,Returning from a Function}.} with |
c906108c | 8609 | |
474c8240 | 8610 | @smallexample |
c906108c | 8611 | set $sp += 4 |
474c8240 | 8612 | @end smallexample |
c906108c SS |
8613 | |
8614 | Whenever possible, these four standard register names are available on | |
8615 | your machine even though the machine has different canonical mnemonics, | |
8616 | so long as there is no conflict. The @code{info registers} command | |
8617 | shows the canonical names. For example, on the SPARC, @code{info | |
8618 | registers} displays the processor status register as @code{$psr} but you | |
d4f3574e SS |
8619 | can also refer to it as @code{$ps}; and on x86-based machines @code{$ps} |
8620 | is an alias for the @sc{eflags} register. | |
c906108c SS |
8621 | |
8622 | @value{GDBN} always considers the contents of an ordinary register as an | |
8623 | integer when the register is examined in this way. Some machines have | |
8624 | special registers which can hold nothing but floating point; these | |
8625 | registers are considered to have floating point values. There is no way | |
8626 | to refer to the contents of an ordinary register as floating point value | |
8627 | (although you can @emph{print} it as a floating point value with | |
8628 | @samp{print/f $@var{regname}}). | |
8629 | ||
8630 | Some registers have distinct ``raw'' and ``virtual'' data formats. This | |
8631 | means that the data format in which the register contents are saved by | |
8632 | the operating system is not the same one that your program normally | |
8633 | sees. For example, the registers of the 68881 floating point | |
8634 | coprocessor are always saved in ``extended'' (raw) format, but all C | |
8635 | programs expect to work with ``double'' (virtual) format. In such | |
5d161b24 | 8636 | cases, @value{GDBN} normally works with the virtual format only (the format |
c906108c SS |
8637 | that makes sense for your program), but the @code{info registers} command |
8638 | prints the data in both formats. | |
8639 | ||
36b80e65 EZ |
8640 | @cindex SSE registers (x86) |
8641 | @cindex MMX registers (x86) | |
8642 | Some machines have special registers whose contents can be interpreted | |
8643 | in several different ways. For example, modern x86-based machines | |
8644 | have SSE and MMX registers that can hold several values packed | |
8645 | together in several different formats. @value{GDBN} refers to such | |
8646 | registers in @code{struct} notation: | |
8647 | ||
8648 | @smallexample | |
8649 | (@value{GDBP}) print $xmm1 | |
8650 | $1 = @{ | |
8651 | v4_float = @{0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044@}, | |
8652 | v2_double = @{9.92129282474342e-303, 2.7585945287983262e-313@}, | |
8653 | v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000", | |
8654 | v8_int16 = @{0, 0, 14072, 315, 11, 0, 13, 0@}, | |
8655 | v4_int32 = @{0, 20657912, 11, 13@}, | |
8656 | v2_int64 = @{88725056443645952, 55834574859@}, | |
8657 | uint128 = 0x0000000d0000000b013b36f800000000 | |
8658 | @} | |
8659 | @end smallexample | |
8660 | ||
8661 | @noindent | |
8662 | To set values of such registers, you need to tell @value{GDBN} which | |
8663 | view of the register you wish to change, as if you were assigning | |
8664 | value to a @code{struct} member: | |
8665 | ||
8666 | @smallexample | |
8667 | (@value{GDBP}) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF | |
8668 | @end smallexample | |
8669 | ||
c906108c | 8670 | Normally, register values are relative to the selected stack frame |
79a6e687 | 8671 | (@pxref{Selection, ,Selecting a Frame}). This means that you get the |
c906108c SS |
8672 | value that the register would contain if all stack frames farther in |
8673 | were exited and their saved registers restored. In order to see the | |
8674 | true contents of hardware registers, you must select the innermost | |
8675 | frame (with @samp{frame 0}). | |
8676 | ||
8677 | However, @value{GDBN} must deduce where registers are saved, from the machine | |
8678 | code generated by your compiler. If some registers are not saved, or if | |
8679 | @value{GDBN} is unable to locate the saved registers, the selected stack | |
8680 | frame makes no difference. | |
8681 | ||
6d2ebf8b | 8682 | @node Floating Point Hardware |
79a6e687 | 8683 | @section Floating Point Hardware |
c906108c SS |
8684 | @cindex floating point |
8685 | ||
8686 | Depending on the configuration, @value{GDBN} may be able to give | |
8687 | you more information about the status of the floating point hardware. | |
8688 | ||
8689 | @table @code | |
8690 | @kindex info float | |
8691 | @item info float | |
8692 | Display hardware-dependent information about the floating | |
8693 | point unit. The exact contents and layout vary depending on the | |
8694 | floating point chip. Currently, @samp{info float} is supported on | |
8695 | the ARM and x86 machines. | |
8696 | @end table | |
c906108c | 8697 | |
e76f1f2e AC |
8698 | @node Vector Unit |
8699 | @section Vector Unit | |
8700 | @cindex vector unit | |
8701 | ||
8702 | Depending on the configuration, @value{GDBN} may be able to give you | |
8703 | more information about the status of the vector unit. | |
8704 | ||
8705 | @table @code | |
8706 | @kindex info vector | |
8707 | @item info vector | |
8708 | Display information about the vector unit. The exact contents and | |
8709 | layout vary depending on the hardware. | |
8710 | @end table | |
8711 | ||
721c2651 | 8712 | @node OS Information |
79a6e687 | 8713 | @section Operating System Auxiliary Information |
721c2651 EZ |
8714 | @cindex OS information |
8715 | ||
8716 | @value{GDBN} provides interfaces to useful OS facilities that can help | |
8717 | you debug your program. | |
8718 | ||
8719 | @cindex @code{ptrace} system call | |
8720 | @cindex @code{struct user} contents | |
8721 | When @value{GDBN} runs on a @dfn{Posix system} (such as GNU or Unix | |
8722 | machines), it interfaces with the inferior via the @code{ptrace} | |
8723 | system call. The operating system creates a special sata structure, | |
8724 | called @code{struct user}, for this interface. You can use the | |
8725 | command @code{info udot} to display the contents of this data | |
8726 | structure. | |
8727 | ||
8728 | @table @code | |
8729 | @item info udot | |
8730 | @kindex info udot | |
8731 | Display the contents of the @code{struct user} maintained by the OS | |
8732 | kernel for the program being debugged. @value{GDBN} displays the | |
8733 | contents of @code{struct user} as a list of hex numbers, similar to | |
8734 | the @code{examine} command. | |
8735 | @end table | |
8736 | ||
b383017d RM |
8737 | @cindex auxiliary vector |
8738 | @cindex vector, auxiliary | |
b383017d RM |
8739 | Some operating systems supply an @dfn{auxiliary vector} to programs at |
8740 | startup. This is akin to the arguments and environment that you | |
8741 | specify for a program, but contains a system-dependent variety of | |
8742 | binary values that tell system libraries important details about the | |
8743 | hardware, operating system, and process. Each value's purpose is | |
8744 | identified by an integer tag; the meanings are well-known but system-specific. | |
8745 | Depending on the configuration and operating system facilities, | |
9c16f35a EZ |
8746 | @value{GDBN} may be able to show you this information. For remote |
8747 | targets, this functionality may further depend on the remote stub's | |
427c3a89 DJ |
8748 | support of the @samp{qXfer:auxv:read} packet, see |
8749 | @ref{qXfer auxiliary vector read}. | |
b383017d RM |
8750 | |
8751 | @table @code | |
8752 | @kindex info auxv | |
8753 | @item info auxv | |
8754 | Display the auxiliary vector of the inferior, which can be either a | |
e4937fc1 | 8755 | live process or a core dump file. @value{GDBN} prints each tag value |
b383017d RM |
8756 | numerically, and also shows names and text descriptions for recognized |
8757 | tags. Some values in the vector are numbers, some bit masks, and some | |
e4937fc1 | 8758 | pointers to strings or other data. @value{GDBN} displays each value in the |
b383017d RM |
8759 | most appropriate form for a recognized tag, and in hexadecimal for |
8760 | an unrecognized tag. | |
8761 | @end table | |
8762 | ||
07e059b5 VP |
8763 | On some targets, @value{GDBN} can access operating-system-specific information |
8764 | and display it to user, without interpretation. For remote targets, | |
8765 | this functionality depends on the remote stub's support of the | |
8766 | @samp{qXfer:osdata:read} packet, see @ref{qXfer osdata read}. | |
8767 | ||
8768 | @table @code | |
a61408f8 SS |
8769 | @kindex info os |
8770 | @item info os | |
8771 | List the types of OS information available for the target. If the | |
8772 | target does not return a list of possible types, this command will | |
8773 | report an error. | |
8774 | ||
07e059b5 VP |
8775 | @kindex info os processes |
8776 | @item info os processes | |
8777 | Display the list of processes on the target. For each process, | |
8778 | @value{GDBN} prints the process identifier, the name of the user, and | |
8779 | the command corresponding to the process. | |
8780 | @end table | |
721c2651 | 8781 | |
29e57380 | 8782 | @node Memory Region Attributes |
79a6e687 | 8783 | @section Memory Region Attributes |
29e57380 C |
8784 | @cindex memory region attributes |
8785 | ||
b383017d | 8786 | @dfn{Memory region attributes} allow you to describe special handling |
fd79ecee DJ |
8787 | required by regions of your target's memory. @value{GDBN} uses |
8788 | attributes to determine whether to allow certain types of memory | |
8789 | accesses; whether to use specific width accesses; and whether to cache | |
8790 | target memory. By default the description of memory regions is | |
8791 | fetched from the target (if the current target supports this), but the | |
8792 | user can override the fetched regions. | |
29e57380 C |
8793 | |
8794 | Defined memory regions can be individually enabled and disabled. When a | |
8795 | memory region is disabled, @value{GDBN} uses the default attributes when | |
8796 | accessing memory in that region. Similarly, if no memory regions have | |
8797 | been defined, @value{GDBN} uses the default attributes when accessing | |
8798 | all memory. | |
8799 | ||
b383017d | 8800 | When a memory region is defined, it is given a number to identify it; |
29e57380 C |
8801 | to enable, disable, or remove a memory region, you specify that number. |
8802 | ||
8803 | @table @code | |
8804 | @kindex mem | |
bfac230e | 8805 | @item mem @var{lower} @var{upper} @var{attributes}@dots{} |
09d4efe1 EZ |
8806 | Define a memory region bounded by @var{lower} and @var{upper} with |
8807 | attributes @var{attributes}@dots{}, and add it to the list of regions | |
8808 | monitored by @value{GDBN}. Note that @var{upper} == 0 is a special | |
d3e8051b | 8809 | case: it is treated as the target's maximum memory address. |
bfac230e | 8810 | (0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.) |
29e57380 | 8811 | |
fd79ecee DJ |
8812 | @item mem auto |
8813 | Discard any user changes to the memory regions and use target-supplied | |
8814 | regions, if available, or no regions if the target does not support. | |
8815 | ||
29e57380 C |
8816 | @kindex delete mem |
8817 | @item delete mem @var{nums}@dots{} | |
09d4efe1 EZ |
8818 | Remove memory regions @var{nums}@dots{} from the list of regions |
8819 | monitored by @value{GDBN}. | |
29e57380 C |
8820 | |
8821 | @kindex disable mem | |
8822 | @item disable mem @var{nums}@dots{} | |
09d4efe1 | 8823 | Disable monitoring of memory regions @var{nums}@dots{}. |
b383017d | 8824 | A disabled memory region is not forgotten. |
29e57380 C |
8825 | It may be enabled again later. |
8826 | ||
8827 | @kindex enable mem | |
8828 | @item enable mem @var{nums}@dots{} | |
09d4efe1 | 8829 | Enable monitoring of memory regions @var{nums}@dots{}. |
29e57380 C |
8830 | |
8831 | @kindex info mem | |
8832 | @item info mem | |
8833 | Print a table of all defined memory regions, with the following columns | |
09d4efe1 | 8834 | for each region: |
29e57380 C |
8835 | |
8836 | @table @emph | |
8837 | @item Memory Region Number | |
8838 | @item Enabled or Disabled. | |
b383017d | 8839 | Enabled memory regions are marked with @samp{y}. |
29e57380 C |
8840 | Disabled memory regions are marked with @samp{n}. |
8841 | ||
8842 | @item Lo Address | |
8843 | The address defining the inclusive lower bound of the memory region. | |
8844 | ||
8845 | @item Hi Address | |
8846 | The address defining the exclusive upper bound of the memory region. | |
8847 | ||
8848 | @item Attributes | |
8849 | The list of attributes set for this memory region. | |
8850 | @end table | |
8851 | @end table | |
8852 | ||
8853 | ||
8854 | @subsection Attributes | |
8855 | ||
b383017d | 8856 | @subsubsection Memory Access Mode |
29e57380 C |
8857 | The access mode attributes set whether @value{GDBN} may make read or |
8858 | write accesses to a memory region. | |
8859 | ||
8860 | While these attributes prevent @value{GDBN} from performing invalid | |
8861 | memory accesses, they do nothing to prevent the target system, I/O DMA, | |
359df76b | 8862 | etc.@: from accessing memory. |
29e57380 C |
8863 | |
8864 | @table @code | |
8865 | @item ro | |
8866 | Memory is read only. | |
8867 | @item wo | |
8868 | Memory is write only. | |
8869 | @item rw | |
6ca652b0 | 8870 | Memory is read/write. This is the default. |
29e57380 C |
8871 | @end table |
8872 | ||
8873 | @subsubsection Memory Access Size | |
d3e8051b | 8874 | The access size attribute tells @value{GDBN} to use specific sized |
29e57380 C |
8875 | accesses in the memory region. Often memory mapped device registers |
8876 | require specific sized accesses. If no access size attribute is | |
8877 | specified, @value{GDBN} may use accesses of any size. | |
8878 | ||
8879 | @table @code | |
8880 | @item 8 | |
8881 | Use 8 bit memory accesses. | |
8882 | @item 16 | |
8883 | Use 16 bit memory accesses. | |
8884 | @item 32 | |
8885 | Use 32 bit memory accesses. | |
8886 | @item 64 | |
8887 | Use 64 bit memory accesses. | |
8888 | @end table | |
8889 | ||
8890 | @c @subsubsection Hardware/Software Breakpoints | |
8891 | @c The hardware/software breakpoint attributes set whether @value{GDBN} | |
8892 | @c will use hardware or software breakpoints for the internal breakpoints | |
8893 | @c used by the step, next, finish, until, etc. commands. | |
8894 | @c | |
8895 | @c @table @code | |
8896 | @c @item hwbreak | |
b383017d | 8897 | @c Always use hardware breakpoints |
29e57380 C |
8898 | @c @item swbreak (default) |
8899 | @c @end table | |
8900 | ||
8901 | @subsubsection Data Cache | |
8902 | The data cache attributes set whether @value{GDBN} will cache target | |
8903 | memory. While this generally improves performance by reducing debug | |
8904 | protocol overhead, it can lead to incorrect results because @value{GDBN} | |
8905 | does not know about volatile variables or memory mapped device | |
8906 | registers. | |
8907 | ||
8908 | @table @code | |
8909 | @item cache | |
b383017d | 8910 | Enable @value{GDBN} to cache target memory. |
6ca652b0 EZ |
8911 | @item nocache |
8912 | Disable @value{GDBN} from caching target memory. This is the default. | |
29e57380 C |
8913 | @end table |
8914 | ||
4b5752d0 VP |
8915 | @subsection Memory Access Checking |
8916 | @value{GDBN} can be instructed to refuse accesses to memory that is | |
8917 | not explicitly described. This can be useful if accessing such | |
8918 | regions has undesired effects for a specific target, or to provide | |
8919 | better error checking. The following commands control this behaviour. | |
8920 | ||
8921 | @table @code | |
8922 | @kindex set mem inaccessible-by-default | |
8923 | @item set mem inaccessible-by-default [on|off] | |
8924 | If @code{on} is specified, make @value{GDBN} treat memory not | |
8925 | explicitly described by the memory ranges as non-existent and refuse accesses | |
8926 | to such memory. The checks are only performed if there's at least one | |
8927 | memory range defined. If @code{off} is specified, make @value{GDBN} | |
8928 | treat the memory not explicitly described by the memory ranges as RAM. | |
56cf5405 | 8929 | The default value is @code{on}. |
4b5752d0 VP |
8930 | @kindex show mem inaccessible-by-default |
8931 | @item show mem inaccessible-by-default | |
8932 | Show the current handling of accesses to unknown memory. | |
8933 | @end table | |
8934 | ||
8935 | ||
29e57380 | 8936 | @c @subsubsection Memory Write Verification |
b383017d | 8937 | @c The memory write verification attributes set whether @value{GDBN} |
29e57380 C |
8938 | @c will re-reads data after each write to verify the write was successful. |
8939 | @c | |
8940 | @c @table @code | |
8941 | @c @item verify | |
8942 | @c @item noverify (default) | |
8943 | @c @end table | |
8944 | ||
16d9dec6 | 8945 | @node Dump/Restore Files |
79a6e687 | 8946 | @section Copy Between Memory and a File |
16d9dec6 MS |
8947 | @cindex dump/restore files |
8948 | @cindex append data to a file | |
8949 | @cindex dump data to a file | |
8950 | @cindex restore data from a file | |
16d9dec6 | 8951 | |
df5215a6 JB |
8952 | You can use the commands @code{dump}, @code{append}, and |
8953 | @code{restore} to copy data between target memory and a file. The | |
8954 | @code{dump} and @code{append} commands write data to a file, and the | |
8955 | @code{restore} command reads data from a file back into the inferior's | |
8956 | memory. Files may be in binary, Motorola S-record, Intel hex, or | |
8957 | Tektronix Hex format; however, @value{GDBN} can only append to binary | |
8958 | files. | |
8959 | ||
8960 | @table @code | |
8961 | ||
8962 | @kindex dump | |
8963 | @item dump @r{[}@var{format}@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
8964 | @itemx dump @r{[}@var{format}@r{]} value @var{filename} @var{expr} | |
8965 | Dump the contents of memory from @var{start_addr} to @var{end_addr}, | |
8966 | or the value of @var{expr}, to @var{filename} in the given format. | |
16d9dec6 | 8967 | |
df5215a6 | 8968 | The @var{format} parameter may be any one of: |
16d9dec6 | 8969 | @table @code |
df5215a6 JB |
8970 | @item binary |
8971 | Raw binary form. | |
8972 | @item ihex | |
8973 | Intel hex format. | |
8974 | @item srec | |
8975 | Motorola S-record format. | |
8976 | @item tekhex | |
8977 | Tektronix Hex format. | |
8978 | @end table | |
8979 | ||
8980 | @value{GDBN} uses the same definitions of these formats as the | |
8981 | @sc{gnu} binary utilities, like @samp{objdump} and @samp{objcopy}. If | |
8982 | @var{format} is omitted, @value{GDBN} dumps the data in raw binary | |
8983 | form. | |
8984 | ||
8985 | @kindex append | |
8986 | @item append @r{[}binary@r{]} memory @var{filename} @var{start_addr} @var{end_addr} | |
8987 | @itemx append @r{[}binary@r{]} value @var{filename} @var{expr} | |
8988 | Append the contents of memory from @var{start_addr} to @var{end_addr}, | |
09d4efe1 | 8989 | or the value of @var{expr}, to the file @var{filename}, in raw binary form. |
df5215a6 JB |
8990 | (@value{GDBN} can only append data to files in raw binary form.) |
8991 | ||
8992 | @kindex restore | |
8993 | @item restore @var{filename} @r{[}binary@r{]} @var{bias} @var{start} @var{end} | |
8994 | Restore the contents of file @var{filename} into memory. The | |
8995 | @code{restore} command can automatically recognize any known @sc{bfd} | |
8996 | file format, except for raw binary. To restore a raw binary file you | |
8997 | must specify the optional keyword @code{binary} after the filename. | |
16d9dec6 | 8998 | |
b383017d | 8999 | If @var{bias} is non-zero, its value will be added to the addresses |
16d9dec6 MS |
9000 | contained in the file. Binary files always start at address zero, so |
9001 | they will be restored at address @var{bias}. Other bfd files have | |
9002 | a built-in location; they will be restored at offset @var{bias} | |
9003 | from that location. | |
9004 | ||
9005 | If @var{start} and/or @var{end} are non-zero, then only data between | |
9006 | file offset @var{start} and file offset @var{end} will be restored. | |
b383017d | 9007 | These offsets are relative to the addresses in the file, before |
16d9dec6 MS |
9008 | the @var{bias} argument is applied. |
9009 | ||
9010 | @end table | |
9011 | ||
384ee23f EZ |
9012 | @node Core File Generation |
9013 | @section How to Produce a Core File from Your Program | |
9014 | @cindex dump core from inferior | |
9015 | ||
9016 | A @dfn{core file} or @dfn{core dump} is a file that records the memory | |
9017 | image of a running process and its process status (register values | |
9018 | etc.). Its primary use is post-mortem debugging of a program that | |
9019 | crashed while it ran outside a debugger. A program that crashes | |
9020 | automatically produces a core file, unless this feature is disabled by | |
9021 | the user. @xref{Files}, for information on invoking @value{GDBN} in | |
9022 | the post-mortem debugging mode. | |
9023 | ||
9024 | Occasionally, you may wish to produce a core file of the program you | |
9025 | are debugging in order to preserve a snapshot of its state. | |
9026 | @value{GDBN} has a special command for that. | |
9027 | ||
9028 | @table @code | |
9029 | @kindex gcore | |
9030 | @kindex generate-core-file | |
9031 | @item generate-core-file [@var{file}] | |
9032 | @itemx gcore [@var{file}] | |
9033 | Produce a core dump of the inferior process. The optional argument | |
9034 | @var{file} specifies the file name where to put the core dump. If not | |
9035 | specified, the file name defaults to @file{core.@var{pid}}, where | |
9036 | @var{pid} is the inferior process ID. | |
9037 | ||
9038 | Note that this command is implemented only for some systems (as of | |
9039 | this writing, @sc{gnu}/Linux, FreeBSD, Solaris, Unixware, and S390). | |
9040 | @end table | |
9041 | ||
a0eb71c5 KB |
9042 | @node Character Sets |
9043 | @section Character Sets | |
9044 | @cindex character sets | |
9045 | @cindex charset | |
9046 | @cindex translating between character sets | |
9047 | @cindex host character set | |
9048 | @cindex target character set | |
9049 | ||
9050 | If the program you are debugging uses a different character set to | |
9051 | represent characters and strings than the one @value{GDBN} uses itself, | |
9052 | @value{GDBN} can automatically translate between the character sets for | |
9053 | you. The character set @value{GDBN} uses we call the @dfn{host | |
9054 | character set}; the one the inferior program uses we call the | |
9055 | @dfn{target character set}. | |
9056 | ||
9057 | For example, if you are running @value{GDBN} on a @sc{gnu}/Linux system, which | |
9058 | uses the ISO Latin 1 character set, but you are using @value{GDBN}'s | |
ea35711c | 9059 | remote protocol (@pxref{Remote Debugging}) to debug a program |
a0eb71c5 KB |
9060 | running on an IBM mainframe, which uses the @sc{ebcdic} character set, |
9061 | then the host character set is Latin-1, and the target character set is | |
9062 | @sc{ebcdic}. If you give @value{GDBN} the command @code{set | |
e33d66ec | 9063 | target-charset EBCDIC-US}, then @value{GDBN} translates between |
a0eb71c5 KB |
9064 | @sc{ebcdic} and Latin 1 as you print character or string values, or use |
9065 | character and string literals in expressions. | |
9066 | ||
9067 | @value{GDBN} has no way to automatically recognize which character set | |
9068 | the inferior program uses; you must tell it, using the @code{set | |
9069 | target-charset} command, described below. | |
9070 | ||
9071 | Here are the commands for controlling @value{GDBN}'s character set | |
9072 | support: | |
9073 | ||
9074 | @table @code | |
9075 | @item set target-charset @var{charset} | |
9076 | @kindex set target-charset | |
10af6951 EZ |
9077 | Set the current target character set to @var{charset}. To display the |
9078 | list of supported target character sets, type | |
9079 | @kbd{@w{set target-charset @key{TAB}@key{TAB}}}. | |
a0eb71c5 | 9080 | |
a0eb71c5 KB |
9081 | @item set host-charset @var{charset} |
9082 | @kindex set host-charset | |
9083 | Set the current host character set to @var{charset}. | |
9084 | ||
9085 | By default, @value{GDBN} uses a host character set appropriate to the | |
9086 | system it is running on; you can override that default using the | |
732f6a93 TT |
9087 | @code{set host-charset} command. On some systems, @value{GDBN} cannot |
9088 | automatically determine the appropriate host character set. In this | |
9089 | case, @value{GDBN} uses @samp{UTF-8}. | |
a0eb71c5 KB |
9090 | |
9091 | @value{GDBN} can only use certain character sets as its host character | |
c1b6b909 | 9092 | set. If you type @kbd{@w{set host-charset @key{TAB}@key{TAB}}}, |
10af6951 | 9093 | @value{GDBN} will list the host character sets it supports. |
a0eb71c5 KB |
9094 | |
9095 | @item set charset @var{charset} | |
9096 | @kindex set charset | |
e33d66ec | 9097 | Set the current host and target character sets to @var{charset}. As |
10af6951 EZ |
9098 | above, if you type @kbd{@w{set charset @key{TAB}@key{TAB}}}, |
9099 | @value{GDBN} will list the names of the character sets that can be used | |
e33d66ec EZ |
9100 | for both host and target. |
9101 | ||
a0eb71c5 | 9102 | @item show charset |
a0eb71c5 | 9103 | @kindex show charset |
10af6951 | 9104 | Show the names of the current host and target character sets. |
e33d66ec | 9105 | |
10af6951 | 9106 | @item show host-charset |
a0eb71c5 | 9107 | @kindex show host-charset |
10af6951 | 9108 | Show the name of the current host character set. |
e33d66ec | 9109 | |
10af6951 | 9110 | @item show target-charset |
a0eb71c5 | 9111 | @kindex show target-charset |
10af6951 | 9112 | Show the name of the current target character set. |
a0eb71c5 | 9113 | |
10af6951 EZ |
9114 | @item set target-wide-charset @var{charset} |
9115 | @kindex set target-wide-charset | |
9116 | Set the current target's wide character set to @var{charset}. This is | |
9117 | the character set used by the target's @code{wchar_t} type. To | |
9118 | display the list of supported wide character sets, type | |
9119 | @kbd{@w{set target-wide-charset @key{TAB}@key{TAB}}}. | |
9120 | ||
9121 | @item show target-wide-charset | |
9122 | @kindex show target-wide-charset | |
9123 | Show the name of the current target's wide character set. | |
a0eb71c5 KB |
9124 | @end table |
9125 | ||
a0eb71c5 KB |
9126 | Here is an example of @value{GDBN}'s character set support in action. |
9127 | Assume that the following source code has been placed in the file | |
9128 | @file{charset-test.c}: | |
9129 | ||
9130 | @smallexample | |
9131 | #include <stdio.h> | |
9132 | ||
9133 | char ascii_hello[] | |
9134 | = @{72, 101, 108, 108, 111, 44, 32, 119, | |
9135 | 111, 114, 108, 100, 33, 10, 0@}; | |
9136 | char ibm1047_hello[] | |
9137 | = @{200, 133, 147, 147, 150, 107, 64, 166, | |
9138 | 150, 153, 147, 132, 90, 37, 0@}; | |
9139 | ||
9140 | main () | |
9141 | @{ | |
9142 | printf ("Hello, world!\n"); | |
9143 | @} | |
10998722 | 9144 | @end smallexample |
a0eb71c5 KB |
9145 | |
9146 | In this program, @code{ascii_hello} and @code{ibm1047_hello} are arrays | |
9147 | containing the string @samp{Hello, world!} followed by a newline, | |
9148 | encoded in the @sc{ascii} and @sc{ibm1047} character sets. | |
9149 | ||
9150 | We compile the program, and invoke the debugger on it: | |
9151 | ||
9152 | @smallexample | |
9153 | $ gcc -g charset-test.c -o charset-test | |
9154 | $ gdb -nw charset-test | |
9155 | GNU gdb 2001-12-19-cvs | |
9156 | Copyright 2001 Free Software Foundation, Inc. | |
9157 | @dots{} | |
f7dc1244 | 9158 | (@value{GDBP}) |
10998722 | 9159 | @end smallexample |
a0eb71c5 KB |
9160 | |
9161 | We can use the @code{show charset} command to see what character sets | |
9162 | @value{GDBN} is currently using to interpret and display characters and | |
9163 | strings: | |
9164 | ||
9165 | @smallexample | |
f7dc1244 | 9166 | (@value{GDBP}) show charset |
e33d66ec | 9167 | The current host and target character set is `ISO-8859-1'. |
f7dc1244 | 9168 | (@value{GDBP}) |
10998722 | 9169 | @end smallexample |
a0eb71c5 KB |
9170 | |
9171 | For the sake of printing this manual, let's use @sc{ascii} as our | |
9172 | initial character set: | |
9173 | @smallexample | |
f7dc1244 EZ |
9174 | (@value{GDBP}) set charset ASCII |
9175 | (@value{GDBP}) show charset | |
e33d66ec | 9176 | The current host and target character set is `ASCII'. |
f7dc1244 | 9177 | (@value{GDBP}) |
10998722 | 9178 | @end smallexample |
a0eb71c5 KB |
9179 | |
9180 | Let's assume that @sc{ascii} is indeed the correct character set for our | |
9181 | host system --- in other words, let's assume that if @value{GDBN} prints | |
9182 | characters using the @sc{ascii} character set, our terminal will display | |
9183 | them properly. Since our current target character set is also | |
9184 | @sc{ascii}, the contents of @code{ascii_hello} print legibly: | |
9185 | ||
9186 | @smallexample | |
f7dc1244 | 9187 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 9188 | $1 = 0x401698 "Hello, world!\n" |
f7dc1244 | 9189 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 9190 | $2 = 72 'H' |
f7dc1244 | 9191 | (@value{GDBP}) |
10998722 | 9192 | @end smallexample |
a0eb71c5 KB |
9193 | |
9194 | @value{GDBN} uses the target character set for character and string | |
9195 | literals you use in expressions: | |
9196 | ||
9197 | @smallexample | |
f7dc1244 | 9198 | (@value{GDBP}) print '+' |
a0eb71c5 | 9199 | $3 = 43 '+' |
f7dc1244 | 9200 | (@value{GDBP}) |
10998722 | 9201 | @end smallexample |
a0eb71c5 KB |
9202 | |
9203 | The @sc{ascii} character set uses the number 43 to encode the @samp{+} | |
9204 | character. | |
9205 | ||
9206 | @value{GDBN} relies on the user to tell it which character set the | |
9207 | target program uses. If we print @code{ibm1047_hello} while our target | |
9208 | character set is still @sc{ascii}, we get jibberish: | |
9209 | ||
9210 | @smallexample | |
f7dc1244 | 9211 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 9212 | $4 = 0x4016a8 "\310\205\223\223\226k@@\246\226\231\223\204Z%" |
f7dc1244 | 9213 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 9214 | $5 = 200 '\310' |
f7dc1244 | 9215 | (@value{GDBP}) |
10998722 | 9216 | @end smallexample |
a0eb71c5 | 9217 | |
e33d66ec | 9218 | If we invoke the @code{set target-charset} followed by @key{TAB}@key{TAB}, |
a0eb71c5 KB |
9219 | @value{GDBN} tells us the character sets it supports: |
9220 | ||
9221 | @smallexample | |
f7dc1244 | 9222 | (@value{GDBP}) set target-charset |
b383017d | 9223 | ASCII EBCDIC-US IBM1047 ISO-8859-1 |
f7dc1244 | 9224 | (@value{GDBP}) set target-charset |
10998722 | 9225 | @end smallexample |
a0eb71c5 KB |
9226 | |
9227 | We can select @sc{ibm1047} as our target character set, and examine the | |
9228 | program's strings again. Now the @sc{ascii} string is wrong, but | |
9229 | @value{GDBN} translates the contents of @code{ibm1047_hello} from the | |
9230 | target character set, @sc{ibm1047}, to the host character set, | |
9231 | @sc{ascii}, and they display correctly: | |
9232 | ||
9233 | @smallexample | |
f7dc1244 EZ |
9234 | (@value{GDBP}) set target-charset IBM1047 |
9235 | (@value{GDBP}) show charset | |
e33d66ec EZ |
9236 | The current host character set is `ASCII'. |
9237 | The current target character set is `IBM1047'. | |
f7dc1244 | 9238 | (@value{GDBP}) print ascii_hello |
a0eb71c5 | 9239 | $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012" |
f7dc1244 | 9240 | (@value{GDBP}) print ascii_hello[0] |
a0eb71c5 | 9241 | $7 = 72 '\110' |
f7dc1244 | 9242 | (@value{GDBP}) print ibm1047_hello |
a0eb71c5 | 9243 | $8 = 0x4016a8 "Hello, world!\n" |
f7dc1244 | 9244 | (@value{GDBP}) print ibm1047_hello[0] |
a0eb71c5 | 9245 | $9 = 200 'H' |
f7dc1244 | 9246 | (@value{GDBP}) |
10998722 | 9247 | @end smallexample |
a0eb71c5 KB |
9248 | |
9249 | As above, @value{GDBN} uses the target character set for character and | |
9250 | string literals you use in expressions: | |
9251 | ||
9252 | @smallexample | |
f7dc1244 | 9253 | (@value{GDBP}) print '+' |
a0eb71c5 | 9254 | $10 = 78 '+' |
f7dc1244 | 9255 | (@value{GDBP}) |
10998722 | 9256 | @end smallexample |
a0eb71c5 | 9257 | |
e33d66ec | 9258 | The @sc{ibm1047} character set uses the number 78 to encode the @samp{+} |
a0eb71c5 KB |
9259 | character. |
9260 | ||
09d4efe1 EZ |
9261 | @node Caching Remote Data |
9262 | @section Caching Data of Remote Targets | |
9263 | @cindex caching data of remote targets | |
9264 | ||
4e5d721f | 9265 | @value{GDBN} caches data exchanged between the debugger and a |
ea35711c | 9266 | remote target (@pxref{Remote Debugging}). Such caching generally improves |
09d4efe1 | 9267 | performance, because it reduces the overhead of the remote protocol by |
4e5d721f DE |
9268 | bundling memory reads and writes into large chunks. Unfortunately, simply |
9269 | caching everything would lead to incorrect results, since @value{GDBN} | |
9270 | does not necessarily know anything about volatile values, memory-mapped I/O | |
29b090c0 DE |
9271 | addresses, etc. Furthermore, in non-stop mode (@pxref{Non-Stop Mode}) |
9272 | memory can be changed @emph{while} a gdb command is executing. | |
9273 | Therefore, by default, @value{GDBN} only caches data | |
9274 | known to be on the stack@footnote{In non-stop mode, it is moderately | |
9275 | rare for a running thread to modify the stack of a stopped thread | |
9276 | in a way that would interfere with a backtrace, and caching of | |
9277 | stack reads provides a significant speed up of remote backtraces.}. | |
9278 | Other regions of memory can be explicitly marked as | |
4e5d721f | 9279 | cacheable; see @pxref{Memory Region Attributes}. |
09d4efe1 EZ |
9280 | |
9281 | @table @code | |
9282 | @kindex set remotecache | |
9283 | @item set remotecache on | |
9284 | @itemx set remotecache off | |
4e5d721f DE |
9285 | This option no longer does anything; it exists for compatibility |
9286 | with old scripts. | |
09d4efe1 EZ |
9287 | |
9288 | @kindex show remotecache | |
9289 | @item show remotecache | |
4e5d721f DE |
9290 | Show the current state of the obsolete remotecache flag. |
9291 | ||
9292 | @kindex set stack-cache | |
9293 | @item set stack-cache on | |
9294 | @itemx set stack-cache off | |
9295 | Enable or disable caching of stack accesses. When @code{ON}, use | |
9296 | caching. By default, this option is @code{ON}. | |
9297 | ||
9298 | @kindex show stack-cache | |
9299 | @item show stack-cache | |
9300 | Show the current state of data caching for memory accesses. | |
09d4efe1 EZ |
9301 | |
9302 | @kindex info dcache | |
4e5d721f | 9303 | @item info dcache @r{[}line@r{]} |
09d4efe1 | 9304 | Print the information about the data cache performance. The |
4e5d721f DE |
9305 | information displayed includes the dcache width and depth, and for |
9306 | each cache line, its number, address, and how many times it was | |
9307 | referenced. This command is useful for debugging the data cache | |
9308 | operation. | |
9309 | ||
9310 | If a line number is specified, the contents of that line will be | |
9311 | printed in hex. | |
09d4efe1 EZ |
9312 | @end table |
9313 | ||
08388c79 DE |
9314 | @node Searching Memory |
9315 | @section Search Memory | |
9316 | @cindex searching memory | |
9317 | ||
9318 | Memory can be searched for a particular sequence of bytes with the | |
9319 | @code{find} command. | |
9320 | ||
9321 | @table @code | |
9322 | @kindex find | |
9323 | @item find @r{[}/@var{sn}@r{]} @var{start_addr}, +@var{len}, @var{val1} @r{[}, @var{val2}, @dots{}@r{]} | |
9324 | @itemx find @r{[}/@var{sn}@r{]} @var{start_addr}, @var{end_addr}, @var{val1} @r{[}, @var{val2}, @dots{}@r{]} | |
9325 | Search memory for the sequence of bytes specified by @var{val1}, @var{val2}, | |
9326 | etc. The search begins at address @var{start_addr} and continues for either | |
9327 | @var{len} bytes or through to @var{end_addr} inclusive. | |
9328 | @end table | |
9329 | ||
9330 | @var{s} and @var{n} are optional parameters. | |
9331 | They may be specified in either order, apart or together. | |
9332 | ||
9333 | @table @r | |
9334 | @item @var{s}, search query size | |
9335 | The size of each search query value. | |
9336 | ||
9337 | @table @code | |
9338 | @item b | |
9339 | bytes | |
9340 | @item h | |
9341 | halfwords (two bytes) | |
9342 | @item w | |
9343 | words (four bytes) | |
9344 | @item g | |
9345 | giant words (eight bytes) | |
9346 | @end table | |
9347 | ||
9348 | All values are interpreted in the current language. | |
9349 | This means, for example, that if the current source language is C/C@t{++} | |
9350 | then searching for the string ``hello'' includes the trailing '\0'. | |
9351 | ||
9352 | If the value size is not specified, it is taken from the | |
9353 | value's type in the current language. | |
9354 | This is useful when one wants to specify the search | |
9355 | pattern as a mixture of types. | |
9356 | Note that this means, for example, that in the case of C-like languages | |
9357 | a search for an untyped 0x42 will search for @samp{(int) 0x42} | |
9358 | which is typically four bytes. | |
9359 | ||
9360 | @item @var{n}, maximum number of finds | |
9361 | The maximum number of matches to print. The default is to print all finds. | |
9362 | @end table | |
9363 | ||
9364 | You can use strings as search values. Quote them with double-quotes | |
9365 | (@code{"}). | |
9366 | The string value is copied into the search pattern byte by byte, | |
9367 | regardless of the endianness of the target and the size specification. | |
9368 | ||
9369 | The address of each match found is printed as well as a count of the | |
9370 | number of matches found. | |
9371 | ||
9372 | The address of the last value found is stored in convenience variable | |
9373 | @samp{$_}. | |
9374 | A count of the number of matches is stored in @samp{$numfound}. | |
9375 | ||
9376 | For example, if stopped at the @code{printf} in this function: | |
9377 | ||
9378 | @smallexample | |
9379 | void | |
9380 | hello () | |
9381 | @{ | |
9382 | static char hello[] = "hello-hello"; | |
9383 | static struct @{ char c; short s; int i; @} | |
9384 | __attribute__ ((packed)) mixed | |
9385 | = @{ 'c', 0x1234, 0x87654321 @}; | |
9386 | printf ("%s\n", hello); | |
9387 | @} | |
9388 | @end smallexample | |
9389 | ||
9390 | @noindent | |
9391 | you get during debugging: | |
9392 | ||
9393 | @smallexample | |
9394 | (gdb) find &hello[0], +sizeof(hello), "hello" | |
9395 | 0x804956d <hello.1620+6> | |
9396 | 1 pattern found | |
9397 | (gdb) find &hello[0], +sizeof(hello), 'h', 'e', 'l', 'l', 'o' | |
9398 | 0x8049567 <hello.1620> | |
9399 | 0x804956d <hello.1620+6> | |
9400 | 2 patterns found | |
9401 | (gdb) find /b1 &hello[0], +sizeof(hello), 'h', 0x65, 'l' | |
9402 | 0x8049567 <hello.1620> | |
9403 | 1 pattern found | |
9404 | (gdb) find &mixed, +sizeof(mixed), (char) 'c', (short) 0x1234, (int) 0x87654321 | |
9405 | 0x8049560 <mixed.1625> | |
9406 | 1 pattern found | |
9407 | (gdb) print $numfound | |
9408 | $1 = 1 | |
9409 | (gdb) print $_ | |
9410 | $2 = (void *) 0x8049560 | |
9411 | @end smallexample | |
a0eb71c5 | 9412 | |
edb3359d DJ |
9413 | @node Optimized Code |
9414 | @chapter Debugging Optimized Code | |
9415 | @cindex optimized code, debugging | |
9416 | @cindex debugging optimized code | |
9417 | ||
9418 | Almost all compilers support optimization. With optimization | |
9419 | disabled, the compiler generates assembly code that corresponds | |
9420 | directly to your source code, in a simplistic way. As the compiler | |
9421 | applies more powerful optimizations, the generated assembly code | |
9422 | diverges from your original source code. With help from debugging | |
9423 | information generated by the compiler, @value{GDBN} can map from | |
9424 | the running program back to constructs from your original source. | |
9425 | ||
9426 | @value{GDBN} is more accurate with optimization disabled. If you | |
9427 | can recompile without optimization, it is easier to follow the | |
9428 | progress of your program during debugging. But, there are many cases | |
9429 | where you may need to debug an optimized version. | |
9430 | ||
9431 | When you debug a program compiled with @samp{-g -O}, remember that the | |
9432 | optimizer has rearranged your code; the debugger shows you what is | |
9433 | really there. Do not be too surprised when the execution path does not | |
9434 | exactly match your source file! An extreme example: if you define a | |
9435 | variable, but never use it, @value{GDBN} never sees that | |
9436 | variable---because the compiler optimizes it out of existence. | |
9437 | ||
9438 | Some things do not work as well with @samp{-g -O} as with just | |
9439 | @samp{-g}, particularly on machines with instruction scheduling. If in | |
9440 | doubt, recompile with @samp{-g} alone, and if this fixes the problem, | |
9441 | please report it to us as a bug (including a test case!). | |
9442 | @xref{Variables}, for more information about debugging optimized code. | |
9443 | ||
9444 | @menu | |
9445 | * Inline Functions:: How @value{GDBN} presents inlining | |
9446 | @end menu | |
9447 | ||
9448 | @node Inline Functions | |
9449 | @section Inline Functions | |
9450 | @cindex inline functions, debugging | |
9451 | ||
9452 | @dfn{Inlining} is an optimization that inserts a copy of the function | |
9453 | body directly at each call site, instead of jumping to a shared | |
9454 | routine. @value{GDBN} displays inlined functions just like | |
9455 | non-inlined functions. They appear in backtraces. You can view their | |
9456 | arguments and local variables, step into them with @code{step}, skip | |
9457 | them with @code{next}, and escape from them with @code{finish}. | |
9458 | You can check whether a function was inlined by using the | |
9459 | @code{info frame} command. | |
9460 | ||
9461 | For @value{GDBN} to support inlined functions, the compiler must | |
9462 | record information about inlining in the debug information --- | |
9463 | @value{NGCC} using the @sc{dwarf 2} format does this, and several | |
9464 | other compilers do also. @value{GDBN} only supports inlined functions | |
9465 | when using @sc{dwarf 2}. Versions of @value{NGCC} before 4.1 | |
9466 | do not emit two required attributes (@samp{DW_AT_call_file} and | |
9467 | @samp{DW_AT_call_line}); @value{GDBN} does not display inlined | |
9468 | function calls with earlier versions of @value{NGCC}. It instead | |
9469 | displays the arguments and local variables of inlined functions as | |
9470 | local variables in the caller. | |
9471 | ||
9472 | The body of an inlined function is directly included at its call site; | |
9473 | unlike a non-inlined function, there are no instructions devoted to | |
9474 | the call. @value{GDBN} still pretends that the call site and the | |
9475 | start of the inlined function are different instructions. Stepping to | |
9476 | the call site shows the call site, and then stepping again shows | |
9477 | the first line of the inlined function, even though no additional | |
9478 | instructions are executed. | |
9479 | ||
9480 | This makes source-level debugging much clearer; you can see both the | |
9481 | context of the call and then the effect of the call. Only stepping by | |
9482 | a single instruction using @code{stepi} or @code{nexti} does not do | |
9483 | this; single instruction steps always show the inlined body. | |
9484 | ||
9485 | There are some ways that @value{GDBN} does not pretend that inlined | |
9486 | function calls are the same as normal calls: | |
9487 | ||
9488 | @itemize @bullet | |
9489 | @item | |
9490 | You cannot set breakpoints on inlined functions. @value{GDBN} | |
9491 | either reports that there is no symbol with that name, or else sets the | |
9492 | breakpoint only on non-inlined copies of the function. This limitation | |
9493 | will be removed in a future version of @value{GDBN}; until then, | |
9494 | set a breakpoint by line number on the first line of the inlined | |
9495 | function instead. | |
9496 | ||
9497 | @item | |
9498 | Setting breakpoints at the call site of an inlined function may not | |
9499 | work, because the call site does not contain any code. @value{GDBN} | |
9500 | may incorrectly move the breakpoint to the next line of the enclosing | |
9501 | function, after the call. This limitation will be removed in a future | |
9502 | version of @value{GDBN}; until then, set a breakpoint on an earlier line | |
9503 | or inside the inlined function instead. | |
9504 | ||
9505 | @item | |
9506 | @value{GDBN} cannot locate the return value of inlined calls after | |
9507 | using the @code{finish} command. This is a limitation of compiler-generated | |
9508 | debugging information; after @code{finish}, you can step to the next line | |
9509 | and print a variable where your program stored the return value. | |
9510 | ||
9511 | @end itemize | |
9512 | ||
9513 | ||
e2e0bcd1 JB |
9514 | @node Macros |
9515 | @chapter C Preprocessor Macros | |
9516 | ||
49efadf5 | 9517 | Some languages, such as C and C@t{++}, provide a way to define and invoke |
e2e0bcd1 JB |
9518 | ``preprocessor macros'' which expand into strings of tokens. |
9519 | @value{GDBN} can evaluate expressions containing macro invocations, show | |
9520 | the result of macro expansion, and show a macro's definition, including | |
9521 | where it was defined. | |
9522 | ||
9523 | You may need to compile your program specially to provide @value{GDBN} | |
9524 | with information about preprocessor macros. Most compilers do not | |
9525 | include macros in their debugging information, even when you compile | |
9526 | with the @option{-g} flag. @xref{Compilation}. | |
9527 | ||
9528 | A program may define a macro at one point, remove that definition later, | |
9529 | and then provide a different definition after that. Thus, at different | |
9530 | points in the program, a macro may have different definitions, or have | |
9531 | no definition at all. If there is a current stack frame, @value{GDBN} | |
9532 | uses the macros in scope at that frame's source code line. Otherwise, | |
9533 | @value{GDBN} uses the macros in scope at the current listing location; | |
9534 | see @ref{List}. | |
9535 | ||
e2e0bcd1 JB |
9536 | Whenever @value{GDBN} evaluates an expression, it always expands any |
9537 | macro invocations present in the expression. @value{GDBN} also provides | |
9538 | the following commands for working with macros explicitly. | |
9539 | ||
9540 | @table @code | |
9541 | ||
9542 | @kindex macro expand | |
9543 | @cindex macro expansion, showing the results of preprocessor | |
9544 | @cindex preprocessor macro expansion, showing the results of | |
9545 | @cindex expanding preprocessor macros | |
9546 | @item macro expand @var{expression} | |
9547 | @itemx macro exp @var{expression} | |
9548 | Show the results of expanding all preprocessor macro invocations in | |
9549 | @var{expression}. Since @value{GDBN} simply expands macros, but does | |
9550 | not parse the result, @var{expression} need not be a valid expression; | |
9551 | it can be any string of tokens. | |
9552 | ||
09d4efe1 | 9553 | @kindex macro exp1 |
e2e0bcd1 JB |
9554 | @item macro expand-once @var{expression} |
9555 | @itemx macro exp1 @var{expression} | |
4644b6e3 | 9556 | @cindex expand macro once |
e2e0bcd1 JB |
9557 | @i{(This command is not yet implemented.)} Show the results of |
9558 | expanding those preprocessor macro invocations that appear explicitly in | |
9559 | @var{expression}. Macro invocations appearing in that expansion are | |
9560 | left unchanged. This command allows you to see the effect of a | |
9561 | particular macro more clearly, without being confused by further | |
9562 | expansions. Since @value{GDBN} simply expands macros, but does not | |
9563 | parse the result, @var{expression} need not be a valid expression; it | |
9564 | can be any string of tokens. | |
9565 | ||
475b0867 | 9566 | @kindex info macro |
e2e0bcd1 JB |
9567 | @cindex macro definition, showing |
9568 | @cindex definition, showing a macro's | |
475b0867 | 9569 | @item info macro @var{macro} |
e2e0bcd1 | 9570 | Show the definition of the macro named @var{macro}, and describe the |
484086b7 | 9571 | source location or compiler command-line where that definition was established. |
e2e0bcd1 JB |
9572 | |
9573 | @kindex macro define | |
9574 | @cindex user-defined macros | |
9575 | @cindex defining macros interactively | |
9576 | @cindex macros, user-defined | |
9577 | @item macro define @var{macro} @var{replacement-list} | |
9578 | @itemx macro define @var{macro}(@var{arglist}) @var{replacement-list} | |
d7d9f01e TT |
9579 | Introduce a definition for a preprocessor macro named @var{macro}, |
9580 | invocations of which are replaced by the tokens given in | |
9581 | @var{replacement-list}. The first form of this command defines an | |
9582 | ``object-like'' macro, which takes no arguments; the second form | |
9583 | defines a ``function-like'' macro, which takes the arguments given in | |
9584 | @var{arglist}. | |
9585 | ||
9586 | A definition introduced by this command is in scope in every | |
9587 | expression evaluated in @value{GDBN}, until it is removed with the | |
9588 | @code{macro undef} command, described below. The definition overrides | |
9589 | all definitions for @var{macro} present in the program being debugged, | |
9590 | as well as any previous user-supplied definition. | |
e2e0bcd1 JB |
9591 | |
9592 | @kindex macro undef | |
9593 | @item macro undef @var{macro} | |
d7d9f01e TT |
9594 | Remove any user-supplied definition for the macro named @var{macro}. |
9595 | This command only affects definitions provided with the @code{macro | |
9596 | define} command, described above; it cannot remove definitions present | |
9597 | in the program being debugged. | |
e2e0bcd1 | 9598 | |
09d4efe1 EZ |
9599 | @kindex macro list |
9600 | @item macro list | |
d7d9f01e | 9601 | List all the macros defined using the @code{macro define} command. |
e2e0bcd1 JB |
9602 | @end table |
9603 | ||
9604 | @cindex macros, example of debugging with | |
9605 | Here is a transcript showing the above commands in action. First, we | |
9606 | show our source files: | |
9607 | ||
9608 | @smallexample | |
9609 | $ cat sample.c | |
9610 | #include <stdio.h> | |
9611 | #include "sample.h" | |
9612 | ||
9613 | #define M 42 | |
9614 | #define ADD(x) (M + x) | |
9615 | ||
9616 | main () | |
9617 | @{ | |
9618 | #define N 28 | |
9619 | printf ("Hello, world!\n"); | |
9620 | #undef N | |
9621 | printf ("We're so creative.\n"); | |
9622 | #define N 1729 | |
9623 | printf ("Goodbye, world!\n"); | |
9624 | @} | |
9625 | $ cat sample.h | |
9626 | #define Q < | |
9627 | $ | |
9628 | @end smallexample | |
9629 | ||
9630 | Now, we compile the program using the @sc{gnu} C compiler, @value{NGCC}. | |
9631 | We pass the @option{-gdwarf-2} and @option{-g3} flags to ensure the | |
9632 | compiler includes information about preprocessor macros in the debugging | |
9633 | information. | |
9634 | ||
9635 | @smallexample | |
9636 | $ gcc -gdwarf-2 -g3 sample.c -o sample | |
9637 | $ | |
9638 | @end smallexample | |
9639 | ||
9640 | Now, we start @value{GDBN} on our sample program: | |
9641 | ||
9642 | @smallexample | |
9643 | $ gdb -nw sample | |
9644 | GNU gdb 2002-05-06-cvs | |
9645 | Copyright 2002 Free Software Foundation, Inc. | |
9646 | GDB is free software, @dots{} | |
f7dc1244 | 9647 | (@value{GDBP}) |
e2e0bcd1 JB |
9648 | @end smallexample |
9649 | ||
9650 | We can expand macros and examine their definitions, even when the | |
9651 | program is not running. @value{GDBN} uses the current listing position | |
9652 | to decide which macro definitions are in scope: | |
9653 | ||
9654 | @smallexample | |
f7dc1244 | 9655 | (@value{GDBP}) list main |
e2e0bcd1 JB |
9656 | 3 |
9657 | 4 #define M 42 | |
9658 | 5 #define ADD(x) (M + x) | |
9659 | 6 | |
9660 | 7 main () | |
9661 | 8 @{ | |
9662 | 9 #define N 28 | |
9663 | 10 printf ("Hello, world!\n"); | |
9664 | 11 #undef N | |
9665 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 9666 | (@value{GDBP}) info macro ADD |
e2e0bcd1 JB |
9667 | Defined at /home/jimb/gdb/macros/play/sample.c:5 |
9668 | #define ADD(x) (M + x) | |
f7dc1244 | 9669 | (@value{GDBP}) info macro Q |
e2e0bcd1 JB |
9670 | Defined at /home/jimb/gdb/macros/play/sample.h:1 |
9671 | included at /home/jimb/gdb/macros/play/sample.c:2 | |
9672 | #define Q < | |
f7dc1244 | 9673 | (@value{GDBP}) macro expand ADD(1) |
e2e0bcd1 | 9674 | expands to: (42 + 1) |
f7dc1244 | 9675 | (@value{GDBP}) macro expand-once ADD(1) |
e2e0bcd1 | 9676 | expands to: once (M + 1) |
f7dc1244 | 9677 | (@value{GDBP}) |
e2e0bcd1 JB |
9678 | @end smallexample |
9679 | ||
d7d9f01e | 9680 | In the example above, note that @code{macro expand-once} expands only |
e2e0bcd1 JB |
9681 | the macro invocation explicit in the original text --- the invocation of |
9682 | @code{ADD} --- but does not expand the invocation of the macro @code{M}, | |
9683 | which was introduced by @code{ADD}. | |
9684 | ||
3f94c067 BW |
9685 | Once the program is running, @value{GDBN} uses the macro definitions in |
9686 | force at the source line of the current stack frame: | |
e2e0bcd1 JB |
9687 | |
9688 | @smallexample | |
f7dc1244 | 9689 | (@value{GDBP}) break main |
e2e0bcd1 | 9690 | Breakpoint 1 at 0x8048370: file sample.c, line 10. |
f7dc1244 | 9691 | (@value{GDBP}) run |
b383017d | 9692 | Starting program: /home/jimb/gdb/macros/play/sample |
e2e0bcd1 JB |
9693 | |
9694 | Breakpoint 1, main () at sample.c:10 | |
9695 | 10 printf ("Hello, world!\n"); | |
f7dc1244 | 9696 | (@value{GDBP}) |
e2e0bcd1 JB |
9697 | @end smallexample |
9698 | ||
9699 | At line 10, the definition of the macro @code{N} at line 9 is in force: | |
9700 | ||
9701 | @smallexample | |
f7dc1244 | 9702 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
9703 | Defined at /home/jimb/gdb/macros/play/sample.c:9 |
9704 | #define N 28 | |
f7dc1244 | 9705 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 9706 | expands to: 28 < 42 |
f7dc1244 | 9707 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 9708 | $1 = 1 |
f7dc1244 | 9709 | (@value{GDBP}) |
e2e0bcd1 JB |
9710 | @end smallexample |
9711 | ||
9712 | As we step over directives that remove @code{N}'s definition, and then | |
9713 | give it a new definition, @value{GDBN} finds the definition (or lack | |
9714 | thereof) in force at each point: | |
9715 | ||
9716 | @smallexample | |
f7dc1244 | 9717 | (@value{GDBP}) next |
e2e0bcd1 JB |
9718 | Hello, world! |
9719 | 12 printf ("We're so creative.\n"); | |
f7dc1244 | 9720 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
9721 | The symbol `N' has no definition as a C/C++ preprocessor macro |
9722 | at /home/jimb/gdb/macros/play/sample.c:12 | |
f7dc1244 | 9723 | (@value{GDBP}) next |
e2e0bcd1 JB |
9724 | We're so creative. |
9725 | 14 printf ("Goodbye, world!\n"); | |
f7dc1244 | 9726 | (@value{GDBP}) info macro N |
e2e0bcd1 JB |
9727 | Defined at /home/jimb/gdb/macros/play/sample.c:13 |
9728 | #define N 1729 | |
f7dc1244 | 9729 | (@value{GDBP}) macro expand N Q M |
e2e0bcd1 | 9730 | expands to: 1729 < 42 |
f7dc1244 | 9731 | (@value{GDBP}) print N Q M |
e2e0bcd1 | 9732 | $2 = 0 |
f7dc1244 | 9733 | (@value{GDBP}) |
e2e0bcd1 JB |
9734 | @end smallexample |
9735 | ||
484086b7 JK |
9736 | In addition to source files, macros can be defined on the compilation command |
9737 | line using the @option{-D@var{name}=@var{value}} syntax. For macros defined in | |
9738 | such a way, @value{GDBN} displays the location of their definition as line zero | |
9739 | of the source file submitted to the compiler. | |
9740 | ||
9741 | @smallexample | |
9742 | (@value{GDBP}) info macro __STDC__ | |
9743 | Defined at /home/jimb/gdb/macros/play/sample.c:0 | |
9744 | -D__STDC__=1 | |
9745 | (@value{GDBP}) | |
9746 | @end smallexample | |
9747 | ||
e2e0bcd1 | 9748 | |
b37052ae EZ |
9749 | @node Tracepoints |
9750 | @chapter Tracepoints | |
9751 | @c This chapter is based on the documentation written by Michael | |
9752 | @c Snyder, David Taylor, Jim Blandy, and Elena Zannoni. | |
9753 | ||
9754 | @cindex tracepoints | |
9755 | In some applications, it is not feasible for the debugger to interrupt | |
9756 | the program's execution long enough for the developer to learn | |
9757 | anything helpful about its behavior. If the program's correctness | |
9758 | depends on its real-time behavior, delays introduced by a debugger | |
9759 | might cause the program to change its behavior drastically, or perhaps | |
9760 | fail, even when the code itself is correct. It is useful to be able | |
9761 | to observe the program's behavior without interrupting it. | |
9762 | ||
9763 | Using @value{GDBN}'s @code{trace} and @code{collect} commands, you can | |
9764 | specify locations in the program, called @dfn{tracepoints}, and | |
9765 | arbitrary expressions to evaluate when those tracepoints are reached. | |
9766 | Later, using the @code{tfind} command, you can examine the values | |
9767 | those expressions had when the program hit the tracepoints. The | |
9768 | expressions may also denote objects in memory---structures or arrays, | |
9769 | for example---whose values @value{GDBN} should record; while visiting | |
9770 | a particular tracepoint, you may inspect those objects as if they were | |
9771 | in memory at that moment. However, because @value{GDBN} records these | |
9772 | values without interacting with you, it can do so quickly and | |
9773 | unobtrusively, hopefully not disturbing the program's behavior. | |
9774 | ||
9775 | The tracepoint facility is currently available only for remote | |
9d29849a JB |
9776 | targets. @xref{Targets}. In addition, your remote target must know |
9777 | how to collect trace data. This functionality is implemented in the | |
9778 | remote stub; however, none of the stubs distributed with @value{GDBN} | |
9779 | support tracepoints as of this writing. The format of the remote | |
9780 | packets used to implement tracepoints are described in @ref{Tracepoint | |
9781 | Packets}. | |
b37052ae | 9782 | |
00bf0b85 SS |
9783 | It is also possible to get trace data from a file, in a manner reminiscent |
9784 | of corefiles; you specify the filename, and use @code{tfind} to search | |
9785 | through the file. @xref{Trace Files}, for more details. | |
9786 | ||
b37052ae EZ |
9787 | This chapter describes the tracepoint commands and features. |
9788 | ||
9789 | @menu | |
b383017d RM |
9790 | * Set Tracepoints:: |
9791 | * Analyze Collected Data:: | |
9792 | * Tracepoint Variables:: | |
00bf0b85 | 9793 | * Trace Files:: |
b37052ae EZ |
9794 | @end menu |
9795 | ||
9796 | @node Set Tracepoints | |
9797 | @section Commands to Set Tracepoints | |
9798 | ||
9799 | Before running such a @dfn{trace experiment}, an arbitrary number of | |
1042e4c0 SS |
9800 | tracepoints can be set. A tracepoint is actually a special type of |
9801 | breakpoint (@pxref{Set Breaks}), so you can manipulate it using | |
9802 | standard breakpoint commands. For instance, as with breakpoints, | |
9803 | tracepoint numbers are successive integers starting from one, and many | |
9804 | of the commands associated with tracepoints take the tracepoint number | |
9805 | as their argument, to identify which tracepoint to work on. | |
b37052ae EZ |
9806 | |
9807 | For each tracepoint, you can specify, in advance, some arbitrary set | |
9808 | of data that you want the target to collect in the trace buffer when | |
9809 | it hits that tracepoint. The collected data can include registers, | |
9810 | local variables, or global data. Later, you can use @value{GDBN} | |
9811 | commands to examine the values these data had at the time the | |
9812 | tracepoint was hit. | |
9813 | ||
7d13fe92 SS |
9814 | Tracepoints do not support every breakpoint feature. Ignore counts on |
9815 | tracepoints have no effect, and tracepoints cannot run @value{GDBN} | |
9816 | commands when they are hit. Tracepoints may not be thread-specific | |
9817 | either. | |
1042e4c0 | 9818 | |
7a697b8d SS |
9819 | @cindex fast tracepoints |
9820 | Some targets may support @dfn{fast tracepoints}, which are inserted in | |
9821 | a different way (such as with a jump instead of a trap), that is | |
9822 | faster but possibly restricted in where they may be installed. | |
9823 | ||
0fb4aa4b PA |
9824 | @cindex static tracepoints |
9825 | @cindex markers, static tracepoints | |
9826 | @cindex probing markers, static tracepoints | |
9827 | Regular and fast tracepoints are dynamic tracing facilities, meaning | |
9828 | that they can be used to insert tracepoints at (almost) any location | |
9829 | in the target. Some targets may also support controlling @dfn{static | |
9830 | tracepoints} from @value{GDBN}. With static tracing, a set of | |
9831 | instrumentation points, also known as @dfn{markers}, are embedded in | |
9832 | the target program, and can be activated or deactivated by name or | |
9833 | address. These are usually placed at locations which facilitate | |
9834 | investigating what the target is actually doing. @value{GDBN}'s | |
9835 | support for static tracing includes being able to list instrumentation | |
9836 | points, and attach them with @value{GDBN} defined high level | |
9837 | tracepoints that expose the whole range of convenience of | |
9838 | @value{GDBN}'s tracepoints support. Namelly, support for collecting | |
9839 | registers values and values of global or local (to the instrumentation | |
9840 | point) variables; tracepoint conditions and trace state variables. | |
9841 | The act of installing a @value{GDBN} static tracepoint on an | |
9842 | instrumentation point, or marker, is referred to as @dfn{probing} a | |
9843 | static tracepoint marker. | |
9844 | ||
fa593d66 PA |
9845 | @code{gdbserver} supports tracepoints on some target systems. |
9846 | @xref{Server,,Tracepoints support in @code{gdbserver}}. | |
9847 | ||
b37052ae EZ |
9848 | This section describes commands to set tracepoints and associated |
9849 | conditions and actions. | |
9850 | ||
9851 | @menu | |
b383017d RM |
9852 | * Create and Delete Tracepoints:: |
9853 | * Enable and Disable Tracepoints:: | |
9854 | * Tracepoint Passcounts:: | |
782b2b07 | 9855 | * Tracepoint Conditions:: |
f61e138d | 9856 | * Trace State Variables:: |
b383017d RM |
9857 | * Tracepoint Actions:: |
9858 | * Listing Tracepoints:: | |
0fb4aa4b | 9859 | * Listing Static Tracepoint Markers:: |
79a6e687 | 9860 | * Starting and Stopping Trace Experiments:: |
c9429232 | 9861 | * Tracepoint Restrictions:: |
b37052ae EZ |
9862 | @end menu |
9863 | ||
9864 | @node Create and Delete Tracepoints | |
9865 | @subsection Create and Delete Tracepoints | |
9866 | ||
9867 | @table @code | |
9868 | @cindex set tracepoint | |
9869 | @kindex trace | |
1042e4c0 | 9870 | @item trace @var{location} |
b37052ae | 9871 | The @code{trace} command is very similar to the @code{break} command. |
1042e4c0 SS |
9872 | Its argument @var{location} can be a source line, a function name, or |
9873 | an address in the target program. @xref{Specify Location}. The | |
9874 | @code{trace} command defines a tracepoint, which is a point in the | |
9875 | target program where the debugger will briefly stop, collect some | |
9876 | data, and then allow the program to continue. Setting a tracepoint or | |
9877 | changing its actions doesn't take effect until the next @code{tstart} | |
9878 | command, and once a trace experiment is running, further changes will | |
9879 | not have any effect until the next trace experiment starts. | |
b37052ae EZ |
9880 | |
9881 | Here are some examples of using the @code{trace} command: | |
9882 | ||
9883 | @smallexample | |
9884 | (@value{GDBP}) @b{trace foo.c:121} // a source file and line number | |
9885 | ||
9886 | (@value{GDBP}) @b{trace +2} // 2 lines forward | |
9887 | ||
9888 | (@value{GDBP}) @b{trace my_function} // first source line of function | |
9889 | ||
9890 | (@value{GDBP}) @b{trace *my_function} // EXACT start address of function | |
9891 | ||
9892 | (@value{GDBP}) @b{trace *0x2117c4} // an address | |
9893 | @end smallexample | |
9894 | ||
9895 | @noindent | |
9896 | You can abbreviate @code{trace} as @code{tr}. | |
9897 | ||
782b2b07 SS |
9898 | @item trace @var{location} if @var{cond} |
9899 | Set a tracepoint with condition @var{cond}; evaluate the expression | |
9900 | @var{cond} each time the tracepoint is reached, and collect data only | |
9901 | if the value is nonzero---that is, if @var{cond} evaluates as true. | |
9902 | @xref{Tracepoint Conditions, ,Tracepoint Conditions}, for more | |
9903 | information on tracepoint conditions. | |
9904 | ||
7a697b8d SS |
9905 | @item ftrace @var{location} [ if @var{cond} ] |
9906 | @cindex set fast tracepoint | |
74c761c1 | 9907 | @cindex fast tracepoints, setting |
7a697b8d SS |
9908 | @kindex ftrace |
9909 | The @code{ftrace} command sets a fast tracepoint. For targets that | |
9910 | support them, fast tracepoints will use a more efficient but possibly | |
9911 | less general technique to trigger data collection, such as a jump | |
9912 | instruction instead of a trap, or some sort of hardware support. It | |
9913 | may not be possible to create a fast tracepoint at the desired | |
9914 | location, in which case the command will exit with an explanatory | |
9915 | message. | |
9916 | ||
9917 | @value{GDBN} handles arguments to @code{ftrace} exactly as for | |
9918 | @code{trace}. | |
9919 | ||
0fb4aa4b | 9920 | @item strace @var{location} [ if @var{cond} ] |
74c761c1 PA |
9921 | @cindex set static tracepoint |
9922 | @cindex static tracepoints, setting | |
9923 | @cindex probe static tracepoint marker | |
0fb4aa4b PA |
9924 | @kindex strace |
9925 | The @code{strace} command sets a static tracepoint. For targets that | |
9926 | support it, setting a static tracepoint probes a static | |
9927 | instrumentation point, or marker, found at @var{location}. It may not | |
9928 | be possible to set a static tracepoint at the desired location, in | |
9929 | which case the command will exit with an explanatory message. | |
9930 | ||
9931 | @value{GDBN} handles arguments to @code{strace} exactly as for | |
9932 | @code{trace}, with the addition that the user can also specify | |
9933 | @code{-m @var{marker}} as @var{location}. This probes the marker | |
9934 | identified by the @var{marker} string identifier. This identifier | |
9935 | depends on the static tracepoint backend library your program is | |
9936 | using. You can find all the marker identifiers in the @samp{ID} field | |
9937 | of the @code{info static-tracepoint-markers} command output. | |
9938 | @xref{Listing Static Tracepoint Markers,,Listing Static Tracepoint | |
9939 | Markers}. For example, in the following small program using the UST | |
9940 | tracing engine: | |
9941 | ||
9942 | @smallexample | |
9943 | main () | |
9944 | @{ | |
9945 | trace_mark(ust, bar33, "str %s", "FOOBAZ"); | |
9946 | @} | |
9947 | @end smallexample | |
9948 | ||
9949 | @noindent | |
9950 | the marker id is composed of joining the first two arguments to the | |
9951 | @code{trace_mark} call with a slash, which translates to: | |
9952 | ||
9953 | @smallexample | |
9954 | (@value{GDBP}) info static-tracepoint-markers | |
9955 | Cnt Enb ID Address What | |
9956 | 1 n ust/bar33 0x0000000000400ddc in main at stexample.c:22 | |
9957 | Data: "str %s" | |
9958 | [etc...] | |
9959 | @end smallexample | |
9960 | ||
9961 | @noindent | |
9962 | so you may probe the marker above with: | |
9963 | ||
9964 | @smallexample | |
9965 | (@value{GDBP}) strace -m ust/bar33 | |
9966 | @end smallexample | |
9967 | ||
9968 | Static tracepoints accept an extra collect action --- @code{collect | |
9969 | $_sdata}. This collects arbitrary user data passed in the probe point | |
9970 | call to the tracing library. In the UST example above, you'll see | |
9971 | that the third argument to @code{trace_mark} is a printf-like format | |
9972 | string. The user data is then the result of running that formating | |
9973 | string against the following arguments. Note that @code{info | |
9974 | static-tracepoint-markers} command output lists that format string in | |
9975 | the @samp{Data:} field. | |
9976 | ||
9977 | You can inspect this data when analyzing the trace buffer, by printing | |
9978 | the $_sdata variable like any other variable available to | |
9979 | @value{GDBN}. @xref{Tracepoint Actions,,Tracepoint Action Lists}. | |
9980 | ||
b37052ae EZ |
9981 | @vindex $tpnum |
9982 | @cindex last tracepoint number | |
9983 | @cindex recent tracepoint number | |
9984 | @cindex tracepoint number | |
9985 | The convenience variable @code{$tpnum} records the tracepoint number | |
9986 | of the most recently set tracepoint. | |
9987 | ||
9988 | @kindex delete tracepoint | |
9989 | @cindex tracepoint deletion | |
9990 | @item delete tracepoint @r{[}@var{num}@r{]} | |
9991 | Permanently delete one or more tracepoints. With no argument, the | |
1042e4c0 SS |
9992 | default is to delete all tracepoints. Note that the regular |
9993 | @code{delete} command can remove tracepoints also. | |
b37052ae EZ |
9994 | |
9995 | Examples: | |
9996 | ||
9997 | @smallexample | |
9998 | (@value{GDBP}) @b{delete trace 1 2 3} // remove three tracepoints | |
9999 | ||
10000 | (@value{GDBP}) @b{delete trace} // remove all tracepoints | |
10001 | @end smallexample | |
10002 | ||
10003 | @noindent | |
10004 | You can abbreviate this command as @code{del tr}. | |
10005 | @end table | |
10006 | ||
10007 | @node Enable and Disable Tracepoints | |
10008 | @subsection Enable and Disable Tracepoints | |
10009 | ||
1042e4c0 SS |
10010 | These commands are deprecated; they are equivalent to plain @code{disable} and @code{enable}. |
10011 | ||
b37052ae EZ |
10012 | @table @code |
10013 | @kindex disable tracepoint | |
10014 | @item disable tracepoint @r{[}@var{num}@r{]} | |
10015 | Disable tracepoint @var{num}, or all tracepoints if no argument | |
10016 | @var{num} is given. A disabled tracepoint will have no effect during | |
10017 | the next trace experiment, but it is not forgotten. You can re-enable | |
10018 | a disabled tracepoint using the @code{enable tracepoint} command. | |
10019 | ||
10020 | @kindex enable tracepoint | |
10021 | @item enable tracepoint @r{[}@var{num}@r{]} | |
10022 | Enable tracepoint @var{num}, or all tracepoints. The enabled | |
10023 | tracepoints will become effective the next time a trace experiment is | |
10024 | run. | |
10025 | @end table | |
10026 | ||
10027 | @node Tracepoint Passcounts | |
10028 | @subsection Tracepoint Passcounts | |
10029 | ||
10030 | @table @code | |
10031 | @kindex passcount | |
10032 | @cindex tracepoint pass count | |
10033 | @item passcount @r{[}@var{n} @r{[}@var{num}@r{]]} | |
10034 | Set the @dfn{passcount} of a tracepoint. The passcount is a way to | |
10035 | automatically stop a trace experiment. If a tracepoint's passcount is | |
10036 | @var{n}, then the trace experiment will be automatically stopped on | |
10037 | the @var{n}'th time that tracepoint is hit. If the tracepoint number | |
10038 | @var{num} is not specified, the @code{passcount} command sets the | |
10039 | passcount of the most recently defined tracepoint. If no passcount is | |
10040 | given, the trace experiment will run until stopped explicitly by the | |
10041 | user. | |
10042 | ||
10043 | Examples: | |
10044 | ||
10045 | @smallexample | |
b383017d | 10046 | (@value{GDBP}) @b{passcount 5 2} // Stop on the 5th execution of |
6826cf00 | 10047 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// tracepoint 2} |
b37052ae EZ |
10048 | |
10049 | (@value{GDBP}) @b{passcount 12} // Stop on the 12th execution of the | |
6826cf00 | 10050 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// most recently defined tracepoint.} |
b37052ae EZ |
10051 | (@value{GDBP}) @b{trace foo} |
10052 | (@value{GDBP}) @b{pass 3} | |
10053 | (@value{GDBP}) @b{trace bar} | |
10054 | (@value{GDBP}) @b{pass 2} | |
10055 | (@value{GDBP}) @b{trace baz} | |
10056 | (@value{GDBP}) @b{pass 1} // Stop tracing when foo has been | |
6826cf00 EZ |
10057 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// executed 3 times OR when bar has} |
10058 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// been executed 2 times} | |
10059 | @exdent @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @code{// OR when baz has been executed 1 time.} | |
b37052ae EZ |
10060 | @end smallexample |
10061 | @end table | |
10062 | ||
782b2b07 SS |
10063 | @node Tracepoint Conditions |
10064 | @subsection Tracepoint Conditions | |
10065 | @cindex conditional tracepoints | |
10066 | @cindex tracepoint conditions | |
10067 | ||
10068 | The simplest sort of tracepoint collects data every time your program | |
10069 | reaches a specified place. You can also specify a @dfn{condition} for | |
10070 | a tracepoint. A condition is just a Boolean expression in your | |
10071 | programming language (@pxref{Expressions, ,Expressions}). A | |
10072 | tracepoint with a condition evaluates the expression each time your | |
10073 | program reaches it, and data collection happens only if the condition | |
10074 | is true. | |
10075 | ||
10076 | Tracepoint conditions can be specified when a tracepoint is set, by | |
10077 | using @samp{if} in the arguments to the @code{trace} command. | |
10078 | @xref{Create and Delete Tracepoints, ,Setting Tracepoints}. They can | |
10079 | also be set or changed at any time with the @code{condition} command, | |
10080 | just as with breakpoints. | |
10081 | ||
10082 | Unlike breakpoint conditions, @value{GDBN} does not actually evaluate | |
10083 | the conditional expression itself. Instead, @value{GDBN} encodes the | |
10084 | expression into an agent expression (@pxref{Agent Expressions} | |
10085 | suitable for execution on the target, independently of @value{GDBN}. | |
10086 | Global variables become raw memory locations, locals become stack | |
10087 | accesses, and so forth. | |
10088 | ||
10089 | For instance, suppose you have a function that is usually called | |
10090 | frequently, but should not be called after an error has occurred. You | |
10091 | could use the following tracepoint command to collect data about calls | |
10092 | of that function that happen while the error code is propagating | |
10093 | through the program; an unconditional tracepoint could end up | |
10094 | collecting thousands of useless trace frames that you would have to | |
10095 | search through. | |
10096 | ||
10097 | @smallexample | |
10098 | (@value{GDBP}) @kbd{trace normal_operation if errcode > 0} | |
10099 | @end smallexample | |
10100 | ||
f61e138d SS |
10101 | @node Trace State Variables |
10102 | @subsection Trace State Variables | |
10103 | @cindex trace state variables | |
10104 | ||
10105 | A @dfn{trace state variable} is a special type of variable that is | |
10106 | created and managed by target-side code. The syntax is the same as | |
10107 | that for GDB's convenience variables (a string prefixed with ``$''), | |
10108 | but they are stored on the target. They must be created explicitly, | |
10109 | using a @code{tvariable} command. They are always 64-bit signed | |
10110 | integers. | |
10111 | ||
10112 | Trace state variables are remembered by @value{GDBN}, and downloaded | |
10113 | to the target along with tracepoint information when the trace | |
10114 | experiment starts. There are no intrinsic limits on the number of | |
10115 | trace state variables, beyond memory limitations of the target. | |
10116 | ||
10117 | @cindex convenience variables, and trace state variables | |
10118 | Although trace state variables are managed by the target, you can use | |
10119 | them in print commands and expressions as if they were convenience | |
10120 | variables; @value{GDBN} will get the current value from the target | |
10121 | while the trace experiment is running. Trace state variables share | |
10122 | the same namespace as other ``$'' variables, which means that you | |
10123 | cannot have trace state variables with names like @code{$23} or | |
10124 | @code{$pc}, nor can you have a trace state variable and a convenience | |
10125 | variable with the same name. | |
10126 | ||
10127 | @table @code | |
10128 | ||
10129 | @item tvariable $@var{name} [ = @var{expression} ] | |
10130 | @kindex tvariable | |
10131 | The @code{tvariable} command creates a new trace state variable named | |
10132 | @code{$@var{name}}, and optionally gives it an initial value of | |
10133 | @var{expression}. @var{expression} is evaluated when this command is | |
10134 | entered; the result will be converted to an integer if possible, | |
10135 | otherwise @value{GDBN} will report an error. A subsequent | |
10136 | @code{tvariable} command specifying the same name does not create a | |
10137 | variable, but instead assigns the supplied initial value to the | |
10138 | existing variable of that name, overwriting any previous initial | |
10139 | value. The default initial value is 0. | |
10140 | ||
10141 | @item info tvariables | |
10142 | @kindex info tvariables | |
10143 | List all the trace state variables along with their initial values. | |
10144 | Their current values may also be displayed, if the trace experiment is | |
10145 | currently running. | |
10146 | ||
10147 | @item delete tvariable @r{[} $@var{name} @dots{} @r{]} | |
10148 | @kindex delete tvariable | |
10149 | Delete the given trace state variables, or all of them if no arguments | |
10150 | are specified. | |
10151 | ||
10152 | @end table | |
10153 | ||
b37052ae EZ |
10154 | @node Tracepoint Actions |
10155 | @subsection Tracepoint Action Lists | |
10156 | ||
10157 | @table @code | |
10158 | @kindex actions | |
10159 | @cindex tracepoint actions | |
10160 | @item actions @r{[}@var{num}@r{]} | |
10161 | This command will prompt for a list of actions to be taken when the | |
10162 | tracepoint is hit. If the tracepoint number @var{num} is not | |
10163 | specified, this command sets the actions for the one that was most | |
10164 | recently defined (so that you can define a tracepoint and then say | |
10165 | @code{actions} without bothering about its number). You specify the | |
10166 | actions themselves on the following lines, one action at a time, and | |
10167 | terminate the actions list with a line containing just @code{end}. So | |
7d13fe92 | 10168 | far, the only defined actions are @code{collect}, @code{teval}, and |
b37052ae EZ |
10169 | @code{while-stepping}. |
10170 | ||
5a9351ae SS |
10171 | @code{actions} is actually equivalent to @code{commands} (@pxref{Break |
10172 | Commands, ,Breakpoint Command Lists}), except that only the defined | |
10173 | actions are allowed; any other @value{GDBN} command is rejected. | |
10174 | ||
b37052ae EZ |
10175 | @cindex remove actions from a tracepoint |
10176 | To remove all actions from a tracepoint, type @samp{actions @var{num}} | |
10177 | and follow it immediately with @samp{end}. | |
10178 | ||
10179 | @smallexample | |
10180 | (@value{GDBP}) @b{collect @var{data}} // collect some data | |
10181 | ||
6826cf00 | 10182 | (@value{GDBP}) @b{while-stepping 5} // single-step 5 times, collect data |
b37052ae | 10183 | |
6826cf00 | 10184 | (@value{GDBP}) @b{end} // signals the end of actions. |
b37052ae EZ |
10185 | @end smallexample |
10186 | ||
10187 | In the following example, the action list begins with @code{collect} | |
10188 | commands indicating the things to be collected when the tracepoint is | |
10189 | hit. Then, in order to single-step and collect additional data | |
10190 | following the tracepoint, a @code{while-stepping} command is used, | |
7d13fe92 SS |
10191 | followed by the list of things to be collected after each step in a |
10192 | sequence of single steps. The @code{while-stepping} command is | |
10193 | terminated by its own separate @code{end} command. Lastly, the action | |
10194 | list is terminated by an @code{end} command. | |
b37052ae EZ |
10195 | |
10196 | @smallexample | |
10197 | (@value{GDBP}) @b{trace foo} | |
10198 | (@value{GDBP}) @b{actions} | |
10199 | Enter actions for tracepoint 1, one per line: | |
10200 | > collect bar,baz | |
10201 | > collect $regs | |
10202 | > while-stepping 12 | |
5a9351ae | 10203 | > collect $pc, arr[i] |
b37052ae EZ |
10204 | > end |
10205 | end | |
10206 | @end smallexample | |
10207 | ||
10208 | @kindex collect @r{(tracepoints)} | |
10209 | @item collect @var{expr1}, @var{expr2}, @dots{} | |
10210 | Collect values of the given expressions when the tracepoint is hit. | |
10211 | This command accepts a comma-separated list of any valid expressions. | |
10212 | In addition to global, static, or local variables, the following | |
10213 | special arguments are supported: | |
10214 | ||
10215 | @table @code | |
10216 | @item $regs | |
0fb4aa4b | 10217 | Collect all registers. |
b37052ae EZ |
10218 | |
10219 | @item $args | |
0fb4aa4b | 10220 | Collect all function arguments. |
b37052ae EZ |
10221 | |
10222 | @item $locals | |
0fb4aa4b PA |
10223 | Collect all local variables. |
10224 | ||
10225 | @item $_sdata | |
10226 | @vindex $_sdata@r{, collect} | |
10227 | Collect static tracepoint marker specific data. Only available for | |
10228 | static tracepoints. @xref{Tracepoint Actions,,Tracepoint Action | |
10229 | Lists}. On the UST static tracepoints library backend, an | |
10230 | instrumentation point resembles a @code{printf} function call. The | |
10231 | tracing library is able to collect user specified data formatted to a | |
10232 | character string using the format provided by the programmer that | |
10233 | instrumented the program. Other backends have similar mechanisms. | |
10234 | Here's an example of a UST marker call: | |
10235 | ||
10236 | @smallexample | |
10237 | const char master_name[] = "$your_name"; | |
10238 | trace_mark(channel1, marker1, "hello %s", master_name) | |
10239 | @end smallexample | |
10240 | ||
10241 | In this case, collecting @code{$_sdata} collects the string | |
10242 | @samp{hello $yourname}. When analyzing the trace buffer, you can | |
10243 | inspect @samp{$_sdata} like any other variable available to | |
10244 | @value{GDBN}. | |
b37052ae EZ |
10245 | @end table |
10246 | ||
10247 | You can give several consecutive @code{collect} commands, each one | |
10248 | with a single argument, or one @code{collect} command with several | |
5a9351ae | 10249 | arguments separated by commas; the effect is the same. |
b37052ae | 10250 | |
f5c37c66 EZ |
10251 | The command @code{info scope} (@pxref{Symbols, info scope}) is |
10252 | particularly useful for figuring out what data to collect. | |
10253 | ||
6da95a67 SS |
10254 | @kindex teval @r{(tracepoints)} |
10255 | @item teval @var{expr1}, @var{expr2}, @dots{} | |
10256 | Evaluate the given expressions when the tracepoint is hit. This | |
10257 | command accepts a comma-separated list of expressions. The results | |
10258 | are discarded, so this is mainly useful for assigning values to trace | |
10259 | state variables (@pxref{Trace State Variables}) without adding those | |
10260 | values to the trace buffer, as would be the case if the @code{collect} | |
10261 | action were used. | |
10262 | ||
b37052ae EZ |
10263 | @kindex while-stepping @r{(tracepoints)} |
10264 | @item while-stepping @var{n} | |
c9429232 | 10265 | Perform @var{n} single-step instruction traces after the tracepoint, |
7d13fe92 | 10266 | collecting new data after each step. The @code{while-stepping} |
c9429232 SS |
10267 | command is followed by the list of what to collect while stepping |
10268 | (followed by its own @code{end} command): | |
b37052ae EZ |
10269 | |
10270 | @smallexample | |
10271 | > while-stepping 12 | |
10272 | > collect $regs, myglobal | |
10273 | > end | |
10274 | > | |
10275 | @end smallexample | |
10276 | ||
10277 | @noindent | |
7d13fe92 SS |
10278 | Note that @code{$pc} is not automatically collected by |
10279 | @code{while-stepping}; you need to explicitly collect that register if | |
10280 | you need it. You may abbreviate @code{while-stepping} as @code{ws} or | |
b37052ae | 10281 | @code{stepping}. |
236f1d4d SS |
10282 | |
10283 | @item set default-collect @var{expr1}, @var{expr2}, @dots{} | |
10284 | @kindex set default-collect | |
10285 | @cindex default collection action | |
10286 | This variable is a list of expressions to collect at each tracepoint | |
10287 | hit. It is effectively an additional @code{collect} action prepended | |
10288 | to every tracepoint action list. The expressions are parsed | |
10289 | individually for each tracepoint, so for instance a variable named | |
10290 | @code{xyz} may be interpreted as a global for one tracepoint, and a | |
10291 | local for another, as appropriate to the tracepoint's location. | |
10292 | ||
10293 | @item show default-collect | |
10294 | @kindex show default-collect | |
10295 | Show the list of expressions that are collected by default at each | |
10296 | tracepoint hit. | |
10297 | ||
b37052ae EZ |
10298 | @end table |
10299 | ||
10300 | @node Listing Tracepoints | |
10301 | @subsection Listing Tracepoints | |
10302 | ||
10303 | @table @code | |
10304 | @kindex info tracepoints | |
09d4efe1 | 10305 | @kindex info tp |
b37052ae EZ |
10306 | @cindex information about tracepoints |
10307 | @item info tracepoints @r{[}@var{num}@r{]} | |
1042e4c0 SS |
10308 | Display information about the tracepoint @var{num}. If you don't |
10309 | specify a tracepoint number, displays information about all the | |
10310 | tracepoints defined so far. The format is similar to that used for | |
10311 | @code{info breakpoints}; in fact, @code{info tracepoints} is the same | |
10312 | command, simply restricting itself to tracepoints. | |
10313 | ||
10314 | A tracepoint's listing may include additional information specific to | |
10315 | tracing: | |
b37052ae EZ |
10316 | |
10317 | @itemize @bullet | |
10318 | @item | |
b37052ae | 10319 | its passcount as given by the @code{passcount @var{n}} command |
b37052ae EZ |
10320 | @end itemize |
10321 | ||
10322 | @smallexample | |
10323 | (@value{GDBP}) @b{info trace} | |
1042e4c0 SS |
10324 | Num Type Disp Enb Address What |
10325 | 1 tracepoint keep y 0x0804ab57 in foo() at main.cxx:7 | |
5a9351ae SS |
10326 | while-stepping 20 |
10327 | collect globfoo, $regs | |
10328 | end | |
10329 | collect globfoo2 | |
10330 | end | |
1042e4c0 | 10331 | pass count 1200 |
b37052ae EZ |
10332 | (@value{GDBP}) |
10333 | @end smallexample | |
10334 | ||
10335 | @noindent | |
10336 | This command can be abbreviated @code{info tp}. | |
10337 | @end table | |
10338 | ||
0fb4aa4b PA |
10339 | @node Listing Static Tracepoint Markers |
10340 | @subsection Listing Static Tracepoint Markers | |
10341 | ||
10342 | @table @code | |
10343 | @kindex info static-tracepoint-markers | |
10344 | @cindex information about static tracepoint markers | |
10345 | @item info static-tracepoint-markers | |
10346 | Display information about all static tracepoint markers defined in the | |
10347 | program. | |
10348 | ||
10349 | For each marker, the following columns are printed: | |
10350 | ||
10351 | @table @emph | |
10352 | @item Count | |
10353 | An incrementing counter, output to help readability. This is not a | |
10354 | stable identifier. | |
10355 | @item ID | |
10356 | The marker ID, as reported by the target. | |
10357 | @item Enabled or Disabled | |
10358 | Probed markers are tagged with @samp{y}. @samp{n} identifies marks | |
10359 | that are not enabled. | |
10360 | @item Address | |
10361 | Where the marker is in your program, as a memory address. | |
10362 | @item What | |
10363 | Where the marker is in the source for your program, as a file and line | |
10364 | number. If the debug information included in the program does not | |
10365 | allow @value{GDBN} to locate the source of the marker, this column | |
10366 | will be left blank. | |
10367 | @end table | |
10368 | ||
10369 | @noindent | |
10370 | In addition, the following information may be printed for each marker: | |
10371 | ||
10372 | @table @emph | |
10373 | @item Data | |
10374 | User data passed to the tracing library by the marker call. In the | |
10375 | UST backend, this is the format string passed as argument to the | |
10376 | marker call. | |
10377 | @item Static tracepoints probing the marker | |
10378 | The list of static tracepoints attached to the marker. | |
10379 | @end table | |
10380 | ||
10381 | @smallexample | |
10382 | (@value{GDBP}) info static-tracepoint-markers | |
10383 | Cnt ID Enb Address What | |
10384 | 1 ust/bar2 y 0x0000000000400e1a in main at stexample.c:25 | |
10385 | Data: number1 %d number2 %d | |
10386 | Probed by static tracepoints: #2 | |
10387 | 2 ust/bar33 n 0x0000000000400c87 in main at stexample.c:24 | |
10388 | Data: str %s | |
10389 | (@value{GDBP}) | |
10390 | @end smallexample | |
10391 | @end table | |
10392 | ||
79a6e687 BW |
10393 | @node Starting and Stopping Trace Experiments |
10394 | @subsection Starting and Stopping Trace Experiments | |
b37052ae EZ |
10395 | |
10396 | @table @code | |
10397 | @kindex tstart | |
10398 | @cindex start a new trace experiment | |
10399 | @cindex collected data discarded | |
10400 | @item tstart | |
10401 | This command takes no arguments. It starts the trace experiment, and | |
10402 | begins collecting data. This has the side effect of discarding all | |
10403 | the data collected in the trace buffer during the previous trace | |
10404 | experiment. | |
10405 | ||
10406 | @kindex tstop | |
10407 | @cindex stop a running trace experiment | |
10408 | @item tstop | |
10409 | This command takes no arguments. It ends the trace experiment, and | |
10410 | stops collecting data. | |
10411 | ||
68c71a2e | 10412 | @strong{Note}: a trace experiment and data collection may stop |
b37052ae EZ |
10413 | automatically if any tracepoint's passcount is reached |
10414 | (@pxref{Tracepoint Passcounts}), or if the trace buffer becomes full. | |
10415 | ||
10416 | @kindex tstatus | |
10417 | @cindex status of trace data collection | |
10418 | @cindex trace experiment, status of | |
10419 | @item tstatus | |
10420 | This command displays the status of the current trace data | |
10421 | collection. | |
10422 | @end table | |
10423 | ||
10424 | Here is an example of the commands we described so far: | |
10425 | ||
10426 | @smallexample | |
10427 | (@value{GDBP}) @b{trace gdb_c_test} | |
10428 | (@value{GDBP}) @b{actions} | |
10429 | Enter actions for tracepoint #1, one per line. | |
10430 | > collect $regs,$locals,$args | |
10431 | > while-stepping 11 | |
10432 | > collect $regs | |
10433 | > end | |
10434 | > end | |
10435 | (@value{GDBP}) @b{tstart} | |
10436 | [time passes @dots{}] | |
10437 | (@value{GDBP}) @b{tstop} | |
10438 | @end smallexample | |
10439 | ||
d5551862 SS |
10440 | @cindex disconnected tracing |
10441 | You can choose to continue running the trace experiment even if | |
10442 | @value{GDBN} disconnects from the target, voluntarily or | |
10443 | involuntarily. For commands such as @code{detach}, the debugger will | |
10444 | ask what you want to do with the trace. But for unexpected | |
10445 | terminations (@value{GDBN} crash, network outage), it would be | |
10446 | unfortunate to lose hard-won trace data, so the variable | |
10447 | @code{disconnected-tracing} lets you decide whether the trace should | |
10448 | continue running without @value{GDBN}. | |
10449 | ||
10450 | @table @code | |
10451 | @item set disconnected-tracing on | |
10452 | @itemx set disconnected-tracing off | |
10453 | @kindex set disconnected-tracing | |
10454 | Choose whether a tracing run should continue to run if @value{GDBN} | |
10455 | has disconnected from the target. Note that @code{detach} or | |
10456 | @code{quit} will ask you directly what to do about a running trace no | |
10457 | matter what this variable's setting, so the variable is mainly useful | |
10458 | for handling unexpected situations, such as loss of the network. | |
10459 | ||
10460 | @item show disconnected-tracing | |
10461 | @kindex show disconnected-tracing | |
10462 | Show the current choice for disconnected tracing. | |
10463 | ||
10464 | @end table | |
10465 | ||
10466 | When you reconnect to the target, the trace experiment may or may not | |
10467 | still be running; it might have filled the trace buffer in the | |
10468 | meantime, or stopped for one of the other reasons. If it is running, | |
10469 | it will continue after reconnection. | |
10470 | ||
10471 | Upon reconnection, the target will upload information about the | |
10472 | tracepoints in effect. @value{GDBN} will then compare that | |
10473 | information to the set of tracepoints currently defined, and attempt | |
10474 | to match them up, allowing for the possibility that the numbers may | |
10475 | have changed due to creation and deletion in the meantime. If one of | |
10476 | the target's tracepoints does not match any in @value{GDBN}, the | |
10477 | debugger will create a new tracepoint, so that you have a number with | |
10478 | which to specify that tracepoint. This matching-up process is | |
10479 | necessarily heuristic, and it may result in useless tracepoints being | |
10480 | created; you may simply delete them if they are of no use. | |
b37052ae | 10481 | |
4daf5ac0 SS |
10482 | @cindex circular trace buffer |
10483 | If your target agent supports a @dfn{circular trace buffer}, then you | |
10484 | can run a trace experiment indefinitely without filling the trace | |
10485 | buffer; when space runs out, the agent deletes already-collected trace | |
10486 | frames, oldest first, until there is enough room to continue | |
10487 | collecting. This is especially useful if your tracepoints are being | |
10488 | hit too often, and your trace gets terminated prematurely because the | |
10489 | buffer is full. To ask for a circular trace buffer, simply set | |
10490 | @samp{circular_trace_buffer} to on. You can set this at any time, | |
10491 | including during tracing; if the agent can do it, it will change | |
10492 | buffer handling on the fly, otherwise it will not take effect until | |
10493 | the next run. | |
10494 | ||
10495 | @table @code | |
10496 | @item set circular-trace-buffer on | |
10497 | @itemx set circular-trace-buffer off | |
10498 | @kindex set circular-trace-buffer | |
10499 | Choose whether a tracing run should use a linear or circular buffer | |
10500 | for trace data. A linear buffer will not lose any trace data, but may | |
10501 | fill up prematurely, while a circular buffer will discard old trace | |
10502 | data, but it will have always room for the latest tracepoint hits. | |
10503 | ||
10504 | @item show circular-trace-buffer | |
10505 | @kindex show circular-trace-buffer | |
10506 | Show the current choice for the trace buffer. Note that this may not | |
10507 | match the agent's current buffer handling, nor is it guaranteed to | |
10508 | match the setting that might have been in effect during a past run, | |
10509 | for instance if you are looking at frames from a trace file. | |
10510 | ||
10511 | @end table | |
10512 | ||
c9429232 SS |
10513 | @node Tracepoint Restrictions |
10514 | @subsection Tracepoint Restrictions | |
10515 | ||
10516 | @cindex tracepoint restrictions | |
10517 | There are a number of restrictions on the use of tracepoints. As | |
10518 | described above, tracepoint data gathering occurs on the target | |
10519 | without interaction from @value{GDBN}. Thus the full capabilities of | |
10520 | the debugger are not available during data gathering, and then at data | |
10521 | examination time, you will be limited by only having what was | |
10522 | collected. The following items describe some common problems, but it | |
10523 | is not exhaustive, and you may run into additional difficulties not | |
10524 | mentioned here. | |
10525 | ||
10526 | @itemize @bullet | |
10527 | ||
10528 | @item | |
10529 | Tracepoint expressions are intended to gather objects (lvalues). Thus | |
10530 | the full flexibility of GDB's expression evaluator is not available. | |
10531 | You cannot call functions, cast objects to aggregate types, access | |
10532 | convenience variables or modify values (except by assignment to trace | |
10533 | state variables). Some language features may implicitly call | |
10534 | functions (for instance Objective-C fields with accessors), and therefore | |
10535 | cannot be collected either. | |
10536 | ||
10537 | @item | |
10538 | Collection of local variables, either individually or in bulk with | |
10539 | @code{$locals} or @code{$args}, during @code{while-stepping} may | |
10540 | behave erratically. The stepping action may enter a new scope (for | |
10541 | instance by stepping into a function), or the location of the variable | |
10542 | may change (for instance it is loaded into a register). The | |
10543 | tracepoint data recorded uses the location information for the | |
10544 | variables that is correct for the tracepoint location. When the | |
10545 | tracepoint is created, it is not possible, in general, to determine | |
10546 | where the steps of a @code{while-stepping} sequence will advance the | |
10547 | program---particularly if a conditional branch is stepped. | |
10548 | ||
10549 | @item | |
10550 | Collection of an incompletely-initialized or partially-destroyed object | |
10551 | may result in something that @value{GDBN} cannot display, or displays | |
10552 | in a misleading way. | |
10553 | ||
10554 | @item | |
10555 | When @value{GDBN} displays a pointer to character it automatically | |
10556 | dereferences the pointer to also display characters of the string | |
10557 | being pointed to. However, collecting the pointer during tracing does | |
10558 | not automatically collect the string. You need to explicitly | |
10559 | dereference the pointer and provide size information if you want to | |
10560 | collect not only the pointer, but the memory pointed to. For example, | |
10561 | @code{*ptr@@50} can be used to collect the 50 element array pointed to | |
10562 | by @code{ptr}. | |
10563 | ||
10564 | @item | |
10565 | It is not possible to collect a complete stack backtrace at a | |
10566 | tracepoint. Instead, you may collect the registers and a few hundred | |
10567 | bytes from the stack pointer with something like @code{*$esp@@300} | |
10568 | (adjust to use the name of the actual stack pointer register on your | |
10569 | target architecture, and the amount of stack you wish to capture). | |
10570 | Then the @code{backtrace} command will show a partial backtrace when | |
10571 | using a trace frame. The number of stack frames that can be examined | |
10572 | depends on the sizes of the frames in the collected stack. Note that | |
10573 | if you ask for a block so large that it goes past the bottom of the | |
10574 | stack, the target agent may report an error trying to read from an | |
10575 | invalid address. | |
10576 | ||
af54718e SS |
10577 | @item |
10578 | If you do not collect registers at a tracepoint, @value{GDBN} can | |
10579 | infer that the value of @code{$pc} must be the same as the address of | |
10580 | the tracepoint and use that when you are looking at a trace frame | |
10581 | for that tracepoint. However, this cannot work if the tracepoint has | |
10582 | multiple locations (for instance if it was set in a function that was | |
10583 | inlined), or if it has a @code{while-stepping} loop. In those cases | |
10584 | @value{GDBN} will warn you that it can't infer @code{$pc}, and default | |
10585 | it to zero. | |
10586 | ||
c9429232 SS |
10587 | @end itemize |
10588 | ||
b37052ae | 10589 | @node Analyze Collected Data |
79a6e687 | 10590 | @section Using the Collected Data |
b37052ae EZ |
10591 | |
10592 | After the tracepoint experiment ends, you use @value{GDBN} commands | |
10593 | for examining the trace data. The basic idea is that each tracepoint | |
10594 | collects a trace @dfn{snapshot} every time it is hit and another | |
10595 | snapshot every time it single-steps. All these snapshots are | |
10596 | consecutively numbered from zero and go into a buffer, and you can | |
10597 | examine them later. The way you examine them is to @dfn{focus} on a | |
10598 | specific trace snapshot. When the remote stub is focused on a trace | |
10599 | snapshot, it will respond to all @value{GDBN} requests for memory and | |
10600 | registers by reading from the buffer which belongs to that snapshot, | |
10601 | rather than from @emph{real} memory or registers of the program being | |
10602 | debugged. This means that @strong{all} @value{GDBN} commands | |
10603 | (@code{print}, @code{info registers}, @code{backtrace}, etc.) will | |
10604 | behave as if we were currently debugging the program state as it was | |
10605 | when the tracepoint occurred. Any requests for data that are not in | |
10606 | the buffer will fail. | |
10607 | ||
10608 | @menu | |
10609 | * tfind:: How to select a trace snapshot | |
10610 | * tdump:: How to display all data for a snapshot | |
6149aea9 | 10611 | * save tracepoints:: How to save tracepoints for a future run |
b37052ae EZ |
10612 | @end menu |
10613 | ||
10614 | @node tfind | |
10615 | @subsection @code{tfind @var{n}} | |
10616 | ||
10617 | @kindex tfind | |
10618 | @cindex select trace snapshot | |
10619 | @cindex find trace snapshot | |
10620 | The basic command for selecting a trace snapshot from the buffer is | |
10621 | @code{tfind @var{n}}, which finds trace snapshot number @var{n}, | |
10622 | counting from zero. If no argument @var{n} is given, the next | |
10623 | snapshot is selected. | |
10624 | ||
10625 | Here are the various forms of using the @code{tfind} command. | |
10626 | ||
10627 | @table @code | |
10628 | @item tfind start | |
10629 | Find the first snapshot in the buffer. This is a synonym for | |
10630 | @code{tfind 0} (since 0 is the number of the first snapshot). | |
10631 | ||
10632 | @item tfind none | |
10633 | Stop debugging trace snapshots, resume @emph{live} debugging. | |
10634 | ||
10635 | @item tfind end | |
10636 | Same as @samp{tfind none}. | |
10637 | ||
10638 | @item tfind | |
10639 | No argument means find the next trace snapshot. | |
10640 | ||
10641 | @item tfind - | |
10642 | Find the previous trace snapshot before the current one. This permits | |
10643 | retracing earlier steps. | |
10644 | ||
10645 | @item tfind tracepoint @var{num} | |
10646 | Find the next snapshot associated with tracepoint @var{num}. Search | |
10647 | proceeds forward from the last examined trace snapshot. If no | |
10648 | argument @var{num} is given, it means find the next snapshot collected | |
10649 | for the same tracepoint as the current snapshot. | |
10650 | ||
10651 | @item tfind pc @var{addr} | |
10652 | Find the next snapshot associated with the value @var{addr} of the | |
10653 | program counter. Search proceeds forward from the last examined trace | |
10654 | snapshot. If no argument @var{addr} is given, it means find the next | |
10655 | snapshot with the same value of PC as the current snapshot. | |
10656 | ||
10657 | @item tfind outside @var{addr1}, @var{addr2} | |
10658 | Find the next snapshot whose PC is outside the given range of | |
081dfbf7 | 10659 | addresses (exclusive). |
b37052ae EZ |
10660 | |
10661 | @item tfind range @var{addr1}, @var{addr2} | |
10662 | Find the next snapshot whose PC is between @var{addr1} and | |
081dfbf7 | 10663 | @var{addr2} (inclusive). |
b37052ae EZ |
10664 | |
10665 | @item tfind line @r{[}@var{file}:@r{]}@var{n} | |
10666 | Find the next snapshot associated with the source line @var{n}. If | |
10667 | the optional argument @var{file} is given, refer to line @var{n} in | |
10668 | that source file. Search proceeds forward from the last examined | |
10669 | trace snapshot. If no argument @var{n} is given, it means find the | |
10670 | next line other than the one currently being examined; thus saying | |
10671 | @code{tfind line} repeatedly can appear to have the same effect as | |
10672 | stepping from line to line in a @emph{live} debugging session. | |
10673 | @end table | |
10674 | ||
10675 | The default arguments for the @code{tfind} commands are specifically | |
10676 | designed to make it easy to scan through the trace buffer. For | |
10677 | instance, @code{tfind} with no argument selects the next trace | |
10678 | snapshot, and @code{tfind -} with no argument selects the previous | |
10679 | trace snapshot. So, by giving one @code{tfind} command, and then | |
10680 | simply hitting @key{RET} repeatedly you can examine all the trace | |
10681 | snapshots in order. Or, by saying @code{tfind -} and then hitting | |
10682 | @key{RET} repeatedly you can examine the snapshots in reverse order. | |
10683 | The @code{tfind line} command with no argument selects the snapshot | |
10684 | for the next source line executed. The @code{tfind pc} command with | |
10685 | no argument selects the next snapshot with the same program counter | |
10686 | (PC) as the current frame. The @code{tfind tracepoint} command with | |
10687 | no argument selects the next trace snapshot collected by the same | |
10688 | tracepoint as the current one. | |
10689 | ||
10690 | In addition to letting you scan through the trace buffer manually, | |
10691 | these commands make it easy to construct @value{GDBN} scripts that | |
10692 | scan through the trace buffer and print out whatever collected data | |
10693 | you are interested in. Thus, if we want to examine the PC, FP, and SP | |
10694 | registers from each trace frame in the buffer, we can say this: | |
10695 | ||
10696 | @smallexample | |
10697 | (@value{GDBP}) @b{tfind start} | |
10698 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
10699 | > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \ | |
10700 | $trace_frame, $pc, $sp, $fp | |
10701 | > tfind | |
10702 | > end | |
10703 | ||
10704 | Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44 | |
10705 | Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44 | |
10706 | Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44 | |
10707 | Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44 | |
10708 | Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44 | |
10709 | Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44 | |
10710 | Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44 | |
10711 | Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44 | |
10712 | Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44 | |
10713 | Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44 | |
10714 | Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14 | |
10715 | @end smallexample | |
10716 | ||
10717 | Or, if we want to examine the variable @code{X} at each source line in | |
10718 | the buffer: | |
10719 | ||
10720 | @smallexample | |
10721 | (@value{GDBP}) @b{tfind start} | |
10722 | (@value{GDBP}) @b{while ($trace_frame != -1)} | |
10723 | > printf "Frame %d, X == %d\n", $trace_frame, X | |
10724 | > tfind line | |
10725 | > end | |
10726 | ||
10727 | Frame 0, X = 1 | |
10728 | Frame 7, X = 2 | |
10729 | Frame 13, X = 255 | |
10730 | @end smallexample | |
10731 | ||
10732 | @node tdump | |
10733 | @subsection @code{tdump} | |
10734 | @kindex tdump | |
10735 | @cindex dump all data collected at tracepoint | |
10736 | @cindex tracepoint data, display | |
10737 | ||
10738 | This command takes no arguments. It prints all the data collected at | |
10739 | the current trace snapshot. | |
10740 | ||
10741 | @smallexample | |
10742 | (@value{GDBP}) @b{trace 444} | |
10743 | (@value{GDBP}) @b{actions} | |
10744 | Enter actions for tracepoint #2, one per line: | |
10745 | > collect $regs, $locals, $args, gdb_long_test | |
10746 | > end | |
10747 | ||
10748 | (@value{GDBP}) @b{tstart} | |
10749 | ||
10750 | (@value{GDBP}) @b{tfind line 444} | |
10751 | #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66) | |
10752 | at gdb_test.c:444 | |
10753 | 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ) | |
10754 | ||
10755 | (@value{GDBP}) @b{tdump} | |
10756 | Data collected at tracepoint 2, trace frame 1: | |
10757 | d0 0xc4aa0085 -995491707 | |
10758 | d1 0x18 24 | |
10759 | d2 0x80 128 | |
10760 | d3 0x33 51 | |
10761 | d4 0x71aea3d 119204413 | |
10762 | d5 0x22 34 | |
10763 | d6 0xe0 224 | |
10764 | d7 0x380035 3670069 | |
10765 | a0 0x19e24a 1696330 | |
10766 | a1 0x3000668 50333288 | |
10767 | a2 0x100 256 | |
10768 | a3 0x322000 3284992 | |
10769 | a4 0x3000698 50333336 | |
10770 | a5 0x1ad3cc 1758156 | |
10771 | fp 0x30bf3c 0x30bf3c | |
10772 | sp 0x30bf34 0x30bf34 | |
10773 | ps 0x0 0 | |
10774 | pc 0x20b2c8 0x20b2c8 | |
10775 | fpcontrol 0x0 0 | |
10776 | fpstatus 0x0 0 | |
10777 | fpiaddr 0x0 0 | |
10778 | p = 0x20e5b4 "gdb-test" | |
10779 | p1 = (void *) 0x11 | |
10780 | p2 = (void *) 0x22 | |
10781 | p3 = (void *) 0x33 | |
10782 | p4 = (void *) 0x44 | |
10783 | p5 = (void *) 0x55 | |
10784 | p6 = (void *) 0x66 | |
10785 | gdb_long_test = 17 '\021' | |
10786 | ||
10787 | (@value{GDBP}) | |
10788 | @end smallexample | |
10789 | ||
af54718e SS |
10790 | @code{tdump} works by scanning the tracepoint's current collection |
10791 | actions and printing the value of each expression listed. So | |
10792 | @code{tdump} can fail, if after a run, you change the tracepoint's | |
10793 | actions to mention variables that were not collected during the run. | |
10794 | ||
10795 | Also, for tracepoints with @code{while-stepping} loops, @code{tdump} | |
10796 | uses the collected value of @code{$pc} to distinguish between trace | |
10797 | frames that were collected at the tracepoint hit, and frames that were | |
10798 | collected while stepping. This allows it to correctly choose whether | |
10799 | to display the basic list of collections, or the collections from the | |
10800 | body of the while-stepping loop. However, if @code{$pc} was not collected, | |
10801 | then @code{tdump} will always attempt to dump using the basic collection | |
10802 | list, and may fail if a while-stepping frame does not include all the | |
10803 | same data that is collected at the tracepoint hit. | |
10804 | @c This is getting pretty arcane, example would be good. | |
10805 | ||
6149aea9 PA |
10806 | @node save tracepoints |
10807 | @subsection @code{save tracepoints @var{filename}} | |
10808 | @kindex save tracepoints | |
b37052ae EZ |
10809 | @kindex save-tracepoints |
10810 | @cindex save tracepoints for future sessions | |
10811 | ||
10812 | This command saves all current tracepoint definitions together with | |
10813 | their actions and passcounts, into a file @file{@var{filename}} | |
10814 | suitable for use in a later debugging session. To read the saved | |
10815 | tracepoint definitions, use the @code{source} command (@pxref{Command | |
6149aea9 PA |
10816 | Files}). The @w{@code{save-tracepoints}} command is a deprecated |
10817 | alias for @w{@code{save tracepoints}} | |
b37052ae EZ |
10818 | |
10819 | @node Tracepoint Variables | |
10820 | @section Convenience Variables for Tracepoints | |
10821 | @cindex tracepoint variables | |
10822 | @cindex convenience variables for tracepoints | |
10823 | ||
10824 | @table @code | |
10825 | @vindex $trace_frame | |
10826 | @item (int) $trace_frame | |
10827 | The current trace snapshot (a.k.a.@: @dfn{frame}) number, or -1 if no | |
10828 | snapshot is selected. | |
10829 | ||
10830 | @vindex $tracepoint | |
10831 | @item (int) $tracepoint | |
10832 | The tracepoint for the current trace snapshot. | |
10833 | ||
10834 | @vindex $trace_line | |
10835 | @item (int) $trace_line | |
10836 | The line number for the current trace snapshot. | |
10837 | ||
10838 | @vindex $trace_file | |
10839 | @item (char []) $trace_file | |
10840 | The source file for the current trace snapshot. | |
10841 | ||
10842 | @vindex $trace_func | |
10843 | @item (char []) $trace_func | |
10844 | The name of the function containing @code{$tracepoint}. | |
10845 | @end table | |
10846 | ||
10847 | Note: @code{$trace_file} is not suitable for use in @code{printf}, | |
10848 | use @code{output} instead. | |
10849 | ||
10850 | Here's a simple example of using these convenience variables for | |
10851 | stepping through all the trace snapshots and printing some of their | |
f61e138d SS |
10852 | data. Note that these are not the same as trace state variables, |
10853 | which are managed by the target. | |
b37052ae EZ |
10854 | |
10855 | @smallexample | |
10856 | (@value{GDBP}) @b{tfind start} | |
10857 | ||
10858 | (@value{GDBP}) @b{while $trace_frame != -1} | |
10859 | > output $trace_file | |
10860 | > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint | |
10861 | > tfind | |
10862 | > end | |
10863 | @end smallexample | |
10864 | ||
00bf0b85 SS |
10865 | @node Trace Files |
10866 | @section Using Trace Files | |
10867 | @cindex trace files | |
10868 | ||
10869 | In some situations, the target running a trace experiment may no | |
10870 | longer be available; perhaps it crashed, or the hardware was needed | |
10871 | for a different activity. To handle these cases, you can arrange to | |
10872 | dump the trace data into a file, and later use that file as a source | |
10873 | of trace data, via the @code{target tfile} command. | |
10874 | ||
10875 | @table @code | |
10876 | ||
10877 | @kindex tsave | |
10878 | @item tsave [ -r ] @var{filename} | |
10879 | Save the trace data to @var{filename}. By default, this command | |
10880 | assumes that @var{filename} refers to the host filesystem, so if | |
10881 | necessary @value{GDBN} will copy raw trace data up from the target and | |
10882 | then save it. If the target supports it, you can also supply the | |
10883 | optional argument @code{-r} (``remote'') to direct the target to save | |
10884 | the data directly into @var{filename} in its own filesystem, which may be | |
10885 | more efficient if the trace buffer is very large. (Note, however, that | |
10886 | @code{target tfile} can only read from files accessible to the host.) | |
10887 | ||
10888 | @kindex target tfile | |
10889 | @kindex tfile | |
10890 | @item target tfile @var{filename} | |
10891 | Use the file named @var{filename} as a source of trace data. Commands | |
10892 | that examine data work as they do with a live target, but it is not | |
10893 | possible to run any new trace experiments. @code{tstatus} will report | |
10894 | the state of the trace run at the moment the data was saved, as well | |
10895 | as the current trace frame you are examining. @var{filename} must be | |
10896 | on a filesystem accessible to the host. | |
10897 | ||
10898 | @end table | |
10899 | ||
df0cd8c5 JB |
10900 | @node Overlays |
10901 | @chapter Debugging Programs That Use Overlays | |
10902 | @cindex overlays | |
10903 | ||
10904 | If your program is too large to fit completely in your target system's | |
10905 | memory, you can sometimes use @dfn{overlays} to work around this | |
10906 | problem. @value{GDBN} provides some support for debugging programs that | |
10907 | use overlays. | |
10908 | ||
10909 | @menu | |
10910 | * How Overlays Work:: A general explanation of overlays. | |
10911 | * Overlay Commands:: Managing overlays in @value{GDBN}. | |
10912 | * Automatic Overlay Debugging:: @value{GDBN} can find out which overlays are | |
10913 | mapped by asking the inferior. | |
10914 | * Overlay Sample Program:: A sample program using overlays. | |
10915 | @end menu | |
10916 | ||
10917 | @node How Overlays Work | |
10918 | @section How Overlays Work | |
10919 | @cindex mapped overlays | |
10920 | @cindex unmapped overlays | |
10921 | @cindex load address, overlay's | |
10922 | @cindex mapped address | |
10923 | @cindex overlay area | |
10924 | ||
10925 | Suppose you have a computer whose instruction address space is only 64 | |
10926 | kilobytes long, but which has much more memory which can be accessed by | |
10927 | other means: special instructions, segment registers, or memory | |
10928 | management hardware, for example. Suppose further that you want to | |
10929 | adapt a program which is larger than 64 kilobytes to run on this system. | |
10930 | ||
10931 | One solution is to identify modules of your program which are relatively | |
10932 | independent, and need not call each other directly; call these modules | |
10933 | @dfn{overlays}. Separate the overlays from the main program, and place | |
10934 | their machine code in the larger memory. Place your main program in | |
10935 | instruction memory, but leave at least enough space there to hold the | |
10936 | largest overlay as well. | |
10937 | ||
10938 | Now, to call a function located in an overlay, you must first copy that | |
10939 | overlay's machine code from the large memory into the space set aside | |
10940 | for it in the instruction memory, and then jump to its entry point | |
10941 | there. | |
10942 | ||
c928edc0 AC |
10943 | @c NB: In the below the mapped area's size is greater or equal to the |
10944 | @c size of all overlays. This is intentional to remind the developer | |
10945 | @c that overlays don't necessarily need to be the same size. | |
10946 | ||
474c8240 | 10947 | @smallexample |
df0cd8c5 | 10948 | @group |
c928edc0 AC |
10949 | Data Instruction Larger |
10950 | Address Space Address Space Address Space | |
10951 | +-----------+ +-----------+ +-----------+ | |
10952 | | | | | | | | |
10953 | +-----------+ +-----------+ +-----------+<-- overlay 1 | |
10954 | | program | | main | .----| overlay 1 | load address | |
10955 | | variables | | program | | +-----------+ | |
10956 | | and heap | | | | | | | |
10957 | +-----------+ | | | +-----------+<-- overlay 2 | |
10958 | | | +-----------+ | | | load address | |
10959 | +-----------+ | | | .-| overlay 2 | | |
10960 | | | | | | | | |
10961 | mapped --->+-----------+ | | +-----------+ | |
10962 | address | | | | | | | |
10963 | | overlay | <-' | | | | |
10964 | | area | <---' +-----------+<-- overlay 3 | |
10965 | | | <---. | | load address | |
10966 | +-----------+ `--| overlay 3 | | |
10967 | | | | | | |
10968 | +-----------+ | | | |
10969 | +-----------+ | |
10970 | | | | |
10971 | +-----------+ | |
10972 | ||
10973 | @anchor{A code overlay}A code overlay | |
df0cd8c5 | 10974 | @end group |
474c8240 | 10975 | @end smallexample |
df0cd8c5 | 10976 | |
c928edc0 AC |
10977 | The diagram (@pxref{A code overlay}) shows a system with separate data |
10978 | and instruction address spaces. To map an overlay, the program copies | |
10979 | its code from the larger address space to the instruction address space. | |
10980 | Since the overlays shown here all use the same mapped address, only one | |
10981 | may be mapped at a time. For a system with a single address space for | |
10982 | data and instructions, the diagram would be similar, except that the | |
10983 | program variables and heap would share an address space with the main | |
10984 | program and the overlay area. | |
df0cd8c5 JB |
10985 | |
10986 | An overlay loaded into instruction memory and ready for use is called a | |
10987 | @dfn{mapped} overlay; its @dfn{mapped address} is its address in the | |
10988 | instruction memory. An overlay not present (or only partially present) | |
10989 | in instruction memory is called @dfn{unmapped}; its @dfn{load address} | |
10990 | is its address in the larger memory. The mapped address is also called | |
10991 | the @dfn{virtual memory address}, or @dfn{VMA}; the load address is also | |
10992 | called the @dfn{load memory address}, or @dfn{LMA}. | |
10993 | ||
10994 | Unfortunately, overlays are not a completely transparent way to adapt a | |
10995 | program to limited instruction memory. They introduce a new set of | |
10996 | global constraints you must keep in mind as you design your program: | |
10997 | ||
10998 | @itemize @bullet | |
10999 | ||
11000 | @item | |
11001 | Before calling or returning to a function in an overlay, your program | |
11002 | must make sure that overlay is actually mapped. Otherwise, the call or | |
11003 | return will transfer control to the right address, but in the wrong | |
11004 | overlay, and your program will probably crash. | |
11005 | ||
11006 | @item | |
11007 | If the process of mapping an overlay is expensive on your system, you | |
11008 | will need to choose your overlays carefully to minimize their effect on | |
11009 | your program's performance. | |
11010 | ||
11011 | @item | |
11012 | The executable file you load onto your system must contain each | |
11013 | overlay's instructions, appearing at the overlay's load address, not its | |
11014 | mapped address. However, each overlay's instructions must be relocated | |
11015 | and its symbols defined as if the overlay were at its mapped address. | |
11016 | You can use GNU linker scripts to specify different load and relocation | |
11017 | addresses for pieces of your program; see @ref{Overlay Description,,, | |
11018 | ld.info, Using ld: the GNU linker}. | |
11019 | ||
11020 | @item | |
11021 | The procedure for loading executable files onto your system must be able | |
11022 | to load their contents into the larger address space as well as the | |
11023 | instruction and data spaces. | |
11024 | ||
11025 | @end itemize | |
11026 | ||
11027 | The overlay system described above is rather simple, and could be | |
11028 | improved in many ways: | |
11029 | ||
11030 | @itemize @bullet | |
11031 | ||
11032 | @item | |
11033 | If your system has suitable bank switch registers or memory management | |
11034 | hardware, you could use those facilities to make an overlay's load area | |
11035 | contents simply appear at their mapped address in instruction space. | |
11036 | This would probably be faster than copying the overlay to its mapped | |
11037 | area in the usual way. | |
11038 | ||
11039 | @item | |
11040 | If your overlays are small enough, you could set aside more than one | |
11041 | overlay area, and have more than one overlay mapped at a time. | |
11042 | ||
11043 | @item | |
11044 | You can use overlays to manage data, as well as instructions. In | |
11045 | general, data overlays are even less transparent to your design than | |
11046 | code overlays: whereas code overlays only require care when you call or | |
11047 | return to functions, data overlays require care every time you access | |
11048 | the data. Also, if you change the contents of a data overlay, you | |
11049 | must copy its contents back out to its load address before you can copy a | |
11050 | different data overlay into the same mapped area. | |
11051 | ||
11052 | @end itemize | |
11053 | ||
11054 | ||
11055 | @node Overlay Commands | |
11056 | @section Overlay Commands | |
11057 | ||
11058 | To use @value{GDBN}'s overlay support, each overlay in your program must | |
11059 | correspond to a separate section of the executable file. The section's | |
11060 | virtual memory address and load memory address must be the overlay's | |
11061 | mapped and load addresses. Identifying overlays with sections allows | |
11062 | @value{GDBN} to determine the appropriate address of a function or | |
11063 | variable, depending on whether the overlay is mapped or not. | |
11064 | ||
11065 | @value{GDBN}'s overlay commands all start with the word @code{overlay}; | |
11066 | you can abbreviate this as @code{ov} or @code{ovly}. The commands are: | |
11067 | ||
11068 | @table @code | |
11069 | @item overlay off | |
4644b6e3 | 11070 | @kindex overlay |
df0cd8c5 JB |
11071 | Disable @value{GDBN}'s overlay support. When overlay support is |
11072 | disabled, @value{GDBN} assumes that all functions and variables are | |
11073 | always present at their mapped addresses. By default, @value{GDBN}'s | |
11074 | overlay support is disabled. | |
11075 | ||
11076 | @item overlay manual | |
df0cd8c5 JB |
11077 | @cindex manual overlay debugging |
11078 | Enable @dfn{manual} overlay debugging. In this mode, @value{GDBN} | |
11079 | relies on you to tell it which overlays are mapped, and which are not, | |
11080 | using the @code{overlay map-overlay} and @code{overlay unmap-overlay} | |
11081 | commands described below. | |
11082 | ||
11083 | @item overlay map-overlay @var{overlay} | |
11084 | @itemx overlay map @var{overlay} | |
df0cd8c5 JB |
11085 | @cindex map an overlay |
11086 | Tell @value{GDBN} that @var{overlay} is now mapped; @var{overlay} must | |
11087 | be the name of the object file section containing the overlay. When an | |
11088 | overlay is mapped, @value{GDBN} assumes it can find the overlay's | |
11089 | functions and variables at their mapped addresses. @value{GDBN} assumes | |
11090 | that any other overlays whose mapped ranges overlap that of | |
11091 | @var{overlay} are now unmapped. | |
11092 | ||
11093 | @item overlay unmap-overlay @var{overlay} | |
11094 | @itemx overlay unmap @var{overlay} | |
df0cd8c5 JB |
11095 | @cindex unmap an overlay |
11096 | Tell @value{GDBN} that @var{overlay} is no longer mapped; @var{overlay} | |
11097 | must be the name of the object file section containing the overlay. | |
11098 | When an overlay is unmapped, @value{GDBN} assumes it can find the | |
11099 | overlay's functions and variables at their load addresses. | |
11100 | ||
11101 | @item overlay auto | |
df0cd8c5 JB |
11102 | Enable @dfn{automatic} overlay debugging. In this mode, @value{GDBN} |
11103 | consults a data structure the overlay manager maintains in the inferior | |
11104 | to see which overlays are mapped. For details, see @ref{Automatic | |
11105 | Overlay Debugging}. | |
11106 | ||
11107 | @item overlay load-target | |
11108 | @itemx overlay load | |
df0cd8c5 JB |
11109 | @cindex reloading the overlay table |
11110 | Re-read the overlay table from the inferior. Normally, @value{GDBN} | |
11111 | re-reads the table @value{GDBN} automatically each time the inferior | |
11112 | stops, so this command should only be necessary if you have changed the | |
11113 | overlay mapping yourself using @value{GDBN}. This command is only | |
11114 | useful when using automatic overlay debugging. | |
11115 | ||
11116 | @item overlay list-overlays | |
11117 | @itemx overlay list | |
11118 | @cindex listing mapped overlays | |
11119 | Display a list of the overlays currently mapped, along with their mapped | |
11120 | addresses, load addresses, and sizes. | |
11121 | ||
11122 | @end table | |
11123 | ||
11124 | Normally, when @value{GDBN} prints a code address, it includes the name | |
11125 | of the function the address falls in: | |
11126 | ||
474c8240 | 11127 | @smallexample |
f7dc1244 | 11128 | (@value{GDBP}) print main |
df0cd8c5 | 11129 | $3 = @{int ()@} 0x11a0 <main> |
474c8240 | 11130 | @end smallexample |
df0cd8c5 JB |
11131 | @noindent |
11132 | When overlay debugging is enabled, @value{GDBN} recognizes code in | |
11133 | unmapped overlays, and prints the names of unmapped functions with | |
11134 | asterisks around them. For example, if @code{foo} is a function in an | |
11135 | unmapped overlay, @value{GDBN} prints it this way: | |
11136 | ||
474c8240 | 11137 | @smallexample |
f7dc1244 | 11138 | (@value{GDBP}) overlay list |
df0cd8c5 | 11139 | No sections are mapped. |
f7dc1244 | 11140 | (@value{GDBP}) print foo |
df0cd8c5 | 11141 | $5 = @{int (int)@} 0x100000 <*foo*> |
474c8240 | 11142 | @end smallexample |
df0cd8c5 JB |
11143 | @noindent |
11144 | When @code{foo}'s overlay is mapped, @value{GDBN} prints the function's | |
11145 | name normally: | |
11146 | ||
474c8240 | 11147 | @smallexample |
f7dc1244 | 11148 | (@value{GDBP}) overlay list |
b383017d | 11149 | Section .ov.foo.text, loaded at 0x100000 - 0x100034, |
df0cd8c5 | 11150 | mapped at 0x1016 - 0x104a |
f7dc1244 | 11151 | (@value{GDBP}) print foo |
df0cd8c5 | 11152 | $6 = @{int (int)@} 0x1016 <foo> |
474c8240 | 11153 | @end smallexample |
df0cd8c5 JB |
11154 | |
11155 | When overlay debugging is enabled, @value{GDBN} can find the correct | |
11156 | address for functions and variables in an overlay, whether or not the | |
11157 | overlay is mapped. This allows most @value{GDBN} commands, like | |
11158 | @code{break} and @code{disassemble}, to work normally, even on unmapped | |
11159 | code. However, @value{GDBN}'s breakpoint support has some limitations: | |
11160 | ||
11161 | @itemize @bullet | |
11162 | @item | |
11163 | @cindex breakpoints in overlays | |
11164 | @cindex overlays, setting breakpoints in | |
11165 | You can set breakpoints in functions in unmapped overlays, as long as | |
11166 | @value{GDBN} can write to the overlay at its load address. | |
11167 | @item | |
11168 | @value{GDBN} can not set hardware or simulator-based breakpoints in | |
11169 | unmapped overlays. However, if you set a breakpoint at the end of your | |
11170 | overlay manager (and tell @value{GDBN} which overlays are now mapped, if | |
11171 | you are using manual overlay management), @value{GDBN} will re-set its | |
11172 | breakpoints properly. | |
11173 | @end itemize | |
11174 | ||
11175 | ||
11176 | @node Automatic Overlay Debugging | |
11177 | @section Automatic Overlay Debugging | |
11178 | @cindex automatic overlay debugging | |
11179 | ||
11180 | @value{GDBN} can automatically track which overlays are mapped and which | |
11181 | are not, given some simple co-operation from the overlay manager in the | |
11182 | inferior. If you enable automatic overlay debugging with the | |
11183 | @code{overlay auto} command (@pxref{Overlay Commands}), @value{GDBN} | |
11184 | looks in the inferior's memory for certain variables describing the | |
11185 | current state of the overlays. | |
11186 | ||
11187 | Here are the variables your overlay manager must define to support | |
11188 | @value{GDBN}'s automatic overlay debugging: | |
11189 | ||
11190 | @table @asis | |
11191 | ||
11192 | @item @code{_ovly_table}: | |
11193 | This variable must be an array of the following structures: | |
11194 | ||
474c8240 | 11195 | @smallexample |
df0cd8c5 JB |
11196 | struct |
11197 | @{ | |
11198 | /* The overlay's mapped address. */ | |
11199 | unsigned long vma; | |
11200 | ||
11201 | /* The size of the overlay, in bytes. */ | |
11202 | unsigned long size; | |
11203 | ||
11204 | /* The overlay's load address. */ | |
11205 | unsigned long lma; | |
11206 | ||
11207 | /* Non-zero if the overlay is currently mapped; | |
11208 | zero otherwise. */ | |
11209 | unsigned long mapped; | |
11210 | @} | |
474c8240 | 11211 | @end smallexample |
df0cd8c5 JB |
11212 | |
11213 | @item @code{_novlys}: | |
11214 | This variable must be a four-byte signed integer, holding the total | |
11215 | number of elements in @code{_ovly_table}. | |
11216 | ||
11217 | @end table | |
11218 | ||
11219 | To decide whether a particular overlay is mapped or not, @value{GDBN} | |
11220 | looks for an entry in @w{@code{_ovly_table}} whose @code{vma} and | |
11221 | @code{lma} members equal the VMA and LMA of the overlay's section in the | |
11222 | executable file. When @value{GDBN} finds a matching entry, it consults | |
11223 | the entry's @code{mapped} member to determine whether the overlay is | |
11224 | currently mapped. | |
11225 | ||
81d46470 | 11226 | In addition, your overlay manager may define a function called |
def71bfa | 11227 | @code{_ovly_debug_event}. If this function is defined, @value{GDBN} |
81d46470 MS |
11228 | will silently set a breakpoint there. If the overlay manager then |
11229 | calls this function whenever it has changed the overlay table, this | |
11230 | will enable @value{GDBN} to accurately keep track of which overlays | |
11231 | are in program memory, and update any breakpoints that may be set | |
b383017d | 11232 | in overlays. This will allow breakpoints to work even if the |
81d46470 MS |
11233 | overlays are kept in ROM or other non-writable memory while they |
11234 | are not being executed. | |
df0cd8c5 JB |
11235 | |
11236 | @node Overlay Sample Program | |
11237 | @section Overlay Sample Program | |
11238 | @cindex overlay example program | |
11239 | ||
11240 | When linking a program which uses overlays, you must place the overlays | |
11241 | at their load addresses, while relocating them to run at their mapped | |
11242 | addresses. To do this, you must write a linker script (@pxref{Overlay | |
11243 | Description,,, ld.info, Using ld: the GNU linker}). Unfortunately, | |
11244 | since linker scripts are specific to a particular host system, target | |
11245 | architecture, and target memory layout, this manual cannot provide | |
11246 | portable sample code demonstrating @value{GDBN}'s overlay support. | |
11247 | ||
11248 | However, the @value{GDBN} source distribution does contain an overlaid | |
11249 | program, with linker scripts for a few systems, as part of its test | |
11250 | suite. The program consists of the following files from | |
11251 | @file{gdb/testsuite/gdb.base}: | |
11252 | ||
11253 | @table @file | |
11254 | @item overlays.c | |
11255 | The main program file. | |
11256 | @item ovlymgr.c | |
11257 | A simple overlay manager, used by @file{overlays.c}. | |
11258 | @item foo.c | |
11259 | @itemx bar.c | |
11260 | @itemx baz.c | |
11261 | @itemx grbx.c | |
11262 | Overlay modules, loaded and used by @file{overlays.c}. | |
11263 | @item d10v.ld | |
11264 | @itemx m32r.ld | |
11265 | Linker scripts for linking the test program on the @code{d10v-elf} | |
11266 | and @code{m32r-elf} targets. | |
11267 | @end table | |
11268 | ||
11269 | You can build the test program using the @code{d10v-elf} GCC | |
11270 | cross-compiler like this: | |
11271 | ||
474c8240 | 11272 | @smallexample |
df0cd8c5 JB |
11273 | $ d10v-elf-gcc -g -c overlays.c |
11274 | $ d10v-elf-gcc -g -c ovlymgr.c | |
11275 | $ d10v-elf-gcc -g -c foo.c | |
11276 | $ d10v-elf-gcc -g -c bar.c | |
11277 | $ d10v-elf-gcc -g -c baz.c | |
11278 | $ d10v-elf-gcc -g -c grbx.c | |
11279 | $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \ | |
11280 | baz.o grbx.o -Wl,-Td10v.ld -o overlays | |
474c8240 | 11281 | @end smallexample |
df0cd8c5 JB |
11282 | |
11283 | The build process is identical for any other architecture, except that | |
11284 | you must substitute the appropriate compiler and linker script for the | |
11285 | target system for @code{d10v-elf-gcc} and @code{d10v.ld}. | |
11286 | ||
11287 | ||
6d2ebf8b | 11288 | @node Languages |
c906108c SS |
11289 | @chapter Using @value{GDBN} with Different Languages |
11290 | @cindex languages | |
11291 | ||
c906108c SS |
11292 | Although programming languages generally have common aspects, they are |
11293 | rarely expressed in the same manner. For instance, in ANSI C, | |
11294 | dereferencing a pointer @code{p} is accomplished by @code{*p}, but in | |
11295 | Modula-2, it is accomplished by @code{p^}. Values can also be | |
5d161b24 | 11296 | represented (and displayed) differently. Hex numbers in C appear as |
c906108c | 11297 | @samp{0x1ae}, while in Modula-2 they appear as @samp{1AEH}. |
c906108c SS |
11298 | |
11299 | @cindex working language | |
11300 | Language-specific information is built into @value{GDBN} for some languages, | |
11301 | allowing you to express operations like the above in your program's | |
11302 | native language, and allowing @value{GDBN} to output values in a manner | |
11303 | consistent with the syntax of your program's native language. The | |
11304 | language you use to build expressions is called the @dfn{working | |
11305 | language}. | |
11306 | ||
11307 | @menu | |
11308 | * Setting:: Switching between source languages | |
11309 | * Show:: Displaying the language | |
c906108c | 11310 | * Checks:: Type and range checks |
79a6e687 BW |
11311 | * Supported Languages:: Supported languages |
11312 | * Unsupported Languages:: Unsupported languages | |
c906108c SS |
11313 | @end menu |
11314 | ||
6d2ebf8b | 11315 | @node Setting |
79a6e687 | 11316 | @section Switching Between Source Languages |
c906108c SS |
11317 | |
11318 | There are two ways to control the working language---either have @value{GDBN} | |
11319 | set it automatically, or select it manually yourself. You can use the | |
11320 | @code{set language} command for either purpose. On startup, @value{GDBN} | |
11321 | defaults to setting the language automatically. The working language is | |
11322 | used to determine how expressions you type are interpreted, how values | |
11323 | are printed, etc. | |
11324 | ||
11325 | In addition to the working language, every source file that | |
11326 | @value{GDBN} knows about has its own working language. For some object | |
11327 | file formats, the compiler might indicate which language a particular | |
11328 | source file is in. However, most of the time @value{GDBN} infers the | |
11329 | language from the name of the file. The language of a source file | |
b37052ae | 11330 | controls whether C@t{++} names are demangled---this way @code{backtrace} can |
c906108c | 11331 | show each frame appropriately for its own language. There is no way to |
d4f3574e SS |
11332 | set the language of a source file from within @value{GDBN}, but you can |
11333 | set the language associated with a filename extension. @xref{Show, , | |
79a6e687 | 11334 | Displaying the Language}. |
c906108c SS |
11335 | |
11336 | This is most commonly a problem when you use a program, such | |
5d161b24 | 11337 | as @code{cfront} or @code{f2c}, that generates C but is written in |
c906108c SS |
11338 | another language. In that case, make the |
11339 | program use @code{#line} directives in its C output; that way | |
11340 | @value{GDBN} will know the correct language of the source code of the original | |
11341 | program, and will display that source code, not the generated C code. | |
11342 | ||
11343 | @menu | |
11344 | * Filenames:: Filename extensions and languages. | |
11345 | * Manually:: Setting the working language manually | |
11346 | * Automatically:: Having @value{GDBN} infer the source language | |
11347 | @end menu | |
11348 | ||
6d2ebf8b | 11349 | @node Filenames |
79a6e687 | 11350 | @subsection List of Filename Extensions and Languages |
c906108c SS |
11351 | |
11352 | If a source file name ends in one of the following extensions, then | |
11353 | @value{GDBN} infers that its language is the one indicated. | |
11354 | ||
11355 | @table @file | |
e07c999f PH |
11356 | @item .ada |
11357 | @itemx .ads | |
11358 | @itemx .adb | |
11359 | @itemx .a | |
11360 | Ada source file. | |
c906108c SS |
11361 | |
11362 | @item .c | |
11363 | C source file | |
11364 | ||
11365 | @item .C | |
11366 | @itemx .cc | |
11367 | @itemx .cp | |
11368 | @itemx .cpp | |
11369 | @itemx .cxx | |
11370 | @itemx .c++ | |
b37052ae | 11371 | C@t{++} source file |
c906108c | 11372 | |
6aecb9c2 JB |
11373 | @item .d |
11374 | D source file | |
11375 | ||
b37303ee AF |
11376 | @item .m |
11377 | Objective-C source file | |
11378 | ||
c906108c SS |
11379 | @item .f |
11380 | @itemx .F | |
11381 | Fortran source file | |
11382 | ||
c906108c SS |
11383 | @item .mod |
11384 | Modula-2 source file | |
c906108c SS |
11385 | |
11386 | @item .s | |
11387 | @itemx .S | |
11388 | Assembler source file. This actually behaves almost like C, but | |
11389 | @value{GDBN} does not skip over function prologues when stepping. | |
11390 | @end table | |
11391 | ||
11392 | In addition, you may set the language associated with a filename | |
79a6e687 | 11393 | extension. @xref{Show, , Displaying the Language}. |
c906108c | 11394 | |
6d2ebf8b | 11395 | @node Manually |
79a6e687 | 11396 | @subsection Setting the Working Language |
c906108c SS |
11397 | |
11398 | If you allow @value{GDBN} to set the language automatically, | |
11399 | expressions are interpreted the same way in your debugging session and | |
11400 | your program. | |
11401 | ||
11402 | @kindex set language | |
11403 | If you wish, you may set the language manually. To do this, issue the | |
11404 | command @samp{set language @var{lang}}, where @var{lang} is the name of | |
5d161b24 | 11405 | a language, such as |
c906108c | 11406 | @code{c} or @code{modula-2}. |
c906108c SS |
11407 | For a list of the supported languages, type @samp{set language}. |
11408 | ||
c906108c SS |
11409 | Setting the language manually prevents @value{GDBN} from updating the working |
11410 | language automatically. This can lead to confusion if you try | |
11411 | to debug a program when the working language is not the same as the | |
11412 | source language, when an expression is acceptable to both | |
11413 | languages---but means different things. For instance, if the current | |
11414 | source file were written in C, and @value{GDBN} was parsing Modula-2, a | |
11415 | command such as: | |
11416 | ||
474c8240 | 11417 | @smallexample |
c906108c | 11418 | print a = b + c |
474c8240 | 11419 | @end smallexample |
c906108c SS |
11420 | |
11421 | @noindent | |
11422 | might not have the effect you intended. In C, this means to add | |
11423 | @code{b} and @code{c} and place the result in @code{a}. The result | |
11424 | printed would be the value of @code{a}. In Modula-2, this means to compare | |
11425 | @code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value. | |
c906108c | 11426 | |
6d2ebf8b | 11427 | @node Automatically |
79a6e687 | 11428 | @subsection Having @value{GDBN} Infer the Source Language |
c906108c SS |
11429 | |
11430 | To have @value{GDBN} set the working language automatically, use | |
11431 | @samp{set language local} or @samp{set language auto}. @value{GDBN} | |
11432 | then infers the working language. That is, when your program stops in a | |
11433 | frame (usually by encountering a breakpoint), @value{GDBN} sets the | |
11434 | working language to the language recorded for the function in that | |
11435 | frame. If the language for a frame is unknown (that is, if the function | |
11436 | or block corresponding to the frame was defined in a source file that | |
11437 | does not have a recognized extension), the current working language is | |
11438 | not changed, and @value{GDBN} issues a warning. | |
11439 | ||
11440 | This may not seem necessary for most programs, which are written | |
11441 | entirely in one source language. However, program modules and libraries | |
11442 | written in one source language can be used by a main program written in | |
11443 | a different source language. Using @samp{set language auto} in this | |
11444 | case frees you from having to set the working language manually. | |
11445 | ||
6d2ebf8b | 11446 | @node Show |
79a6e687 | 11447 | @section Displaying the Language |
c906108c SS |
11448 | |
11449 | The following commands help you find out which language is the | |
11450 | working language, and also what language source files were written in. | |
11451 | ||
c906108c SS |
11452 | @table @code |
11453 | @item show language | |
9c16f35a | 11454 | @kindex show language |
c906108c SS |
11455 | Display the current working language. This is the |
11456 | language you can use with commands such as @code{print} to | |
11457 | build and compute expressions that may involve variables in your program. | |
11458 | ||
11459 | @item info frame | |
4644b6e3 | 11460 | @kindex info frame@r{, show the source language} |
5d161b24 | 11461 | Display the source language for this frame. This language becomes the |
c906108c | 11462 | working language if you use an identifier from this frame. |
79a6e687 | 11463 | @xref{Frame Info, ,Information about a Frame}, to identify the other |
c906108c SS |
11464 | information listed here. |
11465 | ||
11466 | @item info source | |
4644b6e3 | 11467 | @kindex info source@r{, show the source language} |
c906108c | 11468 | Display the source language of this source file. |
5d161b24 | 11469 | @xref{Symbols, ,Examining the Symbol Table}, to identify the other |
c906108c SS |
11470 | information listed here. |
11471 | @end table | |
11472 | ||
11473 | In unusual circumstances, you may have source files with extensions | |
11474 | not in the standard list. You can then set the extension associated | |
11475 | with a language explicitly: | |
11476 | ||
c906108c | 11477 | @table @code |
09d4efe1 | 11478 | @item set extension-language @var{ext} @var{language} |
9c16f35a | 11479 | @kindex set extension-language |
09d4efe1 EZ |
11480 | Tell @value{GDBN} that source files with extension @var{ext} are to be |
11481 | assumed as written in the source language @var{language}. | |
c906108c SS |
11482 | |
11483 | @item info extensions | |
9c16f35a | 11484 | @kindex info extensions |
c906108c SS |
11485 | List all the filename extensions and the associated languages. |
11486 | @end table | |
11487 | ||
6d2ebf8b | 11488 | @node Checks |
79a6e687 | 11489 | @section Type and Range Checking |
c906108c SS |
11490 | |
11491 | @quotation | |
11492 | @emph{Warning:} In this release, the @value{GDBN} commands for type and range | |
11493 | checking are included, but they do not yet have any effect. This | |
11494 | section documents the intended facilities. | |
11495 | @end quotation | |
11496 | @c FIXME remove warning when type/range code added | |
11497 | ||
11498 | Some languages are designed to guard you against making seemingly common | |
11499 | errors through a series of compile- and run-time checks. These include | |
11500 | checking the type of arguments to functions and operators, and making | |
11501 | sure mathematical overflows are caught at run time. Checks such as | |
11502 | these help to ensure a program's correctness once it has been compiled | |
11503 | by eliminating type mismatches, and providing active checks for range | |
11504 | errors when your program is running. | |
11505 | ||
11506 | @value{GDBN} can check for conditions like the above if you wish. | |
9c16f35a EZ |
11507 | Although @value{GDBN} does not check the statements in your program, |
11508 | it can check expressions entered directly into @value{GDBN} for | |
11509 | evaluation via the @code{print} command, for example. As with the | |
11510 | working language, @value{GDBN} can also decide whether or not to check | |
11511 | automatically based on your program's source language. | |
79a6e687 | 11512 | @xref{Supported Languages, ,Supported Languages}, for the default |
9c16f35a | 11513 | settings of supported languages. |
c906108c SS |
11514 | |
11515 | @menu | |
11516 | * Type Checking:: An overview of type checking | |
11517 | * Range Checking:: An overview of range checking | |
11518 | @end menu | |
11519 | ||
11520 | @cindex type checking | |
11521 | @cindex checks, type | |
6d2ebf8b | 11522 | @node Type Checking |
79a6e687 | 11523 | @subsection An Overview of Type Checking |
c906108c SS |
11524 | |
11525 | Some languages, such as Modula-2, are strongly typed, meaning that the | |
11526 | arguments to operators and functions have to be of the correct type, | |
11527 | otherwise an error occurs. These checks prevent type mismatch | |
11528 | errors from ever causing any run-time problems. For example, | |
11529 | ||
11530 | @smallexample | |
11531 | 1 + 2 @result{} 3 | |
11532 | @exdent but | |
11533 | @error{} 1 + 2.3 | |
11534 | @end smallexample | |
11535 | ||
11536 | The second example fails because the @code{CARDINAL} 1 is not | |
11537 | type-compatible with the @code{REAL} 2.3. | |
11538 | ||
5d161b24 DB |
11539 | For the expressions you use in @value{GDBN} commands, you can tell the |
11540 | @value{GDBN} type checker to skip checking; | |
11541 | to treat any mismatches as errors and abandon the expression; | |
11542 | or to only issue warnings when type mismatches occur, | |
c906108c SS |
11543 | but evaluate the expression anyway. When you choose the last of |
11544 | these, @value{GDBN} evaluates expressions like the second example above, but | |
11545 | also issues a warning. | |
11546 | ||
5d161b24 DB |
11547 | Even if you turn type checking off, there may be other reasons |
11548 | related to type that prevent @value{GDBN} from evaluating an expression. | |
11549 | For instance, @value{GDBN} does not know how to add an @code{int} and | |
11550 | a @code{struct foo}. These particular type errors have nothing to do | |
11551 | with the language in use, and usually arise from expressions, such as | |
c906108c SS |
11552 | the one described above, which make little sense to evaluate anyway. |
11553 | ||
11554 | Each language defines to what degree it is strict about type. For | |
11555 | instance, both Modula-2 and C require the arguments to arithmetical | |
11556 | operators to be numbers. In C, enumerated types and pointers can be | |
11557 | represented as numbers, so that they are valid arguments to mathematical | |
79a6e687 | 11558 | operators. @xref{Supported Languages, ,Supported Languages}, for further |
c906108c SS |
11559 | details on specific languages. |
11560 | ||
11561 | @value{GDBN} provides some additional commands for controlling the type checker: | |
11562 | ||
c906108c SS |
11563 | @kindex set check type |
11564 | @kindex show check type | |
11565 | @table @code | |
11566 | @item set check type auto | |
11567 | Set type checking on or off based on the current working language. | |
79a6e687 | 11568 | @xref{Supported Languages, ,Supported Languages}, for the default settings for |
c906108c SS |
11569 | each language. |
11570 | ||
11571 | @item set check type on | |
11572 | @itemx set check type off | |
11573 | Set type checking on or off, overriding the default setting for the | |
11574 | current working language. Issue a warning if the setting does not | |
11575 | match the language default. If any type mismatches occur in | |
d4f3574e | 11576 | evaluating an expression while type checking is on, @value{GDBN} prints a |
c906108c SS |
11577 | message and aborts evaluation of the expression. |
11578 | ||
11579 | @item set check type warn | |
11580 | Cause the type checker to issue warnings, but to always attempt to | |
11581 | evaluate the expression. Evaluating the expression may still | |
11582 | be impossible for other reasons. For example, @value{GDBN} cannot add | |
11583 | numbers and structures. | |
11584 | ||
11585 | @item show type | |
5d161b24 | 11586 | Show the current setting of the type checker, and whether or not @value{GDBN} |
c906108c SS |
11587 | is setting it automatically. |
11588 | @end table | |
11589 | ||
11590 | @cindex range checking | |
11591 | @cindex checks, range | |
6d2ebf8b | 11592 | @node Range Checking |
79a6e687 | 11593 | @subsection An Overview of Range Checking |
c906108c SS |
11594 | |
11595 | In some languages (such as Modula-2), it is an error to exceed the | |
11596 | bounds of a type; this is enforced with run-time checks. Such range | |
11597 | checking is meant to ensure program correctness by making sure | |
11598 | computations do not overflow, or indices on an array element access do | |
11599 | not exceed the bounds of the array. | |
11600 | ||
11601 | For expressions you use in @value{GDBN} commands, you can tell | |
11602 | @value{GDBN} to treat range errors in one of three ways: ignore them, | |
11603 | always treat them as errors and abandon the expression, or issue | |
11604 | warnings but evaluate the expression anyway. | |
11605 | ||
11606 | A range error can result from numerical overflow, from exceeding an | |
11607 | array index bound, or when you type a constant that is not a member | |
11608 | of any type. Some languages, however, do not treat overflows as an | |
11609 | error. In many implementations of C, mathematical overflow causes the | |
11610 | result to ``wrap around'' to lower values---for example, if @var{m} is | |
11611 | the largest integer value, and @var{s} is the smallest, then | |
11612 | ||
474c8240 | 11613 | @smallexample |
c906108c | 11614 | @var{m} + 1 @result{} @var{s} |
474c8240 | 11615 | @end smallexample |
c906108c SS |
11616 | |
11617 | This, too, is specific to individual languages, and in some cases | |
79a6e687 BW |
11618 | specific to individual compilers or machines. @xref{Supported Languages, , |
11619 | Supported Languages}, for further details on specific languages. | |
c906108c SS |
11620 | |
11621 | @value{GDBN} provides some additional commands for controlling the range checker: | |
11622 | ||
c906108c SS |
11623 | @kindex set check range |
11624 | @kindex show check range | |
11625 | @table @code | |
11626 | @item set check range auto | |
11627 | Set range checking on or off based on the current working language. | |
79a6e687 | 11628 | @xref{Supported Languages, ,Supported Languages}, for the default settings for |
c906108c SS |
11629 | each language. |
11630 | ||
11631 | @item set check range on | |
11632 | @itemx set check range off | |
11633 | Set range checking on or off, overriding the default setting for the | |
11634 | current working language. A warning is issued if the setting does not | |
c3f6f71d JM |
11635 | match the language default. If a range error occurs and range checking is on, |
11636 | then a message is printed and evaluation of the expression is aborted. | |
c906108c SS |
11637 | |
11638 | @item set check range warn | |
11639 | Output messages when the @value{GDBN} range checker detects a range error, | |
11640 | but attempt to evaluate the expression anyway. Evaluating the | |
11641 | expression may still be impossible for other reasons, such as accessing | |
11642 | memory that the process does not own (a typical example from many Unix | |
11643 | systems). | |
11644 | ||
11645 | @item show range | |
11646 | Show the current setting of the range checker, and whether or not it is | |
11647 | being set automatically by @value{GDBN}. | |
11648 | @end table | |
c906108c | 11649 | |
79a6e687 BW |
11650 | @node Supported Languages |
11651 | @section Supported Languages | |
c906108c | 11652 | |
f4b8a18d | 11653 | @value{GDBN} supports C, C@t{++}, D, Objective-C, Fortran, Java, OpenCL C, Pascal, |
9c16f35a | 11654 | assembly, Modula-2, and Ada. |
cce74817 | 11655 | @c This is false ... |
c906108c SS |
11656 | Some @value{GDBN} features may be used in expressions regardless of the |
11657 | language you use: the @value{GDBN} @code{@@} and @code{::} operators, | |
11658 | and the @samp{@{type@}addr} construct (@pxref{Expressions, | |
11659 | ,Expressions}) can be used with the constructs of any supported | |
11660 | language. | |
11661 | ||
11662 | The following sections detail to what degree each source language is | |
11663 | supported by @value{GDBN}. These sections are not meant to be language | |
11664 | tutorials or references, but serve only as a reference guide to what the | |
11665 | @value{GDBN} expression parser accepts, and what input and output | |
11666 | formats should look like for different languages. There are many good | |
11667 | books written on each of these languages; please look to these for a | |
11668 | language reference or tutorial. | |
11669 | ||
c906108c | 11670 | @menu |
b37303ee | 11671 | * C:: C and C@t{++} |
6aecb9c2 | 11672 | * D:: D |
b383017d | 11673 | * Objective-C:: Objective-C |
f4b8a18d | 11674 | * OpenCL C:: OpenCL C |
09d4efe1 | 11675 | * Fortran:: Fortran |
9c16f35a | 11676 | * Pascal:: Pascal |
b37303ee | 11677 | * Modula-2:: Modula-2 |
e07c999f | 11678 | * Ada:: Ada |
c906108c SS |
11679 | @end menu |
11680 | ||
6d2ebf8b | 11681 | @node C |
b37052ae | 11682 | @subsection C and C@t{++} |
7a292a7a | 11683 | |
b37052ae EZ |
11684 | @cindex C and C@t{++} |
11685 | @cindex expressions in C or C@t{++} | |
c906108c | 11686 | |
b37052ae | 11687 | Since C and C@t{++} are so closely related, many features of @value{GDBN} apply |
c906108c SS |
11688 | to both languages. Whenever this is the case, we discuss those languages |
11689 | together. | |
11690 | ||
41afff9a EZ |
11691 | @cindex C@t{++} |
11692 | @cindex @code{g++}, @sc{gnu} C@t{++} compiler | |
b37052ae EZ |
11693 | @cindex @sc{gnu} C@t{++} |
11694 | The C@t{++} debugging facilities are jointly implemented by the C@t{++} | |
11695 | compiler and @value{GDBN}. Therefore, to debug your C@t{++} code | |
11696 | effectively, you must compile your C@t{++} programs with a supported | |
11697 | C@t{++} compiler, such as @sc{gnu} @code{g++}, or the HP ANSI C@t{++} | |
c906108c SS |
11698 | compiler (@code{aCC}). |
11699 | ||
0179ffac DC |
11700 | For best results when using @sc{gnu} C@t{++}, use the DWARF 2 debugging |
11701 | format; if it doesn't work on your system, try the stabs+ debugging | |
11702 | format. You can select those formats explicitly with the @code{g++} | |
11703 | command-line options @option{-gdwarf-2} and @option{-gstabs+}. | |
ce9341a1 BW |
11704 | @xref{Debugging Options,,Options for Debugging Your Program or GCC, |
11705 | gcc.info, Using the @sc{gnu} Compiler Collection (GCC)}. | |
c906108c | 11706 | |
c906108c | 11707 | @menu |
b37052ae EZ |
11708 | * C Operators:: C and C@t{++} operators |
11709 | * C Constants:: C and C@t{++} constants | |
79a6e687 | 11710 | * C Plus Plus Expressions:: C@t{++} expressions |
b37052ae EZ |
11711 | * C Defaults:: Default settings for C and C@t{++} |
11712 | * C Checks:: C and C@t{++} type and range checks | |
c906108c | 11713 | * Debugging C:: @value{GDBN} and C |
79a6e687 | 11714 | * Debugging C Plus Plus:: @value{GDBN} features for C@t{++} |
febe4383 | 11715 | * Decimal Floating Point:: Numbers in Decimal Floating Point format |
c906108c | 11716 | @end menu |
c906108c | 11717 | |
6d2ebf8b | 11718 | @node C Operators |
79a6e687 | 11719 | @subsubsection C and C@t{++} Operators |
7a292a7a | 11720 | |
b37052ae | 11721 | @cindex C and C@t{++} operators |
c906108c SS |
11722 | |
11723 | Operators must be defined on values of specific types. For instance, | |
11724 | @code{+} is defined on numbers, but not on structures. Operators are | |
5d161b24 | 11725 | often defined on groups of types. |
c906108c | 11726 | |
b37052ae | 11727 | For the purposes of C and C@t{++}, the following definitions hold: |
c906108c SS |
11728 | |
11729 | @itemize @bullet | |
53a5351d | 11730 | |
c906108c | 11731 | @item |
c906108c | 11732 | @emph{Integral types} include @code{int} with any of its storage-class |
b37052ae | 11733 | specifiers; @code{char}; @code{enum}; and, for C@t{++}, @code{bool}. |
c906108c SS |
11734 | |
11735 | @item | |
d4f3574e SS |
11736 | @emph{Floating-point types} include @code{float}, @code{double}, and |
11737 | @code{long double} (if supported by the target platform). | |
c906108c SS |
11738 | |
11739 | @item | |
53a5351d | 11740 | @emph{Pointer types} include all types defined as @code{(@var{type} *)}. |
c906108c SS |
11741 | |
11742 | @item | |
11743 | @emph{Scalar types} include all of the above. | |
53a5351d | 11744 | |
c906108c SS |
11745 | @end itemize |
11746 | ||
11747 | @noindent | |
11748 | The following operators are supported. They are listed here | |
11749 | in order of increasing precedence: | |
11750 | ||
11751 | @table @code | |
11752 | @item , | |
11753 | The comma or sequencing operator. Expressions in a comma-separated list | |
11754 | are evaluated from left to right, with the result of the entire | |
11755 | expression being the last expression evaluated. | |
11756 | ||
11757 | @item = | |
11758 | Assignment. The value of an assignment expression is the value | |
11759 | assigned. Defined on scalar types. | |
11760 | ||
11761 | @item @var{op}= | |
11762 | Used in an expression of the form @w{@code{@var{a} @var{op}= @var{b}}}, | |
11763 | and translated to @w{@code{@var{a} = @var{a op b}}}. | |
d4f3574e | 11764 | @w{@code{@var{op}=}} and @code{=} have the same precedence. |
c906108c SS |
11765 | @var{op} is any one of the operators @code{|}, @code{^}, @code{&}, |
11766 | @code{<<}, @code{>>}, @code{+}, @code{-}, @code{*}, @code{/}, @code{%}. | |
11767 | ||
11768 | @item ?: | |
11769 | The ternary operator. @code{@var{a} ? @var{b} : @var{c}} can be thought | |
11770 | of as: if @var{a} then @var{b} else @var{c}. @var{a} should be of an | |
11771 | integral type. | |
11772 | ||
11773 | @item || | |
11774 | Logical @sc{or}. Defined on integral types. | |
11775 | ||
11776 | @item && | |
11777 | Logical @sc{and}. Defined on integral types. | |
11778 | ||
11779 | @item | | |
11780 | Bitwise @sc{or}. Defined on integral types. | |
11781 | ||
11782 | @item ^ | |
11783 | Bitwise exclusive-@sc{or}. Defined on integral types. | |
11784 | ||
11785 | @item & | |
11786 | Bitwise @sc{and}. Defined on integral types. | |
11787 | ||
11788 | @item ==@r{, }!= | |
11789 | Equality and inequality. Defined on scalar types. The value of these | |
11790 | expressions is 0 for false and non-zero for true. | |
11791 | ||
11792 | @item <@r{, }>@r{, }<=@r{, }>= | |
11793 | Less than, greater than, less than or equal, greater than or equal. | |
11794 | Defined on scalar types. The value of these expressions is 0 for false | |
11795 | and non-zero for true. | |
11796 | ||
11797 | @item <<@r{, }>> | |
11798 | left shift, and right shift. Defined on integral types. | |
11799 | ||
11800 | @item @@ | |
11801 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
11802 | ||
11803 | @item +@r{, }- | |
11804 | Addition and subtraction. Defined on integral types, floating-point types and | |
11805 | pointer types. | |
11806 | ||
11807 | @item *@r{, }/@r{, }% | |
11808 | Multiplication, division, and modulus. Multiplication and division are | |
11809 | defined on integral and floating-point types. Modulus is defined on | |
11810 | integral types. | |
11811 | ||
11812 | @item ++@r{, }-- | |
11813 | Increment and decrement. When appearing before a variable, the | |
11814 | operation is performed before the variable is used in an expression; | |
11815 | when appearing after it, the variable's value is used before the | |
11816 | operation takes place. | |
11817 | ||
11818 | @item * | |
11819 | Pointer dereferencing. Defined on pointer types. Same precedence as | |
11820 | @code{++}. | |
11821 | ||
11822 | @item & | |
11823 | Address operator. Defined on variables. Same precedence as @code{++}. | |
11824 | ||
b37052ae EZ |
11825 | For debugging C@t{++}, @value{GDBN} implements a use of @samp{&} beyond what is |
11826 | allowed in the C@t{++} language itself: you can use @samp{&(&@var{ref})} | |
b17828ca | 11827 | to examine the address |
b37052ae | 11828 | where a C@t{++} reference variable (declared with @samp{&@var{ref}}) is |
c906108c | 11829 | stored. |
c906108c SS |
11830 | |
11831 | @item - | |
11832 | Negative. Defined on integral and floating-point types. Same | |
11833 | precedence as @code{++}. | |
11834 | ||
11835 | @item ! | |
11836 | Logical negation. Defined on integral types. Same precedence as | |
11837 | @code{++}. | |
11838 | ||
11839 | @item ~ | |
11840 | Bitwise complement operator. Defined on integral types. Same precedence as | |
11841 | @code{++}. | |
11842 | ||
11843 | ||
11844 | @item .@r{, }-> | |
11845 | Structure member, and pointer-to-structure member. For convenience, | |
11846 | @value{GDBN} regards the two as equivalent, choosing whether to dereference a | |
11847 | pointer based on the stored type information. | |
11848 | Defined on @code{struct} and @code{union} data. | |
11849 | ||
c906108c SS |
11850 | @item .*@r{, }->* |
11851 | Dereferences of pointers to members. | |
c906108c SS |
11852 | |
11853 | @item [] | |
11854 | Array indexing. @code{@var{a}[@var{i}]} is defined as | |
11855 | @code{*(@var{a}+@var{i})}. Same precedence as @code{->}. | |
11856 | ||
11857 | @item () | |
11858 | Function parameter list. Same precedence as @code{->}. | |
11859 | ||
c906108c | 11860 | @item :: |
b37052ae | 11861 | C@t{++} scope resolution operator. Defined on @code{struct}, @code{union}, |
7a292a7a | 11862 | and @code{class} types. |
c906108c SS |
11863 | |
11864 | @item :: | |
7a292a7a SS |
11865 | Doubled colons also represent the @value{GDBN} scope operator |
11866 | (@pxref{Expressions, ,Expressions}). Same precedence as @code{::}, | |
11867 | above. | |
c906108c SS |
11868 | @end table |
11869 | ||
c906108c SS |
11870 | If an operator is redefined in the user code, @value{GDBN} usually |
11871 | attempts to invoke the redefined version instead of using the operator's | |
11872 | predefined meaning. | |
c906108c | 11873 | |
6d2ebf8b | 11874 | @node C Constants |
79a6e687 | 11875 | @subsubsection C and C@t{++} Constants |
c906108c | 11876 | |
b37052ae | 11877 | @cindex C and C@t{++} constants |
c906108c | 11878 | |
b37052ae | 11879 | @value{GDBN} allows you to express the constants of C and C@t{++} in the |
c906108c | 11880 | following ways: |
c906108c SS |
11881 | |
11882 | @itemize @bullet | |
11883 | @item | |
11884 | Integer constants are a sequence of digits. Octal constants are | |
6ca652b0 EZ |
11885 | specified by a leading @samp{0} (i.e.@: zero), and hexadecimal constants |
11886 | by a leading @samp{0x} or @samp{0X}. Constants may also end with a letter | |
c906108c SS |
11887 | @samp{l}, specifying that the constant should be treated as a |
11888 | @code{long} value. | |
11889 | ||
11890 | @item | |
11891 | Floating point constants are a sequence of digits, followed by a decimal | |
11892 | point, followed by a sequence of digits, and optionally followed by an | |
11893 | exponent. An exponent is of the form: | |
11894 | @samp{@w{e@r{[[}+@r{]|}-@r{]}@var{nnn}}}, where @var{nnn} is another | |
11895 | sequence of digits. The @samp{+} is optional for positive exponents. | |
d4f3574e SS |
11896 | A floating-point constant may also end with a letter @samp{f} or |
11897 | @samp{F}, specifying that the constant should be treated as being of | |
11898 | the @code{float} (as opposed to the default @code{double}) type; or with | |
11899 | a letter @samp{l} or @samp{L}, which specifies a @code{long double} | |
11900 | constant. | |
c906108c SS |
11901 | |
11902 | @item | |
11903 | Enumerated constants consist of enumerated identifiers, or their | |
11904 | integral equivalents. | |
11905 | ||
11906 | @item | |
11907 | Character constants are a single character surrounded by single quotes | |
11908 | (@code{'}), or a number---the ordinal value of the corresponding character | |
d4f3574e | 11909 | (usually its @sc{ascii} value). Within quotes, the single character may |
c906108c SS |
11910 | be represented by a letter or by @dfn{escape sequences}, which are of |
11911 | the form @samp{\@var{nnn}}, where @var{nnn} is the octal representation | |
11912 | of the character's ordinal value; or of the form @samp{\@var{x}}, where | |
11913 | @samp{@var{x}} is a predefined special character---for example, | |
11914 | @samp{\n} for newline. | |
11915 | ||
11916 | @item | |
96a2c332 SS |
11917 | String constants are a sequence of character constants surrounded by |
11918 | double quotes (@code{"}). Any valid character constant (as described | |
11919 | above) may appear. Double quotes within the string must be preceded by | |
11920 | a backslash, so for instance @samp{"a\"b'c"} is a string of five | |
11921 | characters. | |
c906108c SS |
11922 | |
11923 | @item | |
11924 | Pointer constants are an integral value. You can also write pointers | |
11925 | to constants using the C operator @samp{&}. | |
11926 | ||
11927 | @item | |
11928 | Array constants are comma-separated lists surrounded by braces @samp{@{} | |
11929 | and @samp{@}}; for example, @samp{@{1,2,3@}} is a three-element array of | |
11930 | integers, @samp{@{@{1,2@}, @{3,4@}, @{5,6@}@}} is a three-by-two array, | |
11931 | and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers. | |
11932 | @end itemize | |
11933 | ||
79a6e687 BW |
11934 | @node C Plus Plus Expressions |
11935 | @subsubsection C@t{++} Expressions | |
b37052ae EZ |
11936 | |
11937 | @cindex expressions in C@t{++} | |
11938 | @value{GDBN} expression handling can interpret most C@t{++} expressions. | |
11939 | ||
0179ffac DC |
11940 | @cindex debugging C@t{++} programs |
11941 | @cindex C@t{++} compilers | |
11942 | @cindex debug formats and C@t{++} | |
11943 | @cindex @value{NGCC} and C@t{++} | |
c906108c | 11944 | @quotation |
b37052ae | 11945 | @emph{Warning:} @value{GDBN} can only debug C@t{++} code if you use the |
0179ffac DC |
11946 | proper compiler and the proper debug format. Currently, @value{GDBN} |
11947 | works best when debugging C@t{++} code that is compiled with | |
11948 | @value{NGCC} 2.95.3 or with @value{NGCC} 3.1 or newer, using the options | |
11949 | @option{-gdwarf-2} or @option{-gstabs+}. DWARF 2 is preferred over | |
11950 | stabs+. Most configurations of @value{NGCC} emit either DWARF 2 or | |
11951 | stabs+ as their default debug format, so you usually don't need to | |
11952 | specify a debug format explicitly. Other compilers and/or debug formats | |
11953 | are likely to work badly or not at all when using @value{GDBN} to debug | |
11954 | C@t{++} code. | |
c906108c | 11955 | @end quotation |
c906108c SS |
11956 | |
11957 | @enumerate | |
11958 | ||
11959 | @cindex member functions | |
11960 | @item | |
11961 | Member function calls are allowed; you can use expressions like | |
11962 | ||
474c8240 | 11963 | @smallexample |
c906108c | 11964 | count = aml->GetOriginal(x, y) |
474c8240 | 11965 | @end smallexample |
c906108c | 11966 | |
41afff9a | 11967 | @vindex this@r{, inside C@t{++} member functions} |
b37052ae | 11968 | @cindex namespace in C@t{++} |
c906108c SS |
11969 | @item |
11970 | While a member function is active (in the selected stack frame), your | |
11971 | expressions have the same namespace available as the member function; | |
11972 | that is, @value{GDBN} allows implicit references to the class instance | |
b37052ae | 11973 | pointer @code{this} following the same rules as C@t{++}. |
c906108c | 11974 | |
c906108c | 11975 | @cindex call overloaded functions |
d4f3574e | 11976 | @cindex overloaded functions, calling |
b37052ae | 11977 | @cindex type conversions in C@t{++} |
c906108c SS |
11978 | @item |
11979 | You can call overloaded functions; @value{GDBN} resolves the function | |
d4f3574e | 11980 | call to the right definition, with some restrictions. @value{GDBN} does not |
c906108c SS |
11981 | perform overload resolution involving user-defined type conversions, |
11982 | calls to constructors, or instantiations of templates that do not exist | |
11983 | in the program. It also cannot handle ellipsis argument lists or | |
11984 | default arguments. | |
11985 | ||
11986 | It does perform integral conversions and promotions, floating-point | |
11987 | promotions, arithmetic conversions, pointer conversions, conversions of | |
11988 | class objects to base classes, and standard conversions such as those of | |
11989 | functions or arrays to pointers; it requires an exact match on the | |
11990 | number of function arguments. | |
11991 | ||
11992 | Overload resolution is always performed, unless you have specified | |
79a6e687 BW |
11993 | @code{set overload-resolution off}. @xref{Debugging C Plus Plus, |
11994 | ,@value{GDBN} Features for C@t{++}}. | |
c906108c | 11995 | |
d4f3574e | 11996 | You must specify @code{set overload-resolution off} in order to use an |
c906108c SS |
11997 | explicit function signature to call an overloaded function, as in |
11998 | @smallexample | |
11999 | p 'foo(char,int)'('x', 13) | |
12000 | @end smallexample | |
d4f3574e | 12001 | |
c906108c | 12002 | The @value{GDBN} command-completion facility can simplify this; |
79a6e687 | 12003 | see @ref{Completion, ,Command Completion}. |
c906108c | 12004 | |
c906108c SS |
12005 | @cindex reference declarations |
12006 | @item | |
b37052ae EZ |
12007 | @value{GDBN} understands variables declared as C@t{++} references; you can use |
12008 | them in expressions just as you do in C@t{++} source---they are automatically | |
c906108c SS |
12009 | dereferenced. |
12010 | ||
12011 | In the parameter list shown when @value{GDBN} displays a frame, the values of | |
12012 | reference variables are not displayed (unlike other variables); this | |
12013 | avoids clutter, since references are often used for large structures. | |
12014 | The @emph{address} of a reference variable is always shown, unless | |
12015 | you have specified @samp{set print address off}. | |
12016 | ||
12017 | @item | |
b37052ae | 12018 | @value{GDBN} supports the C@t{++} name resolution operator @code{::}---your |
c906108c SS |
12019 | expressions can use it just as expressions in your program do. Since |
12020 | one scope may be defined in another, you can use @code{::} repeatedly if | |
12021 | necessary, for example in an expression like | |
12022 | @samp{@var{scope1}::@var{scope2}::@var{name}}. @value{GDBN} also allows | |
b37052ae | 12023 | resolving name scope by reference to source files, in both C and C@t{++} |
79a6e687 | 12024 | debugging (@pxref{Variables, ,Program Variables}). |
c906108c SS |
12025 | @end enumerate |
12026 | ||
b37052ae | 12027 | In addition, when used with HP's C@t{++} compiler, @value{GDBN} supports |
53a5351d JM |
12028 | calling virtual functions correctly, printing out virtual bases of |
12029 | objects, calling functions in a base subobject, casting objects, and | |
12030 | invoking user-defined operators. | |
c906108c | 12031 | |
6d2ebf8b | 12032 | @node C Defaults |
79a6e687 | 12033 | @subsubsection C and C@t{++} Defaults |
7a292a7a | 12034 | |
b37052ae | 12035 | @cindex C and C@t{++} defaults |
c906108c | 12036 | |
c906108c SS |
12037 | If you allow @value{GDBN} to set type and range checking automatically, they |
12038 | both default to @code{off} whenever the working language changes to | |
b37052ae | 12039 | C or C@t{++}. This happens regardless of whether you or @value{GDBN} |
c906108c | 12040 | selects the working language. |
c906108c SS |
12041 | |
12042 | If you allow @value{GDBN} to set the language automatically, it | |
12043 | recognizes source files whose names end with @file{.c}, @file{.C}, or | |
12044 | @file{.cc}, etc, and when @value{GDBN} enters code compiled from one of | |
b37052ae | 12045 | these files, it sets the working language to C or C@t{++}. |
79a6e687 | 12046 | @xref{Automatically, ,Having @value{GDBN} Infer the Source Language}, |
c906108c SS |
12047 | for further details. |
12048 | ||
c906108c SS |
12049 | @c Type checking is (a) primarily motivated by Modula-2, and (b) |
12050 | @c unimplemented. If (b) changes, it might make sense to let this node | |
12051 | @c appear even if Mod-2 does not, but meanwhile ignore it. roland 16jul93. | |
7a292a7a | 12052 | |
6d2ebf8b | 12053 | @node C Checks |
79a6e687 | 12054 | @subsubsection C and C@t{++} Type and Range Checks |
7a292a7a | 12055 | |
b37052ae | 12056 | @cindex C and C@t{++} checks |
c906108c | 12057 | |
b37052ae | 12058 | By default, when @value{GDBN} parses C or C@t{++} expressions, type checking |
c906108c SS |
12059 | is not used. However, if you turn type checking on, @value{GDBN} |
12060 | considers two variables type equivalent if: | |
12061 | ||
12062 | @itemize @bullet | |
12063 | @item | |
12064 | The two variables are structured and have the same structure, union, or | |
12065 | enumerated tag. | |
12066 | ||
12067 | @item | |
12068 | The two variables have the same type name, or types that have been | |
12069 | declared equivalent through @code{typedef}. | |
12070 | ||
12071 | @ignore | |
12072 | @c leaving this out because neither J Gilmore nor R Pesch understand it. | |
12073 | @c FIXME--beers? | |
12074 | @item | |
12075 | The two @code{struct}, @code{union}, or @code{enum} variables are | |
12076 | declared in the same declaration. (Note: this may not be true for all C | |
12077 | compilers.) | |
12078 | @end ignore | |
12079 | @end itemize | |
12080 | ||
12081 | Range checking, if turned on, is done on mathematical operations. Array | |
12082 | indices are not checked, since they are often used to index a pointer | |
12083 | that is not itself an array. | |
c906108c | 12084 | |
6d2ebf8b | 12085 | @node Debugging C |
c906108c | 12086 | @subsubsection @value{GDBN} and C |
c906108c SS |
12087 | |
12088 | The @code{set print union} and @code{show print union} commands apply to | |
12089 | the @code{union} type. When set to @samp{on}, any @code{union} that is | |
7a292a7a SS |
12090 | inside a @code{struct} or @code{class} is also printed. Otherwise, it |
12091 | appears as @samp{@{...@}}. | |
c906108c SS |
12092 | |
12093 | The @code{@@} operator aids in the debugging of dynamic arrays, formed | |
12094 | with pointers and a memory allocation function. @xref{Expressions, | |
12095 | ,Expressions}. | |
12096 | ||
79a6e687 BW |
12097 | @node Debugging C Plus Plus |
12098 | @subsubsection @value{GDBN} Features for C@t{++} | |
c906108c | 12099 | |
b37052ae | 12100 | @cindex commands for C@t{++} |
7a292a7a | 12101 | |
b37052ae EZ |
12102 | Some @value{GDBN} commands are particularly useful with C@t{++}, and some are |
12103 | designed specifically for use with C@t{++}. Here is a summary: | |
c906108c SS |
12104 | |
12105 | @table @code | |
12106 | @cindex break in overloaded functions | |
12107 | @item @r{breakpoint menus} | |
12108 | When you want a breakpoint in a function whose name is overloaded, | |
6ba66d6a JB |
12109 | @value{GDBN} has the capability to display a menu of possible breakpoint |
12110 | locations to help you specify which function definition you want. | |
12111 | @xref{Ambiguous Expressions,,Ambiguous Expressions}. | |
c906108c | 12112 | |
b37052ae | 12113 | @cindex overloading in C@t{++} |
c906108c SS |
12114 | @item rbreak @var{regex} |
12115 | Setting breakpoints using regular expressions is helpful for setting | |
12116 | breakpoints on overloaded functions that are not members of any special | |
12117 | classes. | |
79a6e687 | 12118 | @xref{Set Breaks, ,Setting Breakpoints}. |
c906108c | 12119 | |
b37052ae | 12120 | @cindex C@t{++} exception handling |
c906108c SS |
12121 | @item catch throw |
12122 | @itemx catch catch | |
b37052ae | 12123 | Debug C@t{++} exception handling using these commands. @xref{Set |
79a6e687 | 12124 | Catchpoints, , Setting Catchpoints}. |
c906108c SS |
12125 | |
12126 | @cindex inheritance | |
12127 | @item ptype @var{typename} | |
12128 | Print inheritance relationships as well as other information for type | |
12129 | @var{typename}. | |
12130 | @xref{Symbols, ,Examining the Symbol Table}. | |
12131 | ||
b37052ae | 12132 | @cindex C@t{++} symbol display |
c906108c SS |
12133 | @item set print demangle |
12134 | @itemx show print demangle | |
12135 | @itemx set print asm-demangle | |
12136 | @itemx show print asm-demangle | |
b37052ae EZ |
12137 | Control whether C@t{++} symbols display in their source form, both when |
12138 | displaying code as C@t{++} source and when displaying disassemblies. | |
79a6e687 | 12139 | @xref{Print Settings, ,Print Settings}. |
c906108c SS |
12140 | |
12141 | @item set print object | |
12142 | @itemx show print object | |
12143 | Choose whether to print derived (actual) or declared types of objects. | |
79a6e687 | 12144 | @xref{Print Settings, ,Print Settings}. |
c906108c SS |
12145 | |
12146 | @item set print vtbl | |
12147 | @itemx show print vtbl | |
12148 | Control the format for printing virtual function tables. | |
79a6e687 | 12149 | @xref{Print Settings, ,Print Settings}. |
c906108c | 12150 | (The @code{vtbl} commands do not work on programs compiled with the HP |
b37052ae | 12151 | ANSI C@t{++} compiler (@code{aCC}).) |
c906108c SS |
12152 | |
12153 | @kindex set overload-resolution | |
d4f3574e | 12154 | @cindex overloaded functions, overload resolution |
c906108c | 12155 | @item set overload-resolution on |
b37052ae | 12156 | Enable overload resolution for C@t{++} expression evaluation. The default |
c906108c SS |
12157 | is on. For overloaded functions, @value{GDBN} evaluates the arguments |
12158 | and searches for a function whose signature matches the argument types, | |
79a6e687 BW |
12159 | using the standard C@t{++} conversion rules (see @ref{C Plus Plus |
12160 | Expressions, ,C@t{++} Expressions}, for details). | |
12161 | If it cannot find a match, it emits a message. | |
c906108c SS |
12162 | |
12163 | @item set overload-resolution off | |
b37052ae | 12164 | Disable overload resolution for C@t{++} expression evaluation. For |
c906108c SS |
12165 | overloaded functions that are not class member functions, @value{GDBN} |
12166 | chooses the first function of the specified name that it finds in the | |
12167 | symbol table, whether or not its arguments are of the correct type. For | |
12168 | overloaded functions that are class member functions, @value{GDBN} | |
12169 | searches for a function whose signature @emph{exactly} matches the | |
12170 | argument types. | |
c906108c | 12171 | |
9c16f35a EZ |
12172 | @kindex show overload-resolution |
12173 | @item show overload-resolution | |
12174 | Show the current setting of overload resolution. | |
12175 | ||
c906108c SS |
12176 | @item @r{Overloaded symbol names} |
12177 | You can specify a particular definition of an overloaded symbol, using | |
b37052ae | 12178 | the same notation that is used to declare such symbols in C@t{++}: type |
c906108c SS |
12179 | @code{@var{symbol}(@var{types})} rather than just @var{symbol}. You can |
12180 | also use the @value{GDBN} command-line word completion facilities to list the | |
12181 | available choices, or to finish the type list for you. | |
79a6e687 | 12182 | @xref{Completion,, Command Completion}, for details on how to do this. |
c906108c | 12183 | @end table |
c906108c | 12184 | |
febe4383 TJB |
12185 | @node Decimal Floating Point |
12186 | @subsubsection Decimal Floating Point format | |
12187 | @cindex decimal floating point format | |
12188 | ||
12189 | @value{GDBN} can examine, set and perform computations with numbers in | |
12190 | decimal floating point format, which in the C language correspond to the | |
12191 | @code{_Decimal32}, @code{_Decimal64} and @code{_Decimal128} types as | |
12192 | specified by the extension to support decimal floating-point arithmetic. | |
12193 | ||
12194 | There are two encodings in use, depending on the architecture: BID (Binary | |
12195 | Integer Decimal) for x86 and x86-64, and DPD (Densely Packed Decimal) for | |
99e008fe | 12196 | PowerPC. @value{GDBN} will use the appropriate encoding for the configured |
febe4383 TJB |
12197 | target. |
12198 | ||
12199 | Because of a limitation in @file{libdecnumber}, the library used by @value{GDBN} | |
12200 | to manipulate decimal floating point numbers, it is not possible to convert | |
12201 | (using a cast, for example) integers wider than 32-bit to decimal float. | |
12202 | ||
12203 | In addition, in order to imitate @value{GDBN}'s behaviour with binary floating | |
12204 | point computations, error checking in decimal float operations ignores | |
12205 | underflow, overflow and divide by zero exceptions. | |
12206 | ||
4acd40f3 | 12207 | In the PowerPC architecture, @value{GDBN} provides a set of pseudo-registers |
99e008fe EZ |
12208 | to inspect @code{_Decimal128} values stored in floating point registers. |
12209 | See @ref{PowerPC,,PowerPC} for more details. | |
4acd40f3 | 12210 | |
6aecb9c2 JB |
12211 | @node D |
12212 | @subsection D | |
12213 | ||
12214 | @cindex D | |
12215 | @value{GDBN} can be used to debug programs written in D and compiled with | |
12216 | GDC, LDC or DMD compilers. Currently @value{GDBN} supports only one D | |
12217 | specific feature --- dynamic arrays. | |
12218 | ||
b37303ee AF |
12219 | @node Objective-C |
12220 | @subsection Objective-C | |
12221 | ||
12222 | @cindex Objective-C | |
12223 | This section provides information about some commands and command | |
721c2651 EZ |
12224 | options that are useful for debugging Objective-C code. See also |
12225 | @ref{Symbols, info classes}, and @ref{Symbols, info selectors}, for a | |
12226 | few more commands specific to Objective-C support. | |
b37303ee AF |
12227 | |
12228 | @menu | |
b383017d RM |
12229 | * Method Names in Commands:: |
12230 | * The Print Command with Objective-C:: | |
b37303ee AF |
12231 | @end menu |
12232 | ||
c8f4133a | 12233 | @node Method Names in Commands |
b37303ee AF |
12234 | @subsubsection Method Names in Commands |
12235 | ||
12236 | The following commands have been extended to accept Objective-C method | |
12237 | names as line specifications: | |
12238 | ||
12239 | @kindex clear@r{, and Objective-C} | |
12240 | @kindex break@r{, and Objective-C} | |
12241 | @kindex info line@r{, and Objective-C} | |
12242 | @kindex jump@r{, and Objective-C} | |
12243 | @kindex list@r{, and Objective-C} | |
12244 | @itemize | |
12245 | @item @code{clear} | |
12246 | @item @code{break} | |
12247 | @item @code{info line} | |
12248 | @item @code{jump} | |
12249 | @item @code{list} | |
12250 | @end itemize | |
12251 | ||
12252 | A fully qualified Objective-C method name is specified as | |
12253 | ||
12254 | @smallexample | |
12255 | -[@var{Class} @var{methodName}] | |
12256 | @end smallexample | |
12257 | ||
c552b3bb JM |
12258 | where the minus sign is used to indicate an instance method and a |
12259 | plus sign (not shown) is used to indicate a class method. The class | |
12260 | name @var{Class} and method name @var{methodName} are enclosed in | |
12261 | brackets, similar to the way messages are specified in Objective-C | |
12262 | source code. For example, to set a breakpoint at the @code{create} | |
12263 | instance method of class @code{Fruit} in the program currently being | |
12264 | debugged, enter: | |
b37303ee AF |
12265 | |
12266 | @smallexample | |
12267 | break -[Fruit create] | |
12268 | @end smallexample | |
12269 | ||
12270 | To list ten program lines around the @code{initialize} class method, | |
12271 | enter: | |
12272 | ||
12273 | @smallexample | |
12274 | list +[NSText initialize] | |
12275 | @end smallexample | |
12276 | ||
c552b3bb JM |
12277 | In the current version of @value{GDBN}, the plus or minus sign is |
12278 | required. In future versions of @value{GDBN}, the plus or minus | |
12279 | sign will be optional, but you can use it to narrow the search. It | |
12280 | is also possible to specify just a method name: | |
b37303ee AF |
12281 | |
12282 | @smallexample | |
12283 | break create | |
12284 | @end smallexample | |
12285 | ||
12286 | You must specify the complete method name, including any colons. If | |
12287 | your program's source files contain more than one @code{create} method, | |
12288 | you'll be presented with a numbered list of classes that implement that | |
12289 | method. Indicate your choice by number, or type @samp{0} to exit if | |
12290 | none apply. | |
12291 | ||
12292 | As another example, to clear a breakpoint established at the | |
12293 | @code{makeKeyAndOrderFront:} method of the @code{NSWindow} class, enter: | |
12294 | ||
12295 | @smallexample | |
12296 | clear -[NSWindow makeKeyAndOrderFront:] | |
12297 | @end smallexample | |
12298 | ||
12299 | @node The Print Command with Objective-C | |
12300 | @subsubsection The Print Command With Objective-C | |
721c2651 | 12301 | @cindex Objective-C, print objects |
c552b3bb JM |
12302 | @kindex print-object |
12303 | @kindex po @r{(@code{print-object})} | |
b37303ee | 12304 | |
c552b3bb | 12305 | The print command has also been extended to accept methods. For example: |
b37303ee AF |
12306 | |
12307 | @smallexample | |
c552b3bb | 12308 | print -[@var{object} hash] |
b37303ee AF |
12309 | @end smallexample |
12310 | ||
12311 | @cindex print an Objective-C object description | |
c552b3bb JM |
12312 | @cindex @code{_NSPrintForDebugger}, and printing Objective-C objects |
12313 | @noindent | |
12314 | will tell @value{GDBN} to send the @code{hash} message to @var{object} | |
12315 | and print the result. Also, an additional command has been added, | |
12316 | @code{print-object} or @code{po} for short, which is meant to print | |
12317 | the description of an object. However, this command may only work | |
12318 | with certain Objective-C libraries that have a particular hook | |
12319 | function, @code{_NSPrintForDebugger}, defined. | |
b37303ee | 12320 | |
f4b8a18d KW |
12321 | @node OpenCL C |
12322 | @subsection OpenCL C | |
12323 | ||
12324 | @cindex OpenCL C | |
12325 | This section provides information about @value{GDBN}s OpenCL C support. | |
12326 | ||
12327 | @menu | |
12328 | * OpenCL C Datatypes:: | |
12329 | * OpenCL C Expressions:: | |
12330 | * OpenCL C Operators:: | |
12331 | @end menu | |
12332 | ||
12333 | @node OpenCL C Datatypes | |
12334 | @subsubsection OpenCL C Datatypes | |
12335 | ||
12336 | @cindex OpenCL C Datatypes | |
12337 | @value{GDBN} supports the builtin scalar and vector datatypes specified | |
12338 | by OpenCL 1.1. In addition the half- and double-precision floating point | |
12339 | data types of the @code{cl_khr_fp16} and @code{cl_khr_fp64} OpenCL | |
12340 | extensions are also known to @value{GDBN}. | |
12341 | ||
12342 | @node OpenCL C Expressions | |
12343 | @subsubsection OpenCL C Expressions | |
12344 | ||
12345 | @cindex OpenCL C Expressions | |
12346 | @value{GDBN} supports accesses to vector components including the access as | |
12347 | lvalue where possible. Since OpenCL C is based on C99 most C expressions | |
12348 | supported by @value{GDBN} can be used as well. | |
12349 | ||
12350 | @node OpenCL C Operators | |
12351 | @subsubsection OpenCL C Operators | |
12352 | ||
12353 | @cindex OpenCL C Operators | |
12354 | @value{GDBN} supports the operators specified by OpenCL 1.1 for scalar and | |
12355 | vector data types. | |
12356 | ||
09d4efe1 EZ |
12357 | @node Fortran |
12358 | @subsection Fortran | |
12359 | @cindex Fortran-specific support in @value{GDBN} | |
12360 | ||
814e32d7 WZ |
12361 | @value{GDBN} can be used to debug programs written in Fortran, but it |
12362 | currently supports only the features of Fortran 77 language. | |
12363 | ||
12364 | @cindex trailing underscore, in Fortran symbols | |
12365 | Some Fortran compilers (@sc{gnu} Fortran 77 and Fortran 95 compilers | |
12366 | among them) append an underscore to the names of variables and | |
12367 | functions. When you debug programs compiled by those compilers, you | |
12368 | will need to refer to variables and functions with a trailing | |
12369 | underscore. | |
12370 | ||
12371 | @menu | |
12372 | * Fortran Operators:: Fortran operators and expressions | |
12373 | * Fortran Defaults:: Default settings for Fortran | |
79a6e687 | 12374 | * Special Fortran Commands:: Special @value{GDBN} commands for Fortran |
814e32d7 WZ |
12375 | @end menu |
12376 | ||
12377 | @node Fortran Operators | |
79a6e687 | 12378 | @subsubsection Fortran Operators and Expressions |
814e32d7 WZ |
12379 | |
12380 | @cindex Fortran operators and expressions | |
12381 | ||
12382 | Operators must be defined on values of specific types. For instance, | |
12383 | @code{+} is defined on numbers, but not on characters or other non- | |
ff2587ec | 12384 | arithmetic types. Operators are often defined on groups of types. |
814e32d7 WZ |
12385 | |
12386 | @table @code | |
12387 | @item ** | |
99e008fe | 12388 | The exponentiation operator. It raises the first operand to the power |
814e32d7 WZ |
12389 | of the second one. |
12390 | ||
12391 | @item : | |
12392 | The range operator. Normally used in the form of array(low:high) to | |
12393 | represent a section of array. | |
68837c9d MD |
12394 | |
12395 | @item % | |
12396 | The access component operator. Normally used to access elements in derived | |
12397 | types. Also suitable for unions. As unions aren't part of regular Fortran, | |
12398 | this can only happen when accessing a register that uses a gdbarch-defined | |
12399 | union type. | |
814e32d7 WZ |
12400 | @end table |
12401 | ||
12402 | @node Fortran Defaults | |
12403 | @subsubsection Fortran Defaults | |
12404 | ||
12405 | @cindex Fortran Defaults | |
12406 | ||
12407 | Fortran symbols are usually case-insensitive, so @value{GDBN} by | |
12408 | default uses case-insensitive matches for Fortran symbols. You can | |
12409 | change that with the @samp{set case-insensitive} command, see | |
12410 | @ref{Symbols}, for the details. | |
12411 | ||
79a6e687 BW |
12412 | @node Special Fortran Commands |
12413 | @subsubsection Special Fortran Commands | |
814e32d7 WZ |
12414 | |
12415 | @cindex Special Fortran commands | |
12416 | ||
db2e3e2e BW |
12417 | @value{GDBN} has some commands to support Fortran-specific features, |
12418 | such as displaying common blocks. | |
814e32d7 | 12419 | |
09d4efe1 EZ |
12420 | @table @code |
12421 | @cindex @code{COMMON} blocks, Fortran | |
12422 | @kindex info common | |
12423 | @item info common @r{[}@var{common-name}@r{]} | |
12424 | This command prints the values contained in the Fortran @code{COMMON} | |
12425 | block whose name is @var{common-name}. With no argument, the names of | |
d52fb0e9 | 12426 | all @code{COMMON} blocks visible at the current program location are |
09d4efe1 EZ |
12427 | printed. |
12428 | @end table | |
12429 | ||
9c16f35a EZ |
12430 | @node Pascal |
12431 | @subsection Pascal | |
12432 | ||
12433 | @cindex Pascal support in @value{GDBN}, limitations | |
12434 | Debugging Pascal programs which use sets, subranges, file variables, or | |
12435 | nested functions does not currently work. @value{GDBN} does not support | |
12436 | entering expressions, printing values, or similar features using Pascal | |
12437 | syntax. | |
12438 | ||
12439 | The Pascal-specific command @code{set print pascal_static-members} | |
12440 | controls whether static members of Pascal objects are displayed. | |
12441 | @xref{Print Settings, pascal_static-members}. | |
12442 | ||
09d4efe1 | 12443 | @node Modula-2 |
c906108c | 12444 | @subsection Modula-2 |
7a292a7a | 12445 | |
d4f3574e | 12446 | @cindex Modula-2, @value{GDBN} support |
c906108c SS |
12447 | |
12448 | The extensions made to @value{GDBN} to support Modula-2 only support | |
12449 | output from the @sc{gnu} Modula-2 compiler (which is currently being | |
12450 | developed). Other Modula-2 compilers are not currently supported, and | |
12451 | attempting to debug executables produced by them is most likely | |
12452 | to give an error as @value{GDBN} reads in the executable's symbol | |
12453 | table. | |
12454 | ||
12455 | @cindex expressions in Modula-2 | |
12456 | @menu | |
12457 | * M2 Operators:: Built-in operators | |
12458 | * Built-In Func/Proc:: Built-in functions and procedures | |
12459 | * M2 Constants:: Modula-2 constants | |
72019c9c | 12460 | * M2 Types:: Modula-2 types |
c906108c SS |
12461 | * M2 Defaults:: Default settings for Modula-2 |
12462 | * Deviations:: Deviations from standard Modula-2 | |
12463 | * M2 Checks:: Modula-2 type and range checks | |
12464 | * M2 Scope:: The scope operators @code{::} and @code{.} | |
12465 | * GDB/M2:: @value{GDBN} and Modula-2 | |
12466 | @end menu | |
12467 | ||
6d2ebf8b | 12468 | @node M2 Operators |
c906108c SS |
12469 | @subsubsection Operators |
12470 | @cindex Modula-2 operators | |
12471 | ||
12472 | Operators must be defined on values of specific types. For instance, | |
12473 | @code{+} is defined on numbers, but not on structures. Operators are | |
12474 | often defined on groups of types. For the purposes of Modula-2, the | |
12475 | following definitions hold: | |
12476 | ||
12477 | @itemize @bullet | |
12478 | ||
12479 | @item | |
12480 | @emph{Integral types} consist of @code{INTEGER}, @code{CARDINAL}, and | |
12481 | their subranges. | |
12482 | ||
12483 | @item | |
12484 | @emph{Character types} consist of @code{CHAR} and its subranges. | |
12485 | ||
12486 | @item | |
12487 | @emph{Floating-point types} consist of @code{REAL}. | |
12488 | ||
12489 | @item | |
12490 | @emph{Pointer types} consist of anything declared as @code{POINTER TO | |
12491 | @var{type}}. | |
12492 | ||
12493 | @item | |
12494 | @emph{Scalar types} consist of all of the above. | |
12495 | ||
12496 | @item | |
12497 | @emph{Set types} consist of @code{SET} and @code{BITSET} types. | |
12498 | ||
12499 | @item | |
12500 | @emph{Boolean types} consist of @code{BOOLEAN}. | |
12501 | @end itemize | |
12502 | ||
12503 | @noindent | |
12504 | The following operators are supported, and appear in order of | |
12505 | increasing precedence: | |
12506 | ||
12507 | @table @code | |
12508 | @item , | |
12509 | Function argument or array index separator. | |
12510 | ||
12511 | @item := | |
12512 | Assignment. The value of @var{var} @code{:=} @var{value} is | |
12513 | @var{value}. | |
12514 | ||
12515 | @item <@r{, }> | |
12516 | Less than, greater than on integral, floating-point, or enumerated | |
12517 | types. | |
12518 | ||
12519 | @item <=@r{, }>= | |
96a2c332 | 12520 | Less than or equal to, greater than or equal to |
c906108c SS |
12521 | on integral, floating-point and enumerated types, or set inclusion on |
12522 | set types. Same precedence as @code{<}. | |
12523 | ||
12524 | @item =@r{, }<>@r{, }# | |
12525 | Equality and two ways of expressing inequality, valid on scalar types. | |
12526 | Same precedence as @code{<}. In @value{GDBN} scripts, only @code{<>} is | |
12527 | available for inequality, since @code{#} conflicts with the script | |
12528 | comment character. | |
12529 | ||
12530 | @item IN | |
12531 | Set membership. Defined on set types and the types of their members. | |
12532 | Same precedence as @code{<}. | |
12533 | ||
12534 | @item OR | |
12535 | Boolean disjunction. Defined on boolean types. | |
12536 | ||
12537 | @item AND@r{, }& | |
d4f3574e | 12538 | Boolean conjunction. Defined on boolean types. |
c906108c SS |
12539 | |
12540 | @item @@ | |
12541 | The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}). | |
12542 | ||
12543 | @item +@r{, }- | |
12544 | Addition and subtraction on integral and floating-point types, or union | |
12545 | and difference on set types. | |
12546 | ||
12547 | @item * | |
12548 | Multiplication on integral and floating-point types, or set intersection | |
12549 | on set types. | |
12550 | ||
12551 | @item / | |
12552 | Division on floating-point types, or symmetric set difference on set | |
12553 | types. Same precedence as @code{*}. | |
12554 | ||
12555 | @item DIV@r{, }MOD | |
12556 | Integer division and remainder. Defined on integral types. Same | |
12557 | precedence as @code{*}. | |
12558 | ||
12559 | @item - | |
99e008fe | 12560 | Negative. Defined on @code{INTEGER} and @code{REAL} data. |
c906108c SS |
12561 | |
12562 | @item ^ | |
12563 | Pointer dereferencing. Defined on pointer types. | |
12564 | ||
12565 | @item NOT | |
12566 | Boolean negation. Defined on boolean types. Same precedence as | |
12567 | @code{^}. | |
12568 | ||
12569 | @item . | |
12570 | @code{RECORD} field selector. Defined on @code{RECORD} data. Same | |
12571 | precedence as @code{^}. | |
12572 | ||
12573 | @item [] | |
12574 | Array indexing. Defined on @code{ARRAY} data. Same precedence as @code{^}. | |
12575 | ||
12576 | @item () | |
12577 | Procedure argument list. Defined on @code{PROCEDURE} objects. Same precedence | |
12578 | as @code{^}. | |
12579 | ||
12580 | @item ::@r{, }. | |
12581 | @value{GDBN} and Modula-2 scope operators. | |
12582 | @end table | |
12583 | ||
12584 | @quotation | |
72019c9c | 12585 | @emph{Warning:} Set expressions and their operations are not yet supported, so @value{GDBN} |
c906108c SS |
12586 | treats the use of the operator @code{IN}, or the use of operators |
12587 | @code{+}, @code{-}, @code{*}, @code{/}, @code{=}, , @code{<>}, @code{#}, | |
12588 | @code{<=}, and @code{>=} on sets as an error. | |
12589 | @end quotation | |
12590 | ||
cb51c4e0 | 12591 | |
6d2ebf8b | 12592 | @node Built-In Func/Proc |
79a6e687 | 12593 | @subsubsection Built-in Functions and Procedures |
cb51c4e0 | 12594 | @cindex Modula-2 built-ins |
c906108c SS |
12595 | |
12596 | Modula-2 also makes available several built-in procedures and functions. | |
12597 | In describing these, the following metavariables are used: | |
12598 | ||
12599 | @table @var | |
12600 | ||
12601 | @item a | |
12602 | represents an @code{ARRAY} variable. | |
12603 | ||
12604 | @item c | |
12605 | represents a @code{CHAR} constant or variable. | |
12606 | ||
12607 | @item i | |
12608 | represents a variable or constant of integral type. | |
12609 | ||
12610 | @item m | |
12611 | represents an identifier that belongs to a set. Generally used in the | |
12612 | same function with the metavariable @var{s}. The type of @var{s} should | |
12613 | be @code{SET OF @var{mtype}} (where @var{mtype} is the type of @var{m}). | |
12614 | ||
12615 | @item n | |
12616 | represents a variable or constant of integral or floating-point type. | |
12617 | ||
12618 | @item r | |
12619 | represents a variable or constant of floating-point type. | |
12620 | ||
12621 | @item t | |
12622 | represents a type. | |
12623 | ||
12624 | @item v | |
12625 | represents a variable. | |
12626 | ||
12627 | @item x | |
12628 | represents a variable or constant of one of many types. See the | |
12629 | explanation of the function for details. | |
12630 | @end table | |
12631 | ||
12632 | All Modula-2 built-in procedures also return a result, described below. | |
12633 | ||
12634 | @table @code | |
12635 | @item ABS(@var{n}) | |
12636 | Returns the absolute value of @var{n}. | |
12637 | ||
12638 | @item CAP(@var{c}) | |
12639 | If @var{c} is a lower case letter, it returns its upper case | |
c3f6f71d | 12640 | equivalent, otherwise it returns its argument. |
c906108c SS |
12641 | |
12642 | @item CHR(@var{i}) | |
12643 | Returns the character whose ordinal value is @var{i}. | |
12644 | ||
12645 | @item DEC(@var{v}) | |
c3f6f71d | 12646 | Decrements the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
12647 | |
12648 | @item DEC(@var{v},@var{i}) | |
12649 | Decrements the value in the variable @var{v} by @var{i}. Returns the | |
12650 | new value. | |
12651 | ||
12652 | @item EXCL(@var{m},@var{s}) | |
12653 | Removes the element @var{m} from the set @var{s}. Returns the new | |
12654 | set. | |
12655 | ||
12656 | @item FLOAT(@var{i}) | |
12657 | Returns the floating point equivalent of the integer @var{i}. | |
12658 | ||
12659 | @item HIGH(@var{a}) | |
12660 | Returns the index of the last member of @var{a}. | |
12661 | ||
12662 | @item INC(@var{v}) | |
c3f6f71d | 12663 | Increments the value in the variable @var{v} by one. Returns the new value. |
c906108c SS |
12664 | |
12665 | @item INC(@var{v},@var{i}) | |
12666 | Increments the value in the variable @var{v} by @var{i}. Returns the | |
12667 | new value. | |
12668 | ||
12669 | @item INCL(@var{m},@var{s}) | |
12670 | Adds the element @var{m} to the set @var{s} if it is not already | |
12671 | there. Returns the new set. | |
12672 | ||
12673 | @item MAX(@var{t}) | |
12674 | Returns the maximum value of the type @var{t}. | |
12675 | ||
12676 | @item MIN(@var{t}) | |
12677 | Returns the minimum value of the type @var{t}. | |
12678 | ||
12679 | @item ODD(@var{i}) | |
12680 | Returns boolean TRUE if @var{i} is an odd number. | |
12681 | ||
12682 | @item ORD(@var{x}) | |
12683 | Returns the ordinal value of its argument. For example, the ordinal | |
c3f6f71d JM |
12684 | value of a character is its @sc{ascii} value (on machines supporting the |
12685 | @sc{ascii} character set). @var{x} must be of an ordered type, which include | |
c906108c SS |
12686 | integral, character and enumerated types. |
12687 | ||
12688 | @item SIZE(@var{x}) | |
12689 | Returns the size of its argument. @var{x} can be a variable or a type. | |
12690 | ||
12691 | @item TRUNC(@var{r}) | |
12692 | Returns the integral part of @var{r}. | |
12693 | ||
844781a1 GM |
12694 | @item TSIZE(@var{x}) |
12695 | Returns the size of its argument. @var{x} can be a variable or a type. | |
12696 | ||
c906108c SS |
12697 | @item VAL(@var{t},@var{i}) |
12698 | Returns the member of the type @var{t} whose ordinal value is @var{i}. | |
12699 | @end table | |
12700 | ||
12701 | @quotation | |
12702 | @emph{Warning:} Sets and their operations are not yet supported, so | |
12703 | @value{GDBN} treats the use of procedures @code{INCL} and @code{EXCL} as | |
12704 | an error. | |
12705 | @end quotation | |
12706 | ||
12707 | @cindex Modula-2 constants | |
6d2ebf8b | 12708 | @node M2 Constants |
c906108c SS |
12709 | @subsubsection Constants |
12710 | ||
12711 | @value{GDBN} allows you to express the constants of Modula-2 in the following | |
12712 | ways: | |
12713 | ||
12714 | @itemize @bullet | |
12715 | ||
12716 | @item | |
12717 | Integer constants are simply a sequence of digits. When used in an | |
12718 | expression, a constant is interpreted to be type-compatible with the | |
12719 | rest of the expression. Hexadecimal integers are specified by a | |
12720 | trailing @samp{H}, and octal integers by a trailing @samp{B}. | |
12721 | ||
12722 | @item | |
12723 | Floating point constants appear as a sequence of digits, followed by a | |
12724 | decimal point and another sequence of digits. An optional exponent can | |
12725 | then be specified, in the form @samp{E@r{[}+@r{|}-@r{]}@var{nnn}}, where | |
12726 | @samp{@r{[}+@r{|}-@r{]}@var{nnn}} is the desired exponent. All of the | |
12727 | digits of the floating point constant must be valid decimal (base 10) | |
12728 | digits. | |
12729 | ||
12730 | @item | |
12731 | Character constants consist of a single character enclosed by a pair of | |
12732 | like quotes, either single (@code{'}) or double (@code{"}). They may | |
c3f6f71d | 12733 | also be expressed by their ordinal value (their @sc{ascii} value, usually) |
c906108c SS |
12734 | followed by a @samp{C}. |
12735 | ||
12736 | @item | |
12737 | String constants consist of a sequence of characters enclosed by a | |
12738 | pair of like quotes, either single (@code{'}) or double (@code{"}). | |
12739 | Escape sequences in the style of C are also allowed. @xref{C | |
79a6e687 | 12740 | Constants, ,C and C@t{++} Constants}, for a brief explanation of escape |
c906108c SS |
12741 | sequences. |
12742 | ||
12743 | @item | |
12744 | Enumerated constants consist of an enumerated identifier. | |
12745 | ||
12746 | @item | |
12747 | Boolean constants consist of the identifiers @code{TRUE} and | |
12748 | @code{FALSE}. | |
12749 | ||
12750 | @item | |
12751 | Pointer constants consist of integral values only. | |
12752 | ||
12753 | @item | |
12754 | Set constants are not yet supported. | |
12755 | @end itemize | |
12756 | ||
72019c9c GM |
12757 | @node M2 Types |
12758 | @subsubsection Modula-2 Types | |
12759 | @cindex Modula-2 types | |
12760 | ||
12761 | Currently @value{GDBN} can print the following data types in Modula-2 | |
12762 | syntax: array types, record types, set types, pointer types, procedure | |
12763 | types, enumerated types, subrange types and base types. You can also | |
12764 | print the contents of variables declared using these type. | |
12765 | This section gives a number of simple source code examples together with | |
12766 | sample @value{GDBN} sessions. | |
12767 | ||
12768 | The first example contains the following section of code: | |
12769 | ||
12770 | @smallexample | |
12771 | VAR | |
12772 | s: SET OF CHAR ; | |
12773 | r: [20..40] ; | |
12774 | @end smallexample | |
12775 | ||
12776 | @noindent | |
12777 | and you can request @value{GDBN} to interrogate the type and value of | |
12778 | @code{r} and @code{s}. | |
12779 | ||
12780 | @smallexample | |
12781 | (@value{GDBP}) print s | |
12782 | @{'A'..'C', 'Z'@} | |
12783 | (@value{GDBP}) ptype s | |
12784 | SET OF CHAR | |
12785 | (@value{GDBP}) print r | |
12786 | 21 | |
12787 | (@value{GDBP}) ptype r | |
12788 | [20..40] | |
12789 | @end smallexample | |
12790 | ||
12791 | @noindent | |
12792 | Likewise if your source code declares @code{s} as: | |
12793 | ||
12794 | @smallexample | |
12795 | VAR | |
12796 | s: SET ['A'..'Z'] ; | |
12797 | @end smallexample | |
12798 | ||
12799 | @noindent | |
12800 | then you may query the type of @code{s} by: | |
12801 | ||
12802 | @smallexample | |
12803 | (@value{GDBP}) ptype s | |
12804 | type = SET ['A'..'Z'] | |
12805 | @end smallexample | |
12806 | ||
12807 | @noindent | |
12808 | Note that at present you cannot interactively manipulate set | |
12809 | expressions using the debugger. | |
12810 | ||
12811 | The following example shows how you might declare an array in Modula-2 | |
12812 | and how you can interact with @value{GDBN} to print its type and contents: | |
12813 | ||
12814 | @smallexample | |
12815 | VAR | |
12816 | s: ARRAY [-10..10] OF CHAR ; | |
12817 | @end smallexample | |
12818 | ||
12819 | @smallexample | |
12820 | (@value{GDBP}) ptype s | |
12821 | ARRAY [-10..10] OF CHAR | |
12822 | @end smallexample | |
12823 | ||
12824 | Note that the array handling is not yet complete and although the type | |
12825 | is printed correctly, expression handling still assumes that all | |
12826 | arrays have a lower bound of zero and not @code{-10} as in the example | |
844781a1 | 12827 | above. |
72019c9c GM |
12828 | |
12829 | Here are some more type related Modula-2 examples: | |
12830 | ||
12831 | @smallexample | |
12832 | TYPE | |
12833 | colour = (blue, red, yellow, green) ; | |
12834 | t = [blue..yellow] ; | |
12835 | VAR | |
12836 | s: t ; | |
12837 | BEGIN | |
12838 | s := blue ; | |
12839 | @end smallexample | |
12840 | ||
12841 | @noindent | |
12842 | The @value{GDBN} interaction shows how you can query the data type | |
12843 | and value of a variable. | |
12844 | ||
12845 | @smallexample | |
12846 | (@value{GDBP}) print s | |
12847 | $1 = blue | |
12848 | (@value{GDBP}) ptype t | |
12849 | type = [blue..yellow] | |
12850 | @end smallexample | |
12851 | ||
12852 | @noindent | |
12853 | In this example a Modula-2 array is declared and its contents | |
12854 | displayed. Observe that the contents are written in the same way as | |
12855 | their @code{C} counterparts. | |
12856 | ||
12857 | @smallexample | |
12858 | VAR | |
12859 | s: ARRAY [1..5] OF CARDINAL ; | |
12860 | BEGIN | |
12861 | s[1] := 1 ; | |
12862 | @end smallexample | |
12863 | ||
12864 | @smallexample | |
12865 | (@value{GDBP}) print s | |
12866 | $1 = @{1, 0, 0, 0, 0@} | |
12867 | (@value{GDBP}) ptype s | |
12868 | type = ARRAY [1..5] OF CARDINAL | |
12869 | @end smallexample | |
12870 | ||
12871 | The Modula-2 language interface to @value{GDBN} also understands | |
12872 | pointer types as shown in this example: | |
12873 | ||
12874 | @smallexample | |
12875 | VAR | |
12876 | s: POINTER TO ARRAY [1..5] OF CARDINAL ; | |
12877 | BEGIN | |
12878 | NEW(s) ; | |
12879 | s^[1] := 1 ; | |
12880 | @end smallexample | |
12881 | ||
12882 | @noindent | |
12883 | and you can request that @value{GDBN} describes the type of @code{s}. | |
12884 | ||
12885 | @smallexample | |
12886 | (@value{GDBP}) ptype s | |
12887 | type = POINTER TO ARRAY [1..5] OF CARDINAL | |
12888 | @end smallexample | |
12889 | ||
12890 | @value{GDBN} handles compound types as we can see in this example. | |
12891 | Here we combine array types, record types, pointer types and subrange | |
12892 | types: | |
12893 | ||
12894 | @smallexample | |
12895 | TYPE | |
12896 | foo = RECORD | |
12897 | f1: CARDINAL ; | |
12898 | f2: CHAR ; | |
12899 | f3: myarray ; | |
12900 | END ; | |
12901 | ||
12902 | myarray = ARRAY myrange OF CARDINAL ; | |
12903 | myrange = [-2..2] ; | |
12904 | VAR | |
12905 | s: POINTER TO ARRAY myrange OF foo ; | |
12906 | @end smallexample | |
12907 | ||
12908 | @noindent | |
12909 | and you can ask @value{GDBN} to describe the type of @code{s} as shown | |
12910 | below. | |
12911 | ||
12912 | @smallexample | |
12913 | (@value{GDBP}) ptype s | |
12914 | type = POINTER TO ARRAY [-2..2] OF foo = RECORD | |
12915 | f1 : CARDINAL; | |
12916 | f2 : CHAR; | |
12917 | f3 : ARRAY [-2..2] OF CARDINAL; | |
12918 | END | |
12919 | @end smallexample | |
12920 | ||
6d2ebf8b | 12921 | @node M2 Defaults |
79a6e687 | 12922 | @subsubsection Modula-2 Defaults |
c906108c SS |
12923 | @cindex Modula-2 defaults |
12924 | ||
12925 | If type and range checking are set automatically by @value{GDBN}, they | |
12926 | both default to @code{on} whenever the working language changes to | |
d4f3574e | 12927 | Modula-2. This happens regardless of whether you or @value{GDBN} |
c906108c SS |
12928 | selected the working language. |
12929 | ||
12930 | If you allow @value{GDBN} to set the language automatically, then entering | |
12931 | code compiled from a file whose name ends with @file{.mod} sets the | |
79a6e687 BW |
12932 | working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} |
12933 | Infer the Source Language}, for further details. | |
c906108c | 12934 | |
6d2ebf8b | 12935 | @node Deviations |
79a6e687 | 12936 | @subsubsection Deviations from Standard Modula-2 |
c906108c SS |
12937 | @cindex Modula-2, deviations from |
12938 | ||
12939 | A few changes have been made to make Modula-2 programs easier to debug. | |
12940 | This is done primarily via loosening its type strictness: | |
12941 | ||
12942 | @itemize @bullet | |
12943 | @item | |
12944 | Unlike in standard Modula-2, pointer constants can be formed by | |
12945 | integers. This allows you to modify pointer variables during | |
12946 | debugging. (In standard Modula-2, the actual address contained in a | |
12947 | pointer variable is hidden from you; it can only be modified | |
12948 | through direct assignment to another pointer variable or expression that | |
12949 | returned a pointer.) | |
12950 | ||
12951 | @item | |
12952 | C escape sequences can be used in strings and characters to represent | |
12953 | non-printable characters. @value{GDBN} prints out strings with these | |
12954 | escape sequences embedded. Single non-printable characters are | |
12955 | printed using the @samp{CHR(@var{nnn})} format. | |
12956 | ||
12957 | @item | |
12958 | The assignment operator (@code{:=}) returns the value of its right-hand | |
12959 | argument. | |
12960 | ||
12961 | @item | |
12962 | All built-in procedures both modify @emph{and} return their argument. | |
12963 | @end itemize | |
12964 | ||
6d2ebf8b | 12965 | @node M2 Checks |
79a6e687 | 12966 | @subsubsection Modula-2 Type and Range Checks |
c906108c SS |
12967 | @cindex Modula-2 checks |
12968 | ||
12969 | @quotation | |
12970 | @emph{Warning:} in this release, @value{GDBN} does not yet perform type or | |
12971 | range checking. | |
12972 | @end quotation | |
12973 | @c FIXME remove warning when type/range checks added | |
12974 | ||
12975 | @value{GDBN} considers two Modula-2 variables type equivalent if: | |
12976 | ||
12977 | @itemize @bullet | |
12978 | @item | |
12979 | They are of types that have been declared equivalent via a @code{TYPE | |
12980 | @var{t1} = @var{t2}} statement | |
12981 | ||
12982 | @item | |
12983 | They have been declared on the same line. (Note: This is true of the | |
12984 | @sc{gnu} Modula-2 compiler, but it may not be true of other compilers.) | |
12985 | @end itemize | |
12986 | ||
12987 | As long as type checking is enabled, any attempt to combine variables | |
12988 | whose types are not equivalent is an error. | |
12989 | ||
12990 | Range checking is done on all mathematical operations, assignment, array | |
12991 | index bounds, and all built-in functions and procedures. | |
12992 | ||
6d2ebf8b | 12993 | @node M2 Scope |
79a6e687 | 12994 | @subsubsection The Scope Operators @code{::} and @code{.} |
c906108c | 12995 | @cindex scope |
41afff9a | 12996 | @cindex @code{.}, Modula-2 scope operator |
c906108c SS |
12997 | @cindex colon, doubled as scope operator |
12998 | @ifinfo | |
41afff9a | 12999 | @vindex colon-colon@r{, in Modula-2} |
c906108c SS |
13000 | @c Info cannot handle :: but TeX can. |
13001 | @end ifinfo | |
a67ec3f4 | 13002 | @ifnotinfo |
41afff9a | 13003 | @vindex ::@r{, in Modula-2} |
a67ec3f4 | 13004 | @end ifnotinfo |
c906108c SS |
13005 | |
13006 | There are a few subtle differences between the Modula-2 scope operator | |
13007 | (@code{.}) and the @value{GDBN} scope operator (@code{::}). The two have | |
13008 | similar syntax: | |
13009 | ||
474c8240 | 13010 | @smallexample |
c906108c SS |
13011 | |
13012 | @var{module} . @var{id} | |
13013 | @var{scope} :: @var{id} | |
474c8240 | 13014 | @end smallexample |
c906108c SS |
13015 | |
13016 | @noindent | |
13017 | where @var{scope} is the name of a module or a procedure, | |
13018 | @var{module} the name of a module, and @var{id} is any declared | |
13019 | identifier within your program, except another module. | |
13020 | ||
13021 | Using the @code{::} operator makes @value{GDBN} search the scope | |
13022 | specified by @var{scope} for the identifier @var{id}. If it is not | |
13023 | found in the specified scope, then @value{GDBN} searches all scopes | |
13024 | enclosing the one specified by @var{scope}. | |
13025 | ||
13026 | Using the @code{.} operator makes @value{GDBN} search the current scope for | |
13027 | the identifier specified by @var{id} that was imported from the | |
13028 | definition module specified by @var{module}. With this operator, it is | |
13029 | an error if the identifier @var{id} was not imported from definition | |
13030 | module @var{module}, or if @var{id} is not an identifier in | |
13031 | @var{module}. | |
13032 | ||
6d2ebf8b | 13033 | @node GDB/M2 |
c906108c SS |
13034 | @subsubsection @value{GDBN} and Modula-2 |
13035 | ||
13036 | Some @value{GDBN} commands have little use when debugging Modula-2 programs. | |
13037 | Five subcommands of @code{set print} and @code{show print} apply | |
b37052ae | 13038 | specifically to C and C@t{++}: @samp{vtbl}, @samp{demangle}, |
c906108c | 13039 | @samp{asm-demangle}, @samp{object}, and @samp{union}. The first four |
b37052ae | 13040 | apply to C@t{++}, and the last to the C @code{union} type, which has no direct |
c906108c SS |
13041 | analogue in Modula-2. |
13042 | ||
13043 | The @code{@@} operator (@pxref{Expressions, ,Expressions}), while available | |
d4f3574e | 13044 | with any language, is not useful with Modula-2. Its |
c906108c | 13045 | intent is to aid the debugging of @dfn{dynamic arrays}, which cannot be |
b37052ae | 13046 | created in Modula-2 as they can in C or C@t{++}. However, because an |
c906108c | 13047 | address can be specified by an integral constant, the construct |
d4f3574e | 13048 | @samp{@{@var{type}@}@var{adrexp}} is still useful. |
c906108c SS |
13049 | |
13050 | @cindex @code{#} in Modula-2 | |
13051 | In @value{GDBN} scripts, the Modula-2 inequality operator @code{#} is | |
13052 | interpreted as the beginning of a comment. Use @code{<>} instead. | |
c906108c | 13053 | |
e07c999f PH |
13054 | @node Ada |
13055 | @subsection Ada | |
13056 | @cindex Ada | |
13057 | ||
13058 | The extensions made to @value{GDBN} for Ada only support | |
13059 | output from the @sc{gnu} Ada (GNAT) compiler. | |
13060 | Other Ada compilers are not currently supported, and | |
13061 | attempting to debug executables produced by them is most likely | |
13062 | to be difficult. | |
13063 | ||
13064 | ||
13065 | @cindex expressions in Ada | |
13066 | @menu | |
13067 | * Ada Mode Intro:: General remarks on the Ada syntax | |
13068 | and semantics supported by Ada mode | |
13069 | in @value{GDBN}. | |
13070 | * Omissions from Ada:: Restrictions on the Ada expression syntax. | |
13071 | * Additions to Ada:: Extensions of the Ada expression syntax. | |
13072 | * Stopping Before Main Program:: Debugging the program during elaboration. | |
20924a55 JB |
13073 | * Ada Tasks:: Listing and setting breakpoints in tasks. |
13074 | * Ada Tasks and Core Files:: Tasking Support when Debugging Core Files | |
6e1bb179 JB |
13075 | * Ravenscar Profile:: Tasking Support when using the Ravenscar |
13076 | Profile | |
e07c999f PH |
13077 | * Ada Glitches:: Known peculiarities of Ada mode. |
13078 | @end menu | |
13079 | ||
13080 | @node Ada Mode Intro | |
13081 | @subsubsection Introduction | |
13082 | @cindex Ada mode, general | |
13083 | ||
13084 | The Ada mode of @value{GDBN} supports a fairly large subset of Ada expression | |
13085 | syntax, with some extensions. | |
13086 | The philosophy behind the design of this subset is | |
13087 | ||
13088 | @itemize @bullet | |
13089 | @item | |
13090 | That @value{GDBN} should provide basic literals and access to operations for | |
13091 | arithmetic, dereferencing, field selection, indexing, and subprogram calls, | |
13092 | leaving more sophisticated computations to subprograms written into the | |
13093 | program (which therefore may be called from @value{GDBN}). | |
13094 | ||
13095 | @item | |
13096 | That type safety and strict adherence to Ada language restrictions | |
13097 | are not particularly important to the @value{GDBN} user. | |
13098 | ||
13099 | @item | |
13100 | That brevity is important to the @value{GDBN} user. | |
13101 | @end itemize | |
13102 | ||
f3a2dd1a JB |
13103 | Thus, for brevity, the debugger acts as if all names declared in |
13104 | user-written packages are directly visible, even if they are not visible | |
13105 | according to Ada rules, thus making it unnecessary to fully qualify most | |
13106 | names with their packages, regardless of context. Where this causes | |
13107 | ambiguity, @value{GDBN} asks the user's intent. | |
e07c999f PH |
13108 | |
13109 | The debugger will start in Ada mode if it detects an Ada main program. | |
13110 | As for other languages, it will enter Ada mode when stopped in a program that | |
13111 | was translated from an Ada source file. | |
13112 | ||
13113 | While in Ada mode, you may use `@t{--}' for comments. This is useful | |
13114 | mostly for documenting command files. The standard @value{GDBN} comment | |
13115 | (@samp{#}) still works at the beginning of a line in Ada mode, but not in the | |
13116 | middle (to allow based literals). | |
13117 | ||
13118 | The debugger supports limited overloading. Given a subprogram call in which | |
13119 | the function symbol has multiple definitions, it will use the number of | |
13120 | actual parameters and some information about their types to attempt to narrow | |
13121 | the set of definitions. It also makes very limited use of context, preferring | |
13122 | procedures to functions in the context of the @code{call} command, and | |
13123 | functions to procedures elsewhere. | |
13124 | ||
13125 | @node Omissions from Ada | |
13126 | @subsubsection Omissions from Ada | |
13127 | @cindex Ada, omissions from | |
13128 | ||
13129 | Here are the notable omissions from the subset: | |
13130 | ||
13131 | @itemize @bullet | |
13132 | @item | |
13133 | Only a subset of the attributes are supported: | |
13134 | ||
13135 | @itemize @minus | |
13136 | @item | |
13137 | @t{'First}, @t{'Last}, and @t{'Length} | |
13138 | on array objects (not on types and subtypes). | |
13139 | ||
13140 | @item | |
13141 | @t{'Min} and @t{'Max}. | |
13142 | ||
13143 | @item | |
13144 | @t{'Pos} and @t{'Val}. | |
13145 | ||
13146 | @item | |
13147 | @t{'Tag}. | |
13148 | ||
13149 | @item | |
13150 | @t{'Range} on array objects (not subtypes), but only as the right | |
13151 | operand of the membership (@code{in}) operator. | |
13152 | ||
13153 | @item | |
13154 | @t{'Access}, @t{'Unchecked_Access}, and | |
13155 | @t{'Unrestricted_Access} (a GNAT extension). | |
13156 | ||
13157 | @item | |
13158 | @t{'Address}. | |
13159 | @end itemize | |
13160 | ||
13161 | @item | |
13162 | The names in | |
13163 | @code{Characters.Latin_1} are not available and | |
13164 | concatenation is not implemented. Thus, escape characters in strings are | |
13165 | not currently available. | |
13166 | ||
13167 | @item | |
13168 | Equality tests (@samp{=} and @samp{/=}) on arrays test for bitwise | |
13169 | equality of representations. They will generally work correctly | |
13170 | for strings and arrays whose elements have integer or enumeration types. | |
13171 | They may not work correctly for arrays whose element | |
13172 | types have user-defined equality, for arrays of real values | |
13173 | (in particular, IEEE-conformant floating point, because of negative | |
13174 | zeroes and NaNs), and for arrays whose elements contain unused bits with | |
13175 | indeterminate values. | |
13176 | ||
13177 | @item | |
13178 | The other component-by-component array operations (@code{and}, @code{or}, | |
13179 | @code{xor}, @code{not}, and relational tests other than equality) | |
13180 | are not implemented. | |
13181 | ||
13182 | @item | |
860701dc PH |
13183 | @cindex array aggregates (Ada) |
13184 | @cindex record aggregates (Ada) | |
13185 | @cindex aggregates (Ada) | |
13186 | There is limited support for array and record aggregates. They are | |
13187 | permitted only on the right sides of assignments, as in these examples: | |
13188 | ||
13189 | @smallexample | |
077e0a52 JB |
13190 | (@value{GDBP}) set An_Array := (1, 2, 3, 4, 5, 6) |
13191 | (@value{GDBP}) set An_Array := (1, others => 0) | |
13192 | (@value{GDBP}) set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6) | |
13193 | (@value{GDBP}) set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9)) | |
13194 | (@value{GDBP}) set A_Record := (1, "Peter", True); | |
13195 | (@value{GDBP}) set A_Record := (Name => "Peter", Id => 1, Alive => True) | |
860701dc PH |
13196 | @end smallexample |
13197 | ||
13198 | Changing a | |
13199 | discriminant's value by assigning an aggregate has an | |
13200 | undefined effect if that discriminant is used within the record. | |
13201 | However, you can first modify discriminants by directly assigning to | |
13202 | them (which normally would not be allowed in Ada), and then performing an | |
13203 | aggregate assignment. For example, given a variable @code{A_Rec} | |
13204 | declared to have a type such as: | |
13205 | ||
13206 | @smallexample | |
13207 | type Rec (Len : Small_Integer := 0) is record | |
13208 | Id : Integer; | |
13209 | Vals : IntArray (1 .. Len); | |
13210 | end record; | |
13211 | @end smallexample | |
13212 | ||
13213 | you can assign a value with a different size of @code{Vals} with two | |
13214 | assignments: | |
13215 | ||
13216 | @smallexample | |
077e0a52 JB |
13217 | (@value{GDBP}) set A_Rec.Len := 4 |
13218 | (@value{GDBP}) set A_Rec := (Id => 42, Vals => (1, 2, 3, 4)) | |
860701dc PH |
13219 | @end smallexample |
13220 | ||
13221 | As this example also illustrates, @value{GDBN} is very loose about the usual | |
13222 | rules concerning aggregates. You may leave out some of the | |
13223 | components of an array or record aggregate (such as the @code{Len} | |
13224 | component in the assignment to @code{A_Rec} above); they will retain their | |
13225 | original values upon assignment. You may freely use dynamic values as | |
13226 | indices in component associations. You may even use overlapping or | |
13227 | redundant component associations, although which component values are | |
13228 | assigned in such cases is not defined. | |
e07c999f PH |
13229 | |
13230 | @item | |
13231 | Calls to dispatching subprograms are not implemented. | |
13232 | ||
13233 | @item | |
13234 | The overloading algorithm is much more limited (i.e., less selective) | |
ae21e955 BW |
13235 | than that of real Ada. It makes only limited use of the context in |
13236 | which a subexpression appears to resolve its meaning, and it is much | |
13237 | looser in its rules for allowing type matches. As a result, some | |
13238 | function calls will be ambiguous, and the user will be asked to choose | |
13239 | the proper resolution. | |
e07c999f PH |
13240 | |
13241 | @item | |
13242 | The @code{new} operator is not implemented. | |
13243 | ||
13244 | @item | |
13245 | Entry calls are not implemented. | |
13246 | ||
13247 | @item | |
13248 | Aside from printing, arithmetic operations on the native VAX floating-point | |
13249 | formats are not supported. | |
13250 | ||
13251 | @item | |
13252 | It is not possible to slice a packed array. | |
158c7665 PH |
13253 | |
13254 | @item | |
13255 | The names @code{True} and @code{False}, when not part of a qualified name, | |
13256 | are interpreted as if implicitly prefixed by @code{Standard}, regardless of | |
13257 | context. | |
13258 | Should your program | |
13259 | redefine these names in a package or procedure (at best a dubious practice), | |
13260 | you will have to use fully qualified names to access their new definitions. | |
e07c999f PH |
13261 | @end itemize |
13262 | ||
13263 | @node Additions to Ada | |
13264 | @subsubsection Additions to Ada | |
13265 | @cindex Ada, deviations from | |
13266 | ||
13267 | As it does for other languages, @value{GDBN} makes certain generic | |
13268 | extensions to Ada (@pxref{Expressions}): | |
13269 | ||
13270 | @itemize @bullet | |
13271 | @item | |
ae21e955 BW |
13272 | If the expression @var{E} is a variable residing in memory (typically |
13273 | a local variable or array element) and @var{N} is a positive integer, | |
13274 | then @code{@var{E}@@@var{N}} displays the values of @var{E} and the | |
13275 | @var{N}-1 adjacent variables following it in memory as an array. In | |
13276 | Ada, this operator is generally not necessary, since its prime use is | |
13277 | in displaying parts of an array, and slicing will usually do this in | |
13278 | Ada. However, there are occasional uses when debugging programs in | |
13279 | which certain debugging information has been optimized away. | |
e07c999f PH |
13280 | |
13281 | @item | |
ae21e955 BW |
13282 | @code{@var{B}::@var{var}} means ``the variable named @var{var} that |
13283 | appears in function or file @var{B}.'' When @var{B} is a file name, | |
13284 | you must typically surround it in single quotes. | |
e07c999f PH |
13285 | |
13286 | @item | |
13287 | The expression @code{@{@var{type}@} @var{addr}} means ``the variable of type | |
13288 | @var{type} that appears at address @var{addr}.'' | |
13289 | ||
13290 | @item | |
13291 | A name starting with @samp{$} is a convenience variable | |
13292 | (@pxref{Convenience Vars}) or a machine register (@pxref{Registers}). | |
13293 | @end itemize | |
13294 | ||
ae21e955 BW |
13295 | In addition, @value{GDBN} provides a few other shortcuts and outright |
13296 | additions specific to Ada: | |
e07c999f PH |
13297 | |
13298 | @itemize @bullet | |
13299 | @item | |
13300 | The assignment statement is allowed as an expression, returning | |
13301 | its right-hand operand as its value. Thus, you may enter | |
13302 | ||
13303 | @smallexample | |
077e0a52 JB |
13304 | (@value{GDBP}) set x := y + 3 |
13305 | (@value{GDBP}) print A(tmp := y + 1) | |
e07c999f PH |
13306 | @end smallexample |
13307 | ||
13308 | @item | |
13309 | The semicolon is allowed as an ``operator,'' returning as its value | |
13310 | the value of its right-hand operand. | |
13311 | This allows, for example, | |
13312 | complex conditional breaks: | |
13313 | ||
13314 | @smallexample | |
077e0a52 JB |
13315 | (@value{GDBP}) break f |
13316 | (@value{GDBP}) condition 1 (report(i); k += 1; A(k) > 100) | |
e07c999f PH |
13317 | @end smallexample |
13318 | ||
13319 | @item | |
13320 | Rather than use catenation and symbolic character names to introduce special | |
13321 | characters into strings, one may instead use a special bracket notation, | |
13322 | which is also used to print strings. A sequence of characters of the form | |
13323 | @samp{["@var{XX}"]} within a string or character literal denotes the | |
13324 | (single) character whose numeric encoding is @var{XX} in hexadecimal. The | |
13325 | sequence of characters @samp{["""]} also denotes a single quotation mark | |
13326 | in strings. For example, | |
13327 | @smallexample | |
13328 | "One line.["0a"]Next line.["0a"]" | |
13329 | @end smallexample | |
13330 | @noindent | |
ae21e955 BW |
13331 | contains an ASCII newline character (@code{Ada.Characters.Latin_1.LF}) |
13332 | after each period. | |
e07c999f PH |
13333 | |
13334 | @item | |
13335 | The subtype used as a prefix for the attributes @t{'Pos}, @t{'Min}, and | |
13336 | @t{'Max} is optional (and is ignored in any case). For example, it is valid | |
13337 | to write | |
13338 | ||
13339 | @smallexample | |
077e0a52 | 13340 | (@value{GDBP}) print 'max(x, y) |
e07c999f PH |
13341 | @end smallexample |
13342 | ||
13343 | @item | |
13344 | When printing arrays, @value{GDBN} uses positional notation when the | |
13345 | array has a lower bound of 1, and uses a modified named notation otherwise. | |
ae21e955 BW |
13346 | For example, a one-dimensional array of three integers with a lower bound |
13347 | of 3 might print as | |
e07c999f PH |
13348 | |
13349 | @smallexample | |
13350 | (3 => 10, 17, 1) | |
13351 | @end smallexample | |
13352 | ||
13353 | @noindent | |
13354 | That is, in contrast to valid Ada, only the first component has a @code{=>} | |
13355 | clause. | |
13356 | ||
13357 | @item | |
13358 | You may abbreviate attributes in expressions with any unique, | |
13359 | multi-character subsequence of | |
13360 | their names (an exact match gets preference). | |
13361 | For example, you may use @t{a'len}, @t{a'gth}, or @t{a'lh} | |
13362 | in place of @t{a'length}. | |
13363 | ||
13364 | @item | |
13365 | @cindex quoting Ada internal identifiers | |
13366 | Since Ada is case-insensitive, the debugger normally maps identifiers you type | |
13367 | to lower case. The GNAT compiler uses upper-case characters for | |
13368 | some of its internal identifiers, which are normally of no interest to users. | |
13369 | For the rare occasions when you actually have to look at them, | |
13370 | enclose them in angle brackets to avoid the lower-case mapping. | |
13371 | For example, | |
13372 | @smallexample | |
077e0a52 | 13373 | (@value{GDBP}) print <JMPBUF_SAVE>[0] |
e07c999f PH |
13374 | @end smallexample |
13375 | ||
13376 | @item | |
13377 | Printing an object of class-wide type or dereferencing an | |
13378 | access-to-class-wide value will display all the components of the object's | |
13379 | specific type (as indicated by its run-time tag). Likewise, component | |
13380 | selection on such a value will operate on the specific type of the | |
13381 | object. | |
13382 | ||
13383 | @end itemize | |
13384 | ||
13385 | @node Stopping Before Main Program | |
13386 | @subsubsection Stopping at the Very Beginning | |
13387 | ||
13388 | @cindex breakpointing Ada elaboration code | |
13389 | It is sometimes necessary to debug the program during elaboration, and | |
13390 | before reaching the main procedure. | |
13391 | As defined in the Ada Reference | |
13392 | Manual, the elaboration code is invoked from a procedure called | |
13393 | @code{adainit}. To run your program up to the beginning of | |
13394 | elaboration, simply use the following two commands: | |
13395 | @code{tbreak adainit} and @code{run}. | |
13396 | ||
20924a55 JB |
13397 | @node Ada Tasks |
13398 | @subsubsection Extensions for Ada Tasks | |
13399 | @cindex Ada, tasking | |
13400 | ||
13401 | Support for Ada tasks is analogous to that for threads (@pxref{Threads}). | |
13402 | @value{GDBN} provides the following task-related commands: | |
13403 | ||
13404 | @table @code | |
13405 | @kindex info tasks | |
13406 | @item info tasks | |
13407 | This command shows a list of current Ada tasks, as in the following example: | |
13408 | ||
13409 | ||
13410 | @smallexample | |
13411 | @iftex | |
13412 | @leftskip=0.5cm | |
13413 | @end iftex | |
13414 | (@value{GDBP}) info tasks | |
13415 | ID TID P-ID Pri State Name | |
13416 | 1 8088000 0 15 Child Activation Wait main_task | |
13417 | 2 80a4000 1 15 Accept Statement b | |
13418 | 3 809a800 1 15 Child Activation Wait a | |
32cd1edc | 13419 | * 4 80ae800 3 15 Runnable c |
20924a55 JB |
13420 | |
13421 | @end smallexample | |
13422 | ||
13423 | @noindent | |
13424 | In this listing, the asterisk before the last task indicates it to be the | |
13425 | task currently being inspected. | |
13426 | ||
13427 | @table @asis | |
13428 | @item ID | |
13429 | Represents @value{GDBN}'s internal task number. | |
13430 | ||
13431 | @item TID | |
13432 | The Ada task ID. | |
13433 | ||
13434 | @item P-ID | |
13435 | The parent's task ID (@value{GDBN}'s internal task number). | |
13436 | ||
13437 | @item Pri | |
13438 | The base priority of the task. | |
13439 | ||
13440 | @item State | |
13441 | Current state of the task. | |
13442 | ||
13443 | @table @code | |
13444 | @item Unactivated | |
13445 | The task has been created but has not been activated. It cannot be | |
13446 | executing. | |
13447 | ||
20924a55 JB |
13448 | @item Runnable |
13449 | The task is not blocked for any reason known to Ada. (It may be waiting | |
13450 | for a mutex, though.) It is conceptually "executing" in normal mode. | |
13451 | ||
13452 | @item Terminated | |
13453 | The task is terminated, in the sense of ARM 9.3 (5). Any dependents | |
13454 | that were waiting on terminate alternatives have been awakened and have | |
13455 | terminated themselves. | |
13456 | ||
13457 | @item Child Activation Wait | |
13458 | The task is waiting for created tasks to complete activation. | |
13459 | ||
13460 | @item Accept Statement | |
13461 | The task is waiting on an accept or selective wait statement. | |
13462 | ||
13463 | @item Waiting on entry call | |
13464 | The task is waiting on an entry call. | |
13465 | ||
13466 | @item Async Select Wait | |
13467 | The task is waiting to start the abortable part of an asynchronous | |
13468 | select statement. | |
13469 | ||
13470 | @item Delay Sleep | |
13471 | The task is waiting on a select statement with only a delay | |
13472 | alternative open. | |
13473 | ||
13474 | @item Child Termination Wait | |
13475 | The task is sleeping having completed a master within itself, and is | |
13476 | waiting for the tasks dependent on that master to become terminated or | |
13477 | waiting on a terminate Phase. | |
13478 | ||
13479 | @item Wait Child in Term Alt | |
13480 | The task is sleeping waiting for tasks on terminate alternatives to | |
13481 | finish terminating. | |
13482 | ||
13483 | @item Accepting RV with @var{taskno} | |
13484 | The task is accepting a rendez-vous with the task @var{taskno}. | |
13485 | @end table | |
13486 | ||
13487 | @item Name | |
13488 | Name of the task in the program. | |
13489 | ||
13490 | @end table | |
13491 | ||
13492 | @kindex info task @var{taskno} | |
13493 | @item info task @var{taskno} | |
13494 | This command shows detailled informations on the specified task, as in | |
13495 | the following example: | |
13496 | @smallexample | |
13497 | @iftex | |
13498 | @leftskip=0.5cm | |
13499 | @end iftex | |
13500 | (@value{GDBP}) info tasks | |
13501 | ID TID P-ID Pri State Name | |
13502 | 1 8077880 0 15 Child Activation Wait main_task | |
32cd1edc | 13503 | * 2 807c468 1 15 Runnable task_1 |
20924a55 JB |
13504 | (@value{GDBP}) info task 2 |
13505 | Ada Task: 0x807c468 | |
13506 | Name: task_1 | |
13507 | Thread: 0x807f378 | |
13508 | Parent: 1 (main_task) | |
13509 | Base Priority: 15 | |
13510 | State: Runnable | |
13511 | @end smallexample | |
13512 | ||
13513 | @item task | |
13514 | @kindex task@r{ (Ada)} | |
13515 | @cindex current Ada task ID | |
13516 | This command prints the ID of the current task. | |
13517 | ||
13518 | @smallexample | |
13519 | @iftex | |
13520 | @leftskip=0.5cm | |
13521 | @end iftex | |
13522 | (@value{GDBP}) info tasks | |
13523 | ID TID P-ID Pri State Name | |
13524 | 1 8077870 0 15 Child Activation Wait main_task | |
32cd1edc | 13525 | * 2 807c458 1 15 Runnable t |
20924a55 JB |
13526 | (@value{GDBP}) task |
13527 | [Current task is 2] | |
13528 | @end smallexample | |
13529 | ||
13530 | @item task @var{taskno} | |
13531 | @cindex Ada task switching | |
13532 | This command is like the @code{thread @var{threadno}} | |
13533 | command (@pxref{Threads}). It switches the context of debugging | |
13534 | from the current task to the given task. | |
13535 | ||
13536 | @smallexample | |
13537 | @iftex | |
13538 | @leftskip=0.5cm | |
13539 | @end iftex | |
13540 | (@value{GDBP}) info tasks | |
13541 | ID TID P-ID Pri State Name | |
13542 | 1 8077870 0 15 Child Activation Wait main_task | |
32cd1edc | 13543 | * 2 807c458 1 15 Runnable t |
20924a55 JB |
13544 | (@value{GDBP}) task 1 |
13545 | [Switching to task 1] | |
13546 | #0 0x8067726 in pthread_cond_wait () | |
13547 | (@value{GDBP}) bt | |
13548 | #0 0x8067726 in pthread_cond_wait () | |
13549 | #1 0x8056714 in system.os_interface.pthread_cond_wait () | |
13550 | #2 0x805cb63 in system.task_primitives.operations.sleep () | |
13551 | #3 0x806153e in system.tasking.stages.activate_tasks () | |
13552 | #4 0x804aacc in un () at un.adb:5 | |
13553 | @end smallexample | |
13554 | ||
45ac276d JB |
13555 | @item break @var{linespec} task @var{taskno} |
13556 | @itemx break @var{linespec} task @var{taskno} if @dots{} | |
13557 | @cindex breakpoints and tasks, in Ada | |
13558 | @cindex task breakpoints, in Ada | |
13559 | @kindex break @dots{} task @var{taskno}@r{ (Ada)} | |
13560 | These commands are like the @code{break @dots{} thread @dots{}} | |
13561 | command (@pxref{Thread Stops}). | |
13562 | @var{linespec} specifies source lines, as described | |
13563 | in @ref{Specify Location}. | |
13564 | ||
13565 | Use the qualifier @samp{task @var{taskno}} with a breakpoint command | |
13566 | to specify that you only want @value{GDBN} to stop the program when a | |
13567 | particular Ada task reaches this breakpoint. @var{taskno} is one of the | |
13568 | numeric task identifiers assigned by @value{GDBN}, shown in the first | |
13569 | column of the @samp{info tasks} display. | |
13570 | ||
13571 | If you do not specify @samp{task @var{taskno}} when you set a | |
13572 | breakpoint, the breakpoint applies to @emph{all} tasks of your | |
13573 | program. | |
13574 | ||
13575 | You can use the @code{task} qualifier on conditional breakpoints as | |
13576 | well; in this case, place @samp{task @var{taskno}} before the | |
13577 | breakpoint condition (before the @code{if}). | |
13578 | ||
13579 | For example, | |
13580 | ||
13581 | @smallexample | |
13582 | @iftex | |
13583 | @leftskip=0.5cm | |
13584 | @end iftex | |
13585 | (@value{GDBP}) info tasks | |
13586 | ID TID P-ID Pri State Name | |
13587 | 1 140022020 0 15 Child Activation Wait main_task | |
13588 | 2 140045060 1 15 Accept/Select Wait t2 | |
13589 | 3 140044840 1 15 Runnable t1 | |
13590 | * 4 140056040 1 15 Runnable t3 | |
13591 | (@value{GDBP}) b 15 task 2 | |
13592 | Breakpoint 5 at 0x120044cb0: file test_task_debug.adb, line 15. | |
13593 | (@value{GDBP}) cont | |
13594 | Continuing. | |
13595 | task # 1 running | |
13596 | task # 2 running | |
13597 | ||
13598 | Breakpoint 5, test_task_debug () at test_task_debug.adb:15 | |
13599 | 15 flush; | |
13600 | (@value{GDBP}) info tasks | |
13601 | ID TID P-ID Pri State Name | |
13602 | 1 140022020 0 15 Child Activation Wait main_task | |
13603 | * 2 140045060 1 15 Runnable t2 | |
13604 | 3 140044840 1 15 Runnable t1 | |
13605 | 4 140056040 1 15 Delay Sleep t3 | |
13606 | @end smallexample | |
20924a55 JB |
13607 | @end table |
13608 | ||
13609 | @node Ada Tasks and Core Files | |
13610 | @subsubsection Tasking Support when Debugging Core Files | |
13611 | @cindex Ada tasking and core file debugging | |
13612 | ||
13613 | When inspecting a core file, as opposed to debugging a live program, | |
13614 | tasking support may be limited or even unavailable, depending on | |
13615 | the platform being used. | |
13616 | For instance, on x86-linux, the list of tasks is available, but task | |
13617 | switching is not supported. On Tru64, however, task switching will work | |
13618 | as usual. | |
13619 | ||
13620 | On certain platforms, including Tru64, the debugger needs to perform some | |
13621 | memory writes in order to provide Ada tasking support. When inspecting | |
13622 | a core file, this means that the core file must be opened with read-write | |
13623 | privileges, using the command @samp{"set write on"} (@pxref{Patching}). | |
13624 | Under these circumstances, you should make a backup copy of the core | |
13625 | file before inspecting it with @value{GDBN}. | |
13626 | ||
6e1bb179 JB |
13627 | @node Ravenscar Profile |
13628 | @subsubsection Tasking Support when using the Ravenscar Profile | |
13629 | @cindex Ravenscar Profile | |
13630 | ||
13631 | The @dfn{Ravenscar Profile} is a subset of the Ada tasking features, | |
13632 | specifically designed for systems with safety-critical real-time | |
13633 | requirements. | |
13634 | ||
13635 | @table @code | |
13636 | @kindex set ravenscar task-switching on | |
13637 | @cindex task switching with program using Ravenscar Profile | |
13638 | @item set ravenscar task-switching on | |
13639 | Allows task switching when debugging a program that uses the Ravenscar | |
13640 | Profile. This is the default. | |
13641 | ||
13642 | @kindex set ravenscar task-switching off | |
13643 | @item set ravenscar task-switching off | |
13644 | Turn off task switching when debugging a program that uses the Ravenscar | |
13645 | Profile. This is mostly intended to disable the code that adds support | |
13646 | for the Ravenscar Profile, in case a bug in either @value{GDBN} or in | |
13647 | the Ravenscar runtime is preventing @value{GDBN} from working properly. | |
13648 | To be effective, this command should be run before the program is started. | |
13649 | ||
13650 | @kindex show ravenscar task-switching | |
13651 | @item show ravenscar task-switching | |
13652 | Show whether it is possible to switch from task to task in a program | |
13653 | using the Ravenscar Profile. | |
13654 | ||
13655 | @end table | |
13656 | ||
e07c999f PH |
13657 | @node Ada Glitches |
13658 | @subsubsection Known Peculiarities of Ada Mode | |
13659 | @cindex Ada, problems | |
13660 | ||
13661 | Besides the omissions listed previously (@pxref{Omissions from Ada}), | |
13662 | we know of several problems with and limitations of Ada mode in | |
13663 | @value{GDBN}, | |
13664 | some of which will be fixed with planned future releases of the debugger | |
13665 | and the GNU Ada compiler. | |
13666 | ||
13667 | @itemize @bullet | |
13668 | @item | |
13669 | Currently, the debugger | |
13670 | has insufficient information to determine whether certain pointers represent | |
13671 | pointers to objects or the objects themselves. | |
13672 | Thus, the user may have to tack an extra @code{.all} after an expression | |
13673 | to get it printed properly. | |
13674 | ||
13675 | @item | |
13676 | Static constants that the compiler chooses not to materialize as objects in | |
13677 | storage are invisible to the debugger. | |
13678 | ||
13679 | @item | |
13680 | Named parameter associations in function argument lists are ignored (the | |
13681 | argument lists are treated as positional). | |
13682 | ||
13683 | @item | |
13684 | Many useful library packages are currently invisible to the debugger. | |
13685 | ||
13686 | @item | |
13687 | Fixed-point arithmetic, conversions, input, and output is carried out using | |
13688 | floating-point arithmetic, and may give results that only approximate those on | |
13689 | the host machine. | |
13690 | ||
e07c999f PH |
13691 | @item |
13692 | The GNAT compiler never generates the prefix @code{Standard} for any of | |
13693 | the standard symbols defined by the Ada language. @value{GDBN} knows about | |
13694 | this: it will strip the prefix from names when you use it, and will never | |
13695 | look for a name you have so qualified among local symbols, nor match against | |
13696 | symbols in other packages or subprograms. If you have | |
13697 | defined entities anywhere in your program other than parameters and | |
13698 | local variables whose simple names match names in @code{Standard}, | |
13699 | GNAT's lack of qualification here can cause confusion. When this happens, | |
13700 | you can usually resolve the confusion | |
13701 | by qualifying the problematic names with package | |
13702 | @code{Standard} explicitly. | |
13703 | @end itemize | |
13704 | ||
95433b34 JB |
13705 | Older versions of the compiler sometimes generate erroneous debugging |
13706 | information, resulting in the debugger incorrectly printing the value | |
13707 | of affected entities. In some cases, the debugger is able to work | |
13708 | around an issue automatically. In other cases, the debugger is able | |
13709 | to work around the issue, but the work-around has to be specifically | |
13710 | enabled. | |
13711 | ||
13712 | @kindex set ada trust-PAD-over-XVS | |
13713 | @kindex show ada trust-PAD-over-XVS | |
13714 | @table @code | |
13715 | ||
13716 | @item set ada trust-PAD-over-XVS on | |
13717 | Configure GDB to strictly follow the GNAT encoding when computing the | |
13718 | value of Ada entities, particularly when @code{PAD} and @code{PAD___XVS} | |
13719 | types are involved (see @code{ada/exp_dbug.ads} in the GCC sources for | |
13720 | a complete description of the encoding used by the GNAT compiler). | |
13721 | This is the default. | |
13722 | ||
13723 | @item set ada trust-PAD-over-XVS off | |
13724 | This is related to the encoding using by the GNAT compiler. If @value{GDBN} | |
13725 | sometimes prints the wrong value for certain entities, changing @code{ada | |
13726 | trust-PAD-over-XVS} to @code{off} activates a work-around which may fix | |
13727 | the issue. It is always safe to set @code{ada trust-PAD-over-XVS} to | |
13728 | @code{off}, but this incurs a slight performance penalty, so it is | |
13729 | recommended to leave this setting to @code{on} unless necessary. | |
13730 | ||
13731 | @end table | |
13732 | ||
79a6e687 BW |
13733 | @node Unsupported Languages |
13734 | @section Unsupported Languages | |
4e562065 JB |
13735 | |
13736 | @cindex unsupported languages | |
13737 | @cindex minimal language | |
13738 | In addition to the other fully-supported programming languages, | |
13739 | @value{GDBN} also provides a pseudo-language, called @code{minimal}. | |
13740 | It does not represent a real programming language, but provides a set | |
13741 | of capabilities close to what the C or assembly languages provide. | |
13742 | This should allow most simple operations to be performed while debugging | |
13743 | an application that uses a language currently not supported by @value{GDBN}. | |
13744 | ||
13745 | If the language is set to @code{auto}, @value{GDBN} will automatically | |
13746 | select this language if the current frame corresponds to an unsupported | |
13747 | language. | |
13748 | ||
6d2ebf8b | 13749 | @node Symbols |
c906108c SS |
13750 | @chapter Examining the Symbol Table |
13751 | ||
d4f3574e | 13752 | The commands described in this chapter allow you to inquire about the |
c906108c SS |
13753 | symbols (names of variables, functions and types) defined in your |
13754 | program. This information is inherent in the text of your program and | |
13755 | does not change as your program executes. @value{GDBN} finds it in your | |
13756 | program's symbol table, in the file indicated when you started @value{GDBN} | |
79a6e687 BW |
13757 | (@pxref{File Options, ,Choosing Files}), or by one of the |
13758 | file-management commands (@pxref{Files, ,Commands to Specify Files}). | |
c906108c SS |
13759 | |
13760 | @cindex symbol names | |
13761 | @cindex names of symbols | |
13762 | @cindex quoting names | |
13763 | Occasionally, you may need to refer to symbols that contain unusual | |
13764 | characters, which @value{GDBN} ordinarily treats as word delimiters. The | |
13765 | most frequent case is in referring to static variables in other | |
79a6e687 | 13766 | source files (@pxref{Variables,,Program Variables}). File names |
c906108c SS |
13767 | are recorded in object files as debugging symbols, but @value{GDBN} would |
13768 | ordinarily parse a typical file name, like @file{foo.c}, as the three words | |
13769 | @samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize | |
13770 | @samp{foo.c} as a single symbol, enclose it in single quotes; for example, | |
13771 | ||
474c8240 | 13772 | @smallexample |
c906108c | 13773 | p 'foo.c'::x |
474c8240 | 13774 | @end smallexample |
c906108c SS |
13775 | |
13776 | @noindent | |
13777 | looks up the value of @code{x} in the scope of the file @file{foo.c}. | |
13778 | ||
13779 | @table @code | |
a8f24a35 EZ |
13780 | @cindex case-insensitive symbol names |
13781 | @cindex case sensitivity in symbol names | |
13782 | @kindex set case-sensitive | |
13783 | @item set case-sensitive on | |
13784 | @itemx set case-sensitive off | |
13785 | @itemx set case-sensitive auto | |
13786 | Normally, when @value{GDBN} looks up symbols, it matches their names | |
13787 | with case sensitivity determined by the current source language. | |
13788 | Occasionally, you may wish to control that. The command @code{set | |
13789 | case-sensitive} lets you do that by specifying @code{on} for | |
13790 | case-sensitive matches or @code{off} for case-insensitive ones. If | |
13791 | you specify @code{auto}, case sensitivity is reset to the default | |
13792 | suitable for the source language. The default is case-sensitive | |
13793 | matches for all languages except for Fortran, for which the default is | |
13794 | case-insensitive matches. | |
13795 | ||
9c16f35a EZ |
13796 | @kindex show case-sensitive |
13797 | @item show case-sensitive | |
a8f24a35 EZ |
13798 | This command shows the current setting of case sensitivity for symbols |
13799 | lookups. | |
13800 | ||
c906108c | 13801 | @kindex info address |
b37052ae | 13802 | @cindex address of a symbol |
c906108c SS |
13803 | @item info address @var{symbol} |
13804 | Describe where the data for @var{symbol} is stored. For a register | |
13805 | variable, this says which register it is kept in. For a non-register | |
13806 | local variable, this prints the stack-frame offset at which the variable | |
13807 | is always stored. | |
13808 | ||
13809 | Note the contrast with @samp{print &@var{symbol}}, which does not work | |
13810 | at all for a register variable, and for a stack local variable prints | |
13811 | the exact address of the current instantiation of the variable. | |
13812 | ||
3d67e040 | 13813 | @kindex info symbol |
b37052ae | 13814 | @cindex symbol from address |
9c16f35a | 13815 | @cindex closest symbol and offset for an address |
3d67e040 EZ |
13816 | @item info symbol @var{addr} |
13817 | Print the name of a symbol which is stored at the address @var{addr}. | |
13818 | If no symbol is stored exactly at @var{addr}, @value{GDBN} prints the | |
13819 | nearest symbol and an offset from it: | |
13820 | ||
474c8240 | 13821 | @smallexample |
3d67e040 EZ |
13822 | (@value{GDBP}) info symbol 0x54320 |
13823 | _initialize_vx + 396 in section .text | |
474c8240 | 13824 | @end smallexample |
3d67e040 EZ |
13825 | |
13826 | @noindent | |
13827 | This is the opposite of the @code{info address} command. You can use | |
13828 | it to find out the name of a variable or a function given its address. | |
13829 | ||
c14c28ba PP |
13830 | For dynamically linked executables, the name of executable or shared |
13831 | library containing the symbol is also printed: | |
13832 | ||
13833 | @smallexample | |
13834 | (@value{GDBP}) info symbol 0x400225 | |
13835 | _start + 5 in section .text of /tmp/a.out | |
13836 | (@value{GDBP}) info symbol 0x2aaaac2811cf | |
13837 | __read_nocancel + 6 in section .text of /usr/lib64/libc.so.6 | |
13838 | @end smallexample | |
13839 | ||
c906108c | 13840 | @kindex whatis |
62f3a2ba FF |
13841 | @item whatis [@var{arg}] |
13842 | Print the data type of @var{arg}, which can be either an expression or | |
13843 | a data type. With no argument, print the data type of @code{$}, the | |
13844 | last value in the value history. If @var{arg} is an expression, it is | |
13845 | not actually evaluated, and any side-effecting operations (such as | |
13846 | assignments or function calls) inside it do not take place. If | |
13847 | @var{arg} is a type name, it may be the name of a type or typedef, or | |
13848 | for C code it may have the form @samp{class @var{class-name}}, | |
13849 | @samp{struct @var{struct-tag}}, @samp{union @var{union-tag}} or | |
13850 | @samp{enum @var{enum-tag}}. | |
c906108c SS |
13851 | @xref{Expressions, ,Expressions}. |
13852 | ||
c906108c | 13853 | @kindex ptype |
62f3a2ba FF |
13854 | @item ptype [@var{arg}] |
13855 | @code{ptype} accepts the same arguments as @code{whatis}, but prints a | |
13856 | detailed description of the type, instead of just the name of the type. | |
13857 | @xref{Expressions, ,Expressions}. | |
c906108c SS |
13858 | |
13859 | For example, for this variable declaration: | |
13860 | ||
474c8240 | 13861 | @smallexample |
c906108c | 13862 | struct complex @{double real; double imag;@} v; |
474c8240 | 13863 | @end smallexample |
c906108c SS |
13864 | |
13865 | @noindent | |
13866 | the two commands give this output: | |
13867 | ||
474c8240 | 13868 | @smallexample |
c906108c SS |
13869 | @group |
13870 | (@value{GDBP}) whatis v | |
13871 | type = struct complex | |
13872 | (@value{GDBP}) ptype v | |
13873 | type = struct complex @{ | |
13874 | double real; | |
13875 | double imag; | |
13876 | @} | |
13877 | @end group | |
474c8240 | 13878 | @end smallexample |
c906108c SS |
13879 | |
13880 | @noindent | |
13881 | As with @code{whatis}, using @code{ptype} without an argument refers to | |
13882 | the type of @code{$}, the last value in the value history. | |
13883 | ||
ab1adacd EZ |
13884 | @cindex incomplete type |
13885 | Sometimes, programs use opaque data types or incomplete specifications | |
13886 | of complex data structure. If the debug information included in the | |
13887 | program does not allow @value{GDBN} to display a full declaration of | |
13888 | the data type, it will say @samp{<incomplete type>}. For example, | |
13889 | given these declarations: | |
13890 | ||
13891 | @smallexample | |
13892 | struct foo; | |
13893 | struct foo *fooptr; | |
13894 | @end smallexample | |
13895 | ||
13896 | @noindent | |
13897 | but no definition for @code{struct foo} itself, @value{GDBN} will say: | |
13898 | ||
13899 | @smallexample | |
ddb50cd7 | 13900 | (@value{GDBP}) ptype foo |
ab1adacd EZ |
13901 | $1 = <incomplete type> |
13902 | @end smallexample | |
13903 | ||
13904 | @noindent | |
13905 | ``Incomplete type'' is C terminology for data types that are not | |
13906 | completely specified. | |
13907 | ||
c906108c SS |
13908 | @kindex info types |
13909 | @item info types @var{regexp} | |
13910 | @itemx info types | |
09d4efe1 EZ |
13911 | Print a brief description of all types whose names match the regular |
13912 | expression @var{regexp} (or all types in your program, if you supply | |
13913 | no argument). Each complete typename is matched as though it were a | |
13914 | complete line; thus, @samp{i type value} gives information on all | |
13915 | types in your program whose names include the string @code{value}, but | |
13916 | @samp{i type ^value$} gives information only on types whose complete | |
13917 | name is @code{value}. | |
c906108c SS |
13918 | |
13919 | This command differs from @code{ptype} in two ways: first, like | |
13920 | @code{whatis}, it does not print a detailed description; second, it | |
13921 | lists all source files where a type is defined. | |
13922 | ||
b37052ae EZ |
13923 | @kindex info scope |
13924 | @cindex local variables | |
09d4efe1 | 13925 | @item info scope @var{location} |
b37052ae | 13926 | List all the variables local to a particular scope. This command |
09d4efe1 EZ |
13927 | accepts a @var{location} argument---a function name, a source line, or |
13928 | an address preceded by a @samp{*}, and prints all the variables local | |
2a25a5ba EZ |
13929 | to the scope defined by that location. (@xref{Specify Location}, for |
13930 | details about supported forms of @var{location}.) For example: | |
b37052ae EZ |
13931 | |
13932 | @smallexample | |
13933 | (@value{GDBP}) @b{info scope command_line_handler} | |
13934 | Scope for command_line_handler: | |
13935 | Symbol rl is an argument at stack/frame offset 8, length 4. | |
13936 | Symbol linebuffer is in static storage at address 0x150a18, length 4. | |
13937 | Symbol linelength is in static storage at address 0x150a1c, length 4. | |
13938 | Symbol p is a local variable in register $esi, length 4. | |
13939 | Symbol p1 is a local variable in register $ebx, length 4. | |
13940 | Symbol nline is a local variable in register $edx, length 4. | |
13941 | Symbol repeat is a local variable at frame offset -8, length 4. | |
13942 | @end smallexample | |
13943 | ||
f5c37c66 EZ |
13944 | @noindent |
13945 | This command is especially useful for determining what data to collect | |
13946 | during a @dfn{trace experiment}, see @ref{Tracepoint Actions, | |
13947 | collect}. | |
13948 | ||
c906108c SS |
13949 | @kindex info source |
13950 | @item info source | |
919d772c JB |
13951 | Show information about the current source file---that is, the source file for |
13952 | the function containing the current point of execution: | |
13953 | @itemize @bullet | |
13954 | @item | |
13955 | the name of the source file, and the directory containing it, | |
13956 | @item | |
13957 | the directory it was compiled in, | |
13958 | @item | |
13959 | its length, in lines, | |
13960 | @item | |
13961 | which programming language it is written in, | |
13962 | @item | |
13963 | whether the executable includes debugging information for that file, and | |
13964 | if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and | |
13965 | @item | |
13966 | whether the debugging information includes information about | |
13967 | preprocessor macros. | |
13968 | @end itemize | |
13969 | ||
c906108c SS |
13970 | |
13971 | @kindex info sources | |
13972 | @item info sources | |
13973 | Print the names of all source files in your program for which there is | |
13974 | debugging information, organized into two lists: files whose symbols | |
13975 | have already been read, and files whose symbols will be read when needed. | |
13976 | ||
13977 | @kindex info functions | |
13978 | @item info functions | |
13979 | Print the names and data types of all defined functions. | |
13980 | ||
13981 | @item info functions @var{regexp} | |
13982 | Print the names and data types of all defined functions | |
13983 | whose names contain a match for regular expression @var{regexp}. | |
13984 | Thus, @samp{info fun step} finds all functions whose names | |
13985 | include @code{step}; @samp{info fun ^step} finds those whose names | |
b383017d | 13986 | start with @code{step}. If a function name contains characters |
c1468174 | 13987 | that conflict with the regular expression language (e.g.@: |
1c5dfdad | 13988 | @samp{operator*()}), they may be quoted with a backslash. |
c906108c SS |
13989 | |
13990 | @kindex info variables | |
13991 | @item info variables | |
0fe7935b | 13992 | Print the names and data types of all variables that are defined |
6ca652b0 | 13993 | outside of functions (i.e.@: excluding local variables). |
c906108c SS |
13994 | |
13995 | @item info variables @var{regexp} | |
13996 | Print the names and data types of all variables (except for local | |
13997 | variables) whose names contain a match for regular expression | |
13998 | @var{regexp}. | |
13999 | ||
b37303ee | 14000 | @kindex info classes |
721c2651 | 14001 | @cindex Objective-C, classes and selectors |
b37303ee AF |
14002 | @item info classes |
14003 | @itemx info classes @var{regexp} | |
14004 | Display all Objective-C classes in your program, or | |
14005 | (with the @var{regexp} argument) all those matching a particular regular | |
14006 | expression. | |
14007 | ||
14008 | @kindex info selectors | |
14009 | @item info selectors | |
14010 | @itemx info selectors @var{regexp} | |
14011 | Display all Objective-C selectors in your program, or | |
14012 | (with the @var{regexp} argument) all those matching a particular regular | |
14013 | expression. | |
14014 | ||
c906108c SS |
14015 | @ignore |
14016 | This was never implemented. | |
14017 | @kindex info methods | |
14018 | @item info methods | |
14019 | @itemx info methods @var{regexp} | |
14020 | The @code{info methods} command permits the user to examine all defined | |
b37052ae EZ |
14021 | methods within C@t{++} program, or (with the @var{regexp} argument) a |
14022 | specific set of methods found in the various C@t{++} classes. Many | |
14023 | C@t{++} classes provide a large number of methods. Thus, the output | |
c906108c SS |
14024 | from the @code{ptype} command can be overwhelming and hard to use. The |
14025 | @code{info-methods} command filters the methods, printing only those | |
14026 | which match the regular-expression @var{regexp}. | |
14027 | @end ignore | |
14028 | ||
c906108c SS |
14029 | @cindex reloading symbols |
14030 | Some systems allow individual object files that make up your program to | |
7a292a7a SS |
14031 | be replaced without stopping and restarting your program. For example, |
14032 | in VxWorks you can simply recompile a defective object file and keep on | |
14033 | running. If you are running on one of these systems, you can allow | |
14034 | @value{GDBN} to reload the symbols for automatically relinked modules: | |
c906108c SS |
14035 | |
14036 | @table @code | |
14037 | @kindex set symbol-reloading | |
14038 | @item set symbol-reloading on | |
14039 | Replace symbol definitions for the corresponding source file when an | |
14040 | object file with a particular name is seen again. | |
14041 | ||
14042 | @item set symbol-reloading off | |
6d2ebf8b SS |
14043 | Do not replace symbol definitions when encountering object files of the |
14044 | same name more than once. This is the default state; if you are not | |
14045 | running on a system that permits automatic relinking of modules, you | |
14046 | should leave @code{symbol-reloading} off, since otherwise @value{GDBN} | |
14047 | may discard symbols when linking large programs, that may contain | |
14048 | several modules (from different directories or libraries) with the same | |
14049 | name. | |
c906108c SS |
14050 | |
14051 | @kindex show symbol-reloading | |
14052 | @item show symbol-reloading | |
14053 | Show the current @code{on} or @code{off} setting. | |
14054 | @end table | |
c906108c | 14055 | |
9c16f35a | 14056 | @cindex opaque data types |
c906108c SS |
14057 | @kindex set opaque-type-resolution |
14058 | @item set opaque-type-resolution on | |
14059 | Tell @value{GDBN} to resolve opaque types. An opaque type is a type | |
14060 | declared as a pointer to a @code{struct}, @code{class}, or | |
14061 | @code{union}---for example, @code{struct MyType *}---that is used in one | |
14062 | source file although the full declaration of @code{struct MyType} is in | |
14063 | another source file. The default is on. | |
14064 | ||
14065 | A change in the setting of this subcommand will not take effect until | |
14066 | the next time symbols for a file are loaded. | |
14067 | ||
14068 | @item set opaque-type-resolution off | |
14069 | Tell @value{GDBN} not to resolve opaque types. In this case, the type | |
14070 | is printed as follows: | |
14071 | @smallexample | |
14072 | @{<no data fields>@} | |
14073 | @end smallexample | |
14074 | ||
14075 | @kindex show opaque-type-resolution | |
14076 | @item show opaque-type-resolution | |
14077 | Show whether opaque types are resolved or not. | |
c906108c SS |
14078 | |
14079 | @kindex maint print symbols | |
14080 | @cindex symbol dump | |
14081 | @kindex maint print psymbols | |
14082 | @cindex partial symbol dump | |
14083 | @item maint print symbols @var{filename} | |
14084 | @itemx maint print psymbols @var{filename} | |
14085 | @itemx maint print msymbols @var{filename} | |
14086 | Write a dump of debugging symbol data into the file @var{filename}. | |
14087 | These commands are used to debug the @value{GDBN} symbol-reading code. Only | |
14088 | symbols with debugging data are included. If you use @samp{maint print | |
14089 | symbols}, @value{GDBN} includes all the symbols for which it has already | |
14090 | collected full details: that is, @var{filename} reflects symbols for | |
14091 | only those files whose symbols @value{GDBN} has read. You can use the | |
14092 | command @code{info sources} to find out which files these are. If you | |
14093 | use @samp{maint print psymbols} instead, the dump shows information about | |
14094 | symbols that @value{GDBN} only knows partially---that is, symbols defined in | |
14095 | files that @value{GDBN} has skimmed, but not yet read completely. Finally, | |
14096 | @samp{maint print msymbols} dumps just the minimal symbol information | |
14097 | required for each object file from which @value{GDBN} has read some symbols. | |
79a6e687 | 14098 | @xref{Files, ,Commands to Specify Files}, for a discussion of how |
c906108c | 14099 | @value{GDBN} reads symbols (in the description of @code{symbol-file}). |
44ea7b70 | 14100 | |
5e7b2f39 JB |
14101 | @kindex maint info symtabs |
14102 | @kindex maint info psymtabs | |
44ea7b70 JB |
14103 | @cindex listing @value{GDBN}'s internal symbol tables |
14104 | @cindex symbol tables, listing @value{GDBN}'s internal | |
14105 | @cindex full symbol tables, listing @value{GDBN}'s internal | |
14106 | @cindex partial symbol tables, listing @value{GDBN}'s internal | |
5e7b2f39 JB |
14107 | @item maint info symtabs @r{[} @var{regexp} @r{]} |
14108 | @itemx maint info psymtabs @r{[} @var{regexp} @r{]} | |
44ea7b70 JB |
14109 | |
14110 | List the @code{struct symtab} or @code{struct partial_symtab} | |
14111 | structures whose names match @var{regexp}. If @var{regexp} is not | |
14112 | given, list them all. The output includes expressions which you can | |
14113 | copy into a @value{GDBN} debugging this one to examine a particular | |
14114 | structure in more detail. For example: | |
14115 | ||
14116 | @smallexample | |
5e7b2f39 | 14117 | (@value{GDBP}) maint info psymtabs dwarf2read |
44ea7b70 JB |
14118 | @{ objfile /home/gnu/build/gdb/gdb |
14119 | ((struct objfile *) 0x82e69d0) | |
b383017d | 14120 | @{ psymtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
14121 | ((struct partial_symtab *) 0x8474b10) |
14122 | readin no | |
14123 | fullname (null) | |
14124 | text addresses 0x814d3c8 -- 0x8158074 | |
14125 | globals (* (struct partial_symbol **) 0x8507a08 @@ 9) | |
14126 | statics (* (struct partial_symbol **) 0x40e95b78 @@ 2882) | |
14127 | dependencies (none) | |
14128 | @} | |
14129 | @} | |
5e7b2f39 | 14130 | (@value{GDBP}) maint info symtabs |
44ea7b70 JB |
14131 | (@value{GDBP}) |
14132 | @end smallexample | |
14133 | @noindent | |
14134 | We see that there is one partial symbol table whose filename contains | |
14135 | the string @samp{dwarf2read}, belonging to the @samp{gdb} executable; | |
14136 | and we see that @value{GDBN} has not read in any symtabs yet at all. | |
14137 | If we set a breakpoint on a function, that will cause @value{GDBN} to | |
14138 | read the symtab for the compilation unit containing that function: | |
14139 | ||
14140 | @smallexample | |
14141 | (@value{GDBP}) break dwarf2_psymtab_to_symtab | |
14142 | Breakpoint 1 at 0x814e5da: file /home/gnu/src/gdb/dwarf2read.c, | |
14143 | line 1574. | |
5e7b2f39 | 14144 | (@value{GDBP}) maint info symtabs |
b383017d | 14145 | @{ objfile /home/gnu/build/gdb/gdb |
44ea7b70 | 14146 | ((struct objfile *) 0x82e69d0) |
b383017d | 14147 | @{ symtab /home/gnu/src/gdb/dwarf2read.c |
44ea7b70 JB |
14148 | ((struct symtab *) 0x86c1f38) |
14149 | dirname (null) | |
14150 | fullname (null) | |
14151 | blockvector ((struct blockvector *) 0x86c1bd0) (primary) | |
1b39d5c0 | 14152 | linetable ((struct linetable *) 0x8370fa0) |
44ea7b70 JB |
14153 | debugformat DWARF 2 |
14154 | @} | |
14155 | @} | |
b383017d | 14156 | (@value{GDBP}) |
44ea7b70 | 14157 | @end smallexample |
c906108c SS |
14158 | @end table |
14159 | ||
44ea7b70 | 14160 | |
6d2ebf8b | 14161 | @node Altering |
c906108c SS |
14162 | @chapter Altering Execution |
14163 | ||
14164 | Once you think you have found an error in your program, you might want to | |
14165 | find out for certain whether correcting the apparent error would lead to | |
14166 | correct results in the rest of the run. You can find the answer by | |
14167 | experiment, using the @value{GDBN} features for altering execution of the | |
14168 | program. | |
14169 | ||
14170 | For example, you can store new values into variables or memory | |
7a292a7a SS |
14171 | locations, give your program a signal, restart it at a different |
14172 | address, or even return prematurely from a function. | |
c906108c SS |
14173 | |
14174 | @menu | |
14175 | * Assignment:: Assignment to variables | |
14176 | * Jumping:: Continuing at a different address | |
c906108c | 14177 | * Signaling:: Giving your program a signal |
c906108c SS |
14178 | * Returning:: Returning from a function |
14179 | * Calling:: Calling your program's functions | |
14180 | * Patching:: Patching your program | |
14181 | @end menu | |
14182 | ||
6d2ebf8b | 14183 | @node Assignment |
79a6e687 | 14184 | @section Assignment to Variables |
c906108c SS |
14185 | |
14186 | @cindex assignment | |
14187 | @cindex setting variables | |
14188 | To alter the value of a variable, evaluate an assignment expression. | |
14189 | @xref{Expressions, ,Expressions}. For example, | |
14190 | ||
474c8240 | 14191 | @smallexample |
c906108c | 14192 | print x=4 |
474c8240 | 14193 | @end smallexample |
c906108c SS |
14194 | |
14195 | @noindent | |
14196 | stores the value 4 into the variable @code{x}, and then prints the | |
5d161b24 | 14197 | value of the assignment expression (which is 4). |
c906108c SS |
14198 | @xref{Languages, ,Using @value{GDBN} with Different Languages}, for more |
14199 | information on operators in supported languages. | |
c906108c SS |
14200 | |
14201 | @kindex set variable | |
14202 | @cindex variables, setting | |
14203 | If you are not interested in seeing the value of the assignment, use the | |
14204 | @code{set} command instead of the @code{print} command. @code{set} is | |
14205 | really the same as @code{print} except that the expression's value is | |
14206 | not printed and is not put in the value history (@pxref{Value History, | |
79a6e687 | 14207 | ,Value History}). The expression is evaluated only for its effects. |
c906108c | 14208 | |
c906108c SS |
14209 | If the beginning of the argument string of the @code{set} command |
14210 | appears identical to a @code{set} subcommand, use the @code{set | |
14211 | variable} command instead of just @code{set}. This command is identical | |
14212 | to @code{set} except for its lack of subcommands. For example, if your | |
14213 | program has a variable @code{width}, you get an error if you try to set | |
14214 | a new value with just @samp{set width=13}, because @value{GDBN} has the | |
14215 | command @code{set width}: | |
14216 | ||
474c8240 | 14217 | @smallexample |
c906108c SS |
14218 | (@value{GDBP}) whatis width |
14219 | type = double | |
14220 | (@value{GDBP}) p width | |
14221 | $4 = 13 | |
14222 | (@value{GDBP}) set width=47 | |
14223 | Invalid syntax in expression. | |
474c8240 | 14224 | @end smallexample |
c906108c SS |
14225 | |
14226 | @noindent | |
14227 | The invalid expression, of course, is @samp{=47}. In | |
14228 | order to actually set the program's variable @code{width}, use | |
14229 | ||
474c8240 | 14230 | @smallexample |
c906108c | 14231 | (@value{GDBP}) set var width=47 |
474c8240 | 14232 | @end smallexample |
53a5351d | 14233 | |
c906108c SS |
14234 | Because the @code{set} command has many subcommands that can conflict |
14235 | with the names of program variables, it is a good idea to use the | |
14236 | @code{set variable} command instead of just @code{set}. For example, if | |
14237 | your program has a variable @code{g}, you run into problems if you try | |
14238 | to set a new value with just @samp{set g=4}, because @value{GDBN} has | |
14239 | the command @code{set gnutarget}, abbreviated @code{set g}: | |
14240 | ||
474c8240 | 14241 | @smallexample |
c906108c SS |
14242 | @group |
14243 | (@value{GDBP}) whatis g | |
14244 | type = double | |
14245 | (@value{GDBP}) p g | |
14246 | $1 = 1 | |
14247 | (@value{GDBP}) set g=4 | |
2df3850c | 14248 | (@value{GDBP}) p g |
c906108c SS |
14249 | $2 = 1 |
14250 | (@value{GDBP}) r | |
14251 | The program being debugged has been started already. | |
14252 | Start it from the beginning? (y or n) y | |
14253 | Starting program: /home/smith/cc_progs/a.out | |
6d2ebf8b SS |
14254 | "/home/smith/cc_progs/a.out": can't open to read symbols: |
14255 | Invalid bfd target. | |
c906108c SS |
14256 | (@value{GDBP}) show g |
14257 | The current BFD target is "=4". | |
14258 | @end group | |
474c8240 | 14259 | @end smallexample |
c906108c SS |
14260 | |
14261 | @noindent | |
14262 | The program variable @code{g} did not change, and you silently set the | |
14263 | @code{gnutarget} to an invalid value. In order to set the variable | |
14264 | @code{g}, use | |
14265 | ||
474c8240 | 14266 | @smallexample |
c906108c | 14267 | (@value{GDBP}) set var g=4 |
474c8240 | 14268 | @end smallexample |
c906108c SS |
14269 | |
14270 | @value{GDBN} allows more implicit conversions in assignments than C; you can | |
14271 | freely store an integer value into a pointer variable or vice versa, | |
14272 | and you can convert any structure to any other structure that is the | |
14273 | same length or shorter. | |
14274 | @comment FIXME: how do structs align/pad in these conversions? | |
14275 | @comment /doc@cygnus.com 18dec1990 | |
14276 | ||
14277 | To store values into arbitrary places in memory, use the @samp{@{@dots{}@}} | |
14278 | construct to generate a value of specified type at a specified address | |
14279 | (@pxref{Expressions, ,Expressions}). For example, @code{@{int@}0x83040} refers | |
14280 | to memory location @code{0x83040} as an integer (which implies a certain size | |
14281 | and representation in memory), and | |
14282 | ||
474c8240 | 14283 | @smallexample |
c906108c | 14284 | set @{int@}0x83040 = 4 |
474c8240 | 14285 | @end smallexample |
c906108c SS |
14286 | |
14287 | @noindent | |
14288 | stores the value 4 into that memory location. | |
14289 | ||
6d2ebf8b | 14290 | @node Jumping |
79a6e687 | 14291 | @section Continuing at a Different Address |
c906108c SS |
14292 | |
14293 | Ordinarily, when you continue your program, you do so at the place where | |
14294 | it stopped, with the @code{continue} command. You can instead continue at | |
14295 | an address of your own choosing, with the following commands: | |
14296 | ||
14297 | @table @code | |
14298 | @kindex jump | |
14299 | @item jump @var{linespec} | |
2a25a5ba EZ |
14300 | @itemx jump @var{location} |
14301 | Resume execution at line @var{linespec} or at address given by | |
14302 | @var{location}. Execution stops again immediately if there is a | |
14303 | breakpoint there. @xref{Specify Location}, for a description of the | |
14304 | different forms of @var{linespec} and @var{location}. It is common | |
14305 | practice to use the @code{tbreak} command in conjunction with | |
14306 | @code{jump}. @xref{Set Breaks, ,Setting Breakpoints}. | |
c906108c SS |
14307 | |
14308 | The @code{jump} command does not change the current stack frame, or | |
14309 | the stack pointer, or the contents of any memory location or any | |
14310 | register other than the program counter. If line @var{linespec} is in | |
14311 | a different function from the one currently executing, the results may | |
14312 | be bizarre if the two functions expect different patterns of arguments or | |
14313 | of local variables. For this reason, the @code{jump} command requests | |
14314 | confirmation if the specified line is not in the function currently | |
14315 | executing. However, even bizarre results are predictable if you are | |
14316 | well acquainted with the machine-language code of your program. | |
c906108c SS |
14317 | @end table |
14318 | ||
c906108c | 14319 | @c Doesn't work on HP-UX; have to set $pcoqh and $pcoqt. |
53a5351d JM |
14320 | On many systems, you can get much the same effect as the @code{jump} |
14321 | command by storing a new value into the register @code{$pc}. The | |
14322 | difference is that this does not start your program running; it only | |
14323 | changes the address of where it @emph{will} run when you continue. For | |
14324 | example, | |
c906108c | 14325 | |
474c8240 | 14326 | @smallexample |
c906108c | 14327 | set $pc = 0x485 |
474c8240 | 14328 | @end smallexample |
c906108c SS |
14329 | |
14330 | @noindent | |
14331 | makes the next @code{continue} command or stepping command execute at | |
14332 | address @code{0x485}, rather than at the address where your program stopped. | |
79a6e687 | 14333 | @xref{Continuing and Stepping, ,Continuing and Stepping}. |
c906108c SS |
14334 | |
14335 | The most common occasion to use the @code{jump} command is to back | |
14336 | up---perhaps with more breakpoints set---over a portion of a program | |
14337 | that has already executed, in order to examine its execution in more | |
14338 | detail. | |
14339 | ||
c906108c | 14340 | @c @group |
6d2ebf8b | 14341 | @node Signaling |
79a6e687 | 14342 | @section Giving your Program a Signal |
9c16f35a | 14343 | @cindex deliver a signal to a program |
c906108c SS |
14344 | |
14345 | @table @code | |
14346 | @kindex signal | |
14347 | @item signal @var{signal} | |
14348 | Resume execution where your program stopped, but immediately give it the | |
14349 | signal @var{signal}. @var{signal} can be the name or the number of a | |
14350 | signal. For example, on many systems @code{signal 2} and @code{signal | |
14351 | SIGINT} are both ways of sending an interrupt signal. | |
14352 | ||
14353 | Alternatively, if @var{signal} is zero, continue execution without | |
14354 | giving a signal. This is useful when your program stopped on account of | |
14355 | a signal and would ordinary see the signal when resumed with the | |
14356 | @code{continue} command; @samp{signal 0} causes it to resume without a | |
14357 | signal. | |
14358 | ||
14359 | @code{signal} does not repeat when you press @key{RET} a second time | |
14360 | after executing the command. | |
14361 | @end table | |
14362 | @c @end group | |
14363 | ||
14364 | Invoking the @code{signal} command is not the same as invoking the | |
14365 | @code{kill} utility from the shell. Sending a signal with @code{kill} | |
14366 | causes @value{GDBN} to decide what to do with the signal depending on | |
14367 | the signal handling tables (@pxref{Signals}). The @code{signal} command | |
14368 | passes the signal directly to your program. | |
14369 | ||
c906108c | 14370 | |
6d2ebf8b | 14371 | @node Returning |
79a6e687 | 14372 | @section Returning from a Function |
c906108c SS |
14373 | |
14374 | @table @code | |
14375 | @cindex returning from a function | |
14376 | @kindex return | |
14377 | @item return | |
14378 | @itemx return @var{expression} | |
14379 | You can cancel execution of a function call with the @code{return} | |
14380 | command. If you give an | |
14381 | @var{expression} argument, its value is used as the function's return | |
14382 | value. | |
14383 | @end table | |
14384 | ||
14385 | When you use @code{return}, @value{GDBN} discards the selected stack frame | |
14386 | (and all frames within it). You can think of this as making the | |
14387 | discarded frame return prematurely. If you wish to specify a value to | |
14388 | be returned, give that value as the argument to @code{return}. | |
14389 | ||
14390 | This pops the selected stack frame (@pxref{Selection, ,Selecting a | |
79a6e687 | 14391 | Frame}), and any other frames inside of it, leaving its caller as the |
c906108c SS |
14392 | innermost remaining frame. That frame becomes selected. The |
14393 | specified value is stored in the registers used for returning values | |
14394 | of functions. | |
14395 | ||
14396 | The @code{return} command does not resume execution; it leaves the | |
14397 | program stopped in the state that would exist if the function had just | |
14398 | returned. In contrast, the @code{finish} command (@pxref{Continuing | |
79a6e687 | 14399 | and Stepping, ,Continuing and Stepping}) resumes execution until the |
c906108c SS |
14400 | selected stack frame returns naturally. |
14401 | ||
61ff14c6 JK |
14402 | @value{GDBN} needs to know how the @var{expression} argument should be set for |
14403 | the inferior. The concrete registers assignment depends on the OS ABI and the | |
14404 | type being returned by the selected stack frame. For example it is common for | |
14405 | OS ABI to return floating point values in FPU registers while integer values in | |
14406 | CPU registers. Still some ABIs return even floating point values in CPU | |
14407 | registers. Larger integer widths (such as @code{long long int}) also have | |
14408 | specific placement rules. @value{GDBN} already knows the OS ABI from its | |
14409 | current target so it needs to find out also the type being returned to make the | |
14410 | assignment into the right register(s). | |
14411 | ||
14412 | Normally, the selected stack frame has debug info. @value{GDBN} will always | |
14413 | use the debug info instead of the implicit type of @var{expression} when the | |
14414 | debug info is available. For example, if you type @kbd{return -1}, and the | |
14415 | function in the current stack frame is declared to return a @code{long long | |
14416 | int}, @value{GDBN} transparently converts the implicit @code{int} value of -1 | |
14417 | into a @code{long long int}: | |
14418 | ||
14419 | @smallexample | |
14420 | Breakpoint 1, func () at gdb.base/return-nodebug.c:29 | |
14421 | 29 return 31; | |
14422 | (@value{GDBP}) return -1 | |
14423 | Make func return now? (y or n) y | |
14424 | #0 0x004004f6 in main () at gdb.base/return-nodebug.c:43 | |
14425 | 43 printf ("result=%lld\n", func ()); | |
14426 | (@value{GDBP}) | |
14427 | @end smallexample | |
14428 | ||
14429 | However, if the selected stack frame does not have a debug info, e.g., if the | |
14430 | function was compiled without debug info, @value{GDBN} has to find out the type | |
14431 | to return from user. Specifying a different type by mistake may set the value | |
14432 | in different inferior registers than the caller code expects. For example, | |
14433 | typing @kbd{return -1} with its implicit type @code{int} would set only a part | |
14434 | of a @code{long long int} result for a debug info less function (on 32-bit | |
14435 | architectures). Therefore the user is required to specify the return type by | |
14436 | an appropriate cast explicitly: | |
14437 | ||
14438 | @smallexample | |
14439 | Breakpoint 2, 0x0040050b in func () | |
14440 | (@value{GDBP}) return -1 | |
14441 | Return value type not available for selected stack frame. | |
14442 | Please use an explicit cast of the value to return. | |
14443 | (@value{GDBP}) return (long long int) -1 | |
14444 | Make selected stack frame return now? (y or n) y | |
14445 | #0 0x00400526 in main () | |
14446 | (@value{GDBP}) | |
14447 | @end smallexample | |
14448 | ||
6d2ebf8b | 14449 | @node Calling |
79a6e687 | 14450 | @section Calling Program Functions |
c906108c | 14451 | |
f8568604 | 14452 | @table @code |
c906108c | 14453 | @cindex calling functions |
f8568604 EZ |
14454 | @cindex inferior functions, calling |
14455 | @item print @var{expr} | |
d3e8051b | 14456 | Evaluate the expression @var{expr} and display the resulting value. |
f8568604 EZ |
14457 | @var{expr} may include calls to functions in the program being |
14458 | debugged. | |
14459 | ||
c906108c | 14460 | @kindex call |
c906108c SS |
14461 | @item call @var{expr} |
14462 | Evaluate the expression @var{expr} without displaying @code{void} | |
14463 | returned values. | |
c906108c SS |
14464 | |
14465 | You can use this variant of the @code{print} command if you want to | |
f8568604 EZ |
14466 | execute a function from your program that does not return anything |
14467 | (a.k.a.@: @dfn{a void function}), but without cluttering the output | |
14468 | with @code{void} returned values that @value{GDBN} will otherwise | |
14469 | print. If the result is not void, it is printed and saved in the | |
14470 | value history. | |
14471 | @end table | |
14472 | ||
9c16f35a EZ |
14473 | It is possible for the function you call via the @code{print} or |
14474 | @code{call} command to generate a signal (e.g., if there's a bug in | |
14475 | the function, or if you passed it incorrect arguments). What happens | |
14476 | in that case is controlled by the @code{set unwindonsignal} command. | |
14477 | ||
7cd1089b PM |
14478 | Similarly, with a C@t{++} program it is possible for the function you |
14479 | call via the @code{print} or @code{call} command to generate an | |
14480 | exception that is not handled due to the constraints of the dummy | |
14481 | frame. In this case, any exception that is raised in the frame, but has | |
14482 | an out-of-frame exception handler will not be found. GDB builds a | |
14483 | dummy-frame for the inferior function call, and the unwinder cannot | |
14484 | seek for exception handlers outside of this dummy-frame. What happens | |
14485 | in that case is controlled by the | |
14486 | @code{set unwind-on-terminating-exception} command. | |
14487 | ||
9c16f35a EZ |
14488 | @table @code |
14489 | @item set unwindonsignal | |
14490 | @kindex set unwindonsignal | |
14491 | @cindex unwind stack in called functions | |
14492 | @cindex call dummy stack unwinding | |
14493 | Set unwinding of the stack if a signal is received while in a function | |
14494 | that @value{GDBN} called in the program being debugged. If set to on, | |
14495 | @value{GDBN} unwinds the stack it created for the call and restores | |
14496 | the context to what it was before the call. If set to off (the | |
14497 | default), @value{GDBN} stops in the frame where the signal was | |
14498 | received. | |
14499 | ||
14500 | @item show unwindonsignal | |
14501 | @kindex show unwindonsignal | |
14502 | Show the current setting of stack unwinding in the functions called by | |
14503 | @value{GDBN}. | |
7cd1089b PM |
14504 | |
14505 | @item set unwind-on-terminating-exception | |
14506 | @kindex set unwind-on-terminating-exception | |
14507 | @cindex unwind stack in called functions with unhandled exceptions | |
14508 | @cindex call dummy stack unwinding on unhandled exception. | |
14509 | Set unwinding of the stack if a C@t{++} exception is raised, but left | |
14510 | unhandled while in a function that @value{GDBN} called in the program being | |
14511 | debugged. If set to on (the default), @value{GDBN} unwinds the stack | |
14512 | it created for the call and restores the context to what it was before | |
14513 | the call. If set to off, @value{GDBN} the exception is delivered to | |
14514 | the default C@t{++} exception handler and the inferior terminated. | |
14515 | ||
14516 | @item show unwind-on-terminating-exception | |
14517 | @kindex show unwind-on-terminating-exception | |
14518 | Show the current setting of stack unwinding in the functions called by | |
14519 | @value{GDBN}. | |
14520 | ||
9c16f35a EZ |
14521 | @end table |
14522 | ||
f8568604 EZ |
14523 | @cindex weak alias functions |
14524 | Sometimes, a function you wish to call is actually a @dfn{weak alias} | |
14525 | for another function. In such case, @value{GDBN} might not pick up | |
14526 | the type information, including the types of the function arguments, | |
14527 | which causes @value{GDBN} to call the inferior function incorrectly. | |
14528 | As a result, the called function will function erroneously and may | |
14529 | even crash. A solution to that is to use the name of the aliased | |
14530 | function instead. | |
c906108c | 14531 | |
6d2ebf8b | 14532 | @node Patching |
79a6e687 | 14533 | @section Patching Programs |
7a292a7a | 14534 | |
c906108c SS |
14535 | @cindex patching binaries |
14536 | @cindex writing into executables | |
c906108c | 14537 | @cindex writing into corefiles |
c906108c | 14538 | |
7a292a7a SS |
14539 | By default, @value{GDBN} opens the file containing your program's |
14540 | executable code (or the corefile) read-only. This prevents accidental | |
14541 | alterations to machine code; but it also prevents you from intentionally | |
14542 | patching your program's binary. | |
c906108c SS |
14543 | |
14544 | If you'd like to be able to patch the binary, you can specify that | |
14545 | explicitly with the @code{set write} command. For example, you might | |
14546 | want to turn on internal debugging flags, or even to make emergency | |
14547 | repairs. | |
14548 | ||
14549 | @table @code | |
14550 | @kindex set write | |
14551 | @item set write on | |
14552 | @itemx set write off | |
7a292a7a | 14553 | If you specify @samp{set write on}, @value{GDBN} opens executable and |
20924a55 | 14554 | core files for both reading and writing; if you specify @kbd{set write |
c906108c SS |
14555 | off} (the default), @value{GDBN} opens them read-only. |
14556 | ||
14557 | If you have already loaded a file, you must load it again (using the | |
7a292a7a SS |
14558 | @code{exec-file} or @code{core-file} command) after changing @code{set |
14559 | write}, for your new setting to take effect. | |
c906108c SS |
14560 | |
14561 | @item show write | |
14562 | @kindex show write | |
7a292a7a SS |
14563 | Display whether executable files and core files are opened for writing |
14564 | as well as reading. | |
c906108c SS |
14565 | @end table |
14566 | ||
6d2ebf8b | 14567 | @node GDB Files |
c906108c SS |
14568 | @chapter @value{GDBN} Files |
14569 | ||
7a292a7a SS |
14570 | @value{GDBN} needs to know the file name of the program to be debugged, |
14571 | both in order to read its symbol table and in order to start your | |
14572 | program. To debug a core dump of a previous run, you must also tell | |
14573 | @value{GDBN} the name of the core dump file. | |
c906108c SS |
14574 | |
14575 | @menu | |
14576 | * Files:: Commands to specify files | |
5b5d99cf | 14577 | * Separate Debug Files:: Debugging information in separate files |
9291a0cd | 14578 | * Index Files:: Index files speed up GDB |
c906108c | 14579 | * Symbol Errors:: Errors reading symbol files |
b14b1491 | 14580 | * Data Files:: GDB data files |
c906108c SS |
14581 | @end menu |
14582 | ||
6d2ebf8b | 14583 | @node Files |
79a6e687 | 14584 | @section Commands to Specify Files |
c906108c | 14585 | |
7a292a7a | 14586 | @cindex symbol table |
c906108c | 14587 | @cindex core dump file |
7a292a7a SS |
14588 | |
14589 | You may want to specify executable and core dump file names. The usual | |
14590 | way to do this is at start-up time, using the arguments to | |
14591 | @value{GDBN}'s start-up commands (@pxref{Invocation, , Getting In and | |
14592 | Out of @value{GDBN}}). | |
c906108c SS |
14593 | |
14594 | Occasionally it is necessary to change to a different file during a | |
397ca115 EZ |
14595 | @value{GDBN} session. Or you may run @value{GDBN} and forget to |
14596 | specify a file you want to use. Or you are debugging a remote target | |
79a6e687 BW |
14597 | via @code{gdbserver} (@pxref{Server, file, Using the @code{gdbserver} |
14598 | Program}). In these situations the @value{GDBN} commands to specify | |
0869d01b | 14599 | new files are useful. |
c906108c SS |
14600 | |
14601 | @table @code | |
14602 | @cindex executable file | |
14603 | @kindex file | |
14604 | @item file @var{filename} | |
14605 | Use @var{filename} as the program to be debugged. It is read for its | |
14606 | symbols and for the contents of pure memory. It is also the program | |
14607 | executed when you use the @code{run} command. If you do not specify a | |
5d161b24 DB |
14608 | directory and the file is not found in the @value{GDBN} working directory, |
14609 | @value{GDBN} uses the environment variable @code{PATH} as a list of | |
14610 | directories to search, just as the shell does when looking for a program | |
14611 | to run. You can change the value of this variable, for both @value{GDBN} | |
c906108c SS |
14612 | and your program, using the @code{path} command. |
14613 | ||
fc8be69e EZ |
14614 | @cindex unlinked object files |
14615 | @cindex patching object files | |
14616 | You can load unlinked object @file{.o} files into @value{GDBN} using | |
14617 | the @code{file} command. You will not be able to ``run'' an object | |
14618 | file, but you can disassemble functions and inspect variables. Also, | |
14619 | if the underlying BFD functionality supports it, you could use | |
14620 | @kbd{gdb -write} to patch object files using this technique. Note | |
14621 | that @value{GDBN} can neither interpret nor modify relocations in this | |
14622 | case, so branches and some initialized variables will appear to go to | |
14623 | the wrong place. But this feature is still handy from time to time. | |
14624 | ||
c906108c SS |
14625 | @item file |
14626 | @code{file} with no argument makes @value{GDBN} discard any information it | |
14627 | has on both executable file and the symbol table. | |
14628 | ||
14629 | @kindex exec-file | |
14630 | @item exec-file @r{[} @var{filename} @r{]} | |
14631 | Specify that the program to be run (but not the symbol table) is found | |
14632 | in @var{filename}. @value{GDBN} searches the environment variable @code{PATH} | |
14633 | if necessary to locate your program. Omitting @var{filename} means to | |
14634 | discard information on the executable file. | |
14635 | ||
14636 | @kindex symbol-file | |
14637 | @item symbol-file @r{[} @var{filename} @r{]} | |
14638 | Read symbol table information from file @var{filename}. @code{PATH} is | |
14639 | searched when necessary. Use the @code{file} command to get both symbol | |
14640 | table and program to run from the same file. | |
14641 | ||
14642 | @code{symbol-file} with no argument clears out @value{GDBN} information on your | |
14643 | program's symbol table. | |
14644 | ||
ae5a43e0 DJ |
14645 | The @code{symbol-file} command causes @value{GDBN} to forget the contents of |
14646 | some breakpoints and auto-display expressions. This is because they may | |
14647 | contain pointers to the internal data recording symbols and data types, | |
14648 | which are part of the old symbol table data being discarded inside | |
14649 | @value{GDBN}. | |
c906108c SS |
14650 | |
14651 | @code{symbol-file} does not repeat if you press @key{RET} again after | |
14652 | executing it once. | |
14653 | ||
14654 | When @value{GDBN} is configured for a particular environment, it | |
14655 | understands debugging information in whatever format is the standard | |
14656 | generated for that environment; you may use either a @sc{gnu} compiler, or | |
14657 | other compilers that adhere to the local conventions. | |
c906108c | 14658 | Best results are usually obtained from @sc{gnu} compilers; for example, |
e22ea452 | 14659 | using @code{@value{NGCC}} you can generate debugging information for |
c906108c | 14660 | optimized code. |
c906108c SS |
14661 | |
14662 | For most kinds of object files, with the exception of old SVR3 systems | |
14663 | using COFF, the @code{symbol-file} command does not normally read the | |
14664 | symbol table in full right away. Instead, it scans the symbol table | |
14665 | quickly to find which source files and which symbols are present. The | |
14666 | details are read later, one source file at a time, as they are needed. | |
14667 | ||
14668 | The purpose of this two-stage reading strategy is to make @value{GDBN} | |
14669 | start up faster. For the most part, it is invisible except for | |
14670 | occasional pauses while the symbol table details for a particular source | |
14671 | file are being read. (The @code{set verbose} command can turn these | |
14672 | pauses into messages if desired. @xref{Messages/Warnings, ,Optional | |
79a6e687 | 14673 | Warnings and Messages}.) |
c906108c | 14674 | |
c906108c SS |
14675 | We have not implemented the two-stage strategy for COFF yet. When the |
14676 | symbol table is stored in COFF format, @code{symbol-file} reads the | |
14677 | symbol table data in full right away. Note that ``stabs-in-COFF'' | |
14678 | still does the two-stage strategy, since the debug info is actually | |
14679 | in stabs format. | |
14680 | ||
14681 | @kindex readnow | |
14682 | @cindex reading symbols immediately | |
14683 | @cindex symbols, reading immediately | |
6ac33a4e TT |
14684 | @item symbol-file @r{[} -readnow @r{]} @var{filename} |
14685 | @itemx file @r{[} -readnow @r{]} @var{filename} | |
c906108c SS |
14686 | You can override the @value{GDBN} two-stage strategy for reading symbol |
14687 | tables by using the @samp{-readnow} option with any of the commands that | |
14688 | load symbol table information, if you want to be sure @value{GDBN} has the | |
5d161b24 | 14689 | entire symbol table available. |
c906108c | 14690 | |
c906108c SS |
14691 | @c FIXME: for now no mention of directories, since this seems to be in |
14692 | @c flux. 13mar1992 status is that in theory GDB would look either in | |
14693 | @c current dir or in same dir as myprog; but issues like competing | |
14694 | @c GDB's, or clutter in system dirs, mean that in practice right now | |
14695 | @c only current dir is used. FFish says maybe a special GDB hierarchy | |
14696 | @c (eg rooted in val of env var GDBSYMS) could exist for mappable symbol | |
14697 | @c files. | |
14698 | ||
c906108c | 14699 | @kindex core-file |
09d4efe1 | 14700 | @item core-file @r{[}@var{filename}@r{]} |
4644b6e3 | 14701 | @itemx core |
c906108c SS |
14702 | Specify the whereabouts of a core dump file to be used as the ``contents |
14703 | of memory''. Traditionally, core files contain only some parts of the | |
14704 | address space of the process that generated them; @value{GDBN} can access the | |
14705 | executable file itself for other parts. | |
14706 | ||
14707 | @code{core-file} with no argument specifies that no core file is | |
14708 | to be used. | |
14709 | ||
14710 | Note that the core file is ignored when your program is actually running | |
7a292a7a SS |
14711 | under @value{GDBN}. So, if you have been running your program and you |
14712 | wish to debug a core file instead, you must kill the subprocess in which | |
14713 | the program is running. To do this, use the @code{kill} command | |
79a6e687 | 14714 | (@pxref{Kill Process, ,Killing the Child Process}). |
c906108c | 14715 | |
c906108c SS |
14716 | @kindex add-symbol-file |
14717 | @cindex dynamic linking | |
14718 | @item add-symbol-file @var{filename} @var{address} | |
a94ab193 | 14719 | @itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} |
17d9d558 | 14720 | @itemx add-symbol-file @var{filename} @r{-s}@var{section} @var{address} @dots{} |
96a2c332 SS |
14721 | The @code{add-symbol-file} command reads additional symbol table |
14722 | information from the file @var{filename}. You would use this command | |
14723 | when @var{filename} has been dynamically loaded (by some other means) | |
14724 | into the program that is running. @var{address} should be the memory | |
14725 | address at which the file has been loaded; @value{GDBN} cannot figure | |
d167840f EZ |
14726 | this out for itself. You can additionally specify an arbitrary number |
14727 | of @samp{@r{-s}@var{section} @var{address}} pairs, to give an explicit | |
14728 | section name and base address for that section. You can specify any | |
14729 | @var{address} as an expression. | |
c906108c SS |
14730 | |
14731 | The symbol table of the file @var{filename} is added to the symbol table | |
14732 | originally read with the @code{symbol-file} command. You can use the | |
96a2c332 SS |
14733 | @code{add-symbol-file} command any number of times; the new symbol data |
14734 | thus read keeps adding to the old. To discard all old symbol data | |
14735 | instead, use the @code{symbol-file} command without any arguments. | |
c906108c | 14736 | |
17d9d558 JB |
14737 | @cindex relocatable object files, reading symbols from |
14738 | @cindex object files, relocatable, reading symbols from | |
14739 | @cindex reading symbols from relocatable object files | |
14740 | @cindex symbols, reading from relocatable object files | |
14741 | @cindex @file{.o} files, reading symbols from | |
14742 | Although @var{filename} is typically a shared library file, an | |
14743 | executable file, or some other object file which has been fully | |
14744 | relocated for loading into a process, you can also load symbolic | |
14745 | information from relocatable @file{.o} files, as long as: | |
14746 | ||
14747 | @itemize @bullet | |
14748 | @item | |
14749 | the file's symbolic information refers only to linker symbols defined in | |
14750 | that file, not to symbols defined by other object files, | |
14751 | @item | |
14752 | every section the file's symbolic information refers to has actually | |
14753 | been loaded into the inferior, as it appears in the file, and | |
14754 | @item | |
14755 | you can determine the address at which every section was loaded, and | |
14756 | provide these to the @code{add-symbol-file} command. | |
14757 | @end itemize | |
14758 | ||
14759 | @noindent | |
14760 | Some embedded operating systems, like Sun Chorus and VxWorks, can load | |
14761 | relocatable files into an already running program; such systems | |
14762 | typically make the requirements above easy to meet. However, it's | |
14763 | important to recognize that many native systems use complex link | |
49efadf5 | 14764 | procedures (@code{.linkonce} section factoring and C@t{++} constructor table |
17d9d558 JB |
14765 | assembly, for example) that make the requirements difficult to meet. In |
14766 | general, one cannot assume that using @code{add-symbol-file} to read a | |
14767 | relocatable object file's symbolic information will have the same effect | |
14768 | as linking the relocatable object file into the program in the normal | |
14769 | way. | |
14770 | ||
c906108c SS |
14771 | @code{add-symbol-file} does not repeat if you press @key{RET} after using it. |
14772 | ||
c45da7e6 EZ |
14773 | @kindex add-symbol-file-from-memory |
14774 | @cindex @code{syscall DSO} | |
14775 | @cindex load symbols from memory | |
14776 | @item add-symbol-file-from-memory @var{address} | |
14777 | Load symbols from the given @var{address} in a dynamically loaded | |
14778 | object file whose image is mapped directly into the inferior's memory. | |
14779 | For example, the Linux kernel maps a @code{syscall DSO} into each | |
14780 | process's address space; this DSO provides kernel-specific code for | |
14781 | some system calls. The argument can be any expression whose | |
14782 | evaluation yields the address of the file's shared object file header. | |
14783 | For this command to work, you must have used @code{symbol-file} or | |
14784 | @code{exec-file} commands in advance. | |
14785 | ||
09d4efe1 EZ |
14786 | @kindex add-shared-symbol-files |
14787 | @kindex assf | |
14788 | @item add-shared-symbol-files @var{library-file} | |
14789 | @itemx assf @var{library-file} | |
14790 | The @code{add-shared-symbol-files} command can currently be used only | |
14791 | in the Cygwin build of @value{GDBN} on MS-Windows OS, where it is an | |
14792 | alias for the @code{dll-symbols} command (@pxref{Cygwin Native}). | |
14793 | @value{GDBN} automatically looks for shared libraries, however if | |
14794 | @value{GDBN} does not find yours, you can invoke | |
14795 | @code{add-shared-symbol-files}. It takes one argument: the shared | |
14796 | library's file name. @code{assf} is a shorthand alias for | |
14797 | @code{add-shared-symbol-files}. | |
c906108c | 14798 | |
c906108c | 14799 | @kindex section |
09d4efe1 EZ |
14800 | @item section @var{section} @var{addr} |
14801 | The @code{section} command changes the base address of the named | |
14802 | @var{section} of the exec file to @var{addr}. This can be used if the | |
14803 | exec file does not contain section addresses, (such as in the | |
14804 | @code{a.out} format), or when the addresses specified in the file | |
14805 | itself are wrong. Each section must be changed separately. The | |
14806 | @code{info files} command, described below, lists all the sections and | |
14807 | their addresses. | |
c906108c SS |
14808 | |
14809 | @kindex info files | |
14810 | @kindex info target | |
14811 | @item info files | |
14812 | @itemx info target | |
7a292a7a SS |
14813 | @code{info files} and @code{info target} are synonymous; both print the |
14814 | current target (@pxref{Targets, ,Specifying a Debugging Target}), | |
14815 | including the names of the executable and core dump files currently in | |
14816 | use by @value{GDBN}, and the files from which symbols were loaded. The | |
14817 | command @code{help target} lists all possible targets rather than | |
14818 | current ones. | |
14819 | ||
fe95c787 MS |
14820 | @kindex maint info sections |
14821 | @item maint info sections | |
14822 | Another command that can give you extra information about program sections | |
14823 | is @code{maint info sections}. In addition to the section information | |
14824 | displayed by @code{info files}, this command displays the flags and file | |
14825 | offset of each section in the executable and core dump files. In addition, | |
14826 | @code{maint info sections} provides the following command options (which | |
14827 | may be arbitrarily combined): | |
14828 | ||
14829 | @table @code | |
14830 | @item ALLOBJ | |
14831 | Display sections for all loaded object files, including shared libraries. | |
14832 | @item @var{sections} | |
6600abed | 14833 | Display info only for named @var{sections}. |
fe95c787 MS |
14834 | @item @var{section-flags} |
14835 | Display info only for sections for which @var{section-flags} are true. | |
14836 | The section flags that @value{GDBN} currently knows about are: | |
14837 | @table @code | |
14838 | @item ALLOC | |
14839 | Section will have space allocated in the process when loaded. | |
14840 | Set for all sections except those containing debug information. | |
14841 | @item LOAD | |
14842 | Section will be loaded from the file into the child process memory. | |
14843 | Set for pre-initialized code and data, clear for @code{.bss} sections. | |
14844 | @item RELOC | |
14845 | Section needs to be relocated before loading. | |
14846 | @item READONLY | |
14847 | Section cannot be modified by the child process. | |
14848 | @item CODE | |
14849 | Section contains executable code only. | |
6600abed | 14850 | @item DATA |
fe95c787 MS |
14851 | Section contains data only (no executable code). |
14852 | @item ROM | |
14853 | Section will reside in ROM. | |
14854 | @item CONSTRUCTOR | |
14855 | Section contains data for constructor/destructor lists. | |
14856 | @item HAS_CONTENTS | |
14857 | Section is not empty. | |
14858 | @item NEVER_LOAD | |
14859 | An instruction to the linker to not output the section. | |
14860 | @item COFF_SHARED_LIBRARY | |
14861 | A notification to the linker that the section contains | |
14862 | COFF shared library information. | |
14863 | @item IS_COMMON | |
14864 | Section contains common symbols. | |
14865 | @end table | |
14866 | @end table | |
6763aef9 | 14867 | @kindex set trust-readonly-sections |
9c16f35a | 14868 | @cindex read-only sections |
6763aef9 MS |
14869 | @item set trust-readonly-sections on |
14870 | Tell @value{GDBN} that readonly sections in your object file | |
6ca652b0 | 14871 | really are read-only (i.e.@: that their contents will not change). |
6763aef9 MS |
14872 | In that case, @value{GDBN} can fetch values from these sections |
14873 | out of the object file, rather than from the target program. | |
14874 | For some targets (notably embedded ones), this can be a significant | |
14875 | enhancement to debugging performance. | |
14876 | ||
14877 | The default is off. | |
14878 | ||
14879 | @item set trust-readonly-sections off | |
15110bc3 | 14880 | Tell @value{GDBN} not to trust readonly sections. This means that |
6763aef9 MS |
14881 | the contents of the section might change while the program is running, |
14882 | and must therefore be fetched from the target when needed. | |
9c16f35a EZ |
14883 | |
14884 | @item show trust-readonly-sections | |
14885 | Show the current setting of trusting readonly sections. | |
c906108c SS |
14886 | @end table |
14887 | ||
14888 | All file-specifying commands allow both absolute and relative file names | |
14889 | as arguments. @value{GDBN} always converts the file name to an absolute file | |
14890 | name and remembers it that way. | |
14891 | ||
c906108c | 14892 | @cindex shared libraries |
9cceb671 DJ |
14893 | @anchor{Shared Libraries} |
14894 | @value{GDBN} supports @sc{gnu}/Linux, MS-Windows, HP-UX, SunOS, SVr4, Irix, | |
9c16f35a | 14895 | and IBM RS/6000 AIX shared libraries. |
53a5351d | 14896 | |
9cceb671 DJ |
14897 | On MS-Windows @value{GDBN} must be linked with the Expat library to support |
14898 | shared libraries. @xref{Expat}. | |
14899 | ||
c906108c SS |
14900 | @value{GDBN} automatically loads symbol definitions from shared libraries |
14901 | when you use the @code{run} command, or when you examine a core file. | |
14902 | (Before you issue the @code{run} command, @value{GDBN} does not understand | |
14903 | references to a function in a shared library, however---unless you are | |
14904 | debugging a core file). | |
53a5351d JM |
14905 | |
14906 | On HP-UX, if the program loads a library explicitly, @value{GDBN} | |
14907 | automatically loads the symbols at the time of the @code{shl_load} call. | |
14908 | ||
c906108c SS |
14909 | @c FIXME: some @value{GDBN} release may permit some refs to undef |
14910 | @c FIXME...symbols---eg in a break cmd---assuming they are from a shared | |
14911 | @c FIXME...lib; check this from time to time when updating manual | |
14912 | ||
b7209cb4 FF |
14913 | There are times, however, when you may wish to not automatically load |
14914 | symbol definitions from shared libraries, such as when they are | |
14915 | particularly large or there are many of them. | |
14916 | ||
14917 | To control the automatic loading of shared library symbols, use the | |
14918 | commands: | |
14919 | ||
14920 | @table @code | |
14921 | @kindex set auto-solib-add | |
14922 | @item set auto-solib-add @var{mode} | |
14923 | If @var{mode} is @code{on}, symbols from all shared object libraries | |
14924 | will be loaded automatically when the inferior begins execution, you | |
14925 | attach to an independently started inferior, or when the dynamic linker | |
14926 | informs @value{GDBN} that a new library has been loaded. If @var{mode} | |
14927 | is @code{off}, symbols must be loaded manually, using the | |
14928 | @code{sharedlibrary} command. The default value is @code{on}. | |
14929 | ||
dcaf7c2c EZ |
14930 | @cindex memory used for symbol tables |
14931 | If your program uses lots of shared libraries with debug info that | |
14932 | takes large amounts of memory, you can decrease the @value{GDBN} | |
14933 | memory footprint by preventing it from automatically loading the | |
14934 | symbols from shared libraries. To that end, type @kbd{set | |
14935 | auto-solib-add off} before running the inferior, then load each | |
14936 | library whose debug symbols you do need with @kbd{sharedlibrary | |
d3e8051b | 14937 | @var{regexp}}, where @var{regexp} is a regular expression that matches |
dcaf7c2c EZ |
14938 | the libraries whose symbols you want to be loaded. |
14939 | ||
b7209cb4 FF |
14940 | @kindex show auto-solib-add |
14941 | @item show auto-solib-add | |
14942 | Display the current autoloading mode. | |
14943 | @end table | |
14944 | ||
c45da7e6 | 14945 | @cindex load shared library |
b7209cb4 FF |
14946 | To explicitly load shared library symbols, use the @code{sharedlibrary} |
14947 | command: | |
14948 | ||
c906108c SS |
14949 | @table @code |
14950 | @kindex info sharedlibrary | |
14951 | @kindex info share | |
55333a84 DE |
14952 | @item info share @var{regex} |
14953 | @itemx info sharedlibrary @var{regex} | |
14954 | Print the names of the shared libraries which are currently loaded | |
14955 | that match @var{regex}. If @var{regex} is omitted then print | |
14956 | all shared libraries that are loaded. | |
c906108c SS |
14957 | |
14958 | @kindex sharedlibrary | |
14959 | @kindex share | |
14960 | @item sharedlibrary @var{regex} | |
14961 | @itemx share @var{regex} | |
c906108c SS |
14962 | Load shared object library symbols for files matching a |
14963 | Unix regular expression. | |
14964 | As with files loaded automatically, it only loads shared libraries | |
14965 | required by your program for a core file or after typing @code{run}. If | |
14966 | @var{regex} is omitted all shared libraries required by your program are | |
14967 | loaded. | |
c45da7e6 EZ |
14968 | |
14969 | @item nosharedlibrary | |
14970 | @kindex nosharedlibrary | |
14971 | @cindex unload symbols from shared libraries | |
14972 | Unload all shared object library symbols. This discards all symbols | |
14973 | that have been loaded from all shared libraries. Symbols from shared | |
14974 | libraries that were loaded by explicit user requests are not | |
14975 | discarded. | |
c906108c SS |
14976 | @end table |
14977 | ||
721c2651 EZ |
14978 | Sometimes you may wish that @value{GDBN} stops and gives you control |
14979 | when any of shared library events happen. Use the @code{set | |
14980 | stop-on-solib-events} command for this: | |
14981 | ||
14982 | @table @code | |
14983 | @item set stop-on-solib-events | |
14984 | @kindex set stop-on-solib-events | |
14985 | This command controls whether @value{GDBN} should give you control | |
14986 | when the dynamic linker notifies it about some shared library event. | |
14987 | The most common event of interest is loading or unloading of a new | |
14988 | shared library. | |
14989 | ||
14990 | @item show stop-on-solib-events | |
14991 | @kindex show stop-on-solib-events | |
14992 | Show whether @value{GDBN} stops and gives you control when shared | |
14993 | library events happen. | |
14994 | @end table | |
14995 | ||
f5ebfba0 | 14996 | Shared libraries are also supported in many cross or remote debugging |
f1838a98 UW |
14997 | configurations. @value{GDBN} needs to have access to the target's libraries; |
14998 | this can be accomplished either by providing copies of the libraries | |
14999 | on the host system, or by asking @value{GDBN} to automatically retrieve the | |
15000 | libraries from the target. If copies of the target libraries are | |
15001 | provided, they need to be the same as the target libraries, although the | |
f5ebfba0 DJ |
15002 | copies on the target can be stripped as long as the copies on the host are |
15003 | not. | |
15004 | ||
59b7b46f EZ |
15005 | @cindex where to look for shared libraries |
15006 | For remote debugging, you need to tell @value{GDBN} where the target | |
15007 | libraries are, so that it can load the correct copies---otherwise, it | |
15008 | may try to load the host's libraries. @value{GDBN} has two variables | |
15009 | to specify the search directories for target libraries. | |
f5ebfba0 DJ |
15010 | |
15011 | @table @code | |
59b7b46f | 15012 | @cindex prefix for shared library file names |
f822c95b | 15013 | @cindex system root, alternate |
f5ebfba0 | 15014 | @kindex set solib-absolute-prefix |
f822c95b DJ |
15015 | @kindex set sysroot |
15016 | @item set sysroot @var{path} | |
15017 | Use @var{path} as the system root for the program being debugged. Any | |
15018 | absolute shared library paths will be prefixed with @var{path}; many | |
15019 | runtime loaders store the absolute paths to the shared library in the | |
15020 | target program's memory. If you use @code{set sysroot} to find shared | |
15021 | libraries, they need to be laid out in the same way that they are on | |
15022 | the target, with e.g.@: a @file{/lib} and @file{/usr/lib} hierarchy | |
15023 | under @var{path}. | |
15024 | ||
f1838a98 UW |
15025 | If @var{path} starts with the sequence @file{remote:}, @value{GDBN} will |
15026 | retrieve the target libraries from the remote system. This is only | |
15027 | supported when using a remote target that supports the @code{remote get} | |
15028 | command (@pxref{File Transfer,,Sending files to a remote system}). | |
15029 | The part of @var{path} following the initial @file{remote:} | |
15030 | (if present) is used as system root prefix on the remote file system. | |
15031 | @footnote{If you want to specify a local system root using a directory | |
15032 | that happens to be named @file{remote:}, you need to use some equivalent | |
15033 | variant of the name like @file{./remote:}.} | |
15034 | ||
ab38a727 PA |
15035 | For targets with an MS-DOS based filesystem, such as MS-Windows and |
15036 | SymbianOS, @value{GDBN} tries prefixing a few variants of the target | |
15037 | absolute file name with @var{path}. But first, on Unix hosts, | |
15038 | @value{GDBN} converts all backslash directory separators into forward | |
15039 | slashes, because the backslash is not a directory separator on Unix: | |
15040 | ||
15041 | @smallexample | |
15042 | c:\foo\bar.dll @result{} c:/foo/bar.dll | |
15043 | @end smallexample | |
15044 | ||
15045 | Then, @value{GDBN} attempts prefixing the target file name with | |
15046 | @var{path}, and looks for the resulting file name in the host file | |
15047 | system: | |
15048 | ||
15049 | @smallexample | |
15050 | c:/foo/bar.dll @result{} /path/to/sysroot/c:/foo/bar.dll | |
15051 | @end smallexample | |
15052 | ||
15053 | If that does not find the shared library, @value{GDBN} tries removing | |
15054 | the @samp{:} character from the drive spec, both for convenience, and, | |
15055 | for the case of the host file system not supporting file names with | |
15056 | colons: | |
15057 | ||
15058 | @smallexample | |
15059 | c:/foo/bar.dll @result{} /path/to/sysroot/c/foo/bar.dll | |
15060 | @end smallexample | |
15061 | ||
15062 | This makes it possible to have a system root that mirrors a target | |
15063 | with more than one drive. E.g., you may want to setup your local | |
15064 | copies of the target system shared libraries like so (note @samp{c} vs | |
15065 | @samp{z}): | |
15066 | ||
15067 | @smallexample | |
15068 | @file{/path/to/sysroot/c/sys/bin/foo.dll} | |
15069 | @file{/path/to/sysroot/c/sys/bin/bar.dll} | |
15070 | @file{/path/to/sysroot/z/sys/bin/bar.dll} | |
15071 | @end smallexample | |
15072 | ||
15073 | @noindent | |
15074 | and point the system root at @file{/path/to/sysroot}, so that | |
15075 | @value{GDBN} can find the correct copies of both | |
15076 | @file{c:\sys\bin\foo.dll}, and @file{z:\sys\bin\bar.dll}. | |
15077 | ||
15078 | If that still does not find the shared library, @value{GDBN} tries | |
15079 | removing the whole drive spec from the target file name: | |
15080 | ||
15081 | @smallexample | |
15082 | c:/foo/bar.dll @result{} /path/to/sysroot/foo/bar.dll | |
15083 | @end smallexample | |
15084 | ||
15085 | This last lookup makes it possible to not care about the drive name, | |
15086 | if you don't want or need to. | |
15087 | ||
f822c95b DJ |
15088 | The @code{set solib-absolute-prefix} command is an alias for @code{set |
15089 | sysroot}. | |
15090 | ||
15091 | @cindex default system root | |
59b7b46f | 15092 | @cindex @samp{--with-sysroot} |
f822c95b DJ |
15093 | You can set the default system root by using the configure-time |
15094 | @samp{--with-sysroot} option. If the system root is inside | |
15095 | @value{GDBN}'s configured binary prefix (set with @samp{--prefix} or | |
15096 | @samp{--exec-prefix}), then the default system root will be updated | |
15097 | automatically if the installed @value{GDBN} is moved to a new | |
15098 | location. | |
15099 | ||
15100 | @kindex show sysroot | |
15101 | @item show sysroot | |
f5ebfba0 DJ |
15102 | Display the current shared library prefix. |
15103 | ||
15104 | @kindex set solib-search-path | |
15105 | @item set solib-search-path @var{path} | |
f822c95b DJ |
15106 | If this variable is set, @var{path} is a colon-separated list of |
15107 | directories to search for shared libraries. @samp{solib-search-path} | |
15108 | is used after @samp{sysroot} fails to locate the library, or if the | |
15109 | path to the library is relative instead of absolute. If you want to | |
15110 | use @samp{solib-search-path} instead of @samp{sysroot}, be sure to set | |
d3e8051b | 15111 | @samp{sysroot} to a nonexistent directory to prevent @value{GDBN} from |
f822c95b | 15112 | finding your host's libraries. @samp{sysroot} is preferred; setting |
d3e8051b | 15113 | it to a nonexistent directory may interfere with automatic loading |
f822c95b | 15114 | of shared library symbols. |
f5ebfba0 DJ |
15115 | |
15116 | @kindex show solib-search-path | |
15117 | @item show solib-search-path | |
15118 | Display the current shared library search path. | |
ab38a727 PA |
15119 | |
15120 | @cindex DOS file-name semantics of file names. | |
15121 | @kindex set target-file-system-kind (unix|dos-based|auto) | |
15122 | @kindex show target-file-system-kind | |
15123 | @item set target-file-system-kind @var{kind} | |
15124 | Set assumed file system kind for target reported file names. | |
15125 | ||
15126 | Shared library file names as reported by the target system may not | |
15127 | make sense as is on the system @value{GDBN} is running on. For | |
15128 | example, when remote debugging a target that has MS-DOS based file | |
15129 | system semantics, from a Unix host, the target may be reporting to | |
15130 | @value{GDBN} a list of loaded shared libraries with file names such as | |
15131 | @file{c:\Windows\kernel32.dll}. On Unix hosts, there's no concept of | |
15132 | drive letters, so the @samp{c:\} prefix is not normally understood as | |
15133 | indicating an absolute file name, and neither is the backslash | |
15134 | normally considered a directory separator character. In that case, | |
15135 | the native file system would interpret this whole absolute file name | |
15136 | as a relative file name with no directory components. This would make | |
15137 | it impossible to point @value{GDBN} at a copy of the remote target's | |
15138 | shared libraries on the host using @code{set sysroot}, and impractical | |
15139 | with @code{set solib-search-path}. Setting | |
15140 | @code{target-file-system-kind} to @code{dos-based} tells @value{GDBN} | |
15141 | to interpret such file names similarly to how the target would, and to | |
15142 | map them to file names valid on @value{GDBN}'s native file system | |
15143 | semantics. The value of @var{kind} can be @code{"auto"}, in addition | |
15144 | to one of the supported file system kinds. In that case, @value{GDBN} | |
15145 | tries to determine the appropriate file system variant based on the | |
15146 | current target's operating system (@pxref{ABI, ,Configuring the | |
15147 | Current ABI}). The supported file system settings are: | |
15148 | ||
15149 | @table @code | |
15150 | @item unix | |
15151 | Instruct @value{GDBN} to assume the target file system is of Unix | |
15152 | kind. Only file names starting the forward slash (@samp{/}) character | |
15153 | are considered absolute, and the directory separator character is also | |
15154 | the forward slash. | |
15155 | ||
15156 | @item dos-based | |
15157 | Instruct @value{GDBN} to assume the target file system is DOS based. | |
15158 | File names starting with either a forward slash, or a drive letter | |
15159 | followed by a colon (e.g., @samp{c:}), are considered absolute, and | |
15160 | both the slash (@samp{/}) and the backslash (@samp{\\}) characters are | |
15161 | considered directory separators. | |
15162 | ||
15163 | @item auto | |
15164 | Instruct @value{GDBN} to use the file system kind associated with the | |
15165 | target operating system (@pxref{ABI, ,Configuring the Current ABI}). | |
15166 | This is the default. | |
15167 | @end table | |
f5ebfba0 DJ |
15168 | @end table |
15169 | ||
5b5d99cf JB |
15170 | |
15171 | @node Separate Debug Files | |
15172 | @section Debugging Information in Separate Files | |
15173 | @cindex separate debugging information files | |
15174 | @cindex debugging information in separate files | |
15175 | @cindex @file{.debug} subdirectories | |
15176 | @cindex debugging information directory, global | |
15177 | @cindex global debugging information directory | |
c7e83d54 EZ |
15178 | @cindex build ID, and separate debugging files |
15179 | @cindex @file{.build-id} directory | |
5b5d99cf JB |
15180 | |
15181 | @value{GDBN} allows you to put a program's debugging information in a | |
15182 | file separate from the executable itself, in a way that allows | |
15183 | @value{GDBN} to find and load the debugging information automatically. | |
c7e83d54 EZ |
15184 | Since debugging information can be very large---sometimes larger |
15185 | than the executable code itself---some systems distribute debugging | |
5b5d99cf JB |
15186 | information for their executables in separate files, which users can |
15187 | install only when they need to debug a problem. | |
15188 | ||
c7e83d54 EZ |
15189 | @value{GDBN} supports two ways of specifying the separate debug info |
15190 | file: | |
5b5d99cf JB |
15191 | |
15192 | @itemize @bullet | |
15193 | @item | |
c7e83d54 EZ |
15194 | The executable contains a @dfn{debug link} that specifies the name of |
15195 | the separate debug info file. The separate debug file's name is | |
15196 | usually @file{@var{executable}.debug}, where @var{executable} is the | |
15197 | name of the corresponding executable file without leading directories | |
15198 | (e.g., @file{ls.debug} for @file{/usr/bin/ls}). In addition, the | |
99e008fe EZ |
15199 | debug link specifies a 32-bit @dfn{Cyclic Redundancy Check} (CRC) |
15200 | checksum for the debug file, which @value{GDBN} uses to validate that | |
15201 | the executable and the debug file came from the same build. | |
c7e83d54 EZ |
15202 | |
15203 | @item | |
7e27a47a | 15204 | The executable contains a @dfn{build ID}, a unique bit string that is |
c7e83d54 | 15205 | also present in the corresponding debug info file. (This is supported |
7e27a47a EZ |
15206 | only on some operating systems, notably those which use the ELF format |
15207 | for binary files and the @sc{gnu} Binutils.) For more details about | |
15208 | this feature, see the description of the @option{--build-id} | |
15209 | command-line option in @ref{Options, , Command Line Options, ld.info, | |
15210 | The GNU Linker}. The debug info file's name is not specified | |
15211 | explicitly by the build ID, but can be computed from the build ID, see | |
15212 | below. | |
d3750b24 JK |
15213 | @end itemize |
15214 | ||
c7e83d54 EZ |
15215 | Depending on the way the debug info file is specified, @value{GDBN} |
15216 | uses two different methods of looking for the debug file: | |
d3750b24 JK |
15217 | |
15218 | @itemize @bullet | |
15219 | @item | |
c7e83d54 EZ |
15220 | For the ``debug link'' method, @value{GDBN} looks up the named file in |
15221 | the directory of the executable file, then in a subdirectory of that | |
15222 | directory named @file{.debug}, and finally under the global debug | |
15223 | directory, in a subdirectory whose name is identical to the leading | |
15224 | directories of the executable's absolute file name. | |
15225 | ||
15226 | @item | |
83f83d7f | 15227 | For the ``build ID'' method, @value{GDBN} looks in the |
c7e83d54 EZ |
15228 | @file{.build-id} subdirectory of the global debug directory for a file |
15229 | named @file{@var{nn}/@var{nnnnnnnn}.debug}, where @var{nn} are the | |
7e27a47a EZ |
15230 | first 2 hex characters of the build ID bit string, and @var{nnnnnnnn} |
15231 | are the rest of the bit string. (Real build ID strings are 32 or more | |
15232 | hex characters, not 10.) | |
c7e83d54 EZ |
15233 | @end itemize |
15234 | ||
15235 | So, for example, suppose you ask @value{GDBN} to debug | |
7e27a47a EZ |
15236 | @file{/usr/bin/ls}, which has a debug link that specifies the |
15237 | file @file{ls.debug}, and a build ID whose value in hex is | |
c7e83d54 EZ |
15238 | @code{abcdef1234}. If the global debug directory is |
15239 | @file{/usr/lib/debug}, then @value{GDBN} will look for the following | |
15240 | debug information files, in the indicated order: | |
15241 | ||
15242 | @itemize @minus | |
15243 | @item | |
15244 | @file{/usr/lib/debug/.build-id/ab/cdef1234.debug} | |
d3750b24 | 15245 | @item |
c7e83d54 | 15246 | @file{/usr/bin/ls.debug} |
5b5d99cf | 15247 | @item |
c7e83d54 | 15248 | @file{/usr/bin/.debug/ls.debug} |
5b5d99cf | 15249 | @item |
c7e83d54 | 15250 | @file{/usr/lib/debug/usr/bin/ls.debug}. |
5b5d99cf | 15251 | @end itemize |
5b5d99cf JB |
15252 | |
15253 | You can set the global debugging info directory's name, and view the | |
15254 | name @value{GDBN} is currently using. | |
15255 | ||
15256 | @table @code | |
15257 | ||
15258 | @kindex set debug-file-directory | |
24ddea62 JK |
15259 | @item set debug-file-directory @var{directories} |
15260 | Set the directories which @value{GDBN} searches for separate debugging | |
15261 | information files to @var{directory}. Multiple directory components can be set | |
15262 | concatenating them by a directory separator. | |
5b5d99cf JB |
15263 | |
15264 | @kindex show debug-file-directory | |
15265 | @item show debug-file-directory | |
24ddea62 | 15266 | Show the directories @value{GDBN} searches for separate debugging |
5b5d99cf JB |
15267 | information files. |
15268 | ||
15269 | @end table | |
15270 | ||
15271 | @cindex @code{.gnu_debuglink} sections | |
c7e83d54 | 15272 | @cindex debug link sections |
5b5d99cf JB |
15273 | A debug link is a special section of the executable file named |
15274 | @code{.gnu_debuglink}. The section must contain: | |
15275 | ||
15276 | @itemize | |
15277 | @item | |
15278 | A filename, with any leading directory components removed, followed by | |
15279 | a zero byte, | |
15280 | @item | |
15281 | zero to three bytes of padding, as needed to reach the next four-byte | |
15282 | boundary within the section, and | |
15283 | @item | |
15284 | a four-byte CRC checksum, stored in the same endianness used for the | |
15285 | executable file itself. The checksum is computed on the debugging | |
15286 | information file's full contents by the function given below, passing | |
15287 | zero as the @var{crc} argument. | |
15288 | @end itemize | |
15289 | ||
15290 | Any executable file format can carry a debug link, as long as it can | |
15291 | contain a section named @code{.gnu_debuglink} with the contents | |
15292 | described above. | |
15293 | ||
d3750b24 | 15294 | @cindex @code{.note.gnu.build-id} sections |
c7e83d54 | 15295 | @cindex build ID sections |
7e27a47a EZ |
15296 | The build ID is a special section in the executable file (and in other |
15297 | ELF binary files that @value{GDBN} may consider). This section is | |
15298 | often named @code{.note.gnu.build-id}, but that name is not mandatory. | |
15299 | It contains unique identification for the built files---the ID remains | |
15300 | the same across multiple builds of the same build tree. The default | |
15301 | algorithm SHA1 produces 160 bits (40 hexadecimal characters) of the | |
15302 | content for the build ID string. The same section with an identical | |
15303 | value is present in the original built binary with symbols, in its | |
15304 | stripped variant, and in the separate debugging information file. | |
d3750b24 | 15305 | |
5b5d99cf JB |
15306 | The debugging information file itself should be an ordinary |
15307 | executable, containing a full set of linker symbols, sections, and | |
15308 | debugging information. The sections of the debugging information file | |
c7e83d54 EZ |
15309 | should have the same names, addresses, and sizes as the original file, |
15310 | but they need not contain any data---much like a @code{.bss} section | |
5b5d99cf JB |
15311 | in an ordinary executable. |
15312 | ||
7e27a47a | 15313 | The @sc{gnu} binary utilities (Binutils) package includes the |
c7e83d54 EZ |
15314 | @samp{objcopy} utility that can produce |
15315 | the separated executable / debugging information file pairs using the | |
15316 | following commands: | |
15317 | ||
15318 | @smallexample | |
15319 | @kbd{objcopy --only-keep-debug foo foo.debug} | |
15320 | @kbd{strip -g foo} | |
c7e83d54 EZ |
15321 | @end smallexample |
15322 | ||
15323 | @noindent | |
15324 | These commands remove the debugging | |
83f83d7f JK |
15325 | information from the executable file @file{foo} and place it in the file |
15326 | @file{foo.debug}. You can use the first, second or both methods to link the | |
15327 | two files: | |
15328 | ||
15329 | @itemize @bullet | |
15330 | @item | |
15331 | The debug link method needs the following additional command to also leave | |
15332 | behind a debug link in @file{foo}: | |
15333 | ||
15334 | @smallexample | |
15335 | @kbd{objcopy --add-gnu-debuglink=foo.debug foo} | |
15336 | @end smallexample | |
15337 | ||
15338 | Ulrich Drepper's @file{elfutils} package, starting with version 0.53, contains | |
d3750b24 | 15339 | a version of the @code{strip} command such that the command @kbd{strip foo -f |
83f83d7f JK |
15340 | foo.debug} has the same functionality as the two @code{objcopy} commands and |
15341 | the @code{ln -s} command above, together. | |
15342 | ||
15343 | @item | |
15344 | Build ID gets embedded into the main executable using @code{ld --build-id} or | |
15345 | the @value{NGCC} counterpart @code{gcc -Wl,--build-id}. Build ID support plus | |
15346 | compatibility fixes for debug files separation are present in @sc{gnu} binary | |
7e27a47a | 15347 | utilities (Binutils) package since version 2.18. |
83f83d7f JK |
15348 | @end itemize |
15349 | ||
15350 | @noindent | |
d3750b24 | 15351 | |
99e008fe EZ |
15352 | @cindex CRC algorithm definition |
15353 | The CRC used in @code{.gnu_debuglink} is the CRC-32 defined in | |
15354 | IEEE 802.3 using the polynomial: | |
15355 | ||
15356 | @c TexInfo requires naked braces for multi-digit exponents for Tex | |
15357 | @c output, but this causes HTML output to barf. HTML has to be set using | |
15358 | @c raw commands. So we end up having to specify this equation in 2 | |
15359 | @c different ways! | |
15360 | @ifhtml | |
15361 | @display | |
15362 | @html | |
15363 | <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> | |
15364 | + <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 | |
15365 | @end html | |
15366 | @end display | |
15367 | @end ifhtml | |
15368 | @ifnothtml | |
15369 | @display | |
15370 | @math{x^{32} + x^{26} + x^{23} + x^{22} + x^{16} + x^{12} + x^{11}} | |
15371 | @math{+ x^{10} + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1} | |
15372 | @end display | |
15373 | @end ifnothtml | |
15374 | ||
15375 | The function is computed byte at a time, taking the least | |
15376 | significant bit of each byte first. The initial pattern | |
15377 | @code{0xffffffff} is used, to ensure leading zeros affect the CRC and | |
15378 | the final result is inverted to ensure trailing zeros also affect the | |
15379 | CRC. | |
15380 | ||
15381 | @emph{Note:} This is the same CRC polynomial as used in handling the | |
15382 | @dfn{Remote Serial Protocol} @code{qCRC} packet (@pxref{Remote Protocol, | |
15383 | , @value{GDBN} Remote Serial Protocol}). However in the | |
15384 | case of the Remote Serial Protocol, the CRC is computed @emph{most} | |
15385 | significant bit first, and the result is not inverted, so trailing | |
15386 | zeros have no effect on the CRC value. | |
15387 | ||
15388 | To complete the description, we show below the code of the function | |
15389 | which produces the CRC used in @code{.gnu_debuglink}. Inverting the | |
15390 | initially supplied @code{crc} argument means that an initial call to | |
15391 | this function passing in zero will start computing the CRC using | |
15392 | @code{0xffffffff}. | |
5b5d99cf | 15393 | |
4644b6e3 | 15394 | @kindex gnu_debuglink_crc32 |
5b5d99cf JB |
15395 | @smallexample |
15396 | unsigned long | |
15397 | gnu_debuglink_crc32 (unsigned long crc, | |
15398 | unsigned char *buf, size_t len) | |
15399 | @{ | |
15400 | static const unsigned long crc32_table[256] = | |
15401 | @{ | |
15402 | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, | |
15403 | 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, | |
15404 | 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, | |
15405 | 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, | |
15406 | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, | |
15407 | 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, | |
15408 | 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, | |
15409 | 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, | |
15410 | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, | |
15411 | 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, | |
15412 | 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, | |
15413 | 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, | |
15414 | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, | |
15415 | 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, | |
15416 | 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, | |
15417 | 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, | |
15418 | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, | |
15419 | 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, | |
15420 | 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, | |
15421 | 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, | |
15422 | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, | |
15423 | 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, | |
15424 | 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, | |
15425 | 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, | |
15426 | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, | |
15427 | 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, | |
15428 | 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, | |
15429 | 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, | |
15430 | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, | |
15431 | 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, | |
15432 | 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, | |
15433 | 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, | |
15434 | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, | |
15435 | 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, | |
15436 | 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, | |
15437 | 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, | |
15438 | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, | |
15439 | 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, | |
15440 | 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, | |
15441 | 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, | |
15442 | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, | |
15443 | 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, | |
15444 | 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, | |
15445 | 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, | |
15446 | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, | |
15447 | 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, | |
15448 | 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, | |
15449 | 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, | |
15450 | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, | |
15451 | 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, | |
15452 | 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, | |
15453 | 0x2d02ef8d | |
15454 | @}; | |
15455 | unsigned char *end; | |
15456 | ||
15457 | crc = ~crc & 0xffffffff; | |
15458 | for (end = buf + len; buf < end; ++buf) | |
15459 | crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); | |
e7a3abfc | 15460 | return ~crc & 0xffffffff; |
5b5d99cf JB |
15461 | @} |
15462 | @end smallexample | |
15463 | ||
c7e83d54 EZ |
15464 | @noindent |
15465 | This computation does not apply to the ``build ID'' method. | |
15466 | ||
5b5d99cf | 15467 | |
9291a0cd TT |
15468 | @node Index Files |
15469 | @section Index Files Speed Up @value{GDBN} | |
15470 | @cindex index files | |
15471 | @cindex @samp{.gdb_index} section | |
15472 | ||
15473 | When @value{GDBN} finds a symbol file, it scans the symbols in the | |
15474 | file in order to construct an internal symbol table. This lets most | |
15475 | @value{GDBN} operations work quickly---at the cost of a delay early | |
15476 | on. For large programs, this delay can be quite lengthy, so | |
15477 | @value{GDBN} provides a way to build an index, which speeds up | |
15478 | startup. | |
15479 | ||
15480 | The index is stored as a section in the symbol file. @value{GDBN} can | |
15481 | write the index to a file, then you can put it into the symbol file | |
15482 | using @command{objcopy}. | |
15483 | ||
15484 | To create an index file, use the @code{save gdb-index} command: | |
15485 | ||
15486 | @table @code | |
15487 | @item save gdb-index @var{directory} | |
15488 | @kindex save gdb-index | |
15489 | Create an index file for each symbol file currently known by | |
15490 | @value{GDBN}. Each file is named after its corresponding symbol file, | |
15491 | with @samp{.gdb-index} appended, and is written into the given | |
15492 | @var{directory}. | |
15493 | @end table | |
15494 | ||
15495 | Once you have created an index file you can merge it into your symbol | |
15496 | file, here named @file{symfile}, using @command{objcopy}: | |
15497 | ||
15498 | @smallexample | |
15499 | $ objcopy --add-section .gdb_index=symfile.gdb-index \ | |
15500 | --set-section-flags .gdb_index=readonly symfile symfile | |
15501 | @end smallexample | |
15502 | ||
15503 | There are currently some limitation on indices. They only work when | |
15504 | for DWARF debugging information, not stabs. And, they do not | |
15505 | currently work for programs using Ada. | |
15506 | ||
6d2ebf8b | 15507 | @node Symbol Errors |
79a6e687 | 15508 | @section Errors Reading Symbol Files |
c906108c SS |
15509 | |
15510 | While reading a symbol file, @value{GDBN} occasionally encounters problems, | |
15511 | such as symbol types it does not recognize, or known bugs in compiler | |
15512 | output. By default, @value{GDBN} does not notify you of such problems, since | |
15513 | they are relatively common and primarily of interest to people | |
15514 | debugging compilers. If you are interested in seeing information | |
15515 | about ill-constructed symbol tables, you can either ask @value{GDBN} to print | |
15516 | only one message about each such type of problem, no matter how many | |
15517 | times the problem occurs; or you can ask @value{GDBN} to print more messages, | |
15518 | to see how many times the problems occur, with the @code{set | |
79a6e687 BW |
15519 | complaints} command (@pxref{Messages/Warnings, ,Optional Warnings and |
15520 | Messages}). | |
c906108c SS |
15521 | |
15522 | The messages currently printed, and their meanings, include: | |
15523 | ||
15524 | @table @code | |
15525 | @item inner block not inside outer block in @var{symbol} | |
15526 | ||
15527 | The symbol information shows where symbol scopes begin and end | |
15528 | (such as at the start of a function or a block of statements). This | |
15529 | error indicates that an inner scope block is not fully contained | |
15530 | in its outer scope blocks. | |
15531 | ||
15532 | @value{GDBN} circumvents the problem by treating the inner block as if it had | |
15533 | the same scope as the outer block. In the error message, @var{symbol} | |
15534 | may be shown as ``@code{(don't know)}'' if the outer block is not a | |
15535 | function. | |
15536 | ||
15537 | @item block at @var{address} out of order | |
15538 | ||
15539 | The symbol information for symbol scope blocks should occur in | |
15540 | order of increasing addresses. This error indicates that it does not | |
15541 | do so. | |
15542 | ||
15543 | @value{GDBN} does not circumvent this problem, and has trouble | |
15544 | locating symbols in the source file whose symbols it is reading. (You | |
15545 | can often determine what source file is affected by specifying | |
79a6e687 BW |
15546 | @code{set verbose on}. @xref{Messages/Warnings, ,Optional Warnings and |
15547 | Messages}.) | |
c906108c SS |
15548 | |
15549 | @item bad block start address patched | |
15550 | ||
15551 | The symbol information for a symbol scope block has a start address | |
15552 | smaller than the address of the preceding source line. This is known | |
15553 | to occur in the SunOS 4.1.1 (and earlier) C compiler. | |
15554 | ||
15555 | @value{GDBN} circumvents the problem by treating the symbol scope block as | |
15556 | starting on the previous source line. | |
15557 | ||
15558 | @item bad string table offset in symbol @var{n} | |
15559 | ||
15560 | @cindex foo | |
15561 | Symbol number @var{n} contains a pointer into the string table which is | |
15562 | larger than the size of the string table. | |
15563 | ||
15564 | @value{GDBN} circumvents the problem by considering the symbol to have the | |
15565 | name @code{foo}, which may cause other problems if many symbols end up | |
15566 | with this name. | |
15567 | ||
15568 | @item unknown symbol type @code{0x@var{nn}} | |
15569 | ||
7a292a7a SS |
15570 | The symbol information contains new data types that @value{GDBN} does |
15571 | not yet know how to read. @code{0x@var{nn}} is the symbol type of the | |
d4f3574e | 15572 | uncomprehended information, in hexadecimal. |
c906108c | 15573 | |
7a292a7a SS |
15574 | @value{GDBN} circumvents the error by ignoring this symbol information. |
15575 | This usually allows you to debug your program, though certain symbols | |
c906108c | 15576 | are not accessible. If you encounter such a problem and feel like |
7a292a7a SS |
15577 | debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint |
15578 | on @code{complain}, then go up to the function @code{read_dbx_symtab} | |
15579 | and examine @code{*bufp} to see the symbol. | |
c906108c SS |
15580 | |
15581 | @item stub type has NULL name | |
c906108c | 15582 | |
7a292a7a | 15583 | @value{GDBN} could not find the full definition for a struct or class. |
c906108c | 15584 | |
7a292a7a | 15585 | @item const/volatile indicator missing (ok if using g++ v1.x), got@dots{} |
b37052ae | 15586 | The symbol information for a C@t{++} member function is missing some |
7a292a7a SS |
15587 | information that recent versions of the compiler should have output for |
15588 | it. | |
c906108c SS |
15589 | |
15590 | @item info mismatch between compiler and debugger | |
15591 | ||
15592 | @value{GDBN} could not parse a type specification output by the compiler. | |
7a292a7a | 15593 | |
c906108c SS |
15594 | @end table |
15595 | ||
b14b1491 TT |
15596 | @node Data Files |
15597 | @section GDB Data Files | |
15598 | ||
15599 | @cindex prefix for data files | |
15600 | @value{GDBN} will sometimes read an auxiliary data file. These files | |
15601 | are kept in a directory known as the @dfn{data directory}. | |
15602 | ||
15603 | You can set the data directory's name, and view the name @value{GDBN} | |
15604 | is currently using. | |
15605 | ||
15606 | @table @code | |
15607 | @kindex set data-directory | |
15608 | @item set data-directory @var{directory} | |
15609 | Set the directory which @value{GDBN} searches for auxiliary data files | |
15610 | to @var{directory}. | |
15611 | ||
15612 | @kindex show data-directory | |
15613 | @item show data-directory | |
15614 | Show the directory @value{GDBN} searches for auxiliary data files. | |
15615 | @end table | |
15616 | ||
15617 | @cindex default data directory | |
15618 | @cindex @samp{--with-gdb-datadir} | |
15619 | You can set the default data directory by using the configure-time | |
15620 | @samp{--with-gdb-datadir} option. If the data directory is inside | |
15621 | @value{GDBN}'s configured binary prefix (set with @samp{--prefix} or | |
15622 | @samp{--exec-prefix}), then the default data directory will be updated | |
15623 | automatically if the installed @value{GDBN} is moved to a new | |
15624 | location. | |
15625 | ||
aae1c79a DE |
15626 | The data directory may also be specified with the |
15627 | @code{--data-directory} command line option. | |
15628 | @xref{Mode Options}. | |
15629 | ||
6d2ebf8b | 15630 | @node Targets |
c906108c | 15631 | @chapter Specifying a Debugging Target |
7a292a7a | 15632 | |
c906108c | 15633 | @cindex debugging target |
c906108c | 15634 | A @dfn{target} is the execution environment occupied by your program. |
53a5351d JM |
15635 | |
15636 | Often, @value{GDBN} runs in the same host environment as your program; | |
15637 | in that case, the debugging target is specified as a side effect when | |
15638 | you use the @code{file} or @code{core} commands. When you need more | |
c906108c SS |
15639 | flexibility---for example, running @value{GDBN} on a physically separate |
15640 | host, or controlling a standalone system over a serial port or a | |
53a5351d JM |
15641 | realtime system over a TCP/IP connection---you can use the @code{target} |
15642 | command to specify one of the target types configured for @value{GDBN} | |
79a6e687 | 15643 | (@pxref{Target Commands, ,Commands for Managing Targets}). |
c906108c | 15644 | |
a8f24a35 EZ |
15645 | @cindex target architecture |
15646 | It is possible to build @value{GDBN} for several different @dfn{target | |
15647 | architectures}. When @value{GDBN} is built like that, you can choose | |
15648 | one of the available architectures with the @kbd{set architecture} | |
15649 | command. | |
15650 | ||
15651 | @table @code | |
15652 | @kindex set architecture | |
15653 | @kindex show architecture | |
15654 | @item set architecture @var{arch} | |
15655 | This command sets the current target architecture to @var{arch}. The | |
15656 | value of @var{arch} can be @code{"auto"}, in addition to one of the | |
15657 | supported architectures. | |
15658 | ||
15659 | @item show architecture | |
15660 | Show the current target architecture. | |
9c16f35a EZ |
15661 | |
15662 | @item set processor | |
15663 | @itemx processor | |
15664 | @kindex set processor | |
15665 | @kindex show processor | |
15666 | These are alias commands for, respectively, @code{set architecture} | |
15667 | and @code{show architecture}. | |
a8f24a35 EZ |
15668 | @end table |
15669 | ||
c906108c SS |
15670 | @menu |
15671 | * Active Targets:: Active targets | |
15672 | * Target Commands:: Commands for managing targets | |
c906108c | 15673 | * Byte Order:: Choosing target byte order |
c906108c SS |
15674 | @end menu |
15675 | ||
6d2ebf8b | 15676 | @node Active Targets |
79a6e687 | 15677 | @section Active Targets |
7a292a7a | 15678 | |
c906108c SS |
15679 | @cindex stacking targets |
15680 | @cindex active targets | |
15681 | @cindex multiple targets | |
15682 | ||
8ea5bce5 | 15683 | There are multiple classes of targets such as: processes, executable files or |
c0edd9ed JK |
15684 | recording sessions. Core files belong to the process class, making core file |
15685 | and process mutually exclusive. Otherwise, @value{GDBN} can work concurrently | |
15686 | on multiple active targets, one in each class. This allows you to (for | |
15687 | example) start a process and inspect its activity, while still having access to | |
15688 | the executable file after the process finishes. Or if you start process | |
15689 | recording (@pxref{Reverse Execution}) and @code{reverse-step} there, you are | |
15690 | presented a virtual layer of the recording target, while the process target | |
15691 | remains stopped at the chronologically last point of the process execution. | |
15692 | ||
15693 | Use the @code{core-file} and @code{exec-file} commands to select a new core | |
15694 | file or executable target (@pxref{Files, ,Commands to Specify Files}). To | |
15695 | specify as a target a process that is already running, use the @code{attach} | |
15696 | command (@pxref{Attach, ,Debugging an Already-running Process}). | |
c906108c | 15697 | |
6d2ebf8b | 15698 | @node Target Commands |
79a6e687 | 15699 | @section Commands for Managing Targets |
c906108c SS |
15700 | |
15701 | @table @code | |
15702 | @item target @var{type} @var{parameters} | |
7a292a7a SS |
15703 | Connects the @value{GDBN} host environment to a target machine or |
15704 | process. A target is typically a protocol for talking to debugging | |
15705 | facilities. You use the argument @var{type} to specify the type or | |
15706 | protocol of the target machine. | |
c906108c SS |
15707 | |
15708 | Further @var{parameters} are interpreted by the target protocol, but | |
15709 | typically include things like device names or host names to connect | |
15710 | with, process numbers, and baud rates. | |
c906108c SS |
15711 | |
15712 | The @code{target} command does not repeat if you press @key{RET} again | |
15713 | after executing the command. | |
15714 | ||
15715 | @kindex help target | |
15716 | @item help target | |
15717 | Displays the names of all targets available. To display targets | |
15718 | currently selected, use either @code{info target} or @code{info files} | |
79a6e687 | 15719 | (@pxref{Files, ,Commands to Specify Files}). |
c906108c SS |
15720 | |
15721 | @item help target @var{name} | |
15722 | Describe a particular target, including any parameters necessary to | |
15723 | select it. | |
15724 | ||
15725 | @kindex set gnutarget | |
15726 | @item set gnutarget @var{args} | |
5d161b24 | 15727 | @value{GDBN} uses its own library BFD to read your files. @value{GDBN} |
c906108c | 15728 | knows whether it is reading an @dfn{executable}, |
5d161b24 DB |
15729 | a @dfn{core}, or a @dfn{.o} file; however, you can specify the file format |
15730 | with the @code{set gnutarget} command. Unlike most @code{target} commands, | |
c906108c SS |
15731 | with @code{gnutarget} the @code{target} refers to a program, not a machine. |
15732 | ||
d4f3574e | 15733 | @quotation |
c906108c SS |
15734 | @emph{Warning:} To specify a file format with @code{set gnutarget}, |
15735 | you must know the actual BFD name. | |
d4f3574e | 15736 | @end quotation |
c906108c | 15737 | |
d4f3574e | 15738 | @noindent |
79a6e687 | 15739 | @xref{Files, , Commands to Specify Files}. |
c906108c | 15740 | |
5d161b24 | 15741 | @kindex show gnutarget |
c906108c SS |
15742 | @item show gnutarget |
15743 | Use the @code{show gnutarget} command to display what file format | |
15744 | @code{gnutarget} is set to read. If you have not set @code{gnutarget}, | |
15745 | @value{GDBN} will determine the file format for each file automatically, | |
15746 | and @code{show gnutarget} displays @samp{The current BDF target is "auto"}. | |
15747 | @end table | |
15748 | ||
4644b6e3 | 15749 | @cindex common targets |
c906108c SS |
15750 | Here are some common targets (available, or not, depending on the GDB |
15751 | configuration): | |
c906108c SS |
15752 | |
15753 | @table @code | |
4644b6e3 | 15754 | @kindex target |
c906108c | 15755 | @item target exec @var{program} |
4644b6e3 | 15756 | @cindex executable file target |
c906108c SS |
15757 | An executable file. @samp{target exec @var{program}} is the same as |
15758 | @samp{exec-file @var{program}}. | |
15759 | ||
c906108c | 15760 | @item target core @var{filename} |
4644b6e3 | 15761 | @cindex core dump file target |
c906108c SS |
15762 | A core dump file. @samp{target core @var{filename}} is the same as |
15763 | @samp{core-file @var{filename}}. | |
c906108c | 15764 | |
1a10341b | 15765 | @item target remote @var{medium} |
4644b6e3 | 15766 | @cindex remote target |
1a10341b JB |
15767 | A remote system connected to @value{GDBN} via a serial line or network |
15768 | connection. This command tells @value{GDBN} to use its own remote | |
15769 | protocol over @var{medium} for debugging. @xref{Remote Debugging}. | |
15770 | ||
15771 | For example, if you have a board connected to @file{/dev/ttya} on the | |
15772 | machine running @value{GDBN}, you could say: | |
15773 | ||
15774 | @smallexample | |
15775 | target remote /dev/ttya | |
15776 | @end smallexample | |
15777 | ||
15778 | @code{target remote} supports the @code{load} command. This is only | |
15779 | useful if you have some other way of getting the stub to the target | |
15780 | system, and you can put it somewhere in memory where it won't get | |
15781 | clobbered by the download. | |
c906108c | 15782 | |
ee8e71d4 | 15783 | @item target sim @r{[}@var{simargs}@r{]} @dots{} |
4644b6e3 | 15784 | @cindex built-in simulator target |
2df3850c | 15785 | Builtin CPU simulator. @value{GDBN} includes simulators for most architectures. |
104c1213 | 15786 | In general, |
474c8240 | 15787 | @smallexample |
104c1213 JM |
15788 | target sim |
15789 | load | |
15790 | run | |
474c8240 | 15791 | @end smallexample |
d4f3574e | 15792 | @noindent |
104c1213 | 15793 | works; however, you cannot assume that a specific memory map, device |
d4f3574e | 15794 | drivers, or even basic I/O is available, although some simulators do |
104c1213 JM |
15795 | provide these. For info about any processor-specific simulator details, |
15796 | see the appropriate section in @ref{Embedded Processors, ,Embedded | |
15797 | Processors}. | |
15798 | ||
c906108c SS |
15799 | @end table |
15800 | ||
104c1213 | 15801 | Some configurations may include these targets as well: |
c906108c SS |
15802 | |
15803 | @table @code | |
15804 | ||
c906108c | 15805 | @item target nrom @var{dev} |
4644b6e3 | 15806 | @cindex NetROM ROM emulator target |
c906108c SS |
15807 | NetROM ROM emulator. This target only supports downloading. |
15808 | ||
c906108c SS |
15809 | @end table |
15810 | ||
5d161b24 | 15811 | Different targets are available on different configurations of @value{GDBN}; |
c906108c | 15812 | your configuration may have more or fewer targets. |
c906108c | 15813 | |
721c2651 EZ |
15814 | Many remote targets require you to download the executable's code once |
15815 | you've successfully established a connection. You may wish to control | |
3d00d119 DJ |
15816 | various aspects of this process. |
15817 | ||
15818 | @table @code | |
721c2651 EZ |
15819 | |
15820 | @item set hash | |
15821 | @kindex set hash@r{, for remote monitors} | |
15822 | @cindex hash mark while downloading | |
15823 | This command controls whether a hash mark @samp{#} is displayed while | |
15824 | downloading a file to the remote monitor. If on, a hash mark is | |
15825 | displayed after each S-record is successfully downloaded to the | |
15826 | monitor. | |
15827 | ||
15828 | @item show hash | |
15829 | @kindex show hash@r{, for remote monitors} | |
15830 | Show the current status of displaying the hash mark. | |
15831 | ||
15832 | @item set debug monitor | |
15833 | @kindex set debug monitor | |
15834 | @cindex display remote monitor communications | |
15835 | Enable or disable display of communications messages between | |
15836 | @value{GDBN} and the remote monitor. | |
15837 | ||
15838 | @item show debug monitor | |
15839 | @kindex show debug monitor | |
15840 | Show the current status of displaying communications between | |
15841 | @value{GDBN} and the remote monitor. | |
a8f24a35 | 15842 | @end table |
c906108c SS |
15843 | |
15844 | @table @code | |
15845 | ||
15846 | @kindex load @var{filename} | |
15847 | @item load @var{filename} | |
8edfe269 | 15848 | @anchor{load} |
c906108c SS |
15849 | Depending on what remote debugging facilities are configured into |
15850 | @value{GDBN}, the @code{load} command may be available. Where it exists, it | |
15851 | is meant to make @var{filename} (an executable) available for debugging | |
15852 | on the remote system---by downloading, or dynamic linking, for example. | |
15853 | @code{load} also records the @var{filename} symbol table in @value{GDBN}, like | |
15854 | the @code{add-symbol-file} command. | |
15855 | ||
15856 | If your @value{GDBN} does not have a @code{load} command, attempting to | |
15857 | execute it gets the error message ``@code{You can't do that when your | |
15858 | target is @dots{}}'' | |
c906108c SS |
15859 | |
15860 | The file is loaded at whatever address is specified in the executable. | |
15861 | For some object file formats, you can specify the load address when you | |
15862 | link the program; for other formats, like a.out, the object file format | |
15863 | specifies a fixed address. | |
15864 | @c FIXME! This would be a good place for an xref to the GNU linker doc. | |
15865 | ||
68437a39 DJ |
15866 | Depending on the remote side capabilities, @value{GDBN} may be able to |
15867 | load programs into flash memory. | |
15868 | ||
c906108c SS |
15869 | @code{load} does not repeat if you press @key{RET} again after using it. |
15870 | @end table | |
15871 | ||
6d2ebf8b | 15872 | @node Byte Order |
79a6e687 | 15873 | @section Choosing Target Byte Order |
7a292a7a | 15874 | |
c906108c SS |
15875 | @cindex choosing target byte order |
15876 | @cindex target byte order | |
c906108c | 15877 | |
172c2a43 | 15878 | Some types of processors, such as the MIPS, PowerPC, and Renesas SH, |
c906108c SS |
15879 | offer the ability to run either big-endian or little-endian byte |
15880 | orders. Usually the executable or symbol will include a bit to | |
15881 | designate the endian-ness, and you will not need to worry about | |
15882 | which to use. However, you may still find it useful to adjust | |
d4f3574e | 15883 | @value{GDBN}'s idea of processor endian-ness manually. |
c906108c SS |
15884 | |
15885 | @table @code | |
4644b6e3 | 15886 | @kindex set endian |
c906108c SS |
15887 | @item set endian big |
15888 | Instruct @value{GDBN} to assume the target is big-endian. | |
15889 | ||
c906108c SS |
15890 | @item set endian little |
15891 | Instruct @value{GDBN} to assume the target is little-endian. | |
15892 | ||
c906108c SS |
15893 | @item set endian auto |
15894 | Instruct @value{GDBN} to use the byte order associated with the | |
15895 | executable. | |
15896 | ||
15897 | @item show endian | |
15898 | Display @value{GDBN}'s current idea of the target byte order. | |
15899 | ||
15900 | @end table | |
15901 | ||
15902 | Note that these commands merely adjust interpretation of symbolic | |
15903 | data on the host, and that they have absolutely no effect on the | |
15904 | target system. | |
15905 | ||
ea35711c DJ |
15906 | |
15907 | @node Remote Debugging | |
15908 | @chapter Debugging Remote Programs | |
c906108c SS |
15909 | @cindex remote debugging |
15910 | ||
15911 | If you are trying to debug a program running on a machine that cannot run | |
5d161b24 DB |
15912 | @value{GDBN} in the usual way, it is often useful to use remote debugging. |
15913 | For example, you might use remote debugging on an operating system kernel, | |
c906108c SS |
15914 | or on a small system which does not have a general purpose operating system |
15915 | powerful enough to run a full-featured debugger. | |
15916 | ||
15917 | Some configurations of @value{GDBN} have special serial or TCP/IP interfaces | |
15918 | to make this work with particular debugging targets. In addition, | |
5d161b24 | 15919 | @value{GDBN} comes with a generic serial protocol (specific to @value{GDBN}, |
c906108c SS |
15920 | but not specific to any particular target system) which you can use if you |
15921 | write the remote stubs---the code that runs on the remote system to | |
15922 | communicate with @value{GDBN}. | |
15923 | ||
15924 | Other remote targets may be available in your | |
15925 | configuration of @value{GDBN}; use @code{help target} to list them. | |
c906108c | 15926 | |
6b2f586d | 15927 | @menu |
07f31aa6 | 15928 | * Connecting:: Connecting to a remote target |
a6b151f1 | 15929 | * File Transfer:: Sending files to a remote system |
6b2f586d | 15930 | * Server:: Using the gdbserver program |
79a6e687 BW |
15931 | * Remote Configuration:: Remote configuration |
15932 | * Remote Stub:: Implementing a remote stub | |
6b2f586d AC |
15933 | @end menu |
15934 | ||
07f31aa6 | 15935 | @node Connecting |
79a6e687 | 15936 | @section Connecting to a Remote Target |
07f31aa6 DJ |
15937 | |
15938 | On the @value{GDBN} host machine, you will need an unstripped copy of | |
d3e8051b | 15939 | your program, since @value{GDBN} needs symbol and debugging information. |
07f31aa6 DJ |
15940 | Start up @value{GDBN} as usual, using the name of the local copy of your |
15941 | program as the first argument. | |
15942 | ||
86941c27 JB |
15943 | @cindex @code{target remote} |
15944 | @value{GDBN} can communicate with the target over a serial line, or | |
15945 | over an @acronym{IP} network using @acronym{TCP} or @acronym{UDP}. In | |
15946 | each case, @value{GDBN} uses the same protocol for debugging your | |
15947 | program; only the medium carrying the debugging packets varies. The | |
15948 | @code{target remote} command establishes a connection to the target. | |
15949 | Its arguments indicate which medium to use: | |
15950 | ||
15951 | @table @code | |
15952 | ||
15953 | @item target remote @var{serial-device} | |
07f31aa6 | 15954 | @cindex serial line, @code{target remote} |
86941c27 JB |
15955 | Use @var{serial-device} to communicate with the target. For example, |
15956 | to use a serial line connected to the device named @file{/dev/ttyb}: | |
15957 | ||
15958 | @smallexample | |
15959 | target remote /dev/ttyb | |
15960 | @end smallexample | |
15961 | ||
07f31aa6 DJ |
15962 | If you're using a serial line, you may want to give @value{GDBN} the |
15963 | @w{@samp{--baud}} option, or use the @code{set remotebaud} command | |
79a6e687 | 15964 | (@pxref{Remote Configuration, set remotebaud}) before the |
9c16f35a | 15965 | @code{target} command. |
07f31aa6 | 15966 | |
86941c27 JB |
15967 | @item target remote @code{@var{host}:@var{port}} |
15968 | @itemx target remote @code{tcp:@var{host}:@var{port}} | |
15969 | @cindex @acronym{TCP} port, @code{target remote} | |
15970 | Debug using a @acronym{TCP} connection to @var{port} on @var{host}. | |
15971 | The @var{host} may be either a host name or a numeric @acronym{IP} | |
15972 | address; @var{port} must be a decimal number. The @var{host} could be | |
15973 | the target machine itself, if it is directly connected to the net, or | |
15974 | it might be a terminal server which in turn has a serial line to the | |
15975 | target. | |
07f31aa6 | 15976 | |
86941c27 JB |
15977 | For example, to connect to port 2828 on a terminal server named |
15978 | @code{manyfarms}: | |
07f31aa6 DJ |
15979 | |
15980 | @smallexample | |
15981 | target remote manyfarms:2828 | |
15982 | @end smallexample | |
15983 | ||
86941c27 JB |
15984 | If your remote target is actually running on the same machine as your |
15985 | debugger session (e.g.@: a simulator for your target running on the | |
15986 | same host), you can omit the hostname. For example, to connect to | |
15987 | port 1234 on your local machine: | |
07f31aa6 DJ |
15988 | |
15989 | @smallexample | |
15990 | target remote :1234 | |
15991 | @end smallexample | |
15992 | @noindent | |
15993 | ||
15994 | Note that the colon is still required here. | |
15995 | ||
86941c27 JB |
15996 | @item target remote @code{udp:@var{host}:@var{port}} |
15997 | @cindex @acronym{UDP} port, @code{target remote} | |
15998 | Debug using @acronym{UDP} packets to @var{port} on @var{host}. For example, to | |
15999 | connect to @acronym{UDP} port 2828 on a terminal server named @code{manyfarms}: | |
07f31aa6 DJ |
16000 | |
16001 | @smallexample | |
16002 | target remote udp:manyfarms:2828 | |
16003 | @end smallexample | |
16004 | ||
86941c27 JB |
16005 | When using a @acronym{UDP} connection for remote debugging, you should |
16006 | keep in mind that the `U' stands for ``Unreliable''. @acronym{UDP} | |
16007 | can silently drop packets on busy or unreliable networks, which will | |
16008 | cause havoc with your debugging session. | |
16009 | ||
66b8c7f6 JB |
16010 | @item target remote | @var{command} |
16011 | @cindex pipe, @code{target remote} to | |
16012 | Run @var{command} in the background and communicate with it using a | |
16013 | pipe. The @var{command} is a shell command, to be parsed and expanded | |
16014 | by the system's command shell, @code{/bin/sh}; it should expect remote | |
16015 | protocol packets on its standard input, and send replies on its | |
16016 | standard output. You could use this to run a stand-alone simulator | |
16017 | that speaks the remote debugging protocol, to make net connections | |
16018 | using programs like @code{ssh}, or for other similar tricks. | |
16019 | ||
16020 | If @var{command} closes its standard output (perhaps by exiting), | |
16021 | @value{GDBN} will try to send it a @code{SIGTERM} signal. (If the | |
16022 | program has already exited, this will have no effect.) | |
16023 | ||
86941c27 | 16024 | @end table |
07f31aa6 | 16025 | |
86941c27 | 16026 | Once the connection has been established, you can use all the usual |
8edfe269 DJ |
16027 | commands to examine and change data. The remote program is already |
16028 | running; you can use @kbd{step} and @kbd{continue}, and you do not | |
16029 | need to use @kbd{run}. | |
07f31aa6 DJ |
16030 | |
16031 | @cindex interrupting remote programs | |
16032 | @cindex remote programs, interrupting | |
16033 | Whenever @value{GDBN} is waiting for the remote program, if you type the | |
c8aa23ab | 16034 | interrupt character (often @kbd{Ctrl-c}), @value{GDBN} attempts to stop the |
07f31aa6 DJ |
16035 | program. This may or may not succeed, depending in part on the hardware |
16036 | and the serial drivers the remote system uses. If you type the | |
16037 | interrupt character once again, @value{GDBN} displays this prompt: | |
16038 | ||
16039 | @smallexample | |
16040 | Interrupted while waiting for the program. | |
16041 | Give up (and stop debugging it)? (y or n) | |
16042 | @end smallexample | |
16043 | ||
16044 | If you type @kbd{y}, @value{GDBN} abandons the remote debugging session. | |
16045 | (If you decide you want to try again later, you can use @samp{target | |
16046 | remote} again to connect once more.) If you type @kbd{n}, @value{GDBN} | |
16047 | goes back to waiting. | |
16048 | ||
16049 | @table @code | |
16050 | @kindex detach (remote) | |
16051 | @item detach | |
16052 | When you have finished debugging the remote program, you can use the | |
16053 | @code{detach} command to release it from @value{GDBN} control. | |
16054 | Detaching from the target normally resumes its execution, but the results | |
16055 | will depend on your particular remote stub. After the @code{detach} | |
16056 | command, @value{GDBN} is free to connect to another target. | |
16057 | ||
16058 | @kindex disconnect | |
16059 | @item disconnect | |
16060 | The @code{disconnect} command behaves like @code{detach}, except that | |
16061 | the target is generally not resumed. It will wait for @value{GDBN} | |
16062 | (this instance or another one) to connect and continue debugging. After | |
16063 | the @code{disconnect} command, @value{GDBN} is again free to connect to | |
16064 | another target. | |
09d4efe1 EZ |
16065 | |
16066 | @cindex send command to remote monitor | |
fad38dfa EZ |
16067 | @cindex extend @value{GDBN} for remote targets |
16068 | @cindex add new commands for external monitor | |
09d4efe1 EZ |
16069 | @kindex monitor |
16070 | @item monitor @var{cmd} | |
fad38dfa EZ |
16071 | This command allows you to send arbitrary commands directly to the |
16072 | remote monitor. Since @value{GDBN} doesn't care about the commands it | |
16073 | sends like this, this command is the way to extend @value{GDBN}---you | |
16074 | can add new commands that only the external monitor will understand | |
16075 | and implement. | |
07f31aa6 DJ |
16076 | @end table |
16077 | ||
a6b151f1 DJ |
16078 | @node File Transfer |
16079 | @section Sending files to a remote system | |
16080 | @cindex remote target, file transfer | |
16081 | @cindex file transfer | |
16082 | @cindex sending files to remote systems | |
16083 | ||
16084 | Some remote targets offer the ability to transfer files over the same | |
16085 | connection used to communicate with @value{GDBN}. This is convenient | |
16086 | for targets accessible through other means, e.g.@: @sc{gnu}/Linux systems | |
16087 | running @code{gdbserver} over a network interface. For other targets, | |
16088 | e.g.@: embedded devices with only a single serial port, this may be | |
16089 | the only way to upload or download files. | |
16090 | ||
16091 | Not all remote targets support these commands. | |
16092 | ||
16093 | @table @code | |
16094 | @kindex remote put | |
16095 | @item remote put @var{hostfile} @var{targetfile} | |
16096 | Copy file @var{hostfile} from the host system (the machine running | |
16097 | @value{GDBN}) to @var{targetfile} on the target system. | |
16098 | ||
16099 | @kindex remote get | |
16100 | @item remote get @var{targetfile} @var{hostfile} | |
16101 | Copy file @var{targetfile} from the target system to @var{hostfile} | |
16102 | on the host system. | |
16103 | ||
16104 | @kindex remote delete | |
16105 | @item remote delete @var{targetfile} | |
16106 | Delete @var{targetfile} from the target system. | |
16107 | ||
16108 | @end table | |
16109 | ||
6f05cf9f | 16110 | @node Server |
79a6e687 | 16111 | @section Using the @code{gdbserver} Program |
6f05cf9f AC |
16112 | |
16113 | @kindex gdbserver | |
16114 | @cindex remote connection without stubs | |
16115 | @code{gdbserver} is a control program for Unix-like systems, which | |
16116 | allows you to connect your program with a remote @value{GDBN} via | |
16117 | @code{target remote}---but without linking in the usual debugging stub. | |
16118 | ||
16119 | @code{gdbserver} is not a complete replacement for the debugging stubs, | |
16120 | because it requires essentially the same operating-system facilities | |
16121 | that @value{GDBN} itself does. In fact, a system that can run | |
16122 | @code{gdbserver} to connect to a remote @value{GDBN} could also run | |
16123 | @value{GDBN} locally! @code{gdbserver} is sometimes useful nevertheless, | |
16124 | because it is a much smaller program than @value{GDBN} itself. It is | |
16125 | also easier to port than all of @value{GDBN}, so you may be able to get | |
16126 | started more quickly on a new system by using @code{gdbserver}. | |
16127 | Finally, if you develop code for real-time systems, you may find that | |
16128 | the tradeoffs involved in real-time operation make it more convenient to | |
16129 | do as much development work as possible on another system, for example | |
16130 | by cross-compiling. You can use @code{gdbserver} to make a similar | |
16131 | choice for debugging. | |
16132 | ||
16133 | @value{GDBN} and @code{gdbserver} communicate via either a serial line | |
16134 | or a TCP connection, using the standard @value{GDBN} remote serial | |
16135 | protocol. | |
16136 | ||
2d717e4f DJ |
16137 | @quotation |
16138 | @emph{Warning:} @code{gdbserver} does not have any built-in security. | |
16139 | Do not run @code{gdbserver} connected to any public network; a | |
16140 | @value{GDBN} connection to @code{gdbserver} provides access to the | |
16141 | target system with the same privileges as the user running | |
16142 | @code{gdbserver}. | |
16143 | @end quotation | |
16144 | ||
16145 | @subsection Running @code{gdbserver} | |
16146 | @cindex arguments, to @code{gdbserver} | |
16147 | ||
16148 | Run @code{gdbserver} on the target system. You need a copy of the | |
16149 | program you want to debug, including any libraries it requires. | |
6f05cf9f AC |
16150 | @code{gdbserver} does not need your program's symbol table, so you can |
16151 | strip the program if necessary to save space. @value{GDBN} on the host | |
16152 | system does all the symbol handling. | |
16153 | ||
16154 | To use the server, you must tell it how to communicate with @value{GDBN}; | |
56460a61 | 16155 | the name of your program; and the arguments for your program. The usual |
6f05cf9f AC |
16156 | syntax is: |
16157 | ||
16158 | @smallexample | |
16159 | target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ] | |
16160 | @end smallexample | |
16161 | ||
16162 | @var{comm} is either a device name (to use a serial line) or a TCP | |
16163 | hostname and portnumber. For example, to debug Emacs with the argument | |
16164 | @samp{foo.txt} and communicate with @value{GDBN} over the serial port | |
16165 | @file{/dev/com1}: | |
16166 | ||
16167 | @smallexample | |
16168 | target> gdbserver /dev/com1 emacs foo.txt | |
16169 | @end smallexample | |
16170 | ||
16171 | @code{gdbserver} waits passively for the host @value{GDBN} to communicate | |
16172 | with it. | |
16173 | ||
16174 | To use a TCP connection instead of a serial line: | |
16175 | ||
16176 | @smallexample | |
16177 | target> gdbserver host:2345 emacs foo.txt | |
16178 | @end smallexample | |
16179 | ||
16180 | The only difference from the previous example is the first argument, | |
16181 | specifying that you are communicating with the host @value{GDBN} via | |
16182 | TCP. The @samp{host:2345} argument means that @code{gdbserver} is to | |
16183 | expect a TCP connection from machine @samp{host} to local TCP port 2345. | |
16184 | (Currently, the @samp{host} part is ignored.) You can choose any number | |
16185 | you want for the port number as long as it does not conflict with any | |
16186 | TCP ports already in use on the target system (for example, @code{23} is | |
16187 | reserved for @code{telnet}).@footnote{If you choose a port number that | |
16188 | conflicts with another service, @code{gdbserver} prints an error message | |
16189 | and exits.} You must use the same port number with the host @value{GDBN} | |
16190 | @code{target remote} command. | |
16191 | ||
2d717e4f DJ |
16192 | @subsubsection Attaching to a Running Program |
16193 | ||
56460a61 DJ |
16194 | On some targets, @code{gdbserver} can also attach to running programs. |
16195 | This is accomplished via the @code{--attach} argument. The syntax is: | |
16196 | ||
16197 | @smallexample | |
2d717e4f | 16198 | target> gdbserver --attach @var{comm} @var{pid} |
56460a61 DJ |
16199 | @end smallexample |
16200 | ||
16201 | @var{pid} is the process ID of a currently running process. It isn't necessary | |
16202 | to point @code{gdbserver} at a binary for the running process. | |
16203 | ||
b1fe9455 DJ |
16204 | @pindex pidof |
16205 | @cindex attach to a program by name | |
16206 | You can debug processes by name instead of process ID if your target has the | |
16207 | @code{pidof} utility: | |
16208 | ||
16209 | @smallexample | |
2d717e4f | 16210 | target> gdbserver --attach @var{comm} `pidof @var{program}` |
b1fe9455 DJ |
16211 | @end smallexample |
16212 | ||
f822c95b | 16213 | In case more than one copy of @var{program} is running, or @var{program} |
b1fe9455 DJ |
16214 | has multiple threads, most versions of @code{pidof} support the |
16215 | @code{-s} option to only return the first process ID. | |
16216 | ||
2d717e4f DJ |
16217 | @subsubsection Multi-Process Mode for @code{gdbserver} |
16218 | @cindex gdbserver, multiple processes | |
16219 | @cindex multiple processes with gdbserver | |
16220 | ||
16221 | When you connect to @code{gdbserver} using @code{target remote}, | |
16222 | @code{gdbserver} debugs the specified program only once. When the | |
16223 | program exits, or you detach from it, @value{GDBN} closes the connection | |
16224 | and @code{gdbserver} exits. | |
16225 | ||
6e6c6f50 | 16226 | If you connect using @kbd{target extended-remote}, @code{gdbserver} |
2d717e4f DJ |
16227 | enters multi-process mode. When the debugged program exits, or you |
16228 | detach from it, @value{GDBN} stays connected to @code{gdbserver} even | |
16229 | though no program is running. The @code{run} and @code{attach} | |
16230 | commands instruct @code{gdbserver} to run or attach to a new program. | |
16231 | The @code{run} command uses @code{set remote exec-file} (@pxref{set | |
16232 | remote exec-file}) to select the program to run. Command line | |
16233 | arguments are supported, except for wildcard expansion and I/O | |
16234 | redirection (@pxref{Arguments}). | |
16235 | ||
16236 | To start @code{gdbserver} without supplying an initial command to run | |
16237 | or process ID to attach, use the @option{--multi} command line option. | |
6e6c6f50 | 16238 | Then you can connect using @kbd{target extended-remote} and start |
2d717e4f DJ |
16239 | the program you want to debug. |
16240 | ||
16241 | @code{gdbserver} does not automatically exit in multi-process mode. | |
16242 | You can terminate it by using @code{monitor exit} | |
16243 | (@pxref{Monitor Commands for gdbserver}). | |
16244 | ||
16245 | @subsubsection Other Command-Line Arguments for @code{gdbserver} | |
16246 | ||
62709adf PA |
16247 | The @option{--debug} option tells @code{gdbserver} to display extra |
16248 | status information about the debugging process. The | |
16249 | @option{--remote-debug} option tells @code{gdbserver} to display | |
16250 | remote protocol debug output. These options are intended for | |
16251 | @code{gdbserver} development and for bug reports to the developers. | |
2d717e4f | 16252 | |
ccd213ac DJ |
16253 | The @option{--wrapper} option specifies a wrapper to launch programs |
16254 | for debugging. The option should be followed by the name of the | |
16255 | wrapper, then any command-line arguments to pass to the wrapper, then | |
16256 | @kbd{--} indicating the end of the wrapper arguments. | |
16257 | ||
16258 | @code{gdbserver} runs the specified wrapper program with a combined | |
16259 | command line including the wrapper arguments, then the name of the | |
16260 | program to debug, then any arguments to the program. The wrapper | |
16261 | runs until it executes your program, and then @value{GDBN} gains control. | |
16262 | ||
16263 | You can use any program that eventually calls @code{execve} with | |
16264 | its arguments as a wrapper. Several standard Unix utilities do | |
16265 | this, e.g.@: @code{env} and @code{nohup}. Any Unix shell script ending | |
16266 | with @code{exec "$@@"} will also work. | |
16267 | ||
16268 | For example, you can use @code{env} to pass an environment variable to | |
16269 | the debugged program, without setting the variable in @code{gdbserver}'s | |
16270 | environment: | |
16271 | ||
16272 | @smallexample | |
16273 | $ gdbserver --wrapper env LD_PRELOAD=libtest.so -- :2222 ./testprog | |
16274 | @end smallexample | |
16275 | ||
2d717e4f DJ |
16276 | @subsection Connecting to @code{gdbserver} |
16277 | ||
16278 | Run @value{GDBN} on the host system. | |
16279 | ||
16280 | First make sure you have the necessary symbol files. Load symbols for | |
f822c95b DJ |
16281 | your application using the @code{file} command before you connect. Use |
16282 | @code{set sysroot} to locate target libraries (unless your @value{GDBN} | |
2d717e4f | 16283 | was compiled with the correct sysroot using @code{--with-sysroot}). |
f822c95b DJ |
16284 | |
16285 | The symbol file and target libraries must exactly match the executable | |
16286 | and libraries on the target, with one exception: the files on the host | |
16287 | system should not be stripped, even if the files on the target system | |
16288 | are. Mismatched or missing files will lead to confusing results | |
16289 | during debugging. On @sc{gnu}/Linux targets, mismatched or missing | |
16290 | files may also prevent @code{gdbserver} from debugging multi-threaded | |
16291 | programs. | |
16292 | ||
79a6e687 | 16293 | Connect to your target (@pxref{Connecting,,Connecting to a Remote Target}). |
6f05cf9f AC |
16294 | For TCP connections, you must start up @code{gdbserver} prior to using |
16295 | the @code{target remote} command. Otherwise you may get an error whose | |
16296 | text depends on the host system, but which usually looks something like | |
2d717e4f | 16297 | @samp{Connection refused}. Don't use the @code{load} |
397ca115 | 16298 | command in @value{GDBN} when using @code{gdbserver}, since the program is |
f822c95b | 16299 | already on the target. |
07f31aa6 | 16300 | |
79a6e687 | 16301 | @subsection Monitor Commands for @code{gdbserver} |
c74d0ad8 | 16302 | @cindex monitor commands, for @code{gdbserver} |
2d717e4f | 16303 | @anchor{Monitor Commands for gdbserver} |
c74d0ad8 DJ |
16304 | |
16305 | During a @value{GDBN} session using @code{gdbserver}, you can use the | |
16306 | @code{monitor} command to send special requests to @code{gdbserver}. | |
2d717e4f | 16307 | Here are the available commands. |
c74d0ad8 DJ |
16308 | |
16309 | @table @code | |
16310 | @item monitor help | |
16311 | List the available monitor commands. | |
16312 | ||
16313 | @item monitor set debug 0 | |
16314 | @itemx monitor set debug 1 | |
16315 | Disable or enable general debugging messages. | |
16316 | ||
16317 | @item monitor set remote-debug 0 | |
16318 | @itemx monitor set remote-debug 1 | |
16319 | Disable or enable specific debugging messages associated with the remote | |
16320 | protocol (@pxref{Remote Protocol}). | |
16321 | ||
cdbfd419 PP |
16322 | @item monitor set libthread-db-search-path [PATH] |
16323 | @cindex gdbserver, search path for @code{libthread_db} | |
16324 | When this command is issued, @var{path} is a colon-separated list of | |
16325 | directories to search for @code{libthread_db} (@pxref{Threads,,set | |
16326 | libthread-db-search-path}). If you omit @var{path}, | |
16327 | @samp{libthread-db-search-path} will be reset to an empty list. | |
16328 | ||
2d717e4f DJ |
16329 | @item monitor exit |
16330 | Tell gdbserver to exit immediately. This command should be followed by | |
16331 | @code{disconnect} to close the debugging session. @code{gdbserver} will | |
16332 | detach from any attached processes and kill any processes it created. | |
16333 | Use @code{monitor exit} to terminate @code{gdbserver} at the end | |
16334 | of a multi-process mode debug session. | |
16335 | ||
c74d0ad8 DJ |
16336 | @end table |
16337 | ||
fa593d66 PA |
16338 | @subsection Tracepoints support in @code{gdbserver} |
16339 | @cindex tracepoints support in @code{gdbserver} | |
16340 | ||
0fb4aa4b PA |
16341 | On some targets, @code{gdbserver} supports tracepoints, fast |
16342 | tracepoints and static tracepoints. | |
fa593d66 | 16343 | |
0fb4aa4b | 16344 | For fast or static tracepoints to work, a special library called the |
fa593d66 PA |
16345 | @dfn{in-process agent} (IPA), must be loaded in the inferior process. |
16346 | This library is built and distributed as an integral part of | |
0fb4aa4b PA |
16347 | @code{gdbserver}. In addition, support for static tracepoints |
16348 | requires building the in-process agent library with static tracepoints | |
16349 | support. At present, the UST (LTTng Userspace Tracer, | |
16350 | @url{http://lttng.org/ust}) tracing engine is supported. This support | |
16351 | is automatically available if UST development headers are found in the | |
16352 | standard include path when @code{gdbserver} is built, or if | |
16353 | @code{gdbserver} was explicitly configured using @option{--with-ust} | |
16354 | to point at such headers. You can explicitly disable the support | |
16355 | using @option{--with-ust=no}. | |
fa593d66 PA |
16356 | |
16357 | There are several ways to load the in-process agent in your program: | |
16358 | ||
16359 | @table @code | |
16360 | @item Specifying it as dependency at link time | |
16361 | ||
16362 | You can link your program dynamically with the in-process agent | |
16363 | library. On most systems, this is accomplished by adding | |
16364 | @code{-linproctrace} to the link command. | |
16365 | ||
16366 | @item Using the system's preloading mechanisms | |
16367 | ||
16368 | You can force loading the in-process agent at startup time by using | |
16369 | your system's support for preloading shared libraries. Many Unixes | |
16370 | support the concept of preloading user defined libraries. In most | |
16371 | cases, you do that by specifying @code{LD_PRELOAD=libinproctrace.so} | |
16372 | in the environment. See also the description of @code{gdbserver}'s | |
16373 | @option{--wrapper} command line option. | |
16374 | ||
16375 | @item Using @value{GDBN} to force loading the agent at run time | |
16376 | ||
16377 | On some systems, you can force the inferior to load a shared library, | |
16378 | by calling a dynamic loader function in the inferior that takes care | |
16379 | of dynamically looking up and loading a shared library. On most Unix | |
16380 | systems, the function is @code{dlopen}. You'll use the @code{call} | |
16381 | command for that. For example: | |
16382 | ||
16383 | @smallexample | |
16384 | (@value{GDBP}) call dlopen ("libinproctrace.so", ...) | |
16385 | @end smallexample | |
16386 | ||
16387 | Note that on most Unix systems, for the @code{dlopen} function to be | |
16388 | available, the program needs to be linked with @code{-ldl}. | |
16389 | @end table | |
16390 | ||
16391 | On systems that have a userspace dynamic loader, like most Unix | |
16392 | systems, when you connect to @code{gdbserver} using @code{target | |
16393 | remote}, you'll find that the program is stopped at the dynamic | |
16394 | loader's entry point, and no shared library has been loaded in the | |
16395 | program's address space yet, including the in-process agent. In that | |
0fb4aa4b PA |
16396 | case, before being able to use any of the fast or static tracepoints |
16397 | features, you need to let the loader run and load the shared | |
16398 | libraries. The simplest way to do that is to run the program to the | |
16399 | main procedure. E.g., if debugging a C or C@t{++} program, start | |
fa593d66 PA |
16400 | @code{gdbserver} like so: |
16401 | ||
16402 | @smallexample | |
16403 | $ gdbserver :9999 myprogram | |
16404 | @end smallexample | |
16405 | ||
16406 | Start GDB and connect to @code{gdbserver} like so, and run to main: | |
16407 | ||
16408 | @smallexample | |
16409 | $ gdb myprogram | |
16410 | (@value{GDBP}) target remote myhost:9999 | |
16411 | 0x00007f215893ba60 in ?? () from /lib64/ld-linux-x86-64.so.2 | |
16412 | (@value{GDBP}) b main | |
16413 | (@value{GDBP}) continue | |
16414 | @end smallexample | |
16415 | ||
16416 | The in-process tracing agent library should now be loaded into the | |
16417 | process; you can confirm it with the @code{info sharedlibrary} | |
16418 | command, which will list @file{libinproctrace.so} as loaded in the | |
0fb4aa4b PA |
16419 | process. You are now ready to install fast tracepoints, list static |
16420 | tracepoint markers, probe static tracepoints markers, and start | |
fa593d66 PA |
16421 | tracing. |
16422 | ||
79a6e687 BW |
16423 | @node Remote Configuration |
16424 | @section Remote Configuration | |
501eef12 | 16425 | |
9c16f35a EZ |
16426 | @kindex set remote |
16427 | @kindex show remote | |
16428 | This section documents the configuration options available when | |
16429 | debugging remote programs. For the options related to the File I/O | |
fc320d37 | 16430 | extensions of the remote protocol, see @ref{system, |
9c16f35a | 16431 | system-call-allowed}. |
501eef12 AC |
16432 | |
16433 | @table @code | |
9c16f35a | 16434 | @item set remoteaddresssize @var{bits} |
d3e8051b | 16435 | @cindex address size for remote targets |
9c16f35a EZ |
16436 | @cindex bits in remote address |
16437 | Set the maximum size of address in a memory packet to the specified | |
16438 | number of bits. @value{GDBN} will mask off the address bits above | |
16439 | that number, when it passes addresses to the remote target. The | |
16440 | default value is the number of bits in the target's address. | |
16441 | ||
16442 | @item show remoteaddresssize | |
16443 | Show the current value of remote address size in bits. | |
16444 | ||
16445 | @item set remotebaud @var{n} | |
16446 | @cindex baud rate for remote targets | |
16447 | Set the baud rate for the remote serial I/O to @var{n} baud. The | |
16448 | value is used to set the speed of the serial port used for debugging | |
16449 | remote targets. | |
16450 | ||
16451 | @item show remotebaud | |
16452 | Show the current speed of the remote connection. | |
16453 | ||
16454 | @item set remotebreak | |
16455 | @cindex interrupt remote programs | |
16456 | @cindex BREAK signal instead of Ctrl-C | |
9a6253be | 16457 | @anchor{set remotebreak} |
9c16f35a | 16458 | If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote |
c8aa23ab | 16459 | when you type @kbd{Ctrl-c} to interrupt the program running |
9a7a1b36 | 16460 | on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C} |
9c16f35a EZ |
16461 | character instead. The default is off, since most remote systems |
16462 | expect to see @samp{Ctrl-C} as the interrupt signal. | |
16463 | ||
16464 | @item show remotebreak | |
16465 | Show whether @value{GDBN} sends @code{BREAK} or @samp{Ctrl-C} to | |
16466 | interrupt the remote program. | |
16467 | ||
23776285 MR |
16468 | @item set remoteflow on |
16469 | @itemx set remoteflow off | |
16470 | @kindex set remoteflow | |
16471 | Enable or disable hardware flow control (@code{RTS}/@code{CTS}) | |
16472 | on the serial port used to communicate to the remote target. | |
16473 | ||
16474 | @item show remoteflow | |
16475 | @kindex show remoteflow | |
16476 | Show the current setting of hardware flow control. | |
16477 | ||
9c16f35a EZ |
16478 | @item set remotelogbase @var{base} |
16479 | Set the base (a.k.a.@: radix) of logging serial protocol | |
16480 | communications to @var{base}. Supported values of @var{base} are: | |
16481 | @code{ascii}, @code{octal}, and @code{hex}. The default is | |
16482 | @code{ascii}. | |
16483 | ||
16484 | @item show remotelogbase | |
16485 | Show the current setting of the radix for logging remote serial | |
16486 | protocol. | |
16487 | ||
16488 | @item set remotelogfile @var{file} | |
16489 | @cindex record serial communications on file | |
16490 | Record remote serial communications on the named @var{file}. The | |
16491 | default is not to record at all. | |
16492 | ||
16493 | @item show remotelogfile. | |
16494 | Show the current setting of the file name on which to record the | |
16495 | serial communications. | |
16496 | ||
16497 | @item set remotetimeout @var{num} | |
16498 | @cindex timeout for serial communications | |
16499 | @cindex remote timeout | |
16500 | Set the timeout limit to wait for the remote target to respond to | |
16501 | @var{num} seconds. The default is 2 seconds. | |
16502 | ||
16503 | @item show remotetimeout | |
16504 | Show the current number of seconds to wait for the remote target | |
16505 | responses. | |
16506 | ||
16507 | @cindex limit hardware breakpoints and watchpoints | |
16508 | @cindex remote target, limit break- and watchpoints | |
501eef12 AC |
16509 | @anchor{set remote hardware-watchpoint-limit} |
16510 | @anchor{set remote hardware-breakpoint-limit} | |
16511 | @item set remote hardware-watchpoint-limit @var{limit} | |
16512 | @itemx set remote hardware-breakpoint-limit @var{limit} | |
16513 | Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or | |
16514 | watchpoints. A limit of -1, the default, is treated as unlimited. | |
2d717e4f DJ |
16515 | |
16516 | @item set remote exec-file @var{filename} | |
16517 | @itemx show remote exec-file | |
16518 | @anchor{set remote exec-file} | |
16519 | @cindex executable file, for remote target | |
16520 | Select the file used for @code{run} with @code{target | |
16521 | extended-remote}. This should be set to a filename valid on the | |
16522 | target system. If it is not set, the target will use a default | |
16523 | filename (e.g.@: the last program run). | |
84603566 | 16524 | |
9a7071a8 JB |
16525 | @item set remote interrupt-sequence |
16526 | @cindex interrupt remote programs | |
16527 | @cindex select Ctrl-C, BREAK or BREAK-g | |
16528 | Allow the user to select one of @samp{Ctrl-C}, a @code{BREAK} or | |
16529 | @samp{BREAK-g} as the | |
16530 | sequence to the remote target in order to interrupt the execution. | |
16531 | @samp{Ctrl-C} is a default. Some system prefers @code{BREAK} which | |
16532 | is high level of serial line for some certain time. | |
16533 | Linux kernel prefers @samp{BREAK-g}, a.k.a Magic SysRq g. | |
16534 | It is @code{BREAK} signal followed by character @code{g}. | |
16535 | ||
16536 | @item show interrupt-sequence | |
16537 | Show which of @samp{Ctrl-C}, @code{BREAK} or @code{BREAK-g} | |
16538 | is sent by @value{GDBN} to interrupt the remote program. | |
16539 | @code{BREAK-g} is BREAK signal followed by @code{g} and | |
16540 | also known as Magic SysRq g. | |
16541 | ||
16542 | @item set remote interrupt-on-connect | |
16543 | @cindex send interrupt-sequence on start | |
16544 | Specify whether interrupt-sequence is sent to remote target when | |
16545 | @value{GDBN} connects to it. This is mostly needed when you debug | |
16546 | Linux kernel. Linux kernel expects @code{BREAK} followed by @code{g} | |
16547 | which is known as Magic SysRq g in order to connect @value{GDBN}. | |
16548 | ||
16549 | @item show interrupt-on-connect | |
16550 | Show whether interrupt-sequence is sent | |
16551 | to remote target when @value{GDBN} connects to it. | |
16552 | ||
84603566 SL |
16553 | @kindex set tcp |
16554 | @kindex show tcp | |
16555 | @item set tcp auto-retry on | |
16556 | @cindex auto-retry, for remote TCP target | |
16557 | Enable auto-retry for remote TCP connections. This is useful if the remote | |
16558 | debugging agent is launched in parallel with @value{GDBN}; there is a race | |
16559 | condition because the agent may not become ready to accept the connection | |
16560 | before @value{GDBN} attempts to connect. When auto-retry is | |
16561 | enabled, if the initial attempt to connect fails, @value{GDBN} reattempts | |
16562 | to establish the connection using the timeout specified by | |
16563 | @code{set tcp connect-timeout}. | |
16564 | ||
16565 | @item set tcp auto-retry off | |
16566 | Do not auto-retry failed TCP connections. | |
16567 | ||
16568 | @item show tcp auto-retry | |
16569 | Show the current auto-retry setting. | |
16570 | ||
16571 | @item set tcp connect-timeout @var{seconds} | |
16572 | @cindex connection timeout, for remote TCP target | |
16573 | @cindex timeout, for remote target connection | |
16574 | Set the timeout for establishing a TCP connection to the remote target to | |
16575 | @var{seconds}. The timeout affects both polling to retry failed connections | |
16576 | (enabled by @code{set tcp auto-retry on}) and waiting for connections | |
16577 | that are merely slow to complete, and represents an approximate cumulative | |
16578 | value. | |
16579 | ||
16580 | @item show tcp connect-timeout | |
16581 | Show the current connection timeout setting. | |
501eef12 AC |
16582 | @end table |
16583 | ||
427c3a89 DJ |
16584 | @cindex remote packets, enabling and disabling |
16585 | The @value{GDBN} remote protocol autodetects the packets supported by | |
16586 | your debugging stub. If you need to override the autodetection, you | |
16587 | can use these commands to enable or disable individual packets. Each | |
16588 | packet can be set to @samp{on} (the remote target supports this | |
16589 | packet), @samp{off} (the remote target does not support this packet), | |
16590 | or @samp{auto} (detect remote target support for this packet). They | |
16591 | all default to @samp{auto}. For more information about each packet, | |
16592 | see @ref{Remote Protocol}. | |
16593 | ||
16594 | During normal use, you should not have to use any of these commands. | |
16595 | If you do, that may be a bug in your remote debugging stub, or a bug | |
16596 | in @value{GDBN}. You may want to report the problem to the | |
16597 | @value{GDBN} developers. | |
16598 | ||
cfa9d6d9 DJ |
16599 | For each packet @var{name}, the command to enable or disable the |
16600 | packet is @code{set remote @var{name}-packet}. The available settings | |
16601 | are: | |
427c3a89 | 16602 | |
cfa9d6d9 | 16603 | @multitable @columnfractions 0.28 0.32 0.25 |
427c3a89 DJ |
16604 | @item Command Name |
16605 | @tab Remote Packet | |
16606 | @tab Related Features | |
16607 | ||
cfa9d6d9 | 16608 | @item @code{fetch-register} |
427c3a89 DJ |
16609 | @tab @code{p} |
16610 | @tab @code{info registers} | |
16611 | ||
cfa9d6d9 | 16612 | @item @code{set-register} |
427c3a89 DJ |
16613 | @tab @code{P} |
16614 | @tab @code{set} | |
16615 | ||
cfa9d6d9 | 16616 | @item @code{binary-download} |
427c3a89 DJ |
16617 | @tab @code{X} |
16618 | @tab @code{load}, @code{set} | |
16619 | ||
cfa9d6d9 | 16620 | @item @code{read-aux-vector} |
427c3a89 DJ |
16621 | @tab @code{qXfer:auxv:read} |
16622 | @tab @code{info auxv} | |
16623 | ||
cfa9d6d9 | 16624 | @item @code{symbol-lookup} |
427c3a89 DJ |
16625 | @tab @code{qSymbol} |
16626 | @tab Detecting multiple threads | |
16627 | ||
2d717e4f DJ |
16628 | @item @code{attach} |
16629 | @tab @code{vAttach} | |
16630 | @tab @code{attach} | |
16631 | ||
cfa9d6d9 | 16632 | @item @code{verbose-resume} |
427c3a89 DJ |
16633 | @tab @code{vCont} |
16634 | @tab Stepping or resuming multiple threads | |
16635 | ||
2d717e4f DJ |
16636 | @item @code{run} |
16637 | @tab @code{vRun} | |
16638 | @tab @code{run} | |
16639 | ||
cfa9d6d9 | 16640 | @item @code{software-breakpoint} |
427c3a89 DJ |
16641 | @tab @code{Z0} |
16642 | @tab @code{break} | |
16643 | ||
cfa9d6d9 | 16644 | @item @code{hardware-breakpoint} |
427c3a89 DJ |
16645 | @tab @code{Z1} |
16646 | @tab @code{hbreak} | |
16647 | ||
cfa9d6d9 | 16648 | @item @code{write-watchpoint} |
427c3a89 DJ |
16649 | @tab @code{Z2} |
16650 | @tab @code{watch} | |
16651 | ||
cfa9d6d9 | 16652 | @item @code{read-watchpoint} |
427c3a89 DJ |
16653 | @tab @code{Z3} |
16654 | @tab @code{rwatch} | |
16655 | ||
cfa9d6d9 | 16656 | @item @code{access-watchpoint} |
427c3a89 DJ |
16657 | @tab @code{Z4} |
16658 | @tab @code{awatch} | |
16659 | ||
cfa9d6d9 DJ |
16660 | @item @code{target-features} |
16661 | @tab @code{qXfer:features:read} | |
16662 | @tab @code{set architecture} | |
16663 | ||
16664 | @item @code{library-info} | |
16665 | @tab @code{qXfer:libraries:read} | |
16666 | @tab @code{info sharedlibrary} | |
16667 | ||
16668 | @item @code{memory-map} | |
16669 | @tab @code{qXfer:memory-map:read} | |
16670 | @tab @code{info mem} | |
16671 | ||
0fb4aa4b PA |
16672 | @item @code{read-sdata-object} |
16673 | @tab @code{qXfer:sdata:read} | |
16674 | @tab @code{print $_sdata} | |
16675 | ||
cfa9d6d9 DJ |
16676 | @item @code{read-spu-object} |
16677 | @tab @code{qXfer:spu:read} | |
16678 | @tab @code{info spu} | |
16679 | ||
16680 | @item @code{write-spu-object} | |
16681 | @tab @code{qXfer:spu:write} | |
16682 | @tab @code{info spu} | |
16683 | ||
4aa995e1 PA |
16684 | @item @code{read-siginfo-object} |
16685 | @tab @code{qXfer:siginfo:read} | |
16686 | @tab @code{print $_siginfo} | |
16687 | ||
16688 | @item @code{write-siginfo-object} | |
16689 | @tab @code{qXfer:siginfo:write} | |
16690 | @tab @code{set $_siginfo} | |
16691 | ||
dc146f7c VP |
16692 | @item @code{threads} |
16693 | @tab @code{qXfer:threads:read} | |
16694 | @tab @code{info threads} | |
16695 | ||
cfa9d6d9 | 16696 | @item @code{get-thread-local-@*storage-address} |
427c3a89 DJ |
16697 | @tab @code{qGetTLSAddr} |
16698 | @tab Displaying @code{__thread} variables | |
16699 | ||
711e434b PM |
16700 | @item @code{get-thread-information-block-address} |
16701 | @tab @code{qGetTIBAddr} | |
16702 | @tab Display MS-Windows Thread Information Block. | |
16703 | ||
08388c79 DE |
16704 | @item @code{search-memory} |
16705 | @tab @code{qSearch:memory} | |
16706 | @tab @code{find} | |
16707 | ||
427c3a89 DJ |
16708 | @item @code{supported-packets} |
16709 | @tab @code{qSupported} | |
16710 | @tab Remote communications parameters | |
16711 | ||
cfa9d6d9 | 16712 | @item @code{pass-signals} |
89be2091 DJ |
16713 | @tab @code{QPassSignals} |
16714 | @tab @code{handle @var{signal}} | |
16715 | ||
a6b151f1 DJ |
16716 | @item @code{hostio-close-packet} |
16717 | @tab @code{vFile:close} | |
16718 | @tab @code{remote get}, @code{remote put} | |
16719 | ||
16720 | @item @code{hostio-open-packet} | |
16721 | @tab @code{vFile:open} | |
16722 | @tab @code{remote get}, @code{remote put} | |
16723 | ||
16724 | @item @code{hostio-pread-packet} | |
16725 | @tab @code{vFile:pread} | |
16726 | @tab @code{remote get}, @code{remote put} | |
16727 | ||
16728 | @item @code{hostio-pwrite-packet} | |
16729 | @tab @code{vFile:pwrite} | |
16730 | @tab @code{remote get}, @code{remote put} | |
16731 | ||
16732 | @item @code{hostio-unlink-packet} | |
16733 | @tab @code{vFile:unlink} | |
16734 | @tab @code{remote delete} | |
a6f3e723 SL |
16735 | |
16736 | @item @code{noack-packet} | |
16737 | @tab @code{QStartNoAckMode} | |
16738 | @tab Packet acknowledgment | |
07e059b5 VP |
16739 | |
16740 | @item @code{osdata} | |
16741 | @tab @code{qXfer:osdata:read} | |
16742 | @tab @code{info os} | |
0b16c5cf PA |
16743 | |
16744 | @item @code{query-attached} | |
16745 | @tab @code{qAttached} | |
16746 | @tab Querying remote process attach state. | |
427c3a89 DJ |
16747 | @end multitable |
16748 | ||
79a6e687 BW |
16749 | @node Remote Stub |
16750 | @section Implementing a Remote Stub | |
7a292a7a | 16751 | |
8e04817f AC |
16752 | @cindex debugging stub, example |
16753 | @cindex remote stub, example | |
16754 | @cindex stub example, remote debugging | |
16755 | The stub files provided with @value{GDBN} implement the target side of the | |
16756 | communication protocol, and the @value{GDBN} side is implemented in the | |
16757 | @value{GDBN} source file @file{remote.c}. Normally, you can simply allow | |
16758 | these subroutines to communicate, and ignore the details. (If you're | |
16759 | implementing your own stub file, you can still ignore the details: start | |
16760 | with one of the existing stub files. @file{sparc-stub.c} is the best | |
16761 | organized, and therefore the easiest to read.) | |
16762 | ||
104c1213 JM |
16763 | @cindex remote serial debugging, overview |
16764 | To debug a program running on another machine (the debugging | |
16765 | @dfn{target} machine), you must first arrange for all the usual | |
16766 | prerequisites for the program to run by itself. For example, for a C | |
16767 | program, you need: | |
c906108c | 16768 | |
104c1213 JM |
16769 | @enumerate |
16770 | @item | |
16771 | A startup routine to set up the C runtime environment; these usually | |
16772 | have a name like @file{crt0}. The startup routine may be supplied by | |
16773 | your hardware supplier, or you may have to write your own. | |
96baa820 | 16774 | |
5d161b24 | 16775 | @item |
d4f3574e | 16776 | A C subroutine library to support your program's |
104c1213 | 16777 | subroutine calls, notably managing input and output. |
96baa820 | 16778 | |
104c1213 JM |
16779 | @item |
16780 | A way of getting your program to the other machine---for example, a | |
16781 | download program. These are often supplied by the hardware | |
16782 | manufacturer, but you may have to write your own from hardware | |
16783 | documentation. | |
16784 | @end enumerate | |
96baa820 | 16785 | |
104c1213 JM |
16786 | The next step is to arrange for your program to use a serial port to |
16787 | communicate with the machine where @value{GDBN} is running (the @dfn{host} | |
16788 | machine). In general terms, the scheme looks like this: | |
96baa820 | 16789 | |
104c1213 JM |
16790 | @table @emph |
16791 | @item On the host, | |
16792 | @value{GDBN} already understands how to use this protocol; when everything | |
16793 | else is set up, you can simply use the @samp{target remote} command | |
16794 | (@pxref{Targets,,Specifying a Debugging Target}). | |
16795 | ||
16796 | @item On the target, | |
16797 | you must link with your program a few special-purpose subroutines that | |
16798 | implement the @value{GDBN} remote serial protocol. The file containing these | |
16799 | subroutines is called a @dfn{debugging stub}. | |
16800 | ||
16801 | On certain remote targets, you can use an auxiliary program | |
16802 | @code{gdbserver} instead of linking a stub into your program. | |
79a6e687 | 16803 | @xref{Server,,Using the @code{gdbserver} Program}, for details. |
104c1213 | 16804 | @end table |
96baa820 | 16805 | |
104c1213 JM |
16806 | The debugging stub is specific to the architecture of the remote |
16807 | machine; for example, use @file{sparc-stub.c} to debug programs on | |
16808 | @sc{sparc} boards. | |
96baa820 | 16809 | |
104c1213 JM |
16810 | @cindex remote serial stub list |
16811 | These working remote stubs are distributed with @value{GDBN}: | |
96baa820 | 16812 | |
104c1213 JM |
16813 | @table @code |
16814 | ||
16815 | @item i386-stub.c | |
41afff9a | 16816 | @cindex @file{i386-stub.c} |
104c1213 JM |
16817 | @cindex Intel |
16818 | @cindex i386 | |
16819 | For Intel 386 and compatible architectures. | |
16820 | ||
16821 | @item m68k-stub.c | |
41afff9a | 16822 | @cindex @file{m68k-stub.c} |
104c1213 JM |
16823 | @cindex Motorola 680x0 |
16824 | @cindex m680x0 | |
16825 | For Motorola 680x0 architectures. | |
16826 | ||
16827 | @item sh-stub.c | |
41afff9a | 16828 | @cindex @file{sh-stub.c} |
172c2a43 | 16829 | @cindex Renesas |
104c1213 | 16830 | @cindex SH |
172c2a43 | 16831 | For Renesas SH architectures. |
104c1213 JM |
16832 | |
16833 | @item sparc-stub.c | |
41afff9a | 16834 | @cindex @file{sparc-stub.c} |
104c1213 JM |
16835 | @cindex Sparc |
16836 | For @sc{sparc} architectures. | |
16837 | ||
16838 | @item sparcl-stub.c | |
41afff9a | 16839 | @cindex @file{sparcl-stub.c} |
104c1213 JM |
16840 | @cindex Fujitsu |
16841 | @cindex SparcLite | |
16842 | For Fujitsu @sc{sparclite} architectures. | |
16843 | ||
16844 | @end table | |
16845 | ||
16846 | The @file{README} file in the @value{GDBN} distribution may list other | |
16847 | recently added stubs. | |
16848 | ||
16849 | @menu | |
16850 | * Stub Contents:: What the stub can do for you | |
16851 | * Bootstrapping:: What you must do for the stub | |
16852 | * Debug Session:: Putting it all together | |
104c1213 JM |
16853 | @end menu |
16854 | ||
6d2ebf8b | 16855 | @node Stub Contents |
79a6e687 | 16856 | @subsection What the Stub Can Do for You |
104c1213 JM |
16857 | |
16858 | @cindex remote serial stub | |
16859 | The debugging stub for your architecture supplies these three | |
16860 | subroutines: | |
16861 | ||
16862 | @table @code | |
16863 | @item set_debug_traps | |
4644b6e3 | 16864 | @findex set_debug_traps |
104c1213 JM |
16865 | @cindex remote serial stub, initialization |
16866 | This routine arranges for @code{handle_exception} to run when your | |
16867 | program stops. You must call this subroutine explicitly near the | |
16868 | beginning of your program. | |
16869 | ||
16870 | @item handle_exception | |
4644b6e3 | 16871 | @findex handle_exception |
104c1213 JM |
16872 | @cindex remote serial stub, main routine |
16873 | This is the central workhorse, but your program never calls it | |
16874 | explicitly---the setup code arranges for @code{handle_exception} to | |
16875 | run when a trap is triggered. | |
16876 | ||
16877 | @code{handle_exception} takes control when your program stops during | |
16878 | execution (for example, on a breakpoint), and mediates communications | |
16879 | with @value{GDBN} on the host machine. This is where the communications | |
16880 | protocol is implemented; @code{handle_exception} acts as the @value{GDBN} | |
d4f3574e | 16881 | representative on the target machine. It begins by sending summary |
104c1213 JM |
16882 | information on the state of your program, then continues to execute, |
16883 | retrieving and transmitting any information @value{GDBN} needs, until you | |
16884 | execute a @value{GDBN} command that makes your program resume; at that point, | |
16885 | @code{handle_exception} returns control to your own code on the target | |
5d161b24 | 16886 | machine. |
104c1213 JM |
16887 | |
16888 | @item breakpoint | |
16889 | @cindex @code{breakpoint} subroutine, remote | |
16890 | Use this auxiliary subroutine to make your program contain a | |
16891 | breakpoint. Depending on the particular situation, this may be the only | |
16892 | way for @value{GDBN} to get control. For instance, if your target | |
16893 | machine has some sort of interrupt button, you won't need to call this; | |
16894 | pressing the interrupt button transfers control to | |
16895 | @code{handle_exception}---in effect, to @value{GDBN}. On some machines, | |
16896 | simply receiving characters on the serial port may also trigger a trap; | |
16897 | again, in that situation, you don't need to call @code{breakpoint} from | |
16898 | your own program---simply running @samp{target remote} from the host | |
5d161b24 | 16899 | @value{GDBN} session gets control. |
104c1213 JM |
16900 | |
16901 | Call @code{breakpoint} if none of these is true, or if you simply want | |
16902 | to make certain your program stops at a predetermined point for the | |
16903 | start of your debugging session. | |
16904 | @end table | |
16905 | ||
6d2ebf8b | 16906 | @node Bootstrapping |
79a6e687 | 16907 | @subsection What You Must Do for the Stub |
104c1213 JM |
16908 | |
16909 | @cindex remote stub, support routines | |
16910 | The debugging stubs that come with @value{GDBN} are set up for a particular | |
16911 | chip architecture, but they have no information about the rest of your | |
16912 | debugging target machine. | |
16913 | ||
16914 | First of all you need to tell the stub how to communicate with the | |
16915 | serial port. | |
16916 | ||
16917 | @table @code | |
16918 | @item int getDebugChar() | |
4644b6e3 | 16919 | @findex getDebugChar |
104c1213 JM |
16920 | Write this subroutine to read a single character from the serial port. |
16921 | It may be identical to @code{getchar} for your target system; a | |
16922 | different name is used to allow you to distinguish the two if you wish. | |
16923 | ||
16924 | @item void putDebugChar(int) | |
4644b6e3 | 16925 | @findex putDebugChar |
104c1213 | 16926 | Write this subroutine to write a single character to the serial port. |
5d161b24 | 16927 | It may be identical to @code{putchar} for your target system; a |
104c1213 JM |
16928 | different name is used to allow you to distinguish the two if you wish. |
16929 | @end table | |
16930 | ||
16931 | @cindex control C, and remote debugging | |
16932 | @cindex interrupting remote targets | |
16933 | If you want @value{GDBN} to be able to stop your program while it is | |
16934 | running, you need to use an interrupt-driven serial driver, and arrange | |
16935 | for it to stop when it receives a @code{^C} (@samp{\003}, the control-C | |
16936 | character). That is the character which @value{GDBN} uses to tell the | |
16937 | remote system to stop. | |
16938 | ||
16939 | Getting the debugging target to return the proper status to @value{GDBN} | |
16940 | probably requires changes to the standard stub; one quick and dirty way | |
16941 | is to just execute a breakpoint instruction (the ``dirty'' part is that | |
16942 | @value{GDBN} reports a @code{SIGTRAP} instead of a @code{SIGINT}). | |
16943 | ||
16944 | Other routines you need to supply are: | |
16945 | ||
16946 | @table @code | |
16947 | @item void exceptionHandler (int @var{exception_number}, void *@var{exception_address}) | |
4644b6e3 | 16948 | @findex exceptionHandler |
104c1213 JM |
16949 | Write this function to install @var{exception_address} in the exception |
16950 | handling tables. You need to do this because the stub does not have any | |
16951 | way of knowing what the exception handling tables on your target system | |
16952 | are like (for example, the processor's table might be in @sc{rom}, | |
16953 | containing entries which point to a table in @sc{ram}). | |
16954 | @var{exception_number} is the exception number which should be changed; | |
16955 | its meaning is architecture-dependent (for example, different numbers | |
16956 | might represent divide by zero, misaligned access, etc). When this | |
16957 | exception occurs, control should be transferred directly to | |
16958 | @var{exception_address}, and the processor state (stack, registers, | |
16959 | and so on) should be just as it is when a processor exception occurs. So if | |
16960 | you want to use a jump instruction to reach @var{exception_address}, it | |
16961 | should be a simple jump, not a jump to subroutine. | |
16962 | ||
16963 | For the 386, @var{exception_address} should be installed as an interrupt | |
16964 | gate so that interrupts are masked while the handler runs. The gate | |
16965 | should be at privilege level 0 (the most privileged level). The | |
16966 | @sc{sparc} and 68k stubs are able to mask interrupts themselves without | |
16967 | help from @code{exceptionHandler}. | |
16968 | ||
16969 | @item void flush_i_cache() | |
4644b6e3 | 16970 | @findex flush_i_cache |
d4f3574e | 16971 | On @sc{sparc} and @sc{sparclite} only, write this subroutine to flush the |
104c1213 JM |
16972 | instruction cache, if any, on your target machine. If there is no |
16973 | instruction cache, this subroutine may be a no-op. | |
16974 | ||
16975 | On target machines that have instruction caches, @value{GDBN} requires this | |
16976 | function to make certain that the state of your program is stable. | |
16977 | @end table | |
16978 | ||
16979 | @noindent | |
16980 | You must also make sure this library routine is available: | |
16981 | ||
16982 | @table @code | |
16983 | @item void *memset(void *, int, int) | |
4644b6e3 | 16984 | @findex memset |
104c1213 JM |
16985 | This is the standard library function @code{memset} that sets an area of |
16986 | memory to a known value. If you have one of the free versions of | |
16987 | @code{libc.a}, @code{memset} can be found there; otherwise, you must | |
16988 | either obtain it from your hardware manufacturer, or write your own. | |
16989 | @end table | |
16990 | ||
16991 | If you do not use the GNU C compiler, you may need other standard | |
16992 | library subroutines as well; this varies from one stub to another, | |
16993 | but in general the stubs are likely to use any of the common library | |
e22ea452 | 16994 | subroutines which @code{@value{NGCC}} generates as inline code. |
104c1213 JM |
16995 | |
16996 | ||
6d2ebf8b | 16997 | @node Debug Session |
79a6e687 | 16998 | @subsection Putting it All Together |
104c1213 JM |
16999 | |
17000 | @cindex remote serial debugging summary | |
17001 | In summary, when your program is ready to debug, you must follow these | |
17002 | steps. | |
17003 | ||
17004 | @enumerate | |
17005 | @item | |
6d2ebf8b | 17006 | Make sure you have defined the supporting low-level routines |
79a6e687 | 17007 | (@pxref{Bootstrapping,,What You Must Do for the Stub}): |
104c1213 JM |
17008 | @display |
17009 | @code{getDebugChar}, @code{putDebugChar}, | |
17010 | @code{flush_i_cache}, @code{memset}, @code{exceptionHandler}. | |
17011 | @end display | |
17012 | ||
17013 | @item | |
17014 | Insert these lines near the top of your program: | |
17015 | ||
474c8240 | 17016 | @smallexample |
104c1213 JM |
17017 | set_debug_traps(); |
17018 | breakpoint(); | |
474c8240 | 17019 | @end smallexample |
104c1213 JM |
17020 | |
17021 | @item | |
17022 | For the 680x0 stub only, you need to provide a variable called | |
17023 | @code{exceptionHook}. Normally you just use: | |
17024 | ||
474c8240 | 17025 | @smallexample |
104c1213 | 17026 | void (*exceptionHook)() = 0; |
474c8240 | 17027 | @end smallexample |
104c1213 | 17028 | |
d4f3574e | 17029 | @noindent |
104c1213 | 17030 | but if before calling @code{set_debug_traps}, you set it to point to a |
598ca718 | 17031 | function in your program, that function is called when |
104c1213 JM |
17032 | @code{@value{GDBN}} continues after stopping on a trap (for example, bus |
17033 | error). The function indicated by @code{exceptionHook} is called with | |
17034 | one parameter: an @code{int} which is the exception number. | |
17035 | ||
17036 | @item | |
17037 | Compile and link together: your program, the @value{GDBN} debugging stub for | |
17038 | your target architecture, and the supporting subroutines. | |
17039 | ||
17040 | @item | |
17041 | Make sure you have a serial connection between your target machine and | |
17042 | the @value{GDBN} host, and identify the serial port on the host. | |
17043 | ||
17044 | @item | |
17045 | @c The "remote" target now provides a `load' command, so we should | |
17046 | @c document that. FIXME. | |
17047 | Download your program to your target machine (or get it there by | |
17048 | whatever means the manufacturer provides), and start it. | |
17049 | ||
17050 | @item | |
07f31aa6 | 17051 | Start @value{GDBN} on the host, and connect to the target |
79a6e687 | 17052 | (@pxref{Connecting,,Connecting to a Remote Target}). |
9db8d71f | 17053 | |
104c1213 JM |
17054 | @end enumerate |
17055 | ||
8e04817f AC |
17056 | @node Configurations |
17057 | @chapter Configuration-Specific Information | |
104c1213 | 17058 | |
8e04817f AC |
17059 | While nearly all @value{GDBN} commands are available for all native and |
17060 | cross versions of the debugger, there are some exceptions. This chapter | |
17061 | describes things that are only available in certain configurations. | |
104c1213 | 17062 | |
8e04817f AC |
17063 | There are three major categories of configurations: native |
17064 | configurations, where the host and target are the same, embedded | |
17065 | operating system configurations, which are usually the same for several | |
17066 | different processor architectures, and bare embedded processors, which | |
17067 | are quite different from each other. | |
104c1213 | 17068 | |
8e04817f AC |
17069 | @menu |
17070 | * Native:: | |
17071 | * Embedded OS:: | |
17072 | * Embedded Processors:: | |
17073 | * Architectures:: | |
17074 | @end menu | |
104c1213 | 17075 | |
8e04817f AC |
17076 | @node Native |
17077 | @section Native | |
104c1213 | 17078 | |
8e04817f AC |
17079 | This section describes details specific to particular native |
17080 | configurations. | |
6cf7e474 | 17081 | |
8e04817f AC |
17082 | @menu |
17083 | * HP-UX:: HP-UX | |
7561d450 | 17084 | * BSD libkvm Interface:: Debugging BSD kernel memory images |
8e04817f AC |
17085 | * SVR4 Process Information:: SVR4 process information |
17086 | * DJGPP Native:: Features specific to the DJGPP port | |
78c47bea | 17087 | * Cygwin Native:: Features specific to the Cygwin port |
14d6dd68 | 17088 | * Hurd Native:: Features specific to @sc{gnu} Hurd |
a64548ea | 17089 | * Neutrino:: Features specific to QNX Neutrino |
a80b95ba | 17090 | * Darwin:: Features specific to Darwin |
8e04817f | 17091 | @end menu |
6cf7e474 | 17092 | |
8e04817f AC |
17093 | @node HP-UX |
17094 | @subsection HP-UX | |
104c1213 | 17095 | |
8e04817f AC |
17096 | On HP-UX systems, if you refer to a function or variable name that |
17097 | begins with a dollar sign, @value{GDBN} searches for a user or system | |
17098 | name first, before it searches for a convenience variable. | |
104c1213 | 17099 | |
9c16f35a | 17100 | |
7561d450 MK |
17101 | @node BSD libkvm Interface |
17102 | @subsection BSD libkvm Interface | |
17103 | ||
17104 | @cindex libkvm | |
17105 | @cindex kernel memory image | |
17106 | @cindex kernel crash dump | |
17107 | ||
17108 | BSD-derived systems (FreeBSD/NetBSD/OpenBSD) have a kernel memory | |
17109 | interface that provides a uniform interface for accessing kernel virtual | |
17110 | memory images, including live systems and crash dumps. @value{GDBN} | |
17111 | uses this interface to allow you to debug live kernels and kernel crash | |
17112 | dumps on many native BSD configurations. This is implemented as a | |
17113 | special @code{kvm} debugging target. For debugging a live system, load | |
17114 | the currently running kernel into @value{GDBN} and connect to the | |
17115 | @code{kvm} target: | |
17116 | ||
17117 | @smallexample | |
17118 | (@value{GDBP}) @b{target kvm} | |
17119 | @end smallexample | |
17120 | ||
17121 | For debugging crash dumps, provide the file name of the crash dump as an | |
17122 | argument: | |
17123 | ||
17124 | @smallexample | |
17125 | (@value{GDBP}) @b{target kvm /var/crash/bsd.0} | |
17126 | @end smallexample | |
17127 | ||
17128 | Once connected to the @code{kvm} target, the following commands are | |
17129 | available: | |
17130 | ||
17131 | @table @code | |
17132 | @kindex kvm | |
17133 | @item kvm pcb | |
721c2651 | 17134 | Set current context from the @dfn{Process Control Block} (PCB) address. |
7561d450 MK |
17135 | |
17136 | @item kvm proc | |
17137 | Set current context from proc address. This command isn't available on | |
17138 | modern FreeBSD systems. | |
17139 | @end table | |
17140 | ||
8e04817f | 17141 | @node SVR4 Process Information |
79a6e687 | 17142 | @subsection SVR4 Process Information |
60bf7e09 EZ |
17143 | @cindex /proc |
17144 | @cindex examine process image | |
17145 | @cindex process info via @file{/proc} | |
104c1213 | 17146 | |
60bf7e09 EZ |
17147 | Many versions of SVR4 and compatible systems provide a facility called |
17148 | @samp{/proc} that can be used to examine the image of a running | |
17149 | process using file-system subroutines. If @value{GDBN} is configured | |
17150 | for an operating system with this facility, the command @code{info | |
17151 | proc} is available to report information about the process running | |
17152 | your program, or about any process running on your system. @code{info | |
17153 | proc} works only on SVR4 systems that include the @code{procfs} code. | |
17154 | This includes, as of this writing, @sc{gnu}/Linux, OSF/1 (Digital | |
17155 | Unix), Solaris, Irix, and Unixware, but not HP-UX, for example. | |
104c1213 | 17156 | |
8e04817f AC |
17157 | @table @code |
17158 | @kindex info proc | |
60bf7e09 | 17159 | @cindex process ID |
8e04817f | 17160 | @item info proc |
60bf7e09 EZ |
17161 | @itemx info proc @var{process-id} |
17162 | Summarize available information about any running process. If a | |
17163 | process ID is specified by @var{process-id}, display information about | |
17164 | that process; otherwise display information about the program being | |
17165 | debugged. The summary includes the debugged process ID, the command | |
17166 | line used to invoke it, its current working directory, and its | |
17167 | executable file's absolute file name. | |
17168 | ||
17169 | On some systems, @var{process-id} can be of the form | |
17170 | @samp{[@var{pid}]/@var{tid}} which specifies a certain thread ID | |
17171 | within a process. If the optional @var{pid} part is missing, it means | |
17172 | a thread from the process being debugged (the leading @samp{/} still | |
17173 | needs to be present, or else @value{GDBN} will interpret the number as | |
17174 | a process ID rather than a thread ID). | |
6cf7e474 | 17175 | |
8e04817f | 17176 | @item info proc mappings |
60bf7e09 EZ |
17177 | @cindex memory address space mappings |
17178 | Report the memory address space ranges accessible in the program, with | |
17179 | information on whether the process has read, write, or execute access | |
17180 | rights to each range. On @sc{gnu}/Linux systems, each memory range | |
17181 | includes the object file which is mapped to that range, instead of the | |
17182 | memory access rights to that range. | |
17183 | ||
17184 | @item info proc stat | |
17185 | @itemx info proc status | |
17186 | @cindex process detailed status information | |
17187 | These subcommands are specific to @sc{gnu}/Linux systems. They show | |
17188 | the process-related information, including the user ID and group ID; | |
17189 | how many threads are there in the process; its virtual memory usage; | |
17190 | the signals that are pending, blocked, and ignored; its TTY; its | |
17191 | consumption of system and user time; its stack size; its @samp{nice} | |
2eecc4ab | 17192 | value; etc. For more information, see the @samp{proc} man page |
60bf7e09 EZ |
17193 | (type @kbd{man 5 proc} from your shell prompt). |
17194 | ||
17195 | @item info proc all | |
17196 | Show all the information about the process described under all of the | |
17197 | above @code{info proc} subcommands. | |
17198 | ||
8e04817f AC |
17199 | @ignore |
17200 | @comment These sub-options of 'info proc' were not included when | |
17201 | @comment procfs.c was re-written. Keep their descriptions around | |
17202 | @comment against the day when someone finds the time to put them back in. | |
17203 | @kindex info proc times | |
17204 | @item info proc times | |
17205 | Starting time, user CPU time, and system CPU time for your program and | |
17206 | its children. | |
6cf7e474 | 17207 | |
8e04817f AC |
17208 | @kindex info proc id |
17209 | @item info proc id | |
17210 | Report on the process IDs related to your program: its own process ID, | |
17211 | the ID of its parent, the process group ID, and the session ID. | |
8e04817f | 17212 | @end ignore |
721c2651 EZ |
17213 | |
17214 | @item set procfs-trace | |
17215 | @kindex set procfs-trace | |
17216 | @cindex @code{procfs} API calls | |
17217 | This command enables and disables tracing of @code{procfs} API calls. | |
17218 | ||
17219 | @item show procfs-trace | |
17220 | @kindex show procfs-trace | |
17221 | Show the current state of @code{procfs} API call tracing. | |
17222 | ||
17223 | @item set procfs-file @var{file} | |
17224 | @kindex set procfs-file | |
17225 | Tell @value{GDBN} to write @code{procfs} API trace to the named | |
17226 | @var{file}. @value{GDBN} appends the trace info to the previous | |
17227 | contents of the file. The default is to display the trace on the | |
17228 | standard output. | |
17229 | ||
17230 | @item show procfs-file | |
17231 | @kindex show procfs-file | |
17232 | Show the file to which @code{procfs} API trace is written. | |
17233 | ||
17234 | @item proc-trace-entry | |
17235 | @itemx proc-trace-exit | |
17236 | @itemx proc-untrace-entry | |
17237 | @itemx proc-untrace-exit | |
17238 | @kindex proc-trace-entry | |
17239 | @kindex proc-trace-exit | |
17240 | @kindex proc-untrace-entry | |
17241 | @kindex proc-untrace-exit | |
17242 | These commands enable and disable tracing of entries into and exits | |
17243 | from the @code{syscall} interface. | |
17244 | ||
17245 | @item info pidlist | |
17246 | @kindex info pidlist | |
17247 | @cindex process list, QNX Neutrino | |
17248 | For QNX Neutrino only, this command displays the list of all the | |
17249 | processes and all the threads within each process. | |
17250 | ||
17251 | @item info meminfo | |
17252 | @kindex info meminfo | |
17253 | @cindex mapinfo list, QNX Neutrino | |
17254 | For QNX Neutrino only, this command displays the list of all mapinfos. | |
8e04817f | 17255 | @end table |
104c1213 | 17256 | |
8e04817f AC |
17257 | @node DJGPP Native |
17258 | @subsection Features for Debugging @sc{djgpp} Programs | |
17259 | @cindex @sc{djgpp} debugging | |
17260 | @cindex native @sc{djgpp} debugging | |
17261 | @cindex MS-DOS-specific commands | |
104c1213 | 17262 | |
514c4d71 EZ |
17263 | @cindex DPMI |
17264 | @sc{djgpp} is a port of the @sc{gnu} development tools to MS-DOS and | |
8e04817f AC |
17265 | MS-Windows. @sc{djgpp} programs are 32-bit protected-mode programs |
17266 | that use the @dfn{DPMI} (DOS Protected-Mode Interface) API to run on | |
17267 | top of real-mode DOS systems and their emulations. | |
104c1213 | 17268 | |
8e04817f AC |
17269 | @value{GDBN} supports native debugging of @sc{djgpp} programs, and |
17270 | defines a few commands specific to the @sc{djgpp} port. This | |
17271 | subsection describes those commands. | |
104c1213 | 17272 | |
8e04817f AC |
17273 | @table @code |
17274 | @kindex info dos | |
17275 | @item info dos | |
17276 | This is a prefix of @sc{djgpp}-specific commands which print | |
17277 | information about the target system and important OS structures. | |
f1251bdd | 17278 | |
8e04817f AC |
17279 | @kindex sysinfo |
17280 | @cindex MS-DOS system info | |
17281 | @cindex free memory information (MS-DOS) | |
17282 | @item info dos sysinfo | |
17283 | This command displays assorted information about the underlying | |
17284 | platform: the CPU type and features, the OS version and flavor, the | |
17285 | DPMI version, and the available conventional and DPMI memory. | |
104c1213 | 17286 | |
8e04817f AC |
17287 | @cindex GDT |
17288 | @cindex LDT | |
17289 | @cindex IDT | |
17290 | @cindex segment descriptor tables | |
17291 | @cindex descriptor tables display | |
17292 | @item info dos gdt | |
17293 | @itemx info dos ldt | |
17294 | @itemx info dos idt | |
17295 | These 3 commands display entries from, respectively, Global, Local, | |
17296 | and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor | |
17297 | tables are data structures which store a descriptor for each segment | |
17298 | that is currently in use. The segment's selector is an index into a | |
17299 | descriptor table; the table entry for that index holds the | |
17300 | descriptor's base address and limit, and its attributes and access | |
17301 | rights. | |
104c1213 | 17302 | |
8e04817f AC |
17303 | A typical @sc{djgpp} program uses 3 segments: a code segment, a data |
17304 | segment (used for both data and the stack), and a DOS segment (which | |
17305 | allows access to DOS/BIOS data structures and absolute addresses in | |
17306 | conventional memory). However, the DPMI host will usually define | |
17307 | additional segments in order to support the DPMI environment. | |
d4f3574e | 17308 | |
8e04817f AC |
17309 | @cindex garbled pointers |
17310 | These commands allow to display entries from the descriptor tables. | |
17311 | Without an argument, all entries from the specified table are | |
17312 | displayed. An argument, which should be an integer expression, means | |
17313 | display a single entry whose index is given by the argument. For | |
17314 | example, here's a convenient way to display information about the | |
17315 | debugged program's data segment: | |
104c1213 | 17316 | |
8e04817f AC |
17317 | @smallexample |
17318 | @exdent @code{(@value{GDBP}) info dos ldt $ds} | |
17319 | @exdent @code{0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)} | |
17320 | @end smallexample | |
104c1213 | 17321 | |
8e04817f AC |
17322 | @noindent |
17323 | This comes in handy when you want to see whether a pointer is outside | |
17324 | the data segment's limit (i.e.@: @dfn{garbled}). | |
104c1213 | 17325 | |
8e04817f AC |
17326 | @cindex page tables display (MS-DOS) |
17327 | @item info dos pde | |
17328 | @itemx info dos pte | |
17329 | These two commands display entries from, respectively, the Page | |
17330 | Directory and the Page Tables. Page Directories and Page Tables are | |
17331 | data structures which control how virtual memory addresses are mapped | |
17332 | into physical addresses. A Page Table includes an entry for every | |
17333 | page of memory that is mapped into the program's address space; there | |
17334 | may be several Page Tables, each one holding up to 4096 entries. A | |
17335 | Page Directory has up to 4096 entries, one each for every Page Table | |
17336 | that is currently in use. | |
104c1213 | 17337 | |
8e04817f AC |
17338 | Without an argument, @kbd{info dos pde} displays the entire Page |
17339 | Directory, and @kbd{info dos pte} displays all the entries in all of | |
17340 | the Page Tables. An argument, an integer expression, given to the | |
17341 | @kbd{info dos pde} command means display only that entry from the Page | |
17342 | Directory table. An argument given to the @kbd{info dos pte} command | |
17343 | means display entries from a single Page Table, the one pointed to by | |
17344 | the specified entry in the Page Directory. | |
104c1213 | 17345 | |
8e04817f AC |
17346 | @cindex direct memory access (DMA) on MS-DOS |
17347 | These commands are useful when your program uses @dfn{DMA} (Direct | |
17348 | Memory Access), which needs physical addresses to program the DMA | |
17349 | controller. | |
104c1213 | 17350 | |
8e04817f | 17351 | These commands are supported only with some DPMI servers. |
104c1213 | 17352 | |
8e04817f AC |
17353 | @cindex physical address from linear address |
17354 | @item info dos address-pte @var{addr} | |
17355 | This command displays the Page Table entry for a specified linear | |
514c4d71 EZ |
17356 | address. The argument @var{addr} is a linear address which should |
17357 | already have the appropriate segment's base address added to it, | |
17358 | because this command accepts addresses which may belong to @emph{any} | |
17359 | segment. For example, here's how to display the Page Table entry for | |
17360 | the page where a variable @code{i} is stored: | |
104c1213 | 17361 | |
b383017d | 17362 | @smallexample |
8e04817f AC |
17363 | @exdent @code{(@value{GDBP}) info dos address-pte __djgpp_base_address + (char *)&i} |
17364 | @exdent @code{Page Table entry for address 0x11a00d30:} | |
b383017d | 17365 | @exdent @code{Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30} |
8e04817f | 17366 | @end smallexample |
104c1213 | 17367 | |
8e04817f AC |
17368 | @noindent |
17369 | This says that @code{i} is stored at offset @code{0xd30} from the page | |
514c4d71 | 17370 | whose physical base address is @code{0x02698000}, and shows all the |
8e04817f | 17371 | attributes of that page. |
104c1213 | 17372 | |
8e04817f AC |
17373 | Note that you must cast the addresses of variables to a @code{char *}, |
17374 | since otherwise the value of @code{__djgpp_base_address}, the base | |
17375 | address of all variables and functions in a @sc{djgpp} program, will | |
17376 | be added using the rules of C pointer arithmetics: if @code{i} is | |
17377 | declared an @code{int}, @value{GDBN} will add 4 times the value of | |
17378 | @code{__djgpp_base_address} to the address of @code{i}. | |
104c1213 | 17379 | |
8e04817f AC |
17380 | Here's another example, it displays the Page Table entry for the |
17381 | transfer buffer: | |
104c1213 | 17382 | |
8e04817f AC |
17383 | @smallexample |
17384 | @exdent @code{(@value{GDBP}) info dos address-pte *((unsigned *)&_go32_info_block + 3)} | |
17385 | @exdent @code{Page Table entry for address 0x29110:} | |
17386 | @exdent @code{Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110} | |
17387 | @end smallexample | |
104c1213 | 17388 | |
8e04817f AC |
17389 | @noindent |
17390 | (The @code{+ 3} offset is because the transfer buffer's address is the | |
514c4d71 EZ |
17391 | 3rd member of the @code{_go32_info_block} structure.) The output |
17392 | clearly shows that this DPMI server maps the addresses in conventional | |
17393 | memory 1:1, i.e.@: the physical (@code{0x00029000} + @code{0x110}) and | |
17394 | linear (@code{0x29110}) addresses are identical. | |
104c1213 | 17395 | |
8e04817f AC |
17396 | This command is supported only with some DPMI servers. |
17397 | @end table | |
104c1213 | 17398 | |
c45da7e6 | 17399 | @cindex DOS serial data link, remote debugging |
a8f24a35 EZ |
17400 | In addition to native debugging, the DJGPP port supports remote |
17401 | debugging via a serial data link. The following commands are specific | |
17402 | to remote serial debugging in the DJGPP port of @value{GDBN}. | |
17403 | ||
17404 | @table @code | |
17405 | @kindex set com1base | |
17406 | @kindex set com1irq | |
17407 | @kindex set com2base | |
17408 | @kindex set com2irq | |
17409 | @kindex set com3base | |
17410 | @kindex set com3irq | |
17411 | @kindex set com4base | |
17412 | @kindex set com4irq | |
17413 | @item set com1base @var{addr} | |
17414 | This command sets the base I/O port address of the @file{COM1} serial | |
17415 | port. | |
17416 | ||
17417 | @item set com1irq @var{irq} | |
17418 | This command sets the @dfn{Interrupt Request} (@code{IRQ}) line to use | |
17419 | for the @file{COM1} serial port. | |
17420 | ||
17421 | There are similar commands @samp{set com2base}, @samp{set com3irq}, | |
17422 | etc.@: for setting the port address and the @code{IRQ} lines for the | |
17423 | other 3 COM ports. | |
17424 | ||
17425 | @kindex show com1base | |
17426 | @kindex show com1irq | |
17427 | @kindex show com2base | |
17428 | @kindex show com2irq | |
17429 | @kindex show com3base | |
17430 | @kindex show com3irq | |
17431 | @kindex show com4base | |
17432 | @kindex show com4irq | |
17433 | The related commands @samp{show com1base}, @samp{show com1irq} etc.@: | |
17434 | display the current settings of the base address and the @code{IRQ} | |
17435 | lines used by the COM ports. | |
c45da7e6 EZ |
17436 | |
17437 | @item info serial | |
17438 | @kindex info serial | |
17439 | @cindex DOS serial port status | |
17440 | This command prints the status of the 4 DOS serial ports. For each | |
17441 | port, it prints whether it's active or not, its I/O base address and | |
17442 | IRQ number, whether it uses a 16550-style FIFO, its baudrate, and the | |
17443 | counts of various errors encountered so far. | |
a8f24a35 EZ |
17444 | @end table |
17445 | ||
17446 | ||
78c47bea | 17447 | @node Cygwin Native |
79a6e687 | 17448 | @subsection Features for Debugging MS Windows PE Executables |
78c47bea PM |
17449 | @cindex MS Windows debugging |
17450 | @cindex native Cygwin debugging | |
17451 | @cindex Cygwin-specific commands | |
17452 | ||
be448670 | 17453 | @value{GDBN} supports native debugging of MS Windows programs, including |
cbb8f428 EZ |
17454 | DLLs with and without symbolic debugging information. |
17455 | ||
17456 | @cindex Ctrl-BREAK, MS-Windows | |
17457 | @cindex interrupt debuggee on MS-Windows | |
17458 | MS-Windows programs that call @code{SetConsoleMode} to switch off the | |
17459 | special meaning of the @samp{Ctrl-C} keystroke cannot be interrupted | |
17460 | by typing @kbd{C-c}. For this reason, @value{GDBN} on MS-Windows | |
17461 | supports @kbd{C-@key{BREAK}} as an alternative interrupt key | |
17462 | sequence, which can be used to interrupt the debuggee even if it | |
17463 | ignores @kbd{C-c}. | |
17464 | ||
17465 | There are various additional Cygwin-specific commands, described in | |
17466 | this section. Working with DLLs that have no debugging symbols is | |
17467 | described in @ref{Non-debug DLL Symbols}. | |
78c47bea PM |
17468 | |
17469 | @table @code | |
17470 | @kindex info w32 | |
17471 | @item info w32 | |
db2e3e2e | 17472 | This is a prefix of MS Windows-specific commands which print |
78c47bea PM |
17473 | information about the target system and important OS structures. |
17474 | ||
17475 | @item info w32 selector | |
17476 | This command displays information returned by | |
17477 | the Win32 API @code{GetThreadSelectorEntry} function. | |
17478 | It takes an optional argument that is evaluated to | |
17479 | a long value to give the information about this given selector. | |
17480 | Without argument, this command displays information | |
d3e8051b | 17481 | about the six segment registers. |
78c47bea | 17482 | |
711e434b PM |
17483 | @item info w32 thread-information-block |
17484 | This command displays thread specific information stored in the | |
17485 | Thread Information Block (readable on the X86 CPU family using @code{$fs} | |
17486 | selector for 32-bit programs and @code{$gs} for 64-bit programs). | |
17487 | ||
78c47bea PM |
17488 | @kindex info dll |
17489 | @item info dll | |
db2e3e2e | 17490 | This is a Cygwin-specific alias of @code{info shared}. |
78c47bea PM |
17491 | |
17492 | @kindex dll-symbols | |
17493 | @item dll-symbols | |
17494 | This command loads symbols from a dll similarly to | |
17495 | add-sym command but without the need to specify a base address. | |
17496 | ||
be90c084 | 17497 | @kindex set cygwin-exceptions |
e16b02ee EZ |
17498 | @cindex debugging the Cygwin DLL |
17499 | @cindex Cygwin DLL, debugging | |
be90c084 | 17500 | @item set cygwin-exceptions @var{mode} |
e16b02ee EZ |
17501 | If @var{mode} is @code{on}, @value{GDBN} will break on exceptions that |
17502 | happen inside the Cygwin DLL. If @var{mode} is @code{off}, | |
17503 | @value{GDBN} will delay recognition of exceptions, and may ignore some | |
17504 | exceptions which seem to be caused by internal Cygwin DLL | |
17505 | ``bookkeeping''. This option is meant primarily for debugging the | |
17506 | Cygwin DLL itself; the default value is @code{off} to avoid annoying | |
17507 | @value{GDBN} users with false @code{SIGSEGV} signals. | |
be90c084 CF |
17508 | |
17509 | @kindex show cygwin-exceptions | |
17510 | @item show cygwin-exceptions | |
e16b02ee EZ |
17511 | Displays whether @value{GDBN} will break on exceptions that happen |
17512 | inside the Cygwin DLL itself. | |
be90c084 | 17513 | |
b383017d | 17514 | @kindex set new-console |
78c47bea | 17515 | @item set new-console @var{mode} |
b383017d | 17516 | If @var{mode} is @code{on} the debuggee will |
78c47bea | 17517 | be started in a new console on next start. |
e03e5e7b | 17518 | If @var{mode} is @code{off}, the debuggee will |
78c47bea PM |
17519 | be started in the same console as the debugger. |
17520 | ||
17521 | @kindex show new-console | |
17522 | @item show new-console | |
17523 | Displays whether a new console is used | |
17524 | when the debuggee is started. | |
17525 | ||
17526 | @kindex set new-group | |
17527 | @item set new-group @var{mode} | |
17528 | This boolean value controls whether the debuggee should | |
17529 | start a new group or stay in the same group as the debugger. | |
17530 | This affects the way the Windows OS handles | |
c8aa23ab | 17531 | @samp{Ctrl-C}. |
78c47bea PM |
17532 | |
17533 | @kindex show new-group | |
17534 | @item show new-group | |
17535 | Displays current value of new-group boolean. | |
17536 | ||
17537 | @kindex set debugevents | |
17538 | @item set debugevents | |
219eec71 EZ |
17539 | This boolean value adds debug output concerning kernel events related |
17540 | to the debuggee seen by the debugger. This includes events that | |
17541 | signal thread and process creation and exit, DLL loading and | |
17542 | unloading, console interrupts, and debugging messages produced by the | |
17543 | Windows @code{OutputDebugString} API call. | |
78c47bea PM |
17544 | |
17545 | @kindex set debugexec | |
17546 | @item set debugexec | |
b383017d | 17547 | This boolean value adds debug output concerning execute events |
219eec71 | 17548 | (such as resume thread) seen by the debugger. |
78c47bea PM |
17549 | |
17550 | @kindex set debugexceptions | |
17551 | @item set debugexceptions | |
219eec71 EZ |
17552 | This boolean value adds debug output concerning exceptions in the |
17553 | debuggee seen by the debugger. | |
78c47bea PM |
17554 | |
17555 | @kindex set debugmemory | |
17556 | @item set debugmemory | |
219eec71 EZ |
17557 | This boolean value adds debug output concerning debuggee memory reads |
17558 | and writes by the debugger. | |
78c47bea PM |
17559 | |
17560 | @kindex set shell | |
17561 | @item set shell | |
17562 | This boolean values specifies whether the debuggee is called | |
17563 | via a shell or directly (default value is on). | |
17564 | ||
17565 | @kindex show shell | |
17566 | @item show shell | |
17567 | Displays if the debuggee will be started with a shell. | |
17568 | ||
17569 | @end table | |
17570 | ||
be448670 | 17571 | @menu |
79a6e687 | 17572 | * Non-debug DLL Symbols:: Support for DLLs without debugging symbols |
be448670 CF |
17573 | @end menu |
17574 | ||
79a6e687 BW |
17575 | @node Non-debug DLL Symbols |
17576 | @subsubsection Support for DLLs without Debugging Symbols | |
be448670 CF |
17577 | @cindex DLLs with no debugging symbols |
17578 | @cindex Minimal symbols and DLLs | |
17579 | ||
17580 | Very often on windows, some of the DLLs that your program relies on do | |
17581 | not include symbolic debugging information (for example, | |
db2e3e2e | 17582 | @file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging |
be448670 | 17583 | symbols in a DLL, it relies on the minimal amount of symbolic |
db2e3e2e | 17584 | information contained in the DLL's export table. This section |
be448670 CF |
17585 | describes working with such symbols, known internally to @value{GDBN} as |
17586 | ``minimal symbols''. | |
17587 | ||
17588 | Note that before the debugged program has started execution, no DLLs | |
db2e3e2e | 17589 | will have been loaded. The easiest way around this problem is simply to |
be448670 | 17590 | start the program --- either by setting a breakpoint or letting the |
db2e3e2e | 17591 | program run once to completion. It is also possible to force |
be448670 | 17592 | @value{GDBN} to load a particular DLL before starting the executable --- |
12c27660 | 17593 | see the shared library information in @ref{Files}, or the |
db2e3e2e | 17594 | @code{dll-symbols} command in @ref{Cygwin Native}. Currently, |
be448670 CF |
17595 | explicitly loading symbols from a DLL with no debugging information will |
17596 | cause the symbol names to be duplicated in @value{GDBN}'s lookup table, | |
17597 | which may adversely affect symbol lookup performance. | |
17598 | ||
79a6e687 | 17599 | @subsubsection DLL Name Prefixes |
be448670 CF |
17600 | |
17601 | In keeping with the naming conventions used by the Microsoft debugging | |
17602 | tools, DLL export symbols are made available with a prefix based on the | |
17603 | DLL name, for instance @code{KERNEL32!CreateFileA}. The plain name is | |
17604 | also entered into the symbol table, so @code{CreateFileA} is often | |
99e008fe | 17605 | sufficient. In some cases there will be name clashes within a program |
be448670 CF |
17606 | (particularly if the executable itself includes full debugging symbols) |
17607 | necessitating the use of the fully qualified name when referring to the | |
99e008fe | 17608 | contents of the DLL. Use single-quotes around the name to avoid the |
be448670 CF |
17609 | exclamation mark (``!'') being interpreted as a language operator. |
17610 | ||
17611 | Note that the internal name of the DLL may be all upper-case, even | |
99e008fe | 17612 | though the file name of the DLL is lower-case, or vice-versa. Since |
be448670 CF |
17613 | symbols within @value{GDBN} are @emph{case-sensitive} this may cause |
17614 | some confusion. If in doubt, try the @code{info functions} and | |
0869d01b NR |
17615 | @code{info variables} commands or even @code{maint print msymbols} |
17616 | (@pxref{Symbols}). Here's an example: | |
be448670 CF |
17617 | |
17618 | @smallexample | |
f7dc1244 | 17619 | (@value{GDBP}) info function CreateFileA |
be448670 CF |
17620 | All functions matching regular expression "CreateFileA": |
17621 | ||
17622 | Non-debugging symbols: | |
17623 | 0x77e885f4 CreateFileA | |
17624 | 0x77e885f4 KERNEL32!CreateFileA | |
17625 | @end smallexample | |
17626 | ||
17627 | @smallexample | |
f7dc1244 | 17628 | (@value{GDBP}) info function ! |
be448670 CF |
17629 | All functions matching regular expression "!": |
17630 | ||
17631 | Non-debugging symbols: | |
17632 | 0x6100114c cygwin1!__assert | |
17633 | 0x61004034 cygwin1!_dll_crt0@@0 | |
17634 | 0x61004240 cygwin1!dll_crt0(per_process *) | |
17635 | [etc...] | |
17636 | @end smallexample | |
17637 | ||
79a6e687 | 17638 | @subsubsection Working with Minimal Symbols |
be448670 CF |
17639 | |
17640 | Symbols extracted from a DLL's export table do not contain very much | |
17641 | type information. All that @value{GDBN} can do is guess whether a symbol | |
17642 | refers to a function or variable depending on the linker section that | |
17643 | contains the symbol. Also note that the actual contents of the memory | |
17644 | contained in a DLL are not available unless the program is running. This | |
17645 | means that you cannot examine the contents of a variable or disassemble | |
17646 | a function within a DLL without a running program. | |
17647 | ||
17648 | Variables are generally treated as pointers and dereferenced | |
17649 | automatically. For this reason, it is often necessary to prefix a | |
17650 | variable name with the address-of operator (``&'') and provide explicit | |
17651 | type information in the command. Here's an example of the type of | |
17652 | problem: | |
17653 | ||
17654 | @smallexample | |
f7dc1244 | 17655 | (@value{GDBP}) print 'cygwin1!__argv' |
be448670 CF |
17656 | $1 = 268572168 |
17657 | @end smallexample | |
17658 | ||
17659 | @smallexample | |
f7dc1244 | 17660 | (@value{GDBP}) x 'cygwin1!__argv' |
be448670 CF |
17661 | 0x10021610: "\230y\"" |
17662 | @end smallexample | |
17663 | ||
17664 | And two possible solutions: | |
17665 | ||
17666 | @smallexample | |
f7dc1244 | 17667 | (@value{GDBP}) print ((char **)'cygwin1!__argv')[0] |
be448670 CF |
17668 | $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram" |
17669 | @end smallexample | |
17670 | ||
17671 | @smallexample | |
f7dc1244 | 17672 | (@value{GDBP}) x/2x &'cygwin1!__argv' |
be448670 | 17673 | 0x610c0aa8 <cygwin1!__argv>: 0x10021608 0x00000000 |
f7dc1244 | 17674 | (@value{GDBP}) x/x 0x10021608 |
be448670 | 17675 | 0x10021608: 0x0022fd98 |
f7dc1244 | 17676 | (@value{GDBP}) x/s 0x0022fd98 |
be448670 CF |
17677 | 0x22fd98: "/cygdrive/c/mydirectory/myprogram" |
17678 | @end smallexample | |
17679 | ||
17680 | Setting a break point within a DLL is possible even before the program | |
17681 | starts execution. However, under these circumstances, @value{GDBN} can't | |
17682 | examine the initial instructions of the function in order to skip the | |
17683 | function's frame set-up code. You can work around this by using ``*&'' | |
17684 | to set the breakpoint at a raw memory address: | |
17685 | ||
17686 | @smallexample | |
f7dc1244 | 17687 | (@value{GDBP}) break *&'python22!PyOS_Readline' |
be448670 CF |
17688 | Breakpoint 1 at 0x1e04eff0 |
17689 | @end smallexample | |
17690 | ||
17691 | The author of these extensions is not entirely convinced that setting a | |
17692 | break point within a shared DLL like @file{kernel32.dll} is completely | |
17693 | safe. | |
17694 | ||
14d6dd68 | 17695 | @node Hurd Native |
79a6e687 | 17696 | @subsection Commands Specific to @sc{gnu} Hurd Systems |
14d6dd68 EZ |
17697 | @cindex @sc{gnu} Hurd debugging |
17698 | ||
17699 | This subsection describes @value{GDBN} commands specific to the | |
17700 | @sc{gnu} Hurd native debugging. | |
17701 | ||
17702 | @table @code | |
17703 | @item set signals | |
17704 | @itemx set sigs | |
17705 | @kindex set signals@r{, Hurd command} | |
17706 | @kindex set sigs@r{, Hurd command} | |
17707 | This command toggles the state of inferior signal interception by | |
17708 | @value{GDBN}. Mach exceptions, such as breakpoint traps, are not | |
17709 | affected by this command. @code{sigs} is a shorthand alias for | |
17710 | @code{signals}. | |
17711 | ||
17712 | @item show signals | |
17713 | @itemx show sigs | |
17714 | @kindex show signals@r{, Hurd command} | |
17715 | @kindex show sigs@r{, Hurd command} | |
17716 | Show the current state of intercepting inferior's signals. | |
17717 | ||
17718 | @item set signal-thread | |
17719 | @itemx set sigthread | |
17720 | @kindex set signal-thread | |
17721 | @kindex set sigthread | |
17722 | This command tells @value{GDBN} which thread is the @code{libc} signal | |
17723 | thread. That thread is run when a signal is delivered to a running | |
17724 | process. @code{set sigthread} is the shorthand alias of @code{set | |
17725 | signal-thread}. | |
17726 | ||
17727 | @item show signal-thread | |
17728 | @itemx show sigthread | |
17729 | @kindex show signal-thread | |
17730 | @kindex show sigthread | |
17731 | These two commands show which thread will run when the inferior is | |
17732 | delivered a signal. | |
17733 | ||
17734 | @item set stopped | |
17735 | @kindex set stopped@r{, Hurd command} | |
17736 | This commands tells @value{GDBN} that the inferior process is stopped, | |
17737 | as with the @code{SIGSTOP} signal. The stopped process can be | |
17738 | continued by delivering a signal to it. | |
17739 | ||
17740 | @item show stopped | |
17741 | @kindex show stopped@r{, Hurd command} | |
17742 | This command shows whether @value{GDBN} thinks the debuggee is | |
17743 | stopped. | |
17744 | ||
17745 | @item set exceptions | |
17746 | @kindex set exceptions@r{, Hurd command} | |
17747 | Use this command to turn off trapping of exceptions in the inferior. | |
17748 | When exception trapping is off, neither breakpoints nor | |
17749 | single-stepping will work. To restore the default, set exception | |
17750 | trapping on. | |
17751 | ||
17752 | @item show exceptions | |
17753 | @kindex show exceptions@r{, Hurd command} | |
17754 | Show the current state of trapping exceptions in the inferior. | |
17755 | ||
17756 | @item set task pause | |
17757 | @kindex set task@r{, Hurd commands} | |
17758 | @cindex task attributes (@sc{gnu} Hurd) | |
17759 | @cindex pause current task (@sc{gnu} Hurd) | |
17760 | This command toggles task suspension when @value{GDBN} has control. | |
17761 | Setting it to on takes effect immediately, and the task is suspended | |
17762 | whenever @value{GDBN} gets control. Setting it to off will take | |
17763 | effect the next time the inferior is continued. If this option is set | |
17764 | to off, you can use @code{set thread default pause on} or @code{set | |
17765 | thread pause on} (see below) to pause individual threads. | |
17766 | ||
17767 | @item show task pause | |
17768 | @kindex show task@r{, Hurd commands} | |
17769 | Show the current state of task suspension. | |
17770 | ||
17771 | @item set task detach-suspend-count | |
17772 | @cindex task suspend count | |
17773 | @cindex detach from task, @sc{gnu} Hurd | |
17774 | This command sets the suspend count the task will be left with when | |
17775 | @value{GDBN} detaches from it. | |
17776 | ||
17777 | @item show task detach-suspend-count | |
17778 | Show the suspend count the task will be left with when detaching. | |
17779 | ||
17780 | @item set task exception-port | |
17781 | @itemx set task excp | |
17782 | @cindex task exception port, @sc{gnu} Hurd | |
17783 | This command sets the task exception port to which @value{GDBN} will | |
17784 | forward exceptions. The argument should be the value of the @dfn{send | |
17785 | rights} of the task. @code{set task excp} is a shorthand alias. | |
17786 | ||
17787 | @item set noninvasive | |
17788 | @cindex noninvasive task options | |
17789 | This command switches @value{GDBN} to a mode that is the least | |
17790 | invasive as far as interfering with the inferior is concerned. This | |
17791 | is the same as using @code{set task pause}, @code{set exceptions}, and | |
17792 | @code{set signals} to values opposite to the defaults. | |
17793 | ||
17794 | @item info send-rights | |
17795 | @itemx info receive-rights | |
17796 | @itemx info port-rights | |
17797 | @itemx info port-sets | |
17798 | @itemx info dead-names | |
17799 | @itemx info ports | |
17800 | @itemx info psets | |
17801 | @cindex send rights, @sc{gnu} Hurd | |
17802 | @cindex receive rights, @sc{gnu} Hurd | |
17803 | @cindex port rights, @sc{gnu} Hurd | |
17804 | @cindex port sets, @sc{gnu} Hurd | |
17805 | @cindex dead names, @sc{gnu} Hurd | |
17806 | These commands display information about, respectively, send rights, | |
17807 | receive rights, port rights, port sets, and dead names of a task. | |
17808 | There are also shorthand aliases: @code{info ports} for @code{info | |
17809 | port-rights} and @code{info psets} for @code{info port-sets}. | |
17810 | ||
17811 | @item set thread pause | |
17812 | @kindex set thread@r{, Hurd command} | |
17813 | @cindex thread properties, @sc{gnu} Hurd | |
17814 | @cindex pause current thread (@sc{gnu} Hurd) | |
17815 | This command toggles current thread suspension when @value{GDBN} has | |
17816 | control. Setting it to on takes effect immediately, and the current | |
17817 | thread is suspended whenever @value{GDBN} gets control. Setting it to | |
17818 | off will take effect the next time the inferior is continued. | |
17819 | Normally, this command has no effect, since when @value{GDBN} has | |
17820 | control, the whole task is suspended. However, if you used @code{set | |
17821 | task pause off} (see above), this command comes in handy to suspend | |
17822 | only the current thread. | |
17823 | ||
17824 | @item show thread pause | |
17825 | @kindex show thread@r{, Hurd command} | |
17826 | This command shows the state of current thread suspension. | |
17827 | ||
17828 | @item set thread run | |
d3e8051b | 17829 | This command sets whether the current thread is allowed to run. |
14d6dd68 EZ |
17830 | |
17831 | @item show thread run | |
17832 | Show whether the current thread is allowed to run. | |
17833 | ||
17834 | @item set thread detach-suspend-count | |
17835 | @cindex thread suspend count, @sc{gnu} Hurd | |
17836 | @cindex detach from thread, @sc{gnu} Hurd | |
17837 | This command sets the suspend count @value{GDBN} will leave on a | |
17838 | thread when detaching. This number is relative to the suspend count | |
17839 | found by @value{GDBN} when it notices the thread; use @code{set thread | |
17840 | takeover-suspend-count} to force it to an absolute value. | |
17841 | ||
17842 | @item show thread detach-suspend-count | |
17843 | Show the suspend count @value{GDBN} will leave on the thread when | |
17844 | detaching. | |
17845 | ||
17846 | @item set thread exception-port | |
17847 | @itemx set thread excp | |
17848 | Set the thread exception port to which to forward exceptions. This | |
17849 | overrides the port set by @code{set task exception-port} (see above). | |
17850 | @code{set thread excp} is the shorthand alias. | |
17851 | ||
17852 | @item set thread takeover-suspend-count | |
17853 | Normally, @value{GDBN}'s thread suspend counts are relative to the | |
17854 | value @value{GDBN} finds when it notices each thread. This command | |
17855 | changes the suspend counts to be absolute instead. | |
17856 | ||
17857 | @item set thread default | |
17858 | @itemx show thread default | |
17859 | @cindex thread default settings, @sc{gnu} Hurd | |
17860 | Each of the above @code{set thread} commands has a @code{set thread | |
17861 | default} counterpart (e.g., @code{set thread default pause}, @code{set | |
17862 | thread default exception-port}, etc.). The @code{thread default} | |
17863 | variety of commands sets the default thread properties for all | |
17864 | threads; you can then change the properties of individual threads with | |
17865 | the non-default commands. | |
17866 | @end table | |
17867 | ||
17868 | ||
a64548ea EZ |
17869 | @node Neutrino |
17870 | @subsection QNX Neutrino | |
17871 | @cindex QNX Neutrino | |
17872 | ||
17873 | @value{GDBN} provides the following commands specific to the QNX | |
17874 | Neutrino target: | |
17875 | ||
17876 | @table @code | |
17877 | @item set debug nto-debug | |
17878 | @kindex set debug nto-debug | |
17879 | When set to on, enables debugging messages specific to the QNX | |
17880 | Neutrino support. | |
17881 | ||
17882 | @item show debug nto-debug | |
17883 | @kindex show debug nto-debug | |
17884 | Show the current state of QNX Neutrino messages. | |
17885 | @end table | |
17886 | ||
a80b95ba TG |
17887 | @node Darwin |
17888 | @subsection Darwin | |
17889 | @cindex Darwin | |
17890 | ||
17891 | @value{GDBN} provides the following commands specific to the Darwin target: | |
17892 | ||
17893 | @table @code | |
17894 | @item set debug darwin @var{num} | |
17895 | @kindex set debug darwin | |
17896 | When set to a non zero value, enables debugging messages specific to | |
17897 | the Darwin support. Higher values produce more verbose output. | |
17898 | ||
17899 | @item show debug darwin | |
17900 | @kindex show debug darwin | |
17901 | Show the current state of Darwin messages. | |
17902 | ||
17903 | @item set debug mach-o @var{num} | |
17904 | @kindex set debug mach-o | |
17905 | When set to a non zero value, enables debugging messages while | |
17906 | @value{GDBN} is reading Darwin object files. (@dfn{Mach-O} is the | |
17907 | file format used on Darwin for object and executable files.) Higher | |
17908 | values produce more verbose output. This is a command to diagnose | |
17909 | problems internal to @value{GDBN} and should not be needed in normal | |
17910 | usage. | |
17911 | ||
17912 | @item show debug mach-o | |
17913 | @kindex show debug mach-o | |
17914 | Show the current state of Mach-O file messages. | |
17915 | ||
17916 | @item set mach-exceptions on | |
17917 | @itemx set mach-exceptions off | |
17918 | @kindex set mach-exceptions | |
17919 | On Darwin, faults are first reported as a Mach exception and are then | |
17920 | mapped to a Posix signal. Use this command to turn on trapping of | |
17921 | Mach exceptions in the inferior. This might be sometimes useful to | |
17922 | better understand the cause of a fault. The default is off. | |
17923 | ||
17924 | @item show mach-exceptions | |
17925 | @kindex show mach-exceptions | |
17926 | Show the current state of exceptions trapping. | |
17927 | @end table | |
17928 | ||
a64548ea | 17929 | |
8e04817f AC |
17930 | @node Embedded OS |
17931 | @section Embedded Operating Systems | |
104c1213 | 17932 | |
8e04817f AC |
17933 | This section describes configurations involving the debugging of |
17934 | embedded operating systems that are available for several different | |
17935 | architectures. | |
d4f3574e | 17936 | |
8e04817f AC |
17937 | @menu |
17938 | * VxWorks:: Using @value{GDBN} with VxWorks | |
17939 | @end menu | |
104c1213 | 17940 | |
8e04817f AC |
17941 | @value{GDBN} includes the ability to debug programs running on |
17942 | various real-time operating systems. | |
104c1213 | 17943 | |
8e04817f AC |
17944 | @node VxWorks |
17945 | @subsection Using @value{GDBN} with VxWorks | |
104c1213 | 17946 | |
8e04817f | 17947 | @cindex VxWorks |
104c1213 | 17948 | |
8e04817f | 17949 | @table @code |
104c1213 | 17950 | |
8e04817f AC |
17951 | @kindex target vxworks |
17952 | @item target vxworks @var{machinename} | |
17953 | A VxWorks system, attached via TCP/IP. The argument @var{machinename} | |
17954 | is the target system's machine name or IP address. | |
104c1213 | 17955 | |
8e04817f | 17956 | @end table |
104c1213 | 17957 | |
8e04817f AC |
17958 | On VxWorks, @code{load} links @var{filename} dynamically on the |
17959 | current target system as well as adding its symbols in @value{GDBN}. | |
104c1213 | 17960 | |
8e04817f AC |
17961 | @value{GDBN} enables developers to spawn and debug tasks running on networked |
17962 | VxWorks targets from a Unix host. Already-running tasks spawned from | |
17963 | the VxWorks shell can also be debugged. @value{GDBN} uses code that runs on | |
17964 | both the Unix host and on the VxWorks target. The program | |
17965 | @code{@value{GDBP}} is installed and executed on the Unix host. (It may be | |
17966 | installed with the name @code{vxgdb}, to distinguish it from a | |
17967 | @value{GDBN} for debugging programs on the host itself.) | |
104c1213 | 17968 | |
8e04817f AC |
17969 | @table @code |
17970 | @item VxWorks-timeout @var{args} | |
17971 | @kindex vxworks-timeout | |
17972 | All VxWorks-based targets now support the option @code{vxworks-timeout}. | |
17973 | This option is set by the user, and @var{args} represents the number of | |
17974 | seconds @value{GDBN} waits for responses to rpc's. You might use this if | |
17975 | your VxWorks target is a slow software simulator or is on the far side | |
17976 | of a thin network line. | |
17977 | @end table | |
104c1213 | 17978 | |
8e04817f AC |
17979 | The following information on connecting to VxWorks was current when |
17980 | this manual was produced; newer releases of VxWorks may use revised | |
17981 | procedures. | |
104c1213 | 17982 | |
4644b6e3 | 17983 | @findex INCLUDE_RDB |
8e04817f AC |
17984 | To use @value{GDBN} with VxWorks, you must rebuild your VxWorks kernel |
17985 | to include the remote debugging interface routines in the VxWorks | |
17986 | library @file{rdb.a}. To do this, define @code{INCLUDE_RDB} in the | |
17987 | VxWorks configuration file @file{configAll.h} and rebuild your VxWorks | |
17988 | kernel. The resulting kernel contains @file{rdb.a}, and spawns the | |
17989 | source debugging task @code{tRdbTask} when VxWorks is booted. For more | |
17990 | information on configuring and remaking VxWorks, see the manufacturer's | |
17991 | manual. | |
17992 | @c VxWorks, see the @cite{VxWorks Programmer's Guide}. | |
104c1213 | 17993 | |
8e04817f AC |
17994 | Once you have included @file{rdb.a} in your VxWorks system image and set |
17995 | your Unix execution search path to find @value{GDBN}, you are ready to | |
17996 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} (or | |
17997 | @code{vxgdb}, depending on your installation). | |
104c1213 | 17998 | |
8e04817f | 17999 | @value{GDBN} comes up showing the prompt: |
104c1213 | 18000 | |
474c8240 | 18001 | @smallexample |
8e04817f | 18002 | (vxgdb) |
474c8240 | 18003 | @end smallexample |
104c1213 | 18004 | |
8e04817f AC |
18005 | @menu |
18006 | * VxWorks Connection:: Connecting to VxWorks | |
18007 | * VxWorks Download:: VxWorks download | |
18008 | * VxWorks Attach:: Running tasks | |
18009 | @end menu | |
104c1213 | 18010 | |
8e04817f AC |
18011 | @node VxWorks Connection |
18012 | @subsubsection Connecting to VxWorks | |
104c1213 | 18013 | |
8e04817f AC |
18014 | The @value{GDBN} command @code{target} lets you connect to a VxWorks target on the |
18015 | network. To connect to a target whose host name is ``@code{tt}'', type: | |
104c1213 | 18016 | |
474c8240 | 18017 | @smallexample |
8e04817f | 18018 | (vxgdb) target vxworks tt |
474c8240 | 18019 | @end smallexample |
104c1213 | 18020 | |
8e04817f AC |
18021 | @need 750 |
18022 | @value{GDBN} displays messages like these: | |
104c1213 | 18023 | |
8e04817f AC |
18024 | @smallexample |
18025 | Attaching remote machine across net... | |
18026 | Connected to tt. | |
18027 | @end smallexample | |
104c1213 | 18028 | |
8e04817f AC |
18029 | @need 1000 |
18030 | @value{GDBN} then attempts to read the symbol tables of any object modules | |
18031 | loaded into the VxWorks target since it was last booted. @value{GDBN} locates | |
18032 | these files by searching the directories listed in the command search | |
79a6e687 | 18033 | path (@pxref{Environment, ,Your Program's Environment}); if it fails |
8e04817f | 18034 | to find an object file, it displays a message such as: |
5d161b24 | 18035 | |
474c8240 | 18036 | @smallexample |
8e04817f | 18037 | prog.o: No such file or directory. |
474c8240 | 18038 | @end smallexample |
104c1213 | 18039 | |
8e04817f AC |
18040 | When this happens, add the appropriate directory to the search path with |
18041 | the @value{GDBN} command @code{path}, and execute the @code{target} | |
18042 | command again. | |
104c1213 | 18043 | |
8e04817f | 18044 | @node VxWorks Download |
79a6e687 | 18045 | @subsubsection VxWorks Download |
104c1213 | 18046 | |
8e04817f AC |
18047 | @cindex download to VxWorks |
18048 | If you have connected to the VxWorks target and you want to debug an | |
18049 | object that has not yet been loaded, you can use the @value{GDBN} | |
18050 | @code{load} command to download a file from Unix to VxWorks | |
18051 | incrementally. The object file given as an argument to the @code{load} | |
18052 | command is actually opened twice: first by the VxWorks target in order | |
18053 | to download the code, then by @value{GDBN} in order to read the symbol | |
18054 | table. This can lead to problems if the current working directories on | |
18055 | the two systems differ. If both systems have NFS mounted the same | |
18056 | filesystems, you can avoid these problems by using absolute paths. | |
18057 | Otherwise, it is simplest to set the working directory on both systems | |
18058 | to the directory in which the object file resides, and then to reference | |
18059 | the file by its name, without any path. For instance, a program | |
18060 | @file{prog.o} may reside in @file{@var{vxpath}/vw/demo/rdb} in VxWorks | |
18061 | and in @file{@var{hostpath}/vw/demo/rdb} on the host. To load this | |
18062 | program, type this on VxWorks: | |
104c1213 | 18063 | |
474c8240 | 18064 | @smallexample |
8e04817f | 18065 | -> cd "@var{vxpath}/vw/demo/rdb" |
474c8240 | 18066 | @end smallexample |
104c1213 | 18067 | |
8e04817f AC |
18068 | @noindent |
18069 | Then, in @value{GDBN}, type: | |
104c1213 | 18070 | |
474c8240 | 18071 | @smallexample |
8e04817f AC |
18072 | (vxgdb) cd @var{hostpath}/vw/demo/rdb |
18073 | (vxgdb) load prog.o | |
474c8240 | 18074 | @end smallexample |
104c1213 | 18075 | |
8e04817f | 18076 | @value{GDBN} displays a response similar to this: |
104c1213 | 18077 | |
8e04817f AC |
18078 | @smallexample |
18079 | Reading symbol data from wherever/vw/demo/rdb/prog.o... done. | |
18080 | @end smallexample | |
104c1213 | 18081 | |
8e04817f AC |
18082 | You can also use the @code{load} command to reload an object module |
18083 | after editing and recompiling the corresponding source file. Note that | |
18084 | this makes @value{GDBN} delete all currently-defined breakpoints, | |
18085 | auto-displays, and convenience variables, and to clear the value | |
18086 | history. (This is necessary in order to preserve the integrity of | |
18087 | debugger's data structures that reference the target system's symbol | |
18088 | table.) | |
104c1213 | 18089 | |
8e04817f | 18090 | @node VxWorks Attach |
79a6e687 | 18091 | @subsubsection Running Tasks |
104c1213 JM |
18092 | |
18093 | @cindex running VxWorks tasks | |
18094 | You can also attach to an existing task using the @code{attach} command as | |
18095 | follows: | |
18096 | ||
474c8240 | 18097 | @smallexample |
104c1213 | 18098 | (vxgdb) attach @var{task} |
474c8240 | 18099 | @end smallexample |
104c1213 JM |
18100 | |
18101 | @noindent | |
18102 | where @var{task} is the VxWorks hexadecimal task ID. The task can be running | |
18103 | or suspended when you attach to it. Running tasks are suspended at | |
18104 | the time of attachment. | |
18105 | ||
6d2ebf8b | 18106 | @node Embedded Processors |
104c1213 JM |
18107 | @section Embedded Processors |
18108 | ||
18109 | This section goes into details specific to particular embedded | |
18110 | configurations. | |
18111 | ||
c45da7e6 EZ |
18112 | @cindex send command to simulator |
18113 | Whenever a specific embedded processor has a simulator, @value{GDBN} | |
18114 | allows to send an arbitrary command to the simulator. | |
18115 | ||
18116 | @table @code | |
18117 | @item sim @var{command} | |
18118 | @kindex sim@r{, a command} | |
18119 | Send an arbitrary @var{command} string to the simulator. Consult the | |
18120 | documentation for the specific simulator in use for information about | |
18121 | acceptable commands. | |
18122 | @end table | |
18123 | ||
7d86b5d5 | 18124 | |
104c1213 | 18125 | @menu |
c45da7e6 | 18126 | * ARM:: ARM RDI |
172c2a43 | 18127 | * M32R/D:: Renesas M32R/D |
104c1213 | 18128 | * M68K:: Motorola M68K |
08be9d71 | 18129 | * MicroBlaze:: Xilinx MicroBlaze |
104c1213 | 18130 | * MIPS Embedded:: MIPS Embedded |
a37295f9 | 18131 | * OpenRISC 1000:: OpenRisc 1000 |
104c1213 | 18132 | * PA:: HP PA Embedded |
4acd40f3 | 18133 | * PowerPC Embedded:: PowerPC Embedded |
104c1213 JM |
18134 | * Sparclet:: Tsqware Sparclet |
18135 | * Sparclite:: Fujitsu Sparclite | |
104c1213 | 18136 | * Z8000:: Zilog Z8000 |
a64548ea EZ |
18137 | * AVR:: Atmel AVR |
18138 | * CRIS:: CRIS | |
18139 | * Super-H:: Renesas Super-H | |
104c1213 JM |
18140 | @end menu |
18141 | ||
6d2ebf8b | 18142 | @node ARM |
104c1213 | 18143 | @subsection ARM |
c45da7e6 | 18144 | @cindex ARM RDI |
104c1213 JM |
18145 | |
18146 | @table @code | |
8e04817f AC |
18147 | @kindex target rdi |
18148 | @item target rdi @var{dev} | |
18149 | ARM Angel monitor, via RDI library interface to ADP protocol. You may | |
18150 | use this target to communicate with both boards running the Angel | |
18151 | monitor, or with the EmbeddedICE JTAG debug device. | |
18152 | ||
18153 | @kindex target rdp | |
18154 | @item target rdp @var{dev} | |
18155 | ARM Demon monitor. | |
18156 | ||
18157 | @end table | |
18158 | ||
e2f4edfd EZ |
18159 | @value{GDBN} provides the following ARM-specific commands: |
18160 | ||
18161 | @table @code | |
18162 | @item set arm disassembler | |
18163 | @kindex set arm | |
18164 | This commands selects from a list of disassembly styles. The | |
18165 | @code{"std"} style is the standard style. | |
18166 | ||
18167 | @item show arm disassembler | |
18168 | @kindex show arm | |
18169 | Show the current disassembly style. | |
18170 | ||
18171 | @item set arm apcs32 | |
18172 | @cindex ARM 32-bit mode | |
18173 | This command toggles ARM operation mode between 32-bit and 26-bit. | |
18174 | ||
18175 | @item show arm apcs32 | |
18176 | Display the current usage of the ARM 32-bit mode. | |
18177 | ||
18178 | @item set arm fpu @var{fputype} | |
18179 | This command sets the ARM floating-point unit (FPU) type. The | |
18180 | argument @var{fputype} can be one of these: | |
18181 | ||
18182 | @table @code | |
18183 | @item auto | |
18184 | Determine the FPU type by querying the OS ABI. | |
18185 | @item softfpa | |
18186 | Software FPU, with mixed-endian doubles on little-endian ARM | |
18187 | processors. | |
18188 | @item fpa | |
18189 | GCC-compiled FPA co-processor. | |
18190 | @item softvfp | |
18191 | Software FPU with pure-endian doubles. | |
18192 | @item vfp | |
18193 | VFP co-processor. | |
18194 | @end table | |
18195 | ||
18196 | @item show arm fpu | |
18197 | Show the current type of the FPU. | |
18198 | ||
18199 | @item set arm abi | |
18200 | This command forces @value{GDBN} to use the specified ABI. | |
18201 | ||
18202 | @item show arm abi | |
18203 | Show the currently used ABI. | |
18204 | ||
0428b8f5 DJ |
18205 | @item set arm fallback-mode (arm|thumb|auto) |
18206 | @value{GDBN} uses the symbol table, when available, to determine | |
18207 | whether instructions are ARM or Thumb. This command controls | |
18208 | @value{GDBN}'s default behavior when the symbol table is not | |
18209 | available. The default is @samp{auto}, which causes @value{GDBN} to | |
18210 | use the current execution mode (from the @code{T} bit in the @code{CPSR} | |
18211 | register). | |
18212 | ||
18213 | @item show arm fallback-mode | |
18214 | Show the current fallback instruction mode. | |
18215 | ||
18216 | @item set arm force-mode (arm|thumb|auto) | |
18217 | This command overrides use of the symbol table to determine whether | |
18218 | instructions are ARM or Thumb. The default is @samp{auto}, which | |
18219 | causes @value{GDBN} to use the symbol table and then the setting | |
18220 | of @samp{set arm fallback-mode}. | |
18221 | ||
18222 | @item show arm force-mode | |
18223 | Show the current forced instruction mode. | |
18224 | ||
e2f4edfd EZ |
18225 | @item set debug arm |
18226 | Toggle whether to display ARM-specific debugging messages from the ARM | |
18227 | target support subsystem. | |
18228 | ||
18229 | @item show debug arm | |
18230 | Show whether ARM-specific debugging messages are enabled. | |
18231 | @end table | |
18232 | ||
c45da7e6 EZ |
18233 | The following commands are available when an ARM target is debugged |
18234 | using the RDI interface: | |
18235 | ||
18236 | @table @code | |
18237 | @item rdilogfile @r{[}@var{file}@r{]} | |
18238 | @kindex rdilogfile | |
18239 | @cindex ADP (Angel Debugger Protocol) logging | |
18240 | Set the filename for the ADP (Angel Debugger Protocol) packet log. | |
18241 | With an argument, sets the log file to the specified @var{file}. With | |
18242 | no argument, show the current log file name. The default log file is | |
18243 | @file{rdi.log}. | |
18244 | ||
18245 | @item rdilogenable @r{[}@var{arg}@r{]} | |
18246 | @kindex rdilogenable | |
18247 | Control logging of ADP packets. With an argument of 1 or @code{"yes"} | |
18248 | enables logging, with an argument 0 or @code{"no"} disables it. With | |
18249 | no arguments displays the current setting. When logging is enabled, | |
18250 | ADP packets exchanged between @value{GDBN} and the RDI target device | |
18251 | are logged to a file. | |
18252 | ||
18253 | @item set rdiromatzero | |
18254 | @kindex set rdiromatzero | |
18255 | @cindex ROM at zero address, RDI | |
18256 | Tell @value{GDBN} whether the target has ROM at address 0. If on, | |
18257 | vector catching is disabled, so that zero address can be used. If off | |
18258 | (the default), vector catching is enabled. For this command to take | |
18259 | effect, it needs to be invoked prior to the @code{target rdi} command. | |
18260 | ||
18261 | @item show rdiromatzero | |
18262 | @kindex show rdiromatzero | |
18263 | Show the current setting of ROM at zero address. | |
18264 | ||
18265 | @item set rdiheartbeat | |
18266 | @kindex set rdiheartbeat | |
18267 | @cindex RDI heartbeat | |
18268 | Enable or disable RDI heartbeat packets. It is not recommended to | |
18269 | turn on this option, since it confuses ARM and EPI JTAG interface, as | |
18270 | well as the Angel monitor. | |
18271 | ||
18272 | @item show rdiheartbeat | |
18273 | @kindex show rdiheartbeat | |
18274 | Show the setting of RDI heartbeat packets. | |
18275 | @end table | |
18276 | ||
ee8e71d4 EZ |
18277 | @table @code |
18278 | @item target sim @r{[}@var{simargs}@r{]} @dots{} | |
18279 | The @value{GDBN} ARM simulator accepts the following optional arguments. | |
18280 | ||
18281 | @table @code | |
18282 | @item --swi-support=@var{type} | |
18283 | Tell the simulator which SWI interfaces to support. | |
18284 | @var{type} may be a comma separated list of the following values. | |
18285 | The default value is @code{all}. | |
18286 | ||
18287 | @table @code | |
18288 | @item none | |
18289 | @item demon | |
18290 | @item angel | |
18291 | @item redboot | |
18292 | @item all | |
18293 | @end table | |
18294 | @end table | |
18295 | @end table | |
e2f4edfd | 18296 | |
8e04817f | 18297 | @node M32R/D |
ba04e063 | 18298 | @subsection Renesas M32R/D and M32R/SDI |
8e04817f AC |
18299 | |
18300 | @table @code | |
8e04817f AC |
18301 | @kindex target m32r |
18302 | @item target m32r @var{dev} | |
172c2a43 | 18303 | Renesas M32R/D ROM monitor. |
8e04817f | 18304 | |
fb3e19c0 KI |
18305 | @kindex target m32rsdi |
18306 | @item target m32rsdi @var{dev} | |
18307 | Renesas M32R SDI server, connected via parallel port to the board. | |
721c2651 EZ |
18308 | @end table |
18309 | ||
18310 | The following @value{GDBN} commands are specific to the M32R monitor: | |
18311 | ||
18312 | @table @code | |
18313 | @item set download-path @var{path} | |
18314 | @kindex set download-path | |
18315 | @cindex find downloadable @sc{srec} files (M32R) | |
d3e8051b | 18316 | Set the default path for finding downloadable @sc{srec} files. |
721c2651 EZ |
18317 | |
18318 | @item show download-path | |
18319 | @kindex show download-path | |
18320 | Show the default path for downloadable @sc{srec} files. | |
fb3e19c0 | 18321 | |
721c2651 EZ |
18322 | @item set board-address @var{addr} |
18323 | @kindex set board-address | |
18324 | @cindex M32-EVA target board address | |
18325 | Set the IP address for the M32R-EVA target board. | |
18326 | ||
18327 | @item show board-address | |
18328 | @kindex show board-address | |
18329 | Show the current IP address of the target board. | |
18330 | ||
18331 | @item set server-address @var{addr} | |
18332 | @kindex set server-address | |
18333 | @cindex download server address (M32R) | |
18334 | Set the IP address for the download server, which is the @value{GDBN}'s | |
18335 | host machine. | |
18336 | ||
18337 | @item show server-address | |
18338 | @kindex show server-address | |
18339 | Display the IP address of the download server. | |
18340 | ||
18341 | @item upload @r{[}@var{file}@r{]} | |
18342 | @kindex upload@r{, M32R} | |
18343 | Upload the specified @sc{srec} @var{file} via the monitor's Ethernet | |
18344 | upload capability. If no @var{file} argument is given, the current | |
18345 | executable file is uploaded. | |
18346 | ||
18347 | @item tload @r{[}@var{file}@r{]} | |
18348 | @kindex tload@r{, M32R} | |
18349 | Test the @code{upload} command. | |
8e04817f AC |
18350 | @end table |
18351 | ||
ba04e063 EZ |
18352 | The following commands are available for M32R/SDI: |
18353 | ||
18354 | @table @code | |
18355 | @item sdireset | |
18356 | @kindex sdireset | |
18357 | @cindex reset SDI connection, M32R | |
18358 | This command resets the SDI connection. | |
18359 | ||
18360 | @item sdistatus | |
18361 | @kindex sdistatus | |
18362 | This command shows the SDI connection status. | |
18363 | ||
18364 | @item debug_chaos | |
18365 | @kindex debug_chaos | |
18366 | @cindex M32R/Chaos debugging | |
18367 | Instructs the remote that M32R/Chaos debugging is to be used. | |
18368 | ||
18369 | @item use_debug_dma | |
18370 | @kindex use_debug_dma | |
18371 | Instructs the remote to use the DEBUG_DMA method of accessing memory. | |
18372 | ||
18373 | @item use_mon_code | |
18374 | @kindex use_mon_code | |
18375 | Instructs the remote to use the MON_CODE method of accessing memory. | |
18376 | ||
18377 | @item use_ib_break | |
18378 | @kindex use_ib_break | |
18379 | Instructs the remote to set breakpoints by IB break. | |
18380 | ||
18381 | @item use_dbt_break | |
18382 | @kindex use_dbt_break | |
18383 | Instructs the remote to set breakpoints by DBT. | |
18384 | @end table | |
18385 | ||
8e04817f AC |
18386 | @node M68K |
18387 | @subsection M68k | |
18388 | ||
7ce59000 DJ |
18389 | The Motorola m68k configuration includes ColdFire support, and a |
18390 | target command for the following ROM monitor. | |
8e04817f AC |
18391 | |
18392 | @table @code | |
18393 | ||
8e04817f AC |
18394 | @kindex target dbug |
18395 | @item target dbug @var{dev} | |
18396 | dBUG ROM monitor for Motorola ColdFire. | |
18397 | ||
8e04817f AC |
18398 | @end table |
18399 | ||
08be9d71 ME |
18400 | @node MicroBlaze |
18401 | @subsection MicroBlaze | |
18402 | @cindex Xilinx MicroBlaze | |
18403 | @cindex XMD, Xilinx Microprocessor Debugger | |
18404 | ||
18405 | The MicroBlaze is a soft-core processor supported on various Xilinx | |
18406 | FPGAs, such as Spartan or Virtex series. Boards with these processors | |
18407 | usually have JTAG ports which connect to a host system running the Xilinx | |
18408 | Embedded Development Kit (EDK) or Software Development Kit (SDK). | |
18409 | This host system is used to download the configuration bitstream to | |
18410 | the target FPGA. The Xilinx Microprocessor Debugger (XMD) program | |
18411 | communicates with the target board using the JTAG interface and | |
18412 | presents a @code{gdbserver} interface to the board. By default | |
18413 | @code{xmd} uses port @code{1234}. (While it is possible to change | |
18414 | this default port, it requires the use of undocumented @code{xmd} | |
18415 | commands. Contact Xilinx support if you need to do this.) | |
18416 | ||
18417 | Use these GDB commands to connect to the MicroBlaze target processor. | |
18418 | ||
18419 | @table @code | |
18420 | @item target remote :1234 | |
18421 | Use this command to connect to the target if you are running @value{GDBN} | |
18422 | on the same system as @code{xmd}. | |
18423 | ||
18424 | @item target remote @var{xmd-host}:1234 | |
18425 | Use this command to connect to the target if it is connected to @code{xmd} | |
18426 | running on a different system named @var{xmd-host}. | |
18427 | ||
18428 | @item load | |
18429 | Use this command to download a program to the MicroBlaze target. | |
18430 | ||
18431 | @item set debug microblaze @var{n} | |
18432 | Enable MicroBlaze-specific debugging messages if non-zero. | |
18433 | ||
18434 | @item show debug microblaze @var{n} | |
18435 | Show MicroBlaze-specific debugging level. | |
18436 | @end table | |
18437 | ||
8e04817f AC |
18438 | @node MIPS Embedded |
18439 | @subsection MIPS Embedded | |
18440 | ||
18441 | @cindex MIPS boards | |
18442 | @value{GDBN} can use the MIPS remote debugging protocol to talk to a | |
18443 | MIPS board attached to a serial line. This is available when | |
18444 | you configure @value{GDBN} with @samp{--target=mips-idt-ecoff}. | |
104c1213 | 18445 | |
8e04817f AC |
18446 | @need 1000 |
18447 | Use these @value{GDBN} commands to specify the connection to your target board: | |
104c1213 | 18448 | |
8e04817f AC |
18449 | @table @code |
18450 | @item target mips @var{port} | |
18451 | @kindex target mips @var{port} | |
18452 | To run a program on the board, start up @code{@value{GDBP}} with the | |
18453 | name of your program as the argument. To connect to the board, use the | |
18454 | command @samp{target mips @var{port}}, where @var{port} is the name of | |
18455 | the serial port connected to the board. If the program has not already | |
18456 | been downloaded to the board, you may use the @code{load} command to | |
18457 | download it. You can then use all the usual @value{GDBN} commands. | |
104c1213 | 18458 | |
8e04817f AC |
18459 | For example, this sequence connects to the target board through a serial |
18460 | port, and loads and runs a program called @var{prog} through the | |
18461 | debugger: | |
104c1213 | 18462 | |
474c8240 | 18463 | @smallexample |
8e04817f AC |
18464 | host$ @value{GDBP} @var{prog} |
18465 | @value{GDBN} is free software and @dots{} | |
18466 | (@value{GDBP}) target mips /dev/ttyb | |
18467 | (@value{GDBP}) load @var{prog} | |
18468 | (@value{GDBP}) run | |
474c8240 | 18469 | @end smallexample |
104c1213 | 18470 | |
8e04817f AC |
18471 | @item target mips @var{hostname}:@var{portnumber} |
18472 | On some @value{GDBN} host configurations, you can specify a TCP | |
18473 | connection (for instance, to a serial line managed by a terminal | |
18474 | concentrator) instead of a serial port, using the syntax | |
18475 | @samp{@var{hostname}:@var{portnumber}}. | |
104c1213 | 18476 | |
8e04817f AC |
18477 | @item target pmon @var{port} |
18478 | @kindex target pmon @var{port} | |
18479 | PMON ROM monitor. | |
104c1213 | 18480 | |
8e04817f AC |
18481 | @item target ddb @var{port} |
18482 | @kindex target ddb @var{port} | |
18483 | NEC's DDB variant of PMON for Vr4300. | |
104c1213 | 18484 | |
8e04817f AC |
18485 | @item target lsi @var{port} |
18486 | @kindex target lsi @var{port} | |
18487 | LSI variant of PMON. | |
104c1213 | 18488 | |
8e04817f AC |
18489 | @kindex target r3900 |
18490 | @item target r3900 @var{dev} | |
18491 | Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips. | |
104c1213 | 18492 | |
8e04817f AC |
18493 | @kindex target array |
18494 | @item target array @var{dev} | |
18495 | Array Tech LSI33K RAID controller board. | |
104c1213 | 18496 | |
8e04817f | 18497 | @end table |
104c1213 | 18498 | |
104c1213 | 18499 | |
8e04817f AC |
18500 | @noindent |
18501 | @value{GDBN} also supports these special commands for MIPS targets: | |
104c1213 | 18502 | |
8e04817f | 18503 | @table @code |
8e04817f AC |
18504 | @item set mipsfpu double |
18505 | @itemx set mipsfpu single | |
18506 | @itemx set mipsfpu none | |
a64548ea | 18507 | @itemx set mipsfpu auto |
8e04817f AC |
18508 | @itemx show mipsfpu |
18509 | @kindex set mipsfpu | |
18510 | @kindex show mipsfpu | |
18511 | @cindex MIPS remote floating point | |
18512 | @cindex floating point, MIPS remote | |
18513 | If your target board does not support the MIPS floating point | |
18514 | coprocessor, you should use the command @samp{set mipsfpu none} (if you | |
18515 | need this, you may wish to put the command in your @value{GDBN} init | |
18516 | file). This tells @value{GDBN} how to find the return value of | |
18517 | functions which return floating point values. It also allows | |
18518 | @value{GDBN} to avoid saving the floating point registers when calling | |
18519 | functions on the board. If you are using a floating point coprocessor | |
18520 | with only single precision floating point support, as on the @sc{r4650} | |
18521 | processor, use the command @samp{set mipsfpu single}. The default | |
18522 | double precision floating point coprocessor may be selected using | |
18523 | @samp{set mipsfpu double}. | |
104c1213 | 18524 | |
8e04817f AC |
18525 | In previous versions the only choices were double precision or no |
18526 | floating point, so @samp{set mipsfpu on} will select double precision | |
18527 | and @samp{set mipsfpu off} will select no floating point. | |
104c1213 | 18528 | |
8e04817f AC |
18529 | As usual, you can inquire about the @code{mipsfpu} variable with |
18530 | @samp{show mipsfpu}. | |
104c1213 | 18531 | |
8e04817f AC |
18532 | @item set timeout @var{seconds} |
18533 | @itemx set retransmit-timeout @var{seconds} | |
18534 | @itemx show timeout | |
18535 | @itemx show retransmit-timeout | |
18536 | @cindex @code{timeout}, MIPS protocol | |
18537 | @cindex @code{retransmit-timeout}, MIPS protocol | |
18538 | @kindex set timeout | |
18539 | @kindex show timeout | |
18540 | @kindex set retransmit-timeout | |
18541 | @kindex show retransmit-timeout | |
18542 | You can control the timeout used while waiting for a packet, in the MIPS | |
18543 | remote protocol, with the @code{set timeout @var{seconds}} command. The | |
18544 | default is 5 seconds. Similarly, you can control the timeout used while | |
a6f3e723 | 18545 | waiting for an acknowledgment of a packet with the @code{set |
8e04817f AC |
18546 | retransmit-timeout @var{seconds}} command. The default is 3 seconds. |
18547 | You can inspect both values with @code{show timeout} and @code{show | |
18548 | retransmit-timeout}. (These commands are @emph{only} available when | |
18549 | @value{GDBN} is configured for @samp{--target=mips-idt-ecoff}.) | |
104c1213 | 18550 | |
8e04817f AC |
18551 | The timeout set by @code{set timeout} does not apply when @value{GDBN} |
18552 | is waiting for your program to stop. In that case, @value{GDBN} waits | |
18553 | forever because it has no way of knowing how long the program is going | |
18554 | to run before stopping. | |
ba04e063 EZ |
18555 | |
18556 | @item set syn-garbage-limit @var{num} | |
18557 | @kindex set syn-garbage-limit@r{, MIPS remote} | |
18558 | @cindex synchronize with remote MIPS target | |
18559 | Limit the maximum number of characters @value{GDBN} should ignore when | |
18560 | it tries to synchronize with the remote target. The default is 10 | |
18561 | characters. Setting the limit to -1 means there's no limit. | |
18562 | ||
18563 | @item show syn-garbage-limit | |
18564 | @kindex show syn-garbage-limit@r{, MIPS remote} | |
18565 | Show the current limit on the number of characters to ignore when | |
18566 | trying to synchronize with the remote system. | |
18567 | ||
18568 | @item set monitor-prompt @var{prompt} | |
18569 | @kindex set monitor-prompt@r{, MIPS remote} | |
18570 | @cindex remote monitor prompt | |
18571 | Tell @value{GDBN} to expect the specified @var{prompt} string from the | |
18572 | remote monitor. The default depends on the target: | |
18573 | @table @asis | |
18574 | @item pmon target | |
18575 | @samp{PMON} | |
18576 | @item ddb target | |
18577 | @samp{NEC010} | |
18578 | @item lsi target | |
18579 | @samp{PMON>} | |
18580 | @end table | |
18581 | ||
18582 | @item show monitor-prompt | |
18583 | @kindex show monitor-prompt@r{, MIPS remote} | |
18584 | Show the current strings @value{GDBN} expects as the prompt from the | |
18585 | remote monitor. | |
18586 | ||
18587 | @item set monitor-warnings | |
18588 | @kindex set monitor-warnings@r{, MIPS remote} | |
18589 | Enable or disable monitor warnings about hardware breakpoints. This | |
18590 | has effect only for the @code{lsi} target. When on, @value{GDBN} will | |
18591 | display warning messages whose codes are returned by the @code{lsi} | |
18592 | PMON monitor for breakpoint commands. | |
18593 | ||
18594 | @item show monitor-warnings | |
18595 | @kindex show monitor-warnings@r{, MIPS remote} | |
18596 | Show the current setting of printing monitor warnings. | |
18597 | ||
18598 | @item pmon @var{command} | |
18599 | @kindex pmon@r{, MIPS remote} | |
18600 | @cindex send PMON command | |
18601 | This command allows sending an arbitrary @var{command} string to the | |
18602 | monitor. The monitor must be in debug mode for this to work. | |
8e04817f | 18603 | @end table |
104c1213 | 18604 | |
a37295f9 MM |
18605 | @node OpenRISC 1000 |
18606 | @subsection OpenRISC 1000 | |
18607 | @cindex OpenRISC 1000 | |
18608 | ||
18609 | @cindex or1k boards | |
18610 | See OR1k Architecture document (@uref{www.opencores.org}) for more information | |
18611 | about platform and commands. | |
18612 | ||
18613 | @table @code | |
18614 | ||
18615 | @kindex target jtag | |
18616 | @item target jtag jtag://@var{host}:@var{port} | |
18617 | ||
18618 | Connects to remote JTAG server. | |
18619 | JTAG remote server can be either an or1ksim or JTAG server, | |
18620 | connected via parallel port to the board. | |
18621 | ||
18622 | Example: @code{target jtag jtag://localhost:9999} | |
18623 | ||
18624 | @kindex or1ksim | |
18625 | @item or1ksim @var{command} | |
18626 | If connected to @code{or1ksim} OpenRISC 1000 Architectural | |
18627 | Simulator, proprietary commands can be executed. | |
18628 | ||
18629 | @kindex info or1k spr | |
18630 | @item info or1k spr | |
18631 | Displays spr groups. | |
18632 | ||
18633 | @item info or1k spr @var{group} | |
18634 | @itemx info or1k spr @var{groupno} | |
18635 | Displays register names in selected group. | |
18636 | ||
18637 | @item info or1k spr @var{group} @var{register} | |
18638 | @itemx info or1k spr @var{register} | |
18639 | @itemx info or1k spr @var{groupno} @var{registerno} | |
18640 | @itemx info or1k spr @var{registerno} | |
18641 | Shows information about specified spr register. | |
18642 | ||
18643 | @kindex spr | |
18644 | @item spr @var{group} @var{register} @var{value} | |
18645 | @itemx spr @var{register @var{value}} | |
18646 | @itemx spr @var{groupno} @var{registerno @var{value}} | |
18647 | @itemx spr @var{registerno @var{value}} | |
18648 | Writes @var{value} to specified spr register. | |
18649 | @end table | |
18650 | ||
18651 | Some implementations of OpenRISC 1000 Architecture also have hardware trace. | |
18652 | It is very similar to @value{GDBN} trace, except it does not interfere with normal | |
18653 | program execution and is thus much faster. Hardware breakpoints/watchpoint | |
18654 | triggers can be set using: | |
18655 | @table @code | |
18656 | @item $LEA/$LDATA | |
18657 | Load effective address/data | |
18658 | @item $SEA/$SDATA | |
18659 | Store effective address/data | |
18660 | @item $AEA/$ADATA | |
18661 | Access effective address ($SEA or $LEA) or data ($SDATA/$LDATA) | |
18662 | @item $FETCH | |
18663 | Fetch data | |
18664 | @end table | |
18665 | ||
18666 | When triggered, it can capture low level data, like: @code{PC}, @code{LSEA}, | |
18667 | @code{LDATA}, @code{SDATA}, @code{READSPR}, @code{WRITESPR}, @code{INSTR}. | |
18668 | ||
18669 | @code{htrace} commands: | |
18670 | @cindex OpenRISC 1000 htrace | |
18671 | @table @code | |
18672 | @kindex hwatch | |
18673 | @item hwatch @var{conditional} | |
d3e8051b | 18674 | Set hardware watchpoint on combination of Load/Store Effective Address(es) |
a37295f9 MM |
18675 | or Data. For example: |
18676 | ||
18677 | @code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)} | |
18678 | ||
18679 | @code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)} | |
18680 | ||
4644b6e3 | 18681 | @kindex htrace |
a37295f9 MM |
18682 | @item htrace info |
18683 | Display information about current HW trace configuration. | |
18684 | ||
a37295f9 MM |
18685 | @item htrace trigger @var{conditional} |
18686 | Set starting criteria for HW trace. | |
18687 | ||
a37295f9 MM |
18688 | @item htrace qualifier @var{conditional} |
18689 | Set acquisition qualifier for HW trace. | |
18690 | ||
a37295f9 MM |
18691 | @item htrace stop @var{conditional} |
18692 | Set HW trace stopping criteria. | |
18693 | ||
f153cc92 | 18694 | @item htrace record [@var{data}]* |
a37295f9 MM |
18695 | Selects the data to be recorded, when qualifier is met and HW trace was |
18696 | triggered. | |
18697 | ||
a37295f9 | 18698 | @item htrace enable |
a37295f9 MM |
18699 | @itemx htrace disable |
18700 | Enables/disables the HW trace. | |
18701 | ||
f153cc92 | 18702 | @item htrace rewind [@var{filename}] |
a37295f9 MM |
18703 | Clears currently recorded trace data. |
18704 | ||
18705 | If filename is specified, new trace file is made and any newly collected data | |
18706 | will be written there. | |
18707 | ||
f153cc92 | 18708 | @item htrace print [@var{start} [@var{len}]] |
a37295f9 MM |
18709 | Prints trace buffer, using current record configuration. |
18710 | ||
a37295f9 MM |
18711 | @item htrace mode continuous |
18712 | Set continuous trace mode. | |
18713 | ||
a37295f9 MM |
18714 | @item htrace mode suspend |
18715 | Set suspend trace mode. | |
18716 | ||
18717 | @end table | |
18718 | ||
4acd40f3 TJB |
18719 | @node PowerPC Embedded |
18720 | @subsection PowerPC Embedded | |
104c1213 | 18721 | |
66b73624 TJB |
18722 | @cindex DVC register |
18723 | @value{GDBN} supports using the DVC (Data Value Compare) register to | |
18724 | implement in hardware simple hardware watchpoint conditions of the form: | |
18725 | ||
18726 | @smallexample | |
18727 | (@value{GDBP}) watch @var{ADDRESS|VARIABLE} \ | |
18728 | if @var{ADDRESS|VARIABLE} == @var{CONSTANT EXPRESSION} | |
18729 | @end smallexample | |
18730 | ||
18731 | The DVC register will be automatically used whenever @value{GDBN} detects | |
18732 | such pattern in a condition expression. This feature is available in native | |
18733 | @value{GDBN} running on a Linux kernel version 2.6.34 or newer. | |
18734 | ||
55eddb0f DJ |
18735 | @value{GDBN} provides the following PowerPC-specific commands: |
18736 | ||
104c1213 | 18737 | @table @code |
55eddb0f DJ |
18738 | @kindex set powerpc |
18739 | @item set powerpc soft-float | |
18740 | @itemx show powerpc soft-float | |
18741 | Force @value{GDBN} to use (or not use) a software floating point calling | |
18742 | convention. By default, @value{GDBN} selects the calling convention based | |
18743 | on the selected architecture and the provided executable file. | |
18744 | ||
18745 | @item set powerpc vector-abi | |
18746 | @itemx show powerpc vector-abi | |
18747 | Force @value{GDBN} to use the specified calling convention for vector | |
18748 | arguments and return values. The valid options are @samp{auto}; | |
18749 | @samp{generic}, to avoid vector registers even if they are present; | |
18750 | @samp{altivec}, to use AltiVec registers; and @samp{spe} to use SPE | |
18751 | registers. By default, @value{GDBN} selects the calling convention | |
18752 | based on the selected architecture and the provided executable file. | |
18753 | ||
8e04817f AC |
18754 | @kindex target dink32 |
18755 | @item target dink32 @var{dev} | |
18756 | DINK32 ROM monitor. | |
104c1213 | 18757 | |
8e04817f AC |
18758 | @kindex target ppcbug |
18759 | @item target ppcbug @var{dev} | |
18760 | @kindex target ppcbug1 | |
18761 | @item target ppcbug1 @var{dev} | |
18762 | PPCBUG ROM monitor for PowerPC. | |
104c1213 | 18763 | |
8e04817f AC |
18764 | @kindex target sds |
18765 | @item target sds @var{dev} | |
18766 | SDS monitor, running on a PowerPC board (such as Motorola's ADS). | |
c45da7e6 | 18767 | @end table |
8e04817f | 18768 | |
c45da7e6 | 18769 | @cindex SDS protocol |
d52fb0e9 | 18770 | The following commands specific to the SDS protocol are supported |
55eddb0f | 18771 | by @value{GDBN}: |
c45da7e6 EZ |
18772 | |
18773 | @table @code | |
18774 | @item set sdstimeout @var{nsec} | |
18775 | @kindex set sdstimeout | |
18776 | Set the timeout for SDS protocol reads to be @var{nsec} seconds. The | |
18777 | default is 2 seconds. | |
18778 | ||
18779 | @item show sdstimeout | |
18780 | @kindex show sdstimeout | |
18781 | Show the current value of the SDS timeout. | |
18782 | ||
18783 | @item sds @var{command} | |
18784 | @kindex sds@r{, a command} | |
18785 | Send the specified @var{command} string to the SDS monitor. | |
8e04817f AC |
18786 | @end table |
18787 | ||
c45da7e6 | 18788 | |
8e04817f AC |
18789 | @node PA |
18790 | @subsection HP PA Embedded | |
104c1213 JM |
18791 | |
18792 | @table @code | |
18793 | ||
8e04817f AC |
18794 | @kindex target op50n |
18795 | @item target op50n @var{dev} | |
18796 | OP50N monitor, running on an OKI HPPA board. | |
18797 | ||
18798 | @kindex target w89k | |
18799 | @item target w89k @var{dev} | |
18800 | W89K monitor, running on a Winbond HPPA board. | |
104c1213 JM |
18801 | |
18802 | @end table | |
18803 | ||
8e04817f AC |
18804 | @node Sparclet |
18805 | @subsection Tsqware Sparclet | |
104c1213 | 18806 | |
8e04817f AC |
18807 | @cindex Sparclet |
18808 | ||
18809 | @value{GDBN} enables developers to debug tasks running on | |
18810 | Sparclet targets from a Unix host. | |
18811 | @value{GDBN} uses code that runs on | |
18812 | both the Unix host and on the Sparclet target. The program | |
18813 | @code{@value{GDBP}} is installed and executed on the Unix host. | |
104c1213 | 18814 | |
8e04817f AC |
18815 | @table @code |
18816 | @item remotetimeout @var{args} | |
18817 | @kindex remotetimeout | |
18818 | @value{GDBN} supports the option @code{remotetimeout}. | |
18819 | This option is set by the user, and @var{args} represents the number of | |
18820 | seconds @value{GDBN} waits for responses. | |
104c1213 JM |
18821 | @end table |
18822 | ||
8e04817f AC |
18823 | @cindex compiling, on Sparclet |
18824 | When compiling for debugging, include the options @samp{-g} to get debug | |
18825 | information and @samp{-Ttext} to relocate the program to where you wish to | |
18826 | load it on the target. You may also want to add the options @samp{-n} or | |
18827 | @samp{-N} in order to reduce the size of the sections. Example: | |
104c1213 | 18828 | |
474c8240 | 18829 | @smallexample |
8e04817f | 18830 | sparclet-aout-gcc prog.c -Ttext 0x12010000 -g -o prog -N |
474c8240 | 18831 | @end smallexample |
104c1213 | 18832 | |
8e04817f | 18833 | You can use @code{objdump} to verify that the addresses are what you intended: |
104c1213 | 18834 | |
474c8240 | 18835 | @smallexample |
8e04817f | 18836 | sparclet-aout-objdump --headers --syms prog |
474c8240 | 18837 | @end smallexample |
104c1213 | 18838 | |
8e04817f AC |
18839 | @cindex running, on Sparclet |
18840 | Once you have set | |
18841 | your Unix execution search path to find @value{GDBN}, you are ready to | |
18842 | run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} | |
18843 | (or @code{sparclet-aout-gdb}, depending on your installation). | |
104c1213 | 18844 | |
8e04817f AC |
18845 | @value{GDBN} comes up showing the prompt: |
18846 | ||
474c8240 | 18847 | @smallexample |
8e04817f | 18848 | (gdbslet) |
474c8240 | 18849 | @end smallexample |
104c1213 JM |
18850 | |
18851 | @menu | |
8e04817f AC |
18852 | * Sparclet File:: Setting the file to debug |
18853 | * Sparclet Connection:: Connecting to Sparclet | |
18854 | * Sparclet Download:: Sparclet download | |
18855 | * Sparclet Execution:: Running and debugging | |
104c1213 JM |
18856 | @end menu |
18857 | ||
8e04817f | 18858 | @node Sparclet File |
79a6e687 | 18859 | @subsubsection Setting File to Debug |
104c1213 | 18860 | |
8e04817f | 18861 | The @value{GDBN} command @code{file} lets you choose with program to debug. |
104c1213 | 18862 | |
474c8240 | 18863 | @smallexample |
8e04817f | 18864 | (gdbslet) file prog |
474c8240 | 18865 | @end smallexample |
104c1213 | 18866 | |
8e04817f AC |
18867 | @need 1000 |
18868 | @value{GDBN} then attempts to read the symbol table of @file{prog}. | |
18869 | @value{GDBN} locates | |
18870 | the file by searching the directories listed in the command search | |
18871 | path. | |
12c27660 | 18872 | If the file was compiled with debug information (option @samp{-g}), source |
8e04817f AC |
18873 | files will be searched as well. |
18874 | @value{GDBN} locates | |
18875 | the source files by searching the directories listed in the directory search | |
79a6e687 | 18876 | path (@pxref{Environment, ,Your Program's Environment}). |
8e04817f AC |
18877 | If it fails |
18878 | to find a file, it displays a message such as: | |
104c1213 | 18879 | |
474c8240 | 18880 | @smallexample |
8e04817f | 18881 | prog: No such file or directory. |
474c8240 | 18882 | @end smallexample |
104c1213 | 18883 | |
8e04817f AC |
18884 | When this happens, add the appropriate directories to the search paths with |
18885 | the @value{GDBN} commands @code{path} and @code{dir}, and execute the | |
18886 | @code{target} command again. | |
104c1213 | 18887 | |
8e04817f AC |
18888 | @node Sparclet Connection |
18889 | @subsubsection Connecting to Sparclet | |
104c1213 | 18890 | |
8e04817f AC |
18891 | The @value{GDBN} command @code{target} lets you connect to a Sparclet target. |
18892 | To connect to a target on serial port ``@code{ttya}'', type: | |
104c1213 | 18893 | |
474c8240 | 18894 | @smallexample |
8e04817f AC |
18895 | (gdbslet) target sparclet /dev/ttya |
18896 | Remote target sparclet connected to /dev/ttya | |
18897 | main () at ../prog.c:3 | |
474c8240 | 18898 | @end smallexample |
104c1213 | 18899 | |
8e04817f AC |
18900 | @need 750 |
18901 | @value{GDBN} displays messages like these: | |
104c1213 | 18902 | |
474c8240 | 18903 | @smallexample |
8e04817f | 18904 | Connected to ttya. |
474c8240 | 18905 | @end smallexample |
104c1213 | 18906 | |
8e04817f | 18907 | @node Sparclet Download |
79a6e687 | 18908 | @subsubsection Sparclet Download |
104c1213 | 18909 | |
8e04817f AC |
18910 | @cindex download to Sparclet |
18911 | Once connected to the Sparclet target, | |
18912 | you can use the @value{GDBN} | |
18913 | @code{load} command to download the file from the host to the target. | |
18914 | The file name and load offset should be given as arguments to the @code{load} | |
18915 | command. | |
18916 | Since the file format is aout, the program must be loaded to the starting | |
18917 | address. You can use @code{objdump} to find out what this value is. The load | |
18918 | offset is an offset which is added to the VMA (virtual memory address) | |
18919 | of each of the file's sections. | |
18920 | For instance, if the program | |
18921 | @file{prog} was linked to text address 0x1201000, with data at 0x12010160 | |
18922 | and bss at 0x12010170, in @value{GDBN}, type: | |
104c1213 | 18923 | |
474c8240 | 18924 | @smallexample |
8e04817f AC |
18925 | (gdbslet) load prog 0x12010000 |
18926 | Loading section .text, size 0xdb0 vma 0x12010000 | |
474c8240 | 18927 | @end smallexample |
104c1213 | 18928 | |
8e04817f AC |
18929 | If the code is loaded at a different address then what the program was linked |
18930 | to, you may need to use the @code{section} and @code{add-symbol-file} commands | |
18931 | to tell @value{GDBN} where to map the symbol table. | |
18932 | ||
18933 | @node Sparclet Execution | |
79a6e687 | 18934 | @subsubsection Running and Debugging |
8e04817f AC |
18935 | |
18936 | @cindex running and debugging Sparclet programs | |
18937 | You can now begin debugging the task using @value{GDBN}'s execution control | |
18938 | commands, @code{b}, @code{step}, @code{run}, etc. See the @value{GDBN} | |
18939 | manual for the list of commands. | |
18940 | ||
474c8240 | 18941 | @smallexample |
8e04817f AC |
18942 | (gdbslet) b main |
18943 | Breakpoint 1 at 0x12010000: file prog.c, line 3. | |
18944 | (gdbslet) run | |
18945 | Starting program: prog | |
18946 | Breakpoint 1, main (argc=1, argv=0xeffff21c) at prog.c:3 | |
18947 | 3 char *symarg = 0; | |
18948 | (gdbslet) step | |
18949 | 4 char *execarg = "hello!"; | |
18950 | (gdbslet) | |
474c8240 | 18951 | @end smallexample |
8e04817f AC |
18952 | |
18953 | @node Sparclite | |
18954 | @subsection Fujitsu Sparclite | |
104c1213 JM |
18955 | |
18956 | @table @code | |
18957 | ||
8e04817f AC |
18958 | @kindex target sparclite |
18959 | @item target sparclite @var{dev} | |
18960 | Fujitsu sparclite boards, used only for the purpose of loading. | |
18961 | You must use an additional command to debug the program. | |
18962 | For example: target remote @var{dev} using @value{GDBN} standard | |
18963 | remote protocol. | |
104c1213 JM |
18964 | |
18965 | @end table | |
18966 | ||
8e04817f AC |
18967 | @node Z8000 |
18968 | @subsection Zilog Z8000 | |
104c1213 | 18969 | |
8e04817f AC |
18970 | @cindex Z8000 |
18971 | @cindex simulator, Z8000 | |
18972 | @cindex Zilog Z8000 simulator | |
104c1213 | 18973 | |
8e04817f AC |
18974 | When configured for debugging Zilog Z8000 targets, @value{GDBN} includes |
18975 | a Z8000 simulator. | |
18976 | ||
18977 | For the Z8000 family, @samp{target sim} simulates either the Z8002 (the | |
18978 | unsegmented variant of the Z8000 architecture) or the Z8001 (the | |
18979 | segmented variant). The simulator recognizes which architecture is | |
18980 | appropriate by inspecting the object code. | |
104c1213 | 18981 | |
8e04817f AC |
18982 | @table @code |
18983 | @item target sim @var{args} | |
18984 | @kindex sim | |
18985 | @kindex target sim@r{, with Z8000} | |
18986 | Debug programs on a simulated CPU. If the simulator supports setup | |
18987 | options, specify them via @var{args}. | |
104c1213 JM |
18988 | @end table |
18989 | ||
8e04817f AC |
18990 | @noindent |
18991 | After specifying this target, you can debug programs for the simulated | |
18992 | CPU in the same style as programs for your host computer; use the | |
18993 | @code{file} command to load a new program image, the @code{run} command | |
18994 | to run your program, and so on. | |
18995 | ||
18996 | As well as making available all the usual machine registers | |
18997 | (@pxref{Registers, ,Registers}), the Z8000 simulator provides three | |
18998 | additional items of information as specially named registers: | |
104c1213 JM |
18999 | |
19000 | @table @code | |
19001 | ||
8e04817f AC |
19002 | @item cycles |
19003 | Counts clock-ticks in the simulator. | |
104c1213 | 19004 | |
8e04817f AC |
19005 | @item insts |
19006 | Counts instructions run in the simulator. | |
104c1213 | 19007 | |
8e04817f AC |
19008 | @item time |
19009 | Execution time in 60ths of a second. | |
104c1213 | 19010 | |
8e04817f | 19011 | @end table |
104c1213 | 19012 | |
8e04817f AC |
19013 | You can refer to these values in @value{GDBN} expressions with the usual |
19014 | conventions; for example, @w{@samp{b fputc if $cycles>5000}} sets a | |
19015 | conditional breakpoint that suspends only after at least 5000 | |
19016 | simulated clock ticks. | |
104c1213 | 19017 | |
a64548ea EZ |
19018 | @node AVR |
19019 | @subsection Atmel AVR | |
19020 | @cindex AVR | |
19021 | ||
19022 | When configured for debugging the Atmel AVR, @value{GDBN} supports the | |
19023 | following AVR-specific commands: | |
19024 | ||
19025 | @table @code | |
19026 | @item info io_registers | |
19027 | @kindex info io_registers@r{, AVR} | |
19028 | @cindex I/O registers (Atmel AVR) | |
19029 | This command displays information about the AVR I/O registers. For | |
19030 | each register, @value{GDBN} prints its number and value. | |
19031 | @end table | |
19032 | ||
19033 | @node CRIS | |
19034 | @subsection CRIS | |
19035 | @cindex CRIS | |
19036 | ||
19037 | When configured for debugging CRIS, @value{GDBN} provides the | |
19038 | following CRIS-specific commands: | |
19039 | ||
19040 | @table @code | |
19041 | @item set cris-version @var{ver} | |
19042 | @cindex CRIS version | |
e22e55c9 OF |
19043 | Set the current CRIS version to @var{ver}, either @samp{10} or @samp{32}. |
19044 | The CRIS version affects register names and sizes. This command is useful in | |
19045 | case autodetection of the CRIS version fails. | |
a64548ea EZ |
19046 | |
19047 | @item show cris-version | |
19048 | Show the current CRIS version. | |
19049 | ||
19050 | @item set cris-dwarf2-cfi | |
19051 | @cindex DWARF-2 CFI and CRIS | |
e22e55c9 OF |
19052 | Set the usage of DWARF-2 CFI for CRIS debugging. The default is @samp{on}. |
19053 | Change to @samp{off} when using @code{gcc-cris} whose version is below | |
19054 | @code{R59}. | |
a64548ea EZ |
19055 | |
19056 | @item show cris-dwarf2-cfi | |
19057 | Show the current state of using DWARF-2 CFI. | |
e22e55c9 OF |
19058 | |
19059 | @item set cris-mode @var{mode} | |
19060 | @cindex CRIS mode | |
19061 | Set the current CRIS mode to @var{mode}. It should only be changed when | |
19062 | debugging in guru mode, in which case it should be set to | |
19063 | @samp{guru} (the default is @samp{normal}). | |
19064 | ||
19065 | @item show cris-mode | |
19066 | Show the current CRIS mode. | |
a64548ea EZ |
19067 | @end table |
19068 | ||
19069 | @node Super-H | |
19070 | @subsection Renesas Super-H | |
19071 | @cindex Super-H | |
19072 | ||
19073 | For the Renesas Super-H processor, @value{GDBN} provides these | |
19074 | commands: | |
19075 | ||
19076 | @table @code | |
19077 | @item regs | |
19078 | @kindex regs@r{, Super-H} | |
19079 | Show the values of all Super-H registers. | |
c055b101 CV |
19080 | |
19081 | @item set sh calling-convention @var{convention} | |
19082 | @kindex set sh calling-convention | |
19083 | Set the calling-convention used when calling functions from @value{GDBN}. | |
19084 | Allowed values are @samp{gcc}, which is the default setting, and @samp{renesas}. | |
19085 | With the @samp{gcc} setting, functions are called using the @value{NGCC} calling | |
19086 | convention. If the DWARF-2 information of the called function specifies | |
19087 | that the function follows the Renesas calling convention, the function | |
19088 | is called using the Renesas calling convention. If the calling convention | |
19089 | is set to @samp{renesas}, the Renesas calling convention is always used, | |
19090 | regardless of the DWARF-2 information. This can be used to override the | |
19091 | default of @samp{gcc} if debug information is missing, or the compiler | |
19092 | does not emit the DWARF-2 calling convention entry for a function. | |
19093 | ||
19094 | @item show sh calling-convention | |
19095 | @kindex show sh calling-convention | |
19096 | Show the current calling convention setting. | |
19097 | ||
a64548ea EZ |
19098 | @end table |
19099 | ||
19100 | ||
8e04817f AC |
19101 | @node Architectures |
19102 | @section Architectures | |
104c1213 | 19103 | |
8e04817f AC |
19104 | This section describes characteristics of architectures that affect |
19105 | all uses of @value{GDBN} with the architecture, both native and cross. | |
104c1213 | 19106 | |
8e04817f | 19107 | @menu |
9c16f35a | 19108 | * i386:: |
8e04817f AC |
19109 | * A29K:: |
19110 | * Alpha:: | |
19111 | * MIPS:: | |
a64548ea | 19112 | * HPPA:: HP PA architecture |
23d964e7 | 19113 | * SPU:: Cell Broadband Engine SPU architecture |
4acd40f3 | 19114 | * PowerPC:: |
8e04817f | 19115 | @end menu |
104c1213 | 19116 | |
9c16f35a | 19117 | @node i386 |
db2e3e2e | 19118 | @subsection x86 Architecture-specific Issues |
9c16f35a EZ |
19119 | |
19120 | @table @code | |
19121 | @item set struct-convention @var{mode} | |
19122 | @kindex set struct-convention | |
19123 | @cindex struct return convention | |
19124 | @cindex struct/union returned in registers | |
19125 | Set the convention used by the inferior to return @code{struct}s and | |
19126 | @code{union}s from functions to @var{mode}. Possible values of | |
19127 | @var{mode} are @code{"pcc"}, @code{"reg"}, and @code{"default"} (the | |
19128 | default). @code{"default"} or @code{"pcc"} means that @code{struct}s | |
19129 | are returned on the stack, while @code{"reg"} means that a | |
19130 | @code{struct} or a @code{union} whose size is 1, 2, 4, or 8 bytes will | |
19131 | be returned in a register. | |
19132 | ||
19133 | @item show struct-convention | |
19134 | @kindex show struct-convention | |
19135 | Show the current setting of the convention to return @code{struct}s | |
19136 | from functions. | |
19137 | @end table | |
19138 | ||
8e04817f AC |
19139 | @node A29K |
19140 | @subsection A29K | |
104c1213 JM |
19141 | |
19142 | @table @code | |
104c1213 | 19143 | |
8e04817f AC |
19144 | @kindex set rstack_high_address |
19145 | @cindex AMD 29K register stack | |
19146 | @cindex register stack, AMD29K | |
19147 | @item set rstack_high_address @var{address} | |
19148 | On AMD 29000 family processors, registers are saved in a separate | |
19149 | @dfn{register stack}. There is no way for @value{GDBN} to determine the | |
19150 | extent of this stack. Normally, @value{GDBN} just assumes that the | |
19151 | stack is ``large enough''. This may result in @value{GDBN} referencing | |
19152 | memory locations that do not exist. If necessary, you can get around | |
19153 | this problem by specifying the ending address of the register stack with | |
19154 | the @code{set rstack_high_address} command. The argument should be an | |
19155 | address, which you probably want to precede with @samp{0x} to specify in | |
19156 | hexadecimal. | |
104c1213 | 19157 | |
8e04817f AC |
19158 | @kindex show rstack_high_address |
19159 | @item show rstack_high_address | |
19160 | Display the current limit of the register stack, on AMD 29000 family | |
19161 | processors. | |
104c1213 | 19162 | |
8e04817f | 19163 | @end table |
104c1213 | 19164 | |
8e04817f AC |
19165 | @node Alpha |
19166 | @subsection Alpha | |
104c1213 | 19167 | |
8e04817f | 19168 | See the following section. |
104c1213 | 19169 | |
8e04817f AC |
19170 | @node MIPS |
19171 | @subsection MIPS | |
104c1213 | 19172 | |
8e04817f AC |
19173 | @cindex stack on Alpha |
19174 | @cindex stack on MIPS | |
19175 | @cindex Alpha stack | |
19176 | @cindex MIPS stack | |
19177 | Alpha- and MIPS-based computers use an unusual stack frame, which | |
19178 | sometimes requires @value{GDBN} to search backward in the object code to | |
19179 | find the beginning of a function. | |
104c1213 | 19180 | |
8e04817f AC |
19181 | @cindex response time, MIPS debugging |
19182 | To improve response time (especially for embedded applications, where | |
19183 | @value{GDBN} may be restricted to a slow serial line for this search) | |
19184 | you may want to limit the size of this search, using one of these | |
19185 | commands: | |
104c1213 | 19186 | |
8e04817f AC |
19187 | @table @code |
19188 | @cindex @code{heuristic-fence-post} (Alpha, MIPS) | |
19189 | @item set heuristic-fence-post @var{limit} | |
19190 | Restrict @value{GDBN} to examining at most @var{limit} bytes in its | |
19191 | search for the beginning of a function. A value of @var{0} (the | |
19192 | default) means there is no limit. However, except for @var{0}, the | |
19193 | larger the limit the more bytes @code{heuristic-fence-post} must search | |
e2f4edfd EZ |
19194 | and therefore the longer it takes to run. You should only need to use |
19195 | this command when debugging a stripped executable. | |
104c1213 | 19196 | |
8e04817f AC |
19197 | @item show heuristic-fence-post |
19198 | Display the current limit. | |
19199 | @end table | |
104c1213 JM |
19200 | |
19201 | @noindent | |
8e04817f AC |
19202 | These commands are available @emph{only} when @value{GDBN} is configured |
19203 | for debugging programs on Alpha or MIPS processors. | |
104c1213 | 19204 | |
a64548ea EZ |
19205 | Several MIPS-specific commands are available when debugging MIPS |
19206 | programs: | |
19207 | ||
19208 | @table @code | |
a64548ea EZ |
19209 | @item set mips abi @var{arg} |
19210 | @kindex set mips abi | |
19211 | @cindex set ABI for MIPS | |
19212 | Tell @value{GDBN} which MIPS ABI is used by the inferior. Possible | |
19213 | values of @var{arg} are: | |
19214 | ||
19215 | @table @samp | |
19216 | @item auto | |
19217 | The default ABI associated with the current binary (this is the | |
19218 | default). | |
19219 | @item o32 | |
19220 | @item o64 | |
19221 | @item n32 | |
19222 | @item n64 | |
19223 | @item eabi32 | |
19224 | @item eabi64 | |
19225 | @item auto | |
19226 | @end table | |
19227 | ||
19228 | @item show mips abi | |
19229 | @kindex show mips abi | |
19230 | Show the MIPS ABI used by @value{GDBN} to debug the inferior. | |
19231 | ||
19232 | @item set mipsfpu | |
19233 | @itemx show mipsfpu | |
19234 | @xref{MIPS Embedded, set mipsfpu}. | |
19235 | ||
19236 | @item set mips mask-address @var{arg} | |
19237 | @kindex set mips mask-address | |
19238 | @cindex MIPS addresses, masking | |
19239 | This command determines whether the most-significant 32 bits of 64-bit | |
19240 | MIPS addresses are masked off. The argument @var{arg} can be | |
19241 | @samp{on}, @samp{off}, or @samp{auto}. The latter is the default | |
19242 | setting, which lets @value{GDBN} determine the correct value. | |
19243 | ||
19244 | @item show mips mask-address | |
19245 | @kindex show mips mask-address | |
19246 | Show whether the upper 32 bits of MIPS addresses are masked off or | |
19247 | not. | |
19248 | ||
19249 | @item set remote-mips64-transfers-32bit-regs | |
19250 | @kindex set remote-mips64-transfers-32bit-regs | |
19251 | This command controls compatibility with 64-bit MIPS targets that | |
19252 | transfer data in 32-bit quantities. If you have an old MIPS 64 target | |
19253 | that transfers 32 bits for some registers, like @sc{sr} and @sc{fsr}, | |
19254 | and 64 bits for other registers, set this option to @samp{on}. | |
19255 | ||
19256 | @item show remote-mips64-transfers-32bit-regs | |
19257 | @kindex show remote-mips64-transfers-32bit-regs | |
19258 | Show the current setting of compatibility with older MIPS 64 targets. | |
19259 | ||
19260 | @item set debug mips | |
19261 | @kindex set debug mips | |
19262 | This command turns on and off debugging messages for the MIPS-specific | |
19263 | target code in @value{GDBN}. | |
19264 | ||
19265 | @item show debug mips | |
19266 | @kindex show debug mips | |
19267 | Show the current setting of MIPS debugging messages. | |
19268 | @end table | |
19269 | ||
19270 | ||
19271 | @node HPPA | |
19272 | @subsection HPPA | |
19273 | @cindex HPPA support | |
19274 | ||
d3e8051b | 19275 | When @value{GDBN} is debugging the HP PA architecture, it provides the |
a64548ea EZ |
19276 | following special commands: |
19277 | ||
19278 | @table @code | |
19279 | @item set debug hppa | |
19280 | @kindex set debug hppa | |
db2e3e2e | 19281 | This command determines whether HPPA architecture-specific debugging |
a64548ea EZ |
19282 | messages are to be displayed. |
19283 | ||
19284 | @item show debug hppa | |
19285 | Show whether HPPA debugging messages are displayed. | |
19286 | ||
19287 | @item maint print unwind @var{address} | |
19288 | @kindex maint print unwind@r{, HPPA} | |
19289 | This command displays the contents of the unwind table entry at the | |
19290 | given @var{address}. | |
19291 | ||
19292 | @end table | |
19293 | ||
104c1213 | 19294 | |
23d964e7 UW |
19295 | @node SPU |
19296 | @subsection Cell Broadband Engine SPU architecture | |
19297 | @cindex Cell Broadband Engine | |
19298 | @cindex SPU | |
19299 | ||
19300 | When @value{GDBN} is debugging the Cell Broadband Engine SPU architecture, | |
19301 | it provides the following special commands: | |
19302 | ||
19303 | @table @code | |
19304 | @item info spu event | |
19305 | @kindex info spu | |
19306 | Display SPU event facility status. Shows current event mask | |
19307 | and pending event status. | |
19308 | ||
19309 | @item info spu signal | |
19310 | Display SPU signal notification facility status. Shows pending | |
19311 | signal-control word and signal notification mode of both signal | |
19312 | notification channels. | |
19313 | ||
19314 | @item info spu mailbox | |
19315 | Display SPU mailbox facility status. Shows all pending entries, | |
19316 | in order of processing, in each of the SPU Write Outbound, | |
19317 | SPU Write Outbound Interrupt, and SPU Read Inbound mailboxes. | |
19318 | ||
19319 | @item info spu dma | |
19320 | Display MFC DMA status. Shows all pending commands in the MFC | |
19321 | DMA queue. For each entry, opcode, tag, class IDs, effective | |
19322 | and local store addresses and transfer size are shown. | |
19323 | ||
19324 | @item info spu proxydma | |
19325 | Display MFC Proxy-DMA status. Shows all pending commands in the MFC | |
19326 | Proxy-DMA queue. For each entry, opcode, tag, class IDs, effective | |
19327 | and local store addresses and transfer size are shown. | |
19328 | ||
19329 | @end table | |
19330 | ||
3285f3fe UW |
19331 | When @value{GDBN} is debugging a combined PowerPC/SPU application |
19332 | on the Cell Broadband Engine, it provides in addition the following | |
19333 | special commands: | |
19334 | ||
19335 | @table @code | |
19336 | @item set spu stop-on-load @var{arg} | |
19337 | @kindex set spu | |
19338 | Set whether to stop for new SPE threads. When set to @code{on}, @value{GDBN} | |
19339 | will give control to the user when a new SPE thread enters its @code{main} | |
19340 | function. The default is @code{off}. | |
19341 | ||
19342 | @item show spu stop-on-load | |
19343 | @kindex show spu | |
19344 | Show whether to stop for new SPE threads. | |
19345 | ||
ff1a52c6 UW |
19346 | @item set spu auto-flush-cache @var{arg} |
19347 | Set whether to automatically flush the software-managed cache. When set to | |
19348 | @code{on}, @value{GDBN} will automatically cause the SPE software-managed | |
19349 | cache to be flushed whenever SPE execution stops. This provides a consistent | |
19350 | view of PowerPC memory that is accessed via the cache. If an application | |
19351 | does not use the software-managed cache, this option has no effect. | |
19352 | ||
19353 | @item show spu auto-flush-cache | |
19354 | Show whether to automatically flush the software-managed cache. | |
19355 | ||
3285f3fe UW |
19356 | @end table |
19357 | ||
4acd40f3 TJB |
19358 | @node PowerPC |
19359 | @subsection PowerPC | |
19360 | @cindex PowerPC architecture | |
19361 | ||
19362 | When @value{GDBN} is debugging the PowerPC architecture, it provides a set of | |
19363 | pseudo-registers to enable inspection of 128-bit wide Decimal Floating Point | |
19364 | numbers stored in the floating point registers. These values must be stored | |
19365 | in two consecutive registers, always starting at an even register like | |
19366 | @code{f0} or @code{f2}. | |
19367 | ||
19368 | The pseudo-registers go from @code{$dl0} through @code{$dl15}, and are formed | |
19369 | by joining the even/odd register pairs @code{f0} and @code{f1} for @code{$dl0}, | |
19370 | @code{f2} and @code{f3} for @code{$dl1} and so on. | |
19371 | ||
aeac0ff9 | 19372 | For POWER7 processors, @value{GDBN} provides a set of pseudo-registers, the 64-bit |
677c5bb1 LM |
19373 | wide Extended Floating Point Registers (@samp{f32} through @samp{f63}). |
19374 | ||
23d964e7 | 19375 | |
8e04817f AC |
19376 | @node Controlling GDB |
19377 | @chapter Controlling @value{GDBN} | |
19378 | ||
19379 | You can alter the way @value{GDBN} interacts with you by using the | |
19380 | @code{set} command. For commands controlling how @value{GDBN} displays | |
79a6e687 | 19381 | data, see @ref{Print Settings, ,Print Settings}. Other settings are |
8e04817f AC |
19382 | described here. |
19383 | ||
19384 | @menu | |
19385 | * Prompt:: Prompt | |
19386 | * Editing:: Command editing | |
d620b259 | 19387 | * Command History:: Command history |
8e04817f AC |
19388 | * Screen Size:: Screen size |
19389 | * Numbers:: Numbers | |
1e698235 | 19390 | * ABI:: Configuring the current ABI |
8e04817f AC |
19391 | * Messages/Warnings:: Optional warnings and messages |
19392 | * Debugging Output:: Optional messages about internal happenings | |
14fb1bac | 19393 | * Other Misc Settings:: Other Miscellaneous Settings |
8e04817f AC |
19394 | @end menu |
19395 | ||
19396 | @node Prompt | |
19397 | @section Prompt | |
104c1213 | 19398 | |
8e04817f | 19399 | @cindex prompt |
104c1213 | 19400 | |
8e04817f AC |
19401 | @value{GDBN} indicates its readiness to read a command by printing a string |
19402 | called the @dfn{prompt}. This string is normally @samp{(@value{GDBP})}. You | |
19403 | can change the prompt string with the @code{set prompt} command. For | |
19404 | instance, when debugging @value{GDBN} with @value{GDBN}, it is useful to change | |
19405 | the prompt in one of the @value{GDBN} sessions so that you can always tell | |
19406 | which one you are talking to. | |
104c1213 | 19407 | |
8e04817f AC |
19408 | @emph{Note:} @code{set prompt} does not add a space for you after the |
19409 | prompt you set. This allows you to set a prompt which ends in a space | |
19410 | or a prompt that does not. | |
104c1213 | 19411 | |
8e04817f AC |
19412 | @table @code |
19413 | @kindex set prompt | |
19414 | @item set prompt @var{newprompt} | |
19415 | Directs @value{GDBN} to use @var{newprompt} as its prompt string henceforth. | |
104c1213 | 19416 | |
8e04817f AC |
19417 | @kindex show prompt |
19418 | @item show prompt | |
19419 | Prints a line of the form: @samp{Gdb's prompt is: @var{your-prompt}} | |
104c1213 JM |
19420 | @end table |
19421 | ||
8e04817f | 19422 | @node Editing |
79a6e687 | 19423 | @section Command Editing |
8e04817f AC |
19424 | @cindex readline |
19425 | @cindex command line editing | |
104c1213 | 19426 | |
703663ab | 19427 | @value{GDBN} reads its input commands via the @dfn{Readline} interface. This |
8e04817f AC |
19428 | @sc{gnu} library provides consistent behavior for programs which provide a |
19429 | command line interface to the user. Advantages are @sc{gnu} Emacs-style | |
19430 | or @dfn{vi}-style inline editing of commands, @code{csh}-like history | |
19431 | substitution, and a storage and recall of command history across | |
19432 | debugging sessions. | |
104c1213 | 19433 | |
8e04817f AC |
19434 | You may control the behavior of command line editing in @value{GDBN} with the |
19435 | command @code{set}. | |
104c1213 | 19436 | |
8e04817f AC |
19437 | @table @code |
19438 | @kindex set editing | |
19439 | @cindex editing | |
19440 | @item set editing | |
19441 | @itemx set editing on | |
19442 | Enable command line editing (enabled by default). | |
104c1213 | 19443 | |
8e04817f AC |
19444 | @item set editing off |
19445 | Disable command line editing. | |
104c1213 | 19446 | |
8e04817f AC |
19447 | @kindex show editing |
19448 | @item show editing | |
19449 | Show whether command line editing is enabled. | |
104c1213 JM |
19450 | @end table |
19451 | ||
39037522 TT |
19452 | @ifset SYSTEM_READLINE |
19453 | @xref{Command Line Editing, , , rluserman, GNU Readline Library}, | |
19454 | @end ifset | |
19455 | @ifclear SYSTEM_READLINE | |
19456 | @xref{Command Line Editing}, | |
19457 | @end ifclear | |
19458 | for more details about the Readline | |
703663ab EZ |
19459 | interface. Users unfamiliar with @sc{gnu} Emacs or @code{vi} are |
19460 | encouraged to read that chapter. | |
19461 | ||
d620b259 | 19462 | @node Command History |
79a6e687 | 19463 | @section Command History |
703663ab | 19464 | @cindex command history |
8e04817f AC |
19465 | |
19466 | @value{GDBN} can keep track of the commands you type during your | |
19467 | debugging sessions, so that you can be certain of precisely what | |
19468 | happened. Use these commands to manage the @value{GDBN} command | |
19469 | history facility. | |
104c1213 | 19470 | |
703663ab | 19471 | @value{GDBN} uses the @sc{gnu} History library, a part of the Readline |
39037522 TT |
19472 | package, to provide the history facility. |
19473 | @ifset SYSTEM_READLINE | |
19474 | @xref{Using History Interactively, , , history, GNU History Library}, | |
19475 | @end ifset | |
19476 | @ifclear SYSTEM_READLINE | |
19477 | @xref{Using History Interactively}, | |
19478 | @end ifclear | |
19479 | for the detailed description of the History library. | |
703663ab | 19480 | |
d620b259 | 19481 | To issue a command to @value{GDBN} without affecting certain aspects of |
9e6c4bd5 NR |
19482 | the state which is seen by users, prefix it with @samp{server } |
19483 | (@pxref{Server Prefix}). This | |
d620b259 NR |
19484 | means that this command will not affect the command history, nor will it |
19485 | affect @value{GDBN}'s notion of which command to repeat if @key{RET} is | |
19486 | pressed on a line by itself. | |
19487 | ||
19488 | @cindex @code{server}, command prefix | |
19489 | The server prefix does not affect the recording of values into the value | |
19490 | history; to print a value without recording it into the value history, | |
19491 | use the @code{output} command instead of the @code{print} command. | |
19492 | ||
703663ab EZ |
19493 | Here is the description of @value{GDBN} commands related to command |
19494 | history. | |
19495 | ||
104c1213 | 19496 | @table @code |
8e04817f AC |
19497 | @cindex history substitution |
19498 | @cindex history file | |
19499 | @kindex set history filename | |
4644b6e3 | 19500 | @cindex @env{GDBHISTFILE}, environment variable |
8e04817f AC |
19501 | @item set history filename @var{fname} |
19502 | Set the name of the @value{GDBN} command history file to @var{fname}. | |
19503 | This is the file where @value{GDBN} reads an initial command history | |
19504 | list, and where it writes the command history from this session when it | |
19505 | exits. You can access this list through history expansion or through | |
19506 | the history command editing characters listed below. This file defaults | |
19507 | to the value of the environment variable @code{GDBHISTFILE}, or to | |
19508 | @file{./.gdb_history} (@file{./_gdb_history} on MS-DOS) if this variable | |
19509 | is not set. | |
104c1213 | 19510 | |
9c16f35a EZ |
19511 | @cindex save command history |
19512 | @kindex set history save | |
8e04817f AC |
19513 | @item set history save |
19514 | @itemx set history save on | |
19515 | Record command history in a file, whose name may be specified with the | |
19516 | @code{set history filename} command. By default, this option is disabled. | |
104c1213 | 19517 | |
8e04817f AC |
19518 | @item set history save off |
19519 | Stop recording command history in a file. | |
104c1213 | 19520 | |
8e04817f | 19521 | @cindex history size |
9c16f35a | 19522 | @kindex set history size |
6fc08d32 | 19523 | @cindex @env{HISTSIZE}, environment variable |
8e04817f AC |
19524 | @item set history size @var{size} |
19525 | Set the number of commands which @value{GDBN} keeps in its history list. | |
19526 | This defaults to the value of the environment variable | |
19527 | @code{HISTSIZE}, or to 256 if this variable is not set. | |
104c1213 JM |
19528 | @end table |
19529 | ||
8e04817f | 19530 | History expansion assigns special meaning to the character @kbd{!}. |
39037522 TT |
19531 | @ifset SYSTEM_READLINE |
19532 | @xref{Event Designators, , , history, GNU History Library}, | |
19533 | @end ifset | |
19534 | @ifclear SYSTEM_READLINE | |
19535 | @xref{Event Designators}, | |
19536 | @end ifclear | |
19537 | for more details. | |
8e04817f | 19538 | |
703663ab | 19539 | @cindex history expansion, turn on/off |
8e04817f AC |
19540 | Since @kbd{!} is also the logical not operator in C, history expansion |
19541 | is off by default. If you decide to enable history expansion with the | |
19542 | @code{set history expansion on} command, you may sometimes need to | |
19543 | follow @kbd{!} (when it is used as logical not, in an expression) with | |
19544 | a space or a tab to prevent it from being expanded. The readline | |
19545 | history facilities do not attempt substitution on the strings | |
19546 | @kbd{!=} and @kbd{!(}, even when history expansion is enabled. | |
19547 | ||
19548 | The commands to control history expansion are: | |
104c1213 JM |
19549 | |
19550 | @table @code | |
8e04817f AC |
19551 | @item set history expansion on |
19552 | @itemx set history expansion | |
703663ab | 19553 | @kindex set history expansion |
8e04817f | 19554 | Enable history expansion. History expansion is off by default. |
104c1213 | 19555 | |
8e04817f AC |
19556 | @item set history expansion off |
19557 | Disable history expansion. | |
104c1213 | 19558 | |
8e04817f AC |
19559 | @c @group |
19560 | @kindex show history | |
19561 | @item show history | |
19562 | @itemx show history filename | |
19563 | @itemx show history save | |
19564 | @itemx show history size | |
19565 | @itemx show history expansion | |
19566 | These commands display the state of the @value{GDBN} history parameters. | |
19567 | @code{show history} by itself displays all four states. | |
19568 | @c @end group | |
19569 | @end table | |
19570 | ||
19571 | @table @code | |
9c16f35a EZ |
19572 | @kindex show commands |
19573 | @cindex show last commands | |
19574 | @cindex display command history | |
8e04817f AC |
19575 | @item show commands |
19576 | Display the last ten commands in the command history. | |
104c1213 | 19577 | |
8e04817f AC |
19578 | @item show commands @var{n} |
19579 | Print ten commands centered on command number @var{n}. | |
19580 | ||
19581 | @item show commands + | |
19582 | Print ten commands just after the commands last printed. | |
104c1213 JM |
19583 | @end table |
19584 | ||
8e04817f | 19585 | @node Screen Size |
79a6e687 | 19586 | @section Screen Size |
8e04817f AC |
19587 | @cindex size of screen |
19588 | @cindex pauses in output | |
104c1213 | 19589 | |
8e04817f AC |
19590 | Certain commands to @value{GDBN} may produce large amounts of |
19591 | information output to the screen. To help you read all of it, | |
19592 | @value{GDBN} pauses and asks you for input at the end of each page of | |
19593 | output. Type @key{RET} when you want to continue the output, or @kbd{q} | |
19594 | to discard the remaining output. Also, the screen width setting | |
19595 | determines when to wrap lines of output. Depending on what is being | |
19596 | printed, @value{GDBN} tries to break the line at a readable place, | |
19597 | rather than simply letting it overflow onto the following line. | |
19598 | ||
19599 | Normally @value{GDBN} knows the size of the screen from the terminal | |
19600 | driver software. For example, on Unix @value{GDBN} uses the termcap data base | |
19601 | together with the value of the @code{TERM} environment variable and the | |
19602 | @code{stty rows} and @code{stty cols} settings. If this is not correct, | |
19603 | you can override it with the @code{set height} and @code{set | |
19604 | width} commands: | |
19605 | ||
19606 | @table @code | |
19607 | @kindex set height | |
19608 | @kindex set width | |
19609 | @kindex show width | |
19610 | @kindex show height | |
19611 | @item set height @var{lpp} | |
19612 | @itemx show height | |
19613 | @itemx set width @var{cpl} | |
19614 | @itemx show width | |
19615 | These @code{set} commands specify a screen height of @var{lpp} lines and | |
19616 | a screen width of @var{cpl} characters. The associated @code{show} | |
19617 | commands display the current settings. | |
104c1213 | 19618 | |
8e04817f AC |
19619 | If you specify a height of zero lines, @value{GDBN} does not pause during |
19620 | output no matter how long the output is. This is useful if output is to a | |
19621 | file or to an editor buffer. | |
104c1213 | 19622 | |
8e04817f AC |
19623 | Likewise, you can specify @samp{set width 0} to prevent @value{GDBN} |
19624 | from wrapping its output. | |
9c16f35a EZ |
19625 | |
19626 | @item set pagination on | |
19627 | @itemx set pagination off | |
19628 | @kindex set pagination | |
19629 | Turn the output pagination on or off; the default is on. Turning | |
7c953934 TT |
19630 | pagination off is the alternative to @code{set height 0}. Note that |
19631 | running @value{GDBN} with the @option{--batch} option (@pxref{Mode | |
19632 | Options, -batch}) also automatically disables pagination. | |
9c16f35a EZ |
19633 | |
19634 | @item show pagination | |
19635 | @kindex show pagination | |
19636 | Show the current pagination mode. | |
104c1213 JM |
19637 | @end table |
19638 | ||
8e04817f AC |
19639 | @node Numbers |
19640 | @section Numbers | |
19641 | @cindex number representation | |
19642 | @cindex entering numbers | |
104c1213 | 19643 | |
8e04817f AC |
19644 | You can always enter numbers in octal, decimal, or hexadecimal in |
19645 | @value{GDBN} by the usual conventions: octal numbers begin with | |
19646 | @samp{0}, decimal numbers end with @samp{.}, and hexadecimal numbers | |
eb2dae08 EZ |
19647 | begin with @samp{0x}. Numbers that neither begin with @samp{0} or |
19648 | @samp{0x}, nor end with a @samp{.} are, by default, entered in base | |
19649 | 10; likewise, the default display for numbers---when no particular | |
19650 | format is specified---is base 10. You can change the default base for | |
19651 | both input and output with the commands described below. | |
104c1213 | 19652 | |
8e04817f AC |
19653 | @table @code |
19654 | @kindex set input-radix | |
19655 | @item set input-radix @var{base} | |
19656 | Set the default base for numeric input. Supported choices | |
19657 | for @var{base} are decimal 8, 10, or 16. @var{base} must itself be | |
eb2dae08 | 19658 | specified either unambiguously or using the current input radix; for |
8e04817f | 19659 | example, any of |
104c1213 | 19660 | |
8e04817f | 19661 | @smallexample |
9c16f35a EZ |
19662 | set input-radix 012 |
19663 | set input-radix 10. | |
19664 | set input-radix 0xa | |
8e04817f | 19665 | @end smallexample |
104c1213 | 19666 | |
8e04817f | 19667 | @noindent |
9c16f35a | 19668 | sets the input base to decimal. On the other hand, @samp{set input-radix 10} |
eb2dae08 EZ |
19669 | leaves the input radix unchanged, no matter what it was, since |
19670 | @samp{10}, being without any leading or trailing signs of its base, is | |
19671 | interpreted in the current radix. Thus, if the current radix is 16, | |
19672 | @samp{10} is interpreted in hex, i.e.@: as 16 decimal, which doesn't | |
19673 | change the radix. | |
104c1213 | 19674 | |
8e04817f AC |
19675 | @kindex set output-radix |
19676 | @item set output-radix @var{base} | |
19677 | Set the default base for numeric display. Supported choices | |
19678 | for @var{base} are decimal 8, 10, or 16. @var{base} must itself be | |
eb2dae08 | 19679 | specified either unambiguously or using the current input radix. |
104c1213 | 19680 | |
8e04817f AC |
19681 | @kindex show input-radix |
19682 | @item show input-radix | |
19683 | Display the current default base for numeric input. | |
104c1213 | 19684 | |
8e04817f AC |
19685 | @kindex show output-radix |
19686 | @item show output-radix | |
19687 | Display the current default base for numeric display. | |
9c16f35a EZ |
19688 | |
19689 | @item set radix @r{[}@var{base}@r{]} | |
19690 | @itemx show radix | |
19691 | @kindex set radix | |
19692 | @kindex show radix | |
19693 | These commands set and show the default base for both input and output | |
19694 | of numbers. @code{set radix} sets the radix of input and output to | |
19695 | the same base; without an argument, it resets the radix back to its | |
19696 | default value of 10. | |
19697 | ||
8e04817f | 19698 | @end table |
104c1213 | 19699 | |
1e698235 | 19700 | @node ABI |
79a6e687 | 19701 | @section Configuring the Current ABI |
1e698235 DJ |
19702 | |
19703 | @value{GDBN} can determine the @dfn{ABI} (Application Binary Interface) of your | |
19704 | application automatically. However, sometimes you need to override its | |
19705 | conclusions. Use these commands to manage @value{GDBN}'s view of the | |
19706 | current ABI. | |
19707 | ||
98b45e30 DJ |
19708 | @cindex OS ABI |
19709 | @kindex set osabi | |
b4e9345d | 19710 | @kindex show osabi |
98b45e30 DJ |
19711 | |
19712 | One @value{GDBN} configuration can debug binaries for multiple operating | |
b383017d | 19713 | system targets, either via remote debugging or native emulation. |
98b45e30 DJ |
19714 | @value{GDBN} will autodetect the @dfn{OS ABI} (Operating System ABI) in use, |
19715 | but you can override its conclusion using the @code{set osabi} command. | |
19716 | One example where this is useful is in debugging of binaries which use | |
19717 | an alternate C library (e.g.@: @sc{uClibc} for @sc{gnu}/Linux) which does | |
19718 | not have the same identifying marks that the standard C library for your | |
19719 | platform provides. | |
19720 | ||
19721 | @table @code | |
19722 | @item show osabi | |
19723 | Show the OS ABI currently in use. | |
19724 | ||
19725 | @item set osabi | |
19726 | With no argument, show the list of registered available OS ABI's. | |
19727 | ||
19728 | @item set osabi @var{abi} | |
19729 | Set the current OS ABI to @var{abi}. | |
19730 | @end table | |
19731 | ||
1e698235 | 19732 | @cindex float promotion |
1e698235 DJ |
19733 | |
19734 | Generally, the way that an argument of type @code{float} is passed to a | |
19735 | function depends on whether the function is prototyped. For a prototyped | |
19736 | (i.e.@: ANSI/ISO style) function, @code{float} arguments are passed unchanged, | |
19737 | according to the architecture's convention for @code{float}. For unprototyped | |
19738 | (i.e.@: K&R style) functions, @code{float} arguments are first promoted to type | |
19739 | @code{double} and then passed. | |
19740 | ||
19741 | Unfortunately, some forms of debug information do not reliably indicate whether | |
19742 | a function is prototyped. If @value{GDBN} calls a function that is not marked | |
19743 | as prototyped, it consults @kbd{set coerce-float-to-double}. | |
19744 | ||
19745 | @table @code | |
a8f24a35 | 19746 | @kindex set coerce-float-to-double |
1e698235 DJ |
19747 | @item set coerce-float-to-double |
19748 | @itemx set coerce-float-to-double on | |
19749 | Arguments of type @code{float} will be promoted to @code{double} when passed | |
19750 | to an unprototyped function. This is the default setting. | |
19751 | ||
19752 | @item set coerce-float-to-double off | |
19753 | Arguments of type @code{float} will be passed directly to unprototyped | |
19754 | functions. | |
9c16f35a EZ |
19755 | |
19756 | @kindex show coerce-float-to-double | |
19757 | @item show coerce-float-to-double | |
19758 | Show the current setting of promoting @code{float} to @code{double}. | |
1e698235 DJ |
19759 | @end table |
19760 | ||
f1212245 DJ |
19761 | @kindex set cp-abi |
19762 | @kindex show cp-abi | |
19763 | @value{GDBN} needs to know the ABI used for your program's C@t{++} | |
19764 | objects. The correct C@t{++} ABI depends on which C@t{++} compiler was | |
19765 | used to build your application. @value{GDBN} only fully supports | |
19766 | programs with a single C@t{++} ABI; if your program contains code using | |
19767 | multiple C@t{++} ABI's or if @value{GDBN} can not identify your | |
19768 | program's ABI correctly, you can tell @value{GDBN} which ABI to use. | |
19769 | Currently supported ABI's include ``gnu-v2'', for @code{g++} versions | |
19770 | before 3.0, ``gnu-v3'', for @code{g++} versions 3.0 and later, and | |
19771 | ``hpaCC'' for the HP ANSI C@t{++} compiler. Other C@t{++} compilers may | |
19772 | use the ``gnu-v2'' or ``gnu-v3'' ABI's as well. The default setting is | |
19773 | ``auto''. | |
19774 | ||
19775 | @table @code | |
19776 | @item show cp-abi | |
19777 | Show the C@t{++} ABI currently in use. | |
19778 | ||
19779 | @item set cp-abi | |
19780 | With no argument, show the list of supported C@t{++} ABI's. | |
19781 | ||
19782 | @item set cp-abi @var{abi} | |
19783 | @itemx set cp-abi auto | |
19784 | Set the current C@t{++} ABI to @var{abi}, or return to automatic detection. | |
19785 | @end table | |
19786 | ||
8e04817f | 19787 | @node Messages/Warnings |
79a6e687 | 19788 | @section Optional Warnings and Messages |
104c1213 | 19789 | |
9c16f35a EZ |
19790 | @cindex verbose operation |
19791 | @cindex optional warnings | |
8e04817f AC |
19792 | By default, @value{GDBN} is silent about its inner workings. If you are |
19793 | running on a slow machine, you may want to use the @code{set verbose} | |
19794 | command. This makes @value{GDBN} tell you when it does a lengthy | |
19795 | internal operation, so you will not think it has crashed. | |
104c1213 | 19796 | |
8e04817f AC |
19797 | Currently, the messages controlled by @code{set verbose} are those |
19798 | which announce that the symbol table for a source file is being read; | |
79a6e687 | 19799 | see @code{symbol-file} in @ref{Files, ,Commands to Specify Files}. |
104c1213 | 19800 | |
8e04817f AC |
19801 | @table @code |
19802 | @kindex set verbose | |
19803 | @item set verbose on | |
19804 | Enables @value{GDBN} output of certain informational messages. | |
104c1213 | 19805 | |
8e04817f AC |
19806 | @item set verbose off |
19807 | Disables @value{GDBN} output of certain informational messages. | |
104c1213 | 19808 | |
8e04817f AC |
19809 | @kindex show verbose |
19810 | @item show verbose | |
19811 | Displays whether @code{set verbose} is on or off. | |
19812 | @end table | |
104c1213 | 19813 | |
8e04817f AC |
19814 | By default, if @value{GDBN} encounters bugs in the symbol table of an |
19815 | object file, it is silent; but if you are debugging a compiler, you may | |
79a6e687 BW |
19816 | find this information useful (@pxref{Symbol Errors, ,Errors Reading |
19817 | Symbol Files}). | |
104c1213 | 19818 | |
8e04817f | 19819 | @table @code |
104c1213 | 19820 | |
8e04817f AC |
19821 | @kindex set complaints |
19822 | @item set complaints @var{limit} | |
19823 | Permits @value{GDBN} to output @var{limit} complaints about each type of | |
19824 | unusual symbols before becoming silent about the problem. Set | |
19825 | @var{limit} to zero to suppress all complaints; set it to a large number | |
19826 | to prevent complaints from being suppressed. | |
104c1213 | 19827 | |
8e04817f AC |
19828 | @kindex show complaints |
19829 | @item show complaints | |
19830 | Displays how many symbol complaints @value{GDBN} is permitted to produce. | |
104c1213 | 19831 | |
8e04817f | 19832 | @end table |
104c1213 | 19833 | |
d837706a | 19834 | @anchor{confirmation requests} |
8e04817f AC |
19835 | By default, @value{GDBN} is cautious, and asks what sometimes seems to be a |
19836 | lot of stupid questions to confirm certain commands. For example, if | |
19837 | you try to run a program which is already running: | |
104c1213 | 19838 | |
474c8240 | 19839 | @smallexample |
8e04817f AC |
19840 | (@value{GDBP}) run |
19841 | The program being debugged has been started already. | |
19842 | Start it from the beginning? (y or n) | |
474c8240 | 19843 | @end smallexample |
104c1213 | 19844 | |
8e04817f AC |
19845 | If you are willing to unflinchingly face the consequences of your own |
19846 | commands, you can disable this ``feature'': | |
104c1213 | 19847 | |
8e04817f | 19848 | @table @code |
104c1213 | 19849 | |
8e04817f AC |
19850 | @kindex set confirm |
19851 | @cindex flinching | |
19852 | @cindex confirmation | |
19853 | @cindex stupid questions | |
19854 | @item set confirm off | |
7c953934 TT |
19855 | Disables confirmation requests. Note that running @value{GDBN} with |
19856 | the @option{--batch} option (@pxref{Mode Options, -batch}) also | |
19857 | automatically disables confirmation requests. | |
104c1213 | 19858 | |
8e04817f AC |
19859 | @item set confirm on |
19860 | Enables confirmation requests (the default). | |
104c1213 | 19861 | |
8e04817f AC |
19862 | @kindex show confirm |
19863 | @item show confirm | |
19864 | Displays state of confirmation requests. | |
19865 | ||
19866 | @end table | |
104c1213 | 19867 | |
16026cd7 AS |
19868 | @cindex command tracing |
19869 | If you need to debug user-defined commands or sourced files you may find it | |
19870 | useful to enable @dfn{command tracing}. In this mode each command will be | |
19871 | printed as it is executed, prefixed with one or more @samp{+} symbols, the | |
19872 | quantity denoting the call depth of each command. | |
19873 | ||
19874 | @table @code | |
19875 | @kindex set trace-commands | |
19876 | @cindex command scripts, debugging | |
19877 | @item set trace-commands on | |
19878 | Enable command tracing. | |
19879 | @item set trace-commands off | |
19880 | Disable command tracing. | |
19881 | @item show trace-commands | |
19882 | Display the current state of command tracing. | |
19883 | @end table | |
19884 | ||
8e04817f | 19885 | @node Debugging Output |
79a6e687 | 19886 | @section Optional Messages about Internal Happenings |
4644b6e3 EZ |
19887 | @cindex optional debugging messages |
19888 | ||
da316a69 EZ |
19889 | @value{GDBN} has commands that enable optional debugging messages from |
19890 | various @value{GDBN} subsystems; normally these commands are of | |
19891 | interest to @value{GDBN} maintainers, or when reporting a bug. This | |
19892 | section documents those commands. | |
19893 | ||
104c1213 | 19894 | @table @code |
a8f24a35 EZ |
19895 | @kindex set exec-done-display |
19896 | @item set exec-done-display | |
19897 | Turns on or off the notification of asynchronous commands' | |
19898 | completion. When on, @value{GDBN} will print a message when an | |
19899 | asynchronous command finishes its execution. The default is off. | |
19900 | @kindex show exec-done-display | |
19901 | @item show exec-done-display | |
19902 | Displays the current setting of asynchronous command completion | |
19903 | notification. | |
4644b6e3 EZ |
19904 | @kindex set debug |
19905 | @cindex gdbarch debugging info | |
a8f24a35 | 19906 | @cindex architecture debugging info |
8e04817f | 19907 | @item set debug arch |
a8f24a35 | 19908 | Turns on or off display of gdbarch debugging info. The default is off |
4644b6e3 | 19909 | @kindex show debug |
8e04817f AC |
19910 | @item show debug arch |
19911 | Displays the current state of displaying gdbarch debugging info. | |
721c2651 EZ |
19912 | @item set debug aix-thread |
19913 | @cindex AIX threads | |
19914 | Display debugging messages about inner workings of the AIX thread | |
19915 | module. | |
19916 | @item show debug aix-thread | |
19917 | Show the current state of AIX thread debugging info display. | |
d97bc12b DE |
19918 | @item set debug dwarf2-die |
19919 | @cindex DWARF2 DIEs | |
19920 | Dump DWARF2 DIEs after they are read in. | |
19921 | The value is the number of nesting levels to print. | |
19922 | A value of zero turns off the display. | |
19923 | @item show debug dwarf2-die | |
19924 | Show the current state of DWARF2 DIE debugging. | |
237fc4c9 PA |
19925 | @item set debug displaced |
19926 | @cindex displaced stepping debugging info | |
19927 | Turns on or off display of @value{GDBN} debugging info for the | |
19928 | displaced stepping support. The default is off. | |
19929 | @item show debug displaced | |
19930 | Displays the current state of displaying @value{GDBN} debugging info | |
19931 | related to displaced stepping. | |
8e04817f | 19932 | @item set debug event |
4644b6e3 | 19933 | @cindex event debugging info |
a8f24a35 | 19934 | Turns on or off display of @value{GDBN} event debugging info. The |
8e04817f | 19935 | default is off. |
8e04817f AC |
19936 | @item show debug event |
19937 | Displays the current state of displaying @value{GDBN} event debugging | |
19938 | info. | |
8e04817f | 19939 | @item set debug expression |
4644b6e3 | 19940 | @cindex expression debugging info |
721c2651 EZ |
19941 | Turns on or off display of debugging info about @value{GDBN} |
19942 | expression parsing. The default is off. | |
8e04817f | 19943 | @item show debug expression |
721c2651 EZ |
19944 | Displays the current state of displaying debugging info about |
19945 | @value{GDBN} expression parsing. | |
7453dc06 | 19946 | @item set debug frame |
4644b6e3 | 19947 | @cindex frame debugging info |
7453dc06 AC |
19948 | Turns on or off display of @value{GDBN} frame debugging info. The |
19949 | default is off. | |
7453dc06 AC |
19950 | @item show debug frame |
19951 | Displays the current state of displaying @value{GDBN} frame debugging | |
19952 | info. | |
cbe54154 PA |
19953 | @item set debug gnu-nat |
19954 | @cindex @sc{gnu}/Hurd debug messages | |
19955 | Turns on or off debugging messages from the @sc{gnu}/Hurd debug support. | |
19956 | @item show debug gnu-nat | |
19957 | Show the current state of @sc{gnu}/Hurd debugging messages. | |
30e91e0b RC |
19958 | @item set debug infrun |
19959 | @cindex inferior debugging info | |
19960 | Turns on or off display of @value{GDBN} debugging info for running the inferior. | |
19961 | The default is off. @file{infrun.c} contains GDB's runtime state machine used | |
19962 | for implementing operations such as single-stepping the inferior. | |
19963 | @item show debug infrun | |
19964 | Displays the current state of @value{GDBN} inferior debugging. | |
da316a69 EZ |
19965 | @item set debug lin-lwp |
19966 | @cindex @sc{gnu}/Linux LWP debug messages | |
19967 | @cindex Linux lightweight processes | |
721c2651 | 19968 | Turns on or off debugging messages from the Linux LWP debug support. |
da316a69 EZ |
19969 | @item show debug lin-lwp |
19970 | Show the current state of Linux LWP debugging messages. | |
b84876c2 PA |
19971 | @item set debug lin-lwp-async |
19972 | @cindex @sc{gnu}/Linux LWP async debug messages | |
19973 | @cindex Linux lightweight processes | |
19974 | Turns on or off debugging messages from the Linux LWP async debug support. | |
19975 | @item show debug lin-lwp-async | |
19976 | Show the current state of Linux LWP async debugging messages. | |
2b4855ab | 19977 | @item set debug observer |
4644b6e3 | 19978 | @cindex observer debugging info |
2b4855ab AC |
19979 | Turns on or off display of @value{GDBN} observer debugging. This |
19980 | includes info such as the notification of observable events. | |
2b4855ab AC |
19981 | @item show debug observer |
19982 | Displays the current state of observer debugging. | |
8e04817f | 19983 | @item set debug overload |
4644b6e3 | 19984 | @cindex C@t{++} overload debugging info |
8e04817f | 19985 | Turns on or off display of @value{GDBN} C@t{++} overload debugging |
359df76b | 19986 | info. This includes info such as ranking of functions, etc. The default |
8e04817f | 19987 | is off. |
8e04817f AC |
19988 | @item show debug overload |
19989 | Displays the current state of displaying @value{GDBN} C@t{++} overload | |
19990 | debugging info. | |
92981e24 TT |
19991 | @cindex expression parser, debugging info |
19992 | @cindex debug expression parser | |
19993 | @item set debug parser | |
19994 | Turns on or off the display of expression parser debugging output. | |
19995 | Internally, this sets the @code{yydebug} variable in the expression | |
19996 | parser. @xref{Tracing, , Tracing Your Parser, bison, Bison}, for | |
19997 | details. The default is off. | |
19998 | @item show debug parser | |
19999 | Show the current state of expression parser debugging. | |
8e04817f AC |
20000 | @cindex packets, reporting on stdout |
20001 | @cindex serial connections, debugging | |
605a56cb DJ |
20002 | @cindex debug remote protocol |
20003 | @cindex remote protocol debugging | |
20004 | @cindex display remote packets | |
8e04817f AC |
20005 | @item set debug remote |
20006 | Turns on or off display of reports on all packets sent back and forth across | |
20007 | the serial line to the remote machine. The info is printed on the | |
20008 | @value{GDBN} standard output stream. The default is off. | |
8e04817f AC |
20009 | @item show debug remote |
20010 | Displays the state of display of remote packets. | |
8e04817f AC |
20011 | @item set debug serial |
20012 | Turns on or off display of @value{GDBN} serial debugging info. The | |
20013 | default is off. | |
8e04817f AC |
20014 | @item show debug serial |
20015 | Displays the current state of displaying @value{GDBN} serial debugging | |
20016 | info. | |
c45da7e6 EZ |
20017 | @item set debug solib-frv |
20018 | @cindex FR-V shared-library debugging | |
20019 | Turns on or off debugging messages for FR-V shared-library code. | |
20020 | @item show debug solib-frv | |
20021 | Display the current state of FR-V shared-library code debugging | |
20022 | messages. | |
8e04817f | 20023 | @item set debug target |
4644b6e3 | 20024 | @cindex target debugging info |
8e04817f AC |
20025 | Turns on or off display of @value{GDBN} target debugging info. This info |
20026 | includes what is going on at the target level of GDB, as it happens. The | |
701b08bb DJ |
20027 | default is 0. Set it to 1 to track events, and to 2 to also track the |
20028 | value of large memory transfers. Changes to this flag do not take effect | |
20029 | until the next time you connect to a target or use the @code{run} command. | |
8e04817f AC |
20030 | @item show debug target |
20031 | Displays the current state of displaying @value{GDBN} target debugging | |
20032 | info. | |
75feb17d DJ |
20033 | @item set debug timestamp |
20034 | @cindex timestampping debugging info | |
20035 | Turns on or off display of timestamps with @value{GDBN} debugging info. | |
20036 | When enabled, seconds and microseconds are displayed before each debugging | |
20037 | message. | |
20038 | @item show debug timestamp | |
20039 | Displays the current state of displaying timestamps with @value{GDBN} | |
20040 | debugging info. | |
c45da7e6 | 20041 | @item set debugvarobj |
4644b6e3 | 20042 | @cindex variable object debugging info |
8e04817f AC |
20043 | Turns on or off display of @value{GDBN} variable object debugging |
20044 | info. The default is off. | |
c45da7e6 | 20045 | @item show debugvarobj |
8e04817f AC |
20046 | Displays the current state of displaying @value{GDBN} variable object |
20047 | debugging info. | |
e776119f DJ |
20048 | @item set debug xml |
20049 | @cindex XML parser debugging | |
20050 | Turns on or off debugging messages for built-in XML parsers. | |
20051 | @item show debug xml | |
20052 | Displays the current state of XML debugging messages. | |
8e04817f | 20053 | @end table |
104c1213 | 20054 | |
14fb1bac JB |
20055 | @node Other Misc Settings |
20056 | @section Other Miscellaneous Settings | |
20057 | @cindex miscellaneous settings | |
20058 | ||
20059 | @table @code | |
20060 | @kindex set interactive-mode | |
20061 | @item set interactive-mode | |
20062 | If @code{on}, forces @value{GDBN} to operate interactively. | |
20063 | If @code{off}, forces @value{GDBN} to operate non-interactively, | |
20064 | If @code{auto} (the default), @value{GDBN} guesses which mode to use, | |
20065 | based on whether the debugger was started in a terminal or not. | |
20066 | ||
20067 | In the vast majority of cases, the debugger should be able to guess | |
20068 | correctly which mode should be used. But this setting can be useful | |
20069 | in certain specific cases, such as running a MinGW @value{GDBN} | |
20070 | inside a cygwin window. | |
20071 | ||
20072 | @kindex show interactive-mode | |
20073 | @item show interactive-mode | |
20074 | Displays whether the debugger is operating in interactive mode or not. | |
20075 | @end table | |
20076 | ||
d57a3c85 TJB |
20077 | @node Extending GDB |
20078 | @chapter Extending @value{GDBN} | |
20079 | @cindex extending GDB | |
20080 | ||
20081 | @value{GDBN} provides two mechanisms for extension. The first is based | |
20082 | on composition of @value{GDBN} commands, and the second is based on the | |
20083 | Python scripting language. | |
20084 | ||
95433b34 JB |
20085 | To facilitate the use of these extensions, @value{GDBN} is capable |
20086 | of evaluating the contents of a file. When doing so, @value{GDBN} | |
20087 | can recognize which scripting language is being used by looking at | |
20088 | the filename extension. Files with an unrecognized filename extension | |
20089 | are always treated as a @value{GDBN} Command Files. | |
20090 | @xref{Command Files,, Command files}. | |
20091 | ||
20092 | You can control how @value{GDBN} evaluates these files with the following | |
20093 | setting: | |
20094 | ||
20095 | @table @code | |
20096 | @kindex set script-extension | |
20097 | @kindex show script-extension | |
20098 | @item set script-extension off | |
20099 | All scripts are always evaluated as @value{GDBN} Command Files. | |
20100 | ||
20101 | @item set script-extension soft | |
20102 | The debugger determines the scripting language based on filename | |
20103 | extension. If this scripting language is supported, @value{GDBN} | |
20104 | evaluates the script using that language. Otherwise, it evaluates | |
20105 | the file as a @value{GDBN} Command File. | |
20106 | ||
20107 | @item set script-extension strict | |
20108 | The debugger determines the scripting language based on filename | |
20109 | extension, and evaluates the script using that language. If the | |
20110 | language is not supported, then the evaluation fails. | |
20111 | ||
20112 | @item show script-extension | |
20113 | Display the current value of the @code{script-extension} option. | |
20114 | ||
20115 | @end table | |
20116 | ||
d57a3c85 TJB |
20117 | @menu |
20118 | * Sequences:: Canned Sequences of Commands | |
20119 | * Python:: Scripting @value{GDBN} using Python | |
20120 | @end menu | |
20121 | ||
8e04817f | 20122 | @node Sequences |
d57a3c85 | 20123 | @section Canned Sequences of Commands |
104c1213 | 20124 | |
8e04817f | 20125 | Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint |
79a6e687 | 20126 | Command Lists}), @value{GDBN} provides two ways to store sequences of |
8e04817f AC |
20127 | commands for execution as a unit: user-defined commands and command |
20128 | files. | |
104c1213 | 20129 | |
8e04817f | 20130 | @menu |
fcc73fe3 EZ |
20131 | * Define:: How to define your own commands |
20132 | * Hooks:: Hooks for user-defined commands | |
20133 | * Command Files:: How to write scripts of commands to be stored in a file | |
20134 | * Output:: Commands for controlled output | |
8e04817f | 20135 | @end menu |
104c1213 | 20136 | |
8e04817f | 20137 | @node Define |
d57a3c85 | 20138 | @subsection User-defined Commands |
104c1213 | 20139 | |
8e04817f | 20140 | @cindex user-defined command |
fcc73fe3 | 20141 | @cindex arguments, to user-defined commands |
8e04817f AC |
20142 | A @dfn{user-defined command} is a sequence of @value{GDBN} commands to |
20143 | which you assign a new name as a command. This is done with the | |
20144 | @code{define} command. User commands may accept up to 10 arguments | |
20145 | separated by whitespace. Arguments are accessed within the user command | |
c03c782f | 20146 | via @code{$arg0@dots{}$arg9}. A trivial example: |
104c1213 | 20147 | |
8e04817f AC |
20148 | @smallexample |
20149 | define adder | |
20150 | print $arg0 + $arg1 + $arg2 | |
c03c782f | 20151 | end |
8e04817f | 20152 | @end smallexample |
104c1213 JM |
20153 | |
20154 | @noindent | |
8e04817f | 20155 | To execute the command use: |
104c1213 | 20156 | |
8e04817f AC |
20157 | @smallexample |
20158 | adder 1 2 3 | |
20159 | @end smallexample | |
104c1213 | 20160 | |
8e04817f AC |
20161 | @noindent |
20162 | This defines the command @code{adder}, which prints the sum of | |
20163 | its three arguments. Note the arguments are text substitutions, so they may | |
20164 | reference variables, use complex expressions, or even perform inferior | |
20165 | functions calls. | |
104c1213 | 20166 | |
fcc73fe3 EZ |
20167 | @cindex argument count in user-defined commands |
20168 | @cindex how many arguments (user-defined commands) | |
c03c782f AS |
20169 | In addition, @code{$argc} may be used to find out how many arguments have |
20170 | been passed. This expands to a number in the range 0@dots{}10. | |
20171 | ||
20172 | @smallexample | |
20173 | define adder | |
20174 | if $argc == 2 | |
20175 | print $arg0 + $arg1 | |
20176 | end | |
20177 | if $argc == 3 | |
20178 | print $arg0 + $arg1 + $arg2 | |
20179 | end | |
20180 | end | |
20181 | @end smallexample | |
20182 | ||
104c1213 | 20183 | @table @code |
104c1213 | 20184 | |
8e04817f AC |
20185 | @kindex define |
20186 | @item define @var{commandname} | |
20187 | Define a command named @var{commandname}. If there is already a command | |
20188 | by that name, you are asked to confirm that you want to redefine it. | |
adb483fe DJ |
20189 | @var{commandname} may be a bare command name consisting of letters, |
20190 | numbers, dashes, and underscores. It may also start with any predefined | |
20191 | prefix command. For example, @samp{define target my-target} creates | |
20192 | a user-defined @samp{target my-target} command. | |
104c1213 | 20193 | |
8e04817f AC |
20194 | The definition of the command is made up of other @value{GDBN} command lines, |
20195 | which are given following the @code{define} command. The end of these | |
20196 | commands is marked by a line containing @code{end}. | |
104c1213 | 20197 | |
8e04817f | 20198 | @kindex document |
ca91424e | 20199 | @kindex end@r{ (user-defined commands)} |
8e04817f AC |
20200 | @item document @var{commandname} |
20201 | Document the user-defined command @var{commandname}, so that it can be | |
20202 | accessed by @code{help}. The command @var{commandname} must already be | |
20203 | defined. This command reads lines of documentation just as @code{define} | |
20204 | reads the lines of the command definition, ending with @code{end}. | |
20205 | After the @code{document} command is finished, @code{help} on command | |
20206 | @var{commandname} displays the documentation you have written. | |
104c1213 | 20207 | |
8e04817f AC |
20208 | You may use the @code{document} command again to change the |
20209 | documentation of a command. Redefining the command with @code{define} | |
20210 | does not change the documentation. | |
104c1213 | 20211 | |
c45da7e6 EZ |
20212 | @kindex dont-repeat |
20213 | @cindex don't repeat command | |
20214 | @item dont-repeat | |
20215 | Used inside a user-defined command, this tells @value{GDBN} that this | |
20216 | command should not be repeated when the user hits @key{RET} | |
20217 | (@pxref{Command Syntax, repeat last command}). | |
20218 | ||
8e04817f AC |
20219 | @kindex help user-defined |
20220 | @item help user-defined | |
20221 | List all user-defined commands, with the first line of the documentation | |
20222 | (if any) for each. | |
104c1213 | 20223 | |
8e04817f AC |
20224 | @kindex show user |
20225 | @item show user | |
20226 | @itemx show user @var{commandname} | |
20227 | Display the @value{GDBN} commands used to define @var{commandname} (but | |
20228 | not its documentation). If no @var{commandname} is given, display the | |
20229 | definitions for all user-defined commands. | |
104c1213 | 20230 | |
fcc73fe3 | 20231 | @cindex infinite recursion in user-defined commands |
20f01a46 DH |
20232 | @kindex show max-user-call-depth |
20233 | @kindex set max-user-call-depth | |
20234 | @item show max-user-call-depth | |
5ca0cb28 DH |
20235 | @itemx set max-user-call-depth |
20236 | The value of @code{max-user-call-depth} controls how many recursion | |
3f94c067 | 20237 | levels are allowed in user-defined commands before @value{GDBN} suspects an |
5ca0cb28 | 20238 | infinite recursion and aborts the command. |
104c1213 JM |
20239 | @end table |
20240 | ||
fcc73fe3 EZ |
20241 | In addition to the above commands, user-defined commands frequently |
20242 | use control flow commands, described in @ref{Command Files}. | |
20243 | ||
8e04817f AC |
20244 | When user-defined commands are executed, the |
20245 | commands of the definition are not printed. An error in any command | |
20246 | stops execution of the user-defined command. | |
104c1213 | 20247 | |
8e04817f AC |
20248 | If used interactively, commands that would ask for confirmation proceed |
20249 | without asking when used inside a user-defined command. Many @value{GDBN} | |
20250 | commands that normally print messages to say what they are doing omit the | |
20251 | messages when used in a user-defined command. | |
104c1213 | 20252 | |
8e04817f | 20253 | @node Hooks |
d57a3c85 | 20254 | @subsection User-defined Command Hooks |
8e04817f AC |
20255 | @cindex command hooks |
20256 | @cindex hooks, for commands | |
20257 | @cindex hooks, pre-command | |
104c1213 | 20258 | |
8e04817f | 20259 | @kindex hook |
8e04817f AC |
20260 | You may define @dfn{hooks}, which are a special kind of user-defined |
20261 | command. Whenever you run the command @samp{foo}, if the user-defined | |
20262 | command @samp{hook-foo} exists, it is executed (with no arguments) | |
20263 | before that command. | |
104c1213 | 20264 | |
8e04817f AC |
20265 | @cindex hooks, post-command |
20266 | @kindex hookpost | |
8e04817f AC |
20267 | A hook may also be defined which is run after the command you executed. |
20268 | Whenever you run the command @samp{foo}, if the user-defined command | |
20269 | @samp{hookpost-foo} exists, it is executed (with no arguments) after | |
20270 | that command. Post-execution hooks may exist simultaneously with | |
20271 | pre-execution hooks, for the same command. | |
104c1213 | 20272 | |
8e04817f | 20273 | It is valid for a hook to call the command which it hooks. If this |
9f1c6395 | 20274 | occurs, the hook is not re-executed, thereby avoiding infinite recursion. |
104c1213 | 20275 | |
8e04817f AC |
20276 | @c It would be nice if hookpost could be passed a parameter indicating |
20277 | @c if the command it hooks executed properly or not. FIXME! | |
104c1213 | 20278 | |
8e04817f AC |
20279 | @kindex stop@r{, a pseudo-command} |
20280 | In addition, a pseudo-command, @samp{stop} exists. Defining | |
20281 | (@samp{hook-stop}) makes the associated commands execute every time | |
20282 | execution stops in your program: before breakpoint commands are run, | |
20283 | displays are printed, or the stack frame is printed. | |
104c1213 | 20284 | |
8e04817f AC |
20285 | For example, to ignore @code{SIGALRM} signals while |
20286 | single-stepping, but treat them normally during normal execution, | |
20287 | you could define: | |
104c1213 | 20288 | |
474c8240 | 20289 | @smallexample |
8e04817f AC |
20290 | define hook-stop |
20291 | handle SIGALRM nopass | |
20292 | end | |
104c1213 | 20293 | |
8e04817f AC |
20294 | define hook-run |
20295 | handle SIGALRM pass | |
20296 | end | |
104c1213 | 20297 | |
8e04817f | 20298 | define hook-continue |
d3e8051b | 20299 | handle SIGALRM pass |
8e04817f | 20300 | end |
474c8240 | 20301 | @end smallexample |
104c1213 | 20302 | |
d3e8051b | 20303 | As a further example, to hook at the beginning and end of the @code{echo} |
b383017d | 20304 | command, and to add extra text to the beginning and end of the message, |
8e04817f | 20305 | you could define: |
104c1213 | 20306 | |
474c8240 | 20307 | @smallexample |
8e04817f AC |
20308 | define hook-echo |
20309 | echo <<<--- | |
20310 | end | |
104c1213 | 20311 | |
8e04817f AC |
20312 | define hookpost-echo |
20313 | echo --->>>\n | |
20314 | end | |
104c1213 | 20315 | |
8e04817f AC |
20316 | (@value{GDBP}) echo Hello World |
20317 | <<<---Hello World--->>> | |
20318 | (@value{GDBP}) | |
104c1213 | 20319 | |
474c8240 | 20320 | @end smallexample |
104c1213 | 20321 | |
8e04817f AC |
20322 | You can define a hook for any single-word command in @value{GDBN}, but |
20323 | not for command aliases; you should define a hook for the basic command | |
c1468174 | 20324 | name, e.g.@: @code{backtrace} rather than @code{bt}. |
8e04817f AC |
20325 | @c FIXME! So how does Joe User discover whether a command is an alias |
20326 | @c or not? | |
adb483fe DJ |
20327 | You can hook a multi-word command by adding @code{hook-} or |
20328 | @code{hookpost-} to the last word of the command, e.g.@: | |
20329 | @samp{define target hook-remote} to add a hook to @samp{target remote}. | |
20330 | ||
8e04817f AC |
20331 | If an error occurs during the execution of your hook, execution of |
20332 | @value{GDBN} commands stops and @value{GDBN} issues a prompt | |
20333 | (before the command that you actually typed had a chance to run). | |
104c1213 | 20334 | |
8e04817f AC |
20335 | If you try to define a hook which does not match any known command, you |
20336 | get a warning from the @code{define} command. | |
c906108c | 20337 | |
8e04817f | 20338 | @node Command Files |
d57a3c85 | 20339 | @subsection Command Files |
c906108c | 20340 | |
8e04817f | 20341 | @cindex command files |
fcc73fe3 | 20342 | @cindex scripting commands |
6fc08d32 EZ |
20343 | A command file for @value{GDBN} is a text file made of lines that are |
20344 | @value{GDBN} commands. Comments (lines starting with @kbd{#}) may | |
20345 | also be included. An empty line in a command file does nothing; it | |
20346 | does not mean to repeat the last command, as it would from the | |
20347 | terminal. | |
c906108c | 20348 | |
6fc08d32 | 20349 | You can request the execution of a command file with the @code{source} |
95433b34 JB |
20350 | command. Note that the @code{source} command is also used to evaluate |
20351 | scripts that are not Command Files. The exact behavior can be configured | |
20352 | using the @code{script-extension} setting. | |
20353 | @xref{Extending GDB,, Extending GDB}. | |
c906108c | 20354 | |
8e04817f AC |
20355 | @table @code |
20356 | @kindex source | |
ca91424e | 20357 | @cindex execute commands from a file |
3f7b2faa | 20358 | @item source [-s] [-v] @var{filename} |
8e04817f | 20359 | Execute the command file @var{filename}. |
c906108c SS |
20360 | @end table |
20361 | ||
fcc73fe3 EZ |
20362 | The lines in a command file are generally executed sequentially, |
20363 | unless the order of execution is changed by one of the | |
20364 | @emph{flow-control commands} described below. The commands are not | |
a71ec265 DH |
20365 | printed as they are executed. An error in any command terminates |
20366 | execution of the command file and control is returned to the console. | |
c906108c | 20367 | |
08001717 DE |
20368 | @value{GDBN} first searches for @var{filename} in the current directory. |
20369 | If the file is not found there, and @var{filename} does not specify a | |
20370 | directory, then @value{GDBN} also looks for the file on the source search path | |
20371 | (specified with the @samp{directory} command); | |
20372 | except that @file{$cdir} is not searched because the compilation directory | |
20373 | is not relevant to scripts. | |
4b505b12 | 20374 | |
3f7b2faa DE |
20375 | If @code{-s} is specified, then @value{GDBN} searches for @var{filename} |
20376 | on the search path even if @var{filename} specifies a directory. | |
20377 | The search is done by appending @var{filename} to each element of the | |
20378 | search path. So, for example, if @var{filename} is @file{mylib/myscript} | |
20379 | and the search path contains @file{/home/user} then @value{GDBN} will | |
20380 | look for the script @file{/home/user/mylib/myscript}. | |
20381 | The search is also done if @var{filename} is an absolute path. | |
20382 | For example, if @var{filename} is @file{/tmp/myscript} and | |
20383 | the search path contains @file{/home/user} then @value{GDBN} will | |
20384 | look for the script @file{/home/user/tmp/myscript}. | |
20385 | For DOS-like systems, if @var{filename} contains a drive specification, | |
20386 | it is stripped before concatenation. For example, if @var{filename} is | |
20387 | @file{d:myscript} and the search path contains @file{c:/tmp} then @value{GDBN} | |
20388 | will look for the script @file{c:/tmp/myscript}. | |
20389 | ||
16026cd7 AS |
20390 | If @code{-v}, for verbose mode, is given then @value{GDBN} displays |
20391 | each command as it is executed. The option must be given before | |
20392 | @var{filename}, and is interpreted as part of the filename anywhere else. | |
20393 | ||
8e04817f AC |
20394 | Commands that would ask for confirmation if used interactively proceed |
20395 | without asking when used in a command file. Many @value{GDBN} commands that | |
20396 | normally print messages to say what they are doing omit the messages | |
20397 | when called from command files. | |
c906108c | 20398 | |
8e04817f AC |
20399 | @value{GDBN} also accepts command input from standard input. In this |
20400 | mode, normal output goes to standard output and error output goes to | |
20401 | standard error. Errors in a command file supplied on standard input do | |
6fc08d32 | 20402 | not terminate execution of the command file---execution continues with |
8e04817f | 20403 | the next command. |
c906108c | 20404 | |
474c8240 | 20405 | @smallexample |
8e04817f | 20406 | gdb < cmds > log 2>&1 |
474c8240 | 20407 | @end smallexample |
c906108c | 20408 | |
8e04817f AC |
20409 | (The syntax above will vary depending on the shell used.) This example |
20410 | will execute commands from the file @file{cmds}. All output and errors | |
20411 | would be directed to @file{log}. | |
c906108c | 20412 | |
fcc73fe3 EZ |
20413 | Since commands stored on command files tend to be more general than |
20414 | commands typed interactively, they frequently need to deal with | |
20415 | complicated situations, such as different or unexpected values of | |
20416 | variables and symbols, changes in how the program being debugged is | |
20417 | built, etc. @value{GDBN} provides a set of flow-control commands to | |
20418 | deal with these complexities. Using these commands, you can write | |
20419 | complex scripts that loop over data structures, execute commands | |
20420 | conditionally, etc. | |
20421 | ||
20422 | @table @code | |
20423 | @kindex if | |
20424 | @kindex else | |
20425 | @item if | |
20426 | @itemx else | |
20427 | This command allows to include in your script conditionally executed | |
20428 | commands. The @code{if} command takes a single argument, which is an | |
20429 | expression to evaluate. It is followed by a series of commands that | |
20430 | are executed only if the expression is true (its value is nonzero). | |
20431 | There can then optionally be an @code{else} line, followed by a series | |
20432 | of commands that are only executed if the expression was false. The | |
20433 | end of the list is marked by a line containing @code{end}. | |
20434 | ||
20435 | @kindex while | |
20436 | @item while | |
20437 | This command allows to write loops. Its syntax is similar to | |
20438 | @code{if}: the command takes a single argument, which is an expression | |
20439 | to evaluate, and must be followed by the commands to execute, one per | |
20440 | line, terminated by an @code{end}. These commands are called the | |
20441 | @dfn{body} of the loop. The commands in the body of @code{while} are | |
20442 | executed repeatedly as long as the expression evaluates to true. | |
20443 | ||
20444 | @kindex loop_break | |
20445 | @item loop_break | |
20446 | This command exits the @code{while} loop in whose body it is included. | |
20447 | Execution of the script continues after that @code{while}s @code{end} | |
20448 | line. | |
20449 | ||
20450 | @kindex loop_continue | |
20451 | @item loop_continue | |
20452 | This command skips the execution of the rest of the body of commands | |
20453 | in the @code{while} loop in whose body it is included. Execution | |
20454 | branches to the beginning of the @code{while} loop, where it evaluates | |
20455 | the controlling expression. | |
ca91424e EZ |
20456 | |
20457 | @kindex end@r{ (if/else/while commands)} | |
20458 | @item end | |
20459 | Terminate the block of commands that are the body of @code{if}, | |
20460 | @code{else}, or @code{while} flow-control commands. | |
fcc73fe3 EZ |
20461 | @end table |
20462 | ||
20463 | ||
8e04817f | 20464 | @node Output |
d57a3c85 | 20465 | @subsection Commands for Controlled Output |
c906108c | 20466 | |
8e04817f AC |
20467 | During the execution of a command file or a user-defined command, normal |
20468 | @value{GDBN} output is suppressed; the only output that appears is what is | |
20469 | explicitly printed by the commands in the definition. This section | |
20470 | describes three commands useful for generating exactly the output you | |
20471 | want. | |
c906108c SS |
20472 | |
20473 | @table @code | |
8e04817f AC |
20474 | @kindex echo |
20475 | @item echo @var{text} | |
20476 | @c I do not consider backslash-space a standard C escape sequence | |
20477 | @c because it is not in ANSI. | |
20478 | Print @var{text}. Nonprinting characters can be included in | |
20479 | @var{text} using C escape sequences, such as @samp{\n} to print a | |
20480 | newline. @strong{No newline is printed unless you specify one.} | |
20481 | In addition to the standard C escape sequences, a backslash followed | |
20482 | by a space stands for a space. This is useful for displaying a | |
20483 | string with spaces at the beginning or the end, since leading and | |
20484 | trailing spaces are otherwise trimmed from all arguments. | |
20485 | To print @samp{@w{ }and foo =@w{ }}, use the command | |
20486 | @samp{echo \@w{ }and foo = \@w{ }}. | |
c906108c | 20487 | |
8e04817f AC |
20488 | A backslash at the end of @var{text} can be used, as in C, to continue |
20489 | the command onto subsequent lines. For example, | |
c906108c | 20490 | |
474c8240 | 20491 | @smallexample |
8e04817f AC |
20492 | echo This is some text\n\ |
20493 | which is continued\n\ | |
20494 | onto several lines.\n | |
474c8240 | 20495 | @end smallexample |
c906108c | 20496 | |
8e04817f | 20497 | produces the same output as |
c906108c | 20498 | |
474c8240 | 20499 | @smallexample |
8e04817f AC |
20500 | echo This is some text\n |
20501 | echo which is continued\n | |
20502 | echo onto several lines.\n | |
474c8240 | 20503 | @end smallexample |
c906108c | 20504 | |
8e04817f AC |
20505 | @kindex output |
20506 | @item output @var{expression} | |
20507 | Print the value of @var{expression} and nothing but that value: no | |
20508 | newlines, no @samp{$@var{nn} = }. The value is not entered in the | |
20509 | value history either. @xref{Expressions, ,Expressions}, for more information | |
20510 | on expressions. | |
c906108c | 20511 | |
8e04817f AC |
20512 | @item output/@var{fmt} @var{expression} |
20513 | Print the value of @var{expression} in format @var{fmt}. You can use | |
20514 | the same formats as for @code{print}. @xref{Output Formats,,Output | |
79a6e687 | 20515 | Formats}, for more information. |
c906108c | 20516 | |
8e04817f | 20517 | @kindex printf |
82160952 EZ |
20518 | @item printf @var{template}, @var{expressions}@dots{} |
20519 | Print the values of one or more @var{expressions} under the control of | |
20520 | the string @var{template}. To print several values, make | |
20521 | @var{expressions} be a comma-separated list of individual expressions, | |
20522 | which may be either numbers or pointers. Their values are printed as | |
20523 | specified by @var{template}, exactly as a C program would do by | |
20524 | executing the code below: | |
c906108c | 20525 | |
474c8240 | 20526 | @smallexample |
82160952 | 20527 | printf (@var{template}, @var{expressions}@dots{}); |
474c8240 | 20528 | @end smallexample |
c906108c | 20529 | |
82160952 EZ |
20530 | As in @code{C} @code{printf}, ordinary characters in @var{template} |
20531 | are printed verbatim, while @dfn{conversion specification} introduced | |
20532 | by the @samp{%} character cause subsequent @var{expressions} to be | |
20533 | evaluated, their values converted and formatted according to type and | |
20534 | style information encoded in the conversion specifications, and then | |
20535 | printed. | |
20536 | ||
8e04817f | 20537 | For example, you can print two values in hex like this: |
c906108c | 20538 | |
8e04817f AC |
20539 | @smallexample |
20540 | printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo | |
20541 | @end smallexample | |
c906108c | 20542 | |
82160952 EZ |
20543 | @code{printf} supports all the standard @code{C} conversion |
20544 | specifications, including the flags and modifiers between the @samp{%} | |
20545 | character and the conversion letter, with the following exceptions: | |
20546 | ||
20547 | @itemize @bullet | |
20548 | @item | |
20549 | The argument-ordering modifiers, such as @samp{2$}, are not supported. | |
20550 | ||
20551 | @item | |
20552 | The modifier @samp{*} is not supported for specifying precision or | |
20553 | width. | |
20554 | ||
20555 | @item | |
20556 | The @samp{'} flag (for separation of digits into groups according to | |
20557 | @code{LC_NUMERIC'}) is not supported. | |
20558 | ||
20559 | @item | |
20560 | The type modifiers @samp{hh}, @samp{j}, @samp{t}, and @samp{z} are not | |
20561 | supported. | |
20562 | ||
20563 | @item | |
20564 | The conversion letter @samp{n} (as in @samp{%n}) is not supported. | |
20565 | ||
20566 | @item | |
20567 | The conversion letters @samp{a} and @samp{A} are not supported. | |
20568 | @end itemize | |
20569 | ||
20570 | @noindent | |
20571 | Note that the @samp{ll} type modifier is supported only if the | |
20572 | underlying @code{C} implementation used to build @value{GDBN} supports | |
20573 | the @code{long long int} type, and the @samp{L} type modifier is | |
20574 | supported only if @code{long double} type is available. | |
20575 | ||
20576 | As in @code{C}, @code{printf} supports simple backslash-escape | |
20577 | sequences, such as @code{\n}, @samp{\t}, @samp{\\}, @samp{\"}, | |
20578 | @samp{\a}, and @samp{\f}, that consist of backslash followed by a | |
20579 | single character. Octal and hexadecimal escape sequences are not | |
20580 | supported. | |
1a619819 LM |
20581 | |
20582 | Additionally, @code{printf} supports conversion specifications for DFP | |
0aea4bf3 LM |
20583 | (@dfn{Decimal Floating Point}) types using the following length modifiers |
20584 | together with a floating point specifier. | |
1a619819 LM |
20585 | letters: |
20586 | ||
20587 | @itemize @bullet | |
20588 | @item | |
20589 | @samp{H} for printing @code{Decimal32} types. | |
20590 | ||
20591 | @item | |
20592 | @samp{D} for printing @code{Decimal64} types. | |
20593 | ||
20594 | @item | |
20595 | @samp{DD} for printing @code{Decimal128} types. | |
20596 | @end itemize | |
20597 | ||
20598 | If the underlying @code{C} implementation used to build @value{GDBN} has | |
0aea4bf3 | 20599 | support for the three length modifiers for DFP types, other modifiers |
3b784c4f | 20600 | such as width and precision will also be available for @value{GDBN} to use. |
1a619819 LM |
20601 | |
20602 | In case there is no such @code{C} support, no additional modifiers will be | |
20603 | available and the value will be printed in the standard way. | |
20604 | ||
20605 | Here's an example of printing DFP types using the above conversion letters: | |
20606 | @smallexample | |
0aea4bf3 | 20607 | printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl |
1a619819 LM |
20608 | @end smallexample |
20609 | ||
f1421989 HZ |
20610 | @kindex eval |
20611 | @item eval @var{template}, @var{expressions}@dots{} | |
20612 | Convert the values of one or more @var{expressions} under the control of | |
20613 | the string @var{template} to a command line, and call it. | |
20614 | ||
c906108c SS |
20615 | @end table |
20616 | ||
d57a3c85 TJB |
20617 | @node Python |
20618 | @section Scripting @value{GDBN} using Python | |
20619 | @cindex python scripting | |
20620 | @cindex scripting with python | |
20621 | ||
20622 | You can script @value{GDBN} using the @uref{http://www.python.org/, | |
20623 | Python programming language}. This feature is available only if | |
20624 | @value{GDBN} was configured using @option{--with-python}. | |
20625 | ||
9279c692 JB |
20626 | @cindex python directory |
20627 | Python scripts used by @value{GDBN} should be installed in | |
20628 | @file{@var{data-directory}/python}, where @var{data-directory} is | |
9eeee977 DE |
20629 | the data directory as determined at @value{GDBN} startup (@pxref{Data Files}). |
20630 | This directory, known as the @dfn{python directory}, | |
9279c692 JB |
20631 | is automatically added to the Python Search Path in order to allow |
20632 | the Python interpreter to locate all scripts installed at this location. | |
20633 | ||
d57a3c85 TJB |
20634 | @menu |
20635 | * Python Commands:: Accessing Python from @value{GDBN}. | |
20636 | * Python API:: Accessing @value{GDBN} from Python. | |
8a1ea21f | 20637 | * Auto-loading:: Automatically loading Python code. |
0e3509db | 20638 | * Python modules:: Python modules provided by @value{GDBN}. |
d57a3c85 TJB |
20639 | @end menu |
20640 | ||
20641 | @node Python Commands | |
20642 | @subsection Python Commands | |
20643 | @cindex python commands | |
20644 | @cindex commands to access python | |
20645 | ||
20646 | @value{GDBN} provides one command for accessing the Python interpreter, | |
20647 | and one related setting: | |
20648 | ||
20649 | @table @code | |
20650 | @kindex python | |
20651 | @item python @r{[}@var{code}@r{]} | |
20652 | The @code{python} command can be used to evaluate Python code. | |
20653 | ||
20654 | If given an argument, the @code{python} command will evaluate the | |
20655 | argument as a Python command. For example: | |
20656 | ||
20657 | @smallexample | |
20658 | (@value{GDBP}) python print 23 | |
20659 | 23 | |
20660 | @end smallexample | |
20661 | ||
20662 | If you do not provide an argument to @code{python}, it will act as a | |
20663 | multi-line command, like @code{define}. In this case, the Python | |
20664 | script is made up of subsequent command lines, given after the | |
20665 | @code{python} command. This command list is terminated using a line | |
20666 | containing @code{end}. For example: | |
20667 | ||
20668 | @smallexample | |
20669 | (@value{GDBP}) python | |
20670 | Type python script | |
20671 | End with a line saying just "end". | |
20672 | >print 23 | |
20673 | >end | |
20674 | 23 | |
20675 | @end smallexample | |
20676 | ||
20677 | @kindex maint set python print-stack | |
20678 | @item maint set python print-stack | |
20679 | By default, @value{GDBN} will print a stack trace when an error occurs | |
20680 | in a Python script. This can be controlled using @code{maint set | |
20681 | python print-stack}: if @code{on}, the default, then Python stack | |
20682 | printing is enabled; if @code{off}, then Python stack printing is | |
20683 | disabled. | |
20684 | @end table | |
20685 | ||
95433b34 JB |
20686 | It is also possible to execute a Python script from the @value{GDBN} |
20687 | interpreter: | |
20688 | ||
20689 | @table @code | |
20690 | @item source @file{script-name} | |
20691 | The script name must end with @samp{.py} and @value{GDBN} must be configured | |
20692 | to recognize the script language based on filename extension using | |
20693 | the @code{script-extension} setting. @xref{Extending GDB, ,Extending GDB}. | |
20694 | ||
20695 | @item python execfile ("script-name") | |
20696 | This method is based on the @code{execfile} Python built-in function, | |
20697 | and thus is always available. | |
20698 | @end table | |
20699 | ||
d57a3c85 TJB |
20700 | @node Python API |
20701 | @subsection Python API | |
20702 | @cindex python api | |
20703 | @cindex programming in python | |
20704 | ||
20705 | @cindex python stdout | |
20706 | @cindex python pagination | |
20707 | At startup, @value{GDBN} overrides Python's @code{sys.stdout} and | |
20708 | @code{sys.stderr} to print using @value{GDBN}'s output-paging streams. | |
20709 | A Python program which outputs to one of these streams may have its | |
20710 | output interrupted by the user (@pxref{Screen Size}). In this | |
20711 | situation, a Python @code{KeyboardInterrupt} exception is thrown. | |
20712 | ||
20713 | @menu | |
20714 | * Basic Python:: Basic Python Functions. | |
20715 | * Exception Handling:: | |
a08702d6 | 20716 | * Values From Inferior:: |
4c374409 JK |
20717 | * Types In Python:: Python representation of types. |
20718 | * Pretty Printing API:: Pretty-printing values. | |
a6bac58e | 20719 | * Selecting Pretty-Printers:: How GDB chooses a pretty-printer. |
7b51bc51 | 20720 | * Writing a Pretty-Printer:: Writing a Pretty-Printer. |
595939de PM |
20721 | * Inferiors In Python:: Python representation of inferiors (processes) |
20722 | * Threads In Python:: Accessing inferior threads from Python. | |
d8906c6f | 20723 | * Commands In Python:: Implementing new commands in Python. |
d7b32ed3 | 20724 | * Parameters In Python:: Adding new @value{GDBN} parameters. |
bc3b79fd | 20725 | * Functions In Python:: Writing new convenience functions. |
fa33c3cd | 20726 | * Progspaces In Python:: Program spaces. |
89c73ade | 20727 | * Objfiles In Python:: Object files. |
f3e9a817 PM |
20728 | * Frames In Python:: Accessing inferior stack frames from Python. |
20729 | * Blocks In Python:: Accessing frame blocks from Python. | |
20730 | * Symbols In Python:: Python representation of symbols. | |
20731 | * Symbol Tables In Python:: Python representation of symbol tables. | |
be759fcf | 20732 | * Lazy Strings In Python:: Python representation of lazy strings. |
adc36818 | 20733 | * Breakpoints In Python:: Manipulating breakpoints using Python. |
d57a3c85 TJB |
20734 | @end menu |
20735 | ||
20736 | @node Basic Python | |
20737 | @subsubsection Basic Python | |
20738 | ||
20739 | @cindex python functions | |
20740 | @cindex python module | |
20741 | @cindex gdb module | |
20742 | @value{GDBN} introduces a new Python module, named @code{gdb}. All | |
20743 | methods and classes added by @value{GDBN} are placed in this module. | |
20744 | @value{GDBN} automatically @code{import}s the @code{gdb} module for | |
20745 | use in all scripts evaluated by the @code{python} command. | |
20746 | ||
9279c692 JB |
20747 | @findex gdb.PYTHONDIR |
20748 | @defvar PYTHONDIR | |
20749 | A string containing the python directory (@pxref{Python}). | |
20750 | @end defvar | |
20751 | ||
d57a3c85 | 20752 | @findex gdb.execute |
bc9f0842 | 20753 | @defun execute command [from_tty] [to_string] |
d57a3c85 TJB |
20754 | Evaluate @var{command}, a string, as a @value{GDBN} CLI command. |
20755 | If a GDB exception happens while @var{command} runs, it is | |
20756 | translated as described in @ref{Exception Handling,,Exception Handling}. | |
12453b93 TJB |
20757 | |
20758 | @var{from_tty} specifies whether @value{GDBN} ought to consider this | |
20759 | command as having originated from the user invoking it interactively. | |
20760 | It must be a boolean value. If omitted, it defaults to @code{False}. | |
bc9f0842 TT |
20761 | |
20762 | By default, any output produced by @var{command} is sent to | |
20763 | @value{GDBN}'s standard output. If the @var{to_string} parameter is | |
20764 | @code{True}, then output will be collected by @code{gdb.execute} and | |
20765 | returned as a string. The default is @code{False}, in which case the | |
5da1313b JK |
20766 | return value is @code{None}. If @var{to_string} is @code{True}, the |
20767 | @value{GDBN} virtual terminal will be temporarily set to unlimited width | |
20768 | and height, and its pagination will be disabled; @pxref{Screen Size}. | |
d57a3c85 TJB |
20769 | @end defun |
20770 | ||
adc36818 PM |
20771 | @findex gdb.breakpoints |
20772 | @defun breakpoints | |
20773 | Return a sequence holding all of @value{GDBN}'s breakpoints. | |
20774 | @xref{Breakpoints In Python}, for more information. | |
20775 | @end defun | |
20776 | ||
8f500870 TT |
20777 | @findex gdb.parameter |
20778 | @defun parameter parameter | |
d57a3c85 TJB |
20779 | Return the value of a @value{GDBN} parameter. @var{parameter} is a |
20780 | string naming the parameter to look up; @var{parameter} may contain | |
20781 | spaces if the parameter has a multi-part name. For example, | |
20782 | @samp{print object} is a valid parameter name. | |
20783 | ||
20784 | If the named parameter does not exist, this function throws a | |
621c8364 TT |
20785 | @code{gdb.error} (@pxref{Exception Handling}). Otherwise, the |
20786 | parameter's value is converted to a Python value of the appropriate | |
20787 | type, and returned. | |
d57a3c85 TJB |
20788 | @end defun |
20789 | ||
08c637de TJB |
20790 | @findex gdb.history |
20791 | @defun history number | |
20792 | Return a value from @value{GDBN}'s value history (@pxref{Value | |
20793 | History}). @var{number} indicates which history element to return. | |
20794 | If @var{number} is negative, then @value{GDBN} will take its absolute value | |
20795 | and count backward from the last element (i.e., the most recent element) to | |
20796 | find the value to return. If @var{number} is zero, then @value{GDBN} will | |
a0c36267 | 20797 | return the most recent element. If the element specified by @var{number} |
621c8364 | 20798 | doesn't exist in the value history, a @code{gdb.error} exception will be |
08c637de TJB |
20799 | raised. |
20800 | ||
20801 | If no exception is raised, the return value is always an instance of | |
20802 | @code{gdb.Value} (@pxref{Values From Inferior}). | |
20803 | @end defun | |
20804 | ||
57a1d736 TT |
20805 | @findex gdb.parse_and_eval |
20806 | @defun parse_and_eval expression | |
20807 | Parse @var{expression} as an expression in the current language, | |
20808 | evaluate it, and return the result as a @code{gdb.Value}. | |
20809 | @var{expression} must be a string. | |
20810 | ||
20811 | This function can be useful when implementing a new command | |
20812 | (@pxref{Commands In Python}), as it provides a way to parse the | |
20813 | command's argument as an expression. It is also useful simply to | |
20814 | compute values, for example, it is the only way to get the value of a | |
20815 | convenience variable (@pxref{Convenience Vars}) as a @code{gdb.Value}. | |
20816 | @end defun | |
20817 | ||
ca5c20b6 PM |
20818 | @findex gdb.post_event |
20819 | @defun post_event event | |
20820 | Put @var{event}, a callable object taking no arguments, into | |
20821 | @value{GDBN}'s internal event queue. This callable will be invoked at | |
20822 | some later point, during @value{GDBN}'s event processing. Events | |
20823 | posted using @code{post_event} will be run in the order in which they | |
20824 | were posted; however, there is no way to know when they will be | |
20825 | processed relative to other events inside @value{GDBN}. | |
20826 | ||
20827 | @value{GDBN} is not thread-safe. If your Python program uses multiple | |
20828 | threads, you must be careful to only call @value{GDBN}-specific | |
20829 | functions in the main @value{GDBN} thread. @code{post_event} ensures | |
20830 | this. For example: | |
20831 | ||
20832 | @smallexample | |
20833 | (@value{GDBP}) python | |
20834 | >import threading | |
20835 | > | |
20836 | >class Writer(): | |
20837 | > def __init__(self, message): | |
20838 | > self.message = message; | |
20839 | > def __call__(self): | |
20840 | > gdb.write(self.message) | |
20841 | > | |
20842 | >class MyThread1 (threading.Thread): | |
20843 | > def run (self): | |
20844 | > gdb.post_event(Writer("Hello ")) | |
20845 | > | |
20846 | >class MyThread2 (threading.Thread): | |
20847 | > def run (self): | |
20848 | > gdb.post_event(Writer("World\n")) | |
20849 | > | |
20850 | >MyThread1().start() | |
20851 | >MyThread2().start() | |
20852 | >end | |
20853 | (@value{GDBP}) Hello World | |
20854 | @end smallexample | |
20855 | @end defun | |
20856 | ||
d57a3c85 TJB |
20857 | @findex gdb.write |
20858 | @defun write string | |
20859 | Print a string to @value{GDBN}'s paginated standard output stream. | |
20860 | Writing to @code{sys.stdout} or @code{sys.stderr} will automatically | |
20861 | call this function. | |
20862 | @end defun | |
20863 | ||
20864 | @findex gdb.flush | |
20865 | @defun flush | |
20866 | Flush @value{GDBN}'s paginated standard output stream. Flushing | |
20867 | @code{sys.stdout} or @code{sys.stderr} will automatically call this | |
20868 | function. | |
20869 | @end defun | |
20870 | ||
f870a310 TT |
20871 | @findex gdb.target_charset |
20872 | @defun target_charset | |
20873 | Return the name of the current target character set (@pxref{Character | |
20874 | Sets}). This differs from @code{gdb.parameter('target-charset')} in | |
20875 | that @samp{auto} is never returned. | |
20876 | @end defun | |
20877 | ||
20878 | @findex gdb.target_wide_charset | |
20879 | @defun target_wide_charset | |
20880 | Return the name of the current target wide character set | |
20881 | (@pxref{Character Sets}). This differs from | |
20882 | @code{gdb.parameter('target-wide-charset')} in that @samp{auto} is | |
20883 | never returned. | |
20884 | @end defun | |
20885 | ||
cb2e07a6 PM |
20886 | @findex gdb.solib_name |
20887 | @defun solib_name address | |
20888 | Return the name of the shared library holding the given @var{address} | |
20889 | as a string, or @code{None}. | |
20890 | @end defun | |
20891 | ||
20892 | @findex gdb.decode_line | |
20893 | @defun decode_line @r{[}expression@r{]} | |
20894 | Return locations of the line specified by @var{expression}, or of the | |
20895 | current line if no argument was given. This function returns a Python | |
20896 | tuple containing two elements. The first element contains a string | |
20897 | holding any unparsed section of @var{expression} (or @code{None} if | |
20898 | the expression has been fully parsed). The second element contains | |
20899 | either @code{None} or another tuple that contains all the locations | |
20900 | that match the expression represented as @code{gdb.Symtab_and_line} | |
20901 | objects (@pxref{Symbol Tables In Python}). If @var{expression} is | |
20902 | provided, it is decoded the way that @value{GDBN}'s inbuilt | |
20903 | @code{break} or @code{edit} commands do (@pxref{Specify Location}). | |
20904 | @end defun | |
20905 | ||
d57a3c85 TJB |
20906 | @node Exception Handling |
20907 | @subsubsection Exception Handling | |
20908 | @cindex python exceptions | |
20909 | @cindex exceptions, python | |
20910 | ||
20911 | When executing the @code{python} command, Python exceptions | |
20912 | uncaught within the Python code are translated to calls to | |
20913 | @value{GDBN} error-reporting mechanism. If the command that called | |
20914 | @code{python} does not handle the error, @value{GDBN} will | |
20915 | terminate it and print an error message containing the Python | |
20916 | exception name, the associated value, and the Python call stack | |
20917 | backtrace at the point where the exception was raised. Example: | |
20918 | ||
20919 | @smallexample | |
20920 | (@value{GDBP}) python print foo | |
20921 | Traceback (most recent call last): | |
20922 | File "<string>", line 1, in <module> | |
20923 | NameError: name 'foo' is not defined | |
20924 | @end smallexample | |
20925 | ||
621c8364 TT |
20926 | @value{GDBN} errors that happen in @value{GDBN} commands invoked by |
20927 | Python code are converted to Python exceptions. The type of the | |
20928 | Python exception depends on the error. | |
20929 | ||
20930 | @ftable @code | |
20931 | @item gdb.error | |
20932 | This is the base class for most exceptions generated by @value{GDBN}. | |
20933 | It is derived from @code{RuntimeError}, for compatibility with earlier | |
20934 | versions of @value{GDBN}. | |
20935 | ||
20936 | If an error occurring in @value{GDBN} does not fit into some more | |
20937 | specific category, then the generated exception will have this type. | |
20938 | ||
20939 | @item gdb.MemoryError | |
20940 | This is a subclass of @code{gdb.error} which is thrown when an | |
20941 | operation tried to access invalid memory in the inferior. | |
20942 | ||
20943 | @item KeyboardInterrupt | |
20944 | User interrupt (via @kbd{C-c} or by typing @kbd{q} at a pagination | |
20945 | prompt) is translated to a Python @code{KeyboardInterrupt} exception. | |
20946 | @end ftable | |
20947 | ||
20948 | In all cases, your exception handler will see the @value{GDBN} error | |
20949 | message as its value and the Python call stack backtrace at the Python | |
20950 | statement closest to where the @value{GDBN} error occured as the | |
d57a3c85 TJB |
20951 | traceback. |
20952 | ||
07ca107c DE |
20953 | @findex gdb.GdbError |
20954 | When implementing @value{GDBN} commands in Python via @code{gdb.Command}, | |
20955 | it is useful to be able to throw an exception that doesn't cause a | |
20956 | traceback to be printed. For example, the user may have invoked the | |
20957 | command incorrectly. Use the @code{gdb.GdbError} exception | |
20958 | to handle this case. Example: | |
20959 | ||
20960 | @smallexample | |
20961 | (gdb) python | |
20962 | >class HelloWorld (gdb.Command): | |
20963 | > """Greet the whole world.""" | |
20964 | > def __init__ (self): | |
20965 | > super (HelloWorld, self).__init__ ("hello-world", gdb.COMMAND_OBSCURE) | |
20966 | > def invoke (self, args, from_tty): | |
20967 | > argv = gdb.string_to_argv (args) | |
20968 | > if len (argv) != 0: | |
20969 | > raise gdb.GdbError ("hello-world takes no arguments") | |
20970 | > print "Hello, World!" | |
20971 | >HelloWorld () | |
20972 | >end | |
20973 | (gdb) hello-world 42 | |
20974 | hello-world takes no arguments | |
20975 | @end smallexample | |
20976 | ||
a08702d6 TJB |
20977 | @node Values From Inferior |
20978 | @subsubsection Values From Inferior | |
20979 | @cindex values from inferior, with Python | |
20980 | @cindex python, working with values from inferior | |
20981 | ||
20982 | @cindex @code{gdb.Value} | |
20983 | @value{GDBN} provides values it obtains from the inferior program in | |
20984 | an object of type @code{gdb.Value}. @value{GDBN} uses this object | |
20985 | for its internal bookkeeping of the inferior's values, and for | |
20986 | fetching values when necessary. | |
20987 | ||
20988 | Inferior values that are simple scalars can be used directly in | |
20989 | Python expressions that are valid for the value's data type. Here's | |
20990 | an example for an integer or floating-point value @code{some_val}: | |
20991 | ||
20992 | @smallexample | |
20993 | bar = some_val + 2 | |
20994 | @end smallexample | |
20995 | ||
20996 | @noindent | |
20997 | As result of this, @code{bar} will also be a @code{gdb.Value} object | |
20998 | whose values are of the same type as those of @code{some_val}. | |
20999 | ||
21000 | Inferior values that are structures or instances of some class can | |
21001 | be accessed using the Python @dfn{dictionary syntax}. For example, if | |
21002 | @code{some_val} is a @code{gdb.Value} instance holding a structure, you | |
21003 | can access its @code{foo} element with: | |
21004 | ||
21005 | @smallexample | |
21006 | bar = some_val['foo'] | |
21007 | @end smallexample | |
21008 | ||
21009 | Again, @code{bar} will also be a @code{gdb.Value} object. | |
21010 | ||
5374244e PM |
21011 | A @code{gdb.Value} that represents a function can be executed via |
21012 | inferior function call. Any arguments provided to the call must match | |
21013 | the function's prototype, and must be provided in the order specified | |
21014 | by that prototype. | |
21015 | ||
21016 | For example, @code{some_val} is a @code{gdb.Value} instance | |
21017 | representing a function that takes two integers as arguments. To | |
21018 | execute this function, call it like so: | |
21019 | ||
21020 | @smallexample | |
21021 | result = some_val (10,20) | |
21022 | @end smallexample | |
21023 | ||
21024 | Any values returned from a function call will be stored as a | |
21025 | @code{gdb.Value}. | |
21026 | ||
c0c6f777 | 21027 | The following attributes are provided: |
a08702d6 | 21028 | |
def2b000 | 21029 | @table @code |
2c74e833 | 21030 | @defivar Value address |
c0c6f777 TJB |
21031 | If this object is addressable, this read-only attribute holds a |
21032 | @code{gdb.Value} object representing the address. Otherwise, | |
21033 | this attribute holds @code{None}. | |
2c74e833 | 21034 | @end defivar |
c0c6f777 | 21035 | |
def2b000 | 21036 | @cindex optimized out value in Python |
2c74e833 | 21037 | @defivar Value is_optimized_out |
def2b000 TJB |
21038 | This read-only boolean attribute is true if the compiler optimized out |
21039 | this value, thus it is not available for fetching from the inferior. | |
2c74e833 TT |
21040 | @end defivar |
21041 | ||
21042 | @defivar Value type | |
21043 | The type of this @code{gdb.Value}. The value of this attribute is a | |
44592cc4 | 21044 | @code{gdb.Type} object (@pxref{Types In Python}). |
2c74e833 | 21045 | @end defivar |
03f17ccf TT |
21046 | |
21047 | @defivar Value dynamic_type | |
21048 | The dynamic type of this @code{gdb.Value}. This uses C@t{++} run-time | |
fccd1d1e EZ |
21049 | type information (@acronym{RTTI}) to determine the dynamic type of the |
21050 | value. If this value is of class type, it will return the class in | |
21051 | which the value is embedded, if any. If this value is of pointer or | |
21052 | reference to a class type, it will compute the dynamic type of the | |
21053 | referenced object, and return a pointer or reference to that type, | |
21054 | respectively. In all other cases, it will return the value's static | |
21055 | type. | |
21056 | ||
21057 | Note that this feature will only work when debugging a C@t{++} program | |
21058 | that includes @acronym{RTTI} for the object in question. Otherwise, | |
21059 | it will just return the static type of the value as in @kbd{ptype foo} | |
21060 | (@pxref{Symbols, ptype}). | |
03f17ccf | 21061 | @end defivar |
def2b000 TJB |
21062 | @end table |
21063 | ||
21064 | The following methods are provided: | |
21065 | ||
21066 | @table @code | |
e8467610 TT |
21067 | @defmethod Value __init__ @var{val} |
21068 | Many Python values can be converted directly to a @code{gdb.Value} via | |
21069 | this object initializer. Specifically: | |
21070 | ||
21071 | @table @asis | |
21072 | @item Python boolean | |
21073 | A Python boolean is converted to the boolean type from the current | |
21074 | language. | |
21075 | ||
21076 | @item Python integer | |
21077 | A Python integer is converted to the C @code{long} type for the | |
21078 | current architecture. | |
21079 | ||
21080 | @item Python long | |
21081 | A Python long is converted to the C @code{long long} type for the | |
21082 | current architecture. | |
21083 | ||
21084 | @item Python float | |
21085 | A Python float is converted to the C @code{double} type for the | |
21086 | current architecture. | |
21087 | ||
21088 | @item Python string | |
21089 | A Python string is converted to a target string, using the current | |
21090 | target encoding. | |
21091 | ||
21092 | @item @code{gdb.Value} | |
21093 | If @code{val} is a @code{gdb.Value}, then a copy of the value is made. | |
21094 | ||
21095 | @item @code{gdb.LazyString} | |
21096 | If @code{val} is a @code{gdb.LazyString} (@pxref{Lazy Strings In | |
21097 | Python}), then the lazy string's @code{value} method is called, and | |
21098 | its result is used. | |
21099 | @end table | |
21100 | @end defmethod | |
21101 | ||
14ff2235 PM |
21102 | @defmethod Value cast type |
21103 | Return a new instance of @code{gdb.Value} that is the result of | |
21104 | casting this instance to the type described by @var{type}, which must | |
21105 | be a @code{gdb.Type} object. If the cast cannot be performed for some | |
21106 | reason, this method throws an exception. | |
21107 | @end defmethod | |
21108 | ||
a08702d6 | 21109 | @defmethod Value dereference |
def2b000 TJB |
21110 | For pointer data types, this method returns a new @code{gdb.Value} object |
21111 | whose contents is the object pointed to by the pointer. For example, if | |
21112 | @code{foo} is a C pointer to an @code{int}, declared in your C program as | |
a08702d6 TJB |
21113 | |
21114 | @smallexample | |
21115 | int *foo; | |
21116 | @end smallexample | |
21117 | ||
21118 | @noindent | |
21119 | then you can use the corresponding @code{gdb.Value} to access what | |
21120 | @code{foo} points to like this: | |
21121 | ||
21122 | @smallexample | |
21123 | bar = foo.dereference () | |
21124 | @end smallexample | |
21125 | ||
21126 | The result @code{bar} will be a @code{gdb.Value} object holding the | |
21127 | value pointed to by @code{foo}. | |
21128 | @end defmethod | |
21129 | ||
f9ffd4bb TT |
21130 | @defmethod Value dynamic_cast type |
21131 | Like @code{Value.cast}, but works as if the C@t{++} @code{dynamic_cast} | |
21132 | operator were used. Consult a C@t{++} reference for details. | |
21133 | @end defmethod | |
21134 | ||
21135 | @defmethod Value reinterpret_cast type | |
21136 | Like @code{Value.cast}, but works as if the C@t{++} @code{reinterpret_cast} | |
21137 | operator were used. Consult a C@t{++} reference for details. | |
21138 | @end defmethod | |
21139 | ||
fbb8f299 | 21140 | @defmethod Value string @r{[}encoding@r{]} @r{[}errors@r{]} @r{[}length@r{]} |
b6cb8e7d TJB |
21141 | If this @code{gdb.Value} represents a string, then this method |
21142 | converts the contents to a Python string. Otherwise, this method will | |
21143 | throw an exception. | |
21144 | ||
21145 | Strings are recognized in a language-specific way; whether a given | |
21146 | @code{gdb.Value} represents a string is determined by the current | |
21147 | language. | |
21148 | ||
21149 | For C-like languages, a value is a string if it is a pointer to or an | |
21150 | array of characters or ints. The string is assumed to be terminated | |
fbb8f299 PM |
21151 | by a zero of the appropriate width. However if the optional length |
21152 | argument is given, the string will be converted to that given length, | |
21153 | ignoring any embedded zeros that the string may contain. | |
b6cb8e7d TJB |
21154 | |
21155 | If the optional @var{encoding} argument is given, it must be a string | |
21156 | naming the encoding of the string in the @code{gdb.Value}, such as | |
21157 | @code{"ascii"}, @code{"iso-8859-6"} or @code{"utf-8"}. It accepts | |
21158 | the same encodings as the corresponding argument to Python's | |
21159 | @code{string.decode} method, and the Python codec machinery will be used | |
21160 | to convert the string. If @var{encoding} is not given, or if | |
21161 | @var{encoding} is the empty string, then either the @code{target-charset} | |
21162 | (@pxref{Character Sets}) will be used, or a language-specific encoding | |
21163 | will be used, if the current language is able to supply one. | |
21164 | ||
21165 | The optional @var{errors} argument is the same as the corresponding | |
21166 | argument to Python's @code{string.decode} method. | |
fbb8f299 PM |
21167 | |
21168 | If the optional @var{length} argument is given, the string will be | |
21169 | fetched and converted to the given length. | |
b6cb8e7d | 21170 | @end defmethod |
be759fcf PM |
21171 | |
21172 | @defmethod Value lazy_string @r{[}encoding@r{]} @r{[}length@r{]} | |
21173 | If this @code{gdb.Value} represents a string, then this method | |
21174 | converts the contents to a @code{gdb.LazyString} (@pxref{Lazy Strings | |
21175 | In Python}). Otherwise, this method will throw an exception. | |
21176 | ||
21177 | If the optional @var{encoding} argument is given, it must be a string | |
21178 | naming the encoding of the @code{gdb.LazyString}. Some examples are: | |
21179 | @samp{ascii}, @samp{iso-8859-6} or @samp{utf-8}. If the | |
21180 | @var{encoding} argument is an encoding that @value{GDBN} does | |
21181 | recognize, @value{GDBN} will raise an error. | |
21182 | ||
21183 | When a lazy string is printed, the @value{GDBN} encoding machinery is | |
21184 | used to convert the string during printing. If the optional | |
21185 | @var{encoding} argument is not provided, or is an empty string, | |
21186 | @value{GDBN} will automatically select the encoding most suitable for | |
21187 | the string type. For further information on encoding in @value{GDBN} | |
21188 | please see @ref{Character Sets}. | |
21189 | ||
21190 | If the optional @var{length} argument is given, the string will be | |
21191 | fetched and encoded to the length of characters specified. If | |
21192 | the @var{length} argument is not provided, the string will be fetched | |
21193 | and encoded until a null of appropriate width is found. | |
21194 | @end defmethod | |
def2b000 | 21195 | @end table |
b6cb8e7d | 21196 | |
2c74e833 TT |
21197 | @node Types In Python |
21198 | @subsubsection Types In Python | |
21199 | @cindex types in Python | |
21200 | @cindex Python, working with types | |
21201 | ||
21202 | @tindex gdb.Type | |
21203 | @value{GDBN} represents types from the inferior using the class | |
21204 | @code{gdb.Type}. | |
21205 | ||
21206 | The following type-related functions are available in the @code{gdb} | |
21207 | module: | |
21208 | ||
21209 | @findex gdb.lookup_type | |
21210 | @defun lookup_type name [block] | |
21211 | This function looks up a type by name. @var{name} is the name of the | |
21212 | type to look up. It must be a string. | |
21213 | ||
5107b149 PM |
21214 | If @var{block} is given, then @var{name} is looked up in that scope. |
21215 | Otherwise, it is searched for globally. | |
21216 | ||
2c74e833 TT |
21217 | Ordinarily, this function will return an instance of @code{gdb.Type}. |
21218 | If the named type cannot be found, it will throw an exception. | |
21219 | @end defun | |
21220 | ||
21221 | An instance of @code{Type} has the following attributes: | |
21222 | ||
21223 | @table @code | |
21224 | @defivar Type code | |
21225 | The type code for this type. The type code will be one of the | |
21226 | @code{TYPE_CODE_} constants defined below. | |
21227 | @end defivar | |
21228 | ||
21229 | @defivar Type sizeof | |
21230 | The size of this type, in target @code{char} units. Usually, a | |
21231 | target's @code{char} type will be an 8-bit byte. However, on some | |
21232 | unusual platforms, this type may have a different size. | |
21233 | @end defivar | |
21234 | ||
21235 | @defivar Type tag | |
21236 | The tag name for this type. The tag name is the name after | |
21237 | @code{struct}, @code{union}, or @code{enum} in C and C@t{++}; not all | |
21238 | languages have this concept. If this type has no tag name, then | |
21239 | @code{None} is returned. | |
21240 | @end defivar | |
21241 | @end table | |
21242 | ||
21243 | The following methods are provided: | |
21244 | ||
21245 | @table @code | |
21246 | @defmethod Type fields | |
21247 | For structure and union types, this method returns the fields. Range | |
21248 | types have two fields, the minimum and maximum values. Enum types | |
21249 | have one field per enum constant. Function and method types have one | |
21250 | field per parameter. The base types of C@t{++} classes are also | |
21251 | represented as fields. If the type has no fields, or does not fit | |
21252 | into one of these categories, an empty sequence will be returned. | |
21253 | ||
21254 | Each field is an object, with some pre-defined attributes: | |
21255 | @table @code | |
21256 | @item bitpos | |
21257 | This attribute is not available for @code{static} fields (as in | |
21258 | C@t{++} or Java). For non-@code{static} fields, the value is the bit | |
21259 | position of the field. | |
21260 | ||
21261 | @item name | |
21262 | The name of the field, or @code{None} for anonymous fields. | |
21263 | ||
21264 | @item artificial | |
21265 | This is @code{True} if the field is artificial, usually meaning that | |
21266 | it was provided by the compiler and not the user. This attribute is | |
21267 | always provided, and is @code{False} if the field is not artificial. | |
21268 | ||
bfd31e71 PM |
21269 | @item is_base_class |
21270 | This is @code{True} if the field represents a base class of a C@t{++} | |
21271 | structure. This attribute is always provided, and is @code{False} | |
21272 | if the field is not a base class of the type that is the argument of | |
21273 | @code{fields}, or if that type was not a C@t{++} class. | |
21274 | ||
2c74e833 TT |
21275 | @item bitsize |
21276 | If the field is packed, or is a bitfield, then this will have a | |
21277 | non-zero value, which is the size of the field in bits. Otherwise, | |
21278 | this will be zero; in this case the field's size is given by its type. | |
21279 | ||
21280 | @item type | |
21281 | The type of the field. This is usually an instance of @code{Type}, | |
21282 | but it can be @code{None} in some situations. | |
21283 | @end table | |
21284 | @end defmethod | |
21285 | ||
702c2711 TT |
21286 | @defmethod Type array @var{n1} @r{[}@var{n2}@r{]} |
21287 | Return a new @code{gdb.Type} object which represents an array of this | |
21288 | type. If one argument is given, it is the inclusive upper bound of | |
21289 | the array; in this case the lower bound is zero. If two arguments are | |
21290 | given, the first argument is the lower bound of the array, and the | |
21291 | second argument is the upper bound of the array. An array's length | |
21292 | must not be negative, but the bounds can be. | |
21293 | @end defmethod | |
21294 | ||
2c74e833 TT |
21295 | @defmethod Type const |
21296 | Return a new @code{gdb.Type} object which represents a | |
21297 | @code{const}-qualified variant of this type. | |
21298 | @end defmethod | |
21299 | ||
21300 | @defmethod Type volatile | |
21301 | Return a new @code{gdb.Type} object which represents a | |
21302 | @code{volatile}-qualified variant of this type. | |
21303 | @end defmethod | |
21304 | ||
21305 | @defmethod Type unqualified | |
21306 | Return a new @code{gdb.Type} object which represents an unqualified | |
21307 | variant of this type. That is, the result is neither @code{const} nor | |
21308 | @code{volatile}. | |
21309 | @end defmethod | |
21310 | ||
361ae042 PM |
21311 | @defmethod Type range |
21312 | Return a Python @code{Tuple} object that contains two elements: the | |
21313 | low bound of the argument type and the high bound of that type. If | |
21314 | the type does not have a range, @value{GDBN} will raise a | |
621c8364 | 21315 | @code{gdb.error} exception (@pxref{Exception Handling}). |
361ae042 PM |
21316 | @end defmethod |
21317 | ||
2c74e833 TT |
21318 | @defmethod Type reference |
21319 | Return a new @code{gdb.Type} object which represents a reference to this | |
21320 | type. | |
21321 | @end defmethod | |
21322 | ||
7a6973ad TT |
21323 | @defmethod Type pointer |
21324 | Return a new @code{gdb.Type} object which represents a pointer to this | |
21325 | type. | |
21326 | @end defmethod | |
21327 | ||
2c74e833 TT |
21328 | @defmethod Type strip_typedefs |
21329 | Return a new @code{gdb.Type} that represents the real type, | |
21330 | after removing all layers of typedefs. | |
21331 | @end defmethod | |
21332 | ||
21333 | @defmethod Type target | |
21334 | Return a new @code{gdb.Type} object which represents the target type | |
21335 | of this type. | |
21336 | ||
21337 | For a pointer type, the target type is the type of the pointed-to | |
21338 | object. For an array type (meaning C-like arrays), the target type is | |
21339 | the type of the elements of the array. For a function or method type, | |
21340 | the target type is the type of the return value. For a complex type, | |
21341 | the target type is the type of the elements. For a typedef, the | |
21342 | target type is the aliased type. | |
21343 | ||
21344 | If the type does not have a target, this method will throw an | |
21345 | exception. | |
21346 | @end defmethod | |
21347 | ||
5107b149 | 21348 | @defmethod Type template_argument n [block] |
2c74e833 TT |
21349 | If this @code{gdb.Type} is an instantiation of a template, this will |
21350 | return a new @code{gdb.Type} which represents the type of the | |
21351 | @var{n}th template argument. | |
21352 | ||
21353 | If this @code{gdb.Type} is not a template type, this will throw an | |
21354 | exception. Ordinarily, only C@t{++} code will have template types. | |
21355 | ||
5107b149 PM |
21356 | If @var{block} is given, then @var{name} is looked up in that scope. |
21357 | Otherwise, it is searched for globally. | |
2c74e833 TT |
21358 | @end defmethod |
21359 | @end table | |
21360 | ||
21361 | ||
21362 | Each type has a code, which indicates what category this type falls | |
21363 | into. The available type categories are represented by constants | |
21364 | defined in the @code{gdb} module: | |
21365 | ||
21366 | @table @code | |
21367 | @findex TYPE_CODE_PTR | |
21368 | @findex gdb.TYPE_CODE_PTR | |
21369 | @item TYPE_CODE_PTR | |
21370 | The type is a pointer. | |
21371 | ||
21372 | @findex TYPE_CODE_ARRAY | |
21373 | @findex gdb.TYPE_CODE_ARRAY | |
21374 | @item TYPE_CODE_ARRAY | |
21375 | The type is an array. | |
21376 | ||
21377 | @findex TYPE_CODE_STRUCT | |
21378 | @findex gdb.TYPE_CODE_STRUCT | |
21379 | @item TYPE_CODE_STRUCT | |
21380 | The type is a structure. | |
21381 | ||
21382 | @findex TYPE_CODE_UNION | |
21383 | @findex gdb.TYPE_CODE_UNION | |
21384 | @item TYPE_CODE_UNION | |
21385 | The type is a union. | |
21386 | ||
21387 | @findex TYPE_CODE_ENUM | |
21388 | @findex gdb.TYPE_CODE_ENUM | |
21389 | @item TYPE_CODE_ENUM | |
21390 | The type is an enum. | |
21391 | ||
21392 | @findex TYPE_CODE_FLAGS | |
21393 | @findex gdb.TYPE_CODE_FLAGS | |
21394 | @item TYPE_CODE_FLAGS | |
21395 | A bit flags type, used for things such as status registers. | |
21396 | ||
21397 | @findex TYPE_CODE_FUNC | |
21398 | @findex gdb.TYPE_CODE_FUNC | |
21399 | @item TYPE_CODE_FUNC | |
21400 | The type is a function. | |
21401 | ||
21402 | @findex TYPE_CODE_INT | |
21403 | @findex gdb.TYPE_CODE_INT | |
21404 | @item TYPE_CODE_INT | |
21405 | The type is an integer type. | |
21406 | ||
21407 | @findex TYPE_CODE_FLT | |
21408 | @findex gdb.TYPE_CODE_FLT | |
21409 | @item TYPE_CODE_FLT | |
21410 | A floating point type. | |
21411 | ||
21412 | @findex TYPE_CODE_VOID | |
21413 | @findex gdb.TYPE_CODE_VOID | |
21414 | @item TYPE_CODE_VOID | |
21415 | The special type @code{void}. | |
21416 | ||
21417 | @findex TYPE_CODE_SET | |
21418 | @findex gdb.TYPE_CODE_SET | |
21419 | @item TYPE_CODE_SET | |
21420 | A Pascal set type. | |
21421 | ||
21422 | @findex TYPE_CODE_RANGE | |
21423 | @findex gdb.TYPE_CODE_RANGE | |
21424 | @item TYPE_CODE_RANGE | |
21425 | A range type, that is, an integer type with bounds. | |
21426 | ||
21427 | @findex TYPE_CODE_STRING | |
21428 | @findex gdb.TYPE_CODE_STRING | |
21429 | @item TYPE_CODE_STRING | |
21430 | A string type. Note that this is only used for certain languages with | |
21431 | language-defined string types; C strings are not represented this way. | |
21432 | ||
21433 | @findex TYPE_CODE_BITSTRING | |
21434 | @findex gdb.TYPE_CODE_BITSTRING | |
21435 | @item TYPE_CODE_BITSTRING | |
21436 | A string of bits. | |
21437 | ||
21438 | @findex TYPE_CODE_ERROR | |
21439 | @findex gdb.TYPE_CODE_ERROR | |
21440 | @item TYPE_CODE_ERROR | |
21441 | An unknown or erroneous type. | |
21442 | ||
21443 | @findex TYPE_CODE_METHOD | |
21444 | @findex gdb.TYPE_CODE_METHOD | |
21445 | @item TYPE_CODE_METHOD | |
21446 | A method type, as found in C@t{++} or Java. | |
21447 | ||
21448 | @findex TYPE_CODE_METHODPTR | |
21449 | @findex gdb.TYPE_CODE_METHODPTR | |
21450 | @item TYPE_CODE_METHODPTR | |
21451 | A pointer-to-member-function. | |
21452 | ||
21453 | @findex TYPE_CODE_MEMBERPTR | |
21454 | @findex gdb.TYPE_CODE_MEMBERPTR | |
21455 | @item TYPE_CODE_MEMBERPTR | |
21456 | A pointer-to-member. | |
21457 | ||
21458 | @findex TYPE_CODE_REF | |
21459 | @findex gdb.TYPE_CODE_REF | |
21460 | @item TYPE_CODE_REF | |
21461 | A reference type. | |
21462 | ||
21463 | @findex TYPE_CODE_CHAR | |
21464 | @findex gdb.TYPE_CODE_CHAR | |
21465 | @item TYPE_CODE_CHAR | |
21466 | A character type. | |
21467 | ||
21468 | @findex TYPE_CODE_BOOL | |
21469 | @findex gdb.TYPE_CODE_BOOL | |
21470 | @item TYPE_CODE_BOOL | |
21471 | A boolean type. | |
21472 | ||
21473 | @findex TYPE_CODE_COMPLEX | |
21474 | @findex gdb.TYPE_CODE_COMPLEX | |
21475 | @item TYPE_CODE_COMPLEX | |
21476 | A complex float type. | |
21477 | ||
21478 | @findex TYPE_CODE_TYPEDEF | |
21479 | @findex gdb.TYPE_CODE_TYPEDEF | |
21480 | @item TYPE_CODE_TYPEDEF | |
21481 | A typedef to some other type. | |
21482 | ||
21483 | @findex TYPE_CODE_NAMESPACE | |
21484 | @findex gdb.TYPE_CODE_NAMESPACE | |
21485 | @item TYPE_CODE_NAMESPACE | |
21486 | A C@t{++} namespace. | |
21487 | ||
21488 | @findex TYPE_CODE_DECFLOAT | |
21489 | @findex gdb.TYPE_CODE_DECFLOAT | |
21490 | @item TYPE_CODE_DECFLOAT | |
21491 | A decimal floating point type. | |
21492 | ||
21493 | @findex TYPE_CODE_INTERNAL_FUNCTION | |
21494 | @findex gdb.TYPE_CODE_INTERNAL_FUNCTION | |
21495 | @item TYPE_CODE_INTERNAL_FUNCTION | |
21496 | A function internal to @value{GDBN}. This is the type used to represent | |
21497 | convenience functions. | |
21498 | @end table | |
21499 | ||
0e3509db DE |
21500 | Further support for types is provided in the @code{gdb.types} |
21501 | Python module (@pxref{gdb.types}). | |
21502 | ||
4c374409 JK |
21503 | @node Pretty Printing API |
21504 | @subsubsection Pretty Printing API | |
a6bac58e | 21505 | |
4c374409 | 21506 | An example output is provided (@pxref{Pretty Printing}). |
a6bac58e TT |
21507 | |
21508 | A pretty-printer is just an object that holds a value and implements a | |
21509 | specific interface, defined here. | |
21510 | ||
21511 | @defop Operation {pretty printer} children (self) | |
21512 | @value{GDBN} will call this method on a pretty-printer to compute the | |
21513 | children of the pretty-printer's value. | |
21514 | ||
21515 | This method must return an object conforming to the Python iterator | |
21516 | protocol. Each item returned by the iterator must be a tuple holding | |
21517 | two elements. The first element is the ``name'' of the child; the | |
21518 | second element is the child's value. The value can be any Python | |
21519 | object which is convertible to a @value{GDBN} value. | |
21520 | ||
21521 | This method is optional. If it does not exist, @value{GDBN} will act | |
21522 | as though the value has no children. | |
21523 | @end defop | |
21524 | ||
21525 | @defop Operation {pretty printer} display_hint (self) | |
21526 | The CLI may call this method and use its result to change the | |
21527 | formatting of a value. The result will also be supplied to an MI | |
21528 | consumer as a @samp{displayhint} attribute of the variable being | |
21529 | printed. | |
21530 | ||
21531 | This method is optional. If it does exist, this method must return a | |
21532 | string. | |
21533 | ||
21534 | Some display hints are predefined by @value{GDBN}: | |
21535 | ||
21536 | @table @samp | |
21537 | @item array | |
21538 | Indicate that the object being printed is ``array-like''. The CLI | |
21539 | uses this to respect parameters such as @code{set print elements} and | |
21540 | @code{set print array}. | |
21541 | ||
21542 | @item map | |
21543 | Indicate that the object being printed is ``map-like'', and that the | |
21544 | children of this value can be assumed to alternate between keys and | |
21545 | values. | |
21546 | ||
21547 | @item string | |
21548 | Indicate that the object being printed is ``string-like''. If the | |
21549 | printer's @code{to_string} method returns a Python string of some | |
21550 | kind, then @value{GDBN} will call its internal language-specific | |
21551 | string-printing function to format the string. For the CLI this means | |
21552 | adding quotation marks, possibly escaping some characters, respecting | |
21553 | @code{set print elements}, and the like. | |
21554 | @end table | |
21555 | @end defop | |
21556 | ||
21557 | @defop Operation {pretty printer} to_string (self) | |
21558 | @value{GDBN} will call this method to display the string | |
21559 | representation of the value passed to the object's constructor. | |
21560 | ||
21561 | When printing from the CLI, if the @code{to_string} method exists, | |
21562 | then @value{GDBN} will prepend its result to the values returned by | |
21563 | @code{children}. Exactly how this formatting is done is dependent on | |
21564 | the display hint, and may change as more hints are added. Also, | |
21565 | depending on the print settings (@pxref{Print Settings}), the CLI may | |
21566 | print just the result of @code{to_string} in a stack trace, omitting | |
21567 | the result of @code{children}. | |
21568 | ||
21569 | If this method returns a string, it is printed verbatim. | |
21570 | ||
21571 | Otherwise, if this method returns an instance of @code{gdb.Value}, | |
21572 | then @value{GDBN} prints this value. This may result in a call to | |
21573 | another pretty-printer. | |
21574 | ||
21575 | If instead the method returns a Python value which is convertible to a | |
21576 | @code{gdb.Value}, then @value{GDBN} performs the conversion and prints | |
21577 | the resulting value. Again, this may result in a call to another | |
21578 | pretty-printer. Python scalars (integers, floats, and booleans) and | |
21579 | strings are convertible to @code{gdb.Value}; other types are not. | |
21580 | ||
79f283fe PM |
21581 | Finally, if this method returns @code{None} then no further operations |
21582 | are peformed in this method and nothing is printed. | |
21583 | ||
a6bac58e TT |
21584 | If the result is not one of these types, an exception is raised. |
21585 | @end defop | |
21586 | ||
464b3efb TT |
21587 | @value{GDBN} provides a function which can be used to look up the |
21588 | default pretty-printer for a @code{gdb.Value}: | |
21589 | ||
21590 | @findex gdb.default_visualizer | |
21591 | @defun default_visualizer value | |
21592 | This function takes a @code{gdb.Value} object as an argument. If a | |
21593 | pretty-printer for this value exists, then it is returned. If no such | |
21594 | printer exists, then this returns @code{None}. | |
21595 | @end defun | |
21596 | ||
a6bac58e TT |
21597 | @node Selecting Pretty-Printers |
21598 | @subsubsection Selecting Pretty-Printers | |
21599 | ||
21600 | The Python list @code{gdb.pretty_printers} contains an array of | |
967cf477 | 21601 | functions or callable objects that have been registered via addition |
7b51bc51 DE |
21602 | as a pretty-printer. Printers in this list are called @code{global} |
21603 | printers, they're available when debugging all inferiors. | |
fa33c3cd | 21604 | Each @code{gdb.Progspace} contains a @code{pretty_printers} attribute. |
a6bac58e TT |
21605 | Each @code{gdb.Objfile} also contains a @code{pretty_printers} |
21606 | attribute. | |
21607 | ||
7b51bc51 | 21608 | Each function on these lists is passed a single @code{gdb.Value} |
a6bac58e | 21609 | argument and should return a pretty-printer object conforming to the |
4c374409 | 21610 | interface definition above (@pxref{Pretty Printing API}). If a function |
a6bac58e TT |
21611 | cannot create a pretty-printer for the value, it should return |
21612 | @code{None}. | |
21613 | ||
21614 | @value{GDBN} first checks the @code{pretty_printers} attribute of each | |
fa33c3cd | 21615 | @code{gdb.Objfile} in the current program space and iteratively calls |
7b51bc51 DE |
21616 | each enabled lookup routine in the list for that @code{gdb.Objfile} |
21617 | until it receives a pretty-printer object. | |
fa33c3cd DE |
21618 | If no pretty-printer is found in the objfile lists, @value{GDBN} then |
21619 | searches the pretty-printer list of the current program space, | |
967cf477 | 21620 | calling each enabled function until an object is returned. |
a6bac58e | 21621 | After these lists have been exhausted, it tries the global |
967cf477 | 21622 | @code{gdb.pretty_printers} list, again calling each enabled function until an |
a6bac58e TT |
21623 | object is returned. |
21624 | ||
21625 | The order in which the objfiles are searched is not specified. For a | |
21626 | given list, functions are always invoked from the head of the list, | |
21627 | and iterated over sequentially until the end of the list, or a printer | |
21628 | object is returned. | |
21629 | ||
7b51bc51 DE |
21630 | For various reasons a pretty-printer may not work. |
21631 | For example, the underlying data structure may have changed and | |
21632 | the pretty-printer is out of date. | |
21633 | ||
21634 | The consequences of a broken pretty-printer are severe enough that | |
21635 | @value{GDBN} provides support for enabling and disabling individual | |
21636 | printers. For example, if @code{print frame-arguments} is on, | |
21637 | a backtrace can become highly illegible if any argument is printed | |
21638 | with a broken printer. | |
21639 | ||
21640 | Pretty-printers are enabled and disabled by attaching an @code{enabled} | |
21641 | attribute to the registered function or callable object. If this attribute | |
21642 | is present and its value is @code{False}, the printer is disabled, otherwise | |
21643 | the printer is enabled. | |
21644 | ||
21645 | @node Writing a Pretty-Printer | |
21646 | @subsubsection Writing a Pretty-Printer | |
21647 | @cindex writing a pretty-printer | |
21648 | ||
21649 | A pretty-printer consists of two parts: a lookup function to detect | |
21650 | if the type is supported, and the printer itself. | |
21651 | ||
a6bac58e | 21652 | Here is an example showing how a @code{std::string} printer might be |
7b51bc51 DE |
21653 | written. @xref{Pretty Printing API}, for details on the API this class |
21654 | must provide. | |
a6bac58e TT |
21655 | |
21656 | @smallexample | |
7b51bc51 | 21657 | class StdStringPrinter(object): |
a6bac58e TT |
21658 | "Print a std::string" |
21659 | ||
7b51bc51 | 21660 | def __init__(self, val): |
a6bac58e TT |
21661 | self.val = val |
21662 | ||
7b51bc51 | 21663 | def to_string(self): |
a6bac58e TT |
21664 | return self.val['_M_dataplus']['_M_p'] |
21665 | ||
7b51bc51 | 21666 | def display_hint(self): |
a6bac58e TT |
21667 | return 'string' |
21668 | @end smallexample | |
21669 | ||
21670 | And here is an example showing how a lookup function for the printer | |
21671 | example above might be written. | |
21672 | ||
21673 | @smallexample | |
7b51bc51 | 21674 | def str_lookup_function(val): |
a6bac58e | 21675 | lookup_tag = val.type.tag |
a6bac58e TT |
21676 | if lookup_tag == None: |
21677 | return None | |
7b51bc51 DE |
21678 | regex = re.compile("^std::basic_string<char,.*>$") |
21679 | if regex.match(lookup_tag): | |
21680 | return StdStringPrinter(val) | |
a6bac58e TT |
21681 | return None |
21682 | @end smallexample | |
21683 | ||
21684 | The example lookup function extracts the value's type, and attempts to | |
21685 | match it to a type that it can pretty-print. If it is a type the | |
21686 | printer can pretty-print, it will return a printer object. If not, it | |
21687 | returns @code{None}. | |
21688 | ||
21689 | We recommend that you put your core pretty-printers into a Python | |
21690 | package. If your pretty-printers are for use with a library, we | |
21691 | further recommend embedding a version number into the package name. | |
21692 | This practice will enable @value{GDBN} to load multiple versions of | |
21693 | your pretty-printers at the same time, because they will have | |
21694 | different names. | |
21695 | ||
21696 | You should write auto-loaded code (@pxref{Auto-loading}) such that it | |
21697 | can be evaluated multiple times without changing its meaning. An | |
21698 | ideal auto-load file will consist solely of @code{import}s of your | |
21699 | printer modules, followed by a call to a register pretty-printers with | |
21700 | the current objfile. | |
21701 | ||
21702 | Taken as a whole, this approach will scale nicely to multiple | |
21703 | inferiors, each potentially using a different library version. | |
21704 | Embedding a version number in the Python package name will ensure that | |
21705 | @value{GDBN} is able to load both sets of printers simultaneously. | |
21706 | Then, because the search for pretty-printers is done by objfile, and | |
21707 | because your auto-loaded code took care to register your library's | |
21708 | printers with a specific objfile, @value{GDBN} will find the correct | |
21709 | printers for the specific version of the library used by each | |
21710 | inferior. | |
21711 | ||
4c374409 | 21712 | To continue the @code{std::string} example (@pxref{Pretty Printing API}), |
a6bac58e TT |
21713 | this code might appear in @code{gdb.libstdcxx.v6}: |
21714 | ||
21715 | @smallexample | |
7b51bc51 DE |
21716 | def register_printers(objfile): |
21717 | objfile.pretty_printers.add(str_lookup_function) | |
a6bac58e TT |
21718 | @end smallexample |
21719 | ||
21720 | @noindent | |
21721 | And then the corresponding contents of the auto-load file would be: | |
21722 | ||
21723 | @smallexample | |
21724 | import gdb.libstdcxx.v6 | |
7b51bc51 | 21725 | gdb.libstdcxx.v6.register_printers(gdb.current_objfile()) |
a6bac58e TT |
21726 | @end smallexample |
21727 | ||
7b51bc51 DE |
21728 | The previous example illustrates a basic pretty-printer. |
21729 | There are a few things that can be improved on. | |
21730 | The printer doesn't have a name, making it hard to identify in a | |
21731 | list of installed printers. The lookup function has a name, but | |
21732 | lookup functions can have arbitrary, even identical, names. | |
967cf477 | 21733 | |
7b51bc51 DE |
21734 | Second, the printer only handles one type, whereas a library typically has |
21735 | several types. One could install a lookup function for each desired type | |
21736 | in the library, but one could also have a single lookup function recognize | |
21737 | several types. The latter is the conventional way this is handled. | |
21738 | If a pretty-printer can handle multiple data types, then its | |
21739 | @dfn{subprinters} are the printers for the individual data types. | |
967cf477 | 21740 | |
7b51bc51 DE |
21741 | The @code{gdb.printing} module provides a formal way of solving these |
21742 | problems (@pxref{gdb.printing}). | |
21743 | Here is another example that handles multiple types. | |
967cf477 | 21744 | |
7b51bc51 DE |
21745 | These are the types we are going to pretty-print: |
21746 | ||
21747 | @smallexample | |
21748 | struct foo @{ int a, b; @}; | |
21749 | struct bar @{ struct foo x, y; @}; | |
21750 | @end smallexample | |
21751 | ||
21752 | Here are the printers: | |
21753 | ||
21754 | @smallexample | |
21755 | class fooPrinter: | |
21756 | """Print a foo object.""" | |
21757 | ||
21758 | def __init__(self, val): | |
21759 | self.val = val | |
21760 | ||
21761 | def to_string(self): | |
21762 | return ("a=<" + str(self.val["a"]) + | |
21763 | "> b=<" + str(self.val["b"]) + ">") | |
21764 | ||
21765 | class barPrinter: | |
21766 | """Print a bar object.""" | |
21767 | ||
21768 | def __init__(self, val): | |
21769 | self.val = val | |
21770 | ||
21771 | def to_string(self): | |
21772 | return ("x=<" + str(self.val["x"]) + | |
21773 | "> y=<" + str(self.val["y"]) + ">") | |
21774 | @end smallexample | |
21775 | ||
21776 | This example doesn't need a lookup function, that is handled by the | |
21777 | @code{gdb.printing} module. Instead a function is provided to build up | |
21778 | the object that handles the lookup. | |
21779 | ||
21780 | @smallexample | |
21781 | import gdb.printing | |
21782 | ||
21783 | def build_pretty_printer(): | |
21784 | pp = gdb.printing.RegexpCollectionPrettyPrinter( | |
21785 | "my_library") | |
21786 | pp.add_printer('foo', '^foo$', fooPrinter) | |
21787 | pp.add_printer('bar', '^bar$', barPrinter) | |
21788 | return pp | |
21789 | @end smallexample | |
21790 | ||
21791 | And here is the autoload support: | |
21792 | ||
21793 | @smallexample | |
21794 | import gdb.printing | |
21795 | import my_library | |
21796 | gdb.printing.register_pretty_printer( | |
21797 | gdb.current_objfile(), | |
21798 | my_library.build_pretty_printer()) | |
21799 | @end smallexample | |
21800 | ||
21801 | Finally, when this printer is loaded into @value{GDBN}, here is the | |
21802 | corresponding output of @samp{info pretty-printer}: | |
21803 | ||
21804 | @smallexample | |
21805 | (gdb) info pretty-printer | |
21806 | my_library.so: | |
21807 | my_library | |
21808 | foo | |
21809 | bar | |
21810 | @end smallexample | |
967cf477 | 21811 | |
595939de PM |
21812 | @node Inferiors In Python |
21813 | @subsubsection Inferiors In Python | |
21814 | @cindex inferiors in python | |
21815 | ||
21816 | @findex gdb.Inferior | |
21817 | Programs which are being run under @value{GDBN} are called inferiors | |
21818 | (@pxref{Inferiors and Programs}). Python scripts can access | |
21819 | information about and manipulate inferiors controlled by @value{GDBN} | |
21820 | via objects of the @code{gdb.Inferior} class. | |
21821 | ||
21822 | The following inferior-related functions are available in the @code{gdb} | |
21823 | module: | |
21824 | ||
21825 | @defun inferiors | |
21826 | Return a tuple containing all inferior objects. | |
21827 | @end defun | |
21828 | ||
21829 | A @code{gdb.Inferior} object has the following attributes: | |
21830 | ||
21831 | @table @code | |
21832 | @defivar Inferior num | |
21833 | ID of inferior, as assigned by GDB. | |
21834 | @end defivar | |
21835 | ||
21836 | @defivar Inferior pid | |
21837 | Process ID of the inferior, as assigned by the underlying operating | |
21838 | system. | |
21839 | @end defivar | |
21840 | ||
21841 | @defivar Inferior was_attached | |
21842 | Boolean signaling whether the inferior was created using `attach', or | |
21843 | started by @value{GDBN} itself. | |
21844 | @end defivar | |
21845 | @end table | |
21846 | ||
21847 | A @code{gdb.Inferior} object has the following methods: | |
21848 | ||
21849 | @table @code | |
21850 | @defmethod Inferior threads | |
21851 | This method returns a tuple holding all the threads which are valid | |
21852 | when it is called. If there are no valid threads, the method will | |
21853 | return an empty tuple. | |
21854 | @end defmethod | |
21855 | ||
21856 | @findex gdb.read_memory | |
21857 | @defmethod Inferior read_memory address length | |
21858 | Read @var{length} bytes of memory from the inferior, starting at | |
21859 | @var{address}. Returns a buffer object, which behaves much like an array | |
21860 | or a string. It can be modified and given to the @code{gdb.write_memory} | |
21861 | function. | |
21862 | @end defmethod | |
21863 | ||
21864 | @findex gdb.write_memory | |
21865 | @defmethod Inferior write_memory address buffer @r{[}length@r{]} | |
21866 | Write the contents of @var{buffer} to the inferior, starting at | |
21867 | @var{address}. The @var{buffer} parameter must be a Python object | |
21868 | which supports the buffer protocol, i.e., a string, an array or the | |
21869 | object returned from @code{gdb.read_memory}. If given, @var{length} | |
21870 | determines the number of bytes from @var{buffer} to be written. | |
21871 | @end defmethod | |
21872 | ||
21873 | @findex gdb.search_memory | |
21874 | @defmethod Inferior search_memory address length pattern | |
21875 | Search a region of the inferior memory starting at @var{address} with | |
21876 | the given @var{length} using the search pattern supplied in | |
21877 | @var{pattern}. The @var{pattern} parameter must be a Python object | |
21878 | which supports the buffer protocol, i.e., a string, an array or the | |
21879 | object returned from @code{gdb.read_memory}. Returns a Python @code{Long} | |
21880 | containing the address where the pattern was found, or @code{None} if | |
21881 | the pattern could not be found. | |
21882 | @end defmethod | |
21883 | @end table | |
21884 | ||
21885 | @node Threads In Python | |
21886 | @subsubsection Threads In Python | |
21887 | @cindex threads in python | |
21888 | ||
21889 | @findex gdb.InferiorThread | |
21890 | Python scripts can access information about, and manipulate inferior threads | |
21891 | controlled by @value{GDBN}, via objects of the @code{gdb.InferiorThread} class. | |
21892 | ||
21893 | The following thread-related functions are available in the @code{gdb} | |
21894 | module: | |
21895 | ||
21896 | @findex gdb.selected_thread | |
21897 | @defun selected_thread | |
21898 | This function returns the thread object for the selected thread. If there | |
21899 | is no selected thread, this will return @code{None}. | |
21900 | @end defun | |
21901 | ||
21902 | A @code{gdb.InferiorThread} object has the following attributes: | |
21903 | ||
21904 | @table @code | |
21905 | @defivar InferiorThread num | |
21906 | ID of the thread, as assigned by GDB. | |
21907 | @end defivar | |
21908 | ||
21909 | @defivar InferiorThread ptid | |
21910 | ID of the thread, as assigned by the operating system. This attribute is a | |
21911 | tuple containing three integers. The first is the Process ID (PID); the second | |
21912 | is the Lightweight Process ID (LWPID), and the third is the Thread ID (TID). | |
21913 | Either the LWPID or TID may be 0, which indicates that the operating system | |
21914 | does not use that identifier. | |
21915 | @end defivar | |
21916 | @end table | |
21917 | ||
21918 | A @code{gdb.InferiorThread} object has the following methods: | |
21919 | ||
dc3b15be | 21920 | @table @code |
595939de PM |
21921 | @defmethod InferiorThread switch |
21922 | This changes @value{GDBN}'s currently selected thread to the one represented | |
21923 | by this object. | |
21924 | @end defmethod | |
21925 | ||
21926 | @defmethod InferiorThread is_stopped | |
21927 | Return a Boolean indicating whether the thread is stopped. | |
21928 | @end defmethod | |
21929 | ||
21930 | @defmethod InferiorThread is_running | |
21931 | Return a Boolean indicating whether the thread is running. | |
21932 | @end defmethod | |
21933 | ||
21934 | @defmethod InferiorThread is_exited | |
21935 | Return a Boolean indicating whether the thread is exited. | |
21936 | @end defmethod | |
21937 | @end table | |
21938 | ||
d8906c6f TJB |
21939 | @node Commands In Python |
21940 | @subsubsection Commands In Python | |
21941 | ||
21942 | @cindex commands in python | |
21943 | @cindex python commands | |
d8906c6f TJB |
21944 | You can implement new @value{GDBN} CLI commands in Python. A CLI |
21945 | command is implemented using an instance of the @code{gdb.Command} | |
21946 | class, most commonly using a subclass. | |
21947 | ||
cc924cad | 21948 | @defmethod Command __init__ name @var{command_class} @r{[}@var{completer_class}@r{]} @r{[}@var{prefix}@r{]} |
d8906c6f TJB |
21949 | The object initializer for @code{Command} registers the new command |
21950 | with @value{GDBN}. This initializer is normally invoked from the | |
21951 | subclass' own @code{__init__} method. | |
21952 | ||
21953 | @var{name} is the name of the command. If @var{name} consists of | |
21954 | multiple words, then the initial words are looked for as prefix | |
21955 | commands. In this case, if one of the prefix commands does not exist, | |
21956 | an exception is raised. | |
21957 | ||
21958 | There is no support for multi-line commands. | |
21959 | ||
cc924cad | 21960 | @var{command_class} should be one of the @samp{COMMAND_} constants |
d8906c6f TJB |
21961 | defined below. This argument tells @value{GDBN} how to categorize the |
21962 | new command in the help system. | |
21963 | ||
cc924cad | 21964 | @var{completer_class} is an optional argument. If given, it should be |
d8906c6f TJB |
21965 | one of the @samp{COMPLETE_} constants defined below. This argument |
21966 | tells @value{GDBN} how to perform completion for this command. If not | |
21967 | given, @value{GDBN} will attempt to complete using the object's | |
21968 | @code{complete} method (see below); if no such method is found, an | |
21969 | error will occur when completion is attempted. | |
21970 | ||
21971 | @var{prefix} is an optional argument. If @code{True}, then the new | |
21972 | command is a prefix command; sub-commands of this command may be | |
21973 | registered. | |
21974 | ||
21975 | The help text for the new command is taken from the Python | |
21976 | documentation string for the command's class, if there is one. If no | |
21977 | documentation string is provided, the default value ``This command is | |
21978 | not documented.'' is used. | |
21979 | @end defmethod | |
21980 | ||
a0c36267 | 21981 | @cindex don't repeat Python command |
d8906c6f TJB |
21982 | @defmethod Command dont_repeat |
21983 | By default, a @value{GDBN} command is repeated when the user enters a | |
21984 | blank line at the command prompt. A command can suppress this | |
21985 | behavior by invoking the @code{dont_repeat} method. This is similar | |
21986 | to the user command @code{dont-repeat}, see @ref{Define, dont-repeat}. | |
21987 | @end defmethod | |
21988 | ||
21989 | @defmethod Command invoke argument from_tty | |
21990 | This method is called by @value{GDBN} when this command is invoked. | |
21991 | ||
21992 | @var{argument} is a string. It is the argument to the command, after | |
21993 | leading and trailing whitespace has been stripped. | |
21994 | ||
21995 | @var{from_tty} is a boolean argument. When true, this means that the | |
21996 | command was entered by the user at the terminal; when false it means | |
21997 | that the command came from elsewhere. | |
21998 | ||
21999 | If this method throws an exception, it is turned into a @value{GDBN} | |
22000 | @code{error} call. Otherwise, the return value is ignored. | |
07ca107c DE |
22001 | |
22002 | @findex gdb.string_to_argv | |
22003 | To break @var{argument} up into an argv-like string use | |
22004 | @code{gdb.string_to_argv}. This function behaves identically to | |
22005 | @value{GDBN}'s internal argument lexer @code{buildargv}. | |
22006 | It is recommended to use this for consistency. | |
22007 | Arguments are separated by spaces and may be quoted. | |
22008 | Example: | |
22009 | ||
22010 | @smallexample | |
22011 | print gdb.string_to_argv ("1 2\ \\\"3 '4 \"5' \"6 '7\"") | |
22012 | ['1', '2 "3', '4 "5', "6 '7"] | |
22013 | @end smallexample | |
22014 | ||
d8906c6f TJB |
22015 | @end defmethod |
22016 | ||
a0c36267 | 22017 | @cindex completion of Python commands |
d8906c6f TJB |
22018 | @defmethod Command complete text word |
22019 | This method is called by @value{GDBN} when the user attempts | |
22020 | completion on this command. All forms of completion are handled by | |
a0c36267 EZ |
22021 | this method, that is, the @key{TAB} and @key{M-?} key bindings |
22022 | (@pxref{Completion}), and the @code{complete} command (@pxref{Help, | |
22023 | complete}). | |
d8906c6f TJB |
22024 | |
22025 | The arguments @var{text} and @var{word} are both strings. @var{text} | |
22026 | holds the complete command line up to the cursor's location. | |
22027 | @var{word} holds the last word of the command line; this is computed | |
22028 | using a word-breaking heuristic. | |
22029 | ||
22030 | The @code{complete} method can return several values: | |
22031 | @itemize @bullet | |
22032 | @item | |
22033 | If the return value is a sequence, the contents of the sequence are | |
22034 | used as the completions. It is up to @code{complete} to ensure that the | |
22035 | contents actually do complete the word. A zero-length sequence is | |
22036 | allowed, it means that there were no completions available. Only | |
22037 | string elements of the sequence are used; other elements in the | |
22038 | sequence are ignored. | |
22039 | ||
22040 | @item | |
22041 | If the return value is one of the @samp{COMPLETE_} constants defined | |
22042 | below, then the corresponding @value{GDBN}-internal completion | |
22043 | function is invoked, and its result is used. | |
22044 | ||
22045 | @item | |
22046 | All other results are treated as though there were no available | |
22047 | completions. | |
22048 | @end itemize | |
22049 | @end defmethod | |
22050 | ||
d8906c6f TJB |
22051 | When a new command is registered, it must be declared as a member of |
22052 | some general class of commands. This is used to classify top-level | |
22053 | commands in the on-line help system; note that prefix commands are not | |
22054 | listed under their own category but rather that of their top-level | |
22055 | command. The available classifications are represented by constants | |
22056 | defined in the @code{gdb} module: | |
22057 | ||
22058 | @table @code | |
22059 | @findex COMMAND_NONE | |
22060 | @findex gdb.COMMAND_NONE | |
22061 | @item COMMAND_NONE | |
22062 | The command does not belong to any particular class. A command in | |
22063 | this category will not be displayed in any of the help categories. | |
22064 | ||
22065 | @findex COMMAND_RUNNING | |
22066 | @findex gdb.COMMAND_RUNNING | |
a0c36267 | 22067 | @item COMMAND_RUNNING |
d8906c6f TJB |
22068 | The command is related to running the inferior. For example, |
22069 | @code{start}, @code{step}, and @code{continue} are in this category. | |
a0c36267 | 22070 | Type @kbd{help running} at the @value{GDBN} prompt to see a list of |
d8906c6f TJB |
22071 | commands in this category. |
22072 | ||
22073 | @findex COMMAND_DATA | |
22074 | @findex gdb.COMMAND_DATA | |
a0c36267 | 22075 | @item COMMAND_DATA |
d8906c6f TJB |
22076 | The command is related to data or variables. For example, |
22077 | @code{call}, @code{find}, and @code{print} are in this category. Type | |
a0c36267 | 22078 | @kbd{help data} at the @value{GDBN} prompt to see a list of commands |
d8906c6f TJB |
22079 | in this category. |
22080 | ||
22081 | @findex COMMAND_STACK | |
22082 | @findex gdb.COMMAND_STACK | |
22083 | @item COMMAND_STACK | |
22084 | The command has to do with manipulation of the stack. For example, | |
22085 | @code{backtrace}, @code{frame}, and @code{return} are in this | |
a0c36267 | 22086 | category. Type @kbd{help stack} at the @value{GDBN} prompt to see a |
d8906c6f TJB |
22087 | list of commands in this category. |
22088 | ||
22089 | @findex COMMAND_FILES | |
22090 | @findex gdb.COMMAND_FILES | |
22091 | @item COMMAND_FILES | |
22092 | This class is used for file-related commands. For example, | |
22093 | @code{file}, @code{list} and @code{section} are in this category. | |
a0c36267 | 22094 | Type @kbd{help files} at the @value{GDBN} prompt to see a list of |
d8906c6f TJB |
22095 | commands in this category. |
22096 | ||
22097 | @findex COMMAND_SUPPORT | |
22098 | @findex gdb.COMMAND_SUPPORT | |
22099 | @item COMMAND_SUPPORT | |
22100 | This should be used for ``support facilities'', generally meaning | |
22101 | things that are useful to the user when interacting with @value{GDBN}, | |
22102 | but not related to the state of the inferior. For example, | |
22103 | @code{help}, @code{make}, and @code{shell} are in this category. Type | |
a0c36267 | 22104 | @kbd{help support} at the @value{GDBN} prompt to see a list of |
d8906c6f TJB |
22105 | commands in this category. |
22106 | ||
22107 | @findex COMMAND_STATUS | |
22108 | @findex gdb.COMMAND_STATUS | |
a0c36267 | 22109 | @item COMMAND_STATUS |
d8906c6f TJB |
22110 | The command is an @samp{info}-related command, that is, related to the |
22111 | state of @value{GDBN} itself. For example, @code{info}, @code{macro}, | |
a0c36267 | 22112 | and @code{show} are in this category. Type @kbd{help status} at the |
d8906c6f TJB |
22113 | @value{GDBN} prompt to see a list of commands in this category. |
22114 | ||
22115 | @findex COMMAND_BREAKPOINTS | |
22116 | @findex gdb.COMMAND_BREAKPOINTS | |
a0c36267 | 22117 | @item COMMAND_BREAKPOINTS |
d8906c6f | 22118 | The command has to do with breakpoints. For example, @code{break}, |
a0c36267 | 22119 | @code{clear}, and @code{delete} are in this category. Type @kbd{help |
d8906c6f TJB |
22120 | breakpoints} at the @value{GDBN} prompt to see a list of commands in |
22121 | this category. | |
22122 | ||
22123 | @findex COMMAND_TRACEPOINTS | |
22124 | @findex gdb.COMMAND_TRACEPOINTS | |
a0c36267 | 22125 | @item COMMAND_TRACEPOINTS |
d8906c6f TJB |
22126 | The command has to do with tracepoints. For example, @code{trace}, |
22127 | @code{actions}, and @code{tfind} are in this category. Type | |
a0c36267 | 22128 | @kbd{help tracepoints} at the @value{GDBN} prompt to see a list of |
d8906c6f TJB |
22129 | commands in this category. |
22130 | ||
22131 | @findex COMMAND_OBSCURE | |
22132 | @findex gdb.COMMAND_OBSCURE | |
22133 | @item COMMAND_OBSCURE | |
22134 | The command is only used in unusual circumstances, or is not of | |
22135 | general interest to users. For example, @code{checkpoint}, | |
a0c36267 | 22136 | @code{fork}, and @code{stop} are in this category. Type @kbd{help |
d8906c6f TJB |
22137 | obscure} at the @value{GDBN} prompt to see a list of commands in this |
22138 | category. | |
22139 | ||
22140 | @findex COMMAND_MAINTENANCE | |
22141 | @findex gdb.COMMAND_MAINTENANCE | |
22142 | @item COMMAND_MAINTENANCE | |
22143 | The command is only useful to @value{GDBN} maintainers. The | |
22144 | @code{maintenance} and @code{flushregs} commands are in this category. | |
a0c36267 | 22145 | Type @kbd{help internals} at the @value{GDBN} prompt to see a list of |
d8906c6f TJB |
22146 | commands in this category. |
22147 | @end table | |
22148 | ||
d8906c6f TJB |
22149 | A new command can use a predefined completion function, either by |
22150 | specifying it via an argument at initialization, or by returning it | |
22151 | from the @code{complete} method. These predefined completion | |
22152 | constants are all defined in the @code{gdb} module: | |
22153 | ||
22154 | @table @code | |
22155 | @findex COMPLETE_NONE | |
22156 | @findex gdb.COMPLETE_NONE | |
22157 | @item COMPLETE_NONE | |
22158 | This constant means that no completion should be done. | |
22159 | ||
22160 | @findex COMPLETE_FILENAME | |
22161 | @findex gdb.COMPLETE_FILENAME | |
22162 | @item COMPLETE_FILENAME | |
22163 | This constant means that filename completion should be performed. | |
22164 | ||
22165 | @findex COMPLETE_LOCATION | |
22166 | @findex gdb.COMPLETE_LOCATION | |
22167 | @item COMPLETE_LOCATION | |
22168 | This constant means that location completion should be done. | |
22169 | @xref{Specify Location}. | |
22170 | ||
22171 | @findex COMPLETE_COMMAND | |
22172 | @findex gdb.COMPLETE_COMMAND | |
22173 | @item COMPLETE_COMMAND | |
22174 | This constant means that completion should examine @value{GDBN} | |
22175 | command names. | |
22176 | ||
22177 | @findex COMPLETE_SYMBOL | |
22178 | @findex gdb.COMPLETE_SYMBOL | |
22179 | @item COMPLETE_SYMBOL | |
22180 | This constant means that completion should be done using symbol names | |
22181 | as the source. | |
22182 | @end table | |
22183 | ||
22184 | The following code snippet shows how a trivial CLI command can be | |
22185 | implemented in Python: | |
22186 | ||
22187 | @smallexample | |
22188 | class HelloWorld (gdb.Command): | |
22189 | """Greet the whole world.""" | |
22190 | ||
22191 | def __init__ (self): | |
22192 | super (HelloWorld, self).__init__ ("hello-world", gdb.COMMAND_OBSCURE) | |
22193 | ||
22194 | def invoke (self, arg, from_tty): | |
22195 | print "Hello, World!" | |
22196 | ||
22197 | HelloWorld () | |
22198 | @end smallexample | |
22199 | ||
22200 | The last line instantiates the class, and is necessary to trigger the | |
22201 | registration of the command with @value{GDBN}. Depending on how the | |
22202 | Python code is read into @value{GDBN}, you may need to import the | |
22203 | @code{gdb} module explicitly. | |
22204 | ||
d7b32ed3 PM |
22205 | @node Parameters In Python |
22206 | @subsubsection Parameters In Python | |
22207 | ||
22208 | @cindex parameters in python | |
22209 | @cindex python parameters | |
22210 | @tindex gdb.Parameter | |
22211 | @tindex Parameter | |
22212 | You can implement new @value{GDBN} parameters using Python. A new | |
22213 | parameter is implemented as an instance of the @code{gdb.Parameter} | |
22214 | class. | |
22215 | ||
22216 | Parameters are exposed to the user via the @code{set} and | |
22217 | @code{show} commands. @xref{Help}. | |
22218 | ||
22219 | There are many parameters that already exist and can be set in | |
22220 | @value{GDBN}. Two examples are: @code{set follow fork} and | |
22221 | @code{set charset}. Setting these parameters influences certain | |
22222 | behavior in @value{GDBN}. Similarly, you can define parameters that | |
22223 | can be used to influence behavior in custom Python scripts and commands. | |
22224 | ||
22225 | @defmethod Parameter __init__ name @var{command-class} @var{parameter-class} @r{[}@var{enum-sequence}@r{]} | |
22226 | The object initializer for @code{Parameter} registers the new | |
22227 | parameter with @value{GDBN}. This initializer is normally invoked | |
22228 | from the subclass' own @code{__init__} method. | |
22229 | ||
22230 | @var{name} is the name of the new parameter. If @var{name} consists | |
22231 | of multiple words, then the initial words are looked for as prefix | |
22232 | parameters. An example of this can be illustrated with the | |
22233 | @code{set print} set of parameters. If @var{name} is | |
22234 | @code{print foo}, then @code{print} will be searched as the prefix | |
22235 | parameter. In this case the parameter can subsequently be accessed in | |
22236 | @value{GDBN} as @code{set print foo}. | |
22237 | ||
22238 | If @var{name} consists of multiple words, and no prefix parameter group | |
22239 | can be found, an exception is raised. | |
22240 | ||
22241 | @var{command-class} should be one of the @samp{COMMAND_} constants | |
22242 | (@pxref{Commands In Python}). This argument tells @value{GDBN} how to | |
22243 | categorize the new parameter in the help system. | |
22244 | ||
22245 | @var{parameter-class} should be one of the @samp{PARAM_} constants | |
22246 | defined below. This argument tells @value{GDBN} the type of the new | |
22247 | parameter; this information is used for input validation and | |
22248 | completion. | |
22249 | ||
22250 | If @var{parameter-class} is @code{PARAM_ENUM}, then | |
22251 | @var{enum-sequence} must be a sequence of strings. These strings | |
22252 | represent the possible values for the parameter. | |
22253 | ||
22254 | If @var{parameter-class} is not @code{PARAM_ENUM}, then the presence | |
22255 | of a fourth argument will cause an exception to be thrown. | |
22256 | ||
22257 | The help text for the new parameter is taken from the Python | |
22258 | documentation string for the parameter's class, if there is one. If | |
22259 | there is no documentation string, a default value is used. | |
22260 | @end defmethod | |
22261 | ||
22262 | @defivar Parameter set_doc | |
22263 | If this attribute exists, and is a string, then its value is used as | |
22264 | the help text for this parameter's @code{set} command. The value is | |
22265 | examined when @code{Parameter.__init__} is invoked; subsequent changes | |
22266 | have no effect. | |
22267 | @end defivar | |
22268 | ||
22269 | @defivar Parameter show_doc | |
22270 | If this attribute exists, and is a string, then its value is used as | |
22271 | the help text for this parameter's @code{show} command. The value is | |
22272 | examined when @code{Parameter.__init__} is invoked; subsequent changes | |
22273 | have no effect. | |
22274 | @end defivar | |
22275 | ||
22276 | @defivar Parameter value | |
22277 | The @code{value} attribute holds the underlying value of the | |
22278 | parameter. It can be read and assigned to just as any other | |
22279 | attribute. @value{GDBN} does validation when assignments are made. | |
22280 | @end defivar | |
22281 | ||
22282 | ||
22283 | When a new parameter is defined, its type must be specified. The | |
22284 | available types are represented by constants defined in the @code{gdb} | |
22285 | module: | |
22286 | ||
22287 | @table @code | |
22288 | @findex PARAM_BOOLEAN | |
22289 | @findex gdb.PARAM_BOOLEAN | |
22290 | @item PARAM_BOOLEAN | |
22291 | The value is a plain boolean. The Python boolean values, @code{True} | |
22292 | and @code{False} are the only valid values. | |
22293 | ||
22294 | @findex PARAM_AUTO_BOOLEAN | |
22295 | @findex gdb.PARAM_AUTO_BOOLEAN | |
22296 | @item PARAM_AUTO_BOOLEAN | |
22297 | The value has three possible states: true, false, and @samp{auto}. In | |
22298 | Python, true and false are represented using boolean constants, and | |
22299 | @samp{auto} is represented using @code{None}. | |
22300 | ||
22301 | @findex PARAM_UINTEGER | |
22302 | @findex gdb.PARAM_UINTEGER | |
22303 | @item PARAM_UINTEGER | |
22304 | The value is an unsigned integer. The value of 0 should be | |
22305 | interpreted to mean ``unlimited''. | |
22306 | ||
22307 | @findex PARAM_INTEGER | |
22308 | @findex gdb.PARAM_INTEGER | |
22309 | @item PARAM_INTEGER | |
22310 | The value is a signed integer. The value of 0 should be interpreted | |
22311 | to mean ``unlimited''. | |
22312 | ||
22313 | @findex PARAM_STRING | |
22314 | @findex gdb.PARAM_STRING | |
22315 | @item PARAM_STRING | |
22316 | The value is a string. When the user modifies the string, any escape | |
22317 | sequences, such as @samp{\t}, @samp{\f}, and octal escapes, are | |
22318 | translated into corresponding characters and encoded into the current | |
22319 | host charset. | |
22320 | ||
22321 | @findex PARAM_STRING_NOESCAPE | |
22322 | @findex gdb.PARAM_STRING_NOESCAPE | |
22323 | @item PARAM_STRING_NOESCAPE | |
22324 | The value is a string. When the user modifies the string, escapes are | |
22325 | passed through untranslated. | |
22326 | ||
22327 | @findex PARAM_OPTIONAL_FILENAME | |
22328 | @findex gdb.PARAM_OPTIONAL_FILENAME | |
22329 | @item PARAM_OPTIONAL_FILENAME | |
22330 | The value is a either a filename (a string), or @code{None}. | |
22331 | ||
22332 | @findex PARAM_FILENAME | |
22333 | @findex gdb.PARAM_FILENAME | |
22334 | @item PARAM_FILENAME | |
22335 | The value is a filename. This is just like | |
22336 | @code{PARAM_STRING_NOESCAPE}, but uses file names for completion. | |
22337 | ||
22338 | @findex PARAM_ZINTEGER | |
22339 | @findex gdb.PARAM_ZINTEGER | |
22340 | @item PARAM_ZINTEGER | |
22341 | The value is an integer. This is like @code{PARAM_INTEGER}, except 0 | |
22342 | is interpreted as itself. | |
22343 | ||
22344 | @findex PARAM_ENUM | |
22345 | @findex gdb.PARAM_ENUM | |
22346 | @item PARAM_ENUM | |
22347 | The value is a string, which must be one of a collection string | |
22348 | constants provided when the parameter is created. | |
22349 | @end table | |
22350 | ||
bc3b79fd TJB |
22351 | @node Functions In Python |
22352 | @subsubsection Writing new convenience functions | |
22353 | ||
22354 | @cindex writing convenience functions | |
22355 | @cindex convenience functions in python | |
22356 | @cindex python convenience functions | |
22357 | @tindex gdb.Function | |
22358 | @tindex Function | |
22359 | You can implement new convenience functions (@pxref{Convenience Vars}) | |
22360 | in Python. A convenience function is an instance of a subclass of the | |
22361 | class @code{gdb.Function}. | |
22362 | ||
22363 | @defmethod Function __init__ name | |
22364 | The initializer for @code{Function} registers the new function with | |
22365 | @value{GDBN}. The argument @var{name} is the name of the function, | |
22366 | a string. The function will be visible to the user as a convenience | |
22367 | variable of type @code{internal function}, whose name is the same as | |
22368 | the given @var{name}. | |
22369 | ||
22370 | The documentation for the new function is taken from the documentation | |
22371 | string for the new class. | |
22372 | @end defmethod | |
22373 | ||
22374 | @defmethod Function invoke @var{*args} | |
22375 | When a convenience function is evaluated, its arguments are converted | |
22376 | to instances of @code{gdb.Value}, and then the function's | |
22377 | @code{invoke} method is called. Note that @value{GDBN} does not | |
22378 | predetermine the arity of convenience functions. Instead, all | |
22379 | available arguments are passed to @code{invoke}, following the | |
22380 | standard Python calling convention. In particular, a convenience | |
22381 | function can have default values for parameters without ill effect. | |
22382 | ||
22383 | The return value of this method is used as its value in the enclosing | |
22384 | expression. If an ordinary Python value is returned, it is converted | |
22385 | to a @code{gdb.Value} following the usual rules. | |
22386 | @end defmethod | |
22387 | ||
22388 | The following code snippet shows how a trivial convenience function can | |
22389 | be implemented in Python: | |
22390 | ||
22391 | @smallexample | |
22392 | class Greet (gdb.Function): | |
22393 | """Return string to greet someone. | |
22394 | Takes a name as argument.""" | |
22395 | ||
22396 | def __init__ (self): | |
22397 | super (Greet, self).__init__ ("greet") | |
22398 | ||
22399 | def invoke (self, name): | |
22400 | return "Hello, %s!" % name.string () | |
22401 | ||
22402 | Greet () | |
22403 | @end smallexample | |
22404 | ||
22405 | The last line instantiates the class, and is necessary to trigger the | |
22406 | registration of the function with @value{GDBN}. Depending on how the | |
22407 | Python code is read into @value{GDBN}, you may need to import the | |
22408 | @code{gdb} module explicitly. | |
22409 | ||
fa33c3cd DE |
22410 | @node Progspaces In Python |
22411 | @subsubsection Program Spaces In Python | |
22412 | ||
22413 | @cindex progspaces in python | |
22414 | @tindex gdb.Progspace | |
22415 | @tindex Progspace | |
22416 | A program space, or @dfn{progspace}, represents a symbolic view | |
22417 | of an address space. | |
22418 | It consists of all of the objfiles of the program. | |
22419 | @xref{Objfiles In Python}. | |
22420 | @xref{Inferiors and Programs, program spaces}, for more details | |
22421 | about program spaces. | |
22422 | ||
22423 | The following progspace-related functions are available in the | |
22424 | @code{gdb} module: | |
22425 | ||
22426 | @findex gdb.current_progspace | |
22427 | @defun current_progspace | |
22428 | This function returns the program space of the currently selected inferior. | |
22429 | @xref{Inferiors and Programs}. | |
22430 | @end defun | |
22431 | ||
22432 | @findex gdb.progspaces | |
22433 | @defun progspaces | |
22434 | Return a sequence of all the progspaces currently known to @value{GDBN}. | |
22435 | @end defun | |
22436 | ||
22437 | Each progspace is represented by an instance of the @code{gdb.Progspace} | |
22438 | class. | |
22439 | ||
22440 | @defivar Progspace filename | |
22441 | The file name of the progspace as a string. | |
22442 | @end defivar | |
22443 | ||
22444 | @defivar Progspace pretty_printers | |
22445 | The @code{pretty_printers} attribute is a list of functions. It is | |
22446 | used to look up pretty-printers. A @code{Value} is passed to each | |
22447 | function in order; if the function returns @code{None}, then the | |
22448 | search continues. Otherwise, the return value should be an object | |
4c374409 | 22449 | which is used to format the value. @xref{Pretty Printing API}, for more |
fa33c3cd DE |
22450 | information. |
22451 | @end defivar | |
22452 | ||
89c73ade TT |
22453 | @node Objfiles In Python |
22454 | @subsubsection Objfiles In Python | |
22455 | ||
22456 | @cindex objfiles in python | |
22457 | @tindex gdb.Objfile | |
22458 | @tindex Objfile | |
22459 | @value{GDBN} loads symbols for an inferior from various | |
22460 | symbol-containing files (@pxref{Files}). These include the primary | |
22461 | executable file, any shared libraries used by the inferior, and any | |
22462 | separate debug info files (@pxref{Separate Debug Files}). | |
22463 | @value{GDBN} calls these symbol-containing files @dfn{objfiles}. | |
22464 | ||
22465 | The following objfile-related functions are available in the | |
22466 | @code{gdb} module: | |
22467 | ||
22468 | @findex gdb.current_objfile | |
22469 | @defun current_objfile | |
22470 | When auto-loading a Python script (@pxref{Auto-loading}), @value{GDBN} | |
22471 | sets the ``current objfile'' to the corresponding objfile. This | |
22472 | function returns the current objfile. If there is no current objfile, | |
22473 | this function returns @code{None}. | |
22474 | @end defun | |
22475 | ||
22476 | @findex gdb.objfiles | |
22477 | @defun objfiles | |
22478 | Return a sequence of all the objfiles current known to @value{GDBN}. | |
22479 | @xref{Objfiles In Python}. | |
22480 | @end defun | |
22481 | ||
22482 | Each objfile is represented by an instance of the @code{gdb.Objfile} | |
22483 | class. | |
22484 | ||
22485 | @defivar Objfile filename | |
22486 | The file name of the objfile as a string. | |
22487 | @end defivar | |
22488 | ||
22489 | @defivar Objfile pretty_printers | |
22490 | The @code{pretty_printers} attribute is a list of functions. It is | |
22491 | used to look up pretty-printers. A @code{Value} is passed to each | |
22492 | function in order; if the function returns @code{None}, then the | |
22493 | search continues. Otherwise, the return value should be an object | |
4c374409 | 22494 | which is used to format the value. @xref{Pretty Printing API}, for more |
a6bac58e | 22495 | information. |
89c73ade TT |
22496 | @end defivar |
22497 | ||
f8f6f20b | 22498 | @node Frames In Python |
f3e9a817 | 22499 | @subsubsection Accessing inferior stack frames from Python. |
f8f6f20b TJB |
22500 | |
22501 | @cindex frames in python | |
22502 | When the debugged program stops, @value{GDBN} is able to analyze its call | |
22503 | stack (@pxref{Frames,,Stack frames}). The @code{gdb.Frame} class | |
22504 | represents a frame in the stack. A @code{gdb.Frame} object is only valid | |
22505 | while its corresponding frame exists in the inferior's stack. If you try | |
621c8364 TT |
22506 | to use an invalid frame object, @value{GDBN} will throw a @code{gdb.error} |
22507 | exception (@pxref{Exception Handling}). | |
f8f6f20b TJB |
22508 | |
22509 | Two @code{gdb.Frame} objects can be compared for equality with the @code{==} | |
22510 | operator, like: | |
22511 | ||
22512 | @smallexample | |
22513 | (@value{GDBP}) python print gdb.newest_frame() == gdb.selected_frame () | |
22514 | True | |
22515 | @end smallexample | |
22516 | ||
22517 | The following frame-related functions are available in the @code{gdb} module: | |
22518 | ||
22519 | @findex gdb.selected_frame | |
22520 | @defun selected_frame | |
22521 | Return the selected frame object. (@pxref{Selection,,Selecting a Frame}). | |
22522 | @end defun | |
22523 | ||
22524 | @defun frame_stop_reason_string reason | |
22525 | Return a string explaining the reason why @value{GDBN} stopped unwinding | |
22526 | frames, as expressed by the given @var{reason} code (an integer, see the | |
22527 | @code{unwind_stop_reason} method further down in this section). | |
22528 | @end defun | |
22529 | ||
22530 | A @code{gdb.Frame} object has the following methods: | |
22531 | ||
22532 | @table @code | |
22533 | @defmethod Frame is_valid | |
22534 | Returns true if the @code{gdb.Frame} object is valid, false if not. | |
22535 | A frame object can become invalid if the frame it refers to doesn't | |
22536 | exist anymore in the inferior. All @code{gdb.Frame} methods will throw | |
22537 | an exception if it is invalid at the time the method is called. | |
22538 | @end defmethod | |
22539 | ||
22540 | @defmethod Frame name | |
22541 | Returns the function name of the frame, or @code{None} if it can't be | |
22542 | obtained. | |
22543 | @end defmethod | |
22544 | ||
22545 | @defmethod Frame type | |
22546 | Returns the type of the frame. The value can be one of | |
22547 | @code{gdb.NORMAL_FRAME}, @code{gdb.DUMMY_FRAME}, @code{gdb.SIGTRAMP_FRAME} | |
22548 | or @code{gdb.SENTINEL_FRAME}. | |
22549 | @end defmethod | |
22550 | ||
22551 | @defmethod Frame unwind_stop_reason | |
22552 | Return an integer representing the reason why it's not possible to find | |
22553 | more frames toward the outermost frame. Use | |
22554 | @code{gdb.frame_stop_reason_string} to convert the value returned by this | |
22555 | function to a string. | |
22556 | @end defmethod | |
22557 | ||
22558 | @defmethod Frame pc | |
22559 | Returns the frame's resume address. | |
22560 | @end defmethod | |
22561 | ||
f3e9a817 PM |
22562 | @defmethod Frame block |
22563 | Return the frame's code block. @xref{Blocks In Python}. | |
22564 | @end defmethod | |
22565 | ||
22566 | @defmethod Frame function | |
22567 | Return the symbol for the function corresponding to this frame. | |
22568 | @xref{Symbols In Python}. | |
22569 | @end defmethod | |
22570 | ||
f8f6f20b TJB |
22571 | @defmethod Frame older |
22572 | Return the frame that called this frame. | |
22573 | @end defmethod | |
22574 | ||
22575 | @defmethod Frame newer | |
22576 | Return the frame called by this frame. | |
22577 | @end defmethod | |
22578 | ||
f3e9a817 PM |
22579 | @defmethod Frame find_sal |
22580 | Return the frame's symtab and line object. | |
22581 | @xref{Symbol Tables In Python}. | |
22582 | @end defmethod | |
22583 | ||
dc00d89f PM |
22584 | @defmethod Frame read_var variable @r{[}block@r{]} |
22585 | Return the value of @var{variable} in this frame. If the optional | |
22586 | argument @var{block} is provided, search for the variable from that | |
22587 | block; otherwise start at the frame's current block (which is | |
22588 | determined by the frame's current program counter). @var{variable} | |
22589 | must be a string or a @code{gdb.Symbol} object. @var{block} must be a | |
22590 | @code{gdb.Block} object. | |
f8f6f20b | 22591 | @end defmethod |
f3e9a817 PM |
22592 | |
22593 | @defmethod Frame select | |
22594 | Set this frame to be the selected frame. @xref{Stack, ,Examining the | |
22595 | Stack}. | |
22596 | @end defmethod | |
22597 | @end table | |
22598 | ||
22599 | @node Blocks In Python | |
22600 | @subsubsection Accessing frame blocks from Python. | |
22601 | ||
22602 | @cindex blocks in python | |
22603 | @tindex gdb.Block | |
22604 | ||
22605 | Within each frame, @value{GDBN} maintains information on each block | |
22606 | stored in that frame. These blocks are organized hierarchically, and | |
22607 | are represented individually in Python as a @code{gdb.Block}. | |
22608 | Please see @ref{Frames In Python}, for a more in-depth discussion on | |
22609 | frames. Furthermore, see @ref{Stack, ,Examining the Stack}, for more | |
22610 | detailed technical information on @value{GDBN}'s book-keeping of the | |
22611 | stack. | |
22612 | ||
22613 | The following block-related functions are available in the @code{gdb} | |
22614 | module: | |
22615 | ||
22616 | @findex gdb.block_for_pc | |
22617 | @defun block_for_pc pc | |
22618 | Return the @code{gdb.Block} containing the given @var{pc} value. If the | |
22619 | block cannot be found for the @var{pc} value specified, the function | |
22620 | will return @code{None}. | |
22621 | @end defun | |
22622 | ||
22623 | A @code{gdb.Block} object has the following attributes: | |
22624 | ||
22625 | @table @code | |
22626 | @defivar Block start | |
22627 | The start address of the block. This attribute is not writable. | |
22628 | @end defivar | |
22629 | ||
22630 | @defivar Block end | |
22631 | The end address of the block. This attribute is not writable. | |
22632 | @end defivar | |
22633 | ||
22634 | @defivar Block function | |
22635 | The name of the block represented as a @code{gdb.Symbol}. If the | |
22636 | block is not named, then this attribute holds @code{None}. This | |
22637 | attribute is not writable. | |
22638 | @end defivar | |
22639 | ||
22640 | @defivar Block superblock | |
22641 | The block containing this block. If this parent block does not exist, | |
22642 | this attribute holds @code{None}. This attribute is not writable. | |
22643 | @end defivar | |
22644 | @end table | |
22645 | ||
22646 | @node Symbols In Python | |
22647 | @subsubsection Python representation of Symbols. | |
22648 | ||
22649 | @cindex symbols in python | |
22650 | @tindex gdb.Symbol | |
22651 | ||
22652 | @value{GDBN} represents every variable, function and type as an | |
22653 | entry in a symbol table. @xref{Symbols, ,Examining the Symbol Table}. | |
22654 | Similarly, Python represents these symbols in @value{GDBN} with the | |
22655 | @code{gdb.Symbol} object. | |
22656 | ||
22657 | The following symbol-related functions are available in the @code{gdb} | |
22658 | module: | |
22659 | ||
22660 | @findex gdb.lookup_symbol | |
22661 | @defun lookup_symbol name [block] [domain] | |
22662 | This function searches for a symbol by name. The search scope can be | |
22663 | restricted to the parameters defined in the optional domain and block | |
22664 | arguments. | |
22665 | ||
22666 | @var{name} is the name of the symbol. It must be a string. The | |
22667 | optional @var{block} argument restricts the search to symbols visible | |
22668 | in that @var{block}. The @var{block} argument must be a | |
22669 | @code{gdb.Block} object. The optional @var{domain} argument restricts | |
22670 | the search to the domain type. The @var{domain} argument must be a | |
22671 | domain constant defined in the @code{gdb} module and described later | |
22672 | in this chapter. | |
22673 | @end defun | |
22674 | ||
22675 | A @code{gdb.Symbol} object has the following attributes: | |
22676 | ||
22677 | @table @code | |
22678 | @defivar Symbol symtab | |
22679 | The symbol table in which the symbol appears. This attribute is | |
22680 | represented as a @code{gdb.Symtab} object. @xref{Symbol Tables In | |
22681 | Python}. This attribute is not writable. | |
22682 | @end defivar | |
22683 | ||
22684 | @defivar Symbol name | |
22685 | The name of the symbol as a string. This attribute is not writable. | |
22686 | @end defivar | |
22687 | ||
22688 | @defivar Symbol linkage_name | |
22689 | The name of the symbol, as used by the linker (i.e., may be mangled). | |
22690 | This attribute is not writable. | |
22691 | @end defivar | |
22692 | ||
22693 | @defivar Symbol print_name | |
22694 | The name of the symbol in a form suitable for output. This is either | |
22695 | @code{name} or @code{linkage_name}, depending on whether the user | |
22696 | asked @value{GDBN} to display demangled or mangled names. | |
22697 | @end defivar | |
22698 | ||
22699 | @defivar Symbol addr_class | |
22700 | The address class of the symbol. This classifies how to find the value | |
22701 | of a symbol. Each address class is a constant defined in the | |
22702 | @code{gdb} module and described later in this chapter. | |
22703 | @end defivar | |
22704 | ||
22705 | @defivar Symbol is_argument | |
22706 | @code{True} if the symbol is an argument of a function. | |
22707 | @end defivar | |
22708 | ||
22709 | @defivar Symbol is_constant | |
22710 | @code{True} if the symbol is a constant. | |
22711 | @end defivar | |
22712 | ||
22713 | @defivar Symbol is_function | |
22714 | @code{True} if the symbol is a function or a method. | |
22715 | @end defivar | |
22716 | ||
22717 | @defivar Symbol is_variable | |
22718 | @code{True} if the symbol is a variable. | |
22719 | @end defivar | |
22720 | @end table | |
22721 | ||
22722 | The available domain categories in @code{gdb.Symbol} are represented | |
22723 | as constants in the @code{gdb} module: | |
22724 | ||
22725 | @table @code | |
22726 | @findex SYMBOL_UNDEF_DOMAIN | |
22727 | @findex gdb.SYMBOL_UNDEF_DOMAIN | |
22728 | @item SYMBOL_UNDEF_DOMAIN | |
22729 | This is used when a domain has not been discovered or none of the | |
22730 | following domains apply. This usually indicates an error either | |
22731 | in the symbol information or in @value{GDBN}'s handling of symbols. | |
22732 | @findex SYMBOL_VAR_DOMAIN | |
22733 | @findex gdb.SYMBOL_VAR_DOMAIN | |
22734 | @item SYMBOL_VAR_DOMAIN | |
22735 | This domain contains variables, function names, typedef names and enum | |
22736 | type values. | |
22737 | @findex SYMBOL_STRUCT_DOMAIN | |
22738 | @findex gdb.SYMBOL_STRUCT_DOMAIN | |
22739 | @item SYMBOL_STRUCT_DOMAIN | |
22740 | This domain holds struct, union and enum type names. | |
22741 | @findex SYMBOL_LABEL_DOMAIN | |
22742 | @findex gdb.SYMBOL_LABEL_DOMAIN | |
22743 | @item SYMBOL_LABEL_DOMAIN | |
22744 | This domain contains names of labels (for gotos). | |
22745 | @findex SYMBOL_VARIABLES_DOMAIN | |
22746 | @findex gdb.SYMBOL_VARIABLES_DOMAIN | |
22747 | @item SYMBOL_VARIABLES_DOMAIN | |
22748 | This domain holds a subset of the @code{SYMBOLS_VAR_DOMAIN}; it | |
22749 | contains everything minus functions and types. | |
22750 | @findex SYMBOL_FUNCTIONS_DOMAIN | |
22751 | @findex gdb.SYMBOL_FUNCTIONS_DOMAIN | |
22752 | @item SYMBOL_FUNCTION_DOMAIN | |
22753 | This domain contains all functions. | |
22754 | @findex SYMBOL_TYPES_DOMAIN | |
22755 | @findex gdb.SYMBOL_TYPES_DOMAIN | |
22756 | @item SYMBOL_TYPES_DOMAIN | |
22757 | This domain contains all types. | |
22758 | @end table | |
22759 | ||
22760 | The available address class categories in @code{gdb.Symbol} are represented | |
22761 | as constants in the @code{gdb} module: | |
22762 | ||
22763 | @table @code | |
22764 | @findex SYMBOL_LOC_UNDEF | |
22765 | @findex gdb.SYMBOL_LOC_UNDEF | |
22766 | @item SYMBOL_LOC_UNDEF | |
22767 | If this is returned by address class, it indicates an error either in | |
22768 | the symbol information or in @value{GDBN}'s handling of symbols. | |
22769 | @findex SYMBOL_LOC_CONST | |
22770 | @findex gdb.SYMBOL_LOC_CONST | |
22771 | @item SYMBOL_LOC_CONST | |
22772 | Value is constant int. | |
22773 | @findex SYMBOL_LOC_STATIC | |
22774 | @findex gdb.SYMBOL_LOC_STATIC | |
22775 | @item SYMBOL_LOC_STATIC | |
22776 | Value is at a fixed address. | |
22777 | @findex SYMBOL_LOC_REGISTER | |
22778 | @findex gdb.SYMBOL_LOC_REGISTER | |
22779 | @item SYMBOL_LOC_REGISTER | |
22780 | Value is in a register. | |
22781 | @findex SYMBOL_LOC_ARG | |
22782 | @findex gdb.SYMBOL_LOC_ARG | |
22783 | @item SYMBOL_LOC_ARG | |
22784 | Value is an argument. This value is at the offset stored within the | |
22785 | symbol inside the frame's argument list. | |
22786 | @findex SYMBOL_LOC_REF_ARG | |
22787 | @findex gdb.SYMBOL_LOC_REF_ARG | |
22788 | @item SYMBOL_LOC_REF_ARG | |
22789 | Value address is stored in the frame's argument list. Just like | |
22790 | @code{LOC_ARG} except that the value's address is stored at the | |
22791 | offset, not the value itself. | |
22792 | @findex SYMBOL_LOC_REGPARM_ADDR | |
22793 | @findex gdb.SYMBOL_LOC_REGPARM_ADDR | |
22794 | @item SYMBOL_LOC_REGPARM_ADDR | |
22795 | Value is a specified register. Just like @code{LOC_REGISTER} except | |
22796 | the register holds the address of the argument instead of the argument | |
22797 | itself. | |
22798 | @findex SYMBOL_LOC_LOCAL | |
22799 | @findex gdb.SYMBOL_LOC_LOCAL | |
22800 | @item SYMBOL_LOC_LOCAL | |
22801 | Value is a local variable. | |
22802 | @findex SYMBOL_LOC_TYPEDEF | |
22803 | @findex gdb.SYMBOL_LOC_TYPEDEF | |
22804 | @item SYMBOL_LOC_TYPEDEF | |
22805 | Value not used. Symbols in the domain @code{SYMBOL_STRUCT_DOMAIN} all | |
22806 | have this class. | |
22807 | @findex SYMBOL_LOC_BLOCK | |
22808 | @findex gdb.SYMBOL_LOC_BLOCK | |
22809 | @item SYMBOL_LOC_BLOCK | |
22810 | Value is a block. | |
22811 | @findex SYMBOL_LOC_CONST_BYTES | |
22812 | @findex gdb.SYMBOL_LOC_CONST_BYTES | |
22813 | @item SYMBOL_LOC_CONST_BYTES | |
22814 | Value is a byte-sequence. | |
22815 | @findex SYMBOL_LOC_UNRESOLVED | |
22816 | @findex gdb.SYMBOL_LOC_UNRESOLVED | |
22817 | @item SYMBOL_LOC_UNRESOLVED | |
22818 | Value is at a fixed address, but the address of the variable has to be | |
22819 | determined from the minimal symbol table whenever the variable is | |
22820 | referenced. | |
22821 | @findex SYMBOL_LOC_OPTIMIZED_OUT | |
22822 | @findex gdb.SYMBOL_LOC_OPTIMIZED_OUT | |
22823 | @item SYMBOL_LOC_OPTIMIZED_OUT | |
22824 | The value does not actually exist in the program. | |
22825 | @findex SYMBOL_LOC_COMPUTED | |
22826 | @findex gdb.SYMBOL_LOC_COMPUTED | |
22827 | @item SYMBOL_LOC_COMPUTED | |
22828 | The value's address is a computed location. | |
22829 | @end table | |
22830 | ||
22831 | @node Symbol Tables In Python | |
22832 | @subsubsection Symbol table representation in Python. | |
22833 | ||
22834 | @cindex symbol tables in python | |
22835 | @tindex gdb.Symtab | |
22836 | @tindex gdb.Symtab_and_line | |
22837 | ||
22838 | Access to symbol table data maintained by @value{GDBN} on the inferior | |
22839 | is exposed to Python via two objects: @code{gdb.Symtab_and_line} and | |
22840 | @code{gdb.Symtab}. Symbol table and line data for a frame is returned | |
22841 | from the @code{find_sal} method in @code{gdb.Frame} object. | |
22842 | @xref{Frames In Python}. | |
22843 | ||
22844 | For more information on @value{GDBN}'s symbol table management, see | |
22845 | @ref{Symbols, ,Examining the Symbol Table}, for more information. | |
22846 | ||
22847 | A @code{gdb.Symtab_and_line} object has the following attributes: | |
22848 | ||
22849 | @table @code | |
22850 | @defivar Symtab_and_line symtab | |
22851 | The symbol table object (@code{gdb.Symtab}) for this frame. | |
22852 | This attribute is not writable. | |
22853 | @end defivar | |
22854 | ||
22855 | @defivar Symtab_and_line pc | |
22856 | Indicates the current program counter address. This attribute is not | |
22857 | writable. | |
22858 | @end defivar | |
22859 | ||
22860 | @defivar Symtab_and_line line | |
22861 | Indicates the current line number for this object. This | |
22862 | attribute is not writable. | |
22863 | @end defivar | |
22864 | @end table | |
22865 | ||
22866 | A @code{gdb.Symtab} object has the following attributes: | |
22867 | ||
22868 | @table @code | |
22869 | @defivar Symtab filename | |
22870 | The symbol table's source filename. This attribute is not writable. | |
22871 | @end defivar | |
22872 | ||
22873 | @defivar Symtab objfile | |
22874 | The symbol table's backing object file. @xref{Objfiles In Python}. | |
22875 | This attribute is not writable. | |
22876 | @end defivar | |
22877 | @end table | |
22878 | ||
22879 | The following methods are provided: | |
22880 | ||
22881 | @table @code | |
22882 | @defmethod Symtab fullname | |
22883 | Return the symbol table's source absolute file name. | |
22884 | @end defmethod | |
f8f6f20b TJB |
22885 | @end table |
22886 | ||
adc36818 PM |
22887 | @node Breakpoints In Python |
22888 | @subsubsection Manipulating breakpoints using Python | |
22889 | ||
22890 | @cindex breakpoints in python | |
22891 | @tindex gdb.Breakpoint | |
22892 | ||
22893 | Python code can manipulate breakpoints via the @code{gdb.Breakpoint} | |
22894 | class. | |
22895 | ||
84f4c1fe | 22896 | @defmethod Breakpoint __init__ spec @r{[}type@r{]} @r{[}wp_class@r{]} @r{[}internal@r{]} |
adc36818 PM |
22897 | Create a new breakpoint. @var{spec} is a string naming the |
22898 | location of the breakpoint, or an expression that defines a | |
22899 | watchpoint. The contents can be any location recognized by the | |
22900 | @code{break} command, or in the case of a watchpoint, by the @code{watch} | |
22901 | command. The optional @var{type} denotes the breakpoint to create | |
22902 | from the types defined later in this chapter. This argument can be | |
22903 | either: @code{BP_BREAKPOINT} or @code{BP_WATCHPOINT}. @var{type} | |
84f4c1fe PM |
22904 | defaults to @code{BP_BREAKPOINT}. The optional @var{internal} argument |
22905 | allows the breakpoint to become invisible to the user. The breakpoint | |
22906 | will neither be reported when created, nor will it be listed in the | |
22907 | output from @code{info breakpoints} (but will be listed with the | |
22908 | @code{maint info breakpoints} command). The optional @var{wp_class} | |
adc36818 | 22909 | argument defines the class of watchpoint to create, if @var{type} is |
84f4c1fe PM |
22910 | @code{BP_WATCHPOINT}. If a watchpoint class is not provided, it is |
22911 | assumed to be a @var{WP_WRITE} class. | |
adc36818 PM |
22912 | @end defmethod |
22913 | ||
22914 | The available watchpoint types represented by constants are defined in the | |
22915 | @code{gdb} module: | |
22916 | ||
22917 | @table @code | |
22918 | @findex WP_READ | |
22919 | @findex gdb.WP_READ | |
22920 | @item WP_READ | |
22921 | Read only watchpoint. | |
22922 | ||
22923 | @findex WP_WRITE | |
22924 | @findex gdb.WP_WRITE | |
22925 | @item WP_WRITE | |
22926 | Write only watchpoint. | |
22927 | ||
22928 | @findex WP_ACCESS | |
22929 | @findex gdb.WP_ACCESS | |
22930 | @item WP_ACCESS | |
22931 | Read/Write watchpoint. | |
22932 | @end table | |
22933 | ||
22934 | @defmethod Breakpoint is_valid | |
22935 | Return @code{True} if this @code{Breakpoint} object is valid, | |
22936 | @code{False} otherwise. A @code{Breakpoint} object can become invalid | |
22937 | if the user deletes the breakpoint. In this case, the object still | |
22938 | exists, but the underlying breakpoint does not. In the cases of | |
22939 | watchpoint scope, the watchpoint remains valid even if execution of the | |
22940 | inferior leaves the scope of that watchpoint. | |
22941 | @end defmethod | |
22942 | ||
94b6973e PM |
22943 | @defmethod Breakpoint delete |
22944 | Permanently deletes the @value{GDBN} breakpoint. This also | |
22945 | invalidates the Python @code{Breakpoint} object. Any further access | |
22946 | to this object's attributes or methods will raise an error. | |
22947 | @end defmethod | |
22948 | ||
adc36818 PM |
22949 | @defivar Breakpoint enabled |
22950 | This attribute is @code{True} if the breakpoint is enabled, and | |
22951 | @code{False} otherwise. This attribute is writable. | |
22952 | @end defivar | |
22953 | ||
22954 | @defivar Breakpoint silent | |
22955 | This attribute is @code{True} if the breakpoint is silent, and | |
22956 | @code{False} otherwise. This attribute is writable. | |
22957 | ||
22958 | Note that a breakpoint can also be silent if it has commands and the | |
22959 | first command is @code{silent}. This is not reported by the | |
22960 | @code{silent} attribute. | |
22961 | @end defivar | |
22962 | ||
22963 | @defivar Breakpoint thread | |
22964 | If the breakpoint is thread-specific, this attribute holds the thread | |
22965 | id. If the breakpoint is not thread-specific, this attribute is | |
22966 | @code{None}. This attribute is writable. | |
22967 | @end defivar | |
22968 | ||
22969 | @defivar Breakpoint task | |
22970 | If the breakpoint is Ada task-specific, this attribute holds the Ada task | |
22971 | id. If the breakpoint is not task-specific (or the underlying | |
22972 | language is not Ada), this attribute is @code{None}. This attribute | |
22973 | is writable. | |
22974 | @end defivar | |
22975 | ||
22976 | @defivar Breakpoint ignore_count | |
22977 | This attribute holds the ignore count for the breakpoint, an integer. | |
22978 | This attribute is writable. | |
22979 | @end defivar | |
22980 | ||
22981 | @defivar Breakpoint number | |
22982 | This attribute holds the breakpoint's number --- the identifier used by | |
22983 | the user to manipulate the breakpoint. This attribute is not writable. | |
22984 | @end defivar | |
22985 | ||
22986 | @defivar Breakpoint type | |
22987 | This attribute holds the breakpoint's type --- the identifier used to | |
22988 | determine the actual breakpoint type or use-case. This attribute is not | |
22989 | writable. | |
22990 | @end defivar | |
22991 | ||
84f4c1fe PM |
22992 | @defivar Breakpoint visible |
22993 | This attribute tells whether the breakpoint is visible to the user | |
22994 | when set, or when the @samp{info breakpoints} command is run. This | |
22995 | attribute is not writable. | |
22996 | @end defivar | |
22997 | ||
adc36818 PM |
22998 | The available types are represented by constants defined in the @code{gdb} |
22999 | module: | |
23000 | ||
23001 | @table @code | |
23002 | @findex BP_BREAKPOINT | |
23003 | @findex gdb.BP_BREAKPOINT | |
23004 | @item BP_BREAKPOINT | |
23005 | Normal code breakpoint. | |
23006 | ||
23007 | @findex BP_WATCHPOINT | |
23008 | @findex gdb.BP_WATCHPOINT | |
23009 | @item BP_WATCHPOINT | |
23010 | Watchpoint breakpoint. | |
23011 | ||
23012 | @findex BP_HARDWARE_WATCHPOINT | |
23013 | @findex gdb.BP_HARDWARE_WATCHPOINT | |
23014 | @item BP_HARDWARE_WATCHPOINT | |
23015 | Hardware assisted watchpoint. | |
23016 | ||
23017 | @findex BP_READ_WATCHPOINT | |
23018 | @findex gdb.BP_READ_WATCHPOINT | |
23019 | @item BP_READ_WATCHPOINT | |
23020 | Hardware assisted read watchpoint. | |
23021 | ||
23022 | @findex BP_ACCESS_WATCHPOINT | |
23023 | @findex gdb.BP_ACCESS_WATCHPOINT | |
23024 | @item BP_ACCESS_WATCHPOINT | |
23025 | Hardware assisted access watchpoint. | |
23026 | @end table | |
23027 | ||
23028 | @defivar Breakpoint hit_count | |
23029 | This attribute holds the hit count for the breakpoint, an integer. | |
23030 | This attribute is writable, but currently it can only be set to zero. | |
23031 | @end defivar | |
23032 | ||
23033 | @defivar Breakpoint location | |
23034 | This attribute holds the location of the breakpoint, as specified by | |
23035 | the user. It is a string. If the breakpoint does not have a location | |
23036 | (that is, it is a watchpoint) the attribute's value is @code{None}. This | |
23037 | attribute is not writable. | |
23038 | @end defivar | |
23039 | ||
23040 | @defivar Breakpoint expression | |
23041 | This attribute holds a breakpoint expression, as specified by | |
23042 | the user. It is a string. If the breakpoint does not have an | |
23043 | expression (the breakpoint is not a watchpoint) the attribute's value | |
23044 | is @code{None}. This attribute is not writable. | |
23045 | @end defivar | |
23046 | ||
23047 | @defivar Breakpoint condition | |
23048 | This attribute holds the condition of the breakpoint, as specified by | |
23049 | the user. It is a string. If there is no condition, this attribute's | |
23050 | value is @code{None}. This attribute is writable. | |
23051 | @end defivar | |
23052 | ||
23053 | @defivar Breakpoint commands | |
23054 | This attribute holds the commands attached to the breakpoint. If | |
23055 | there are commands, this attribute's value is a string holding all the | |
23056 | commands, separated by newlines. If there are no commands, this | |
23057 | attribute is @code{None}. This attribute is not writable. | |
23058 | @end defivar | |
23059 | ||
be759fcf PM |
23060 | @node Lazy Strings In Python |
23061 | @subsubsection Python representation of lazy strings. | |
23062 | ||
23063 | @cindex lazy strings in python | |
23064 | @tindex gdb.LazyString | |
23065 | ||
23066 | A @dfn{lazy string} is a string whose contents is not retrieved or | |
23067 | encoded until it is needed. | |
23068 | ||
23069 | A @code{gdb.LazyString} is represented in @value{GDBN} as an | |
23070 | @code{address} that points to a region of memory, an @code{encoding} | |
23071 | that will be used to encode that region of memory, and a @code{length} | |
23072 | to delimit the region of memory that represents the string. The | |
23073 | difference between a @code{gdb.LazyString} and a string wrapped within | |
23074 | a @code{gdb.Value} is that a @code{gdb.LazyString} will be treated | |
23075 | differently by @value{GDBN} when printing. A @code{gdb.LazyString} is | |
23076 | retrieved and encoded during printing, while a @code{gdb.Value} | |
23077 | wrapping a string is immediately retrieved and encoded on creation. | |
23078 | ||
23079 | A @code{gdb.LazyString} object has the following functions: | |
23080 | ||
23081 | @defmethod LazyString value | |
23082 | Convert the @code{gdb.LazyString} to a @code{gdb.Value}. This value | |
23083 | will point to the string in memory, but will lose all the delayed | |
23084 | retrieval, encoding and handling that @value{GDBN} applies to a | |
23085 | @code{gdb.LazyString}. | |
23086 | @end defmethod | |
23087 | ||
23088 | @defivar LazyString address | |
23089 | This attribute holds the address of the string. This attribute is not | |
23090 | writable. | |
23091 | @end defivar | |
23092 | ||
23093 | @defivar LazyString length | |
23094 | This attribute holds the length of the string in characters. If the | |
23095 | length is -1, then the string will be fetched and encoded up to the | |
23096 | first null of appropriate width. This attribute is not writable. | |
23097 | @end defivar | |
23098 | ||
23099 | @defivar LazyString encoding | |
23100 | This attribute holds the encoding that will be applied to the string | |
23101 | when the string is printed by @value{GDBN}. If the encoding is not | |
23102 | set, or contains an empty string, then @value{GDBN} will select the | |
23103 | most appropriate encoding when the string is printed. This attribute | |
23104 | is not writable. | |
23105 | @end defivar | |
23106 | ||
23107 | @defivar LazyString type | |
23108 | This attribute holds the type that is represented by the lazy string's | |
23109 | type. For a lazy string this will always be a pointer type. To | |
23110 | resolve this to the lazy string's character type, use the type's | |
23111 | @code{target} method. @xref{Types In Python}. This attribute is not | |
23112 | writable. | |
23113 | @end defivar | |
23114 | ||
8a1ea21f DE |
23115 | @node Auto-loading |
23116 | @subsection Auto-loading | |
23117 | @cindex auto-loading, Python | |
23118 | ||
23119 | When a new object file is read (for example, due to the @code{file} | |
23120 | command, or because the inferior has loaded a shared library), | |
23121 | @value{GDBN} will look for Python support scripts in several ways: | |
23122 | @file{@var{objfile}-gdb.py} and @code{.debug_gdb_scripts} section. | |
23123 | ||
23124 | @menu | |
23125 | * objfile-gdb.py file:: The @file{@var{objfile}-gdb.py} file | |
23126 | * .debug_gdb_scripts section:: The @code{.debug_gdb_scripts} section | |
23127 | * Which flavor to choose?:: | |
23128 | @end menu | |
23129 | ||
23130 | The auto-loading feature is useful for supplying application-specific | |
23131 | debugging commands and scripts. | |
23132 | ||
23133 | Auto-loading can be enabled or disabled. | |
23134 | ||
23135 | @table @code | |
a86caf66 DE |
23136 | @kindex set auto-load-scripts |
23137 | @item set auto-load-scripts [yes|no] | |
23138 | Enable or disable the auto-loading of Python scripts. | |
8a1ea21f | 23139 | |
a86caf66 DE |
23140 | @kindex show auto-load-scripts |
23141 | @item show auto-load-scripts | |
23142 | Show whether auto-loading of Python scripts is enabled or disabled. | |
8a1ea21f DE |
23143 | @end table |
23144 | ||
23145 | When reading an auto-loaded file, @value{GDBN} sets the | |
23146 | @dfn{current objfile}. This is available via the @code{gdb.current_objfile} | |
23147 | function (@pxref{Objfiles In Python}). This can be useful for | |
23148 | registering objfile-specific pretty-printers. | |
23149 | ||
23150 | @node objfile-gdb.py file | |
23151 | @subsubsection The @file{@var{objfile}-gdb.py} file | |
23152 | @cindex @file{@var{objfile}-gdb.py} | |
23153 | ||
23154 | When a new object file is read, @value{GDBN} looks for | |
23155 | a file named @file{@var{objfile}-gdb.py}, | |
23156 | where @var{objfile} is the object file's real name, formed by ensuring | |
23157 | that the file name is absolute, following all symlinks, and resolving | |
23158 | @code{.} and @code{..} components. If this file exists and is | |
23159 | readable, @value{GDBN} will evaluate it as a Python script. | |
23160 | ||
23161 | If this file does not exist, and if the parameter | |
23162 | @code{debug-file-directory} is set (@pxref{Separate Debug Files}), | |
23163 | then @value{GDBN} will look for @var{real-name} in all of the | |
23164 | directories mentioned in the value of @code{debug-file-directory}. | |
23165 | ||
23166 | Finally, if this file does not exist, then @value{GDBN} will look for | |
23167 | a file named @file{@var{data-directory}/python/auto-load/@var{real-name}}, where | |
23168 | @var{data-directory} is @value{GDBN}'s data directory (available via | |
23169 | @code{show data-directory}, @pxref{Data Files}), and @var{real-name} | |
23170 | is the object file's real name, as described above. | |
23171 | ||
23172 | @value{GDBN} does not track which files it has already auto-loaded this way. | |
23173 | @value{GDBN} will load the associated script every time the corresponding | |
23174 | @var{objfile} is opened. | |
23175 | So your @file{-gdb.py} file should be careful to avoid errors if it | |
23176 | is evaluated more than once. | |
23177 | ||
23178 | @node .debug_gdb_scripts section | |
23179 | @subsubsection The @code{.debug_gdb_scripts} section | |
23180 | @cindex @code{.debug_gdb_scripts} section | |
23181 | ||
23182 | For systems using file formats like ELF and COFF, | |
23183 | when @value{GDBN} loads a new object file | |
23184 | it will look for a special section named @samp{.debug_gdb_scripts}. | |
23185 | If this section exists, its contents is a list of names of scripts to load. | |
23186 | ||
23187 | @value{GDBN} will look for each specified script file first in the | |
23188 | current directory and then along the source search path | |
23189 | (@pxref{Source Path, ,Specifying Source Directories}), | |
23190 | except that @file{$cdir} is not searched, since the compilation | |
23191 | directory is not relevant to scripts. | |
23192 | ||
23193 | Entries can be placed in section @code{.debug_gdb_scripts} with, | |
23194 | for example, this GCC macro: | |
23195 | ||
23196 | @example | |
a3a7127e | 23197 | /* Note: The "MS" section flags are to remove duplicates. */ |
8a1ea21f DE |
23198 | #define DEFINE_GDB_SCRIPT(script_name) \ |
23199 | asm("\ | |
23200 | .pushsection \".debug_gdb_scripts\", \"MS\",@@progbits,1\n\ | |
23201 | .byte 1\n\ | |
23202 | .asciz \"" script_name "\"\n\ | |
23203 | .popsection \n\ | |
23204 | "); | |
23205 | @end example | |
23206 | ||
23207 | @noindent | |
23208 | Then one can reference the macro in a header or source file like this: | |
23209 | ||
23210 | @example | |
23211 | DEFINE_GDB_SCRIPT ("my-app-scripts.py") | |
23212 | @end example | |
23213 | ||
23214 | The script name may include directories if desired. | |
23215 | ||
23216 | If the macro is put in a header, any application or library | |
23217 | using this header will get a reference to the specified script. | |
23218 | ||
23219 | @node Which flavor to choose? | |
23220 | @subsubsection Which flavor to choose? | |
23221 | ||
23222 | Given the multiple ways of auto-loading Python scripts, it might not always | |
23223 | be clear which one to choose. This section provides some guidance. | |
23224 | ||
23225 | Benefits of the @file{-gdb.py} way: | |
23226 | ||
23227 | @itemize @bullet | |
23228 | @item | |
23229 | Can be used with file formats that don't support multiple sections. | |
23230 | ||
23231 | @item | |
23232 | Ease of finding scripts for public libraries. | |
23233 | ||
23234 | Scripts specified in the @code{.debug_gdb_scripts} section are searched for | |
23235 | in the source search path. | |
23236 | For publicly installed libraries, e.g., @file{libstdc++}, there typically | |
23237 | isn't a source directory in which to find the script. | |
23238 | ||
23239 | @item | |
23240 | Doesn't require source code additions. | |
23241 | @end itemize | |
23242 | ||
23243 | Benefits of the @code{.debug_gdb_scripts} way: | |
23244 | ||
23245 | @itemize @bullet | |
23246 | @item | |
23247 | Works with static linking. | |
23248 | ||
23249 | Scripts for libraries done the @file{-gdb.py} way require an objfile to | |
23250 | trigger their loading. When an application is statically linked the only | |
23251 | objfile available is the executable, and it is cumbersome to attach all the | |
23252 | scripts from all the input libraries to the executable's @file{-gdb.py} script. | |
23253 | ||
23254 | @item | |
23255 | Works with classes that are entirely inlined. | |
23256 | ||
23257 | Some classes can be entirely inlined, and thus there may not be an associated | |
23258 | shared library to attach a @file{-gdb.py} script to. | |
23259 | ||
23260 | @item | |
23261 | Scripts needn't be copied out of the source tree. | |
23262 | ||
23263 | In some circumstances, apps can be built out of large collections of internal | |
23264 | libraries, and the build infrastructure necessary to install the | |
23265 | @file{-gdb.py} scripts in a place where @value{GDBN} can find them is | |
23266 | cumbersome. It may be easier to specify the scripts in the | |
23267 | @code{.debug_gdb_scripts} section as relative paths, and add a path to the | |
23268 | top of the source tree to the source search path. | |
23269 | @end itemize | |
23270 | ||
0e3509db DE |
23271 | @node Python modules |
23272 | @subsection Python modules | |
23273 | @cindex python modules | |
23274 | ||
0e3509db DE |
23275 | @value{GDBN} comes with a module to assist writing Python code. |
23276 | ||
23277 | @menu | |
7b51bc51 | 23278 | * gdb.printing:: Building and registering pretty-printers. |
0e3509db DE |
23279 | * gdb.types:: Utilities for working with types. |
23280 | @end menu | |
23281 | ||
7b51bc51 DE |
23282 | @node gdb.printing |
23283 | @subsubsection gdb.printing | |
23284 | @cindex gdb.printing | |
23285 | ||
23286 | This module provides a collection of utilities for working with | |
23287 | pretty-printers. | |
23288 | ||
23289 | @table @code | |
23290 | @item PrettyPrinter (@var{name}, @var{subprinters}=None) | |
23291 | This class specifies the API that makes @samp{info pretty-printer}, | |
23292 | @samp{enable pretty-printer} and @samp{disable pretty-printer} work. | |
23293 | Pretty-printers should generally inherit from this class. | |
23294 | ||
23295 | @item SubPrettyPrinter (@var{name}) | |
23296 | For printers that handle multiple types, this class specifies the | |
23297 | corresponding API for the subprinters. | |
23298 | ||
23299 | @item RegexpCollectionPrettyPrinter (@var{name}) | |
23300 | Utility class for handling multiple printers, all recognized via | |
23301 | regular expressions. | |
23302 | @xref{Writing a Pretty-Printer}, for an example. | |
23303 | ||
23304 | @item register_pretty_printer (@var{obj}, @var{printer}) | |
23305 | Register @var{printer} with the pretty-printer list of @var{obj}. | |
23306 | @end table | |
23307 | ||
0e3509db DE |
23308 | @node gdb.types |
23309 | @subsubsection gdb.types | |
7b51bc51 | 23310 | @cindex gdb.types |
0e3509db DE |
23311 | |
23312 | This module provides a collection of utilities for working with | |
23313 | @code{gdb.Types} objects. | |
23314 | ||
23315 | @table @code | |
23316 | @item get_basic_type (@var{type}) | |
23317 | Return @var{type} with const and volatile qualifiers stripped, | |
23318 | and with typedefs and C@t{++} references converted to the underlying type. | |
23319 | ||
23320 | C@t{++} example: | |
23321 | ||
23322 | @smallexample | |
23323 | typedef const int const_int; | |
23324 | const_int foo (3); | |
23325 | const_int& foo_ref (foo); | |
23326 | int main () @{ return 0; @} | |
23327 | @end smallexample | |
23328 | ||
23329 | Then in gdb: | |
23330 | ||
23331 | @smallexample | |
23332 | (gdb) start | |
23333 | (gdb) python import gdb.types | |
23334 | (gdb) python foo_ref = gdb.parse_and_eval("foo_ref") | |
23335 | (gdb) python print gdb.types.get_basic_type(foo_ref.type) | |
23336 | int | |
23337 | @end smallexample | |
23338 | ||
23339 | @item has_field (@var{type}, @var{field}) | |
23340 | Return @code{True} if @var{type}, assumed to be a type with fields | |
23341 | (e.g., a structure or union), has field @var{field}. | |
23342 | ||
23343 | @item make_enum_dict (@var{enum_type}) | |
23344 | Return a Python @code{dictionary} type produced from @var{enum_type}. | |
23345 | @end table | |
23346 | ||
21c294e6 AC |
23347 | @node Interpreters |
23348 | @chapter Command Interpreters | |
23349 | @cindex command interpreters | |
23350 | ||
23351 | @value{GDBN} supports multiple command interpreters, and some command | |
23352 | infrastructure to allow users or user interface writers to switch | |
23353 | between interpreters or run commands in other interpreters. | |
23354 | ||
23355 | @value{GDBN} currently supports two command interpreters, the console | |
23356 | interpreter (sometimes called the command-line interpreter or @sc{cli}) | |
23357 | and the machine interface interpreter (or @sc{gdb/mi}). This manual | |
23358 | describes both of these interfaces in great detail. | |
23359 | ||
23360 | By default, @value{GDBN} will start with the console interpreter. | |
23361 | However, the user may choose to start @value{GDBN} with another | |
23362 | interpreter by specifying the @option{-i} or @option{--interpreter} | |
23363 | startup options. Defined interpreters include: | |
23364 | ||
23365 | @table @code | |
23366 | @item console | |
23367 | @cindex console interpreter | |
23368 | The traditional console or command-line interpreter. This is the most often | |
23369 | used interpreter with @value{GDBN}. With no interpreter specified at runtime, | |
23370 | @value{GDBN} will use this interpreter. | |
23371 | ||
23372 | @item mi | |
23373 | @cindex mi interpreter | |
23374 | The newest @sc{gdb/mi} interface (currently @code{mi2}). Used primarily | |
23375 | by programs wishing to use @value{GDBN} as a backend for a debugger GUI | |
23376 | or an IDE. For more information, see @ref{GDB/MI, ,The @sc{gdb/mi} | |
23377 | Interface}. | |
23378 | ||
23379 | @item mi2 | |
23380 | @cindex mi2 interpreter | |
23381 | The current @sc{gdb/mi} interface. | |
23382 | ||
23383 | @item mi1 | |
23384 | @cindex mi1 interpreter | |
23385 | The @sc{gdb/mi} interface included in @value{GDBN} 5.1, 5.2, and 5.3. | |
23386 | ||
23387 | @end table | |
23388 | ||
23389 | @cindex invoke another interpreter | |
23390 | The interpreter being used by @value{GDBN} may not be dynamically | |
23391 | switched at runtime. Although possible, this could lead to a very | |
23392 | precarious situation. Consider an IDE using @sc{gdb/mi}. If a user | |
23393 | enters the command "interpreter-set console" in a console view, | |
23394 | @value{GDBN} would switch to using the console interpreter, rendering | |
23395 | the IDE inoperable! | |
23396 | ||
23397 | @kindex interpreter-exec | |
23398 | Although you may only choose a single interpreter at startup, you may execute | |
23399 | commands in any interpreter from the current interpreter using the appropriate | |
23400 | command. If you are running the console interpreter, simply use the | |
23401 | @code{interpreter-exec} command: | |
23402 | ||
23403 | @smallexample | |
23404 | interpreter-exec mi "-data-list-register-names" | |
23405 | @end smallexample | |
23406 | ||
23407 | @sc{gdb/mi} has a similar command, although it is only available in versions of | |
23408 | @value{GDBN} which support @sc{gdb/mi} version 2 (or greater). | |
23409 | ||
8e04817f AC |
23410 | @node TUI |
23411 | @chapter @value{GDBN} Text User Interface | |
23412 | @cindex TUI | |
d0d5df6f | 23413 | @cindex Text User Interface |
c906108c | 23414 | |
8e04817f AC |
23415 | @menu |
23416 | * TUI Overview:: TUI overview | |
23417 | * TUI Keys:: TUI key bindings | |
7cf36c78 | 23418 | * TUI Single Key Mode:: TUI single key mode |
db2e3e2e | 23419 | * TUI Commands:: TUI-specific commands |
8e04817f AC |
23420 | * TUI Configuration:: TUI configuration variables |
23421 | @end menu | |
c906108c | 23422 | |
46ba6afa | 23423 | The @value{GDBN} Text User Interface (TUI) is a terminal |
d0d5df6f AC |
23424 | interface which uses the @code{curses} library to show the source |
23425 | file, the assembly output, the program registers and @value{GDBN} | |
46ba6afa BW |
23426 | commands in separate text windows. The TUI mode is supported only |
23427 | on platforms where a suitable version of the @code{curses} library | |
23428 | is available. | |
d0d5df6f | 23429 | |
46ba6afa BW |
23430 | @pindex @value{GDBTUI} |
23431 | The TUI mode is enabled by default when you invoke @value{GDBN} as | |
23432 | either @samp{@value{GDBTUI}} or @samp{@value{GDBP} -tui}. | |
23433 | You can also switch in and out of TUI mode while @value{GDBN} runs by | |
23434 | using various TUI commands and key bindings, such as @kbd{C-x C-a}. | |
23435 | @xref{TUI Keys, ,TUI Key Bindings}. | |
c906108c | 23436 | |
8e04817f | 23437 | @node TUI Overview |
79a6e687 | 23438 | @section TUI Overview |
c906108c | 23439 | |
46ba6afa | 23440 | In TUI mode, @value{GDBN} can display several text windows: |
c906108c | 23441 | |
8e04817f AC |
23442 | @table @emph |
23443 | @item command | |
23444 | This window is the @value{GDBN} command window with the @value{GDBN} | |
46ba6afa BW |
23445 | prompt and the @value{GDBN} output. The @value{GDBN} input is still |
23446 | managed using readline. | |
c906108c | 23447 | |
8e04817f AC |
23448 | @item source |
23449 | The source window shows the source file of the program. The current | |
46ba6afa | 23450 | line and active breakpoints are displayed in this window. |
c906108c | 23451 | |
8e04817f AC |
23452 | @item assembly |
23453 | The assembly window shows the disassembly output of the program. | |
c906108c | 23454 | |
8e04817f | 23455 | @item register |
46ba6afa BW |
23456 | This window shows the processor registers. Registers are highlighted |
23457 | when their values change. | |
c906108c SS |
23458 | @end table |
23459 | ||
269c21fe | 23460 | The source and assembly windows show the current program position |
46ba6afa BW |
23461 | by highlighting the current line and marking it with a @samp{>} marker. |
23462 | Breakpoints are indicated with two markers. The first marker | |
269c21fe SC |
23463 | indicates the breakpoint type: |
23464 | ||
23465 | @table @code | |
23466 | @item B | |
23467 | Breakpoint which was hit at least once. | |
23468 | ||
23469 | @item b | |
23470 | Breakpoint which was never hit. | |
23471 | ||
23472 | @item H | |
23473 | Hardware breakpoint which was hit at least once. | |
23474 | ||
23475 | @item h | |
23476 | Hardware breakpoint which was never hit. | |
269c21fe SC |
23477 | @end table |
23478 | ||
23479 | The second marker indicates whether the breakpoint is enabled or not: | |
23480 | ||
23481 | @table @code | |
23482 | @item + | |
23483 | Breakpoint is enabled. | |
23484 | ||
23485 | @item - | |
23486 | Breakpoint is disabled. | |
269c21fe SC |
23487 | @end table |
23488 | ||
46ba6afa BW |
23489 | The source, assembly and register windows are updated when the current |
23490 | thread changes, when the frame changes, or when the program counter | |
23491 | changes. | |
23492 | ||
23493 | These windows are not all visible at the same time. The command | |
23494 | window is always visible. The others can be arranged in several | |
23495 | layouts: | |
c906108c | 23496 | |
8e04817f AC |
23497 | @itemize @bullet |
23498 | @item | |
46ba6afa | 23499 | source only, |
2df3850c | 23500 | |
8e04817f | 23501 | @item |
46ba6afa | 23502 | assembly only, |
8e04817f AC |
23503 | |
23504 | @item | |
46ba6afa | 23505 | source and assembly, |
8e04817f AC |
23506 | |
23507 | @item | |
46ba6afa | 23508 | source and registers, or |
c906108c | 23509 | |
8e04817f | 23510 | @item |
46ba6afa | 23511 | assembly and registers. |
8e04817f | 23512 | @end itemize |
c906108c | 23513 | |
46ba6afa | 23514 | A status line above the command window shows the following information: |
b7bb15bc SC |
23515 | |
23516 | @table @emph | |
23517 | @item target | |
46ba6afa | 23518 | Indicates the current @value{GDBN} target. |
b7bb15bc SC |
23519 | (@pxref{Targets, ,Specifying a Debugging Target}). |
23520 | ||
23521 | @item process | |
46ba6afa | 23522 | Gives the current process or thread number. |
b7bb15bc SC |
23523 | When no process is being debugged, this field is set to @code{No process}. |
23524 | ||
23525 | @item function | |
23526 | Gives the current function name for the selected frame. | |
23527 | The name is demangled if demangling is turned on (@pxref{Print Settings}). | |
46ba6afa | 23528 | When there is no symbol corresponding to the current program counter, |
b7bb15bc SC |
23529 | the string @code{??} is displayed. |
23530 | ||
23531 | @item line | |
23532 | Indicates the current line number for the selected frame. | |
46ba6afa | 23533 | When the current line number is not known, the string @code{??} is displayed. |
b7bb15bc SC |
23534 | |
23535 | @item pc | |
23536 | Indicates the current program counter address. | |
b7bb15bc SC |
23537 | @end table |
23538 | ||
8e04817f AC |
23539 | @node TUI Keys |
23540 | @section TUI Key Bindings | |
23541 | @cindex TUI key bindings | |
c906108c | 23542 | |
8e04817f | 23543 | The TUI installs several key bindings in the readline keymaps |
39037522 TT |
23544 | @ifset SYSTEM_READLINE |
23545 | (@pxref{Command Line Editing, , , rluserman, GNU Readline Library}). | |
23546 | @end ifset | |
23547 | @ifclear SYSTEM_READLINE | |
23548 | (@pxref{Command Line Editing}). | |
23549 | @end ifclear | |
23550 | The following key bindings are installed for both TUI mode and the | |
23551 | @value{GDBN} standard mode. | |
c906108c | 23552 | |
8e04817f AC |
23553 | @table @kbd |
23554 | @kindex C-x C-a | |
23555 | @item C-x C-a | |
23556 | @kindex C-x a | |
23557 | @itemx C-x a | |
23558 | @kindex C-x A | |
23559 | @itemx C-x A | |
46ba6afa BW |
23560 | Enter or leave the TUI mode. When leaving the TUI mode, |
23561 | the curses window management stops and @value{GDBN} operates using | |
23562 | its standard mode, writing on the terminal directly. When reentering | |
23563 | the TUI mode, control is given back to the curses windows. | |
8e04817f | 23564 | The screen is then refreshed. |
c906108c | 23565 | |
8e04817f AC |
23566 | @kindex C-x 1 |
23567 | @item C-x 1 | |
23568 | Use a TUI layout with only one window. The layout will | |
23569 | either be @samp{source} or @samp{assembly}. When the TUI mode | |
23570 | is not active, it will switch to the TUI mode. | |
2df3850c | 23571 | |
8e04817f | 23572 | Think of this key binding as the Emacs @kbd{C-x 1} binding. |
c906108c | 23573 | |
8e04817f AC |
23574 | @kindex C-x 2 |
23575 | @item C-x 2 | |
23576 | Use a TUI layout with at least two windows. When the current | |
46ba6afa | 23577 | layout already has two windows, the next layout with two windows is used. |
8e04817f AC |
23578 | When a new layout is chosen, one window will always be common to the |
23579 | previous layout and the new one. | |
c906108c | 23580 | |
8e04817f | 23581 | Think of it as the Emacs @kbd{C-x 2} binding. |
2df3850c | 23582 | |
72ffddc9 SC |
23583 | @kindex C-x o |
23584 | @item C-x o | |
23585 | Change the active window. The TUI associates several key bindings | |
46ba6afa | 23586 | (like scrolling and arrow keys) with the active window. This command |
72ffddc9 SC |
23587 | gives the focus to the next TUI window. |
23588 | ||
23589 | Think of it as the Emacs @kbd{C-x o} binding. | |
23590 | ||
7cf36c78 SC |
23591 | @kindex C-x s |
23592 | @item C-x s | |
46ba6afa BW |
23593 | Switch in and out of the TUI SingleKey mode that binds single |
23594 | keys to @value{GDBN} commands (@pxref{TUI Single Key Mode}). | |
c906108c SS |
23595 | @end table |
23596 | ||
46ba6afa | 23597 | The following key bindings only work in the TUI mode: |
5d161b24 | 23598 | |
46ba6afa | 23599 | @table @asis |
8e04817f | 23600 | @kindex PgUp |
46ba6afa | 23601 | @item @key{PgUp} |
8e04817f | 23602 | Scroll the active window one page up. |
c906108c | 23603 | |
8e04817f | 23604 | @kindex PgDn |
46ba6afa | 23605 | @item @key{PgDn} |
8e04817f | 23606 | Scroll the active window one page down. |
c906108c | 23607 | |
8e04817f | 23608 | @kindex Up |
46ba6afa | 23609 | @item @key{Up} |
8e04817f | 23610 | Scroll the active window one line up. |
c906108c | 23611 | |
8e04817f | 23612 | @kindex Down |
46ba6afa | 23613 | @item @key{Down} |
8e04817f | 23614 | Scroll the active window one line down. |
c906108c | 23615 | |
8e04817f | 23616 | @kindex Left |
46ba6afa | 23617 | @item @key{Left} |
8e04817f | 23618 | Scroll the active window one column left. |
c906108c | 23619 | |
8e04817f | 23620 | @kindex Right |
46ba6afa | 23621 | @item @key{Right} |
8e04817f | 23622 | Scroll the active window one column right. |
c906108c | 23623 | |
8e04817f | 23624 | @kindex C-L |
46ba6afa | 23625 | @item @kbd{C-L} |
8e04817f | 23626 | Refresh the screen. |
8e04817f | 23627 | @end table |
c906108c | 23628 | |
46ba6afa BW |
23629 | Because the arrow keys scroll the active window in the TUI mode, they |
23630 | are not available for their normal use by readline unless the command | |
23631 | window has the focus. When another window is active, you must use | |
23632 | other readline key bindings such as @kbd{C-p}, @kbd{C-n}, @kbd{C-b} | |
23633 | and @kbd{C-f} to control the command window. | |
8e04817f | 23634 | |
7cf36c78 SC |
23635 | @node TUI Single Key Mode |
23636 | @section TUI Single Key Mode | |
23637 | @cindex TUI single key mode | |
23638 | ||
46ba6afa BW |
23639 | The TUI also provides a @dfn{SingleKey} mode, which binds several |
23640 | frequently used @value{GDBN} commands to single keys. Type @kbd{C-x s} to | |
23641 | switch into this mode, where the following key bindings are used: | |
7cf36c78 SC |
23642 | |
23643 | @table @kbd | |
23644 | @kindex c @r{(SingleKey TUI key)} | |
23645 | @item c | |
23646 | continue | |
23647 | ||
23648 | @kindex d @r{(SingleKey TUI key)} | |
23649 | @item d | |
23650 | down | |
23651 | ||
23652 | @kindex f @r{(SingleKey TUI key)} | |
23653 | @item f | |
23654 | finish | |
23655 | ||
23656 | @kindex n @r{(SingleKey TUI key)} | |
23657 | @item n | |
23658 | next | |
23659 | ||
23660 | @kindex q @r{(SingleKey TUI key)} | |
23661 | @item q | |
46ba6afa | 23662 | exit the SingleKey mode. |
7cf36c78 SC |
23663 | |
23664 | @kindex r @r{(SingleKey TUI key)} | |
23665 | @item r | |
23666 | run | |
23667 | ||
23668 | @kindex s @r{(SingleKey TUI key)} | |
23669 | @item s | |
23670 | step | |
23671 | ||
23672 | @kindex u @r{(SingleKey TUI key)} | |
23673 | @item u | |
23674 | up | |
23675 | ||
23676 | @kindex v @r{(SingleKey TUI key)} | |
23677 | @item v | |
23678 | info locals | |
23679 | ||
23680 | @kindex w @r{(SingleKey TUI key)} | |
23681 | @item w | |
23682 | where | |
7cf36c78 SC |
23683 | @end table |
23684 | ||
23685 | Other keys temporarily switch to the @value{GDBN} command prompt. | |
23686 | The key that was pressed is inserted in the editing buffer so that | |
23687 | it is possible to type most @value{GDBN} commands without interaction | |
46ba6afa BW |
23688 | with the TUI SingleKey mode. Once the command is entered the TUI |
23689 | SingleKey mode is restored. The only way to permanently leave | |
7f9087cb | 23690 | this mode is by typing @kbd{q} or @kbd{C-x s}. |
7cf36c78 SC |
23691 | |
23692 | ||
8e04817f | 23693 | @node TUI Commands |
db2e3e2e | 23694 | @section TUI-specific Commands |
8e04817f AC |
23695 | @cindex TUI commands |
23696 | ||
23697 | The TUI has specific commands to control the text windows. | |
46ba6afa BW |
23698 | These commands are always available, even when @value{GDBN} is not in |
23699 | the TUI mode. When @value{GDBN} is in the standard mode, most | |
23700 | of these commands will automatically switch to the TUI mode. | |
c906108c | 23701 | |
ff12863f PA |
23702 | Note that if @value{GDBN}'s @code{stdout} is not connected to a |
23703 | terminal, or @value{GDBN} has been started with the machine interface | |
23704 | interpreter (@pxref{GDB/MI, ,The @sc{gdb/mi} Interface}), most of | |
23705 | these commands will fail with an error, because it would not be | |
23706 | possible or desirable to enable curses window management. | |
23707 | ||
c906108c | 23708 | @table @code |
3d757584 SC |
23709 | @item info win |
23710 | @kindex info win | |
23711 | List and give the size of all displayed windows. | |
23712 | ||
8e04817f | 23713 | @item layout next |
4644b6e3 | 23714 | @kindex layout |
8e04817f | 23715 | Display the next layout. |
2df3850c | 23716 | |
8e04817f | 23717 | @item layout prev |
8e04817f | 23718 | Display the previous layout. |
c906108c | 23719 | |
8e04817f | 23720 | @item layout src |
8e04817f | 23721 | Display the source window only. |
c906108c | 23722 | |
8e04817f | 23723 | @item layout asm |
8e04817f | 23724 | Display the assembly window only. |
c906108c | 23725 | |
8e04817f | 23726 | @item layout split |
8e04817f | 23727 | Display the source and assembly window. |
c906108c | 23728 | |
8e04817f | 23729 | @item layout regs |
8e04817f AC |
23730 | Display the register window together with the source or assembly window. |
23731 | ||
46ba6afa | 23732 | @item focus next |
8e04817f | 23733 | @kindex focus |
46ba6afa BW |
23734 | Make the next window active for scrolling. |
23735 | ||
23736 | @item focus prev | |
23737 | Make the previous window active for scrolling. | |
23738 | ||
23739 | @item focus src | |
23740 | Make the source window active for scrolling. | |
23741 | ||
23742 | @item focus asm | |
23743 | Make the assembly window active for scrolling. | |
23744 | ||
23745 | @item focus regs | |
23746 | Make the register window active for scrolling. | |
23747 | ||
23748 | @item focus cmd | |
23749 | Make the command window active for scrolling. | |
c906108c | 23750 | |
8e04817f AC |
23751 | @item refresh |
23752 | @kindex refresh | |
7f9087cb | 23753 | Refresh the screen. This is similar to typing @kbd{C-L}. |
c906108c | 23754 | |
6a1b180d SC |
23755 | @item tui reg float |
23756 | @kindex tui reg | |
23757 | Show the floating point registers in the register window. | |
23758 | ||
23759 | @item tui reg general | |
23760 | Show the general registers in the register window. | |
23761 | ||
23762 | @item tui reg next | |
23763 | Show the next register group. The list of register groups as well as | |
23764 | their order is target specific. The predefined register groups are the | |
23765 | following: @code{general}, @code{float}, @code{system}, @code{vector}, | |
23766 | @code{all}, @code{save}, @code{restore}. | |
23767 | ||
23768 | @item tui reg system | |
23769 | Show the system registers in the register window. | |
23770 | ||
8e04817f AC |
23771 | @item update |
23772 | @kindex update | |
23773 | Update the source window and the current execution point. | |
c906108c | 23774 | |
8e04817f AC |
23775 | @item winheight @var{name} +@var{count} |
23776 | @itemx winheight @var{name} -@var{count} | |
23777 | @kindex winheight | |
23778 | Change the height of the window @var{name} by @var{count} | |
23779 | lines. Positive counts increase the height, while negative counts | |
23780 | decrease it. | |
2df3850c | 23781 | |
46ba6afa BW |
23782 | @item tabset @var{nchars} |
23783 | @kindex tabset | |
c45da7e6 | 23784 | Set the width of tab stops to be @var{nchars} characters. |
c906108c SS |
23785 | @end table |
23786 | ||
8e04817f | 23787 | @node TUI Configuration |
79a6e687 | 23788 | @section TUI Configuration Variables |
8e04817f | 23789 | @cindex TUI configuration variables |
c906108c | 23790 | |
46ba6afa | 23791 | Several configuration variables control the appearance of TUI windows. |
c906108c | 23792 | |
8e04817f AC |
23793 | @table @code |
23794 | @item set tui border-kind @var{kind} | |
23795 | @kindex set tui border-kind | |
23796 | Select the border appearance for the source, assembly and register windows. | |
23797 | The possible values are the following: | |
23798 | @table @code | |
23799 | @item space | |
23800 | Use a space character to draw the border. | |
c906108c | 23801 | |
8e04817f | 23802 | @item ascii |
46ba6afa | 23803 | Use @sc{ascii} characters @samp{+}, @samp{-} and @samp{|} to draw the border. |
c906108c | 23804 | |
8e04817f AC |
23805 | @item acs |
23806 | Use the Alternate Character Set to draw the border. The border is | |
23807 | drawn using character line graphics if the terminal supports them. | |
8e04817f | 23808 | @end table |
c78b4128 | 23809 | |
8e04817f AC |
23810 | @item set tui border-mode @var{mode} |
23811 | @kindex set tui border-mode | |
46ba6afa BW |
23812 | @itemx set tui active-border-mode @var{mode} |
23813 | @kindex set tui active-border-mode | |
23814 | Select the display attributes for the borders of the inactive windows | |
23815 | or the active window. The @var{mode} can be one of the following: | |
8e04817f AC |
23816 | @table @code |
23817 | @item normal | |
23818 | Use normal attributes to display the border. | |
c906108c | 23819 | |
8e04817f AC |
23820 | @item standout |
23821 | Use standout mode. | |
c906108c | 23822 | |
8e04817f AC |
23823 | @item reverse |
23824 | Use reverse video mode. | |
c906108c | 23825 | |
8e04817f AC |
23826 | @item half |
23827 | Use half bright mode. | |
c906108c | 23828 | |
8e04817f AC |
23829 | @item half-standout |
23830 | Use half bright and standout mode. | |
c906108c | 23831 | |
8e04817f AC |
23832 | @item bold |
23833 | Use extra bright or bold mode. | |
c78b4128 | 23834 | |
8e04817f AC |
23835 | @item bold-standout |
23836 | Use extra bright or bold and standout mode. | |
8e04817f | 23837 | @end table |
8e04817f | 23838 | @end table |
c78b4128 | 23839 | |
8e04817f AC |
23840 | @node Emacs |
23841 | @chapter Using @value{GDBN} under @sc{gnu} Emacs | |
c78b4128 | 23842 | |
8e04817f AC |
23843 | @cindex Emacs |
23844 | @cindex @sc{gnu} Emacs | |
23845 | A special interface allows you to use @sc{gnu} Emacs to view (and | |
23846 | edit) the source files for the program you are debugging with | |
23847 | @value{GDBN}. | |
c906108c | 23848 | |
8e04817f AC |
23849 | To use this interface, use the command @kbd{M-x gdb} in Emacs. Give the |
23850 | executable file you want to debug as an argument. This command starts | |
23851 | @value{GDBN} as a subprocess of Emacs, with input and output through a newly | |
23852 | created Emacs buffer. | |
23853 | @c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.) | |
c906108c | 23854 | |
5e252a2e | 23855 | Running @value{GDBN} under Emacs can be just like running @value{GDBN} normally except for two |
8e04817f | 23856 | things: |
c906108c | 23857 | |
8e04817f AC |
23858 | @itemize @bullet |
23859 | @item | |
5e252a2e NR |
23860 | All ``terminal'' input and output goes through an Emacs buffer, called |
23861 | the GUD buffer. | |
c906108c | 23862 | |
8e04817f AC |
23863 | This applies both to @value{GDBN} commands and their output, and to the input |
23864 | and output done by the program you are debugging. | |
bf0184be | 23865 | |
8e04817f AC |
23866 | This is useful because it means that you can copy the text of previous |
23867 | commands and input them again; you can even use parts of the output | |
23868 | in this way. | |
bf0184be | 23869 | |
8e04817f AC |
23870 | All the facilities of Emacs' Shell mode are available for interacting |
23871 | with your program. In particular, you can send signals the usual | |
23872 | way---for example, @kbd{C-c C-c} for an interrupt, @kbd{C-c C-z} for a | |
23873 | stop. | |
bf0184be ND |
23874 | |
23875 | @item | |
8e04817f | 23876 | @value{GDBN} displays source code through Emacs. |
bf0184be | 23877 | |
8e04817f AC |
23878 | Each time @value{GDBN} displays a stack frame, Emacs automatically finds the |
23879 | source file for that frame and puts an arrow (@samp{=>}) at the | |
23880 | left margin of the current line. Emacs uses a separate buffer for | |
23881 | source display, and splits the screen to show both your @value{GDBN} session | |
23882 | and the source. | |
bf0184be | 23883 | |
8e04817f AC |
23884 | Explicit @value{GDBN} @code{list} or search commands still produce output as |
23885 | usual, but you probably have no reason to use them from Emacs. | |
5e252a2e NR |
23886 | @end itemize |
23887 | ||
23888 | We call this @dfn{text command mode}. Emacs 22.1, and later, also uses | |
23889 | a graphical mode, enabled by default, which provides further buffers | |
23890 | that can control the execution and describe the state of your program. | |
23891 | @xref{GDB Graphical Interface,,, Emacs, The @sc{gnu} Emacs Manual}. | |
c906108c | 23892 | |
64fabec2 AC |
23893 | If you specify an absolute file name when prompted for the @kbd{M-x |
23894 | gdb} argument, then Emacs sets your current working directory to where | |
23895 | your program resides. If you only specify the file name, then Emacs | |
23896 | sets your current working directory to to the directory associated | |
23897 | with the previous buffer. In this case, @value{GDBN} may find your | |
23898 | program by searching your environment's @code{PATH} variable, but on | |
23899 | some operating systems it might not find the source. So, although the | |
23900 | @value{GDBN} input and output session proceeds normally, the auxiliary | |
23901 | buffer does not display the current source and line of execution. | |
23902 | ||
23903 | The initial working directory of @value{GDBN} is printed on the top | |
5e252a2e NR |
23904 | line of the GUD buffer and this serves as a default for the commands |
23905 | that specify files for @value{GDBN} to operate on. @xref{Files, | |
23906 | ,Commands to Specify Files}. | |
64fabec2 AC |
23907 | |
23908 | By default, @kbd{M-x gdb} calls the program called @file{gdb}. If you | |
23909 | need to call @value{GDBN} by a different name (for example, if you | |
23910 | keep several configurations around, with different names) you can | |
23911 | customize the Emacs variable @code{gud-gdb-command-name} to run the | |
23912 | one you want. | |
8e04817f | 23913 | |
5e252a2e | 23914 | In the GUD buffer, you can use these special Emacs commands in |
8e04817f | 23915 | addition to the standard Shell mode commands: |
c906108c | 23916 | |
8e04817f AC |
23917 | @table @kbd |
23918 | @item C-h m | |
5e252a2e | 23919 | Describe the features of Emacs' GUD Mode. |
c906108c | 23920 | |
64fabec2 | 23921 | @item C-c C-s |
8e04817f AC |
23922 | Execute to another source line, like the @value{GDBN} @code{step} command; also |
23923 | update the display window to show the current file and location. | |
c906108c | 23924 | |
64fabec2 | 23925 | @item C-c C-n |
8e04817f AC |
23926 | Execute to next source line in this function, skipping all function |
23927 | calls, like the @value{GDBN} @code{next} command. Then update the display window | |
23928 | to show the current file and location. | |
c906108c | 23929 | |
64fabec2 | 23930 | @item C-c C-i |
8e04817f AC |
23931 | Execute one instruction, like the @value{GDBN} @code{stepi} command; update |
23932 | display window accordingly. | |
c906108c | 23933 | |
8e04817f AC |
23934 | @item C-c C-f |
23935 | Execute until exit from the selected stack frame, like the @value{GDBN} | |
23936 | @code{finish} command. | |
c906108c | 23937 | |
64fabec2 | 23938 | @item C-c C-r |
8e04817f AC |
23939 | Continue execution of your program, like the @value{GDBN} @code{continue} |
23940 | command. | |
b433d00b | 23941 | |
64fabec2 | 23942 | @item C-c < |
8e04817f AC |
23943 | Go up the number of frames indicated by the numeric argument |
23944 | (@pxref{Arguments, , Numeric Arguments, Emacs, The @sc{gnu} Emacs Manual}), | |
23945 | like the @value{GDBN} @code{up} command. | |
b433d00b | 23946 | |
64fabec2 | 23947 | @item C-c > |
8e04817f AC |
23948 | Go down the number of frames indicated by the numeric argument, like the |
23949 | @value{GDBN} @code{down} command. | |
8e04817f | 23950 | @end table |
c906108c | 23951 | |
7f9087cb | 23952 | In any source file, the Emacs command @kbd{C-x @key{SPC}} (@code{gud-break}) |
8e04817f | 23953 | tells @value{GDBN} to set a breakpoint on the source line point is on. |
c906108c | 23954 | |
5e252a2e NR |
23955 | In text command mode, if you type @kbd{M-x speedbar}, Emacs displays a |
23956 | separate frame which shows a backtrace when the GUD buffer is current. | |
23957 | Move point to any frame in the stack and type @key{RET} to make it | |
23958 | become the current frame and display the associated source in the | |
23959 | source buffer. Alternatively, click @kbd{Mouse-2} to make the | |
23960 | selected frame become the current one. In graphical mode, the | |
23961 | speedbar displays watch expressions. | |
64fabec2 | 23962 | |
8e04817f AC |
23963 | If you accidentally delete the source-display buffer, an easy way to get |
23964 | it back is to type the command @code{f} in the @value{GDBN} buffer, to | |
23965 | request a frame display; when you run under Emacs, this recreates | |
23966 | the source buffer if necessary to show you the context of the current | |
23967 | frame. | |
c906108c | 23968 | |
8e04817f AC |
23969 | The source files displayed in Emacs are in ordinary Emacs buffers |
23970 | which are visiting the source files in the usual way. You can edit | |
23971 | the files with these buffers if you wish; but keep in mind that @value{GDBN} | |
23972 | communicates with Emacs in terms of line numbers. If you add or | |
23973 | delete lines from the text, the line numbers that @value{GDBN} knows cease | |
23974 | to correspond properly with the code. | |
b383017d | 23975 | |
5e252a2e NR |
23976 | A more detailed description of Emacs' interaction with @value{GDBN} is |
23977 | given in the Emacs manual (@pxref{Debuggers,,, Emacs, The @sc{gnu} | |
23978 | Emacs Manual}). | |
c906108c | 23979 | |
8e04817f AC |
23980 | @c The following dropped because Epoch is nonstandard. Reactivate |
23981 | @c if/when v19 does something similar. ---doc@cygnus.com 19dec1990 | |
23982 | @ignore | |
23983 | @kindex Emacs Epoch environment | |
23984 | @kindex Epoch | |
23985 | @kindex inspect | |
c906108c | 23986 | |
8e04817f AC |
23987 | Version 18 of @sc{gnu} Emacs has a built-in window system |
23988 | called the @code{epoch} | |
23989 | environment. Users of this environment can use a new command, | |
23990 | @code{inspect} which performs identically to @code{print} except that | |
23991 | each value is printed in its own window. | |
23992 | @end ignore | |
c906108c | 23993 | |
922fbb7b AC |
23994 | |
23995 | @node GDB/MI | |
23996 | @chapter The @sc{gdb/mi} Interface | |
23997 | ||
23998 | @unnumberedsec Function and Purpose | |
23999 | ||
24000 | @cindex @sc{gdb/mi}, its purpose | |
6b5e8c01 NR |
24001 | @sc{gdb/mi} is a line based machine oriented text interface to |
24002 | @value{GDBN} and is activated by specifying using the | |
24003 | @option{--interpreter} command line option (@pxref{Mode Options}). It | |
24004 | is specifically intended to support the development of systems which | |
24005 | use the debugger as just one small component of a larger system. | |
922fbb7b AC |
24006 | |
24007 | This chapter is a specification of the @sc{gdb/mi} interface. It is written | |
24008 | in the form of a reference manual. | |
24009 | ||
24010 | Note that @sc{gdb/mi} is still under construction, so some of the | |
af6eff6f NR |
24011 | features described below are incomplete and subject to change |
24012 | (@pxref{GDB/MI Development and Front Ends, , @sc{gdb/mi} Development and Front Ends}). | |
922fbb7b AC |
24013 | |
24014 | @unnumberedsec Notation and Terminology | |
24015 | ||
24016 | @cindex notational conventions, for @sc{gdb/mi} | |
24017 | This chapter uses the following notation: | |
24018 | ||
24019 | @itemize @bullet | |
24020 | @item | |
24021 | @code{|} separates two alternatives. | |
24022 | ||
24023 | @item | |
24024 | @code{[ @var{something} ]} indicates that @var{something} is optional: | |
24025 | it may or may not be given. | |
24026 | ||
24027 | @item | |
24028 | @code{( @var{group} )*} means that @var{group} inside the parentheses | |
24029 | may repeat zero or more times. | |
24030 | ||
24031 | @item | |
24032 | @code{( @var{group} )+} means that @var{group} inside the parentheses | |
24033 | may repeat one or more times. | |
24034 | ||
24035 | @item | |
24036 | @code{"@var{string}"} means a literal @var{string}. | |
24037 | @end itemize | |
24038 | ||
24039 | @ignore | |
24040 | @heading Dependencies | |
24041 | @end ignore | |
24042 | ||
922fbb7b | 24043 | @menu |
c3b108f7 | 24044 | * GDB/MI General Design:: |
922fbb7b AC |
24045 | * GDB/MI Command Syntax:: |
24046 | * GDB/MI Compatibility with CLI:: | |
af6eff6f | 24047 | * GDB/MI Development and Front Ends:: |
922fbb7b | 24048 | * GDB/MI Output Records:: |
ef21caaf | 24049 | * GDB/MI Simple Examples:: |
922fbb7b | 24050 | * GDB/MI Command Description Format:: |
ef21caaf | 24051 | * GDB/MI Breakpoint Commands:: |
a2c02241 NR |
24052 | * GDB/MI Program Context:: |
24053 | * GDB/MI Thread Commands:: | |
24054 | * GDB/MI Program Execution:: | |
24055 | * GDB/MI Stack Manipulation:: | |
24056 | * GDB/MI Variable Objects:: | |
922fbb7b | 24057 | * GDB/MI Data Manipulation:: |
a2c02241 NR |
24058 | * GDB/MI Tracepoint Commands:: |
24059 | * GDB/MI Symbol Query:: | |
351ff01a | 24060 | * GDB/MI File Commands:: |
922fbb7b AC |
24061 | @ignore |
24062 | * GDB/MI Kod Commands:: | |
24063 | * GDB/MI Memory Overlay Commands:: | |
24064 | * GDB/MI Signal Handling Commands:: | |
24065 | @end ignore | |
922fbb7b | 24066 | * GDB/MI Target Manipulation:: |
a6b151f1 | 24067 | * GDB/MI File Transfer Commands:: |
ef21caaf | 24068 | * GDB/MI Miscellaneous Commands:: |
922fbb7b AC |
24069 | @end menu |
24070 | ||
c3b108f7 VP |
24071 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24072 | @node GDB/MI General Design | |
24073 | @section @sc{gdb/mi} General Design | |
24074 | @cindex GDB/MI General Design | |
24075 | ||
24076 | Interaction of a @sc{GDB/MI} frontend with @value{GDBN} involves three | |
24077 | parts---commands sent to @value{GDBN}, responses to those commands | |
24078 | and notifications. Each command results in exactly one response, | |
24079 | indicating either successful completion of the command, or an error. | |
24080 | For the commands that do not resume the target, the response contains the | |
24081 | requested information. For the commands that resume the target, the | |
24082 | response only indicates whether the target was successfully resumed. | |
24083 | Notifications is the mechanism for reporting changes in the state of the | |
24084 | target, or in @value{GDBN} state, that cannot conveniently be associated with | |
24085 | a command and reported as part of that command response. | |
24086 | ||
24087 | The important examples of notifications are: | |
24088 | @itemize @bullet | |
24089 | ||
24090 | @item | |
24091 | Exec notifications. These are used to report changes in | |
24092 | target state---when a target is resumed, or stopped. It would not | |
24093 | be feasible to include this information in response of resuming | |
24094 | commands, because one resume commands can result in multiple events in | |
24095 | different threads. Also, quite some time may pass before any event | |
24096 | happens in the target, while a frontend needs to know whether the resuming | |
24097 | command itself was successfully executed. | |
24098 | ||
24099 | @item | |
24100 | Console output, and status notifications. Console output | |
24101 | notifications are used to report output of CLI commands, as well as | |
24102 | diagnostics for other commands. Status notifications are used to | |
24103 | report the progress of a long-running operation. Naturally, including | |
24104 | this information in command response would mean no output is produced | |
24105 | until the command is finished, which is undesirable. | |
24106 | ||
24107 | @item | |
24108 | General notifications. Commands may have various side effects on | |
24109 | the @value{GDBN} or target state beyond their official purpose. For example, | |
24110 | a command may change the selected thread. Although such changes can | |
24111 | be included in command response, using notification allows for more | |
24112 | orthogonal frontend design. | |
24113 | ||
24114 | @end itemize | |
24115 | ||
24116 | There's no guarantee that whenever an MI command reports an error, | |
24117 | @value{GDBN} or the target are in any specific state, and especially, | |
24118 | the state is not reverted to the state before the MI command was | |
24119 | processed. Therefore, whenever an MI command results in an error, | |
24120 | we recommend that the frontend refreshes all the information shown in | |
24121 | the user interface. | |
24122 | ||
508094de NR |
24123 | |
24124 | @menu | |
24125 | * Context management:: | |
24126 | * Asynchronous and non-stop modes:: | |
24127 | * Thread groups:: | |
24128 | @end menu | |
24129 | ||
24130 | @node Context management | |
c3b108f7 VP |
24131 | @subsection Context management |
24132 | ||
24133 | In most cases when @value{GDBN} accesses the target, this access is | |
24134 | done in context of a specific thread and frame (@pxref{Frames}). | |
24135 | Often, even when accessing global data, the target requires that a thread | |
24136 | be specified. The CLI interface maintains the selected thread and frame, | |
24137 | and supplies them to target on each command. This is convenient, | |
24138 | because a command line user would not want to specify that information | |
24139 | explicitly on each command, and because user interacts with | |
24140 | @value{GDBN} via a single terminal, so no confusion is possible as | |
24141 | to what thread and frame are the current ones. | |
24142 | ||
24143 | In the case of MI, the concept of selected thread and frame is less | |
24144 | useful. First, a frontend can easily remember this information | |
24145 | itself. Second, a graphical frontend can have more than one window, | |
24146 | each one used for debugging a different thread, and the frontend might | |
24147 | want to access additional threads for internal purposes. This | |
24148 | increases the risk that by relying on implicitly selected thread, the | |
24149 | frontend may be operating on a wrong one. Therefore, each MI command | |
24150 | should explicitly specify which thread and frame to operate on. To | |
24151 | make it possible, each MI command accepts the @samp{--thread} and | |
24152 | @samp{--frame} options, the value to each is @value{GDBN} identifier | |
24153 | for thread and frame to operate on. | |
24154 | ||
24155 | Usually, each top-level window in a frontend allows the user to select | |
24156 | a thread and a frame, and remembers the user selection for further | |
24157 | operations. However, in some cases @value{GDBN} may suggest that the | |
24158 | current thread be changed. For example, when stopping on a breakpoint | |
24159 | it is reasonable to switch to the thread where breakpoint is hit. For | |
24160 | another example, if the user issues the CLI @samp{thread} command via | |
24161 | the frontend, it is desirable to change the frontend's selected thread to the | |
24162 | one specified by user. @value{GDBN} communicates the suggestion to | |
24163 | change current thread using the @samp{=thread-selected} notification. | |
24164 | No such notification is available for the selected frame at the moment. | |
24165 | ||
24166 | Note that historically, MI shares the selected thread with CLI, so | |
24167 | frontends used the @code{-thread-select} to execute commands in the | |
24168 | right context. However, getting this to work right is cumbersome. The | |
24169 | simplest way is for frontend to emit @code{-thread-select} command | |
24170 | before every command. This doubles the number of commands that need | |
24171 | to be sent. The alternative approach is to suppress @code{-thread-select} | |
24172 | if the selected thread in @value{GDBN} is supposed to be identical to the | |
24173 | thread the frontend wants to operate on. However, getting this | |
24174 | optimization right can be tricky. In particular, if the frontend | |
24175 | sends several commands to @value{GDBN}, and one of the commands changes the | |
24176 | selected thread, then the behaviour of subsequent commands will | |
24177 | change. So, a frontend should either wait for response from such | |
24178 | problematic commands, or explicitly add @code{-thread-select} for | |
24179 | all subsequent commands. No frontend is known to do this exactly | |
24180 | right, so it is suggested to just always pass the @samp{--thread} and | |
24181 | @samp{--frame} options. | |
24182 | ||
508094de | 24183 | @node Asynchronous and non-stop modes |
c3b108f7 VP |
24184 | @subsection Asynchronous command execution and non-stop mode |
24185 | ||
24186 | On some targets, @value{GDBN} is capable of processing MI commands | |
24187 | even while the target is running. This is called @dfn{asynchronous | |
24188 | command execution} (@pxref{Background Execution}). The frontend may | |
24189 | specify a preferrence for asynchronous execution using the | |
24190 | @code{-gdb-set target-async 1} command, which should be emitted before | |
24191 | either running the executable or attaching to the target. After the | |
24192 | frontend has started the executable or attached to the target, it can | |
24193 | find if asynchronous execution is enabled using the | |
24194 | @code{-list-target-features} command. | |
24195 | ||
24196 | Even if @value{GDBN} can accept a command while target is running, | |
24197 | many commands that access the target do not work when the target is | |
24198 | running. Therefore, asynchronous command execution is most useful | |
24199 | when combined with non-stop mode (@pxref{Non-Stop Mode}). Then, | |
24200 | it is possible to examine the state of one thread, while other threads | |
24201 | are running. | |
24202 | ||
24203 | When a given thread is running, MI commands that try to access the | |
24204 | target in the context of that thread may not work, or may work only on | |
24205 | some targets. In particular, commands that try to operate on thread's | |
24206 | stack will not work, on any target. Commands that read memory, or | |
24207 | modify breakpoints, may work or not work, depending on the target. Note | |
24208 | that even commands that operate on global state, such as @code{print}, | |
24209 | @code{set}, and breakpoint commands, still access the target in the | |
24210 | context of a specific thread, so frontend should try to find a | |
24211 | stopped thread and perform the operation on that thread (using the | |
24212 | @samp{--thread} option). | |
24213 | ||
24214 | Which commands will work in the context of a running thread is | |
24215 | highly target dependent. However, the two commands | |
24216 | @code{-exec-interrupt}, to stop a thread, and @code{-thread-info}, | |
24217 | to find the state of a thread, will always work. | |
24218 | ||
508094de | 24219 | @node Thread groups |
c3b108f7 VP |
24220 | @subsection Thread groups |
24221 | @value{GDBN} may be used to debug several processes at the same time. | |
24222 | On some platfroms, @value{GDBN} may support debugging of several | |
24223 | hardware systems, each one having several cores with several different | |
24224 | processes running on each core. This section describes the MI | |
24225 | mechanism to support such debugging scenarios. | |
24226 | ||
24227 | The key observation is that regardless of the structure of the | |
24228 | target, MI can have a global list of threads, because most commands that | |
24229 | accept the @samp{--thread} option do not need to know what process that | |
24230 | thread belongs to. Therefore, it is not necessary to introduce | |
24231 | neither additional @samp{--process} option, nor an notion of the | |
24232 | current process in the MI interface. The only strictly new feature | |
24233 | that is required is the ability to find how the threads are grouped | |
24234 | into processes. | |
24235 | ||
24236 | To allow the user to discover such grouping, and to support arbitrary | |
24237 | hierarchy of machines/cores/processes, MI introduces the concept of a | |
24238 | @dfn{thread group}. Thread group is a collection of threads and other | |
24239 | thread groups. A thread group always has a string identifier, a type, | |
24240 | and may have additional attributes specific to the type. A new | |
24241 | command, @code{-list-thread-groups}, returns the list of top-level | |
24242 | thread groups, which correspond to processes that @value{GDBN} is | |
24243 | debugging at the moment. By passing an identifier of a thread group | |
24244 | to the @code{-list-thread-groups} command, it is possible to obtain | |
24245 | the members of specific thread group. | |
24246 | ||
24247 | To allow the user to easily discover processes, and other objects, he | |
24248 | wishes to debug, a concept of @dfn{available thread group} is | |
24249 | introduced. Available thread group is an thread group that | |
24250 | @value{GDBN} is not debugging, but that can be attached to, using the | |
24251 | @code{-target-attach} command. The list of available top-level thread | |
24252 | groups can be obtained using @samp{-list-thread-groups --available}. | |
24253 | In general, the content of a thread group may be only retrieved only | |
24254 | after attaching to that thread group. | |
24255 | ||
a79b8f6e VP |
24256 | Thread groups are related to inferiors (@pxref{Inferiors and |
24257 | Programs}). Each inferior corresponds to a thread group of a special | |
24258 | type @samp{process}, and some additional operations are permitted on | |
24259 | such thread groups. | |
24260 | ||
922fbb7b AC |
24261 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24262 | @node GDB/MI Command Syntax | |
24263 | @section @sc{gdb/mi} Command Syntax | |
24264 | ||
24265 | @menu | |
24266 | * GDB/MI Input Syntax:: | |
24267 | * GDB/MI Output Syntax:: | |
922fbb7b AC |
24268 | @end menu |
24269 | ||
24270 | @node GDB/MI Input Syntax | |
24271 | @subsection @sc{gdb/mi} Input Syntax | |
24272 | ||
24273 | @cindex input syntax for @sc{gdb/mi} | |
24274 | @cindex @sc{gdb/mi}, input syntax | |
24275 | @table @code | |
24276 | @item @var{command} @expansion{} | |
24277 | @code{@var{cli-command} | @var{mi-command}} | |
24278 | ||
24279 | @item @var{cli-command} @expansion{} | |
24280 | @code{[ @var{token} ] @var{cli-command} @var{nl}}, where | |
24281 | @var{cli-command} is any existing @value{GDBN} CLI command. | |
24282 | ||
24283 | @item @var{mi-command} @expansion{} | |
24284 | @code{[ @var{token} ] "-" @var{operation} ( " " @var{option} )* | |
24285 | @code{[} " --" @code{]} ( " " @var{parameter} )* @var{nl}} | |
24286 | ||
24287 | @item @var{token} @expansion{} | |
24288 | "any sequence of digits" | |
24289 | ||
24290 | @item @var{option} @expansion{} | |
24291 | @code{"-" @var{parameter} [ " " @var{parameter} ]} | |
24292 | ||
24293 | @item @var{parameter} @expansion{} | |
24294 | @code{@var{non-blank-sequence} | @var{c-string}} | |
24295 | ||
24296 | @item @var{operation} @expansion{} | |
24297 | @emph{any of the operations described in this chapter} | |
24298 | ||
24299 | @item @var{non-blank-sequence} @expansion{} | |
24300 | @emph{anything, provided it doesn't contain special characters such as | |
24301 | "-", @var{nl}, """ and of course " "} | |
24302 | ||
24303 | @item @var{c-string} @expansion{} | |
24304 | @code{""" @var{seven-bit-iso-c-string-content} """} | |
24305 | ||
24306 | @item @var{nl} @expansion{} | |
24307 | @code{CR | CR-LF} | |
24308 | @end table | |
24309 | ||
24310 | @noindent | |
24311 | Notes: | |
24312 | ||
24313 | @itemize @bullet | |
24314 | @item | |
24315 | The CLI commands are still handled by the @sc{mi} interpreter; their | |
24316 | output is described below. | |
24317 | ||
24318 | @item | |
24319 | The @code{@var{token}}, when present, is passed back when the command | |
24320 | finishes. | |
24321 | ||
24322 | @item | |
24323 | Some @sc{mi} commands accept optional arguments as part of the parameter | |
24324 | list. Each option is identified by a leading @samp{-} (dash) and may be | |
24325 | followed by an optional argument parameter. Options occur first in the | |
24326 | parameter list and can be delimited from normal parameters using | |
24327 | @samp{--} (this is useful when some parameters begin with a dash). | |
24328 | @end itemize | |
24329 | ||
24330 | Pragmatics: | |
24331 | ||
24332 | @itemize @bullet | |
24333 | @item | |
24334 | We want easy access to the existing CLI syntax (for debugging). | |
24335 | ||
24336 | @item | |
24337 | We want it to be easy to spot a @sc{mi} operation. | |
24338 | @end itemize | |
24339 | ||
24340 | @node GDB/MI Output Syntax | |
24341 | @subsection @sc{gdb/mi} Output Syntax | |
24342 | ||
24343 | @cindex output syntax of @sc{gdb/mi} | |
24344 | @cindex @sc{gdb/mi}, output syntax | |
24345 | The output from @sc{gdb/mi} consists of zero or more out-of-band records | |
24346 | followed, optionally, by a single result record. This result record | |
24347 | is for the most recent command. The sequence of output records is | |
594fe323 | 24348 | terminated by @samp{(gdb)}. |
922fbb7b AC |
24349 | |
24350 | If an input command was prefixed with a @code{@var{token}} then the | |
24351 | corresponding output for that command will also be prefixed by that same | |
24352 | @var{token}. | |
24353 | ||
24354 | @table @code | |
24355 | @item @var{output} @expansion{} | |
594fe323 | 24356 | @code{( @var{out-of-band-record} )* [ @var{result-record} ] "(gdb)" @var{nl}} |
922fbb7b AC |
24357 | |
24358 | @item @var{result-record} @expansion{} | |
24359 | @code{ [ @var{token} ] "^" @var{result-class} ( "," @var{result} )* @var{nl}} | |
24360 | ||
24361 | @item @var{out-of-band-record} @expansion{} | |
24362 | @code{@var{async-record} | @var{stream-record}} | |
24363 | ||
24364 | @item @var{async-record} @expansion{} | |
24365 | @code{@var{exec-async-output} | @var{status-async-output} | @var{notify-async-output}} | |
24366 | ||
24367 | @item @var{exec-async-output} @expansion{} | |
24368 | @code{[ @var{token} ] "*" @var{async-output}} | |
24369 | ||
24370 | @item @var{status-async-output} @expansion{} | |
24371 | @code{[ @var{token} ] "+" @var{async-output}} | |
24372 | ||
24373 | @item @var{notify-async-output} @expansion{} | |
24374 | @code{[ @var{token} ] "=" @var{async-output}} | |
24375 | ||
24376 | @item @var{async-output} @expansion{} | |
24377 | @code{@var{async-class} ( "," @var{result} )* @var{nl}} | |
24378 | ||
24379 | @item @var{result-class} @expansion{} | |
24380 | @code{"done" | "running" | "connected" | "error" | "exit"} | |
24381 | ||
24382 | @item @var{async-class} @expansion{} | |
24383 | @code{"stopped" | @var{others}} (where @var{others} will be added | |
24384 | depending on the needs---this is still in development). | |
24385 | ||
24386 | @item @var{result} @expansion{} | |
24387 | @code{ @var{variable} "=" @var{value}} | |
24388 | ||
24389 | @item @var{variable} @expansion{} | |
24390 | @code{ @var{string} } | |
24391 | ||
24392 | @item @var{value} @expansion{} | |
24393 | @code{ @var{const} | @var{tuple} | @var{list} } | |
24394 | ||
24395 | @item @var{const} @expansion{} | |
24396 | @code{@var{c-string}} | |
24397 | ||
24398 | @item @var{tuple} @expansion{} | |
24399 | @code{ "@{@}" | "@{" @var{result} ( "," @var{result} )* "@}" } | |
24400 | ||
24401 | @item @var{list} @expansion{} | |
24402 | @code{ "[]" | "[" @var{value} ( "," @var{value} )* "]" | "[" | |
24403 | @var{result} ( "," @var{result} )* "]" } | |
24404 | ||
24405 | @item @var{stream-record} @expansion{} | |
24406 | @code{@var{console-stream-output} | @var{target-stream-output} | @var{log-stream-output}} | |
24407 | ||
24408 | @item @var{console-stream-output} @expansion{} | |
24409 | @code{"~" @var{c-string}} | |
24410 | ||
24411 | @item @var{target-stream-output} @expansion{} | |
24412 | @code{"@@" @var{c-string}} | |
24413 | ||
24414 | @item @var{log-stream-output} @expansion{} | |
24415 | @code{"&" @var{c-string}} | |
24416 | ||
24417 | @item @var{nl} @expansion{} | |
24418 | @code{CR | CR-LF} | |
24419 | ||
24420 | @item @var{token} @expansion{} | |
24421 | @emph{any sequence of digits}. | |
24422 | @end table | |
24423 | ||
24424 | @noindent | |
24425 | Notes: | |
24426 | ||
24427 | @itemize @bullet | |
24428 | @item | |
24429 | All output sequences end in a single line containing a period. | |
24430 | ||
24431 | @item | |
721c02de VP |
24432 | The @code{@var{token}} is from the corresponding request. Note that |
24433 | for all async output, while the token is allowed by the grammar and | |
24434 | may be output by future versions of @value{GDBN} for select async | |
24435 | output messages, it is generally omitted. Frontends should treat | |
24436 | all async output as reporting general changes in the state of the | |
24437 | target and there should be no need to associate async output to any | |
24438 | prior command. | |
922fbb7b AC |
24439 | |
24440 | @item | |
24441 | @cindex status output in @sc{gdb/mi} | |
24442 | @var{status-async-output} contains on-going status information about the | |
24443 | progress of a slow operation. It can be discarded. All status output is | |
24444 | prefixed by @samp{+}. | |
24445 | ||
24446 | @item | |
24447 | @cindex async output in @sc{gdb/mi} | |
24448 | @var{exec-async-output} contains asynchronous state change on the target | |
24449 | (stopped, started, disappeared). All async output is prefixed by | |
24450 | @samp{*}. | |
24451 | ||
24452 | @item | |
24453 | @cindex notify output in @sc{gdb/mi} | |
24454 | @var{notify-async-output} contains supplementary information that the | |
24455 | client should handle (e.g., a new breakpoint information). All notify | |
24456 | output is prefixed by @samp{=}. | |
24457 | ||
24458 | @item | |
24459 | @cindex console output in @sc{gdb/mi} | |
24460 | @var{console-stream-output} is output that should be displayed as is in the | |
24461 | console. It is the textual response to a CLI command. All the console | |
24462 | output is prefixed by @samp{~}. | |
24463 | ||
24464 | @item | |
24465 | @cindex target output in @sc{gdb/mi} | |
24466 | @var{target-stream-output} is the output produced by the target program. | |
24467 | All the target output is prefixed by @samp{@@}. | |
24468 | ||
24469 | @item | |
24470 | @cindex log output in @sc{gdb/mi} | |
24471 | @var{log-stream-output} is output text coming from @value{GDBN}'s internals, for | |
24472 | instance messages that should be displayed as part of an error log. All | |
24473 | the log output is prefixed by @samp{&}. | |
24474 | ||
24475 | @item | |
24476 | @cindex list output in @sc{gdb/mi} | |
24477 | New @sc{gdb/mi} commands should only output @var{lists} containing | |
24478 | @var{values}. | |
24479 | ||
24480 | ||
24481 | @end itemize | |
24482 | ||
24483 | @xref{GDB/MI Stream Records, , @sc{gdb/mi} Stream Records}, for more | |
24484 | details about the various output records. | |
24485 | ||
922fbb7b AC |
24486 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24487 | @node GDB/MI Compatibility with CLI | |
24488 | @section @sc{gdb/mi} Compatibility with CLI | |
24489 | ||
24490 | @cindex compatibility, @sc{gdb/mi} and CLI | |
24491 | @cindex @sc{gdb/mi}, compatibility with CLI | |
922fbb7b | 24492 | |
a2c02241 NR |
24493 | For the developers convenience CLI commands can be entered directly, |
24494 | but there may be some unexpected behaviour. For example, commands | |
24495 | that query the user will behave as if the user replied yes, breakpoint | |
24496 | command lists are not executed and some CLI commands, such as | |
24497 | @code{if}, @code{when} and @code{define}, prompt for further input with | |
24498 | @samp{>}, which is not valid MI output. | |
ef21caaf NR |
24499 | |
24500 | This feature may be removed at some stage in the future and it is | |
a2c02241 NR |
24501 | recommended that front ends use the @code{-interpreter-exec} command |
24502 | (@pxref{-interpreter-exec}). | |
922fbb7b | 24503 | |
af6eff6f NR |
24504 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24505 | @node GDB/MI Development and Front Ends | |
24506 | @section @sc{gdb/mi} Development and Front Ends | |
24507 | @cindex @sc{gdb/mi} development | |
24508 | ||
24509 | The application which takes the MI output and presents the state of the | |
24510 | program being debugged to the user is called a @dfn{front end}. | |
24511 | ||
24512 | Although @sc{gdb/mi} is still incomplete, it is currently being used | |
24513 | by a variety of front ends to @value{GDBN}. This makes it difficult | |
24514 | to introduce new functionality without breaking existing usage. This | |
24515 | section tries to minimize the problems by describing how the protocol | |
24516 | might change. | |
24517 | ||
24518 | Some changes in MI need not break a carefully designed front end, and | |
24519 | for these the MI version will remain unchanged. The following is a | |
24520 | list of changes that may occur within one level, so front ends should | |
24521 | parse MI output in a way that can handle them: | |
24522 | ||
24523 | @itemize @bullet | |
24524 | @item | |
24525 | New MI commands may be added. | |
24526 | ||
24527 | @item | |
24528 | New fields may be added to the output of any MI command. | |
24529 | ||
36ece8b3 NR |
24530 | @item |
24531 | The range of values for fields with specified values, e.g., | |
9f708cb2 | 24532 | @code{in_scope} (@pxref{-var-update}) may be extended. |
36ece8b3 | 24533 | |
af6eff6f NR |
24534 | @c The format of field's content e.g type prefix, may change so parse it |
24535 | @c at your own risk. Yes, in general? | |
24536 | ||
24537 | @c The order of fields may change? Shouldn't really matter but it might | |
24538 | @c resolve inconsistencies. | |
24539 | @end itemize | |
24540 | ||
24541 | If the changes are likely to break front ends, the MI version level | |
24542 | will be increased by one. This will allow the front end to parse the | |
24543 | output according to the MI version. Apart from mi0, new versions of | |
24544 | @value{GDBN} will not support old versions of MI and it will be the | |
24545 | responsibility of the front end to work with the new one. | |
24546 | ||
24547 | @c Starting with mi3, add a new command -mi-version that prints the MI | |
24548 | @c version? | |
24549 | ||
24550 | The best way to avoid unexpected changes in MI that might break your front | |
24551 | end is to make your project known to @value{GDBN} developers and | |
7a9a6b69 | 24552 | follow development on @email{gdb@@sourceware.org} and |
fa0f268d | 24553 | @email{gdb-patches@@sourceware.org}. |
af6eff6f NR |
24554 | @cindex mailing lists |
24555 | ||
922fbb7b AC |
24556 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24557 | @node GDB/MI Output Records | |
24558 | @section @sc{gdb/mi} Output Records | |
24559 | ||
24560 | @menu | |
24561 | * GDB/MI Result Records:: | |
24562 | * GDB/MI Stream Records:: | |
82f68b1c | 24563 | * GDB/MI Async Records:: |
c3b108f7 | 24564 | * GDB/MI Frame Information:: |
dc146f7c | 24565 | * GDB/MI Thread Information:: |
922fbb7b AC |
24566 | @end menu |
24567 | ||
24568 | @node GDB/MI Result Records | |
24569 | @subsection @sc{gdb/mi} Result Records | |
24570 | ||
24571 | @cindex result records in @sc{gdb/mi} | |
24572 | @cindex @sc{gdb/mi}, result records | |
24573 | In addition to a number of out-of-band notifications, the response to a | |
24574 | @sc{gdb/mi} command includes one of the following result indications: | |
24575 | ||
24576 | @table @code | |
24577 | @findex ^done | |
24578 | @item "^done" [ "," @var{results} ] | |
24579 | The synchronous operation was successful, @code{@var{results}} are the return | |
24580 | values. | |
24581 | ||
24582 | @item "^running" | |
24583 | @findex ^running | |
8e9c5e02 VP |
24584 | This result record is equivalent to @samp{^done}. Historically, it |
24585 | was output instead of @samp{^done} if the command has resumed the | |
24586 | target. This behaviour is maintained for backward compatibility, but | |
24587 | all frontends should treat @samp{^done} and @samp{^running} | |
24588 | identically and rely on the @samp{*running} output record to determine | |
24589 | which threads are resumed. | |
922fbb7b | 24590 | |
ef21caaf NR |
24591 | @item "^connected" |
24592 | @findex ^connected | |
3f94c067 | 24593 | @value{GDBN} has connected to a remote target. |
ef21caaf | 24594 | |
922fbb7b AC |
24595 | @item "^error" "," @var{c-string} |
24596 | @findex ^error | |
24597 | The operation failed. The @code{@var{c-string}} contains the corresponding | |
24598 | error message. | |
ef21caaf NR |
24599 | |
24600 | @item "^exit" | |
24601 | @findex ^exit | |
3f94c067 | 24602 | @value{GDBN} has terminated. |
ef21caaf | 24603 | |
922fbb7b AC |
24604 | @end table |
24605 | ||
24606 | @node GDB/MI Stream Records | |
24607 | @subsection @sc{gdb/mi} Stream Records | |
24608 | ||
24609 | @cindex @sc{gdb/mi}, stream records | |
24610 | @cindex stream records in @sc{gdb/mi} | |
24611 | @value{GDBN} internally maintains a number of output streams: the console, the | |
24612 | target, and the log. The output intended for each of these streams is | |
24613 | funneled through the @sc{gdb/mi} interface using @dfn{stream records}. | |
24614 | ||
24615 | Each stream record begins with a unique @dfn{prefix character} which | |
24616 | identifies its stream (@pxref{GDB/MI Output Syntax, , @sc{gdb/mi} Output | |
24617 | Syntax}). In addition to the prefix, each stream record contains a | |
24618 | @code{@var{string-output}}. This is either raw text (with an implicit new | |
24619 | line) or a quoted C string (which does not contain an implicit newline). | |
24620 | ||
24621 | @table @code | |
24622 | @item "~" @var{string-output} | |
24623 | The console output stream contains text that should be displayed in the | |
24624 | CLI console window. It contains the textual responses to CLI commands. | |
24625 | ||
24626 | @item "@@" @var{string-output} | |
24627 | The target output stream contains any textual output from the running | |
ef21caaf NR |
24628 | target. This is only present when GDB's event loop is truly |
24629 | asynchronous, which is currently only the case for remote targets. | |
922fbb7b AC |
24630 | |
24631 | @item "&" @var{string-output} | |
24632 | The log stream contains debugging messages being produced by @value{GDBN}'s | |
24633 | internals. | |
24634 | @end table | |
24635 | ||
82f68b1c VP |
24636 | @node GDB/MI Async Records |
24637 | @subsection @sc{gdb/mi} Async Records | |
922fbb7b | 24638 | |
82f68b1c VP |
24639 | @cindex async records in @sc{gdb/mi} |
24640 | @cindex @sc{gdb/mi}, async records | |
24641 | @dfn{Async} records are used to notify the @sc{gdb/mi} client of | |
922fbb7b | 24642 | additional changes that have occurred. Those changes can either be a |
82f68b1c | 24643 | consequence of @sc{gdb/mi} commands (e.g., a breakpoint modified) or a result of |
922fbb7b AC |
24644 | target activity (e.g., target stopped). |
24645 | ||
8eb41542 | 24646 | The following is the list of possible async records: |
922fbb7b AC |
24647 | |
24648 | @table @code | |
034dad6f | 24649 | |
e1ac3328 VP |
24650 | @item *running,thread-id="@var{thread}" |
24651 | The target is now running. The @var{thread} field tells which | |
24652 | specific thread is now running, and can be @samp{all} if all threads | |
24653 | are running. The frontend should assume that no interaction with a | |
24654 | running thread is possible after this notification is produced. | |
24655 | The frontend should not assume that this notification is output | |
24656 | only once for any command. @value{GDBN} may emit this notification | |
24657 | several times, either for different threads, because it cannot resume | |
24658 | all threads together, or even for a single thread, if the thread must | |
24659 | be stepped though some code before letting it run freely. | |
24660 | ||
dc146f7c | 24661 | @item *stopped,reason="@var{reason}",thread-id="@var{id}",stopped-threads="@var{stopped}",core="@var{core}" |
82f68b1c VP |
24662 | The target has stopped. The @var{reason} field can have one of the |
24663 | following values: | |
034dad6f BR |
24664 | |
24665 | @table @code | |
24666 | @item breakpoint-hit | |
24667 | A breakpoint was reached. | |
24668 | @item watchpoint-trigger | |
24669 | A watchpoint was triggered. | |
24670 | @item read-watchpoint-trigger | |
24671 | A read watchpoint was triggered. | |
24672 | @item access-watchpoint-trigger | |
24673 | An access watchpoint was triggered. | |
24674 | @item function-finished | |
24675 | An -exec-finish or similar CLI command was accomplished. | |
24676 | @item location-reached | |
24677 | An -exec-until or similar CLI command was accomplished. | |
24678 | @item watchpoint-scope | |
24679 | A watchpoint has gone out of scope. | |
24680 | @item end-stepping-range | |
24681 | An -exec-next, -exec-next-instruction, -exec-step, -exec-step-instruction or | |
24682 | similar CLI command was accomplished. | |
24683 | @item exited-signalled | |
24684 | The inferior exited because of a signal. | |
24685 | @item exited | |
24686 | The inferior exited. | |
24687 | @item exited-normally | |
24688 | The inferior exited normally. | |
24689 | @item signal-received | |
24690 | A signal was received by the inferior. | |
922fbb7b AC |
24691 | @end table |
24692 | ||
c3b108f7 VP |
24693 | The @var{id} field identifies the thread that directly caused the stop |
24694 | -- for example by hitting a breakpoint. Depending on whether all-stop | |
24695 | mode is in effect (@pxref{All-Stop Mode}), @value{GDBN} may either | |
24696 | stop all threads, or only the thread that directly triggered the stop. | |
24697 | If all threads are stopped, the @var{stopped} field will have the | |
24698 | value of @code{"all"}. Otherwise, the value of the @var{stopped} | |
24699 | field will be a list of thread identifiers. Presently, this list will | |
24700 | always include a single thread, but frontend should be prepared to see | |
dc146f7c VP |
24701 | several threads in the list. The @var{core} field reports the |
24702 | processor core on which the stop event has happened. This field may be absent | |
24703 | if such information is not available. | |
c3b108f7 | 24704 | |
a79b8f6e VP |
24705 | @item =thread-group-added,id="@var{id}" |
24706 | @itemx =thread-group-removed,id="@var{id}" | |
24707 | A thread group was either added or removed. The @var{id} field | |
24708 | contains the @value{GDBN} identifier of the thread group. When a thread | |
24709 | group is added, it generally might not be associated with a running | |
24710 | process. When a thread group is removed, its id becomes invalid and | |
24711 | cannot be used in any way. | |
24712 | ||
24713 | @item =thread-group-started,id="@var{id}",pid="@var{pid}" | |
24714 | A thread group became associated with a running program, | |
24715 | either because the program was just started or the thread group | |
24716 | was attached to a program. The @var{id} field contains the | |
24717 | @value{GDBN} identifier of the thread group. The @var{pid} field | |
24718 | contains process identifier, specific to the operating system. | |
24719 | ||
c3b108f7 | 24720 | @itemx =thread-group-exited,id="@var{id}" |
a79b8f6e VP |
24721 | A thread group is no longer associated with a running program, |
24722 | either because the program has exited, or because it was detached | |
c3b108f7 VP |
24723 | from. The @var{id} field contains the @value{GDBN} identifier of the |
24724 | thread group. | |
24725 | ||
24726 | @item =thread-created,id="@var{id}",group-id="@var{gid}" | |
24727 | @itemx =thread-exited,id="@var{id}",group-id="@var{gid}" | |
82f68b1c | 24728 | A thread either was created, or has exited. The @var{id} field |
c3b108f7 VP |
24729 | contains the @value{GDBN} identifier of the thread. The @var{gid} |
24730 | field identifies the thread group this thread belongs to. | |
66bb093b VP |
24731 | |
24732 | @item =thread-selected,id="@var{id}" | |
24733 | Informs that the selected thread was changed as result of the last | |
24734 | command. This notification is not emitted as result of @code{-thread-select} | |
24735 | command but is emitted whenever an MI command that is not documented | |
24736 | to change the selected thread actually changes it. In particular, | |
24737 | invoking, directly or indirectly (via user-defined command), the CLI | |
24738 | @code{thread} command, will generate this notification. | |
24739 | ||
24740 | We suggest that in response to this notification, front ends | |
24741 | highlight the selected thread and cause subsequent commands to apply to | |
24742 | that thread. | |
24743 | ||
c86cf029 VP |
24744 | @item =library-loaded,... |
24745 | Reports that a new library file was loaded by the program. This | |
24746 | notification has 4 fields---@var{id}, @var{target-name}, | |
134eb42c | 24747 | @var{host-name}, and @var{symbols-loaded}. The @var{id} field is an |
c86cf029 VP |
24748 | opaque identifier of the library. For remote debugging case, |
24749 | @var{target-name} and @var{host-name} fields give the name of the | |
134eb42c VP |
24750 | library file on the target, and on the host respectively. For native |
24751 | debugging, both those fields have the same value. The | |
c86cf029 | 24752 | @var{symbols-loaded} field reports if the debug symbols for this |
a79b8f6e VP |
24753 | library are loaded. The @var{thread-group} field, if present, |
24754 | specifies the id of the thread group in whose context the library was loaded. | |
24755 | If the field is absent, it means the library was loaded in the context | |
24756 | of all present thread groups. | |
c86cf029 VP |
24757 | |
24758 | @item =library-unloaded,... | |
134eb42c | 24759 | Reports that a library was unloaded by the program. This notification |
c86cf029 | 24760 | has 3 fields---@var{id}, @var{target-name} and @var{host-name} with |
a79b8f6e VP |
24761 | the same meaning as for the @code{=library-loaded} notification. |
24762 | The @var{thread-group} field, if present, specifies the id of the | |
24763 | thread group in whose context the library was unloaded. If the field is | |
24764 | absent, it means the library was unloaded in the context of all present | |
24765 | thread groups. | |
c86cf029 | 24766 | |
82f68b1c VP |
24767 | @end table |
24768 | ||
c3b108f7 VP |
24769 | @node GDB/MI Frame Information |
24770 | @subsection @sc{gdb/mi} Frame Information | |
24771 | ||
24772 | Response from many MI commands includes an information about stack | |
24773 | frame. This information is a tuple that may have the following | |
24774 | fields: | |
24775 | ||
24776 | @table @code | |
24777 | @item level | |
24778 | The level of the stack frame. The innermost frame has the level of | |
24779 | zero. This field is always present. | |
24780 | ||
24781 | @item func | |
24782 | The name of the function corresponding to the frame. This field may | |
24783 | be absent if @value{GDBN} is unable to determine the function name. | |
24784 | ||
24785 | @item addr | |
24786 | The code address for the frame. This field is always present. | |
24787 | ||
24788 | @item file | |
24789 | The name of the source files that correspond to the frame's code | |
24790 | address. This field may be absent. | |
24791 | ||
24792 | @item line | |
24793 | The source line corresponding to the frames' code address. This field | |
24794 | may be absent. | |
24795 | ||
24796 | @item from | |
24797 | The name of the binary file (either executable or shared library) the | |
24798 | corresponds to the frame's code address. This field may be absent. | |
24799 | ||
24800 | @end table | |
82f68b1c | 24801 | |
dc146f7c VP |
24802 | @node GDB/MI Thread Information |
24803 | @subsection @sc{gdb/mi} Thread Information | |
24804 | ||
24805 | Whenever @value{GDBN} has to report an information about a thread, it | |
24806 | uses a tuple with the following fields: | |
24807 | ||
24808 | @table @code | |
24809 | @item id | |
24810 | The numeric id assigned to the thread by @value{GDBN}. This field is | |
24811 | always present. | |
24812 | ||
24813 | @item target-id | |
24814 | Target-specific string identifying the thread. This field is always present. | |
24815 | ||
24816 | @item details | |
24817 | Additional information about the thread provided by the target. | |
24818 | It is supposed to be human-readable and not interpreted by the | |
24819 | frontend. This field is optional. | |
24820 | ||
24821 | @item state | |
24822 | Either @samp{stopped} or @samp{running}, depending on whether the | |
24823 | thread is presently running. This field is always present. | |
24824 | ||
24825 | @item core | |
24826 | The value of this field is an integer number of the processor core the | |
24827 | thread was last seen on. This field is optional. | |
24828 | @end table | |
24829 | ||
922fbb7b | 24830 | |
ef21caaf NR |
24831 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24832 | @node GDB/MI Simple Examples | |
24833 | @section Simple Examples of @sc{gdb/mi} Interaction | |
24834 | @cindex @sc{gdb/mi}, simple examples | |
24835 | ||
24836 | This subsection presents several simple examples of interaction using | |
24837 | the @sc{gdb/mi} interface. In these examples, @samp{->} means that the | |
24838 | following line is passed to @sc{gdb/mi} as input, while @samp{<-} means | |
24839 | the output received from @sc{gdb/mi}. | |
24840 | ||
d3e8051b | 24841 | Note the line breaks shown in the examples are here only for |
ef21caaf NR |
24842 | readability, they don't appear in the real output. |
24843 | ||
79a6e687 | 24844 | @subheading Setting a Breakpoint |
ef21caaf NR |
24845 | |
24846 | Setting a breakpoint generates synchronous output which contains detailed | |
24847 | information of the breakpoint. | |
24848 | ||
24849 | @smallexample | |
24850 | -> -break-insert main | |
24851 | <- ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
24852 | enabled="y",addr="0x08048564",func="main",file="myprog.c", | |
24853 | fullname="/home/nickrob/myprog.c",line="68",times="0"@} | |
24854 | <- (gdb) | |
24855 | @end smallexample | |
24856 | ||
24857 | @subheading Program Execution | |
24858 | ||
24859 | Program execution generates asynchronous records and MI gives the | |
24860 | reason that execution stopped. | |
24861 | ||
24862 | @smallexample | |
24863 | -> -exec-run | |
24864 | <- ^running | |
24865 | <- (gdb) | |
a47ec5fe | 24866 | <- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", |
ef21caaf NR |
24867 | frame=@{addr="0x08048564",func="main", |
24868 | args=[@{name="argc",value="1"@},@{name="argv",value="0xbfc4d4d4"@}], | |
24869 | file="myprog.c",fullname="/home/nickrob/myprog.c",line="68"@} | |
24870 | <- (gdb) | |
24871 | -> -exec-continue | |
24872 | <- ^running | |
24873 | <- (gdb) | |
24874 | <- *stopped,reason="exited-normally" | |
24875 | <- (gdb) | |
24876 | @end smallexample | |
24877 | ||
3f94c067 | 24878 | @subheading Quitting @value{GDBN} |
ef21caaf | 24879 | |
3f94c067 | 24880 | Quitting @value{GDBN} just prints the result class @samp{^exit}. |
ef21caaf NR |
24881 | |
24882 | @smallexample | |
24883 | -> (gdb) | |
24884 | <- -gdb-exit | |
24885 | <- ^exit | |
24886 | @end smallexample | |
24887 | ||
a6b29f87 VP |
24888 | Please note that @samp{^exit} is printed immediately, but it might |
24889 | take some time for @value{GDBN} to actually exit. During that time, @value{GDBN} | |
24890 | performs necessary cleanups, including killing programs being debugged | |
24891 | or disconnecting from debug hardware, so the frontend should wait till | |
24892 | @value{GDBN} exits and should only forcibly kill @value{GDBN} if it | |
24893 | fails to exit in reasonable time. | |
24894 | ||
a2c02241 | 24895 | @subheading A Bad Command |
ef21caaf NR |
24896 | |
24897 | Here's what happens if you pass a non-existent command: | |
24898 | ||
24899 | @smallexample | |
24900 | -> -rubbish | |
24901 | <- ^error,msg="Undefined MI command: rubbish" | |
594fe323 | 24902 | <- (gdb) |
ef21caaf NR |
24903 | @end smallexample |
24904 | ||
24905 | ||
922fbb7b AC |
24906 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
24907 | @node GDB/MI Command Description Format | |
24908 | @section @sc{gdb/mi} Command Description Format | |
24909 | ||
24910 | The remaining sections describe blocks of commands. Each block of | |
24911 | commands is laid out in a fashion similar to this section. | |
24912 | ||
922fbb7b AC |
24913 | @subheading Motivation |
24914 | ||
24915 | The motivation for this collection of commands. | |
24916 | ||
24917 | @subheading Introduction | |
24918 | ||
24919 | A brief introduction to this collection of commands as a whole. | |
24920 | ||
24921 | @subheading Commands | |
24922 | ||
24923 | For each command in the block, the following is described: | |
24924 | ||
24925 | @subsubheading Synopsis | |
24926 | ||
24927 | @smallexample | |
24928 | -command @var{args}@dots{} | |
24929 | @end smallexample | |
24930 | ||
922fbb7b AC |
24931 | @subsubheading Result |
24932 | ||
265eeb58 | 24933 | @subsubheading @value{GDBN} Command |
922fbb7b | 24934 | |
265eeb58 | 24935 | The corresponding @value{GDBN} CLI command(s), if any. |
922fbb7b AC |
24936 | |
24937 | @subsubheading Example | |
24938 | ||
ef21caaf NR |
24939 | Example(s) formatted for readability. Some of the described commands have |
24940 | not been implemented yet and these are labeled N.A.@: (not available). | |
24941 | ||
24942 | ||
922fbb7b | 24943 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
ef21caaf NR |
24944 | @node GDB/MI Breakpoint Commands |
24945 | @section @sc{gdb/mi} Breakpoint Commands | |
922fbb7b AC |
24946 | |
24947 | @cindex breakpoint commands for @sc{gdb/mi} | |
24948 | @cindex @sc{gdb/mi}, breakpoint commands | |
24949 | This section documents @sc{gdb/mi} commands for manipulating | |
24950 | breakpoints. | |
24951 | ||
24952 | @subheading The @code{-break-after} Command | |
24953 | @findex -break-after | |
24954 | ||
24955 | @subsubheading Synopsis | |
24956 | ||
24957 | @smallexample | |
24958 | -break-after @var{number} @var{count} | |
24959 | @end smallexample | |
24960 | ||
24961 | The breakpoint number @var{number} is not in effect until it has been | |
24962 | hit @var{count} times. To see how this is reflected in the output of | |
24963 | the @samp{-break-list} command, see the description of the | |
24964 | @samp{-break-list} command below. | |
24965 | ||
24966 | @subsubheading @value{GDBN} Command | |
24967 | ||
24968 | The corresponding @value{GDBN} command is @samp{ignore}. | |
24969 | ||
24970 | @subsubheading Example | |
24971 | ||
24972 | @smallexample | |
594fe323 | 24973 | (gdb) |
922fbb7b | 24974 | -break-insert main |
a47ec5fe AR |
24975 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep", |
24976 | enabled="y",addr="0x000100d0",func="main",file="hello.c", | |
948d5102 | 24977 | fullname="/home/foo/hello.c",line="5",times="0"@} |
594fe323 | 24978 | (gdb) |
922fbb7b AC |
24979 | -break-after 1 3 |
24980 | ~ | |
24981 | ^done | |
594fe323 | 24982 | (gdb) |
922fbb7b AC |
24983 | -break-list |
24984 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
24985 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
24986 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
24987 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
24988 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
24989 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
24990 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
24991 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 NR |
24992 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
24993 | line="5",times="0",ignore="3"@}]@} | |
594fe323 | 24994 | (gdb) |
922fbb7b AC |
24995 | @end smallexample |
24996 | ||
24997 | @ignore | |
24998 | @subheading The @code{-break-catch} Command | |
24999 | @findex -break-catch | |
48cb2d85 | 25000 | @end ignore |
922fbb7b AC |
25001 | |
25002 | @subheading The @code{-break-commands} Command | |
25003 | @findex -break-commands | |
922fbb7b | 25004 | |
48cb2d85 VP |
25005 | @subsubheading Synopsis |
25006 | ||
25007 | @smallexample | |
25008 | -break-commands @var{number} [ @var{command1} ... @var{commandN} ] | |
25009 | @end smallexample | |
25010 | ||
25011 | Specifies the CLI commands that should be executed when breakpoint | |
25012 | @var{number} is hit. The parameters @var{command1} to @var{commandN} | |
25013 | are the commands. If no command is specified, any previously-set | |
25014 | commands are cleared. @xref{Break Commands}. Typical use of this | |
25015 | functionality is tracing a program, that is, printing of values of | |
25016 | some variables whenever breakpoint is hit and then continuing. | |
25017 | ||
25018 | @subsubheading @value{GDBN} Command | |
25019 | ||
25020 | The corresponding @value{GDBN} command is @samp{commands}. | |
25021 | ||
25022 | @subsubheading Example | |
25023 | ||
25024 | @smallexample | |
25025 | (gdb) | |
25026 | -break-insert main | |
25027 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep", | |
25028 | enabled="y",addr="0x000100d0",func="main",file="hello.c", | |
25029 | fullname="/home/foo/hello.c",line="5",times="0"@} | |
25030 | (gdb) | |
25031 | -break-commands 1 "print v" "continue" | |
25032 | ^done | |
25033 | (gdb) | |
25034 | @end smallexample | |
922fbb7b AC |
25035 | |
25036 | @subheading The @code{-break-condition} Command | |
25037 | @findex -break-condition | |
25038 | ||
25039 | @subsubheading Synopsis | |
25040 | ||
25041 | @smallexample | |
25042 | -break-condition @var{number} @var{expr} | |
25043 | @end smallexample | |
25044 | ||
25045 | Breakpoint @var{number} will stop the program only if the condition in | |
25046 | @var{expr} is true. The condition becomes part of the | |
25047 | @samp{-break-list} output (see the description of the @samp{-break-list} | |
25048 | command below). | |
25049 | ||
25050 | @subsubheading @value{GDBN} Command | |
25051 | ||
25052 | The corresponding @value{GDBN} command is @samp{condition}. | |
25053 | ||
25054 | @subsubheading Example | |
25055 | ||
25056 | @smallexample | |
594fe323 | 25057 | (gdb) |
922fbb7b AC |
25058 | -break-condition 1 1 |
25059 | ^done | |
594fe323 | 25060 | (gdb) |
922fbb7b AC |
25061 | -break-list |
25062 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25063 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25064 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25065 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25066 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25067 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25068 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25069 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 NR |
25070 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
25071 | line="5",cond="1",times="0",ignore="3"@}]@} | |
594fe323 | 25072 | (gdb) |
922fbb7b AC |
25073 | @end smallexample |
25074 | ||
25075 | @subheading The @code{-break-delete} Command | |
25076 | @findex -break-delete | |
25077 | ||
25078 | @subsubheading Synopsis | |
25079 | ||
25080 | @smallexample | |
25081 | -break-delete ( @var{breakpoint} )+ | |
25082 | @end smallexample | |
25083 | ||
25084 | Delete the breakpoint(s) whose number(s) are specified in the argument | |
25085 | list. This is obviously reflected in the breakpoint list. | |
25086 | ||
79a6e687 | 25087 | @subsubheading @value{GDBN} Command |
922fbb7b AC |
25088 | |
25089 | The corresponding @value{GDBN} command is @samp{delete}. | |
25090 | ||
25091 | @subsubheading Example | |
25092 | ||
25093 | @smallexample | |
594fe323 | 25094 | (gdb) |
922fbb7b AC |
25095 | -break-delete 1 |
25096 | ^done | |
594fe323 | 25097 | (gdb) |
922fbb7b AC |
25098 | -break-list |
25099 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
25100 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25101 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25102 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25103 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25104 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25105 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25106 | body=[]@} | |
594fe323 | 25107 | (gdb) |
922fbb7b AC |
25108 | @end smallexample |
25109 | ||
25110 | @subheading The @code{-break-disable} Command | |
25111 | @findex -break-disable | |
25112 | ||
25113 | @subsubheading Synopsis | |
25114 | ||
25115 | @smallexample | |
25116 | -break-disable ( @var{breakpoint} )+ | |
25117 | @end smallexample | |
25118 | ||
25119 | Disable the named @var{breakpoint}(s). The field @samp{enabled} in the | |
25120 | break list is now set to @samp{n} for the named @var{breakpoint}(s). | |
25121 | ||
25122 | @subsubheading @value{GDBN} Command | |
25123 | ||
25124 | The corresponding @value{GDBN} command is @samp{disable}. | |
25125 | ||
25126 | @subsubheading Example | |
25127 | ||
25128 | @smallexample | |
594fe323 | 25129 | (gdb) |
922fbb7b AC |
25130 | -break-disable 2 |
25131 | ^done | |
594fe323 | 25132 | (gdb) |
922fbb7b AC |
25133 | -break-list |
25134 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25135 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25136 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25137 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25138 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25139 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25140 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25141 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="n", | |
948d5102 NR |
25142 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
25143 | line="5",times="0"@}]@} | |
594fe323 | 25144 | (gdb) |
922fbb7b AC |
25145 | @end smallexample |
25146 | ||
25147 | @subheading The @code{-break-enable} Command | |
25148 | @findex -break-enable | |
25149 | ||
25150 | @subsubheading Synopsis | |
25151 | ||
25152 | @smallexample | |
25153 | -break-enable ( @var{breakpoint} )+ | |
25154 | @end smallexample | |
25155 | ||
25156 | Enable (previously disabled) @var{breakpoint}(s). | |
25157 | ||
25158 | @subsubheading @value{GDBN} Command | |
25159 | ||
25160 | The corresponding @value{GDBN} command is @samp{enable}. | |
25161 | ||
25162 | @subsubheading Example | |
25163 | ||
25164 | @smallexample | |
594fe323 | 25165 | (gdb) |
922fbb7b AC |
25166 | -break-enable 2 |
25167 | ^done | |
594fe323 | 25168 | (gdb) |
922fbb7b AC |
25169 | -break-list |
25170 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25171 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25172 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25173 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25174 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25175 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25176 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25177 | body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
948d5102 NR |
25178 | addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", |
25179 | line="5",times="0"@}]@} | |
594fe323 | 25180 | (gdb) |
922fbb7b AC |
25181 | @end smallexample |
25182 | ||
25183 | @subheading The @code{-break-info} Command | |
25184 | @findex -break-info | |
25185 | ||
25186 | @subsubheading Synopsis | |
25187 | ||
25188 | @smallexample | |
25189 | -break-info @var{breakpoint} | |
25190 | @end smallexample | |
25191 | ||
25192 | @c REDUNDANT??? | |
25193 | Get information about a single breakpoint. | |
25194 | ||
79a6e687 | 25195 | @subsubheading @value{GDBN} Command |
922fbb7b AC |
25196 | |
25197 | The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}. | |
25198 | ||
25199 | @subsubheading Example | |
25200 | N.A. | |
25201 | ||
25202 | @subheading The @code{-break-insert} Command | |
25203 | @findex -break-insert | |
25204 | ||
25205 | @subsubheading Synopsis | |
25206 | ||
25207 | @smallexample | |
18148017 | 25208 | -break-insert [ -t ] [ -h ] [ -f ] [ -d ] [ -a ] |
922fbb7b | 25209 | [ -c @var{condition} ] [ -i @var{ignore-count} ] |
afe8ab22 | 25210 | [ -p @var{thread} ] [ @var{location} ] |
922fbb7b AC |
25211 | @end smallexample |
25212 | ||
25213 | @noindent | |
afe8ab22 | 25214 | If specified, @var{location}, can be one of: |
922fbb7b AC |
25215 | |
25216 | @itemize @bullet | |
25217 | @item function | |
25218 | @c @item +offset | |
25219 | @c @item -offset | |
25220 | @c @item linenum | |
25221 | @item filename:linenum | |
25222 | @item filename:function | |
25223 | @item *address | |
25224 | @end itemize | |
25225 | ||
25226 | The possible optional parameters of this command are: | |
25227 | ||
25228 | @table @samp | |
25229 | @item -t | |
948d5102 | 25230 | Insert a temporary breakpoint. |
922fbb7b AC |
25231 | @item -h |
25232 | Insert a hardware breakpoint. | |
25233 | @item -c @var{condition} | |
25234 | Make the breakpoint conditional on @var{condition}. | |
25235 | @item -i @var{ignore-count} | |
25236 | Initialize the @var{ignore-count}. | |
afe8ab22 VP |
25237 | @item -f |
25238 | If @var{location} cannot be parsed (for example if it | |
25239 | refers to unknown files or functions), create a pending | |
25240 | breakpoint. Without this flag, @value{GDBN} will report | |
25241 | an error, and won't create a breakpoint, if @var{location} | |
25242 | cannot be parsed. | |
41447f92 VP |
25243 | @item -d |
25244 | Create a disabled breakpoint. | |
18148017 VP |
25245 | @item -a |
25246 | Create a tracepoint. @xref{Tracepoints}. When this parameter | |
25247 | is used together with @samp{-h}, a fast tracepoint is created. | |
922fbb7b AC |
25248 | @end table |
25249 | ||
25250 | @subsubheading Result | |
25251 | ||
25252 | The result is in the form: | |
25253 | ||
25254 | @smallexample | |
948d5102 NR |
25255 | ^done,bkpt=@{number="@var{number}",type="@var{type}",disp="del"|"keep", |
25256 | enabled="y"|"n",addr="@var{hex}",func="@var{funcname}",file="@var{filename}", | |
ef21caaf NR |
25257 | fullname="@var{full_filename}",line="@var{lineno}",[thread="@var{threadno},] |
25258 | times="@var{times}"@} | |
922fbb7b AC |
25259 | @end smallexample |
25260 | ||
25261 | @noindent | |
948d5102 NR |
25262 | where @var{number} is the @value{GDBN} number for this breakpoint, |
25263 | @var{funcname} is the name of the function where the breakpoint was | |
25264 | inserted, @var{filename} is the name of the source file which contains | |
25265 | this function, @var{lineno} is the source line number within that file | |
25266 | and @var{times} the number of times that the breakpoint has been hit | |
25267 | (always 0 for -break-insert but may be greater for -break-info or -break-list | |
25268 | which use the same output). | |
922fbb7b AC |
25269 | |
25270 | Note: this format is open to change. | |
25271 | @c An out-of-band breakpoint instead of part of the result? | |
25272 | ||
25273 | @subsubheading @value{GDBN} Command | |
25274 | ||
25275 | The corresponding @value{GDBN} commands are @samp{break}, @samp{tbreak}, | |
25276 | @samp{hbreak}, @samp{thbreak}, and @samp{rbreak}. | |
25277 | ||
25278 | @subsubheading Example | |
25279 | ||
25280 | @smallexample | |
594fe323 | 25281 | (gdb) |
922fbb7b | 25282 | -break-insert main |
948d5102 NR |
25283 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c", |
25284 | fullname="/home/foo/recursive2.c,line="4",times="0"@} | |
594fe323 | 25285 | (gdb) |
922fbb7b | 25286 | -break-insert -t foo |
948d5102 NR |
25287 | ^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c", |
25288 | fullname="/home/foo/recursive2.c,line="11",times="0"@} | |
594fe323 | 25289 | (gdb) |
922fbb7b AC |
25290 | -break-list |
25291 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
25292 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25293 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25294 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25295 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25296 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25297 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25298 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
948d5102 NR |
25299 | addr="0x0001072c", func="main",file="recursive2.c", |
25300 | fullname="/home/foo/recursive2.c,"line="4",times="0"@}, | |
922fbb7b | 25301 | bkpt=@{number="2",type="breakpoint",disp="del",enabled="y", |
948d5102 NR |
25302 | addr="0x00010774",func="foo",file="recursive2.c", |
25303 | fullname="/home/foo/recursive2.c",line="11",times="0"@}]@} | |
594fe323 | 25304 | (gdb) |
922fbb7b AC |
25305 | -break-insert -r foo.* |
25306 | ~int foo(int, int); | |
948d5102 NR |
25307 | ^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c, |
25308 | "fullname="/home/foo/recursive2.c",line="11",times="0"@} | |
594fe323 | 25309 | (gdb) |
922fbb7b AC |
25310 | @end smallexample |
25311 | ||
25312 | @subheading The @code{-break-list} Command | |
25313 | @findex -break-list | |
25314 | ||
25315 | @subsubheading Synopsis | |
25316 | ||
25317 | @smallexample | |
25318 | -break-list | |
25319 | @end smallexample | |
25320 | ||
25321 | Displays the list of inserted breakpoints, showing the following fields: | |
25322 | ||
25323 | @table @samp | |
25324 | @item Number | |
25325 | number of the breakpoint | |
25326 | @item Type | |
25327 | type of the breakpoint: @samp{breakpoint} or @samp{watchpoint} | |
25328 | @item Disposition | |
25329 | should the breakpoint be deleted or disabled when it is hit: @samp{keep} | |
25330 | or @samp{nokeep} | |
25331 | @item Enabled | |
25332 | is the breakpoint enabled or no: @samp{y} or @samp{n} | |
25333 | @item Address | |
25334 | memory location at which the breakpoint is set | |
25335 | @item What | |
25336 | logical location of the breakpoint, expressed by function name, file | |
25337 | name, line number | |
25338 | @item Times | |
25339 | number of times the breakpoint has been hit | |
25340 | @end table | |
25341 | ||
25342 | If there are no breakpoints or watchpoints, the @code{BreakpointTable} | |
25343 | @code{body} field is an empty list. | |
25344 | ||
25345 | @subsubheading @value{GDBN} Command | |
25346 | ||
25347 | The corresponding @value{GDBN} command is @samp{info break}. | |
25348 | ||
25349 | @subsubheading Example | |
25350 | ||
25351 | @smallexample | |
594fe323 | 25352 | (gdb) |
922fbb7b AC |
25353 | -break-list |
25354 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
25355 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25356 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25357 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25358 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25359 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25360 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25361 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
25362 | addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}, | |
25363 | bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y", | |
948d5102 NR |
25364 | addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c", |
25365 | line="13",times="0"@}]@} | |
594fe323 | 25366 | (gdb) |
922fbb7b AC |
25367 | @end smallexample |
25368 | ||
25369 | Here's an example of the result when there are no breakpoints: | |
25370 | ||
25371 | @smallexample | |
594fe323 | 25372 | (gdb) |
922fbb7b AC |
25373 | -break-list |
25374 | ^done,BreakpointTable=@{nr_rows="0",nr_cols="6", | |
25375 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25376 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25377 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25378 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25379 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25380 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25381 | body=[]@} | |
594fe323 | 25382 | (gdb) |
922fbb7b AC |
25383 | @end smallexample |
25384 | ||
18148017 VP |
25385 | @subheading The @code{-break-passcount} Command |
25386 | @findex -break-passcount | |
25387 | ||
25388 | @subsubheading Synopsis | |
25389 | ||
25390 | @smallexample | |
25391 | -break-passcount @var{tracepoint-number} @var{passcount} | |
25392 | @end smallexample | |
25393 | ||
25394 | Set the passcount for tracepoint @var{tracepoint-number} to | |
25395 | @var{passcount}. If the breakpoint referred to by @var{tracepoint-number} | |
25396 | is not a tracepoint, error is emitted. This corresponds to CLI | |
25397 | command @samp{passcount}. | |
25398 | ||
922fbb7b AC |
25399 | @subheading The @code{-break-watch} Command |
25400 | @findex -break-watch | |
25401 | ||
25402 | @subsubheading Synopsis | |
25403 | ||
25404 | @smallexample | |
25405 | -break-watch [ -a | -r ] | |
25406 | @end smallexample | |
25407 | ||
25408 | Create a watchpoint. With the @samp{-a} option it will create an | |
d3e8051b | 25409 | @dfn{access} watchpoint, i.e., a watchpoint that triggers either on a |
922fbb7b | 25410 | read from or on a write to the memory location. With the @samp{-r} |
d3e8051b | 25411 | option, the watchpoint created is a @dfn{read} watchpoint, i.e., it will |
922fbb7b AC |
25412 | trigger only when the memory location is accessed for reading. Without |
25413 | either of the options, the watchpoint created is a regular watchpoint, | |
d3e8051b | 25414 | i.e., it will trigger when the memory location is accessed for writing. |
79a6e687 | 25415 | @xref{Set Watchpoints, , Setting Watchpoints}. |
922fbb7b AC |
25416 | |
25417 | Note that @samp{-break-list} will report a single list of watchpoints and | |
25418 | breakpoints inserted. | |
25419 | ||
25420 | @subsubheading @value{GDBN} Command | |
25421 | ||
25422 | The corresponding @value{GDBN} commands are @samp{watch}, @samp{awatch}, and | |
25423 | @samp{rwatch}. | |
25424 | ||
25425 | @subsubheading Example | |
25426 | ||
25427 | Setting a watchpoint on a variable in the @code{main} function: | |
25428 | ||
25429 | @smallexample | |
594fe323 | 25430 | (gdb) |
922fbb7b AC |
25431 | -break-watch x |
25432 | ^done,wpt=@{number="2",exp="x"@} | |
594fe323 | 25433 | (gdb) |
922fbb7b AC |
25434 | -exec-continue |
25435 | ^running | |
0869d01b NR |
25436 | (gdb) |
25437 | *stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@}, | |
922fbb7b | 25438 | value=@{old="-268439212",new="55"@}, |
76ff342d | 25439 | frame=@{func="main",args=[],file="recursive2.c", |
948d5102 | 25440 | fullname="/home/foo/bar/recursive2.c",line="5"@} |
594fe323 | 25441 | (gdb) |
922fbb7b AC |
25442 | @end smallexample |
25443 | ||
25444 | Setting a watchpoint on a variable local to a function. @value{GDBN} will stop | |
25445 | the program execution twice: first for the variable changing value, then | |
25446 | for the watchpoint going out of scope. | |
25447 | ||
25448 | @smallexample | |
594fe323 | 25449 | (gdb) |
922fbb7b AC |
25450 | -break-watch C |
25451 | ^done,wpt=@{number="5",exp="C"@} | |
594fe323 | 25452 | (gdb) |
922fbb7b AC |
25453 | -exec-continue |
25454 | ^running | |
0869d01b NR |
25455 | (gdb) |
25456 | *stopped,reason="watchpoint-trigger", | |
922fbb7b AC |
25457 | wpt=@{number="5",exp="C"@},value=@{old="-276895068",new="3"@}, |
25458 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
25459 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25460 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
594fe323 | 25461 | (gdb) |
922fbb7b AC |
25462 | -exec-continue |
25463 | ^running | |
0869d01b NR |
25464 | (gdb) |
25465 | *stopped,reason="watchpoint-scope",wpnum="5", | |
922fbb7b AC |
25466 | frame=@{func="callee3",args=[@{name="strarg", |
25467 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
25468 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25469 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 25470 | (gdb) |
922fbb7b AC |
25471 | @end smallexample |
25472 | ||
25473 | Listing breakpoints and watchpoints, at different points in the program | |
25474 | execution. Note that once the watchpoint goes out of scope, it is | |
25475 | deleted. | |
25476 | ||
25477 | @smallexample | |
594fe323 | 25478 | (gdb) |
922fbb7b AC |
25479 | -break-watch C |
25480 | ^done,wpt=@{number="2",exp="C"@} | |
594fe323 | 25481 | (gdb) |
922fbb7b AC |
25482 | -break-list |
25483 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
25484 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25485 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25486 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25487 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25488 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25489 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25490 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
25491 | addr="0x00010734",func="callee4", | |
948d5102 NR |
25492 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25493 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",times="1"@}, | |
922fbb7b AC |
25494 | bkpt=@{number="2",type="watchpoint",disp="keep", |
25495 | enabled="y",addr="",what="C",times="0"@}]@} | |
594fe323 | 25496 | (gdb) |
922fbb7b AC |
25497 | -exec-continue |
25498 | ^running | |
0869d01b NR |
25499 | (gdb) |
25500 | *stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@}, | |
922fbb7b AC |
25501 | value=@{old="-276895068",new="3"@}, |
25502 | frame=@{func="callee4",args=[], | |
76ff342d DJ |
25503 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25504 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"@} | |
594fe323 | 25505 | (gdb) |
922fbb7b AC |
25506 | -break-list |
25507 | ^done,BreakpointTable=@{nr_rows="2",nr_cols="6", | |
25508 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25509 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25510 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25511 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25512 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25513 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25514 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
25515 | addr="0x00010734",func="callee4", | |
948d5102 NR |
25516 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25517 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}, | |
922fbb7b AC |
25518 | bkpt=@{number="2",type="watchpoint",disp="keep", |
25519 | enabled="y",addr="",what="C",times="-5"@}]@} | |
594fe323 | 25520 | (gdb) |
922fbb7b AC |
25521 | -exec-continue |
25522 | ^running | |
25523 | ^done,reason="watchpoint-scope",wpnum="2", | |
25524 | frame=@{func="callee3",args=[@{name="strarg", | |
25525 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
25526 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25527 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 25528 | (gdb) |
922fbb7b AC |
25529 | -break-list |
25530 | ^done,BreakpointTable=@{nr_rows="1",nr_cols="6", | |
25531 | hdr=[@{width="3",alignment="-1",col_name="number",colhdr="Num"@}, | |
25532 | @{width="14",alignment="-1",col_name="type",colhdr="Type"@}, | |
25533 | @{width="4",alignment="-1",col_name="disp",colhdr="Disp"@}, | |
25534 | @{width="3",alignment="-1",col_name="enabled",colhdr="Enb"@}, | |
25535 | @{width="10",alignment="-1",col_name="addr",colhdr="Address"@}, | |
25536 | @{width="40",alignment="2",col_name="what",colhdr="What"@}], | |
25537 | body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
25538 | addr="0x00010734",func="callee4", | |
948d5102 NR |
25539 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
25540 | fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8", | |
25541 | times="1"@}]@} | |
594fe323 | 25542 | (gdb) |
922fbb7b AC |
25543 | @end smallexample |
25544 | ||
25545 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
a2c02241 NR |
25546 | @node GDB/MI Program Context |
25547 | @section @sc{gdb/mi} Program Context | |
922fbb7b | 25548 | |
a2c02241 NR |
25549 | @subheading The @code{-exec-arguments} Command |
25550 | @findex -exec-arguments | |
922fbb7b | 25551 | |
922fbb7b AC |
25552 | |
25553 | @subsubheading Synopsis | |
25554 | ||
25555 | @smallexample | |
a2c02241 | 25556 | -exec-arguments @var{args} |
922fbb7b AC |
25557 | @end smallexample |
25558 | ||
a2c02241 NR |
25559 | Set the inferior program arguments, to be used in the next |
25560 | @samp{-exec-run}. | |
922fbb7b | 25561 | |
a2c02241 | 25562 | @subsubheading @value{GDBN} Command |
922fbb7b | 25563 | |
a2c02241 | 25564 | The corresponding @value{GDBN} command is @samp{set args}. |
922fbb7b | 25565 | |
a2c02241 | 25566 | @subsubheading Example |
922fbb7b | 25567 | |
fbc5282e MK |
25568 | @smallexample |
25569 | (gdb) | |
25570 | -exec-arguments -v word | |
25571 | ^done | |
25572 | (gdb) | |
25573 | @end smallexample | |
922fbb7b | 25574 | |
a2c02241 | 25575 | |
9901a55b | 25576 | @ignore |
a2c02241 NR |
25577 | @subheading The @code{-exec-show-arguments} Command |
25578 | @findex -exec-show-arguments | |
25579 | ||
25580 | @subsubheading Synopsis | |
25581 | ||
25582 | @smallexample | |
25583 | -exec-show-arguments | |
25584 | @end smallexample | |
25585 | ||
25586 | Print the arguments of the program. | |
922fbb7b AC |
25587 | |
25588 | @subsubheading @value{GDBN} Command | |
25589 | ||
a2c02241 | 25590 | The corresponding @value{GDBN} command is @samp{show args}. |
922fbb7b AC |
25591 | |
25592 | @subsubheading Example | |
a2c02241 | 25593 | N.A. |
9901a55b | 25594 | @end ignore |
922fbb7b | 25595 | |
922fbb7b | 25596 | |
a2c02241 NR |
25597 | @subheading The @code{-environment-cd} Command |
25598 | @findex -environment-cd | |
922fbb7b | 25599 | |
a2c02241 | 25600 | @subsubheading Synopsis |
922fbb7b AC |
25601 | |
25602 | @smallexample | |
a2c02241 | 25603 | -environment-cd @var{pathdir} |
922fbb7b AC |
25604 | @end smallexample |
25605 | ||
a2c02241 | 25606 | Set @value{GDBN}'s working directory. |
922fbb7b | 25607 | |
a2c02241 | 25608 | @subsubheading @value{GDBN} Command |
922fbb7b | 25609 | |
a2c02241 NR |
25610 | The corresponding @value{GDBN} command is @samp{cd}. |
25611 | ||
25612 | @subsubheading Example | |
922fbb7b AC |
25613 | |
25614 | @smallexample | |
594fe323 | 25615 | (gdb) |
a2c02241 NR |
25616 | -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb |
25617 | ^done | |
594fe323 | 25618 | (gdb) |
922fbb7b AC |
25619 | @end smallexample |
25620 | ||
25621 | ||
a2c02241 NR |
25622 | @subheading The @code{-environment-directory} Command |
25623 | @findex -environment-directory | |
922fbb7b AC |
25624 | |
25625 | @subsubheading Synopsis | |
25626 | ||
25627 | @smallexample | |
a2c02241 | 25628 | -environment-directory [ -r ] [ @var{pathdir} ]+ |
922fbb7b AC |
25629 | @end smallexample |
25630 | ||
a2c02241 NR |
25631 | Add directories @var{pathdir} to beginning of search path for source files. |
25632 | If the @samp{-r} option is used, the search path is reset to the default | |
25633 | search path. If directories @var{pathdir} are supplied in addition to the | |
25634 | @samp{-r} option, the search path is first reset and then addition | |
25635 | occurs as normal. | |
25636 | Multiple directories may be specified, separated by blanks. Specifying | |
25637 | multiple directories in a single command | |
25638 | results in the directories added to the beginning of the | |
25639 | search path in the same order they were presented in the command. | |
25640 | If blanks are needed as | |
25641 | part of a directory name, double-quotes should be used around | |
25642 | the name. In the command output, the path will show up separated | |
d3e8051b | 25643 | by the system directory-separator character. The directory-separator |
a2c02241 NR |
25644 | character must not be used |
25645 | in any directory name. | |
25646 | If no directories are specified, the current search path is displayed. | |
922fbb7b AC |
25647 | |
25648 | @subsubheading @value{GDBN} Command | |
25649 | ||
a2c02241 | 25650 | The corresponding @value{GDBN} command is @samp{dir}. |
922fbb7b AC |
25651 | |
25652 | @subsubheading Example | |
25653 | ||
922fbb7b | 25654 | @smallexample |
594fe323 | 25655 | (gdb) |
a2c02241 NR |
25656 | -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb |
25657 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
594fe323 | 25658 | (gdb) |
a2c02241 NR |
25659 | -environment-directory "" |
25660 | ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" | |
594fe323 | 25661 | (gdb) |
a2c02241 NR |
25662 | -environment-directory -r /home/jjohnstn/src/gdb /usr/src |
25663 | ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" | |
594fe323 | 25664 | (gdb) |
a2c02241 NR |
25665 | -environment-directory -r |
25666 | ^done,source-path="$cdir:$cwd" | |
594fe323 | 25667 | (gdb) |
922fbb7b AC |
25668 | @end smallexample |
25669 | ||
25670 | ||
a2c02241 NR |
25671 | @subheading The @code{-environment-path} Command |
25672 | @findex -environment-path | |
922fbb7b AC |
25673 | |
25674 | @subsubheading Synopsis | |
25675 | ||
25676 | @smallexample | |
a2c02241 | 25677 | -environment-path [ -r ] [ @var{pathdir} ]+ |
922fbb7b AC |
25678 | @end smallexample |
25679 | ||
a2c02241 NR |
25680 | Add directories @var{pathdir} to beginning of search path for object files. |
25681 | If the @samp{-r} option is used, the search path is reset to the original | |
25682 | search path that existed at gdb start-up. If directories @var{pathdir} are | |
25683 | supplied in addition to the | |
25684 | @samp{-r} option, the search path is first reset and then addition | |
25685 | occurs as normal. | |
25686 | Multiple directories may be specified, separated by blanks. Specifying | |
25687 | multiple directories in a single command | |
25688 | results in the directories added to the beginning of the | |
25689 | search path in the same order they were presented in the command. | |
25690 | If blanks are needed as | |
25691 | part of a directory name, double-quotes should be used around | |
25692 | the name. In the command output, the path will show up separated | |
d3e8051b | 25693 | by the system directory-separator character. The directory-separator |
a2c02241 NR |
25694 | character must not be used |
25695 | in any directory name. | |
25696 | If no directories are specified, the current path is displayed. | |
25697 | ||
922fbb7b AC |
25698 | |
25699 | @subsubheading @value{GDBN} Command | |
25700 | ||
a2c02241 | 25701 | The corresponding @value{GDBN} command is @samp{path}. |
922fbb7b AC |
25702 | |
25703 | @subsubheading Example | |
25704 | ||
922fbb7b | 25705 | @smallexample |
594fe323 | 25706 | (gdb) |
a2c02241 NR |
25707 | -environment-path |
25708 | ^done,path="/usr/bin" | |
594fe323 | 25709 | (gdb) |
a2c02241 NR |
25710 | -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin |
25711 | ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" | |
594fe323 | 25712 | (gdb) |
a2c02241 NR |
25713 | -environment-path -r /usr/local/bin |
25714 | ^done,path="/usr/local/bin:/usr/bin" | |
594fe323 | 25715 | (gdb) |
922fbb7b AC |
25716 | @end smallexample |
25717 | ||
25718 | ||
a2c02241 NR |
25719 | @subheading The @code{-environment-pwd} Command |
25720 | @findex -environment-pwd | |
922fbb7b AC |
25721 | |
25722 | @subsubheading Synopsis | |
25723 | ||
25724 | @smallexample | |
a2c02241 | 25725 | -environment-pwd |
922fbb7b AC |
25726 | @end smallexample |
25727 | ||
a2c02241 | 25728 | Show the current working directory. |
922fbb7b | 25729 | |
79a6e687 | 25730 | @subsubheading @value{GDBN} Command |
922fbb7b | 25731 | |
a2c02241 | 25732 | The corresponding @value{GDBN} command is @samp{pwd}. |
922fbb7b AC |
25733 | |
25734 | @subsubheading Example | |
25735 | ||
922fbb7b | 25736 | @smallexample |
594fe323 | 25737 | (gdb) |
a2c02241 NR |
25738 | -environment-pwd |
25739 | ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" | |
594fe323 | 25740 | (gdb) |
922fbb7b AC |
25741 | @end smallexample |
25742 | ||
a2c02241 NR |
25743 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25744 | @node GDB/MI Thread Commands | |
25745 | @section @sc{gdb/mi} Thread Commands | |
25746 | ||
25747 | ||
25748 | @subheading The @code{-thread-info} Command | |
25749 | @findex -thread-info | |
922fbb7b AC |
25750 | |
25751 | @subsubheading Synopsis | |
25752 | ||
25753 | @smallexample | |
8e8901c5 | 25754 | -thread-info [ @var{thread-id} ] |
922fbb7b AC |
25755 | @end smallexample |
25756 | ||
8e8901c5 VP |
25757 | Reports information about either a specific thread, if |
25758 | the @var{thread-id} parameter is present, or about all | |
25759 | threads. When printing information about all threads, | |
25760 | also reports the current thread. | |
25761 | ||
79a6e687 | 25762 | @subsubheading @value{GDBN} Command |
922fbb7b | 25763 | |
8e8901c5 VP |
25764 | The @samp{info thread} command prints the same information |
25765 | about all threads. | |
922fbb7b AC |
25766 | |
25767 | @subsubheading Example | |
922fbb7b AC |
25768 | |
25769 | @smallexample | |
8e8901c5 VP |
25770 | -thread-info |
25771 | ^done,threads=[ | |
25772 | @{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", | |
c3b108f7 | 25773 | frame=@{level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]@},state="running"@}, |
8e8901c5 VP |
25774 | @{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", |
25775 | frame=@{level="0",addr="0x0804891f",func="foo",args=[@{name="i",value="10"@}], | |
c3b108f7 | 25776 | file="/tmp/a.c",fullname="/tmp/a.c",line="158"@},state="running"@}], |
8e8901c5 VP |
25777 | current-thread-id="1" |
25778 | (gdb) | |
922fbb7b AC |
25779 | @end smallexample |
25780 | ||
c3b108f7 VP |
25781 | The @samp{state} field may have the following values: |
25782 | ||
25783 | @table @code | |
25784 | @item stopped | |
25785 | The thread is stopped. Frame information is available for stopped | |
25786 | threads. | |
25787 | ||
25788 | @item running | |
25789 | The thread is running. There's no frame information for running | |
25790 | threads. | |
25791 | ||
25792 | @end table | |
25793 | ||
a2c02241 NR |
25794 | @subheading The @code{-thread-list-ids} Command |
25795 | @findex -thread-list-ids | |
922fbb7b | 25796 | |
a2c02241 | 25797 | @subsubheading Synopsis |
922fbb7b | 25798 | |
a2c02241 NR |
25799 | @smallexample |
25800 | -thread-list-ids | |
25801 | @end smallexample | |
922fbb7b | 25802 | |
a2c02241 NR |
25803 | Produces a list of the currently known @value{GDBN} thread ids. At the |
25804 | end of the list it also prints the total number of such threads. | |
922fbb7b | 25805 | |
c3b108f7 VP |
25806 | This command is retained for historical reasons, the |
25807 | @code{-thread-info} command should be used instead. | |
25808 | ||
922fbb7b AC |
25809 | @subsubheading @value{GDBN} Command |
25810 | ||
a2c02241 | 25811 | Part of @samp{info threads} supplies the same information. |
922fbb7b AC |
25812 | |
25813 | @subsubheading Example | |
25814 | ||
922fbb7b | 25815 | @smallexample |
594fe323 | 25816 | (gdb) |
a2c02241 NR |
25817 | -thread-list-ids |
25818 | ^done,thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
592375cd | 25819 | current-thread-id="1",number-of-threads="3" |
594fe323 | 25820 | (gdb) |
922fbb7b AC |
25821 | @end smallexample |
25822 | ||
a2c02241 NR |
25823 | |
25824 | @subheading The @code{-thread-select} Command | |
25825 | @findex -thread-select | |
922fbb7b AC |
25826 | |
25827 | @subsubheading Synopsis | |
25828 | ||
25829 | @smallexample | |
a2c02241 | 25830 | -thread-select @var{threadnum} |
922fbb7b AC |
25831 | @end smallexample |
25832 | ||
a2c02241 NR |
25833 | Make @var{threadnum} the current thread. It prints the number of the new |
25834 | current thread, and the topmost frame for that thread. | |
922fbb7b | 25835 | |
c3b108f7 VP |
25836 | This command is deprecated in favor of explicitly using the |
25837 | @samp{--thread} option to each command. | |
25838 | ||
922fbb7b AC |
25839 | @subsubheading @value{GDBN} Command |
25840 | ||
a2c02241 | 25841 | The corresponding @value{GDBN} command is @samp{thread}. |
922fbb7b AC |
25842 | |
25843 | @subsubheading Example | |
922fbb7b AC |
25844 | |
25845 | @smallexample | |
594fe323 | 25846 | (gdb) |
a2c02241 NR |
25847 | -exec-next |
25848 | ^running | |
594fe323 | 25849 | (gdb) |
a2c02241 NR |
25850 | *stopped,reason="end-stepping-range",thread-id="2",line="187", |
25851 | file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c" | |
594fe323 | 25852 | (gdb) |
a2c02241 NR |
25853 | -thread-list-ids |
25854 | ^done, | |
25855 | thread-ids=@{thread-id="3",thread-id="2",thread-id="1"@}, | |
25856 | number-of-threads="3" | |
594fe323 | 25857 | (gdb) |
a2c02241 NR |
25858 | -thread-select 3 |
25859 | ^done,new-thread-id="3", | |
25860 | frame=@{level="0",func="vprintf", | |
25861 | args=[@{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""@}, | |
25862 | @{name="arg",value="0x2"@}],file="vprintf.c",line="31"@} | |
594fe323 | 25863 | (gdb) |
922fbb7b AC |
25864 | @end smallexample |
25865 | ||
a2c02241 NR |
25866 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
25867 | @node GDB/MI Program Execution | |
25868 | @section @sc{gdb/mi} Program Execution | |
922fbb7b | 25869 | |
ef21caaf | 25870 | These are the asynchronous commands which generate the out-of-band |
3f94c067 | 25871 | record @samp{*stopped}. Currently @value{GDBN} only really executes |
ef21caaf NR |
25872 | asynchronously with remote targets and this interaction is mimicked in |
25873 | other cases. | |
922fbb7b | 25874 | |
922fbb7b AC |
25875 | @subheading The @code{-exec-continue} Command |
25876 | @findex -exec-continue | |
25877 | ||
25878 | @subsubheading Synopsis | |
25879 | ||
25880 | @smallexample | |
540aa8e7 | 25881 | -exec-continue [--reverse] [--all|--thread-group N] |
922fbb7b AC |
25882 | @end smallexample |
25883 | ||
540aa8e7 MS |
25884 | Resumes the execution of the inferior program, which will continue |
25885 | to execute until it reaches a debugger stop event. If the | |
25886 | @samp{--reverse} option is specified, execution resumes in reverse until | |
25887 | it reaches a stop event. Stop events may include | |
25888 | @itemize @bullet | |
25889 | @item | |
25890 | breakpoints or watchpoints | |
25891 | @item | |
25892 | signals or exceptions | |
25893 | @item | |
25894 | the end of the process (or its beginning under @samp{--reverse}) | |
25895 | @item | |
25896 | the end or beginning of a replay log if one is being used. | |
25897 | @end itemize | |
25898 | In all-stop mode (@pxref{All-Stop | |
25899 | Mode}), may resume only one thread, or all threads, depending on the | |
25900 | value of the @samp{scheduler-locking} variable. If @samp{--all} is | |
a79b8f6e | 25901 | specified, all threads (in all inferiors) will be resumed. The @samp{--all} option is |
540aa8e7 MS |
25902 | ignored in all-stop mode. If the @samp{--thread-group} options is |
25903 | specified, then all threads in that thread group are resumed. | |
922fbb7b AC |
25904 | |
25905 | @subsubheading @value{GDBN} Command | |
25906 | ||
25907 | The corresponding @value{GDBN} corresponding is @samp{continue}. | |
25908 | ||
25909 | @subsubheading Example | |
25910 | ||
25911 | @smallexample | |
25912 | -exec-continue | |
25913 | ^running | |
594fe323 | 25914 | (gdb) |
922fbb7b | 25915 | @@Hello world |
a47ec5fe AR |
25916 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",frame=@{ |
25917 | func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c", | |
25918 | line="13"@} | |
594fe323 | 25919 | (gdb) |
922fbb7b AC |
25920 | @end smallexample |
25921 | ||
25922 | ||
25923 | @subheading The @code{-exec-finish} Command | |
25924 | @findex -exec-finish | |
25925 | ||
25926 | @subsubheading Synopsis | |
25927 | ||
25928 | @smallexample | |
540aa8e7 | 25929 | -exec-finish [--reverse] |
922fbb7b AC |
25930 | @end smallexample |
25931 | ||
ef21caaf NR |
25932 | Resumes the execution of the inferior program until the current |
25933 | function is exited. Displays the results returned by the function. | |
540aa8e7 MS |
25934 | If the @samp{--reverse} option is specified, resumes the reverse |
25935 | execution of the inferior program until the point where current | |
25936 | function was called. | |
922fbb7b AC |
25937 | |
25938 | @subsubheading @value{GDBN} Command | |
25939 | ||
25940 | The corresponding @value{GDBN} command is @samp{finish}. | |
25941 | ||
25942 | @subsubheading Example | |
25943 | ||
25944 | Function returning @code{void}. | |
25945 | ||
25946 | @smallexample | |
25947 | -exec-finish | |
25948 | ^running | |
594fe323 | 25949 | (gdb) |
922fbb7b AC |
25950 | @@hello from foo |
25951 | *stopped,reason="function-finished",frame=@{func="main",args=[], | |
948d5102 | 25952 | file="hello.c",fullname="/home/foo/bar/hello.c",line="7"@} |
594fe323 | 25953 | (gdb) |
922fbb7b AC |
25954 | @end smallexample |
25955 | ||
25956 | Function returning other than @code{void}. The name of the internal | |
25957 | @value{GDBN} variable storing the result is printed, together with the | |
25958 | value itself. | |
25959 | ||
25960 | @smallexample | |
25961 | -exec-finish | |
25962 | ^running | |
594fe323 | 25963 | (gdb) |
922fbb7b AC |
25964 | *stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo", |
25965 | args=[@{name="a",value="1"],@{name="b",value="9"@}@}, | |
948d5102 | 25966 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, |
922fbb7b | 25967 | gdb-result-var="$1",return-value="0" |
594fe323 | 25968 | (gdb) |
922fbb7b AC |
25969 | @end smallexample |
25970 | ||
25971 | ||
25972 | @subheading The @code{-exec-interrupt} Command | |
25973 | @findex -exec-interrupt | |
25974 | ||
25975 | @subsubheading Synopsis | |
25976 | ||
25977 | @smallexample | |
c3b108f7 | 25978 | -exec-interrupt [--all|--thread-group N] |
922fbb7b AC |
25979 | @end smallexample |
25980 | ||
ef21caaf NR |
25981 | Interrupts the background execution of the target. Note how the token |
25982 | associated with the stop message is the one for the execution command | |
25983 | that has been interrupted. The token for the interrupt itself only | |
25984 | appears in the @samp{^done} output. If the user is trying to | |
922fbb7b AC |
25985 | interrupt a non-running program, an error message will be printed. |
25986 | ||
c3b108f7 VP |
25987 | Note that when asynchronous execution is enabled, this command is |
25988 | asynchronous just like other execution commands. That is, first the | |
25989 | @samp{^done} response will be printed, and the target stop will be | |
25990 | reported after that using the @samp{*stopped} notification. | |
25991 | ||
25992 | In non-stop mode, only the context thread is interrupted by default. | |
a79b8f6e VP |
25993 | All threads (in all inferiors) will be interrupted if the |
25994 | @samp{--all} option is specified. If the @samp{--thread-group} | |
25995 | option is specified, all threads in that group will be interrupted. | |
c3b108f7 | 25996 | |
922fbb7b AC |
25997 | @subsubheading @value{GDBN} Command |
25998 | ||
25999 | The corresponding @value{GDBN} command is @samp{interrupt}. | |
26000 | ||
26001 | @subsubheading Example | |
26002 | ||
26003 | @smallexample | |
594fe323 | 26004 | (gdb) |
922fbb7b AC |
26005 | 111-exec-continue |
26006 | 111^running | |
26007 | ||
594fe323 | 26008 | (gdb) |
922fbb7b AC |
26009 | 222-exec-interrupt |
26010 | 222^done | |
594fe323 | 26011 | (gdb) |
922fbb7b | 26012 | 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt", |
76ff342d | 26013 | frame=@{addr="0x00010140",func="foo",args=[],file="try.c", |
948d5102 | 26014 | fullname="/home/foo/bar/try.c",line="13"@} |
594fe323 | 26015 | (gdb) |
922fbb7b | 26016 | |
594fe323 | 26017 | (gdb) |
922fbb7b AC |
26018 | -exec-interrupt |
26019 | ^error,msg="mi_cmd_exec_interrupt: Inferior not executing." | |
594fe323 | 26020 | (gdb) |
922fbb7b AC |
26021 | @end smallexample |
26022 | ||
83eba9b7 VP |
26023 | @subheading The @code{-exec-jump} Command |
26024 | @findex -exec-jump | |
26025 | ||
26026 | @subsubheading Synopsis | |
26027 | ||
26028 | @smallexample | |
26029 | -exec-jump @var{location} | |
26030 | @end smallexample | |
26031 | ||
26032 | Resumes execution of the inferior program at the location specified by | |
26033 | parameter. @xref{Specify Location}, for a description of the | |
26034 | different forms of @var{location}. | |
26035 | ||
26036 | @subsubheading @value{GDBN} Command | |
26037 | ||
26038 | The corresponding @value{GDBN} command is @samp{jump}. | |
26039 | ||
26040 | @subsubheading Example | |
26041 | ||
26042 | @smallexample | |
26043 | -exec-jump foo.c:10 | |
26044 | *running,thread-id="all" | |
26045 | ^running | |
26046 | @end smallexample | |
26047 | ||
922fbb7b AC |
26048 | |
26049 | @subheading The @code{-exec-next} Command | |
26050 | @findex -exec-next | |
26051 | ||
26052 | @subsubheading Synopsis | |
26053 | ||
26054 | @smallexample | |
540aa8e7 | 26055 | -exec-next [--reverse] |
922fbb7b AC |
26056 | @end smallexample |
26057 | ||
ef21caaf NR |
26058 | Resumes execution of the inferior program, stopping when the beginning |
26059 | of the next source line is reached. | |
922fbb7b | 26060 | |
540aa8e7 MS |
26061 | If the @samp{--reverse} option is specified, resumes reverse execution |
26062 | of the inferior program, stopping at the beginning of the previous | |
26063 | source line. If you issue this command on the first line of a | |
26064 | function, it will take you back to the caller of that function, to the | |
26065 | source line where the function was called. | |
26066 | ||
26067 | ||
922fbb7b AC |
26068 | @subsubheading @value{GDBN} Command |
26069 | ||
26070 | The corresponding @value{GDBN} command is @samp{next}. | |
26071 | ||
26072 | @subsubheading Example | |
26073 | ||
26074 | @smallexample | |
26075 | -exec-next | |
26076 | ^running | |
594fe323 | 26077 | (gdb) |
922fbb7b | 26078 | *stopped,reason="end-stepping-range",line="8",file="hello.c" |
594fe323 | 26079 | (gdb) |
922fbb7b AC |
26080 | @end smallexample |
26081 | ||
26082 | ||
26083 | @subheading The @code{-exec-next-instruction} Command | |
26084 | @findex -exec-next-instruction | |
26085 | ||
26086 | @subsubheading Synopsis | |
26087 | ||
26088 | @smallexample | |
540aa8e7 | 26089 | -exec-next-instruction [--reverse] |
922fbb7b AC |
26090 | @end smallexample |
26091 | ||
ef21caaf NR |
26092 | Executes one machine instruction. If the instruction is a function |
26093 | call, continues until the function returns. If the program stops at an | |
26094 | instruction in the middle of a source line, the address will be | |
26095 | printed as well. | |
922fbb7b | 26096 | |
540aa8e7 MS |
26097 | If the @samp{--reverse} option is specified, resumes reverse execution |
26098 | of the inferior program, stopping at the previous instruction. If the | |
26099 | previously executed instruction was a return from another function, | |
26100 | it will continue to execute in reverse until the call to that function | |
26101 | (from the current stack frame) is reached. | |
26102 | ||
922fbb7b AC |
26103 | @subsubheading @value{GDBN} Command |
26104 | ||
26105 | The corresponding @value{GDBN} command is @samp{nexti}. | |
26106 | ||
26107 | @subsubheading Example | |
26108 | ||
26109 | @smallexample | |
594fe323 | 26110 | (gdb) |
922fbb7b AC |
26111 | -exec-next-instruction |
26112 | ^running | |
26113 | ||
594fe323 | 26114 | (gdb) |
922fbb7b AC |
26115 | *stopped,reason="end-stepping-range", |
26116 | addr="0x000100d4",line="5",file="hello.c" | |
594fe323 | 26117 | (gdb) |
922fbb7b AC |
26118 | @end smallexample |
26119 | ||
26120 | ||
26121 | @subheading The @code{-exec-return} Command | |
26122 | @findex -exec-return | |
26123 | ||
26124 | @subsubheading Synopsis | |
26125 | ||
26126 | @smallexample | |
26127 | -exec-return | |
26128 | @end smallexample | |
26129 | ||
26130 | Makes current function return immediately. Doesn't execute the inferior. | |
26131 | Displays the new current frame. | |
26132 | ||
26133 | @subsubheading @value{GDBN} Command | |
26134 | ||
26135 | The corresponding @value{GDBN} command is @samp{return}. | |
26136 | ||
26137 | @subsubheading Example | |
26138 | ||
26139 | @smallexample | |
594fe323 | 26140 | (gdb) |
922fbb7b AC |
26141 | 200-break-insert callee4 |
26142 | 200^done,bkpt=@{number="1",addr="0x00010734", | |
26143 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
594fe323 | 26144 | (gdb) |
922fbb7b AC |
26145 | 000-exec-run |
26146 | 000^running | |
594fe323 | 26147 | (gdb) |
a47ec5fe | 26148 | 000*stopped,reason="breakpoint-hit",disp="keep",bkptno="1", |
922fbb7b | 26149 | frame=@{func="callee4",args=[], |
76ff342d DJ |
26150 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26151 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@} | |
594fe323 | 26152 | (gdb) |
922fbb7b AC |
26153 | 205-break-delete |
26154 | 205^done | |
594fe323 | 26155 | (gdb) |
922fbb7b AC |
26156 | 111-exec-return |
26157 | 111^done,frame=@{level="0",func="callee3", | |
26158 | args=[@{name="strarg", | |
26159 | value="0x11940 \"A string argument.\""@}], | |
76ff342d DJ |
26160 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", |
26161 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"@} | |
594fe323 | 26162 | (gdb) |
922fbb7b AC |
26163 | @end smallexample |
26164 | ||
26165 | ||
26166 | @subheading The @code{-exec-run} Command | |
26167 | @findex -exec-run | |
26168 | ||
26169 | @subsubheading Synopsis | |
26170 | ||
26171 | @smallexample | |
a79b8f6e | 26172 | -exec-run [--all | --thread-group N] |
922fbb7b AC |
26173 | @end smallexample |
26174 | ||
ef21caaf NR |
26175 | Starts execution of the inferior from the beginning. The inferior |
26176 | executes until either a breakpoint is encountered or the program | |
26177 | exits. In the latter case the output will include an exit code, if | |
26178 | the program has exited exceptionally. | |
922fbb7b | 26179 | |
a79b8f6e VP |
26180 | When no option is specified, the current inferior is started. If the |
26181 | @samp{--thread-group} option is specified, it should refer to a thread | |
26182 | group of type @samp{process}, and that thread group will be started. | |
26183 | If the @samp{--all} option is specified, then all inferiors will be started. | |
26184 | ||
922fbb7b AC |
26185 | @subsubheading @value{GDBN} Command |
26186 | ||
26187 | The corresponding @value{GDBN} command is @samp{run}. | |
26188 | ||
ef21caaf | 26189 | @subsubheading Examples |
922fbb7b AC |
26190 | |
26191 | @smallexample | |
594fe323 | 26192 | (gdb) |
922fbb7b AC |
26193 | -break-insert main |
26194 | ^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@} | |
594fe323 | 26195 | (gdb) |
922fbb7b AC |
26196 | -exec-run |
26197 | ^running | |
594fe323 | 26198 | (gdb) |
a47ec5fe | 26199 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1", |
76ff342d | 26200 | frame=@{func="main",args=[],file="recursive2.c", |
948d5102 | 26201 | fullname="/home/foo/bar/recursive2.c",line="4"@} |
594fe323 | 26202 | (gdb) |
922fbb7b AC |
26203 | @end smallexample |
26204 | ||
ef21caaf NR |
26205 | @noindent |
26206 | Program exited normally: | |
26207 | ||
26208 | @smallexample | |
594fe323 | 26209 | (gdb) |
ef21caaf NR |
26210 | -exec-run |
26211 | ^running | |
594fe323 | 26212 | (gdb) |
ef21caaf NR |
26213 | x = 55 |
26214 | *stopped,reason="exited-normally" | |
594fe323 | 26215 | (gdb) |
ef21caaf NR |
26216 | @end smallexample |
26217 | ||
26218 | @noindent | |
26219 | Program exited exceptionally: | |
26220 | ||
26221 | @smallexample | |
594fe323 | 26222 | (gdb) |
ef21caaf NR |
26223 | -exec-run |
26224 | ^running | |
594fe323 | 26225 | (gdb) |
ef21caaf NR |
26226 | x = 55 |
26227 | *stopped,reason="exited",exit-code="01" | |
594fe323 | 26228 | (gdb) |
ef21caaf NR |
26229 | @end smallexample |
26230 | ||
26231 | Another way the program can terminate is if it receives a signal such as | |
26232 | @code{SIGINT}. In this case, @sc{gdb/mi} displays this: | |
26233 | ||
26234 | @smallexample | |
594fe323 | 26235 | (gdb) |
ef21caaf NR |
26236 | *stopped,reason="exited-signalled",signal-name="SIGINT", |
26237 | signal-meaning="Interrupt" | |
26238 | @end smallexample | |
26239 | ||
922fbb7b | 26240 | |
a2c02241 NR |
26241 | @c @subheading -exec-signal |
26242 | ||
26243 | ||
26244 | @subheading The @code{-exec-step} Command | |
26245 | @findex -exec-step | |
922fbb7b AC |
26246 | |
26247 | @subsubheading Synopsis | |
26248 | ||
26249 | @smallexample | |
540aa8e7 | 26250 | -exec-step [--reverse] |
922fbb7b AC |
26251 | @end smallexample |
26252 | ||
a2c02241 NR |
26253 | Resumes execution of the inferior program, stopping when the beginning |
26254 | of the next source line is reached, if the next source line is not a | |
26255 | function call. If it is, stop at the first instruction of the called | |
540aa8e7 MS |
26256 | function. If the @samp{--reverse} option is specified, resumes reverse |
26257 | execution of the inferior program, stopping at the beginning of the | |
26258 | previously executed source line. | |
922fbb7b AC |
26259 | |
26260 | @subsubheading @value{GDBN} Command | |
26261 | ||
a2c02241 | 26262 | The corresponding @value{GDBN} command is @samp{step}. |
922fbb7b AC |
26263 | |
26264 | @subsubheading Example | |
26265 | ||
26266 | Stepping into a function: | |
26267 | ||
26268 | @smallexample | |
26269 | -exec-step | |
26270 | ^running | |
594fe323 | 26271 | (gdb) |
922fbb7b AC |
26272 | *stopped,reason="end-stepping-range", |
26273 | frame=@{func="foo",args=[@{name="a",value="10"@}, | |
76ff342d | 26274 | @{name="b",value="0"@}],file="recursive2.c", |
948d5102 | 26275 | fullname="/home/foo/bar/recursive2.c",line="11"@} |
594fe323 | 26276 | (gdb) |
922fbb7b AC |
26277 | @end smallexample |
26278 | ||
26279 | Regular stepping: | |
26280 | ||
26281 | @smallexample | |
26282 | -exec-step | |
26283 | ^running | |
594fe323 | 26284 | (gdb) |
922fbb7b | 26285 | *stopped,reason="end-stepping-range",line="14",file="recursive2.c" |
594fe323 | 26286 | (gdb) |
922fbb7b AC |
26287 | @end smallexample |
26288 | ||
26289 | ||
26290 | @subheading The @code{-exec-step-instruction} Command | |
26291 | @findex -exec-step-instruction | |
26292 | ||
26293 | @subsubheading Synopsis | |
26294 | ||
26295 | @smallexample | |
540aa8e7 | 26296 | -exec-step-instruction [--reverse] |
922fbb7b AC |
26297 | @end smallexample |
26298 | ||
540aa8e7 MS |
26299 | Resumes the inferior which executes one machine instruction. If the |
26300 | @samp{--reverse} option is specified, resumes reverse execution of the | |
26301 | inferior program, stopping at the previously executed instruction. | |
26302 | The output, once @value{GDBN} has stopped, will vary depending on | |
26303 | whether we have stopped in the middle of a source line or not. In the | |
26304 | former case, the address at which the program stopped will be printed | |
26305 | as well. | |
922fbb7b AC |
26306 | |
26307 | @subsubheading @value{GDBN} Command | |
26308 | ||
26309 | The corresponding @value{GDBN} command is @samp{stepi}. | |
26310 | ||
26311 | @subsubheading Example | |
26312 | ||
26313 | @smallexample | |
594fe323 | 26314 | (gdb) |
922fbb7b AC |
26315 | -exec-step-instruction |
26316 | ^running | |
26317 | ||
594fe323 | 26318 | (gdb) |
922fbb7b | 26319 | *stopped,reason="end-stepping-range", |
76ff342d | 26320 | frame=@{func="foo",args=[],file="try.c", |
948d5102 | 26321 | fullname="/home/foo/bar/try.c",line="10"@} |
594fe323 | 26322 | (gdb) |
922fbb7b AC |
26323 | -exec-step-instruction |
26324 | ^running | |
26325 | ||
594fe323 | 26326 | (gdb) |
922fbb7b | 26327 | *stopped,reason="end-stepping-range", |
76ff342d | 26328 | frame=@{addr="0x000100f4",func="foo",args=[],file="try.c", |
948d5102 | 26329 | fullname="/home/foo/bar/try.c",line="10"@} |
594fe323 | 26330 | (gdb) |
922fbb7b AC |
26331 | @end smallexample |
26332 | ||
26333 | ||
26334 | @subheading The @code{-exec-until} Command | |
26335 | @findex -exec-until | |
26336 | ||
26337 | @subsubheading Synopsis | |
26338 | ||
26339 | @smallexample | |
26340 | -exec-until [ @var{location} ] | |
26341 | @end smallexample | |
26342 | ||
ef21caaf NR |
26343 | Executes the inferior until the @var{location} specified in the |
26344 | argument is reached. If there is no argument, the inferior executes | |
26345 | until a source line greater than the current one is reached. The | |
26346 | reason for stopping in this case will be @samp{location-reached}. | |
922fbb7b AC |
26347 | |
26348 | @subsubheading @value{GDBN} Command | |
26349 | ||
26350 | The corresponding @value{GDBN} command is @samp{until}. | |
26351 | ||
26352 | @subsubheading Example | |
26353 | ||
26354 | @smallexample | |
594fe323 | 26355 | (gdb) |
922fbb7b AC |
26356 | -exec-until recursive2.c:6 |
26357 | ^running | |
594fe323 | 26358 | (gdb) |
922fbb7b AC |
26359 | x = 55 |
26360 | *stopped,reason="location-reached",frame=@{func="main",args=[], | |
948d5102 | 26361 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6"@} |
594fe323 | 26362 | (gdb) |
922fbb7b AC |
26363 | @end smallexample |
26364 | ||
26365 | @ignore | |
26366 | @subheading -file-clear | |
26367 | Is this going away???? | |
26368 | @end ignore | |
26369 | ||
351ff01a | 26370 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
a2c02241 NR |
26371 | @node GDB/MI Stack Manipulation |
26372 | @section @sc{gdb/mi} Stack Manipulation Commands | |
351ff01a | 26373 | |
922fbb7b | 26374 | |
a2c02241 NR |
26375 | @subheading The @code{-stack-info-frame} Command |
26376 | @findex -stack-info-frame | |
922fbb7b AC |
26377 | |
26378 | @subsubheading Synopsis | |
26379 | ||
26380 | @smallexample | |
a2c02241 | 26381 | -stack-info-frame |
922fbb7b AC |
26382 | @end smallexample |
26383 | ||
a2c02241 | 26384 | Get info on the selected frame. |
922fbb7b AC |
26385 | |
26386 | @subsubheading @value{GDBN} Command | |
26387 | ||
a2c02241 NR |
26388 | The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame} |
26389 | (without arguments). | |
922fbb7b AC |
26390 | |
26391 | @subsubheading Example | |
26392 | ||
26393 | @smallexample | |
594fe323 | 26394 | (gdb) |
a2c02241 NR |
26395 | -stack-info-frame |
26396 | ^done,frame=@{level="1",addr="0x0001076c",func="callee3", | |
26397 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
26398 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@} | |
594fe323 | 26399 | (gdb) |
922fbb7b AC |
26400 | @end smallexample |
26401 | ||
a2c02241 NR |
26402 | @subheading The @code{-stack-info-depth} Command |
26403 | @findex -stack-info-depth | |
922fbb7b AC |
26404 | |
26405 | @subsubheading Synopsis | |
26406 | ||
26407 | @smallexample | |
a2c02241 | 26408 | -stack-info-depth [ @var{max-depth} ] |
922fbb7b AC |
26409 | @end smallexample |
26410 | ||
a2c02241 NR |
26411 | Return the depth of the stack. If the integer argument @var{max-depth} |
26412 | is specified, do not count beyond @var{max-depth} frames. | |
922fbb7b AC |
26413 | |
26414 | @subsubheading @value{GDBN} Command | |
26415 | ||
a2c02241 | 26416 | There's no equivalent @value{GDBN} command. |
922fbb7b AC |
26417 | |
26418 | @subsubheading Example | |
26419 | ||
a2c02241 NR |
26420 | For a stack with frame levels 0 through 11: |
26421 | ||
922fbb7b | 26422 | @smallexample |
594fe323 | 26423 | (gdb) |
a2c02241 NR |
26424 | -stack-info-depth |
26425 | ^done,depth="12" | |
594fe323 | 26426 | (gdb) |
a2c02241 NR |
26427 | -stack-info-depth 4 |
26428 | ^done,depth="4" | |
594fe323 | 26429 | (gdb) |
a2c02241 NR |
26430 | -stack-info-depth 12 |
26431 | ^done,depth="12" | |
594fe323 | 26432 | (gdb) |
a2c02241 NR |
26433 | -stack-info-depth 11 |
26434 | ^done,depth="11" | |
594fe323 | 26435 | (gdb) |
a2c02241 NR |
26436 | -stack-info-depth 13 |
26437 | ^done,depth="12" | |
594fe323 | 26438 | (gdb) |
922fbb7b AC |
26439 | @end smallexample |
26440 | ||
a2c02241 NR |
26441 | @subheading The @code{-stack-list-arguments} Command |
26442 | @findex -stack-list-arguments | |
922fbb7b AC |
26443 | |
26444 | @subsubheading Synopsis | |
26445 | ||
26446 | @smallexample | |
3afae151 | 26447 | -stack-list-arguments @var{print-values} |
a2c02241 | 26448 | [ @var{low-frame} @var{high-frame} ] |
922fbb7b AC |
26449 | @end smallexample |
26450 | ||
a2c02241 NR |
26451 | Display a list of the arguments for the frames between @var{low-frame} |
26452 | and @var{high-frame} (inclusive). If @var{low-frame} and | |
2f1acb09 VP |
26453 | @var{high-frame} are not provided, list the arguments for the whole |
26454 | call stack. If the two arguments are equal, show the single frame | |
26455 | at the corresponding level. It is an error if @var{low-frame} is | |
26456 | larger than the actual number of frames. On the other hand, | |
26457 | @var{high-frame} may be larger than the actual number of frames, in | |
26458 | which case only existing frames will be returned. | |
a2c02241 | 26459 | |
3afae151 VP |
26460 | If @var{print-values} is 0 or @code{--no-values}, print only the names of |
26461 | the variables; if it is 1 or @code{--all-values}, print also their | |
26462 | values; and if it is 2 or @code{--simple-values}, print the name, | |
26463 | type and value for simple data types, and the name and type for arrays, | |
26464 | structures and unions. | |
922fbb7b | 26465 | |
b3372f91 VP |
26466 | Use of this command to obtain arguments in a single frame is |
26467 | deprecated in favor of the @samp{-stack-list-variables} command. | |
26468 | ||
922fbb7b AC |
26469 | @subsubheading @value{GDBN} Command |
26470 | ||
a2c02241 NR |
26471 | @value{GDBN} does not have an equivalent command. @code{gdbtk} has a |
26472 | @samp{gdb_get_args} command which partially overlaps with the | |
26473 | functionality of @samp{-stack-list-arguments}. | |
922fbb7b AC |
26474 | |
26475 | @subsubheading Example | |
922fbb7b | 26476 | |
a2c02241 | 26477 | @smallexample |
594fe323 | 26478 | (gdb) |
a2c02241 NR |
26479 | -stack-list-frames |
26480 | ^done, | |
26481 | stack=[ | |
26482 | frame=@{level="0",addr="0x00010734",func="callee4", | |
26483 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
26484 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"@}, | |
26485 | frame=@{level="1",addr="0x0001076c",func="callee3", | |
26486 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
26487 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@}, | |
26488 | frame=@{level="2",addr="0x0001078c",func="callee2", | |
26489 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
26490 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22"@}, | |
26491 | frame=@{level="3",addr="0x000107b4",func="callee1", | |
26492 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
26493 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27"@}, | |
26494 | frame=@{level="4",addr="0x000107e0",func="main", | |
26495 | file="../../../devo/gdb/testsuite/gdb.mi/basics.c", | |
26496 | fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32"@}] | |
594fe323 | 26497 | (gdb) |
a2c02241 NR |
26498 | -stack-list-arguments 0 |
26499 | ^done, | |
26500 | stack-args=[ | |
26501 | frame=@{level="0",args=[]@}, | |
26502 | frame=@{level="1",args=[name="strarg"]@}, | |
26503 | frame=@{level="2",args=[name="intarg",name="strarg"]@}, | |
26504 | frame=@{level="3",args=[name="intarg",name="strarg",name="fltarg"]@}, | |
26505 | frame=@{level="4",args=[]@}] | |
594fe323 | 26506 | (gdb) |
a2c02241 NR |
26507 | -stack-list-arguments 1 |
26508 | ^done, | |
26509 | stack-args=[ | |
26510 | frame=@{level="0",args=[]@}, | |
26511 | frame=@{level="1", | |
26512 | args=[@{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
26513 | frame=@{level="2",args=[ | |
26514 | @{name="intarg",value="2"@}, | |
26515 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}, | |
26516 | @{frame=@{level="3",args=[ | |
26517 | @{name="intarg",value="2"@}, | |
26518 | @{name="strarg",value="0x11940 \"A string argument.\""@}, | |
26519 | @{name="fltarg",value="3.5"@}]@}, | |
26520 | frame=@{level="4",args=[]@}] | |
594fe323 | 26521 | (gdb) |
a2c02241 NR |
26522 | -stack-list-arguments 0 2 2 |
26523 | ^done,stack-args=[frame=@{level="2",args=[name="intarg",name="strarg"]@}] | |
594fe323 | 26524 | (gdb) |
a2c02241 NR |
26525 | -stack-list-arguments 1 2 2 |
26526 | ^done,stack-args=[frame=@{level="2", | |
26527 | args=[@{name="intarg",value="2"@}, | |
26528 | @{name="strarg",value="0x11940 \"A string argument.\""@}]@}] | |
594fe323 | 26529 | (gdb) |
a2c02241 NR |
26530 | @end smallexample |
26531 | ||
26532 | @c @subheading -stack-list-exception-handlers | |
922fbb7b | 26533 | |
a2c02241 NR |
26534 | |
26535 | @subheading The @code{-stack-list-frames} Command | |
26536 | @findex -stack-list-frames | |
1abaf70c BR |
26537 | |
26538 | @subsubheading Synopsis | |
26539 | ||
26540 | @smallexample | |
a2c02241 | 26541 | -stack-list-frames [ @var{low-frame} @var{high-frame} ] |
1abaf70c BR |
26542 | @end smallexample |
26543 | ||
a2c02241 NR |
26544 | List the frames currently on the stack. For each frame it displays the |
26545 | following info: | |
26546 | ||
26547 | @table @samp | |
26548 | @item @var{level} | |
d3e8051b | 26549 | The frame number, 0 being the topmost frame, i.e., the innermost function. |
a2c02241 NR |
26550 | @item @var{addr} |
26551 | The @code{$pc} value for that frame. | |
26552 | @item @var{func} | |
26553 | Function name. | |
26554 | @item @var{file} | |
26555 | File name of the source file where the function lives. | |
7d288aaa TT |
26556 | @item @var{fullname} |
26557 | The full file name of the source file where the function lives. | |
a2c02241 NR |
26558 | @item @var{line} |
26559 | Line number corresponding to the @code{$pc}. | |
7d288aaa TT |
26560 | @item @var{from} |
26561 | The shared library where this function is defined. This is only given | |
26562 | if the frame's function is not known. | |
a2c02241 NR |
26563 | @end table |
26564 | ||
26565 | If invoked without arguments, this command prints a backtrace for the | |
26566 | whole stack. If given two integer arguments, it shows the frames whose | |
26567 | levels are between the two arguments (inclusive). If the two arguments | |
2ab1eb7a VP |
26568 | are equal, it shows the single frame at the corresponding level. It is |
26569 | an error if @var{low-frame} is larger than the actual number of | |
a5451f4e | 26570 | frames. On the other hand, @var{high-frame} may be larger than the |
2ab1eb7a | 26571 | actual number of frames, in which case only existing frames will be returned. |
1abaf70c BR |
26572 | |
26573 | @subsubheading @value{GDBN} Command | |
26574 | ||
a2c02241 | 26575 | The corresponding @value{GDBN} commands are @samp{backtrace} and @samp{where}. |
1abaf70c BR |
26576 | |
26577 | @subsubheading Example | |
26578 | ||
a2c02241 NR |
26579 | Full stack backtrace: |
26580 | ||
1abaf70c | 26581 | @smallexample |
594fe323 | 26582 | (gdb) |
a2c02241 NR |
26583 | -stack-list-frames |
26584 | ^done,stack= | |
26585 | [frame=@{level="0",addr="0x0001076c",func="foo", | |
26586 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11"@}, | |
26587 | frame=@{level="1",addr="0x000107a4",func="foo", | |
26588 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26589 | frame=@{level="2",addr="0x000107a4",func="foo", | |
26590 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26591 | frame=@{level="3",addr="0x000107a4",func="foo", | |
26592 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26593 | frame=@{level="4",addr="0x000107a4",func="foo", | |
26594 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26595 | frame=@{level="5",addr="0x000107a4",func="foo", | |
26596 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26597 | frame=@{level="6",addr="0x000107a4",func="foo", | |
26598 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26599 | frame=@{level="7",addr="0x000107a4",func="foo", | |
26600 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26601 | frame=@{level="8",addr="0x000107a4",func="foo", | |
26602 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26603 | frame=@{level="9",addr="0x000107a4",func="foo", | |
26604 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26605 | frame=@{level="10",addr="0x000107a4",func="foo", | |
26606 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26607 | frame=@{level="11",addr="0x00010738",func="main", | |
26608 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4"@}] | |
594fe323 | 26609 | (gdb) |
1abaf70c BR |
26610 | @end smallexample |
26611 | ||
a2c02241 | 26612 | Show frames between @var{low_frame} and @var{high_frame}: |
1abaf70c | 26613 | |
a2c02241 | 26614 | @smallexample |
594fe323 | 26615 | (gdb) |
a2c02241 NR |
26616 | -stack-list-frames 3 5 |
26617 | ^done,stack= | |
26618 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
26619 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26620 | frame=@{level="4",addr="0x000107a4",func="foo", | |
26621 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}, | |
26622 | frame=@{level="5",addr="0x000107a4",func="foo", | |
26623 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}] | |
594fe323 | 26624 | (gdb) |
a2c02241 | 26625 | @end smallexample |
922fbb7b | 26626 | |
a2c02241 | 26627 | Show a single frame: |
922fbb7b AC |
26628 | |
26629 | @smallexample | |
594fe323 | 26630 | (gdb) |
a2c02241 NR |
26631 | -stack-list-frames 3 3 |
26632 | ^done,stack= | |
26633 | [frame=@{level="3",addr="0x000107a4",func="foo", | |
26634 | file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}] | |
594fe323 | 26635 | (gdb) |
922fbb7b AC |
26636 | @end smallexample |
26637 | ||
922fbb7b | 26638 | |
a2c02241 NR |
26639 | @subheading The @code{-stack-list-locals} Command |
26640 | @findex -stack-list-locals | |
57c22c6c | 26641 | |
a2c02241 | 26642 | @subsubheading Synopsis |
922fbb7b AC |
26643 | |
26644 | @smallexample | |
a2c02241 | 26645 | -stack-list-locals @var{print-values} |
922fbb7b AC |
26646 | @end smallexample |
26647 | ||
a2c02241 NR |
26648 | Display the local variable names for the selected frame. If |
26649 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
26650 | the variables; if it is 1 or @code{--all-values}, print also their | |
26651 | values; and if it is 2 or @code{--simple-values}, print the name, | |
3afae151 | 26652 | type and value for simple data types, and the name and type for arrays, |
a2c02241 NR |
26653 | structures and unions. In this last case, a frontend can immediately |
26654 | display the value of simple data types and create variable objects for | |
d3e8051b | 26655 | other data types when the user wishes to explore their values in |
a2c02241 | 26656 | more detail. |
922fbb7b | 26657 | |
b3372f91 VP |
26658 | This command is deprecated in favor of the |
26659 | @samp{-stack-list-variables} command. | |
26660 | ||
922fbb7b AC |
26661 | @subsubheading @value{GDBN} Command |
26662 | ||
a2c02241 | 26663 | @samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}. |
922fbb7b AC |
26664 | |
26665 | @subsubheading Example | |
922fbb7b AC |
26666 | |
26667 | @smallexample | |
594fe323 | 26668 | (gdb) |
a2c02241 NR |
26669 | -stack-list-locals 0 |
26670 | ^done,locals=[name="A",name="B",name="C"] | |
594fe323 | 26671 | (gdb) |
a2c02241 NR |
26672 | -stack-list-locals --all-values |
26673 | ^done,locals=[@{name="A",value="1"@},@{name="B",value="2"@}, | |
26674 | @{name="C",value="@{1, 2, 3@}"@}] | |
26675 | -stack-list-locals --simple-values | |
26676 | ^done,locals=[@{name="A",type="int",value="1"@}, | |
26677 | @{name="B",type="int",value="2"@},@{name="C",type="int [3]"@}] | |
594fe323 | 26678 | (gdb) |
922fbb7b AC |
26679 | @end smallexample |
26680 | ||
b3372f91 VP |
26681 | @subheading The @code{-stack-list-variables} Command |
26682 | @findex -stack-list-variables | |
26683 | ||
26684 | @subsubheading Synopsis | |
26685 | ||
26686 | @smallexample | |
26687 | -stack-list-variables @var{print-values} | |
26688 | @end smallexample | |
26689 | ||
26690 | Display the names of local variables and function arguments for the selected frame. If | |
26691 | @var{print-values} is 0 or @code{--no-values}, print only the names of | |
26692 | the variables; if it is 1 or @code{--all-values}, print also their | |
26693 | values; and if it is 2 or @code{--simple-values}, print the name, | |
3afae151 | 26694 | type and value for simple data types, and the name and type for arrays, |
b3372f91 VP |
26695 | structures and unions. |
26696 | ||
26697 | @subsubheading Example | |
26698 | ||
26699 | @smallexample | |
26700 | (gdb) | |
26701 | -stack-list-variables --thread 1 --frame 0 --all-values | |
4f412fd0 | 26702 | ^done,variables=[@{name="x",value="11"@},@{name="s",value="@{a = 1, b = 2@}"@}] |
b3372f91 VP |
26703 | (gdb) |
26704 | @end smallexample | |
26705 | ||
922fbb7b | 26706 | |
a2c02241 NR |
26707 | @subheading The @code{-stack-select-frame} Command |
26708 | @findex -stack-select-frame | |
922fbb7b AC |
26709 | |
26710 | @subsubheading Synopsis | |
26711 | ||
26712 | @smallexample | |
a2c02241 | 26713 | -stack-select-frame @var{framenum} |
922fbb7b AC |
26714 | @end smallexample |
26715 | ||
a2c02241 NR |
26716 | Change the selected frame. Select a different frame @var{framenum} on |
26717 | the stack. | |
922fbb7b | 26718 | |
c3b108f7 VP |
26719 | This command in deprecated in favor of passing the @samp{--frame} |
26720 | option to every command. | |
26721 | ||
922fbb7b AC |
26722 | @subsubheading @value{GDBN} Command |
26723 | ||
a2c02241 NR |
26724 | The corresponding @value{GDBN} commands are @samp{frame}, @samp{up}, |
26725 | @samp{down}, @samp{select-frame}, @samp{up-silent}, and @samp{down-silent}. | |
922fbb7b AC |
26726 | |
26727 | @subsubheading Example | |
26728 | ||
26729 | @smallexample | |
594fe323 | 26730 | (gdb) |
a2c02241 | 26731 | -stack-select-frame 2 |
922fbb7b | 26732 | ^done |
594fe323 | 26733 | (gdb) |
922fbb7b AC |
26734 | @end smallexample |
26735 | ||
26736 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
a2c02241 NR |
26737 | @node GDB/MI Variable Objects |
26738 | @section @sc{gdb/mi} Variable Objects | |
922fbb7b | 26739 | |
a1b5960f | 26740 | @ignore |
922fbb7b | 26741 | |
a2c02241 | 26742 | @subheading Motivation for Variable Objects in @sc{gdb/mi} |
922fbb7b | 26743 | |
a2c02241 NR |
26744 | For the implementation of a variable debugger window (locals, watched |
26745 | expressions, etc.), we are proposing the adaptation of the existing code | |
26746 | used by @code{Insight}. | |
922fbb7b | 26747 | |
a2c02241 | 26748 | The two main reasons for that are: |
922fbb7b | 26749 | |
a2c02241 NR |
26750 | @enumerate 1 |
26751 | @item | |
26752 | It has been proven in practice (it is already on its second generation). | |
922fbb7b | 26753 | |
a2c02241 NR |
26754 | @item |
26755 | It will shorten development time (needless to say how important it is | |
26756 | now). | |
26757 | @end enumerate | |
922fbb7b | 26758 | |
a2c02241 NR |
26759 | The original interface was designed to be used by Tcl code, so it was |
26760 | slightly changed so it could be used through @sc{gdb/mi}. This section | |
26761 | describes the @sc{gdb/mi} operations that will be available and gives some | |
26762 | hints about their use. | |
922fbb7b | 26763 | |
a2c02241 NR |
26764 | @emph{Note}: In addition to the set of operations described here, we |
26765 | expect the @sc{gui} implementation of a variable window to require, at | |
26766 | least, the following operations: | |
922fbb7b | 26767 | |
a2c02241 NR |
26768 | @itemize @bullet |
26769 | @item @code{-gdb-show} @code{output-radix} | |
26770 | @item @code{-stack-list-arguments} | |
26771 | @item @code{-stack-list-locals} | |
26772 | @item @code{-stack-select-frame} | |
26773 | @end itemize | |
922fbb7b | 26774 | |
a1b5960f VP |
26775 | @end ignore |
26776 | ||
c8b2f53c | 26777 | @subheading Introduction to Variable Objects |
922fbb7b | 26778 | |
a2c02241 | 26779 | @cindex variable objects in @sc{gdb/mi} |
c8b2f53c VP |
26780 | |
26781 | Variable objects are "object-oriented" MI interface for examining and | |
26782 | changing values of expressions. Unlike some other MI interfaces that | |
26783 | work with expressions, variable objects are specifically designed for | |
26784 | simple and efficient presentation in the frontend. A variable object | |
26785 | is identified by string name. When a variable object is created, the | |
26786 | frontend specifies the expression for that variable object. The | |
26787 | expression can be a simple variable, or it can be an arbitrary complex | |
26788 | expression, and can even involve CPU registers. After creating a | |
26789 | variable object, the frontend can invoke other variable object | |
26790 | operations---for example to obtain or change the value of a variable | |
26791 | object, or to change display format. | |
26792 | ||
26793 | Variable objects have hierarchical tree structure. Any variable object | |
26794 | that corresponds to a composite type, such as structure in C, has | |
26795 | a number of child variable objects, for example corresponding to each | |
26796 | element of a structure. A child variable object can itself have | |
26797 | children, recursively. Recursion ends when we reach | |
25d5ea92 VP |
26798 | leaf variable objects, which always have built-in types. Child variable |
26799 | objects are created only by explicit request, so if a frontend | |
26800 | is not interested in the children of a particular variable object, no | |
26801 | child will be created. | |
c8b2f53c VP |
26802 | |
26803 | For a leaf variable object it is possible to obtain its value as a | |
26804 | string, or set the value from a string. String value can be also | |
26805 | obtained for a non-leaf variable object, but it's generally a string | |
26806 | that only indicates the type of the object, and does not list its | |
26807 | contents. Assignment to a non-leaf variable object is not allowed. | |
26808 | ||
26809 | A frontend does not need to read the values of all variable objects each time | |
26810 | the program stops. Instead, MI provides an update command that lists all | |
26811 | variable objects whose values has changed since the last update | |
26812 | operation. This considerably reduces the amount of data that must | |
25d5ea92 VP |
26813 | be transferred to the frontend. As noted above, children variable |
26814 | objects are created on demand, and only leaf variable objects have a | |
26815 | real value. As result, gdb will read target memory only for leaf | |
26816 | variables that frontend has created. | |
26817 | ||
26818 | The automatic update is not always desirable. For example, a frontend | |
26819 | might want to keep a value of some expression for future reference, | |
26820 | and never update it. For another example, fetching memory is | |
26821 | relatively slow for embedded targets, so a frontend might want | |
26822 | to disable automatic update for the variables that are either not | |
26823 | visible on the screen, or ``closed''. This is possible using so | |
26824 | called ``frozen variable objects''. Such variable objects are never | |
26825 | implicitly updated. | |
922fbb7b | 26826 | |
c3b108f7 VP |
26827 | Variable objects can be either @dfn{fixed} or @dfn{floating}. For the |
26828 | fixed variable object, the expression is parsed when the variable | |
26829 | object is created, including associating identifiers to specific | |
26830 | variables. The meaning of expression never changes. For a floating | |
26831 | variable object the values of variables whose names appear in the | |
26832 | expressions are re-evaluated every time in the context of the current | |
26833 | frame. Consider this example: | |
26834 | ||
26835 | @smallexample | |
26836 | void do_work(...) | |
26837 | @{ | |
26838 | struct work_state state; | |
26839 | ||
26840 | if (...) | |
26841 | do_work(...); | |
26842 | @} | |
26843 | @end smallexample | |
26844 | ||
26845 | If a fixed variable object for the @code{state} variable is created in | |
26846 | this function, and we enter the recursive call, the the variable | |
26847 | object will report the value of @code{state} in the top-level | |
26848 | @code{do_work} invocation. On the other hand, a floating variable | |
26849 | object will report the value of @code{state} in the current frame. | |
26850 | ||
26851 | If an expression specified when creating a fixed variable object | |
26852 | refers to a local variable, the variable object becomes bound to the | |
26853 | thread and frame in which the variable object is created. When such | |
26854 | variable object is updated, @value{GDBN} makes sure that the | |
26855 | thread/frame combination the variable object is bound to still exists, | |
26856 | and re-evaluates the variable object in context of that thread/frame. | |
26857 | ||
a2c02241 NR |
26858 | The following is the complete set of @sc{gdb/mi} operations defined to |
26859 | access this functionality: | |
922fbb7b | 26860 | |
a2c02241 NR |
26861 | @multitable @columnfractions .4 .6 |
26862 | @item @strong{Operation} | |
26863 | @tab @strong{Description} | |
922fbb7b | 26864 | |
0cc7d26f TT |
26865 | @item @code{-enable-pretty-printing} |
26866 | @tab enable Python-based pretty-printing | |
a2c02241 NR |
26867 | @item @code{-var-create} |
26868 | @tab create a variable object | |
26869 | @item @code{-var-delete} | |
22d8a470 | 26870 | @tab delete the variable object and/or its children |
a2c02241 NR |
26871 | @item @code{-var-set-format} |
26872 | @tab set the display format of this variable | |
26873 | @item @code{-var-show-format} | |
26874 | @tab show the display format of this variable | |
26875 | @item @code{-var-info-num-children} | |
26876 | @tab tells how many children this object has | |
26877 | @item @code{-var-list-children} | |
26878 | @tab return a list of the object's children | |
26879 | @item @code{-var-info-type} | |
26880 | @tab show the type of this variable object | |
26881 | @item @code{-var-info-expression} | |
02142340 VP |
26882 | @tab print parent-relative expression that this variable object represents |
26883 | @item @code{-var-info-path-expression} | |
26884 | @tab print full expression that this variable object represents | |
a2c02241 NR |
26885 | @item @code{-var-show-attributes} |
26886 | @tab is this variable editable? does it exist here? | |
26887 | @item @code{-var-evaluate-expression} | |
26888 | @tab get the value of this variable | |
26889 | @item @code{-var-assign} | |
26890 | @tab set the value of this variable | |
26891 | @item @code{-var-update} | |
26892 | @tab update the variable and its children | |
25d5ea92 VP |
26893 | @item @code{-var-set-frozen} |
26894 | @tab set frozeness attribute | |
0cc7d26f TT |
26895 | @item @code{-var-set-update-range} |
26896 | @tab set range of children to display on update | |
a2c02241 | 26897 | @end multitable |
922fbb7b | 26898 | |
a2c02241 NR |
26899 | In the next subsection we describe each operation in detail and suggest |
26900 | how it can be used. | |
922fbb7b | 26901 | |
a2c02241 | 26902 | @subheading Description And Use of Operations on Variable Objects |
922fbb7b | 26903 | |
0cc7d26f TT |
26904 | @subheading The @code{-enable-pretty-printing} Command |
26905 | @findex -enable-pretty-printing | |
26906 | ||
26907 | @smallexample | |
26908 | -enable-pretty-printing | |
26909 | @end smallexample | |
26910 | ||
26911 | @value{GDBN} allows Python-based visualizers to affect the output of the | |
26912 | MI variable object commands. However, because there was no way to | |
26913 | implement this in a fully backward-compatible way, a front end must | |
26914 | request that this functionality be enabled. | |
26915 | ||
26916 | Once enabled, this feature cannot be disabled. | |
26917 | ||
26918 | Note that if Python support has not been compiled into @value{GDBN}, | |
26919 | this command will still succeed (and do nothing). | |
26920 | ||
f43030c4 TT |
26921 | This feature is currently (as of @value{GDBN} 7.0) experimental, and |
26922 | may work differently in future versions of @value{GDBN}. | |
26923 | ||
a2c02241 NR |
26924 | @subheading The @code{-var-create} Command |
26925 | @findex -var-create | |
ef21caaf | 26926 | |
a2c02241 | 26927 | @subsubheading Synopsis |
ef21caaf | 26928 | |
a2c02241 NR |
26929 | @smallexample |
26930 | -var-create @{@var{name} | "-"@} | |
c3b108f7 | 26931 | @{@var{frame-addr} | "*" | "@@"@} @var{expression} |
a2c02241 NR |
26932 | @end smallexample |
26933 | ||
26934 | This operation creates a variable object, which allows the monitoring of | |
26935 | a variable, the result of an expression, a memory cell or a CPU | |
26936 | register. | |
ef21caaf | 26937 | |
a2c02241 NR |
26938 | The @var{name} parameter is the string by which the object can be |
26939 | referenced. It must be unique. If @samp{-} is specified, the varobj | |
26940 | system will generate a string ``varNNNNNN'' automatically. It will be | |
c3b108f7 | 26941 | unique provided that one does not specify @var{name} of that format. |
a2c02241 | 26942 | The command fails if a duplicate name is found. |
ef21caaf | 26943 | |
a2c02241 NR |
26944 | The frame under which the expression should be evaluated can be |
26945 | specified by @var{frame-addr}. A @samp{*} indicates that the current | |
c3b108f7 VP |
26946 | frame should be used. A @samp{@@} indicates that a floating variable |
26947 | object must be created. | |
922fbb7b | 26948 | |
a2c02241 NR |
26949 | @var{expression} is any expression valid on the current language set (must not |
26950 | begin with a @samp{*}), or one of the following: | |
922fbb7b | 26951 | |
a2c02241 NR |
26952 | @itemize @bullet |
26953 | @item | |
26954 | @samp{*@var{addr}}, where @var{addr} is the address of a memory cell | |
922fbb7b | 26955 | |
a2c02241 NR |
26956 | @item |
26957 | @samp{*@var{addr}-@var{addr}} --- a memory address range (TBD) | |
922fbb7b | 26958 | |
a2c02241 NR |
26959 | @item |
26960 | @samp{$@var{regname}} --- a CPU register name | |
26961 | @end itemize | |
922fbb7b | 26962 | |
0cc7d26f TT |
26963 | @cindex dynamic varobj |
26964 | A varobj's contents may be provided by a Python-based pretty-printer. In this | |
26965 | case the varobj is known as a @dfn{dynamic varobj}. Dynamic varobjs | |
26966 | have slightly different semantics in some cases. If the | |
26967 | @code{-enable-pretty-printing} command is not sent, then @value{GDBN} | |
26968 | will never create a dynamic varobj. This ensures backward | |
26969 | compatibility for existing clients. | |
26970 | ||
a2c02241 | 26971 | @subsubheading Result |
922fbb7b | 26972 | |
0cc7d26f TT |
26973 | This operation returns attributes of the newly-created varobj. These |
26974 | are: | |
26975 | ||
26976 | @table @samp | |
26977 | @item name | |
26978 | The name of the varobj. | |
26979 | ||
26980 | @item numchild | |
26981 | The number of children of the varobj. This number is not necessarily | |
26982 | reliable for a dynamic varobj. Instead, you must examine the | |
26983 | @samp{has_more} attribute. | |
26984 | ||
26985 | @item value | |
26986 | The varobj's scalar value. For a varobj whose type is some sort of | |
26987 | aggregate (e.g., a @code{struct}), or for a dynamic varobj, this value | |
26988 | will not be interesting. | |
26989 | ||
26990 | @item type | |
26991 | The varobj's type. This is a string representation of the type, as | |
26992 | would be printed by the @value{GDBN} CLI. | |
26993 | ||
26994 | @item thread-id | |
26995 | If a variable object is bound to a specific thread, then this is the | |
26996 | thread's identifier. | |
26997 | ||
26998 | @item has_more | |
26999 | For a dynamic varobj, this indicates whether there appear to be any | |
27000 | children available. For a non-dynamic varobj, this will be 0. | |
27001 | ||
27002 | @item dynamic | |
27003 | This attribute will be present and have the value @samp{1} if the | |
27004 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
27005 | then this attribute will not be present. | |
27006 | ||
27007 | @item displayhint | |
27008 | A dynamic varobj can supply a display hint to the front end. The | |
27009 | value comes directly from the Python pretty-printer object's | |
4c374409 | 27010 | @code{display_hint} method. @xref{Pretty Printing API}. |
0cc7d26f TT |
27011 | @end table |
27012 | ||
27013 | Typical output will look like this: | |
922fbb7b AC |
27014 | |
27015 | @smallexample | |
0cc7d26f TT |
27016 | name="@var{name}",numchild="@var{N}",type="@var{type}",thread-id="@var{M}", |
27017 | has_more="@var{has_more}" | |
dcaaae04 NR |
27018 | @end smallexample |
27019 | ||
a2c02241 NR |
27020 | |
27021 | @subheading The @code{-var-delete} Command | |
27022 | @findex -var-delete | |
922fbb7b AC |
27023 | |
27024 | @subsubheading Synopsis | |
27025 | ||
27026 | @smallexample | |
22d8a470 | 27027 | -var-delete [ -c ] @var{name} |
922fbb7b AC |
27028 | @end smallexample |
27029 | ||
a2c02241 | 27030 | Deletes a previously created variable object and all of its children. |
22d8a470 | 27031 | With the @samp{-c} option, just deletes the children. |
922fbb7b | 27032 | |
a2c02241 | 27033 | Returns an error if the object @var{name} is not found. |
922fbb7b | 27034 | |
922fbb7b | 27035 | |
a2c02241 NR |
27036 | @subheading The @code{-var-set-format} Command |
27037 | @findex -var-set-format | |
922fbb7b | 27038 | |
a2c02241 | 27039 | @subsubheading Synopsis |
922fbb7b AC |
27040 | |
27041 | @smallexample | |
a2c02241 | 27042 | -var-set-format @var{name} @var{format-spec} |
922fbb7b AC |
27043 | @end smallexample |
27044 | ||
a2c02241 NR |
27045 | Sets the output format for the value of the object @var{name} to be |
27046 | @var{format-spec}. | |
27047 | ||
de051565 | 27048 | @anchor{-var-set-format} |
a2c02241 NR |
27049 | The syntax for the @var{format-spec} is as follows: |
27050 | ||
27051 | @smallexample | |
27052 | @var{format-spec} @expansion{} | |
27053 | @{binary | decimal | hexadecimal | octal | natural@} | |
27054 | @end smallexample | |
27055 | ||
c8b2f53c VP |
27056 | The natural format is the default format choosen automatically |
27057 | based on the variable type (like decimal for an @code{int}, hex | |
27058 | for pointers, etc.). | |
27059 | ||
27060 | For a variable with children, the format is set only on the | |
27061 | variable itself, and the children are not affected. | |
a2c02241 NR |
27062 | |
27063 | @subheading The @code{-var-show-format} Command | |
27064 | @findex -var-show-format | |
922fbb7b AC |
27065 | |
27066 | @subsubheading Synopsis | |
27067 | ||
27068 | @smallexample | |
a2c02241 | 27069 | -var-show-format @var{name} |
922fbb7b AC |
27070 | @end smallexample |
27071 | ||
a2c02241 | 27072 | Returns the format used to display the value of the object @var{name}. |
922fbb7b | 27073 | |
a2c02241 NR |
27074 | @smallexample |
27075 | @var{format} @expansion{} | |
27076 | @var{format-spec} | |
27077 | @end smallexample | |
922fbb7b | 27078 | |
922fbb7b | 27079 | |
a2c02241 NR |
27080 | @subheading The @code{-var-info-num-children} Command |
27081 | @findex -var-info-num-children | |
27082 | ||
27083 | @subsubheading Synopsis | |
27084 | ||
27085 | @smallexample | |
27086 | -var-info-num-children @var{name} | |
27087 | @end smallexample | |
27088 | ||
27089 | Returns the number of children of a variable object @var{name}: | |
27090 | ||
27091 | @smallexample | |
27092 | numchild=@var{n} | |
27093 | @end smallexample | |
27094 | ||
0cc7d26f TT |
27095 | Note that this number is not completely reliable for a dynamic varobj. |
27096 | It will return the current number of children, but more children may | |
27097 | be available. | |
27098 | ||
a2c02241 NR |
27099 | |
27100 | @subheading The @code{-var-list-children} Command | |
27101 | @findex -var-list-children | |
27102 | ||
27103 | @subsubheading Synopsis | |
27104 | ||
27105 | @smallexample | |
0cc7d26f | 27106 | -var-list-children [@var{print-values}] @var{name} [@var{from} @var{to}] |
a2c02241 | 27107 | @end smallexample |
b569d230 | 27108 | @anchor{-var-list-children} |
a2c02241 NR |
27109 | |
27110 | Return a list of the children of the specified variable object and | |
27111 | create variable objects for them, if they do not already exist. With | |
f5011d11 | 27112 | a single argument or if @var{print-values} has a value of 0 or |
a2c02241 NR |
27113 | @code{--no-values}, print only the names of the variables; if |
27114 | @var{print-values} is 1 or @code{--all-values}, also print their | |
27115 | values; and if it is 2 or @code{--simple-values} print the name and | |
27116 | value for simple data types and just the name for arrays, structures | |
27117 | and unions. | |
922fbb7b | 27118 | |
0cc7d26f TT |
27119 | @var{from} and @var{to}, if specified, indicate the range of children |
27120 | to report. If @var{from} or @var{to} is less than zero, the range is | |
27121 | reset and all children will be reported. Otherwise, children starting | |
27122 | at @var{from} (zero-based) and up to and excluding @var{to} will be | |
27123 | reported. | |
27124 | ||
27125 | If a child range is requested, it will only affect the current call to | |
27126 | @code{-var-list-children}, but not future calls to @code{-var-update}. | |
27127 | For this, you must instead use @code{-var-set-update-range}. The | |
27128 | intent of this approach is to enable a front end to implement any | |
27129 | update approach it likes; for example, scrolling a view may cause the | |
27130 | front end to request more children with @code{-var-list-children}, and | |
27131 | then the front end could call @code{-var-set-update-range} with a | |
27132 | different range to ensure that future updates are restricted to just | |
27133 | the visible items. | |
27134 | ||
b569d230 EZ |
27135 | For each child the following results are returned: |
27136 | ||
27137 | @table @var | |
27138 | ||
27139 | @item name | |
27140 | Name of the variable object created for this child. | |
27141 | ||
27142 | @item exp | |
27143 | The expression to be shown to the user by the front end to designate this child. | |
27144 | For example this may be the name of a structure member. | |
27145 | ||
0cc7d26f TT |
27146 | For a dynamic varobj, this value cannot be used to form an |
27147 | expression. There is no way to do this at all with a dynamic varobj. | |
27148 | ||
b569d230 EZ |
27149 | For C/C@t{++} structures there are several pseudo children returned to |
27150 | designate access qualifiers. For these pseudo children @var{exp} is | |
27151 | @samp{public}, @samp{private}, or @samp{protected}. In this case the | |
27152 | type and value are not present. | |
27153 | ||
0cc7d26f TT |
27154 | A dynamic varobj will not report the access qualifying |
27155 | pseudo-children, regardless of the language. This information is not | |
27156 | available at all with a dynamic varobj. | |
27157 | ||
b569d230 | 27158 | @item numchild |
0cc7d26f TT |
27159 | Number of children this child has. For a dynamic varobj, this will be |
27160 | 0. | |
b569d230 EZ |
27161 | |
27162 | @item type | |
27163 | The type of the child. | |
27164 | ||
27165 | @item value | |
27166 | If values were requested, this is the value. | |
27167 | ||
27168 | @item thread-id | |
27169 | If this variable object is associated with a thread, this is the thread id. | |
27170 | Otherwise this result is not present. | |
27171 | ||
27172 | @item frozen | |
27173 | If the variable object is frozen, this variable will be present with a value of 1. | |
27174 | @end table | |
27175 | ||
0cc7d26f TT |
27176 | The result may have its own attributes: |
27177 | ||
27178 | @table @samp | |
27179 | @item displayhint | |
27180 | A dynamic varobj can supply a display hint to the front end. The | |
27181 | value comes directly from the Python pretty-printer object's | |
4c374409 | 27182 | @code{display_hint} method. @xref{Pretty Printing API}. |
0cc7d26f TT |
27183 | |
27184 | @item has_more | |
27185 | This is an integer attribute which is nonzero if there are children | |
27186 | remaining after the end of the selected range. | |
27187 | @end table | |
27188 | ||
922fbb7b AC |
27189 | @subsubheading Example |
27190 | ||
27191 | @smallexample | |
594fe323 | 27192 | (gdb) |
a2c02241 | 27193 | -var-list-children n |
b569d230 | 27194 | ^done,numchild=@var{n},children=[child=@{name=@var{name},exp=@var{exp}, |
a2c02241 | 27195 | numchild=@var{n},type=@var{type}@},@r{(repeats N times)}] |
594fe323 | 27196 | (gdb) |
a2c02241 | 27197 | -var-list-children --all-values n |
b569d230 | 27198 | ^done,numchild=@var{n},children=[child=@{name=@var{name},exp=@var{exp}, |
a2c02241 | 27199 | numchild=@var{n},value=@var{value},type=@var{type}@},@r{(repeats N times)}] |
922fbb7b AC |
27200 | @end smallexample |
27201 | ||
922fbb7b | 27202 | |
a2c02241 NR |
27203 | @subheading The @code{-var-info-type} Command |
27204 | @findex -var-info-type | |
922fbb7b | 27205 | |
a2c02241 NR |
27206 | @subsubheading Synopsis |
27207 | ||
27208 | @smallexample | |
27209 | -var-info-type @var{name} | |
27210 | @end smallexample | |
27211 | ||
27212 | Returns the type of the specified variable @var{name}. The type is | |
27213 | returned as a string in the same format as it is output by the | |
27214 | @value{GDBN} CLI: | |
27215 | ||
27216 | @smallexample | |
27217 | type=@var{typename} | |
27218 | @end smallexample | |
27219 | ||
27220 | ||
27221 | @subheading The @code{-var-info-expression} Command | |
27222 | @findex -var-info-expression | |
922fbb7b AC |
27223 | |
27224 | @subsubheading Synopsis | |
27225 | ||
27226 | @smallexample | |
a2c02241 | 27227 | -var-info-expression @var{name} |
922fbb7b AC |
27228 | @end smallexample |
27229 | ||
02142340 VP |
27230 | Returns a string that is suitable for presenting this |
27231 | variable object in user interface. The string is generally | |
27232 | not valid expression in the current language, and cannot be evaluated. | |
27233 | ||
27234 | For example, if @code{a} is an array, and variable object | |
27235 | @code{A} was created for @code{a}, then we'll get this output: | |
922fbb7b | 27236 | |
a2c02241 | 27237 | @smallexample |
02142340 VP |
27238 | (gdb) -var-info-expression A.1 |
27239 | ^done,lang="C",exp="1" | |
a2c02241 | 27240 | @end smallexample |
922fbb7b | 27241 | |
a2c02241 | 27242 | @noindent |
02142340 VP |
27243 | Here, the values of @code{lang} can be @code{@{"C" | "C++" | "Java"@}}. |
27244 | ||
27245 | Note that the output of the @code{-var-list-children} command also | |
27246 | includes those expressions, so the @code{-var-info-expression} command | |
27247 | is of limited use. | |
27248 | ||
27249 | @subheading The @code{-var-info-path-expression} Command | |
27250 | @findex -var-info-path-expression | |
27251 | ||
27252 | @subsubheading Synopsis | |
27253 | ||
27254 | @smallexample | |
27255 | -var-info-path-expression @var{name} | |
27256 | @end smallexample | |
27257 | ||
27258 | Returns an expression that can be evaluated in the current | |
27259 | context and will yield the same value that a variable object has. | |
27260 | Compare this with the @code{-var-info-expression} command, which | |
27261 | result can be used only for UI presentation. Typical use of | |
27262 | the @code{-var-info-path-expression} command is creating a | |
27263 | watchpoint from a variable object. | |
27264 | ||
0cc7d26f TT |
27265 | This command is currently not valid for children of a dynamic varobj, |
27266 | and will give an error when invoked on one. | |
27267 | ||
02142340 VP |
27268 | For example, suppose @code{C} is a C@t{++} class, derived from class |
27269 | @code{Base}, and that the @code{Base} class has a member called | |
27270 | @code{m_size}. Assume a variable @code{c} is has the type of | |
27271 | @code{C} and a variable object @code{C} was created for variable | |
27272 | @code{c}. Then, we'll get this output: | |
27273 | @smallexample | |
27274 | (gdb) -var-info-path-expression C.Base.public.m_size | |
27275 | ^done,path_expr=((Base)c).m_size) | |
27276 | @end smallexample | |
922fbb7b | 27277 | |
a2c02241 NR |
27278 | @subheading The @code{-var-show-attributes} Command |
27279 | @findex -var-show-attributes | |
922fbb7b | 27280 | |
a2c02241 | 27281 | @subsubheading Synopsis |
922fbb7b | 27282 | |
a2c02241 NR |
27283 | @smallexample |
27284 | -var-show-attributes @var{name} | |
27285 | @end smallexample | |
922fbb7b | 27286 | |
a2c02241 | 27287 | List attributes of the specified variable object @var{name}: |
922fbb7b AC |
27288 | |
27289 | @smallexample | |
a2c02241 | 27290 | status=@var{attr} [ ( ,@var{attr} )* ] |
922fbb7b AC |
27291 | @end smallexample |
27292 | ||
a2c02241 NR |
27293 | @noindent |
27294 | where @var{attr} is @code{@{ @{ editable | noneditable @} | TBD @}}. | |
27295 | ||
27296 | @subheading The @code{-var-evaluate-expression} Command | |
27297 | @findex -var-evaluate-expression | |
27298 | ||
27299 | @subsubheading Synopsis | |
27300 | ||
27301 | @smallexample | |
de051565 | 27302 | -var-evaluate-expression [-f @var{format-spec}] @var{name} |
a2c02241 NR |
27303 | @end smallexample |
27304 | ||
27305 | Evaluates the expression that is represented by the specified variable | |
de051565 MK |
27306 | object and returns its value as a string. The format of the string |
27307 | can be specified with the @samp{-f} option. The possible values of | |
27308 | this option are the same as for @code{-var-set-format} | |
27309 | (@pxref{-var-set-format}). If the @samp{-f} option is not specified, | |
27310 | the current display format will be used. The current display format | |
27311 | can be changed using the @code{-var-set-format} command. | |
a2c02241 NR |
27312 | |
27313 | @smallexample | |
27314 | value=@var{value} | |
27315 | @end smallexample | |
27316 | ||
27317 | Note that one must invoke @code{-var-list-children} for a variable | |
27318 | before the value of a child variable can be evaluated. | |
27319 | ||
27320 | @subheading The @code{-var-assign} Command | |
27321 | @findex -var-assign | |
27322 | ||
27323 | @subsubheading Synopsis | |
27324 | ||
27325 | @smallexample | |
27326 | -var-assign @var{name} @var{expression} | |
27327 | @end smallexample | |
27328 | ||
27329 | Assigns the value of @var{expression} to the variable object specified | |
27330 | by @var{name}. The object must be @samp{editable}. If the variable's | |
27331 | value is altered by the assign, the variable will show up in any | |
27332 | subsequent @code{-var-update} list. | |
27333 | ||
27334 | @subsubheading Example | |
922fbb7b AC |
27335 | |
27336 | @smallexample | |
594fe323 | 27337 | (gdb) |
a2c02241 NR |
27338 | -var-assign var1 3 |
27339 | ^done,value="3" | |
594fe323 | 27340 | (gdb) |
a2c02241 NR |
27341 | -var-update * |
27342 | ^done,changelist=[@{name="var1",in_scope="true",type_changed="false"@}] | |
594fe323 | 27343 | (gdb) |
922fbb7b AC |
27344 | @end smallexample |
27345 | ||
a2c02241 NR |
27346 | @subheading The @code{-var-update} Command |
27347 | @findex -var-update | |
27348 | ||
27349 | @subsubheading Synopsis | |
27350 | ||
27351 | @smallexample | |
27352 | -var-update [@var{print-values}] @{@var{name} | "*"@} | |
27353 | @end smallexample | |
27354 | ||
c8b2f53c VP |
27355 | Reevaluate the expressions corresponding to the variable object |
27356 | @var{name} and all its direct and indirect children, and return the | |
36ece8b3 NR |
27357 | list of variable objects whose values have changed; @var{name} must |
27358 | be a root variable object. Here, ``changed'' means that the result of | |
27359 | @code{-var-evaluate-expression} before and after the | |
27360 | @code{-var-update} is different. If @samp{*} is used as the variable | |
9f708cb2 VP |
27361 | object names, all existing variable objects are updated, except |
27362 | for frozen ones (@pxref{-var-set-frozen}). The option | |
36ece8b3 | 27363 | @var{print-values} determines whether both names and values, or just |
de051565 | 27364 | names are printed. The possible values of this option are the same |
36ece8b3 NR |
27365 | as for @code{-var-list-children} (@pxref{-var-list-children}). It is |
27366 | recommended to use the @samp{--all-values} option, to reduce the | |
27367 | number of MI commands needed on each program stop. | |
c8b2f53c | 27368 | |
c3b108f7 VP |
27369 | With the @samp{*} parameter, if a variable object is bound to a |
27370 | currently running thread, it will not be updated, without any | |
27371 | diagnostic. | |
a2c02241 | 27372 | |
0cc7d26f TT |
27373 | If @code{-var-set-update-range} was previously used on a varobj, then |
27374 | only the selected range of children will be reported. | |
922fbb7b | 27375 | |
0cc7d26f TT |
27376 | @code{-var-update} reports all the changed varobjs in a tuple named |
27377 | @samp{changelist}. | |
27378 | ||
27379 | Each item in the change list is itself a tuple holding: | |
27380 | ||
27381 | @table @samp | |
27382 | @item name | |
27383 | The name of the varobj. | |
27384 | ||
27385 | @item value | |
27386 | If values were requested for this update, then this field will be | |
27387 | present and will hold the value of the varobj. | |
922fbb7b | 27388 | |
0cc7d26f | 27389 | @item in_scope |
9f708cb2 | 27390 | @anchor{-var-update} |
0cc7d26f | 27391 | This field is a string which may take one of three values: |
36ece8b3 NR |
27392 | |
27393 | @table @code | |
27394 | @item "true" | |
27395 | The variable object's current value is valid. | |
27396 | ||
27397 | @item "false" | |
27398 | The variable object does not currently hold a valid value but it may | |
27399 | hold one in the future if its associated expression comes back into | |
27400 | scope. | |
27401 | ||
27402 | @item "invalid" | |
27403 | The variable object no longer holds a valid value. | |
27404 | This can occur when the executable file being debugged has changed, | |
27405 | either through recompilation or by using the @value{GDBN} @code{file} | |
27406 | command. The front end should normally choose to delete these variable | |
27407 | objects. | |
27408 | @end table | |
27409 | ||
27410 | In the future new values may be added to this list so the front should | |
27411 | be prepared for this possibility. @xref{GDB/MI Development and Front Ends, ,@sc{GDB/MI} Development and Front Ends}. | |
27412 | ||
0cc7d26f TT |
27413 | @item type_changed |
27414 | This is only present if the varobj is still valid. If the type | |
27415 | changed, then this will be the string @samp{true}; otherwise it will | |
27416 | be @samp{false}. | |
27417 | ||
27418 | @item new_type | |
27419 | If the varobj's type changed, then this field will be present and will | |
27420 | hold the new type. | |
27421 | ||
27422 | @item new_num_children | |
27423 | For a dynamic varobj, if the number of children changed, or if the | |
27424 | type changed, this will be the new number of children. | |
27425 | ||
27426 | The @samp{numchild} field in other varobj responses is generally not | |
27427 | valid for a dynamic varobj -- it will show the number of children that | |
27428 | @value{GDBN} knows about, but because dynamic varobjs lazily | |
27429 | instantiate their children, this will not reflect the number of | |
27430 | children which may be available. | |
27431 | ||
27432 | The @samp{new_num_children} attribute only reports changes to the | |
27433 | number of children known by @value{GDBN}. This is the only way to | |
27434 | detect whether an update has removed children (which necessarily can | |
27435 | only happen at the end of the update range). | |
27436 | ||
27437 | @item displayhint | |
27438 | The display hint, if any. | |
27439 | ||
27440 | @item has_more | |
27441 | This is an integer value, which will be 1 if there are more children | |
27442 | available outside the varobj's update range. | |
27443 | ||
27444 | @item dynamic | |
27445 | This attribute will be present and have the value @samp{1} if the | |
27446 | varobj is a dynamic varobj. If the varobj is not a dynamic varobj, | |
27447 | then this attribute will not be present. | |
27448 | ||
27449 | @item new_children | |
27450 | If new children were added to a dynamic varobj within the selected | |
27451 | update range (as set by @code{-var-set-update-range}), then they will | |
27452 | be listed in this attribute. | |
27453 | @end table | |
27454 | ||
27455 | @subsubheading Example | |
27456 | ||
27457 | @smallexample | |
27458 | (gdb) | |
27459 | -var-assign var1 3 | |
27460 | ^done,value="3" | |
27461 | (gdb) | |
27462 | -var-update --all-values var1 | |
27463 | ^done,changelist=[@{name="var1",value="3",in_scope="true", | |
27464 | type_changed="false"@}] | |
27465 | (gdb) | |
27466 | @end smallexample | |
27467 | ||
25d5ea92 VP |
27468 | @subheading The @code{-var-set-frozen} Command |
27469 | @findex -var-set-frozen | |
9f708cb2 | 27470 | @anchor{-var-set-frozen} |
25d5ea92 VP |
27471 | |
27472 | @subsubheading Synopsis | |
27473 | ||
27474 | @smallexample | |
9f708cb2 | 27475 | -var-set-frozen @var{name} @var{flag} |
25d5ea92 VP |
27476 | @end smallexample |
27477 | ||
9f708cb2 | 27478 | Set the frozenness flag on the variable object @var{name}. The |
25d5ea92 | 27479 | @var{flag} parameter should be either @samp{1} to make the variable |
9f708cb2 | 27480 | frozen or @samp{0} to make it unfrozen. If a variable object is |
25d5ea92 | 27481 | frozen, then neither itself, nor any of its children, are |
9f708cb2 | 27482 | implicitly updated by @code{-var-update} of |
25d5ea92 VP |
27483 | a parent variable or by @code{-var-update *}. Only |
27484 | @code{-var-update} of the variable itself will update its value and | |
27485 | values of its children. After a variable object is unfrozen, it is | |
27486 | implicitly updated by all subsequent @code{-var-update} operations. | |
27487 | Unfreezing a variable does not update it, only subsequent | |
27488 | @code{-var-update} does. | |
27489 | ||
27490 | @subsubheading Example | |
27491 | ||
27492 | @smallexample | |
27493 | (gdb) | |
27494 | -var-set-frozen V 1 | |
27495 | ^done | |
27496 | (gdb) | |
27497 | @end smallexample | |
27498 | ||
0cc7d26f TT |
27499 | @subheading The @code{-var-set-update-range} command |
27500 | @findex -var-set-update-range | |
27501 | @anchor{-var-set-update-range} | |
27502 | ||
27503 | @subsubheading Synopsis | |
27504 | ||
27505 | @smallexample | |
27506 | -var-set-update-range @var{name} @var{from} @var{to} | |
27507 | @end smallexample | |
27508 | ||
27509 | Set the range of children to be returned by future invocations of | |
27510 | @code{-var-update}. | |
27511 | ||
27512 | @var{from} and @var{to} indicate the range of children to report. If | |
27513 | @var{from} or @var{to} is less than zero, the range is reset and all | |
27514 | children will be reported. Otherwise, children starting at @var{from} | |
27515 | (zero-based) and up to and excluding @var{to} will be reported. | |
27516 | ||
27517 | @subsubheading Example | |
27518 | ||
27519 | @smallexample | |
27520 | (gdb) | |
27521 | -var-set-update-range V 1 2 | |
27522 | ^done | |
27523 | @end smallexample | |
27524 | ||
b6313243 TT |
27525 | @subheading The @code{-var-set-visualizer} command |
27526 | @findex -var-set-visualizer | |
27527 | @anchor{-var-set-visualizer} | |
27528 | ||
27529 | @subsubheading Synopsis | |
27530 | ||
27531 | @smallexample | |
27532 | -var-set-visualizer @var{name} @var{visualizer} | |
27533 | @end smallexample | |
27534 | ||
27535 | Set a visualizer for the variable object @var{name}. | |
27536 | ||
27537 | @var{visualizer} is the visualizer to use. The special value | |
27538 | @samp{None} means to disable any visualizer in use. | |
27539 | ||
27540 | If not @samp{None}, @var{visualizer} must be a Python expression. | |
27541 | This expression must evaluate to a callable object which accepts a | |
27542 | single argument. @value{GDBN} will call this object with the value of | |
27543 | the varobj @var{name} as an argument (this is done so that the same | |
27544 | Python pretty-printing code can be used for both the CLI and MI). | |
27545 | When called, this object must return an object which conforms to the | |
4c374409 | 27546 | pretty-printing interface (@pxref{Pretty Printing API}). |
b6313243 TT |
27547 | |
27548 | The pre-defined function @code{gdb.default_visualizer} may be used to | |
27549 | select a visualizer by following the built-in process | |
27550 | (@pxref{Selecting Pretty-Printers}). This is done automatically when | |
27551 | a varobj is created, and so ordinarily is not needed. | |
27552 | ||
27553 | This feature is only available if Python support is enabled. The MI | |
27554 | command @code{-list-features} (@pxref{GDB/MI Miscellaneous Commands}) | |
27555 | can be used to check this. | |
27556 | ||
27557 | @subsubheading Example | |
27558 | ||
27559 | Resetting the visualizer: | |
27560 | ||
27561 | @smallexample | |
27562 | (gdb) | |
27563 | -var-set-visualizer V None | |
27564 | ^done | |
27565 | @end smallexample | |
27566 | ||
27567 | Reselecting the default (type-based) visualizer: | |
27568 | ||
27569 | @smallexample | |
27570 | (gdb) | |
27571 | -var-set-visualizer V gdb.default_visualizer | |
27572 | ^done | |
27573 | @end smallexample | |
27574 | ||
27575 | Suppose @code{SomeClass} is a visualizer class. A lambda expression | |
27576 | can be used to instantiate this class for a varobj: | |
27577 | ||
27578 | @smallexample | |
27579 | (gdb) | |
27580 | -var-set-visualizer V "lambda val: SomeClass()" | |
27581 | ^done | |
27582 | @end smallexample | |
25d5ea92 | 27583 | |
a2c02241 NR |
27584 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
27585 | @node GDB/MI Data Manipulation | |
27586 | @section @sc{gdb/mi} Data Manipulation | |
922fbb7b | 27587 | |
a2c02241 NR |
27588 | @cindex data manipulation, in @sc{gdb/mi} |
27589 | @cindex @sc{gdb/mi}, data manipulation | |
27590 | This section describes the @sc{gdb/mi} commands that manipulate data: | |
27591 | examine memory and registers, evaluate expressions, etc. | |
27592 | ||
27593 | @c REMOVED FROM THE INTERFACE. | |
27594 | @c @subheading -data-assign | |
27595 | @c Change the value of a program variable. Plenty of side effects. | |
79a6e687 | 27596 | @c @subsubheading GDB Command |
a2c02241 NR |
27597 | @c set variable |
27598 | @c @subsubheading Example | |
27599 | @c N.A. | |
27600 | ||
27601 | @subheading The @code{-data-disassemble} Command | |
27602 | @findex -data-disassemble | |
922fbb7b AC |
27603 | |
27604 | @subsubheading Synopsis | |
27605 | ||
27606 | @smallexample | |
a2c02241 NR |
27607 | -data-disassemble |
27608 | [ -s @var{start-addr} -e @var{end-addr} ] | |
27609 | | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ] | |
27610 | -- @var{mode} | |
922fbb7b AC |
27611 | @end smallexample |
27612 | ||
a2c02241 NR |
27613 | @noindent |
27614 | Where: | |
27615 | ||
27616 | @table @samp | |
27617 | @item @var{start-addr} | |
27618 | is the beginning address (or @code{$pc}) | |
27619 | @item @var{end-addr} | |
27620 | is the end address | |
27621 | @item @var{filename} | |
27622 | is the name of the file to disassemble | |
27623 | @item @var{linenum} | |
27624 | is the line number to disassemble around | |
27625 | @item @var{lines} | |
d3e8051b | 27626 | is the number of disassembly lines to be produced. If it is -1, |
a2c02241 NR |
27627 | the whole function will be disassembled, in case no @var{end-addr} is |
27628 | specified. If @var{end-addr} is specified as a non-zero value, and | |
27629 | @var{lines} is lower than the number of disassembly lines between | |
27630 | @var{start-addr} and @var{end-addr}, only @var{lines} lines are | |
27631 | displayed; if @var{lines} is higher than the number of lines between | |
27632 | @var{start-addr} and @var{end-addr}, only the lines up to @var{end-addr} | |
27633 | are displayed. | |
27634 | @item @var{mode} | |
27635 | is either 0 (meaning only disassembly) or 1 (meaning mixed source and | |
27636 | disassembly). | |
27637 | @end table | |
27638 | ||
27639 | @subsubheading Result | |
27640 | ||
27641 | The output for each instruction is composed of four fields: | |
27642 | ||
27643 | @itemize @bullet | |
27644 | @item Address | |
27645 | @item Func-name | |
27646 | @item Offset | |
27647 | @item Instruction | |
27648 | @end itemize | |
27649 | ||
27650 | Note that whatever included in the instruction field, is not manipulated | |
d3e8051b | 27651 | directly by @sc{gdb/mi}, i.e., it is not possible to adjust its format. |
922fbb7b AC |
27652 | |
27653 | @subsubheading @value{GDBN} Command | |
27654 | ||
a2c02241 | 27655 | There's no direct mapping from this command to the CLI. |
922fbb7b AC |
27656 | |
27657 | @subsubheading Example | |
27658 | ||
a2c02241 NR |
27659 | Disassemble from the current value of @code{$pc} to @code{$pc + 20}: |
27660 | ||
922fbb7b | 27661 | @smallexample |
594fe323 | 27662 | (gdb) |
a2c02241 NR |
27663 | -data-disassemble -s $pc -e "$pc + 20" -- 0 |
27664 | ^done, | |
27665 | asm_insns=[ | |
27666 | @{address="0x000107c0",func-name="main",offset="4", | |
27667 | inst="mov 2, %o0"@}, | |
27668 | @{address="0x000107c4",func-name="main",offset="8", | |
27669 | inst="sethi %hi(0x11800), %o2"@}, | |
27670 | @{address="0x000107c8",func-name="main",offset="12", | |
27671 | inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"@}, | |
27672 | @{address="0x000107cc",func-name="main",offset="16", | |
27673 | inst="sethi %hi(0x11800), %o2"@}, | |
27674 | @{address="0x000107d0",func-name="main",offset="20", | |
27675 | inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"@}] | |
594fe323 | 27676 | (gdb) |
a2c02241 NR |
27677 | @end smallexample |
27678 | ||
27679 | Disassemble the whole @code{main} function. Line 32 is part of | |
27680 | @code{main}. | |
27681 | ||
27682 | @smallexample | |
27683 | -data-disassemble -f basics.c -l 32 -- 0 | |
27684 | ^done,asm_insns=[ | |
27685 | @{address="0x000107bc",func-name="main",offset="0", | |
27686 | inst="save %sp, -112, %sp"@}, | |
27687 | @{address="0x000107c0",func-name="main",offset="4", | |
27688 | inst="mov 2, %o0"@}, | |
27689 | @{address="0x000107c4",func-name="main",offset="8", | |
27690 | inst="sethi %hi(0x11800), %o2"@}, | |
27691 | [@dots{}] | |
27692 | @{address="0x0001081c",func-name="main",offset="96",inst="ret "@}, | |
27693 | @{address="0x00010820",func-name="main",offset="100",inst="restore "@}] | |
594fe323 | 27694 | (gdb) |
922fbb7b AC |
27695 | @end smallexample |
27696 | ||
a2c02241 | 27697 | Disassemble 3 instructions from the start of @code{main}: |
922fbb7b | 27698 | |
a2c02241 | 27699 | @smallexample |
594fe323 | 27700 | (gdb) |
a2c02241 NR |
27701 | -data-disassemble -f basics.c -l 32 -n 3 -- 0 |
27702 | ^done,asm_insns=[ | |
27703 | @{address="0x000107bc",func-name="main",offset="0", | |
27704 | inst="save %sp, -112, %sp"@}, | |
27705 | @{address="0x000107c0",func-name="main",offset="4", | |
27706 | inst="mov 2, %o0"@}, | |
27707 | @{address="0x000107c4",func-name="main",offset="8", | |
27708 | inst="sethi %hi(0x11800), %o2"@}] | |
594fe323 | 27709 | (gdb) |
a2c02241 NR |
27710 | @end smallexample |
27711 | ||
27712 | Disassemble 3 instructions from the start of @code{main} in mixed mode: | |
27713 | ||
27714 | @smallexample | |
594fe323 | 27715 | (gdb) |
a2c02241 NR |
27716 | -data-disassemble -f basics.c -l 32 -n 3 -- 1 |
27717 | ^done,asm_insns=[ | |
27718 | src_and_asm_line=@{line="31", | |
27719 | file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \ | |
27720 | testsuite/gdb.mi/basics.c",line_asm_insn=[ | |
27721 | @{address="0x000107bc",func-name="main",offset="0", | |
27722 | inst="save %sp, -112, %sp"@}]@}, | |
27723 | src_and_asm_line=@{line="32", | |
27724 | file="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb/ \ | |
27725 | testsuite/gdb.mi/basics.c",line_asm_insn=[ | |
27726 | @{address="0x000107c0",func-name="main",offset="4", | |
27727 | inst="mov 2, %o0"@}, | |
27728 | @{address="0x000107c4",func-name="main",offset="8", | |
27729 | inst="sethi %hi(0x11800), %o2"@}]@}] | |
594fe323 | 27730 | (gdb) |
a2c02241 NR |
27731 | @end smallexample |
27732 | ||
27733 | ||
27734 | @subheading The @code{-data-evaluate-expression} Command | |
27735 | @findex -data-evaluate-expression | |
922fbb7b AC |
27736 | |
27737 | @subsubheading Synopsis | |
27738 | ||
27739 | @smallexample | |
a2c02241 | 27740 | -data-evaluate-expression @var{expr} |
922fbb7b AC |
27741 | @end smallexample |
27742 | ||
a2c02241 NR |
27743 | Evaluate @var{expr} as an expression. The expression could contain an |
27744 | inferior function call. The function call will execute synchronously. | |
27745 | If the expression contains spaces, it must be enclosed in double quotes. | |
922fbb7b AC |
27746 | |
27747 | @subsubheading @value{GDBN} Command | |
27748 | ||
a2c02241 NR |
27749 | The corresponding @value{GDBN} commands are @samp{print}, @samp{output}, and |
27750 | @samp{call}. In @code{gdbtk} only, there's a corresponding | |
27751 | @samp{gdb_eval} command. | |
922fbb7b AC |
27752 | |
27753 | @subsubheading Example | |
27754 | ||
a2c02241 NR |
27755 | In the following example, the numbers that precede the commands are the |
27756 | @dfn{tokens} described in @ref{GDB/MI Command Syntax, ,@sc{gdb/mi} | |
27757 | Command Syntax}. Notice how @sc{gdb/mi} returns the same tokens in its | |
27758 | output. | |
27759 | ||
922fbb7b | 27760 | @smallexample |
a2c02241 NR |
27761 | 211-data-evaluate-expression A |
27762 | 211^done,value="1" | |
594fe323 | 27763 | (gdb) |
a2c02241 NR |
27764 | 311-data-evaluate-expression &A |
27765 | 311^done,value="0xefffeb7c" | |
594fe323 | 27766 | (gdb) |
a2c02241 NR |
27767 | 411-data-evaluate-expression A+3 |
27768 | 411^done,value="4" | |
594fe323 | 27769 | (gdb) |
a2c02241 NR |
27770 | 511-data-evaluate-expression "A + 3" |
27771 | 511^done,value="4" | |
594fe323 | 27772 | (gdb) |
a2c02241 | 27773 | @end smallexample |
922fbb7b AC |
27774 | |
27775 | ||
a2c02241 NR |
27776 | @subheading The @code{-data-list-changed-registers} Command |
27777 | @findex -data-list-changed-registers | |
922fbb7b AC |
27778 | |
27779 | @subsubheading Synopsis | |
27780 | ||
27781 | @smallexample | |
a2c02241 | 27782 | -data-list-changed-registers |
922fbb7b AC |
27783 | @end smallexample |
27784 | ||
a2c02241 | 27785 | Display a list of the registers that have changed. |
922fbb7b AC |
27786 | |
27787 | @subsubheading @value{GDBN} Command | |
27788 | ||
a2c02241 NR |
27789 | @value{GDBN} doesn't have a direct analog for this command; @code{gdbtk} |
27790 | has the corresponding command @samp{gdb_changed_register_list}. | |
922fbb7b AC |
27791 | |
27792 | @subsubheading Example | |
922fbb7b | 27793 | |
a2c02241 | 27794 | On a PPC MBX board: |
922fbb7b AC |
27795 | |
27796 | @smallexample | |
594fe323 | 27797 | (gdb) |
a2c02241 NR |
27798 | -exec-continue |
27799 | ^running | |
922fbb7b | 27800 | |
594fe323 | 27801 | (gdb) |
a47ec5fe AR |
27802 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame=@{ |
27803 | func="main",args=[],file="try.c",fullname="/home/foo/bar/try.c", | |
27804 | line="5"@} | |
594fe323 | 27805 | (gdb) |
a2c02241 NR |
27806 | -data-list-changed-registers |
27807 | ^done,changed-registers=["0","1","2","4","5","6","7","8","9", | |
27808 | "10","11","13","14","15","16","17","18","19","20","21","22","23", | |
27809 | "24","25","26","27","28","30","31","64","65","66","67","69"] | |
594fe323 | 27810 | (gdb) |
a2c02241 | 27811 | @end smallexample |
922fbb7b AC |
27812 | |
27813 | ||
a2c02241 NR |
27814 | @subheading The @code{-data-list-register-names} Command |
27815 | @findex -data-list-register-names | |
922fbb7b AC |
27816 | |
27817 | @subsubheading Synopsis | |
27818 | ||
27819 | @smallexample | |
a2c02241 | 27820 | -data-list-register-names [ ( @var{regno} )+ ] |
922fbb7b AC |
27821 | @end smallexample |
27822 | ||
a2c02241 NR |
27823 | Show a list of register names for the current target. If no arguments |
27824 | are given, it shows a list of the names of all the registers. If | |
27825 | integer numbers are given as arguments, it will print a list of the | |
27826 | names of the registers corresponding to the arguments. To ensure | |
27827 | consistency between a register name and its number, the output list may | |
27828 | include empty register names. | |
922fbb7b AC |
27829 | |
27830 | @subsubheading @value{GDBN} Command | |
27831 | ||
a2c02241 NR |
27832 | @value{GDBN} does not have a command which corresponds to |
27833 | @samp{-data-list-register-names}. In @code{gdbtk} there is a | |
27834 | corresponding command @samp{gdb_regnames}. | |
922fbb7b AC |
27835 | |
27836 | @subsubheading Example | |
922fbb7b | 27837 | |
a2c02241 NR |
27838 | For the PPC MBX board: |
27839 | @smallexample | |
594fe323 | 27840 | (gdb) |
a2c02241 NR |
27841 | -data-list-register-names |
27842 | ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7", | |
27843 | "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18", | |
27844 | "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29", | |
27845 | "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9", | |
27846 | "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20", | |
27847 | "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31", | |
27848 | "", "pc","ps","cr","lr","ctr","xer"] | |
594fe323 | 27849 | (gdb) |
a2c02241 NR |
27850 | -data-list-register-names 1 2 3 |
27851 | ^done,register-names=["r1","r2","r3"] | |
594fe323 | 27852 | (gdb) |
a2c02241 | 27853 | @end smallexample |
922fbb7b | 27854 | |
a2c02241 NR |
27855 | @subheading The @code{-data-list-register-values} Command |
27856 | @findex -data-list-register-values | |
922fbb7b AC |
27857 | |
27858 | @subsubheading Synopsis | |
27859 | ||
27860 | @smallexample | |
a2c02241 | 27861 | -data-list-register-values @var{fmt} [ ( @var{regno} )*] |
922fbb7b AC |
27862 | @end smallexample |
27863 | ||
a2c02241 NR |
27864 | Display the registers' contents. @var{fmt} is the format according to |
27865 | which the registers' contents are to be returned, followed by an optional | |
27866 | list of numbers specifying the registers to display. A missing list of | |
27867 | numbers indicates that the contents of all the registers must be returned. | |
27868 | ||
27869 | Allowed formats for @var{fmt} are: | |
27870 | ||
27871 | @table @code | |
27872 | @item x | |
27873 | Hexadecimal | |
27874 | @item o | |
27875 | Octal | |
27876 | @item t | |
27877 | Binary | |
27878 | @item d | |
27879 | Decimal | |
27880 | @item r | |
27881 | Raw | |
27882 | @item N | |
27883 | Natural | |
27884 | @end table | |
922fbb7b AC |
27885 | |
27886 | @subsubheading @value{GDBN} Command | |
27887 | ||
a2c02241 NR |
27888 | The corresponding @value{GDBN} commands are @samp{info reg}, @samp{info |
27889 | all-reg}, and (in @code{gdbtk}) @samp{gdb_fetch_registers}. | |
922fbb7b AC |
27890 | |
27891 | @subsubheading Example | |
922fbb7b | 27892 | |
a2c02241 NR |
27893 | For a PPC MBX board (note: line breaks are for readability only, they |
27894 | don't appear in the actual output): | |
27895 | ||
27896 | @smallexample | |
594fe323 | 27897 | (gdb) |
a2c02241 NR |
27898 | -data-list-register-values r 64 65 |
27899 | ^done,register-values=[@{number="64",value="0xfe00a300"@}, | |
27900 | @{number="65",value="0x00029002"@}] | |
594fe323 | 27901 | (gdb) |
a2c02241 NR |
27902 | -data-list-register-values x |
27903 | ^done,register-values=[@{number="0",value="0xfe0043c8"@}, | |
27904 | @{number="1",value="0x3fff88"@},@{number="2",value="0xfffffffe"@}, | |
27905 | @{number="3",value="0x0"@},@{number="4",value="0xa"@}, | |
27906 | @{number="5",value="0x3fff68"@},@{number="6",value="0x3fff58"@}, | |
27907 | @{number="7",value="0xfe011e98"@},@{number="8",value="0x2"@}, | |
27908 | @{number="9",value="0xfa202820"@},@{number="10",value="0xfa202808"@}, | |
27909 | @{number="11",value="0x1"@},@{number="12",value="0x0"@}, | |
27910 | @{number="13",value="0x4544"@},@{number="14",value="0xffdfffff"@}, | |
27911 | @{number="15",value="0xffffffff"@},@{number="16",value="0xfffffeff"@}, | |
27912 | @{number="17",value="0xefffffed"@},@{number="18",value="0xfffffffe"@}, | |
27913 | @{number="19",value="0xffffffff"@},@{number="20",value="0xffffffff"@}, | |
27914 | @{number="21",value="0xffffffff"@},@{number="22",value="0xfffffff7"@}, | |
27915 | @{number="23",value="0xffffffff"@},@{number="24",value="0xffffffff"@}, | |
27916 | @{number="25",value="0xffffffff"@},@{number="26",value="0xfffffffb"@}, | |
27917 | @{number="27",value="0xffffffff"@},@{number="28",value="0xf7bfffff"@}, | |
27918 | @{number="29",value="0x0"@},@{number="30",value="0xfe010000"@}, | |
27919 | @{number="31",value="0x0"@},@{number="32",value="0x0"@}, | |
27920 | @{number="33",value="0x0"@},@{number="34",value="0x0"@}, | |
27921 | @{number="35",value="0x0"@},@{number="36",value="0x0"@}, | |
27922 | @{number="37",value="0x0"@},@{number="38",value="0x0"@}, | |
27923 | @{number="39",value="0x0"@},@{number="40",value="0x0"@}, | |
27924 | @{number="41",value="0x0"@},@{number="42",value="0x0"@}, | |
27925 | @{number="43",value="0x0"@},@{number="44",value="0x0"@}, | |
27926 | @{number="45",value="0x0"@},@{number="46",value="0x0"@}, | |
27927 | @{number="47",value="0x0"@},@{number="48",value="0x0"@}, | |
27928 | @{number="49",value="0x0"@},@{number="50",value="0x0"@}, | |
27929 | @{number="51",value="0x0"@},@{number="52",value="0x0"@}, | |
27930 | @{number="53",value="0x0"@},@{number="54",value="0x0"@}, | |
27931 | @{number="55",value="0x0"@},@{number="56",value="0x0"@}, | |
27932 | @{number="57",value="0x0"@},@{number="58",value="0x0"@}, | |
27933 | @{number="59",value="0x0"@},@{number="60",value="0x0"@}, | |
27934 | @{number="61",value="0x0"@},@{number="62",value="0x0"@}, | |
27935 | @{number="63",value="0x0"@},@{number="64",value="0xfe00a300"@}, | |
27936 | @{number="65",value="0x29002"@},@{number="66",value="0x202f04b5"@}, | |
27937 | @{number="67",value="0xfe0043b0"@},@{number="68",value="0xfe00b3e4"@}, | |
27938 | @{number="69",value="0x20002b03"@}] | |
594fe323 | 27939 | (gdb) |
a2c02241 | 27940 | @end smallexample |
922fbb7b | 27941 | |
a2c02241 NR |
27942 | |
27943 | @subheading The @code{-data-read-memory} Command | |
27944 | @findex -data-read-memory | |
922fbb7b | 27945 | |
8dedea02 VP |
27946 | This command is deprecated, use @code{-data-read-memory-bytes} instead. |
27947 | ||
922fbb7b AC |
27948 | @subsubheading Synopsis |
27949 | ||
27950 | @smallexample | |
a2c02241 NR |
27951 | -data-read-memory [ -o @var{byte-offset} ] |
27952 | @var{address} @var{word-format} @var{word-size} | |
27953 | @var{nr-rows} @var{nr-cols} [ @var{aschar} ] | |
922fbb7b AC |
27954 | @end smallexample |
27955 | ||
a2c02241 NR |
27956 | @noindent |
27957 | where: | |
922fbb7b | 27958 | |
a2c02241 NR |
27959 | @table @samp |
27960 | @item @var{address} | |
27961 | An expression specifying the address of the first memory word to be | |
27962 | read. Complex expressions containing embedded white space should be | |
27963 | quoted using the C convention. | |
922fbb7b | 27964 | |
a2c02241 NR |
27965 | @item @var{word-format} |
27966 | The format to be used to print the memory words. The notation is the | |
27967 | same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats, | |
79a6e687 | 27968 | ,Output Formats}). |
922fbb7b | 27969 | |
a2c02241 NR |
27970 | @item @var{word-size} |
27971 | The size of each memory word in bytes. | |
922fbb7b | 27972 | |
a2c02241 NR |
27973 | @item @var{nr-rows} |
27974 | The number of rows in the output table. | |
922fbb7b | 27975 | |
a2c02241 NR |
27976 | @item @var{nr-cols} |
27977 | The number of columns in the output table. | |
922fbb7b | 27978 | |
a2c02241 NR |
27979 | @item @var{aschar} |
27980 | If present, indicates that each row should include an @sc{ascii} dump. The | |
27981 | value of @var{aschar} is used as a padding character when a byte is not a | |
27982 | member of the printable @sc{ascii} character set (printable @sc{ascii} | |
27983 | characters are those whose code is between 32 and 126, inclusively). | |
922fbb7b | 27984 | |
a2c02241 NR |
27985 | @item @var{byte-offset} |
27986 | An offset to add to the @var{address} before fetching memory. | |
27987 | @end table | |
922fbb7b | 27988 | |
a2c02241 NR |
27989 | This command displays memory contents as a table of @var{nr-rows} by |
27990 | @var{nr-cols} words, each word being @var{word-size} bytes. In total, | |
27991 | @code{@var{nr-rows} * @var{nr-cols} * @var{word-size}} bytes are read | |
27992 | (returned as @samp{total-bytes}). Should less than the requested number | |
27993 | of bytes be returned by the target, the missing words are identified | |
27994 | using @samp{N/A}. The number of bytes read from the target is returned | |
27995 | in @samp{nr-bytes} and the starting address used to read memory in | |
27996 | @samp{addr}. | |
27997 | ||
27998 | The address of the next/previous row or page is available in | |
27999 | @samp{next-row} and @samp{prev-row}, @samp{next-page} and | |
28000 | @samp{prev-page}. | |
922fbb7b AC |
28001 | |
28002 | @subsubheading @value{GDBN} Command | |
28003 | ||
a2c02241 NR |
28004 | The corresponding @value{GDBN} command is @samp{x}. @code{gdbtk} has |
28005 | @samp{gdb_get_mem} memory read command. | |
922fbb7b AC |
28006 | |
28007 | @subsubheading Example | |
32e7087d | 28008 | |
a2c02241 NR |
28009 | Read six bytes of memory starting at @code{bytes+6} but then offset by |
28010 | @code{-6} bytes. Format as three rows of two columns. One byte per | |
28011 | word. Display each word in hex. | |
32e7087d JB |
28012 | |
28013 | @smallexample | |
594fe323 | 28014 | (gdb) |
a2c02241 NR |
28015 | 9-data-read-memory -o -6 -- bytes+6 x 1 3 2 |
28016 | 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6", | |
28017 | next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396", | |
28018 | prev-page="0x0000138a",memory=[ | |
28019 | @{addr="0x00001390",data=["0x00","0x01"]@}, | |
28020 | @{addr="0x00001392",data=["0x02","0x03"]@}, | |
28021 | @{addr="0x00001394",data=["0x04","0x05"]@}] | |
594fe323 | 28022 | (gdb) |
32e7087d JB |
28023 | @end smallexample |
28024 | ||
a2c02241 NR |
28025 | Read two bytes of memory starting at address @code{shorts + 64} and |
28026 | display as a single word formatted in decimal. | |
32e7087d | 28027 | |
32e7087d | 28028 | @smallexample |
594fe323 | 28029 | (gdb) |
a2c02241 NR |
28030 | 5-data-read-memory shorts+64 d 2 1 1 |
28031 | 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2", | |
28032 | next-row="0x00001512",prev-row="0x0000150e", | |
28033 | next-page="0x00001512",prev-page="0x0000150e",memory=[ | |
28034 | @{addr="0x00001510",data=["128"]@}] | |
594fe323 | 28035 | (gdb) |
32e7087d JB |
28036 | @end smallexample |
28037 | ||
a2c02241 NR |
28038 | Read thirty two bytes of memory starting at @code{bytes+16} and format |
28039 | as eight rows of four columns. Include a string encoding with @samp{x} | |
28040 | used as the non-printable character. | |
922fbb7b AC |
28041 | |
28042 | @smallexample | |
594fe323 | 28043 | (gdb) |
a2c02241 NR |
28044 | 4-data-read-memory bytes+16 x 1 8 4 x |
28045 | 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32", | |
28046 | next-row="0x000013c0",prev-row="0x0000139c", | |
28047 | next-page="0x000013c0",prev-page="0x00001380",memory=[ | |
28048 | @{addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"@}, | |
28049 | @{addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"@}, | |
28050 | @{addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"@}, | |
28051 | @{addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"@}, | |
28052 | @{addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"@}, | |
28053 | @{addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"@}, | |
28054 | @{addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"@}, | |
28055 | @{addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"@}] | |
594fe323 | 28056 | (gdb) |
922fbb7b AC |
28057 | @end smallexample |
28058 | ||
8dedea02 VP |
28059 | @subheading The @code{-data-read-memory-bytes} Command |
28060 | @findex -data-read-memory-bytes | |
28061 | ||
28062 | @subsubheading Synopsis | |
28063 | ||
28064 | @smallexample | |
28065 | -data-read-memory-bytes [ -o @var{byte-offset} ] | |
28066 | @var{address} @var{count} | |
28067 | @end smallexample | |
28068 | ||
28069 | @noindent | |
28070 | where: | |
28071 | ||
28072 | @table @samp | |
28073 | @item @var{address} | |
28074 | An expression specifying the address of the first memory word to be | |
28075 | read. Complex expressions containing embedded white space should be | |
28076 | quoted using the C convention. | |
28077 | ||
28078 | @item @var{count} | |
28079 | The number of bytes to read. This should be an integer literal. | |
28080 | ||
28081 | @item @var{byte-offset} | |
28082 | The offsets in bytes relative to @var{address} at which to start | |
28083 | reading. This should be an integer literal. This option is provided | |
28084 | so that a frontend is not required to first evaluate address and then | |
28085 | perform address arithmetics itself. | |
28086 | ||
28087 | @end table | |
28088 | ||
28089 | This command attempts to read all accessible memory regions in the | |
28090 | specified range. First, all regions marked as unreadable in the memory | |
28091 | map (if one is defined) will be skipped. @xref{Memory Region | |
28092 | Attributes}. Second, @value{GDBN} will attempt to read the remaining | |
28093 | regions. For each one, if reading full region results in an errors, | |
28094 | @value{GDBN} will try to read a subset of the region. | |
28095 | ||
28096 | In general, every single byte in the region may be readable or not, | |
28097 | and the only way to read every readable byte is to try a read at | |
28098 | every address, which is not practical. Therefore, @value{GDBN} will | |
28099 | attempt to read all accessible bytes at either beginning or the end | |
28100 | of the region, using a binary division scheme. This heuristic works | |
28101 | well for reading accross a memory map boundary. Note that if a region | |
28102 | has a readable range that is neither at the beginning or the end, | |
28103 | @value{GDBN} will not read it. | |
28104 | ||
28105 | The result record (@pxref{GDB/MI Result Records}) that is output of | |
28106 | the command includes a field named @samp{memory} whose content is a | |
28107 | list of tuples. Each tuple represent a successfully read memory block | |
28108 | and has the following fields: | |
28109 | ||
28110 | @table @code | |
28111 | @item begin | |
28112 | The start address of the memory block, as hexadecimal literal. | |
28113 | ||
28114 | @item end | |
28115 | The end address of the memory block, as hexadecimal literal. | |
28116 | ||
28117 | @item offset | |
28118 | The offset of the memory block, as hexadecimal literal, relative to | |
28119 | the start address passed to @code{-data-read-memory-bytes}. | |
28120 | ||
28121 | @item contents | |
28122 | The contents of the memory block, in hex. | |
28123 | ||
28124 | @end table | |
28125 | ||
28126 | ||
28127 | ||
28128 | @subsubheading @value{GDBN} Command | |
28129 | ||
28130 | The corresponding @value{GDBN} command is @samp{x}. | |
28131 | ||
28132 | @subsubheading Example | |
28133 | ||
28134 | @smallexample | |
28135 | (gdb) | |
28136 | -data-read-memory-bytes &a 10 | |
28137 | ^done,memory=[@{begin="0xbffff154",offset="0x00000000", | |
28138 | end="0xbffff15e", | |
28139 | contents="01000000020000000300"@}] | |
28140 | (gdb) | |
28141 | @end smallexample | |
28142 | ||
28143 | ||
28144 | @subheading The @code{-data-write-memory-bytes} Command | |
28145 | @findex -data-write-memory-bytes | |
28146 | ||
28147 | @subsubheading Synopsis | |
28148 | ||
28149 | @smallexample | |
28150 | -data-write-memory-bytes @var{address} @var{contents} | |
28151 | @end smallexample | |
28152 | ||
28153 | @noindent | |
28154 | where: | |
28155 | ||
28156 | @table @samp | |
28157 | @item @var{address} | |
28158 | An expression specifying the address of the first memory word to be | |
28159 | read. Complex expressions containing embedded white space should be | |
28160 | quoted using the C convention. | |
28161 | ||
28162 | @item @var{contents} | |
28163 | The hex-encoded bytes to write. | |
28164 | ||
28165 | @end table | |
28166 | ||
28167 | @subsubheading @value{GDBN} Command | |
28168 | ||
28169 | There's no corresponding @value{GDBN} command. | |
28170 | ||
28171 | @subsubheading Example | |
28172 | ||
28173 | @smallexample | |
28174 | (gdb) | |
28175 | -data-write-memory-bytes &a "aabbccdd" | |
28176 | ^done | |
28177 | (gdb) | |
28178 | @end smallexample | |
28179 | ||
28180 | ||
a2c02241 NR |
28181 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
28182 | @node GDB/MI Tracepoint Commands | |
28183 | @section @sc{gdb/mi} Tracepoint Commands | |
922fbb7b | 28184 | |
18148017 VP |
28185 | The commands defined in this section implement MI support for |
28186 | tracepoints. For detailed introduction, see @ref{Tracepoints}. | |
28187 | ||
28188 | @subheading The @code{-trace-find} Command | |
28189 | @findex -trace-find | |
28190 | ||
28191 | @subsubheading Synopsis | |
28192 | ||
28193 | @smallexample | |
28194 | -trace-find @var{mode} [@var{parameters}@dots{}] | |
28195 | @end smallexample | |
28196 | ||
28197 | Find a trace frame using criteria defined by @var{mode} and | |
28198 | @var{parameters}. The following table lists permissible | |
28199 | modes and their parameters. For details of operation, see @ref{tfind}. | |
28200 | ||
28201 | @table @samp | |
28202 | ||
28203 | @item none | |
28204 | No parameters are required. Stops examining trace frames. | |
28205 | ||
28206 | @item frame-number | |
28207 | An integer is required as parameter. Selects tracepoint frame with | |
28208 | that index. | |
28209 | ||
28210 | @item tracepoint-number | |
28211 | An integer is required as parameter. Finds next | |
28212 | trace frame that corresponds to tracepoint with the specified number. | |
28213 | ||
28214 | @item pc | |
28215 | An address is required as parameter. Finds | |
28216 | next trace frame that corresponds to any tracepoint at the specified | |
28217 | address. | |
28218 | ||
28219 | @item pc-inside-range | |
28220 | Two addresses are required as parameters. Finds next trace | |
28221 | frame that corresponds to a tracepoint at an address inside the | |
28222 | specified range. Both bounds are considered to be inside the range. | |
28223 | ||
28224 | @item pc-outside-range | |
28225 | Two addresses are required as parameters. Finds | |
28226 | next trace frame that corresponds to a tracepoint at an address outside | |
28227 | the specified range. Both bounds are considered to be inside the range. | |
28228 | ||
28229 | @item line | |
28230 | Line specification is required as parameter. @xref{Specify Location}. | |
28231 | Finds next trace frame that corresponds to a tracepoint at | |
28232 | the specified location. | |
28233 | ||
28234 | @end table | |
28235 | ||
28236 | If @samp{none} was passed as @var{mode}, the response does not | |
28237 | have fields. Otherwise, the response may have the following fields: | |
28238 | ||
28239 | @table @samp | |
28240 | @item found | |
28241 | This field has either @samp{0} or @samp{1} as the value, depending | |
28242 | on whether a matching tracepoint was found. | |
28243 | ||
28244 | @item traceframe | |
28245 | The index of the found traceframe. This field is present iff | |
28246 | the @samp{found} field has value of @samp{1}. | |
28247 | ||
28248 | @item tracepoint | |
28249 | The index of the found tracepoint. This field is present iff | |
28250 | the @samp{found} field has value of @samp{1}. | |
28251 | ||
28252 | @item frame | |
28253 | The information about the frame corresponding to the found trace | |
28254 | frame. This field is present only if a trace frame was found. | |
cd64ee31 | 28255 | @xref{GDB/MI Frame Information}, for description of this field. |
18148017 VP |
28256 | |
28257 | @end table | |
28258 | ||
7d13fe92 SS |
28259 | @subsubheading @value{GDBN} Command |
28260 | ||
28261 | The corresponding @value{GDBN} command is @samp{tfind}. | |
28262 | ||
18148017 VP |
28263 | @subheading -trace-define-variable |
28264 | @findex -trace-define-variable | |
28265 | ||
28266 | @subsubheading Synopsis | |
28267 | ||
28268 | @smallexample | |
28269 | -trace-define-variable @var{name} [ @var{value} ] | |
28270 | @end smallexample | |
28271 | ||
28272 | Create trace variable @var{name} if it does not exist. If | |
28273 | @var{value} is specified, sets the initial value of the specified | |
28274 | trace variable to that value. Note that the @var{name} should start | |
28275 | with the @samp{$} character. | |
28276 | ||
7d13fe92 SS |
28277 | @subsubheading @value{GDBN} Command |
28278 | ||
28279 | The corresponding @value{GDBN} command is @samp{tvariable}. | |
28280 | ||
18148017 VP |
28281 | @subheading -trace-list-variables |
28282 | @findex -trace-list-variables | |
922fbb7b | 28283 | |
18148017 | 28284 | @subsubheading Synopsis |
922fbb7b | 28285 | |
18148017 VP |
28286 | @smallexample |
28287 | -trace-list-variables | |
28288 | @end smallexample | |
922fbb7b | 28289 | |
18148017 VP |
28290 | Return a table of all defined trace variables. Each element of the |
28291 | table has the following fields: | |
922fbb7b | 28292 | |
18148017 VP |
28293 | @table @samp |
28294 | @item name | |
28295 | The name of the trace variable. This field is always present. | |
922fbb7b | 28296 | |
18148017 VP |
28297 | @item initial |
28298 | The initial value. This is a 64-bit signed integer. This | |
28299 | field is always present. | |
922fbb7b | 28300 | |
18148017 VP |
28301 | @item current |
28302 | The value the trace variable has at the moment. This is a 64-bit | |
28303 | signed integer. This field is absent iff current value is | |
28304 | not defined, for example if the trace was never run, or is | |
28305 | presently running. | |
922fbb7b | 28306 | |
18148017 | 28307 | @end table |
922fbb7b | 28308 | |
7d13fe92 SS |
28309 | @subsubheading @value{GDBN} Command |
28310 | ||
28311 | The corresponding @value{GDBN} command is @samp{tvariables}. | |
28312 | ||
18148017 | 28313 | @subsubheading Example |
922fbb7b | 28314 | |
18148017 VP |
28315 | @smallexample |
28316 | (gdb) | |
28317 | -trace-list-variables | |
28318 | ^done,trace-variables=@{nr_rows="1",nr_cols="3", | |
28319 | hdr=[@{width="15",alignment="-1",col_name="name",colhdr="Name"@}, | |
28320 | @{width="11",alignment="-1",col_name="initial",colhdr="Initial"@}, | |
28321 | @{width="11",alignment="-1",col_name="current",colhdr="Current"@}], | |
28322 | body=[variable=@{name="$trace_timestamp",initial="0"@} | |
28323 | variable=@{name="$foo",initial="10",current="15"@}]@} | |
28324 | (gdb) | |
28325 | @end smallexample | |
922fbb7b | 28326 | |
18148017 VP |
28327 | @subheading -trace-save |
28328 | @findex -trace-save | |
922fbb7b | 28329 | |
18148017 VP |
28330 | @subsubheading Synopsis |
28331 | ||
28332 | @smallexample | |
28333 | -trace-save [-r ] @var{filename} | |
28334 | @end smallexample | |
28335 | ||
28336 | Saves the collected trace data to @var{filename}. Without the | |
28337 | @samp{-r} option, the data is downloaded from the target and saved | |
28338 | in a local file. With the @samp{-r} option the target is asked | |
28339 | to perform the save. | |
28340 | ||
7d13fe92 SS |
28341 | @subsubheading @value{GDBN} Command |
28342 | ||
28343 | The corresponding @value{GDBN} command is @samp{tsave}. | |
28344 | ||
18148017 VP |
28345 | |
28346 | @subheading -trace-start | |
28347 | @findex -trace-start | |
28348 | ||
28349 | @subsubheading Synopsis | |
28350 | ||
28351 | @smallexample | |
28352 | -trace-start | |
28353 | @end smallexample | |
922fbb7b | 28354 | |
18148017 VP |
28355 | Starts a tracing experiments. The result of this command does not |
28356 | have any fields. | |
922fbb7b | 28357 | |
7d13fe92 SS |
28358 | @subsubheading @value{GDBN} Command |
28359 | ||
28360 | The corresponding @value{GDBN} command is @samp{tstart}. | |
28361 | ||
18148017 VP |
28362 | @subheading -trace-status |
28363 | @findex -trace-status | |
922fbb7b | 28364 | |
18148017 VP |
28365 | @subsubheading Synopsis |
28366 | ||
28367 | @smallexample | |
28368 | -trace-status | |
28369 | @end smallexample | |
28370 | ||
a97153c7 | 28371 | Obtains the status of a tracing experiment. The result may include |
18148017 VP |
28372 | the following fields: |
28373 | ||
28374 | @table @samp | |
28375 | ||
28376 | @item supported | |
28377 | May have a value of either @samp{0}, when no tracing operations are | |
28378 | supported, @samp{1}, when all tracing operations are supported, or | |
28379 | @samp{file} when examining trace file. In the latter case, examining | |
28380 | of trace frame is possible but new tracing experiement cannot be | |
28381 | started. This field is always present. | |
28382 | ||
28383 | @item running | |
28384 | May have a value of either @samp{0} or @samp{1} depending on whether | |
28385 | tracing experiement is in progress on target. This field is present | |
28386 | if @samp{supported} field is not @samp{0}. | |
28387 | ||
28388 | @item stop-reason | |
28389 | Report the reason why the tracing was stopped last time. This field | |
28390 | may be absent iff tracing was never stopped on target yet. The | |
28391 | value of @samp{request} means the tracing was stopped as result of | |
28392 | the @code{-trace-stop} command. The value of @samp{overflow} means | |
28393 | the tracing buffer is full. The value of @samp{disconnection} means | |
28394 | tracing was automatically stopped when @value{GDBN} has disconnected. | |
28395 | The value of @samp{passcount} means tracing was stopped when a | |
28396 | tracepoint was passed a maximal number of times for that tracepoint. | |
28397 | This field is present if @samp{supported} field is not @samp{0}. | |
28398 | ||
28399 | @item stopping-tracepoint | |
28400 | The number of tracepoint whose passcount as exceeded. This field is | |
28401 | present iff the @samp{stop-reason} field has the value of | |
28402 | @samp{passcount}. | |
28403 | ||
28404 | @item frames | |
87290684 SS |
28405 | @itemx frames-created |
28406 | The @samp{frames} field is a count of the total number of trace frames | |
28407 | in the trace buffer, while @samp{frames-created} is the total created | |
28408 | during the run, including ones that were discarded, such as when a | |
28409 | circular trace buffer filled up. Both fields are optional. | |
18148017 VP |
28410 | |
28411 | @item buffer-size | |
28412 | @itemx buffer-free | |
28413 | These fields tell the current size of the tracing buffer and the | |
87290684 | 28414 | remaining space. These fields are optional. |
18148017 | 28415 | |
a97153c7 PA |
28416 | @item circular |
28417 | The value of the circular trace buffer flag. @code{1} means that the | |
28418 | trace buffer is circular and old trace frames will be discarded if | |
28419 | necessary to make room, @code{0} means that the trace buffer is linear | |
28420 | and may fill up. | |
28421 | ||
28422 | @item disconnected | |
28423 | The value of the disconnected tracing flag. @code{1} means that | |
28424 | tracing will continue after @value{GDBN} disconnects, @code{0} means | |
28425 | that the trace run will stop. | |
28426 | ||
18148017 VP |
28427 | @end table |
28428 | ||
7d13fe92 SS |
28429 | @subsubheading @value{GDBN} Command |
28430 | ||
28431 | The corresponding @value{GDBN} command is @samp{tstatus}. | |
28432 | ||
18148017 VP |
28433 | @subheading -trace-stop |
28434 | @findex -trace-stop | |
28435 | ||
28436 | @subsubheading Synopsis | |
28437 | ||
28438 | @smallexample | |
28439 | -trace-stop | |
28440 | @end smallexample | |
922fbb7b | 28441 | |
18148017 VP |
28442 | Stops a tracing experiment. The result of this command has the same |
28443 | fields as @code{-trace-status}, except that the @samp{supported} and | |
28444 | @samp{running} fields are not output. | |
922fbb7b | 28445 | |
7d13fe92 SS |
28446 | @subsubheading @value{GDBN} Command |
28447 | ||
28448 | The corresponding @value{GDBN} command is @samp{tstop}. | |
28449 | ||
922fbb7b | 28450 | |
a2c02241 NR |
28451 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
28452 | @node GDB/MI Symbol Query | |
28453 | @section @sc{gdb/mi} Symbol Query Commands | |
922fbb7b AC |
28454 | |
28455 | ||
9901a55b | 28456 | @ignore |
a2c02241 NR |
28457 | @subheading The @code{-symbol-info-address} Command |
28458 | @findex -symbol-info-address | |
922fbb7b AC |
28459 | |
28460 | @subsubheading Synopsis | |
28461 | ||
28462 | @smallexample | |
a2c02241 | 28463 | -symbol-info-address @var{symbol} |
922fbb7b AC |
28464 | @end smallexample |
28465 | ||
a2c02241 | 28466 | Describe where @var{symbol} is stored. |
922fbb7b AC |
28467 | |
28468 | @subsubheading @value{GDBN} Command | |
28469 | ||
a2c02241 | 28470 | The corresponding @value{GDBN} command is @samp{info address}. |
922fbb7b AC |
28471 | |
28472 | @subsubheading Example | |
28473 | N.A. | |
28474 | ||
28475 | ||
a2c02241 NR |
28476 | @subheading The @code{-symbol-info-file} Command |
28477 | @findex -symbol-info-file | |
922fbb7b AC |
28478 | |
28479 | @subsubheading Synopsis | |
28480 | ||
28481 | @smallexample | |
a2c02241 | 28482 | -symbol-info-file |
922fbb7b AC |
28483 | @end smallexample |
28484 | ||
a2c02241 | 28485 | Show the file for the symbol. |
922fbb7b | 28486 | |
a2c02241 | 28487 | @subsubheading @value{GDBN} Command |
922fbb7b | 28488 | |
a2c02241 NR |
28489 | There's no equivalent @value{GDBN} command. @code{gdbtk} has |
28490 | @samp{gdb_find_file}. | |
922fbb7b AC |
28491 | |
28492 | @subsubheading Example | |
28493 | N.A. | |
28494 | ||
28495 | ||
a2c02241 NR |
28496 | @subheading The @code{-symbol-info-function} Command |
28497 | @findex -symbol-info-function | |
922fbb7b AC |
28498 | |
28499 | @subsubheading Synopsis | |
28500 | ||
28501 | @smallexample | |
a2c02241 | 28502 | -symbol-info-function |
922fbb7b AC |
28503 | @end smallexample |
28504 | ||
a2c02241 | 28505 | Show which function the symbol lives in. |
922fbb7b AC |
28506 | |
28507 | @subsubheading @value{GDBN} Command | |
28508 | ||
a2c02241 | 28509 | @samp{gdb_get_function} in @code{gdbtk}. |
922fbb7b AC |
28510 | |
28511 | @subsubheading Example | |
28512 | N.A. | |
28513 | ||
28514 | ||
a2c02241 NR |
28515 | @subheading The @code{-symbol-info-line} Command |
28516 | @findex -symbol-info-line | |
922fbb7b AC |
28517 | |
28518 | @subsubheading Synopsis | |
28519 | ||
28520 | @smallexample | |
a2c02241 | 28521 | -symbol-info-line |
922fbb7b AC |
28522 | @end smallexample |
28523 | ||
a2c02241 | 28524 | Show the core addresses of the code for a source line. |
922fbb7b | 28525 | |
a2c02241 | 28526 | @subsubheading @value{GDBN} Command |
922fbb7b | 28527 | |
a2c02241 NR |
28528 | The corresponding @value{GDBN} command is @samp{info line}. |
28529 | @code{gdbtk} has the @samp{gdb_get_line} and @samp{gdb_get_file} commands. | |
922fbb7b AC |
28530 | |
28531 | @subsubheading Example | |
a2c02241 | 28532 | N.A. |
922fbb7b AC |
28533 | |
28534 | ||
a2c02241 NR |
28535 | @subheading The @code{-symbol-info-symbol} Command |
28536 | @findex -symbol-info-symbol | |
07f31aa6 DJ |
28537 | |
28538 | @subsubheading Synopsis | |
28539 | ||
a2c02241 NR |
28540 | @smallexample |
28541 | -symbol-info-symbol @var{addr} | |
28542 | @end smallexample | |
07f31aa6 | 28543 | |
a2c02241 | 28544 | Describe what symbol is at location @var{addr}. |
07f31aa6 | 28545 | |
a2c02241 | 28546 | @subsubheading @value{GDBN} Command |
07f31aa6 | 28547 | |
a2c02241 | 28548 | The corresponding @value{GDBN} command is @samp{info symbol}. |
07f31aa6 DJ |
28549 | |
28550 | @subsubheading Example | |
a2c02241 | 28551 | N.A. |
07f31aa6 DJ |
28552 | |
28553 | ||
a2c02241 NR |
28554 | @subheading The @code{-symbol-list-functions} Command |
28555 | @findex -symbol-list-functions | |
922fbb7b AC |
28556 | |
28557 | @subsubheading Synopsis | |
28558 | ||
28559 | @smallexample | |
a2c02241 | 28560 | -symbol-list-functions |
922fbb7b AC |
28561 | @end smallexample |
28562 | ||
a2c02241 | 28563 | List the functions in the executable. |
922fbb7b AC |
28564 | |
28565 | @subsubheading @value{GDBN} Command | |
28566 | ||
a2c02241 NR |
28567 | @samp{info functions} in @value{GDBN}, @samp{gdb_listfunc} and |
28568 | @samp{gdb_search} in @code{gdbtk}. | |
922fbb7b AC |
28569 | |
28570 | @subsubheading Example | |
a2c02241 | 28571 | N.A. |
9901a55b | 28572 | @end ignore |
922fbb7b AC |
28573 | |
28574 | ||
a2c02241 NR |
28575 | @subheading The @code{-symbol-list-lines} Command |
28576 | @findex -symbol-list-lines | |
922fbb7b AC |
28577 | |
28578 | @subsubheading Synopsis | |
28579 | ||
28580 | @smallexample | |
a2c02241 | 28581 | -symbol-list-lines @var{filename} |
922fbb7b AC |
28582 | @end smallexample |
28583 | ||
a2c02241 NR |
28584 | Print the list of lines that contain code and their associated program |
28585 | addresses for the given source filename. The entries are sorted in | |
28586 | ascending PC order. | |
922fbb7b AC |
28587 | |
28588 | @subsubheading @value{GDBN} Command | |
28589 | ||
a2c02241 | 28590 | There is no corresponding @value{GDBN} command. |
922fbb7b AC |
28591 | |
28592 | @subsubheading Example | |
a2c02241 | 28593 | @smallexample |
594fe323 | 28594 | (gdb) |
a2c02241 NR |
28595 | -symbol-list-lines basics.c |
28596 | ^done,lines=[@{pc="0x08048554",line="7"@},@{pc="0x0804855a",line="8"@}] | |
594fe323 | 28597 | (gdb) |
a2c02241 | 28598 | @end smallexample |
922fbb7b AC |
28599 | |
28600 | ||
9901a55b | 28601 | @ignore |
a2c02241 NR |
28602 | @subheading The @code{-symbol-list-types} Command |
28603 | @findex -symbol-list-types | |
922fbb7b AC |
28604 | |
28605 | @subsubheading Synopsis | |
28606 | ||
28607 | @smallexample | |
a2c02241 | 28608 | -symbol-list-types |
922fbb7b AC |
28609 | @end smallexample |
28610 | ||
a2c02241 | 28611 | List all the type names. |
922fbb7b AC |
28612 | |
28613 | @subsubheading @value{GDBN} Command | |
28614 | ||
a2c02241 NR |
28615 | The corresponding commands are @samp{info types} in @value{GDBN}, |
28616 | @samp{gdb_search} in @code{gdbtk}. | |
922fbb7b AC |
28617 | |
28618 | @subsubheading Example | |
28619 | N.A. | |
28620 | ||
28621 | ||
a2c02241 NR |
28622 | @subheading The @code{-symbol-list-variables} Command |
28623 | @findex -symbol-list-variables | |
922fbb7b AC |
28624 | |
28625 | @subsubheading Synopsis | |
28626 | ||
28627 | @smallexample | |
a2c02241 | 28628 | -symbol-list-variables |
922fbb7b AC |
28629 | @end smallexample |
28630 | ||
a2c02241 | 28631 | List all the global and static variable names. |
922fbb7b AC |
28632 | |
28633 | @subsubheading @value{GDBN} Command | |
28634 | ||
a2c02241 | 28635 | @samp{info variables} in @value{GDBN}, @samp{gdb_search} in @code{gdbtk}. |
922fbb7b AC |
28636 | |
28637 | @subsubheading Example | |
28638 | N.A. | |
28639 | ||
28640 | ||
a2c02241 NR |
28641 | @subheading The @code{-symbol-locate} Command |
28642 | @findex -symbol-locate | |
922fbb7b AC |
28643 | |
28644 | @subsubheading Synopsis | |
28645 | ||
28646 | @smallexample | |
a2c02241 | 28647 | -symbol-locate |
922fbb7b AC |
28648 | @end smallexample |
28649 | ||
922fbb7b AC |
28650 | @subsubheading @value{GDBN} Command |
28651 | ||
a2c02241 | 28652 | @samp{gdb_loc} in @code{gdbtk}. |
922fbb7b AC |
28653 | |
28654 | @subsubheading Example | |
28655 | N.A. | |
28656 | ||
28657 | ||
a2c02241 NR |
28658 | @subheading The @code{-symbol-type} Command |
28659 | @findex -symbol-type | |
922fbb7b AC |
28660 | |
28661 | @subsubheading Synopsis | |
28662 | ||
28663 | @smallexample | |
a2c02241 | 28664 | -symbol-type @var{variable} |
922fbb7b AC |
28665 | @end smallexample |
28666 | ||
a2c02241 | 28667 | Show type of @var{variable}. |
922fbb7b | 28668 | |
a2c02241 | 28669 | @subsubheading @value{GDBN} Command |
922fbb7b | 28670 | |
a2c02241 NR |
28671 | The corresponding @value{GDBN} command is @samp{ptype}, @code{gdbtk} has |
28672 | @samp{gdb_obj_variable}. | |
28673 | ||
28674 | @subsubheading Example | |
28675 | N.A. | |
9901a55b | 28676 | @end ignore |
a2c02241 NR |
28677 | |
28678 | ||
28679 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
28680 | @node GDB/MI File Commands | |
28681 | @section @sc{gdb/mi} File Commands | |
28682 | ||
28683 | This section describes the GDB/MI commands to specify executable file names | |
28684 | and to read in and obtain symbol table information. | |
28685 | ||
28686 | @subheading The @code{-file-exec-and-symbols} Command | |
28687 | @findex -file-exec-and-symbols | |
28688 | ||
28689 | @subsubheading Synopsis | |
922fbb7b AC |
28690 | |
28691 | @smallexample | |
a2c02241 | 28692 | -file-exec-and-symbols @var{file} |
922fbb7b AC |
28693 | @end smallexample |
28694 | ||
a2c02241 NR |
28695 | Specify the executable file to be debugged. This file is the one from |
28696 | which the symbol table is also read. If no file is specified, the | |
28697 | command clears the executable and symbol information. If breakpoints | |
28698 | are set when using this command with no arguments, @value{GDBN} will produce | |
28699 | error messages. Otherwise, no output is produced, except a completion | |
28700 | notification. | |
28701 | ||
922fbb7b AC |
28702 | @subsubheading @value{GDBN} Command |
28703 | ||
a2c02241 | 28704 | The corresponding @value{GDBN} command is @samp{file}. |
922fbb7b AC |
28705 | |
28706 | @subsubheading Example | |
28707 | ||
28708 | @smallexample | |
594fe323 | 28709 | (gdb) |
a2c02241 NR |
28710 | -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
28711 | ^done | |
594fe323 | 28712 | (gdb) |
922fbb7b AC |
28713 | @end smallexample |
28714 | ||
922fbb7b | 28715 | |
a2c02241 NR |
28716 | @subheading The @code{-file-exec-file} Command |
28717 | @findex -file-exec-file | |
922fbb7b AC |
28718 | |
28719 | @subsubheading Synopsis | |
28720 | ||
28721 | @smallexample | |
a2c02241 | 28722 | -file-exec-file @var{file} |
922fbb7b AC |
28723 | @end smallexample |
28724 | ||
a2c02241 NR |
28725 | Specify the executable file to be debugged. Unlike |
28726 | @samp{-file-exec-and-symbols}, the symbol table is @emph{not} read | |
28727 | from this file. If used without argument, @value{GDBN} clears the information | |
28728 | about the executable file. No output is produced, except a completion | |
28729 | notification. | |
922fbb7b | 28730 | |
a2c02241 NR |
28731 | @subsubheading @value{GDBN} Command |
28732 | ||
28733 | The corresponding @value{GDBN} command is @samp{exec-file}. | |
922fbb7b AC |
28734 | |
28735 | @subsubheading Example | |
a2c02241 NR |
28736 | |
28737 | @smallexample | |
594fe323 | 28738 | (gdb) |
a2c02241 NR |
28739 | -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
28740 | ^done | |
594fe323 | 28741 | (gdb) |
a2c02241 | 28742 | @end smallexample |
922fbb7b AC |
28743 | |
28744 | ||
9901a55b | 28745 | @ignore |
a2c02241 NR |
28746 | @subheading The @code{-file-list-exec-sections} Command |
28747 | @findex -file-list-exec-sections | |
922fbb7b AC |
28748 | |
28749 | @subsubheading Synopsis | |
28750 | ||
28751 | @smallexample | |
a2c02241 | 28752 | -file-list-exec-sections |
922fbb7b AC |
28753 | @end smallexample |
28754 | ||
a2c02241 NR |
28755 | List the sections of the current executable file. |
28756 | ||
922fbb7b AC |
28757 | @subsubheading @value{GDBN} Command |
28758 | ||
a2c02241 NR |
28759 | The @value{GDBN} command @samp{info file} shows, among the rest, the same |
28760 | information as this command. @code{gdbtk} has a corresponding command | |
28761 | @samp{gdb_load_info}. | |
922fbb7b AC |
28762 | |
28763 | @subsubheading Example | |
28764 | N.A. | |
9901a55b | 28765 | @end ignore |
922fbb7b AC |
28766 | |
28767 | ||
a2c02241 NR |
28768 | @subheading The @code{-file-list-exec-source-file} Command |
28769 | @findex -file-list-exec-source-file | |
922fbb7b AC |
28770 | |
28771 | @subsubheading Synopsis | |
28772 | ||
28773 | @smallexample | |
a2c02241 | 28774 | -file-list-exec-source-file |
922fbb7b AC |
28775 | @end smallexample |
28776 | ||
a2c02241 | 28777 | List the line number, the current source file, and the absolute path |
44288b44 NR |
28778 | to the current source file for the current executable. The macro |
28779 | information field has a value of @samp{1} or @samp{0} depending on | |
28780 | whether or not the file includes preprocessor macro information. | |
922fbb7b AC |
28781 | |
28782 | @subsubheading @value{GDBN} Command | |
28783 | ||
a2c02241 | 28784 | The @value{GDBN} equivalent is @samp{info source} |
922fbb7b AC |
28785 | |
28786 | @subsubheading Example | |
28787 | ||
922fbb7b | 28788 | @smallexample |
594fe323 | 28789 | (gdb) |
a2c02241 | 28790 | 123-file-list-exec-source-file |
44288b44 | 28791 | 123^done,line="1",file="foo.c",fullname="/home/bar/foo.c,macro-info="1" |
594fe323 | 28792 | (gdb) |
922fbb7b AC |
28793 | @end smallexample |
28794 | ||
28795 | ||
a2c02241 NR |
28796 | @subheading The @code{-file-list-exec-source-files} Command |
28797 | @findex -file-list-exec-source-files | |
922fbb7b AC |
28798 | |
28799 | @subsubheading Synopsis | |
28800 | ||
28801 | @smallexample | |
a2c02241 | 28802 | -file-list-exec-source-files |
922fbb7b AC |
28803 | @end smallexample |
28804 | ||
a2c02241 NR |
28805 | List the source files for the current executable. |
28806 | ||
3f94c067 BW |
28807 | It will always output the filename, but only when @value{GDBN} can find |
28808 | the absolute file name of a source file, will it output the fullname. | |
922fbb7b AC |
28809 | |
28810 | @subsubheading @value{GDBN} Command | |
28811 | ||
a2c02241 NR |
28812 | The @value{GDBN} equivalent is @samp{info sources}. |
28813 | @code{gdbtk} has an analogous command @samp{gdb_listfiles}. | |
922fbb7b AC |
28814 | |
28815 | @subsubheading Example | |
922fbb7b | 28816 | @smallexample |
594fe323 | 28817 | (gdb) |
a2c02241 NR |
28818 | -file-list-exec-source-files |
28819 | ^done,files=[ | |
28820 | @{file=foo.c,fullname=/home/foo.c@}, | |
28821 | @{file=/home/bar.c,fullname=/home/bar.c@}, | |
28822 | @{file=gdb_could_not_find_fullpath.c@}] | |
594fe323 | 28823 | (gdb) |
922fbb7b AC |
28824 | @end smallexample |
28825 | ||
9901a55b | 28826 | @ignore |
a2c02241 NR |
28827 | @subheading The @code{-file-list-shared-libraries} Command |
28828 | @findex -file-list-shared-libraries | |
922fbb7b | 28829 | |
a2c02241 | 28830 | @subsubheading Synopsis |
922fbb7b | 28831 | |
a2c02241 NR |
28832 | @smallexample |
28833 | -file-list-shared-libraries | |
28834 | @end smallexample | |
922fbb7b | 28835 | |
a2c02241 | 28836 | List the shared libraries in the program. |
922fbb7b | 28837 | |
a2c02241 | 28838 | @subsubheading @value{GDBN} Command |
922fbb7b | 28839 | |
a2c02241 | 28840 | The corresponding @value{GDBN} command is @samp{info shared}. |
922fbb7b | 28841 | |
a2c02241 NR |
28842 | @subsubheading Example |
28843 | N.A. | |
922fbb7b AC |
28844 | |
28845 | ||
a2c02241 NR |
28846 | @subheading The @code{-file-list-symbol-files} Command |
28847 | @findex -file-list-symbol-files | |
922fbb7b | 28848 | |
a2c02241 | 28849 | @subsubheading Synopsis |
922fbb7b | 28850 | |
a2c02241 NR |
28851 | @smallexample |
28852 | -file-list-symbol-files | |
28853 | @end smallexample | |
922fbb7b | 28854 | |
a2c02241 | 28855 | List symbol files. |
922fbb7b | 28856 | |
a2c02241 | 28857 | @subsubheading @value{GDBN} Command |
922fbb7b | 28858 | |
a2c02241 | 28859 | The corresponding @value{GDBN} command is @samp{info file} (part of it). |
922fbb7b | 28860 | |
a2c02241 NR |
28861 | @subsubheading Example |
28862 | N.A. | |
9901a55b | 28863 | @end ignore |
922fbb7b | 28864 | |
922fbb7b | 28865 | |
a2c02241 NR |
28866 | @subheading The @code{-file-symbol-file} Command |
28867 | @findex -file-symbol-file | |
922fbb7b | 28868 | |
a2c02241 | 28869 | @subsubheading Synopsis |
922fbb7b | 28870 | |
a2c02241 NR |
28871 | @smallexample |
28872 | -file-symbol-file @var{file} | |
28873 | @end smallexample | |
922fbb7b | 28874 | |
a2c02241 NR |
28875 | Read symbol table info from the specified @var{file} argument. When |
28876 | used without arguments, clears @value{GDBN}'s symbol table info. No output is | |
28877 | produced, except for a completion notification. | |
922fbb7b | 28878 | |
a2c02241 | 28879 | @subsubheading @value{GDBN} Command |
922fbb7b | 28880 | |
a2c02241 | 28881 | The corresponding @value{GDBN} command is @samp{symbol-file}. |
922fbb7b | 28882 | |
a2c02241 | 28883 | @subsubheading Example |
922fbb7b | 28884 | |
a2c02241 | 28885 | @smallexample |
594fe323 | 28886 | (gdb) |
a2c02241 NR |
28887 | -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx |
28888 | ^done | |
594fe323 | 28889 | (gdb) |
a2c02241 | 28890 | @end smallexample |
922fbb7b | 28891 | |
a2c02241 | 28892 | @ignore |
a2c02241 NR |
28893 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
28894 | @node GDB/MI Memory Overlay Commands | |
28895 | @section @sc{gdb/mi} Memory Overlay Commands | |
922fbb7b | 28896 | |
a2c02241 | 28897 | The memory overlay commands are not implemented. |
922fbb7b | 28898 | |
a2c02241 | 28899 | @c @subheading -overlay-auto |
922fbb7b | 28900 | |
a2c02241 | 28901 | @c @subheading -overlay-list-mapping-state |
922fbb7b | 28902 | |
a2c02241 | 28903 | @c @subheading -overlay-list-overlays |
922fbb7b | 28904 | |
a2c02241 | 28905 | @c @subheading -overlay-map |
922fbb7b | 28906 | |
a2c02241 | 28907 | @c @subheading -overlay-off |
922fbb7b | 28908 | |
a2c02241 | 28909 | @c @subheading -overlay-on |
922fbb7b | 28910 | |
a2c02241 | 28911 | @c @subheading -overlay-unmap |
922fbb7b | 28912 | |
a2c02241 NR |
28913 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
28914 | @node GDB/MI Signal Handling Commands | |
28915 | @section @sc{gdb/mi} Signal Handling Commands | |
922fbb7b | 28916 | |
a2c02241 | 28917 | Signal handling commands are not implemented. |
922fbb7b | 28918 | |
a2c02241 | 28919 | @c @subheading -signal-handle |
922fbb7b | 28920 | |
a2c02241 | 28921 | @c @subheading -signal-list-handle-actions |
922fbb7b | 28922 | |
a2c02241 NR |
28923 | @c @subheading -signal-list-signal-types |
28924 | @end ignore | |
922fbb7b | 28925 | |
922fbb7b | 28926 | |
a2c02241 NR |
28927 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
28928 | @node GDB/MI Target Manipulation | |
28929 | @section @sc{gdb/mi} Target Manipulation Commands | |
922fbb7b AC |
28930 | |
28931 | ||
a2c02241 NR |
28932 | @subheading The @code{-target-attach} Command |
28933 | @findex -target-attach | |
922fbb7b AC |
28934 | |
28935 | @subsubheading Synopsis | |
28936 | ||
28937 | @smallexample | |
c3b108f7 | 28938 | -target-attach @var{pid} | @var{gid} | @var{file} |
922fbb7b AC |
28939 | @end smallexample |
28940 | ||
c3b108f7 VP |
28941 | Attach to a process @var{pid} or a file @var{file} outside of |
28942 | @value{GDBN}, or a thread group @var{gid}. If attaching to a thread | |
28943 | group, the id previously returned by | |
28944 | @samp{-list-thread-groups --available} must be used. | |
922fbb7b | 28945 | |
79a6e687 | 28946 | @subsubheading @value{GDBN} Command |
922fbb7b | 28947 | |
a2c02241 | 28948 | The corresponding @value{GDBN} command is @samp{attach}. |
922fbb7b | 28949 | |
a2c02241 | 28950 | @subsubheading Example |
b56e7235 VP |
28951 | @smallexample |
28952 | (gdb) | |
28953 | -target-attach 34 | |
28954 | =thread-created,id="1" | |
5ae4183a | 28955 | *stopped,thread-id="1",frame=@{addr="0xb7f7e410",func="bar",args=[]@} |
b56e7235 VP |
28956 | ^done |
28957 | (gdb) | |
28958 | @end smallexample | |
a2c02241 | 28959 | |
9901a55b | 28960 | @ignore |
a2c02241 NR |
28961 | @subheading The @code{-target-compare-sections} Command |
28962 | @findex -target-compare-sections | |
922fbb7b AC |
28963 | |
28964 | @subsubheading Synopsis | |
28965 | ||
28966 | @smallexample | |
a2c02241 | 28967 | -target-compare-sections [ @var{section} ] |
922fbb7b AC |
28968 | @end smallexample |
28969 | ||
a2c02241 NR |
28970 | Compare data of section @var{section} on target to the exec file. |
28971 | Without the argument, all sections are compared. | |
922fbb7b | 28972 | |
a2c02241 | 28973 | @subsubheading @value{GDBN} Command |
922fbb7b | 28974 | |
a2c02241 | 28975 | The @value{GDBN} equivalent is @samp{compare-sections}. |
922fbb7b | 28976 | |
a2c02241 NR |
28977 | @subsubheading Example |
28978 | N.A. | |
9901a55b | 28979 | @end ignore |
a2c02241 NR |
28980 | |
28981 | ||
28982 | @subheading The @code{-target-detach} Command | |
28983 | @findex -target-detach | |
922fbb7b AC |
28984 | |
28985 | @subsubheading Synopsis | |
28986 | ||
28987 | @smallexample | |
c3b108f7 | 28988 | -target-detach [ @var{pid} | @var{gid} ] |
922fbb7b AC |
28989 | @end smallexample |
28990 | ||
a2c02241 | 28991 | Detach from the remote target which normally resumes its execution. |
c3b108f7 VP |
28992 | If either @var{pid} or @var{gid} is specified, detaches from either |
28993 | the specified process, or specified thread group. There's no output. | |
a2c02241 | 28994 | |
79a6e687 | 28995 | @subsubheading @value{GDBN} Command |
a2c02241 NR |
28996 | |
28997 | The corresponding @value{GDBN} command is @samp{detach}. | |
28998 | ||
28999 | @subsubheading Example | |
922fbb7b AC |
29000 | |
29001 | @smallexample | |
594fe323 | 29002 | (gdb) |
a2c02241 NR |
29003 | -target-detach |
29004 | ^done | |
594fe323 | 29005 | (gdb) |
922fbb7b AC |
29006 | @end smallexample |
29007 | ||
29008 | ||
a2c02241 NR |
29009 | @subheading The @code{-target-disconnect} Command |
29010 | @findex -target-disconnect | |
922fbb7b AC |
29011 | |
29012 | @subsubheading Synopsis | |
29013 | ||
123dc839 | 29014 | @smallexample |
a2c02241 | 29015 | -target-disconnect |
123dc839 | 29016 | @end smallexample |
922fbb7b | 29017 | |
a2c02241 NR |
29018 | Disconnect from the remote target. There's no output and the target is |
29019 | generally not resumed. | |
29020 | ||
79a6e687 | 29021 | @subsubheading @value{GDBN} Command |
a2c02241 NR |
29022 | |
29023 | The corresponding @value{GDBN} command is @samp{disconnect}. | |
bc8ced35 NR |
29024 | |
29025 | @subsubheading Example | |
922fbb7b AC |
29026 | |
29027 | @smallexample | |
594fe323 | 29028 | (gdb) |
a2c02241 NR |
29029 | -target-disconnect |
29030 | ^done | |
594fe323 | 29031 | (gdb) |
922fbb7b AC |
29032 | @end smallexample |
29033 | ||
29034 | ||
a2c02241 NR |
29035 | @subheading The @code{-target-download} Command |
29036 | @findex -target-download | |
922fbb7b AC |
29037 | |
29038 | @subsubheading Synopsis | |
29039 | ||
29040 | @smallexample | |
a2c02241 | 29041 | -target-download |
922fbb7b AC |
29042 | @end smallexample |
29043 | ||
a2c02241 NR |
29044 | Loads the executable onto the remote target. |
29045 | It prints out an update message every half second, which includes the fields: | |
29046 | ||
29047 | @table @samp | |
29048 | @item section | |
29049 | The name of the section. | |
29050 | @item section-sent | |
29051 | The size of what has been sent so far for that section. | |
29052 | @item section-size | |
29053 | The size of the section. | |
29054 | @item total-sent | |
29055 | The total size of what was sent so far (the current and the previous sections). | |
29056 | @item total-size | |
29057 | The size of the overall executable to download. | |
29058 | @end table | |
29059 | ||
29060 | @noindent | |
29061 | Each message is sent as status record (@pxref{GDB/MI Output Syntax, , | |
29062 | @sc{gdb/mi} Output Syntax}). | |
29063 | ||
29064 | In addition, it prints the name and size of the sections, as they are | |
29065 | downloaded. These messages include the following fields: | |
29066 | ||
29067 | @table @samp | |
29068 | @item section | |
29069 | The name of the section. | |
29070 | @item section-size | |
29071 | The size of the section. | |
29072 | @item total-size | |
29073 | The size of the overall executable to download. | |
29074 | @end table | |
29075 | ||
29076 | @noindent | |
29077 | At the end, a summary is printed. | |
29078 | ||
29079 | @subsubheading @value{GDBN} Command | |
29080 | ||
29081 | The corresponding @value{GDBN} command is @samp{load}. | |
29082 | ||
29083 | @subsubheading Example | |
29084 | ||
29085 | Note: each status message appears on a single line. Here the messages | |
29086 | have been broken down so that they can fit onto a page. | |
922fbb7b AC |
29087 | |
29088 | @smallexample | |
594fe323 | 29089 | (gdb) |
a2c02241 NR |
29090 | -target-download |
29091 | +download,@{section=".text",section-size="6668",total-size="9880"@} | |
29092 | +download,@{section=".text",section-sent="512",section-size="6668", | |
29093 | total-sent="512",total-size="9880"@} | |
29094 | +download,@{section=".text",section-sent="1024",section-size="6668", | |
29095 | total-sent="1024",total-size="9880"@} | |
29096 | +download,@{section=".text",section-sent="1536",section-size="6668", | |
29097 | total-sent="1536",total-size="9880"@} | |
29098 | +download,@{section=".text",section-sent="2048",section-size="6668", | |
29099 | total-sent="2048",total-size="9880"@} | |
29100 | +download,@{section=".text",section-sent="2560",section-size="6668", | |
29101 | total-sent="2560",total-size="9880"@} | |
29102 | +download,@{section=".text",section-sent="3072",section-size="6668", | |
29103 | total-sent="3072",total-size="9880"@} | |
29104 | +download,@{section=".text",section-sent="3584",section-size="6668", | |
29105 | total-sent="3584",total-size="9880"@} | |
29106 | +download,@{section=".text",section-sent="4096",section-size="6668", | |
29107 | total-sent="4096",total-size="9880"@} | |
29108 | +download,@{section=".text",section-sent="4608",section-size="6668", | |
29109 | total-sent="4608",total-size="9880"@} | |
29110 | +download,@{section=".text",section-sent="5120",section-size="6668", | |
29111 | total-sent="5120",total-size="9880"@} | |
29112 | +download,@{section=".text",section-sent="5632",section-size="6668", | |
29113 | total-sent="5632",total-size="9880"@} | |
29114 | +download,@{section=".text",section-sent="6144",section-size="6668", | |
29115 | total-sent="6144",total-size="9880"@} | |
29116 | +download,@{section=".text",section-sent="6656",section-size="6668", | |
29117 | total-sent="6656",total-size="9880"@} | |
29118 | +download,@{section=".init",section-size="28",total-size="9880"@} | |
29119 | +download,@{section=".fini",section-size="28",total-size="9880"@} | |
29120 | +download,@{section=".data",section-size="3156",total-size="9880"@} | |
29121 | +download,@{section=".data",section-sent="512",section-size="3156", | |
29122 | total-sent="7236",total-size="9880"@} | |
29123 | +download,@{section=".data",section-sent="1024",section-size="3156", | |
29124 | total-sent="7748",total-size="9880"@} | |
29125 | +download,@{section=".data",section-sent="1536",section-size="3156", | |
29126 | total-sent="8260",total-size="9880"@} | |
29127 | +download,@{section=".data",section-sent="2048",section-size="3156", | |
29128 | total-sent="8772",total-size="9880"@} | |
29129 | +download,@{section=".data",section-sent="2560",section-size="3156", | |
29130 | total-sent="9284",total-size="9880"@} | |
29131 | +download,@{section=".data",section-sent="3072",section-size="3156", | |
29132 | total-sent="9796",total-size="9880"@} | |
29133 | ^done,address="0x10004",load-size="9880",transfer-rate="6586", | |
29134 | write-rate="429" | |
594fe323 | 29135 | (gdb) |
922fbb7b AC |
29136 | @end smallexample |
29137 | ||
29138 | ||
9901a55b | 29139 | @ignore |
a2c02241 NR |
29140 | @subheading The @code{-target-exec-status} Command |
29141 | @findex -target-exec-status | |
922fbb7b AC |
29142 | |
29143 | @subsubheading Synopsis | |
29144 | ||
29145 | @smallexample | |
a2c02241 | 29146 | -target-exec-status |
922fbb7b AC |
29147 | @end smallexample |
29148 | ||
a2c02241 NR |
29149 | Provide information on the state of the target (whether it is running or |
29150 | not, for instance). | |
922fbb7b | 29151 | |
a2c02241 | 29152 | @subsubheading @value{GDBN} Command |
922fbb7b | 29153 | |
a2c02241 NR |
29154 | There's no equivalent @value{GDBN} command. |
29155 | ||
29156 | @subsubheading Example | |
29157 | N.A. | |
922fbb7b | 29158 | |
a2c02241 NR |
29159 | |
29160 | @subheading The @code{-target-list-available-targets} Command | |
29161 | @findex -target-list-available-targets | |
922fbb7b AC |
29162 | |
29163 | @subsubheading Synopsis | |
29164 | ||
29165 | @smallexample | |
a2c02241 | 29166 | -target-list-available-targets |
922fbb7b AC |
29167 | @end smallexample |
29168 | ||
a2c02241 | 29169 | List the possible targets to connect to. |
922fbb7b | 29170 | |
a2c02241 | 29171 | @subsubheading @value{GDBN} Command |
922fbb7b | 29172 | |
a2c02241 | 29173 | The corresponding @value{GDBN} command is @samp{help target}. |
922fbb7b | 29174 | |
a2c02241 NR |
29175 | @subsubheading Example |
29176 | N.A. | |
29177 | ||
29178 | ||
29179 | @subheading The @code{-target-list-current-targets} Command | |
29180 | @findex -target-list-current-targets | |
922fbb7b AC |
29181 | |
29182 | @subsubheading Synopsis | |
29183 | ||
29184 | @smallexample | |
a2c02241 | 29185 | -target-list-current-targets |
922fbb7b AC |
29186 | @end smallexample |
29187 | ||
a2c02241 | 29188 | Describe the current target. |
922fbb7b | 29189 | |
a2c02241 | 29190 | @subsubheading @value{GDBN} Command |
922fbb7b | 29191 | |
a2c02241 NR |
29192 | The corresponding information is printed by @samp{info file} (among |
29193 | other things). | |
922fbb7b | 29194 | |
a2c02241 NR |
29195 | @subsubheading Example |
29196 | N.A. | |
29197 | ||
29198 | ||
29199 | @subheading The @code{-target-list-parameters} Command | |
29200 | @findex -target-list-parameters | |
922fbb7b AC |
29201 | |
29202 | @subsubheading Synopsis | |
29203 | ||
29204 | @smallexample | |
a2c02241 | 29205 | -target-list-parameters |
922fbb7b AC |
29206 | @end smallexample |
29207 | ||
a2c02241 | 29208 | @c ???? |
9901a55b | 29209 | @end ignore |
a2c02241 NR |
29210 | |
29211 | @subsubheading @value{GDBN} Command | |
29212 | ||
29213 | No equivalent. | |
922fbb7b AC |
29214 | |
29215 | @subsubheading Example | |
a2c02241 NR |
29216 | N.A. |
29217 | ||
29218 | ||
29219 | @subheading The @code{-target-select} Command | |
29220 | @findex -target-select | |
29221 | ||
29222 | @subsubheading Synopsis | |
922fbb7b AC |
29223 | |
29224 | @smallexample | |
a2c02241 | 29225 | -target-select @var{type} @var{parameters @dots{}} |
922fbb7b AC |
29226 | @end smallexample |
29227 | ||
a2c02241 | 29228 | Connect @value{GDBN} to the remote target. This command takes two args: |
922fbb7b | 29229 | |
a2c02241 NR |
29230 | @table @samp |
29231 | @item @var{type} | |
75c99385 | 29232 | The type of target, for instance @samp{remote}, etc. |
a2c02241 NR |
29233 | @item @var{parameters} |
29234 | Device names, host names and the like. @xref{Target Commands, , | |
79a6e687 | 29235 | Commands for Managing Targets}, for more details. |
a2c02241 NR |
29236 | @end table |
29237 | ||
29238 | The output is a connection notification, followed by the address at | |
29239 | which the target program is, in the following form: | |
922fbb7b AC |
29240 | |
29241 | @smallexample | |
a2c02241 NR |
29242 | ^connected,addr="@var{address}",func="@var{function name}", |
29243 | args=[@var{arg list}] | |
922fbb7b AC |
29244 | @end smallexample |
29245 | ||
a2c02241 NR |
29246 | @subsubheading @value{GDBN} Command |
29247 | ||
29248 | The corresponding @value{GDBN} command is @samp{target}. | |
265eeb58 NR |
29249 | |
29250 | @subsubheading Example | |
922fbb7b | 29251 | |
265eeb58 | 29252 | @smallexample |
594fe323 | 29253 | (gdb) |
75c99385 | 29254 | -target-select remote /dev/ttya |
a2c02241 | 29255 | ^connected,addr="0xfe00a300",func="??",args=[] |
594fe323 | 29256 | (gdb) |
265eeb58 | 29257 | @end smallexample |
ef21caaf | 29258 | |
a6b151f1 DJ |
29259 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
29260 | @node GDB/MI File Transfer Commands | |
29261 | @section @sc{gdb/mi} File Transfer Commands | |
29262 | ||
29263 | ||
29264 | @subheading The @code{-target-file-put} Command | |
29265 | @findex -target-file-put | |
29266 | ||
29267 | @subsubheading Synopsis | |
29268 | ||
29269 | @smallexample | |
29270 | -target-file-put @var{hostfile} @var{targetfile} | |
29271 | @end smallexample | |
29272 | ||
29273 | Copy file @var{hostfile} from the host system (the machine running | |
29274 | @value{GDBN}) to @var{targetfile} on the target system. | |
29275 | ||
29276 | @subsubheading @value{GDBN} Command | |
29277 | ||
29278 | The corresponding @value{GDBN} command is @samp{remote put}. | |
29279 | ||
29280 | @subsubheading Example | |
29281 | ||
29282 | @smallexample | |
29283 | (gdb) | |
29284 | -target-file-put localfile remotefile | |
29285 | ^done | |
29286 | (gdb) | |
29287 | @end smallexample | |
29288 | ||
29289 | ||
1763a388 | 29290 | @subheading The @code{-target-file-get} Command |
a6b151f1 DJ |
29291 | @findex -target-file-get |
29292 | ||
29293 | @subsubheading Synopsis | |
29294 | ||
29295 | @smallexample | |
29296 | -target-file-get @var{targetfile} @var{hostfile} | |
29297 | @end smallexample | |
29298 | ||
29299 | Copy file @var{targetfile} from the target system to @var{hostfile} | |
29300 | on the host system. | |
29301 | ||
29302 | @subsubheading @value{GDBN} Command | |
29303 | ||
29304 | The corresponding @value{GDBN} command is @samp{remote get}. | |
29305 | ||
29306 | @subsubheading Example | |
29307 | ||
29308 | @smallexample | |
29309 | (gdb) | |
29310 | -target-file-get remotefile localfile | |
29311 | ^done | |
29312 | (gdb) | |
29313 | @end smallexample | |
29314 | ||
29315 | ||
29316 | @subheading The @code{-target-file-delete} Command | |
29317 | @findex -target-file-delete | |
29318 | ||
29319 | @subsubheading Synopsis | |
29320 | ||
29321 | @smallexample | |
29322 | -target-file-delete @var{targetfile} | |
29323 | @end smallexample | |
29324 | ||
29325 | Delete @var{targetfile} from the target system. | |
29326 | ||
29327 | @subsubheading @value{GDBN} Command | |
29328 | ||
29329 | The corresponding @value{GDBN} command is @samp{remote delete}. | |
29330 | ||
29331 | @subsubheading Example | |
29332 | ||
29333 | @smallexample | |
29334 | (gdb) | |
29335 | -target-file-delete remotefile | |
29336 | ^done | |
29337 | (gdb) | |
29338 | @end smallexample | |
29339 | ||
29340 | ||
ef21caaf NR |
29341 | @c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
29342 | @node GDB/MI Miscellaneous Commands | |
29343 | @section Miscellaneous @sc{gdb/mi} Commands | |
29344 | ||
29345 | @c @subheading -gdb-complete | |
29346 | ||
29347 | @subheading The @code{-gdb-exit} Command | |
29348 | @findex -gdb-exit | |
29349 | ||
29350 | @subsubheading Synopsis | |
29351 | ||
29352 | @smallexample | |
29353 | -gdb-exit | |
29354 | @end smallexample | |
29355 | ||
29356 | Exit @value{GDBN} immediately. | |
29357 | ||
29358 | @subsubheading @value{GDBN} Command | |
29359 | ||
29360 | Approximately corresponds to @samp{quit}. | |
29361 | ||
29362 | @subsubheading Example | |
29363 | ||
29364 | @smallexample | |
594fe323 | 29365 | (gdb) |
ef21caaf NR |
29366 | -gdb-exit |
29367 | ^exit | |
29368 | @end smallexample | |
29369 | ||
a2c02241 | 29370 | |
9901a55b | 29371 | @ignore |
a2c02241 NR |
29372 | @subheading The @code{-exec-abort} Command |
29373 | @findex -exec-abort | |
29374 | ||
29375 | @subsubheading Synopsis | |
29376 | ||
29377 | @smallexample | |
29378 | -exec-abort | |
29379 | @end smallexample | |
29380 | ||
29381 | Kill the inferior running program. | |
29382 | ||
29383 | @subsubheading @value{GDBN} Command | |
29384 | ||
29385 | The corresponding @value{GDBN} command is @samp{kill}. | |
29386 | ||
29387 | @subsubheading Example | |
29388 | N.A. | |
9901a55b | 29389 | @end ignore |
a2c02241 NR |
29390 | |
29391 | ||
ef21caaf NR |
29392 | @subheading The @code{-gdb-set} Command |
29393 | @findex -gdb-set | |
29394 | ||
29395 | @subsubheading Synopsis | |
29396 | ||
29397 | @smallexample | |
29398 | -gdb-set | |
29399 | @end smallexample | |
29400 | ||
29401 | Set an internal @value{GDBN} variable. | |
29402 | @c IS THIS A DOLLAR VARIABLE? OR SOMETHING LIKE ANNOTATE ????? | |
29403 | ||
29404 | @subsubheading @value{GDBN} Command | |
29405 | ||
29406 | The corresponding @value{GDBN} command is @samp{set}. | |
29407 | ||
29408 | @subsubheading Example | |
29409 | ||
29410 | @smallexample | |
594fe323 | 29411 | (gdb) |
ef21caaf NR |
29412 | -gdb-set $foo=3 |
29413 | ^done | |
594fe323 | 29414 | (gdb) |
ef21caaf NR |
29415 | @end smallexample |
29416 | ||
29417 | ||
29418 | @subheading The @code{-gdb-show} Command | |
29419 | @findex -gdb-show | |
29420 | ||
29421 | @subsubheading Synopsis | |
29422 | ||
29423 | @smallexample | |
29424 | -gdb-show | |
29425 | @end smallexample | |
29426 | ||
29427 | Show the current value of a @value{GDBN} variable. | |
29428 | ||
79a6e687 | 29429 | @subsubheading @value{GDBN} Command |
ef21caaf NR |
29430 | |
29431 | The corresponding @value{GDBN} command is @samp{show}. | |
29432 | ||
29433 | @subsubheading Example | |
29434 | ||
29435 | @smallexample | |
594fe323 | 29436 | (gdb) |
ef21caaf NR |
29437 | -gdb-show annotate |
29438 | ^done,value="0" | |
594fe323 | 29439 | (gdb) |
ef21caaf NR |
29440 | @end smallexample |
29441 | ||
29442 | @c @subheading -gdb-source | |
29443 | ||
29444 | ||
29445 | @subheading The @code{-gdb-version} Command | |
29446 | @findex -gdb-version | |
29447 | ||
29448 | @subsubheading Synopsis | |
29449 | ||
29450 | @smallexample | |
29451 | -gdb-version | |
29452 | @end smallexample | |
29453 | ||
29454 | Show version information for @value{GDBN}. Used mostly in testing. | |
29455 | ||
29456 | @subsubheading @value{GDBN} Command | |
29457 | ||
29458 | The @value{GDBN} equivalent is @samp{show version}. @value{GDBN} by | |
29459 | default shows this information when you start an interactive session. | |
29460 | ||
29461 | @subsubheading Example | |
29462 | ||
29463 | @c This example modifies the actual output from GDB to avoid overfull | |
29464 | @c box in TeX. | |
29465 | @smallexample | |
594fe323 | 29466 | (gdb) |
ef21caaf NR |
29467 | -gdb-version |
29468 | ~GNU gdb 5.2.1 | |
29469 | ~Copyright 2000 Free Software Foundation, Inc. | |
29470 | ~GDB is free software, covered by the GNU General Public License, and | |
29471 | ~you are welcome to change it and/or distribute copies of it under | |
29472 | ~ certain conditions. | |
29473 | ~Type "show copying" to see the conditions. | |
29474 | ~There is absolutely no warranty for GDB. Type "show warranty" for | |
29475 | ~ details. | |
29476 | ~This GDB was configured as | |
29477 | "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". | |
29478 | ^done | |
594fe323 | 29479 | (gdb) |
ef21caaf NR |
29480 | @end smallexample |
29481 | ||
084344da VP |
29482 | @subheading The @code{-list-features} Command |
29483 | @findex -list-features | |
29484 | ||
29485 | Returns a list of particular features of the MI protocol that | |
29486 | this version of gdb implements. A feature can be a command, | |
29487 | or a new field in an output of some command, or even an | |
29488 | important bugfix. While a frontend can sometimes detect presence | |
29489 | of a feature at runtime, it is easier to perform detection at debugger | |
29490 | startup. | |
29491 | ||
29492 | The command returns a list of strings, with each string naming an | |
29493 | available feature. Each returned string is just a name, it does not | |
29494 | have any internal structure. The list of possible feature names | |
29495 | is given below. | |
29496 | ||
29497 | Example output: | |
29498 | ||
29499 | @smallexample | |
29500 | (gdb) -list-features | |
29501 | ^done,result=["feature1","feature2"] | |
29502 | @end smallexample | |
29503 | ||
29504 | The current list of features is: | |
29505 | ||
30e026bb VP |
29506 | @table @samp |
29507 | @item frozen-varobjs | |
29508 | Indicates presence of the @code{-var-set-frozen} command, as well | |
29509 | as possible presense of the @code{frozen} field in the output | |
29510 | of @code{-varobj-create}. | |
29511 | @item pending-breakpoints | |
29512 | Indicates presence of the @option{-f} option to the @code{-break-insert} command. | |
b6313243 TT |
29513 | @item python |
29514 | Indicates presence of Python scripting support, Python-based | |
29515 | pretty-printing commands, and possible presence of the | |
29516 | @samp{display_hint} field in the output of @code{-var-list-children} | |
30e026bb VP |
29517 | @item thread-info |
29518 | Indicates presence of the @code{-thread-info} command. | |
8dedea02 VP |
29519 | @item data-read-memory-bytes |
29520 | Indicates presense of the @code{-data-read-memory-bytes} and the | |
29521 | @code{-data-write-memory-bytes} commands. | |
8b4ed427 | 29522 | |
30e026bb | 29523 | @end table |
084344da | 29524 | |
c6ebd6cf VP |
29525 | @subheading The @code{-list-target-features} Command |
29526 | @findex -list-target-features | |
29527 | ||
29528 | Returns a list of particular features that are supported by the | |
29529 | target. Those features affect the permitted MI commands, but | |
29530 | unlike the features reported by the @code{-list-features} command, the | |
29531 | features depend on which target GDB is using at the moment. Whenever | |
29532 | a target can change, due to commands such as @code{-target-select}, | |
29533 | @code{-target-attach} or @code{-exec-run}, the list of target features | |
29534 | may change, and the frontend should obtain it again. | |
29535 | Example output: | |
29536 | ||
29537 | @smallexample | |
29538 | (gdb) -list-features | |
29539 | ^done,result=["async"] | |
29540 | @end smallexample | |
29541 | ||
29542 | The current list of features is: | |
29543 | ||
29544 | @table @samp | |
29545 | @item async | |
29546 | Indicates that the target is capable of asynchronous command | |
29547 | execution, which means that @value{GDBN} will accept further commands | |
29548 | while the target is running. | |
29549 | ||
f75d858b MK |
29550 | @item reverse |
29551 | Indicates that the target is capable of reverse execution. | |
29552 | @xref{Reverse Execution}, for more information. | |
29553 | ||
c6ebd6cf VP |
29554 | @end table |
29555 | ||
c3b108f7 VP |
29556 | @subheading The @code{-list-thread-groups} Command |
29557 | @findex -list-thread-groups | |
29558 | ||
29559 | @subheading Synopsis | |
29560 | ||
29561 | @smallexample | |
dc146f7c | 29562 | -list-thread-groups [ --available ] [ --recurse 1 ] [ @var{group} ... ] |
c3b108f7 VP |
29563 | @end smallexample |
29564 | ||
dc146f7c VP |
29565 | Lists thread groups (@pxref{Thread groups}). When a single thread |
29566 | group is passed as the argument, lists the children of that group. | |
29567 | When several thread group are passed, lists information about those | |
29568 | thread groups. Without any parameters, lists information about all | |
29569 | top-level thread groups. | |
29570 | ||
29571 | Normally, thread groups that are being debugged are reported. | |
29572 | With the @samp{--available} option, @value{GDBN} reports thread groups | |
29573 | available on the target. | |
29574 | ||
29575 | The output of this command may have either a @samp{threads} result or | |
29576 | a @samp{groups} result. The @samp{thread} result has a list of tuples | |
29577 | as value, with each tuple describing a thread (@pxref{GDB/MI Thread | |
29578 | Information}). The @samp{groups} result has a list of tuples as value, | |
29579 | each tuple describing a thread group. If top-level groups are | |
29580 | requested (that is, no parameter is passed), or when several groups | |
29581 | are passed, the output always has a @samp{groups} result. The format | |
29582 | of the @samp{group} result is described below. | |
29583 | ||
29584 | To reduce the number of roundtrips it's possible to list thread groups | |
29585 | together with their children, by passing the @samp{--recurse} option | |
29586 | and the recursion depth. Presently, only recursion depth of 1 is | |
29587 | permitted. If this option is present, then every reported thread group | |
29588 | will also include its children, either as @samp{group} or | |
29589 | @samp{threads} field. | |
29590 | ||
29591 | In general, any combination of option and parameters is permitted, with | |
29592 | the following caveats: | |
29593 | ||
29594 | @itemize @bullet | |
29595 | @item | |
29596 | When a single thread group is passed, the output will typically | |
29597 | be the @samp{threads} result. Because threads may not contain | |
29598 | anything, the @samp{recurse} option will be ignored. | |
29599 | ||
29600 | @item | |
29601 | When the @samp{--available} option is passed, limited information may | |
29602 | be available. In particular, the list of threads of a process might | |
29603 | be inaccessible. Further, specifying specific thread groups might | |
29604 | not give any performance advantage over listing all thread groups. | |
29605 | The frontend should assume that @samp{-list-thread-groups --available} | |
29606 | is always an expensive operation and cache the results. | |
29607 | ||
29608 | @end itemize | |
29609 | ||
29610 | The @samp{groups} result is a list of tuples, where each tuple may | |
29611 | have the following fields: | |
29612 | ||
29613 | @table @code | |
29614 | @item id | |
29615 | Identifier of the thread group. This field is always present. | |
a79b8f6e VP |
29616 | The identifier is an opaque string; frontends should not try to |
29617 | convert it to an integer, even though it might look like one. | |
dc146f7c VP |
29618 | |
29619 | @item type | |
29620 | The type of the thread group. At present, only @samp{process} is a | |
29621 | valid type. | |
29622 | ||
29623 | @item pid | |
29624 | The target-specific process identifier. This field is only present | |
a79b8f6e | 29625 | for thread groups of type @samp{process} and only if the process exists. |
c3b108f7 | 29626 | |
dc146f7c VP |
29627 | @item num_children |
29628 | The number of children this thread group has. This field may be | |
29629 | absent for an available thread group. | |
29630 | ||
29631 | @item threads | |
29632 | This field has a list of tuples as value, each tuple describing a | |
29633 | thread. It may be present if the @samp{--recurse} option is | |
29634 | specified, and it's actually possible to obtain the threads. | |
29635 | ||
29636 | @item cores | |
29637 | This field is a list of integers, each identifying a core that one | |
29638 | thread of the group is running on. This field may be absent if | |
29639 | such information is not available. | |
29640 | ||
a79b8f6e VP |
29641 | @item executable |
29642 | The name of the executable file that corresponds to this thread group. | |
29643 | The field is only present for thread groups of type @samp{process}, | |
29644 | and only if there is a corresponding executable file. | |
29645 | ||
dc146f7c | 29646 | @end table |
c3b108f7 VP |
29647 | |
29648 | @subheading Example | |
29649 | ||
29650 | @smallexample | |
29651 | @value{GDBP} | |
29652 | -list-thread-groups | |
29653 | ^done,groups=[@{id="17",type="process",pid="yyy",num_children="2"@}] | |
29654 | -list-thread-groups 17 | |
29655 | ^done,threads=[@{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", | |
29656 | frame=@{level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]@},state="running"@}, | |
29657 | @{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", | |
29658 | frame=@{level="0",addr="0x0804891f",func="foo",args=[@{name="i",value="10"@}], | |
29659 | file="/tmp/a.c",fullname="/tmp/a.c",line="158"@},state="running"@}]] | |
dc146f7c VP |
29660 | -list-thread-groups --available |
29661 | ^done,groups=[@{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]@}] | |
29662 | -list-thread-groups --available --recurse 1 | |
29663 | ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], | |
29664 | threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@}, | |
29665 | @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},..] | |
29666 | -list-thread-groups --available --recurse 1 17 18 | |
29667 | ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], | |
29668 | threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@}, | |
29669 | @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},...] | |
c3b108f7 | 29670 | @end smallexample |
c6ebd6cf | 29671 | |
a79b8f6e VP |
29672 | |
29673 | @subheading The @code{-add-inferior} Command | |
29674 | @findex -add-inferior | |
29675 | ||
29676 | @subheading Synopsis | |
29677 | ||
29678 | @smallexample | |
29679 | -add-inferior | |
29680 | @end smallexample | |
29681 | ||
29682 | Creates a new inferior (@pxref{Inferiors and Programs}). The created | |
29683 | inferior is not associated with any executable. Such association may | |
29684 | be established with the @samp{-file-exec-and-symbols} command | |
29685 | (@pxref{GDB/MI File Commands}). The command response has a single | |
29686 | field, @samp{thread-group}, whose value is the identifier of the | |
29687 | thread group corresponding to the new inferior. | |
29688 | ||
29689 | @subheading Example | |
29690 | ||
29691 | @smallexample | |
29692 | @value{GDBP} | |
29693 | -add-inferior | |
29694 | ^done,thread-group="i3" | |
29695 | @end smallexample | |
29696 | ||
ef21caaf NR |
29697 | @subheading The @code{-interpreter-exec} Command |
29698 | @findex -interpreter-exec | |
29699 | ||
29700 | @subheading Synopsis | |
29701 | ||
29702 | @smallexample | |
29703 | -interpreter-exec @var{interpreter} @var{command} | |
29704 | @end smallexample | |
a2c02241 | 29705 | @anchor{-interpreter-exec} |
ef21caaf NR |
29706 | |
29707 | Execute the specified @var{command} in the given @var{interpreter}. | |
29708 | ||
29709 | @subheading @value{GDBN} Command | |
29710 | ||
29711 | The corresponding @value{GDBN} command is @samp{interpreter-exec}. | |
29712 | ||
29713 | @subheading Example | |
29714 | ||
29715 | @smallexample | |
594fe323 | 29716 | (gdb) |
ef21caaf NR |
29717 | -interpreter-exec console "break main" |
29718 | &"During symbol reading, couldn't parse type; debugger out of date?.\n" | |
29719 | &"During symbol reading, bad structure-type format.\n" | |
29720 | ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n" | |
29721 | ^done | |
594fe323 | 29722 | (gdb) |
ef21caaf NR |
29723 | @end smallexample |
29724 | ||
29725 | @subheading The @code{-inferior-tty-set} Command | |
29726 | @findex -inferior-tty-set | |
29727 | ||
29728 | @subheading Synopsis | |
29729 | ||
29730 | @smallexample | |
29731 | -inferior-tty-set /dev/pts/1 | |
29732 | @end smallexample | |
29733 | ||
29734 | Set terminal for future runs of the program being debugged. | |
29735 | ||
29736 | @subheading @value{GDBN} Command | |
29737 | ||
29738 | The corresponding @value{GDBN} command is @samp{set inferior-tty} /dev/pts/1. | |
29739 | ||
29740 | @subheading Example | |
29741 | ||
29742 | @smallexample | |
594fe323 | 29743 | (gdb) |
ef21caaf NR |
29744 | -inferior-tty-set /dev/pts/1 |
29745 | ^done | |
594fe323 | 29746 | (gdb) |
ef21caaf NR |
29747 | @end smallexample |
29748 | ||
29749 | @subheading The @code{-inferior-tty-show} Command | |
29750 | @findex -inferior-tty-show | |
29751 | ||
29752 | @subheading Synopsis | |
29753 | ||
29754 | @smallexample | |
29755 | -inferior-tty-show | |
29756 | @end smallexample | |
29757 | ||
29758 | Show terminal for future runs of program being debugged. | |
29759 | ||
29760 | @subheading @value{GDBN} Command | |
29761 | ||
29762 | The corresponding @value{GDBN} command is @samp{show inferior-tty}. | |
29763 | ||
29764 | @subheading Example | |
29765 | ||
29766 | @smallexample | |
594fe323 | 29767 | (gdb) |
ef21caaf NR |
29768 | -inferior-tty-set /dev/pts/1 |
29769 | ^done | |
594fe323 | 29770 | (gdb) |
ef21caaf NR |
29771 | -inferior-tty-show |
29772 | ^done,inferior_tty_terminal="/dev/pts/1" | |
594fe323 | 29773 | (gdb) |
ef21caaf | 29774 | @end smallexample |
922fbb7b | 29775 | |
a4eefcd8 NR |
29776 | @subheading The @code{-enable-timings} Command |
29777 | @findex -enable-timings | |
29778 | ||
29779 | @subheading Synopsis | |
29780 | ||
29781 | @smallexample | |
29782 | -enable-timings [yes | no] | |
29783 | @end smallexample | |
29784 | ||
29785 | Toggle the printing of the wallclock, user and system times for an MI | |
29786 | command as a field in its output. This command is to help frontend | |
29787 | developers optimize the performance of their code. No argument is | |
29788 | equivalent to @samp{yes}. | |
29789 | ||
29790 | @subheading @value{GDBN} Command | |
29791 | ||
29792 | No equivalent. | |
29793 | ||
29794 | @subheading Example | |
29795 | ||
29796 | @smallexample | |
29797 | (gdb) | |
29798 | -enable-timings | |
29799 | ^done | |
29800 | (gdb) | |
29801 | -break-insert main | |
29802 | ^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y", | |
29803 | addr="0x080484ed",func="main",file="myprog.c", | |
29804 | fullname="/home/nickrob/myprog.c",line="73",times="0"@}, | |
29805 | time=@{wallclock="0.05185",user="0.00800",system="0.00000"@} | |
29806 | (gdb) | |
29807 | -enable-timings no | |
29808 | ^done | |
29809 | (gdb) | |
29810 | -exec-run | |
29811 | ^running | |
29812 | (gdb) | |
a47ec5fe | 29813 | *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", |
a4eefcd8 NR |
29814 | frame=@{addr="0x080484ed",func="main",args=[@{name="argc",value="1"@}, |
29815 | @{name="argv",value="0xbfb60364"@}],file="myprog.c", | |
29816 | fullname="/home/nickrob/myprog.c",line="73"@} | |
29817 | (gdb) | |
29818 | @end smallexample | |
29819 | ||
922fbb7b AC |
29820 | @node Annotations |
29821 | @chapter @value{GDBN} Annotations | |
29822 | ||
086432e2 AC |
29823 | This chapter describes annotations in @value{GDBN}. Annotations were |
29824 | designed to interface @value{GDBN} to graphical user interfaces or other | |
29825 | similar programs which want to interact with @value{GDBN} at a | |
922fbb7b AC |
29826 | relatively high level. |
29827 | ||
d3e8051b | 29828 | The annotation mechanism has largely been superseded by @sc{gdb/mi} |
086432e2 AC |
29829 | (@pxref{GDB/MI}). |
29830 | ||
922fbb7b AC |
29831 | @ignore |
29832 | This is Edition @value{EDITION}, @value{DATE}. | |
29833 | @end ignore | |
29834 | ||
29835 | @menu | |
29836 | * Annotations Overview:: What annotations are; the general syntax. | |
9e6c4bd5 | 29837 | * Server Prefix:: Issuing a command without affecting user state. |
922fbb7b AC |
29838 | * Prompting:: Annotations marking @value{GDBN}'s need for input. |
29839 | * Errors:: Annotations for error messages. | |
922fbb7b AC |
29840 | * Invalidation:: Some annotations describe things now invalid. |
29841 | * Annotations for Running:: | |
29842 | Whether the program is running, how it stopped, etc. | |
29843 | * Source Annotations:: Annotations describing source code. | |
922fbb7b AC |
29844 | @end menu |
29845 | ||
29846 | @node Annotations Overview | |
29847 | @section What is an Annotation? | |
29848 | @cindex annotations | |
29849 | ||
922fbb7b AC |
29850 | Annotations start with a newline character, two @samp{control-z} |
29851 | characters, and the name of the annotation. If there is no additional | |
29852 | information associated with this annotation, the name of the annotation | |
29853 | is followed immediately by a newline. If there is additional | |
29854 | information, the name of the annotation is followed by a space, the | |
29855 | additional information, and a newline. The additional information | |
29856 | cannot contain newline characters. | |
29857 | ||
29858 | Any output not beginning with a newline and two @samp{control-z} | |
29859 | characters denotes literal output from @value{GDBN}. Currently there is | |
29860 | no need for @value{GDBN} to output a newline followed by two | |
29861 | @samp{control-z} characters, but if there was such a need, the | |
29862 | annotations could be extended with an @samp{escape} annotation which | |
29863 | means those three characters as output. | |
29864 | ||
086432e2 AC |
29865 | The annotation @var{level}, which is specified using the |
29866 | @option{--annotate} command line option (@pxref{Mode Options}), controls | |
29867 | how much information @value{GDBN} prints together with its prompt, | |
29868 | values of expressions, source lines, and other types of output. Level 0 | |
d3e8051b | 29869 | is for no annotations, level 1 is for use when @value{GDBN} is run as a |
086432e2 AC |
29870 | subprocess of @sc{gnu} Emacs, level 3 is the maximum annotation suitable |
29871 | for programs that control @value{GDBN}, and level 2 annotations have | |
29872 | been made obsolete (@pxref{Limitations, , Limitations of the Annotation | |
09d4efe1 EZ |
29873 | Interface, annotate, GDB's Obsolete Annotations}). |
29874 | ||
29875 | @table @code | |
29876 | @kindex set annotate | |
29877 | @item set annotate @var{level} | |
e09f16f9 | 29878 | The @value{GDBN} command @code{set annotate} sets the level of |
09d4efe1 | 29879 | annotations to the specified @var{level}. |
9c16f35a EZ |
29880 | |
29881 | @item show annotate | |
29882 | @kindex show annotate | |
29883 | Show the current annotation level. | |
09d4efe1 EZ |
29884 | @end table |
29885 | ||
29886 | This chapter describes level 3 annotations. | |
086432e2 | 29887 | |
922fbb7b AC |
29888 | A simple example of starting up @value{GDBN} with annotations is: |
29889 | ||
29890 | @smallexample | |
086432e2 AC |
29891 | $ @kbd{gdb --annotate=3} |
29892 | GNU gdb 6.0 | |
29893 | Copyright 2003 Free Software Foundation, Inc. | |
922fbb7b AC |
29894 | GDB is free software, covered by the GNU General Public License, |
29895 | and you are welcome to change it and/or distribute copies of it | |
29896 | under certain conditions. | |
29897 | Type "show copying" to see the conditions. | |
29898 | There is absolutely no warranty for GDB. Type "show warranty" | |
29899 | for details. | |
086432e2 | 29900 | This GDB was configured as "i386-pc-linux-gnu" |
922fbb7b AC |
29901 | |
29902 | ^Z^Zpre-prompt | |
f7dc1244 | 29903 | (@value{GDBP}) |
922fbb7b | 29904 | ^Z^Zprompt |
086432e2 | 29905 | @kbd{quit} |
922fbb7b AC |
29906 | |
29907 | ^Z^Zpost-prompt | |
b383017d | 29908 | $ |
922fbb7b AC |
29909 | @end smallexample |
29910 | ||
29911 | Here @samp{quit} is input to @value{GDBN}; the rest is output from | |
29912 | @value{GDBN}. The three lines beginning @samp{^Z^Z} (where @samp{^Z} | |
29913 | denotes a @samp{control-z} character) are annotations; the rest is | |
29914 | output from @value{GDBN}. | |
29915 | ||
9e6c4bd5 NR |
29916 | @node Server Prefix |
29917 | @section The Server Prefix | |
29918 | @cindex server prefix | |
29919 | ||
29920 | If you prefix a command with @samp{server } then it will not affect | |
29921 | the command history, nor will it affect @value{GDBN}'s notion of which | |
29922 | command to repeat if @key{RET} is pressed on a line by itself. This | |
29923 | means that commands can be run behind a user's back by a front-end in | |
29924 | a transparent manner. | |
29925 | ||
d837706a NR |
29926 | The @code{server } prefix does not affect the recording of values into |
29927 | the value history; to print a value without recording it into the | |
29928 | value history, use the @code{output} command instead of the | |
29929 | @code{print} command. | |
29930 | ||
29931 | Using this prefix also disables confirmation requests | |
29932 | (@pxref{confirmation requests}). | |
9e6c4bd5 | 29933 | |
922fbb7b AC |
29934 | @node Prompting |
29935 | @section Annotation for @value{GDBN} Input | |
29936 | ||
29937 | @cindex annotations for prompts | |
29938 | When @value{GDBN} prompts for input, it annotates this fact so it is possible | |
29939 | to know when to send output, when the output from a given command is | |
29940 | over, etc. | |
29941 | ||
29942 | Different kinds of input each have a different @dfn{input type}. Each | |
29943 | input type has three annotations: a @code{pre-} annotation, which | |
29944 | denotes the beginning of any prompt which is being output, a plain | |
29945 | annotation, which denotes the end of the prompt, and then a @code{post-} | |
29946 | annotation which denotes the end of any echo which may (or may not) be | |
29947 | associated with the input. For example, the @code{prompt} input type | |
29948 | features the following annotations: | |
29949 | ||
29950 | @smallexample | |
29951 | ^Z^Zpre-prompt | |
29952 | ^Z^Zprompt | |
29953 | ^Z^Zpost-prompt | |
29954 | @end smallexample | |
29955 | ||
29956 | The input types are | |
29957 | ||
29958 | @table @code | |
e5ac9b53 EZ |
29959 | @findex pre-prompt annotation |
29960 | @findex prompt annotation | |
29961 | @findex post-prompt annotation | |
922fbb7b AC |
29962 | @item prompt |
29963 | When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt). | |
29964 | ||
e5ac9b53 EZ |
29965 | @findex pre-commands annotation |
29966 | @findex commands annotation | |
29967 | @findex post-commands annotation | |
922fbb7b AC |
29968 | @item commands |
29969 | When @value{GDBN} prompts for a set of commands, like in the @code{commands} | |
29970 | command. The annotations are repeated for each command which is input. | |
29971 | ||
e5ac9b53 EZ |
29972 | @findex pre-overload-choice annotation |
29973 | @findex overload-choice annotation | |
29974 | @findex post-overload-choice annotation | |
922fbb7b AC |
29975 | @item overload-choice |
29976 | When @value{GDBN} wants the user to select between various overloaded functions. | |
29977 | ||
e5ac9b53 EZ |
29978 | @findex pre-query annotation |
29979 | @findex query annotation | |
29980 | @findex post-query annotation | |
922fbb7b AC |
29981 | @item query |
29982 | When @value{GDBN} wants the user to confirm a potentially dangerous operation. | |
29983 | ||
e5ac9b53 EZ |
29984 | @findex pre-prompt-for-continue annotation |
29985 | @findex prompt-for-continue annotation | |
29986 | @findex post-prompt-for-continue annotation | |
922fbb7b AC |
29987 | @item prompt-for-continue |
29988 | When @value{GDBN} is asking the user to press return to continue. Note: Don't | |
29989 | expect this to work well; instead use @code{set height 0} to disable | |
29990 | prompting. This is because the counting of lines is buggy in the | |
29991 | presence of annotations. | |
29992 | @end table | |
29993 | ||
29994 | @node Errors | |
29995 | @section Errors | |
29996 | @cindex annotations for errors, warnings and interrupts | |
29997 | ||
e5ac9b53 | 29998 | @findex quit annotation |
922fbb7b AC |
29999 | @smallexample |
30000 | ^Z^Zquit | |
30001 | @end smallexample | |
30002 | ||
30003 | This annotation occurs right before @value{GDBN} responds to an interrupt. | |
30004 | ||
e5ac9b53 | 30005 | @findex error annotation |
922fbb7b AC |
30006 | @smallexample |
30007 | ^Z^Zerror | |
30008 | @end smallexample | |
30009 | ||
30010 | This annotation occurs right before @value{GDBN} responds to an error. | |
30011 | ||
30012 | Quit and error annotations indicate that any annotations which @value{GDBN} was | |
30013 | in the middle of may end abruptly. For example, if a | |
30014 | @code{value-history-begin} annotation is followed by a @code{error}, one | |
30015 | cannot expect to receive the matching @code{value-history-end}. One | |
30016 | cannot expect not to receive it either, however; an error annotation | |
30017 | does not necessarily mean that @value{GDBN} is immediately returning all the way | |
30018 | to the top level. | |
30019 | ||
e5ac9b53 | 30020 | @findex error-begin annotation |
922fbb7b AC |
30021 | A quit or error annotation may be preceded by |
30022 | ||
30023 | @smallexample | |
30024 | ^Z^Zerror-begin | |
30025 | @end smallexample | |
30026 | ||
30027 | Any output between that and the quit or error annotation is the error | |
30028 | message. | |
30029 | ||
30030 | Warning messages are not yet annotated. | |
30031 | @c If we want to change that, need to fix warning(), type_error(), | |
30032 | @c range_error(), and possibly other places. | |
30033 | ||
922fbb7b AC |
30034 | @node Invalidation |
30035 | @section Invalidation Notices | |
30036 | ||
30037 | @cindex annotations for invalidation messages | |
30038 | The following annotations say that certain pieces of state may have | |
30039 | changed. | |
30040 | ||
30041 | @table @code | |
e5ac9b53 | 30042 | @findex frames-invalid annotation |
922fbb7b AC |
30043 | @item ^Z^Zframes-invalid |
30044 | ||
30045 | The frames (for example, output from the @code{backtrace} command) may | |
30046 | have changed. | |
30047 | ||
e5ac9b53 | 30048 | @findex breakpoints-invalid annotation |
922fbb7b AC |
30049 | @item ^Z^Zbreakpoints-invalid |
30050 | ||
30051 | The breakpoints may have changed. For example, the user just added or | |
30052 | deleted a breakpoint. | |
30053 | @end table | |
30054 | ||
30055 | @node Annotations for Running | |
30056 | @section Running the Program | |
30057 | @cindex annotations for running programs | |
30058 | ||
e5ac9b53 EZ |
30059 | @findex starting annotation |
30060 | @findex stopping annotation | |
922fbb7b | 30061 | When the program starts executing due to a @value{GDBN} command such as |
b383017d | 30062 | @code{step} or @code{continue}, |
922fbb7b AC |
30063 | |
30064 | @smallexample | |
30065 | ^Z^Zstarting | |
30066 | @end smallexample | |
30067 | ||
b383017d | 30068 | is output. When the program stops, |
922fbb7b AC |
30069 | |
30070 | @smallexample | |
30071 | ^Z^Zstopped | |
30072 | @end smallexample | |
30073 | ||
30074 | is output. Before the @code{stopped} annotation, a variety of | |
30075 | annotations describe how the program stopped. | |
30076 | ||
30077 | @table @code | |
e5ac9b53 | 30078 | @findex exited annotation |
922fbb7b AC |
30079 | @item ^Z^Zexited @var{exit-status} |
30080 | The program exited, and @var{exit-status} is the exit status (zero for | |
30081 | successful exit, otherwise nonzero). | |
30082 | ||
e5ac9b53 EZ |
30083 | @findex signalled annotation |
30084 | @findex signal-name annotation | |
30085 | @findex signal-name-end annotation | |
30086 | @findex signal-string annotation | |
30087 | @findex signal-string-end annotation | |
922fbb7b AC |
30088 | @item ^Z^Zsignalled |
30089 | The program exited with a signal. After the @code{^Z^Zsignalled}, the | |
30090 | annotation continues: | |
30091 | ||
30092 | @smallexample | |
30093 | @var{intro-text} | |
30094 | ^Z^Zsignal-name | |
30095 | @var{name} | |
30096 | ^Z^Zsignal-name-end | |
30097 | @var{middle-text} | |
30098 | ^Z^Zsignal-string | |
30099 | @var{string} | |
30100 | ^Z^Zsignal-string-end | |
30101 | @var{end-text} | |
30102 | @end smallexample | |
30103 | ||
30104 | @noindent | |
30105 | where @var{name} is the name of the signal, such as @code{SIGILL} or | |
30106 | @code{SIGSEGV}, and @var{string} is the explanation of the signal, such | |
30107 | as @code{Illegal Instruction} or @code{Segmentation fault}. | |
30108 | @var{intro-text}, @var{middle-text}, and @var{end-text} are for the | |
30109 | user's benefit and have no particular format. | |
30110 | ||
e5ac9b53 | 30111 | @findex signal annotation |
922fbb7b AC |
30112 | @item ^Z^Zsignal |
30113 | The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is | |
30114 | just saying that the program received the signal, not that it was | |
30115 | terminated with it. | |
30116 | ||
e5ac9b53 | 30117 | @findex breakpoint annotation |
922fbb7b AC |
30118 | @item ^Z^Zbreakpoint @var{number} |
30119 | The program hit breakpoint number @var{number}. | |
30120 | ||
e5ac9b53 | 30121 | @findex watchpoint annotation |
922fbb7b AC |
30122 | @item ^Z^Zwatchpoint @var{number} |
30123 | The program hit watchpoint number @var{number}. | |
30124 | @end table | |
30125 | ||
30126 | @node Source Annotations | |
30127 | @section Displaying Source | |
30128 | @cindex annotations for source display | |
30129 | ||
e5ac9b53 | 30130 | @findex source annotation |
922fbb7b AC |
30131 | The following annotation is used instead of displaying source code: |
30132 | ||
30133 | @smallexample | |
30134 | ^Z^Zsource @var{filename}:@var{line}:@var{character}:@var{middle}:@var{addr} | |
30135 | @end smallexample | |
30136 | ||
30137 | where @var{filename} is an absolute file name indicating which source | |
30138 | file, @var{line} is the line number within that file (where 1 is the | |
30139 | first line in the file), @var{character} is the character position | |
30140 | within the file (where 0 is the first character in the file) (for most | |
30141 | debug formats this will necessarily point to the beginning of a line), | |
30142 | @var{middle} is @samp{middle} if @var{addr} is in the middle of the | |
30143 | line, or @samp{beg} if @var{addr} is at the beginning of the line, and | |
30144 | @var{addr} is the address in the target program associated with the | |
30145 | source which is being displayed. @var{addr} is in the form @samp{0x} | |
30146 | followed by one or more lowercase hex digits (note that this does not | |
30147 | depend on the language). | |
30148 | ||
4efc6507 DE |
30149 | @node JIT Interface |
30150 | @chapter JIT Compilation Interface | |
30151 | @cindex just-in-time compilation | |
30152 | @cindex JIT compilation interface | |
30153 | ||
30154 | This chapter documents @value{GDBN}'s @dfn{just-in-time} (JIT) compilation | |
30155 | interface. A JIT compiler is a program or library that generates native | |
30156 | executable code at runtime and executes it, usually in order to achieve good | |
30157 | performance while maintaining platform independence. | |
30158 | ||
30159 | Programs that use JIT compilation are normally difficult to debug because | |
30160 | portions of their code are generated at runtime, instead of being loaded from | |
30161 | object files, which is where @value{GDBN} normally finds the program's symbols | |
30162 | and debug information. In order to debug programs that use JIT compilation, | |
30163 | @value{GDBN} has an interface that allows the program to register in-memory | |
30164 | symbol files with @value{GDBN} at runtime. | |
30165 | ||
30166 | If you are using @value{GDBN} to debug a program that uses this interface, then | |
30167 | it should work transparently so long as you have not stripped the binary. If | |
30168 | you are developing a JIT compiler, then the interface is documented in the rest | |
30169 | of this chapter. At this time, the only known client of this interface is the | |
30170 | LLVM JIT. | |
30171 | ||
30172 | Broadly speaking, the JIT interface mirrors the dynamic loader interface. The | |
30173 | JIT compiler communicates with @value{GDBN} by writing data into a global | |
30174 | variable and calling a fuction at a well-known symbol. When @value{GDBN} | |
30175 | attaches, it reads a linked list of symbol files from the global variable to | |
30176 | find existing code, and puts a breakpoint in the function so that it can find | |
30177 | out about additional code. | |
30178 | ||
30179 | @menu | |
30180 | * Declarations:: Relevant C struct declarations | |
30181 | * Registering Code:: Steps to register code | |
30182 | * Unregistering Code:: Steps to unregister code | |
30183 | @end menu | |
30184 | ||
30185 | @node Declarations | |
30186 | @section JIT Declarations | |
30187 | ||
30188 | These are the relevant struct declarations that a C program should include to | |
30189 | implement the interface: | |
30190 | ||
30191 | @smallexample | |
30192 | typedef enum | |
30193 | @{ | |
30194 | JIT_NOACTION = 0, | |
30195 | JIT_REGISTER_FN, | |
30196 | JIT_UNREGISTER_FN | |
30197 | @} jit_actions_t; | |
30198 | ||
30199 | struct jit_code_entry | |
30200 | @{ | |
30201 | struct jit_code_entry *next_entry; | |
30202 | struct jit_code_entry *prev_entry; | |
30203 | const char *symfile_addr; | |
30204 | uint64_t symfile_size; | |
30205 | @}; | |
30206 | ||
30207 | struct jit_descriptor | |
30208 | @{ | |
30209 | uint32_t version; | |
30210 | /* This type should be jit_actions_t, but we use uint32_t | |
30211 | to be explicit about the bitwidth. */ | |
30212 | uint32_t action_flag; | |
30213 | struct jit_code_entry *relevant_entry; | |
30214 | struct jit_code_entry *first_entry; | |
30215 | @}; | |
30216 | ||
30217 | /* GDB puts a breakpoint in this function. */ | |
30218 | void __attribute__((noinline)) __jit_debug_register_code() @{ @}; | |
30219 | ||
30220 | /* Make sure to specify the version statically, because the | |
30221 | debugger may check the version before we can set it. */ | |
30222 | struct jit_descriptor __jit_debug_descriptor = @{ 1, 0, 0, 0 @}; | |
30223 | @end smallexample | |
30224 | ||
30225 | If the JIT is multi-threaded, then it is important that the JIT synchronize any | |
30226 | modifications to this global data properly, which can easily be done by putting | |
30227 | a global mutex around modifications to these structures. | |
30228 | ||
30229 | @node Registering Code | |
30230 | @section Registering Code | |
30231 | ||
30232 | To register code with @value{GDBN}, the JIT should follow this protocol: | |
30233 | ||
30234 | @itemize @bullet | |
30235 | @item | |
30236 | Generate an object file in memory with symbols and other desired debug | |
30237 | information. The file must include the virtual addresses of the sections. | |
30238 | ||
30239 | @item | |
30240 | Create a code entry for the file, which gives the start and size of the symbol | |
30241 | file. | |
30242 | ||
30243 | @item | |
30244 | Add it to the linked list in the JIT descriptor. | |
30245 | ||
30246 | @item | |
30247 | Point the relevant_entry field of the descriptor at the entry. | |
30248 | ||
30249 | @item | |
30250 | Set @code{action_flag} to @code{JIT_REGISTER} and call | |
30251 | @code{__jit_debug_register_code}. | |
30252 | @end itemize | |
30253 | ||
30254 | When @value{GDBN} is attached and the breakpoint fires, @value{GDBN} uses the | |
30255 | @code{relevant_entry} pointer so it doesn't have to walk the list looking for | |
30256 | new code. However, the linked list must still be maintained in order to allow | |
30257 | @value{GDBN} to attach to a running process and still find the symbol files. | |
30258 | ||
30259 | @node Unregistering Code | |
30260 | @section Unregistering Code | |
30261 | ||
30262 | If code is freed, then the JIT should use the following protocol: | |
30263 | ||
30264 | @itemize @bullet | |
30265 | @item | |
30266 | Remove the code entry corresponding to the code from the linked list. | |
30267 | ||
30268 | @item | |
30269 | Point the @code{relevant_entry} field of the descriptor at the code entry. | |
30270 | ||
30271 | @item | |
30272 | Set @code{action_flag} to @code{JIT_UNREGISTER} and call | |
30273 | @code{__jit_debug_register_code}. | |
30274 | @end itemize | |
30275 | ||
30276 | If the JIT frees or recompiles code without unregistering it, then @value{GDBN} | |
30277 | and the JIT will leak the memory used for the associated symbol files. | |
30278 | ||
8e04817f AC |
30279 | @node GDB Bugs |
30280 | @chapter Reporting Bugs in @value{GDBN} | |
30281 | @cindex bugs in @value{GDBN} | |
30282 | @cindex reporting bugs in @value{GDBN} | |
c906108c | 30283 | |
8e04817f | 30284 | Your bug reports play an essential role in making @value{GDBN} reliable. |
c906108c | 30285 | |
8e04817f AC |
30286 | Reporting a bug may help you by bringing a solution to your problem, or it |
30287 | may not. But in any case the principal function of a bug report is to help | |
30288 | the entire community by making the next version of @value{GDBN} work better. Bug | |
30289 | reports are your contribution to the maintenance of @value{GDBN}. | |
c906108c | 30290 | |
8e04817f AC |
30291 | In order for a bug report to serve its purpose, you must include the |
30292 | information that enables us to fix the bug. | |
c4555f82 SC |
30293 | |
30294 | @menu | |
8e04817f AC |
30295 | * Bug Criteria:: Have you found a bug? |
30296 | * Bug Reporting:: How to report bugs | |
c4555f82 SC |
30297 | @end menu |
30298 | ||
8e04817f | 30299 | @node Bug Criteria |
79a6e687 | 30300 | @section Have You Found a Bug? |
8e04817f | 30301 | @cindex bug criteria |
c4555f82 | 30302 | |
8e04817f | 30303 | If you are not sure whether you have found a bug, here are some guidelines: |
c4555f82 SC |
30304 | |
30305 | @itemize @bullet | |
8e04817f AC |
30306 | @cindex fatal signal |
30307 | @cindex debugger crash | |
30308 | @cindex crash of debugger | |
c4555f82 | 30309 | @item |
8e04817f AC |
30310 | If the debugger gets a fatal signal, for any input whatever, that is a |
30311 | @value{GDBN} bug. Reliable debuggers never crash. | |
30312 | ||
30313 | @cindex error on valid input | |
30314 | @item | |
30315 | If @value{GDBN} produces an error message for valid input, that is a | |
30316 | bug. (Note that if you're cross debugging, the problem may also be | |
30317 | somewhere in the connection to the target.) | |
c4555f82 | 30318 | |
8e04817f | 30319 | @cindex invalid input |
c4555f82 | 30320 | @item |
8e04817f AC |
30321 | If @value{GDBN} does not produce an error message for invalid input, |
30322 | that is a bug. However, you should note that your idea of | |
30323 | ``invalid input'' might be our idea of ``an extension'' or ``support | |
30324 | for traditional practice''. | |
30325 | ||
30326 | @item | |
30327 | If you are an experienced user of debugging tools, your suggestions | |
30328 | for improvement of @value{GDBN} are welcome in any case. | |
c4555f82 SC |
30329 | @end itemize |
30330 | ||
8e04817f | 30331 | @node Bug Reporting |
79a6e687 | 30332 | @section How to Report Bugs |
8e04817f AC |
30333 | @cindex bug reports |
30334 | @cindex @value{GDBN} bugs, reporting | |
30335 | ||
30336 | A number of companies and individuals offer support for @sc{gnu} products. | |
30337 | If you obtained @value{GDBN} from a support organization, we recommend you | |
30338 | contact that organization first. | |
30339 | ||
30340 | You can find contact information for many support companies and | |
30341 | individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs | |
30342 | distribution. | |
30343 | @c should add a web page ref... | |
30344 | ||
c16158bc JM |
30345 | @ifset BUGURL |
30346 | @ifset BUGURL_DEFAULT | |
129188f6 | 30347 | In any event, we also recommend that you submit bug reports for |
d3e8051b | 30348 | @value{GDBN}. The preferred method is to submit them directly using |
129188f6 AC |
30349 | @uref{http://www.gnu.org/software/gdb/bugs/, @value{GDBN}'s Bugs web |
30350 | page}. Alternatively, the @email{bug-gdb@@gnu.org, e-mail gateway} can | |
30351 | be used. | |
8e04817f AC |
30352 | |
30353 | @strong{Do not send bug reports to @samp{info-gdb}, or to | |
30354 | @samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do | |
30355 | not want to receive bug reports. Those that do have arranged to receive | |
30356 | @samp{bug-gdb}. | |
30357 | ||
30358 | The mailing list @samp{bug-gdb} has a newsgroup @samp{gnu.gdb.bug} which | |
30359 | serves as a repeater. The mailing list and the newsgroup carry exactly | |
30360 | the same messages. Often people think of posting bug reports to the | |
30361 | newsgroup instead of mailing them. This appears to work, but it has one | |
30362 | problem which can be crucial: a newsgroup posting often lacks a mail | |
30363 | path back to the sender. Thus, if we need to ask for more information, | |
30364 | we may be unable to reach you. For this reason, it is better to send | |
30365 | bug reports to the mailing list. | |
c16158bc JM |
30366 | @end ifset |
30367 | @ifclear BUGURL_DEFAULT | |
30368 | In any event, we also recommend that you submit bug reports for | |
30369 | @value{GDBN} to @value{BUGURL}. | |
30370 | @end ifclear | |
30371 | @end ifset | |
c4555f82 | 30372 | |
8e04817f AC |
30373 | The fundamental principle of reporting bugs usefully is this: |
30374 | @strong{report all the facts}. If you are not sure whether to state a | |
30375 | fact or leave it out, state it! | |
c4555f82 | 30376 | |
8e04817f AC |
30377 | Often people omit facts because they think they know what causes the |
30378 | problem and assume that some details do not matter. Thus, you might | |
30379 | assume that the name of the variable you use in an example does not matter. | |
30380 | Well, probably it does not, but one cannot be sure. Perhaps the bug is a | |
30381 | stray memory reference which happens to fetch from the location where that | |
30382 | name is stored in memory; perhaps, if the name were different, the contents | |
30383 | of that location would fool the debugger into doing the right thing despite | |
30384 | the bug. Play it safe and give a specific, complete example. That is the | |
30385 | easiest thing for you to do, and the most helpful. | |
c4555f82 | 30386 | |
8e04817f AC |
30387 | Keep in mind that the purpose of a bug report is to enable us to fix the |
30388 | bug. It may be that the bug has been reported previously, but neither | |
30389 | you nor we can know that unless your bug report is complete and | |
30390 | self-contained. | |
c4555f82 | 30391 | |
8e04817f AC |
30392 | Sometimes people give a few sketchy facts and ask, ``Does this ring a |
30393 | bell?'' Those bug reports are useless, and we urge everyone to | |
30394 | @emph{refuse to respond to them} except to chide the sender to report | |
30395 | bugs properly. | |
30396 | ||
30397 | To enable us to fix the bug, you should include all these things: | |
c4555f82 SC |
30398 | |
30399 | @itemize @bullet | |
30400 | @item | |
8e04817f AC |
30401 | The version of @value{GDBN}. @value{GDBN} announces it if you start |
30402 | with no arguments; you can also print it at any time using @code{show | |
30403 | version}. | |
c4555f82 | 30404 | |
8e04817f AC |
30405 | Without this, we will not know whether there is any point in looking for |
30406 | the bug in the current version of @value{GDBN}. | |
c4555f82 SC |
30407 | |
30408 | @item | |
8e04817f AC |
30409 | The type of machine you are using, and the operating system name and |
30410 | version number. | |
c4555f82 SC |
30411 | |
30412 | @item | |
c1468174 | 30413 | What compiler (and its version) was used to compile @value{GDBN}---e.g.@: |
8e04817f | 30414 | ``@value{GCC}--2.8.1''. |
c4555f82 SC |
30415 | |
30416 | @item | |
8e04817f | 30417 | What compiler (and its version) was used to compile the program you are |
c1468174 | 30418 | debugging---e.g.@: ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP |
3f94c067 BW |
30419 | C Compiler''. For @value{NGCC}, you can say @kbd{@value{GCC} --version} |
30420 | to get this information; for other compilers, see the documentation for | |
30421 | those compilers. | |
c4555f82 | 30422 | |
8e04817f AC |
30423 | @item |
30424 | The command arguments you gave the compiler to compile your example and | |
30425 | observe the bug. For example, did you use @samp{-O}? To guarantee | |
30426 | you will not omit something important, list them all. A copy of the | |
30427 | Makefile (or the output from make) is sufficient. | |
c4555f82 | 30428 | |
8e04817f AC |
30429 | If we were to try to guess the arguments, we would probably guess wrong |
30430 | and then we might not encounter the bug. | |
c4555f82 | 30431 | |
8e04817f AC |
30432 | @item |
30433 | A complete input script, and all necessary source files, that will | |
30434 | reproduce the bug. | |
c4555f82 | 30435 | |
8e04817f AC |
30436 | @item |
30437 | A description of what behavior you observe that you believe is | |
30438 | incorrect. For example, ``It gets a fatal signal.'' | |
c4555f82 | 30439 | |
8e04817f AC |
30440 | Of course, if the bug is that @value{GDBN} gets a fatal signal, then we |
30441 | will certainly notice it. But if the bug is incorrect output, we might | |
30442 | not notice unless it is glaringly wrong. You might as well not give us | |
30443 | a chance to make a mistake. | |
c4555f82 | 30444 | |
8e04817f AC |
30445 | Even if the problem you experience is a fatal signal, you should still |
30446 | say so explicitly. Suppose something strange is going on, such as, your | |
30447 | copy of @value{GDBN} is out of synch, or you have encountered a bug in | |
30448 | the C library on your system. (This has happened!) Your copy might | |
30449 | crash and ours would not. If you told us to expect a crash, then when | |
30450 | ours fails to crash, we would know that the bug was not happening for | |
30451 | us. If you had not told us to expect a crash, then we would not be able | |
30452 | to draw any conclusion from our observations. | |
c4555f82 | 30453 | |
e0c07bf0 MC |
30454 | @pindex script |
30455 | @cindex recording a session script | |
30456 | To collect all this information, you can use a session recording program | |
30457 | such as @command{script}, which is available on many Unix systems. | |
30458 | Just run your @value{GDBN} session inside @command{script} and then | |
30459 | include the @file{typescript} file with your bug report. | |
30460 | ||
30461 | Another way to record a @value{GDBN} session is to run @value{GDBN} | |
30462 | inside Emacs and then save the entire buffer to a file. | |
30463 | ||
8e04817f AC |
30464 | @item |
30465 | If you wish to suggest changes to the @value{GDBN} source, send us context | |
30466 | diffs. If you even discuss something in the @value{GDBN} source, refer to | |
30467 | it by context, not by line number. | |
c4555f82 | 30468 | |
8e04817f AC |
30469 | The line numbers in our development sources will not match those in your |
30470 | sources. Your line numbers would convey no useful information to us. | |
c4555f82 | 30471 | |
8e04817f | 30472 | @end itemize |
c4555f82 | 30473 | |
8e04817f | 30474 | Here are some things that are not necessary: |
c4555f82 | 30475 | |
8e04817f AC |
30476 | @itemize @bullet |
30477 | @item | |
30478 | A description of the envelope of the bug. | |
c4555f82 | 30479 | |
8e04817f AC |
30480 | Often people who encounter a bug spend a lot of time investigating |
30481 | which changes to the input file will make the bug go away and which | |
30482 | changes will not affect it. | |
c4555f82 | 30483 | |
8e04817f AC |
30484 | This is often time consuming and not very useful, because the way we |
30485 | will find the bug is by running a single example under the debugger | |
30486 | with breakpoints, not by pure deduction from a series of examples. | |
30487 | We recommend that you save your time for something else. | |
c4555f82 | 30488 | |
8e04817f AC |
30489 | Of course, if you can find a simpler example to report @emph{instead} |
30490 | of the original one, that is a convenience for us. Errors in the | |
30491 | output will be easier to spot, running under the debugger will take | |
30492 | less time, and so on. | |
c4555f82 | 30493 | |
8e04817f AC |
30494 | However, simplification is not vital; if you do not want to do this, |
30495 | report the bug anyway and send us the entire test case you used. | |
c4555f82 | 30496 | |
8e04817f AC |
30497 | @item |
30498 | A patch for the bug. | |
c4555f82 | 30499 | |
8e04817f AC |
30500 | A patch for the bug does help us if it is a good one. But do not omit |
30501 | the necessary information, such as the test case, on the assumption that | |
30502 | a patch is all we need. We might see problems with your patch and decide | |
30503 | to fix the problem another way, or we might not understand it at all. | |
c4555f82 | 30504 | |
8e04817f AC |
30505 | Sometimes with a program as complicated as @value{GDBN} it is very hard to |
30506 | construct an example that will make the program follow a certain path | |
30507 | through the code. If you do not send us the example, we will not be able | |
30508 | to construct one, so we will not be able to verify that the bug is fixed. | |
c4555f82 | 30509 | |
8e04817f AC |
30510 | And if we cannot understand what bug you are trying to fix, or why your |
30511 | patch should be an improvement, we will not install it. A test case will | |
30512 | help us to understand. | |
c4555f82 | 30513 | |
8e04817f AC |
30514 | @item |
30515 | A guess about what the bug is or what it depends on. | |
c4555f82 | 30516 | |
8e04817f AC |
30517 | Such guesses are usually wrong. Even we cannot guess right about such |
30518 | things without first using the debugger to find the facts. | |
30519 | @end itemize | |
c4555f82 | 30520 | |
8e04817f AC |
30521 | @c The readline documentation is distributed with the readline code |
30522 | @c and consists of the two following files: | |
30523 | @c rluser.texinfo | |
30524 | @c inc-hist.texinfo | |
30525 | @c Use -I with makeinfo to point to the appropriate directory, | |
30526 | @c environment var TEXINPUTS with TeX. | |
39037522 | 30527 | @ifclear SYSTEM_READLINE |
5bdf8622 | 30528 | @include rluser.texi |
8e04817f | 30529 | @include inc-hist.texinfo |
39037522 | 30530 | @end ifclear |
c4555f82 | 30531 | |
c4555f82 | 30532 | |
8e04817f AC |
30533 | @node Formatting Documentation |
30534 | @appendix Formatting Documentation | |
c4555f82 | 30535 | |
8e04817f AC |
30536 | @cindex @value{GDBN} reference card |
30537 | @cindex reference card | |
30538 | The @value{GDBN} 4 release includes an already-formatted reference card, ready | |
30539 | for printing with PostScript or Ghostscript, in the @file{gdb} | |
30540 | subdirectory of the main source directory@footnote{In | |
30541 | @file{gdb-@value{GDBVN}/gdb/refcard.ps} of the version @value{GDBVN} | |
30542 | release.}. If you can use PostScript or Ghostscript with your printer, | |
30543 | you can print the reference card immediately with @file{refcard.ps}. | |
c4555f82 | 30544 | |
8e04817f AC |
30545 | The release also includes the source for the reference card. You |
30546 | can format it, using @TeX{}, by typing: | |
c4555f82 | 30547 | |
474c8240 | 30548 | @smallexample |
8e04817f | 30549 | make refcard.dvi |
474c8240 | 30550 | @end smallexample |
c4555f82 | 30551 | |
8e04817f AC |
30552 | The @value{GDBN} reference card is designed to print in @dfn{landscape} |
30553 | mode on US ``letter'' size paper; | |
30554 | that is, on a sheet 11 inches wide by 8.5 inches | |
30555 | high. You will need to specify this form of printing as an option to | |
30556 | your @sc{dvi} output program. | |
c4555f82 | 30557 | |
8e04817f | 30558 | @cindex documentation |
c4555f82 | 30559 | |
8e04817f AC |
30560 | All the documentation for @value{GDBN} comes as part of the machine-readable |
30561 | distribution. The documentation is written in Texinfo format, which is | |
30562 | a documentation system that uses a single source file to produce both | |
30563 | on-line information and a printed manual. You can use one of the Info | |
30564 | formatting commands to create the on-line version of the documentation | |
30565 | and @TeX{} (or @code{texi2roff}) to typeset the printed version. | |
c4555f82 | 30566 | |
8e04817f AC |
30567 | @value{GDBN} includes an already formatted copy of the on-line Info |
30568 | version of this manual in the @file{gdb} subdirectory. The main Info | |
30569 | file is @file{gdb-@value{GDBVN}/gdb/gdb.info}, and it refers to | |
30570 | subordinate files matching @samp{gdb.info*} in the same directory. If | |
30571 | necessary, you can print out these files, or read them with any editor; | |
30572 | but they are easier to read using the @code{info} subsystem in @sc{gnu} | |
30573 | Emacs or the standalone @code{info} program, available as part of the | |
30574 | @sc{gnu} Texinfo distribution. | |
c4555f82 | 30575 | |
8e04817f AC |
30576 | If you want to format these Info files yourself, you need one of the |
30577 | Info formatting programs, such as @code{texinfo-format-buffer} or | |
30578 | @code{makeinfo}. | |
c4555f82 | 30579 | |
8e04817f AC |
30580 | If you have @code{makeinfo} installed, and are in the top level |
30581 | @value{GDBN} source directory (@file{gdb-@value{GDBVN}}, in the case of | |
30582 | version @value{GDBVN}), you can make the Info file by typing: | |
c4555f82 | 30583 | |
474c8240 | 30584 | @smallexample |
8e04817f AC |
30585 | cd gdb |
30586 | make gdb.info | |
474c8240 | 30587 | @end smallexample |
c4555f82 | 30588 | |
8e04817f AC |
30589 | If you want to typeset and print copies of this manual, you need @TeX{}, |
30590 | a program to print its @sc{dvi} output files, and @file{texinfo.tex}, the | |
30591 | Texinfo definitions file. | |
c4555f82 | 30592 | |
8e04817f AC |
30593 | @TeX{} is a typesetting program; it does not print files directly, but |
30594 | produces output files called @sc{dvi} files. To print a typeset | |
30595 | document, you need a program to print @sc{dvi} files. If your system | |
30596 | has @TeX{} installed, chances are it has such a program. The precise | |
30597 | command to use depends on your system; @kbd{lpr -d} is common; another | |
30598 | (for PostScript devices) is @kbd{dvips}. The @sc{dvi} print command may | |
30599 | require a file name without any extension or a @samp{.dvi} extension. | |
c4555f82 | 30600 | |
8e04817f AC |
30601 | @TeX{} also requires a macro definitions file called |
30602 | @file{texinfo.tex}. This file tells @TeX{} how to typeset a document | |
30603 | written in Texinfo format. On its own, @TeX{} cannot either read or | |
30604 | typeset a Texinfo file. @file{texinfo.tex} is distributed with GDB | |
30605 | and is located in the @file{gdb-@var{version-number}/texinfo} | |
30606 | directory. | |
c4555f82 | 30607 | |
8e04817f | 30608 | If you have @TeX{} and a @sc{dvi} printer program installed, you can |
d3e8051b | 30609 | typeset and print this manual. First switch to the @file{gdb} |
8e04817f AC |
30610 | subdirectory of the main source directory (for example, to |
30611 | @file{gdb-@value{GDBVN}/gdb}) and type: | |
c4555f82 | 30612 | |
474c8240 | 30613 | @smallexample |
8e04817f | 30614 | make gdb.dvi |
474c8240 | 30615 | @end smallexample |
c4555f82 | 30616 | |
8e04817f | 30617 | Then give @file{gdb.dvi} to your @sc{dvi} printing program. |
c4555f82 | 30618 | |
8e04817f AC |
30619 | @node Installing GDB |
30620 | @appendix Installing @value{GDBN} | |
8e04817f | 30621 | @cindex installation |
c4555f82 | 30622 | |
7fa2210b DJ |
30623 | @menu |
30624 | * Requirements:: Requirements for building @value{GDBN} | |
db2e3e2e | 30625 | * Running Configure:: Invoking the @value{GDBN} @file{configure} script |
7fa2210b DJ |
30626 | * Separate Objdir:: Compiling @value{GDBN} in another directory |
30627 | * Config Names:: Specifying names for hosts and targets | |
30628 | * Configure Options:: Summary of options for configure | |
098b41a6 | 30629 | * System-wide configuration:: Having a system-wide init file |
7fa2210b DJ |
30630 | @end menu |
30631 | ||
30632 | @node Requirements | |
79a6e687 | 30633 | @section Requirements for Building @value{GDBN} |
7fa2210b DJ |
30634 | @cindex building @value{GDBN}, requirements for |
30635 | ||
30636 | Building @value{GDBN} requires various tools and packages to be available. | |
30637 | Other packages will be used only if they are found. | |
30638 | ||
79a6e687 | 30639 | @heading Tools/Packages Necessary for Building @value{GDBN} |
7fa2210b DJ |
30640 | @table @asis |
30641 | @item ISO C90 compiler | |
30642 | @value{GDBN} is written in ISO C90. It should be buildable with any | |
30643 | working C90 compiler, e.g.@: GCC. | |
30644 | ||
30645 | @end table | |
30646 | ||
79a6e687 | 30647 | @heading Tools/Packages Optional for Building @value{GDBN} |
7fa2210b DJ |
30648 | @table @asis |
30649 | @item Expat | |
123dc839 | 30650 | @anchor{Expat} |
7fa2210b DJ |
30651 | @value{GDBN} can use the Expat XML parsing library. This library may be |
30652 | included with your operating system distribution; if it is not, you | |
30653 | can get the latest version from @url{http://expat.sourceforge.net}. | |
db2e3e2e | 30654 | The @file{configure} script will search for this library in several |
7fa2210b DJ |
30655 | standard locations; if it is installed in an unusual path, you can |
30656 | use the @option{--with-libexpat-prefix} option to specify its location. | |
30657 | ||
9cceb671 DJ |
30658 | Expat is used for: |
30659 | ||
30660 | @itemize @bullet | |
30661 | @item | |
30662 | Remote protocol memory maps (@pxref{Memory Map Format}) | |
30663 | @item | |
30664 | Target descriptions (@pxref{Target Descriptions}) | |
30665 | @item | |
30666 | Remote shared library lists (@pxref{Library List Format}) | |
30667 | @item | |
30668 | MS-Windows shared libraries (@pxref{Shared Libraries}) | |
30669 | @end itemize | |
7fa2210b | 30670 | |
31fffb02 CS |
30671 | @item zlib |
30672 | @cindex compressed debug sections | |
30673 | @value{GDBN} will use the @samp{zlib} library, if available, to read | |
30674 | compressed debug sections. Some linkers, such as GNU gold, are capable | |
30675 | of producing binaries with compressed debug sections. If @value{GDBN} | |
30676 | is compiled with @samp{zlib}, it will be able to read the debug | |
30677 | information in such binaries. | |
30678 | ||
30679 | The @samp{zlib} library is likely included with your operating system | |
30680 | distribution; if it is not, you can get the latest version from | |
30681 | @url{http://zlib.net}. | |
30682 | ||
6c7a06a3 TT |
30683 | @item iconv |
30684 | @value{GDBN}'s features related to character sets (@pxref{Character | |
30685 | Sets}) require a functioning @code{iconv} implementation. If you are | |
30686 | on a GNU system, then this is provided by the GNU C Library. Some | |
30687 | other systems also provide a working @code{iconv}. | |
30688 | ||
30689 | On systems with @code{iconv}, you can install GNU Libiconv. If you | |
30690 | have previously installed Libiconv, you can use the | |
30691 | @option{--with-libiconv-prefix} option to configure. | |
30692 | ||
30693 | @value{GDBN}'s top-level @file{configure} and @file{Makefile} will | |
30694 | arrange to build Libiconv if a directory named @file{libiconv} appears | |
30695 | in the top-most source directory. If Libiconv is built this way, and | |
30696 | if the operating system does not provide a suitable @code{iconv} | |
30697 | implementation, then the just-built library will automatically be used | |
30698 | by @value{GDBN}. One easy way to set this up is to download GNU | |
30699 | Libiconv, unpack it, and then rename the directory holding the | |
30700 | Libiconv source code to @samp{libiconv}. | |
7fa2210b DJ |
30701 | @end table |
30702 | ||
30703 | @node Running Configure | |
db2e3e2e | 30704 | @section Invoking the @value{GDBN} @file{configure} Script |
7fa2210b | 30705 | @cindex configuring @value{GDBN} |
db2e3e2e | 30706 | @value{GDBN} comes with a @file{configure} script that automates the process |
8e04817f AC |
30707 | of preparing @value{GDBN} for installation; you can then use @code{make} to |
30708 | build the @code{gdb} program. | |
30709 | @iftex | |
30710 | @c irrelevant in info file; it's as current as the code it lives with. | |
30711 | @footnote{If you have a more recent version of @value{GDBN} than @value{GDBVN}, | |
30712 | look at the @file{README} file in the sources; we may have improved the | |
30713 | installation procedures since publishing this manual.} | |
30714 | @end iftex | |
c4555f82 | 30715 | |
8e04817f AC |
30716 | The @value{GDBN} distribution includes all the source code you need for |
30717 | @value{GDBN} in a single directory, whose name is usually composed by | |
30718 | appending the version number to @samp{gdb}. | |
c4555f82 | 30719 | |
8e04817f AC |
30720 | For example, the @value{GDBN} version @value{GDBVN} distribution is in the |
30721 | @file{gdb-@value{GDBVN}} directory. That directory contains: | |
c4555f82 | 30722 | |
8e04817f AC |
30723 | @table @code |
30724 | @item gdb-@value{GDBVN}/configure @r{(and supporting files)} | |
30725 | script for configuring @value{GDBN} and all its supporting libraries | |
c4555f82 | 30726 | |
8e04817f AC |
30727 | @item gdb-@value{GDBVN}/gdb |
30728 | the source specific to @value{GDBN} itself | |
c4555f82 | 30729 | |
8e04817f AC |
30730 | @item gdb-@value{GDBVN}/bfd |
30731 | source for the Binary File Descriptor library | |
c906108c | 30732 | |
8e04817f AC |
30733 | @item gdb-@value{GDBVN}/include |
30734 | @sc{gnu} include files | |
c906108c | 30735 | |
8e04817f AC |
30736 | @item gdb-@value{GDBVN}/libiberty |
30737 | source for the @samp{-liberty} free software library | |
c906108c | 30738 | |
8e04817f AC |
30739 | @item gdb-@value{GDBVN}/opcodes |
30740 | source for the library of opcode tables and disassemblers | |
c906108c | 30741 | |
8e04817f AC |
30742 | @item gdb-@value{GDBVN}/readline |
30743 | source for the @sc{gnu} command-line interface | |
c906108c | 30744 | |
8e04817f AC |
30745 | @item gdb-@value{GDBVN}/glob |
30746 | source for the @sc{gnu} filename pattern-matching subroutine | |
c906108c | 30747 | |
8e04817f AC |
30748 | @item gdb-@value{GDBVN}/mmalloc |
30749 | source for the @sc{gnu} memory-mapped malloc package | |
30750 | @end table | |
c906108c | 30751 | |
db2e3e2e | 30752 | The simplest way to configure and build @value{GDBN} is to run @file{configure} |
8e04817f AC |
30753 | from the @file{gdb-@var{version-number}} source directory, which in |
30754 | this example is the @file{gdb-@value{GDBVN}} directory. | |
c906108c | 30755 | |
8e04817f | 30756 | First switch to the @file{gdb-@var{version-number}} source directory |
db2e3e2e | 30757 | if you are not already in it; then run @file{configure}. Pass the |
8e04817f AC |
30758 | identifier for the platform on which @value{GDBN} will run as an |
30759 | argument. | |
c906108c | 30760 | |
8e04817f | 30761 | For example: |
c906108c | 30762 | |
474c8240 | 30763 | @smallexample |
8e04817f AC |
30764 | cd gdb-@value{GDBVN} |
30765 | ./configure @var{host} | |
30766 | make | |
474c8240 | 30767 | @end smallexample |
c906108c | 30768 | |
8e04817f AC |
30769 | @noindent |
30770 | where @var{host} is an identifier such as @samp{sun4} or | |
30771 | @samp{decstation}, that identifies the platform where @value{GDBN} will run. | |
db2e3e2e | 30772 | (You can often leave off @var{host}; @file{configure} tries to guess the |
8e04817f | 30773 | correct value by examining your system.) |
c906108c | 30774 | |
8e04817f AC |
30775 | Running @samp{configure @var{host}} and then running @code{make} builds the |
30776 | @file{bfd}, @file{readline}, @file{mmalloc}, and @file{libiberty} | |
30777 | libraries, then @code{gdb} itself. The configured source files, and the | |
30778 | binaries, are left in the corresponding source directories. | |
c906108c | 30779 | |
8e04817f | 30780 | @need 750 |
db2e3e2e | 30781 | @file{configure} is a Bourne-shell (@code{/bin/sh}) script; if your |
8e04817f AC |
30782 | system does not recognize this automatically when you run a different |
30783 | shell, you may need to run @code{sh} on it explicitly: | |
c906108c | 30784 | |
474c8240 | 30785 | @smallexample |
8e04817f | 30786 | sh configure @var{host} |
474c8240 | 30787 | @end smallexample |
c906108c | 30788 | |
db2e3e2e | 30789 | If you run @file{configure} from a directory that contains source |
8e04817f | 30790 | directories for multiple libraries or programs, such as the |
db2e3e2e BW |
30791 | @file{gdb-@value{GDBVN}} source directory for version @value{GDBVN}, |
30792 | @file{configure} | |
8e04817f AC |
30793 | creates configuration files for every directory level underneath (unless |
30794 | you tell it not to, with the @samp{--norecursion} option). | |
30795 | ||
db2e3e2e | 30796 | You should run the @file{configure} script from the top directory in the |
94e91d6d | 30797 | source tree, the @file{gdb-@var{version-number}} directory. If you run |
db2e3e2e | 30798 | @file{configure} from one of the subdirectories, you will configure only |
94e91d6d | 30799 | that subdirectory. That is usually not what you want. In particular, |
db2e3e2e | 30800 | if you run the first @file{configure} from the @file{gdb} subdirectory |
94e91d6d MC |
30801 | of the @file{gdb-@var{version-number}} directory, you will omit the |
30802 | configuration of @file{bfd}, @file{readline}, and other sibling | |
30803 | directories of the @file{gdb} subdirectory. This leads to build errors | |
30804 | about missing include files such as @file{bfd/bfd.h}. | |
c906108c | 30805 | |
8e04817f AC |
30806 | You can install @code{@value{GDBP}} anywhere; it has no hardwired paths. |
30807 | However, you should make sure that the shell on your path (named by | |
30808 | the @samp{SHELL} environment variable) is publicly readable. Remember | |
30809 | that @value{GDBN} uses the shell to start your program---some systems refuse to | |
30810 | let @value{GDBN} debug child processes whose programs are not readable. | |
c906108c | 30811 | |
8e04817f | 30812 | @node Separate Objdir |
79a6e687 | 30813 | @section Compiling @value{GDBN} in Another Directory |
c906108c | 30814 | |
8e04817f AC |
30815 | If you want to run @value{GDBN} versions for several host or target machines, |
30816 | you need a different @code{gdb} compiled for each combination of | |
db2e3e2e | 30817 | host and target. @file{configure} is designed to make this easy by |
8e04817f AC |
30818 | allowing you to generate each configuration in a separate subdirectory, |
30819 | rather than in the source directory. If your @code{make} program | |
30820 | handles the @samp{VPATH} feature (@sc{gnu} @code{make} does), running | |
30821 | @code{make} in each of these directories builds the @code{gdb} | |
30822 | program specified there. | |
c906108c | 30823 | |
db2e3e2e | 30824 | To build @code{gdb} in a separate directory, run @file{configure} |
8e04817f | 30825 | with the @samp{--srcdir} option to specify where to find the source. |
db2e3e2e BW |
30826 | (You also need to specify a path to find @file{configure} |
30827 | itself from your working directory. If the path to @file{configure} | |
8e04817f AC |
30828 | would be the same as the argument to @samp{--srcdir}, you can leave out |
30829 | the @samp{--srcdir} option; it is assumed.) | |
c906108c | 30830 | |
8e04817f AC |
30831 | For example, with version @value{GDBVN}, you can build @value{GDBN} in a |
30832 | separate directory for a Sun 4 like this: | |
c906108c | 30833 | |
474c8240 | 30834 | @smallexample |
8e04817f AC |
30835 | @group |
30836 | cd gdb-@value{GDBVN} | |
30837 | mkdir ../gdb-sun4 | |
30838 | cd ../gdb-sun4 | |
30839 | ../gdb-@value{GDBVN}/configure sun4 | |
30840 | make | |
30841 | @end group | |
474c8240 | 30842 | @end smallexample |
c906108c | 30843 | |
db2e3e2e | 30844 | When @file{configure} builds a configuration using a remote source |
8e04817f AC |
30845 | directory, it creates a tree for the binaries with the same structure |
30846 | (and using the same names) as the tree under the source directory. In | |
30847 | the example, you'd find the Sun 4 library @file{libiberty.a} in the | |
30848 | directory @file{gdb-sun4/libiberty}, and @value{GDBN} itself in | |
30849 | @file{gdb-sun4/gdb}. | |
c906108c | 30850 | |
94e91d6d MC |
30851 | Make sure that your path to the @file{configure} script has just one |
30852 | instance of @file{gdb} in it. If your path to @file{configure} looks | |
30853 | like @file{../gdb-@value{GDBVN}/gdb/configure}, you are configuring only | |
30854 | one subdirectory of @value{GDBN}, not the whole package. This leads to | |
30855 | build errors about missing include files such as @file{bfd/bfd.h}. | |
30856 | ||
8e04817f AC |
30857 | One popular reason to build several @value{GDBN} configurations in separate |
30858 | directories is to configure @value{GDBN} for cross-compiling (where | |
30859 | @value{GDBN} runs on one machine---the @dfn{host}---while debugging | |
30860 | programs that run on another machine---the @dfn{target}). | |
30861 | You specify a cross-debugging target by | |
db2e3e2e | 30862 | giving the @samp{--target=@var{target}} option to @file{configure}. |
c906108c | 30863 | |
8e04817f AC |
30864 | When you run @code{make} to build a program or library, you must run |
30865 | it in a configured directory---whatever directory you were in when you | |
db2e3e2e | 30866 | called @file{configure} (or one of its subdirectories). |
c906108c | 30867 | |
db2e3e2e | 30868 | The @code{Makefile} that @file{configure} generates in each source |
8e04817f AC |
30869 | directory also runs recursively. If you type @code{make} in a source |
30870 | directory such as @file{gdb-@value{GDBVN}} (or in a separate configured | |
30871 | directory configured with @samp{--srcdir=@var{dirname}/gdb-@value{GDBVN}}), you | |
30872 | will build all the required libraries, and then build GDB. | |
c906108c | 30873 | |
8e04817f AC |
30874 | When you have multiple hosts or targets configured in separate |
30875 | directories, you can run @code{make} on them in parallel (for example, | |
30876 | if they are NFS-mounted on each of the hosts); they will not interfere | |
30877 | with each other. | |
c906108c | 30878 | |
8e04817f | 30879 | @node Config Names |
79a6e687 | 30880 | @section Specifying Names for Hosts and Targets |
c906108c | 30881 | |
db2e3e2e | 30882 | The specifications used for hosts and targets in the @file{configure} |
8e04817f AC |
30883 | script are based on a three-part naming scheme, but some short predefined |
30884 | aliases are also supported. The full naming scheme encodes three pieces | |
30885 | of information in the following pattern: | |
c906108c | 30886 | |
474c8240 | 30887 | @smallexample |
8e04817f | 30888 | @var{architecture}-@var{vendor}-@var{os} |
474c8240 | 30889 | @end smallexample |
c906108c | 30890 | |
8e04817f AC |
30891 | For example, you can use the alias @code{sun4} as a @var{host} argument, |
30892 | or as the value for @var{target} in a @code{--target=@var{target}} | |
30893 | option. The equivalent full name is @samp{sparc-sun-sunos4}. | |
c906108c | 30894 | |
db2e3e2e | 30895 | The @file{configure} script accompanying @value{GDBN} does not provide |
8e04817f | 30896 | any query facility to list all supported host and target names or |
db2e3e2e | 30897 | aliases. @file{configure} calls the Bourne shell script |
8e04817f AC |
30898 | @code{config.sub} to map abbreviations to full names; you can read the |
30899 | script, if you wish, or you can use it to test your guesses on | |
30900 | abbreviations---for example: | |
c906108c | 30901 | |
8e04817f AC |
30902 | @smallexample |
30903 | % sh config.sub i386-linux | |
30904 | i386-pc-linux-gnu | |
30905 | % sh config.sub alpha-linux | |
30906 | alpha-unknown-linux-gnu | |
30907 | % sh config.sub hp9k700 | |
30908 | hppa1.1-hp-hpux | |
30909 | % sh config.sub sun4 | |
30910 | sparc-sun-sunos4.1.1 | |
30911 | % sh config.sub sun3 | |
30912 | m68k-sun-sunos4.1.1 | |
30913 | % sh config.sub i986v | |
30914 | Invalid configuration `i986v': machine `i986v' not recognized | |
30915 | @end smallexample | |
c906108c | 30916 | |
8e04817f AC |
30917 | @noindent |
30918 | @code{config.sub} is also distributed in the @value{GDBN} source | |
30919 | directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}). | |
d700128c | 30920 | |
8e04817f | 30921 | @node Configure Options |
db2e3e2e | 30922 | @section @file{configure} Options |
c906108c | 30923 | |
db2e3e2e BW |
30924 | Here is a summary of the @file{configure} options and arguments that |
30925 | are most often useful for building @value{GDBN}. @file{configure} also has | |
8e04817f | 30926 | several other options not listed here. @inforef{What Configure |
db2e3e2e | 30927 | Does,,configure.info}, for a full explanation of @file{configure}. |
c906108c | 30928 | |
474c8240 | 30929 | @smallexample |
8e04817f AC |
30930 | configure @r{[}--help@r{]} |
30931 | @r{[}--prefix=@var{dir}@r{]} | |
30932 | @r{[}--exec-prefix=@var{dir}@r{]} | |
30933 | @r{[}--srcdir=@var{dirname}@r{]} | |
30934 | @r{[}--norecursion@r{]} @r{[}--rm@r{]} | |
30935 | @r{[}--target=@var{target}@r{]} | |
30936 | @var{host} | |
474c8240 | 30937 | @end smallexample |
c906108c | 30938 | |
8e04817f AC |
30939 | @noindent |
30940 | You may introduce options with a single @samp{-} rather than | |
30941 | @samp{--} if you prefer; but you may abbreviate option names if you use | |
30942 | @samp{--}. | |
c906108c | 30943 | |
8e04817f AC |
30944 | @table @code |
30945 | @item --help | |
db2e3e2e | 30946 | Display a quick summary of how to invoke @file{configure}. |
c906108c | 30947 | |
8e04817f AC |
30948 | @item --prefix=@var{dir} |
30949 | Configure the source to install programs and files under directory | |
30950 | @file{@var{dir}}. | |
c906108c | 30951 | |
8e04817f AC |
30952 | @item --exec-prefix=@var{dir} |
30953 | Configure the source to install programs under directory | |
30954 | @file{@var{dir}}. | |
c906108c | 30955 | |
8e04817f AC |
30956 | @c avoid splitting the warning from the explanation: |
30957 | @need 2000 | |
30958 | @item --srcdir=@var{dirname} | |
30959 | @strong{Warning: using this option requires @sc{gnu} @code{make}, or another | |
30960 | @code{make} that implements the @code{VPATH} feature.}@* | |
30961 | Use this option to make configurations in directories separate from the | |
30962 | @value{GDBN} source directories. Among other things, you can use this to | |
30963 | build (or maintain) several configurations simultaneously, in separate | |
db2e3e2e | 30964 | directories. @file{configure} writes configuration-specific files in |
8e04817f | 30965 | the current directory, but arranges for them to use the source in the |
db2e3e2e | 30966 | directory @var{dirname}. @file{configure} creates directories under |
8e04817f AC |
30967 | the working directory in parallel to the source directories below |
30968 | @var{dirname}. | |
c906108c | 30969 | |
8e04817f | 30970 | @item --norecursion |
db2e3e2e | 30971 | Configure only the directory level where @file{configure} is executed; do not |
8e04817f | 30972 | propagate configuration to subdirectories. |
c906108c | 30973 | |
8e04817f AC |
30974 | @item --target=@var{target} |
30975 | Configure @value{GDBN} for cross-debugging programs running on the specified | |
30976 | @var{target}. Without this option, @value{GDBN} is configured to debug | |
30977 | programs that run on the same machine (@var{host}) as @value{GDBN} itself. | |
c906108c | 30978 | |
8e04817f | 30979 | There is no convenient way to generate a list of all available targets. |
c906108c | 30980 | |
8e04817f AC |
30981 | @item @var{host} @dots{} |
30982 | Configure @value{GDBN} to run on the specified @var{host}. | |
c906108c | 30983 | |
8e04817f AC |
30984 | There is no convenient way to generate a list of all available hosts. |
30985 | @end table | |
c906108c | 30986 | |
8e04817f AC |
30987 | There are many other options available as well, but they are generally |
30988 | needed for special purposes only. | |
c906108c | 30989 | |
098b41a6 JG |
30990 | @node System-wide configuration |
30991 | @section System-wide configuration and settings | |
30992 | @cindex system-wide init file | |
30993 | ||
30994 | @value{GDBN} can be configured to have a system-wide init file; | |
30995 | this file will be read and executed at startup (@pxref{Startup, , What | |
30996 | @value{GDBN} does during startup}). | |
30997 | ||
30998 | Here is the corresponding configure option: | |
30999 | ||
31000 | @table @code | |
31001 | @item --with-system-gdbinit=@var{file} | |
31002 | Specify that the default location of the system-wide init file is | |
31003 | @var{file}. | |
31004 | @end table | |
31005 | ||
31006 | If @value{GDBN} has been configured with the option @option{--prefix=$prefix}, | |
31007 | it may be subject to relocation. Two possible cases: | |
31008 | ||
31009 | @itemize @bullet | |
31010 | @item | |
31011 | If the default location of this init file contains @file{$prefix}, | |
31012 | it will be subject to relocation. Suppose that the configure options | |
31013 | are @option{--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit}; | |
31014 | if @value{GDBN} is moved from @file{$prefix} to @file{$install}, the system | |
31015 | init file is looked for as @file{$install/etc/gdbinit} instead of | |
31016 | @file{$prefix/etc/gdbinit}. | |
31017 | ||
31018 | @item | |
31019 | By contrast, if the default location does not contain the prefix, | |
31020 | it will not be relocated. E.g.@: if @value{GDBN} has been configured with | |
31021 | @option{--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit}, | |
31022 | then @value{GDBN} will always look for @file{/usr/share/gdb/gdbinit}, | |
31023 | wherever @value{GDBN} is installed. | |
31024 | @end itemize | |
31025 | ||
8e04817f AC |
31026 | @node Maintenance Commands |
31027 | @appendix Maintenance Commands | |
31028 | @cindex maintenance commands | |
31029 | @cindex internal commands | |
c906108c | 31030 | |
8e04817f | 31031 | In addition to commands intended for @value{GDBN} users, @value{GDBN} |
09d4efe1 EZ |
31032 | includes a number of commands intended for @value{GDBN} developers, |
31033 | that are not documented elsewhere in this manual. These commands are | |
da316a69 EZ |
31034 | provided here for reference. (For commands that turn on debugging |
31035 | messages, see @ref{Debugging Output}.) | |
c906108c | 31036 | |
8e04817f | 31037 | @table @code |
09d4efe1 | 31038 | @kindex maint agent |
782b2b07 | 31039 | @kindex maint agent-eval |
09d4efe1 | 31040 | @item maint agent @var{expression} |
782b2b07 | 31041 | @itemx maint agent-eval @var{expression} |
09d4efe1 EZ |
31042 | Translate the given @var{expression} into remote agent bytecodes. |
31043 | This command is useful for debugging the Agent Expression mechanism | |
782b2b07 SS |
31044 | (@pxref{Agent Expressions}). The @samp{agent} version produces an |
31045 | expression useful for data collection, such as by tracepoints, while | |
31046 | @samp{maint agent-eval} produces an expression that evaluates directly | |
31047 | to a result. For instance, a collection expression for @code{globa + | |
31048 | globb} will include bytecodes to record four bytes of memory at each | |
31049 | of the addresses of @code{globa} and @code{globb}, while discarding | |
31050 | the result of the addition, while an evaluation expression will do the | |
31051 | addition and return the sum. | |
09d4efe1 | 31052 | |
8e04817f AC |
31053 | @kindex maint info breakpoints |
31054 | @item @anchor{maint info breakpoints}maint info breakpoints | |
31055 | Using the same format as @samp{info breakpoints}, display both the | |
31056 | breakpoints you've set explicitly, and those @value{GDBN} is using for | |
31057 | internal purposes. Internal breakpoints are shown with negative | |
31058 | breakpoint numbers. The type column identifies what kind of breakpoint | |
31059 | is shown: | |
c906108c | 31060 | |
8e04817f AC |
31061 | @table @code |
31062 | @item breakpoint | |
31063 | Normal, explicitly set breakpoint. | |
c906108c | 31064 | |
8e04817f AC |
31065 | @item watchpoint |
31066 | Normal, explicitly set watchpoint. | |
c906108c | 31067 | |
8e04817f AC |
31068 | @item longjmp |
31069 | Internal breakpoint, used to handle correctly stepping through | |
31070 | @code{longjmp} calls. | |
c906108c | 31071 | |
8e04817f AC |
31072 | @item longjmp resume |
31073 | Internal breakpoint at the target of a @code{longjmp}. | |
c906108c | 31074 | |
8e04817f AC |
31075 | @item until |
31076 | Temporary internal breakpoint used by the @value{GDBN} @code{until} command. | |
c906108c | 31077 | |
8e04817f AC |
31078 | @item finish |
31079 | Temporary internal breakpoint used by the @value{GDBN} @code{finish} command. | |
c906108c | 31080 | |
8e04817f AC |
31081 | @item shlib events |
31082 | Shared library events. | |
c906108c | 31083 | |
8e04817f | 31084 | @end table |
c906108c | 31085 | |
fff08868 HZ |
31086 | @kindex set displaced-stepping |
31087 | @kindex show displaced-stepping | |
237fc4c9 PA |
31088 | @cindex displaced stepping support |
31089 | @cindex out-of-line single-stepping | |
fff08868 HZ |
31090 | @item set displaced-stepping |
31091 | @itemx show displaced-stepping | |
237fc4c9 | 31092 | Control whether or not @value{GDBN} will do @dfn{displaced stepping} |
fff08868 HZ |
31093 | if the target supports it. Displaced stepping is a way to single-step |
31094 | over breakpoints without removing them from the inferior, by executing | |
31095 | an out-of-line copy of the instruction that was originally at the | |
31096 | breakpoint location. It is also known as out-of-line single-stepping. | |
31097 | ||
31098 | @table @code | |
31099 | @item set displaced-stepping on | |
31100 | If the target architecture supports it, @value{GDBN} will use | |
31101 | displaced stepping to step over breakpoints. | |
31102 | ||
31103 | @item set displaced-stepping off | |
31104 | @value{GDBN} will not use displaced stepping to step over breakpoints, | |
31105 | even if such is supported by the target architecture. | |
31106 | ||
31107 | @cindex non-stop mode, and @samp{set displaced-stepping} | |
31108 | @item set displaced-stepping auto | |
31109 | This is the default mode. @value{GDBN} will use displaced stepping | |
31110 | only if non-stop mode is active (@pxref{Non-Stop Mode}) and the target | |
31111 | architecture supports displaced stepping. | |
31112 | @end table | |
237fc4c9 | 31113 | |
09d4efe1 EZ |
31114 | @kindex maint check-symtabs |
31115 | @item maint check-symtabs | |
31116 | Check the consistency of psymtabs and symtabs. | |
31117 | ||
31118 | @kindex maint cplus first_component | |
31119 | @item maint cplus first_component @var{name} | |
31120 | Print the first C@t{++} class/namespace component of @var{name}. | |
31121 | ||
31122 | @kindex maint cplus namespace | |
31123 | @item maint cplus namespace | |
31124 | Print the list of possible C@t{++} namespaces. | |
31125 | ||
31126 | @kindex maint demangle | |
31127 | @item maint demangle @var{name} | |
d3e8051b | 31128 | Demangle a C@t{++} or Objective-C mangled @var{name}. |
09d4efe1 EZ |
31129 | |
31130 | @kindex maint deprecate | |
31131 | @kindex maint undeprecate | |
31132 | @cindex deprecated commands | |
31133 | @item maint deprecate @var{command} @r{[}@var{replacement}@r{]} | |
31134 | @itemx maint undeprecate @var{command} | |
31135 | Deprecate or undeprecate the named @var{command}. Deprecated commands | |
31136 | cause @value{GDBN} to issue a warning when you use them. The optional | |
31137 | argument @var{replacement} says which newer command should be used in | |
31138 | favor of the deprecated one; if it is given, @value{GDBN} will mention | |
31139 | the replacement as part of the warning. | |
31140 | ||
31141 | @kindex maint dump-me | |
31142 | @item maint dump-me | |
721c2651 | 31143 | @cindex @code{SIGQUIT} signal, dump core of @value{GDBN} |
09d4efe1 | 31144 | Cause a fatal signal in the debugger and force it to dump its core. |
721c2651 EZ |
31145 | This is supported only on systems which support aborting a program |
31146 | with the @code{SIGQUIT} signal. | |
09d4efe1 | 31147 | |
8d30a00d AC |
31148 | @kindex maint internal-error |
31149 | @kindex maint internal-warning | |
09d4efe1 EZ |
31150 | @item maint internal-error @r{[}@var{message-text}@r{]} |
31151 | @itemx maint internal-warning @r{[}@var{message-text}@r{]} | |
8d30a00d AC |
31152 | Cause @value{GDBN} to call the internal function @code{internal_error} |
31153 | or @code{internal_warning} and hence behave as though an internal error | |
31154 | or internal warning has been detected. In addition to reporting the | |
31155 | internal problem, these functions give the user the opportunity to | |
31156 | either quit @value{GDBN} or create a core file of the current | |
31157 | @value{GDBN} session. | |
31158 | ||
09d4efe1 EZ |
31159 | These commands take an optional parameter @var{message-text} that is |
31160 | used as the text of the error or warning message. | |
31161 | ||
d3e8051b | 31162 | Here's an example of using @code{internal-error}: |
09d4efe1 | 31163 | |
8d30a00d | 31164 | @smallexample |
f7dc1244 | 31165 | (@value{GDBP}) @kbd{maint internal-error testing, 1, 2} |
8d30a00d AC |
31166 | @dots{}/maint.c:121: internal-error: testing, 1, 2 |
31167 | A problem internal to GDB has been detected. Further | |
31168 | debugging may prove unreliable. | |
31169 | Quit this debugging session? (y or n) @kbd{n} | |
31170 | Create a core file? (y or n) @kbd{n} | |
f7dc1244 | 31171 | (@value{GDBP}) |
8d30a00d AC |
31172 | @end smallexample |
31173 | ||
3c16cced PA |
31174 | @cindex @value{GDBN} internal error |
31175 | @cindex internal errors, control of @value{GDBN} behavior | |
31176 | ||
31177 | @kindex maint set internal-error | |
31178 | @kindex maint show internal-error | |
31179 | @kindex maint set internal-warning | |
31180 | @kindex maint show internal-warning | |
31181 | @item maint set internal-error @var{action} [ask|yes|no] | |
31182 | @itemx maint show internal-error @var{action} | |
31183 | @itemx maint set internal-warning @var{action} [ask|yes|no] | |
31184 | @itemx maint show internal-warning @var{action} | |
31185 | When @value{GDBN} reports an internal problem (error or warning) it | |
31186 | gives the user the opportunity to both quit @value{GDBN} and create a | |
31187 | core file of the current @value{GDBN} session. These commands let you | |
31188 | override the default behaviour for each particular @var{action}, | |
31189 | described in the table below. | |
31190 | ||
31191 | @table @samp | |
31192 | @item quit | |
31193 | You can specify that @value{GDBN} should always (yes) or never (no) | |
31194 | quit. The default is to ask the user what to do. | |
31195 | ||
31196 | @item corefile | |
31197 | You can specify that @value{GDBN} should always (yes) or never (no) | |
31198 | create a core file. The default is to ask the user what to do. | |
31199 | @end table | |
31200 | ||
09d4efe1 EZ |
31201 | @kindex maint packet |
31202 | @item maint packet @var{text} | |
31203 | If @value{GDBN} is talking to an inferior via the serial protocol, | |
31204 | then this command sends the string @var{text} to the inferior, and | |
31205 | displays the response packet. @value{GDBN} supplies the initial | |
31206 | @samp{$} character, the terminating @samp{#} character, and the | |
31207 | checksum. | |
31208 | ||
31209 | @kindex maint print architecture | |
31210 | @item maint print architecture @r{[}@var{file}@r{]} | |
31211 | Print the entire architecture configuration. The optional argument | |
31212 | @var{file} names the file where the output goes. | |
8d30a00d | 31213 | |
81adfced DJ |
31214 | @kindex maint print c-tdesc |
31215 | @item maint print c-tdesc | |
31216 | Print the current target description (@pxref{Target Descriptions}) as | |
31217 | a C source file. The created source file can be used in @value{GDBN} | |
31218 | when an XML parser is not available to parse the description. | |
31219 | ||
00905d52 AC |
31220 | @kindex maint print dummy-frames |
31221 | @item maint print dummy-frames | |
00905d52 AC |
31222 | Prints the contents of @value{GDBN}'s internal dummy-frame stack. |
31223 | ||
31224 | @smallexample | |
f7dc1244 | 31225 | (@value{GDBP}) @kbd{b add} |
00905d52 | 31226 | @dots{} |
f7dc1244 | 31227 | (@value{GDBP}) @kbd{print add(2,3)} |
00905d52 AC |
31228 | Breakpoint 2, add (a=2, b=3) at @dots{} |
31229 | 58 return (a + b); | |
31230 | The program being debugged stopped while in a function called from GDB. | |
31231 | @dots{} | |
f7dc1244 | 31232 | (@value{GDBP}) @kbd{maint print dummy-frames} |
00905d52 AC |
31233 | 0x1a57c80: pc=0x01014068 fp=0x0200bddc sp=0x0200bdd6 |
31234 | top=0x0200bdd4 id=@{stack=0x200bddc,code=0x101405c@} | |
31235 | call_lo=0x01014000 call_hi=0x01014001 | |
f7dc1244 | 31236 | (@value{GDBP}) |
00905d52 AC |
31237 | @end smallexample |
31238 | ||
31239 | Takes an optional file parameter. | |
31240 | ||
0680b120 AC |
31241 | @kindex maint print registers |
31242 | @kindex maint print raw-registers | |
31243 | @kindex maint print cooked-registers | |
617073a9 | 31244 | @kindex maint print register-groups |
09d4efe1 EZ |
31245 | @item maint print registers @r{[}@var{file}@r{]} |
31246 | @itemx maint print raw-registers @r{[}@var{file}@r{]} | |
31247 | @itemx maint print cooked-registers @r{[}@var{file}@r{]} | |
31248 | @itemx maint print register-groups @r{[}@var{file}@r{]} | |
0680b120 AC |
31249 | Print @value{GDBN}'s internal register data structures. |
31250 | ||
617073a9 AC |
31251 | The command @code{maint print raw-registers} includes the contents of |
31252 | the raw register cache; the command @code{maint print cooked-registers} | |
5c5dcc1b L |
31253 | includes the (cooked) value of all registers, including registers which |
31254 | aren't available on the target nor visible to user; and the | |
31255 | command @code{maint print register-groups} includes the groups that each | |
617073a9 AC |
31256 | register is a member of. @xref{Registers,, Registers, gdbint, |
31257 | @value{GDBN} Internals}. | |
0680b120 | 31258 | |
09d4efe1 EZ |
31259 | These commands take an optional parameter, a file name to which to |
31260 | write the information. | |
0680b120 | 31261 | |
617073a9 | 31262 | @kindex maint print reggroups |
09d4efe1 EZ |
31263 | @item maint print reggroups @r{[}@var{file}@r{]} |
31264 | Print @value{GDBN}'s internal register group data structures. The | |
31265 | optional argument @var{file} tells to what file to write the | |
31266 | information. | |
617073a9 | 31267 | |
09d4efe1 | 31268 | The register groups info looks like this: |
617073a9 AC |
31269 | |
31270 | @smallexample | |
f7dc1244 | 31271 | (@value{GDBP}) @kbd{maint print reggroups} |
b383017d RM |
31272 | Group Type |
31273 | general user | |
31274 | float user | |
31275 | all user | |
31276 | vector user | |
31277 | system user | |
31278 | save internal | |
31279 | restore internal | |
617073a9 AC |
31280 | @end smallexample |
31281 | ||
09d4efe1 EZ |
31282 | @kindex flushregs |
31283 | @item flushregs | |
31284 | This command forces @value{GDBN} to flush its internal register cache. | |
31285 | ||
31286 | @kindex maint print objfiles | |
31287 | @cindex info for known object files | |
31288 | @item maint print objfiles | |
31289 | Print a dump of all known object files. For each object file, this | |
31290 | command prints its name, address in memory, and all of its psymtabs | |
31291 | and symtabs. | |
31292 | ||
8a1ea21f DE |
31293 | @kindex maint print section-scripts |
31294 | @cindex info for known .debug_gdb_scripts-loaded scripts | |
31295 | @item maint print section-scripts [@var{regexp}] | |
31296 | Print a dump of scripts specified in the @code{.debug_gdb_section} section. | |
31297 | If @var{regexp} is specified, only print scripts loaded by object files | |
31298 | matching @var{regexp}. | |
31299 | For each script, this command prints its name as specified in the objfile, | |
31300 | and the full path if known. | |
31301 | @xref{.debug_gdb_scripts section}. | |
31302 | ||
09d4efe1 EZ |
31303 | @kindex maint print statistics |
31304 | @cindex bcache statistics | |
31305 | @item maint print statistics | |
31306 | This command prints, for each object file in the program, various data | |
31307 | about that object file followed by the byte cache (@dfn{bcache}) | |
31308 | statistics for the object file. The objfile data includes the number | |
d3e8051b | 31309 | of minimal, partial, full, and stabs symbols, the number of types |
09d4efe1 EZ |
31310 | defined by the objfile, the number of as yet unexpanded psym tables, |
31311 | the number of line tables and string tables, and the amount of memory | |
31312 | used by the various tables. The bcache statistics include the counts, | |
31313 | sizes, and counts of duplicates of all and unique objects, max, | |
31314 | average, and median entry size, total memory used and its overhead and | |
31315 | savings, and various measures of the hash table size and chain | |
31316 | lengths. | |
31317 | ||
c7ba131e JB |
31318 | @kindex maint print target-stack |
31319 | @cindex target stack description | |
31320 | @item maint print target-stack | |
31321 | A @dfn{target} is an interface between the debugger and a particular | |
31322 | kind of file or process. Targets can be stacked in @dfn{strata}, | |
31323 | so that more than one target can potentially respond to a request. | |
31324 | In particular, memory accesses will walk down the stack of targets | |
31325 | until they find a target that is interested in handling that particular | |
31326 | address. | |
31327 | ||
31328 | This command prints a short description of each layer that was pushed on | |
31329 | the @dfn{target stack}, starting from the top layer down to the bottom one. | |
31330 | ||
09d4efe1 EZ |
31331 | @kindex maint print type |
31332 | @cindex type chain of a data type | |
31333 | @item maint print type @var{expr} | |
31334 | Print the type chain for a type specified by @var{expr}. The argument | |
31335 | can be either a type name or a symbol. If it is a symbol, the type of | |
31336 | that symbol is described. The type chain produced by this command is | |
31337 | a recursive definition of the data type as stored in @value{GDBN}'s | |
31338 | data structures, including its flags and contained types. | |
31339 | ||
9eae7c52 TT |
31340 | @kindex maint set dwarf2 always-disassemble |
31341 | @kindex maint show dwarf2 always-disassemble | |
31342 | @item maint set dwarf2 always-disassemble | |
31343 | @item maint show dwarf2 always-disassemble | |
31344 | Control the behavior of @code{info address} when using DWARF debugging | |
31345 | information. | |
31346 | ||
31347 | The default is @code{off}, which means that @value{GDBN} should try to | |
31348 | describe a variable's location in an easily readable format. When | |
31349 | @code{on}, @value{GDBN} will instead display the DWARF location | |
31350 | expression in an assembly-like format. Note that some locations are | |
31351 | too complex for @value{GDBN} to describe simply; in this case you will | |
31352 | always see the disassembly form. | |
31353 | ||
31354 | Here is an example of the resulting disassembly: | |
31355 | ||
31356 | @smallexample | |
31357 | (gdb) info addr argc | |
31358 | Symbol "argc" is a complex DWARF expression: | |
31359 | 1: DW_OP_fbreg 0 | |
31360 | @end smallexample | |
31361 | ||
31362 | For more information on these expressions, see | |
31363 | @uref{http://www.dwarfstd.org/, the DWARF standard}. | |
31364 | ||
09d4efe1 EZ |
31365 | @kindex maint set dwarf2 max-cache-age |
31366 | @kindex maint show dwarf2 max-cache-age | |
31367 | @item maint set dwarf2 max-cache-age | |
31368 | @itemx maint show dwarf2 max-cache-age | |
31369 | Control the DWARF 2 compilation unit cache. | |
31370 | ||
31371 | @cindex DWARF 2 compilation units cache | |
31372 | In object files with inter-compilation-unit references, such as those | |
31373 | produced by the GCC option @samp{-feliminate-dwarf2-dups}, the DWARF 2 | |
31374 | reader needs to frequently refer to previously read compilation units. | |
31375 | This setting controls how long a compilation unit will remain in the | |
31376 | cache if it is not referenced. A higher limit means that cached | |
31377 | compilation units will be stored in memory longer, and more total | |
31378 | memory will be used. Setting it to zero disables caching, which will | |
31379 | slow down @value{GDBN} startup, but reduce memory consumption. | |
31380 | ||
e7ba9c65 DJ |
31381 | @kindex maint set profile |
31382 | @kindex maint show profile | |
31383 | @cindex profiling GDB | |
31384 | @item maint set profile | |
31385 | @itemx maint show profile | |
31386 | Control profiling of @value{GDBN}. | |
31387 | ||
31388 | Profiling will be disabled until you use the @samp{maint set profile} | |
31389 | command to enable it. When you enable profiling, the system will begin | |
31390 | collecting timing and execution count data; when you disable profiling or | |
31391 | exit @value{GDBN}, the results will be written to a log file. Remember that | |
31392 | if you use profiling, @value{GDBN} will overwrite the profiling log file | |
31393 | (often called @file{gmon.out}). If you have a record of important profiling | |
31394 | data in a @file{gmon.out} file, be sure to move it to a safe location. | |
31395 | ||
31396 | Configuring with @samp{--enable-profiling} arranges for @value{GDBN} to be | |
b383017d | 31397 | compiled with the @samp{-pg} compiler option. |
e7ba9c65 | 31398 | |
cbe54154 PA |
31399 | @kindex maint set show-debug-regs |
31400 | @kindex maint show show-debug-regs | |
eac35c4e | 31401 | @cindex hardware debug registers |
cbe54154 PA |
31402 | @item maint set show-debug-regs |
31403 | @itemx maint show show-debug-regs | |
eac35c4e | 31404 | Control whether to show variables that mirror the hardware debug |
09d4efe1 | 31405 | registers. Use @code{ON} to enable, @code{OFF} to disable. If |
3f94c067 | 31406 | enabled, the debug registers values are shown when @value{GDBN} inserts or |
09d4efe1 EZ |
31407 | removes a hardware breakpoint or watchpoint, and when the inferior |
31408 | triggers a hardware-assisted breakpoint or watchpoint. | |
31409 | ||
711e434b PM |
31410 | @kindex maint set show-all-tib |
31411 | @kindex maint show show-all-tib | |
31412 | @item maint set show-all-tib | |
31413 | @itemx maint show show-all-tib | |
31414 | Control whether to show all non zero areas within a 1k block starting | |
31415 | at thread local base, when using the @samp{info w32 thread-information-block} | |
31416 | command. | |
31417 | ||
09d4efe1 EZ |
31418 | @kindex maint space |
31419 | @cindex memory used by commands | |
31420 | @item maint space | |
31421 | Control whether to display memory usage for each command. If set to a | |
31422 | nonzero value, @value{GDBN} will display how much memory each command | |
31423 | took, following the command's own output. This can also be requested | |
31424 | by invoking @value{GDBN} with the @option{--statistics} command-line | |
31425 | switch (@pxref{Mode Options}). | |
31426 | ||
31427 | @kindex maint time | |
31428 | @cindex time of command execution | |
31429 | @item maint time | |
31430 | Control whether to display the execution time for each command. If | |
31431 | set to a nonzero value, @value{GDBN} will display how much time it | |
31432 | took to execute each command, following the command's own output. | |
e2b7ddea VP |
31433 | The time is not printed for the commands that run the target, since |
31434 | there's no mechanism currently to compute how much time was spend | |
31435 | by @value{GDBN} and how much time was spend by the program been debugged. | |
31436 | it's not possibly currently | |
09d4efe1 EZ |
31437 | This can also be requested by invoking @value{GDBN} with the |
31438 | @option{--statistics} command-line switch (@pxref{Mode Options}). | |
31439 | ||
31440 | @kindex maint translate-address | |
31441 | @item maint translate-address @r{[}@var{section}@r{]} @var{addr} | |
31442 | Find the symbol stored at the location specified by the address | |
31443 | @var{addr} and an optional section name @var{section}. If found, | |
31444 | @value{GDBN} prints the name of the closest symbol and an offset from | |
31445 | the symbol's location to the specified address. This is similar to | |
31446 | the @code{info address} command (@pxref{Symbols}), except that this | |
31447 | command also allows to find symbols in other sections. | |
ae038cb0 | 31448 | |
c14c28ba PP |
31449 | If section was not specified, the section in which the symbol was found |
31450 | is also printed. For dynamically linked executables, the name of | |
31451 | executable or shared library containing the symbol is printed as well. | |
31452 | ||
8e04817f | 31453 | @end table |
c906108c | 31454 | |
9c16f35a EZ |
31455 | The following command is useful for non-interactive invocations of |
31456 | @value{GDBN}, such as in the test suite. | |
31457 | ||
31458 | @table @code | |
31459 | @item set watchdog @var{nsec} | |
31460 | @kindex set watchdog | |
31461 | @cindex watchdog timer | |
31462 | @cindex timeout for commands | |
31463 | Set the maximum number of seconds @value{GDBN} will wait for the | |
31464 | target operation to finish. If this time expires, @value{GDBN} | |
31465 | reports and error and the command is aborted. | |
31466 | ||
31467 | @item show watchdog | |
31468 | Show the current setting of the target wait timeout. | |
31469 | @end table | |
c906108c | 31470 | |
e0ce93ac | 31471 | @node Remote Protocol |
8e04817f | 31472 | @appendix @value{GDBN} Remote Serial Protocol |
c906108c | 31473 | |
ee2d5c50 AC |
31474 | @menu |
31475 | * Overview:: | |
31476 | * Packets:: | |
31477 | * Stop Reply Packets:: | |
31478 | * General Query Packets:: | |
a1dcb23a | 31479 | * Architecture-Specific Protocol Details:: |
9d29849a | 31480 | * Tracepoint Packets:: |
a6b151f1 | 31481 | * Host I/O Packets:: |
9a6253be | 31482 | * Interrupts:: |
8b23ecc4 SL |
31483 | * Notification Packets:: |
31484 | * Remote Non-Stop:: | |
a6f3e723 | 31485 | * Packet Acknowledgment:: |
ee2d5c50 | 31486 | * Examples:: |
79a6e687 | 31487 | * File-I/O Remote Protocol Extension:: |
cfa9d6d9 | 31488 | * Library List Format:: |
79a6e687 | 31489 | * Memory Map Format:: |
dc146f7c | 31490 | * Thread List Format:: |
ee2d5c50 AC |
31491 | @end menu |
31492 | ||
31493 | @node Overview | |
31494 | @section Overview | |
31495 | ||
8e04817f AC |
31496 | There may be occasions when you need to know something about the |
31497 | protocol---for example, if there is only one serial port to your target | |
31498 | machine, you might want your program to do something special if it | |
31499 | recognizes a packet meant for @value{GDBN}. | |
c906108c | 31500 | |
d2c6833e | 31501 | In the examples below, @samp{->} and @samp{<-} are used to indicate |
bf06d120 | 31502 | transmitted and received data, respectively. |
c906108c | 31503 | |
8e04817f AC |
31504 | @cindex protocol, @value{GDBN} remote serial |
31505 | @cindex serial protocol, @value{GDBN} remote | |
31506 | @cindex remote serial protocol | |
8b23ecc4 SL |
31507 | All @value{GDBN} commands and responses (other than acknowledgments |
31508 | and notifications, see @ref{Notification Packets}) are sent as a | |
31509 | @var{packet}. A @var{packet} is introduced with the character | |
8e04817f AC |
31510 | @samp{$}, the actual @var{packet-data}, and the terminating character |
31511 | @samp{#} followed by a two-digit @var{checksum}: | |
c906108c | 31512 | |
474c8240 | 31513 | @smallexample |
8e04817f | 31514 | @code{$}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 31515 | @end smallexample |
8e04817f | 31516 | @noindent |
c906108c | 31517 | |
8e04817f AC |
31518 | @cindex checksum, for @value{GDBN} remote |
31519 | @noindent | |
31520 | The two-digit @var{checksum} is computed as the modulo 256 sum of all | |
31521 | characters between the leading @samp{$} and the trailing @samp{#} (an | |
31522 | eight bit unsigned checksum). | |
c906108c | 31523 | |
8e04817f AC |
31524 | Implementors should note that prior to @value{GDBN} 5.0 the protocol |
31525 | specification also included an optional two-digit @var{sequence-id}: | |
c906108c | 31526 | |
474c8240 | 31527 | @smallexample |
8e04817f | 31528 | @code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum} |
474c8240 | 31529 | @end smallexample |
c906108c | 31530 | |
8e04817f AC |
31531 | @cindex sequence-id, for @value{GDBN} remote |
31532 | @noindent | |
31533 | That @var{sequence-id} was appended to the acknowledgment. @value{GDBN} | |
31534 | has never output @var{sequence-id}s. Stubs that handle packets added | |
31535 | since @value{GDBN} 5.0 must not accept @var{sequence-id}. | |
c906108c | 31536 | |
8e04817f AC |
31537 | When either the host or the target machine receives a packet, the first |
31538 | response expected is an acknowledgment: either @samp{+} (to indicate | |
31539 | the package was received correctly) or @samp{-} (to request | |
31540 | retransmission): | |
c906108c | 31541 | |
474c8240 | 31542 | @smallexample |
d2c6833e AC |
31543 | -> @code{$}@var{packet-data}@code{#}@var{checksum} |
31544 | <- @code{+} | |
474c8240 | 31545 | @end smallexample |
8e04817f | 31546 | @noindent |
53a5351d | 31547 | |
a6f3e723 SL |
31548 | The @samp{+}/@samp{-} acknowledgments can be disabled |
31549 | once a connection is established. | |
31550 | @xref{Packet Acknowledgment}, for details. | |
31551 | ||
8e04817f AC |
31552 | The host (@value{GDBN}) sends @var{command}s, and the target (the |
31553 | debugging stub incorporated in your program) sends a @var{response}. In | |
31554 | the case of step and continue @var{command}s, the response is only sent | |
8b23ecc4 SL |
31555 | when the operation has completed, and the target has again stopped all |
31556 | threads in all attached processes. This is the default all-stop mode | |
31557 | behavior, but the remote protocol also supports @value{GDBN}'s non-stop | |
31558 | execution mode; see @ref{Remote Non-Stop}, for details. | |
c906108c | 31559 | |
8e04817f AC |
31560 | @var{packet-data} consists of a sequence of characters with the |
31561 | exception of @samp{#} and @samp{$} (see @samp{X} packet for additional | |
31562 | exceptions). | |
c906108c | 31563 | |
ee2d5c50 | 31564 | @cindex remote protocol, field separator |
0876f84a | 31565 | Fields within the packet should be separated using @samp{,} @samp{;} or |
8e04817f | 31566 | @samp{:}. Except where otherwise noted all numbers are represented in |
ee2d5c50 | 31567 | @sc{hex} with leading zeros suppressed. |
c906108c | 31568 | |
8e04817f AC |
31569 | Implementors should note that prior to @value{GDBN} 5.0, the character |
31570 | @samp{:} could not appear as the third character in a packet (as it | |
31571 | would potentially conflict with the @var{sequence-id}). | |
c906108c | 31572 | |
0876f84a DJ |
31573 | @cindex remote protocol, binary data |
31574 | @anchor{Binary Data} | |
31575 | Binary data in most packets is encoded either as two hexadecimal | |
31576 | digits per byte of binary data. This allowed the traditional remote | |
31577 | protocol to work over connections which were only seven-bit clean. | |
31578 | Some packets designed more recently assume an eight-bit clean | |
31579 | connection, and use a more efficient encoding to send and receive | |
31580 | binary data. | |
31581 | ||
31582 | The binary data representation uses @code{7d} (@sc{ascii} @samp{@}}) | |
31583 | as an escape character. Any escaped byte is transmitted as the escape | |
31584 | character followed by the original character XORed with @code{0x20}. | |
31585 | For example, the byte @code{0x7d} would be transmitted as the two | |
31586 | bytes @code{0x7d 0x5d}. The bytes @code{0x23} (@sc{ascii} @samp{#}), | |
31587 | @code{0x24} (@sc{ascii} @samp{$}), and @code{0x7d} (@sc{ascii} | |
31588 | @samp{@}}) must always be escaped. Responses sent by the stub | |
31589 | must also escape @code{0x2a} (@sc{ascii} @samp{*}), so that it | |
31590 | is not interpreted as the start of a run-length encoded sequence | |
31591 | (described next). | |
31592 | ||
1d3811f6 DJ |
31593 | Response @var{data} can be run-length encoded to save space. |
31594 | Run-length encoding replaces runs of identical characters with one | |
31595 | instance of the repeated character, followed by a @samp{*} and a | |
31596 | repeat count. The repeat count is itself sent encoded, to avoid | |
31597 | binary characters in @var{data}: a value of @var{n} is sent as | |
31598 | @code{@var{n}+29}. For a repeat count greater or equal to 3, this | |
31599 | produces a printable @sc{ascii} character, e.g.@: a space (@sc{ascii} | |
31600 | code 32) for a repeat count of 3. (This is because run-length | |
31601 | encoding starts to win for counts 3 or more.) Thus, for example, | |
31602 | @samp{0* } is a run-length encoding of ``0000'': the space character | |
31603 | after @samp{*} means repeat the leading @code{0} @w{@code{32 - 29 = | |
31604 | 3}} more times. | |
31605 | ||
31606 | The printable characters @samp{#} and @samp{$} or with a numeric value | |
31607 | greater than 126 must not be used. Runs of six repeats (@samp{#}) or | |
31608 | seven repeats (@samp{$}) can be expanded using a repeat count of only | |
31609 | five (@samp{"}). For example, @samp{00000000} can be encoded as | |
31610 | @samp{0*"00}. | |
c906108c | 31611 | |
8e04817f AC |
31612 | The error response returned for some packets includes a two character |
31613 | error number. That number is not well defined. | |
c906108c | 31614 | |
f8da2bff | 31615 | @cindex empty response, for unsupported packets |
8e04817f AC |
31616 | For any @var{command} not supported by the stub, an empty response |
31617 | (@samp{$#00}) should be returned. That way it is possible to extend the | |
31618 | protocol. A newer @value{GDBN} can tell if a packet is supported based | |
31619 | on that response. | |
c906108c | 31620 | |
b383017d RM |
31621 | A stub is required to support the @samp{g}, @samp{G}, @samp{m}, @samp{M}, |
31622 | @samp{c}, and @samp{s} @var{command}s. All other @var{command}s are | |
8e04817f | 31623 | optional. |
c906108c | 31624 | |
ee2d5c50 AC |
31625 | @node Packets |
31626 | @section Packets | |
31627 | ||
31628 | The following table provides a complete list of all currently defined | |
31629 | @var{command}s and their corresponding response @var{data}. | |
79a6e687 | 31630 | @xref{File-I/O Remote Protocol Extension}, for details about the File |
9c16f35a | 31631 | I/O extension of the remote protocol. |
ee2d5c50 | 31632 | |
b8ff78ce JB |
31633 | Each packet's description has a template showing the packet's overall |
31634 | syntax, followed by an explanation of the packet's meaning. We | |
31635 | include spaces in some of the templates for clarity; these are not | |
31636 | part of the packet's syntax. No @value{GDBN} packet uses spaces to | |
31637 | separate its components. For example, a template like @samp{foo | |
31638 | @var{bar} @var{baz}} describes a packet beginning with the three ASCII | |
31639 | bytes @samp{foo}, followed by a @var{bar}, followed directly by a | |
3f94c067 | 31640 | @var{baz}. @value{GDBN} does not transmit a space character between the |
b8ff78ce JB |
31641 | @samp{foo} and the @var{bar}, or between the @var{bar} and the |
31642 | @var{baz}. | |
31643 | ||
b90a069a SL |
31644 | @cindex @var{thread-id}, in remote protocol |
31645 | @anchor{thread-id syntax} | |
31646 | Several packets and replies include a @var{thread-id} field to identify | |
31647 | a thread. Normally these are positive numbers with a target-specific | |
31648 | interpretation, formatted as big-endian hex strings. A @var{thread-id} | |
31649 | can also be a literal @samp{-1} to indicate all threads, or @samp{0} to | |
31650 | pick any thread. | |
31651 | ||
31652 | In addition, the remote protocol supports a multiprocess feature in | |
31653 | which the @var{thread-id} syntax is extended to optionally include both | |
31654 | process and thread ID fields, as @samp{p@var{pid}.@var{tid}}. | |
31655 | The @var{pid} (process) and @var{tid} (thread) components each have the | |
31656 | format described above: a positive number with target-specific | |
31657 | interpretation formatted as a big-endian hex string, literal @samp{-1} | |
31658 | to indicate all processes or threads (respectively), or @samp{0} to | |
31659 | indicate an arbitrary process or thread. Specifying just a process, as | |
31660 | @samp{p@var{pid}}, is equivalent to @samp{p@var{pid}.-1}. It is an | |
31661 | error to specify all processes but a specific thread, such as | |
31662 | @samp{p-1.@var{tid}}. Note that the @samp{p} prefix is @emph{not} used | |
31663 | for those packets and replies explicitly documented to include a process | |
31664 | ID, rather than a @var{thread-id}. | |
31665 | ||
31666 | The multiprocess @var{thread-id} syntax extensions are only used if both | |
31667 | @value{GDBN} and the stub report support for the @samp{multiprocess} | |
31668 | feature using @samp{qSupported}. @xref{multiprocess extensions}, for | |
31669 | more information. | |
31670 | ||
8ffe2530 JB |
31671 | Note that all packet forms beginning with an upper- or lower-case |
31672 | letter, other than those described here, are reserved for future use. | |
31673 | ||
b8ff78ce | 31674 | Here are the packet descriptions. |
ee2d5c50 | 31675 | |
b8ff78ce | 31676 | @table @samp |
ee2d5c50 | 31677 | |
b8ff78ce JB |
31678 | @item ! |
31679 | @cindex @samp{!} packet | |
2d717e4f | 31680 | @anchor{extended mode} |
8e04817f AC |
31681 | Enable extended mode. In extended mode, the remote server is made |
31682 | persistent. The @samp{R} packet is used to restart the program being | |
31683 | debugged. | |
ee2d5c50 AC |
31684 | |
31685 | Reply: | |
31686 | @table @samp | |
31687 | @item OK | |
8e04817f | 31688 | The remote target both supports and has enabled extended mode. |
ee2d5c50 | 31689 | @end table |
c906108c | 31690 | |
b8ff78ce JB |
31691 | @item ? |
31692 | @cindex @samp{?} packet | |
ee2d5c50 | 31693 | Indicate the reason the target halted. The reply is the same as for |
8b23ecc4 SL |
31694 | step and continue. This packet has a special interpretation when the |
31695 | target is in non-stop mode; see @ref{Remote Non-Stop}. | |
c906108c | 31696 | |
ee2d5c50 AC |
31697 | Reply: |
31698 | @xref{Stop Reply Packets}, for the reply specifications. | |
31699 | ||
b8ff78ce JB |
31700 | @item A @var{arglen},@var{argnum},@var{arg},@dots{} |
31701 | @cindex @samp{A} packet | |
31702 | Initialized @code{argv[]} array passed into program. @var{arglen} | |
31703 | specifies the number of bytes in the hex encoded byte stream | |
31704 | @var{arg}. See @code{gdbserver} for more details. | |
ee2d5c50 AC |
31705 | |
31706 | Reply: | |
31707 | @table @samp | |
31708 | @item OK | |
b8ff78ce JB |
31709 | The arguments were set. |
31710 | @item E @var{NN} | |
31711 | An error occurred. | |
ee2d5c50 AC |
31712 | @end table |
31713 | ||
b8ff78ce JB |
31714 | @item b @var{baud} |
31715 | @cindex @samp{b} packet | |
31716 | (Don't use this packet; its behavior is not well-defined.) | |
ee2d5c50 AC |
31717 | Change the serial line speed to @var{baud}. |
31718 | ||
31719 | JTC: @emph{When does the transport layer state change? When it's | |
31720 | received, or after the ACK is transmitted. In either case, there are | |
31721 | problems if the command or the acknowledgment packet is dropped.} | |
31722 | ||
31723 | Stan: @emph{If people really wanted to add something like this, and get | |
31724 | it working for the first time, they ought to modify ser-unix.c to send | |
31725 | some kind of out-of-band message to a specially-setup stub and have the | |
31726 | switch happen "in between" packets, so that from remote protocol's point | |
31727 | of view, nothing actually happened.} | |
31728 | ||
b8ff78ce JB |
31729 | @item B @var{addr},@var{mode} |
31730 | @cindex @samp{B} packet | |
8e04817f | 31731 | Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a |
2f870471 AC |
31732 | breakpoint at @var{addr}. |
31733 | ||
b8ff78ce | 31734 | Don't use this packet. Use the @samp{Z} and @samp{z} packets instead |
2f870471 | 31735 | (@pxref{insert breakpoint or watchpoint packet}). |
c906108c | 31736 | |
bacec72f | 31737 | @cindex @samp{bc} packet |
0d772ac9 MS |
31738 | @anchor{bc} |
31739 | @item bc | |
bacec72f MS |
31740 | Backward continue. Execute the target system in reverse. No parameter. |
31741 | @xref{Reverse Execution}, for more information. | |
31742 | ||
31743 | Reply: | |
31744 | @xref{Stop Reply Packets}, for the reply specifications. | |
31745 | ||
bacec72f | 31746 | @cindex @samp{bs} packet |
0d772ac9 MS |
31747 | @anchor{bs} |
31748 | @item bs | |
bacec72f MS |
31749 | Backward single step. Execute one instruction in reverse. No parameter. |
31750 | @xref{Reverse Execution}, for more information. | |
31751 | ||
31752 | Reply: | |
31753 | @xref{Stop Reply Packets}, for the reply specifications. | |
31754 | ||
4f553f88 | 31755 | @item c @r{[}@var{addr}@r{]} |
b8ff78ce JB |
31756 | @cindex @samp{c} packet |
31757 | Continue. @var{addr} is address to resume. If @var{addr} is omitted, | |
31758 | resume at current address. | |
c906108c | 31759 | |
ee2d5c50 AC |
31760 | Reply: |
31761 | @xref{Stop Reply Packets}, for the reply specifications. | |
31762 | ||
4f553f88 | 31763 | @item C @var{sig}@r{[};@var{addr}@r{]} |
b8ff78ce | 31764 | @cindex @samp{C} packet |
8e04817f | 31765 | Continue with signal @var{sig} (hex signal number). If |
b8ff78ce | 31766 | @samp{;@var{addr}} is omitted, resume at same address. |
c906108c | 31767 | |
ee2d5c50 AC |
31768 | Reply: |
31769 | @xref{Stop Reply Packets}, for the reply specifications. | |
c906108c | 31770 | |
b8ff78ce JB |
31771 | @item d |
31772 | @cindex @samp{d} packet | |
ee2d5c50 AC |
31773 | Toggle debug flag. |
31774 | ||
b8ff78ce JB |
31775 | Don't use this packet; instead, define a general set packet |
31776 | (@pxref{General Query Packets}). | |
ee2d5c50 | 31777 | |
b8ff78ce | 31778 | @item D |
b90a069a | 31779 | @itemx D;@var{pid} |
b8ff78ce | 31780 | @cindex @samp{D} packet |
b90a069a SL |
31781 | The first form of the packet is used to detach @value{GDBN} from the |
31782 | remote system. It is sent to the remote target | |
07f31aa6 | 31783 | before @value{GDBN} disconnects via the @code{detach} command. |
ee2d5c50 | 31784 | |
b90a069a SL |
31785 | The second form, including a process ID, is used when multiprocess |
31786 | protocol extensions are enabled (@pxref{multiprocess extensions}), to | |
31787 | detach only a specific process. The @var{pid} is specified as a | |
31788 | big-endian hex string. | |
31789 | ||
ee2d5c50 AC |
31790 | Reply: |
31791 | @table @samp | |
10fac096 NW |
31792 | @item OK |
31793 | for success | |
b8ff78ce | 31794 | @item E @var{NN} |
10fac096 | 31795 | for an error |
ee2d5c50 | 31796 | @end table |
c906108c | 31797 | |
b8ff78ce JB |
31798 | @item F @var{RC},@var{EE},@var{CF};@var{XX} |
31799 | @cindex @samp{F} packet | |
31800 | A reply from @value{GDBN} to an @samp{F} packet sent by the target. | |
31801 | This is part of the File-I/O protocol extension. @xref{File-I/O | |
79a6e687 | 31802 | Remote Protocol Extension}, for the specification. |
ee2d5c50 | 31803 | |
b8ff78ce | 31804 | @item g |
ee2d5c50 | 31805 | @anchor{read registers packet} |
b8ff78ce | 31806 | @cindex @samp{g} packet |
ee2d5c50 AC |
31807 | Read general registers. |
31808 | ||
31809 | Reply: | |
31810 | @table @samp | |
31811 | @item @var{XX@dots{}} | |
8e04817f AC |
31812 | Each byte of register data is described by two hex digits. The bytes |
31813 | with the register are transmitted in target byte order. The size of | |
b8ff78ce | 31814 | each register and their position within the @samp{g} packet are |
4a9bb1df UW |
31815 | determined by the @value{GDBN} internal gdbarch functions |
31816 | @code{DEPRECATED_REGISTER_RAW_SIZE} and @code{gdbarch_register_name}. The | |
b8ff78ce JB |
31817 | specification of several standard @samp{g} packets is specified below. |
31818 | @item E @var{NN} | |
ee2d5c50 AC |
31819 | for an error. |
31820 | @end table | |
c906108c | 31821 | |
b8ff78ce JB |
31822 | @item G @var{XX@dots{}} |
31823 | @cindex @samp{G} packet | |
31824 | Write general registers. @xref{read registers packet}, for a | |
31825 | description of the @var{XX@dots{}} data. | |
ee2d5c50 AC |
31826 | |
31827 | Reply: | |
31828 | @table @samp | |
31829 | @item OK | |
31830 | for success | |
b8ff78ce | 31831 | @item E @var{NN} |
ee2d5c50 AC |
31832 | for an error |
31833 | @end table | |
31834 | ||
b90a069a | 31835 | @item H @var{c} @var{thread-id} |
b8ff78ce | 31836 | @cindex @samp{H} packet |
8e04817f | 31837 | Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g}, |
ee2d5c50 AC |
31838 | @samp{G}, et.al.). @var{c} depends on the operation to be performed: it |
31839 | should be @samp{c} for step and continue operations, @samp{g} for other | |
b90a069a SL |
31840 | operations. The thread designator @var{thread-id} has the format and |
31841 | interpretation described in @ref{thread-id syntax}. | |
ee2d5c50 AC |
31842 | |
31843 | Reply: | |
31844 | @table @samp | |
31845 | @item OK | |
31846 | for success | |
b8ff78ce | 31847 | @item E @var{NN} |
ee2d5c50 AC |
31848 | for an error |
31849 | @end table | |
c906108c | 31850 | |
8e04817f AC |
31851 | @c FIXME: JTC: |
31852 | @c 'H': How restrictive (or permissive) is the thread model. If a | |
31853 | @c thread is selected and stopped, are other threads allowed | |
31854 | @c to continue to execute? As I mentioned above, I think the | |
31855 | @c semantics of each command when a thread is selected must be | |
31856 | @c described. For example: | |
31857 | @c | |
31858 | @c 'g': If the stub supports threads and a specific thread is | |
31859 | @c selected, returns the register block from that thread; | |
31860 | @c otherwise returns current registers. | |
31861 | @c | |
31862 | @c 'G' If the stub supports threads and a specific thread is | |
31863 | @c selected, sets the registers of the register block of | |
31864 | @c that thread; otherwise sets current registers. | |
c906108c | 31865 | |
b8ff78ce | 31866 | @item i @r{[}@var{addr}@r{[},@var{nnn}@r{]]} |
ee2d5c50 | 31867 | @anchor{cycle step packet} |
b8ff78ce JB |
31868 | @cindex @samp{i} packet |
31869 | Step the remote target by a single clock cycle. If @samp{,@var{nnn}} is | |
8e04817f AC |
31870 | present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle |
31871 | step starting at that address. | |
c906108c | 31872 | |
b8ff78ce JB |
31873 | @item I |
31874 | @cindex @samp{I} packet | |
31875 | Signal, then cycle step. @xref{step with signal packet}. @xref{cycle | |
31876 | step packet}. | |
ee2d5c50 | 31877 | |
b8ff78ce JB |
31878 | @item k |
31879 | @cindex @samp{k} packet | |
31880 | Kill request. | |
c906108c | 31881 | |
ac282366 | 31882 | FIXME: @emph{There is no description of how to operate when a specific |
ee2d5c50 AC |
31883 | thread context has been selected (i.e.@: does 'k' kill only that |
31884 | thread?)}. | |
c906108c | 31885 | |
b8ff78ce JB |
31886 | @item m @var{addr},@var{length} |
31887 | @cindex @samp{m} packet | |
8e04817f | 31888 | Read @var{length} bytes of memory starting at address @var{addr}. |
fb031cdf JB |
31889 | Note that @var{addr} may not be aligned to any particular boundary. |
31890 | ||
31891 | The stub need not use any particular size or alignment when gathering | |
31892 | data from memory for the response; even if @var{addr} is word-aligned | |
31893 | and @var{length} is a multiple of the word size, the stub is free to | |
31894 | use byte accesses, or not. For this reason, this packet may not be | |
31895 | suitable for accessing memory-mapped I/O devices. | |
c43c5473 JB |
31896 | @cindex alignment of remote memory accesses |
31897 | @cindex size of remote memory accesses | |
31898 | @cindex memory, alignment and size of remote accesses | |
c906108c | 31899 | |
ee2d5c50 AC |
31900 | Reply: |
31901 | @table @samp | |
31902 | @item @var{XX@dots{}} | |
599b237a | 31903 | Memory contents; each byte is transmitted as a two-digit hexadecimal |
b8ff78ce JB |
31904 | number. The reply may contain fewer bytes than requested if the |
31905 | server was able to read only part of the region of memory. | |
31906 | @item E @var{NN} | |
ee2d5c50 AC |
31907 | @var{NN} is errno |
31908 | @end table | |
31909 | ||
b8ff78ce JB |
31910 | @item M @var{addr},@var{length}:@var{XX@dots{}} |
31911 | @cindex @samp{M} packet | |
8e04817f | 31912 | Write @var{length} bytes of memory starting at address @var{addr}. |
b8ff78ce | 31913 | @var{XX@dots{}} is the data; each byte is transmitted as a two-digit |
599b237a | 31914 | hexadecimal number. |
ee2d5c50 AC |
31915 | |
31916 | Reply: | |
31917 | @table @samp | |
31918 | @item OK | |
31919 | for success | |
b8ff78ce | 31920 | @item E @var{NN} |
8e04817f AC |
31921 | for an error (this includes the case where only part of the data was |
31922 | written). | |
ee2d5c50 | 31923 | @end table |
c906108c | 31924 | |
b8ff78ce JB |
31925 | @item p @var{n} |
31926 | @cindex @samp{p} packet | |
31927 | Read the value of register @var{n}; @var{n} is in hex. | |
2e868123 AC |
31928 | @xref{read registers packet}, for a description of how the returned |
31929 | register value is encoded. | |
ee2d5c50 AC |
31930 | |
31931 | Reply: | |
31932 | @table @samp | |
2e868123 AC |
31933 | @item @var{XX@dots{}} |
31934 | the register's value | |
b8ff78ce | 31935 | @item E @var{NN} |
2e868123 AC |
31936 | for an error |
31937 | @item | |
31938 | Indicating an unrecognized @var{query}. | |
ee2d5c50 AC |
31939 | @end table |
31940 | ||
b8ff78ce | 31941 | @item P @var{n@dots{}}=@var{r@dots{}} |
ee2d5c50 | 31942 | @anchor{write register packet} |
b8ff78ce JB |
31943 | @cindex @samp{P} packet |
31944 | Write register @var{n@dots{}} with value @var{r@dots{}}. The register | |
599b237a | 31945 | number @var{n} is in hexadecimal, and @var{r@dots{}} contains two hex |
8e04817f | 31946 | digits for each byte in the register (target byte order). |
c906108c | 31947 | |
ee2d5c50 AC |
31948 | Reply: |
31949 | @table @samp | |
31950 | @item OK | |
31951 | for success | |
b8ff78ce | 31952 | @item E @var{NN} |
ee2d5c50 AC |
31953 | for an error |
31954 | @end table | |
31955 | ||
5f3bebba JB |
31956 | @item q @var{name} @var{params}@dots{} |
31957 | @itemx Q @var{name} @var{params}@dots{} | |
b8ff78ce | 31958 | @cindex @samp{q} packet |
b8ff78ce | 31959 | @cindex @samp{Q} packet |
5f3bebba JB |
31960 | General query (@samp{q}) and set (@samp{Q}). These packets are |
31961 | described fully in @ref{General Query Packets}. | |
c906108c | 31962 | |
b8ff78ce JB |
31963 | @item r |
31964 | @cindex @samp{r} packet | |
8e04817f | 31965 | Reset the entire system. |
c906108c | 31966 | |
b8ff78ce | 31967 | Don't use this packet; use the @samp{R} packet instead. |
ee2d5c50 | 31968 | |
b8ff78ce JB |
31969 | @item R @var{XX} |
31970 | @cindex @samp{R} packet | |
8e04817f | 31971 | Restart the program being debugged. @var{XX}, while needed, is ignored. |
2d717e4f | 31972 | This packet is only available in extended mode (@pxref{extended mode}). |
ee2d5c50 | 31973 | |
8e04817f | 31974 | The @samp{R} packet has no reply. |
ee2d5c50 | 31975 | |
4f553f88 | 31976 | @item s @r{[}@var{addr}@r{]} |
b8ff78ce JB |
31977 | @cindex @samp{s} packet |
31978 | Single step. @var{addr} is the address at which to resume. If | |
31979 | @var{addr} is omitted, resume at same address. | |
c906108c | 31980 | |
ee2d5c50 AC |
31981 | Reply: |
31982 | @xref{Stop Reply Packets}, for the reply specifications. | |
31983 | ||
4f553f88 | 31984 | @item S @var{sig}@r{[};@var{addr}@r{]} |
ee2d5c50 | 31985 | @anchor{step with signal packet} |
b8ff78ce JB |
31986 | @cindex @samp{S} packet |
31987 | Step with signal. This is analogous to the @samp{C} packet, but | |
31988 | requests a single-step, rather than a normal resumption of execution. | |
c906108c | 31989 | |
ee2d5c50 AC |
31990 | Reply: |
31991 | @xref{Stop Reply Packets}, for the reply specifications. | |
31992 | ||
b8ff78ce JB |
31993 | @item t @var{addr}:@var{PP},@var{MM} |
31994 | @cindex @samp{t} packet | |
8e04817f | 31995 | Search backwards starting at address @var{addr} for a match with pattern |
ee2d5c50 AC |
31996 | @var{PP} and mask @var{MM}. @var{PP} and @var{MM} are 4 bytes. |
31997 | @var{addr} must be at least 3 digits. | |
c906108c | 31998 | |
b90a069a | 31999 | @item T @var{thread-id} |
b8ff78ce | 32000 | @cindex @samp{T} packet |
b90a069a | 32001 | Find out if the thread @var{thread-id} is alive. @xref{thread-id syntax}. |
c906108c | 32002 | |
ee2d5c50 AC |
32003 | Reply: |
32004 | @table @samp | |
32005 | @item OK | |
32006 | thread is still alive | |
b8ff78ce | 32007 | @item E @var{NN} |
ee2d5c50 AC |
32008 | thread is dead |
32009 | @end table | |
32010 | ||
b8ff78ce JB |
32011 | @item v |
32012 | Packets starting with @samp{v} are identified by a multi-letter name, | |
32013 | up to the first @samp{;} or @samp{?} (or the end of the packet). | |
86d30acc | 32014 | |
2d717e4f DJ |
32015 | @item vAttach;@var{pid} |
32016 | @cindex @samp{vAttach} packet | |
8b23ecc4 SL |
32017 | Attach to a new process with the specified process ID @var{pid}. |
32018 | The process ID is a | |
32019 | hexadecimal integer identifying the process. In all-stop mode, all | |
32020 | threads in the attached process are stopped; in non-stop mode, it may be | |
32021 | attached without being stopped if that is supported by the target. | |
32022 | ||
32023 | @c In non-stop mode, on a successful vAttach, the stub should set the | |
32024 | @c current thread to a thread of the newly-attached process. After | |
32025 | @c attaching, GDB queries for the attached process's thread ID with qC. | |
32026 | @c Also note that, from a user perspective, whether or not the | |
32027 | @c target is stopped on attach in non-stop mode depends on whether you | |
32028 | @c use the foreground or background version of the attach command, not | |
32029 | @c on what vAttach does; GDB does the right thing with respect to either | |
32030 | @c stopping or restarting threads. | |
2d717e4f DJ |
32031 | |
32032 | This packet is only available in extended mode (@pxref{extended mode}). | |
32033 | ||
32034 | Reply: | |
32035 | @table @samp | |
32036 | @item E @var{nn} | |
32037 | for an error | |
32038 | @item @r{Any stop packet} | |
8b23ecc4 SL |
32039 | for success in all-stop mode (@pxref{Stop Reply Packets}) |
32040 | @item OK | |
32041 | for success in non-stop mode (@pxref{Remote Non-Stop}) | |
2d717e4f DJ |
32042 | @end table |
32043 | ||
b90a069a | 32044 | @item vCont@r{[};@var{action}@r{[}:@var{thread-id}@r{]]}@dots{} |
b8ff78ce JB |
32045 | @cindex @samp{vCont} packet |
32046 | Resume the inferior, specifying different actions for each thread. | |
b90a069a | 32047 | If an action is specified with no @var{thread-id}, then it is applied to any |
86d30acc | 32048 | threads that don't have a specific action specified; if no default action is |
8b23ecc4 SL |
32049 | specified then other threads should remain stopped in all-stop mode and |
32050 | in their current state in non-stop mode. | |
32051 | Specifying multiple | |
86d30acc | 32052 | default actions is an error; specifying no actions is also an error. |
b90a069a SL |
32053 | Thread IDs are specified using the syntax described in @ref{thread-id syntax}. |
32054 | ||
32055 | Currently supported actions are: | |
86d30acc | 32056 | |
b8ff78ce | 32057 | @table @samp |
86d30acc DJ |
32058 | @item c |
32059 | Continue. | |
b8ff78ce | 32060 | @item C @var{sig} |
8b23ecc4 | 32061 | Continue with signal @var{sig}. The signal @var{sig} should be two hex digits. |
86d30acc DJ |
32062 | @item s |
32063 | Step. | |
b8ff78ce | 32064 | @item S @var{sig} |
8b23ecc4 SL |
32065 | Step with signal @var{sig}. The signal @var{sig} should be two hex digits. |
32066 | @item t | |
32067 | Stop. | |
86d30acc DJ |
32068 | @end table |
32069 | ||
8b23ecc4 SL |
32070 | The optional argument @var{addr} normally associated with the |
32071 | @samp{c}, @samp{C}, @samp{s}, and @samp{S} packets is | |
b8ff78ce | 32072 | not supported in @samp{vCont}. |
86d30acc | 32073 | |
08a0efd0 PA |
32074 | The @samp{t} action is only relevant in non-stop mode |
32075 | (@pxref{Remote Non-Stop}) and may be ignored by the stub otherwise. | |
8b23ecc4 SL |
32076 | A stop reply should be generated for any affected thread not already stopped. |
32077 | When a thread is stopped by means of a @samp{t} action, | |
32078 | the corresponding stop reply should indicate that the thread has stopped with | |
32079 | signal @samp{0}, regardless of whether the target uses some other signal | |
32080 | as an implementation detail. | |
32081 | ||
86d30acc DJ |
32082 | Reply: |
32083 | @xref{Stop Reply Packets}, for the reply specifications. | |
32084 | ||
b8ff78ce JB |
32085 | @item vCont? |
32086 | @cindex @samp{vCont?} packet | |
d3e8051b | 32087 | Request a list of actions supported by the @samp{vCont} packet. |
86d30acc DJ |
32088 | |
32089 | Reply: | |
32090 | @table @samp | |
b8ff78ce JB |
32091 | @item vCont@r{[};@var{action}@dots{}@r{]} |
32092 | The @samp{vCont} packet is supported. Each @var{action} is a supported | |
32093 | command in the @samp{vCont} packet. | |
86d30acc | 32094 | @item |
b8ff78ce | 32095 | The @samp{vCont} packet is not supported. |
86d30acc | 32096 | @end table |
ee2d5c50 | 32097 | |
a6b151f1 DJ |
32098 | @item vFile:@var{operation}:@var{parameter}@dots{} |
32099 | @cindex @samp{vFile} packet | |
32100 | Perform a file operation on the target system. For details, | |
32101 | see @ref{Host I/O Packets}. | |
32102 | ||
68437a39 DJ |
32103 | @item vFlashErase:@var{addr},@var{length} |
32104 | @cindex @samp{vFlashErase} packet | |
32105 | Direct the stub to erase @var{length} bytes of flash starting at | |
32106 | @var{addr}. The region may enclose any number of flash blocks, but | |
32107 | its start and end must fall on block boundaries, as indicated by the | |
79a6e687 BW |
32108 | flash block size appearing in the memory map (@pxref{Memory Map |
32109 | Format}). @value{GDBN} groups flash memory programming operations | |
68437a39 DJ |
32110 | together, and sends a @samp{vFlashDone} request after each group; the |
32111 | stub is allowed to delay erase operation until the @samp{vFlashDone} | |
32112 | packet is received. | |
32113 | ||
b90a069a SL |
32114 | The stub must support @samp{vCont} if it reports support for |
32115 | multiprocess extensions (@pxref{multiprocess extensions}). Note that in | |
32116 | this case @samp{vCont} actions can be specified to apply to all threads | |
32117 | in a process by using the @samp{p@var{pid}.-1} form of the | |
32118 | @var{thread-id}. | |
32119 | ||
68437a39 DJ |
32120 | Reply: |
32121 | @table @samp | |
32122 | @item OK | |
32123 | for success | |
32124 | @item E @var{NN} | |
32125 | for an error | |
32126 | @end table | |
32127 | ||
32128 | @item vFlashWrite:@var{addr}:@var{XX@dots{}} | |
32129 | @cindex @samp{vFlashWrite} packet | |
32130 | Direct the stub to write data to flash address @var{addr}. The data | |
32131 | is passed in binary form using the same encoding as for the @samp{X} | |
32132 | packet (@pxref{Binary Data}). The memory ranges specified by | |
32133 | @samp{vFlashWrite} packets preceding a @samp{vFlashDone} packet must | |
32134 | not overlap, and must appear in order of increasing addresses | |
32135 | (although @samp{vFlashErase} packets for higher addresses may already | |
32136 | have been received; the ordering is guaranteed only between | |
32137 | @samp{vFlashWrite} packets). If a packet writes to an address that was | |
32138 | neither erased by a preceding @samp{vFlashErase} packet nor by some other | |
32139 | target-specific method, the results are unpredictable. | |
32140 | ||
32141 | ||
32142 | Reply: | |
32143 | @table @samp | |
32144 | @item OK | |
32145 | for success | |
32146 | @item E.memtype | |
32147 | for vFlashWrite addressing non-flash memory | |
32148 | @item E @var{NN} | |
32149 | for an error | |
32150 | @end table | |
32151 | ||
32152 | @item vFlashDone | |
32153 | @cindex @samp{vFlashDone} packet | |
32154 | Indicate to the stub that flash programming operation is finished. | |
32155 | The stub is permitted to delay or batch the effects of a group of | |
32156 | @samp{vFlashErase} and @samp{vFlashWrite} packets until a | |
32157 | @samp{vFlashDone} packet is received. The contents of the affected | |
32158 | regions of flash memory are unpredictable until the @samp{vFlashDone} | |
32159 | request is completed. | |
32160 | ||
b90a069a SL |
32161 | @item vKill;@var{pid} |
32162 | @cindex @samp{vKill} packet | |
32163 | Kill the process with the specified process ID. @var{pid} is a | |
32164 | hexadecimal integer identifying the process. This packet is used in | |
32165 | preference to @samp{k} when multiprocess protocol extensions are | |
32166 | supported; see @ref{multiprocess extensions}. | |
32167 | ||
32168 | Reply: | |
32169 | @table @samp | |
32170 | @item E @var{nn} | |
32171 | for an error | |
32172 | @item OK | |
32173 | for success | |
32174 | @end table | |
32175 | ||
2d717e4f DJ |
32176 | @item vRun;@var{filename}@r{[};@var{argument}@r{]}@dots{} |
32177 | @cindex @samp{vRun} packet | |
32178 | Run the program @var{filename}, passing it each @var{argument} on its | |
32179 | command line. The file and arguments are hex-encoded strings. If | |
32180 | @var{filename} is an empty string, the stub may use a default program | |
32181 | (e.g.@: the last program run). The program is created in the stopped | |
9b562ab8 | 32182 | state. |
2d717e4f | 32183 | |
8b23ecc4 SL |
32184 | @c FIXME: What about non-stop mode? |
32185 | ||
2d717e4f DJ |
32186 | This packet is only available in extended mode (@pxref{extended mode}). |
32187 | ||
32188 | Reply: | |
32189 | @table @samp | |
32190 | @item E @var{nn} | |
32191 | for an error | |
32192 | @item @r{Any stop packet} | |
32193 | for success (@pxref{Stop Reply Packets}) | |
32194 | @end table | |
32195 | ||
8b23ecc4 SL |
32196 | @item vStopped |
32197 | @anchor{vStopped packet} | |
32198 | @cindex @samp{vStopped} packet | |
32199 | ||
32200 | In non-stop mode (@pxref{Remote Non-Stop}), acknowledge a previous stop | |
32201 | reply and prompt for the stub to report another one. | |
32202 | ||
32203 | Reply: | |
32204 | @table @samp | |
32205 | @item @r{Any stop packet} | |
32206 | if there is another unreported stop event (@pxref{Stop Reply Packets}) | |
32207 | @item OK | |
32208 | if there are no unreported stop events | |
32209 | @end table | |
32210 | ||
b8ff78ce | 32211 | @item X @var{addr},@var{length}:@var{XX@dots{}} |
9a6253be | 32212 | @anchor{X packet} |
b8ff78ce JB |
32213 | @cindex @samp{X} packet |
32214 | Write data to memory, where the data is transmitted in binary. | |
32215 | @var{addr} is address, @var{length} is number of bytes, | |
0876f84a | 32216 | @samp{@var{XX}@dots{}} is binary data (@pxref{Binary Data}). |
c906108c | 32217 | |
ee2d5c50 AC |
32218 | Reply: |
32219 | @table @samp | |
32220 | @item OK | |
32221 | for success | |
b8ff78ce | 32222 | @item E @var{NN} |
ee2d5c50 AC |
32223 | for an error |
32224 | @end table | |
32225 | ||
a1dcb23a DJ |
32226 | @item z @var{type},@var{addr},@var{kind} |
32227 | @itemx Z @var{type},@var{addr},@var{kind} | |
2f870471 | 32228 | @anchor{insert breakpoint or watchpoint packet} |
b8ff78ce JB |
32229 | @cindex @samp{z} packet |
32230 | @cindex @samp{Z} packets | |
32231 | Insert (@samp{Z}) or remove (@samp{z}) a @var{type} breakpoint or | |
a1dcb23a | 32232 | watchpoint starting at address @var{address} of kind @var{kind}. |
ee2d5c50 | 32233 | |
2f870471 AC |
32234 | Each breakpoint and watchpoint packet @var{type} is documented |
32235 | separately. | |
32236 | ||
512217c7 AC |
32237 | @emph{Implementation notes: A remote target shall return an empty string |
32238 | for an unrecognized breakpoint or watchpoint packet @var{type}. A | |
32239 | remote target shall support either both or neither of a given | |
b8ff78ce | 32240 | @samp{Z@var{type}@dots{}} and @samp{z@var{type}@dots{}} packet pair. To |
2f870471 AC |
32241 | avoid potential problems with duplicate packets, the operations should |
32242 | be implemented in an idempotent way.} | |
32243 | ||
a1dcb23a DJ |
32244 | @item z0,@var{addr},@var{kind} |
32245 | @itemx Z0,@var{addr},@var{kind} | |
b8ff78ce JB |
32246 | @cindex @samp{z0} packet |
32247 | @cindex @samp{Z0} packet | |
32248 | Insert (@samp{Z0}) or remove (@samp{z0}) a memory breakpoint at address | |
a1dcb23a | 32249 | @var{addr} of type @var{kind}. |
2f870471 AC |
32250 | |
32251 | A memory breakpoint is implemented by replacing the instruction at | |
32252 | @var{addr} with a software breakpoint or trap instruction. The | |
a1dcb23a DJ |
32253 | @var{kind} is target-specific and typically indicates the size of |
32254 | the breakpoint in bytes that should be inserted. E.g., the @sc{arm} | |
32255 | and @sc{mips} can insert either a 2 or 4 byte breakpoint. Some | |
32256 | architectures have additional meanings for @var{kind}; | |
32257 | see @ref{Architecture-Specific Protocol Details}. | |
c906108c | 32258 | |
2f870471 AC |
32259 | @emph{Implementation note: It is possible for a target to copy or move |
32260 | code that contains memory breakpoints (e.g., when implementing | |
32261 | overlays). The behavior of this packet, in the presence of such a | |
32262 | target, is not defined.} | |
c906108c | 32263 | |
ee2d5c50 AC |
32264 | Reply: |
32265 | @table @samp | |
2f870471 AC |
32266 | @item OK |
32267 | success | |
32268 | @item | |
32269 | not supported | |
b8ff78ce | 32270 | @item E @var{NN} |
ee2d5c50 | 32271 | for an error |
2f870471 AC |
32272 | @end table |
32273 | ||
a1dcb23a DJ |
32274 | @item z1,@var{addr},@var{kind} |
32275 | @itemx Z1,@var{addr},@var{kind} | |
b8ff78ce JB |
32276 | @cindex @samp{z1} packet |
32277 | @cindex @samp{Z1} packet | |
32278 | Insert (@samp{Z1}) or remove (@samp{z1}) a hardware breakpoint at | |
a1dcb23a | 32279 | address @var{addr}. |
2f870471 AC |
32280 | |
32281 | A hardware breakpoint is implemented using a mechanism that is not | |
a1dcb23a DJ |
32282 | dependant on being able to modify the target's memory. @var{kind} |
32283 | has the same meaning as in @samp{Z0} packets. | |
2f870471 AC |
32284 | |
32285 | @emph{Implementation note: A hardware breakpoint is not affected by code | |
32286 | movement.} | |
32287 | ||
32288 | Reply: | |
32289 | @table @samp | |
ee2d5c50 | 32290 | @item OK |
2f870471 AC |
32291 | success |
32292 | @item | |
32293 | not supported | |
b8ff78ce | 32294 | @item E @var{NN} |
2f870471 AC |
32295 | for an error |
32296 | @end table | |
32297 | ||
a1dcb23a DJ |
32298 | @item z2,@var{addr},@var{kind} |
32299 | @itemx Z2,@var{addr},@var{kind} | |
b8ff78ce JB |
32300 | @cindex @samp{z2} packet |
32301 | @cindex @samp{Z2} packet | |
a1dcb23a DJ |
32302 | Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint at @var{addr}. |
32303 | @var{kind} is interpreted as the number of bytes to watch. | |
2f870471 AC |
32304 | |
32305 | Reply: | |
32306 | @table @samp | |
32307 | @item OK | |
32308 | success | |
32309 | @item | |
32310 | not supported | |
b8ff78ce | 32311 | @item E @var{NN} |
2f870471 AC |
32312 | for an error |
32313 | @end table | |
32314 | ||
a1dcb23a DJ |
32315 | @item z3,@var{addr},@var{kind} |
32316 | @itemx Z3,@var{addr},@var{kind} | |
b8ff78ce JB |
32317 | @cindex @samp{z3} packet |
32318 | @cindex @samp{Z3} packet | |
a1dcb23a DJ |
32319 | Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint at @var{addr}. |
32320 | @var{kind} is interpreted as the number of bytes to watch. | |
2f870471 AC |
32321 | |
32322 | Reply: | |
32323 | @table @samp | |
32324 | @item OK | |
32325 | success | |
32326 | @item | |
32327 | not supported | |
b8ff78ce | 32328 | @item E @var{NN} |
2f870471 AC |
32329 | for an error |
32330 | @end table | |
32331 | ||
a1dcb23a DJ |
32332 | @item z4,@var{addr},@var{kind} |
32333 | @itemx Z4,@var{addr},@var{kind} | |
b8ff78ce JB |
32334 | @cindex @samp{z4} packet |
32335 | @cindex @samp{Z4} packet | |
a1dcb23a DJ |
32336 | Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint at @var{addr}. |
32337 | @var{kind} is interpreted as the number of bytes to watch. | |
2f870471 AC |
32338 | |
32339 | Reply: | |
32340 | @table @samp | |
32341 | @item OK | |
32342 | success | |
32343 | @item | |
32344 | not supported | |
b8ff78ce | 32345 | @item E @var{NN} |
2f870471 | 32346 | for an error |
ee2d5c50 AC |
32347 | @end table |
32348 | ||
32349 | @end table | |
c906108c | 32350 | |
ee2d5c50 AC |
32351 | @node Stop Reply Packets |
32352 | @section Stop Reply Packets | |
32353 | @cindex stop reply packets | |
c906108c | 32354 | |
8b23ecc4 SL |
32355 | The @samp{C}, @samp{c}, @samp{S}, @samp{s}, @samp{vCont}, |
32356 | @samp{vAttach}, @samp{vRun}, @samp{vStopped}, and @samp{?} packets can | |
32357 | receive any of the below as a reply. Except for @samp{?} | |
32358 | and @samp{vStopped}, that reply is only returned | |
b8ff78ce | 32359 | when the target halts. In the below the exact meaning of @dfn{signal |
89be2091 DJ |
32360 | number} is defined by the header @file{include/gdb/signals.h} in the |
32361 | @value{GDBN} source code. | |
c906108c | 32362 | |
b8ff78ce JB |
32363 | As in the description of request packets, we include spaces in the |
32364 | reply templates for clarity; these are not part of the reply packet's | |
32365 | syntax. No @value{GDBN} stop reply packet uses spaces to separate its | |
32366 | components. | |
c906108c | 32367 | |
b8ff78ce | 32368 | @table @samp |
ee2d5c50 | 32369 | |
b8ff78ce | 32370 | @item S @var{AA} |
599b237a | 32371 | The program received signal number @var{AA} (a two-digit hexadecimal |
940178d3 JB |
32372 | number). This is equivalent to a @samp{T} response with no |
32373 | @var{n}:@var{r} pairs. | |
c906108c | 32374 | |
b8ff78ce JB |
32375 | @item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{} |
32376 | @cindex @samp{T} packet reply | |
599b237a | 32377 | The program received signal number @var{AA} (a two-digit hexadecimal |
940178d3 JB |
32378 | number). This is equivalent to an @samp{S} response, except that the |
32379 | @samp{@var{n}:@var{r}} pairs can carry values of important registers | |
32380 | and other information directly in the stop reply packet, reducing | |
32381 | round-trip latency. Single-step and breakpoint traps are reported | |
32382 | this way. Each @samp{@var{n}:@var{r}} pair is interpreted as follows: | |
cfa9d6d9 DJ |
32383 | |
32384 | @itemize @bullet | |
b8ff78ce | 32385 | @item |
599b237a | 32386 | If @var{n} is a hexadecimal number, it is a register number, and the |
b8ff78ce JB |
32387 | corresponding @var{r} gives that register's value. @var{r} is a |
32388 | series of bytes in target byte order, with each byte given by a | |
32389 | two-digit hex number. | |
cfa9d6d9 | 32390 | |
b8ff78ce | 32391 | @item |
b90a069a SL |
32392 | If @var{n} is @samp{thread}, then @var{r} is the @var{thread-id} of |
32393 | the stopped thread, as specified in @ref{thread-id syntax}. | |
cfa9d6d9 | 32394 | |
dc146f7c VP |
32395 | @item |
32396 | If @var{n} is @samp{core}, then @var{r} is the hexadecimal number of | |
32397 | the core on which the stop event was detected. | |
32398 | ||
b8ff78ce | 32399 | @item |
cfa9d6d9 DJ |
32400 | If @var{n} is a recognized @dfn{stop reason}, it describes a more |
32401 | specific event that stopped the target. The currently defined stop | |
32402 | reasons are listed below. @var{aa} should be @samp{05}, the trap | |
32403 | signal. At most one stop reason should be present. | |
32404 | ||
b8ff78ce JB |
32405 | @item |
32406 | Otherwise, @value{GDBN} should ignore this @samp{@var{n}:@var{r}} pair | |
32407 | and go on to the next; this allows us to extend the protocol in the | |
32408 | future. | |
cfa9d6d9 DJ |
32409 | @end itemize |
32410 | ||
32411 | The currently defined stop reasons are: | |
32412 | ||
32413 | @table @samp | |
32414 | @item watch | |
32415 | @itemx rwatch | |
32416 | @itemx awatch | |
32417 | The packet indicates a watchpoint hit, and @var{r} is the data address, in | |
32418 | hex. | |
32419 | ||
32420 | @cindex shared library events, remote reply | |
32421 | @item library | |
32422 | The packet indicates that the loaded libraries have changed. | |
32423 | @value{GDBN} should use @samp{qXfer:libraries:read} to fetch a new | |
32424 | list of loaded libraries. @var{r} is ignored. | |
bacec72f MS |
32425 | |
32426 | @cindex replay log events, remote reply | |
32427 | @item replaylog | |
32428 | The packet indicates that the target cannot continue replaying | |
32429 | logged execution events, because it has reached the end (or the | |
32430 | beginning when executing backward) of the log. The value of @var{r} | |
32431 | will be either @samp{begin} or @samp{end}. @xref{Reverse Execution}, | |
32432 | for more information. | |
cfa9d6d9 | 32433 | @end table |
ee2d5c50 | 32434 | |
b8ff78ce | 32435 | @item W @var{AA} |
b90a069a | 32436 | @itemx W @var{AA} ; process:@var{pid} |
8e04817f | 32437 | The process exited, and @var{AA} is the exit status. This is only |
ee2d5c50 AC |
32438 | applicable to certain targets. |
32439 | ||
b90a069a SL |
32440 | The second form of the response, including the process ID of the exited |
32441 | process, can be used only when @value{GDBN} has reported support for | |
32442 | multiprocess protocol extensions; see @ref{multiprocess extensions}. | |
32443 | The @var{pid} is formatted as a big-endian hex string. | |
32444 | ||
b8ff78ce | 32445 | @item X @var{AA} |
b90a069a | 32446 | @itemx X @var{AA} ; process:@var{pid} |
8e04817f | 32447 | The process terminated with signal @var{AA}. |
c906108c | 32448 | |
b90a069a SL |
32449 | The second form of the response, including the process ID of the |
32450 | terminated process, can be used only when @value{GDBN} has reported | |
32451 | support for multiprocess protocol extensions; see @ref{multiprocess | |
32452 | extensions}. The @var{pid} is formatted as a big-endian hex string. | |
32453 | ||
b8ff78ce JB |
32454 | @item O @var{XX}@dots{} |
32455 | @samp{@var{XX}@dots{}} is hex encoding of @sc{ascii} data, to be | |
32456 | written as the program's console output. This can happen at any time | |
32457 | while the program is running and the debugger should continue to wait | |
8b23ecc4 | 32458 | for @samp{W}, @samp{T}, etc. This reply is not permitted in non-stop mode. |
0ce1b118 | 32459 | |
b8ff78ce | 32460 | @item F @var{call-id},@var{parameter}@dots{} |
0ce1b118 CV |
32461 | @var{call-id} is the identifier which says which host system call should |
32462 | be called. This is just the name of the function. Translation into the | |
32463 | correct system call is only applicable as it's defined in @value{GDBN}. | |
79a6e687 | 32464 | @xref{File-I/O Remote Protocol Extension}, for a list of implemented |
0ce1b118 CV |
32465 | system calls. |
32466 | ||
b8ff78ce JB |
32467 | @samp{@var{parameter}@dots{}} is a list of parameters as defined for |
32468 | this very system call. | |
0ce1b118 | 32469 | |
b8ff78ce JB |
32470 | The target replies with this packet when it expects @value{GDBN} to |
32471 | call a host system call on behalf of the target. @value{GDBN} replies | |
32472 | with an appropriate @samp{F} packet and keeps up waiting for the next | |
32473 | reply packet from the target. The latest @samp{C}, @samp{c}, @samp{S} | |
79a6e687 BW |
32474 | or @samp{s} action is expected to be continued. @xref{File-I/O Remote |
32475 | Protocol Extension}, for more details. | |
0ce1b118 | 32476 | |
ee2d5c50 AC |
32477 | @end table |
32478 | ||
32479 | @node General Query Packets | |
32480 | @section General Query Packets | |
9c16f35a | 32481 | @cindex remote query requests |
c906108c | 32482 | |
5f3bebba JB |
32483 | Packets starting with @samp{q} are @dfn{general query packets}; |
32484 | packets starting with @samp{Q} are @dfn{general set packets}. General | |
32485 | query and set packets are a semi-unified form for retrieving and | |
32486 | sending information to and from the stub. | |
32487 | ||
32488 | The initial letter of a query or set packet is followed by a name | |
32489 | indicating what sort of thing the packet applies to. For example, | |
32490 | @value{GDBN} may use a @samp{qSymbol} packet to exchange symbol | |
32491 | definitions with the stub. These packet names follow some | |
32492 | conventions: | |
32493 | ||
32494 | @itemize @bullet | |
32495 | @item | |
32496 | The name must not contain commas, colons or semicolons. | |
32497 | @item | |
32498 | Most @value{GDBN} query and set packets have a leading upper case | |
32499 | letter. | |
32500 | @item | |
32501 | The names of custom vendor packets should use a company prefix, in | |
32502 | lower case, followed by a period. For example, packets designed at | |
32503 | the Acme Corporation might begin with @samp{qacme.foo} (for querying | |
32504 | foos) or @samp{Qacme.bar} (for setting bars). | |
32505 | @end itemize | |
32506 | ||
aa56d27a JB |
32507 | The name of a query or set packet should be separated from any |
32508 | parameters by a @samp{:}; the parameters themselves should be | |
32509 | separated by @samp{,} or @samp{;}. Stubs must be careful to match the | |
369af7bd DJ |
32510 | full packet name, and check for a separator or the end of the packet, |
32511 | in case two packet names share a common prefix. New packets should not begin | |
32512 | with @samp{qC}, @samp{qP}, or @samp{qL}@footnote{The @samp{qP} and @samp{qL} | |
32513 | packets predate these conventions, and have arguments without any terminator | |
32514 | for the packet name; we suspect they are in widespread use in places that | |
32515 | are difficult to upgrade. The @samp{qC} packet has no arguments, but some | |
32516 | existing stubs (e.g.@: RedBoot) are known to not check for the end of the | |
32517 | packet.}. | |
c906108c | 32518 | |
b8ff78ce JB |
32519 | Like the descriptions of the other packets, each description here |
32520 | has a template showing the packet's overall syntax, followed by an | |
32521 | explanation of the packet's meaning. We include spaces in some of the | |
32522 | templates for clarity; these are not part of the packet's syntax. No | |
32523 | @value{GDBN} packet uses spaces to separate its components. | |
32524 | ||
5f3bebba JB |
32525 | Here are the currently defined query and set packets: |
32526 | ||
b8ff78ce | 32527 | @table @samp |
c906108c | 32528 | |
d914c394 SS |
32529 | @item QAllow:@var{op}:@var{val}@dots{} |
32530 | @cindex @samp{QAllow} packet | |
32531 | Specify which operations @value{GDBN} expects to request of the | |
32532 | target, as a semicolon-separated list of operation name and value | |
32533 | pairs. Possible values for @var{op} include @samp{WriteReg}, | |
32534 | @samp{WriteMem}, @samp{InsertBreak}, @samp{InsertTrace}, | |
32535 | @samp{InsertFastTrace}, and @samp{Stop}. @var{val} is either 0, | |
32536 | indicating that @value{GDBN} will not request the operation, or 1, | |
32537 | indicating that it may. (The target can then use this to set up its | |
32538 | own internals optimally, for instance if the debugger never expects to | |
32539 | insert breakpoints, it may not need to install its own trap handler.) | |
32540 | ||
b8ff78ce | 32541 | @item qC |
9c16f35a | 32542 | @cindex current thread, remote request |
b8ff78ce | 32543 | @cindex @samp{qC} packet |
b90a069a | 32544 | Return the current thread ID. |
ee2d5c50 AC |
32545 | |
32546 | Reply: | |
32547 | @table @samp | |
b90a069a SL |
32548 | @item QC @var{thread-id} |
32549 | Where @var{thread-id} is a thread ID as documented in | |
32550 | @ref{thread-id syntax}. | |
b8ff78ce | 32551 | @item @r{(anything else)} |
b90a069a | 32552 | Any other reply implies the old thread ID. |
ee2d5c50 AC |
32553 | @end table |
32554 | ||
b8ff78ce | 32555 | @item qCRC:@var{addr},@var{length} |
ff2587ec | 32556 | @cindex CRC of memory block, remote request |
b8ff78ce | 32557 | @cindex @samp{qCRC} packet |
99e008fe EZ |
32558 | Compute the CRC checksum of a block of memory using CRC-32 defined in |
32559 | IEEE 802.3. The CRC is computed byte at a time, taking the most | |
32560 | significant bit of each byte first. The initial pattern code | |
32561 | @code{0xffffffff} is used to ensure leading zeros affect the CRC. | |
32562 | ||
32563 | @emph{Note:} This is the same CRC used in validating separate debug | |
32564 | files (@pxref{Separate Debug Files, , Debugging Information in Separate | |
32565 | Files}). However the algorithm is slightly different. When validating | |
32566 | separate debug files, the CRC is computed taking the @emph{least} | |
32567 | significant bit of each byte first, and the final result is inverted to | |
32568 | detect trailing zeros. | |
32569 | ||
ff2587ec WZ |
32570 | Reply: |
32571 | @table @samp | |
b8ff78ce | 32572 | @item E @var{NN} |
ff2587ec | 32573 | An error (such as memory fault) |
b8ff78ce JB |
32574 | @item C @var{crc32} |
32575 | The specified memory region's checksum is @var{crc32}. | |
ff2587ec WZ |
32576 | @end table |
32577 | ||
b8ff78ce JB |
32578 | @item qfThreadInfo |
32579 | @itemx qsThreadInfo | |
9c16f35a | 32580 | @cindex list active threads, remote request |
b8ff78ce JB |
32581 | @cindex @samp{qfThreadInfo} packet |
32582 | @cindex @samp{qsThreadInfo} packet | |
b90a069a | 32583 | Obtain a list of all active thread IDs from the target (OS). Since there |
8e04817f AC |
32584 | may be too many active threads to fit into one reply packet, this query |
32585 | works iteratively: it may require more than one query/reply sequence to | |
32586 | obtain the entire list of threads. The first query of the sequence will | |
b8ff78ce JB |
32587 | be the @samp{qfThreadInfo} query; subsequent queries in the |
32588 | sequence will be the @samp{qsThreadInfo} query. | |
ee2d5c50 | 32589 | |
b8ff78ce | 32590 | NOTE: This packet replaces the @samp{qL} query (see below). |
ee2d5c50 AC |
32591 | |
32592 | Reply: | |
32593 | @table @samp | |
b90a069a SL |
32594 | @item m @var{thread-id} |
32595 | A single thread ID | |
32596 | @item m @var{thread-id},@var{thread-id}@dots{} | |
32597 | a comma-separated list of thread IDs | |
b8ff78ce JB |
32598 | @item l |
32599 | (lower case letter @samp{L}) denotes end of list. | |
ee2d5c50 AC |
32600 | @end table |
32601 | ||
32602 | In response to each query, the target will reply with a list of one or | |
b90a069a | 32603 | more thread IDs, separated by commas. |
e1aac25b | 32604 | @value{GDBN} will respond to each reply with a request for more thread |
b8ff78ce | 32605 | ids (using the @samp{qs} form of the query), until the target responds |
501994c0 | 32606 | with @samp{l} (lower-case ell, for @dfn{last}). |
b90a069a SL |
32607 | Refer to @ref{thread-id syntax}, for the format of the @var{thread-id} |
32608 | fields. | |
c906108c | 32609 | |
b8ff78ce | 32610 | @item qGetTLSAddr:@var{thread-id},@var{offset},@var{lm} |
ff2587ec | 32611 | @cindex get thread-local storage address, remote request |
b8ff78ce | 32612 | @cindex @samp{qGetTLSAddr} packet |
ff2587ec WZ |
32613 | Fetch the address associated with thread local storage specified |
32614 | by @var{thread-id}, @var{offset}, and @var{lm}. | |
32615 | ||
b90a069a SL |
32616 | @var{thread-id} is the thread ID associated with the |
32617 | thread for which to fetch the TLS address. @xref{thread-id syntax}. | |
ff2587ec WZ |
32618 | |
32619 | @var{offset} is the (big endian, hex encoded) offset associated with the | |
32620 | thread local variable. (This offset is obtained from the debug | |
32621 | information associated with the variable.) | |
32622 | ||
db2e3e2e | 32623 | @var{lm} is the (big endian, hex encoded) OS/ABI-specific encoding of the |
ff2587ec WZ |
32624 | the load module associated with the thread local storage. For example, |
32625 | a @sc{gnu}/Linux system will pass the link map address of the shared | |
32626 | object associated with the thread local storage under consideration. | |
32627 | Other operating environments may choose to represent the load module | |
32628 | differently, so the precise meaning of this parameter will vary. | |
ee2d5c50 AC |
32629 | |
32630 | Reply: | |
b8ff78ce JB |
32631 | @table @samp |
32632 | @item @var{XX}@dots{} | |
ff2587ec WZ |
32633 | Hex encoded (big endian) bytes representing the address of the thread |
32634 | local storage requested. | |
32635 | ||
b8ff78ce JB |
32636 | @item E @var{nn} |
32637 | An error occurred. @var{nn} are hex digits. | |
ff2587ec | 32638 | |
b8ff78ce JB |
32639 | @item |
32640 | An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub. | |
ee2d5c50 AC |
32641 | @end table |
32642 | ||
711e434b PM |
32643 | @item qGetTIBAddr:@var{thread-id} |
32644 | @cindex get thread information block address | |
32645 | @cindex @samp{qGetTIBAddr} packet | |
32646 | Fetch address of the Windows OS specific Thread Information Block. | |
32647 | ||
32648 | @var{thread-id} is the thread ID associated with the thread. | |
32649 | ||
32650 | Reply: | |
32651 | @table @samp | |
32652 | @item @var{XX}@dots{} | |
32653 | Hex encoded (big endian) bytes representing the linear address of the | |
32654 | thread information block. | |
32655 | ||
32656 | @item E @var{nn} | |
32657 | An error occured. This means that either the thread was not found, or the | |
32658 | address could not be retrieved. | |
32659 | ||
32660 | @item | |
32661 | An empty reply indicates that @samp{qGetTIBAddr} is not supported by the stub. | |
32662 | @end table | |
32663 | ||
b8ff78ce | 32664 | @item qL @var{startflag} @var{threadcount} @var{nextthread} |
8e04817f AC |
32665 | Obtain thread information from RTOS. Where: @var{startflag} (one hex |
32666 | digit) is one to indicate the first query and zero to indicate a | |
32667 | subsequent query; @var{threadcount} (two hex digits) is the maximum | |
32668 | number of threads the response packet can contain; and @var{nextthread} | |
32669 | (eight hex digits), for subsequent queries (@var{startflag} is zero), is | |
32670 | returned in the response as @var{argthread}. | |
ee2d5c50 | 32671 | |
b8ff78ce | 32672 | Don't use this packet; use the @samp{qfThreadInfo} query instead (see above). |
ee2d5c50 AC |
32673 | |
32674 | Reply: | |
32675 | @table @samp | |
b8ff78ce | 32676 | @item qM @var{count} @var{done} @var{argthread} @var{thread}@dots{} |
8e04817f AC |
32677 | Where: @var{count} (two hex digits) is the number of threads being |
32678 | returned; @var{done} (one hex digit) is zero to indicate more threads | |
32679 | and one indicates no further threads; @var{argthreadid} (eight hex | |
b8ff78ce | 32680 | digits) is @var{nextthread} from the request packet; @var{thread}@dots{} |
ee2d5c50 | 32681 | is a sequence of thread IDs from the target. @var{threadid} (eight hex |
8e04817f | 32682 | digits). See @code{remote.c:parse_threadlist_response()}. |
ee2d5c50 | 32683 | @end table |
c906108c | 32684 | |
b8ff78ce | 32685 | @item qOffsets |
9c16f35a | 32686 | @cindex section offsets, remote request |
b8ff78ce | 32687 | @cindex @samp{qOffsets} packet |
31d99776 DJ |
32688 | Get section offsets that the target used when relocating the downloaded |
32689 | image. | |
c906108c | 32690 | |
ee2d5c50 AC |
32691 | Reply: |
32692 | @table @samp | |
31d99776 DJ |
32693 | @item Text=@var{xxx};Data=@var{yyy}@r{[};Bss=@var{zzz}@r{]} |
32694 | Relocate the @code{Text} section by @var{xxx} from its original address. | |
32695 | Relocate the @code{Data} section by @var{yyy} from its original address. | |
32696 | If the object file format provides segment information (e.g.@: @sc{elf} | |
32697 | @samp{PT_LOAD} program headers), @value{GDBN} will relocate entire | |
32698 | segments by the supplied offsets. | |
32699 | ||
32700 | @emph{Note: while a @code{Bss} offset may be included in the response, | |
32701 | @value{GDBN} ignores this and instead applies the @code{Data} offset | |
32702 | to the @code{Bss} section.} | |
32703 | ||
32704 | @item TextSeg=@var{xxx}@r{[};DataSeg=@var{yyy}@r{]} | |
32705 | Relocate the first segment of the object file, which conventionally | |
32706 | contains program code, to a starting address of @var{xxx}. If | |
32707 | @samp{DataSeg} is specified, relocate the second segment, which | |
32708 | conventionally contains modifiable data, to a starting address of | |
32709 | @var{yyy}. @value{GDBN} will report an error if the object file | |
32710 | does not contain segment information, or does not contain at least | |
32711 | as many segments as mentioned in the reply. Extra segments are | |
32712 | kept at fixed offsets relative to the last relocated segment. | |
ee2d5c50 AC |
32713 | @end table |
32714 | ||
b90a069a | 32715 | @item qP @var{mode} @var{thread-id} |
9c16f35a | 32716 | @cindex thread information, remote request |
b8ff78ce | 32717 | @cindex @samp{qP} packet |
b90a069a SL |
32718 | Returns information on @var{thread-id}. Where: @var{mode} is a hex |
32719 | encoded 32 bit mode; @var{thread-id} is a thread ID | |
32720 | (@pxref{thread-id syntax}). | |
ee2d5c50 | 32721 | |
aa56d27a JB |
32722 | Don't use this packet; use the @samp{qThreadExtraInfo} query instead |
32723 | (see below). | |
32724 | ||
b8ff78ce | 32725 | Reply: see @code{remote.c:remote_unpack_thread_info_response()}. |
c906108c | 32726 | |
8b23ecc4 SL |
32727 | @item QNonStop:1 |
32728 | @item QNonStop:0 | |
32729 | @cindex non-stop mode, remote request | |
32730 | @cindex @samp{QNonStop} packet | |
32731 | @anchor{QNonStop} | |
32732 | Enter non-stop (@samp{QNonStop:1}) or all-stop (@samp{QNonStop:0}) mode. | |
32733 | @xref{Remote Non-Stop}, for more information. | |
32734 | ||
32735 | Reply: | |
32736 | @table @samp | |
32737 | @item OK | |
32738 | The request succeeded. | |
32739 | ||
32740 | @item E @var{nn} | |
32741 | An error occurred. @var{nn} are hex digits. | |
32742 | ||
32743 | @item | |
32744 | An empty reply indicates that @samp{QNonStop} is not supported by | |
32745 | the stub. | |
32746 | @end table | |
32747 | ||
32748 | This packet is not probed by default; the remote stub must request it, | |
32749 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
32750 | Use of this packet is controlled by the @code{set non-stop} command; | |
32751 | @pxref{Non-Stop Mode}. | |
32752 | ||
89be2091 DJ |
32753 | @item QPassSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{} |
32754 | @cindex pass signals to inferior, remote request | |
32755 | @cindex @samp{QPassSignals} packet | |
23181151 | 32756 | @anchor{QPassSignals} |
89be2091 DJ |
32757 | Each listed @var{signal} should be passed directly to the inferior process. |
32758 | Signals are numbered identically to continue packets and stop replies | |
32759 | (@pxref{Stop Reply Packets}). Each @var{signal} list item should be | |
32760 | strictly greater than the previous item. These signals do not need to stop | |
32761 | the inferior, or be reported to @value{GDBN}. All other signals should be | |
32762 | reported to @value{GDBN}. Multiple @samp{QPassSignals} packets do not | |
32763 | combine; any earlier @samp{QPassSignals} list is completely replaced by the | |
32764 | new list. This packet improves performance when using @samp{handle | |
32765 | @var{signal} nostop noprint pass}. | |
32766 | ||
32767 | Reply: | |
32768 | @table @samp | |
32769 | @item OK | |
32770 | The request succeeded. | |
32771 | ||
32772 | @item E @var{nn} | |
32773 | An error occurred. @var{nn} are hex digits. | |
32774 | ||
32775 | @item | |
32776 | An empty reply indicates that @samp{QPassSignals} is not supported by | |
32777 | the stub. | |
32778 | @end table | |
32779 | ||
32780 | Use of this packet is controlled by the @code{set remote pass-signals} | |
79a6e687 | 32781 | command (@pxref{Remote Configuration, set remote pass-signals}). |
89be2091 DJ |
32782 | This packet is not probed by default; the remote stub must request it, |
32783 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
32784 | ||
b8ff78ce | 32785 | @item qRcmd,@var{command} |
ff2587ec | 32786 | @cindex execute remote command, remote request |
b8ff78ce | 32787 | @cindex @samp{qRcmd} packet |
ff2587ec | 32788 | @var{command} (hex encoded) is passed to the local interpreter for |
b8ff78ce JB |
32789 | execution. Invalid commands should be reported using the output |
32790 | string. Before the final result packet, the target may also respond | |
32791 | with a number of intermediate @samp{O@var{output}} console output | |
32792 | packets. @emph{Implementors should note that providing access to a | |
32793 | stubs's interpreter may have security implications}. | |
fa93a9d8 | 32794 | |
ff2587ec WZ |
32795 | Reply: |
32796 | @table @samp | |
32797 | @item OK | |
32798 | A command response with no output. | |
32799 | @item @var{OUTPUT} | |
32800 | A command response with the hex encoded output string @var{OUTPUT}. | |
b8ff78ce | 32801 | @item E @var{NN} |
ff2587ec | 32802 | Indicate a badly formed request. |
b8ff78ce JB |
32803 | @item |
32804 | An empty reply indicates that @samp{qRcmd} is not recognized. | |
ff2587ec | 32805 | @end table |
fa93a9d8 | 32806 | |
aa56d27a JB |
32807 | (Note that the @code{qRcmd} packet's name is separated from the |
32808 | command by a @samp{,}, not a @samp{:}, contrary to the naming | |
32809 | conventions above. Please don't use this packet as a model for new | |
32810 | packets.) | |
32811 | ||
08388c79 DE |
32812 | @item qSearch:memory:@var{address};@var{length};@var{search-pattern} |
32813 | @cindex searching memory, in remote debugging | |
32814 | @cindex @samp{qSearch:memory} packet | |
32815 | @anchor{qSearch memory} | |
32816 | Search @var{length} bytes at @var{address} for @var{search-pattern}. | |
32817 | @var{address} and @var{length} are encoded in hex. | |
32818 | @var{search-pattern} is a sequence of bytes, hex encoded. | |
32819 | ||
32820 | Reply: | |
32821 | @table @samp | |
32822 | @item 0 | |
32823 | The pattern was not found. | |
32824 | @item 1,address | |
32825 | The pattern was found at @var{address}. | |
32826 | @item E @var{NN} | |
32827 | A badly formed request or an error was encountered while searching memory. | |
32828 | @item | |
32829 | An empty reply indicates that @samp{qSearch:memory} is not recognized. | |
32830 | @end table | |
32831 | ||
a6f3e723 SL |
32832 | @item QStartNoAckMode |
32833 | @cindex @samp{QStartNoAckMode} packet | |
32834 | @anchor{QStartNoAckMode} | |
32835 | Request that the remote stub disable the normal @samp{+}/@samp{-} | |
32836 | protocol acknowledgments (@pxref{Packet Acknowledgment}). | |
32837 | ||
32838 | Reply: | |
32839 | @table @samp | |
32840 | @item OK | |
32841 | The stub has switched to no-acknowledgment mode. | |
32842 | @value{GDBN} acknowledges this reponse, | |
32843 | but neither the stub nor @value{GDBN} shall send or expect further | |
32844 | @samp{+}/@samp{-} acknowledgments in the current connection. | |
32845 | @item | |
32846 | An empty reply indicates that the stub does not support no-acknowledgment mode. | |
32847 | @end table | |
32848 | ||
be2a5f71 DJ |
32849 | @item qSupported @r{[}:@var{gdbfeature} @r{[};@var{gdbfeature}@r{]}@dots{} @r{]} |
32850 | @cindex supported packets, remote query | |
32851 | @cindex features of the remote protocol | |
32852 | @cindex @samp{qSupported} packet | |
0876f84a | 32853 | @anchor{qSupported} |
be2a5f71 DJ |
32854 | Tell the remote stub about features supported by @value{GDBN}, and |
32855 | query the stub for features it supports. This packet allows | |
32856 | @value{GDBN} and the remote stub to take advantage of each others' | |
32857 | features. @samp{qSupported} also consolidates multiple feature probes | |
32858 | at startup, to improve @value{GDBN} performance---a single larger | |
32859 | packet performs better than multiple smaller probe packets on | |
32860 | high-latency links. Some features may enable behavior which must not | |
32861 | be on by default, e.g.@: because it would confuse older clients or | |
32862 | stubs. Other features may describe packets which could be | |
32863 | automatically probed for, but are not. These features must be | |
32864 | reported before @value{GDBN} will use them. This ``default | |
32865 | unsupported'' behavior is not appropriate for all packets, but it | |
32866 | helps to keep the initial connection time under control with new | |
32867 | versions of @value{GDBN} which support increasing numbers of packets. | |
32868 | ||
32869 | Reply: | |
32870 | @table @samp | |
32871 | @item @var{stubfeature} @r{[};@var{stubfeature}@r{]}@dots{} | |
32872 | The stub supports or does not support each returned @var{stubfeature}, | |
32873 | depending on the form of each @var{stubfeature} (see below for the | |
32874 | possible forms). | |
32875 | @item | |
32876 | An empty reply indicates that @samp{qSupported} is not recognized, | |
32877 | or that no features needed to be reported to @value{GDBN}. | |
32878 | @end table | |
32879 | ||
32880 | The allowed forms for each feature (either a @var{gdbfeature} in the | |
32881 | @samp{qSupported} packet, or a @var{stubfeature} in the response) | |
32882 | are: | |
32883 | ||
32884 | @table @samp | |
32885 | @item @var{name}=@var{value} | |
32886 | The remote protocol feature @var{name} is supported, and associated | |
32887 | with the specified @var{value}. The format of @var{value} depends | |
32888 | on the feature, but it must not include a semicolon. | |
32889 | @item @var{name}+ | |
32890 | The remote protocol feature @var{name} is supported, and does not | |
32891 | need an associated value. | |
32892 | @item @var{name}- | |
32893 | The remote protocol feature @var{name} is not supported. | |
32894 | @item @var{name}? | |
32895 | The remote protocol feature @var{name} may be supported, and | |
32896 | @value{GDBN} should auto-detect support in some other way when it is | |
32897 | needed. This form will not be used for @var{gdbfeature} notifications, | |
32898 | but may be used for @var{stubfeature} responses. | |
32899 | @end table | |
32900 | ||
32901 | Whenever the stub receives a @samp{qSupported} request, the | |
32902 | supplied set of @value{GDBN} features should override any previous | |
32903 | request. This allows @value{GDBN} to put the stub in a known | |
32904 | state, even if the stub had previously been communicating with | |
32905 | a different version of @value{GDBN}. | |
32906 | ||
b90a069a SL |
32907 | The following values of @var{gdbfeature} (for the packet sent by @value{GDBN}) |
32908 | are defined: | |
32909 | ||
32910 | @table @samp | |
32911 | @item multiprocess | |
32912 | This feature indicates whether @value{GDBN} supports multiprocess | |
32913 | extensions to the remote protocol. @value{GDBN} does not use such | |
32914 | extensions unless the stub also reports that it supports them by | |
32915 | including @samp{multiprocess+} in its @samp{qSupported} reply. | |
32916 | @xref{multiprocess extensions}, for details. | |
c8d5aac9 L |
32917 | |
32918 | @item xmlRegisters | |
32919 | This feature indicates that @value{GDBN} supports the XML target | |
32920 | description. If the stub sees @samp{xmlRegisters=} with target | |
32921 | specific strings separated by a comma, it will report register | |
32922 | description. | |
dde08ee1 PA |
32923 | |
32924 | @item qRelocInsn | |
32925 | This feature indicates whether @value{GDBN} supports the | |
32926 | @samp{qRelocInsn} packet (@pxref{Tracepoint Packets,,Relocate | |
32927 | instruction reply packet}). | |
b90a069a SL |
32928 | @end table |
32929 | ||
32930 | Stubs should ignore any unknown values for | |
be2a5f71 DJ |
32931 | @var{gdbfeature}. Any @value{GDBN} which sends a @samp{qSupported} |
32932 | packet supports receiving packets of unlimited length (earlier | |
b90a069a | 32933 | versions of @value{GDBN} may reject overly long responses). Additional values |
be2a5f71 DJ |
32934 | for @var{gdbfeature} may be defined in the future to let the stub take |
32935 | advantage of new features in @value{GDBN}, e.g.@: incompatible | |
b90a069a SL |
32936 | improvements in the remote protocol---the @samp{multiprocess} feature is |
32937 | an example of such a feature. The stub's reply should be independent | |
be2a5f71 DJ |
32938 | of the @var{gdbfeature} entries sent by @value{GDBN}; first @value{GDBN} |
32939 | describes all the features it supports, and then the stub replies with | |
32940 | all the features it supports. | |
32941 | ||
32942 | Similarly, @value{GDBN} will silently ignore unrecognized stub feature | |
32943 | responses, as long as each response uses one of the standard forms. | |
32944 | ||
32945 | Some features are flags. A stub which supports a flag feature | |
32946 | should respond with a @samp{+} form response. Other features | |
32947 | require values, and the stub should respond with an @samp{=} | |
32948 | form response. | |
32949 | ||
32950 | Each feature has a default value, which @value{GDBN} will use if | |
32951 | @samp{qSupported} is not available or if the feature is not mentioned | |
32952 | in the @samp{qSupported} response. The default values are fixed; a | |
32953 | stub is free to omit any feature responses that match the defaults. | |
32954 | ||
32955 | Not all features can be probed, but for those which can, the probing | |
32956 | mechanism is useful: in some cases, a stub's internal | |
32957 | architecture may not allow the protocol layer to know some information | |
32958 | about the underlying target in advance. This is especially common in | |
32959 | stubs which may be configured for multiple targets. | |
32960 | ||
32961 | These are the currently defined stub features and their properties: | |
32962 | ||
cfa9d6d9 | 32963 | @multitable @columnfractions 0.35 0.2 0.12 0.2 |
be2a5f71 DJ |
32964 | @c NOTE: The first row should be @headitem, but we do not yet require |
32965 | @c a new enough version of Texinfo (4.7) to use @headitem. | |
0876f84a | 32966 | @item Feature Name |
be2a5f71 DJ |
32967 | @tab Value Required |
32968 | @tab Default | |
32969 | @tab Probe Allowed | |
32970 | ||
32971 | @item @samp{PacketSize} | |
32972 | @tab Yes | |
32973 | @tab @samp{-} | |
32974 | @tab No | |
32975 | ||
0876f84a DJ |
32976 | @item @samp{qXfer:auxv:read} |
32977 | @tab No | |
32978 | @tab @samp{-} | |
32979 | @tab Yes | |
32980 | ||
23181151 DJ |
32981 | @item @samp{qXfer:features:read} |
32982 | @tab No | |
32983 | @tab @samp{-} | |
32984 | @tab Yes | |
32985 | ||
cfa9d6d9 DJ |
32986 | @item @samp{qXfer:libraries:read} |
32987 | @tab No | |
32988 | @tab @samp{-} | |
32989 | @tab Yes | |
32990 | ||
68437a39 DJ |
32991 | @item @samp{qXfer:memory-map:read} |
32992 | @tab No | |
32993 | @tab @samp{-} | |
32994 | @tab Yes | |
32995 | ||
0fb4aa4b PA |
32996 | @item @samp{qXfer:sdata:read} |
32997 | @tab No | |
32998 | @tab @samp{-} | |
32999 | @tab Yes | |
33000 | ||
0e7f50da UW |
33001 | @item @samp{qXfer:spu:read} |
33002 | @tab No | |
33003 | @tab @samp{-} | |
33004 | @tab Yes | |
33005 | ||
33006 | @item @samp{qXfer:spu:write} | |
33007 | @tab No | |
33008 | @tab @samp{-} | |
33009 | @tab Yes | |
33010 | ||
4aa995e1 PA |
33011 | @item @samp{qXfer:siginfo:read} |
33012 | @tab No | |
33013 | @tab @samp{-} | |
33014 | @tab Yes | |
33015 | ||
33016 | @item @samp{qXfer:siginfo:write} | |
33017 | @tab No | |
33018 | @tab @samp{-} | |
33019 | @tab Yes | |
33020 | ||
dc146f7c VP |
33021 | @item @samp{qXfer:threads:read} |
33022 | @tab No | |
33023 | @tab @samp{-} | |
33024 | @tab Yes | |
33025 | ||
33026 | ||
8b23ecc4 SL |
33027 | @item @samp{QNonStop} |
33028 | @tab No | |
33029 | @tab @samp{-} | |
33030 | @tab Yes | |
33031 | ||
89be2091 DJ |
33032 | @item @samp{QPassSignals} |
33033 | @tab No | |
33034 | @tab @samp{-} | |
33035 | @tab Yes | |
33036 | ||
a6f3e723 SL |
33037 | @item @samp{QStartNoAckMode} |
33038 | @tab No | |
33039 | @tab @samp{-} | |
33040 | @tab Yes | |
33041 | ||
b90a069a SL |
33042 | @item @samp{multiprocess} |
33043 | @tab No | |
33044 | @tab @samp{-} | |
33045 | @tab No | |
33046 | ||
782b2b07 SS |
33047 | @item @samp{ConditionalTracepoints} |
33048 | @tab No | |
33049 | @tab @samp{-} | |
33050 | @tab No | |
33051 | ||
0d772ac9 MS |
33052 | @item @samp{ReverseContinue} |
33053 | @tab No | |
2f8132f3 | 33054 | @tab @samp{-} |
0d772ac9 MS |
33055 | @tab No |
33056 | ||
33057 | @item @samp{ReverseStep} | |
33058 | @tab No | |
2f8132f3 | 33059 | @tab @samp{-} |
0d772ac9 MS |
33060 | @tab No |
33061 | ||
409873ef SS |
33062 | @item @samp{TracepointSource} |
33063 | @tab No | |
33064 | @tab @samp{-} | |
33065 | @tab No | |
33066 | ||
d914c394 SS |
33067 | @item @samp{QAllow} |
33068 | @tab No | |
33069 | @tab @samp{-} | |
33070 | @tab No | |
33071 | ||
be2a5f71 DJ |
33072 | @end multitable |
33073 | ||
33074 | These are the currently defined stub features, in more detail: | |
33075 | ||
33076 | @table @samp | |
33077 | @cindex packet size, remote protocol | |
33078 | @item PacketSize=@var{bytes} | |
33079 | The remote stub can accept packets up to at least @var{bytes} in | |
33080 | length. @value{GDBN} will send packets up to this size for bulk | |
33081 | transfers, and will never send larger packets. This is a limit on the | |
33082 | data characters in the packet, including the frame and checksum. | |
33083 | There is no trailing NUL byte in a remote protocol packet; if the stub | |
33084 | stores packets in a NUL-terminated format, it should allow an extra | |
33085 | byte in its buffer for the NUL. If this stub feature is not supported, | |
33086 | @value{GDBN} guesses based on the size of the @samp{g} packet response. | |
33087 | ||
0876f84a DJ |
33088 | @item qXfer:auxv:read |
33089 | The remote stub understands the @samp{qXfer:auxv:read} packet | |
33090 | (@pxref{qXfer auxiliary vector read}). | |
33091 | ||
23181151 DJ |
33092 | @item qXfer:features:read |
33093 | The remote stub understands the @samp{qXfer:features:read} packet | |
33094 | (@pxref{qXfer target description read}). | |
33095 | ||
cfa9d6d9 DJ |
33096 | @item qXfer:libraries:read |
33097 | The remote stub understands the @samp{qXfer:libraries:read} packet | |
33098 | (@pxref{qXfer library list read}). | |
33099 | ||
23181151 DJ |
33100 | @item qXfer:memory-map:read |
33101 | The remote stub understands the @samp{qXfer:memory-map:read} packet | |
33102 | (@pxref{qXfer memory map read}). | |
33103 | ||
0fb4aa4b PA |
33104 | @item qXfer:sdata:read |
33105 | The remote stub understands the @samp{qXfer:sdata:read} packet | |
33106 | (@pxref{qXfer sdata read}). | |
33107 | ||
0e7f50da UW |
33108 | @item qXfer:spu:read |
33109 | The remote stub understands the @samp{qXfer:spu:read} packet | |
33110 | (@pxref{qXfer spu read}). | |
33111 | ||
33112 | @item qXfer:spu:write | |
33113 | The remote stub understands the @samp{qXfer:spu:write} packet | |
33114 | (@pxref{qXfer spu write}). | |
33115 | ||
4aa995e1 PA |
33116 | @item qXfer:siginfo:read |
33117 | The remote stub understands the @samp{qXfer:siginfo:read} packet | |
33118 | (@pxref{qXfer siginfo read}). | |
33119 | ||
33120 | @item qXfer:siginfo:write | |
33121 | The remote stub understands the @samp{qXfer:siginfo:write} packet | |
33122 | (@pxref{qXfer siginfo write}). | |
33123 | ||
dc146f7c VP |
33124 | @item qXfer:threads:read |
33125 | The remote stub understands the @samp{qXfer:threads:read} packet | |
33126 | (@pxref{qXfer threads read}). | |
33127 | ||
8b23ecc4 SL |
33128 | @item QNonStop |
33129 | The remote stub understands the @samp{QNonStop} packet | |
33130 | (@pxref{QNonStop}). | |
33131 | ||
23181151 DJ |
33132 | @item QPassSignals |
33133 | The remote stub understands the @samp{QPassSignals} packet | |
33134 | (@pxref{QPassSignals}). | |
33135 | ||
a6f3e723 SL |
33136 | @item QStartNoAckMode |
33137 | The remote stub understands the @samp{QStartNoAckMode} packet and | |
33138 | prefers to operate in no-acknowledgment mode. @xref{Packet Acknowledgment}. | |
33139 | ||
b90a069a SL |
33140 | @item multiprocess |
33141 | @anchor{multiprocess extensions} | |
33142 | @cindex multiprocess extensions, in remote protocol | |
33143 | The remote stub understands the multiprocess extensions to the remote | |
33144 | protocol syntax. The multiprocess extensions affect the syntax of | |
33145 | thread IDs in both packets and replies (@pxref{thread-id syntax}), and | |
33146 | add process IDs to the @samp{D} packet and @samp{W} and @samp{X} | |
33147 | replies. Note that reporting this feature indicates support for the | |
33148 | syntactic extensions only, not that the stub necessarily supports | |
33149 | debugging of more than one process at a time. The stub must not use | |
33150 | multiprocess extensions in packet replies unless @value{GDBN} has also | |
33151 | indicated it supports them in its @samp{qSupported} request. | |
33152 | ||
07e059b5 VP |
33153 | @item qXfer:osdata:read |
33154 | The remote stub understands the @samp{qXfer:osdata:read} packet | |
33155 | ((@pxref{qXfer osdata read}). | |
33156 | ||
782b2b07 SS |
33157 | @item ConditionalTracepoints |
33158 | The remote stub accepts and implements conditional expressions defined | |
33159 | for tracepoints (@pxref{Tracepoint Conditions}). | |
33160 | ||
0d772ac9 MS |
33161 | @item ReverseContinue |
33162 | The remote stub accepts and implements the reverse continue packet | |
33163 | (@pxref{bc}). | |
33164 | ||
33165 | @item ReverseStep | |
33166 | The remote stub accepts and implements the reverse step packet | |
33167 | (@pxref{bs}). | |
33168 | ||
409873ef SS |
33169 | @item TracepointSource |
33170 | The remote stub understands the @samp{QTDPsrc} packet that supplies | |
33171 | the source form of tracepoint definitions. | |
33172 | ||
d914c394 SS |
33173 | @item QAllow |
33174 | The remote stub understands the @samp{QAllow} packet. | |
33175 | ||
0fb4aa4b PA |
33176 | @item StaticTracepoint |
33177 | @cindex static tracepoints, in remote protocol | |
33178 | The remote stub supports static tracepoints. | |
33179 | ||
be2a5f71 DJ |
33180 | @end table |
33181 | ||
b8ff78ce | 33182 | @item qSymbol:: |
ff2587ec | 33183 | @cindex symbol lookup, remote request |
b8ff78ce | 33184 | @cindex @samp{qSymbol} packet |
ff2587ec WZ |
33185 | Notify the target that @value{GDBN} is prepared to serve symbol lookup |
33186 | requests. Accept requests from the target for the values of symbols. | |
fa93a9d8 JB |
33187 | |
33188 | Reply: | |
ff2587ec | 33189 | @table @samp |
b8ff78ce | 33190 | @item OK |
ff2587ec | 33191 | The target does not need to look up any (more) symbols. |
b8ff78ce | 33192 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
33193 | The target requests the value of symbol @var{sym_name} (hex encoded). |
33194 | @value{GDBN} may provide the value by using the | |
b8ff78ce JB |
33195 | @samp{qSymbol:@var{sym_value}:@var{sym_name}} message, described |
33196 | below. | |
ff2587ec | 33197 | @end table |
83761cbd | 33198 | |
b8ff78ce | 33199 | @item qSymbol:@var{sym_value}:@var{sym_name} |
ff2587ec WZ |
33200 | Set the value of @var{sym_name} to @var{sym_value}. |
33201 | ||
33202 | @var{sym_name} (hex encoded) is the name of a symbol whose value the | |
33203 | target has previously requested. | |
33204 | ||
33205 | @var{sym_value} (hex) is the value for symbol @var{sym_name}. If | |
33206 | @value{GDBN} cannot supply a value for @var{sym_name}, then this field | |
33207 | will be empty. | |
33208 | ||
33209 | Reply: | |
33210 | @table @samp | |
b8ff78ce | 33211 | @item OK |
ff2587ec | 33212 | The target does not need to look up any (more) symbols. |
b8ff78ce | 33213 | @item qSymbol:@var{sym_name} |
ff2587ec WZ |
33214 | The target requests the value of a new symbol @var{sym_name} (hex |
33215 | encoded). @value{GDBN} will continue to supply the values of symbols | |
33216 | (if available), until the target ceases to request them. | |
fa93a9d8 | 33217 | @end table |
0abb7bc7 | 33218 | |
00bf0b85 | 33219 | @item qTBuffer |
4daf5ac0 | 33220 | @item QTBuffer |
d5551862 SS |
33221 | @item QTDisconnected |
33222 | @itemx QTDP | |
409873ef | 33223 | @itemx QTDPsrc |
d5551862 | 33224 | @itemx QTDV |
00bf0b85 SS |
33225 | @itemx qTfP |
33226 | @itemx qTfV | |
9d29849a JB |
33227 | @itemx QTFrame |
33228 | @xref{Tracepoint Packets}. | |
33229 | ||
b90a069a | 33230 | @item qThreadExtraInfo,@var{thread-id} |
ff2587ec | 33231 | @cindex thread attributes info, remote request |
b8ff78ce JB |
33232 | @cindex @samp{qThreadExtraInfo} packet |
33233 | Obtain a printable string description of a thread's attributes from | |
b90a069a SL |
33234 | the target OS. @var{thread-id} is a thread ID; |
33235 | see @ref{thread-id syntax}. This | |
b8ff78ce JB |
33236 | string may contain anything that the target OS thinks is interesting |
33237 | for @value{GDBN} to tell the user about the thread. The string is | |
33238 | displayed in @value{GDBN}'s @code{info threads} display. Some | |
33239 | examples of possible thread extra info strings are @samp{Runnable}, or | |
33240 | @samp{Blocked on Mutex}. | |
ff2587ec WZ |
33241 | |
33242 | Reply: | |
33243 | @table @samp | |
b8ff78ce JB |
33244 | @item @var{XX}@dots{} |
33245 | Where @samp{@var{XX}@dots{}} is a hex encoding of @sc{ascii} data, | |
33246 | comprising the printable string containing the extra information about | |
33247 | the thread's attributes. | |
ff2587ec | 33248 | @end table |
814e32d7 | 33249 | |
aa56d27a JB |
33250 | (Note that the @code{qThreadExtraInfo} packet's name is separated from |
33251 | the command by a @samp{,}, not a @samp{:}, contrary to the naming | |
33252 | conventions above. Please don't use this packet as a model for new | |
33253 | packets.) | |
33254 | ||
00bf0b85 SS |
33255 | @item QTSave |
33256 | @item qTsP | |
33257 | @item qTsV | |
d5551862 | 33258 | @itemx QTStart |
9d29849a JB |
33259 | @itemx QTStop |
33260 | @itemx QTinit | |
33261 | @itemx QTro | |
33262 | @itemx qTStatus | |
d5551862 | 33263 | @itemx qTV |
0fb4aa4b PA |
33264 | @itemx qTfSTM |
33265 | @itemx qTsSTM | |
33266 | @itemx qTSTMat | |
9d29849a JB |
33267 | @xref{Tracepoint Packets}. |
33268 | ||
0876f84a DJ |
33269 | @item qXfer:@var{object}:read:@var{annex}:@var{offset},@var{length} |
33270 | @cindex read special object, remote request | |
33271 | @cindex @samp{qXfer} packet | |
68437a39 | 33272 | @anchor{qXfer read} |
0876f84a DJ |
33273 | Read uninterpreted bytes from the target's special data area |
33274 | identified by the keyword @var{object}. Request @var{length} bytes | |
33275 | starting at @var{offset} bytes into the data. The content and | |
0e7f50da | 33276 | encoding of @var{annex} is specific to @var{object}; it can supply |
0876f84a DJ |
33277 | additional details about what data to access. |
33278 | ||
33279 | Here are the specific requests of this form defined so far. All | |
33280 | @samp{qXfer:@var{object}:read:@dots{}} requests use the same reply | |
33281 | formats, listed below. | |
33282 | ||
33283 | @table @samp | |
33284 | @item qXfer:auxv:read::@var{offset},@var{length} | |
33285 | @anchor{qXfer auxiliary vector read} | |
33286 | Access the target's @dfn{auxiliary vector}. @xref{OS Information, | |
427c3a89 | 33287 | auxiliary vector}. Note @var{annex} must be empty. |
0876f84a DJ |
33288 | |
33289 | This packet is not probed by default; the remote stub must request it, | |
89be2091 | 33290 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). |
0876f84a | 33291 | |
23181151 DJ |
33292 | @item qXfer:features:read:@var{annex}:@var{offset},@var{length} |
33293 | @anchor{qXfer target description read} | |
33294 | Access the @dfn{target description}. @xref{Target Descriptions}. The | |
33295 | annex specifies which XML document to access. The main description is | |
33296 | always loaded from the @samp{target.xml} annex. | |
33297 | ||
33298 | This packet is not probed by default; the remote stub must request it, | |
33299 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
33300 | ||
cfa9d6d9 DJ |
33301 | @item qXfer:libraries:read:@var{annex}:@var{offset},@var{length} |
33302 | @anchor{qXfer library list read} | |
33303 | Access the target's list of loaded libraries. @xref{Library List Format}. | |
33304 | The annex part of the generic @samp{qXfer} packet must be empty | |
33305 | (@pxref{qXfer read}). | |
33306 | ||
33307 | Targets which maintain a list of libraries in the program's memory do | |
33308 | not need to implement this packet; it is designed for platforms where | |
33309 | the operating system manages the list of loaded libraries. | |
33310 | ||
33311 | This packet is not probed by default; the remote stub must request it, | |
33312 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
33313 | ||
68437a39 DJ |
33314 | @item qXfer:memory-map:read::@var{offset},@var{length} |
33315 | @anchor{qXfer memory map read} | |
79a6e687 | 33316 | Access the target's @dfn{memory-map}. @xref{Memory Map Format}. The |
68437a39 DJ |
33317 | annex part of the generic @samp{qXfer} packet must be empty |
33318 | (@pxref{qXfer read}). | |
33319 | ||
0e7f50da UW |
33320 | This packet is not probed by default; the remote stub must request it, |
33321 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
33322 | ||
0fb4aa4b PA |
33323 | @item qXfer:sdata:read::@var{offset},@var{length} |
33324 | @anchor{qXfer sdata read} | |
33325 | ||
33326 | Read contents of the extra collected static tracepoint marker | |
33327 | information. The annex part of the generic @samp{qXfer} packet must | |
33328 | be empty (@pxref{qXfer read}). @xref{Tracepoint Actions,,Tracepoint | |
33329 | Action Lists}. | |
33330 | ||
33331 | This packet is not probed by default; the remote stub must request it, | |
33332 | by supplying an appropriate @samp{qSupported} response | |
33333 | (@pxref{qSupported}). | |
33334 | ||
4aa995e1 PA |
33335 | @item qXfer:siginfo:read::@var{offset},@var{length} |
33336 | @anchor{qXfer siginfo read} | |
33337 | Read contents of the extra signal information on the target | |
33338 | system. The annex part of the generic @samp{qXfer} packet must be | |
33339 | empty (@pxref{qXfer read}). | |
33340 | ||
33341 | This packet is not probed by default; the remote stub must request it, | |
33342 | by supplying an appropriate @samp{qSupported} response | |
33343 | (@pxref{qSupported}). | |
33344 | ||
0e7f50da UW |
33345 | @item qXfer:spu:read:@var{annex}:@var{offset},@var{length} |
33346 | @anchor{qXfer spu read} | |
33347 | Read contents of an @code{spufs} file on the target system. The | |
33348 | annex specifies which file to read; it must be of the form | |
33349 | @file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID | |
33350 | in the target process, and @var{name} identifes the @code{spufs} file | |
33351 | in that context to be accessed. | |
33352 | ||
68437a39 | 33353 | This packet is not probed by default; the remote stub must request it, |
07e059b5 VP |
33354 | by supplying an appropriate @samp{qSupported} response |
33355 | (@pxref{qSupported}). | |
33356 | ||
dc146f7c VP |
33357 | @item qXfer:threads:read::@var{offset},@var{length} |
33358 | @anchor{qXfer threads read} | |
33359 | Access the list of threads on target. @xref{Thread List Format}. The | |
33360 | annex part of the generic @samp{qXfer} packet must be empty | |
33361 | (@pxref{qXfer read}). | |
33362 | ||
33363 | This packet is not probed by default; the remote stub must request it, | |
33364 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
33365 | ||
07e059b5 VP |
33366 | @item qXfer:osdata:read::@var{offset},@var{length} |
33367 | @anchor{qXfer osdata read} | |
33368 | Access the target's @dfn{operating system information}. | |
33369 | @xref{Operating System Information}. | |
33370 | ||
68437a39 DJ |
33371 | @end table |
33372 | ||
0876f84a DJ |
33373 | Reply: |
33374 | @table @samp | |
33375 | @item m @var{data} | |
33376 | Data @var{data} (@pxref{Binary Data}) has been read from the | |
33377 | target. There may be more data at a higher address (although | |
33378 | it is permitted to return @samp{m} even for the last valid | |
33379 | block of data, as long as at least one byte of data was read). | |
33380 | @var{data} may have fewer bytes than the @var{length} in the | |
33381 | request. | |
33382 | ||
33383 | @item l @var{data} | |
33384 | Data @var{data} (@pxref{Binary Data}) has been read from the target. | |
33385 | There is no more data to be read. @var{data} may have fewer bytes | |
33386 | than the @var{length} in the request. | |
33387 | ||
33388 | @item l | |
33389 | The @var{offset} in the request is at the end of the data. | |
33390 | There is no more data to be read. | |
33391 | ||
33392 | @item E00 | |
33393 | The request was malformed, or @var{annex} was invalid. | |
33394 | ||
33395 | @item E @var{nn} | |
33396 | The offset was invalid, or there was an error encountered reading the data. | |
33397 | @var{nn} is a hex-encoded @code{errno} value. | |
33398 | ||
33399 | @item | |
33400 | An empty reply indicates the @var{object} string was not recognized by | |
33401 | the stub, or that the object does not support reading. | |
33402 | @end table | |
33403 | ||
33404 | @item qXfer:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{} | |
33405 | @cindex write data into object, remote request | |
4aa995e1 | 33406 | @anchor{qXfer write} |
0876f84a DJ |
33407 | Write uninterpreted bytes into the target's special data area |
33408 | identified by the keyword @var{object}, starting at @var{offset} bytes | |
0e7f50da | 33409 | into the data. @var{data}@dots{} is the binary-encoded data |
0876f84a | 33410 | (@pxref{Binary Data}) to be written. The content and encoding of @var{annex} |
0e7f50da | 33411 | is specific to @var{object}; it can supply additional details about what data |
0876f84a DJ |
33412 | to access. |
33413 | ||
0e7f50da UW |
33414 | Here are the specific requests of this form defined so far. All |
33415 | @samp{qXfer:@var{object}:write:@dots{}} requests use the same reply | |
33416 | formats, listed below. | |
33417 | ||
33418 | @table @samp | |
4aa995e1 PA |
33419 | @item qXfer:siginfo:write::@var{offset}:@var{data}@dots{} |
33420 | @anchor{qXfer siginfo write} | |
33421 | Write @var{data} to the extra signal information on the target system. | |
33422 | The annex part of the generic @samp{qXfer} packet must be | |
33423 | empty (@pxref{qXfer write}). | |
33424 | ||
33425 | This packet is not probed by default; the remote stub must request it, | |
33426 | by supplying an appropriate @samp{qSupported} response | |
33427 | (@pxref{qSupported}). | |
33428 | ||
84fcdf95 | 33429 | @item qXfer:spu:write:@var{annex}:@var{offset}:@var{data}@dots{} |
0e7f50da UW |
33430 | @anchor{qXfer spu write} |
33431 | Write @var{data} to an @code{spufs} file on the target system. The | |
33432 | annex specifies which file to write; it must be of the form | |
33433 | @file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID | |
33434 | in the target process, and @var{name} identifes the @code{spufs} file | |
33435 | in that context to be accessed. | |
33436 | ||
33437 | This packet is not probed by default; the remote stub must request it, | |
33438 | by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). | |
33439 | @end table | |
0876f84a DJ |
33440 | |
33441 | Reply: | |
33442 | @table @samp | |
33443 | @item @var{nn} | |
33444 | @var{nn} (hex encoded) is the number of bytes written. | |
33445 | This may be fewer bytes than supplied in the request. | |
33446 | ||
33447 | @item E00 | |
33448 | The request was malformed, or @var{annex} was invalid. | |
33449 | ||
33450 | @item E @var{nn} | |
33451 | The offset was invalid, or there was an error encountered writing the data. | |
33452 | @var{nn} is a hex-encoded @code{errno} value. | |
33453 | ||
33454 | @item | |
33455 | An empty reply indicates the @var{object} string was not | |
33456 | recognized by the stub, or that the object does not support writing. | |
33457 | @end table | |
33458 | ||
33459 | @item qXfer:@var{object}:@var{operation}:@dots{} | |
33460 | Requests of this form may be added in the future. When a stub does | |
33461 | not recognize the @var{object} keyword, or its support for | |
33462 | @var{object} does not recognize the @var{operation} keyword, the stub | |
33463 | must respond with an empty packet. | |
33464 | ||
0b16c5cf PA |
33465 | @item qAttached:@var{pid} |
33466 | @cindex query attached, remote request | |
33467 | @cindex @samp{qAttached} packet | |
33468 | Return an indication of whether the remote server attached to an | |
33469 | existing process or created a new process. When the multiprocess | |
33470 | protocol extensions are supported (@pxref{multiprocess extensions}), | |
33471 | @var{pid} is an integer in hexadecimal format identifying the target | |
33472 | process. Otherwise, @value{GDBN} will omit the @var{pid} field and | |
33473 | the query packet will be simplified as @samp{qAttached}. | |
33474 | ||
33475 | This query is used, for example, to know whether the remote process | |
33476 | should be detached or killed when a @value{GDBN} session is ended with | |
33477 | the @code{quit} command. | |
33478 | ||
33479 | Reply: | |
33480 | @table @samp | |
33481 | @item 1 | |
33482 | The remote server attached to an existing process. | |
33483 | @item 0 | |
33484 | The remote server created a new process. | |
33485 | @item E @var{NN} | |
33486 | A badly formed request or an error was encountered. | |
33487 | @end table | |
33488 | ||
ee2d5c50 AC |
33489 | @end table |
33490 | ||
a1dcb23a DJ |
33491 | @node Architecture-Specific Protocol Details |
33492 | @section Architecture-Specific Protocol Details | |
33493 | ||
33494 | This section describes how the remote protocol is applied to specific | |
33495 | target architectures. Also see @ref{Standard Target Features}, for | |
33496 | details of XML target descriptions for each architecture. | |
33497 | ||
33498 | @subsection ARM | |
33499 | ||
33500 | @subsubsection Breakpoint Kinds | |
33501 | ||
33502 | These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets. | |
33503 | ||
33504 | @table @r | |
33505 | ||
33506 | @item 2 | |
33507 | 16-bit Thumb mode breakpoint. | |
33508 | ||
33509 | @item 3 | |
33510 | 32-bit Thumb mode (Thumb-2) breakpoint. | |
33511 | ||
33512 | @item 4 | |
33513 | 32-bit ARM mode breakpoint. | |
33514 | ||
33515 | @end table | |
33516 | ||
33517 | @subsection MIPS | |
33518 | ||
33519 | @subsubsection Register Packet Format | |
eb12ee30 | 33520 | |
b8ff78ce | 33521 | The following @code{g}/@code{G} packets have previously been defined. |
ee2d5c50 AC |
33522 | In the below, some thirty-two bit registers are transferred as |
33523 | sixty-four bits. Those registers should be zero/sign extended (which?) | |
599b237a BW |
33524 | to fill the space allocated. Register bytes are transferred in target |
33525 | byte order. The two nibbles within a register byte are transferred | |
ee2d5c50 | 33526 | most-significant - least-significant. |
eb12ee30 | 33527 | |
ee2d5c50 | 33528 | @table @r |
eb12ee30 | 33529 | |
8e04817f | 33530 | @item MIPS32 |
ee2d5c50 | 33531 | |
599b237a | 33532 | All registers are transferred as thirty-two bit quantities in the order: |
8e04817f AC |
33533 | 32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point |
33534 | registers; fsr; fir; fp. | |
eb12ee30 | 33535 | |
8e04817f | 33536 | @item MIPS64 |
ee2d5c50 | 33537 | |
599b237a | 33538 | All registers are transferred as sixty-four bit quantities (including |
8e04817f AC |
33539 | thirty-two bit registers such as @code{sr}). The ordering is the same |
33540 | as @code{MIPS32}. | |
eb12ee30 | 33541 | |
ee2d5c50 AC |
33542 | @end table |
33543 | ||
9d29849a JB |
33544 | @node Tracepoint Packets |
33545 | @section Tracepoint Packets | |
33546 | @cindex tracepoint packets | |
33547 | @cindex packets, tracepoint | |
33548 | ||
33549 | Here we describe the packets @value{GDBN} uses to implement | |
33550 | tracepoints (@pxref{Tracepoints}). | |
33551 | ||
33552 | @table @samp | |
33553 | ||
7a697b8d | 33554 | @item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}[:F@var{flen}][:X@var{len},@var{bytes}]@r{[}-@r{]} |
9d29849a JB |
33555 | Create a new tracepoint, number @var{n}, at @var{addr}. If @var{ena} |
33556 | is @samp{E}, then the tracepoint is enabled; if it is @samp{D}, then | |
33557 | the tracepoint is disabled. @var{step} is the tracepoint's step | |
7a697b8d SS |
33558 | count, and @var{pass} is its pass count. If an @samp{F} is present, |
33559 | then the tracepoint is to be a fast tracepoint, and the @var{flen} is | |
33560 | the number of bytes that the target should copy elsewhere to make room | |
33561 | for the tracepoint. If an @samp{X} is present, it introduces a | |
33562 | tracepoint condition, which consists of a hexadecimal length, followed | |
33563 | by a comma and hex-encoded bytes, in a manner similar to action | |
33564 | encodings as described below. If the trailing @samp{-} is present, | |
33565 | further @samp{QTDP} packets will follow to specify this tracepoint's | |
33566 | actions. | |
9d29849a JB |
33567 | |
33568 | Replies: | |
33569 | @table @samp | |
33570 | @item OK | |
33571 | The packet was understood and carried out. | |
dde08ee1 PA |
33572 | @item qRelocInsn |
33573 | @xref{Tracepoint Packets,,Relocate instruction reply packet}. | |
9d29849a JB |
33574 | @item |
33575 | The packet was not recognized. | |
33576 | @end table | |
33577 | ||
33578 | @item QTDP:-@var{n}:@var{addr}:@r{[}S@r{]}@var{action}@dots{}@r{[}-@r{]} | |
33579 | Define actions to be taken when a tracepoint is hit. @var{n} and | |
33580 | @var{addr} must be the same as in the initial @samp{QTDP} packet for | |
33581 | this tracepoint. This packet may only be sent immediately after | |
33582 | another @samp{QTDP} packet that ended with a @samp{-}. If the | |
33583 | trailing @samp{-} is present, further @samp{QTDP} packets will follow, | |
33584 | specifying more actions for this tracepoint. | |
33585 | ||
33586 | In the series of action packets for a given tracepoint, at most one | |
33587 | can have an @samp{S} before its first @var{action}. If such a packet | |
33588 | is sent, it and the following packets define ``while-stepping'' | |
33589 | actions. Any prior packets define ordinary actions --- that is, those | |
33590 | taken when the tracepoint is first hit. If no action packet has an | |
33591 | @samp{S}, then all the packets in the series specify ordinary | |
33592 | tracepoint actions. | |
33593 | ||
33594 | The @samp{@var{action}@dots{}} portion of the packet is a series of | |
33595 | actions, concatenated without separators. Each action has one of the | |
33596 | following forms: | |
33597 | ||
33598 | @table @samp | |
33599 | ||
33600 | @item R @var{mask} | |
33601 | Collect the registers whose bits are set in @var{mask}. @var{mask} is | |
599b237a | 33602 | a hexadecimal number whose @var{i}'th bit is set if register number |
9d29849a JB |
33603 | @var{i} should be collected. (The least significant bit is numbered |
33604 | zero.) Note that @var{mask} may be any number of digits long; it may | |
33605 | not fit in a 32-bit word. | |
33606 | ||
33607 | @item M @var{basereg},@var{offset},@var{len} | |
33608 | Collect @var{len} bytes of memory starting at the address in register | |
33609 | number @var{basereg}, plus @var{offset}. If @var{basereg} is | |
33610 | @samp{-1}, then the range has a fixed address: @var{offset} is the | |
33611 | address of the lowest byte to collect. The @var{basereg}, | |
599b237a | 33612 | @var{offset}, and @var{len} parameters are all unsigned hexadecimal |
9d29849a JB |
33613 | values (the @samp{-1} value for @var{basereg} is a special case). |
33614 | ||
33615 | @item X @var{len},@var{expr} | |
33616 | Evaluate @var{expr}, whose length is @var{len}, and collect memory as | |
33617 | it directs. @var{expr} is an agent expression, as described in | |
33618 | @ref{Agent Expressions}. Each byte of the expression is encoded as a | |
33619 | two-digit hex number in the packet; @var{len} is the number of bytes | |
33620 | in the expression (and thus one-half the number of hex digits in the | |
33621 | packet). | |
33622 | ||
33623 | @end table | |
33624 | ||
33625 | Any number of actions may be packed together in a single @samp{QTDP} | |
33626 | packet, as long as the packet does not exceed the maximum packet | |
c1947b85 JB |
33627 | length (400 bytes, for many stubs). There may be only one @samp{R} |
33628 | action per tracepoint, and it must precede any @samp{M} or @samp{X} | |
33629 | actions. Any registers referred to by @samp{M} and @samp{X} actions | |
33630 | must be collected by a preceding @samp{R} action. (The | |
33631 | ``while-stepping'' actions are treated as if they were attached to a | |
33632 | separate tracepoint, as far as these restrictions are concerned.) | |
9d29849a JB |
33633 | |
33634 | Replies: | |
33635 | @table @samp | |
33636 | @item OK | |
33637 | The packet was understood and carried out. | |
dde08ee1 PA |
33638 | @item qRelocInsn |
33639 | @xref{Tracepoint Packets,,Relocate instruction reply packet}. | |
9d29849a JB |
33640 | @item |
33641 | The packet was not recognized. | |
33642 | @end table | |
33643 | ||
409873ef SS |
33644 | @item QTDPsrc:@var{n}:@var{addr}:@var{type}:@var{start}:@var{slen}:@var{bytes} |
33645 | @cindex @samp{QTDPsrc} packet | |
33646 | Specify a source string of tracepoint @var{n} at address @var{addr}. | |
33647 | This is useful to get accurate reproduction of the tracepoints | |
33648 | originally downloaded at the beginning of the trace run. @var{type} | |
33649 | is the name of the tracepoint part, such as @samp{cond} for the | |
33650 | tracepoint's conditional expression (see below for a list of types), while | |
33651 | @var{bytes} is the string, encoded in hexadecimal. | |
33652 | ||
33653 | @var{start} is the offset of the @var{bytes} within the overall source | |
33654 | string, while @var{slen} is the total length of the source string. | |
33655 | This is intended for handling source strings that are longer than will | |
33656 | fit in a single packet. | |
33657 | @c Add detailed example when this info is moved into a dedicated | |
33658 | @c tracepoint descriptions section. | |
33659 | ||
33660 | The available string types are @samp{at} for the location, | |
33661 | @samp{cond} for the conditional, and @samp{cmd} for an action command. | |
33662 | @value{GDBN} sends a separate packet for each command in the action | |
33663 | list, in the same order in which the commands are stored in the list. | |
33664 | ||
33665 | The target does not need to do anything with source strings except | |
33666 | report them back as part of the replies to the @samp{qTfP}/@samp{qTsP} | |
33667 | query packets. | |
33668 | ||
33669 | Although this packet is optional, and @value{GDBN} will only send it | |
33670 | if the target replies with @samp{TracepointSource} @xref{General | |
33671 | Query Packets}, it makes both disconnected tracing and trace files | |
33672 | much easier to use. Otherwise the user must be careful that the | |
33673 | tracepoints in effect while looking at trace frames are identical to | |
33674 | the ones in effect during the trace run; even a small discrepancy | |
33675 | could cause @samp{tdump} not to work, or a particular trace frame not | |
33676 | be found. | |
33677 | ||
f61e138d SS |
33678 | @item QTDV:@var{n}:@var{value} |
33679 | @cindex define trace state variable, remote request | |
33680 | @cindex @samp{QTDV} packet | |
33681 | Create a new trace state variable, number @var{n}, with an initial | |
33682 | value of @var{value}, which is a 64-bit signed integer. Both @var{n} | |
33683 | and @var{value} are encoded as hexadecimal values. @value{GDBN} has | |
33684 | the option of not using this packet for initial values of zero; the | |
33685 | target should simply create the trace state variables as they are | |
33686 | mentioned in expressions. | |
33687 | ||
9d29849a JB |
33688 | @item QTFrame:@var{n} |
33689 | Select the @var{n}'th tracepoint frame from the buffer, and use the | |
33690 | register and memory contents recorded there to answer subsequent | |
33691 | request packets from @value{GDBN}. | |
33692 | ||
33693 | A successful reply from the stub indicates that the stub has found the | |
33694 | requested frame. The response is a series of parts, concatenated | |
33695 | without separators, describing the frame we selected. Each part has | |
33696 | one of the following forms: | |
33697 | ||
33698 | @table @samp | |
33699 | @item F @var{f} | |
33700 | The selected frame is number @var{n} in the trace frame buffer; | |
599b237a | 33701 | @var{f} is a hexadecimal number. If @var{f} is @samp{-1}, then there |
9d29849a JB |
33702 | was no frame matching the criteria in the request packet. |
33703 | ||
33704 | @item T @var{t} | |
33705 | The selected trace frame records a hit of tracepoint number @var{t}; | |
599b237a | 33706 | @var{t} is a hexadecimal number. |
9d29849a JB |
33707 | |
33708 | @end table | |
33709 | ||
33710 | @item QTFrame:pc:@var{addr} | |
33711 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
33712 | currently selected frame whose PC is @var{addr}; | |
599b237a | 33713 | @var{addr} is a hexadecimal number. |
9d29849a JB |
33714 | |
33715 | @item QTFrame:tdp:@var{t} | |
33716 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
33717 | currently selected frame that is a hit of tracepoint @var{t}; @var{t} | |
599b237a | 33718 | is a hexadecimal number. |
9d29849a JB |
33719 | |
33720 | @item QTFrame:range:@var{start}:@var{end} | |
33721 | Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the | |
33722 | currently selected frame whose PC is between @var{start} (inclusive) | |
081dfbf7 | 33723 | and @var{end} (inclusive); @var{start} and @var{end} are hexadecimal |
9d29849a JB |
33724 | numbers. |
33725 | ||
33726 | @item QTFrame:outside:@var{start}:@var{end} | |
33727 | Like @samp{QTFrame:range:@var{start}:@var{end}}, but select the first | |
081dfbf7 | 33728 | frame @emph{outside} the given range of addresses (exclusive). |
9d29849a JB |
33729 | |
33730 | @item QTStart | |
dde08ee1 PA |
33731 | Begin the tracepoint experiment. Begin collecting data from |
33732 | tracepoint hits in the trace frame buffer. This packet supports the | |
33733 | @samp{qRelocInsn} reply (@pxref{Tracepoint Packets,,Relocate | |
33734 | instruction reply packet}). | |
9d29849a JB |
33735 | |
33736 | @item QTStop | |
33737 | End the tracepoint experiment. Stop collecting trace frames. | |
33738 | ||
33739 | @item QTinit | |
33740 | Clear the table of tracepoints, and empty the trace frame buffer. | |
33741 | ||
33742 | @item QTro:@var{start1},@var{end1}:@var{start2},@var{end2}:@dots{} | |
33743 | Establish the given ranges of memory as ``transparent''. The stub | |
33744 | will answer requests for these ranges from memory's current contents, | |
33745 | if they were not collected as part of the tracepoint hit. | |
33746 | ||
33747 | @value{GDBN} uses this to mark read-only regions of memory, like those | |
33748 | containing program code. Since these areas never change, they should | |
33749 | still have the same contents they did when the tracepoint was hit, so | |
33750 | there's no reason for the stub to refuse to provide their contents. | |
33751 | ||
d5551862 SS |
33752 | @item QTDisconnected:@var{value} |
33753 | Set the choice to what to do with the tracing run when @value{GDBN} | |
33754 | disconnects from the target. A @var{value} of 1 directs the target to | |
33755 | continue the tracing run, while 0 tells the target to stop tracing if | |
33756 | @value{GDBN} is no longer in the picture. | |
33757 | ||
9d29849a JB |
33758 | @item qTStatus |
33759 | Ask the stub if there is a trace experiment running right now. | |
33760 | ||
4daf5ac0 SS |
33761 | The reply has the form: |
33762 | ||
33763 | @table @samp | |
33764 | ||
33765 | @item T@var{running}@r{[};@var{field}@r{]}@dots{} | |
33766 | @var{running} is a single digit @code{1} if the trace is presently | |
33767 | running, or @code{0} if not. It is followed by semicolon-separated | |
33768 | optional fields that an agent may use to report additional status. | |
33769 | ||
33770 | @end table | |
33771 | ||
33772 | If the trace is not running, the agent may report any of several | |
33773 | explanations as one of the optional fields: | |
33774 | ||
33775 | @table @samp | |
33776 | ||
33777 | @item tnotrun:0 | |
33778 | No trace has been run yet. | |
33779 | ||
33780 | @item tstop:0 | |
33781 | The trace was stopped by a user-originated stop command. | |
33782 | ||
33783 | @item tfull:0 | |
33784 | The trace stopped because the trace buffer filled up. | |
33785 | ||
33786 | @item tdisconnected:0 | |
33787 | The trace stopped because @value{GDBN} disconnected from the target. | |
33788 | ||
33789 | @item tpasscount:@var{tpnum} | |
33790 | The trace stopped because tracepoint @var{tpnum} exceeded its pass count. | |
33791 | ||
6c28cbf2 SS |
33792 | @item terror:@var{text}:@var{tpnum} |
33793 | The trace stopped because tracepoint @var{tpnum} had an error. The | |
33794 | string @var{text} is available to describe the nature of the error | |
33795 | (for instance, a divide by zero in the condition expression). | |
99b5e152 | 33796 | @var{text} is hex encoded. |
6c28cbf2 | 33797 | |
4daf5ac0 SS |
33798 | @item tunknown:0 |
33799 | The trace stopped for some other reason. | |
33800 | ||
33801 | @end table | |
33802 | ||
33da3f1c SS |
33803 | Additional optional fields supply statistical and other information. |
33804 | Although not required, they are extremely useful for users monitoring | |
33805 | the progress of a trace run. If a trace has stopped, and these | |
33806 | numbers are reported, they must reflect the state of the just-stopped | |
33807 | trace. | |
4daf5ac0 | 33808 | |
9d29849a | 33809 | @table @samp |
4daf5ac0 SS |
33810 | |
33811 | @item tframes:@var{n} | |
33812 | The number of trace frames in the buffer. | |
33813 | ||
33814 | @item tcreated:@var{n} | |
33815 | The total number of trace frames created during the run. This may | |
33816 | be larger than the trace frame count, if the buffer is circular. | |
33817 | ||
33818 | @item tsize:@var{n} | |
33819 | The total size of the trace buffer, in bytes. | |
33820 | ||
33821 | @item tfree:@var{n} | |
33822 | The number of bytes still unused in the buffer. | |
33823 | ||
33da3f1c SS |
33824 | @item circular:@var{n} |
33825 | The value of the circular trace buffer flag. @code{1} means that the | |
33826 | trace buffer is circular and old trace frames will be discarded if | |
33827 | necessary to make room, @code{0} means that the trace buffer is linear | |
33828 | and may fill up. | |
33829 | ||
33830 | @item disconn:@var{n} | |
33831 | The value of the disconnected tracing flag. @code{1} means that | |
33832 | tracing will continue after @value{GDBN} disconnects, @code{0} means | |
33833 | that the trace run will stop. | |
33834 | ||
9d29849a JB |
33835 | @end table |
33836 | ||
f61e138d SS |
33837 | @item qTV:@var{var} |
33838 | @cindex trace state variable value, remote request | |
33839 | @cindex @samp{qTV} packet | |
33840 | Ask the stub for the value of the trace state variable number @var{var}. | |
33841 | ||
33842 | Replies: | |
33843 | @table @samp | |
33844 | @item V@var{value} | |
33845 | The value of the variable is @var{value}. This will be the current | |
33846 | value of the variable if the user is examining a running target, or a | |
33847 | saved value if the variable was collected in the trace frame that the | |
33848 | user is looking at. Note that multiple requests may result in | |
33849 | different reply values, such as when requesting values while the | |
33850 | program is running. | |
33851 | ||
33852 | @item U | |
33853 | The value of the variable is unknown. This would occur, for example, | |
33854 | if the user is examining a trace frame in which the requested variable | |
33855 | was not collected. | |
9d29849a JB |
33856 | @end table |
33857 | ||
d5551862 SS |
33858 | @item qTfP |
33859 | @itemx qTsP | |
33860 | These packets request data about tracepoints that are being used by | |
33861 | the target. @value{GDBN} sends @code{qTfP} to get the first piece | |
33862 | of data, and multiple @code{qTsP} to get additional pieces. Replies | |
33863 | to these packets generally take the form of the @code{QTDP} packets | |
33864 | that define tracepoints. (FIXME add detailed syntax) | |
33865 | ||
00bf0b85 SS |
33866 | @item qTfV |
33867 | @itemx qTsV | |
33868 | These packets request data about trace state variables that are on the | |
33869 | target. @value{GDBN} sends @code{qTfV} to get the first vari of data, | |
33870 | and multiple @code{qTsV} to get additional variables. Replies to | |
33871 | these packets follow the syntax of the @code{QTDV} packets that define | |
33872 | trace state variables. | |
33873 | ||
0fb4aa4b PA |
33874 | @item qTfSTM |
33875 | @itemx qTsSTM | |
33876 | These packets request data about static tracepoint markers that exist | |
33877 | in the target program. @value{GDBN} sends @code{qTfSTM} to get the | |
33878 | first piece of data, and multiple @code{qTsSTM} to get additional | |
33879 | pieces. Replies to these packets take the following form: | |
33880 | ||
33881 | Reply: | |
33882 | @table @samp | |
33883 | @item m @var{address}:@var{id}:@var{extra} | |
33884 | A single marker | |
33885 | @item m @var{address}:@var{id}:@var{extra},@var{address}:@var{id}:@var{extra}@dots{} | |
33886 | a comma-separated list of markers | |
33887 | @item l | |
33888 | (lower case letter @samp{L}) denotes end of list. | |
33889 | @item E @var{nn} | |
33890 | An error occurred. @var{nn} are hex digits. | |
33891 | @item | |
33892 | An empty reply indicates that the request is not supported by the | |
33893 | stub. | |
33894 | @end table | |
33895 | ||
33896 | @var{address} is encoded in hex. | |
33897 | @var{id} and @var{extra} are strings encoded in hex. | |
33898 | ||
33899 | In response to each query, the target will reply with a list of one or | |
33900 | more markers, separated by commas. @value{GDBN} will respond to each | |
33901 | reply with a request for more markers (using the @samp{qs} form of the | |
33902 | query), until the target responds with @samp{l} (lower-case ell, for | |
33903 | @dfn{last}). | |
33904 | ||
33905 | @item qTSTMat:@var{address} | |
33906 | This packets requests data about static tracepoint markers in the | |
33907 | target program at @var{address}. Replies to this packet follow the | |
33908 | syntax of the @samp{qTfSTM} and @code{qTsSTM} packets that list static | |
33909 | tracepoint markers. | |
33910 | ||
00bf0b85 SS |
33911 | @item QTSave:@var{filename} |
33912 | This packet directs the target to save trace data to the file name | |
33913 | @var{filename} in the target's filesystem. @var{filename} is encoded | |
33914 | as a hex string; the interpretation of the file name (relative vs | |
33915 | absolute, wild cards, etc) is up to the target. | |
33916 | ||
33917 | @item qTBuffer:@var{offset},@var{len} | |
33918 | Return up to @var{len} bytes of the current contents of trace buffer, | |
33919 | starting at @var{offset}. The trace buffer is treated as if it were | |
33920 | a contiguous collection of traceframes, as per the trace file format. | |
33921 | The reply consists as many hex-encoded bytes as the target can deliver | |
33922 | in a packet; it is not an error to return fewer than were asked for. | |
33923 | A reply consisting of just @code{l} indicates that no bytes are | |
33924 | available. | |
33925 | ||
4daf5ac0 SS |
33926 | @item QTBuffer:circular:@var{value} |
33927 | This packet directs the target to use a circular trace buffer if | |
33928 | @var{value} is 1, or a linear buffer if the value is 0. | |
33929 | ||
f61e138d | 33930 | @end table |
9d29849a | 33931 | |
dde08ee1 PA |
33932 | @subsection Relocate instruction reply packet |
33933 | When installing fast tracepoints in memory, the target may need to | |
33934 | relocate the instruction currently at the tracepoint address to a | |
33935 | different address in memory. For most instructions, a simple copy is | |
33936 | enough, but, for example, call instructions that implicitly push the | |
33937 | return address on the stack, and relative branches or other | |
33938 | PC-relative instructions require offset adjustment, so that the effect | |
33939 | of executing the instruction at a different address is the same as if | |
33940 | it had executed in the original location. | |
33941 | ||
33942 | In response to several of the tracepoint packets, the target may also | |
33943 | respond with a number of intermediate @samp{qRelocInsn} request | |
33944 | packets before the final result packet, to have @value{GDBN} handle | |
33945 | this relocation operation. If a packet supports this mechanism, its | |
33946 | documentation will explicitly say so. See for example the above | |
33947 | descriptions for the @samp{QTStart} and @samp{QTDP} packets. The | |
33948 | format of the request is: | |
33949 | ||
33950 | @table @samp | |
33951 | @item qRelocInsn:@var{from};@var{to} | |
33952 | ||
33953 | This requests @value{GDBN} to copy instruction at address @var{from} | |
33954 | to address @var{to}, possibly adjusted so that executing the | |
33955 | instruction at @var{to} has the same effect as executing it at | |
33956 | @var{from}. @value{GDBN} writes the adjusted instruction to target | |
33957 | memory starting at @var{to}. | |
33958 | @end table | |
33959 | ||
33960 | Replies: | |
33961 | @table @samp | |
33962 | @item qRelocInsn:@var{adjusted_size} | |
33963 | Informs the stub the relocation is complete. @var{adjusted_size} is | |
33964 | the length in bytes of resulting relocated instruction sequence. | |
33965 | @item E @var{NN} | |
33966 | A badly formed request was detected, or an error was encountered while | |
33967 | relocating the instruction. | |
33968 | @end table | |
33969 | ||
a6b151f1 DJ |
33970 | @node Host I/O Packets |
33971 | @section Host I/O Packets | |
33972 | @cindex Host I/O, remote protocol | |
33973 | @cindex file transfer, remote protocol | |
33974 | ||
33975 | The @dfn{Host I/O} packets allow @value{GDBN} to perform I/O | |
33976 | operations on the far side of a remote link. For example, Host I/O is | |
33977 | used to upload and download files to a remote target with its own | |
33978 | filesystem. Host I/O uses the same constant values and data structure | |
33979 | layout as the target-initiated File-I/O protocol. However, the | |
33980 | Host I/O packets are structured differently. The target-initiated | |
33981 | protocol relies on target memory to store parameters and buffers. | |
33982 | Host I/O requests are initiated by @value{GDBN}, and the | |
33983 | target's memory is not involved. @xref{File-I/O Remote Protocol | |
33984 | Extension}, for more details on the target-initiated protocol. | |
33985 | ||
33986 | The Host I/O request packets all encode a single operation along with | |
33987 | its arguments. They have this format: | |
33988 | ||
33989 | @table @samp | |
33990 | ||
33991 | @item vFile:@var{operation}: @var{parameter}@dots{} | |
33992 | @var{operation} is the name of the particular request; the target | |
33993 | should compare the entire packet name up to the second colon when checking | |
33994 | for a supported operation. The format of @var{parameter} depends on | |
33995 | the operation. Numbers are always passed in hexadecimal. Negative | |
33996 | numbers have an explicit minus sign (i.e.@: two's complement is not | |
33997 | used). Strings (e.g.@: filenames) are encoded as a series of | |
33998 | hexadecimal bytes. The last argument to a system call may be a | |
33999 | buffer of escaped binary data (@pxref{Binary Data}). | |
34000 | ||
34001 | @end table | |
34002 | ||
34003 | The valid responses to Host I/O packets are: | |
34004 | ||
34005 | @table @samp | |
34006 | ||
34007 | @item F @var{result} [, @var{errno}] [; @var{attachment}] | |
34008 | @var{result} is the integer value returned by this operation, usually | |
34009 | non-negative for success and -1 for errors. If an error has occured, | |
34010 | @var{errno} will be included in the result. @var{errno} will have a | |
34011 | value defined by the File-I/O protocol (@pxref{Errno Values}). For | |
34012 | operations which return data, @var{attachment} supplies the data as a | |
34013 | binary buffer. Binary buffers in response packets are escaped in the | |
34014 | normal way (@pxref{Binary Data}). See the individual packet | |
34015 | documentation for the interpretation of @var{result} and | |
34016 | @var{attachment}. | |
34017 | ||
34018 | @item | |
34019 | An empty response indicates that this operation is not recognized. | |
34020 | ||
34021 | @end table | |
34022 | ||
34023 | These are the supported Host I/O operations: | |
34024 | ||
34025 | @table @samp | |
34026 | @item vFile:open: @var{pathname}, @var{flags}, @var{mode} | |
34027 | Open a file at @var{pathname} and return a file descriptor for it, or | |
34028 | return -1 if an error occurs. @var{pathname} is a string, | |
34029 | @var{flags} is an integer indicating a mask of open flags | |
34030 | (@pxref{Open Flags}), and @var{mode} is an integer indicating a mask | |
34031 | of mode bits to use if the file is created (@pxref{mode_t Values}). | |
c1c25a1a | 34032 | @xref{open}, for details of the open flags and mode values. |
a6b151f1 DJ |
34033 | |
34034 | @item vFile:close: @var{fd} | |
34035 | Close the open file corresponding to @var{fd} and return 0, or | |
34036 | -1 if an error occurs. | |
34037 | ||
34038 | @item vFile:pread: @var{fd}, @var{count}, @var{offset} | |
34039 | Read data from the open file corresponding to @var{fd}. Up to | |
34040 | @var{count} bytes will be read from the file, starting at @var{offset} | |
34041 | relative to the start of the file. The target may read fewer bytes; | |
34042 | common reasons include packet size limits and an end-of-file | |
34043 | condition. The number of bytes read is returned. Zero should only be | |
34044 | returned for a successful read at the end of the file, or if | |
34045 | @var{count} was zero. | |
34046 | ||
34047 | The data read should be returned as a binary attachment on success. | |
34048 | If zero bytes were read, the response should include an empty binary | |
34049 | attachment (i.e.@: a trailing semicolon). The return value is the | |
34050 | number of target bytes read; the binary attachment may be longer if | |
34051 | some characters were escaped. | |
34052 | ||
34053 | @item vFile:pwrite: @var{fd}, @var{offset}, @var{data} | |
34054 | Write @var{data} (a binary buffer) to the open file corresponding | |
34055 | to @var{fd}. Start the write at @var{offset} from the start of the | |
34056 | file. Unlike many @code{write} system calls, there is no | |
34057 | separate @var{count} argument; the length of @var{data} in the | |
34058 | packet is used. @samp{vFile:write} returns the number of bytes written, | |
34059 | which may be shorter than the length of @var{data}, or -1 if an | |
34060 | error occurred. | |
34061 | ||
34062 | @item vFile:unlink: @var{pathname} | |
34063 | Delete the file at @var{pathname} on the target. Return 0, | |
34064 | or -1 if an error occurs. @var{pathname} is a string. | |
34065 | ||
34066 | @end table | |
34067 | ||
9a6253be KB |
34068 | @node Interrupts |
34069 | @section Interrupts | |
34070 | @cindex interrupts (remote protocol) | |
34071 | ||
34072 | When a program on the remote target is running, @value{GDBN} may | |
9a7071a8 JB |
34073 | attempt to interrupt it by sending a @samp{Ctrl-C}, @code{BREAK} or |
34074 | a @code{BREAK} followed by @code{g}, | |
34075 | control of which is specified via @value{GDBN}'s @samp{interrupt-sequence}. | |
9a6253be KB |
34076 | |
34077 | The precise meaning of @code{BREAK} is defined by the transport | |
8775bb90 MS |
34078 | mechanism and may, in fact, be undefined. @value{GDBN} does not |
34079 | currently define a @code{BREAK} mechanism for any of the network | |
34080 | interfaces except for TCP, in which case @value{GDBN} sends the | |
34081 | @code{telnet} BREAK sequence. | |
9a6253be KB |
34082 | |
34083 | @samp{Ctrl-C}, on the other hand, is defined and implemented for all | |
34084 | transport mechanisms. It is represented by sending the single byte | |
34085 | @code{0x03} without any of the usual packet overhead described in | |
34086 | the Overview section (@pxref{Overview}). When a @code{0x03} byte is | |
34087 | transmitted as part of a packet, it is considered to be packet data | |
34088 | and does @emph{not} represent an interrupt. E.g., an @samp{X} packet | |
0876f84a | 34089 | (@pxref{X packet}), used for binary downloads, may include an unescaped |
9a6253be KB |
34090 | @code{0x03} as part of its packet. |
34091 | ||
9a7071a8 JB |
34092 | @code{BREAK} followed by @code{g} is also known as Magic SysRq g. |
34093 | When Linux kernel receives this sequence from serial port, | |
34094 | it stops execution and connects to gdb. | |
34095 | ||
9a6253be KB |
34096 | Stubs are not required to recognize these interrupt mechanisms and the |
34097 | precise meaning associated with receipt of the interrupt is | |
8b23ecc4 SL |
34098 | implementation defined. If the target supports debugging of multiple |
34099 | threads and/or processes, it should attempt to interrupt all | |
34100 | currently-executing threads and processes. | |
34101 | If the stub is successful at interrupting the | |
34102 | running program, it should send one of the stop | |
34103 | reply packets (@pxref{Stop Reply Packets}) to @value{GDBN} as a result | |
34104 | of successfully stopping the program in all-stop mode, and a stop reply | |
34105 | for each stopped thread in non-stop mode. | |
34106 | Interrupts received while the | |
34107 | program is stopped are discarded. | |
34108 | ||
34109 | @node Notification Packets | |
34110 | @section Notification Packets | |
34111 | @cindex notification packets | |
34112 | @cindex packets, notification | |
34113 | ||
34114 | The @value{GDBN} remote serial protocol includes @dfn{notifications}, | |
34115 | packets that require no acknowledgment. Both the GDB and the stub | |
34116 | may send notifications (although the only notifications defined at | |
34117 | present are sent by the stub). Notifications carry information | |
34118 | without incurring the round-trip latency of an acknowledgment, and so | |
34119 | are useful for low-impact communications where occasional packet loss | |
34120 | is not a problem. | |
34121 | ||
34122 | A notification packet has the form @samp{% @var{data} # | |
34123 | @var{checksum}}, where @var{data} is the content of the notification, | |
34124 | and @var{checksum} is a checksum of @var{data}, computed and formatted | |
34125 | as for ordinary @value{GDBN} packets. A notification's @var{data} | |
34126 | never contains @samp{$}, @samp{%} or @samp{#} characters. Upon | |
34127 | receiving a notification, the recipient sends no @samp{+} or @samp{-} | |
34128 | to acknowledge the notification's receipt or to report its corruption. | |
34129 | ||
34130 | Every notification's @var{data} begins with a name, which contains no | |
34131 | colon characters, followed by a colon character. | |
34132 | ||
34133 | Recipients should silently ignore corrupted notifications and | |
34134 | notifications they do not understand. Recipients should restart | |
34135 | timeout periods on receipt of a well-formed notification, whether or | |
34136 | not they understand it. | |
34137 | ||
34138 | Senders should only send the notifications described here when this | |
34139 | protocol description specifies that they are permitted. In the | |
34140 | future, we may extend the protocol to permit existing notifications in | |
34141 | new contexts; this rule helps older senders avoid confusing newer | |
34142 | recipients. | |
34143 | ||
34144 | (Older versions of @value{GDBN} ignore bytes received until they see | |
34145 | the @samp{$} byte that begins an ordinary packet, so new stubs may | |
34146 | transmit notifications without fear of confusing older clients. There | |
34147 | are no notifications defined for @value{GDBN} to send at the moment, but we | |
34148 | assume that most older stubs would ignore them, as well.) | |
34149 | ||
34150 | The following notification packets from the stub to @value{GDBN} are | |
34151 | defined: | |
34152 | ||
34153 | @table @samp | |
34154 | @item Stop: @var{reply} | |
34155 | Report an asynchronous stop event in non-stop mode. | |
34156 | The @var{reply} has the form of a stop reply, as | |
34157 | described in @ref{Stop Reply Packets}. Refer to @ref{Remote Non-Stop}, | |
34158 | for information on how these notifications are acknowledged by | |
34159 | @value{GDBN}. | |
34160 | @end table | |
34161 | ||
34162 | @node Remote Non-Stop | |
34163 | @section Remote Protocol Support for Non-Stop Mode | |
34164 | ||
34165 | @value{GDBN}'s remote protocol supports non-stop debugging of | |
34166 | multi-threaded programs, as described in @ref{Non-Stop Mode}. If the stub | |
34167 | supports non-stop mode, it should report that to @value{GDBN} by including | |
34168 | @samp{QNonStop+} in its @samp{qSupported} response (@pxref{qSupported}). | |
34169 | ||
34170 | @value{GDBN} typically sends a @samp{QNonStop} packet only when | |
34171 | establishing a new connection with the stub. Entering non-stop mode | |
34172 | does not alter the state of any currently-running threads, but targets | |
34173 | must stop all threads in any already-attached processes when entering | |
34174 | all-stop mode. @value{GDBN} uses the @samp{?} packet as necessary to | |
34175 | probe the target state after a mode change. | |
34176 | ||
34177 | In non-stop mode, when an attached process encounters an event that | |
34178 | would otherwise be reported with a stop reply, it uses the | |
34179 | asynchronous notification mechanism (@pxref{Notification Packets}) to | |
34180 | inform @value{GDBN}. In contrast to all-stop mode, where all threads | |
34181 | in all processes are stopped when a stop reply is sent, in non-stop | |
34182 | mode only the thread reporting the stop event is stopped. That is, | |
34183 | when reporting a @samp{S} or @samp{T} response to indicate completion | |
34184 | of a step operation, hitting a breakpoint, or a fault, only the | |
34185 | affected thread is stopped; any other still-running threads continue | |
34186 | to run. When reporting a @samp{W} or @samp{X} response, all running | |
34187 | threads belonging to other attached processes continue to run. | |
34188 | ||
34189 | Only one stop reply notification at a time may be pending; if | |
34190 | additional stop events occur before @value{GDBN} has acknowledged the | |
34191 | previous notification, they must be queued by the stub for later | |
34192 | synchronous transmission in response to @samp{vStopped} packets from | |
34193 | @value{GDBN}. Because the notification mechanism is unreliable, | |
34194 | the stub is permitted to resend a stop reply notification | |
34195 | if it believes @value{GDBN} may not have received it. @value{GDBN} | |
34196 | ignores additional stop reply notifications received before it has | |
34197 | finished processing a previous notification and the stub has completed | |
34198 | sending any queued stop events. | |
34199 | ||
34200 | Otherwise, @value{GDBN} must be prepared to receive a stop reply | |
34201 | notification at any time. Specifically, they may appear when | |
34202 | @value{GDBN} is not otherwise reading input from the stub, or when | |
34203 | @value{GDBN} is expecting to read a normal synchronous response or a | |
34204 | @samp{+}/@samp{-} acknowledgment to a packet it has sent. | |
34205 | Notification packets are distinct from any other communication from | |
34206 | the stub so there is no ambiguity. | |
34207 | ||
34208 | After receiving a stop reply notification, @value{GDBN} shall | |
34209 | acknowledge it by sending a @samp{vStopped} packet (@pxref{vStopped packet}) | |
34210 | as a regular, synchronous request to the stub. Such acknowledgment | |
34211 | is not required to happen immediately, as @value{GDBN} is permitted to | |
34212 | send other, unrelated packets to the stub first, which the stub should | |
34213 | process normally. | |
34214 | ||
34215 | Upon receiving a @samp{vStopped} packet, if the stub has other queued | |
34216 | stop events to report to @value{GDBN}, it shall respond by sending a | |
34217 | normal stop reply response. @value{GDBN} shall then send another | |
34218 | @samp{vStopped} packet to solicit further responses; again, it is | |
34219 | permitted to send other, unrelated packets as well which the stub | |
34220 | should process normally. | |
34221 | ||
34222 | If the stub receives a @samp{vStopped} packet and there are no | |
34223 | additional stop events to report, the stub shall return an @samp{OK} | |
34224 | response. At this point, if further stop events occur, the stub shall | |
34225 | send a new stop reply notification, @value{GDBN} shall accept the | |
34226 | notification, and the process shall be repeated. | |
34227 | ||
34228 | In non-stop mode, the target shall respond to the @samp{?} packet as | |
34229 | follows. First, any incomplete stop reply notification/@samp{vStopped} | |
34230 | sequence in progress is abandoned. The target must begin a new | |
34231 | sequence reporting stop events for all stopped threads, whether or not | |
34232 | it has previously reported those events to @value{GDBN}. The first | |
34233 | stop reply is sent as a synchronous reply to the @samp{?} packet, and | |
34234 | subsequent stop replies are sent as responses to @samp{vStopped} packets | |
34235 | using the mechanism described above. The target must not send | |
34236 | asynchronous stop reply notifications until the sequence is complete. | |
34237 | If all threads are running when the target receives the @samp{?} packet, | |
34238 | or if the target is not attached to any process, it shall respond | |
34239 | @samp{OK}. | |
9a6253be | 34240 | |
a6f3e723 SL |
34241 | @node Packet Acknowledgment |
34242 | @section Packet Acknowledgment | |
34243 | ||
34244 | @cindex acknowledgment, for @value{GDBN} remote | |
34245 | @cindex packet acknowledgment, for @value{GDBN} remote | |
34246 | By default, when either the host or the target machine receives a packet, | |
34247 | the first response expected is an acknowledgment: either @samp{+} (to indicate | |
34248 | the package was received correctly) or @samp{-} (to request retransmission). | |
34249 | This mechanism allows the @value{GDBN} remote protocol to operate over | |
34250 | unreliable transport mechanisms, such as a serial line. | |
34251 | ||
34252 | In cases where the transport mechanism is itself reliable (such as a pipe or | |
34253 | TCP connection), the @samp{+}/@samp{-} acknowledgments are redundant. | |
34254 | It may be desirable to disable them in that case to reduce communication | |
34255 | overhead, or for other reasons. This can be accomplished by means of the | |
34256 | @samp{QStartNoAckMode} packet; @pxref{QStartNoAckMode}. | |
34257 | ||
34258 | When in no-acknowledgment mode, neither the stub nor @value{GDBN} shall send or | |
34259 | expect @samp{+}/@samp{-} protocol acknowledgments. The packet | |
34260 | and response format still includes the normal checksum, as described in | |
34261 | @ref{Overview}, but the checksum may be ignored by the receiver. | |
34262 | ||
34263 | If the stub supports @samp{QStartNoAckMode} and prefers to operate in | |
34264 | no-acknowledgment mode, it should report that to @value{GDBN} | |
34265 | by including @samp{QStartNoAckMode+} in its response to @samp{qSupported}; | |
34266 | @pxref{qSupported}. | |
34267 | If @value{GDBN} also supports @samp{QStartNoAckMode} and it has not been | |
34268 | disabled via the @code{set remote noack-packet off} command | |
34269 | (@pxref{Remote Configuration}), | |
34270 | @value{GDBN} may then send a @samp{QStartNoAckMode} packet to the stub. | |
34271 | Only then may the stub actually turn off packet acknowledgments. | |
34272 | @value{GDBN} sends a final @samp{+} acknowledgment of the stub's @samp{OK} | |
34273 | response, which can be safely ignored by the stub. | |
34274 | ||
34275 | Note that @code{set remote noack-packet} command only affects negotiation | |
34276 | between @value{GDBN} and the stub when subsequent connections are made; | |
34277 | it does not affect the protocol acknowledgment state for any current | |
34278 | connection. | |
34279 | Since @samp{+}/@samp{-} acknowledgments are enabled by default when a | |
34280 | new connection is established, | |
34281 | there is also no protocol request to re-enable the acknowledgments | |
34282 | for the current connection, once disabled. | |
34283 | ||
ee2d5c50 AC |
34284 | @node Examples |
34285 | @section Examples | |
eb12ee30 | 34286 | |
8e04817f AC |
34287 | Example sequence of a target being re-started. Notice how the restart |
34288 | does not get any direct output: | |
eb12ee30 | 34289 | |
474c8240 | 34290 | @smallexample |
d2c6833e AC |
34291 | -> @code{R00} |
34292 | <- @code{+} | |
8e04817f | 34293 | @emph{target restarts} |
d2c6833e | 34294 | -> @code{?} |
8e04817f | 34295 | <- @code{+} |
d2c6833e AC |
34296 | <- @code{T001:1234123412341234} |
34297 | -> @code{+} | |
474c8240 | 34298 | @end smallexample |
eb12ee30 | 34299 | |
8e04817f | 34300 | Example sequence of a target being stepped by a single instruction: |
eb12ee30 | 34301 | |
474c8240 | 34302 | @smallexample |
d2c6833e | 34303 | -> @code{G1445@dots{}} |
8e04817f | 34304 | <- @code{+} |
d2c6833e AC |
34305 | -> @code{s} |
34306 | <- @code{+} | |
34307 | @emph{time passes} | |
34308 | <- @code{T001:1234123412341234} | |
8e04817f | 34309 | -> @code{+} |
d2c6833e | 34310 | -> @code{g} |
8e04817f | 34311 | <- @code{+} |
d2c6833e AC |
34312 | <- @code{1455@dots{}} |
34313 | -> @code{+} | |
474c8240 | 34314 | @end smallexample |
eb12ee30 | 34315 | |
79a6e687 BW |
34316 | @node File-I/O Remote Protocol Extension |
34317 | @section File-I/O Remote Protocol Extension | |
0ce1b118 CV |
34318 | @cindex File-I/O remote protocol extension |
34319 | ||
34320 | @menu | |
34321 | * File-I/O Overview:: | |
79a6e687 BW |
34322 | * Protocol Basics:: |
34323 | * The F Request Packet:: | |
34324 | * The F Reply Packet:: | |
34325 | * The Ctrl-C Message:: | |
0ce1b118 | 34326 | * Console I/O:: |
79a6e687 | 34327 | * List of Supported Calls:: |
db2e3e2e | 34328 | * Protocol-specific Representation of Datatypes:: |
0ce1b118 CV |
34329 | * Constants:: |
34330 | * File-I/O Examples:: | |
34331 | @end menu | |
34332 | ||
34333 | @node File-I/O Overview | |
34334 | @subsection File-I/O Overview | |
34335 | @cindex file-i/o overview | |
34336 | ||
9c16f35a | 34337 | The @dfn{File I/O remote protocol extension} (short: File-I/O) allows the |
fc320d37 | 34338 | target to use the host's file system and console I/O to perform various |
0ce1b118 | 34339 | system calls. System calls on the target system are translated into a |
fc320d37 SL |
34340 | remote protocol packet to the host system, which then performs the needed |
34341 | actions and returns a response packet to the target system. | |
0ce1b118 CV |
34342 | This simulates file system operations even on targets that lack file systems. |
34343 | ||
fc320d37 SL |
34344 | The protocol is defined to be independent of both the host and target systems. |
34345 | It uses its own internal representation of datatypes and values. Both | |
0ce1b118 | 34346 | @value{GDBN} and the target's @value{GDBN} stub are responsible for |
fc320d37 SL |
34347 | translating the system-dependent value representations into the internal |
34348 | protocol representations when data is transmitted. | |
0ce1b118 | 34349 | |
fc320d37 SL |
34350 | The communication is synchronous. A system call is possible only when |
34351 | @value{GDBN} is waiting for a response from the @samp{C}, @samp{c}, @samp{S} | |
34352 | or @samp{s} packets. While @value{GDBN} handles the request for a system call, | |
0ce1b118 | 34353 | the target is stopped to allow deterministic access to the target's |
fc320d37 SL |
34354 | memory. Therefore File-I/O is not interruptible by target signals. On |
34355 | the other hand, it is possible to interrupt File-I/O by a user interrupt | |
c8aa23ab | 34356 | (@samp{Ctrl-C}) within @value{GDBN}. |
0ce1b118 CV |
34357 | |
34358 | The target's request to perform a host system call does not finish | |
34359 | the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means, | |
34360 | after finishing the system call, the target returns to continuing the | |
34361 | previous activity (continue, step). No additional continue or step | |
34362 | request from @value{GDBN} is required. | |
34363 | ||
34364 | @smallexample | |
f7dc1244 | 34365 | (@value{GDBP}) continue |
0ce1b118 CV |
34366 | <- target requests 'system call X' |
34367 | target is stopped, @value{GDBN} executes system call | |
3f94c067 BW |
34368 | -> @value{GDBN} returns result |
34369 | ... target continues, @value{GDBN} returns to wait for the target | |
0ce1b118 CV |
34370 | <- target hits breakpoint and sends a Txx packet |
34371 | @end smallexample | |
34372 | ||
fc320d37 SL |
34373 | The protocol only supports I/O on the console and to regular files on |
34374 | the host file system. Character or block special devices, pipes, | |
34375 | named pipes, sockets or any other communication method on the host | |
0ce1b118 CV |
34376 | system are not supported by this protocol. |
34377 | ||
8b23ecc4 SL |
34378 | File I/O is not supported in non-stop mode. |
34379 | ||
79a6e687 BW |
34380 | @node Protocol Basics |
34381 | @subsection Protocol Basics | |
0ce1b118 CV |
34382 | @cindex protocol basics, file-i/o |
34383 | ||
fc320d37 SL |
34384 | The File-I/O protocol uses the @code{F} packet as the request as well |
34385 | as reply packet. Since a File-I/O system call can only occur when | |
34386 | @value{GDBN} is waiting for a response from the continuing or stepping target, | |
34387 | the File-I/O request is a reply that @value{GDBN} has to expect as a result | |
34388 | of a previous @samp{C}, @samp{c}, @samp{S} or @samp{s} packet. | |
0ce1b118 CV |
34389 | This @code{F} packet contains all information needed to allow @value{GDBN} |
34390 | to call the appropriate host system call: | |
34391 | ||
34392 | @itemize @bullet | |
b383017d | 34393 | @item |
0ce1b118 CV |
34394 | A unique identifier for the requested system call. |
34395 | ||
34396 | @item | |
34397 | All parameters to the system call. Pointers are given as addresses | |
34398 | in the target memory address space. Pointers to strings are given as | |
b383017d | 34399 | pointer/length pair. Numerical values are given as they are. |
db2e3e2e | 34400 | Numerical control flags are given in a protocol-specific representation. |
0ce1b118 CV |
34401 | |
34402 | @end itemize | |
34403 | ||
fc320d37 | 34404 | At this point, @value{GDBN} has to perform the following actions. |
0ce1b118 CV |
34405 | |
34406 | @itemize @bullet | |
b383017d | 34407 | @item |
fc320d37 SL |
34408 | If the parameters include pointer values to data needed as input to a |
34409 | system call, @value{GDBN} requests this data from the target with a | |
0ce1b118 CV |
34410 | standard @code{m} packet request. This additional communication has to be |
34411 | expected by the target implementation and is handled as any other @code{m} | |
34412 | packet. | |
34413 | ||
34414 | @item | |
34415 | @value{GDBN} translates all value from protocol representation to host | |
34416 | representation as needed. Datatypes are coerced into the host types. | |
34417 | ||
34418 | @item | |
fc320d37 | 34419 | @value{GDBN} calls the system call. |
0ce1b118 CV |
34420 | |
34421 | @item | |
34422 | It then coerces datatypes back to protocol representation. | |
34423 | ||
34424 | @item | |
fc320d37 SL |
34425 | If the system call is expected to return data in buffer space specified |
34426 | by pointer parameters to the call, the data is transmitted to the | |
0ce1b118 CV |
34427 | target using a @code{M} or @code{X} packet. This packet has to be expected |
34428 | by the target implementation and is handled as any other @code{M} or @code{X} | |
34429 | packet. | |
34430 | ||
34431 | @end itemize | |
34432 | ||
34433 | Eventually @value{GDBN} replies with another @code{F} packet which contains all | |
34434 | necessary information for the target to continue. This at least contains | |
34435 | ||
34436 | @itemize @bullet | |
34437 | @item | |
34438 | Return value. | |
34439 | ||
34440 | @item | |
34441 | @code{errno}, if has been changed by the system call. | |
34442 | ||
34443 | @item | |
34444 | ``Ctrl-C'' flag. | |
34445 | ||
34446 | @end itemize | |
34447 | ||
34448 | After having done the needed type and value coercion, the target continues | |
34449 | the latest continue or step action. | |
34450 | ||
79a6e687 BW |
34451 | @node The F Request Packet |
34452 | @subsection The @code{F} Request Packet | |
0ce1b118 CV |
34453 | @cindex file-i/o request packet |
34454 | @cindex @code{F} request packet | |
34455 | ||
34456 | The @code{F} request packet has the following format: | |
34457 | ||
34458 | @table @samp | |
fc320d37 | 34459 | @item F@var{call-id},@var{parameter@dots{}} |
0ce1b118 CV |
34460 | |
34461 | @var{call-id} is the identifier to indicate the host system call to be called. | |
34462 | This is just the name of the function. | |
34463 | ||
fc320d37 SL |
34464 | @var{parameter@dots{}} are the parameters to the system call. |
34465 | Parameters are hexadecimal integer values, either the actual values in case | |
34466 | of scalar datatypes, pointers to target buffer space in case of compound | |
34467 | datatypes and unspecified memory areas, or pointer/length pairs in case | |
34468 | of string parameters. These are appended to the @var{call-id} as a | |
34469 | comma-delimited list. All values are transmitted in ASCII | |
34470 | string representation, pointer/length pairs separated by a slash. | |
0ce1b118 | 34471 | |
b383017d | 34472 | @end table |
0ce1b118 | 34473 | |
fc320d37 | 34474 | |
0ce1b118 | 34475 | |
79a6e687 BW |
34476 | @node The F Reply Packet |
34477 | @subsection The @code{F} Reply Packet | |
0ce1b118 CV |
34478 | @cindex file-i/o reply packet |
34479 | @cindex @code{F} reply packet | |
34480 | ||
34481 | The @code{F} reply packet has the following format: | |
34482 | ||
34483 | @table @samp | |
34484 | ||
d3bdde98 | 34485 | @item F@var{retcode},@var{errno},@var{Ctrl-C flag};@var{call-specific attachment} |
0ce1b118 CV |
34486 | |
34487 | @var{retcode} is the return code of the system call as hexadecimal value. | |
34488 | ||
db2e3e2e BW |
34489 | @var{errno} is the @code{errno} set by the call, in protocol-specific |
34490 | representation. | |
0ce1b118 CV |
34491 | This parameter can be omitted if the call was successful. |
34492 | ||
fc320d37 SL |
34493 | @var{Ctrl-C flag} is only sent if the user requested a break. In this |
34494 | case, @var{errno} must be sent as well, even if the call was successful. | |
34495 | The @var{Ctrl-C flag} itself consists of the character @samp{C}: | |
0ce1b118 CV |
34496 | |
34497 | @smallexample | |
34498 | F0,0,C | |
34499 | @end smallexample | |
34500 | ||
34501 | @noindent | |
fc320d37 | 34502 | or, if the call was interrupted before the host call has been performed: |
0ce1b118 CV |
34503 | |
34504 | @smallexample | |
34505 | F-1,4,C | |
34506 | @end smallexample | |
34507 | ||
34508 | @noindent | |
db2e3e2e | 34509 | assuming 4 is the protocol-specific representation of @code{EINTR}. |
0ce1b118 CV |
34510 | |
34511 | @end table | |
34512 | ||
0ce1b118 | 34513 | |
79a6e687 BW |
34514 | @node The Ctrl-C Message |
34515 | @subsection The @samp{Ctrl-C} Message | |
0ce1b118 CV |
34516 | @cindex ctrl-c message, in file-i/o protocol |
34517 | ||
c8aa23ab | 34518 | If the @samp{Ctrl-C} flag is set in the @value{GDBN} |
79a6e687 | 34519 | reply packet (@pxref{The F Reply Packet}), |
fc320d37 | 34520 | the target should behave as if it had |
0ce1b118 | 34521 | gotten a break message. The meaning for the target is ``system call |
fc320d37 | 34522 | interrupted by @code{SIGINT}''. Consequentially, the target should actually stop |
0ce1b118 | 34523 | (as with a break message) and return to @value{GDBN} with a @code{T02} |
c8aa23ab | 34524 | packet. |
fc320d37 SL |
34525 | |
34526 | It's important for the target to know in which | |
34527 | state the system call was interrupted. There are two possible cases: | |
0ce1b118 CV |
34528 | |
34529 | @itemize @bullet | |
34530 | @item | |
34531 | The system call hasn't been performed on the host yet. | |
34532 | ||
34533 | @item | |
34534 | The system call on the host has been finished. | |
34535 | ||
34536 | @end itemize | |
34537 | ||
34538 | These two states can be distinguished by the target by the value of the | |
34539 | returned @code{errno}. If it's the protocol representation of @code{EINTR}, the system | |
34540 | call hasn't been performed. This is equivalent to the @code{EINTR} handling | |
34541 | on POSIX systems. In any other case, the target may presume that the | |
fc320d37 | 34542 | system call has been finished --- successfully or not --- and should behave |
0ce1b118 CV |
34543 | as if the break message arrived right after the system call. |
34544 | ||
fc320d37 | 34545 | @value{GDBN} must behave reliably. If the system call has not been called |
0ce1b118 CV |
34546 | yet, @value{GDBN} may send the @code{F} reply immediately, setting @code{EINTR} as |
34547 | @code{errno} in the packet. If the system call on the host has been finished | |
fc320d37 SL |
34548 | before the user requests a break, the full action must be finished by |
34549 | @value{GDBN}. This requires sending @code{M} or @code{X} packets as necessary. | |
34550 | The @code{F} packet may only be sent when either nothing has happened | |
0ce1b118 CV |
34551 | or the full action has been completed. |
34552 | ||
34553 | @node Console I/O | |
34554 | @subsection Console I/O | |
34555 | @cindex console i/o as part of file-i/o | |
34556 | ||
d3e8051b | 34557 | By default and if not explicitly closed by the target system, the file |
0ce1b118 CV |
34558 | descriptors 0, 1 and 2 are connected to the @value{GDBN} console. Output |
34559 | on the @value{GDBN} console is handled as any other file output operation | |
34560 | (@code{write(1, @dots{})} or @code{write(2, @dots{})}). Console input is handled | |
34561 | by @value{GDBN} so that after the target read request from file descriptor | |
34562 | 0 all following typing is buffered until either one of the following | |
34563 | conditions is met: | |
34564 | ||
34565 | @itemize @bullet | |
34566 | @item | |
c8aa23ab | 34567 | The user types @kbd{Ctrl-c}. The behaviour is as explained above, and the |
0ce1b118 CV |
34568 | @code{read} |
34569 | system call is treated as finished. | |
34570 | ||
34571 | @item | |
7f9087cb | 34572 | The user presses @key{RET}. This is treated as end of input with a trailing |
fc320d37 | 34573 | newline. |
0ce1b118 CV |
34574 | |
34575 | @item | |
c8aa23ab EZ |
34576 | The user types @kbd{Ctrl-d}. This is treated as end of input. No trailing |
34577 | character (neither newline nor @samp{Ctrl-D}) is appended to the input. | |
0ce1b118 CV |
34578 | |
34579 | @end itemize | |
34580 | ||
fc320d37 SL |
34581 | If the user has typed more characters than fit in the buffer given to |
34582 | the @code{read} call, the trailing characters are buffered in @value{GDBN} until | |
34583 | either another @code{read(0, @dots{})} is requested by the target, or debugging | |
34584 | is stopped at the user's request. | |
0ce1b118 | 34585 | |
0ce1b118 | 34586 | |
79a6e687 BW |
34587 | @node List of Supported Calls |
34588 | @subsection List of Supported Calls | |
0ce1b118 CV |
34589 | @cindex list of supported file-i/o calls |
34590 | ||
34591 | @menu | |
34592 | * open:: | |
34593 | * close:: | |
34594 | * read:: | |
34595 | * write:: | |
34596 | * lseek:: | |
34597 | * rename:: | |
34598 | * unlink:: | |
34599 | * stat/fstat:: | |
34600 | * gettimeofday:: | |
34601 | * isatty:: | |
34602 | * system:: | |
34603 | @end menu | |
34604 | ||
34605 | @node open | |
34606 | @unnumberedsubsubsec open | |
34607 | @cindex open, file-i/o system call | |
34608 | ||
fc320d37 SL |
34609 | @table @asis |
34610 | @item Synopsis: | |
0ce1b118 | 34611 | @smallexample |
0ce1b118 CV |
34612 | int open(const char *pathname, int flags); |
34613 | int open(const char *pathname, int flags, mode_t mode); | |
0ce1b118 CV |
34614 | @end smallexample |
34615 | ||
fc320d37 SL |
34616 | @item Request: |
34617 | @samp{Fopen,@var{pathptr}/@var{len},@var{flags},@var{mode}} | |
34618 | ||
0ce1b118 | 34619 | @noindent |
fc320d37 | 34620 | @var{flags} is the bitwise @code{OR} of the following values: |
0ce1b118 CV |
34621 | |
34622 | @table @code | |
b383017d | 34623 | @item O_CREAT |
0ce1b118 CV |
34624 | If the file does not exist it will be created. The host |
34625 | rules apply as far as file ownership and time stamps | |
34626 | are concerned. | |
34627 | ||
b383017d | 34628 | @item O_EXCL |
fc320d37 | 34629 | When used with @code{O_CREAT}, if the file already exists it is |
0ce1b118 CV |
34630 | an error and open() fails. |
34631 | ||
b383017d | 34632 | @item O_TRUNC |
0ce1b118 | 34633 | If the file already exists and the open mode allows |
fc320d37 SL |
34634 | writing (@code{O_RDWR} or @code{O_WRONLY} is given) it will be |
34635 | truncated to zero length. | |
0ce1b118 | 34636 | |
b383017d | 34637 | @item O_APPEND |
0ce1b118 CV |
34638 | The file is opened in append mode. |
34639 | ||
b383017d | 34640 | @item O_RDONLY |
0ce1b118 CV |
34641 | The file is opened for reading only. |
34642 | ||
b383017d | 34643 | @item O_WRONLY |
0ce1b118 CV |
34644 | The file is opened for writing only. |
34645 | ||
b383017d | 34646 | @item O_RDWR |
0ce1b118 | 34647 | The file is opened for reading and writing. |
fc320d37 | 34648 | @end table |
0ce1b118 CV |
34649 | |
34650 | @noindent | |
fc320d37 | 34651 | Other bits are silently ignored. |
0ce1b118 | 34652 | |
0ce1b118 CV |
34653 | |
34654 | @noindent | |
fc320d37 | 34655 | @var{mode} is the bitwise @code{OR} of the following values: |
0ce1b118 CV |
34656 | |
34657 | @table @code | |
b383017d | 34658 | @item S_IRUSR |
0ce1b118 CV |
34659 | User has read permission. |
34660 | ||
b383017d | 34661 | @item S_IWUSR |
0ce1b118 CV |
34662 | User has write permission. |
34663 | ||
b383017d | 34664 | @item S_IRGRP |
0ce1b118 CV |
34665 | Group has read permission. |
34666 | ||
b383017d | 34667 | @item S_IWGRP |
0ce1b118 CV |
34668 | Group has write permission. |
34669 | ||
b383017d | 34670 | @item S_IROTH |
0ce1b118 CV |
34671 | Others have read permission. |
34672 | ||
b383017d | 34673 | @item S_IWOTH |
0ce1b118 | 34674 | Others have write permission. |
fc320d37 | 34675 | @end table |
0ce1b118 CV |
34676 | |
34677 | @noindent | |
fc320d37 | 34678 | Other bits are silently ignored. |
0ce1b118 | 34679 | |
0ce1b118 | 34680 | |
fc320d37 SL |
34681 | @item Return value: |
34682 | @code{open} returns the new file descriptor or -1 if an error | |
34683 | occurred. | |
0ce1b118 | 34684 | |
fc320d37 | 34685 | @item Errors: |
0ce1b118 CV |
34686 | |
34687 | @table @code | |
b383017d | 34688 | @item EEXIST |
fc320d37 | 34689 | @var{pathname} already exists and @code{O_CREAT} and @code{O_EXCL} were used. |
0ce1b118 | 34690 | |
b383017d | 34691 | @item EISDIR |
fc320d37 | 34692 | @var{pathname} refers to a directory. |
0ce1b118 | 34693 | |
b383017d | 34694 | @item EACCES |
0ce1b118 CV |
34695 | The requested access is not allowed. |
34696 | ||
34697 | @item ENAMETOOLONG | |
fc320d37 | 34698 | @var{pathname} was too long. |
0ce1b118 | 34699 | |
b383017d | 34700 | @item ENOENT |
fc320d37 | 34701 | A directory component in @var{pathname} does not exist. |
0ce1b118 | 34702 | |
b383017d | 34703 | @item ENODEV |
fc320d37 | 34704 | @var{pathname} refers to a device, pipe, named pipe or socket. |
0ce1b118 | 34705 | |
b383017d | 34706 | @item EROFS |
fc320d37 | 34707 | @var{pathname} refers to a file on a read-only filesystem and |
0ce1b118 CV |
34708 | write access was requested. |
34709 | ||
b383017d | 34710 | @item EFAULT |
fc320d37 | 34711 | @var{pathname} is an invalid pointer value. |
0ce1b118 | 34712 | |
b383017d | 34713 | @item ENOSPC |
0ce1b118 CV |
34714 | No space on device to create the file. |
34715 | ||
b383017d | 34716 | @item EMFILE |
0ce1b118 CV |
34717 | The process already has the maximum number of files open. |
34718 | ||
b383017d | 34719 | @item ENFILE |
0ce1b118 CV |
34720 | The limit on the total number of files open on the system |
34721 | has been reached. | |
34722 | ||
b383017d | 34723 | @item EINTR |
0ce1b118 CV |
34724 | The call was interrupted by the user. |
34725 | @end table | |
34726 | ||
fc320d37 SL |
34727 | @end table |
34728 | ||
0ce1b118 CV |
34729 | @node close |
34730 | @unnumberedsubsubsec close | |
34731 | @cindex close, file-i/o system call | |
34732 | ||
fc320d37 SL |
34733 | @table @asis |
34734 | @item Synopsis: | |
0ce1b118 | 34735 | @smallexample |
0ce1b118 | 34736 | int close(int fd); |
fc320d37 | 34737 | @end smallexample |
0ce1b118 | 34738 | |
fc320d37 SL |
34739 | @item Request: |
34740 | @samp{Fclose,@var{fd}} | |
0ce1b118 | 34741 | |
fc320d37 SL |
34742 | @item Return value: |
34743 | @code{close} returns zero on success, or -1 if an error occurred. | |
0ce1b118 | 34744 | |
fc320d37 | 34745 | @item Errors: |
0ce1b118 CV |
34746 | |
34747 | @table @code | |
b383017d | 34748 | @item EBADF |
fc320d37 | 34749 | @var{fd} isn't a valid open file descriptor. |
0ce1b118 | 34750 | |
b383017d | 34751 | @item EINTR |
0ce1b118 CV |
34752 | The call was interrupted by the user. |
34753 | @end table | |
34754 | ||
fc320d37 SL |
34755 | @end table |
34756 | ||
0ce1b118 CV |
34757 | @node read |
34758 | @unnumberedsubsubsec read | |
34759 | @cindex read, file-i/o system call | |
34760 | ||
fc320d37 SL |
34761 | @table @asis |
34762 | @item Synopsis: | |
0ce1b118 | 34763 | @smallexample |
0ce1b118 | 34764 | int read(int fd, void *buf, unsigned int count); |
fc320d37 | 34765 | @end smallexample |
0ce1b118 | 34766 | |
fc320d37 SL |
34767 | @item Request: |
34768 | @samp{Fread,@var{fd},@var{bufptr},@var{count}} | |
0ce1b118 | 34769 | |
fc320d37 | 34770 | @item Return value: |
0ce1b118 CV |
34771 | On success, the number of bytes read is returned. |
34772 | Zero indicates end of file. If count is zero, read | |
b383017d | 34773 | returns zero as well. On error, -1 is returned. |
0ce1b118 | 34774 | |
fc320d37 | 34775 | @item Errors: |
0ce1b118 CV |
34776 | |
34777 | @table @code | |
b383017d | 34778 | @item EBADF |
fc320d37 | 34779 | @var{fd} is not a valid file descriptor or is not open for |
0ce1b118 CV |
34780 | reading. |
34781 | ||
b383017d | 34782 | @item EFAULT |
fc320d37 | 34783 | @var{bufptr} is an invalid pointer value. |
0ce1b118 | 34784 | |
b383017d | 34785 | @item EINTR |
0ce1b118 CV |
34786 | The call was interrupted by the user. |
34787 | @end table | |
34788 | ||
fc320d37 SL |
34789 | @end table |
34790 | ||
0ce1b118 CV |
34791 | @node write |
34792 | @unnumberedsubsubsec write | |
34793 | @cindex write, file-i/o system call | |
34794 | ||
fc320d37 SL |
34795 | @table @asis |
34796 | @item Synopsis: | |
0ce1b118 | 34797 | @smallexample |
0ce1b118 | 34798 | int write(int fd, const void *buf, unsigned int count); |
fc320d37 | 34799 | @end smallexample |
0ce1b118 | 34800 | |
fc320d37 SL |
34801 | @item Request: |
34802 | @samp{Fwrite,@var{fd},@var{bufptr},@var{count}} | |
0ce1b118 | 34803 | |
fc320d37 | 34804 | @item Return value: |
0ce1b118 CV |
34805 | On success, the number of bytes written are returned. |
34806 | Zero indicates nothing was written. On error, -1 | |
34807 | is returned. | |
34808 | ||
fc320d37 | 34809 | @item Errors: |
0ce1b118 CV |
34810 | |
34811 | @table @code | |
b383017d | 34812 | @item EBADF |
fc320d37 | 34813 | @var{fd} is not a valid file descriptor or is not open for |
0ce1b118 CV |
34814 | writing. |
34815 | ||
b383017d | 34816 | @item EFAULT |
fc320d37 | 34817 | @var{bufptr} is an invalid pointer value. |
0ce1b118 | 34818 | |
b383017d | 34819 | @item EFBIG |
0ce1b118 | 34820 | An attempt was made to write a file that exceeds the |
db2e3e2e | 34821 | host-specific maximum file size allowed. |
0ce1b118 | 34822 | |
b383017d | 34823 | @item ENOSPC |
0ce1b118 CV |
34824 | No space on device to write the data. |
34825 | ||
b383017d | 34826 | @item EINTR |
0ce1b118 CV |
34827 | The call was interrupted by the user. |
34828 | @end table | |
34829 | ||
fc320d37 SL |
34830 | @end table |
34831 | ||
0ce1b118 CV |
34832 | @node lseek |
34833 | @unnumberedsubsubsec lseek | |
34834 | @cindex lseek, file-i/o system call | |
34835 | ||
fc320d37 SL |
34836 | @table @asis |
34837 | @item Synopsis: | |
0ce1b118 | 34838 | @smallexample |
0ce1b118 | 34839 | long lseek (int fd, long offset, int flag); |
0ce1b118 CV |
34840 | @end smallexample |
34841 | ||
fc320d37 SL |
34842 | @item Request: |
34843 | @samp{Flseek,@var{fd},@var{offset},@var{flag}} | |
34844 | ||
34845 | @var{flag} is one of: | |
0ce1b118 CV |
34846 | |
34847 | @table @code | |
b383017d | 34848 | @item SEEK_SET |
fc320d37 | 34849 | The offset is set to @var{offset} bytes. |
0ce1b118 | 34850 | |
b383017d | 34851 | @item SEEK_CUR |
fc320d37 | 34852 | The offset is set to its current location plus @var{offset} |
0ce1b118 CV |
34853 | bytes. |
34854 | ||
b383017d | 34855 | @item SEEK_END |
fc320d37 | 34856 | The offset is set to the size of the file plus @var{offset} |
0ce1b118 CV |
34857 | bytes. |
34858 | @end table | |
34859 | ||
fc320d37 | 34860 | @item Return value: |
0ce1b118 CV |
34861 | On success, the resulting unsigned offset in bytes from |
34862 | the beginning of the file is returned. Otherwise, a | |
34863 | value of -1 is returned. | |
34864 | ||
fc320d37 | 34865 | @item Errors: |
0ce1b118 CV |
34866 | |
34867 | @table @code | |
b383017d | 34868 | @item EBADF |
fc320d37 | 34869 | @var{fd} is not a valid open file descriptor. |
0ce1b118 | 34870 | |
b383017d | 34871 | @item ESPIPE |
fc320d37 | 34872 | @var{fd} is associated with the @value{GDBN} console. |
0ce1b118 | 34873 | |
b383017d | 34874 | @item EINVAL |
fc320d37 | 34875 | @var{flag} is not a proper value. |
0ce1b118 | 34876 | |
b383017d | 34877 | @item EINTR |
0ce1b118 CV |
34878 | The call was interrupted by the user. |
34879 | @end table | |
34880 | ||
fc320d37 SL |
34881 | @end table |
34882 | ||
0ce1b118 CV |
34883 | @node rename |
34884 | @unnumberedsubsubsec rename | |
34885 | @cindex rename, file-i/o system call | |
34886 | ||
fc320d37 SL |
34887 | @table @asis |
34888 | @item Synopsis: | |
0ce1b118 | 34889 | @smallexample |
0ce1b118 | 34890 | int rename(const char *oldpath, const char *newpath); |
fc320d37 | 34891 | @end smallexample |
0ce1b118 | 34892 | |
fc320d37 SL |
34893 | @item Request: |
34894 | @samp{Frename,@var{oldpathptr}/@var{len},@var{newpathptr}/@var{len}} | |
0ce1b118 | 34895 | |
fc320d37 | 34896 | @item Return value: |
0ce1b118 CV |
34897 | On success, zero is returned. On error, -1 is returned. |
34898 | ||
fc320d37 | 34899 | @item Errors: |
0ce1b118 CV |
34900 | |
34901 | @table @code | |
b383017d | 34902 | @item EISDIR |
fc320d37 | 34903 | @var{newpath} is an existing directory, but @var{oldpath} is not a |
0ce1b118 CV |
34904 | directory. |
34905 | ||
b383017d | 34906 | @item EEXIST |
fc320d37 | 34907 | @var{newpath} is a non-empty directory. |
0ce1b118 | 34908 | |
b383017d | 34909 | @item EBUSY |
fc320d37 | 34910 | @var{oldpath} or @var{newpath} is a directory that is in use by some |
0ce1b118 CV |
34911 | process. |
34912 | ||
b383017d | 34913 | @item EINVAL |
0ce1b118 CV |
34914 | An attempt was made to make a directory a subdirectory |
34915 | of itself. | |
34916 | ||
b383017d | 34917 | @item ENOTDIR |
fc320d37 SL |
34918 | A component used as a directory in @var{oldpath} or new |
34919 | path is not a directory. Or @var{oldpath} is a directory | |
34920 | and @var{newpath} exists but is not a directory. | |
0ce1b118 | 34921 | |
b383017d | 34922 | @item EFAULT |
fc320d37 | 34923 | @var{oldpathptr} or @var{newpathptr} are invalid pointer values. |
0ce1b118 | 34924 | |
b383017d | 34925 | @item EACCES |
0ce1b118 CV |
34926 | No access to the file or the path of the file. |
34927 | ||
34928 | @item ENAMETOOLONG | |
b383017d | 34929 | |
fc320d37 | 34930 | @var{oldpath} or @var{newpath} was too long. |
0ce1b118 | 34931 | |
b383017d | 34932 | @item ENOENT |
fc320d37 | 34933 | A directory component in @var{oldpath} or @var{newpath} does not exist. |
0ce1b118 | 34934 | |
b383017d | 34935 | @item EROFS |
0ce1b118 CV |
34936 | The file is on a read-only filesystem. |
34937 | ||
b383017d | 34938 | @item ENOSPC |
0ce1b118 CV |
34939 | The device containing the file has no room for the new |
34940 | directory entry. | |
34941 | ||
b383017d | 34942 | @item EINTR |
0ce1b118 CV |
34943 | The call was interrupted by the user. |
34944 | @end table | |
34945 | ||
fc320d37 SL |
34946 | @end table |
34947 | ||
0ce1b118 CV |
34948 | @node unlink |
34949 | @unnumberedsubsubsec unlink | |
34950 | @cindex unlink, file-i/o system call | |
34951 | ||
fc320d37 SL |
34952 | @table @asis |
34953 | @item Synopsis: | |
0ce1b118 | 34954 | @smallexample |
0ce1b118 | 34955 | int unlink(const char *pathname); |
fc320d37 | 34956 | @end smallexample |
0ce1b118 | 34957 | |
fc320d37 SL |
34958 | @item Request: |
34959 | @samp{Funlink,@var{pathnameptr}/@var{len}} | |
0ce1b118 | 34960 | |
fc320d37 | 34961 | @item Return value: |
0ce1b118 CV |
34962 | On success, zero is returned. On error, -1 is returned. |
34963 | ||
fc320d37 | 34964 | @item Errors: |
0ce1b118 CV |
34965 | |
34966 | @table @code | |
b383017d | 34967 | @item EACCES |
0ce1b118 CV |
34968 | No access to the file or the path of the file. |
34969 | ||
b383017d | 34970 | @item EPERM |
0ce1b118 CV |
34971 | The system does not allow unlinking of directories. |
34972 | ||
b383017d | 34973 | @item EBUSY |
fc320d37 | 34974 | The file @var{pathname} cannot be unlinked because it's |
0ce1b118 CV |
34975 | being used by another process. |
34976 | ||
b383017d | 34977 | @item EFAULT |
fc320d37 | 34978 | @var{pathnameptr} is an invalid pointer value. |
0ce1b118 CV |
34979 | |
34980 | @item ENAMETOOLONG | |
fc320d37 | 34981 | @var{pathname} was too long. |
0ce1b118 | 34982 | |
b383017d | 34983 | @item ENOENT |
fc320d37 | 34984 | A directory component in @var{pathname} does not exist. |
0ce1b118 | 34985 | |
b383017d | 34986 | @item ENOTDIR |
0ce1b118 CV |
34987 | A component of the path is not a directory. |
34988 | ||
b383017d | 34989 | @item EROFS |
0ce1b118 CV |
34990 | The file is on a read-only filesystem. |
34991 | ||
b383017d | 34992 | @item EINTR |
0ce1b118 CV |
34993 | The call was interrupted by the user. |
34994 | @end table | |
34995 | ||
fc320d37 SL |
34996 | @end table |
34997 | ||
0ce1b118 CV |
34998 | @node stat/fstat |
34999 | @unnumberedsubsubsec stat/fstat | |
35000 | @cindex fstat, file-i/o system call | |
35001 | @cindex stat, file-i/o system call | |
35002 | ||
fc320d37 SL |
35003 | @table @asis |
35004 | @item Synopsis: | |
0ce1b118 | 35005 | @smallexample |
0ce1b118 CV |
35006 | int stat(const char *pathname, struct stat *buf); |
35007 | int fstat(int fd, struct stat *buf); | |
fc320d37 | 35008 | @end smallexample |
0ce1b118 | 35009 | |
fc320d37 SL |
35010 | @item Request: |
35011 | @samp{Fstat,@var{pathnameptr}/@var{len},@var{bufptr}}@* | |
35012 | @samp{Ffstat,@var{fd},@var{bufptr}} | |
0ce1b118 | 35013 | |
fc320d37 | 35014 | @item Return value: |
0ce1b118 CV |
35015 | On success, zero is returned. On error, -1 is returned. |
35016 | ||
fc320d37 | 35017 | @item Errors: |
0ce1b118 CV |
35018 | |
35019 | @table @code | |
b383017d | 35020 | @item EBADF |
fc320d37 | 35021 | @var{fd} is not a valid open file. |
0ce1b118 | 35022 | |
b383017d | 35023 | @item ENOENT |
fc320d37 | 35024 | A directory component in @var{pathname} does not exist or the |
0ce1b118 CV |
35025 | path is an empty string. |
35026 | ||
b383017d | 35027 | @item ENOTDIR |
0ce1b118 CV |
35028 | A component of the path is not a directory. |
35029 | ||
b383017d | 35030 | @item EFAULT |
fc320d37 | 35031 | @var{pathnameptr} is an invalid pointer value. |
0ce1b118 | 35032 | |
b383017d | 35033 | @item EACCES |
0ce1b118 CV |
35034 | No access to the file or the path of the file. |
35035 | ||
35036 | @item ENAMETOOLONG | |
fc320d37 | 35037 | @var{pathname} was too long. |
0ce1b118 | 35038 | |
b383017d | 35039 | @item EINTR |
0ce1b118 CV |
35040 | The call was interrupted by the user. |
35041 | @end table | |
35042 | ||
fc320d37 SL |
35043 | @end table |
35044 | ||
0ce1b118 CV |
35045 | @node gettimeofday |
35046 | @unnumberedsubsubsec gettimeofday | |
35047 | @cindex gettimeofday, file-i/o system call | |
35048 | ||
fc320d37 SL |
35049 | @table @asis |
35050 | @item Synopsis: | |
0ce1b118 | 35051 | @smallexample |
0ce1b118 | 35052 | int gettimeofday(struct timeval *tv, void *tz); |
fc320d37 | 35053 | @end smallexample |
0ce1b118 | 35054 | |
fc320d37 SL |
35055 | @item Request: |
35056 | @samp{Fgettimeofday,@var{tvptr},@var{tzptr}} | |
0ce1b118 | 35057 | |
fc320d37 | 35058 | @item Return value: |
0ce1b118 CV |
35059 | On success, 0 is returned, -1 otherwise. |
35060 | ||
fc320d37 | 35061 | @item Errors: |
0ce1b118 CV |
35062 | |
35063 | @table @code | |
b383017d | 35064 | @item EINVAL |
fc320d37 | 35065 | @var{tz} is a non-NULL pointer. |
0ce1b118 | 35066 | |
b383017d | 35067 | @item EFAULT |
fc320d37 SL |
35068 | @var{tvptr} and/or @var{tzptr} is an invalid pointer value. |
35069 | @end table | |
35070 | ||
0ce1b118 CV |
35071 | @end table |
35072 | ||
35073 | @node isatty | |
35074 | @unnumberedsubsubsec isatty | |
35075 | @cindex isatty, file-i/o system call | |
35076 | ||
fc320d37 SL |
35077 | @table @asis |
35078 | @item Synopsis: | |
0ce1b118 | 35079 | @smallexample |
0ce1b118 | 35080 | int isatty(int fd); |
fc320d37 | 35081 | @end smallexample |
0ce1b118 | 35082 | |
fc320d37 SL |
35083 | @item Request: |
35084 | @samp{Fisatty,@var{fd}} | |
0ce1b118 | 35085 | |
fc320d37 SL |
35086 | @item Return value: |
35087 | Returns 1 if @var{fd} refers to the @value{GDBN} console, 0 otherwise. | |
0ce1b118 | 35088 | |
fc320d37 | 35089 | @item Errors: |
0ce1b118 CV |
35090 | |
35091 | @table @code | |
b383017d | 35092 | @item EINTR |
0ce1b118 CV |
35093 | The call was interrupted by the user. |
35094 | @end table | |
35095 | ||
fc320d37 SL |
35096 | @end table |
35097 | ||
35098 | Note that the @code{isatty} call is treated as a special case: it returns | |
35099 | 1 to the target if the file descriptor is attached | |
35100 | to the @value{GDBN} console, 0 otherwise. Implementing through system calls | |
35101 | would require implementing @code{ioctl} and would be more complex than | |
35102 | needed. | |
35103 | ||
35104 | ||
0ce1b118 CV |
35105 | @node system |
35106 | @unnumberedsubsubsec system | |
35107 | @cindex system, file-i/o system call | |
35108 | ||
fc320d37 SL |
35109 | @table @asis |
35110 | @item Synopsis: | |
0ce1b118 | 35111 | @smallexample |
0ce1b118 | 35112 | int system(const char *command); |
fc320d37 | 35113 | @end smallexample |
0ce1b118 | 35114 | |
fc320d37 SL |
35115 | @item Request: |
35116 | @samp{Fsystem,@var{commandptr}/@var{len}} | |
0ce1b118 | 35117 | |
fc320d37 | 35118 | @item Return value: |
5600ea19 NS |
35119 | If @var{len} is zero, the return value indicates whether a shell is |
35120 | available. A zero return value indicates a shell is not available. | |
35121 | For non-zero @var{len}, the value returned is -1 on error and the | |
35122 | return status of the command otherwise. Only the exit status of the | |
35123 | command is returned, which is extracted from the host's @code{system} | |
35124 | return value by calling @code{WEXITSTATUS(retval)}. In case | |
35125 | @file{/bin/sh} could not be executed, 127 is returned. | |
0ce1b118 | 35126 | |
fc320d37 | 35127 | @item Errors: |
0ce1b118 CV |
35128 | |
35129 | @table @code | |
b383017d | 35130 | @item EINTR |
0ce1b118 CV |
35131 | The call was interrupted by the user. |
35132 | @end table | |
35133 | ||
fc320d37 SL |
35134 | @end table |
35135 | ||
35136 | @value{GDBN} takes over the full task of calling the necessary host calls | |
35137 | to perform the @code{system} call. The return value of @code{system} on | |
35138 | the host is simplified before it's returned | |
35139 | to the target. Any termination signal information from the child process | |
35140 | is discarded, and the return value consists | |
35141 | entirely of the exit status of the called command. | |
35142 | ||
35143 | Due to security concerns, the @code{system} call is by default refused | |
35144 | by @value{GDBN}. The user has to allow this call explicitly with the | |
35145 | @code{set remote system-call-allowed 1} command. | |
35146 | ||
35147 | @table @code | |
35148 | @item set remote system-call-allowed | |
35149 | @kindex set remote system-call-allowed | |
35150 | Control whether to allow the @code{system} calls in the File I/O | |
35151 | protocol for the remote target. The default is zero (disabled). | |
35152 | ||
35153 | @item show remote system-call-allowed | |
35154 | @kindex show remote system-call-allowed | |
35155 | Show whether the @code{system} calls are allowed in the File I/O | |
35156 | protocol. | |
35157 | @end table | |
35158 | ||
db2e3e2e BW |
35159 | @node Protocol-specific Representation of Datatypes |
35160 | @subsection Protocol-specific Representation of Datatypes | |
35161 | @cindex protocol-specific representation of datatypes, in file-i/o protocol | |
0ce1b118 CV |
35162 | |
35163 | @menu | |
79a6e687 BW |
35164 | * Integral Datatypes:: |
35165 | * Pointer Values:: | |
35166 | * Memory Transfer:: | |
0ce1b118 CV |
35167 | * struct stat:: |
35168 | * struct timeval:: | |
35169 | @end menu | |
35170 | ||
79a6e687 BW |
35171 | @node Integral Datatypes |
35172 | @unnumberedsubsubsec Integral Datatypes | |
0ce1b118 CV |
35173 | @cindex integral datatypes, in file-i/o protocol |
35174 | ||
fc320d37 SL |
35175 | The integral datatypes used in the system calls are @code{int}, |
35176 | @code{unsigned int}, @code{long}, @code{unsigned long}, | |
35177 | @code{mode_t}, and @code{time_t}. | |
0ce1b118 | 35178 | |
fc320d37 | 35179 | @code{int}, @code{unsigned int}, @code{mode_t} and @code{time_t} are |
0ce1b118 CV |
35180 | implemented as 32 bit values in this protocol. |
35181 | ||
fc320d37 | 35182 | @code{long} and @code{unsigned long} are implemented as 64 bit types. |
b383017d | 35183 | |
0ce1b118 CV |
35184 | @xref{Limits}, for corresponding MIN and MAX values (similar to those |
35185 | in @file{limits.h}) to allow range checking on host and target. | |
35186 | ||
35187 | @code{time_t} datatypes are defined as seconds since the Epoch. | |
35188 | ||
35189 | All integral datatypes transferred as part of a memory read or write of a | |
35190 | structured datatype e.g.@: a @code{struct stat} have to be given in big endian | |
35191 | byte order. | |
35192 | ||
79a6e687 BW |
35193 | @node Pointer Values |
35194 | @unnumberedsubsubsec Pointer Values | |
0ce1b118 CV |
35195 | @cindex pointer values, in file-i/o protocol |
35196 | ||
35197 | Pointers to target data are transmitted as they are. An exception | |
35198 | is made for pointers to buffers for which the length isn't | |
35199 | transmitted as part of the function call, namely strings. Strings | |
35200 | are transmitted as a pointer/length pair, both as hex values, e.g.@: | |
35201 | ||
35202 | @smallexample | |
35203 | @code{1aaf/12} | |
35204 | @end smallexample | |
35205 | ||
35206 | @noindent | |
35207 | which is a pointer to data of length 18 bytes at position 0x1aaf. | |
35208 | The length is defined as the full string length in bytes, including | |
fc320d37 SL |
35209 | the trailing null byte. For example, the string @code{"hello world"} |
35210 | at address 0x123456 is transmitted as | |
0ce1b118 CV |
35211 | |
35212 | @smallexample | |
fc320d37 | 35213 | @code{123456/d} |
0ce1b118 CV |
35214 | @end smallexample |
35215 | ||
79a6e687 BW |
35216 | @node Memory Transfer |
35217 | @unnumberedsubsubsec Memory Transfer | |
fc320d37 SL |
35218 | @cindex memory transfer, in file-i/o protocol |
35219 | ||
35220 | Structured data which is transferred using a memory read or write (for | |
db2e3e2e | 35221 | example, a @code{struct stat}) is expected to be in a protocol-specific format |
fc320d37 SL |
35222 | with all scalar multibyte datatypes being big endian. Translation to |
35223 | this representation needs to be done both by the target before the @code{F} | |
35224 | packet is sent, and by @value{GDBN} before | |
35225 | it transfers memory to the target. Transferred pointers to structured | |
35226 | data should point to the already-coerced data at any time. | |
0ce1b118 | 35227 | |
0ce1b118 CV |
35228 | |
35229 | @node struct stat | |
35230 | @unnumberedsubsubsec struct stat | |
35231 | @cindex struct stat, in file-i/o protocol | |
35232 | ||
fc320d37 SL |
35233 | The buffer of type @code{struct stat} used by the target and @value{GDBN} |
35234 | is defined as follows: | |
0ce1b118 CV |
35235 | |
35236 | @smallexample | |
35237 | struct stat @{ | |
35238 | unsigned int st_dev; /* device */ | |
35239 | unsigned int st_ino; /* inode */ | |
35240 | mode_t st_mode; /* protection */ | |
35241 | unsigned int st_nlink; /* number of hard links */ | |
35242 | unsigned int st_uid; /* user ID of owner */ | |
35243 | unsigned int st_gid; /* group ID of owner */ | |
35244 | unsigned int st_rdev; /* device type (if inode device) */ | |
35245 | unsigned long st_size; /* total size, in bytes */ | |
35246 | unsigned long st_blksize; /* blocksize for filesystem I/O */ | |
35247 | unsigned long st_blocks; /* number of blocks allocated */ | |
35248 | time_t st_atime; /* time of last access */ | |
35249 | time_t st_mtime; /* time of last modification */ | |
35250 | time_t st_ctime; /* time of last change */ | |
35251 | @}; | |
35252 | @end smallexample | |
35253 | ||
fc320d37 | 35254 | The integral datatypes conform to the definitions given in the |
79a6e687 | 35255 | appropriate section (see @ref{Integral Datatypes}, for details) so this |
0ce1b118 CV |
35256 | structure is of size 64 bytes. |
35257 | ||
35258 | The values of several fields have a restricted meaning and/or | |
35259 | range of values. | |
35260 | ||
fc320d37 | 35261 | @table @code |
0ce1b118 | 35262 | |
fc320d37 SL |
35263 | @item st_dev |
35264 | A value of 0 represents a file, 1 the console. | |
0ce1b118 | 35265 | |
fc320d37 SL |
35266 | @item st_ino |
35267 | No valid meaning for the target. Transmitted unchanged. | |
0ce1b118 | 35268 | |
fc320d37 SL |
35269 | @item st_mode |
35270 | Valid mode bits are described in @ref{Constants}. Any other | |
35271 | bits have currently no meaning for the target. | |
0ce1b118 | 35272 | |
fc320d37 SL |
35273 | @item st_uid |
35274 | @itemx st_gid | |
35275 | @itemx st_rdev | |
35276 | No valid meaning for the target. Transmitted unchanged. | |
0ce1b118 | 35277 | |
fc320d37 SL |
35278 | @item st_atime |
35279 | @itemx st_mtime | |
35280 | @itemx st_ctime | |
35281 | These values have a host and file system dependent | |
35282 | accuracy. Especially on Windows hosts, the file system may not | |
35283 | support exact timing values. | |
35284 | @end table | |
0ce1b118 | 35285 | |
fc320d37 SL |
35286 | The target gets a @code{struct stat} of the above representation and is |
35287 | responsible for coercing it to the target representation before | |
0ce1b118 CV |
35288 | continuing. |
35289 | ||
fc320d37 SL |
35290 | Note that due to size differences between the host, target, and protocol |
35291 | representations of @code{struct stat} members, these members could eventually | |
0ce1b118 CV |
35292 | get truncated on the target. |
35293 | ||
35294 | @node struct timeval | |
35295 | @unnumberedsubsubsec struct timeval | |
35296 | @cindex struct timeval, in file-i/o protocol | |
35297 | ||
fc320d37 | 35298 | The buffer of type @code{struct timeval} used by the File-I/O protocol |
0ce1b118 CV |
35299 | is defined as follows: |
35300 | ||
35301 | @smallexample | |
b383017d | 35302 | struct timeval @{ |
0ce1b118 CV |
35303 | time_t tv_sec; /* second */ |
35304 | long tv_usec; /* microsecond */ | |
35305 | @}; | |
35306 | @end smallexample | |
35307 | ||
fc320d37 | 35308 | The integral datatypes conform to the definitions given in the |
79a6e687 | 35309 | appropriate section (see @ref{Integral Datatypes}, for details) so this |
0ce1b118 CV |
35310 | structure is of size 8 bytes. |
35311 | ||
35312 | @node Constants | |
35313 | @subsection Constants | |
35314 | @cindex constants, in file-i/o protocol | |
35315 | ||
35316 | The following values are used for the constants inside of the | |
fc320d37 | 35317 | protocol. @value{GDBN} and target are responsible for translating these |
0ce1b118 CV |
35318 | values before and after the call as needed. |
35319 | ||
35320 | @menu | |
79a6e687 BW |
35321 | * Open Flags:: |
35322 | * mode_t Values:: | |
35323 | * Errno Values:: | |
35324 | * Lseek Flags:: | |
0ce1b118 CV |
35325 | * Limits:: |
35326 | @end menu | |
35327 | ||
79a6e687 BW |
35328 | @node Open Flags |
35329 | @unnumberedsubsubsec Open Flags | |
0ce1b118 CV |
35330 | @cindex open flags, in file-i/o protocol |
35331 | ||
35332 | All values are given in hexadecimal representation. | |
35333 | ||
35334 | @smallexample | |
35335 | O_RDONLY 0x0 | |
35336 | O_WRONLY 0x1 | |
35337 | O_RDWR 0x2 | |
35338 | O_APPEND 0x8 | |
35339 | O_CREAT 0x200 | |
35340 | O_TRUNC 0x400 | |
35341 | O_EXCL 0x800 | |
35342 | @end smallexample | |
35343 | ||
79a6e687 BW |
35344 | @node mode_t Values |
35345 | @unnumberedsubsubsec mode_t Values | |
0ce1b118 CV |
35346 | @cindex mode_t values, in file-i/o protocol |
35347 | ||
35348 | All values are given in octal representation. | |
35349 | ||
35350 | @smallexample | |
35351 | S_IFREG 0100000 | |
35352 | S_IFDIR 040000 | |
35353 | S_IRUSR 0400 | |
35354 | S_IWUSR 0200 | |
35355 | S_IXUSR 0100 | |
35356 | S_IRGRP 040 | |
35357 | S_IWGRP 020 | |
35358 | S_IXGRP 010 | |
35359 | S_IROTH 04 | |
35360 | S_IWOTH 02 | |
35361 | S_IXOTH 01 | |
35362 | @end smallexample | |
35363 | ||
79a6e687 BW |
35364 | @node Errno Values |
35365 | @unnumberedsubsubsec Errno Values | |
0ce1b118 CV |
35366 | @cindex errno values, in file-i/o protocol |
35367 | ||
35368 | All values are given in decimal representation. | |
35369 | ||
35370 | @smallexample | |
35371 | EPERM 1 | |
35372 | ENOENT 2 | |
35373 | EINTR 4 | |
35374 | EBADF 9 | |
35375 | EACCES 13 | |
35376 | EFAULT 14 | |
35377 | EBUSY 16 | |
35378 | EEXIST 17 | |
35379 | ENODEV 19 | |
35380 | ENOTDIR 20 | |
35381 | EISDIR 21 | |
35382 | EINVAL 22 | |
35383 | ENFILE 23 | |
35384 | EMFILE 24 | |
35385 | EFBIG 27 | |
35386 | ENOSPC 28 | |
35387 | ESPIPE 29 | |
35388 | EROFS 30 | |
35389 | ENAMETOOLONG 91 | |
35390 | EUNKNOWN 9999 | |
35391 | @end smallexample | |
35392 | ||
fc320d37 | 35393 | @code{EUNKNOWN} is used as a fallback error value if a host system returns |
0ce1b118 CV |
35394 | any error value not in the list of supported error numbers. |
35395 | ||
79a6e687 BW |
35396 | @node Lseek Flags |
35397 | @unnumberedsubsubsec Lseek Flags | |
0ce1b118 CV |
35398 | @cindex lseek flags, in file-i/o protocol |
35399 | ||
35400 | @smallexample | |
35401 | SEEK_SET 0 | |
35402 | SEEK_CUR 1 | |
35403 | SEEK_END 2 | |
35404 | @end smallexample | |
35405 | ||
35406 | @node Limits | |
35407 | @unnumberedsubsubsec Limits | |
35408 | @cindex limits, in file-i/o protocol | |
35409 | ||
35410 | All values are given in decimal representation. | |
35411 | ||
35412 | @smallexample | |
35413 | INT_MIN -2147483648 | |
35414 | INT_MAX 2147483647 | |
35415 | UINT_MAX 4294967295 | |
35416 | LONG_MIN -9223372036854775808 | |
35417 | LONG_MAX 9223372036854775807 | |
35418 | ULONG_MAX 18446744073709551615 | |
35419 | @end smallexample | |
35420 | ||
35421 | @node File-I/O Examples | |
35422 | @subsection File-I/O Examples | |
35423 | @cindex file-i/o examples | |
35424 | ||
35425 | Example sequence of a write call, file descriptor 3, buffer is at target | |
35426 | address 0x1234, 6 bytes should be written: | |
35427 | ||
35428 | @smallexample | |
35429 | <- @code{Fwrite,3,1234,6} | |
35430 | @emph{request memory read from target} | |
35431 | -> @code{m1234,6} | |
35432 | <- XXXXXX | |
35433 | @emph{return "6 bytes written"} | |
35434 | -> @code{F6} | |
35435 | @end smallexample | |
35436 | ||
35437 | Example sequence of a read call, file descriptor 3, buffer is at target | |
35438 | address 0x1234, 6 bytes should be read: | |
35439 | ||
35440 | @smallexample | |
35441 | <- @code{Fread,3,1234,6} | |
35442 | @emph{request memory write to target} | |
35443 | -> @code{X1234,6:XXXXXX} | |
35444 | @emph{return "6 bytes read"} | |
35445 | -> @code{F6} | |
35446 | @end smallexample | |
35447 | ||
35448 | Example sequence of a read call, call fails on the host due to invalid | |
fc320d37 | 35449 | file descriptor (@code{EBADF}): |
0ce1b118 CV |
35450 | |
35451 | @smallexample | |
35452 | <- @code{Fread,3,1234,6} | |
35453 | -> @code{F-1,9} | |
35454 | @end smallexample | |
35455 | ||
c8aa23ab | 35456 | Example sequence of a read call, user presses @kbd{Ctrl-c} before syscall on |
0ce1b118 CV |
35457 | host is called: |
35458 | ||
35459 | @smallexample | |
35460 | <- @code{Fread,3,1234,6} | |
35461 | -> @code{F-1,4,C} | |
35462 | <- @code{T02} | |
35463 | @end smallexample | |
35464 | ||
c8aa23ab | 35465 | Example sequence of a read call, user presses @kbd{Ctrl-c} after syscall on |
0ce1b118 CV |
35466 | host is called: |
35467 | ||
35468 | @smallexample | |
35469 | <- @code{Fread,3,1234,6} | |
35470 | -> @code{X1234,6:XXXXXX} | |
35471 | <- @code{T02} | |
35472 | @end smallexample | |
35473 | ||
cfa9d6d9 DJ |
35474 | @node Library List Format |
35475 | @section Library List Format | |
35476 | @cindex library list format, remote protocol | |
35477 | ||
35478 | On some platforms, a dynamic loader (e.g.@: @file{ld.so}) runs in the | |
35479 | same process as your application to manage libraries. In this case, | |
35480 | @value{GDBN} can use the loader's symbol table and normal memory | |
35481 | operations to maintain a list of shared libraries. On other | |
35482 | platforms, the operating system manages loaded libraries. | |
35483 | @value{GDBN} can not retrieve the list of currently loaded libraries | |
35484 | through memory operations, so it uses the @samp{qXfer:libraries:read} | |
35485 | packet (@pxref{qXfer library list read}) instead. The remote stub | |
35486 | queries the target's operating system and reports which libraries | |
35487 | are loaded. | |
35488 | ||
35489 | The @samp{qXfer:libraries:read} packet returns an XML document which | |
35490 | lists loaded libraries and their offsets. Each library has an | |
1fddbabb PA |
35491 | associated name and one or more segment or section base addresses, |
35492 | which report where the library was loaded in memory. | |
35493 | ||
35494 | For the common case of libraries that are fully linked binaries, the | |
35495 | library should have a list of segments. If the target supports | |
35496 | dynamic linking of a relocatable object file, its library XML element | |
35497 | should instead include a list of allocated sections. The segment or | |
35498 | section bases are start addresses, not relocation offsets; they do not | |
35499 | depend on the library's link-time base addresses. | |
cfa9d6d9 | 35500 | |
9cceb671 DJ |
35501 | @value{GDBN} must be linked with the Expat library to support XML |
35502 | library lists. @xref{Expat}. | |
35503 | ||
cfa9d6d9 DJ |
35504 | A simple memory map, with one loaded library relocated by a single |
35505 | offset, looks like this: | |
35506 | ||
35507 | @smallexample | |
35508 | <library-list> | |
35509 | <library name="/lib/libc.so.6"> | |
35510 | <segment address="0x10000000"/> | |
35511 | </library> | |
35512 | </library-list> | |
35513 | @end smallexample | |
35514 | ||
1fddbabb PA |
35515 | Another simple memory map, with one loaded library with three |
35516 | allocated sections (.text, .data, .bss), looks like this: | |
35517 | ||
35518 | @smallexample | |
35519 | <library-list> | |
35520 | <library name="sharedlib.o"> | |
35521 | <section address="0x10000000"/> | |
35522 | <section address="0x20000000"/> | |
35523 | <section address="0x30000000"/> | |
35524 | </library> | |
35525 | </library-list> | |
35526 | @end smallexample | |
35527 | ||
cfa9d6d9 DJ |
35528 | The format of a library list is described by this DTD: |
35529 | ||
35530 | @smallexample | |
35531 | <!-- library-list: Root element with versioning --> | |
35532 | <!ELEMENT library-list (library)*> | |
35533 | <!ATTLIST library-list version CDATA #FIXED "1.0"> | |
1fddbabb | 35534 | <!ELEMENT library (segment*, section*)> |
cfa9d6d9 DJ |
35535 | <!ATTLIST library name CDATA #REQUIRED> |
35536 | <!ELEMENT segment EMPTY> | |
35537 | <!ATTLIST segment address CDATA #REQUIRED> | |
1fddbabb PA |
35538 | <!ELEMENT section EMPTY> |
35539 | <!ATTLIST section address CDATA #REQUIRED> | |
cfa9d6d9 DJ |
35540 | @end smallexample |
35541 | ||
1fddbabb PA |
35542 | In addition, segments and section descriptors cannot be mixed within a |
35543 | single library element, and you must supply at least one segment or | |
35544 | section for each library. | |
35545 | ||
79a6e687 BW |
35546 | @node Memory Map Format |
35547 | @section Memory Map Format | |
68437a39 DJ |
35548 | @cindex memory map format |
35549 | ||
35550 | To be able to write into flash memory, @value{GDBN} needs to obtain a | |
35551 | memory map from the target. This section describes the format of the | |
35552 | memory map. | |
35553 | ||
35554 | The memory map is obtained using the @samp{qXfer:memory-map:read} | |
35555 | (@pxref{qXfer memory map read}) packet and is an XML document that | |
9cceb671 DJ |
35556 | lists memory regions. |
35557 | ||
35558 | @value{GDBN} must be linked with the Expat library to support XML | |
35559 | memory maps. @xref{Expat}. | |
35560 | ||
35561 | The top-level structure of the document is shown below: | |
68437a39 DJ |
35562 | |
35563 | @smallexample | |
35564 | <?xml version="1.0"?> | |
35565 | <!DOCTYPE memory-map | |
35566 | PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN" | |
35567 | "http://sourceware.org/gdb/gdb-memory-map.dtd"> | |
35568 | <memory-map> | |
35569 | region... | |
35570 | </memory-map> | |
35571 | @end smallexample | |
35572 | ||
35573 | Each region can be either: | |
35574 | ||
35575 | @itemize | |
35576 | ||
35577 | @item | |
35578 | A region of RAM starting at @var{addr} and extending for @var{length} | |
35579 | bytes from there: | |
35580 | ||
35581 | @smallexample | |
35582 | <memory type="ram" start="@var{addr}" length="@var{length}"/> | |
35583 | @end smallexample | |
35584 | ||
35585 | ||
35586 | @item | |
35587 | A region of read-only memory: | |
35588 | ||
35589 | @smallexample | |
35590 | <memory type="rom" start="@var{addr}" length="@var{length}"/> | |
35591 | @end smallexample | |
35592 | ||
35593 | ||
35594 | @item | |
35595 | A region of flash memory, with erasure blocks @var{blocksize} | |
35596 | bytes in length: | |
35597 | ||
35598 | @smallexample | |
35599 | <memory type="flash" start="@var{addr}" length="@var{length}"> | |
35600 | <property name="blocksize">@var{blocksize}</property> | |
35601 | </memory> | |
35602 | @end smallexample | |
35603 | ||
35604 | @end itemize | |
35605 | ||
35606 | Regions must not overlap. @value{GDBN} assumes that areas of memory not covered | |
35607 | by the memory map are RAM, and uses the ordinary @samp{M} and @samp{X} | |
35608 | packets to write to addresses in such ranges. | |
35609 | ||
35610 | The formal DTD for memory map format is given below: | |
35611 | ||
35612 | @smallexample | |
35613 | <!-- ................................................... --> | |
35614 | <!-- Memory Map XML DTD ................................ --> | |
35615 | <!-- File: memory-map.dtd .............................. --> | |
35616 | <!-- .................................... .............. --> | |
35617 | <!-- memory-map.dtd --> | |
35618 | <!-- memory-map: Root element with versioning --> | |
35619 | <!ELEMENT memory-map (memory | property)> | |
35620 | <!ATTLIST memory-map version CDATA #FIXED "1.0.0"> | |
35621 | <!ELEMENT memory (property)> | |
35622 | <!-- memory: Specifies a memory region, | |
35623 | and its type, or device. --> | |
35624 | <!ATTLIST memory type CDATA #REQUIRED | |
35625 | start CDATA #REQUIRED | |
35626 | length CDATA #REQUIRED | |
35627 | device CDATA #IMPLIED> | |
35628 | <!-- property: Generic attribute tag --> | |
35629 | <!ELEMENT property (#PCDATA | property)*> | |
35630 | <!ATTLIST property name CDATA #REQUIRED> | |
35631 | @end smallexample | |
35632 | ||
dc146f7c VP |
35633 | @node Thread List Format |
35634 | @section Thread List Format | |
35635 | @cindex thread list format | |
35636 | ||
35637 | To efficiently update the list of threads and their attributes, | |
35638 | @value{GDBN} issues the @samp{qXfer:threads:read} packet | |
35639 | (@pxref{qXfer threads read}) and obtains the XML document with | |
35640 | the following structure: | |
35641 | ||
35642 | @smallexample | |
35643 | <?xml version="1.0"?> | |
35644 | <threads> | |
35645 | <thread id="id" core="0"> | |
35646 | ... description ... | |
35647 | </thread> | |
35648 | </threads> | |
35649 | @end smallexample | |
35650 | ||
35651 | Each @samp{thread} element must have the @samp{id} attribute that | |
35652 | identifies the thread (@pxref{thread-id syntax}). The | |
35653 | @samp{core} attribute, if present, specifies which processor core | |
35654 | the thread was last executing on. The content of the of @samp{thread} | |
35655 | element is interpreted as human-readable auxilliary information. | |
35656 | ||
f418dd93 DJ |
35657 | @include agentexpr.texi |
35658 | ||
00bf0b85 SS |
35659 | @node Trace File Format |
35660 | @appendix Trace File Format | |
35661 | @cindex trace file format | |
35662 | ||
35663 | The trace file comes in three parts: a header, a textual description | |
35664 | section, and a trace frame section with binary data. | |
35665 | ||
35666 | The header has the form @code{\x7fTRACE0\n}. The first byte is | |
35667 | @code{0x7f} so as to indicate that the file contains binary data, | |
35668 | while the @code{0} is a version number that may have different values | |
35669 | in the future. | |
35670 | ||
35671 | The description section consists of multiple lines of @sc{ascii} text | |
35672 | separated by newline characters (@code{0xa}). The lines may include a | |
35673 | variety of optional descriptive or context-setting information, such | |
35674 | as tracepoint definitions or register set size. @value{GDBN} will | |
35675 | ignore any line that it does not recognize. An empty line marks the end | |
35676 | of this section. | |
35677 | ||
35678 | @c FIXME add some specific types of data | |
35679 | ||
35680 | The trace frame section consists of a number of consecutive frames. | |
35681 | Each frame begins with a two-byte tracepoint number, followed by a | |
35682 | four-byte size giving the amount of data in the frame. The data in | |
35683 | the frame consists of a number of blocks, each introduced by a | |
35684 | character indicating its type (at least register, memory, and trace | |
35685 | state variable). The data in this section is raw binary, not a | |
35686 | hexadecimal or other encoding; its endianness matches the target's | |
35687 | endianness. | |
35688 | ||
35689 | @c FIXME bi-arch may require endianness/arch info in description section | |
35690 | ||
35691 | @table @code | |
35692 | @item R @var{bytes} | |
35693 | Register block. The number and ordering of bytes matches that of a | |
35694 | @code{g} packet in the remote protocol. Note that these are the | |
35695 | actual bytes, in target order and @value{GDBN} register order, not a | |
35696 | hexadecimal encoding. | |
35697 | ||
35698 | @item M @var{address} @var{length} @var{bytes}... | |
35699 | Memory block. This is a contiguous block of memory, at the 8-byte | |
35700 | address @var{address}, with a 2-byte length @var{length}, followed by | |
35701 | @var{length} bytes. | |
35702 | ||
35703 | @item V @var{number} @var{value} | |
35704 | Trace state variable block. This records the 8-byte signed value | |
35705 | @var{value} of trace state variable numbered @var{number}. | |
35706 | ||
35707 | @end table | |
35708 | ||
35709 | Future enhancements of the trace file format may include additional types | |
35710 | of blocks. | |
35711 | ||
23181151 DJ |
35712 | @node Target Descriptions |
35713 | @appendix Target Descriptions | |
35714 | @cindex target descriptions | |
35715 | ||
35716 | @strong{Warning:} target descriptions are still under active development, | |
35717 | and the contents and format may change between @value{GDBN} releases. | |
35718 | The format is expected to stabilize in the future. | |
35719 | ||
35720 | One of the challenges of using @value{GDBN} to debug embedded systems | |
35721 | is that there are so many minor variants of each processor | |
35722 | architecture in use. It is common practice for vendors to start with | |
35723 | a standard processor core --- ARM, PowerPC, or MIPS, for example --- | |
35724 | and then make changes to adapt it to a particular market niche. Some | |
35725 | architectures have hundreds of variants, available from dozens of | |
35726 | vendors. This leads to a number of problems: | |
35727 | ||
35728 | @itemize @bullet | |
35729 | @item | |
35730 | With so many different customized processors, it is difficult for | |
35731 | the @value{GDBN} maintainers to keep up with the changes. | |
35732 | @item | |
35733 | Since individual variants may have short lifetimes or limited | |
35734 | audiences, it may not be worthwhile to carry information about every | |
35735 | variant in the @value{GDBN} source tree. | |
35736 | @item | |
35737 | When @value{GDBN} does support the architecture of the embedded system | |
35738 | at hand, the task of finding the correct architecture name to give the | |
35739 | @command{set architecture} command can be error-prone. | |
35740 | @end itemize | |
35741 | ||
35742 | To address these problems, the @value{GDBN} remote protocol allows a | |
35743 | target system to not only identify itself to @value{GDBN}, but to | |
35744 | actually describe its own features. This lets @value{GDBN} support | |
35745 | processor variants it has never seen before --- to the extent that the | |
35746 | descriptions are accurate, and that @value{GDBN} understands them. | |
35747 | ||
9cceb671 DJ |
35748 | @value{GDBN} must be linked with the Expat library to support XML |
35749 | target descriptions. @xref{Expat}. | |
123dc839 | 35750 | |
23181151 DJ |
35751 | @menu |
35752 | * Retrieving Descriptions:: How descriptions are fetched from a target. | |
35753 | * Target Description Format:: The contents of a target description. | |
123dc839 DJ |
35754 | * Predefined Target Types:: Standard types available for target |
35755 | descriptions. | |
35756 | * Standard Target Features:: Features @value{GDBN} knows about. | |
23181151 DJ |
35757 | @end menu |
35758 | ||
35759 | @node Retrieving Descriptions | |
35760 | @section Retrieving Descriptions | |
35761 | ||
35762 | Target descriptions can be read from the target automatically, or | |
35763 | specified by the user manually. The default behavior is to read the | |
35764 | description from the target. @value{GDBN} retrieves it via the remote | |
35765 | protocol using @samp{qXfer} requests (@pxref{General Query Packets, | |
35766 | qXfer}). The @var{annex} in the @samp{qXfer} packet will be | |
35767 | @samp{target.xml}. The contents of the @samp{target.xml} annex are an | |
35768 | XML document, of the form described in @ref{Target Description | |
35769 | Format}. | |
35770 | ||
35771 | Alternatively, you can specify a file to read for the target description. | |
35772 | If a file is set, the target will not be queried. The commands to | |
35773 | specify a file are: | |
35774 | ||
35775 | @table @code | |
35776 | @cindex set tdesc filename | |
35777 | @item set tdesc filename @var{path} | |
35778 | Read the target description from @var{path}. | |
35779 | ||
35780 | @cindex unset tdesc filename | |
35781 | @item unset tdesc filename | |
35782 | Do not read the XML target description from a file. @value{GDBN} | |
35783 | will use the description supplied by the current target. | |
35784 | ||
35785 | @cindex show tdesc filename | |
35786 | @item show tdesc filename | |
35787 | Show the filename to read for a target description, if any. | |
35788 | @end table | |
35789 | ||
35790 | ||
35791 | @node Target Description Format | |
35792 | @section Target Description Format | |
35793 | @cindex target descriptions, XML format | |
35794 | ||
35795 | A target description annex is an @uref{http://www.w3.org/XML/, XML} | |
35796 | document which complies with the Document Type Definition provided in | |
35797 | the @value{GDBN} sources in @file{gdb/features/gdb-target.dtd}. This | |
35798 | means you can use generally available tools like @command{xmllint} to | |
35799 | check that your feature descriptions are well-formed and valid. | |
35800 | However, to help people unfamiliar with XML write descriptions for | |
35801 | their targets, we also describe the grammar here. | |
35802 | ||
123dc839 DJ |
35803 | Target descriptions can identify the architecture of the remote target |
35804 | and (for some architectures) provide information about custom register | |
08d16641 PA |
35805 | sets. They can also identify the OS ABI of the remote target. |
35806 | @value{GDBN} can use this information to autoconfigure for your | |
123dc839 | 35807 | target, or to warn you if you connect to an unsupported target. |
23181151 DJ |
35808 | |
35809 | Here is a simple target description: | |
35810 | ||
123dc839 | 35811 | @smallexample |
1780a0ed | 35812 | <target version="1.0"> |
23181151 DJ |
35813 | <architecture>i386:x86-64</architecture> |
35814 | </target> | |
123dc839 | 35815 | @end smallexample |
23181151 DJ |
35816 | |
35817 | @noindent | |
35818 | This minimal description only says that the target uses | |
35819 | the x86-64 architecture. | |
35820 | ||
123dc839 DJ |
35821 | A target description has the following overall form, with [ ] marking |
35822 | optional elements and @dots{} marking repeatable elements. The elements | |
35823 | are explained further below. | |
23181151 | 35824 | |
123dc839 | 35825 | @smallexample |
23181151 DJ |
35826 | <?xml version="1.0"?> |
35827 | <!DOCTYPE target SYSTEM "gdb-target.dtd"> | |
1780a0ed | 35828 | <target version="1.0"> |
123dc839 | 35829 | @r{[}@var{architecture}@r{]} |
08d16641 | 35830 | @r{[}@var{osabi}@r{]} |
e35359c5 | 35831 | @r{[}@var{compatible}@r{]} |
123dc839 | 35832 | @r{[}@var{feature}@dots{}@r{]} |
23181151 | 35833 | </target> |
123dc839 | 35834 | @end smallexample |
23181151 DJ |
35835 | |
35836 | @noindent | |
35837 | The description is generally insensitive to whitespace and line | |
35838 | breaks, under the usual common-sense rules. The XML version | |
35839 | declaration and document type declaration can generally be omitted | |
35840 | (@value{GDBN} does not require them), but specifying them may be | |
1780a0ed DJ |
35841 | useful for XML validation tools. The @samp{version} attribute for |
35842 | @samp{<target>} may also be omitted, but we recommend | |
35843 | including it; if future versions of @value{GDBN} use an incompatible | |
35844 | revision of @file{gdb-target.dtd}, they will detect and report | |
35845 | the version mismatch. | |
23181151 | 35846 | |
108546a0 DJ |
35847 | @subsection Inclusion |
35848 | @cindex target descriptions, inclusion | |
35849 | @cindex XInclude | |
35850 | @ifnotinfo | |
35851 | @cindex <xi:include> | |
35852 | @end ifnotinfo | |
35853 | ||
35854 | It can sometimes be valuable to split a target description up into | |
35855 | several different annexes, either for organizational purposes, or to | |
35856 | share files between different possible target descriptions. You can | |
35857 | divide a description into multiple files by replacing any element of | |
35858 | the target description with an inclusion directive of the form: | |
35859 | ||
123dc839 | 35860 | @smallexample |
108546a0 | 35861 | <xi:include href="@var{document}"/> |
123dc839 | 35862 | @end smallexample |
108546a0 DJ |
35863 | |
35864 | @noindent | |
35865 | When @value{GDBN} encounters an element of this form, it will retrieve | |
35866 | the named XML @var{document}, and replace the inclusion directive with | |
35867 | the contents of that document. If the current description was read | |
35868 | using @samp{qXfer}, then so will be the included document; | |
35869 | @var{document} will be interpreted as the name of an annex. If the | |
35870 | current description was read from a file, @value{GDBN} will look for | |
35871 | @var{document} as a file in the same directory where it found the | |
35872 | original description. | |
35873 | ||
123dc839 DJ |
35874 | @subsection Architecture |
35875 | @cindex <architecture> | |
35876 | ||
35877 | An @samp{<architecture>} element has this form: | |
35878 | ||
35879 | @smallexample | |
35880 | <architecture>@var{arch}</architecture> | |
35881 | @end smallexample | |
35882 | ||
e35359c5 UW |
35883 | @var{arch} is one of the architectures from the set accepted by |
35884 | @code{set architecture} (@pxref{Targets, ,Specifying a Debugging Target}). | |
123dc839 | 35885 | |
08d16641 PA |
35886 | @subsection OS ABI |
35887 | @cindex @code{<osabi>} | |
35888 | ||
35889 | This optional field was introduced in @value{GDBN} version 7.0. | |
35890 | Previous versions of @value{GDBN} ignore it. | |
35891 | ||
35892 | An @samp{<osabi>} element has this form: | |
35893 | ||
35894 | @smallexample | |
35895 | <osabi>@var{abi-name}</osabi> | |
35896 | @end smallexample | |
35897 | ||
35898 | @var{abi-name} is an OS ABI name from the same selection accepted by | |
35899 | @w{@code{set osabi}} (@pxref{ABI, ,Configuring the Current ABI}). | |
35900 | ||
e35359c5 UW |
35901 | @subsection Compatible Architecture |
35902 | @cindex @code{<compatible>} | |
35903 | ||
35904 | This optional field was introduced in @value{GDBN} version 7.0. | |
35905 | Previous versions of @value{GDBN} ignore it. | |
35906 | ||
35907 | A @samp{<compatible>} element has this form: | |
35908 | ||
35909 | @smallexample | |
35910 | <compatible>@var{arch}</compatible> | |
35911 | @end smallexample | |
35912 | ||
35913 | @var{arch} is one of the architectures from the set accepted by | |
35914 | @code{set architecture} (@pxref{Targets, ,Specifying a Debugging Target}). | |
35915 | ||
35916 | A @samp{<compatible>} element is used to specify that the target | |
35917 | is able to run binaries in some other than the main target architecture | |
35918 | given by the @samp{<architecture>} element. For example, on the | |
35919 | Cell Broadband Engine, the main architecture is @code{powerpc:common} | |
35920 | or @code{powerpc:common64}, but the system is able to run binaries | |
35921 | in the @code{spu} architecture as well. The way to describe this | |
35922 | capability with @samp{<compatible>} is as follows: | |
35923 | ||
35924 | @smallexample | |
35925 | <architecture>powerpc:common</architecture> | |
35926 | <compatible>spu</compatible> | |
35927 | @end smallexample | |
35928 | ||
123dc839 DJ |
35929 | @subsection Features |
35930 | @cindex <feature> | |
35931 | ||
35932 | Each @samp{<feature>} describes some logical portion of the target | |
35933 | system. Features are currently used to describe available CPU | |
35934 | registers and the types of their contents. A @samp{<feature>} element | |
35935 | has this form: | |
35936 | ||
35937 | @smallexample | |
35938 | <feature name="@var{name}"> | |
35939 | @r{[}@var{type}@dots{}@r{]} | |
35940 | @var{reg}@dots{} | |
35941 | </feature> | |
35942 | @end smallexample | |
35943 | ||
35944 | @noindent | |
35945 | Each feature's name should be unique within the description. The name | |
35946 | of a feature does not matter unless @value{GDBN} has some special | |
35947 | knowledge of the contents of that feature; if it does, the feature | |
35948 | should have its standard name. @xref{Standard Target Features}. | |
35949 | ||
35950 | @subsection Types | |
35951 | ||
35952 | Any register's value is a collection of bits which @value{GDBN} must | |
35953 | interpret. The default interpretation is a two's complement integer, | |
35954 | but other types can be requested by name in the register description. | |
35955 | Some predefined types are provided by @value{GDBN} (@pxref{Predefined | |
35956 | Target Types}), and the description can define additional composite types. | |
35957 | ||
35958 | Each type element must have an @samp{id} attribute, which gives | |
35959 | a unique (within the containing @samp{<feature>}) name to the type. | |
35960 | Types must be defined before they are used. | |
35961 | ||
35962 | @cindex <vector> | |
35963 | Some targets offer vector registers, which can be treated as arrays | |
35964 | of scalar elements. These types are written as @samp{<vector>} elements, | |
35965 | specifying the array element type, @var{type}, and the number of elements, | |
35966 | @var{count}: | |
35967 | ||
35968 | @smallexample | |
35969 | <vector id="@var{id}" type="@var{type}" count="@var{count}"/> | |
35970 | @end smallexample | |
35971 | ||
35972 | @cindex <union> | |
35973 | If a register's value is usefully viewed in multiple ways, define it | |
35974 | with a union type containing the useful representations. The | |
35975 | @samp{<union>} element contains one or more @samp{<field>} elements, | |
35976 | each of which has a @var{name} and a @var{type}: | |
35977 | ||
35978 | @smallexample | |
35979 | <union id="@var{id}"> | |
35980 | <field name="@var{name}" type="@var{type}"/> | |
35981 | @dots{} | |
35982 | </union> | |
35983 | @end smallexample | |
35984 | ||
f5dff777 DJ |
35985 | @cindex <struct> |
35986 | If a register's value is composed from several separate values, define | |
35987 | it with a structure type. There are two forms of the @samp{<struct>} | |
35988 | element; a @samp{<struct>} element must either contain only bitfields | |
35989 | or contain no bitfields. If the structure contains only bitfields, | |
35990 | its total size in bytes must be specified, each bitfield must have an | |
35991 | explicit start and end, and bitfields are automatically assigned an | |
35992 | integer type. The field's @var{start} should be less than or | |
35993 | equal to its @var{end}, and zero represents the least significant bit. | |
35994 | ||
35995 | @smallexample | |
35996 | <struct id="@var{id}" size="@var{size}"> | |
35997 | <field name="@var{name}" start="@var{start}" end="@var{end}"/> | |
35998 | @dots{} | |
35999 | </struct> | |
36000 | @end smallexample | |
36001 | ||
36002 | If the structure contains no bitfields, then each field has an | |
36003 | explicit type, and no implicit padding is added. | |
36004 | ||
36005 | @smallexample | |
36006 | <struct id="@var{id}"> | |
36007 | <field name="@var{name}" type="@var{type}"/> | |
36008 | @dots{} | |
36009 | </struct> | |
36010 | @end smallexample | |
36011 | ||
36012 | @cindex <flags> | |
36013 | If a register's value is a series of single-bit flags, define it with | |
36014 | a flags type. The @samp{<flags>} element has an explicit @var{size} | |
36015 | and contains one or more @samp{<field>} elements. Each field has a | |
36016 | @var{name}, a @var{start}, and an @var{end}. Only single-bit flags | |
36017 | are supported. | |
36018 | ||
36019 | @smallexample | |
36020 | <flags id="@var{id}" size="@var{size}"> | |
36021 | <field name="@var{name}" start="@var{start}" end="@var{end}"/> | |
36022 | @dots{} | |
36023 | </flags> | |
36024 | @end smallexample | |
36025 | ||
123dc839 DJ |
36026 | @subsection Registers |
36027 | @cindex <reg> | |
36028 | ||
36029 | Each register is represented as an element with this form: | |
36030 | ||
36031 | @smallexample | |
36032 | <reg name="@var{name}" | |
36033 | bitsize="@var{size}" | |
36034 | @r{[}regnum="@var{num}"@r{]} | |
36035 | @r{[}save-restore="@var{save-restore}"@r{]} | |
36036 | @r{[}type="@var{type}"@r{]} | |
36037 | @r{[}group="@var{group}"@r{]}/> | |
36038 | @end smallexample | |
36039 | ||
36040 | @noindent | |
36041 | The components are as follows: | |
36042 | ||
36043 | @table @var | |
36044 | ||
36045 | @item name | |
36046 | The register's name; it must be unique within the target description. | |
36047 | ||
36048 | @item bitsize | |
36049 | The register's size, in bits. | |
36050 | ||
36051 | @item regnum | |
36052 | The register's number. If omitted, a register's number is one greater | |
36053 | than that of the previous register (either in the current feature or in | |
36054 | a preceeding feature); the first register in the target description | |
36055 | defaults to zero. This register number is used to read or write | |
36056 | the register; e.g.@: it is used in the remote @code{p} and @code{P} | |
36057 | packets, and registers appear in the @code{g} and @code{G} packets | |
36058 | in order of increasing register number. | |
36059 | ||
36060 | @item save-restore | |
36061 | Whether the register should be preserved across inferior function | |
36062 | calls; this must be either @code{yes} or @code{no}. The default is | |
36063 | @code{yes}, which is appropriate for most registers except for | |
36064 | some system control registers; this is not related to the target's | |
36065 | ABI. | |
36066 | ||
36067 | @item type | |
36068 | The type of the register. @var{type} may be a predefined type, a type | |
36069 | defined in the current feature, or one of the special types @code{int} | |
36070 | and @code{float}. @code{int} is an integer type of the correct size | |
36071 | for @var{bitsize}, and @code{float} is a floating point type (in the | |
36072 | architecture's normal floating point format) of the correct size for | |
36073 | @var{bitsize}. The default is @code{int}. | |
36074 | ||
36075 | @item group | |
36076 | The register group to which this register belongs. @var{group} must | |
36077 | be either @code{general}, @code{float}, or @code{vector}. If no | |
36078 | @var{group} is specified, @value{GDBN} will not display the register | |
36079 | in @code{info registers}. | |
36080 | ||
36081 | @end table | |
36082 | ||
36083 | @node Predefined Target Types | |
36084 | @section Predefined Target Types | |
36085 | @cindex target descriptions, predefined types | |
36086 | ||
36087 | Type definitions in the self-description can build up composite types | |
36088 | from basic building blocks, but can not define fundamental types. Instead, | |
36089 | standard identifiers are provided by @value{GDBN} for the fundamental | |
36090 | types. The currently supported types are: | |
36091 | ||
36092 | @table @code | |
36093 | ||
36094 | @item int8 | |
36095 | @itemx int16 | |
36096 | @itemx int32 | |
36097 | @itemx int64 | |
7cc46491 | 36098 | @itemx int128 |
123dc839 DJ |
36099 | Signed integer types holding the specified number of bits. |
36100 | ||
36101 | @item uint8 | |
36102 | @itemx uint16 | |
36103 | @itemx uint32 | |
36104 | @itemx uint64 | |
7cc46491 | 36105 | @itemx uint128 |
123dc839 DJ |
36106 | Unsigned integer types holding the specified number of bits. |
36107 | ||
36108 | @item code_ptr | |
36109 | @itemx data_ptr | |
36110 | Pointers to unspecified code and data. The program counter and | |
36111 | any dedicated return address register may be marked as code | |
36112 | pointers; printing a code pointer converts it into a symbolic | |
36113 | address. The stack pointer and any dedicated address registers | |
36114 | may be marked as data pointers. | |
36115 | ||
6e3bbd1a PB |
36116 | @item ieee_single |
36117 | Single precision IEEE floating point. | |
36118 | ||
36119 | @item ieee_double | |
36120 | Double precision IEEE floating point. | |
36121 | ||
123dc839 DJ |
36122 | @item arm_fpa_ext |
36123 | The 12-byte extended precision format used by ARM FPA registers. | |
36124 | ||
075b51b7 L |
36125 | @item i387_ext |
36126 | The 10-byte extended precision format used by x87 registers. | |
36127 | ||
36128 | @item i386_eflags | |
36129 | 32bit @sc{eflags} register used by x86. | |
36130 | ||
36131 | @item i386_mxcsr | |
36132 | 32bit @sc{mxcsr} register used by x86. | |
36133 | ||
123dc839 DJ |
36134 | @end table |
36135 | ||
36136 | @node Standard Target Features | |
36137 | @section Standard Target Features | |
36138 | @cindex target descriptions, standard features | |
36139 | ||
36140 | A target description must contain either no registers or all the | |
36141 | target's registers. If the description contains no registers, then | |
36142 | @value{GDBN} will assume a default register layout, selected based on | |
36143 | the architecture. If the description contains any registers, the | |
36144 | default layout will not be used; the standard registers must be | |
36145 | described in the target description, in such a way that @value{GDBN} | |
36146 | can recognize them. | |
36147 | ||
36148 | This is accomplished by giving specific names to feature elements | |
36149 | which contain standard registers. @value{GDBN} will look for features | |
36150 | with those names and verify that they contain the expected registers; | |
36151 | if any known feature is missing required registers, or if any required | |
36152 | feature is missing, @value{GDBN} will reject the target | |
36153 | description. You can add additional registers to any of the | |
36154 | standard features --- @value{GDBN} will display them just as if | |
36155 | they were added to an unrecognized feature. | |
36156 | ||
36157 | This section lists the known features and their expected contents. | |
36158 | Sample XML documents for these features are included in the | |
36159 | @value{GDBN} source tree, in the directory @file{gdb/features}. | |
36160 | ||
36161 | Names recognized by @value{GDBN} should include the name of the | |
36162 | company or organization which selected the name, and the overall | |
36163 | architecture to which the feature applies; so e.g.@: the feature | |
36164 | containing ARM core registers is named @samp{org.gnu.gdb.arm.core}. | |
36165 | ||
ff6f572f DJ |
36166 | The names of registers are not case sensitive for the purpose |
36167 | of recognizing standard features, but @value{GDBN} will only display | |
36168 | registers using the capitalization used in the description. | |
36169 | ||
e9c17194 VP |
36170 | @menu |
36171 | * ARM Features:: | |
3bb8d5c3 | 36172 | * i386 Features:: |
1e26b4f8 | 36173 | * MIPS Features:: |
e9c17194 | 36174 | * M68K Features:: |
1e26b4f8 | 36175 | * PowerPC Features:: |
e9c17194 VP |
36176 | @end menu |
36177 | ||
36178 | ||
36179 | @node ARM Features | |
123dc839 DJ |
36180 | @subsection ARM Features |
36181 | @cindex target descriptions, ARM features | |
36182 | ||
9779414d DJ |
36183 | The @samp{org.gnu.gdb.arm.core} feature is required for non-M-profile |
36184 | ARM targets. | |
123dc839 DJ |
36185 | It should contain registers @samp{r0} through @samp{r13}, @samp{sp}, |
36186 | @samp{lr}, @samp{pc}, and @samp{cpsr}. | |
36187 | ||
9779414d DJ |
36188 | For M-profile targets (e.g. Cortex-M3), the @samp{org.gnu.gdb.arm.core} |
36189 | feature is replaced by @samp{org.gnu.gdb.arm.m-profile}. It should contain | |
36190 | registers @samp{r0} through @samp{r13}, @samp{sp}, @samp{lr}, @samp{pc}, | |
36191 | and @samp{xpsr}. | |
36192 | ||
123dc839 DJ |
36193 | The @samp{org.gnu.gdb.arm.fpa} feature is optional. If present, it |
36194 | should contain registers @samp{f0} through @samp{f7} and @samp{fps}. | |
36195 | ||
ff6f572f DJ |
36196 | The @samp{org.gnu.gdb.xscale.iwmmxt} feature is optional. If present, |
36197 | it should contain at least registers @samp{wR0} through @samp{wR15} and | |
36198 | @samp{wCGR0} through @samp{wCGR3}. The @samp{wCID}, @samp{wCon}, | |
36199 | @samp{wCSSF}, and @samp{wCASF} registers are optional. | |
23181151 | 36200 | |
58d6951d DJ |
36201 | The @samp{org.gnu.gdb.arm.vfp} feature is optional. If present, it |
36202 | should contain at least registers @samp{d0} through @samp{d15}. If | |
36203 | they are present, @samp{d16} through @samp{d31} should also be included. | |
36204 | @value{GDBN} will synthesize the single-precision registers from | |
36205 | halves of the double-precision registers. | |
36206 | ||
36207 | The @samp{org.gnu.gdb.arm.neon} feature is optional. It does not | |
36208 | need to contain registers; it instructs @value{GDBN} to display the | |
36209 | VFP double-precision registers as vectors and to synthesize the | |
36210 | quad-precision registers from pairs of double-precision registers. | |
36211 | If this feature is present, @samp{org.gnu.gdb.arm.vfp} must also | |
36212 | be present and include 32 double-precision registers. | |
36213 | ||
3bb8d5c3 L |
36214 | @node i386 Features |
36215 | @subsection i386 Features | |
36216 | @cindex target descriptions, i386 features | |
36217 | ||
36218 | The @samp{org.gnu.gdb.i386.core} feature is required for i386/amd64 | |
36219 | targets. It should describe the following registers: | |
36220 | ||
36221 | @itemize @minus | |
36222 | @item | |
36223 | @samp{eax} through @samp{edi} plus @samp{eip} for i386 | |
36224 | @item | |
36225 | @samp{rax} through @samp{r15} plus @samp{rip} for amd64 | |
36226 | @item | |
36227 | @samp{eflags}, @samp{cs}, @samp{ss}, @samp{ds}, @samp{es}, | |
36228 | @samp{fs}, @samp{gs} | |
36229 | @item | |
36230 | @samp{st0} through @samp{st7} | |
36231 | @item | |
36232 | @samp{fctrl}, @samp{fstat}, @samp{ftag}, @samp{fiseg}, @samp{fioff}, | |
36233 | @samp{foseg}, @samp{fooff} and @samp{fop} | |
36234 | @end itemize | |
36235 | ||
36236 | The register sets may be different, depending on the target. | |
36237 | ||
3a13a53b | 36238 | The @samp{org.gnu.gdb.i386.sse} feature is optional. It should |
3bb8d5c3 L |
36239 | describe registers: |
36240 | ||
36241 | @itemize @minus | |
36242 | @item | |
36243 | @samp{xmm0} through @samp{xmm7} for i386 | |
36244 | @item | |
36245 | @samp{xmm0} through @samp{xmm15} for amd64 | |
36246 | @item | |
36247 | @samp{mxcsr} | |
36248 | @end itemize | |
36249 | ||
3a13a53b L |
36250 | The @samp{org.gnu.gdb.i386.avx} feature is optional and requires the |
36251 | @samp{org.gnu.gdb.i386.sse} feature. It should | |
f68eb612 L |
36252 | describe the upper 128 bits of @sc{ymm} registers: |
36253 | ||
36254 | @itemize @minus | |
36255 | @item | |
36256 | @samp{ymm0h} through @samp{ymm7h} for i386 | |
36257 | @item | |
36258 | @samp{ymm0h} through @samp{ymm15h} for amd64 | |
f68eb612 L |
36259 | @end itemize |
36260 | ||
3bb8d5c3 L |
36261 | The @samp{org.gnu.gdb.i386.linux} feature is optional. It should |
36262 | describe a single register, @samp{orig_eax}. | |
36263 | ||
1e26b4f8 | 36264 | @node MIPS Features |
f8b73d13 DJ |
36265 | @subsection MIPS Features |
36266 | @cindex target descriptions, MIPS features | |
36267 | ||
36268 | The @samp{org.gnu.gdb.mips.cpu} feature is required for MIPS targets. | |
36269 | It should contain registers @samp{r0} through @samp{r31}, @samp{lo}, | |
36270 | @samp{hi}, and @samp{pc}. They may be 32-bit or 64-bit depending | |
36271 | on the target. | |
36272 | ||
36273 | The @samp{org.gnu.gdb.mips.cp0} feature is also required. It should | |
36274 | contain at least the @samp{status}, @samp{badvaddr}, and @samp{cause} | |
36275 | registers. They may be 32-bit or 64-bit depending on the target. | |
36276 | ||
36277 | The @samp{org.gnu.gdb.mips.fpu} feature is currently required, though | |
36278 | it may be optional in a future version of @value{GDBN}. It should | |
36279 | contain registers @samp{f0} through @samp{f31}, @samp{fcsr}, and | |
36280 | @samp{fir}. They may be 32-bit or 64-bit depending on the target. | |
36281 | ||
822b6570 DJ |
36282 | The @samp{org.gnu.gdb.mips.linux} feature is optional. It should |
36283 | contain a single register, @samp{restart}, which is used by the | |
36284 | Linux kernel to control restartable syscalls. | |
36285 | ||
e9c17194 VP |
36286 | @node M68K Features |
36287 | @subsection M68K Features | |
36288 | @cindex target descriptions, M68K features | |
36289 | ||
36290 | @table @code | |
36291 | @item @samp{org.gnu.gdb.m68k.core} | |
36292 | @itemx @samp{org.gnu.gdb.coldfire.core} | |
36293 | @itemx @samp{org.gnu.gdb.fido.core} | |
36294 | One of those features must be always present. | |
249e1128 | 36295 | The feature that is present determines which flavor of m68k is |
e9c17194 VP |
36296 | used. The feature that is present should contain registers |
36297 | @samp{d0} through @samp{d7}, @samp{a0} through @samp{a5}, @samp{fp}, | |
36298 | @samp{sp}, @samp{ps} and @samp{pc}. | |
36299 | ||
36300 | @item @samp{org.gnu.gdb.coldfire.fp} | |
36301 | This feature is optional. If present, it should contain registers | |
36302 | @samp{fp0} through @samp{fp7}, @samp{fpcontrol}, @samp{fpstatus} and | |
36303 | @samp{fpiaddr}. | |
36304 | @end table | |
36305 | ||
1e26b4f8 | 36306 | @node PowerPC Features |
7cc46491 DJ |
36307 | @subsection PowerPC Features |
36308 | @cindex target descriptions, PowerPC features | |
36309 | ||
36310 | The @samp{org.gnu.gdb.power.core} feature is required for PowerPC | |
36311 | targets. It should contain registers @samp{r0} through @samp{r31}, | |
36312 | @samp{pc}, @samp{msr}, @samp{cr}, @samp{lr}, @samp{ctr}, and | |
36313 | @samp{xer}. They may be 32-bit or 64-bit depending on the target. | |
36314 | ||
36315 | The @samp{org.gnu.gdb.power.fpu} feature is optional. It should | |
36316 | contain registers @samp{f0} through @samp{f31} and @samp{fpscr}. | |
36317 | ||
36318 | The @samp{org.gnu.gdb.power.altivec} feature is optional. It should | |
36319 | contain registers @samp{vr0} through @samp{vr31}, @samp{vscr}, | |
36320 | and @samp{vrsave}. | |
36321 | ||
677c5bb1 LM |
36322 | The @samp{org.gnu.gdb.power.vsx} feature is optional. It should |
36323 | contain registers @samp{vs0h} through @samp{vs31h}. @value{GDBN} | |
36324 | will combine these registers with the floating point registers | |
36325 | (@samp{f0} through @samp{f31}) and the altivec registers (@samp{vr0} | |
aeac0ff9 | 36326 | through @samp{vr31}) to present the 128-bit wide registers @samp{vs0} |
677c5bb1 LM |
36327 | through @samp{vs63}, the set of vector registers for POWER7. |
36328 | ||
7cc46491 DJ |
36329 | The @samp{org.gnu.gdb.power.spe} feature is optional. It should |
36330 | contain registers @samp{ev0h} through @samp{ev31h}, @samp{acc}, and | |
36331 | @samp{spefscr}. SPE targets should provide 32-bit registers in | |
36332 | @samp{org.gnu.gdb.power.core} and provide the upper halves in | |
36333 | @samp{ev0h} through @samp{ev31h}. @value{GDBN} will combine | |
36334 | these to present registers @samp{ev0} through @samp{ev31} to the | |
36335 | user. | |
36336 | ||
07e059b5 VP |
36337 | @node Operating System Information |
36338 | @appendix Operating System Information | |
36339 | @cindex operating system information | |
36340 | ||
36341 | @menu | |
36342 | * Process list:: | |
36343 | @end menu | |
36344 | ||
36345 | Users of @value{GDBN} often wish to obtain information about the state of | |
36346 | the operating system running on the target---for example the list of | |
36347 | processes, or the list of open files. This section describes the | |
36348 | mechanism that makes it possible. This mechanism is similar to the | |
36349 | target features mechanism (@pxref{Target Descriptions}), but focuses | |
36350 | on a different aspect of target. | |
36351 | ||
36352 | Operating system information is retrived from the target via the | |
36353 | remote protocol, using @samp{qXfer} requests (@pxref{qXfer osdata | |
36354 | read}). The object name in the request should be @samp{osdata}, and | |
36355 | the @var{annex} identifies the data to be fetched. | |
36356 | ||
36357 | @node Process list | |
36358 | @appendixsection Process list | |
36359 | @cindex operating system information, process list | |
36360 | ||
36361 | When requesting the process list, the @var{annex} field in the | |
36362 | @samp{qXfer} request should be @samp{processes}. The returned data is | |
36363 | an XML document. The formal syntax of this document is defined in | |
36364 | @file{gdb/features/osdata.dtd}. | |
36365 | ||
36366 | An example document is: | |
36367 | ||
36368 | @smallexample | |
36369 | <?xml version="1.0"?> | |
36370 | <!DOCTYPE target SYSTEM "osdata.dtd"> | |
36371 | <osdata type="processes"> | |
36372 | <item> | |
36373 | <column name="pid">1</column> | |
36374 | <column name="user">root</column> | |
36375 | <column name="command">/sbin/init</column> | |
dc146f7c | 36376 | <column name="cores">1,2,3</column> |
07e059b5 VP |
36377 | </item> |
36378 | </osdata> | |
36379 | @end smallexample | |
36380 | ||
36381 | Each item should include a column whose name is @samp{pid}. The value | |
36382 | of that column should identify the process on the target. The | |
36383 | @samp{user} and @samp{command} columns are optional, and will be | |
dc146f7c VP |
36384 | displayed by @value{GDBN}. The @samp{cores} column, if present, |
36385 | should contain a comma-separated list of cores that this process | |
36386 | is running on. Target may provide additional columns, | |
07e059b5 VP |
36387 | which @value{GDBN} currently ignores. |
36388 | ||
aab4e0ec | 36389 | @include gpl.texi |
eb12ee30 | 36390 | |
e4c0cfae SS |
36391 | @node GNU Free Documentation License |
36392 | @appendix GNU Free Documentation License | |
6826cf00 EZ |
36393 | @include fdl.texi |
36394 | ||
6d2ebf8b | 36395 | @node Index |
c906108c SS |
36396 | @unnumbered Index |
36397 | ||
36398 | @printindex cp | |
36399 | ||
36400 | @tex | |
36401 | % I think something like @colophon should be in texinfo. In the | |
36402 | % meantime: | |
36403 | \long\def\colophon{\hbox to0pt{}\vfill | |
36404 | \centerline{The body of this manual is set in} | |
36405 | \centerline{\fontname\tenrm,} | |
36406 | \centerline{with headings in {\bf\fontname\tenbf}} | |
36407 | \centerline{and examples in {\tt\fontname\tentt}.} | |
36408 | \centerline{{\it\fontname\tenit\/},} | |
36409 | \centerline{{\bf\fontname\tenbf}, and} | |
36410 | \centerline{{\sl\fontname\tensl\/}} | |
36411 | \centerline{are used for emphasis.}\vfill} | |
36412 | \page\colophon | |
36413 | % Blame: doc@cygnus.com, 1991. | |
36414 | @end tex | |
36415 | ||
c906108c | 36416 | @bye |