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9742079a | 1 | \input texinfo @c -*- texinfo -*- |
c906108c | 2 | @setfilename gdbint.info |
25822942 | 3 | @include gdb-cfg.texi |
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4 | @dircategory Programming & development tools. |
5 | @direntry | |
c906108c | 6 | * Gdb-Internals: (gdbint). The GNU debugger's internals. |
e9c75b65 | 7 | @end direntry |
c906108c SS |
8 | |
9 | @ifinfo | |
25822942 | 10 | This file documents the internals of the GNU debugger @value{GDBN}. |
1e698235 | 11 | Copyright 1990,1991,1992,1993,1994,1996,1998,1999,2000,2001,2002,2003 |
e9c75b65 | 12 | Free Software Foundation, Inc. |
c906108c SS |
13 | Contributed by Cygnus Solutions. Written by John Gilmore. |
14 | Second Edition by Stan Shebs. | |
15 | ||
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16 | Permission is granted to copy, distribute and/or modify this document |
17 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
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18 | any later version published by the Free Software Foundation; with no |
19 | Invariant Sections, with the Front-Cover Texts being ``A GNU Manual,'' | |
20 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 21 | |
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22 | (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify |
23 | this GNU Manual, like GNU software. Copies published by the Free | |
24 | Software Foundation raise funds for GNU development.'' | |
c906108c SS |
25 | @end ifinfo |
26 | ||
27 | @setchapternewpage off | |
25822942 | 28 | @settitle @value{GDBN} Internals |
c906108c | 29 | |
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30 | @syncodeindex fn cp |
31 | @syncodeindex vr cp | |
32 | ||
c906108c | 33 | @titlepage |
25822942 | 34 | @title @value{GDBN} Internals |
c906108c SS |
35 | @subtitle{A guide to the internals of the GNU debugger} |
36 | @author John Gilmore | |
37 | @author Cygnus Solutions | |
38 | @author Second Edition: | |
39 | @author Stan Shebs | |
40 | @author Cygnus Solutions | |
41 | @page | |
42 | @tex | |
43 | \def\$#1${{#1}} % Kluge: collect RCS revision info without $...$ | |
44 | \xdef\manvers{\$Revision$} % For use in headers, footers too | |
45 | {\parskip=0pt | |
46 | \hfill Cygnus Solutions\par | |
47 | \hfill \manvers\par | |
48 | \hfill \TeX{}info \texinfoversion\par | |
49 | } | |
50 | @end tex | |
51 | ||
52 | @vskip 0pt plus 1filll | |
1e698235 DJ |
53 | Copyright @copyright{} 1990,1991,1992,1993,1994,1996,1998,1999,2000,2001, |
54 | 2002, 2003 Free Software Foundation, Inc. | |
c906108c | 55 | |
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56 | Permission is granted to copy, distribute and/or modify this document |
57 | under the terms of the GNU Free Documentation License, Version 1.1 or | |
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58 | any later version published by the Free Software Foundation; with no |
59 | Invariant Sections, with the Front-Cover Texts being ``A GNU Manual,'' | |
60 | and with the Back-Cover Texts as in (a) below. | |
c906108c | 61 | |
e9c75b65 EZ |
62 | (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify |
63 | this GNU Manual, like GNU software. Copies published by the Free | |
64 | Software Foundation raise funds for GNU development.'' | |
c906108c SS |
65 | @end titlepage |
66 | ||
449f3b6c | 67 | @contents |
449f3b6c | 68 | |
c906108c SS |
69 | @node Top |
70 | @c Perhaps this should be the title of the document (but only for info, | |
71 | @c not for TeX). Existing GNU manuals seem inconsistent on this point. | |
72 | @top Scope of this Document | |
73 | ||
25822942 DB |
74 | This document documents the internals of the GNU debugger, @value{GDBN}. It |
75 | includes description of @value{GDBN}'s key algorithms and operations, as well | |
76 | as the mechanisms that adapt @value{GDBN} to specific hosts and targets. | |
c906108c SS |
77 | |
78 | @menu | |
79 | * Requirements:: | |
80 | * Overall Structure:: | |
81 | * Algorithms:: | |
82 | * User Interface:: | |
89437448 | 83 | * libgdb:: |
c906108c SS |
84 | * Symbol Handling:: |
85 | * Language Support:: | |
86 | * Host Definition:: | |
87 | * Target Architecture Definition:: | |
88 | * Target Vector Definition:: | |
89 | * Native Debugging:: | |
90 | * Support Libraries:: | |
91 | * Coding:: | |
92 | * Porting GDB:: | |
8973da3a | 93 | * Releasing GDB:: |
085dd6e6 | 94 | * Testsuite:: |
c906108c | 95 | * Hints:: |
aab4e0ec | 96 | |
bcd7e15f | 97 | * GDB Observers:: @value{GDBN} Currently available observers |
aab4e0ec | 98 | * GNU Free Documentation License:: The license for this documentation |
56caf160 | 99 | * Index:: |
c906108c SS |
100 | @end menu |
101 | ||
102 | @node Requirements | |
103 | ||
104 | @chapter Requirements | |
56caf160 | 105 | @cindex requirements for @value{GDBN} |
c906108c SS |
106 | |
107 | Before diving into the internals, you should understand the formal | |
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108 | requirements and other expectations for @value{GDBN}. Although some |
109 | of these may seem obvious, there have been proposals for @value{GDBN} | |
110 | that have run counter to these requirements. | |
c906108c | 111 | |
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112 | First of all, @value{GDBN} is a debugger. It's not designed to be a |
113 | front panel for embedded systems. It's not a text editor. It's not a | |
114 | shell. It's not a programming environment. | |
c906108c | 115 | |
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116 | @value{GDBN} is an interactive tool. Although a batch mode is |
117 | available, @value{GDBN}'s primary role is to interact with a human | |
118 | programmer. | |
c906108c | 119 | |
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120 | @value{GDBN} should be responsive to the user. A programmer hot on |
121 | the trail of a nasty bug, and operating under a looming deadline, is | |
122 | going to be very impatient of everything, including the response time | |
123 | to debugger commands. | |
c906108c | 124 | |
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125 | @value{GDBN} should be relatively permissive, such as for expressions. |
126 | While the compiler should be picky (or have the option to be made | |
be9c6c35 | 127 | picky), since source code lives for a long time usually, the |
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128 | programmer doing debugging shouldn't be spending time figuring out to |
129 | mollify the debugger. | |
c906108c | 130 | |
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131 | @value{GDBN} will be called upon to deal with really large programs. |
132 | Executable sizes of 50 to 100 megabytes occur regularly, and we've | |
133 | heard reports of programs approaching 1 gigabyte in size. | |
c906108c | 134 | |
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135 | @value{GDBN} should be able to run everywhere. No other debugger is |
136 | available for even half as many configurations as @value{GDBN} | |
137 | supports. | |
c906108c SS |
138 | |
139 | ||
140 | @node Overall Structure | |
141 | ||
142 | @chapter Overall Structure | |
143 | ||
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144 | @value{GDBN} consists of three major subsystems: user interface, |
145 | symbol handling (the @dfn{symbol side}), and target system handling (the | |
146 | @dfn{target side}). | |
c906108c | 147 | |
2e685b93 | 148 | The user interface consists of several actual interfaces, plus |
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149 | supporting code. |
150 | ||
151 | The symbol side consists of object file readers, debugging info | |
152 | interpreters, symbol table management, source language expression | |
153 | parsing, type and value printing. | |
154 | ||
155 | The target side consists of execution control, stack frame analysis, and | |
156 | physical target manipulation. | |
157 | ||
158 | The target side/symbol side division is not formal, and there are a | |
159 | number of exceptions. For instance, core file support involves symbolic | |
160 | elements (the basic core file reader is in BFD) and target elements (it | |
161 | supplies the contents of memory and the values of registers). Instead, | |
162 | this division is useful for understanding how the minor subsystems | |
163 | should fit together. | |
164 | ||
165 | @section The Symbol Side | |
166 | ||
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167 | The symbolic side of @value{GDBN} can be thought of as ``everything |
168 | you can do in @value{GDBN} without having a live program running''. | |
169 | For instance, you can look at the types of variables, and evaluate | |
170 | many kinds of expressions. | |
c906108c SS |
171 | |
172 | @section The Target Side | |
173 | ||
56caf160 EZ |
174 | The target side of @value{GDBN} is the ``bits and bytes manipulator''. |
175 | Although it may make reference to symbolic info here and there, most | |
176 | of the target side will run with only a stripped executable | |
177 | available---or even no executable at all, in remote debugging cases. | |
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178 | |
179 | Operations such as disassembly, stack frame crawls, and register | |
180 | display, are able to work with no symbolic info at all. In some cases, | |
25822942 | 181 | such as disassembly, @value{GDBN} will use symbolic info to present addresses |
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182 | relative to symbols rather than as raw numbers, but it will work either |
183 | way. | |
184 | ||
185 | @section Configurations | |
186 | ||
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187 | @cindex host |
188 | @cindex target | |
25822942 | 189 | @dfn{Host} refers to attributes of the system where @value{GDBN} runs. |
c906108c SS |
190 | @dfn{Target} refers to the system where the program being debugged |
191 | executes. In most cases they are the same machine, in which case a | |
192 | third type of @dfn{Native} attributes come into play. | |
193 | ||
194 | Defines and include files needed to build on the host are host support. | |
195 | Examples are tty support, system defined types, host byte order, host | |
196 | float format. | |
197 | ||
198 | Defines and information needed to handle the target format are target | |
199 | dependent. Examples are the stack frame format, instruction set, | |
200 | breakpoint instruction, registers, and how to set up and tear down the stack | |
201 | to call a function. | |
202 | ||
203 | Information that is only needed when the host and target are the same, | |
204 | is native dependent. One example is Unix child process support; if the | |
205 | host and target are not the same, doing a fork to start the target | |
206 | process is a bad idea. The various macros needed for finding the | |
207 | registers in the @code{upage}, running @code{ptrace}, and such are all | |
208 | in the native-dependent files. | |
209 | ||
210 | Another example of native-dependent code is support for features that | |
211 | are really part of the target environment, but which require | |
212 | @code{#include} files that are only available on the host system. Core | |
213 | file handling and @code{setjmp} handling are two common cases. | |
214 | ||
25822942 | 215 | When you want to make @value{GDBN} work ``native'' on a particular machine, you |
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216 | have to include all three kinds of information. |
217 | ||
218 | ||
219 | @node Algorithms | |
220 | ||
221 | @chapter Algorithms | |
56caf160 | 222 | @cindex algorithms |
c906108c | 223 | |
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224 | @value{GDBN} uses a number of debugging-specific algorithms. They are |
225 | often not very complicated, but get lost in the thicket of special | |
226 | cases and real-world issues. This chapter describes the basic | |
227 | algorithms and mentions some of the specific target definitions that | |
228 | they use. | |
c906108c SS |
229 | |
230 | @section Frames | |
231 | ||
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232 | @cindex frame |
233 | @cindex call stack frame | |
234 | A frame is a construct that @value{GDBN} uses to keep track of calling | |
235 | and called functions. | |
c906108c | 236 | |
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237 | @findex create_new_frame |
238 | @vindex FRAME_FP | |
c906108c | 239 | @code{FRAME_FP} in the machine description has no meaning to the |
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240 | machine-independent part of @value{GDBN}, except that it is used when |
241 | setting up a new frame from scratch, as follows: | |
c906108c | 242 | |
474c8240 | 243 | @smallexample |
0ba6dca9 | 244 | create_new_frame (read_register (DEPRECATED_FP_REGNUM), read_pc ())); |
474c8240 | 245 | @end smallexample |
c906108c | 246 | |
56caf160 | 247 | @cindex frame pointer register |
0ba6dca9 AC |
248 | Other than that, all the meaning imparted to @code{DEPRECATED_FP_REGNUM} |
249 | is imparted by the machine-dependent code. So, | |
250 | @code{DEPRECATED_FP_REGNUM} can have any value that is convenient for | |
251 | the code that creates new frames. (@code{create_new_frame} calls | |
252 | @code{DEPRECATED_INIT_EXTRA_FRAME_INFO} if it is defined; that is where | |
253 | you should use the @code{DEPRECATED_FP_REGNUM} value, if your frames are | |
254 | nonstandard.) | |
c906108c | 255 | |
56caf160 | 256 | @cindex frame chain |
618ce49f AC |
257 | Given a @value{GDBN} frame, define @code{DEPRECATED_FRAME_CHAIN} to |
258 | determine the address of the calling function's frame. This will be | |
259 | used to create a new @value{GDBN} frame struct, and then | |
e9582e71 | 260 | @code{DEPRECATED_INIT_EXTRA_FRAME_INFO} and |
a5afb99f | 261 | @code{DEPRECATED_INIT_FRAME_PC} will be called for the new frame. |
c906108c SS |
262 | |
263 | @section Breakpoint Handling | |
264 | ||
56caf160 | 265 | @cindex breakpoints |
c906108c SS |
266 | In general, a breakpoint is a user-designated location in the program |
267 | where the user wants to regain control if program execution ever reaches | |
268 | that location. | |
269 | ||
270 | There are two main ways to implement breakpoints; either as ``hardware'' | |
271 | breakpoints or as ``software'' breakpoints. | |
272 | ||
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273 | @cindex hardware breakpoints |
274 | @cindex program counter | |
c906108c SS |
275 | Hardware breakpoints are sometimes available as a builtin debugging |
276 | features with some chips. Typically these work by having dedicated | |
277 | register into which the breakpoint address may be stored. If the PC | |
56caf160 | 278 | (shorthand for @dfn{program counter}) |
c906108c | 279 | ever matches a value in a breakpoint registers, the CPU raises an |
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280 | exception and reports it to @value{GDBN}. |
281 | ||
282 | Another possibility is when an emulator is in use; many emulators | |
283 | include circuitry that watches the address lines coming out from the | |
284 | processor, and force it to stop if the address matches a breakpoint's | |
285 | address. | |
286 | ||
287 | A third possibility is that the target already has the ability to do | |
288 | breakpoints somehow; for instance, a ROM monitor may do its own | |
289 | software breakpoints. So although these are not literally ``hardware | |
290 | breakpoints'', from @value{GDBN}'s point of view they work the same; | |
50e3ee83 | 291 | @value{GDBN} need not do anything more than set the breakpoint and wait |
56caf160 | 292 | for something to happen. |
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293 | |
294 | Since they depend on hardware resources, hardware breakpoints may be | |
56caf160 | 295 | limited in number; when the user asks for more, @value{GDBN} will |
9742079a | 296 | start trying to set software breakpoints. (On some architectures, |
937f164b | 297 | notably the 32-bit x86 platforms, @value{GDBN} cannot always know |
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298 | whether there's enough hardware resources to insert all the hardware |
299 | breakpoints and watchpoints. On those platforms, @value{GDBN} prints | |
300 | an error message only when the program being debugged is continued.) | |
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301 | |
302 | @cindex software breakpoints | |
303 | Software breakpoints require @value{GDBN} to do somewhat more work. | |
304 | The basic theory is that @value{GDBN} will replace a program | |
305 | instruction with a trap, illegal divide, or some other instruction | |
306 | that will cause an exception, and then when it's encountered, | |
307 | @value{GDBN} will take the exception and stop the program. When the | |
308 | user says to continue, @value{GDBN} will restore the original | |
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309 | instruction, single-step, re-insert the trap, and continue on. |
310 | ||
311 | Since it literally overwrites the program being tested, the program area | |
be9c6c35 | 312 | must be writable, so this technique won't work on programs in ROM. It |
c906108c | 313 | can also distort the behavior of programs that examine themselves, |
56caf160 | 314 | although such a situation would be highly unusual. |
c906108c SS |
315 | |
316 | Also, the software breakpoint instruction should be the smallest size of | |
317 | instruction, so it doesn't overwrite an instruction that might be a jump | |
318 | target, and cause disaster when the program jumps into the middle of the | |
319 | breakpoint instruction. (Strictly speaking, the breakpoint must be no | |
320 | larger than the smallest interval between instructions that may be jump | |
321 | targets; perhaps there is an architecture where only even-numbered | |
322 | instructions may jumped to.) Note that it's possible for an instruction | |
323 | set not to have any instructions usable for a software breakpoint, | |
324 | although in practice only the ARC has failed to define such an | |
325 | instruction. | |
326 | ||
56caf160 | 327 | @findex BREAKPOINT |
c906108c SS |
328 | The basic definition of the software breakpoint is the macro |
329 | @code{BREAKPOINT}. | |
330 | ||
331 | Basic breakpoint object handling is in @file{breakpoint.c}. However, | |
332 | much of the interesting breakpoint action is in @file{infrun.c}. | |
333 | ||
334 | @section Single Stepping | |
335 | ||
336 | @section Signal Handling | |
337 | ||
338 | @section Thread Handling | |
339 | ||
340 | @section Inferior Function Calls | |
341 | ||
342 | @section Longjmp Support | |
343 | ||
56caf160 | 344 | @cindex @code{longjmp} debugging |
25822942 | 345 | @value{GDBN} has support for figuring out that the target is doing a |
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346 | @code{longjmp} and for stopping at the target of the jump, if we are |
347 | stepping. This is done with a few specialized internal breakpoints, | |
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348 | which are visible in the output of the @samp{maint info breakpoint} |
349 | command. | |
c906108c | 350 | |
56caf160 | 351 | @findex GET_LONGJMP_TARGET |
c906108c SS |
352 | To make this work, you need to define a macro called |
353 | @code{GET_LONGJMP_TARGET}, which will examine the @code{jmp_buf} | |
354 | structure and extract the longjmp target address. Since @code{jmp_buf} | |
355 | is target specific, you will need to define it in the appropriate | |
56caf160 | 356 | @file{tm-@var{target}.h} file. Look in @file{tm-sun4os4.h} and |
c906108c SS |
357 | @file{sparc-tdep.c} for examples of how to do this. |
358 | ||
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359 | @section Watchpoints |
360 | @cindex watchpoints | |
361 | ||
362 | Watchpoints are a special kind of breakpoints (@pxref{Algorithms, | |
363 | breakpoints}) which break when data is accessed rather than when some | |
364 | instruction is executed. When you have data which changes without | |
365 | your knowing what code does that, watchpoints are the silver bullet to | |
366 | hunt down and kill such bugs. | |
367 | ||
368 | @cindex hardware watchpoints | |
369 | @cindex software watchpoints | |
370 | Watchpoints can be either hardware-assisted or not; the latter type is | |
371 | known as ``software watchpoints.'' @value{GDBN} always uses | |
372 | hardware-assisted watchpoints if they are available, and falls back on | |
373 | software watchpoints otherwise. Typical situations where @value{GDBN} | |
374 | will use software watchpoints are: | |
375 | ||
376 | @itemize @bullet | |
377 | @item | |
378 | The watched memory region is too large for the underlying hardware | |
379 | watchpoint support. For example, each x86 debug register can watch up | |
380 | to 4 bytes of memory, so trying to watch data structures whose size is | |
381 | more than 16 bytes will cause @value{GDBN} to use software | |
382 | watchpoints. | |
383 | ||
384 | @item | |
385 | The value of the expression to be watched depends on data held in | |
386 | registers (as opposed to memory). | |
387 | ||
388 | @item | |
389 | Too many different watchpoints requested. (On some architectures, | |
390 | this situation is impossible to detect until the debugged program is | |
391 | resumed.) Note that x86 debug registers are used both for hardware | |
392 | breakpoints and for watchpoints, so setting too many hardware | |
393 | breakpoints might cause watchpoint insertion to fail. | |
394 | ||
395 | @item | |
396 | No hardware-assisted watchpoints provided by the target | |
397 | implementation. | |
398 | @end itemize | |
399 | ||
400 | Software watchpoints are very slow, since @value{GDBN} needs to | |
401 | single-step the program being debugged and test the value of the | |
402 | watched expression(s) after each instruction. The rest of this | |
403 | section is mostly irrelevant for software watchpoints. | |
404 | ||
405 | @value{GDBN} uses several macros and primitives to support hardware | |
406 | watchpoints: | |
407 | ||
408 | @table @code | |
409 | @findex TARGET_HAS_HARDWARE_WATCHPOINTS | |
410 | @item TARGET_HAS_HARDWARE_WATCHPOINTS | |
411 | If defined, the target supports hardware watchpoints. | |
412 | ||
413 | @findex TARGET_CAN_USE_HARDWARE_WATCHPOINT | |
414 | @item TARGET_CAN_USE_HARDWARE_WATCHPOINT (@var{type}, @var{count}, @var{other}) | |
415 | Return the number of hardware watchpoints of type @var{type} that are | |
416 | possible to be set. The value is positive if @var{count} watchpoints | |
417 | of this type can be set, zero if setting watchpoints of this type is | |
418 | not supported, and negative if @var{count} is more than the maximum | |
419 | number of watchpoints of type @var{type} that can be set. @var{other} | |
420 | is non-zero if other types of watchpoints are currently enabled (there | |
421 | are architectures which cannot set watchpoints of different types at | |
422 | the same time). | |
423 | ||
424 | @findex TARGET_REGION_OK_FOR_HW_WATCHPOINT | |
425 | @item TARGET_REGION_OK_FOR_HW_WATCHPOINT (@var{addr}, @var{len}) | |
426 | Return non-zero if hardware watchpoints can be used to watch a region | |
427 | whose address is @var{addr} and whose length in bytes is @var{len}. | |
428 | ||
429 | @findex TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT | |
430 | @item TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT (@var{size}) | |
431 | Return non-zero if hardware watchpoints can be used to watch a region | |
432 | whose size is @var{size}. @value{GDBN} only uses this macro as a | |
433 | fall-back, in case @code{TARGET_REGION_OK_FOR_HW_WATCHPOINT} is not | |
434 | defined. | |
435 | ||
436 | @findex TARGET_DISABLE_HW_WATCHPOINTS | |
437 | @item TARGET_DISABLE_HW_WATCHPOINTS (@var{pid}) | |
438 | Disables watchpoints in the process identified by @var{pid}. This is | |
439 | used, e.g., on HP-UX which provides operations to disable and enable | |
440 | the page-level memory protection that implements hardware watchpoints | |
441 | on that platform. | |
442 | ||
443 | @findex TARGET_ENABLE_HW_WATCHPOINTS | |
444 | @item TARGET_ENABLE_HW_WATCHPOINTS (@var{pid}) | |
445 | Enables watchpoints in the process identified by @var{pid}. This is | |
446 | used, e.g., on HP-UX which provides operations to disable and enable | |
447 | the page-level memory protection that implements hardware watchpoints | |
448 | on that platform. | |
449 | ||
9742079a EZ |
450 | @findex target_insert_watchpoint |
451 | @findex target_remove_watchpoint | |
452 | @item target_insert_watchpoint (@var{addr}, @var{len}, @var{type}) | |
453 | @itemx target_remove_watchpoint (@var{addr}, @var{len}, @var{type}) | |
454 | Insert or remove a hardware watchpoint starting at @var{addr}, for | |
455 | @var{len} bytes. @var{type} is the watchpoint type, one of the | |
456 | possible values of the enumerated data type @code{target_hw_bp_type}, | |
457 | defined by @file{breakpoint.h} as follows: | |
458 | ||
474c8240 | 459 | @smallexample |
9742079a EZ |
460 | enum target_hw_bp_type |
461 | @{ | |
462 | hw_write = 0, /* Common (write) HW watchpoint */ | |
463 | hw_read = 1, /* Read HW watchpoint */ | |
464 | hw_access = 2, /* Access (read or write) HW watchpoint */ | |
465 | hw_execute = 3 /* Execute HW breakpoint */ | |
466 | @}; | |
474c8240 | 467 | @end smallexample |
9742079a EZ |
468 | |
469 | @noindent | |
470 | These two macros should return 0 for success, non-zero for failure. | |
471 | ||
472 | @cindex insert or remove hardware breakpoint | |
473 | @findex target_remove_hw_breakpoint | |
474 | @findex target_insert_hw_breakpoint | |
475 | @item target_remove_hw_breakpoint (@var{addr}, @var{shadow}) | |
476 | @itemx target_insert_hw_breakpoint (@var{addr}, @var{shadow}) | |
477 | Insert or remove a hardware-assisted breakpoint at address @var{addr}. | |
478 | Returns zero for success, non-zero for failure. @var{shadow} is the | |
479 | real contents of the byte where the breakpoint has been inserted; it | |
480 | is generally not valid when hardware breakpoints are used, but since | |
481 | no other code touches these values, the implementations of the above | |
482 | two macros can use them for their internal purposes. | |
483 | ||
484 | @findex target_stopped_data_address | |
485 | @item target_stopped_data_address () | |
486 | If the inferior has some watchpoint that triggered, return the address | |
487 | associated with that watchpoint. Otherwise, return zero. | |
488 | ||
489 | @findex DECR_PC_AFTER_HW_BREAK | |
490 | @item DECR_PC_AFTER_HW_BREAK | |
491 | If defined, @value{GDBN} decrements the program counter by the value | |
492 | of @code{DECR_PC_AFTER_HW_BREAK} after a hardware break-point. This | |
493 | overrides the value of @code{DECR_PC_AFTER_BREAK} when a breakpoint | |
494 | that breaks is a hardware-assisted breakpoint. | |
495 | ||
496 | @findex HAVE_STEPPABLE_WATCHPOINT | |
497 | @item HAVE_STEPPABLE_WATCHPOINT | |
498 | If defined to a non-zero value, it is not necessary to disable a | |
499 | watchpoint to step over it. | |
500 | ||
501 | @findex HAVE_NONSTEPPABLE_WATCHPOINT | |
502 | @item HAVE_NONSTEPPABLE_WATCHPOINT | |
503 | If defined to a non-zero value, @value{GDBN} should disable a | |
504 | watchpoint to step the inferior over it. | |
505 | ||
506 | @findex HAVE_CONTINUABLE_WATCHPOINT | |
507 | @item HAVE_CONTINUABLE_WATCHPOINT | |
508 | If defined to a non-zero value, it is possible to continue the | |
509 | inferior after a watchpoint has been hit. | |
510 | ||
511 | @findex CANNOT_STEP_HW_WATCHPOINTS | |
512 | @item CANNOT_STEP_HW_WATCHPOINTS | |
513 | If this is defined to a non-zero value, @value{GDBN} will remove all | |
514 | watchpoints before stepping the inferior. | |
515 | ||
516 | @findex STOPPED_BY_WATCHPOINT | |
517 | @item STOPPED_BY_WATCHPOINT (@var{wait_status}) | |
518 | Return non-zero if stopped by a watchpoint. @var{wait_status} is of | |
519 | the type @code{struct target_waitstatus}, defined by @file{target.h}. | |
520 | @end table | |
521 | ||
522 | @subsection x86 Watchpoints | |
523 | @cindex x86 debug registers | |
524 | @cindex watchpoints, on x86 | |
525 | ||
526 | The 32-bit Intel x86 (a.k.a.@: ia32) processors feature special debug | |
527 | registers designed to facilitate debugging. @value{GDBN} provides a | |
528 | generic library of functions that x86-based ports can use to implement | |
529 | support for watchpoints and hardware-assisted breakpoints. This | |
530 | subsection documents the x86 watchpoint facilities in @value{GDBN}. | |
531 | ||
532 | To use the generic x86 watchpoint support, a port should do the | |
533 | following: | |
534 | ||
535 | @itemize @bullet | |
536 | @findex I386_USE_GENERIC_WATCHPOINTS | |
537 | @item | |
538 | Define the macro @code{I386_USE_GENERIC_WATCHPOINTS} somewhere in the | |
539 | target-dependent headers. | |
540 | ||
541 | @item | |
542 | Include the @file{config/i386/nm-i386.h} header file @emph{after} | |
543 | defining @code{I386_USE_GENERIC_WATCHPOINTS}. | |
544 | ||
545 | @item | |
546 | Add @file{i386-nat.o} to the value of the Make variable | |
547 | @code{NATDEPFILES} (@pxref{Native Debugging, NATDEPFILES}) or | |
548 | @code{TDEPFILES} (@pxref{Target Architecture Definition, TDEPFILES}). | |
549 | ||
550 | @item | |
551 | Provide implementations for the @code{I386_DR_LOW_*} macros described | |
552 | below. Typically, each macro should call a target-specific function | |
553 | which does the real work. | |
554 | @end itemize | |
555 | ||
556 | The x86 watchpoint support works by maintaining mirror images of the | |
557 | debug registers. Values are copied between the mirror images and the | |
558 | real debug registers via a set of macros which each target needs to | |
559 | provide: | |
560 | ||
561 | @table @code | |
562 | @findex I386_DR_LOW_SET_CONTROL | |
563 | @item I386_DR_LOW_SET_CONTROL (@var{val}) | |
564 | Set the Debug Control (DR7) register to the value @var{val}. | |
565 | ||
566 | @findex I386_DR_LOW_SET_ADDR | |
567 | @item I386_DR_LOW_SET_ADDR (@var{idx}, @var{addr}) | |
568 | Put the address @var{addr} into the debug register number @var{idx}. | |
569 | ||
570 | @findex I386_DR_LOW_RESET_ADDR | |
571 | @item I386_DR_LOW_RESET_ADDR (@var{idx}) | |
572 | Reset (i.e.@: zero out) the address stored in the debug register | |
573 | number @var{idx}. | |
574 | ||
575 | @findex I386_DR_LOW_GET_STATUS | |
576 | @item I386_DR_LOW_GET_STATUS | |
577 | Return the value of the Debug Status (DR6) register. This value is | |
578 | used immediately after it is returned by | |
579 | @code{I386_DR_LOW_GET_STATUS}, so as to support per-thread status | |
580 | register values. | |
581 | @end table | |
582 | ||
583 | For each one of the 4 debug registers (whose indices are from 0 to 3) | |
584 | that store addresses, a reference count is maintained by @value{GDBN}, | |
585 | to allow sharing of debug registers by several watchpoints. This | |
586 | allows users to define several watchpoints that watch the same | |
587 | expression, but with different conditions and/or commands, without | |
588 | wasting debug registers which are in short supply. @value{GDBN} | |
589 | maintains the reference counts internally, targets don't have to do | |
590 | anything to use this feature. | |
591 | ||
592 | The x86 debug registers can each watch a region that is 1, 2, or 4 | |
593 | bytes long. The ia32 architecture requires that each watched region | |
594 | be appropriately aligned: 2-byte region on 2-byte boundary, 4-byte | |
595 | region on 4-byte boundary. However, the x86 watchpoint support in | |
596 | @value{GDBN} can watch unaligned regions and regions larger than 4 | |
597 | bytes (up to 16 bytes) by allocating several debug registers to watch | |
598 | a single region. This allocation of several registers per a watched | |
599 | region is also done automatically without target code intervention. | |
600 | ||
601 | The generic x86 watchpoint support provides the following API for the | |
602 | @value{GDBN}'s application code: | |
603 | ||
604 | @table @code | |
605 | @findex i386_region_ok_for_watchpoint | |
606 | @item i386_region_ok_for_watchpoint (@var{addr}, @var{len}) | |
607 | The macro @code{TARGET_REGION_OK_FOR_HW_WATCHPOINT} is set to call | |
608 | this function. It counts the number of debug registers required to | |
609 | watch a given region, and returns a non-zero value if that number is | |
610 | less than 4, the number of debug registers available to x86 | |
611 | processors. | |
612 | ||
613 | @findex i386_stopped_data_address | |
614 | @item i386_stopped_data_address (void) | |
615 | The macros @code{STOPPED_BY_WATCHPOINT} and | |
616 | @code{target_stopped_data_address} are set to call this function. The | |
617 | argument passed to @code{STOPPED_BY_WATCHPOINT} is ignored. This | |
618 | function examines the breakpoint condition bits in the DR6 Debug | |
619 | Status register, as returned by the @code{I386_DR_LOW_GET_STATUS} | |
620 | macro, and returns the address associated with the first bit that is | |
621 | set in DR6. | |
622 | ||
623 | @findex i386_insert_watchpoint | |
624 | @findex i386_remove_watchpoint | |
625 | @item i386_insert_watchpoint (@var{addr}, @var{len}, @var{type}) | |
626 | @itemx i386_remove_watchpoint (@var{addr}, @var{len}, @var{type}) | |
627 | Insert or remove a watchpoint. The macros | |
628 | @code{target_insert_watchpoint} and @code{target_remove_watchpoint} | |
629 | are set to call these functions. @code{i386_insert_watchpoint} first | |
630 | looks for a debug register which is already set to watch the same | |
631 | region for the same access types; if found, it just increments the | |
632 | reference count of that debug register, thus implementing debug | |
633 | register sharing between watchpoints. If no such register is found, | |
937f164b FF |
634 | the function looks for a vacant debug register, sets its mirrored |
635 | value to @var{addr}, sets the mirrored value of DR7 Debug Control | |
9742079a EZ |
636 | register as appropriate for the @var{len} and @var{type} parameters, |
637 | and then passes the new values of the debug register and DR7 to the | |
638 | inferior by calling @code{I386_DR_LOW_SET_ADDR} and | |
639 | @code{I386_DR_LOW_SET_CONTROL}. If more than one debug register is | |
640 | required to cover the given region, the above process is repeated for | |
641 | each debug register. | |
642 | ||
643 | @code{i386_remove_watchpoint} does the opposite: it resets the address | |
937f164b FF |
644 | in the mirrored value of the debug register and its read/write and |
645 | length bits in the mirrored value of DR7, then passes these new | |
9742079a EZ |
646 | values to the inferior via @code{I386_DR_LOW_RESET_ADDR} and |
647 | @code{I386_DR_LOW_SET_CONTROL}. If a register is shared by several | |
648 | watchpoints, each time a @code{i386_remove_watchpoint} is called, it | |
649 | decrements the reference count, and only calls | |
650 | @code{I386_DR_LOW_RESET_ADDR} and @code{I386_DR_LOW_SET_CONTROL} when | |
651 | the count goes to zero. | |
652 | ||
653 | @findex i386_insert_hw_breakpoint | |
654 | @findex i386_remove_hw_breakpoint | |
655 | @item i386_insert_hw_breakpoint (@var{addr}, @var{shadow} | |
656 | @itemx i386_remove_hw_breakpoint (@var{addr}, @var{shadow}) | |
657 | These functions insert and remove hardware-assisted breakpoints. The | |
658 | macros @code{target_insert_hw_breakpoint} and | |
659 | @code{target_remove_hw_breakpoint} are set to call these functions. | |
660 | These functions work like @code{i386_insert_watchpoint} and | |
661 | @code{i386_remove_watchpoint}, respectively, except that they set up | |
662 | the debug registers to watch instruction execution, and each | |
663 | hardware-assisted breakpoint always requires exactly one debug | |
664 | register. | |
665 | ||
666 | @findex i386_stopped_by_hwbp | |
667 | @item i386_stopped_by_hwbp (void) | |
668 | This function returns non-zero if the inferior has some watchpoint or | |
669 | hardware breakpoint that triggered. It works like | |
670 | @code{i386_stopped_data_address}, except that it doesn't return the | |
671 | address whose watchpoint triggered. | |
672 | ||
673 | @findex i386_cleanup_dregs | |
674 | @item i386_cleanup_dregs (void) | |
675 | This function clears all the reference counts, addresses, and control | |
676 | bits in the mirror images of the debug registers. It doesn't affect | |
677 | the actual debug registers in the inferior process. | |
678 | @end table | |
679 | ||
680 | @noindent | |
681 | @strong{Notes:} | |
682 | @enumerate 1 | |
683 | @item | |
684 | x86 processors support setting watchpoints on I/O reads or writes. | |
685 | However, since no target supports this (as of March 2001), and since | |
686 | @code{enum target_hw_bp_type} doesn't even have an enumeration for I/O | |
687 | watchpoints, this feature is not yet available to @value{GDBN} running | |
688 | on x86. | |
689 | ||
690 | @item | |
691 | x86 processors can enable watchpoints locally, for the current task | |
692 | only, or globally, for all the tasks. For each debug register, | |
693 | there's a bit in the DR7 Debug Control register that determines | |
694 | whether the associated address is watched locally or globally. The | |
695 | current implementation of x86 watchpoint support in @value{GDBN} | |
696 | always sets watchpoints to be locally enabled, since global | |
697 | watchpoints might interfere with the underlying OS and are probably | |
698 | unavailable in many platforms. | |
699 | @end enumerate | |
700 | ||
bcd7e15f JB |
701 | @section Observing changes in @value{GDBN} internals |
702 | @cindex observer pattern interface | |
703 | @cindex notifications about changes in internals | |
704 | ||
705 | In order to function properly, several modules need to be notified when | |
706 | some changes occur in the @value{GDBN} internals. Traditionally, these | |
707 | modules have relied on several paradigms, the most common ones being | |
708 | hooks and gdb-events. Unfortunately, none of these paradigms was | |
709 | versatile enough to become the standard notification mechanism in | |
710 | @value{GDBN}. The fact that they only supported one ``client'' was also | |
711 | a strong limitation. | |
712 | ||
713 | A new paradigm, based on the Observer pattern of the @cite{Design | |
714 | Patterns} book, has therefore been implemented. The goal was to provide | |
715 | a new interface overcoming the issues with the notification mechanisms | |
716 | previously available. This new interface needed to be strongly typed, | |
717 | easy to extend, and versatile enough to be used as the standard | |
718 | interface when adding new notifications. | |
719 | ||
720 | See @ref{GDB Observers} for a brief description of the observers | |
721 | currently implemented in GDB. The rationale for the current | |
722 | implementation is also briefly discussed. | |
723 | ||
c906108c SS |
724 | @node User Interface |
725 | ||
726 | @chapter User Interface | |
727 | ||
25822942 | 728 | @value{GDBN} has several user interfaces. Although the command-line interface |
c906108c SS |
729 | is the most common and most familiar, there are others. |
730 | ||
731 | @section Command Interpreter | |
732 | ||
56caf160 | 733 | @cindex command interpreter |
0ee54786 | 734 | @cindex CLI |
25822942 | 735 | The command interpreter in @value{GDBN} is fairly simple. It is designed to |
c906108c SS |
736 | allow for the set of commands to be augmented dynamically, and also |
737 | has a recursive subcommand capability, where the first argument to | |
738 | a command may itself direct a lookup on a different command list. | |
739 | ||
56caf160 EZ |
740 | For instance, the @samp{set} command just starts a lookup on the |
741 | @code{setlist} command list, while @samp{set thread} recurses | |
c906108c SS |
742 | to the @code{set_thread_cmd_list}. |
743 | ||
56caf160 EZ |
744 | @findex add_cmd |
745 | @findex add_com | |
c906108c SS |
746 | To add commands in general, use @code{add_cmd}. @code{add_com} adds to |
747 | the main command list, and should be used for those commands. The usual | |
cfeada60 | 748 | place to add commands is in the @code{_initialize_@var{xyz}} routines at |
9742079a | 749 | the ends of most source files. |
cfeada60 | 750 | |
40dd2248 TT |
751 | @findex add_setshow_cmd |
752 | @findex add_setshow_cmd_full | |
753 | To add paired @samp{set} and @samp{show} commands, use | |
754 | @code{add_setshow_cmd} or @code{add_setshow_cmd_full}. The former is | |
755 | a slightly simpler interface which is useful when you don't need to | |
756 | further modify the new command structures, while the latter returns | |
757 | the new command structures for manipulation. | |
758 | ||
56caf160 EZ |
759 | @cindex deprecating commands |
760 | @findex deprecate_cmd | |
cfeada60 FN |
761 | Before removing commands from the command set it is a good idea to |
762 | deprecate them for some time. Use @code{deprecate_cmd} on commands or | |
763 | aliases to set the deprecated flag. @code{deprecate_cmd} takes a | |
764 | @code{struct cmd_list_element} as it's first argument. You can use the | |
765 | return value from @code{add_com} or @code{add_cmd} to deprecate the | |
766 | command immediately after it is created. | |
767 | ||
c72e7388 | 768 | The first time a command is used the user will be warned and offered a |
cfeada60 FN |
769 | replacement (if one exists). Note that the replacement string passed to |
770 | @code{deprecate_cmd} should be the full name of the command, i.e. the | |
771 | entire string the user should type at the command line. | |
c906108c | 772 | |
0ee54786 EZ |
773 | @section UI-Independent Output---the @code{ui_out} Functions |
774 | @c This section is based on the documentation written by Fernando | |
775 | @c Nasser <fnasser@redhat.com>. | |
776 | ||
777 | @cindex @code{ui_out} functions | |
778 | The @code{ui_out} functions present an abstraction level for the | |
779 | @value{GDBN} output code. They hide the specifics of different user | |
780 | interfaces supported by @value{GDBN}, and thus free the programmer | |
781 | from the need to write several versions of the same code, one each for | |
782 | every UI, to produce output. | |
783 | ||
784 | @subsection Overview and Terminology | |
785 | ||
786 | In general, execution of each @value{GDBN} command produces some sort | |
787 | of output, and can even generate an input request. | |
788 | ||
789 | Output can be generated for the following purposes: | |
790 | ||
791 | @itemize @bullet | |
792 | @item | |
793 | to display a @emph{result} of an operation; | |
794 | ||
795 | @item | |
796 | to convey @emph{info} or produce side-effects of a requested | |
797 | operation; | |
798 | ||
799 | @item | |
800 | to provide a @emph{notification} of an asynchronous event (including | |
801 | progress indication of a prolonged asynchronous operation); | |
802 | ||
803 | @item | |
804 | to display @emph{error messages} (including warnings); | |
805 | ||
806 | @item | |
807 | to show @emph{debug data}; | |
808 | ||
809 | @item | |
810 | to @emph{query} or prompt a user for input (a special case). | |
811 | @end itemize | |
812 | ||
813 | @noindent | |
814 | This section mainly concentrates on how to build result output, | |
815 | although some of it also applies to other kinds of output. | |
816 | ||
817 | Generation of output that displays the results of an operation | |
818 | involves one or more of the following: | |
819 | ||
820 | @itemize @bullet | |
821 | @item | |
822 | output of the actual data | |
823 | ||
824 | @item | |
825 | formatting the output as appropriate for console output, to make it | |
826 | easily readable by humans | |
827 | ||
828 | @item | |
829 | machine oriented formatting--a more terse formatting to allow for easy | |
830 | parsing by programs which read @value{GDBN}'s output | |
831 | ||
832 | @item | |
c72e7388 AC |
833 | annotation, whose purpose is to help legacy GUIs to identify interesting |
834 | parts in the output | |
0ee54786 EZ |
835 | @end itemize |
836 | ||
837 | The @code{ui_out} routines take care of the first three aspects. | |
c72e7388 AC |
838 | Annotations are provided by separate annotation routines. Note that use |
839 | of annotations for an interface between a GUI and @value{GDBN} is | |
0ee54786 EZ |
840 | deprecated. |
841 | ||
c72e7388 AC |
842 | Output can be in the form of a single item, which we call a @dfn{field}; |
843 | a @dfn{list} consisting of identical fields; a @dfn{tuple} consisting of | |
844 | non-identical fields; or a @dfn{table}, which is a tuple consisting of a | |
845 | header and a body. In a BNF-like form: | |
0ee54786 | 846 | |
c72e7388 AC |
847 | @table @code |
848 | @item <table> @expansion{} | |
849 | @code{<header> <body>} | |
850 | @item <header> @expansion{} | |
851 | @code{@{ <column> @}} | |
852 | @item <column> @expansion{} | |
853 | @code{<width> <alignment> <title>} | |
854 | @item <body> @expansion{} | |
855 | @code{@{<row>@}} | |
856 | @end table | |
0ee54786 EZ |
857 | |
858 | ||
859 | @subsection General Conventions | |
860 | ||
c72e7388 AC |
861 | Most @code{ui_out} routines are of type @code{void}, the exceptions are |
862 | @code{ui_out_stream_new} (which returns a pointer to the newly created | |
863 | object) and the @code{make_cleanup} routines. | |
0ee54786 | 864 | |
c72e7388 AC |
865 | The first parameter is always the @code{ui_out} vector object, a pointer |
866 | to a @code{struct ui_out}. | |
0ee54786 | 867 | |
c72e7388 AC |
868 | The @var{format} parameter is like in @code{printf} family of functions. |
869 | When it is present, there must also be a variable list of arguments | |
870 | sufficient used to satisfy the @code{%} specifiers in the supplied | |
0ee54786 EZ |
871 | format. |
872 | ||
c72e7388 AC |
873 | When a character string argument is not used in a @code{ui_out} function |
874 | call, a @code{NULL} pointer has to be supplied instead. | |
0ee54786 EZ |
875 | |
876 | ||
c72e7388 | 877 | @subsection Table, Tuple and List Functions |
0ee54786 EZ |
878 | |
879 | @cindex list output functions | |
880 | @cindex table output functions | |
c72e7388 AC |
881 | @cindex tuple output functions |
882 | This section introduces @code{ui_out} routines for building lists, | |
883 | tuples and tables. The routines to output the actual data items | |
884 | (fields) are presented in the next section. | |
0ee54786 | 885 | |
c72e7388 AC |
886 | To recap: A @dfn{tuple} is a sequence of @dfn{fields}, each field |
887 | containing information about an object; a @dfn{list} is a sequence of | |
888 | fields where each field describes an identical object. | |
0ee54786 | 889 | |
c72e7388 AC |
890 | Use the @dfn{table} functions when your output consists of a list of |
891 | rows (tuples) and the console output should include a heading. Use this | |
892 | even when you are listing just one object but you still want the header. | |
0ee54786 EZ |
893 | |
894 | @cindex nesting level in @code{ui_out} functions | |
c72e7388 AC |
895 | Tables can not be nested. Tuples and lists can be nested up to a |
896 | maximum of five levels. | |
0ee54786 EZ |
897 | |
898 | The overall structure of the table output code is something like this: | |
899 | ||
474c8240 | 900 | @smallexample |
0ee54786 EZ |
901 | ui_out_table_begin |
902 | ui_out_table_header | |
c72e7388 | 903 | @dots{} |
0ee54786 | 904 | ui_out_table_body |
c72e7388 | 905 | ui_out_tuple_begin |
0ee54786 | 906 | ui_out_field_* |
c72e7388 AC |
907 | @dots{} |
908 | ui_out_tuple_end | |
909 | @dots{} | |
0ee54786 | 910 | ui_out_table_end |
474c8240 | 911 | @end smallexample |
0ee54786 | 912 | |
c72e7388 | 913 | Here is the description of table-, tuple- and list-related @code{ui_out} |
0ee54786 EZ |
914 | functions: |
915 | ||
c72e7388 AC |
916 | @deftypefun void ui_out_table_begin (struct ui_out *@var{uiout}, int @var{nbrofcols}, int @var{nr_rows}, const char *@var{tblid}) |
917 | The function @code{ui_out_table_begin} marks the beginning of the output | |
918 | of a table. It should always be called before any other @code{ui_out} | |
919 | function for a given table. @var{nbrofcols} is the number of columns in | |
920 | the table. @var{nr_rows} is the number of rows in the table. | |
921 | @var{tblid} is an optional string identifying the table. The string | |
922 | pointed to by @var{tblid} is copied by the implementation of | |
923 | @code{ui_out_table_begin}, so the application can free the string if it | |
924 | was @code{malloc}ed. | |
0ee54786 EZ |
925 | |
926 | The companion function @code{ui_out_table_end}, described below, marks | |
927 | the end of the table's output. | |
928 | @end deftypefun | |
929 | ||
c72e7388 AC |
930 | @deftypefun void ui_out_table_header (struct ui_out *@var{uiout}, int @var{width}, enum ui_align @var{alignment}, const char *@var{colhdr}) |
931 | @code{ui_out_table_header} provides the header information for a single | |
932 | table column. You call this function several times, one each for every | |
933 | column of the table, after @code{ui_out_table_begin}, but before | |
934 | @code{ui_out_table_body}. | |
0ee54786 EZ |
935 | |
936 | The value of @var{width} gives the column width in characters. The | |
937 | value of @var{alignment} is one of @code{left}, @code{center}, and | |
938 | @code{right}, and it specifies how to align the header: left-justify, | |
939 | center, or right-justify it. @var{colhdr} points to a string that | |
940 | specifies the column header; the implementation copies that string, so | |
c72e7388 AC |
941 | column header strings in @code{malloc}ed storage can be freed after the |
942 | call. | |
0ee54786 EZ |
943 | @end deftypefun |
944 | ||
945 | @deftypefun void ui_out_table_body (struct ui_out *@var{uiout}) | |
c72e7388 | 946 | This function delimits the table header from the table body. |
0ee54786 EZ |
947 | @end deftypefun |
948 | ||
949 | @deftypefun void ui_out_table_end (struct ui_out *@var{uiout}) | |
c72e7388 AC |
950 | This function signals the end of a table's output. It should be called |
951 | after the table body has been produced by the list and field output | |
952 | functions. | |
0ee54786 EZ |
953 | |
954 | There should be exactly one call to @code{ui_out_table_end} for each | |
c72e7388 AC |
955 | call to @code{ui_out_table_begin}, otherwise the @code{ui_out} functions |
956 | will signal an internal error. | |
0ee54786 EZ |
957 | @end deftypefun |
958 | ||
c72e7388 | 959 | The output of the tuples that represent the table rows must follow the |
0ee54786 | 960 | call to @code{ui_out_table_body} and precede the call to |
c72e7388 AC |
961 | @code{ui_out_table_end}. You build a tuple by calling |
962 | @code{ui_out_tuple_begin} and @code{ui_out_tuple_end}, with suitable | |
0ee54786 EZ |
963 | calls to functions which actually output fields between them. |
964 | ||
c72e7388 AC |
965 | @deftypefun void ui_out_tuple_begin (struct ui_out *@var{uiout}, const char *@var{id}) |
966 | This function marks the beginning of a tuple output. @var{id} points | |
967 | to an optional string that identifies the tuple; it is copied by the | |
968 | implementation, and so strings in @code{malloc}ed storage can be freed | |
969 | after the call. | |
970 | @end deftypefun | |
971 | ||
972 | @deftypefun void ui_out_tuple_end (struct ui_out *@var{uiout}) | |
973 | This function signals an end of a tuple output. There should be exactly | |
974 | one call to @code{ui_out_tuple_end} for each call to | |
975 | @code{ui_out_tuple_begin}, otherwise an internal @value{GDBN} error will | |
976 | be signaled. | |
977 | @end deftypefun | |
978 | ||
979 | @deftypefun struct cleanup *make_cleanup_ui_out_tuple_begin_end (struct ui_out *@var{uiout}, const char *@var{id}) | |
980 | This function first opens the tuple and then establishes a cleanup | |
981 | (@pxref{Coding, Cleanups}) to close the tuple. It provides a convenient | |
982 | and correct implementation of the non-portable@footnote{The function | |
b9aa90c9 | 983 | cast is not portable ISO C.} code sequence: |
c72e7388 AC |
984 | @smallexample |
985 | struct cleanup *old_cleanup; | |
986 | ui_out_tuple_begin (uiout, "..."); | |
987 | old_cleanup = make_cleanup ((void(*)(void *)) ui_out_tuple_end, | |
988 | uiout); | |
989 | @end smallexample | |
990 | @end deftypefun | |
991 | ||
992 | @deftypefun void ui_out_list_begin (struct ui_out *@var{uiout}, const char *@var{id}) | |
993 | This function marks the beginning of a list output. @var{id} points to | |
994 | an optional string that identifies the list; it is copied by the | |
995 | implementation, and so strings in @code{malloc}ed storage can be freed | |
996 | after the call. | |
0ee54786 EZ |
997 | @end deftypefun |
998 | ||
999 | @deftypefun void ui_out_list_end (struct ui_out *@var{uiout}) | |
c72e7388 AC |
1000 | This function signals an end of a list output. There should be exactly |
1001 | one call to @code{ui_out_list_end} for each call to | |
1002 | @code{ui_out_list_begin}, otherwise an internal @value{GDBN} error will | |
1003 | be signaled. | |
1004 | @end deftypefun | |
1005 | ||
1006 | @deftypefun struct cleanup *make_cleanup_ui_out_list_begin_end (struct ui_out *@var{uiout}, const char *@var{id}) | |
1007 | Similar to @code{make_cleanup_ui_out_tuple_begin_end}, this function | |
1008 | opens a list and then establishes cleanup (@pxref{Coding, Cleanups}) | |
1009 | that will close the list.list. | |
0ee54786 EZ |
1010 | @end deftypefun |
1011 | ||
1012 | @subsection Item Output Functions | |
1013 | ||
1014 | @cindex item output functions | |
1015 | @cindex field output functions | |
1016 | @cindex data output | |
1017 | The functions described below produce output for the actual data | |
1018 | items, or fields, which contain information about the object. | |
1019 | ||
1020 | Choose the appropriate function accordingly to your particular needs. | |
1021 | ||
1022 | @deftypefun void ui_out_field_fmt (struct ui_out *@var{uiout}, char *@var{fldname}, char *@var{format}, ...) | |
1023 | This is the most general output function. It produces the | |
1024 | representation of the data in the variable-length argument list | |
1025 | according to formatting specifications in @var{format}, a | |
1026 | @code{printf}-like format string. The optional argument @var{fldname} | |
1027 | supplies the name of the field. The data items themselves are | |
1028 | supplied as additional arguments after @var{format}. | |
1029 | ||
1030 | This generic function should be used only when it is not possible to | |
1031 | use one of the specialized versions (see below). | |
1032 | @end deftypefun | |
1033 | ||
c72e7388 | 1034 | @deftypefun void ui_out_field_int (struct ui_out *@var{uiout}, const char *@var{fldname}, int @var{value}) |
0ee54786 EZ |
1035 | This function outputs a value of an @code{int} variable. It uses the |
1036 | @code{"%d"} output conversion specification. @var{fldname} specifies | |
1037 | the name of the field. | |
1038 | @end deftypefun | |
8d19fbd2 JJ |
1039 | |
1040 | @deftypefun void ui_out_field_fmt_int (struct ui_out *@var{uiout}, int @var{width}, enum ui_align @var{alignment}, const char *@var{fldname}, int @var{value}) | |
1041 | This function outputs a value of an @code{int} variable. It differs from | |
1042 | @code{ui_out_field_int} in that the caller specifies the desired @var{width} and @var{alignment} of the output. | |
1043 | @var{fldname} specifies | |
1044 | the name of the field. | |
1045 | @end deftypefun | |
0ee54786 | 1046 | |
c72e7388 | 1047 | @deftypefun void ui_out_field_core_addr (struct ui_out *@var{uiout}, const char *@var{fldname}, CORE_ADDR @var{address}) |
0ee54786 EZ |
1048 | This function outputs an address. |
1049 | @end deftypefun | |
1050 | ||
c72e7388 | 1051 | @deftypefun void ui_out_field_string (struct ui_out *@var{uiout}, const char *@var{fldname}, const char *@var{string}) |
0ee54786 EZ |
1052 | This function outputs a string using the @code{"%s"} conversion |
1053 | specification. | |
1054 | @end deftypefun | |
1055 | ||
1056 | Sometimes, there's a need to compose your output piece by piece using | |
1057 | functions that operate on a stream, such as @code{value_print} or | |
1058 | @code{fprintf_symbol_filtered}. These functions accept an argument of | |
1059 | the type @code{struct ui_file *}, a pointer to a @code{ui_file} object | |
1060 | used to store the data stream used for the output. When you use one | |
1061 | of these functions, you need a way to pass their results stored in a | |
1062 | @code{ui_file} object to the @code{ui_out} functions. To this end, | |
1063 | you first create a @code{ui_stream} object by calling | |
1064 | @code{ui_out_stream_new}, pass the @code{stream} member of that | |
1065 | @code{ui_stream} object to @code{value_print} and similar functions, | |
1066 | and finally call @code{ui_out_field_stream} to output the field you | |
1067 | constructed. When the @code{ui_stream} object is no longer needed, | |
1068 | you should destroy it and free its memory by calling | |
1069 | @code{ui_out_stream_delete}. | |
1070 | ||
1071 | @deftypefun struct ui_stream *ui_out_stream_new (struct ui_out *@var{uiout}) | |
1072 | This function creates a new @code{ui_stream} object which uses the | |
1073 | same output methods as the @code{ui_out} object whose pointer is | |
1074 | passed in @var{uiout}. It returns a pointer to the newly created | |
1075 | @code{ui_stream} object. | |
1076 | @end deftypefun | |
1077 | ||
1078 | @deftypefun void ui_out_stream_delete (struct ui_stream *@var{streambuf}) | |
1079 | This functions destroys a @code{ui_stream} object specified by | |
1080 | @var{streambuf}. | |
1081 | @end deftypefun | |
1082 | ||
c72e7388 | 1083 | @deftypefun void ui_out_field_stream (struct ui_out *@var{uiout}, const char *@var{fieldname}, struct ui_stream *@var{streambuf}) |
0ee54786 EZ |
1084 | This function consumes all the data accumulated in |
1085 | @code{streambuf->stream} and outputs it like | |
1086 | @code{ui_out_field_string} does. After a call to | |
1087 | @code{ui_out_field_stream}, the accumulated data no longer exists, but | |
1088 | the stream is still valid and may be used for producing more fields. | |
1089 | @end deftypefun | |
1090 | ||
1091 | @strong{Important:} If there is any chance that your code could bail | |
1092 | out before completing output generation and reaching the point where | |
1093 | @code{ui_out_stream_delete} is called, it is necessary to set up a | |
1094 | cleanup, to avoid leaking memory and other resources. Here's a | |
1095 | skeleton code to do that: | |
1096 | ||
1097 | @smallexample | |
1098 | struct ui_stream *mybuf = ui_out_stream_new (uiout); | |
1099 | struct cleanup *old = make_cleanup (ui_out_stream_delete, mybuf); | |
1100 | ... | |
1101 | do_cleanups (old); | |
1102 | @end smallexample | |
1103 | ||
1104 | If the function already has the old cleanup chain set (for other kinds | |
1105 | of cleanups), you just have to add your cleanup to it: | |
1106 | ||
1107 | @smallexample | |
1108 | mybuf = ui_out_stream_new (uiout); | |
1109 | make_cleanup (ui_out_stream_delete, mybuf); | |
1110 | @end smallexample | |
1111 | ||
1112 | Note that with cleanups in place, you should not call | |
1113 | @code{ui_out_stream_delete} directly, or you would attempt to free the | |
1114 | same buffer twice. | |
1115 | ||
1116 | @subsection Utility Output Functions | |
1117 | ||
c72e7388 | 1118 | @deftypefun void ui_out_field_skip (struct ui_out *@var{uiout}, const char *@var{fldname}) |
0ee54786 EZ |
1119 | This function skips a field in a table. Use it if you have to leave |
1120 | an empty field without disrupting the table alignment. The argument | |
1121 | @var{fldname} specifies a name for the (missing) filed. | |
1122 | @end deftypefun | |
1123 | ||
c72e7388 | 1124 | @deftypefun void ui_out_text (struct ui_out *@var{uiout}, const char *@var{string}) |
0ee54786 EZ |
1125 | This function outputs the text in @var{string} in a way that makes it |
1126 | easy to be read by humans. For example, the console implementation of | |
1127 | this method filters the text through a built-in pager, to prevent it | |
1128 | from scrolling off the visible portion of the screen. | |
1129 | ||
1130 | Use this function for printing relatively long chunks of text around | |
1131 | the actual field data: the text it produces is not aligned according | |
1132 | to the table's format. Use @code{ui_out_field_string} to output a | |
1133 | string field, and use @code{ui_out_message}, described below, to | |
1134 | output short messages. | |
1135 | @end deftypefun | |
1136 | ||
1137 | @deftypefun void ui_out_spaces (struct ui_out *@var{uiout}, int @var{nspaces}) | |
1138 | This function outputs @var{nspaces} spaces. It is handy to align the | |
1139 | text produced by @code{ui_out_text} with the rest of the table or | |
1140 | list. | |
1141 | @end deftypefun | |
1142 | ||
c72e7388 | 1143 | @deftypefun void ui_out_message (struct ui_out *@var{uiout}, int @var{verbosity}, const char *@var{format}, ...) |
0ee54786 EZ |
1144 | This function produces a formatted message, provided that the current |
1145 | verbosity level is at least as large as given by @var{verbosity}. The | |
1146 | current verbosity level is specified by the user with the @samp{set | |
1147 | verbositylevel} command.@footnote{As of this writing (April 2001), | |
1148 | setting verbosity level is not yet implemented, and is always returned | |
1149 | as zero. So calling @code{ui_out_message} with a @var{verbosity} | |
1150 | argument more than zero will cause the message to never be printed.} | |
1151 | @end deftypefun | |
1152 | ||
1153 | @deftypefun void ui_out_wrap_hint (struct ui_out *@var{uiout}, char *@var{indent}) | |
1154 | This function gives the console output filter (a paging filter) a hint | |
1155 | of where to break lines which are too long. Ignored for all other | |
1156 | output consumers. @var{indent}, if non-@code{NULL}, is the string to | |
1157 | be printed to indent the wrapped text on the next line; it must remain | |
1158 | accessible until the next call to @code{ui_out_wrap_hint}, or until an | |
1159 | explicit newline is produced by one of the other functions. If | |
1160 | @var{indent} is @code{NULL}, the wrapped text will not be indented. | |
1161 | @end deftypefun | |
1162 | ||
1163 | @deftypefun void ui_out_flush (struct ui_out *@var{uiout}) | |
1164 | This function flushes whatever output has been accumulated so far, if | |
1165 | the UI buffers output. | |
1166 | @end deftypefun | |
1167 | ||
1168 | ||
1169 | @subsection Examples of Use of @code{ui_out} functions | |
1170 | ||
1171 | @cindex using @code{ui_out} functions | |
1172 | @cindex @code{ui_out} functions, usage examples | |
1173 | This section gives some practical examples of using the @code{ui_out} | |
1174 | functions to generalize the old console-oriented code in | |
1175 | @value{GDBN}. The examples all come from functions defined on the | |
1176 | @file{breakpoints.c} file. | |
1177 | ||
1178 | This example, from the @code{breakpoint_1} function, shows how to | |
1179 | produce a table. | |
1180 | ||
1181 | The original code was: | |
1182 | ||
474c8240 | 1183 | @smallexample |
0ee54786 EZ |
1184 | if (!found_a_breakpoint++) |
1185 | @{ | |
1186 | annotate_breakpoints_headers (); | |
1187 | ||
1188 | annotate_field (0); | |
1189 | printf_filtered ("Num "); | |
1190 | annotate_field (1); | |
1191 | printf_filtered ("Type "); | |
1192 | annotate_field (2); | |
1193 | printf_filtered ("Disp "); | |
1194 | annotate_field (3); | |
1195 | printf_filtered ("Enb "); | |
1196 | if (addressprint) | |
1197 | @{ | |
1198 | annotate_field (4); | |
1199 | printf_filtered ("Address "); | |
1200 | @} | |
1201 | annotate_field (5); | |
1202 | printf_filtered ("What\n"); | |
1203 | ||
1204 | annotate_breakpoints_table (); | |
1205 | @} | |
474c8240 | 1206 | @end smallexample |
0ee54786 EZ |
1207 | |
1208 | Here's the new version: | |
1209 | ||
474c8240 | 1210 | @smallexample |
c72e7388 AC |
1211 | nr_printable_breakpoints = @dots{}; |
1212 | ||
1213 | if (addressprint) | |
1214 | ui_out_table_begin (ui, 6, nr_printable_breakpoints, "BreakpointTable"); | |
1215 | else | |
1216 | ui_out_table_begin (ui, 5, nr_printable_breakpoints, "BreakpointTable"); | |
1217 | ||
1218 | if (nr_printable_breakpoints > 0) | |
1219 | annotate_breakpoints_headers (); | |
1220 | if (nr_printable_breakpoints > 0) | |
1221 | annotate_field (0); | |
1222 | ui_out_table_header (uiout, 3, ui_left, "number", "Num"); /* 1 */ | |
1223 | if (nr_printable_breakpoints > 0) | |
1224 | annotate_field (1); | |
1225 | ui_out_table_header (uiout, 14, ui_left, "type", "Type"); /* 2 */ | |
1226 | if (nr_printable_breakpoints > 0) | |
1227 | annotate_field (2); | |
1228 | ui_out_table_header (uiout, 4, ui_left, "disp", "Disp"); /* 3 */ | |
1229 | if (nr_printable_breakpoints > 0) | |
1230 | annotate_field (3); | |
1231 | ui_out_table_header (uiout, 3, ui_left, "enabled", "Enb"); /* 4 */ | |
1232 | if (addressprint) | |
1233 | @{ | |
1234 | if (nr_printable_breakpoints > 0) | |
1235 | annotate_field (4); | |
1236 | if (TARGET_ADDR_BIT <= 32) | |
1237 | ui_out_table_header (uiout, 10, ui_left, "addr", "Address");/* 5 */ | |
0ee54786 | 1238 | else |
c72e7388 AC |
1239 | ui_out_table_header (uiout, 18, ui_left, "addr", "Address");/* 5 */ |
1240 | @} | |
1241 | if (nr_printable_breakpoints > 0) | |
1242 | annotate_field (5); | |
1243 | ui_out_table_header (uiout, 40, ui_noalign, "what", "What"); /* 6 */ | |
1244 | ui_out_table_body (uiout); | |
1245 | if (nr_printable_breakpoints > 0) | |
1246 | annotate_breakpoints_table (); | |
474c8240 | 1247 | @end smallexample |
0ee54786 EZ |
1248 | |
1249 | This example, from the @code{print_one_breakpoint} function, shows how | |
1250 | to produce the actual data for the table whose structure was defined | |
1251 | in the above example. The original code was: | |
1252 | ||
474c8240 | 1253 | @smallexample |
0ee54786 EZ |
1254 | annotate_record (); |
1255 | annotate_field (0); | |
1256 | printf_filtered ("%-3d ", b->number); | |
1257 | annotate_field (1); | |
1258 | if ((int)b->type > (sizeof(bptypes)/sizeof(bptypes[0])) | |
1259 | || ((int) b->type != bptypes[(int) b->type].type)) | |
1260 | internal_error ("bptypes table does not describe type #%d.", | |
1261 | (int)b->type); | |
1262 | printf_filtered ("%-14s ", bptypes[(int)b->type].description); | |
1263 | annotate_field (2); | |
1264 | printf_filtered ("%-4s ", bpdisps[(int)b->disposition]); | |
1265 | annotate_field (3); | |
1266 | printf_filtered ("%-3c ", bpenables[(int)b->enable]); | |
c72e7388 | 1267 | @dots{} |
474c8240 | 1268 | @end smallexample |
0ee54786 EZ |
1269 | |
1270 | This is the new version: | |
1271 | ||
474c8240 | 1272 | @smallexample |
0ee54786 | 1273 | annotate_record (); |
c72e7388 | 1274 | ui_out_tuple_begin (uiout, "bkpt"); |
0ee54786 EZ |
1275 | annotate_field (0); |
1276 | ui_out_field_int (uiout, "number", b->number); | |
1277 | annotate_field (1); | |
1278 | if (((int) b->type > (sizeof (bptypes) / sizeof (bptypes[0]))) | |
1279 | || ((int) b->type != bptypes[(int) b->type].type)) | |
1280 | internal_error ("bptypes table does not describe type #%d.", | |
1281 | (int) b->type); | |
1282 | ui_out_field_string (uiout, "type", bptypes[(int)b->type].description); | |
1283 | annotate_field (2); | |
1284 | ui_out_field_string (uiout, "disp", bpdisps[(int)b->disposition]); | |
1285 | annotate_field (3); | |
1286 | ui_out_field_fmt (uiout, "enabled", "%c", bpenables[(int)b->enable]); | |
c72e7388 | 1287 | @dots{} |
474c8240 | 1288 | @end smallexample |
0ee54786 EZ |
1289 | |
1290 | This example, also from @code{print_one_breakpoint}, shows how to | |
1291 | produce a complicated output field using the @code{print_expression} | |
1292 | functions which requires a stream to be passed. It also shows how to | |
1293 | automate stream destruction with cleanups. The original code was: | |
1294 | ||
474c8240 | 1295 | @smallexample |
0ee54786 EZ |
1296 | annotate_field (5); |
1297 | print_expression (b->exp, gdb_stdout); | |
474c8240 | 1298 | @end smallexample |
0ee54786 EZ |
1299 | |
1300 | The new version is: | |
1301 | ||
474c8240 | 1302 | @smallexample |
0ee54786 EZ |
1303 | struct ui_stream *stb = ui_out_stream_new (uiout); |
1304 | struct cleanup *old_chain = make_cleanup_ui_out_stream_delete (stb); | |
1305 | ... | |
1306 | annotate_field (5); | |
1307 | print_expression (b->exp, stb->stream); | |
1308 | ui_out_field_stream (uiout, "what", local_stream); | |
474c8240 | 1309 | @end smallexample |
0ee54786 EZ |
1310 | |
1311 | This example, also from @code{print_one_breakpoint}, shows how to use | |
1312 | @code{ui_out_text} and @code{ui_out_field_string}. The original code | |
1313 | was: | |
1314 | ||
474c8240 | 1315 | @smallexample |
0ee54786 EZ |
1316 | annotate_field (5); |
1317 | if (b->dll_pathname == NULL) | |
1318 | printf_filtered ("<any library> "); | |
1319 | else | |
1320 | printf_filtered ("library \"%s\" ", b->dll_pathname); | |
474c8240 | 1321 | @end smallexample |
0ee54786 EZ |
1322 | |
1323 | It became: | |
1324 | ||
474c8240 | 1325 | @smallexample |
0ee54786 EZ |
1326 | annotate_field (5); |
1327 | if (b->dll_pathname == NULL) | |
1328 | @{ | |
1329 | ui_out_field_string (uiout, "what", "<any library>"); | |
1330 | ui_out_spaces (uiout, 1); | |
1331 | @} | |
1332 | else | |
1333 | @{ | |
1334 | ui_out_text (uiout, "library \""); | |
1335 | ui_out_field_string (uiout, "what", b->dll_pathname); | |
1336 | ui_out_text (uiout, "\" "); | |
1337 | @} | |
474c8240 | 1338 | @end smallexample |
0ee54786 EZ |
1339 | |
1340 | The following example from @code{print_one_breakpoint} shows how to | |
1341 | use @code{ui_out_field_int} and @code{ui_out_spaces}. The original | |
1342 | code was: | |
1343 | ||
474c8240 | 1344 | @smallexample |
0ee54786 EZ |
1345 | annotate_field (5); |
1346 | if (b->forked_inferior_pid != 0) | |
1347 | printf_filtered ("process %d ", b->forked_inferior_pid); | |
474c8240 | 1348 | @end smallexample |
0ee54786 EZ |
1349 | |
1350 | It became: | |
1351 | ||
474c8240 | 1352 | @smallexample |
0ee54786 EZ |
1353 | annotate_field (5); |
1354 | if (b->forked_inferior_pid != 0) | |
1355 | @{ | |
1356 | ui_out_text (uiout, "process "); | |
1357 | ui_out_field_int (uiout, "what", b->forked_inferior_pid); | |
1358 | ui_out_spaces (uiout, 1); | |
1359 | @} | |
474c8240 | 1360 | @end smallexample |
0ee54786 EZ |
1361 | |
1362 | Here's an example of using @code{ui_out_field_string}. The original | |
1363 | code was: | |
1364 | ||
474c8240 | 1365 | @smallexample |
0ee54786 EZ |
1366 | annotate_field (5); |
1367 | if (b->exec_pathname != NULL) | |
1368 | printf_filtered ("program \"%s\" ", b->exec_pathname); | |
474c8240 | 1369 | @end smallexample |
0ee54786 EZ |
1370 | |
1371 | It became: | |
1372 | ||
474c8240 | 1373 | @smallexample |
0ee54786 EZ |
1374 | annotate_field (5); |
1375 | if (b->exec_pathname != NULL) | |
1376 | @{ | |
1377 | ui_out_text (uiout, "program \""); | |
1378 | ui_out_field_string (uiout, "what", b->exec_pathname); | |
1379 | ui_out_text (uiout, "\" "); | |
1380 | @} | |
474c8240 | 1381 | @end smallexample |
0ee54786 EZ |
1382 | |
1383 | Finally, here's an example of printing an address. The original code: | |
1384 | ||
474c8240 | 1385 | @smallexample |
0ee54786 EZ |
1386 | annotate_field (4); |
1387 | printf_filtered ("%s ", | |
1388 | local_hex_string_custom ((unsigned long) b->address, "08l")); | |
474c8240 | 1389 | @end smallexample |
0ee54786 EZ |
1390 | |
1391 | It became: | |
1392 | ||
474c8240 | 1393 | @smallexample |
0ee54786 EZ |
1394 | annotate_field (4); |
1395 | ui_out_field_core_addr (uiout, "Address", b->address); | |
474c8240 | 1396 | @end smallexample |
0ee54786 EZ |
1397 | |
1398 | ||
c906108c SS |
1399 | @section Console Printing |
1400 | ||
1401 | @section TUI | |
1402 | ||
89437448 | 1403 | @node libgdb |
c906108c | 1404 | |
89437448 AC |
1405 | @chapter libgdb |
1406 | ||
1407 | @section libgdb 1.0 | |
1408 | @cindex @code{libgdb} | |
1409 | @code{libgdb} 1.0 was an abortive project of years ago. The theory was | |
1410 | to provide an API to @value{GDBN}'s functionality. | |
1411 | ||
1412 | @section libgdb 2.0 | |
56caf160 | 1413 | @cindex @code{libgdb} |
89437448 AC |
1414 | @code{libgdb} 2.0 is an ongoing effort to update @value{GDBN} so that is |
1415 | better able to support graphical and other environments. | |
1416 | ||
1417 | Since @code{libgdb} development is on-going, its architecture is still | |
1418 | evolving. The following components have so far been identified: | |
1419 | ||
1420 | @itemize @bullet | |
1421 | @item | |
1422 | Observer - @file{gdb-events.h}. | |
1423 | @item | |
1424 | Builder - @file{ui-out.h} | |
1425 | @item | |
1426 | Event Loop - @file{event-loop.h} | |
1427 | @item | |
1428 | Library - @file{gdb.h} | |
1429 | @end itemize | |
1430 | ||
1431 | The model that ties these components together is described below. | |
1432 | ||
1433 | @section The @code{libgdb} Model | |
1434 | ||
1435 | A client of @code{libgdb} interacts with the library in two ways. | |
1436 | ||
1437 | @itemize @bullet | |
1438 | @item | |
1439 | As an observer (using @file{gdb-events}) receiving notifications from | |
1440 | @code{libgdb} of any internal state changes (break point changes, run | |
1441 | state, etc). | |
1442 | @item | |
1443 | As a client querying @code{libgdb} (using the @file{ui-out} builder) to | |
1444 | obtain various status values from @value{GDBN}. | |
1445 | @end itemize | |
1446 | ||
1447 | Since @code{libgdb} could have multiple clients (e.g. a GUI supporting | |
1448 | the existing @value{GDBN} CLI), those clients must co-operate when | |
1449 | controlling @code{libgdb}. In particular, a client must ensure that | |
1450 | @code{libgdb} is idle (i.e. no other client is using @code{libgdb}) | |
1451 | before responding to a @file{gdb-event} by making a query. | |
1452 | ||
1453 | @section CLI support | |
1454 | ||
1455 | At present @value{GDBN}'s CLI is very much entangled in with the core of | |
1456 | @code{libgdb}. Consequently, a client wishing to include the CLI in | |
1457 | their interface needs to carefully co-ordinate its own and the CLI's | |
1458 | requirements. | |
1459 | ||
1460 | It is suggested that the client set @code{libgdb} up to be bi-modal | |
1461 | (alternate between CLI and client query modes). The notes below sketch | |
1462 | out the theory: | |
1463 | ||
1464 | @itemize @bullet | |
1465 | @item | |
1466 | The client registers itself as an observer of @code{libgdb}. | |
1467 | @item | |
1468 | The client create and install @code{cli-out} builder using its own | |
1469 | versions of the @code{ui-file} @code{gdb_stderr}, @code{gdb_stdtarg} and | |
1470 | @code{gdb_stdout} streams. | |
1471 | @item | |
1472 | The client creates a separate custom @code{ui-out} builder that is only | |
1473 | used while making direct queries to @code{libgdb}. | |
1474 | @end itemize | |
1475 | ||
1476 | When the client receives input intended for the CLI, it simply passes it | |
1477 | along. Since the @code{cli-out} builder is installed by default, all | |
1478 | the CLI output in response to that command is routed (pronounced rooted) | |
1479 | through to the client controlled @code{gdb_stdout} et.@: al.@: streams. | |
1480 | At the same time, the client is kept abreast of internal changes by | |
1481 | virtue of being a @code{libgdb} observer. | |
1482 | ||
1483 | The only restriction on the client is that it must wait until | |
1484 | @code{libgdb} becomes idle before initiating any queries (using the | |
1485 | client's custom builder). | |
1486 | ||
1487 | @section @code{libgdb} components | |
1488 | ||
1489 | @subheading Observer - @file{gdb-events.h} | |
1490 | @file{gdb-events} provides the client with a very raw mechanism that can | |
1491 | be used to implement an observer. At present it only allows for one | |
1492 | observer and that observer must, internally, handle the need to delay | |
1493 | the processing of any event notifications until after @code{libgdb} has | |
1494 | finished the current command. | |
1495 | ||
1496 | @subheading Builder - @file{ui-out.h} | |
1497 | @file{ui-out} provides the infrastructure necessary for a client to | |
1498 | create a builder. That builder is then passed down to @code{libgdb} | |
1499 | when doing any queries. | |
1500 | ||
1501 | @subheading Event Loop - @file{event-loop.h} | |
1502 | @c There could be an entire section on the event-loop | |
1503 | @file{event-loop}, currently non-re-entrant, provides a simple event | |
1504 | loop. A client would need to either plug its self into this loop or, | |
1505 | implement a new event-loop that GDB would use. | |
1506 | ||
1507 | The event-loop will eventually be made re-entrant. This is so that | |
a9f12a31 | 1508 | @value{GDBN} can better handle the problem of some commands blocking |
89437448 AC |
1509 | instead of returning. |
1510 | ||
1511 | @subheading Library - @file{gdb.h} | |
1512 | @file{libgdb} is the most obvious component of this system. It provides | |
1513 | the query interface. Each function is parameterized by a @code{ui-out} | |
1514 | builder. The result of the query is constructed using that builder | |
1515 | before the query function returns. | |
c906108c SS |
1516 | |
1517 | @node Symbol Handling | |
1518 | ||
1519 | @chapter Symbol Handling | |
1520 | ||
25822942 | 1521 | Symbols are a key part of @value{GDBN}'s operation. Symbols include variables, |
c906108c SS |
1522 | functions, and types. |
1523 | ||
1524 | @section Symbol Reading | |
1525 | ||
56caf160 EZ |
1526 | @cindex symbol reading |
1527 | @cindex reading of symbols | |
1528 | @cindex symbol files | |
1529 | @value{GDBN} reads symbols from @dfn{symbol files}. The usual symbol | |
1530 | file is the file containing the program which @value{GDBN} is | |
1531 | debugging. @value{GDBN} can be directed to use a different file for | |
1532 | symbols (with the @samp{symbol-file} command), and it can also read | |
1533 | more symbols via the @samp{add-file} and @samp{load} commands, or while | |
1534 | reading symbols from shared libraries. | |
1535 | ||
1536 | @findex find_sym_fns | |
1537 | Symbol files are initially opened by code in @file{symfile.c} using | |
1538 | the BFD library (@pxref{Support Libraries}). BFD identifies the type | |
1539 | of the file by examining its header. @code{find_sym_fns} then uses | |
1540 | this identification to locate a set of symbol-reading functions. | |
1541 | ||
1542 | @findex add_symtab_fns | |
1543 | @cindex @code{sym_fns} structure | |
1544 | @cindex adding a symbol-reading module | |
1545 | Symbol-reading modules identify themselves to @value{GDBN} by calling | |
c906108c SS |
1546 | @code{add_symtab_fns} during their module initialization. The argument |
1547 | to @code{add_symtab_fns} is a @code{struct sym_fns} which contains the | |
1548 | name (or name prefix) of the symbol format, the length of the prefix, | |
1549 | and pointers to four functions. These functions are called at various | |
56caf160 | 1550 | times to process symbol files whose identification matches the specified |
c906108c SS |
1551 | prefix. |
1552 | ||
1553 | The functions supplied by each module are: | |
1554 | ||
1555 | @table @code | |
1556 | @item @var{xyz}_symfile_init(struct sym_fns *sf) | |
1557 | ||
56caf160 | 1558 | @cindex secondary symbol file |
c906108c SS |
1559 | Called from @code{symbol_file_add} when we are about to read a new |
1560 | symbol file. This function should clean up any internal state (possibly | |
1561 | resulting from half-read previous files, for example) and prepare to | |
56caf160 EZ |
1562 | read a new symbol file. Note that the symbol file which we are reading |
1563 | might be a new ``main'' symbol file, or might be a secondary symbol file | |
c906108c SS |
1564 | whose symbols are being added to the existing symbol table. |
1565 | ||
1566 | The argument to @code{@var{xyz}_symfile_init} is a newly allocated | |
1567 | @code{struct sym_fns} whose @code{bfd} field contains the BFD for the | |
1568 | new symbol file being read. Its @code{private} field has been zeroed, | |
1569 | and can be modified as desired. Typically, a struct of private | |
1570 | information will be @code{malloc}'d, and a pointer to it will be placed | |
1571 | in the @code{private} field. | |
1572 | ||
1573 | There is no result from @code{@var{xyz}_symfile_init}, but it can call | |
1574 | @code{error} if it detects an unavoidable problem. | |
1575 | ||
1576 | @item @var{xyz}_new_init() | |
1577 | ||
1578 | Called from @code{symbol_file_add} when discarding existing symbols. | |
56caf160 EZ |
1579 | This function needs only handle the symbol-reading module's internal |
1580 | state; the symbol table data structures visible to the rest of | |
1581 | @value{GDBN} will be discarded by @code{symbol_file_add}. It has no | |
1582 | arguments and no result. It may be called after | |
1583 | @code{@var{xyz}_symfile_init}, if a new symbol table is being read, or | |
1584 | may be called alone if all symbols are simply being discarded. | |
c906108c SS |
1585 | |
1586 | @item @var{xyz}_symfile_read(struct sym_fns *sf, CORE_ADDR addr, int mainline) | |
1587 | ||
1588 | Called from @code{symbol_file_add} to actually read the symbols from a | |
1589 | symbol-file into a set of psymtabs or symtabs. | |
1590 | ||
56caf160 | 1591 | @code{sf} points to the @code{struct sym_fns} originally passed to |
c906108c SS |
1592 | @code{@var{xyz}_sym_init} for possible initialization. @code{addr} is |
1593 | the offset between the file's specified start address and its true | |
1594 | address in memory. @code{mainline} is 1 if this is the main symbol | |
1595 | table being read, and 0 if a secondary symbol file (e.g. shared library | |
1596 | or dynamically loaded file) is being read.@refill | |
1597 | @end table | |
1598 | ||
1599 | In addition, if a symbol-reading module creates psymtabs when | |
1600 | @var{xyz}_symfile_read is called, these psymtabs will contain a pointer | |
1601 | to a function @code{@var{xyz}_psymtab_to_symtab}, which can be called | |
25822942 | 1602 | from any point in the @value{GDBN} symbol-handling code. |
c906108c SS |
1603 | |
1604 | @table @code | |
1605 | @item @var{xyz}_psymtab_to_symtab (struct partial_symtab *pst) | |
1606 | ||
56caf160 | 1607 | Called from @code{psymtab_to_symtab} (or the @code{PSYMTAB_TO_SYMTAB} macro) if |
c906108c SS |
1608 | the psymtab has not already been read in and had its @code{pst->symtab} |
1609 | pointer set. The argument is the psymtab to be fleshed-out into a | |
56caf160 EZ |
1610 | symtab. Upon return, @code{pst->readin} should have been set to 1, and |
1611 | @code{pst->symtab} should contain a pointer to the new corresponding symtab, or | |
c906108c SS |
1612 | zero if there were no symbols in that part of the symbol file. |
1613 | @end table | |
1614 | ||
1615 | @section Partial Symbol Tables | |
1616 | ||
56caf160 | 1617 | @value{GDBN} has three types of symbol tables: |
c906108c SS |
1618 | |
1619 | @itemize @bullet | |
56caf160 EZ |
1620 | @cindex full symbol table |
1621 | @cindex symtabs | |
1622 | @item | |
1623 | Full symbol tables (@dfn{symtabs}). These contain the main | |
1624 | information about symbols and addresses. | |
c906108c | 1625 | |
56caf160 EZ |
1626 | @cindex psymtabs |
1627 | @item | |
1628 | Partial symbol tables (@dfn{psymtabs}). These contain enough | |
c906108c SS |
1629 | information to know when to read the corresponding part of the full |
1630 | symbol table. | |
1631 | ||
56caf160 EZ |
1632 | @cindex minimal symbol table |
1633 | @cindex minsymtabs | |
1634 | @item | |
1635 | Minimal symbol tables (@dfn{msymtabs}). These contain information | |
c906108c | 1636 | gleaned from non-debugging symbols. |
c906108c SS |
1637 | @end itemize |
1638 | ||
56caf160 | 1639 | @cindex partial symbol table |
c906108c SS |
1640 | This section describes partial symbol tables. |
1641 | ||
1642 | A psymtab is constructed by doing a very quick pass over an executable | |
1643 | file's debugging information. Small amounts of information are | |
56caf160 | 1644 | extracted---enough to identify which parts of the symbol table will |
c906108c | 1645 | need to be re-read and fully digested later, when the user needs the |
25822942 | 1646 | information. The speed of this pass causes @value{GDBN} to start up very |
c906108c SS |
1647 | quickly. Later, as the detailed rereading occurs, it occurs in small |
1648 | pieces, at various times, and the delay therefrom is mostly invisible to | |
1649 | the user. | |
1650 | @c (@xref{Symbol Reading}.) | |
1651 | ||
1652 | The symbols that show up in a file's psymtab should be, roughly, those | |
1653 | visible to the debugger's user when the program is not running code from | |
1654 | that file. These include external symbols and types, static symbols and | |
56caf160 | 1655 | types, and @code{enum} values declared at file scope. |
c906108c SS |
1656 | |
1657 | The psymtab also contains the range of instruction addresses that the | |
1658 | full symbol table would represent. | |
1659 | ||
56caf160 EZ |
1660 | @cindex finding a symbol |
1661 | @cindex symbol lookup | |
c906108c SS |
1662 | The idea is that there are only two ways for the user (or much of the |
1663 | code in the debugger) to reference a symbol: | |
1664 | ||
1665 | @itemize @bullet | |
56caf160 EZ |
1666 | @findex find_pc_function |
1667 | @findex find_pc_line | |
1668 | @item | |
1669 | By its address (e.g. execution stops at some address which is inside a | |
1670 | function in this file). The address will be noticed to be in the | |
1671 | range of this psymtab, and the full symtab will be read in. | |
1672 | @code{find_pc_function}, @code{find_pc_line}, and other | |
1673 | @code{find_pc_@dots{}} functions handle this. | |
c906108c | 1674 | |
56caf160 EZ |
1675 | @cindex lookup_symbol |
1676 | @item | |
1677 | By its name | |
c906108c SS |
1678 | (e.g. the user asks to print a variable, or set a breakpoint on a |
1679 | function). Global names and file-scope names will be found in the | |
1680 | psymtab, which will cause the symtab to be pulled in. Local names will | |
1681 | have to be qualified by a global name, or a file-scope name, in which | |
1682 | case we will have already read in the symtab as we evaluated the | |
56caf160 | 1683 | qualifier. Or, a local symbol can be referenced when we are ``in'' a |
c906108c SS |
1684 | local scope, in which case the first case applies. @code{lookup_symbol} |
1685 | does most of the work here. | |
c906108c SS |
1686 | @end itemize |
1687 | ||
1688 | The only reason that psymtabs exist is to cause a symtab to be read in | |
1689 | at the right moment. Any symbol that can be elided from a psymtab, | |
1690 | while still causing that to happen, should not appear in it. Since | |
1691 | psymtabs don't have the idea of scope, you can't put local symbols in | |
1692 | them anyway. Psymtabs don't have the idea of the type of a symbol, | |
1693 | either, so types need not appear, unless they will be referenced by | |
1694 | name. | |
1695 | ||
56caf160 EZ |
1696 | It is a bug for @value{GDBN} to behave one way when only a psymtab has |
1697 | been read, and another way if the corresponding symtab has been read | |
1698 | in. Such bugs are typically caused by a psymtab that does not contain | |
1699 | all the visible symbols, or which has the wrong instruction address | |
1700 | ranges. | |
c906108c | 1701 | |
56caf160 | 1702 | The psymtab for a particular section of a symbol file (objfile) could be |
c906108c SS |
1703 | thrown away after the symtab has been read in. The symtab should always |
1704 | be searched before the psymtab, so the psymtab will never be used (in a | |
1705 | bug-free environment). Currently, psymtabs are allocated on an obstack, | |
1706 | and all the psymbols themselves are allocated in a pair of large arrays | |
1707 | on an obstack, so there is little to be gained by trying to free them | |
1708 | unless you want to do a lot more work. | |
1709 | ||
1710 | @section Types | |
1711 | ||
56caf160 | 1712 | @unnumberedsubsec Fundamental Types (e.g., @code{FT_VOID}, @code{FT_BOOLEAN}). |
c906108c | 1713 | |
56caf160 | 1714 | @cindex fundamental types |
25822942 | 1715 | These are the fundamental types that @value{GDBN} uses internally. Fundamental |
c906108c SS |
1716 | types from the various debugging formats (stabs, ELF, etc) are mapped |
1717 | into one of these. They are basically a union of all fundamental types | |
56caf160 EZ |
1718 | that @value{GDBN} knows about for all the languages that @value{GDBN} |
1719 | knows about. | |
c906108c | 1720 | |
56caf160 | 1721 | @unnumberedsubsec Type Codes (e.g., @code{TYPE_CODE_PTR}, @code{TYPE_CODE_ARRAY}). |
c906108c | 1722 | |
56caf160 EZ |
1723 | @cindex type codes |
1724 | Each time @value{GDBN} builds an internal type, it marks it with one | |
1725 | of these types. The type may be a fundamental type, such as | |
1726 | @code{TYPE_CODE_INT}, or a derived type, such as @code{TYPE_CODE_PTR} | |
1727 | which is a pointer to another type. Typically, several @code{FT_*} | |
1728 | types map to one @code{TYPE_CODE_*} type, and are distinguished by | |
1729 | other members of the type struct, such as whether the type is signed | |
1730 | or unsigned, and how many bits it uses. | |
c906108c | 1731 | |
56caf160 | 1732 | @unnumberedsubsec Builtin Types (e.g., @code{builtin_type_void}, @code{builtin_type_char}). |
c906108c SS |
1733 | |
1734 | These are instances of type structs that roughly correspond to | |
56caf160 EZ |
1735 | fundamental types and are created as global types for @value{GDBN} to |
1736 | use for various ugly historical reasons. We eventually want to | |
1737 | eliminate these. Note for example that @code{builtin_type_int} | |
1738 | initialized in @file{gdbtypes.c} is basically the same as a | |
1739 | @code{TYPE_CODE_INT} type that is initialized in @file{c-lang.c} for | |
1740 | an @code{FT_INTEGER} fundamental type. The difference is that the | |
1741 | @code{builtin_type} is not associated with any particular objfile, and | |
1742 | only one instance exists, while @file{c-lang.c} builds as many | |
1743 | @code{TYPE_CODE_INT} types as needed, with each one associated with | |
1744 | some particular objfile. | |
c906108c SS |
1745 | |
1746 | @section Object File Formats | |
56caf160 | 1747 | @cindex object file formats |
c906108c SS |
1748 | |
1749 | @subsection a.out | |
1750 | ||
56caf160 EZ |
1751 | @cindex @code{a.out} format |
1752 | The @code{a.out} format is the original file format for Unix. It | |
1753 | consists of three sections: @code{text}, @code{data}, and @code{bss}, | |
1754 | which are for program code, initialized data, and uninitialized data, | |
1755 | respectively. | |
c906108c | 1756 | |
56caf160 | 1757 | The @code{a.out} format is so simple that it doesn't have any reserved |
c906108c | 1758 | place for debugging information. (Hey, the original Unix hackers used |
56caf160 EZ |
1759 | @samp{adb}, which is a machine-language debugger!) The only debugging |
1760 | format for @code{a.out} is stabs, which is encoded as a set of normal | |
c906108c SS |
1761 | symbols with distinctive attributes. |
1762 | ||
56caf160 | 1763 | The basic @code{a.out} reader is in @file{dbxread.c}. |
c906108c SS |
1764 | |
1765 | @subsection COFF | |
1766 | ||
56caf160 | 1767 | @cindex COFF format |
c906108c SS |
1768 | The COFF format was introduced with System V Release 3 (SVR3) Unix. |
1769 | COFF files may have multiple sections, each prefixed by a header. The | |
1770 | number of sections is limited. | |
1771 | ||
1772 | The COFF specification includes support for debugging. Although this | |
1773 | was a step forward, the debugging information was woefully limited. For | |
1774 | instance, it was not possible to represent code that came from an | |
1775 | included file. | |
1776 | ||
1777 | The COFF reader is in @file{coffread.c}. | |
1778 | ||
1779 | @subsection ECOFF | |
1780 | ||
56caf160 | 1781 | @cindex ECOFF format |
c906108c SS |
1782 | ECOFF is an extended COFF originally introduced for Mips and Alpha |
1783 | workstations. | |
1784 | ||
1785 | The basic ECOFF reader is in @file{mipsread.c}. | |
1786 | ||
1787 | @subsection XCOFF | |
1788 | ||
56caf160 | 1789 | @cindex XCOFF format |
c906108c SS |
1790 | The IBM RS/6000 running AIX uses an object file format called XCOFF. |
1791 | The COFF sections, symbols, and line numbers are used, but debugging | |
56caf160 EZ |
1792 | symbols are @code{dbx}-style stabs whose strings are located in the |
1793 | @code{.debug} section (rather than the string table). For more | |
1794 | information, see @ref{Top,,,stabs,The Stabs Debugging Format}. | |
c906108c SS |
1795 | |
1796 | The shared library scheme has a clean interface for figuring out what | |
1797 | shared libraries are in use, but the catch is that everything which | |
1798 | refers to addresses (symbol tables and breakpoints at least) needs to be | |
1799 | relocated for both shared libraries and the main executable. At least | |
1800 | using the standard mechanism this can only be done once the program has | |
1801 | been run (or the core file has been read). | |
1802 | ||
1803 | @subsection PE | |
1804 | ||
56caf160 EZ |
1805 | @cindex PE-COFF format |
1806 | Windows 95 and NT use the PE (@dfn{Portable Executable}) format for their | |
c906108c SS |
1807 | executables. PE is basically COFF with additional headers. |
1808 | ||
25822942 | 1809 | While BFD includes special PE support, @value{GDBN} needs only the basic |
c906108c SS |
1810 | COFF reader. |
1811 | ||
1812 | @subsection ELF | |
1813 | ||
56caf160 | 1814 | @cindex ELF format |
c906108c SS |
1815 | The ELF format came with System V Release 4 (SVR4) Unix. ELF is similar |
1816 | to COFF in being organized into a number of sections, but it removes | |
1817 | many of COFF's limitations. | |
1818 | ||
1819 | The basic ELF reader is in @file{elfread.c}. | |
1820 | ||
1821 | @subsection SOM | |
1822 | ||
56caf160 | 1823 | @cindex SOM format |
c906108c SS |
1824 | SOM is HP's object file and debug format (not to be confused with IBM's |
1825 | SOM, which is a cross-language ABI). | |
1826 | ||
1827 | The SOM reader is in @file{hpread.c}. | |
1828 | ||
1829 | @subsection Other File Formats | |
1830 | ||
56caf160 | 1831 | @cindex Netware Loadable Module format |
25822942 | 1832 | Other file formats that have been supported by @value{GDBN} include Netware |
4a98ee0e | 1833 | Loadable Modules (@file{nlmread.c}). |
c906108c SS |
1834 | |
1835 | @section Debugging File Formats | |
1836 | ||
1837 | This section describes characteristics of debugging information that | |
1838 | are independent of the object file format. | |
1839 | ||
1840 | @subsection stabs | |
1841 | ||
56caf160 | 1842 | @cindex stabs debugging info |
c906108c SS |
1843 | @code{stabs} started out as special symbols within the @code{a.out} |
1844 | format. Since then, it has been encapsulated into other file | |
1845 | formats, such as COFF and ELF. | |
1846 | ||
1847 | While @file{dbxread.c} does some of the basic stab processing, | |
1848 | including for encapsulated versions, @file{stabsread.c} does | |
1849 | the real work. | |
1850 | ||
1851 | @subsection COFF | |
1852 | ||
56caf160 | 1853 | @cindex COFF debugging info |
c906108c SS |
1854 | The basic COFF definition includes debugging information. The level |
1855 | of support is minimal and non-extensible, and is not often used. | |
1856 | ||
1857 | @subsection Mips debug (Third Eye) | |
1858 | ||
56caf160 | 1859 | @cindex ECOFF debugging info |
c906108c SS |
1860 | ECOFF includes a definition of a special debug format. |
1861 | ||
1862 | The file @file{mdebugread.c} implements reading for this format. | |
1863 | ||
1864 | @subsection DWARF 1 | |
1865 | ||
56caf160 | 1866 | @cindex DWARF 1 debugging info |
c906108c SS |
1867 | DWARF 1 is a debugging format that was originally designed to be |
1868 | used with ELF in SVR4 systems. | |
1869 | ||
c906108c SS |
1870 | @c GCC_PRODUCER |
1871 | @c GPLUS_PRODUCER | |
1872 | @c LCC_PRODUCER | |
1873 | @c If defined, these are the producer strings in a DWARF 1 file. All of | |
1874 | @c these have reasonable defaults already. | |
1875 | ||
1876 | The DWARF 1 reader is in @file{dwarfread.c}. | |
1877 | ||
1878 | @subsection DWARF 2 | |
1879 | ||
56caf160 | 1880 | @cindex DWARF 2 debugging info |
c906108c SS |
1881 | DWARF 2 is an improved but incompatible version of DWARF 1. |
1882 | ||
1883 | The DWARF 2 reader is in @file{dwarf2read.c}. | |
1884 | ||
1885 | @subsection SOM | |
1886 | ||
56caf160 | 1887 | @cindex SOM debugging info |
c906108c SS |
1888 | Like COFF, the SOM definition includes debugging information. |
1889 | ||
25822942 | 1890 | @section Adding a New Symbol Reader to @value{GDBN} |
c906108c | 1891 | |
56caf160 EZ |
1892 | @cindex adding debugging info reader |
1893 | If you are using an existing object file format (@code{a.out}, COFF, ELF, etc), | |
c906108c SS |
1894 | there is probably little to be done. |
1895 | ||
1896 | If you need to add a new object file format, you must first add it to | |
1897 | BFD. This is beyond the scope of this document. | |
1898 | ||
1899 | You must then arrange for the BFD code to provide access to the | |
25822942 | 1900 | debugging symbols. Generally @value{GDBN} will have to call swapping routines |
c906108c | 1901 | from BFD and a few other BFD internal routines to locate the debugging |
25822942 | 1902 | information. As much as possible, @value{GDBN} should not depend on the BFD |
c906108c SS |
1903 | internal data structures. |
1904 | ||
1905 | For some targets (e.g., COFF), there is a special transfer vector used | |
1906 | to call swapping routines, since the external data structures on various | |
1907 | platforms have different sizes and layouts. Specialized routines that | |
1908 | will only ever be implemented by one object file format may be called | |
1909 | directly. This interface should be described in a file | |
56caf160 | 1910 | @file{bfd/lib@var{xyz}.h}, which is included by @value{GDBN}. |
c906108c SS |
1911 | |
1912 | ||
1913 | @node Language Support | |
1914 | ||
1915 | @chapter Language Support | |
1916 | ||
56caf160 EZ |
1917 | @cindex language support |
1918 | @value{GDBN}'s language support is mainly driven by the symbol reader, | |
1919 | although it is possible for the user to set the source language | |
1920 | manually. | |
c906108c | 1921 | |
56caf160 EZ |
1922 | @value{GDBN} chooses the source language by looking at the extension |
1923 | of the file recorded in the debug info; @file{.c} means C, @file{.f} | |
1924 | means Fortran, etc. It may also use a special-purpose language | |
1925 | identifier if the debug format supports it, like with DWARF. | |
c906108c | 1926 | |
25822942 | 1927 | @section Adding a Source Language to @value{GDBN} |
c906108c | 1928 | |
56caf160 EZ |
1929 | @cindex adding source language |
1930 | To add other languages to @value{GDBN}'s expression parser, follow the | |
1931 | following steps: | |
c906108c SS |
1932 | |
1933 | @table @emph | |
1934 | @item Create the expression parser. | |
1935 | ||
56caf160 | 1936 | @cindex expression parser |
c906108c | 1937 | This should reside in a file @file{@var{lang}-exp.y}. Routines for |
56caf160 | 1938 | building parsed expressions into a @code{union exp_element} list are in |
c906108c SS |
1939 | @file{parse.c}. |
1940 | ||
56caf160 | 1941 | @cindex language parser |
c906108c SS |
1942 | Since we can't depend upon everyone having Bison, and YACC produces |
1943 | parsers that define a bunch of global names, the following lines | |
56caf160 | 1944 | @strong{must} be included at the top of the YACC parser, to prevent the |
c906108c SS |
1945 | various parsers from defining the same global names: |
1946 | ||
474c8240 | 1947 | @smallexample |
56caf160 EZ |
1948 | #define yyparse @var{lang}_parse |
1949 | #define yylex @var{lang}_lex | |
1950 | #define yyerror @var{lang}_error | |
1951 | #define yylval @var{lang}_lval | |
1952 | #define yychar @var{lang}_char | |
1953 | #define yydebug @var{lang}_debug | |
1954 | #define yypact @var{lang}_pact | |
1955 | #define yyr1 @var{lang}_r1 | |
1956 | #define yyr2 @var{lang}_r2 | |
1957 | #define yydef @var{lang}_def | |
1958 | #define yychk @var{lang}_chk | |
1959 | #define yypgo @var{lang}_pgo | |
1960 | #define yyact @var{lang}_act | |
1961 | #define yyexca @var{lang}_exca | |
1962 | #define yyerrflag @var{lang}_errflag | |
1963 | #define yynerrs @var{lang}_nerrs | |
474c8240 | 1964 | @end smallexample |
c906108c SS |
1965 | |
1966 | At the bottom of your parser, define a @code{struct language_defn} and | |
1967 | initialize it with the right values for your language. Define an | |
1968 | @code{initialize_@var{lang}} routine and have it call | |
25822942 | 1969 | @samp{add_language(@var{lang}_language_defn)} to tell the rest of @value{GDBN} |
c906108c SS |
1970 | that your language exists. You'll need some other supporting variables |
1971 | and functions, which will be used via pointers from your | |
1972 | @code{@var{lang}_language_defn}. See the declaration of @code{struct | |
1973 | language_defn} in @file{language.h}, and the other @file{*-exp.y} files, | |
1974 | for more information. | |
1975 | ||
1976 | @item Add any evaluation routines, if necessary | |
1977 | ||
56caf160 EZ |
1978 | @cindex expression evaluation routines |
1979 | @findex evaluate_subexp | |
1980 | @findex prefixify_subexp | |
1981 | @findex length_of_subexp | |
c906108c SS |
1982 | If you need new opcodes (that represent the operations of the language), |
1983 | add them to the enumerated type in @file{expression.h}. Add support | |
56caf160 EZ |
1984 | code for these operations in the @code{evaluate_subexp} function |
1985 | defined in the file @file{eval.c}. Add cases | |
c906108c | 1986 | for new opcodes in two functions from @file{parse.c}: |
56caf160 | 1987 | @code{prefixify_subexp} and @code{length_of_subexp}. These compute |
c906108c SS |
1988 | the number of @code{exp_element}s that a given operation takes up. |
1989 | ||
1990 | @item Update some existing code | |
1991 | ||
1992 | Add an enumerated identifier for your language to the enumerated type | |
1993 | @code{enum language} in @file{defs.h}. | |
1994 | ||
1995 | Update the routines in @file{language.c} so your language is included. | |
1996 | These routines include type predicates and such, which (in some cases) | |
1997 | are language dependent. If your language does not appear in the switch | |
1998 | statement, an error is reported. | |
1999 | ||
56caf160 | 2000 | @vindex current_language |
c906108c SS |
2001 | Also included in @file{language.c} is the code that updates the variable |
2002 | @code{current_language}, and the routines that translate the | |
2003 | @code{language_@var{lang}} enumerated identifier into a printable | |
2004 | string. | |
2005 | ||
56caf160 | 2006 | @findex _initialize_language |
c906108c SS |
2007 | Update the function @code{_initialize_language} to include your |
2008 | language. This function picks the default language upon startup, so is | |
25822942 | 2009 | dependent upon which languages that @value{GDBN} is built for. |
c906108c | 2010 | |
56caf160 | 2011 | @findex allocate_symtab |
c906108c SS |
2012 | Update @code{allocate_symtab} in @file{symfile.c} and/or symbol-reading |
2013 | code so that the language of each symtab (source file) is set properly. | |
2014 | This is used to determine the language to use at each stack frame level. | |
2015 | Currently, the language is set based upon the extension of the source | |
2016 | file. If the language can be better inferred from the symbol | |
2017 | information, please set the language of the symtab in the symbol-reading | |
2018 | code. | |
2019 | ||
56caf160 EZ |
2020 | @findex print_subexp |
2021 | @findex op_print_tab | |
2022 | Add helper code to @code{print_subexp} (in @file{expprint.c}) to handle any new | |
c906108c SS |
2023 | expression opcodes you have added to @file{expression.h}. Also, add the |
2024 | printed representations of your operators to @code{op_print_tab}. | |
2025 | ||
2026 | @item Add a place of call | |
2027 | ||
56caf160 | 2028 | @findex parse_exp_1 |
c906108c | 2029 | Add a call to @code{@var{lang}_parse()} and @code{@var{lang}_error} in |
56caf160 | 2030 | @code{parse_exp_1} (defined in @file{parse.c}). |
c906108c SS |
2031 | |
2032 | @item Use macros to trim code | |
2033 | ||
56caf160 | 2034 | @cindex trimming language-dependent code |
25822942 DB |
2035 | The user has the option of building @value{GDBN} for some or all of the |
2036 | languages. If the user decides to build @value{GDBN} for the language | |
c906108c SS |
2037 | @var{lang}, then every file dependent on @file{language.h} will have the |
2038 | macro @code{_LANG_@var{lang}} defined in it. Use @code{#ifdef}s to | |
2039 | leave out large routines that the user won't need if he or she is not | |
2040 | using your language. | |
2041 | ||
25822942 | 2042 | Note that you do not need to do this in your YACC parser, since if @value{GDBN} |
c906108c | 2043 | is not build for @var{lang}, then @file{@var{lang}-exp.tab.o} (the |
25822942 | 2044 | compiled form of your parser) is not linked into @value{GDBN} at all. |
c906108c | 2045 | |
56caf160 EZ |
2046 | See the file @file{configure.in} for how @value{GDBN} is configured |
2047 | for different languages. | |
c906108c SS |
2048 | |
2049 | @item Edit @file{Makefile.in} | |
2050 | ||
2051 | Add dependencies in @file{Makefile.in}. Make sure you update the macro | |
2052 | variables such as @code{HFILES} and @code{OBJS}, otherwise your code may | |
2053 | not get linked in, or, worse yet, it may not get @code{tar}red into the | |
2054 | distribution! | |
c906108c SS |
2055 | @end table |
2056 | ||
2057 | ||
2058 | @node Host Definition | |
2059 | ||
2060 | @chapter Host Definition | |
2061 | ||
56caf160 | 2062 | With the advent of Autoconf, it's rarely necessary to have host |
7fd60527 AC |
2063 | definition machinery anymore. The following information is provided, |
2064 | mainly, as an historical reference. | |
c906108c SS |
2065 | |
2066 | @section Adding a New Host | |
2067 | ||
56caf160 EZ |
2068 | @cindex adding a new host |
2069 | @cindex host, adding | |
7fd60527 AC |
2070 | @value{GDBN}'s host configuration support normally happens via Autoconf. |
2071 | New host-specific definitions should not be needed. Older hosts | |
2072 | @value{GDBN} still use the host-specific definitions and files listed | |
2073 | below, but these mostly exist for historical reasons, and will | |
56caf160 | 2074 | eventually disappear. |
c906108c | 2075 | |
c906108c | 2076 | @table @file |
c906108c | 2077 | @item gdb/config/@var{arch}/@var{xyz}.mh |
7fd60527 AC |
2078 | This file once contained both host and native configuration information |
2079 | (@pxref{Native Debugging}) for the machine @var{xyz}. The host | |
2080 | configuration information is now handed by Autoconf. | |
2081 | ||
2082 | Host configuration information included a definition of | |
2083 | @code{XM_FILE=xm-@var{xyz}.h} and possibly definitions for @code{CC}, | |
7708fa01 AC |
2084 | @code{SYSV_DEFINE}, @code{XM_CFLAGS}, @code{XM_ADD_FILES}, |
2085 | @code{XM_CLIBS}, @code{XM_CDEPS}, etc.; see @file{Makefile.in}. | |
c906108c | 2086 | |
7fd60527 AC |
2087 | New host only configurations do not need this file. |
2088 | ||
c906108c | 2089 | @item gdb/config/@var{arch}/xm-@var{xyz}.h |
7fd60527 AC |
2090 | This file once contained definitions and includes required when hosting |
2091 | gdb on machine @var{xyz}. Those definitions and includes are now | |
2092 | handled by Autoconf. | |
2093 | ||
2094 | New host and native configurations do not need this file. | |
2095 | ||
2096 | @emph{Maintainer's note: Some hosts continue to use the @file{xm-xyz.h} | |
2097 | file to define the macros @var{HOST_FLOAT_FORMAT}, | |
2098 | @var{HOST_DOUBLE_FORMAT} and @var{HOST_LONG_DOUBLE_FORMAT}. That code | |
2099 | also needs to be replaced with either an Autoconf or run-time test.} | |
c906108c | 2100 | |
c906108c SS |
2101 | @end table |
2102 | ||
2103 | @subheading Generic Host Support Files | |
2104 | ||
56caf160 | 2105 | @cindex generic host support |
c906108c SS |
2106 | There are some ``generic'' versions of routines that can be used by |
2107 | various systems. These can be customized in various ways by macros | |
2108 | defined in your @file{xm-@var{xyz}.h} file. If these routines work for | |
2109 | the @var{xyz} host, you can just include the generic file's name (with | |
2110 | @samp{.o}, not @samp{.c}) in @code{XDEPFILES}. | |
2111 | ||
2112 | Otherwise, if your machine needs custom support routines, you will need | |
2113 | to write routines that perform the same functions as the generic file. | |
2114 | Put them into @code{@var{xyz}-xdep.c}, and put @code{@var{xyz}-xdep.o} | |
2115 | into @code{XDEPFILES}. | |
2116 | ||
2117 | @table @file | |
56caf160 EZ |
2118 | @cindex remote debugging support |
2119 | @cindex serial line support | |
c906108c SS |
2120 | @item ser-unix.c |
2121 | This contains serial line support for Unix systems. This is always | |
2122 | included, via the makefile variable @code{SER_HARDWIRE}; override this | |
2123 | variable in the @file{.mh} file to avoid it. | |
2124 | ||
2125 | @item ser-go32.c | |
2126 | This contains serial line support for 32-bit programs running under DOS, | |
56caf160 | 2127 | using the DJGPP (a.k.a.@: GO32) execution environment. |
c906108c | 2128 | |
56caf160 | 2129 | @cindex TCP remote support |
c906108c SS |
2130 | @item ser-tcp.c |
2131 | This contains generic TCP support using sockets. | |
c906108c SS |
2132 | @end table |
2133 | ||
2134 | @section Host Conditionals | |
2135 | ||
56caf160 EZ |
2136 | When @value{GDBN} is configured and compiled, various macros are |
2137 | defined or left undefined, to control compilation based on the | |
2138 | attributes of the host system. These macros and their meanings (or if | |
2139 | the meaning is not documented here, then one of the source files where | |
2140 | they are used is indicated) are: | |
c906108c | 2141 | |
56caf160 | 2142 | @ftable @code |
25822942 | 2143 | @item @value{GDBN}INIT_FILENAME |
56caf160 EZ |
2144 | The default name of @value{GDBN}'s initialization file (normally |
2145 | @file{.gdbinit}). | |
c906108c | 2146 | |
cce74817 JM |
2147 | @item NO_STD_REGS |
2148 | This macro is deprecated. | |
2149 | ||
c906108c SS |
2150 | @item NO_SYS_FILE |
2151 | Define this if your system does not have a @code{<sys/file.h>}. | |
2152 | ||
2153 | @item SIGWINCH_HANDLER | |
2154 | If your host defines @code{SIGWINCH}, you can define this to be the name | |
2155 | of a function to be called if @code{SIGWINCH} is received. | |
2156 | ||
2157 | @item SIGWINCH_HANDLER_BODY | |
2158 | Define this to expand into code that will define the function named by | |
2159 | the expansion of @code{SIGWINCH_HANDLER}. | |
2160 | ||
2161 | @item ALIGN_STACK_ON_STARTUP | |
56caf160 | 2162 | @cindex stack alignment |
c906108c SS |
2163 | Define this if your system is of a sort that will crash in |
2164 | @code{tgetent} if the stack happens not to be longword-aligned when | |
2165 | @code{main} is called. This is a rare situation, but is known to occur | |
2166 | on several different types of systems. | |
2167 | ||
2168 | @item CRLF_SOURCE_FILES | |
56caf160 | 2169 | @cindex DOS text files |
c906108c SS |
2170 | Define this if host files use @code{\r\n} rather than @code{\n} as a |
2171 | line terminator. This will cause source file listings to omit @code{\r} | |
56caf160 EZ |
2172 | characters when printing and it will allow @code{\r\n} line endings of files |
2173 | which are ``sourced'' by gdb. It must be possible to open files in binary | |
c906108c SS |
2174 | mode using @code{O_BINARY} or, for fopen, @code{"rb"}. |
2175 | ||
2176 | @item DEFAULT_PROMPT | |
56caf160 | 2177 | @cindex prompt |
c906108c SS |
2178 | The default value of the prompt string (normally @code{"(gdb) "}). |
2179 | ||
2180 | @item DEV_TTY | |
56caf160 | 2181 | @cindex terminal device |
c906108c SS |
2182 | The name of the generic TTY device, defaults to @code{"/dev/tty"}. |
2183 | ||
2184 | @item FCLOSE_PROVIDED | |
2185 | Define this if the system declares @code{fclose} in the headers included | |
2186 | in @code{defs.h}. This isn't needed unless your compiler is unusually | |
2187 | anal. | |
2188 | ||
2189 | @item FOPEN_RB | |
2190 | Define this if binary files are opened the same way as text files. | |
2191 | ||
2192 | @item GETENV_PROVIDED | |
2193 | Define this if the system declares @code{getenv} in its headers included | |
56caf160 | 2194 | in @code{defs.h}. This isn't needed unless your compiler is unusually |
c906108c SS |
2195 | anal. |
2196 | ||
2197 | @item HAVE_MMAP | |
56caf160 | 2198 | @findex mmap |
c906108c SS |
2199 | In some cases, use the system call @code{mmap} for reading symbol |
2200 | tables. For some machines this allows for sharing and quick updates. | |
2201 | ||
c906108c SS |
2202 | @item HAVE_TERMIO |
2203 | Define this if the host system has @code{termio.h}. | |
2204 | ||
c906108c | 2205 | @item INT_MAX |
9742079a EZ |
2206 | @itemx INT_MIN |
2207 | @itemx LONG_MAX | |
2208 | @itemx UINT_MAX | |
2209 | @itemx ULONG_MAX | |
c906108c SS |
2210 | Values for host-side constants. |
2211 | ||
2212 | @item ISATTY | |
2213 | Substitute for isatty, if not available. | |
2214 | ||
2215 | @item LONGEST | |
2216 | This is the longest integer type available on the host. If not defined, | |
2217 | it will default to @code{long long} or @code{long}, depending on | |
2218 | @code{CC_HAS_LONG_LONG}. | |
2219 | ||
2220 | @item CC_HAS_LONG_LONG | |
56caf160 EZ |
2221 | @cindex @code{long long} data type |
2222 | Define this if the host C compiler supports @code{long long}. This is set | |
2223 | by the @code{configure} script. | |
c906108c SS |
2224 | |
2225 | @item PRINTF_HAS_LONG_LONG | |
2226 | Define this if the host can handle printing of long long integers via | |
56caf160 EZ |
2227 | the printf format conversion specifier @code{ll}. This is set by the |
2228 | @code{configure} script. | |
c906108c SS |
2229 | |
2230 | @item HAVE_LONG_DOUBLE | |
56caf160 EZ |
2231 | Define this if the host C compiler supports @code{long double}. This is |
2232 | set by the @code{configure} script. | |
c906108c SS |
2233 | |
2234 | @item PRINTF_HAS_LONG_DOUBLE | |
2235 | Define this if the host can handle printing of long double float-point | |
56caf160 EZ |
2236 | numbers via the printf format conversion specifier @code{Lg}. This is |
2237 | set by the @code{configure} script. | |
c906108c SS |
2238 | |
2239 | @item SCANF_HAS_LONG_DOUBLE | |
2240 | Define this if the host can handle the parsing of long double | |
56caf160 EZ |
2241 | float-point numbers via the scanf format conversion specifier |
2242 | @code{Lg}. This is set by the @code{configure} script. | |
c906108c SS |
2243 | |
2244 | @item LSEEK_NOT_LINEAR | |
2245 | Define this if @code{lseek (n)} does not necessarily move to byte number | |
2246 | @code{n} in the file. This is only used when reading source files. It | |
2247 | is normally faster to define @code{CRLF_SOURCE_FILES} when possible. | |
2248 | ||
2249 | @item L_SET | |
56caf160 EZ |
2250 | This macro is used as the argument to @code{lseek} (or, most commonly, |
2251 | @code{bfd_seek}). FIXME, should be replaced by SEEK_SET instead, | |
2252 | which is the POSIX equivalent. | |
c906108c | 2253 | |
c906108c SS |
2254 | @item MMAP_BASE_ADDRESS |
2255 | When using HAVE_MMAP, the first mapping should go at this address. | |
2256 | ||
2257 | @item MMAP_INCREMENT | |
2258 | when using HAVE_MMAP, this is the increment between mappings. | |
2259 | ||
c906108c SS |
2260 | @item NORETURN |
2261 | If defined, this should be one or more tokens, such as @code{volatile}, | |
2262 | that can be used in both the declaration and definition of functions to | |
2263 | indicate that they never return. The default is already set correctly | |
2264 | if compiling with GCC. This will almost never need to be defined. | |
2265 | ||
2266 | @item ATTR_NORETURN | |
2267 | If defined, this should be one or more tokens, such as | |
2268 | @code{__attribute__ ((noreturn))}, that can be used in the declarations | |
2269 | of functions to indicate that they never return. The default is already | |
2270 | set correctly if compiling with GCC. This will almost never need to be | |
2271 | defined. | |
2272 | ||
2273 | @item USE_MMALLOC | |
56caf160 EZ |
2274 | @findex mmalloc |
2275 | @value{GDBN} will use the @code{mmalloc} library for memory allocation | |
2276 | for symbol reading if this symbol is defined. Be careful defining it | |
2277 | since there are systems on which @code{mmalloc} does not work for some | |
2278 | reason. One example is the DECstation, where its RPC library can't | |
2279 | cope with our redefinition of @code{malloc} to call @code{mmalloc}. | |
2280 | When defining @code{USE_MMALLOC}, you will also have to set | |
2281 | @code{MMALLOC} in the Makefile, to point to the @code{mmalloc} library. This | |
2282 | define is set when you configure with @samp{--with-mmalloc}. | |
c906108c SS |
2283 | |
2284 | @item NO_MMCHECK | |
56caf160 | 2285 | @findex mmcheck |
c906108c SS |
2286 | Define this if you are using @code{mmalloc}, but don't want the overhead |
2287 | of checking the heap with @code{mmcheck}. Note that on some systems, | |
56caf160 | 2288 | the C runtime makes calls to @code{malloc} prior to calling @code{main}, and if |
c906108c SS |
2289 | @code{free} is ever called with these pointers after calling |
2290 | @code{mmcheck} to enable checking, a memory corruption abort is certain | |
56caf160 EZ |
2291 | to occur. These systems can still use @code{mmalloc}, but must define |
2292 | @code{NO_MMCHECK}. | |
c906108c SS |
2293 | |
2294 | @item MMCHECK_FORCE | |
2295 | Define this to 1 if the C runtime allocates memory prior to | |
2296 | @code{mmcheck} being called, but that memory is never freed so we don't | |
2297 | have to worry about it triggering a memory corruption abort. The | |
2298 | default is 0, which means that @code{mmcheck} will only install the heap | |
2299 | checking functions if there has not yet been any memory allocation | |
56caf160 | 2300 | calls, and if it fails to install the functions, @value{GDBN} will issue a |
c906108c | 2301 | warning. This is currently defined if you configure using |
56caf160 | 2302 | @samp{--with-mmalloc}. |
c906108c SS |
2303 | |
2304 | @item NO_SIGINTERRUPT | |
56caf160 EZ |
2305 | @findex siginterrupt |
2306 | Define this to indicate that @code{siginterrupt} is not available. | |
c906108c | 2307 | |
c906108c | 2308 | @item SEEK_CUR |
9742079a | 2309 | @itemx SEEK_SET |
56caf160 | 2310 | Define these to appropriate value for the system @code{lseek}, if not already |
c906108c SS |
2311 | defined. |
2312 | ||
2313 | @item STOP_SIGNAL | |
56caf160 EZ |
2314 | This is the signal for stopping @value{GDBN}. Defaults to |
2315 | @code{SIGTSTP}. (Only redefined for the Convex.) | |
c906108c SS |
2316 | |
2317 | @item USE_O_NOCTTY | |
56caf160 | 2318 | Define this if the interior's tty should be opened with the @code{O_NOCTTY} |
c906108c SS |
2319 | flag. (FIXME: This should be a native-only flag, but @file{inflow.c} is |
2320 | always linked in.) | |
2321 | ||
2322 | @item USG | |
2323 | Means that System V (prior to SVR4) include files are in use. (FIXME: | |
7ca9f392 AC |
2324 | This symbol is abused in @file{infrun.c}, @file{regex.c}, and |
2325 | @file{utils.c} for other things, at the moment.) | |
c906108c SS |
2326 | |
2327 | @item lint | |
56caf160 | 2328 | Define this to help placate @code{lint} in some situations. |
c906108c SS |
2329 | |
2330 | @item volatile | |
2331 | Define this to override the defaults of @code{__volatile__} or | |
2332 | @code{/**/}. | |
56caf160 | 2333 | @end ftable |
c906108c SS |
2334 | |
2335 | ||
2336 | @node Target Architecture Definition | |
2337 | ||
2338 | @chapter Target Architecture Definition | |
2339 | ||
56caf160 EZ |
2340 | @cindex target architecture definition |
2341 | @value{GDBN}'s target architecture defines what sort of | |
2342 | machine-language programs @value{GDBN} can work with, and how it works | |
2343 | with them. | |
c906108c | 2344 | |
af6c57ea AC |
2345 | The target architecture object is implemented as the C structure |
2346 | @code{struct gdbarch *}. The structure, and its methods, are generated | |
93c2c750 | 2347 | using the Bourne shell script @file{gdbarch.sh}. |
c906108c | 2348 | |
70f80edf JT |
2349 | @section Operating System ABI Variant Handling |
2350 | @cindex OS ABI variants | |
2351 | ||
2352 | @value{GDBN} provides a mechanism for handling variations in OS | |
2353 | ABIs. An OS ABI variant may have influence over any number of | |
2354 | variables in the target architecture definition. There are two major | |
2355 | components in the OS ABI mechanism: sniffers and handlers. | |
2356 | ||
2357 | A @dfn{sniffer} examines a file matching a BFD architecture/flavour pair | |
2358 | (the architecture may be wildcarded) in an attempt to determine the | |
2359 | OS ABI of that file. Sniffers with a wildcarded architecture are considered | |
2360 | to be @dfn{generic}, while sniffers for a specific architecture are | |
2361 | considered to be @dfn{specific}. A match from a specific sniffer | |
2362 | overrides a match from a generic sniffer. Multiple sniffers for an | |
2363 | architecture/flavour may exist, in order to differentiate between two | |
2364 | different operating systems which use the same basic file format. The | |
2365 | OS ABI framework provides a generic sniffer for ELF-format files which | |
2366 | examines the @code{EI_OSABI} field of the ELF header, as well as note | |
2367 | sections known to be used by several operating systems. | |
2368 | ||
2369 | @cindex fine-tuning @code{gdbarch} structure | |
2370 | A @dfn{handler} is used to fine-tune the @code{gdbarch} structure for the | |
2371 | selected OS ABI. There may be only one handler for a given OS ABI | |
2372 | for each BFD architecture. | |
2373 | ||
2374 | The following OS ABI variants are defined in @file{osabi.h}: | |
2375 | ||
2376 | @table @code | |
2377 | ||
2378 | @findex GDB_OSABI_UNKNOWN | |
2379 | @item GDB_OSABI_UNKNOWN | |
2380 | The ABI of the inferior is unknown. The default @code{gdbarch} | |
2381 | settings for the architecture will be used. | |
2382 | ||
2383 | @findex GDB_OSABI_SVR4 | |
2384 | @item GDB_OSABI_SVR4 | |
2385 | UNIX System V Release 4 | |
2386 | ||
2387 | @findex GDB_OSABI_HURD | |
2388 | @item GDB_OSABI_HURD | |
2389 | GNU using the Hurd kernel | |
2390 | ||
2391 | @findex GDB_OSABI_SOLARIS | |
2392 | @item GDB_OSABI_SOLARIS | |
2393 | Sun Solaris | |
2394 | ||
2395 | @findex GDB_OSABI_OSF1 | |
2396 | @item GDB_OSABI_OSF1 | |
2397 | OSF/1, including Digital UNIX and Compaq Tru64 UNIX | |
2398 | ||
2399 | @findex GDB_OSABI_LINUX | |
2400 | @item GDB_OSABI_LINUX | |
2401 | GNU using the Linux kernel | |
2402 | ||
2403 | @findex GDB_OSABI_FREEBSD_AOUT | |
2404 | @item GDB_OSABI_FREEBSD_AOUT | |
2405 | FreeBSD using the a.out executable format | |
2406 | ||
2407 | @findex GDB_OSABI_FREEBSD_ELF | |
2408 | @item GDB_OSABI_FREEBSD_ELF | |
2409 | FreeBSD using the ELF executable format | |
2410 | ||
2411 | @findex GDB_OSABI_NETBSD_AOUT | |
2412 | @item GDB_OSABI_NETBSD_AOUT | |
2413 | NetBSD using the a.out executable format | |
2414 | ||
2415 | @findex GDB_OSABI_NETBSD_ELF | |
2416 | @item GDB_OSABI_NETBSD_ELF | |
2417 | NetBSD using the ELF executable format | |
2418 | ||
2419 | @findex GDB_OSABI_WINCE | |
2420 | @item GDB_OSABI_WINCE | |
2421 | Windows CE | |
2422 | ||
1029b7fa MK |
2423 | @findex GDB_OSABI_GO32 |
2424 | @item GDB_OSABI_GO32 | |
2425 | DJGPP | |
2426 | ||
2427 | @findex GDB_OSABI_NETWARE | |
2428 | @item GDB_OSABI_NETWARE | |
2429 | Novell NetWare | |
2430 | ||
70f80edf JT |
2431 | @findex GDB_OSABI_ARM_EABI_V1 |
2432 | @item GDB_OSABI_ARM_EABI_V1 | |
2433 | ARM Embedded ABI version 1 | |
2434 | ||
2435 | @findex GDB_OSABI_ARM_EABI_V2 | |
2436 | @item GDB_OSABI_ARM_EABI_V2 | |
2437 | ARM Embedded ABI version 2 | |
2438 | ||
2439 | @findex GDB_OSABI_ARM_APCS | |
2440 | @item GDB_OSABI_ARM_APCS | |
2441 | Generic ARM Procedure Call Standard | |
2442 | ||
2443 | @end table | |
2444 | ||
2445 | Here are the functions that make up the OS ABI framework: | |
2446 | ||
2447 | @deftypefun const char *gdbarch_osabi_name (enum gdb_osabi @var{osabi}) | |
2448 | Return the name of the OS ABI corresponding to @var{osabi}. | |
2449 | @end deftypefun | |
2450 | ||
c133ab7a | 2451 | @deftypefun void gdbarch_register_osabi (enum bfd_architecture @var{arch}, unsigned long @var{machine}, enum gdb_osabi @var{osabi}, void (*@var{init_osabi})(struct gdbarch_info @var{info}, struct gdbarch *@var{gdbarch})) |
70f80edf | 2452 | Register the OS ABI handler specified by @var{init_osabi} for the |
c133ab7a MK |
2453 | architecture, machine type and OS ABI specified by @var{arch}, |
2454 | @var{machine} and @var{osabi}. In most cases, a value of zero for the | |
2455 | machine type, which implies the architecture's default machine type, | |
2456 | will suffice. | |
70f80edf JT |
2457 | @end deftypefun |
2458 | ||
2459 | @deftypefun void gdbarch_register_osabi_sniffer (enum bfd_architecture @var{arch}, enum bfd_flavour @var{flavour}, enum gdb_osabi (*@var{sniffer})(bfd *@var{abfd})) | |
2460 | Register the OS ABI file sniffer specified by @var{sniffer} for the | |
2461 | BFD architecture/flavour pair specified by @var{arch} and @var{flavour}. | |
2462 | If @var{arch} is @code{bfd_arch_unknown}, the sniffer is considered to | |
2463 | be generic, and is allowed to examine @var{flavour}-flavoured files for | |
2464 | any architecture. | |
2465 | @end deftypefun | |
2466 | ||
2467 | @deftypefun enum gdb_osabi gdbarch_lookup_osabi (bfd *@var{abfd}) | |
2468 | Examine the file described by @var{abfd} to determine its OS ABI. | |
2469 | The value @code{GDB_OSABI_UNKNOWN} is returned if the OS ABI cannot | |
2470 | be determined. | |
2471 | @end deftypefun | |
2472 | ||
2473 | @deftypefun void gdbarch_init_osabi (struct gdbarch info @var{info}, struct gdbarch *@var{gdbarch}, enum gdb_osabi @var{osabi}) | |
2474 | Invoke the OS ABI handler corresponding to @var{osabi} to fine-tune the | |
2475 | @code{gdbarch} structure specified by @var{gdbarch}. If a handler | |
2476 | corresponding to @var{osabi} has not been registered for @var{gdbarch}'s | |
2477 | architecture, a warning will be issued and the debugging session will continue | |
2478 | with the defaults already established for @var{gdbarch}. | |
2479 | @end deftypefun | |
2480 | ||
c906108c SS |
2481 | @section Registers and Memory |
2482 | ||
56caf160 EZ |
2483 | @value{GDBN}'s model of the target machine is rather simple. |
2484 | @value{GDBN} assumes the machine includes a bank of registers and a | |
2485 | block of memory. Each register may have a different size. | |
c906108c | 2486 | |
56caf160 EZ |
2487 | @value{GDBN} does not have a magical way to match up with the |
2488 | compiler's idea of which registers are which; however, it is critical | |
2489 | that they do match up accurately. The only way to make this work is | |
2490 | to get accurate information about the order that the compiler uses, | |
2491 | and to reflect that in the @code{REGISTER_NAME} and related macros. | |
c906108c | 2492 | |
25822942 | 2493 | @value{GDBN} can handle big-endian, little-endian, and bi-endian architectures. |
c906108c | 2494 | |
93e79dbd JB |
2495 | @section Pointers Are Not Always Addresses |
2496 | @cindex pointer representation | |
2497 | @cindex address representation | |
2498 | @cindex word-addressed machines | |
2499 | @cindex separate data and code address spaces | |
2500 | @cindex spaces, separate data and code address | |
2501 | @cindex address spaces, separate data and code | |
2502 | @cindex code pointers, word-addressed | |
2503 | @cindex converting between pointers and addresses | |
2504 | @cindex D10V addresses | |
2505 | ||
2506 | On almost all 32-bit architectures, the representation of a pointer is | |
2507 | indistinguishable from the representation of some fixed-length number | |
2508 | whose value is the byte address of the object pointed to. On such | |
56caf160 | 2509 | machines, the words ``pointer'' and ``address'' can be used interchangeably. |
93e79dbd JB |
2510 | However, architectures with smaller word sizes are often cramped for |
2511 | address space, so they may choose a pointer representation that breaks this | |
2512 | identity, and allows a larger code address space. | |
2513 | ||
2514 | For example, the Mitsubishi D10V is a 16-bit VLIW processor whose | |
2515 | instructions are 32 bits long@footnote{Some D10V instructions are | |
2516 | actually pairs of 16-bit sub-instructions. However, since you can't | |
2517 | jump into the middle of such a pair, code addresses can only refer to | |
2518 | full 32 bit instructions, which is what matters in this explanation.}. | |
2519 | If the D10V used ordinary byte addresses to refer to code locations, | |
2520 | then the processor would only be able to address 64kb of instructions. | |
2521 | However, since instructions must be aligned on four-byte boundaries, the | |
56caf160 EZ |
2522 | low two bits of any valid instruction's byte address are always |
2523 | zero---byte addresses waste two bits. So instead of byte addresses, | |
2524 | the D10V uses word addresses---byte addresses shifted right two bits---to | |
93e79dbd JB |
2525 | refer to code. Thus, the D10V can use 16-bit words to address 256kb of |
2526 | code space. | |
2527 | ||
2528 | However, this means that code pointers and data pointers have different | |
2529 | forms on the D10V. The 16-bit word @code{0xC020} refers to byte address | |
2530 | @code{0xC020} when used as a data address, but refers to byte address | |
2531 | @code{0x30080} when used as a code address. | |
2532 | ||
2533 | (The D10V also uses separate code and data address spaces, which also | |
2534 | affects the correspondence between pointers and addresses, but we're | |
2535 | going to ignore that here; this example is already too long.) | |
2536 | ||
56caf160 EZ |
2537 | To cope with architectures like this---the D10V is not the only |
2538 | one!---@value{GDBN} tries to distinguish between @dfn{addresses}, which are | |
93e79dbd JB |
2539 | byte numbers, and @dfn{pointers}, which are the target's representation |
2540 | of an address of a particular type of data. In the example above, | |
2541 | @code{0xC020} is the pointer, which refers to one of the addresses | |
2542 | @code{0xC020} or @code{0x30080}, depending on the type imposed upon it. | |
2543 | @value{GDBN} provides functions for turning a pointer into an address | |
2544 | and vice versa, in the appropriate way for the current architecture. | |
2545 | ||
2546 | Unfortunately, since addresses and pointers are identical on almost all | |
2547 | processors, this distinction tends to bit-rot pretty quickly. Thus, | |
2548 | each time you port @value{GDBN} to an architecture which does | |
2549 | distinguish between pointers and addresses, you'll probably need to | |
2550 | clean up some architecture-independent code. | |
2551 | ||
2552 | Here are functions which convert between pointers and addresses: | |
2553 | ||
2554 | @deftypefun CORE_ADDR extract_typed_address (void *@var{buf}, struct type *@var{type}) | |
2555 | Treat the bytes at @var{buf} as a pointer or reference of type | |
2556 | @var{type}, and return the address it represents, in a manner | |
2557 | appropriate for the current architecture. This yields an address | |
2558 | @value{GDBN} can use to read target memory, disassemble, etc. Note that | |
2559 | @var{buf} refers to a buffer in @value{GDBN}'s memory, not the | |
2560 | inferior's. | |
2561 | ||
2562 | For example, if the current architecture is the Intel x86, this function | |
2563 | extracts a little-endian integer of the appropriate length from | |
2564 | @var{buf} and returns it. However, if the current architecture is the | |
2565 | D10V, this function will return a 16-bit integer extracted from | |
2566 | @var{buf}, multiplied by four if @var{type} is a pointer to a function. | |
2567 | ||
2568 | If @var{type} is not a pointer or reference type, then this function | |
2569 | will signal an internal error. | |
2570 | @end deftypefun | |
2571 | ||
2572 | @deftypefun CORE_ADDR store_typed_address (void *@var{buf}, struct type *@var{type}, CORE_ADDR @var{addr}) | |
2573 | Store the address @var{addr} in @var{buf}, in the proper format for a | |
2574 | pointer of type @var{type} in the current architecture. Note that | |
2575 | @var{buf} refers to a buffer in @value{GDBN}'s memory, not the | |
2576 | inferior's. | |
2577 | ||
2578 | For example, if the current architecture is the Intel x86, this function | |
2579 | stores @var{addr} unmodified as a little-endian integer of the | |
2580 | appropriate length in @var{buf}. However, if the current architecture | |
2581 | is the D10V, this function divides @var{addr} by four if @var{type} is | |
2582 | a pointer to a function, and then stores it in @var{buf}. | |
2583 | ||
2584 | If @var{type} is not a pointer or reference type, then this function | |
2585 | will signal an internal error. | |
2586 | @end deftypefun | |
2587 | ||
f23631e4 | 2588 | @deftypefun CORE_ADDR value_as_address (struct value *@var{val}) |
93e79dbd JB |
2589 | Assuming that @var{val} is a pointer, return the address it represents, |
2590 | as appropriate for the current architecture. | |
2591 | ||
2592 | This function actually works on integral values, as well as pointers. | |
2593 | For pointers, it performs architecture-specific conversions as | |
2594 | described above for @code{extract_typed_address}. | |
2595 | @end deftypefun | |
2596 | ||
2597 | @deftypefun CORE_ADDR value_from_pointer (struct type *@var{type}, CORE_ADDR @var{addr}) | |
2598 | Create and return a value representing a pointer of type @var{type} to | |
2599 | the address @var{addr}, as appropriate for the current architecture. | |
2600 | This function performs architecture-specific conversions as described | |
2601 | above for @code{store_typed_address}. | |
2602 | @end deftypefun | |
2603 | ||
93e79dbd JB |
2604 | Here are some macros which architectures can define to indicate the |
2605 | relationship between pointers and addresses. These have default | |
2606 | definitions, appropriate for architectures on which all pointers are | |
fc0c74b1 | 2607 | simple unsigned byte addresses. |
93e79dbd JB |
2608 | |
2609 | @deftypefn {Target Macro} CORE_ADDR POINTER_TO_ADDRESS (struct type *@var{type}, char *@var{buf}) | |
2610 | Assume that @var{buf} holds a pointer of type @var{type}, in the | |
2611 | appropriate format for the current architecture. Return the byte | |
2612 | address the pointer refers to. | |
2613 | ||
2614 | This function may safely assume that @var{type} is either a pointer or a | |
56caf160 | 2615 | C@t{++} reference type. |
93e79dbd JB |
2616 | @end deftypefn |
2617 | ||
2618 | @deftypefn {Target Macro} void ADDRESS_TO_POINTER (struct type *@var{type}, char *@var{buf}, CORE_ADDR @var{addr}) | |
2619 | Store in @var{buf} a pointer of type @var{type} representing the address | |
2620 | @var{addr}, in the appropriate format for the current architecture. | |
2621 | ||
2622 | This function may safely assume that @var{type} is either a pointer or a | |
56caf160 | 2623 | C@t{++} reference type. |
93e79dbd JB |
2624 | @end deftypefn |
2625 | ||
b5b0480a KB |
2626 | @section Address Classes |
2627 | @cindex address classes | |
2628 | @cindex DW_AT_byte_size | |
2629 | @cindex DW_AT_address_class | |
2630 | ||
2631 | Sometimes information about different kinds of addresses is available | |
2632 | via the debug information. For example, some programming environments | |
2633 | define addresses of several different sizes. If the debug information | |
2634 | distinguishes these kinds of address classes through either the size | |
2635 | info (e.g, @code{DW_AT_byte_size} in @w{DWARF 2}) or through an explicit | |
2636 | address class attribute (e.g, @code{DW_AT_address_class} in @w{DWARF 2}), the | |
2637 | following macros should be defined in order to disambiguate these | |
2638 | types within @value{GDBN} as well as provide the added information to | |
2639 | a @value{GDBN} user when printing type expressions. | |
2640 | ||
2641 | @deftypefn {Target Macro} int ADDRESS_CLASS_TYPE_FLAGS (int @var{byte_size}, int @var{dwarf2_addr_class}) | |
2642 | Returns the type flags needed to construct a pointer type whose size | |
2643 | is @var{byte_size} and whose address class is @var{dwarf2_addr_class}. | |
2644 | This function is normally called from within a symbol reader. See | |
2645 | @file{dwarf2read.c}. | |
2646 | @end deftypefn | |
2647 | ||
2648 | @deftypefn {Target Macro} char *ADDRESS_CLASS_TYPE_FLAGS_TO_NAME (int @var{type_flags}) | |
2649 | Given the type flags representing an address class qualifier, return | |
2650 | its name. | |
2651 | @end deftypefn | |
2652 | @deftypefn {Target Macro} int ADDRESS_CLASS_NAME_to_TYPE_FLAGS (int @var{name}, int *var{type_flags_ptr}) | |
2653 | Given an address qualifier name, set the @code{int} refererenced by @var{type_flags_ptr} to the type flags | |
2654 | for that address class qualifier. | |
2655 | @end deftypefn | |
2656 | ||
2657 | Since the need for address classes is rather rare, none of | |
2658 | the address class macros defined by default. Predicate | |
2659 | macros are provided to detect when they are defined. | |
2660 | ||
2661 | Consider a hypothetical architecture in which addresses are normally | |
2662 | 32-bits wide, but 16-bit addresses are also supported. Furthermore, | |
2663 | suppose that the @w{DWARF 2} information for this architecture simply | |
2664 | uses a @code{DW_AT_byte_size} value of 2 to indicate the use of one | |
2665 | of these "short" pointers. The following functions could be defined | |
2666 | to implement the address class macros: | |
2667 | ||
2668 | @smallexample | |
2669 | somearch_address_class_type_flags (int byte_size, | |
2670 | int dwarf2_addr_class) | |
f2abfe65 | 2671 | @{ |
b5b0480a KB |
2672 | if (byte_size == 2) |
2673 | return TYPE_FLAG_ADDRESS_CLASS_1; | |
2674 | else | |
2675 | return 0; | |
f2abfe65 | 2676 | @} |
b5b0480a KB |
2677 | |
2678 | static char * | |
2679 | somearch_address_class_type_flags_to_name (int type_flags) | |
f2abfe65 | 2680 | @{ |
b5b0480a KB |
2681 | if (type_flags & TYPE_FLAG_ADDRESS_CLASS_1) |
2682 | return "short"; | |
2683 | else | |
2684 | return NULL; | |
f2abfe65 | 2685 | @} |
b5b0480a KB |
2686 | |
2687 | int | |
2688 | somearch_address_class_name_to_type_flags (char *name, | |
2689 | int *type_flags_ptr) | |
f2abfe65 | 2690 | @{ |
b5b0480a | 2691 | if (strcmp (name, "short") == 0) |
f2abfe65 | 2692 | @{ |
b5b0480a KB |
2693 | *type_flags_ptr = TYPE_FLAG_ADDRESS_CLASS_1; |
2694 | return 1; | |
f2abfe65 | 2695 | @} |
b5b0480a KB |
2696 | else |
2697 | return 0; | |
f2abfe65 | 2698 | @} |
b5b0480a KB |
2699 | @end smallexample |
2700 | ||
2701 | The qualifier @code{@@short} is used in @value{GDBN}'s type expressions | |
2702 | to indicate the presence of one of these "short" pointers. E.g, if | |
2703 | the debug information indicates that @code{short_ptr_var} is one of these | |
2704 | short pointers, @value{GDBN} might show the following behavior: | |
2705 | ||
2706 | @smallexample | |
2707 | (gdb) ptype short_ptr_var | |
2708 | type = int * @@short | |
2709 | @end smallexample | |
2710 | ||
93e79dbd | 2711 | |
13d01224 AC |
2712 | @section Raw and Virtual Register Representations |
2713 | @cindex raw register representation | |
2714 | @cindex virtual register representation | |
2715 | @cindex representations, raw and virtual registers | |
2716 | ||
2717 | @emph{Maintainer note: This section is pretty much obsolete. The | |
2718 | functionality described here has largely been replaced by | |
2719 | pseudo-registers and the mechanisms described in @ref{Target | |
2720 | Architecture Definition, , Using Different Register and Memory Data | |
2721 | Representations}. See also @uref{http://www.gnu.org/software/gdb/bugs/, | |
2722 | Bug Tracking Database} and | |
2723 | @uref{http://sources.redhat.com/gdb/current/ari/, ARI Index} for more | |
2724 | up-to-date information.} | |
af6c57ea | 2725 | |
9fb4dd36 JB |
2726 | Some architectures use one representation for a value when it lives in a |
2727 | register, but use a different representation when it lives in memory. | |
25822942 | 2728 | In @value{GDBN}'s terminology, the @dfn{raw} representation is the one used in |
9fb4dd36 | 2729 | the target registers, and the @dfn{virtual} representation is the one |
25822942 | 2730 | used in memory, and within @value{GDBN} @code{struct value} objects. |
9fb4dd36 | 2731 | |
13d01224 AC |
2732 | @emph{Maintainer note: Notice that the same mechanism is being used to |
2733 | both convert a register to a @code{struct value} and alternative | |
2734 | register forms.} | |
2735 | ||
9fb4dd36 JB |
2736 | For almost all data types on almost all architectures, the virtual and |
2737 | raw representations are identical, and no special handling is needed. | |
2738 | However, they do occasionally differ. For example: | |
2739 | ||
2740 | @itemize @bullet | |
9fb4dd36 | 2741 | @item |
56caf160 | 2742 | The x86 architecture supports an 80-bit @code{long double} type. However, when |
9fb4dd36 JB |
2743 | we store those values in memory, they occupy twelve bytes: the |
2744 | floating-point number occupies the first ten, and the final two bytes | |
2745 | are unused. This keeps the values aligned on four-byte boundaries, | |
2746 | allowing more efficient access. Thus, the x86 80-bit floating-point | |
2747 | type is the raw representation, and the twelve-byte loosely-packed | |
2748 | arrangement is the virtual representation. | |
2749 | ||
2750 | @item | |
25822942 DB |
2751 | Some 64-bit MIPS targets present 32-bit registers to @value{GDBN} as 64-bit |
2752 | registers, with garbage in their upper bits. @value{GDBN} ignores the top 32 | |
9fb4dd36 JB |
2753 | bits. Thus, the 64-bit form, with garbage in the upper 32 bits, is the |
2754 | raw representation, and the trimmed 32-bit representation is the | |
2755 | virtual representation. | |
9fb4dd36 JB |
2756 | @end itemize |
2757 | ||
2758 | In general, the raw representation is determined by the architecture, or | |
25822942 DB |
2759 | @value{GDBN}'s interface to the architecture, while the virtual representation |
2760 | can be chosen for @value{GDBN}'s convenience. @value{GDBN}'s register file, | |
56caf160 EZ |
2761 | @code{registers}, holds the register contents in raw format, and the |
2762 | @value{GDBN} remote protocol transmits register values in raw format. | |
9fb4dd36 | 2763 | |
56caf160 EZ |
2764 | Your architecture may define the following macros to request |
2765 | conversions between the raw and virtual format: | |
9fb4dd36 JB |
2766 | |
2767 | @deftypefn {Target Macro} int REGISTER_CONVERTIBLE (int @var{reg}) | |
2768 | Return non-zero if register number @var{reg}'s value needs different raw | |
2769 | and virtual formats. | |
6f6ef15a EZ |
2770 | |
2771 | You should not use @code{REGISTER_CONVERT_TO_VIRTUAL} for a register | |
2772 | unless this macro returns a non-zero value for that register. | |
9fb4dd36 JB |
2773 | @end deftypefn |
2774 | ||
2775 | @deftypefn {Target Macro} int REGISTER_RAW_SIZE (int @var{reg}) | |
2776 | The size of register number @var{reg}'s raw value. This is the number | |
25822942 | 2777 | of bytes the register will occupy in @code{registers}, or in a @value{GDBN} |
9fb4dd36 JB |
2778 | remote protocol packet. |
2779 | @end deftypefn | |
2780 | ||
2781 | @deftypefn {Target Macro} int REGISTER_VIRTUAL_SIZE (int @var{reg}) | |
2782 | The size of register number @var{reg}'s value, in its virtual format. | |
2783 | This is the size a @code{struct value}'s buffer will have, holding that | |
2784 | register's value. | |
2785 | @end deftypefn | |
2786 | ||
2787 | @deftypefn {Target Macro} struct type *REGISTER_VIRTUAL_TYPE (int @var{reg}) | |
2788 | This is the type of the virtual representation of register number | |
2789 | @var{reg}. Note that there is no need for a macro giving a type for the | |
25822942 | 2790 | register's raw form; once the register's value has been obtained, @value{GDBN} |
9fb4dd36 JB |
2791 | always uses the virtual form. |
2792 | @end deftypefn | |
2793 | ||
2794 | @deftypefn {Target Macro} void REGISTER_CONVERT_TO_VIRTUAL (int @var{reg}, struct type *@var{type}, char *@var{from}, char *@var{to}) | |
2795 | Convert the value of register number @var{reg} to @var{type}, which | |
2796 | should always be @code{REGISTER_VIRTUAL_TYPE (@var{reg})}. The buffer | |
2797 | at @var{from} holds the register's value in raw format; the macro should | |
2798 | convert the value to virtual format, and place it at @var{to}. | |
2799 | ||
6f6ef15a EZ |
2800 | Note that @code{REGISTER_CONVERT_TO_VIRTUAL} and |
2801 | @code{REGISTER_CONVERT_TO_RAW} take their @var{reg} and @var{type} | |
2802 | arguments in different orders. | |
2803 | ||
2804 | You should only use @code{REGISTER_CONVERT_TO_VIRTUAL} with registers | |
2805 | for which the @code{REGISTER_CONVERTIBLE} macro returns a non-zero | |
2806 | value. | |
9fb4dd36 JB |
2807 | @end deftypefn |
2808 | ||
2809 | @deftypefn {Target Macro} void REGISTER_CONVERT_TO_RAW (struct type *@var{type}, int @var{reg}, char *@var{from}, char *@var{to}) | |
2810 | Convert the value of register number @var{reg} to @var{type}, which | |
2811 | should always be @code{REGISTER_VIRTUAL_TYPE (@var{reg})}. The buffer | |
2812 | at @var{from} holds the register's value in raw format; the macro should | |
2813 | convert the value to virtual format, and place it at @var{to}. | |
2814 | ||
2815 | Note that REGISTER_CONVERT_TO_VIRTUAL and REGISTER_CONVERT_TO_RAW take | |
2816 | their @var{reg} and @var{type} arguments in different orders. | |
2817 | @end deftypefn | |
2818 | ||
2819 | ||
13d01224 AC |
2820 | @section Using Different Register and Memory Data Representations |
2821 | @cindex register representation | |
2822 | @cindex memory representation | |
2823 | @cindex representations, register and memory | |
2824 | @cindex register data formats, converting | |
2825 | @cindex @code{struct value}, converting register contents to | |
2826 | ||
2827 | @emph{Maintainer's note: The way GDB manipulates registers is undergoing | |
2828 | significant change. Many of the macros and functions refered to in this | |
2829 | section are likely to be subject to further revision. See | |
2830 | @uref{http://sources.redhat.com/gdb/current/ari/, A.R. Index} and | |
2831 | @uref{http://www.gnu.org/software/gdb/bugs, Bug Tracking Database} for | |
2832 | further information. cagney/2002-05-06.} | |
2833 | ||
2834 | Some architectures can represent a data object in a register using a | |
2835 | form that is different to the objects more normal memory representation. | |
2836 | For example: | |
2837 | ||
2838 | @itemize @bullet | |
2839 | ||
2840 | @item | |
2841 | The Alpha architecture can represent 32 bit integer values in | |
2842 | floating-point registers. | |
2843 | ||
2844 | @item | |
2845 | The x86 architecture supports 80-bit floating-point registers. The | |
2846 | @code{long double} data type occupies 96 bits in memory but only 80 bits | |
2847 | when stored in a register. | |
2848 | ||
2849 | @end itemize | |
2850 | ||
2851 | In general, the register representation of a data type is determined by | |
2852 | the architecture, or @value{GDBN}'s interface to the architecture, while | |
2853 | the memory representation is determined by the Application Binary | |
2854 | Interface. | |
2855 | ||
2856 | For almost all data types on almost all architectures, the two | |
2857 | representations are identical, and no special handling is needed. | |
2858 | However, they do occasionally differ. Your architecture may define the | |
2859 | following macros to request conversions between the register and memory | |
2860 | representations of a data type: | |
2861 | ||
2862 | @deftypefn {Target Macro} int CONVERT_REGISTER_P (int @var{reg}) | |
2863 | Return non-zero if the representation of a data value stored in this | |
2864 | register may be different to the representation of that same data value | |
2865 | when stored in memory. | |
2866 | ||
2867 | When non-zero, the macros @code{REGISTER_TO_VALUE} and | |
2868 | @code{VALUE_TO_REGISTER} are used to perform any necessary conversion. | |
2869 | @end deftypefn | |
2870 | ||
2871 | @deftypefn {Target Macro} void REGISTER_TO_VALUE (int @var{reg}, struct type *@var{type}, char *@var{from}, char *@var{to}) | |
2872 | Convert the value of register number @var{reg} to a data object of type | |
2873 | @var{type}. The buffer at @var{from} holds the register's value in raw | |
2874 | format; the converted value should be placed in the buffer at @var{to}. | |
2875 | ||
2876 | Note that @code{REGISTER_TO_VALUE} and @code{VALUE_TO_REGISTER} take | |
2877 | their @var{reg} and @var{type} arguments in different orders. | |
2878 | ||
2879 | You should only use @code{REGISTER_TO_VALUE} with registers for which | |
2880 | the @code{CONVERT_REGISTER_P} macro returns a non-zero value. | |
2881 | @end deftypefn | |
2882 | ||
2883 | @deftypefn {Target Macro} void VALUE_TO_REGISTER (struct type *@var{type}, int @var{reg}, char *@var{from}, char *@var{to}) | |
2884 | Convert a data value of type @var{type} to register number @var{reg}' | |
2885 | raw format. | |
2886 | ||
2887 | Note that @code{REGISTER_TO_VALUE} and @code{VALUE_TO_REGISTER} take | |
2888 | their @var{reg} and @var{type} arguments in different orders. | |
2889 | ||
2890 | You should only use @code{VALUE_TO_REGISTER} with registers for which | |
2891 | the @code{CONVERT_REGISTER_P} macro returns a non-zero value. | |
2892 | @end deftypefn | |
2893 | ||
2894 | @deftypefn {Target Macro} void REGISTER_CONVERT_TO_TYPE (int @var{regnum}, struct type *@var{type}, char *@var{buf}) | |
2895 | See @file{mips-tdep.c}. It does not do what you want. | |
2896 | @end deftypefn | |
2897 | ||
2898 | ||
c906108c SS |
2899 | @section Frame Interpretation |
2900 | ||
2901 | @section Inferior Call Setup | |
2902 | ||
2903 | @section Compiler Characteristics | |
2904 | ||
2905 | @section Target Conditionals | |
2906 | ||
2907 | This section describes the macros that you can use to define the target | |
2908 | machine. | |
2909 | ||
2910 | @table @code | |
2911 | ||
c906108c | 2912 | @item ADDR_BITS_REMOVE (addr) |
56caf160 | 2913 | @findex ADDR_BITS_REMOVE |
adf40b2e JM |
2914 | If a raw machine instruction address includes any bits that are not |
2915 | really part of the address, then define this macro to expand into an | |
56caf160 | 2916 | expression that zeroes those bits in @var{addr}. This is only used for |
adf40b2e JM |
2917 | addresses of instructions, and even then not in all contexts. |
2918 | ||
2919 | For example, the two low-order bits of the PC on the Hewlett-Packard PA | |
2920 | 2.0 architecture contain the privilege level of the corresponding | |
2921 | instruction. Since instructions must always be aligned on four-byte | |
2922 | boundaries, the processor masks out these bits to generate the actual | |
2923 | address of the instruction. ADDR_BITS_REMOVE should filter out these | |
2924 | bits with an expression such as @code{((addr) & ~3)}. | |
c906108c | 2925 | |
b5b0480a KB |
2926 | @item ADDRESS_CLASS_NAME_TO_TYPE_FLAGS (@var{name}, @var{type_flags_ptr}) |
2927 | @findex ADDRESS_CLASS_NAME_TO_TYPE_FLAGS | |
2928 | If @var{name} is a valid address class qualifier name, set the @code{int} | |
2929 | referenced by @var{type_flags_ptr} to the mask representing the qualifier | |
2930 | and return 1. If @var{name} is not a valid address class qualifier name, | |
2931 | return 0. | |
2932 | ||
2933 | The value for @var{type_flags_ptr} should be one of | |
2934 | @code{TYPE_FLAG_ADDRESS_CLASS_1}, @code{TYPE_FLAG_ADDRESS_CLASS_2}, or | |
2935 | possibly some combination of these values or'd together. | |
2936 | @xref{Target Architecture Definition, , Address Classes}. | |
2937 | ||
2938 | @item ADDRESS_CLASS_NAME_TO_TYPE_FLAGS_P () | |
2939 | @findex ADDRESS_CLASS_NAME_TO_TYPE_FLAGS_P | |
2940 | Predicate which indicates whether @code{ADDRESS_CLASS_NAME_TO_TYPE_FLAGS} | |
2941 | has been defined. | |
2942 | ||
2943 | @item ADDRESS_CLASS_TYPE_FLAGS (@var{byte_size}, @var{dwarf2_addr_class}) | |
2944 | @findex ADDRESS_CLASS_TYPE_FLAGS (@var{byte_size}, @var{dwarf2_addr_class}) | |
2945 | Given a pointers byte size (as described by the debug information) and | |
2946 | the possible @code{DW_AT_address_class} value, return the type flags | |
2947 | used by @value{GDBN} to represent this address class. The value | |
2948 | returned should be one of @code{TYPE_FLAG_ADDRESS_CLASS_1}, | |
2949 | @code{TYPE_FLAG_ADDRESS_CLASS_2}, or possibly some combination of these | |
2950 | values or'd together. | |
2951 | @xref{Target Architecture Definition, , Address Classes}. | |
2952 | ||
2953 | @item ADDRESS_CLASS_TYPE_FLAGS_P () | |
2954 | @findex ADDRESS_CLASS_TYPE_FLAGS_P | |
2955 | Predicate which indicates whether @code{ADDRESS_CLASS_TYPE_FLAGS} has | |
2956 | been defined. | |
2957 | ||
2958 | @item ADDRESS_CLASS_TYPE_FLAGS_TO_NAME (@var{type_flags}) | |
2959 | @findex ADDRESS_CLASS_TYPE_FLAGS_TO_NAME | |
2960 | Return the name of the address class qualifier associated with the type | |
2961 | flags given by @var{type_flags}. | |
2962 | ||
2963 | @item ADDRESS_CLASS_TYPE_FLAGS_TO_NAME_P () | |
2964 | @findex ADDRESS_CLASS_TYPE_FLAGS_TO_NAME_P | |
2965 | Predicate which indicates whether @code{ADDRESS_CLASS_TYPE_FLAGS_TO_NAME} has | |
2966 | been defined. | |
2967 | @xref{Target Architecture Definition, , Address Classes}. | |
2968 | ||
93e79dbd | 2969 | @item ADDRESS_TO_POINTER (@var{type}, @var{buf}, @var{addr}) |
56caf160 | 2970 | @findex ADDRESS_TO_POINTER |
93e79dbd JB |
2971 | Store in @var{buf} a pointer of type @var{type} representing the address |
2972 | @var{addr}, in the appropriate format for the current architecture. | |
2973 | This macro may safely assume that @var{type} is either a pointer or a | |
56caf160 | 2974 | C@t{++} reference type. |
93e79dbd JB |
2975 | @xref{Target Architecture Definition, , Pointers Are Not Always Addresses}. |
2976 | ||
c906108c | 2977 | @item BELIEVE_PCC_PROMOTION |
56caf160 EZ |
2978 | @findex BELIEVE_PCC_PROMOTION |
2979 | Define if the compiler promotes a @code{short} or @code{char} | |
2980 | parameter to an @code{int}, but still reports the parameter as its | |
2981 | original type, rather than the promoted type. | |
c906108c SS |
2982 | |
2983 | @item BELIEVE_PCC_PROMOTION_TYPE | |
56caf160 EZ |
2984 | @findex BELIEVE_PCC_PROMOTION_TYPE |
2985 | Define this if @value{GDBN} should believe the type of a @code{short} | |
2986 | argument when compiled by @code{pcc}, but look within a full int space to get | |
2987 | its value. Only defined for Sun-3 at present. | |
c906108c SS |
2988 | |
2989 | @item BITS_BIG_ENDIAN | |
56caf160 EZ |
2990 | @findex BITS_BIG_ENDIAN |
2991 | Define this if the numbering of bits in the targets does @strong{not} match the | |
c906108c | 2992 | endianness of the target byte order. A value of 1 means that the bits |
56caf160 | 2993 | are numbered in a big-endian bit order, 0 means little-endian. |
c906108c SS |
2994 | |
2995 | @item BREAKPOINT | |
56caf160 | 2996 | @findex BREAKPOINT |
c906108c SS |
2997 | This is the character array initializer for the bit pattern to put into |
2998 | memory where a breakpoint is set. Although it's common to use a trap | |
2999 | instruction for a breakpoint, it's not required; for instance, the bit | |
3000 | pattern could be an invalid instruction. The breakpoint must be no | |
3001 | longer than the shortest instruction of the architecture. | |
3002 | ||
56caf160 EZ |
3003 | @code{BREAKPOINT} has been deprecated in favor of |
3004 | @code{BREAKPOINT_FROM_PC}. | |
7a292a7a | 3005 | |
c906108c | 3006 | @item BIG_BREAKPOINT |
56caf160 EZ |
3007 | @itemx LITTLE_BREAKPOINT |
3008 | @findex LITTLE_BREAKPOINT | |
3009 | @findex BIG_BREAKPOINT | |
c906108c SS |
3010 | Similar to BREAKPOINT, but used for bi-endian targets. |
3011 | ||
56caf160 EZ |
3012 | @code{BIG_BREAKPOINT} and @code{LITTLE_BREAKPOINT} have been deprecated in |
3013 | favor of @code{BREAKPOINT_FROM_PC}. | |
7a292a7a | 3014 | |
2dd0da42 AC |
3015 | @item DEPRECATED_REMOTE_BREAKPOINT |
3016 | @itemx DEPRECATED_LITTLE_REMOTE_BREAKPOINT | |
3017 | @itemx DEPRECATED_BIG_REMOTE_BREAKPOINT | |
3018 | @findex DEPRECATED_BIG_REMOTE_BREAKPOINT | |
3019 | @findex DEPRECATED_LITTLE_REMOTE_BREAKPOINT | |
3020 | @findex DEPRECATED_REMOTE_BREAKPOINT | |
3021 | Specify the breakpoint instruction sequence for a remote target. | |
3022 | @code{DEPRECATED_REMOTE_BREAKPOINT}, | |
3023 | @code{DEPRECATED_BIG_REMOTE_BREAKPOINT} and | |
3024 | @code{DEPRECATED_LITTLE_REMOTE_BREAKPOINT} have been deprecated in | |
3025 | favor of @code{BREAKPOINT_FROM_PC} (@pxref{BREAKPOINT_FROM_PC}). | |
c906108c | 3026 | |
56caf160 EZ |
3027 | @item BREAKPOINT_FROM_PC (@var{pcptr}, @var{lenptr}) |
3028 | @findex BREAKPOINT_FROM_PC | |
2dd0da42 AC |
3029 | @anchor{BREAKPOINT_FROM_PC} Use the program counter to determine the |
3030 | contents and size of a breakpoint instruction. It returns a pointer to | |
3031 | a string of bytes that encode a breakpoint instruction, stores the | |
3032 | length of the string to @code{*@var{lenptr}}, and adjusts the program | |
3033 | counter (if necessary) to point to the actual memory location where the | |
3034 | breakpoint should be inserted. | |
c906108c SS |
3035 | |
3036 | Although it is common to use a trap instruction for a breakpoint, it's | |
3037 | not required; for instance, the bit pattern could be an invalid | |
3038 | instruction. The breakpoint must be no longer than the shortest | |
3039 | instruction of the architecture. | |
3040 | ||
7a292a7a SS |
3041 | Replaces all the other @var{BREAKPOINT} macros. |
3042 | ||
56caf160 EZ |
3043 | @item MEMORY_INSERT_BREAKPOINT (@var{addr}, @var{contents_cache}) |
3044 | @itemx MEMORY_REMOVE_BREAKPOINT (@var{addr}, @var{contents_cache}) | |
3045 | @findex MEMORY_REMOVE_BREAKPOINT | |
3046 | @findex MEMORY_INSERT_BREAKPOINT | |
917317f4 JM |
3047 | Insert or remove memory based breakpoints. Reasonable defaults |
3048 | (@code{default_memory_insert_breakpoint} and | |
3049 | @code{default_memory_remove_breakpoint} respectively) have been | |
3050 | provided so that it is not necessary to define these for most | |
3051 | architectures. Architectures which may want to define | |
56caf160 | 3052 | @code{MEMORY_INSERT_BREAKPOINT} and @code{MEMORY_REMOVE_BREAKPOINT} will |
917317f4 JM |
3053 | likely have instructions that are oddly sized or are not stored in a |
3054 | conventional manner. | |
3055 | ||
3056 | It may also be desirable (from an efficiency standpoint) to define | |
3057 | custom breakpoint insertion and removal routines if | |
56caf160 | 3058 | @code{BREAKPOINT_FROM_PC} needs to read the target's memory for some |
917317f4 JM |
3059 | reason. |
3060 | ||
b1e29e33 AC |
3061 | @item DEPRECATED_CALL_DUMMY_WORDS |
3062 | @findex DEPRECATED_CALL_DUMMY_WORDS | |
56caf160 | 3063 | Pointer to an array of @code{LONGEST} words of data containing |
b8b527c5 AC |
3064 | host-byte-ordered @code{DEPRECATED_REGISTER_SIZE} sized values that |
3065 | partially specify the sequence of instructions needed for an inferior | |
3066 | function call. | |
7a292a7a | 3067 | |
56caf160 | 3068 | Should be deprecated in favor of a macro that uses target-byte-ordered |
7a292a7a SS |
3069 | data. |
3070 | ||
7043d8dc AC |
3071 | This method has been replaced by @code{push_dummy_code} |
3072 | (@pxref{push_dummy_code}). | |
3073 | ||
b1e29e33 AC |
3074 | @item DEPRECATED_SIZEOF_CALL_DUMMY_WORDS |
3075 | @findex DEPRECATED_SIZEOF_CALL_DUMMY_WORDS | |
3076 | The size of @code{DEPRECATED_CALL_DUMMY_WORDS}. This must return a | |
3077 | positive value. See also @code{DEPRECATED_CALL_DUMMY_LENGTH}. | |
c906108c | 3078 | |
7043d8dc AC |
3079 | This method has been replaced by @code{push_dummy_code} |
3080 | (@pxref{push_dummy_code}). | |
3081 | ||
c906108c | 3082 | @item CALL_DUMMY |
56caf160 | 3083 | @findex CALL_DUMMY |
b1e29e33 AC |
3084 | A static initializer for @code{DEPRECATED_CALL_DUMMY_WORDS}. |
3085 | Deprecated. | |
7a292a7a | 3086 | |
7043d8dc AC |
3087 | This method has been replaced by @code{push_dummy_code} |
3088 | (@pxref{push_dummy_code}). | |
3089 | ||
c906108c | 3090 | @item CALL_DUMMY_LOCATION |
56caf160 EZ |
3091 | @findex CALL_DUMMY_LOCATION |
3092 | See the file @file{inferior.h}. | |
7a292a7a | 3093 | |
7043d8dc AC |
3094 | This method has been replaced by @code{push_dummy_code} |
3095 | (@pxref{push_dummy_code}). | |
3096 | ||
1bf6d5cc AC |
3097 | @item DEPRECATED_CALL_DUMMY_STACK_ADJUST |
3098 | @findex DEPRECATED_CALL_DUMMY_STACK_ADJUST | |
3099 | Stack adjustment needed when performing an inferior function call. This | |
b81774d8 | 3100 | function is no longer needed. @xref{push_dummy_call}, which can handle |
1bf6d5cc | 3101 | all alignment directly. |
c906108c | 3102 | |
56caf160 EZ |
3103 | @item CANNOT_FETCH_REGISTER (@var{regno}) |
3104 | @findex CANNOT_FETCH_REGISTER | |
c906108c SS |
3105 | A C expression that should be nonzero if @var{regno} cannot be fetched |
3106 | from an inferior process. This is only relevant if | |
3107 | @code{FETCH_INFERIOR_REGISTERS} is not defined. | |
3108 | ||
56caf160 EZ |
3109 | @item CANNOT_STORE_REGISTER (@var{regno}) |
3110 | @findex CANNOT_STORE_REGISTER | |
c906108c SS |
3111 | A C expression that should be nonzero if @var{regno} should not be |
3112 | written to the target. This is often the case for program counters, | |
56caf160 EZ |
3113 | status words, and other special registers. If this is not defined, |
3114 | @value{GDBN} will assume that all registers may be written. | |
c906108c SS |
3115 | |
3116 | @item DO_DEFERRED_STORES | |
a5d7c491 | 3117 | @itemx CLEAR_DEFERRED_STORES |
56caf160 EZ |
3118 | @findex CLEAR_DEFERRED_STORES |
3119 | @findex DO_DEFERRED_STORES | |
c906108c SS |
3120 | Define this to execute any deferred stores of registers into the inferior, |
3121 | and to cancel any deferred stores. | |
3122 | ||
3123 | Currently only implemented correctly for native Sparc configurations? | |
3124 | ||
13d01224 AC |
3125 | @item int CONVERT_REGISTER_P(@var{regnum}) |
3126 | @findex CONVERT_REGISTER_P | |
3127 | Return non-zero if register @var{regnum} can represent data values in a | |
3128 | non-standard form. | |
3129 | @xref{Target Architecture Definition, , Using Different Register and Memory Data Representations}. | |
3130 | ||
c906108c | 3131 | @item DECR_PC_AFTER_BREAK |
56caf160 | 3132 | @findex DECR_PC_AFTER_BREAK |
c906108c SS |
3133 | Define this to be the amount by which to decrement the PC after the |
3134 | program encounters a breakpoint. This is often the number of bytes in | |
56caf160 | 3135 | @code{BREAKPOINT}, though not always. For most targets this value will be 0. |
c906108c SS |
3136 | |
3137 | @item DECR_PC_AFTER_HW_BREAK | |
56caf160 | 3138 | @findex DECR_PC_AFTER_HW_BREAK |
c906108c SS |
3139 | Similarly, for hardware breakpoints. |
3140 | ||
56caf160 EZ |
3141 | @item DISABLE_UNSETTABLE_BREAK (@var{addr}) |
3142 | @findex DISABLE_UNSETTABLE_BREAK | |
c906108c SS |
3143 | If defined, this should evaluate to 1 if @var{addr} is in a shared |
3144 | library in which breakpoints cannot be set and so should be disabled. | |
3145 | ||
5e74b15c | 3146 | @item PRINT_FLOAT_INFO() |
0ab7a791 | 3147 | @findex PRINT_FLOAT_INFO |
5e74b15c RE |
3148 | If defined, then the @samp{info float} command will print information about |
3149 | the processor's floating point unit. | |
3150 | ||
0ab7a791 AC |
3151 | @item print_registers_info (@var{gdbarch}, @var{frame}, @var{regnum}, @var{all}) |
3152 | @findex print_registers_info | |
3153 | If defined, pretty print the value of the register @var{regnum} for the | |
3154 | specified @var{frame}. If the value of @var{regnum} is -1, pretty print | |
3155 | either all registers (@var{all} is non zero) or a select subset of | |
3156 | registers (@var{all} is zero). | |
3157 | ||
3158 | The default method prints one register per line, and if @var{all} is | |
3159 | zero omits floating-point registers. | |
3160 | ||
e76f1f2e AC |
3161 | @item PRINT_VECTOR_INFO() |
3162 | @findex PRINT_VECTOR_INFO | |
3163 | If defined, then the @samp{info vector} command will call this function | |
3164 | to print information about the processor's vector unit. | |
3165 | ||
3166 | By default, the @samp{info vector} command will print all vector | |
3167 | registers (the register's type having the vector attribute). | |
3168 | ||
0dcedd82 | 3169 | @item DWARF_REG_TO_REGNUM |
56caf160 | 3170 | @findex DWARF_REG_TO_REGNUM |
0dcedd82 AC |
3171 | Convert DWARF register number into @value{GDBN} regnum. If not defined, |
3172 | no conversion will be performed. | |
3173 | ||
3174 | @item DWARF2_REG_TO_REGNUM | |
56caf160 | 3175 | @findex DWARF2_REG_TO_REGNUM |
0dcedd82 AC |
3176 | Convert DWARF2 register number into @value{GDBN} regnum. If not |
3177 | defined, no conversion will be performed. | |
3178 | ||
3179 | @item ECOFF_REG_TO_REGNUM | |
56caf160 | 3180 | @findex ECOFF_REG_TO_REGNUM |
0dcedd82 AC |
3181 | Convert ECOFF register number into @value{GDBN} regnum. If not defined, |
3182 | no conversion will be performed. | |
3183 | ||
c906108c | 3184 | @item END_OF_TEXT_DEFAULT |
56caf160 EZ |
3185 | @findex END_OF_TEXT_DEFAULT |
3186 | This is an expression that should designate the end of the text section. | |
3187 | @c (? FIXME ?) | |
c906108c | 3188 | |
56caf160 EZ |
3189 | @item EXTRACT_RETURN_VALUE(@var{type}, @var{regbuf}, @var{valbuf}) |
3190 | @findex EXTRACT_RETURN_VALUE | |
c906108c SS |
3191 | Define this to extract a function's return value of type @var{type} from |
3192 | the raw register state @var{regbuf} and copy that, in virtual format, | |
3193 | into @var{valbuf}. | |
3194 | ||
56caf160 EZ |
3195 | @item EXTRACT_STRUCT_VALUE_ADDRESS(@var{regbuf}) |
3196 | @findex EXTRACT_STRUCT_VALUE_ADDRESS | |
83aa8bc6 AC |
3197 | When defined, extract from the array @var{regbuf} (containing the raw |
3198 | register state) the @code{CORE_ADDR} at which a function should return | |
3199 | its structure value. | |
ac9a91a7 | 3200 | |
83aa8bc6 AC |
3201 | If not defined, @code{EXTRACT_RETURN_VALUE} is used. |
3202 | ||
3203 | @item EXTRACT_STRUCT_VALUE_ADDRESS_P() | |
56caf160 EZ |
3204 | @findex EXTRACT_STRUCT_VALUE_ADDRESS_P |
3205 | Predicate for @code{EXTRACT_STRUCT_VALUE_ADDRESS}. | |
c906108c | 3206 | |
0ba6dca9 AC |
3207 | @item DEPRECATED_FP_REGNUM |
3208 | @findex DEPRECATED_FP_REGNUM | |
cce74817 JM |
3209 | If the virtual frame pointer is kept in a register, then define this |
3210 | macro to be the number (greater than or equal to zero) of that register. | |
3211 | ||
0ba6dca9 AC |
3212 | This should only need to be defined if @code{DEPRECATED_TARGET_READ_FP} |
3213 | is not defined. | |
c906108c | 3214 | |
56caf160 EZ |
3215 | @item FRAMELESS_FUNCTION_INVOCATION(@var{fi}) |
3216 | @findex FRAMELESS_FUNCTION_INVOCATION | |
392a587b JM |
3217 | Define this to an expression that returns 1 if the function invocation |
3218 | represented by @var{fi} does not have a stack frame associated with it. | |
3219 | Otherwise return 0. | |
c906108c | 3220 | |
790eb8f5 AC |
3221 | @item frame_align (@var{address}) |
3222 | @anchor{frame_align} | |
3223 | @findex frame_align | |
3224 | Define this to adjust @var{address} so that it meets the alignment | |
3225 | requirements for the start of a new stack frame. A stack frame's | |
3226 | alignment requirements are typically stronger than a target processors | |
3227 | stack alignment requirements (@pxref{STACK_ALIGN}). | |
3228 | ||
3229 | This function is used to ensure that, when creating a dummy frame, both | |
3230 | the initial stack pointer and (if needed) the address of the return | |
3231 | value are correctly aligned. | |
3232 | ||
3233 | Unlike @code{STACK_ALIGN}, this function always adjusts the address in | |
3234 | the direction of stack growth. | |
3235 | ||
3236 | By default, no frame based stack alignment is performed. | |
3237 | ||
618ce49f AC |
3238 | @item DEPRECATED_FRAME_CHAIN(@var{frame}) |
3239 | @findex DEPRECATED_FRAME_CHAIN | |
c906108c SS |
3240 | Given @var{frame}, return a pointer to the calling frame. |
3241 | ||
618ce49f AC |
3242 | @item DEPRECATED_FRAME_CHAIN_VALID(@var{chain}, @var{thisframe}) |
3243 | @findex DEPRECATED_FRAME_CHAIN_VALID | |
95f90d25 DJ |
3244 | Define this to be an expression that returns zero if the given frame is an |
3245 | outermost frame, with no caller, and nonzero otherwise. Most normal | |
3246 | situations can be handled without defining this macro, including @code{NULL} | |
3247 | chain pointers, dummy frames, and frames whose PC values are inside the | |
3248 | startup file (e.g.@: @file{crt0.o}), inside @code{main}, or inside | |
3249 | @code{_start}. | |
c906108c | 3250 | |
f30ee0bc AC |
3251 | @item DEPRECATED_FRAME_INIT_SAVED_REGS(@var{frame}) |
3252 | @findex DEPRECATED_FRAME_INIT_SAVED_REGS | |
c906108c SS |
3253 | See @file{frame.h}. Determines the address of all registers in the |
3254 | current stack frame storing each in @code{frame->saved_regs}. Space for | |
3255 | @code{frame->saved_regs} shall be allocated by | |
f30ee0bc AC |
3256 | @code{DEPRECATED_FRAME_INIT_SAVED_REGS} using |
3257 | @code{frame_saved_regs_zalloc}. | |
c906108c | 3258 | |
fb8f8949 | 3259 | @code{FRAME_FIND_SAVED_REGS} is deprecated. |
c906108c | 3260 | |
56caf160 EZ |
3261 | @item FRAME_NUM_ARGS (@var{fi}) |
3262 | @findex FRAME_NUM_ARGS | |
392a587b JM |
3263 | For the frame described by @var{fi} return the number of arguments that |
3264 | are being passed. If the number of arguments is not known, return | |
3265 | @code{-1}. | |
c906108c | 3266 | |
8bedc050 AC |
3267 | @item DEPRECATED_FRAME_SAVED_PC(@var{frame}) |
3268 | @findex DEPRECATED_FRAME_SAVED_PC | |
3269 | @anchor{DEPRECATED_FRAME_SAVED_PC} Given @var{frame}, return the pc | |
3270 | saved there. This is the return address. | |
12cc2063 AC |
3271 | |
3272 | This method is deprecated. @xref{unwind_pc}. | |
3273 | ||
3274 | @item CORE_ADDR unwind_pc (struct frame_info *@var{this_frame}) | |
3275 | @findex unwind_pc | |
3276 | @anchor{unwind_pc} Return the instruction address, in @var{this_frame}'s | |
3277 | caller, at which execution will resume after @var{this_frame} returns. | |
3278 | This is commonly refered to as the return address. | |
3279 | ||
3280 | The implementation, which must be frame agnostic (work with any frame), | |
3281 | is typically no more than: | |
3282 | ||
3283 | @smallexample | |
3284 | ULONGEST pc; | |
3285 | frame_unwind_unsigned_register (this_frame, D10V_PC_REGNUM, &pc); | |
3286 | return d10v_make_iaddr (pc); | |
3287 | @end smallexample | |
3288 | ||
3289 | @noindent | |
8bedc050 | 3290 | @xref{DEPRECATED_FRAME_SAVED_PC}, which this method replaces. |
c906108c | 3291 | |
a9e5fdc2 AC |
3292 | @item CORE_ADDR unwind_sp (struct frame_info *@var{this_frame}) |
3293 | @findex unwind_sp | |
3294 | @anchor{unwind_sp} Return the frame's inner most stack address. This is | |
3295 | commonly refered to as the frame's @dfn{stack pointer}. | |
3296 | ||
3297 | The implementation, which must be frame agnostic (work with any frame), | |
3298 | is typically no more than: | |
3299 | ||
3300 | @smallexample | |
3301 | ULONGEST sp; | |
3302 | frame_unwind_unsigned_register (this_frame, D10V_SP_REGNUM, &sp); | |
3303 | return d10v_make_daddr (sp); | |
3304 | @end smallexample | |
3305 | ||
3306 | @noindent | |
3307 | @xref{TARGET_READ_SP}, which this method replaces. | |
3308 | ||
c906108c | 3309 | @item FUNCTION_EPILOGUE_SIZE |
56caf160 | 3310 | @findex FUNCTION_EPILOGUE_SIZE |
c906108c SS |
3311 | For some COFF targets, the @code{x_sym.x_misc.x_fsize} field of the |
3312 | function end symbol is 0. For such targets, you must define | |
3313 | @code{FUNCTION_EPILOGUE_SIZE} to expand into the standard size of a | |
3314 | function's epilogue. | |
3315 | ||
f7cb2b90 | 3316 | @item FUNCTION_START_OFFSET |
56caf160 | 3317 | @findex FUNCTION_START_OFFSET |
f7cb2b90 JB |
3318 | An integer, giving the offset in bytes from a function's address (as |
3319 | used in the values of symbols, function pointers, etc.), and the | |
3320 | function's first genuine instruction. | |
3321 | ||
3322 | This is zero on almost all machines: the function's address is usually | |
3323 | the address of its first instruction. However, on the VAX, for example, | |
3324 | each function starts with two bytes containing a bitmask indicating | |
3325 | which registers to save upon entry to the function. The VAX @code{call} | |
3326 | instructions check this value, and save the appropriate registers | |
3327 | automatically. Thus, since the offset from the function's address to | |
3328 | its first instruction is two bytes, @code{FUNCTION_START_OFFSET} would | |
3329 | be 2 on the VAX. | |
3330 | ||
c906108c | 3331 | @item GCC_COMPILED_FLAG_SYMBOL |
56caf160 EZ |
3332 | @itemx GCC2_COMPILED_FLAG_SYMBOL |
3333 | @findex GCC2_COMPILED_FLAG_SYMBOL | |
3334 | @findex GCC_COMPILED_FLAG_SYMBOL | |
3335 | If defined, these are the names of the symbols that @value{GDBN} will | |
3336 | look for to detect that GCC compiled the file. The default symbols | |
3337 | are @code{gcc_compiled.} and @code{gcc2_compiled.}, | |
3338 | respectively. (Currently only defined for the Delta 68.) | |
c906108c | 3339 | |
25822942 | 3340 | @item @value{GDBN}_MULTI_ARCH |
56caf160 | 3341 | @findex @value{GDBN}_MULTI_ARCH |
937f164b | 3342 | If defined and non-zero, enables support for multiple architectures |
25822942 | 3343 | within @value{GDBN}. |
0f71a2f6 | 3344 | |
56caf160 | 3345 | This support can be enabled at two levels. At level one, only |
0f71a2f6 | 3346 | definitions for previously undefined macros are provided; at level two, |
937f164b | 3347 | a multi-arch definition of all architecture dependent macros will be |
0f71a2f6 JM |
3348 | defined. |
3349 | ||
25822942 | 3350 | @item @value{GDBN}_TARGET_IS_HPPA |
56caf160 EZ |
3351 | @findex @value{GDBN}_TARGET_IS_HPPA |
3352 | This determines whether horrible kludge code in @file{dbxread.c} and | |
3353 | @file{partial-stab.h} is used to mangle multiple-symbol-table files from | |
3354 | HPPA's. This should all be ripped out, and a scheme like @file{elfread.c} | |
3355 | used instead. | |
c906108c | 3356 | |
c906108c | 3357 | @item GET_LONGJMP_TARGET |
56caf160 | 3358 | @findex GET_LONGJMP_TARGET |
c906108c SS |
3359 | For most machines, this is a target-dependent parameter. On the |
3360 | DECstation and the Iris, this is a native-dependent parameter, since | |
937f164b | 3361 | the header file @file{setjmp.h} is needed to define it. |
c906108c | 3362 | |
56caf160 EZ |
3363 | This macro determines the target PC address that @code{longjmp} will jump to, |
3364 | assuming that we have just stopped at a @code{longjmp} breakpoint. It takes a | |
3365 | @code{CORE_ADDR *} as argument, and stores the target PC value through this | |
c906108c SS |
3366 | pointer. It examines the current state of the machine as needed. |
3367 | ||
ac2adee5 AC |
3368 | @item DEPRECATED_GET_SAVED_REGISTER |
3369 | @findex DEPRECATED_GET_SAVED_REGISTER | |
c906108c | 3370 | Define this if you need to supply your own definition for the function |
ac2adee5 | 3371 | @code{DEPRECATED_GET_SAVED_REGISTER}. |
c906108c | 3372 | |
c906108c | 3373 | @item IBM6000_TARGET |
56caf160 | 3374 | @findex IBM6000_TARGET |
c906108c SS |
3375 | Shows that we are configured for an IBM RS/6000 target. This |
3376 | conditional should be eliminated (FIXME) and replaced by | |
56caf160 | 3377 | feature-specific macros. It was introduced in a haste and we are |
c906108c SS |
3378 | repenting at leisure. |
3379 | ||
9742079a EZ |
3380 | @item I386_USE_GENERIC_WATCHPOINTS |
3381 | An x86-based target can define this to use the generic x86 watchpoint | |
3382 | support; see @ref{Algorithms, I386_USE_GENERIC_WATCHPOINTS}. | |
3383 | ||
2df3850c | 3384 | @item SYMBOLS_CAN_START_WITH_DOLLAR |
56caf160 | 3385 | @findex SYMBOLS_CAN_START_WITH_DOLLAR |
2df3850c | 3386 | Some systems have routines whose names start with @samp{$}. Giving this |
25822942 | 3387 | macro a non-zero value tells @value{GDBN}'s expression parser to check for such |
2df3850c JM |
3388 | routines when parsing tokens that begin with @samp{$}. |
3389 | ||
3390 | On HP-UX, certain system routines (millicode) have names beginning with | |
3391 | @samp{$} or @samp{$$}. For example, @code{$$dyncall} is a millicode | |
3392 | routine that handles inter-space procedure calls on PA-RISC. | |
3393 | ||
e9582e71 AC |
3394 | @item DEPRECATED_INIT_EXTRA_FRAME_INFO (@var{fromleaf}, @var{frame}) |
3395 | @findex DEPRECATED_INIT_EXTRA_FRAME_INFO | |
c906108c SS |
3396 | If additional information about the frame is required this should be |
3397 | stored in @code{frame->extra_info}. Space for @code{frame->extra_info} | |
372613e3 | 3398 | is allocated using @code{frame_extra_info_zalloc}. |
c906108c | 3399 | |
a5afb99f AC |
3400 | @item DEPRECATED_INIT_FRAME_PC (@var{fromleaf}, @var{prev}) |
3401 | @findex DEPRECATED_INIT_FRAME_PC | |
c906108c SS |
3402 | This is a C statement that sets the pc of the frame pointed to by |
3403 | @var{prev}. [By default...] | |
3404 | ||
56caf160 EZ |
3405 | @item INNER_THAN (@var{lhs}, @var{rhs}) |
3406 | @findex INNER_THAN | |
c906108c SS |
3407 | Returns non-zero if stack address @var{lhs} is inner than (nearer to the |
3408 | stack top) stack address @var{rhs}. Define this as @code{lhs < rhs} if | |
3409 | the target's stack grows downward in memory, or @code{lhs > rsh} if the | |
3410 | stack grows upward. | |
3411 | ||
9e5abb06 CV |
3412 | @item gdbarch_in_function_epilogue_p (@var{gdbarch}, @var{pc}) |
3413 | @findex gdbarch_in_function_epilogue_p | |
3414 | Returns non-zero if the given @var{pc} is in the epilogue of a function. | |
3415 | The epilogue of a function is defined as the part of a function where | |
3416 | the stack frame of the function already has been destroyed up to the | |
3417 | final `return from function call' instruction. | |
3418 | ||
56caf160 EZ |
3419 | @item SIGTRAMP_START (@var{pc}) |
3420 | @findex SIGTRAMP_START | |
3421 | @itemx SIGTRAMP_END (@var{pc}) | |
3422 | @findex SIGTRAMP_END | |
3423 | Define these to be the start and end address of the @code{sigtramp} for the | |
c906108c SS |
3424 | given @var{pc}. On machines where the address is just a compile time |
3425 | constant, the macro expansion will typically just ignore the supplied | |
3426 | @var{pc}. | |
3427 | ||
56caf160 EZ |
3428 | @item IN_SOLIB_CALL_TRAMPOLINE (@var{pc}, @var{name}) |
3429 | @findex IN_SOLIB_CALL_TRAMPOLINE | |
c906108c SS |
3430 | Define this to evaluate to nonzero if the program is stopped in the |
3431 | trampoline that connects to a shared library. | |
3432 | ||
56caf160 EZ |
3433 | @item IN_SOLIB_RETURN_TRAMPOLINE (@var{pc}, @var{name}) |
3434 | @findex IN_SOLIB_RETURN_TRAMPOLINE | |
c906108c SS |
3435 | Define this to evaluate to nonzero if the program is stopped in the |
3436 | trampoline that returns from a shared library. | |
3437 | ||
56caf160 EZ |
3438 | @item IN_SOLIB_DYNSYM_RESOLVE_CODE (@var{pc}) |
3439 | @findex IN_SOLIB_DYNSYM_RESOLVE_CODE | |
d4f3574e SS |
3440 | Define this to evaluate to nonzero if the program is stopped in the |
3441 | dynamic linker. | |
3442 | ||
56caf160 EZ |
3443 | @item SKIP_SOLIB_RESOLVER (@var{pc}) |
3444 | @findex SKIP_SOLIB_RESOLVER | |
d4f3574e SS |
3445 | Define this to evaluate to the (nonzero) address at which execution |
3446 | should continue to get past the dynamic linker's symbol resolution | |
3447 | function. A zero value indicates that it is not important or necessary | |
3448 | to set a breakpoint to get through the dynamic linker and that single | |
3449 | stepping will suffice. | |
3450 | ||
fc0c74b1 AC |
3451 | @item INTEGER_TO_ADDRESS (@var{type}, @var{buf}) |
3452 | @findex INTEGER_TO_ADDRESS | |
3453 | @cindex converting integers to addresses | |
3454 | Define this when the architecture needs to handle non-pointer to address | |
3455 | conversions specially. Converts that value to an address according to | |
3456 | the current architectures conventions. | |
3457 | ||
3458 | @emph{Pragmatics: When the user copies a well defined expression from | |
3459 | their source code and passes it, as a parameter, to @value{GDBN}'s | |
3460 | @code{print} command, they should get the same value as would have been | |
3461 | computed by the target program. Any deviation from this rule can cause | |
3462 | major confusion and annoyance, and needs to be justified carefully. In | |
3463 | other words, @value{GDBN} doesn't really have the freedom to do these | |
3464 | conversions in clever and useful ways. It has, however, been pointed | |
3465 | out that users aren't complaining about how @value{GDBN} casts integers | |
3466 | to pointers; they are complaining that they can't take an address from a | |
3467 | disassembly listing and give it to @code{x/i}. Adding an architecture | |
3468 | method like @code{INTEGER_TO_ADDRESS} certainly makes it possible for | |
3469 | @value{GDBN} to ``get it right'' in all circumstances.} | |
3470 | ||
3471 | @xref{Target Architecture Definition, , Pointers Are Not Always | |
3472 | Addresses}. | |
3473 | ||
c906108c | 3474 | @item NEED_TEXT_START_END |
56caf160 | 3475 | @findex NEED_TEXT_START_END |
25822942 | 3476 | Define this if @value{GDBN} should determine the start and end addresses of the |
c906108c SS |
3477 | text section. (Seems dubious.) |
3478 | ||
3479 | @item NO_HIF_SUPPORT | |
56caf160 | 3480 | @findex NO_HIF_SUPPORT |
c906108c SS |
3481 | (Specific to the a29k.) |
3482 | ||
93e79dbd | 3483 | @item POINTER_TO_ADDRESS (@var{type}, @var{buf}) |
56caf160 | 3484 | @findex POINTER_TO_ADDRESS |
93e79dbd JB |
3485 | Assume that @var{buf} holds a pointer of type @var{type}, in the |
3486 | appropriate format for the current architecture. Return the byte | |
3487 | address the pointer refers to. | |
3488 | @xref{Target Architecture Definition, , Pointers Are Not Always Addresses}. | |
3489 | ||
9fb4dd36 | 3490 | @item REGISTER_CONVERTIBLE (@var{reg}) |
56caf160 | 3491 | @findex REGISTER_CONVERTIBLE |
9fb4dd36 | 3492 | Return non-zero if @var{reg} uses different raw and virtual formats. |
13d01224 AC |
3493 | @xref{Target Architecture Definition, , Raw and Virtual Register Representations}. |
3494 | ||
3495 | @item REGISTER_TO_VALUE(@var{regnum}, @var{type}, @var{from}, @var{to}) | |
3496 | @findex REGISTER_TO_VALUE | |
3497 | Convert the raw contents of register @var{regnum} into a value of type | |
3498 | @var{type}. | |
4281a42e | 3499 | @xref{Target Architecture Definition, , Using Different Register and Memory Data Representations}. |
9fb4dd36 JB |
3500 | |
3501 | @item REGISTER_RAW_SIZE (@var{reg}) | |
56caf160 | 3502 | @findex REGISTER_RAW_SIZE |
b2e75d78 AC |
3503 | Return the raw size of @var{reg}; defaults to the size of the register's |
3504 | virtual type. | |
13d01224 | 3505 | @xref{Target Architecture Definition, , Raw and Virtual Register Representations}. |
9fb4dd36 | 3506 | |
617073a9 AC |
3507 | @item register_reggroup_p (@var{gdbarch}, @var{regnum}, @var{reggroup}) |
3508 | @findex register_reggroup_p | |
3509 | @cindex register groups | |
3510 | Return non-zero if register @var{regnum} is a member of the register | |
3511 | group @var{reggroup}. | |
3512 | ||
3513 | By default, registers are grouped as follows: | |
3514 | ||
3515 | @table @code | |
3516 | @item float_reggroup | |
3517 | Any register with a valid name and a floating-point type. | |
3518 | @item vector_reggroup | |
3519 | Any register with a valid name and a vector type. | |
3520 | @item general_reggroup | |
3521 | Any register with a valid name and a type other than vector or | |
3522 | floating-point. @samp{float_reggroup}. | |
3523 | @item save_reggroup | |
3524 | @itemx restore_reggroup | |
3525 | @itemx all_reggroup | |
3526 | Any register with a valid name. | |
3527 | @end table | |
3528 | ||
9fb4dd36 | 3529 | @item REGISTER_VIRTUAL_SIZE (@var{reg}) |
56caf160 | 3530 | @findex REGISTER_VIRTUAL_SIZE |
b2e75d78 AC |
3531 | Return the virtual size of @var{reg}; defaults to the size of the |
3532 | register's virtual type. | |
13d01224 AC |
3533 | Return the virtual size of @var{reg}. |
3534 | @xref{Target Architecture Definition, , Raw and Virtual Register Representations}. | |
9fb4dd36 JB |
3535 | |
3536 | @item REGISTER_VIRTUAL_TYPE (@var{reg}) | |
56caf160 | 3537 | @findex REGISTER_VIRTUAL_TYPE |
9fb4dd36 | 3538 | Return the virtual type of @var{reg}. |
13d01224 | 3539 | @xref{Target Architecture Definition, , Raw and Virtual Register Representations}. |
9fb4dd36 | 3540 | |
77e7e267 AC |
3541 | @item struct type *register_type (@var{gdbarch}, @var{reg}) |
3542 | @findex register_type | |
3543 | If defined, return the type of register @var{reg}. This function | |
3544 | superseeds @code{REGISTER_VIRTUAL_TYPE}. @xref{Target Architecture | |
3545 | Definition, , Raw and Virtual Register Representations}. | |
3546 | ||
9fb4dd36 | 3547 | @item REGISTER_CONVERT_TO_VIRTUAL(@var{reg}, @var{type}, @var{from}, @var{to}) |
56caf160 | 3548 | @findex REGISTER_CONVERT_TO_VIRTUAL |
9fb4dd36 | 3549 | Convert the value of register @var{reg} from its raw form to its virtual |
4281a42e | 3550 | form. |
13d01224 | 3551 | @xref{Target Architecture Definition, , Raw and Virtual Register Representations}. |
9fb4dd36 JB |
3552 | |
3553 | @item REGISTER_CONVERT_TO_RAW(@var{type}, @var{reg}, @var{from}, @var{to}) | |
56caf160 | 3554 | @findex REGISTER_CONVERT_TO_RAW |
9fb4dd36 | 3555 | Convert the value of register @var{reg} from its virtual form to its raw |
4281a42e | 3556 | form. |
13d01224 | 3557 | @xref{Target Architecture Definition, , Raw and Virtual Register Representations}. |
9fb4dd36 | 3558 | |
e5419804 JB |
3559 | @item RETURN_VALUE_ON_STACK(@var{type}) |
3560 | @findex RETURN_VALUE_ON_STACK | |
3561 | @cindex returning structures by value | |
3562 | @cindex structures, returning by value | |
3563 | ||
3564 | Return non-zero if values of type TYPE are returned on the stack, using | |
3565 | the ``struct convention'' (i.e., the caller provides a pointer to a | |
3566 | buffer in which the callee should store the return value). This | |
3567 | controls how the @samp{finish} command finds a function's return value, | |
3568 | and whether an inferior function call reserves space on the stack for | |
3569 | the return value. | |
3570 | ||
3571 | The full logic @value{GDBN} uses here is kind of odd. | |
e5419804 | 3572 | |
56caf160 | 3573 | @itemize @bullet |
e5419804 JB |
3574 | @item |
3575 | If the type being returned by value is not a structure, union, or array, | |
3576 | and @code{RETURN_VALUE_ON_STACK} returns zero, then @value{GDBN} | |
3577 | concludes the value is not returned using the struct convention. | |
3578 | ||
3579 | @item | |
3580 | Otherwise, @value{GDBN} calls @code{USE_STRUCT_CONVENTION} (see below). | |
3581 | If that returns non-zero, @value{GDBN} assumes the struct convention is | |
3582 | in use. | |
e5419804 JB |
3583 | @end itemize |
3584 | ||
3585 | In other words, to indicate that a given type is returned by value using | |
3586 | the struct convention, that type must be either a struct, union, array, | |
3587 | or something @code{RETURN_VALUE_ON_STACK} likes, @emph{and} something | |
3588 | that @code{USE_STRUCT_CONVENTION} likes. | |
3589 | ||
56caf160 | 3590 | Note that, in C and C@t{++}, arrays are never returned by value. In those |
e5419804 JB |
3591 | languages, these predicates will always see a pointer type, never an |
3592 | array type. All the references above to arrays being returned by value | |
3593 | apply only to other languages. | |
3594 | ||
b0ed3589 | 3595 | @item SOFTWARE_SINGLE_STEP_P() |
56caf160 | 3596 | @findex SOFTWARE_SINGLE_STEP_P |
c906108c | 3597 | Define this as 1 if the target does not have a hardware single-step |
56caf160 | 3598 | mechanism. The macro @code{SOFTWARE_SINGLE_STEP} must also be defined. |
c906108c | 3599 | |
56caf160 EZ |
3600 | @item SOFTWARE_SINGLE_STEP(@var{signal}, @var{insert_breapoints_p}) |
3601 | @findex SOFTWARE_SINGLE_STEP | |
3602 | A function that inserts or removes (depending on | |
c906108c | 3603 | @var{insert_breapoints_p}) breakpoints at each possible destinations of |
56caf160 | 3604 | the next instruction. See @file{sparc-tdep.c} and @file{rs6000-tdep.c} |
c906108c SS |
3605 | for examples. |
3606 | ||
da59e081 | 3607 | @item SOFUN_ADDRESS_MAYBE_MISSING |
56caf160 | 3608 | @findex SOFUN_ADDRESS_MAYBE_MISSING |
da59e081 JM |
3609 | Somebody clever observed that, the more actual addresses you have in the |
3610 | debug information, the more time the linker has to spend relocating | |
3611 | them. So whenever there's some other way the debugger could find the | |
3612 | address it needs, you should omit it from the debug info, to make | |
3613 | linking faster. | |
3614 | ||
3615 | @code{SOFUN_ADDRESS_MAYBE_MISSING} indicates that a particular set of | |
3616 | hacks of this sort are in use, affecting @code{N_SO} and @code{N_FUN} | |
3617 | entries in stabs-format debugging information. @code{N_SO} stabs mark | |
3618 | the beginning and ending addresses of compilation units in the text | |
3619 | segment. @code{N_FUN} stabs mark the starts and ends of functions. | |
3620 | ||
3621 | @code{SOFUN_ADDRESS_MAYBE_MISSING} means two things: | |
da59e081 | 3622 | |
56caf160 | 3623 | @itemize @bullet |
da59e081 JM |
3624 | @item |
3625 | @code{N_FUN} stabs have an address of zero. Instead, you should find the | |
3626 | addresses where the function starts by taking the function name from | |
56caf160 EZ |
3627 | the stab, and then looking that up in the minsyms (the |
3628 | linker/assembler symbol table). In other words, the stab has the | |
3629 | name, and the linker/assembler symbol table is the only place that carries | |
da59e081 JM |
3630 | the address. |
3631 | ||
3632 | @item | |
3633 | @code{N_SO} stabs have an address of zero, too. You just look at the | |
3634 | @code{N_FUN} stabs that appear before and after the @code{N_SO} stab, | |
3635 | and guess the starting and ending addresses of the compilation unit from | |
3636 | them. | |
da59e081 JM |
3637 | @end itemize |
3638 | ||
c906108c | 3639 | @item PCC_SOL_BROKEN |
56caf160 | 3640 | @findex PCC_SOL_BROKEN |
c906108c SS |
3641 | (Used only in the Convex target.) |
3642 | ||
d7bd68ca AC |
3643 | @item PC_IN_SIGTRAMP (@var{pc}, @var{name}) |
3644 | @findex PC_IN_SIGTRAMP | |
3645 | @cindex sigtramp | |
3646 | The @dfn{sigtramp} is a routine that the kernel calls (which then calls | |
3647 | the signal handler). On most machines it is a library routine that is | |
3648 | linked into the executable. | |
3649 | ||
3650 | This function, given a program counter value in @var{pc} and the | |
3651 | (possibly NULL) name of the function in which that @var{pc} resides, | |
3652 | returns nonzero if the @var{pc} and/or @var{name} show that we are in | |
3653 | sigtramp. | |
3654 | ||
c906108c | 3655 | @item PC_LOAD_SEGMENT |
56caf160 | 3656 | @findex PC_LOAD_SEGMENT |
c906108c SS |
3657 | If defined, print information about the load segment for the program |
3658 | counter. (Defined only for the RS/6000.) | |
3659 | ||
3660 | @item PC_REGNUM | |
56caf160 | 3661 | @findex PC_REGNUM |
c906108c | 3662 | If the program counter is kept in a register, then define this macro to |
cce74817 JM |
3663 | be the number (greater than or equal to zero) of that register. |
3664 | ||
3665 | This should only need to be defined if @code{TARGET_READ_PC} and | |
3666 | @code{TARGET_WRITE_PC} are not defined. | |
c906108c SS |
3667 | |
3668 | @item NPC_REGNUM | |
56caf160 | 3669 | @findex NPC_REGNUM |
c906108c SS |
3670 | The number of the ``next program counter'' register, if defined. |
3671 | ||
2df3850c | 3672 | @item PARM_BOUNDARY |
56caf160 | 3673 | @findex PARM_BOUNDARY |
2df3850c JM |
3674 | If non-zero, round arguments to a boundary of this many bits before |
3675 | pushing them on the stack. | |
3676 | ||
c906108c | 3677 | @item PROCESS_LINENUMBER_HOOK |
56caf160 | 3678 | @findex PROCESS_LINENUMBER_HOOK |
c906108c SS |
3679 | A hook defined for XCOFF reading. |
3680 | ||
3681 | @item PROLOGUE_FIRSTLINE_OVERLAP | |
56caf160 | 3682 | @findex PROLOGUE_FIRSTLINE_OVERLAP |
c906108c SS |
3683 | (Only used in unsupported Convex configuration.) |
3684 | ||
3685 | @item PS_REGNUM | |
56caf160 | 3686 | @findex PS_REGNUM |
c906108c SS |
3687 | If defined, this is the number of the processor status register. (This |
3688 | definition is only used in generic code when parsing "$ps".) | |
3689 | ||
749b82f6 AC |
3690 | @item DEPRECATED_POP_FRAME |
3691 | @findex DEPRECATED_POP_FRAME | |
3692 | @findex frame_pop | |
3693 | If defined, used by @code{frame_pop} to remove a stack frame. This | |
3694 | method has been superseeded by generic code. | |
c906108c | 3695 | |
39fe6e80 | 3696 | @item push_dummy_call (@var{gdbarch}, @var{func_addr}, @var{regcache}, @var{pc_addr}, @var{nargs}, @var{args}, @var{sp}, @var{struct_return}, @var{struct_addr}) |
b81774d8 AC |
3697 | @findex push_dummy_call |
3698 | @findex DEPRECATED_PUSH_ARGUMENTS. | |
39fe6e80 AC |
3699 | @anchor{push_dummy_call} Define this to push the dummy frame's call to |
3700 | the inferior function onto the stack. In addition to pushing | |
3701 | @var{nargs}, the code should push @var{struct_addr} (when | |
3702 | @var{struct_return}), and the return address (@var{bp_addr}). | |
c906108c | 3703 | |
b24da7d0 | 3704 | Returns the updated top-of-stack pointer. |
b81774d8 AC |
3705 | |
3706 | This method replaces @code{DEPRECATED_PUSH_ARGUMENTS}. | |
3707 | ||
7043d8dc AC |
3708 | @item CORE_ADDR push_dummy_code (@var{gdbarch}, @var{sp}, @var{funaddr}, @var{using_gcc}, @var{args}, @var{nargs}, @var{value_type}, @var{real_pc}, @var{bp_addr}) |
3709 | @findex push_dummy_code | |
b1e29e33 | 3710 | @findex DEPRECATED_FIX_CALL_DUMMY |
7043d8dc AC |
3711 | @anchor{push_dummy_code} Given a stack based call dummy, push the |
3712 | instruction sequence (including space for a breakpoint) to which the | |
3713 | called function should return. | |
3714 | ||
3715 | Set @var{bp_addr} to the address at which the breakpoint instruction | |
3716 | should be inserted, @var{real_pc} to the resume address when starting | |
3717 | the call sequence, and return the updated inner-most stack address. | |
3718 | ||
3719 | By default, the stack is grown sufficient to hold a frame-aligned | |
3720 | (@pxref{frame_align}) breakpoint, @var{bp_addr} is set to the address | |
3721 | reserved for that breakpoint, and @var{real_pc} set to @var{funaddr}. | |
3722 | ||
b1e29e33 AC |
3723 | This method replaces @code{DEPRECATED_CALL_DUMMY_WORDS}, |
3724 | @code{DEPRECATED_SIZEOF_CALL_DUMMY_WORDS}, @code{CALL_DUMMY}, | |
3725 | @code{CALL_DUMMY_LOCATION}, @code{DEPRECATED_REGISTER_SIZE}, | |
3726 | @code{GDB_TARGET_IS_HPPA}, | |
3727 | @code{DEPRECATED_CALL_DUMMY_BREAKPOINT_OFFSET}, and | |
3728 | @code{DEPRECATED_FIX_CALL_DUMMY}. | |
7043d8dc | 3729 | |
b81774d8 AC |
3730 | @item DEPRECATED_PUSH_DUMMY_FRAME |
3731 | @findex DEPRECATED_PUSH_DUMMY_FRAME | |
c906108c SS |
3732 | Used in @samp{call_function_by_hand} to create an artificial stack frame. |
3733 | ||
b8b527c5 AC |
3734 | @item DEPRECATED_REGISTER_BYTES |
3735 | @findex DEPRECATED_REGISTER_BYTES | |
3736 | The total amount of space needed to store @value{GDBN}'s copy of the | |
3737 | machine's register state. | |
3738 | ||
3739 | This is no longer needed. @value{GDBN} instead computes the size of the | |
3740 | register buffer at run-time. | |
c906108c | 3741 | |
56caf160 EZ |
3742 | @item REGISTER_NAME(@var{i}) |
3743 | @findex REGISTER_NAME | |
3744 | Return the name of register @var{i} as a string. May return @code{NULL} | |
3745 | or @code{NUL} to indicate that register @var{i} is not valid. | |
c906108c | 3746 | |
7a292a7a | 3747 | @item REGISTER_NAMES |
56caf160 EZ |
3748 | @findex REGISTER_NAMES |
3749 | Deprecated in favor of @code{REGISTER_NAME}. | |
7a292a7a | 3750 | |
56caf160 EZ |
3751 | @item REG_STRUCT_HAS_ADDR (@var{gcc_p}, @var{type}) |
3752 | @findex REG_STRUCT_HAS_ADDR | |
c906108c SS |
3753 | Define this to return 1 if the given type will be passed by pointer |
3754 | rather than directly. | |
3755 | ||
b24da7d0 AC |
3756 | @item SAVE_DUMMY_FRAME_TOS (@var{sp}) |
3757 | @findex SAVE_DUMMY_FRAME_TOS | |
3758 | @anchor{SAVE_DUMMY_FRAME_TOS} Used in @samp{call_function_by_hand} to | |
3759 | notify the target dependent code of the top-of-stack value that will be | |
3760 | passed to the the inferior code. This is the value of the @code{SP} | |
3761 | after both the dummy frame and space for parameters/results have been | |
3762 | allocated on the stack. @xref{unwind_dummy_id}. | |
43ff13b4 | 3763 | |
c906108c | 3764 | @item SDB_REG_TO_REGNUM |
56caf160 | 3765 | @findex SDB_REG_TO_REGNUM |
25822942 | 3766 | Define this to convert sdb register numbers into @value{GDBN} regnums. If not |
c906108c SS |
3767 | defined, no conversion will be done. |
3768 | ||
c2c6d25f | 3769 | @item SKIP_PERMANENT_BREAKPOINT |
56caf160 | 3770 | @findex SKIP_PERMANENT_BREAKPOINT |
25822942 | 3771 | Advance the inferior's PC past a permanent breakpoint. @value{GDBN} normally |
c2c6d25f JM |
3772 | steps over a breakpoint by removing it, stepping one instruction, and |
3773 | re-inserting the breakpoint. However, permanent breakpoints are | |
3774 | hardwired into the inferior, and can't be removed, so this strategy | |
56caf160 | 3775 | doesn't work. Calling @code{SKIP_PERMANENT_BREAKPOINT} adjusts the processor's |
c2c6d25f JM |
3776 | state so that execution will resume just after the breakpoint. This |
3777 | macro does the right thing even when the breakpoint is in the delay slot | |
3778 | of a branch or jump. | |
3779 | ||
56caf160 EZ |
3780 | @item SKIP_PROLOGUE (@var{pc}) |
3781 | @findex SKIP_PROLOGUE | |
b83266a0 SS |
3782 | A C expression that returns the address of the ``real'' code beyond the |
3783 | function entry prologue found at @var{pc}. | |
c906108c | 3784 | |
56caf160 EZ |
3785 | @item SKIP_TRAMPOLINE_CODE (@var{pc}) |
3786 | @findex SKIP_TRAMPOLINE_CODE | |
c906108c SS |
3787 | If the target machine has trampoline code that sits between callers and |
3788 | the functions being called, then define this macro to return a new PC | |
3789 | that is at the start of the real function. | |
3790 | ||
3791 | @item SP_REGNUM | |
56caf160 | 3792 | @findex SP_REGNUM |
cce74817 | 3793 | If the stack-pointer is kept in a register, then define this macro to be |
6c0e89ed AC |
3794 | the number (greater than or equal to zero) of that register, or -1 if |
3795 | there is no such register. | |
c906108c SS |
3796 | |
3797 | @item STAB_REG_TO_REGNUM | |
56caf160 | 3798 | @findex STAB_REG_TO_REGNUM |
c906108c | 3799 | Define this to convert stab register numbers (as gotten from `r' |
25822942 | 3800 | declarations) into @value{GDBN} regnums. If not defined, no conversion will be |
c906108c SS |
3801 | done. |
3802 | ||
56caf160 | 3803 | @item STACK_ALIGN (@var{addr}) |
790eb8f5 | 3804 | @anchor{STACK_ALIGN} |
56caf160 | 3805 | @findex STACK_ALIGN |
790eb8f5 AC |
3806 | Define this to increase @var{addr} so that it meets the alignment |
3807 | requirements for the processor's stack. | |
3808 | ||
3809 | Unlike @ref{frame_align}, this function always adjusts @var{addr} | |
3810 | upwards. | |
3811 | ||
3812 | By default, no stack alignment is performed. | |
c906108c | 3813 | |
56caf160 EZ |
3814 | @item STEP_SKIPS_DELAY (@var{addr}) |
3815 | @findex STEP_SKIPS_DELAY | |
c906108c SS |
3816 | Define this to return true if the address is of an instruction with a |
3817 | delay slot. If a breakpoint has been placed in the instruction's delay | |
25822942 | 3818 | slot, @value{GDBN} will single-step over that instruction before resuming |
c906108c SS |
3819 | normally. Currently only defined for the Mips. |
3820 | ||
ebba8386 | 3821 | @item STORE_RETURN_VALUE (@var{type}, @var{regcache}, @var{valbuf}) |
56caf160 | 3822 | @findex STORE_RETURN_VALUE |
ebba8386 AC |
3823 | A C expression that writes the function return value, found in |
3824 | @var{valbuf}, into the @var{regcache}. @var{type} is the type of the | |
3825 | value that is to be returned. | |
c906108c SS |
3826 | |
3827 | @item SUN_FIXED_LBRAC_BUG | |
56caf160 | 3828 | @findex SUN_FIXED_LBRAC_BUG |
c906108c SS |
3829 | (Used only for Sun-3 and Sun-4 targets.) |
3830 | ||
3831 | @item SYMBOL_RELOADING_DEFAULT | |
56caf160 EZ |
3832 | @findex SYMBOL_RELOADING_DEFAULT |
3833 | The default value of the ``symbol-reloading'' variable. (Never defined in | |
c906108c SS |
3834 | current sources.) |
3835 | ||
c906108c | 3836 | @item TARGET_CHAR_BIT |
56caf160 | 3837 | @findex TARGET_CHAR_BIT |
c906108c SS |
3838 | Number of bits in a char; defaults to 8. |
3839 | ||
c3d3ce5b JB |
3840 | @item TARGET_CHAR_SIGNED |
3841 | @findex TARGET_CHAR_SIGNED | |
3842 | Non-zero if @code{char} is normally signed on this architecture; zero if | |
3843 | it should be unsigned. | |
3844 | ||
3845 | The ISO C standard requires the compiler to treat @code{char} as | |
3846 | equivalent to either @code{signed char} or @code{unsigned char}; any | |
3847 | character in the standard execution set is supposed to be positive. | |
3848 | Most compilers treat @code{char} as signed, but @code{char} is unsigned | |
3849 | on the IBM S/390, RS6000, and PowerPC targets. | |
3850 | ||
c906108c | 3851 | @item TARGET_COMPLEX_BIT |
56caf160 | 3852 | @findex TARGET_COMPLEX_BIT |
c906108c SS |
3853 | Number of bits in a complex number; defaults to @code{2 * TARGET_FLOAT_BIT}. |
3854 | ||
ac9a91a7 JM |
3855 | At present this macro is not used. |
3856 | ||
c906108c | 3857 | @item TARGET_DOUBLE_BIT |
56caf160 | 3858 | @findex TARGET_DOUBLE_BIT |
c906108c SS |
3859 | Number of bits in a double float; defaults to @code{8 * TARGET_CHAR_BIT}. |
3860 | ||
3861 | @item TARGET_DOUBLE_COMPLEX_BIT | |
56caf160 | 3862 | @findex TARGET_DOUBLE_COMPLEX_BIT |
c906108c SS |
3863 | Number of bits in a double complex; defaults to @code{2 * TARGET_DOUBLE_BIT}. |
3864 | ||
ac9a91a7 JM |
3865 | At present this macro is not used. |
3866 | ||
c906108c | 3867 | @item TARGET_FLOAT_BIT |
56caf160 | 3868 | @findex TARGET_FLOAT_BIT |
c906108c SS |
3869 | Number of bits in a float; defaults to @code{4 * TARGET_CHAR_BIT}. |
3870 | ||
3871 | @item TARGET_INT_BIT | |
56caf160 | 3872 | @findex TARGET_INT_BIT |
c906108c SS |
3873 | Number of bits in an integer; defaults to @code{4 * TARGET_CHAR_BIT}. |
3874 | ||
3875 | @item TARGET_LONG_BIT | |
56caf160 | 3876 | @findex TARGET_LONG_BIT |
c906108c SS |
3877 | Number of bits in a long integer; defaults to @code{4 * TARGET_CHAR_BIT}. |
3878 | ||
3879 | @item TARGET_LONG_DOUBLE_BIT | |
56caf160 | 3880 | @findex TARGET_LONG_DOUBLE_BIT |
c906108c SS |
3881 | Number of bits in a long double float; |
3882 | defaults to @code{2 * TARGET_DOUBLE_BIT}. | |
3883 | ||
3884 | @item TARGET_LONG_LONG_BIT | |
56caf160 | 3885 | @findex TARGET_LONG_LONG_BIT |
c906108c SS |
3886 | Number of bits in a long long integer; defaults to @code{2 * TARGET_LONG_BIT}. |
3887 | ||
3888 | @item TARGET_PTR_BIT | |
56caf160 | 3889 | @findex TARGET_PTR_BIT |
c906108c SS |
3890 | Number of bits in a pointer; defaults to @code{TARGET_INT_BIT}. |
3891 | ||
3892 | @item TARGET_SHORT_BIT | |
56caf160 | 3893 | @findex TARGET_SHORT_BIT |
c906108c SS |
3894 | Number of bits in a short integer; defaults to @code{2 * TARGET_CHAR_BIT}. |
3895 | ||
3896 | @item TARGET_READ_PC | |
56caf160 EZ |
3897 | @findex TARGET_READ_PC |
3898 | @itemx TARGET_WRITE_PC (@var{val}, @var{pid}) | |
3899 | @findex TARGET_WRITE_PC | |
3900 | @itemx TARGET_READ_SP | |
3901 | @findex TARGET_READ_SP | |
56caf160 EZ |
3902 | @itemx TARGET_READ_FP |
3903 | @findex TARGET_READ_FP | |
56caf160 EZ |
3904 | @findex read_pc |
3905 | @findex write_pc | |
3906 | @findex read_sp | |
56caf160 | 3907 | @findex read_fp |
a9e5fdc2 AC |
3908 | @anchor{TARGET_READ_SP} These change the behavior of @code{read_pc}, |
3909 | @code{write_pc}, @code{read_sp} and @code{deprecated_read_fp}. For most | |
3910 | targets, these may be left undefined. @value{GDBN} will call the read | |
3911 | and write register functions with the relevant @code{_REGNUM} argument. | |
c906108c SS |
3912 | |
3913 | These macros are useful when a target keeps one of these registers in a | |
3914 | hard to get at place; for example, part in a segment register and part | |
3915 | in an ordinary register. | |
3916 | ||
a9e5fdc2 AC |
3917 | @xref{unwind_sp}, which replaces @code{TARGET_READ_SP}. |
3918 | ||
56caf160 EZ |
3919 | @item TARGET_VIRTUAL_FRAME_POINTER(@var{pc}, @var{regp}, @var{offsetp}) |
3920 | @findex TARGET_VIRTUAL_FRAME_POINTER | |
0ba6dca9 AC |
3921 | Returns a @code{(register, offset)} pair representing the virtual frame |
3922 | pointer in use at the code address @var{pc}. If virtual frame pointers | |
3923 | are not used, a default definition simply returns | |
3924 | @code{DEPRECATED_FP_REGNUM}, with an offset of zero. | |
c906108c | 3925 | |
9742079a EZ |
3926 | @item TARGET_HAS_HARDWARE_WATCHPOINTS |
3927 | If non-zero, the target has support for hardware-assisted | |
3928 | watchpoints. @xref{Algorithms, watchpoints}, for more details and | |
3929 | other related macros. | |
3930 | ||
7ccaa899 EZ |
3931 | @item TARGET_PRINT_INSN (@var{addr}, @var{info}) |
3932 | @findex TARGET_PRINT_INSN | |
3933 | This is the function used by @value{GDBN} to print an assembly | |
3934 | instruction. It prints the instruction at address @var{addr} in | |
3935 | debugged memory and returns the length of the instruction, in bytes. If | |
3936 | a target doesn't define its own printing routine, it defaults to an | |
d7a27068 AC |
3937 | accessor function for the global pointer |
3938 | @code{deprecated_tm_print_insn}. This usually points to a function in | |
3939 | the @code{opcodes} library (@pxref{Support Libraries, ,Opcodes}). | |
3940 | @var{info} is a structure (of type @code{disassemble_info}) defined in | |
3941 | @file{include/dis-asm.h} used to pass information to the instruction | |
3942 | decoding routine. | |
7ccaa899 | 3943 | |
6314f104 AC |
3944 | @item struct frame_id unwind_dummy_id (struct frame_info *@var{frame}) |
3945 | @findex unwind_dummy_id | |
3946 | @anchor{unwind_dummy_id} Given @var{frame} return a @code{struct | |
3947 | frame_id} that uniquely identifies an inferior function call's dummy | |
b24da7d0 AC |
3948 | frame. The value returned must match the dummy frame stack value |
3949 | previously saved using @code{SAVE_DUMMY_FRAME_TOS}. | |
3950 | @xref{SAVE_DUMMY_FRAME_TOS}. | |
6314f104 | 3951 | |
56caf160 EZ |
3952 | @item USE_STRUCT_CONVENTION (@var{gcc_p}, @var{type}) |
3953 | @findex USE_STRUCT_CONVENTION | |
c906108c SS |
3954 | If defined, this must be an expression that is nonzero if a value of the |
3955 | given @var{type} being returned from a function must have space | |
3956 | allocated for it on the stack. @var{gcc_p} is true if the function | |
3957 | being considered is known to have been compiled by GCC; this is helpful | |
3958 | for systems where GCC is known to use different calling convention than | |
3959 | other compilers. | |
3960 | ||
13d01224 AC |
3961 | @item VALUE_TO_REGISTER(@var{type}, @var{regnum}, @var{from}, @var{to}) |
3962 | @findex VALUE_TO_REGISTER | |
3963 | Convert a value of type @var{type} into the raw contents of register | |
3964 | @var{regnum}'s. | |
3965 | @xref{Target Architecture Definition, , Using Different Register and Memory Data Representations}. | |
3966 | ||
56caf160 EZ |
3967 | @item VARIABLES_INSIDE_BLOCK (@var{desc}, @var{gcc_p}) |
3968 | @findex VARIABLES_INSIDE_BLOCK | |
c906108c SS |
3969 | For dbx-style debugging information, if the compiler puts variable |
3970 | declarations inside LBRAC/RBRAC blocks, this should be defined to be | |
3971 | nonzero. @var{desc} is the value of @code{n_desc} from the | |
25822942 | 3972 | @code{N_RBRAC} symbol, and @var{gcc_p} is true if @value{GDBN} has noticed the |
c906108c SS |
3973 | presence of either the @code{GCC_COMPILED_SYMBOL} or the |
3974 | @code{GCC2_COMPILED_SYMBOL}. By default, this is 0. | |
3975 | ||
56caf160 EZ |
3976 | @item OS9K_VARIABLES_INSIDE_BLOCK (@var{desc}, @var{gcc_p}) |
3977 | @findex OS9K_VARIABLES_INSIDE_BLOCK | |
c906108c | 3978 | Similarly, for OS/9000. Defaults to 1. |
c906108c SS |
3979 | @end table |
3980 | ||
3981 | Motorola M68K target conditionals. | |
3982 | ||
56caf160 | 3983 | @ftable @code |
c906108c SS |
3984 | @item BPT_VECTOR |
3985 | Define this to be the 4-bit location of the breakpoint trap vector. If | |
3986 | not defined, it will default to @code{0xf}. | |
3987 | ||
3988 | @item REMOTE_BPT_VECTOR | |
3989 | Defaults to @code{1}. | |
a23a7bf1 JB |
3990 | |
3991 | @item NAME_OF_MALLOC | |
3992 | @findex NAME_OF_MALLOC | |
3993 | A string containing the name of the function to call in order to | |
3994 | allocate some memory in the inferior. The default value is "malloc". | |
3995 | ||
56caf160 | 3996 | @end ftable |
c906108c SS |
3997 | |
3998 | @section Adding a New Target | |
3999 | ||
56caf160 | 4000 | @cindex adding a target |
af6c57ea | 4001 | The following files add a target to @value{GDBN}: |
c906108c SS |
4002 | |
4003 | @table @file | |
56caf160 | 4004 | @vindex TDEPFILES |
c906108c SS |
4005 | @item gdb/config/@var{arch}/@var{ttt}.mt |
4006 | Contains a Makefile fragment specific to this target. Specifies what | |
4007 | object files are needed for target @var{ttt}, by defining | |
104c1213 JM |
4008 | @samp{TDEPFILES=@dots{}} and @samp{TDEPLIBS=@dots{}}. Also specifies |
4009 | the header file which describes @var{ttt}, by defining @samp{TM_FILE= | |
4010 | tm-@var{ttt}.h}. | |
4011 | ||
4012 | You can also define @samp{TM_CFLAGS}, @samp{TM_CLIBS}, @samp{TM_CDEPS}, | |
4013 | but these are now deprecated, replaced by autoconf, and may go away in | |
25822942 | 4014 | future versions of @value{GDBN}. |
c906108c | 4015 | |
c906108c SS |
4016 | @item gdb/@var{ttt}-tdep.c |
4017 | Contains any miscellaneous code required for this target machine. On | |
4018 | some machines it doesn't exist at all. Sometimes the macros in | |
4019 | @file{tm-@var{ttt}.h} become very complicated, so they are implemented | |
4020 | as functions here instead, and the macro is simply defined to call the | |
4021 | function. This is vastly preferable, since it is easier to understand | |
4022 | and debug. | |
4023 | ||
af6c57ea AC |
4024 | @item gdb/@var{arch}-tdep.c |
4025 | @itemx gdb/@var{arch}-tdep.h | |
4026 | This often exists to describe the basic layout of the target machine's | |
4027 | processor chip (registers, stack, etc.). If used, it is included by | |
4028 | @file{@var{ttt}-tdep.h}. It can be shared among many targets that use | |
4029 | the same processor. | |
4030 | ||
4031 | @item gdb/config/@var{arch}/tm-@var{ttt}.h | |
4032 | (@file{tm.h} is a link to this file, created by @code{configure}). Contains | |
4033 | macro definitions about the target machine's registers, stack frame | |
4034 | format and instructions. | |
4035 | ||
4036 | New targets do not need this file and should not create it. | |
4037 | ||
c906108c SS |
4038 | @item gdb/config/@var{arch}/tm-@var{arch}.h |
4039 | This often exists to describe the basic layout of the target machine's | |
56caf160 | 4040 | processor chip (registers, stack, etc.). If used, it is included by |
c906108c SS |
4041 | @file{tm-@var{ttt}.h}. It can be shared among many targets that use the |
4042 | same processor. | |
4043 | ||
af6c57ea AC |
4044 | New targets do not need this file and should not create it. |
4045 | ||
c906108c SS |
4046 | @end table |
4047 | ||
4048 | If you are adding a new operating system for an existing CPU chip, add a | |
4049 | @file{config/tm-@var{os}.h} file that describes the operating system | |
4050 | facilities that are unusual (extra symbol table info; the breakpoint | |
56caf160 | 4051 | instruction needed; etc.). Then write a @file{@var{arch}/tm-@var{os}.h} |
c906108c SS |
4052 | that just @code{#include}s @file{tm-@var{arch}.h} and |
4053 | @file{config/tm-@var{os}.h}. | |
4054 | ||
4055 | ||
3352e23e AC |
4056 | @section Converting an existing Target Architecture to Multi-arch |
4057 | @cindex converting targets to multi-arch | |
4058 | ||
4059 | This section describes the current accepted best practice for converting | |
4060 | an existing target architecture to the multi-arch framework. | |
4061 | ||
4062 | The process consists of generating, testing, posting and committing a | |
4063 | sequence of patches. Each patch must contain a single change, for | |
4064 | instance: | |
4065 | ||
4066 | @itemize @bullet | |
4067 | ||
4068 | @item | |
4069 | Directly convert a group of functions into macros (the conversion does | |
4070 | not change the behavior of any of the functions). | |
4071 | ||
4072 | @item | |
4073 | Replace a non-multi-arch with a multi-arch mechanism (e.g., | |
4074 | @code{FRAME_INFO}). | |
4075 | ||
4076 | @item | |
4077 | Enable multi-arch level one. | |
4078 | ||
4079 | @item | |
4080 | Delete one or more files. | |
4081 | ||
4082 | @end itemize | |
4083 | ||
4084 | @noindent | |
4085 | There isn't a size limit on a patch, however, a developer is strongly | |
4086 | encouraged to keep the patch size down. | |
4087 | ||
4088 | Since each patch is well defined, and since each change has been tested | |
4089 | and shows no regressions, the patches are considered @emph{fairly} | |
4090 | obvious. Such patches, when submitted by developers listed in the | |
4091 | @file{MAINTAINERS} file, do not need approval. Occasional steps in the | |
4092 | process may be more complicated and less clear. The developer is | |
4093 | expected to use their judgment and is encouraged to seek advice as | |
4094 | needed. | |
4095 | ||
4096 | @subsection Preparation | |
4097 | ||
4098 | The first step is to establish control. Build (with @option{-Werror} | |
4099 | enabled) and test the target so that there is a baseline against which | |
4100 | the debugger can be compared. | |
4101 | ||
4102 | At no stage can the test results regress or @value{GDBN} stop compiling | |
4103 | with @option{-Werror}. | |
4104 | ||
4105 | @subsection Add the multi-arch initialization code | |
4106 | ||
4107 | The objective of this step is to establish the basic multi-arch | |
4108 | framework. It involves | |
4109 | ||
4110 | @itemize @bullet | |
4111 | ||
4112 | @item | |
4113 | The addition of a @code{@var{arch}_gdbarch_init} function@footnote{The | |
4114 | above is from the original example and uses K&R C. @value{GDBN} | |
4115 | has since converted to ISO C but lets ignore that.} that creates | |
4116 | the architecture: | |
4117 | @smallexample | |
4118 | static struct gdbarch * | |
4119 | d10v_gdbarch_init (info, arches) | |
4120 | struct gdbarch_info info; | |
4121 | struct gdbarch_list *arches; | |
4122 | @{ | |
4123 | struct gdbarch *gdbarch; | |
4124 | /* there is only one d10v architecture */ | |
4125 | if (arches != NULL) | |
4126 | return arches->gdbarch; | |
4127 | gdbarch = gdbarch_alloc (&info, NULL); | |
4128 | return gdbarch; | |
4129 | @} | |
4130 | @end smallexample | |
4131 | @noindent | |
4132 | @emph{} | |
4133 | ||
4134 | @item | |
4135 | A per-architecture dump function to print any architecture specific | |
4136 | information: | |
4137 | @smallexample | |
4138 | static void | |
4139 | mips_dump_tdep (struct gdbarch *current_gdbarch, | |
4140 | struct ui_file *file) | |
4141 | @{ | |
4142 | @dots{} code to print architecture specific info @dots{} | |
4143 | @} | |
4144 | @end smallexample | |
4145 | ||
4146 | @item | |
4147 | A change to @code{_initialize_@var{arch}_tdep} to register this new | |
4148 | architecture: | |
4149 | @smallexample | |
4150 | void | |
4151 | _initialize_mips_tdep (void) | |
4152 | @{ | |
4153 | gdbarch_register (bfd_arch_mips, mips_gdbarch_init, | |
4154 | mips_dump_tdep); | |
4155 | @end smallexample | |
4156 | ||
4157 | @item | |
4158 | Add the macro @code{GDB_MULTI_ARCH}, defined as 0 (zero), to the file@* | |
4159 | @file{config/@var{arch}/tm-@var{arch}.h}. | |
4160 | ||
4161 | @end itemize | |
4162 | ||
4163 | @subsection Update multi-arch incompatible mechanisms | |
4164 | ||
4165 | Some mechanisms do not work with multi-arch. They include: | |
4166 | ||
4167 | @table @code | |
3352e23e | 4168 | @item FRAME_FIND_SAVED_REGS |
f30ee0bc | 4169 | Replaced with @code{DEPRECATED_FRAME_INIT_SAVED_REGS} |
3352e23e AC |
4170 | @end table |
4171 | ||
4172 | @noindent | |
4173 | At this stage you could also consider converting the macros into | |
4174 | functions. | |
4175 | ||
4176 | @subsection Prepare for multi-arch level to one | |
4177 | ||
4178 | Temporally set @code{GDB_MULTI_ARCH} to @code{GDB_MULTI_ARCH_PARTIAL} | |
4179 | and then build and start @value{GDBN} (the change should not be | |
4180 | committed). @value{GDBN} may not build, and once built, it may die with | |
4181 | an internal error listing the architecture methods that must be | |
4182 | provided. | |
4183 | ||
4184 | Fix any build problems (patch(es)). | |
4185 | ||
4186 | Convert all the architecture methods listed, which are only macros, into | |
4187 | functions (patch(es)). | |
4188 | ||
4189 | Update @code{@var{arch}_gdbarch_init} to set all the missing | |
4190 | architecture methods and wrap the corresponding macros in @code{#if | |
4191 | !GDB_MULTI_ARCH} (patch(es)). | |
4192 | ||
4193 | @subsection Set multi-arch level one | |
4194 | ||
4195 | Change the value of @code{GDB_MULTI_ARCH} to GDB_MULTI_ARCH_PARTIAL (a | |
4196 | single patch). | |
4197 | ||
4198 | Any problems with throwing ``the switch'' should have been fixed | |
4199 | already. | |
4200 | ||
4201 | @subsection Convert remaining macros | |
4202 | ||
4203 | Suggest converting macros into functions (and setting the corresponding | |
4204 | architecture method) in small batches. | |
4205 | ||
4206 | @subsection Set multi-arch level to two | |
4207 | ||
4208 | This should go smoothly. | |
4209 | ||
4210 | @subsection Delete the TM file | |
4211 | ||
4212 | The @file{tm-@var{arch}.h} can be deleted. @file{@var{arch}.mt} and | |
4213 | @file{configure.in} updated. | |
4214 | ||
4215 | ||
c906108c SS |
4216 | @node Target Vector Definition |
4217 | ||
4218 | @chapter Target Vector Definition | |
56caf160 | 4219 | @cindex target vector |
c906108c | 4220 | |
56caf160 EZ |
4221 | The target vector defines the interface between @value{GDBN}'s |
4222 | abstract handling of target systems, and the nitty-gritty code that | |
4223 | actually exercises control over a process or a serial port. | |
4224 | @value{GDBN} includes some 30-40 different target vectors; however, | |
4225 | each configuration of @value{GDBN} includes only a few of them. | |
c906108c SS |
4226 | |
4227 | @section File Targets | |
4228 | ||
4229 | Both executables and core files have target vectors. | |
4230 | ||
4231 | @section Standard Protocol and Remote Stubs | |
4232 | ||
56caf160 EZ |
4233 | @value{GDBN}'s file @file{remote.c} talks a serial protocol to code |
4234 | that runs in the target system. @value{GDBN} provides several sample | |
4235 | @dfn{stubs} that can be integrated into target programs or operating | |
4236 | systems for this purpose; they are named @file{*-stub.c}. | |
c906108c | 4237 | |
56caf160 EZ |
4238 | The @value{GDBN} user's manual describes how to put such a stub into |
4239 | your target code. What follows is a discussion of integrating the | |
4240 | SPARC stub into a complicated operating system (rather than a simple | |
4241 | program), by Stu Grossman, the author of this stub. | |
c906108c SS |
4242 | |
4243 | The trap handling code in the stub assumes the following upon entry to | |
56caf160 | 4244 | @code{trap_low}: |
c906108c SS |
4245 | |
4246 | @enumerate | |
56caf160 EZ |
4247 | @item |
4248 | %l1 and %l2 contain pc and npc respectively at the time of the trap; | |
c906108c | 4249 | |
56caf160 EZ |
4250 | @item |
4251 | traps are disabled; | |
c906108c | 4252 | |
56caf160 EZ |
4253 | @item |
4254 | you are in the correct trap window. | |
c906108c SS |
4255 | @end enumerate |
4256 | ||
4257 | As long as your trap handler can guarantee those conditions, then there | |
56caf160 | 4258 | is no reason why you shouldn't be able to ``share'' traps with the stub. |
c906108c SS |
4259 | The stub has no requirement that it be jumped to directly from the |
4260 | hardware trap vector. That is why it calls @code{exceptionHandler()}, | |
4261 | which is provided by the external environment. For instance, this could | |
56caf160 | 4262 | set up the hardware traps to actually execute code which calls the stub |
c906108c SS |
4263 | first, and then transfers to its own trap handler. |
4264 | ||
4265 | For the most point, there probably won't be much of an issue with | |
56caf160 | 4266 | ``sharing'' traps, as the traps we use are usually not used by the kernel, |
c906108c SS |
4267 | and often indicate unrecoverable error conditions. Anyway, this is all |
4268 | controlled by a table, and is trivial to modify. The most important | |
4269 | trap for us is for @code{ta 1}. Without that, we can't single step or | |
4270 | do breakpoints. Everything else is unnecessary for the proper operation | |
4271 | of the debugger/stub. | |
4272 | ||
4273 | From reading the stub, it's probably not obvious how breakpoints work. | |
25822942 | 4274 | They are simply done by deposit/examine operations from @value{GDBN}. |
c906108c SS |
4275 | |
4276 | @section ROM Monitor Interface | |
4277 | ||
4278 | @section Custom Protocols | |
4279 | ||
4280 | @section Transport Layer | |
4281 | ||
4282 | @section Builtin Simulator | |
4283 | ||
4284 | ||
4285 | @node Native Debugging | |
4286 | ||
4287 | @chapter Native Debugging | |
56caf160 | 4288 | @cindex native debugging |
c906108c | 4289 | |
25822942 | 4290 | Several files control @value{GDBN}'s configuration for native support: |
c906108c SS |
4291 | |
4292 | @table @file | |
56caf160 | 4293 | @vindex NATDEPFILES |
c906108c | 4294 | @item gdb/config/@var{arch}/@var{xyz}.mh |
7fd60527 | 4295 | Specifies Makefile fragments needed by a @emph{native} configuration on |
c906108c SS |
4296 | machine @var{xyz}. In particular, this lists the required |
4297 | native-dependent object files, by defining @samp{NATDEPFILES=@dots{}}. | |
4298 | Also specifies the header file which describes native support on | |
4299 | @var{xyz}, by defining @samp{NAT_FILE= nm-@var{xyz}.h}. You can also | |
4300 | define @samp{NAT_CFLAGS}, @samp{NAT_ADD_FILES}, @samp{NAT_CLIBS}, | |
4301 | @samp{NAT_CDEPS}, etc.; see @file{Makefile.in}. | |
4302 | ||
7fd60527 AC |
4303 | @emph{Maintainer's note: The @file{.mh} suffix is because this file |
4304 | originally contained @file{Makefile} fragments for hosting @value{GDBN} | |
4305 | on machine @var{xyz}. While the file is no longer used for this | |
937f164b | 4306 | purpose, the @file{.mh} suffix remains. Perhaps someone will |
7fd60527 AC |
4307 | eventually rename these fragments so that they have a @file{.mn} |
4308 | suffix.} | |
4309 | ||
c906108c | 4310 | @item gdb/config/@var{arch}/nm-@var{xyz}.h |
56caf160 | 4311 | (@file{nm.h} is a link to this file, created by @code{configure}). Contains C |
c906108c SS |
4312 | macro definitions describing the native system environment, such as |
4313 | child process control and core file support. | |
4314 | ||
4315 | @item gdb/@var{xyz}-nat.c | |
4316 | Contains any miscellaneous C code required for this native support of | |
4317 | this machine. On some machines it doesn't exist at all. | |
c906108c SS |
4318 | @end table |
4319 | ||
4320 | There are some ``generic'' versions of routines that can be used by | |
4321 | various systems. These can be customized in various ways by macros | |
4322 | defined in your @file{nm-@var{xyz}.h} file. If these routines work for | |
4323 | the @var{xyz} host, you can just include the generic file's name (with | |
4324 | @samp{.o}, not @samp{.c}) in @code{NATDEPFILES}. | |
4325 | ||
4326 | Otherwise, if your machine needs custom support routines, you will need | |
4327 | to write routines that perform the same functions as the generic file. | |
56caf160 | 4328 | Put them into @file{@var{xyz}-nat.c}, and put @file{@var{xyz}-nat.o} |
c906108c SS |
4329 | into @code{NATDEPFILES}. |
4330 | ||
4331 | @table @file | |
c906108c SS |
4332 | @item inftarg.c |
4333 | This contains the @emph{target_ops vector} that supports Unix child | |
4334 | processes on systems which use ptrace and wait to control the child. | |
4335 | ||
4336 | @item procfs.c | |
4337 | This contains the @emph{target_ops vector} that supports Unix child | |
4338 | processes on systems which use /proc to control the child. | |
4339 | ||
4340 | @item fork-child.c | |
56caf160 EZ |
4341 | This does the low-level grunge that uses Unix system calls to do a ``fork |
4342 | and exec'' to start up a child process. | |
c906108c SS |
4343 | |
4344 | @item infptrace.c | |
4345 | This is the low level interface to inferior processes for systems using | |
4346 | the Unix @code{ptrace} call in a vanilla way. | |
c906108c SS |
4347 | @end table |
4348 | ||
4349 | @section Native core file Support | |
56caf160 | 4350 | @cindex native core files |
c906108c SS |
4351 | |
4352 | @table @file | |
56caf160 | 4353 | @findex fetch_core_registers |
c906108c SS |
4354 | @item core-aout.c::fetch_core_registers() |
4355 | Support for reading registers out of a core file. This routine calls | |
4356 | @code{register_addr()}, see below. Now that BFD is used to read core | |
4357 | files, virtually all machines should use @code{core-aout.c}, and should | |
4358 | just provide @code{fetch_core_registers} in @code{@var{xyz}-nat.c} (or | |
4359 | @code{REGISTER_U_ADDR} in @code{nm-@var{xyz}.h}). | |
4360 | ||
4361 | @item core-aout.c::register_addr() | |
4362 | If your @code{nm-@var{xyz}.h} file defines the macro | |
4363 | @code{REGISTER_U_ADDR(addr, blockend, regno)}, it should be defined to | |
25822942 | 4364 | set @code{addr} to the offset within the @samp{user} struct of @value{GDBN} |
c906108c SS |
4365 | register number @code{regno}. @code{blockend} is the offset within the |
4366 | ``upage'' of @code{u.u_ar0}. If @code{REGISTER_U_ADDR} is defined, | |
4367 | @file{core-aout.c} will define the @code{register_addr()} function and | |
4368 | use the macro in it. If you do not define @code{REGISTER_U_ADDR}, but | |
4369 | you are using the standard @code{fetch_core_registers()}, you will need | |
4370 | to define your own version of @code{register_addr()}, put it into your | |
4371 | @code{@var{xyz}-nat.c} file, and be sure @code{@var{xyz}-nat.o} is in | |
4372 | the @code{NATDEPFILES} list. If you have your own | |
4373 | @code{fetch_core_registers()}, you may not need a separate | |
4374 | @code{register_addr()}. Many custom @code{fetch_core_registers()} | |
4375 | implementations simply locate the registers themselves.@refill | |
c906108c SS |
4376 | @end table |
4377 | ||
25822942 | 4378 | When making @value{GDBN} run native on a new operating system, to make it |
c906108c SS |
4379 | possible to debug core files, you will need to either write specific |
4380 | code for parsing your OS's core files, or customize | |
4381 | @file{bfd/trad-core.c}. First, use whatever @code{#include} files your | |
4382 | machine uses to define the struct of registers that is accessible | |
4383 | (possibly in the u-area) in a core file (rather than | |
4384 | @file{machine/reg.h}), and an include file that defines whatever header | |
56caf160 EZ |
4385 | exists on a core file (e.g. the u-area or a @code{struct core}). Then |
4386 | modify @code{trad_unix_core_file_p} to use these values to set up the | |
c906108c SS |
4387 | section information for the data segment, stack segment, any other |
4388 | segments in the core file (perhaps shared library contents or control | |
4389 | information), ``registers'' segment, and if there are two discontiguous | |
4390 | sets of registers (e.g. integer and float), the ``reg2'' segment. This | |
4391 | section information basically delimits areas in the core file in a | |
4392 | standard way, which the section-reading routines in BFD know how to seek | |
4393 | around in. | |
4394 | ||
25822942 | 4395 | Then back in @value{GDBN}, you need a matching routine called |
56caf160 | 4396 | @code{fetch_core_registers}. If you can use the generic one, it's in |
c906108c SS |
4397 | @file{core-aout.c}; if not, it's in your @file{@var{xyz}-nat.c} file. |
4398 | It will be passed a char pointer to the entire ``registers'' segment, | |
4399 | its length, and a zero; or a char pointer to the entire ``regs2'' | |
4400 | segment, its length, and a 2. The routine should suck out the supplied | |
25822942 | 4401 | register values and install them into @value{GDBN}'s ``registers'' array. |
c906108c SS |
4402 | |
4403 | If your system uses @file{/proc} to control processes, and uses ELF | |
4404 | format core files, then you may be able to use the same routines for | |
4405 | reading the registers out of processes and out of core files. | |
4406 | ||
4407 | @section ptrace | |
4408 | ||
4409 | @section /proc | |
4410 | ||
4411 | @section win32 | |
4412 | ||
4413 | @section shared libraries | |
4414 | ||
4415 | @section Native Conditionals | |
56caf160 | 4416 | @cindex native conditionals |
c906108c | 4417 | |
56caf160 EZ |
4418 | When @value{GDBN} is configured and compiled, various macros are |
4419 | defined or left undefined, to control compilation when the host and | |
4420 | target systems are the same. These macros should be defined (or left | |
4421 | undefined) in @file{nm-@var{system}.h}. | |
c906108c SS |
4422 | |
4423 | @table @code | |
c906108c | 4424 | @item ATTACH_DETACH |
56caf160 | 4425 | @findex ATTACH_DETACH |
25822942 | 4426 | If defined, then @value{GDBN} will include support for the @code{attach} and |
c906108c SS |
4427 | @code{detach} commands. |
4428 | ||
4429 | @item CHILD_PREPARE_TO_STORE | |
56caf160 | 4430 | @findex CHILD_PREPARE_TO_STORE |
c906108c SS |
4431 | If the machine stores all registers at once in the child process, then |
4432 | define this to ensure that all values are correct. This usually entails | |
4433 | a read from the child. | |
4434 | ||
4435 | [Note that this is incorrectly defined in @file{xm-@var{system}.h} files | |
4436 | currently.] | |
4437 | ||
4438 | @item FETCH_INFERIOR_REGISTERS | |
56caf160 | 4439 | @findex FETCH_INFERIOR_REGISTERS |
c906108c SS |
4440 | Define this if the native-dependent code will provide its own routines |
4441 | @code{fetch_inferior_registers} and @code{store_inferior_registers} in | |
56caf160 | 4442 | @file{@var{host}-nat.c}. If this symbol is @emph{not} defined, and |
c906108c SS |
4443 | @file{infptrace.c} is included in this configuration, the default |
4444 | routines in @file{infptrace.c} are used for these functions. | |
4445 | ||
4446 | @item FILES_INFO_HOOK | |
56caf160 | 4447 | @findex FILES_INFO_HOOK |
c906108c SS |
4448 | (Only defined for Convex.) |
4449 | ||
4450 | @item FP0_REGNUM | |
56caf160 | 4451 | @findex FP0_REGNUM |
c906108c SS |
4452 | This macro is normally defined to be the number of the first floating |
4453 | point register, if the machine has such registers. As such, it would | |
56caf160 | 4454 | appear only in target-specific code. However, @file{/proc} support uses this |
c906108c SS |
4455 | to decide whether floats are in use on this target. |
4456 | ||
4457 | @item GET_LONGJMP_TARGET | |
56caf160 | 4458 | @findex GET_LONGJMP_TARGET |
c906108c SS |
4459 | For most machines, this is a target-dependent parameter. On the |
4460 | DECstation and the Iris, this is a native-dependent parameter, since | |
56caf160 | 4461 | @file{setjmp.h} is needed to define it. |
c906108c | 4462 | |
56caf160 | 4463 | This macro determines the target PC address that @code{longjmp} will jump to, |
c906108c | 4464 | assuming that we have just stopped at a longjmp breakpoint. It takes a |
56caf160 | 4465 | @code{CORE_ADDR *} as argument, and stores the target PC value through this |
c906108c SS |
4466 | pointer. It examines the current state of the machine as needed. |
4467 | ||
9742079a EZ |
4468 | @item I386_USE_GENERIC_WATCHPOINTS |
4469 | An x86-based machine can define this to use the generic x86 watchpoint | |
4470 | support; see @ref{Algorithms, I386_USE_GENERIC_WATCHPOINTS}. | |
4471 | ||
c906108c | 4472 | @item KERNEL_U_ADDR |
56caf160 | 4473 | @findex KERNEL_U_ADDR |
c906108c | 4474 | Define this to the address of the @code{u} structure (the ``user |
25822942 | 4475 | struct'', also known as the ``u-page'') in kernel virtual memory. @value{GDBN} |
c906108c SS |
4476 | needs to know this so that it can subtract this address from absolute |
4477 | addresses in the upage, that are obtained via ptrace or from core files. | |
4478 | On systems that don't need this value, set it to zero. | |
4479 | ||
4480 | @item KERNEL_U_ADDR_BSD | |
56caf160 | 4481 | @findex KERNEL_U_ADDR_BSD |
25822942 | 4482 | Define this to cause @value{GDBN} to determine the address of @code{u} at |
c906108c SS |
4483 | runtime, by using Berkeley-style @code{nlist} on the kernel's image in |
4484 | the root directory. | |
4485 | ||
4486 | @item KERNEL_U_ADDR_HPUX | |
56caf160 | 4487 | @findex KERNEL_U_ADDR_HPUX |
25822942 | 4488 | Define this to cause @value{GDBN} to determine the address of @code{u} at |
c906108c SS |
4489 | runtime, by using HP-style @code{nlist} on the kernel's image in the |
4490 | root directory. | |
4491 | ||
4492 | @item ONE_PROCESS_WRITETEXT | |
56caf160 | 4493 | @findex ONE_PROCESS_WRITETEXT |
c906108c SS |
4494 | Define this to be able to, when a breakpoint insertion fails, warn the |
4495 | user that another process may be running with the same executable. | |
4496 | ||
4497 | @item PROC_NAME_FMT | |
56caf160 | 4498 | @findex PROC_NAME_FMT |
c906108c SS |
4499 | Defines the format for the name of a @file{/proc} device. Should be |
4500 | defined in @file{nm.h} @emph{only} in order to override the default | |
4501 | definition in @file{procfs.c}. | |
4502 | ||
4503 | @item PTRACE_FP_BUG | |
56caf160 EZ |
4504 | @findex PTRACE_FP_BUG |
4505 | See @file{mach386-xdep.c}. | |
c906108c SS |
4506 | |
4507 | @item PTRACE_ARG3_TYPE | |
56caf160 | 4508 | @findex PTRACE_ARG3_TYPE |
c906108c SS |
4509 | The type of the third argument to the @code{ptrace} system call, if it |
4510 | exists and is different from @code{int}. | |
4511 | ||
4512 | @item REGISTER_U_ADDR | |
56caf160 | 4513 | @findex REGISTER_U_ADDR |
c906108c SS |
4514 | Defines the offset of the registers in the ``u area''. |
4515 | ||
4516 | @item SHELL_COMMAND_CONCAT | |
56caf160 | 4517 | @findex SHELL_COMMAND_CONCAT |
c906108c SS |
4518 | If defined, is a string to prefix on the shell command used to start the |
4519 | inferior. | |
4520 | ||
4521 | @item SHELL_FILE | |
56caf160 | 4522 | @findex SHELL_FILE |
c906108c SS |
4523 | If defined, this is the name of the shell to use to run the inferior. |
4524 | Defaults to @code{"/bin/sh"}. | |
4525 | ||
990f9fe3 | 4526 | @item SOLIB_ADD (@var{filename}, @var{from_tty}, @var{targ}, @var{readsyms}) |
56caf160 | 4527 | @findex SOLIB_ADD |
c906108c | 4528 | Define this to expand into an expression that will cause the symbols in |
990f9fe3 FF |
4529 | @var{filename} to be added to @value{GDBN}'s symbol table. If |
4530 | @var{readsyms} is zero symbols are not read but any necessary low level | |
4531 | processing for @var{filename} is still done. | |
c906108c SS |
4532 | |
4533 | @item SOLIB_CREATE_INFERIOR_HOOK | |
56caf160 | 4534 | @findex SOLIB_CREATE_INFERIOR_HOOK |
c906108c SS |
4535 | Define this to expand into any shared-library-relocation code that you |
4536 | want to be run just after the child process has been forked. | |
4537 | ||
4538 | @item START_INFERIOR_TRAPS_EXPECTED | |
56caf160 EZ |
4539 | @findex START_INFERIOR_TRAPS_EXPECTED |
4540 | When starting an inferior, @value{GDBN} normally expects to trap | |
4541 | twice; once when | |
c906108c SS |
4542 | the shell execs, and once when the program itself execs. If the actual |
4543 | number of traps is something other than 2, then define this macro to | |
4544 | expand into the number expected. | |
4545 | ||
4546 | @item SVR4_SHARED_LIBS | |
56caf160 | 4547 | @findex SVR4_SHARED_LIBS |
c906108c SS |
4548 | Define this to indicate that SVR4-style shared libraries are in use. |
4549 | ||
4550 | @item USE_PROC_FS | |
56caf160 | 4551 | @findex USE_PROC_FS |
c906108c | 4552 | This determines whether small routines in @file{*-tdep.c}, which |
56caf160 EZ |
4553 | translate register values between @value{GDBN}'s internal |
4554 | representation and the @file{/proc} representation, are compiled. | |
c906108c SS |
4555 | |
4556 | @item U_REGS_OFFSET | |
56caf160 | 4557 | @findex U_REGS_OFFSET |
c906108c SS |
4558 | This is the offset of the registers in the upage. It need only be |
4559 | defined if the generic ptrace register access routines in | |
4560 | @file{infptrace.c} are being used (that is, @file{infptrace.c} is | |
4561 | configured in, and @code{FETCH_INFERIOR_REGISTERS} is not defined). If | |
4562 | the default value from @file{infptrace.c} is good enough, leave it | |
4563 | undefined. | |
4564 | ||
4565 | The default value means that u.u_ar0 @emph{points to} the location of | |
4566 | the registers. I'm guessing that @code{#define U_REGS_OFFSET 0} means | |
56caf160 | 4567 | that @code{u.u_ar0} @emph{is} the location of the registers. |
c906108c SS |
4568 | |
4569 | @item CLEAR_SOLIB | |
56caf160 EZ |
4570 | @findex CLEAR_SOLIB |
4571 | See @file{objfiles.c}. | |
c906108c SS |
4572 | |
4573 | @item DEBUG_PTRACE | |
56caf160 EZ |
4574 | @findex DEBUG_PTRACE |
4575 | Define this to debug @code{ptrace} calls. | |
c906108c SS |
4576 | @end table |
4577 | ||
4578 | ||
4579 | @node Support Libraries | |
4580 | ||
4581 | @chapter Support Libraries | |
4582 | ||
4583 | @section BFD | |
56caf160 | 4584 | @cindex BFD library |
c906108c | 4585 | |
25822942 | 4586 | BFD provides support for @value{GDBN} in several ways: |
c906108c SS |
4587 | |
4588 | @table @emph | |
c906108c SS |
4589 | @item identifying executable and core files |
4590 | BFD will identify a variety of file types, including a.out, coff, and | |
4591 | several variants thereof, as well as several kinds of core files. | |
4592 | ||
4593 | @item access to sections of files | |
4594 | BFD parses the file headers to determine the names, virtual addresses, | |
4595 | sizes, and file locations of all the various named sections in files | |
56caf160 EZ |
4596 | (such as the text section or the data section). @value{GDBN} simply |
4597 | calls BFD to read or write section @var{x} at byte offset @var{y} for | |
4598 | length @var{z}. | |
c906108c SS |
4599 | |
4600 | @item specialized core file support | |
4601 | BFD provides routines to determine the failing command name stored in a | |
4602 | core file, the signal with which the program failed, and whether a core | |
56caf160 | 4603 | file matches (i.e.@: could be a core dump of) a particular executable |
c906108c SS |
4604 | file. |
4605 | ||
4606 | @item locating the symbol information | |
25822942 DB |
4607 | @value{GDBN} uses an internal interface of BFD to determine where to find the |
4608 | symbol information in an executable file or symbol-file. @value{GDBN} itself | |
c906108c | 4609 | handles the reading of symbols, since BFD does not ``understand'' debug |
25822942 | 4610 | symbols, but @value{GDBN} uses BFD's cached information to find the symbols, |
c906108c | 4611 | string table, etc. |
c906108c SS |
4612 | @end table |
4613 | ||
4614 | @section opcodes | |
56caf160 | 4615 | @cindex opcodes library |
c906108c | 4616 | |
25822942 | 4617 | The opcodes library provides @value{GDBN}'s disassembler. (It's a separate |
c906108c SS |
4618 | library because it's also used in binutils, for @file{objdump}). |
4619 | ||
4620 | @section readline | |
4621 | ||
4622 | @section mmalloc | |
4623 | ||
4624 | @section libiberty | |
4625 | ||
4626 | @section gnu-regex | |
56caf160 | 4627 | @cindex regular expressions library |
c906108c SS |
4628 | |
4629 | Regex conditionals. | |
4630 | ||
4631 | @table @code | |
c906108c SS |
4632 | @item C_ALLOCA |
4633 | ||
4634 | @item NFAILURES | |
4635 | ||
4636 | @item RE_NREGS | |
4637 | ||
4638 | @item SIGN_EXTEND_CHAR | |
4639 | ||
4640 | @item SWITCH_ENUM_BUG | |
4641 | ||
4642 | @item SYNTAX_TABLE | |
4643 | ||
4644 | @item Sword | |
4645 | ||
4646 | @item sparc | |
c906108c SS |
4647 | @end table |
4648 | ||
4649 | @section include | |
4650 | ||
4651 | @node Coding | |
4652 | ||
4653 | @chapter Coding | |
4654 | ||
4655 | This chapter covers topics that are lower-level than the major | |
25822942 | 4656 | algorithms of @value{GDBN}. |
c906108c SS |
4657 | |
4658 | @section Cleanups | |
56caf160 | 4659 | @cindex cleanups |
c906108c SS |
4660 | |
4661 | Cleanups are a structured way to deal with things that need to be done | |
cc1cb004 | 4662 | later. |
c906108c | 4663 | |
cc1cb004 AC |
4664 | When your code does something (e.g., @code{xmalloc} some memory, or |
4665 | @code{open} a file) that needs to be undone later (e.g., @code{xfree} | |
4666 | the memory or @code{close} the file), it can make a cleanup. The | |
4667 | cleanup will be done at some future point: when the command is finished | |
4668 | and control returns to the top level; when an error occurs and the stack | |
4669 | is unwound; or when your code decides it's time to explicitly perform | |
4670 | cleanups. Alternatively you can elect to discard the cleanups you | |
4671 | created. | |
c906108c SS |
4672 | |
4673 | Syntax: | |
4674 | ||
4675 | @table @code | |
c906108c SS |
4676 | @item struct cleanup *@var{old_chain}; |
4677 | Declare a variable which will hold a cleanup chain handle. | |
4678 | ||
56caf160 | 4679 | @findex make_cleanup |
c906108c SS |
4680 | @item @var{old_chain} = make_cleanup (@var{function}, @var{arg}); |
4681 | Make a cleanup which will cause @var{function} to be called with | |
4682 | @var{arg} (a @code{char *}) later. The result, @var{old_chain}, is a | |
cc1cb004 AC |
4683 | handle that can later be passed to @code{do_cleanups} or |
4684 | @code{discard_cleanups}. Unless you are going to call | |
4685 | @code{do_cleanups} or @code{discard_cleanups}, you can ignore the result | |
4686 | from @code{make_cleanup}. | |
c906108c | 4687 | |
56caf160 | 4688 | @findex do_cleanups |
c906108c | 4689 | @item do_cleanups (@var{old_chain}); |
cc1cb004 AC |
4690 | Do all cleanups added to the chain since the corresponding |
4691 | @code{make_cleanup} call was made. | |
4692 | ||
4693 | @findex discard_cleanups | |
4694 | @item discard_cleanups (@var{old_chain}); | |
4695 | Same as @code{do_cleanups} except that it just removes the cleanups from | |
4696 | the chain and does not call the specified functions. | |
4697 | @end table | |
4698 | ||
4699 | Cleanups are implemented as a chain. The handle returned by | |
4700 | @code{make_cleanups} includes the cleanup passed to the call and any | |
4701 | later cleanups appended to the chain (but not yet discarded or | |
4702 | performed). E.g.: | |
56caf160 | 4703 | |
474c8240 | 4704 | @smallexample |
c906108c | 4705 | make_cleanup (a, 0); |
cc1cb004 AC |
4706 | @{ |
4707 | struct cleanup *old = make_cleanup (b, 0); | |
4708 | make_cleanup (c, 0) | |
4709 | ... | |
4710 | do_cleanups (old); | |
4711 | @} | |
474c8240 | 4712 | @end smallexample |
56caf160 | 4713 | |
c906108c | 4714 | @noindent |
cc1cb004 AC |
4715 | will call @code{c()} and @code{b()} but will not call @code{a()}. The |
4716 | cleanup that calls @code{a()} will remain in the cleanup chain, and will | |
4717 | be done later unless otherwise discarded.@refill | |
4718 | ||
4719 | Your function should explicitly do or discard the cleanups it creates. | |
4720 | Failing to do this leads to non-deterministic behavior since the caller | |
4721 | will arbitrarily do or discard your functions cleanups. This need leads | |
4722 | to two common cleanup styles. | |
4723 | ||
4724 | The first style is try/finally. Before it exits, your code-block calls | |
4725 | @code{do_cleanups} with the old cleanup chain and thus ensures that your | |
4726 | code-block's cleanups are always performed. For instance, the following | |
4727 | code-segment avoids a memory leak problem (even when @code{error} is | |
4728 | called and a forced stack unwind occurs) by ensuring that the | |
4729 | @code{xfree} will always be called: | |
c906108c | 4730 | |
474c8240 | 4731 | @smallexample |
cc1cb004 AC |
4732 | struct cleanup *old = make_cleanup (null_cleanup, 0); |
4733 | data = xmalloc (sizeof blah); | |
4734 | make_cleanup (xfree, data); | |
4735 | ... blah blah ... | |
4736 | do_cleanups (old); | |
474c8240 | 4737 | @end smallexample |
cc1cb004 AC |
4738 | |
4739 | The second style is try/except. Before it exits, your code-block calls | |
4740 | @code{discard_cleanups} with the old cleanup chain and thus ensures that | |
4741 | any created cleanups are not performed. For instance, the following | |
4742 | code segment, ensures that the file will be closed but only if there is | |
4743 | an error: | |
4744 | ||
474c8240 | 4745 | @smallexample |
cc1cb004 AC |
4746 | FILE *file = fopen ("afile", "r"); |
4747 | struct cleanup *old = make_cleanup (close_file, file); | |
4748 | ... blah blah ... | |
4749 | discard_cleanups (old); | |
4750 | return file; | |
474c8240 | 4751 | @end smallexample |
c906108c SS |
4752 | |
4753 | Some functions, e.g. @code{fputs_filtered()} or @code{error()}, specify | |
4754 | that they ``should not be called when cleanups are not in place''. This | |
4755 | means that any actions you need to reverse in the case of an error or | |
4756 | interruption must be on the cleanup chain before you call these | |
4757 | functions, since they might never return to your code (they | |
4758 | @samp{longjmp} instead). | |
4759 | ||
ba8c9337 AC |
4760 | @section Per-architecture module data |
4761 | @cindex per-architecture module data | |
4762 | @cindex multi-arch data | |
4763 | @cindex data-pointer, per-architecture/per-module | |
4764 | ||
4765 | The multi-arch framework includes a mechanism for adding module specific | |
4766 | per-architecture data-pointers to the @code{struct gdbarch} architecture | |
4767 | object. | |
4768 | ||
4769 | A module registers one or more per-architecture data-pointers using the | |
4770 | function @code{register_gdbarch_data}: | |
4771 | ||
4772 | @deftypefun struct gdbarch_data *register_gdbarch_data (gdbarch_data_init_ftype *@var{init}, gdbarch_data_free_ftype *@var{free}) | |
4773 | ||
4774 | The @var{init} function is used to obtain an initial value for a | |
4775 | per-architecture data-pointer. The function is called, after the | |
4776 | architecture has been created, when the data-pointer is still | |
4777 | uninitialized (@code{NULL}) and its value has been requested via a call | |
4778 | to @code{gdbarch_data}. A data-pointer can also be initialize | |
4779 | explicitly using @code{set_gdbarch_data}. | |
4780 | ||
4781 | The @var{free} function is called when a data-pointer needs to be | |
4782 | destroyed. This occurs when either the corresponding @code{struct | |
4783 | gdbarch} object is being destroyed or when @code{set_gdbarch_data} is | |
4784 | overriding a non-@code{NULL} data-pointer value. | |
4785 | ||
4786 | The function @code{register_gdbarch_data} returns a @code{struct | |
4787 | gdbarch_data} that is used to identify the data-pointer that was added | |
4788 | to the module. | |
4789 | ||
4790 | @end deftypefun | |
4791 | ||
4792 | A typical module has @code{init} and @code{free} functions of the form: | |
4793 | ||
4794 | @smallexample | |
4795 | static struct gdbarch_data *nozel_handle; | |
4796 | static void * | |
4797 | nozel_init (struct gdbarch *gdbarch) | |
4798 | @{ | |
4799 | struct nozel *data = XMALLOC (struct nozel); | |
4800 | @dots{} | |
4801 | return data; | |
4802 | @} | |
4803 | @dots{} | |
4804 | static void | |
4805 | nozel_free (struct gdbarch *gdbarch, void *data) | |
4806 | @{ | |
4807 | xfree (data); | |
4808 | @} | |
4809 | @end smallexample | |
4810 | ||
4811 | Since uninitialized (@code{NULL}) data-pointers are initialized | |
4812 | on-demand, an @code{init} function is free to call other modules that | |
4813 | use data-pointers. Those modules data-pointers will be initialized as | |
4814 | needed. Care should be taken to ensure that the @code{init} call graph | |
4815 | does not contain cycles. | |
4816 | ||
4817 | The data-pointer is registered with the call: | |
4818 | ||
4819 | @smallexample | |
4820 | void | |
4821 | _initialize_nozel (void) | |
4822 | @{ | |
4823 | nozel_handle = register_gdbarch_data (nozel_init, nozel_free); | |
4824 | @dots{} | |
4825 | @end smallexample | |
4826 | ||
4827 | The per-architecture data-pointer is accessed using the function: | |
4828 | ||
4829 | @deftypefun void *gdbarch_data (struct gdbarch *@var{gdbarch}, struct gdbarch_data *@var{data_handle}) | |
4830 | Given the architecture @var{arch} and module data handle | |
4831 | @var{data_handle} (returned by @code{register_gdbarch_data}, this | |
4832 | function returns the current value of the per-architecture data-pointer. | |
4833 | @end deftypefun | |
4834 | ||
4835 | The non-@code{NULL} data-pointer returned by @code{gdbarch_data} should | |
4836 | be saved in a local variable and then used directly: | |
4837 | ||
4838 | @smallexample | |
4839 | int | |
4840 | nozel_total (struct gdbarch *gdbarch) | |
4841 | @{ | |
4842 | int total; | |
4843 | struct nozel *data = gdbarch_data (gdbarch, nozel_handle); | |
4844 | @dots{} | |
4845 | return total; | |
4846 | @} | |
4847 | @end smallexample | |
4848 | ||
4849 | It is also possible to directly initialize the data-pointer using: | |
4850 | ||
4851 | @deftypefun void set_gdbarch_data (struct gdbarch *@var{gdbarch}, struct gdbarch_data *handle, void *@var{pointer}) | |
4852 | Update the data-pointer corresponding to @var{handle} with the value of | |
4853 | @var{pointer}. If the previous data-pointer value is non-NULL, then it | |
4854 | is freed using data-pointers @var{free} function. | |
4855 | @end deftypefun | |
4856 | ||
4857 | This function is used by modules that require a mechanism for explicitly | |
4858 | setting the per-architecture data-pointer during architecture creation: | |
4859 | ||
4860 | @smallexample | |
4861 | /* Called during architecture creation. */ | |
4862 | extern void | |
4863 | set_gdbarch_nozel (struct gdbarch *gdbarch, | |
4864 | int total) | |
4865 | @{ | |
4866 | struct nozel *data = XMALLOC (struct nozel); | |
4867 | @dots{} | |
4868 | set_gdbarch_data (gdbarch, nozel_handle, nozel); | |
4869 | @} | |
4870 | @end smallexample | |
4871 | ||
4872 | @smallexample | |
4873 | /* Default, called when nozel not set by set_gdbarch_nozel(). */ | |
4874 | static void * | |
4875 | nozel_init (struct gdbarch *gdbarch) | |
4876 | @{ | |
4877 | struct nozel *default_nozel = XMALLOC (struc nozel); | |
4878 | @dots{} | |
4879 | return default_nozel; | |
4880 | @} | |
4881 | @end smallexample | |
4882 | ||
4883 | @smallexample | |
4884 | void | |
4885 | _initialize_nozel (void) | |
4886 | @{ | |
4887 | nozel_handle = register_gdbarch_data (nozel_init, NULL); | |
4888 | @dots{} | |
4889 | @end smallexample | |
4890 | ||
4891 | @noindent | |
4892 | Note that an @code{init} function still needs to be registered. It is | |
4893 | used to initialize the data-pointer when the architecture creation phase | |
4894 | fail to set an initial value. | |
4895 | ||
4896 | ||
c906108c | 4897 | @section Wrapping Output Lines |
56caf160 | 4898 | @cindex line wrap in output |
c906108c | 4899 | |
56caf160 | 4900 | @findex wrap_here |
c906108c SS |
4901 | Output that goes through @code{printf_filtered} or @code{fputs_filtered} |
4902 | or @code{fputs_demangled} needs only to have calls to @code{wrap_here} | |
4903 | added in places that would be good breaking points. The utility | |
4904 | routines will take care of actually wrapping if the line width is | |
4905 | exceeded. | |
4906 | ||
4907 | The argument to @code{wrap_here} is an indentation string which is | |
4908 | printed @emph{only} if the line breaks there. This argument is saved | |
4909 | away and used later. It must remain valid until the next call to | |
4910 | @code{wrap_here} or until a newline has been printed through the | |
4911 | @code{*_filtered} functions. Don't pass in a local variable and then | |
4912 | return! | |
4913 | ||
56caf160 | 4914 | It is usually best to call @code{wrap_here} after printing a comma or |
c906108c SS |
4915 | space. If you call it before printing a space, make sure that your |
4916 | indentation properly accounts for the leading space that will print if | |
4917 | the line wraps there. | |
4918 | ||
4919 | Any function or set of functions that produce filtered output must | |
4920 | finish by printing a newline, to flush the wrap buffer, before switching | |
56caf160 | 4921 | to unfiltered (@code{printf}) output. Symbol reading routines that |
c906108c SS |
4922 | print warnings are a good example. |
4923 | ||
25822942 | 4924 | @section @value{GDBN} Coding Standards |
56caf160 | 4925 | @cindex coding standards |
c906108c | 4926 | |
25822942 | 4927 | @value{GDBN} follows the GNU coding standards, as described in |
c906108c | 4928 | @file{etc/standards.texi}. This file is also available for anonymous |
af6c57ea AC |
4929 | FTP from GNU archive sites. @value{GDBN} takes a strict interpretation |
4930 | of the standard; in general, when the GNU standard recommends a practice | |
4931 | but does not require it, @value{GDBN} requires it. | |
c906108c | 4932 | |
56caf160 EZ |
4933 | @value{GDBN} follows an additional set of coding standards specific to |
4934 | @value{GDBN}, as described in the following sections. | |
c906108c | 4935 | |
af6c57ea | 4936 | |
b9aa90c9 | 4937 | @subsection ISO C |
af6c57ea | 4938 | |
b9aa90c9 AC |
4939 | @value{GDBN} assumes an ISO/IEC 9899:1990 (a.k.a.@: ISO C90) compliant |
4940 | compiler. | |
af6c57ea | 4941 | |
b9aa90c9 | 4942 | @value{GDBN} does not assume an ISO C or POSIX compliant C library. |
af6c57ea AC |
4943 | |
4944 | ||
4945 | @subsection Memory Management | |
4946 | ||
4947 | @value{GDBN} does not use the functions @code{malloc}, @code{realloc}, | |
4948 | @code{calloc}, @code{free} and @code{asprintf}. | |
4949 | ||
4950 | @value{GDBN} uses the functions @code{xmalloc}, @code{xrealloc} and | |
4951 | @code{xcalloc} when allocating memory. Unlike @code{malloc} et.al.@: | |
4952 | these functions do not return when the memory pool is empty. Instead, | |
4953 | they unwind the stack using cleanups. These functions return | |
4954 | @code{NULL} when requested to allocate a chunk of memory of size zero. | |
4955 | ||
4956 | @emph{Pragmatics: By using these functions, the need to check every | |
4957 | memory allocation is removed. These functions provide portable | |
4958 | behavior.} | |
4959 | ||
4960 | @value{GDBN} does not use the function @code{free}. | |
4961 | ||
4962 | @value{GDBN} uses the function @code{xfree} to return memory to the | |
4963 | memory pool. Consistent with ISO-C, this function ignores a request to | |
4964 | free a @code{NULL} pointer. | |
4965 | ||
4966 | @emph{Pragmatics: On some systems @code{free} fails when passed a | |
4967 | @code{NULL} pointer.} | |
4968 | ||
4969 | @value{GDBN} can use the non-portable function @code{alloca} for the | |
4970 | allocation of small temporary values (such as strings). | |
4971 | ||
4972 | @emph{Pragmatics: This function is very non-portable. Some systems | |
4973 | restrict the memory being allocated to no more than a few kilobytes.} | |
4974 | ||
4975 | @value{GDBN} uses the string function @code{xstrdup} and the print | |
4976 | function @code{xasprintf}. | |
4977 | ||
4978 | @emph{Pragmatics: @code{asprintf} and @code{strdup} can fail. Print | |
4979 | functions such as @code{sprintf} are very prone to buffer overflow | |
4980 | errors.} | |
4981 | ||
4982 | ||
4983 | @subsection Compiler Warnings | |
56caf160 | 4984 | @cindex compiler warnings |
af6c57ea AC |
4985 | |
4986 | With few exceptions, developers should include the configuration option | |
4987 | @samp{--enable-gdb-build-warnings=,-Werror} when building @value{GDBN}. | |
4988 | The exceptions are listed in the file @file{gdb/MAINTAINERS}. | |
4989 | ||
4990 | This option causes @value{GDBN} (when built using GCC) to be compiled | |
4991 | with a carefully selected list of compiler warning flags. Any warnings | |
4992 | from those flags being treated as errors. | |
4993 | ||
4994 | The current list of warning flags includes: | |
4995 | ||
4996 | @table @samp | |
4997 | @item -Wimplicit | |
4998 | Since @value{GDBN} coding standard requires all functions to be declared | |
4999 | using a prototype, the flag has the side effect of ensuring that | |
5000 | prototyped functions are always visible with out resorting to | |
5001 | @samp{-Wstrict-prototypes}. | |
5002 | ||
5003 | @item -Wreturn-type | |
5004 | Such code often appears to work except on instruction set architectures | |
5005 | that use register windows. | |
5006 | ||
5007 | @item -Wcomment | |
5008 | ||
5009 | @item -Wtrigraphs | |
5010 | ||
5011 | @item -Wformat | |
153721e6 | 5012 | @itemx -Wformat-nonliteral |
af6c57ea | 5013 | Since @value{GDBN} uses the @code{format printf} attribute on all |
153721e6 | 5014 | @code{printf} like functions these check not just @code{printf} calls |
af6c57ea AC |
5015 | but also calls to functions such as @code{fprintf_unfiltered}. |
5016 | ||
5017 | @item -Wparentheses | |
5018 | This warning includes uses of the assignment operator within an | |
5019 | @code{if} statement. | |
5020 | ||
5021 | @item -Wpointer-arith | |
5022 | ||
5023 | @item -Wuninitialized | |
5024 | @end table | |
5025 | ||
5026 | @emph{Pragmatics: Due to the way that @value{GDBN} is implemented most | |
5027 | functions have unused parameters. Consequently the warning | |
5028 | @samp{-Wunused-parameter} is precluded from the list. The macro | |
5029 | @code{ATTRIBUTE_UNUSED} is not used as it leads to false negatives --- | |
5030 | it is not an error to have @code{ATTRIBUTE_UNUSED} on a parameter that | |
5031 | is being used. The options @samp{-Wall} and @samp{-Wunused} are also | |
5032 | precluded because they both include @samp{-Wunused-parameter}.} | |
5033 | ||
5034 | @emph{Pragmatics: @value{GDBN} has not simply accepted the warnings | |
5035 | enabled by @samp{-Wall -Werror -W...}. Instead it is selecting warnings | |
5036 | when and where their benefits can be demonstrated.} | |
c906108c SS |
5037 | |
5038 | @subsection Formatting | |
5039 | ||
56caf160 | 5040 | @cindex source code formatting |
c906108c SS |
5041 | The standard GNU recommendations for formatting must be followed |
5042 | strictly. | |
5043 | ||
af6c57ea AC |
5044 | A function declaration should not have its name in column zero. A |
5045 | function definition should have its name in column zero. | |
5046 | ||
474c8240 | 5047 | @smallexample |
af6c57ea AC |
5048 | /* Declaration */ |
5049 | static void foo (void); | |
5050 | /* Definition */ | |
5051 | void | |
5052 | foo (void) | |
5053 | @{ | |
5054 | @} | |
474c8240 | 5055 | @end smallexample |
af6c57ea AC |
5056 | |
5057 | @emph{Pragmatics: This simplifies scripting. Function definitions can | |
5058 | be found using @samp{^function-name}.} | |
c906108c | 5059 | |
af6c57ea AC |
5060 | There must be a space between a function or macro name and the opening |
5061 | parenthesis of its argument list (except for macro definitions, as | |
5062 | required by C). There must not be a space after an open paren/bracket | |
5063 | or before a close paren/bracket. | |
c906108c SS |
5064 | |
5065 | While additional whitespace is generally helpful for reading, do not use | |
5066 | more than one blank line to separate blocks, and avoid adding whitespace | |
af6c57ea AC |
5067 | after the end of a program line (as of 1/99, some 600 lines had |
5068 | whitespace after the semicolon). Excess whitespace causes difficulties | |
5069 | for @code{diff} and @code{patch} utilities. | |
5070 | ||
5071 | Pointers are declared using the traditional K&R C style: | |
5072 | ||
474c8240 | 5073 | @smallexample |
af6c57ea | 5074 | void *foo; |
474c8240 | 5075 | @end smallexample |
af6c57ea AC |
5076 | |
5077 | @noindent | |
5078 | and not: | |
5079 | ||
474c8240 | 5080 | @smallexample |
af6c57ea AC |
5081 | void * foo; |
5082 | void* foo; | |
474c8240 | 5083 | @end smallexample |
c906108c SS |
5084 | |
5085 | @subsection Comments | |
5086 | ||
56caf160 | 5087 | @cindex comment formatting |
c906108c SS |
5088 | The standard GNU requirements on comments must be followed strictly. |
5089 | ||
af6c57ea AC |
5090 | Block comments must appear in the following form, with no @code{/*}- or |
5091 | @code{*/}-only lines, and no leading @code{*}: | |
c906108c | 5092 | |
474c8240 | 5093 | @smallexample |
c906108c SS |
5094 | /* Wait for control to return from inferior to debugger. If inferior |
5095 | gets a signal, we may decide to start it up again instead of | |
5096 | returning. That is why there is a loop in this function. When | |
5097 | this function actually returns it means the inferior should be left | |
25822942 | 5098 | stopped and @value{GDBN} should read more commands. */ |
474c8240 | 5099 | @end smallexample |
c906108c SS |
5100 | |
5101 | (Note that this format is encouraged by Emacs; tabbing for a multi-line | |
56caf160 | 5102 | comment works correctly, and @kbd{M-q} fills the block consistently.) |
c906108c SS |
5103 | |
5104 | Put a blank line between the block comments preceding function or | |
5105 | variable definitions, and the definition itself. | |
5106 | ||
5107 | In general, put function-body comments on lines by themselves, rather | |
5108 | than trying to fit them into the 20 characters left at the end of a | |
5109 | line, since either the comment or the code will inevitably get longer | |
5110 | than will fit, and then somebody will have to move it anyhow. | |
5111 | ||
5112 | @subsection C Usage | |
5113 | ||
56caf160 | 5114 | @cindex C data types |
c906108c SS |
5115 | Code must not depend on the sizes of C data types, the format of the |
5116 | host's floating point numbers, the alignment of anything, or the order | |
5117 | of evaluation of expressions. | |
5118 | ||
56caf160 | 5119 | @cindex function usage |
c906108c | 5120 | Use functions freely. There are only a handful of compute-bound areas |
56caf160 EZ |
5121 | in @value{GDBN} that might be affected by the overhead of a function |
5122 | call, mainly in symbol reading. Most of @value{GDBN}'s performance is | |
5123 | limited by the target interface (whether serial line or system call). | |
c906108c SS |
5124 | |
5125 | However, use functions with moderation. A thousand one-line functions | |
5126 | are just as hard to understand as a single thousand-line function. | |
5127 | ||
af6c57ea | 5128 | @emph{Macros are bad, M'kay.} |
9e678452 CF |
5129 | (But if you have to use a macro, make sure that the macro arguments are |
5130 | protected with parentheses.) | |
af6c57ea AC |
5131 | |
5132 | @cindex types | |
c906108c | 5133 | |
af6c57ea AC |
5134 | Declarations like @samp{struct foo *} should be used in preference to |
5135 | declarations like @samp{typedef struct foo @{ @dots{} @} *foo_ptr}. | |
5136 | ||
5137 | ||
5138 | @subsection Function Prototypes | |
56caf160 | 5139 | @cindex function prototypes |
af6c57ea AC |
5140 | |
5141 | Prototypes must be used when both @emph{declaring} and @emph{defining} | |
5142 | a function. Prototypes for @value{GDBN} functions must include both the | |
5143 | argument type and name, with the name matching that used in the actual | |
5144 | function definition. | |
c906108c | 5145 | |
53a5351d JM |
5146 | All external functions should have a declaration in a header file that |
5147 | callers include, except for @code{_initialize_*} functions, which must | |
5148 | be external so that @file{init.c} construction works, but shouldn't be | |
5149 | visible to random source files. | |
c906108c | 5150 | |
af6c57ea AC |
5151 | Where a source file needs a forward declaration of a static function, |
5152 | that declaration must appear in a block near the top of the source file. | |
5153 | ||
5154 | ||
5155 | @subsection Internal Error Recovery | |
5156 | ||
5157 | During its execution, @value{GDBN} can encounter two types of errors. | |
5158 | User errors and internal errors. User errors include not only a user | |
5159 | entering an incorrect command but also problems arising from corrupt | |
5160 | object files and system errors when interacting with the target. | |
937f164b FF |
5161 | Internal errors include situations where @value{GDBN} has detected, at |
5162 | run time, a corrupt or erroneous situation. | |
af6c57ea AC |
5163 | |
5164 | When reporting an internal error, @value{GDBN} uses | |
5165 | @code{internal_error} and @code{gdb_assert}. | |
5166 | ||
5167 | @value{GDBN} must not call @code{abort} or @code{assert}. | |
5168 | ||
5169 | @emph{Pragmatics: There is no @code{internal_warning} function. Either | |
5170 | the code detected a user error, recovered from it and issued a | |
5171 | @code{warning} or the code failed to correctly recover from the user | |
5172 | error and issued an @code{internal_error}.} | |
5173 | ||
5174 | @subsection File Names | |
5175 | ||
5176 | Any file used when building the core of @value{GDBN} must be in lower | |
5177 | case. Any file used when building the core of @value{GDBN} must be 8.3 | |
5178 | unique. These requirements apply to both source and generated files. | |
5179 | ||
5180 | @emph{Pragmatics: The core of @value{GDBN} must be buildable on many | |
5181 | platforms including DJGPP and MacOS/HFS. Every time an unfriendly file | |
5182 | is introduced to the build process both @file{Makefile.in} and | |
5183 | @file{configure.in} need to be modified accordingly. Compare the | |
5184 | convoluted conversion process needed to transform @file{COPYING} into | |
5185 | @file{copying.c} with the conversion needed to transform | |
5186 | @file{version.in} into @file{version.c}.} | |
5187 | ||
5188 | Any file non 8.3 compliant file (that is not used when building the core | |
5189 | of @value{GDBN}) must be added to @file{gdb/config/djgpp/fnchange.lst}. | |
5190 | ||
5191 | @emph{Pragmatics: This is clearly a compromise.} | |
5192 | ||
5193 | When @value{GDBN} has a local version of a system header file (ex | |
5194 | @file{string.h}) the file name based on the POSIX header prefixed with | |
b4177fca DJ |
5195 | @file{gdb_} (@file{gdb_string.h}). These headers should be relatively |
5196 | independent: they should use only macros defined by @file{configure}, | |
5197 | the compiler, or the host; they should include only system headers; they | |
5198 | should refer only to system types. They may be shared between multiple | |
5199 | programs, e.g.@: @value{GDBN} and @sc{gdbserver}. | |
af6c57ea AC |
5200 | |
5201 | For other files @samp{-} is used as the separator. | |
5202 | ||
5203 | ||
5204 | @subsection Include Files | |
5205 | ||
e2b28d04 | 5206 | A @file{.c} file should include @file{defs.h} first. |
af6c57ea | 5207 | |
e2b28d04 AC |
5208 | A @file{.c} file should directly include the @code{.h} file of every |
5209 | declaration and/or definition it directly refers to. It cannot rely on | |
5210 | indirect inclusion. | |
af6c57ea | 5211 | |
e2b28d04 AC |
5212 | A @file{.h} file should directly include the @code{.h} file of every |
5213 | declaration and/or definition it directly refers to. It cannot rely on | |
5214 | indirect inclusion. Exception: The file @file{defs.h} does not need to | |
5215 | be directly included. | |
af6c57ea | 5216 | |
e2b28d04 | 5217 | An external declaration should only appear in one include file. |
af6c57ea | 5218 | |
e2b28d04 AC |
5219 | An external declaration should never appear in a @code{.c} file. |
5220 | Exception: a declaration for the @code{_initialize} function that | |
5221 | pacifies @option{-Wmissing-declaration}. | |
5222 | ||
5223 | A @code{typedef} definition should only appear in one include file. | |
5224 | ||
5225 | An opaque @code{struct} declaration can appear in multiple @file{.h} | |
5226 | files. Where possible, a @file{.h} file should use an opaque | |
5227 | @code{struct} declaration instead of an include. | |
5228 | ||
5229 | All @file{.h} files should be wrapped in: | |
af6c57ea | 5230 | |
474c8240 | 5231 | @smallexample |
af6c57ea AC |
5232 | #ifndef INCLUDE_FILE_NAME_H |
5233 | #define INCLUDE_FILE_NAME_H | |
5234 | header body | |
5235 | #endif | |
474c8240 | 5236 | @end smallexample |
af6c57ea | 5237 | |
c906108c | 5238 | |
dab11f21 | 5239 | @subsection Clean Design and Portable Implementation |
c906108c | 5240 | |
56caf160 | 5241 | @cindex design |
c906108c | 5242 | In addition to getting the syntax right, there's the little question of |
25822942 | 5243 | semantics. Some things are done in certain ways in @value{GDBN} because long |
c906108c SS |
5244 | experience has shown that the more obvious ways caused various kinds of |
5245 | trouble. | |
5246 | ||
56caf160 | 5247 | @cindex assumptions about targets |
c906108c SS |
5248 | You can't assume the byte order of anything that comes from a target |
5249 | (including @var{value}s, object files, and instructions). Such things | |
56caf160 EZ |
5250 | must be byte-swapped using @code{SWAP_TARGET_AND_HOST} in |
5251 | @value{GDBN}, or one of the swap routines defined in @file{bfd.h}, | |
5252 | such as @code{bfd_get_32}. | |
c906108c SS |
5253 | |
5254 | You can't assume that you know what interface is being used to talk to | |
5255 | the target system. All references to the target must go through the | |
5256 | current @code{target_ops} vector. | |
5257 | ||
5258 | You can't assume that the host and target machines are the same machine | |
5259 | (except in the ``native'' support modules). In particular, you can't | |
5260 | assume that the target machine's header files will be available on the | |
5261 | host machine. Target code must bring along its own header files -- | |
5262 | written from scratch or explicitly donated by their owner, to avoid | |
5263 | copyright problems. | |
5264 | ||
56caf160 | 5265 | @cindex portability |
c906108c SS |
5266 | Insertion of new @code{#ifdef}'s will be frowned upon. It's much better |
5267 | to write the code portably than to conditionalize it for various | |
5268 | systems. | |
5269 | ||
56caf160 | 5270 | @cindex system dependencies |
c906108c SS |
5271 | New @code{#ifdef}'s which test for specific compilers or manufacturers |
5272 | or operating systems are unacceptable. All @code{#ifdef}'s should test | |
5273 | for features. The information about which configurations contain which | |
5274 | features should be segregated into the configuration files. Experience | |
5275 | has proven far too often that a feature unique to one particular system | |
5276 | often creeps into other systems; and that a conditional based on some | |
5277 | predefined macro for your current system will become worthless over | |
5278 | time, as new versions of your system come out that behave differently | |
5279 | with regard to this feature. | |
5280 | ||
5281 | Adding code that handles specific architectures, operating systems, | |
af6c57ea | 5282 | target interfaces, or hosts, is not acceptable in generic code. |
c906108c | 5283 | |
dab11f21 EZ |
5284 | @cindex portable file name handling |
5285 | @cindex file names, portability | |
5286 | One particularly notorious area where system dependencies tend to | |
5287 | creep in is handling of file names. The mainline @value{GDBN} code | |
5288 | assumes Posix semantics of file names: absolute file names begin with | |
5289 | a forward slash @file{/}, slashes are used to separate leading | |
5290 | directories, case-sensitive file names. These assumptions are not | |
5291 | necessarily true on non-Posix systems such as MS-Windows. To avoid | |
5292 | system-dependent code where you need to take apart or construct a file | |
5293 | name, use the following portable macros: | |
5294 | ||
5295 | @table @code | |
5296 | @findex HAVE_DOS_BASED_FILE_SYSTEM | |
5297 | @item HAVE_DOS_BASED_FILE_SYSTEM | |
5298 | This preprocessing symbol is defined to a non-zero value on hosts | |
5299 | whose filesystems belong to the MS-DOS/MS-Windows family. Use this | |
5300 | symbol to write conditional code which should only be compiled for | |
5301 | such hosts. | |
5302 | ||
5303 | @findex IS_DIR_SEPARATOR | |
4be31470 | 5304 | @item IS_DIR_SEPARATOR (@var{c}) |
dab11f21 EZ |
5305 | Evaluates to a non-zero value if @var{c} is a directory separator |
5306 | character. On Unix and GNU/Linux systems, only a slash @file{/} is | |
5307 | such a character, but on Windows, both @file{/} and @file{\} will | |
5308 | pass. | |
5309 | ||
5310 | @findex IS_ABSOLUTE_PATH | |
5311 | @item IS_ABSOLUTE_PATH (@var{file}) | |
5312 | Evaluates to a non-zero value if @var{file} is an absolute file name. | |
5313 | For Unix and GNU/Linux hosts, a name which begins with a slash | |
5314 | @file{/} is absolute. On DOS and Windows, @file{d:/foo} and | |
5315 | @file{x:\bar} are also absolute file names. | |
5316 | ||
5317 | @findex FILENAME_CMP | |
5318 | @item FILENAME_CMP (@var{f1}, @var{f2}) | |
5319 | Calls a function which compares file names @var{f1} and @var{f2} as | |
5320 | appropriate for the underlying host filesystem. For Posix systems, | |
5321 | this simply calls @code{strcmp}; on case-insensitive filesystems it | |
5322 | will call @code{strcasecmp} instead. | |
5323 | ||
5324 | @findex DIRNAME_SEPARATOR | |
5325 | @item DIRNAME_SEPARATOR | |
5326 | Evaluates to a character which separates directories in | |
5327 | @code{PATH}-style lists, typically held in environment variables. | |
5328 | This character is @samp{:} on Unix, @samp{;} on DOS and Windows. | |
5329 | ||
5330 | @findex SLASH_STRING | |
5331 | @item SLASH_STRING | |
5332 | This evaluates to a constant string you should use to produce an | |
5333 | absolute filename from leading directories and the file's basename. | |
5334 | @code{SLASH_STRING} is @code{"/"} on most systems, but might be | |
5335 | @code{"\\"} for some Windows-based ports. | |
5336 | @end table | |
5337 | ||
5338 | In addition to using these macros, be sure to use portable library | |
5339 | functions whenever possible. For example, to extract a directory or a | |
5340 | basename part from a file name, use the @code{dirname} and | |
5341 | @code{basename} library functions (available in @code{libiberty} for | |
5342 | platforms which don't provide them), instead of searching for a slash | |
5343 | with @code{strrchr}. | |
5344 | ||
25822942 DB |
5345 | Another way to generalize @value{GDBN} along a particular interface is with an |
5346 | attribute struct. For example, @value{GDBN} has been generalized to handle | |
56caf160 EZ |
5347 | multiple kinds of remote interfaces---not by @code{#ifdef}s everywhere, but |
5348 | by defining the @code{target_ops} structure and having a current target (as | |
c906108c SS |
5349 | well as a stack of targets below it, for memory references). Whenever |
5350 | something needs to be done that depends on which remote interface we are | |
56caf160 EZ |
5351 | using, a flag in the current target_ops structure is tested (e.g., |
5352 | @code{target_has_stack}), or a function is called through a pointer in the | |
c906108c | 5353 | current target_ops structure. In this way, when a new remote interface |
56caf160 | 5354 | is added, only one module needs to be touched---the one that actually |
c906108c SS |
5355 | implements the new remote interface. Other examples of |
5356 | attribute-structs are BFD access to multiple kinds of object file | |
25822942 | 5357 | formats, or @value{GDBN}'s access to multiple source languages. |
c906108c | 5358 | |
56caf160 EZ |
5359 | Please avoid duplicating code. For example, in @value{GDBN} 3.x all |
5360 | the code interfacing between @code{ptrace} and the rest of | |
5361 | @value{GDBN} was duplicated in @file{*-dep.c}, and so changing | |
5362 | something was very painful. In @value{GDBN} 4.x, these have all been | |
5363 | consolidated into @file{infptrace.c}. @file{infptrace.c} can deal | |
5364 | with variations between systems the same way any system-independent | |
5365 | file would (hooks, @code{#if defined}, etc.), and machines which are | |
5366 | radically different don't need to use @file{infptrace.c} at all. | |
c906108c | 5367 | |
af6c57ea AC |
5368 | All debugging code must be controllable using the @samp{set debug |
5369 | @var{module}} command. Do not use @code{printf} to print trace | |
5370 | messages. Use @code{fprintf_unfiltered(gdb_stdlog, ...}. Do not use | |
5371 | @code{#ifdef DEBUG}. | |
5372 | ||
c906108c | 5373 | |
8487521e | 5374 | @node Porting GDB |
c906108c | 5375 | |
25822942 | 5376 | @chapter Porting @value{GDBN} |
56caf160 | 5377 | @cindex porting to new machines |
c906108c | 5378 | |
56caf160 EZ |
5379 | Most of the work in making @value{GDBN} compile on a new machine is in |
5380 | specifying the configuration of the machine. This is done in a | |
5381 | dizzying variety of header files and configuration scripts, which we | |
5382 | hope to make more sensible soon. Let's say your new host is called an | |
5383 | @var{xyz} (e.g., @samp{sun4}), and its full three-part configuration | |
5384 | name is @code{@var{arch}-@var{xvend}-@var{xos}} (e.g., | |
5385 | @samp{sparc-sun-sunos4}). In particular: | |
c906108c | 5386 | |
56caf160 EZ |
5387 | @itemize @bullet |
5388 | @item | |
c906108c SS |
5389 | In the top level directory, edit @file{config.sub} and add @var{arch}, |
5390 | @var{xvend}, and @var{xos} to the lists of supported architectures, | |
5391 | vendors, and operating systems near the bottom of the file. Also, add | |
5392 | @var{xyz} as an alias that maps to | |
5393 | @code{@var{arch}-@var{xvend}-@var{xos}}. You can test your changes by | |
5394 | running | |
5395 | ||
474c8240 | 5396 | @smallexample |
c906108c | 5397 | ./config.sub @var{xyz} |
474c8240 | 5398 | @end smallexample |
56caf160 | 5399 | |
c906108c SS |
5400 | @noindent |
5401 | and | |
56caf160 | 5402 | |
474c8240 | 5403 | @smallexample |
c906108c | 5404 | ./config.sub @code{@var{arch}-@var{xvend}-@var{xos}} |
474c8240 | 5405 | @end smallexample |
56caf160 | 5406 | |
c906108c SS |
5407 | @noindent |
5408 | which should both respond with @code{@var{arch}-@var{xvend}-@var{xos}} | |
5409 | and no error messages. | |
5410 | ||
56caf160 | 5411 | @noindent |
c906108c SS |
5412 | You need to port BFD, if that hasn't been done already. Porting BFD is |
5413 | beyond the scope of this manual. | |
5414 | ||
56caf160 | 5415 | @item |
25822942 | 5416 | To configure @value{GDBN} itself, edit @file{gdb/configure.host} to recognize |
c906108c SS |
5417 | your system and set @code{gdb_host} to @var{xyz}, and (unless your |
5418 | desired target is already available) also edit @file{gdb/configure.tgt}, | |
5419 | setting @code{gdb_target} to something appropriate (for instance, | |
5420 | @var{xyz}). | |
5421 | ||
7fd60527 AC |
5422 | @emph{Maintainer's note: Work in progress. The file |
5423 | @file{gdb/configure.host} originally needed to be modified when either a | |
5424 | new native target or a new host machine was being added to @value{GDBN}. | |
5425 | Recent changes have removed this requirement. The file now only needs | |
5426 | to be modified when adding a new native configuration. This will likely | |
5427 | changed again in the future.} | |
5428 | ||
56caf160 | 5429 | @item |
25822942 | 5430 | Finally, you'll need to specify and define @value{GDBN}'s host-, native-, and |
c906108c SS |
5431 | target-dependent @file{.h} and @file{.c} files used for your |
5432 | configuration. | |
56caf160 | 5433 | @end itemize |
c906108c | 5434 | |
8973da3a AC |
5435 | @node Releasing GDB |
5436 | ||
5437 | @chapter Releasing @value{GDBN} | |
5438 | @cindex making a new release of gdb | |
5439 | ||
fb0ff88f AC |
5440 | @section Versions and Branches |
5441 | ||
5442 | @subsection Version Identifiers | |
5443 | ||
5444 | @value{GDBN}'s version is determined by the file @file{gdb/version.in}. | |
5445 | ||
5446 | @value{GDBN}'s mainline uses ISO dates to differentiate between | |
5447 | versions. The CVS repository uses @var{YYYY}-@var{MM}-@var{DD}-cvs | |
5448 | while the corresponding snapshot uses @var{YYYYMMDD}. | |
5449 | ||
5450 | @value{GDBN}'s release branch uses a slightly more complicated scheme. | |
5451 | When the branch is first cut, the mainline version identifier is | |
5452 | prefixed with the @var{major}.@var{minor} from of the previous release | |
5453 | series but with .90 appended. As draft releases are drawn from the | |
5454 | branch, the minor minor number (.90) is incremented. Once the first | |
5455 | release (@var{M}.@var{N}) has been made, the version prefix is updated | |
5456 | to @var{M}.@var{N}.0.90 (dot zero, dot ninety). Follow on releases have | |
5457 | an incremented minor minor version number (.0). | |
5458 | ||
5459 | Using 5.1 (previous) and 5.2 (current), the example below illustrates a | |
5460 | typical sequence of version identifiers: | |
5461 | ||
5462 | @table @asis | |
5463 | @item 5.1.1 | |
5464 | final release from previous branch | |
5465 | @item 2002-03-03-cvs | |
5466 | main-line the day the branch is cut | |
5467 | @item 5.1.90-2002-03-03-cvs | |
5468 | corresponding branch version | |
5469 | @item 5.1.91 | |
5470 | first draft release candidate | |
5471 | @item 5.1.91-2002-03-17-cvs | |
5472 | updated branch version | |
5473 | @item 5.1.92 | |
5474 | second draft release candidate | |
5475 | @item 5.1.92-2002-03-31-cvs | |
5476 | updated branch version | |
5477 | @item 5.1.93 | |
5478 | final release candidate (see below) | |
5479 | @item 5.2 | |
5480 | official release | |
5481 | @item 5.2.0.90-2002-04-07-cvs | |
5482 | updated CVS branch version | |
5483 | @item 5.2.1 | |
5484 | second official release | |
5485 | @end table | |
5486 | ||
5487 | Notes: | |
5488 | ||
5489 | @itemize @bullet | |
5490 | @item | |
5491 | Minor minor minor draft release candidates such as 5.2.0.91 have been | |
5492 | omitted from the example. Such release candidates are, typically, never | |
5493 | made. | |
5494 | @item | |
5495 | For 5.1.93 the bziped tar ball @file{gdb-5.1.93.tar.bz2} is just the | |
5496 | official @file{gdb-5.2.tar} renamed and compressed. | |
5497 | @end itemize | |
5498 | ||
5499 | To avoid version conflicts, vendors are expected to modify the file | |
5500 | @file{gdb/version.in} to include a vendor unique alphabetic identifier | |
5501 | (an official @value{GDBN} release never uses alphabetic characters in | |
5502 | its version identifer). | |
5503 | ||
5504 | Since @value{GDBN} does not make minor minor minor releases (e.g., | |
5505 | 5.1.0.1) the conflict between that and a minor minor draft release | |
5506 | identifier (e.g., 5.1.0.90) is avoided. | |
5507 | ||
5508 | ||
5509 | @subsection Branches | |
5510 | ||
5511 | @value{GDBN} draws a release series (5.2, 5.2.1, @dots{}) from a single | |
5512 | release branch (gdb_5_2-branch). Since minor minor minor releases | |
5513 | (5.1.0.1) are not made, the need to branch the release branch is avoided | |
5514 | (it also turns out that the effort required for such a a branch and | |
5515 | release is significantly greater than the effort needed to create a new | |
5516 | release from the head of the release branch). | |
5517 | ||
5518 | Releases 5.0 and 5.1 used branch and release tags of the form: | |
5519 | ||
474c8240 | 5520 | @smallexample |
fb0ff88f AC |
5521 | gdb_N_M-YYYY-MM-DD-branchpoint |
5522 | gdb_N_M-YYYY-MM-DD-branch | |
5523 | gdb_M_N-YYYY-MM-DD-release | |
474c8240 | 5524 | @end smallexample |
fb0ff88f AC |
5525 | |
5526 | Release 5.2 is trialing the branch and release tags: | |
5527 | ||
474c8240 | 5528 | @smallexample |
fb0ff88f AC |
5529 | gdb_N_M-YYYY-MM-DD-branchpoint |
5530 | gdb_N_M-branch | |
5531 | gdb_M_N-YYYY-MM-DD-release | |
474c8240 | 5532 | @end smallexample |
fb0ff88f AC |
5533 | |
5534 | @emph{Pragmatics: The branchpoint and release tags need to identify when | |
5535 | a branch and release are made. The branch tag, denoting the head of the | |
5536 | branch, does not have this criteria.} | |
5537 | ||
5538 | ||
9bb0a4d8 AC |
5539 | @section Branch Commit Policy |
5540 | ||
5541 | The branch commit policy is pretty slack. @value{GDBN} releases 5.0, | |
5542 | 5.1 and 5.2 all used the below: | |
5543 | ||
5544 | @itemize @bullet | |
5545 | @item | |
5546 | The @file{gdb/MAINTAINERS} file still holds. | |
5547 | @item | |
5548 | Don't fix something on the branch unless/until it is also fixed in the | |
5549 | trunk. If this isn't possible, mentioning it in the @file{gdb/PROBLEMS} | |
4be31470 | 5550 | file is better than committing a hack. |
9bb0a4d8 AC |
5551 | @item |
5552 | When considering a patch for the branch, suggested criteria include: | |
5553 | Does it fix a build? Does it fix the sequence @kbd{break main; run} | |
5554 | when debugging a static binary? | |
5555 | @item | |
5556 | The further a change is from the core of @value{GDBN}, the less likely | |
5557 | the change will worry anyone (e.g., target specific code). | |
5558 | @item | |
5559 | Only post a proposal to change the core of @value{GDBN} after you've | |
5560 | sent individual bribes to all the people listed in the | |
5561 | @file{MAINTAINERS} file @t{;-)} | |
5562 | @end itemize | |
5563 | ||
5564 | @emph{Pragmatics: Provided updates are restricted to non-core | |
5565 | functionality there is little chance that a broken change will be fatal. | |
5566 | This means that changes such as adding a new architectures or (within | |
5567 | reason) support for a new host are considered acceptable.} | |
5568 | ||
5569 | ||
cbb09e6a | 5570 | @section Obsoleting code |
8973da3a | 5571 | |
8642bc8f | 5572 | Before anything else, poke the other developers (and around the source |
4be31470 EZ |
5573 | code) to see if there is anything that can be removed from @value{GDBN} |
5574 | (an old target, an unused file). | |
8973da3a | 5575 | |
8642bc8f | 5576 | Obsolete code is identified by adding an @code{OBSOLETE} prefix to every |
cbb09e6a AC |
5577 | line. Doing this means that it is easy to identify something that has |
5578 | been obsoleted when greping through the sources. | |
8973da3a | 5579 | |
cbb09e6a AC |
5580 | The process is done in stages --- this is mainly to ensure that the |
5581 | wider @value{GDBN} community has a reasonable opportunity to respond. | |
5582 | Remember, everything on the Internet takes a week. | |
8973da3a | 5583 | |
cbb09e6a | 5584 | @enumerate |
8973da3a | 5585 | @item |
cbb09e6a AC |
5586 | Post the proposal on @email{gdb@@sources.redhat.com, the GDB mailing |
5587 | list} Creating a bug report to track the task's state, is also highly | |
5588 | recommended. | |
8973da3a | 5589 | @item |
cbb09e6a | 5590 | Wait a week or so. |
8973da3a | 5591 | @item |
cbb09e6a AC |
5592 | Post the proposal on @email{gdb-announce@@sources.redhat.com, the GDB |
5593 | Announcement mailing list}. | |
8973da3a | 5594 | @item |
cbb09e6a | 5595 | Wait a week or so. |
8973da3a | 5596 | @item |
cbb09e6a AC |
5597 | Go through and edit all relevant files and lines so that they are |
5598 | prefixed with the word @code{OBSOLETE}. | |
5599 | @item | |
5600 | Wait until the next GDB version, containing this obsolete code, has been | |
5601 | released. | |
5602 | @item | |
5603 | Remove the obsolete code. | |
5604 | @end enumerate | |
5605 | ||
5606 | @noindent | |
5607 | @emph{Maintainer note: While removing old code is regrettable it is | |
5608 | hopefully better for @value{GDBN}'s long term development. Firstly it | |
5609 | helps the developers by removing code that is either no longer relevant | |
5610 | or simply wrong. Secondly since it removes any history associated with | |
5611 | the file (effectively clearing the slate) the developer has a much freer | |
5612 | hand when it comes to fixing broken files.} | |
8973da3a | 5613 | |
8973da3a | 5614 | |
9ae8b82c AC |
5615 | |
5616 | @section Before the Branch | |
8973da3a | 5617 | |
8642bc8f AC |
5618 | The most important objective at this stage is to find and fix simple |
5619 | changes that become a pain to track once the branch is created. For | |
5620 | instance, configuration problems that stop @value{GDBN} from even | |
5621 | building. If you can't get the problem fixed, document it in the | |
5622 | @file{gdb/PROBLEMS} file. | |
8973da3a | 5623 | |
9ae8b82c | 5624 | @subheading Prompt for @file{gdb/NEWS} |
8973da3a | 5625 | |
9ae8b82c AC |
5626 | People always forget. Send a post reminding them but also if you know |
5627 | something interesting happened add it yourself. The @code{schedule} | |
5628 | script will mention this in its e-mail. | |
8973da3a | 5629 | |
9ae8b82c | 5630 | @subheading Review @file{gdb/README} |
8973da3a | 5631 | |
9ae8b82c AC |
5632 | Grab one of the nightly snapshots and then walk through the |
5633 | @file{gdb/README} looking for anything that can be improved. The | |
5634 | @code{schedule} script will mention this in its e-mail. | |
8642bc8f AC |
5635 | |
5636 | @subheading Refresh any imported files. | |
8973da3a | 5637 | |
8642bc8f | 5638 | A number of files are taken from external repositories. They include: |
8973da3a | 5639 | |
8642bc8f AC |
5640 | @itemize @bullet |
5641 | @item | |
5642 | @file{texinfo/texinfo.tex} | |
5643 | @item | |
9ae8b82c AC |
5644 | @file{config.guess} et.@: al.@: (see the top-level @file{MAINTAINERS} |
5645 | file) | |
5646 | @item | |
5647 | @file{etc/standards.texi}, @file{etc/make-stds.texi} | |
8642bc8f AC |
5648 | @end itemize |
5649 | ||
9ae8b82c | 5650 | @subheading Check the ARI |
8642bc8f | 5651 | |
9ae8b82c AC |
5652 | @uref{http://sources.redhat.com/gdb/ari,,A.R.I.} is an @code{awk} script |
5653 | (Awk Regression Index ;-) that checks for a number of errors and coding | |
5654 | conventions. The checks include things like using @code{malloc} instead | |
5655 | of @code{xmalloc} and file naming problems. There shouldn't be any | |
5656 | regressions. | |
8642bc8f | 5657 | |
9ae8b82c | 5658 | @subsection Review the bug data base |
8642bc8f | 5659 | |
9ae8b82c | 5660 | Close anything obviously fixed. |
8642bc8f | 5661 | |
9ae8b82c | 5662 | @subsection Check all cross targets build |
8642bc8f | 5663 | |
9ae8b82c | 5664 | The targets are listed in @file{gdb/MAINTAINERS}. |
8642bc8f | 5665 | |
8642bc8f | 5666 | |
30107679 | 5667 | @section Cut the Branch |
8642bc8f | 5668 | |
30107679 | 5669 | @subheading Create the branch |
8642bc8f | 5670 | |
474c8240 | 5671 | @smallexample |
30107679 AC |
5672 | $ u=5.1 |
5673 | $ v=5.2 | |
5674 | $ V=`echo $v | sed 's/\./_/g'` | |
5675 | $ D=`date -u +%Y-%m-%d` | |
5676 | $ echo $u $V $D | |
5677 | 5.1 5_2 2002-03-03 | |
5678 | $ echo cvs -f -d :ext:sources.redhat.com:/cvs/src rtag \ | |
5679 | -D $D-gmt gdb_$V-$D-branchpoint insight+dejagnu | |
5680 | cvs -f -d :ext:sources.redhat.com:/cvs/src rtag | |
5681 | -D 2002-03-03-gmt gdb_5_2-2002-03-03-branchpoint insight+dejagnu | |
5682 | $ ^echo ^^ | |
5683 | ... | |
5684 | $ echo cvs -f -d :ext:sources.redhat.com:/cvs/src rtag \ | |
5685 | -b -r gdb_$V-$D-branchpoint gdb_$V-branch insight+dejagnu | |
5686 | cvs -f -d :ext:sources.redhat.com:/cvs/src rtag \ | |
5687 | -b -r gdb_5_2-2002-03-03-branchpoint gdb_5_2-branch insight+dejagnu | |
5688 | $ ^echo ^^ | |
5689 | ... | |
8642bc8f | 5690 | $ |
474c8240 | 5691 | @end smallexample |
8642bc8f AC |
5692 | |
5693 | @itemize @bullet | |
5694 | @item | |
30107679 AC |
5695 | by using @kbd{-D YYYY-MM-DD-gmt} the branch is forced to an exact |
5696 | date/time. | |
5697 | @item | |
5698 | the trunk is first taged so that the branch point can easily be found | |
5699 | @item | |
5700 | Insight (which includes GDB) and dejagnu are all tagged at the same time | |
8642bc8f | 5701 | @item |
30107679 | 5702 | @file{version.in} gets bumped to avoid version number conflicts |
8642bc8f | 5703 | @item |
30107679 AC |
5704 | the reading of @file{.cvsrc} is disabled using @file{-f} |
5705 | @end itemize | |
5706 | ||
5707 | @subheading Update @file{version.in} | |
5708 | ||
5709 | @smallexample | |
5710 | $ u=5.1 | |
5711 | $ v=5.2 | |
5712 | $ V=`echo $v | sed 's/\./_/g'` | |
5713 | $ echo $u $v$V | |
5714 | 5.1 5_2 | |
5715 | $ cd /tmp | |
5716 | $ echo cvs -f -d :ext:sources.redhat.com:/cvs/src co \ | |
5717 | -r gdb_$V-branch src/gdb/version.in | |
5718 | cvs -f -d :ext:sources.redhat.com:/cvs/src co | |
5719 | -r gdb_5_2-branch src/gdb/version.in | |
5720 | $ ^echo ^^ | |
5721 | U src/gdb/version.in | |
5722 | $ cd src/gdb | |
5723 | $ echo $u.90-0000-00-00-cvs > version.in | |
5724 | $ cat version.in | |
5725 | 5.1.90-0000-00-00-cvs | |
5726 | $ cvs -f commit version.in | |
5727 | @end smallexample | |
5728 | ||
5729 | @itemize @bullet | |
5730 | @item | |
5731 | @file{0000-00-00} is used as a date to pump prime the version.in update | |
5732 | mechanism | |
5733 | @item | |
5734 | @file{.90} and the previous branch version are used as fairly arbitrary | |
5735 | initial branch version number | |
8642bc8f AC |
5736 | @end itemize |
5737 | ||
8642bc8f AC |
5738 | |
5739 | @subheading Update the web and news pages | |
5740 | ||
30107679 AC |
5741 | Something? |
5742 | ||
8642bc8f AC |
5743 | @subheading Tweak cron to track the new branch |
5744 | ||
30107679 AC |
5745 | The file @file{gdbadmin/cron/crontab} contains gdbadmin's cron table. |
5746 | This file needs to be updated so that: | |
5747 | ||
5748 | @itemize @bullet | |
5749 | @item | |
5750 | a daily timestamp is added to the file @file{version.in} | |
5751 | @item | |
5752 | the new branch is included in the snapshot process | |
5753 | @end itemize | |
5754 | ||
5755 | @noindent | |
5756 | See the file @file{gdbadmin/cron/README} for how to install the updated | |
5757 | cron table. | |
5758 | ||
5759 | The file @file{gdbadmin/ss/README} should also be reviewed to reflect | |
5760 | any changes. That file is copied to both the branch/ and current/ | |
5761 | snapshot directories. | |
5762 | ||
5763 | ||
5764 | @subheading Update the NEWS and README files | |
5765 | ||
5766 | The @file{NEWS} file needs to be updated so that on the branch it refers | |
5767 | to @emph{changes in the current release} while on the trunk it also | |
5768 | refers to @emph{changes since the current release}. | |
5769 | ||
5770 | The @file{README} file needs to be updated so that it refers to the | |
5771 | current release. | |
5772 | ||
5773 | @subheading Post the branch info | |
5774 | ||
5775 | Send an announcement to the mailing lists: | |
5776 | ||
5777 | @itemize @bullet | |
5778 | @item | |
5779 | @email{gdb-announce@@sources.redhat.com, GDB Announcement mailing list} | |
5780 | @item | |
5781 | @email{gdb@@sources.redhat.com, GDB Discsussion mailing list} and | |
5782 | @email{gdb-testers@@sources.redhat.com, GDB Discsussion mailing list} | |
16737d73 | 5783 | @end itemize |
30107679 AC |
5784 | |
5785 | @emph{Pragmatics: The branch creation is sent to the announce list to | |
5786 | ensure that people people not subscribed to the higher volume discussion | |
5787 | list are alerted.} | |
5788 | ||
5789 | The announcement should include: | |
5790 | ||
5791 | @itemize @bullet | |
5792 | @item | |
5793 | the branch tag | |
5794 | @item | |
5795 | how to check out the branch using CVS | |
5796 | @item | |
5797 | the date/number of weeks until the release | |
5798 | @item | |
5799 | the branch commit policy | |
5800 | still holds. | |
16737d73 | 5801 | @end itemize |
30107679 | 5802 | |
8642bc8f AC |
5803 | @section Stabilize the branch |
5804 | ||
5805 | Something goes here. | |
5806 | ||
5807 | @section Create a Release | |
5808 | ||
0816590b AC |
5809 | The process of creating and then making available a release is broken |
5810 | down into a number of stages. The first part addresses the technical | |
5811 | process of creating a releasable tar ball. The later stages address the | |
5812 | process of releasing that tar ball. | |
8973da3a | 5813 | |
0816590b AC |
5814 | When making a release candidate just the first section is needed. |
5815 | ||
5816 | @subsection Create a release candidate | |
5817 | ||
5818 | The objective at this stage is to create a set of tar balls that can be | |
5819 | made available as a formal release (or as a less formal release | |
5820 | candidate). | |
5821 | ||
5822 | @subsubheading Freeze the branch | |
5823 | ||
5824 | Send out an e-mail notifying everyone that the branch is frozen to | |
5825 | @email{gdb-patches@@sources.redhat.com}. | |
5826 | ||
5827 | @subsubheading Establish a few defaults. | |
8973da3a | 5828 | |
474c8240 | 5829 | @smallexample |
0816590b AC |
5830 | $ b=gdb_5_2-branch |
5831 | $ v=5.2 | |
8642bc8f AC |
5832 | $ t=/sourceware/snapshot-tmp/gdbadmin-tmp |
5833 | $ echo $t/$b/$v | |
0816590b | 5834 | /sourceware/snapshot-tmp/gdbadmin-tmp/gdb_5_2-branch/5.2 |
8642bc8f AC |
5835 | $ mkdir -p $t/$b/$v |
5836 | $ cd $t/$b/$v | |
5837 | $ pwd | |
0816590b | 5838 | /sourceware/snapshot-tmp/gdbadmin-tmp/gdb_5_2-branch/5.2 |
8973da3a AC |
5839 | $ which autoconf |
5840 | /home/gdbadmin/bin/autoconf | |
8642bc8f | 5841 | $ |
474c8240 | 5842 | @end smallexample |
8973da3a | 5843 | |
0816590b AC |
5844 | @noindent |
5845 | Notes: | |
8973da3a | 5846 | |
0816590b AC |
5847 | @itemize @bullet |
5848 | @item | |
5849 | Check the @code{autoconf} version carefully. You want to be using the | |
4a2b4636 JB |
5850 | version taken from the @file{binutils} snapshot directory, which can be |
5851 | found at @uref{ftp://sources.redhat.com/pub/binutils/}. It is very | |
0816590b AC |
5852 | unlikely that a system installed version of @code{autoconf} (e.g., |
5853 | @file{/usr/bin/autoconf}) is correct. | |
5854 | @end itemize | |
5855 | ||
5856 | @subsubheading Check out the relevant modules: | |
8973da3a | 5857 | |
474c8240 | 5858 | @smallexample |
8642bc8f AC |
5859 | $ for m in gdb insight dejagnu |
5860 | do | |
8973da3a AC |
5861 | ( mkdir -p $m && cd $m && cvs -q -f -d /cvs/src co -P -r $b $m ) |
5862 | done | |
8642bc8f | 5863 | $ |
474c8240 | 5864 | @end smallexample |
8973da3a | 5865 | |
0816590b AC |
5866 | @noindent |
5867 | Note: | |
8642bc8f | 5868 | |
0816590b AC |
5869 | @itemize @bullet |
5870 | @item | |
5871 | The reading of @file{.cvsrc} is disabled (@file{-f}) so that there isn't | |
5872 | any confusion between what is written here and what your local | |
5873 | @code{cvs} really does. | |
5874 | @end itemize | |
5875 | ||
5876 | @subsubheading Update relevant files. | |
8973da3a | 5877 | |
0816590b AC |
5878 | @table @file |
5879 | ||
5880 | @item gdb/NEWS | |
8642bc8f AC |
5881 | |
5882 | Major releases get their comments added as part of the mainline. Minor | |
5883 | releases should probably mention any significant bugs that were fixed. | |
5884 | ||
0816590b | 5885 | Don't forget to include the @file{ChangeLog} entry. |
8973da3a | 5886 | |
474c8240 | 5887 | @smallexample |
8642bc8f AC |
5888 | $ emacs gdb/src/gdb/NEWS |
5889 | ... | |
5890 | c-x 4 a | |
5891 | ... | |
5892 | c-x c-s c-x c-c | |
5893 | $ cp gdb/src/gdb/NEWS insight/src/gdb/NEWS | |
5894 | $ cp gdb/src/gdb/ChangeLog insight/src/gdb/ChangeLog | |
474c8240 | 5895 | @end smallexample |
8973da3a | 5896 | |
0816590b AC |
5897 | @item gdb/README |
5898 | ||
5899 | You'll need to update: | |
8973da3a | 5900 | |
0816590b AC |
5901 | @itemize @bullet |
5902 | @item | |
5903 | the version | |
5904 | @item | |
5905 | the update date | |
5906 | @item | |
5907 | who did it | |
5908 | @end itemize | |
8973da3a | 5909 | |
474c8240 | 5910 | @smallexample |
8642bc8f AC |
5911 | $ emacs gdb/src/gdb/README |
5912 | ... | |
8973da3a | 5913 | c-x 4 a |
8642bc8f | 5914 | ... |
8973da3a | 5915 | c-x c-s c-x c-c |
8642bc8f AC |
5916 | $ cp gdb/src/gdb/README insight/src/gdb/README |
5917 | $ cp gdb/src/gdb/ChangeLog insight/src/gdb/ChangeLog | |
474c8240 | 5918 | @end smallexample |
8973da3a | 5919 | |
0816590b AC |
5920 | @emph{Maintainer note: Hopefully the @file{README} file was reviewed |
5921 | before the initial branch was cut so just a simple substitute is needed | |
5922 | to get it updated.} | |
8973da3a | 5923 | |
8642bc8f AC |
5924 | @emph{Maintainer note: Other projects generate @file{README} and |
5925 | @file{INSTALL} from the core documentation. This might be worth | |
5926 | pursuing.} | |
8973da3a | 5927 | |
0816590b | 5928 | @item gdb/version.in |
8973da3a | 5929 | |
474c8240 | 5930 | @smallexample |
8642bc8f | 5931 | $ echo $v > gdb/src/gdb/version.in |
0816590b AC |
5932 | $ cat gdb/src/gdb/version.in |
5933 | 5.2 | |
8642bc8f | 5934 | $ emacs gdb/src/gdb/version.in |
8973da3a AC |
5935 | ... |
5936 | c-x 4 a | |
0816590b | 5937 | ... Bump to version ... |
8973da3a | 5938 | c-x c-s c-x c-c |
8642bc8f AC |
5939 | $ cp gdb/src/gdb/version.in insight/src/gdb/version.in |
5940 | $ cp gdb/src/gdb/ChangeLog insight/src/gdb/ChangeLog | |
474c8240 | 5941 | @end smallexample |
8973da3a | 5942 | |
0816590b | 5943 | @item dejagnu/src/dejagnu/configure.in |
8642bc8f AC |
5944 | |
5945 | Dejagnu is more complicated. The version number is a parameter to | |
0816590b | 5946 | @code{AM_INIT_AUTOMAKE}. Tweak it to read something like gdb-5.1.91. |
8642bc8f | 5947 | |
0816590b | 5948 | Don't forget to re-generate @file{configure}. |
8642bc8f | 5949 | |
0816590b | 5950 | Don't forget to include a @file{ChangeLog} entry. |
8642bc8f | 5951 | |
0816590b AC |
5952 | @smallexample |
5953 | $ emacs dejagnu/src/dejagnu/configure.in | |
5954 | ... | |
5955 | c-x 4 a | |
5956 | ... | |
5957 | c-x c-s c-x c-c | |
5958 | $ ( cd dejagnu/src/dejagnu && autoconf ) | |
5959 | @end smallexample | |
8642bc8f | 5960 | |
0816590b AC |
5961 | @end table |
5962 | ||
5963 | @subsubheading Do the dirty work | |
5964 | ||
5965 | This is identical to the process used to create the daily snapshot. | |
8973da3a | 5966 | |
4ce8657e MC |
5967 | @smallexample |
5968 | $ for m in gdb insight | |
5969 | do | |
5970 | ( cd $m/src && gmake -f src-release $m.tar ) | |
5971 | done | |
5972 | $ ( m=dejagnu; cd $m/src && gmake -f src-release $m.tar.bz2 ) | |
5973 | @end smallexample | |
5974 | ||
5975 | If the top level source directory does not have @file{src-release} | |
5976 | (@value{GDBN} version 5.3.1 or earlier), try these commands instead: | |
5977 | ||
474c8240 | 5978 | @smallexample |
0816590b | 5979 | $ for m in gdb insight |
8642bc8f | 5980 | do |
0816590b | 5981 | ( cd $m/src && gmake -f Makefile.in $m.tar ) |
8973da3a | 5982 | done |
0816590b | 5983 | $ ( m=dejagnu; cd $m/src && gmake -f Makefile.in $m.tar.bz2 ) |
474c8240 | 5984 | @end smallexample |
8973da3a | 5985 | |
0816590b | 5986 | @subsubheading Check the source files |
8642bc8f | 5987 | |
0816590b | 5988 | You're looking for files that have mysteriously disappeared. |
8642bc8f AC |
5989 | @kbd{distclean} has the habit of deleting files it shouldn't. Watch out |
5990 | for the @file{version.in} update @kbd{cronjob}. | |
8973da3a | 5991 | |
474c8240 | 5992 | @smallexample |
8642bc8f AC |
5993 | $ ( cd gdb/src && cvs -f -q -n update ) |
5994 | M djunpack.bat | |
0816590b | 5995 | ? gdb-5.1.91.tar |
8642bc8f | 5996 | ? proto-toplev |
0816590b | 5997 | @dots{} lots of generated files @dots{} |
8642bc8f AC |
5998 | M gdb/ChangeLog |
5999 | M gdb/NEWS | |
6000 | M gdb/README | |
6001 | M gdb/version.in | |
0816590b | 6002 | @dots{} lots of generated files @dots{} |
8642bc8f | 6003 | $ |
474c8240 | 6004 | @end smallexample |
8973da3a | 6005 | |
0816590b | 6006 | @noindent |
8642bc8f AC |
6007 | @emph{Don't worry about the @file{gdb.info-??} or |
6008 | @file{gdb/p-exp.tab.c}. They were generated (and yes @file{gdb.info-1} | |
6009 | was also generated only something strange with CVS means that they | |
6010 | didn't get supressed). Fixing it would be nice though.} | |
8973da3a | 6011 | |
0816590b | 6012 | @subsubheading Create compressed versions of the release |
8973da3a | 6013 | |
474c8240 | 6014 | @smallexample |
0816590b AC |
6015 | $ cp */src/*.tar . |
6016 | $ cp */src/*.bz2 . | |
6017 | $ ls -F | |
6018 | dejagnu/ dejagnu-gdb-5.2.tar.bz2 gdb/ gdb-5.2.tar insight/ insight-5.2.tar | |
6019 | $ for m in gdb insight | |
6020 | do | |
6021 | bzip2 -v -9 -c $m-$v.tar > $m-$v.tar.bz2 | |
6022 | gzip -v -9 -c $m-$v.tar > $m-$v.tar.gz | |
6023 | done | |
6024 | $ | |
474c8240 | 6025 | @end smallexample |
8973da3a | 6026 | |
0816590b AC |
6027 | @noindent |
6028 | Note: | |
6029 | ||
6030 | @itemize @bullet | |
6031 | @item | |
6032 | A pipe such as @kbd{bunzip2 < xxx.bz2 | gzip -9 > xxx.gz} is not since, | |
6033 | in that mode, @code{gzip} does not know the name of the file and, hence, | |
6034 | can not include it in the compressed file. This is also why the release | |
6035 | process runs @code{tar} and @code{bzip2} as separate passes. | |
6036 | @end itemize | |
6037 | ||
6038 | @subsection Sanity check the tar ball | |
8973da3a | 6039 | |
0816590b | 6040 | Pick a popular machine (Solaris/PPC?) and try the build on that. |
8973da3a | 6041 | |
0816590b AC |
6042 | @smallexample |
6043 | $ bunzip2 < gdb-5.2.tar.bz2 | tar xpf - | |
6044 | $ cd gdb-5.2 | |
6045 | $ ./configure | |
6046 | $ make | |
6047 | @dots{} | |
6048 | $ ./gdb/gdb ./gdb/gdb | |
6049 | GNU gdb 5.2 | |
6050 | @dots{} | |
6051 | (gdb) b main | |
6052 | Breakpoint 1 at 0x80732bc: file main.c, line 734. | |
6053 | (gdb) run | |
6054 | Starting program: /tmp/gdb-5.2/gdb/gdb | |
6055 | ||
6056 | Breakpoint 1, main (argc=1, argv=0xbffff8b4) at main.c:734 | |
6057 | 734 catch_errors (captured_main, &args, "", RETURN_MASK_ALL); | |
6058 | (gdb) print args | |
6059 | $1 = @{argc = 136426532, argv = 0x821b7f0@} | |
6060 | (gdb) | |
6061 | @end smallexample | |
8973da3a | 6062 | |
0816590b | 6063 | @subsection Make a release candidate available |
8973da3a | 6064 | |
0816590b | 6065 | If this is a release candidate then the only remaining steps are: |
8642bc8f | 6066 | |
0816590b AC |
6067 | @enumerate |
6068 | @item | |
6069 | Commit @file{version.in} and @file{ChangeLog} | |
6070 | @item | |
6071 | Tweak @file{version.in} (and @file{ChangeLog} to read | |
6072 | @var{L}.@var{M}.@var{N}-0000-00-00-cvs so that the version update | |
6073 | process can restart. | |
6074 | @item | |
6075 | Make the release candidate available in | |
6076 | @uref{ftp://sources.redhat.com/pub/gdb/snapshots/branch} | |
6077 | @item | |
6078 | Notify the relevant mailing lists ( @email{gdb@@sources.redhat.com} and | |
6079 | @email{gdb-testers@@sources.redhat.com} that the candidate is available. | |
6080 | @end enumerate | |
8642bc8f | 6081 | |
0816590b | 6082 | @subsection Make a formal release available |
8642bc8f | 6083 | |
0816590b | 6084 | (And you thought all that was required was to post an e-mail.) |
8642bc8f | 6085 | |
0816590b | 6086 | @subsubheading Install on sware |
8642bc8f | 6087 | |
0816590b | 6088 | Copy the new files to both the release and the old release directory: |
8642bc8f | 6089 | |
474c8240 | 6090 | @smallexample |
0816590b | 6091 | $ cp *.bz2 *.gz ~ftp/pub/gdb/old-releases/ |
8642bc8f | 6092 | $ cp *.bz2 *.gz ~ftp/pub/gdb/releases |
474c8240 | 6093 | @end smallexample |
8642bc8f | 6094 | |
0816590b AC |
6095 | @noindent |
6096 | Clean up the releases directory so that only the most recent releases | |
6097 | are available (e.g. keep 5.2 and 5.2.1 but remove 5.1): | |
6098 | ||
6099 | @smallexample | |
6100 | $ cd ~ftp/pub/gdb/releases | |
6101 | $ rm @dots{} | |
6102 | @end smallexample | |
6103 | ||
6104 | @noindent | |
6105 | Update the file @file{README} and @file{.message} in the releases | |
6106 | directory: | |
6107 | ||
6108 | @smallexample | |
6109 | $ vi README | |
6110 | @dots{} | |
6111 | $ rm -f .message | |
6112 | $ ln README .message | |
6113 | @end smallexample | |
8642bc8f | 6114 | |
0816590b | 6115 | @subsubheading Update the web pages. |
8973da3a | 6116 | |
0816590b AC |
6117 | @table @file |
6118 | ||
6119 | @item htdocs/download/ANNOUNCEMENT | |
6120 | This file, which is posted as the official announcement, includes: | |
8973da3a AC |
6121 | @itemize @bullet |
6122 | @item | |
0816590b | 6123 | General announcement |
8642bc8f | 6124 | @item |
0816590b AC |
6125 | News. If making an @var{M}.@var{N}.1 release, retain the news from |
6126 | earlier @var{M}.@var{N} release. | |
8973da3a | 6127 | @item |
0816590b AC |
6128 | Errata |
6129 | @end itemize | |
6130 | ||
6131 | @item htdocs/index.html | |
6132 | @itemx htdocs/news/index.html | |
6133 | @itemx htdocs/download/index.html | |
6134 | These files include: | |
6135 | @itemize @bullet | |
8642bc8f | 6136 | @item |
0816590b | 6137 | announcement of the most recent release |
8642bc8f | 6138 | @item |
0816590b | 6139 | news entry (remember to update both the top level and the news directory). |
8973da3a | 6140 | @end itemize |
0816590b | 6141 | These pages also need to be regenerate using @code{index.sh}. |
8973da3a | 6142 | |
0816590b | 6143 | @item download/onlinedocs/ |
8642bc8f AC |
6144 | You need to find the magic command that is used to generate the online |
6145 | docs from the @file{.tar.bz2}. The best way is to look in the output | |
0816590b | 6146 | from one of the nightly @code{cron} jobs and then just edit accordingly. |
8642bc8f AC |
6147 | Something like: |
6148 | ||
474c8240 | 6149 | @smallexample |
8642bc8f | 6150 | $ ~/ss/update-web-docs \ |
0816590b | 6151 | ~ftp/pub/gdb/releases/gdb-5.2.tar.bz2 \ |
8642bc8f | 6152 | $PWD/www \ |
0816590b | 6153 | /www/sourceware/htdocs/gdb/download/onlinedocs \ |
8642bc8f | 6154 | gdb |
474c8240 | 6155 | @end smallexample |
8642bc8f | 6156 | |
0816590b AC |
6157 | @item download/ari/ |
6158 | Just like the online documentation. Something like: | |
8642bc8f | 6159 | |
0816590b AC |
6160 | @smallexample |
6161 | $ /bin/sh ~/ss/update-web-ari \ | |
6162 | ~ftp/pub/gdb/releases/gdb-5.2.tar.bz2 \ | |
6163 | $PWD/www \ | |
6164 | /www/sourceware/htdocs/gdb/download/ari \ | |
6165 | gdb | |
6166 | @end smallexample | |
6167 | ||
6168 | @end table | |
6169 | ||
6170 | @subsubheading Shadow the pages onto gnu | |
6171 | ||
6172 | Something goes here. | |
6173 | ||
6174 | ||
6175 | @subsubheading Install the @value{GDBN} tar ball on GNU | |
6176 | ||
6177 | At the time of writing, the GNU machine was @kbd{gnudist.gnu.org} in | |
6178 | @file{~ftp/gnu/gdb}. | |
6179 | ||
6180 | @subsubheading Make the @file{ANNOUNCEMENT} | |
6181 | ||
6182 | Post the @file{ANNOUNCEMENT} file you created above to: | |
8642bc8f AC |
6183 | |
6184 | @itemize @bullet | |
6185 | @item | |
6186 | @email{gdb-announce@@sources.redhat.com, GDB Announcement mailing list} | |
6187 | @item | |
0816590b AC |
6188 | @email{info-gnu@@gnu.org, General GNU Announcement list} (but delay it a |
6189 | day or so to let things get out) | |
6190 | @item | |
6191 | @email{bug-gdb@@gnu.org, GDB Bug Report mailing list} | |
8642bc8f AC |
6192 | @end itemize |
6193 | ||
0816590b | 6194 | @subsection Cleanup |
8642bc8f | 6195 | |
0816590b | 6196 | The release is out but you're still not finished. |
8642bc8f | 6197 | |
0816590b | 6198 | @subsubheading Commit outstanding changes |
8642bc8f | 6199 | |
0816590b | 6200 | In particular you'll need to commit any changes to: |
8642bc8f AC |
6201 | |
6202 | @itemize @bullet | |
6203 | @item | |
6204 | @file{gdb/ChangeLog} | |
6205 | @item | |
6206 | @file{gdb/version.in} | |
6207 | @item | |
6208 | @file{gdb/NEWS} | |
6209 | @item | |
6210 | @file{gdb/README} | |
6211 | @end itemize | |
6212 | ||
0816590b | 6213 | @subsubheading Tag the release |
8642bc8f AC |
6214 | |
6215 | Something like: | |
6216 | ||
474c8240 | 6217 | @smallexample |
8642bc8f AC |
6218 | $ d=`date -u +%Y-%m-%d` |
6219 | $ echo $d | |
6220 | 2002-01-24 | |
6221 | $ ( cd insight/src/gdb && cvs -f -q update ) | |
0816590b | 6222 | $ ( cd insight/src && cvs -f -q tag gdb_5_2-$d-release ) |
474c8240 | 6223 | @end smallexample |
8642bc8f | 6224 | |
0816590b AC |
6225 | Insight is used since that contains more of the release than |
6226 | @value{GDBN} (@code{dejagnu} doesn't get tagged but I think we can live | |
6227 | with that). | |
6228 | ||
6229 | @subsubheading Mention the release on the trunk | |
8642bc8f | 6230 | |
0816590b AC |
6231 | Just put something in the @file{ChangeLog} so that the trunk also |
6232 | indicates when the release was made. | |
6233 | ||
6234 | @subsubheading Restart @file{gdb/version.in} | |
8642bc8f AC |
6235 | |
6236 | If @file{gdb/version.in} does not contain an ISO date such as | |
6237 | @kbd{2002-01-24} then the daily @code{cronjob} won't update it. Having | |
6238 | committed all the release changes it can be set to | |
0816590b | 6239 | @file{5.2.0_0000-00-00-cvs} which will restart things (yes the @kbd{_} |
8642bc8f AC |
6240 | is important - it affects the snapshot process). |
6241 | ||
6242 | Don't forget the @file{ChangeLog}. | |
6243 | ||
0816590b | 6244 | @subsubheading Merge into trunk |
8973da3a | 6245 | |
8642bc8f AC |
6246 | The files committed to the branch may also need changes merged into the |
6247 | trunk. | |
8973da3a | 6248 | |
0816590b AC |
6249 | @subsubheading Revise the release schedule |
6250 | ||
6251 | Post a revised release schedule to @email{gdb@@sources.redhat.com, GDB | |
6252 | Discussion List} with an updated announcement. The schedule can be | |
6253 | generated by running: | |
6254 | ||
6255 | @smallexample | |
6256 | $ ~/ss/schedule `date +%s` schedule | |
6257 | @end smallexample | |
6258 | ||
6259 | @noindent | |
6260 | The first parameter is approximate date/time in seconds (from the epoch) | |
6261 | of the most recent release. | |
6262 | ||
6263 | Also update the schedule @code{cronjob}. | |
6264 | ||
8642bc8f | 6265 | @section Post release |
8973da3a | 6266 | |
8642bc8f | 6267 | Remove any @code{OBSOLETE} code. |
8973da3a | 6268 | |
085dd6e6 JM |
6269 | @node Testsuite |
6270 | ||
6271 | @chapter Testsuite | |
56caf160 | 6272 | @cindex test suite |
085dd6e6 | 6273 | |
56caf160 EZ |
6274 | The testsuite is an important component of the @value{GDBN} package. |
6275 | While it is always worthwhile to encourage user testing, in practice | |
6276 | this is rarely sufficient; users typically use only a small subset of | |
6277 | the available commands, and it has proven all too common for a change | |
6278 | to cause a significant regression that went unnoticed for some time. | |
085dd6e6 | 6279 | |
56caf160 EZ |
6280 | The @value{GDBN} testsuite uses the DejaGNU testing framework. |
6281 | DejaGNU is built using @code{Tcl} and @code{expect}. The tests | |
6282 | themselves are calls to various @code{Tcl} procs; the framework runs all the | |
6283 | procs and summarizes the passes and fails. | |
085dd6e6 JM |
6284 | |
6285 | @section Using the Testsuite | |
6286 | ||
56caf160 | 6287 | @cindex running the test suite |
25822942 | 6288 | To run the testsuite, simply go to the @value{GDBN} object directory (or to the |
085dd6e6 JM |
6289 | testsuite's objdir) and type @code{make check}. This just sets up some |
6290 | environment variables and invokes DejaGNU's @code{runtest} script. While | |
6291 | the testsuite is running, you'll get mentions of which test file is in use, | |
6292 | and a mention of any unexpected passes or fails. When the testsuite is | |
6293 | finished, you'll get a summary that looks like this: | |
56caf160 | 6294 | |
474c8240 | 6295 | @smallexample |
085dd6e6 JM |
6296 | === gdb Summary === |
6297 | ||
6298 | # of expected passes 6016 | |
6299 | # of unexpected failures 58 | |
6300 | # of unexpected successes 5 | |
6301 | # of expected failures 183 | |
6302 | # of unresolved testcases 3 | |
6303 | # of untested testcases 5 | |
474c8240 | 6304 | @end smallexample |
56caf160 | 6305 | |
085dd6e6 JM |
6306 | The ideal test run consists of expected passes only; however, reality |
6307 | conspires to keep us from this ideal. Unexpected failures indicate | |
56caf160 EZ |
6308 | real problems, whether in @value{GDBN} or in the testsuite. Expected |
6309 | failures are still failures, but ones which have been decided are too | |
6310 | hard to deal with at the time; for instance, a test case might work | |
6311 | everywhere except on AIX, and there is no prospect of the AIX case | |
6312 | being fixed in the near future. Expected failures should not be added | |
6313 | lightly, since you may be masking serious bugs in @value{GDBN}. | |
6314 | Unexpected successes are expected fails that are passing for some | |
6315 | reason, while unresolved and untested cases often indicate some minor | |
6316 | catastrophe, such as the compiler being unable to deal with a test | |
6317 | program. | |
6318 | ||
6319 | When making any significant change to @value{GDBN}, you should run the | |
6320 | testsuite before and after the change, to confirm that there are no | |
6321 | regressions. Note that truly complete testing would require that you | |
6322 | run the testsuite with all supported configurations and a variety of | |
6323 | compilers; however this is more than really necessary. In many cases | |
6324 | testing with a single configuration is sufficient. Other useful | |
6325 | options are to test one big-endian (Sparc) and one little-endian (x86) | |
6326 | host, a cross config with a builtin simulator (powerpc-eabi, | |
6327 | mips-elf), or a 64-bit host (Alpha). | |
6328 | ||
6329 | If you add new functionality to @value{GDBN}, please consider adding | |
6330 | tests for it as well; this way future @value{GDBN} hackers can detect | |
6331 | and fix their changes that break the functionality you added. | |
6332 | Similarly, if you fix a bug that was not previously reported as a test | |
6333 | failure, please add a test case for it. Some cases are extremely | |
6334 | difficult to test, such as code that handles host OS failures or bugs | |
6335 | in particular versions of compilers, and it's OK not to try to write | |
6336 | tests for all of those. | |
085dd6e6 JM |
6337 | |
6338 | @section Testsuite Organization | |
6339 | ||
56caf160 | 6340 | @cindex test suite organization |
085dd6e6 JM |
6341 | The testsuite is entirely contained in @file{gdb/testsuite}. While the |
6342 | testsuite includes some makefiles and configury, these are very minimal, | |
6343 | and used for little besides cleaning up, since the tests themselves | |
25822942 | 6344 | handle the compilation of the programs that @value{GDBN} will run. The file |
085dd6e6 | 6345 | @file{testsuite/lib/gdb.exp} contains common utility procs useful for |
25822942 | 6346 | all @value{GDBN} tests, while the directory @file{testsuite/config} contains |
085dd6e6 JM |
6347 | configuration-specific files, typically used for special-purpose |
6348 | definitions of procs like @code{gdb_load} and @code{gdb_start}. | |
6349 | ||
6350 | The tests themselves are to be found in @file{testsuite/gdb.*} and | |
6351 | subdirectories of those. The names of the test files must always end | |
6352 | with @file{.exp}. DejaGNU collects the test files by wildcarding | |
6353 | in the test directories, so both subdirectories and individual files | |
6354 | get chosen and run in alphabetical order. | |
6355 | ||
6356 | The following table lists the main types of subdirectories and what they | |
6357 | are for. Since DejaGNU finds test files no matter where they are | |
6358 | located, and since each test file sets up its own compilation and | |
6359 | execution environment, this organization is simply for convenience and | |
6360 | intelligibility. | |
6361 | ||
56caf160 | 6362 | @table @file |
085dd6e6 | 6363 | @item gdb.base |
085dd6e6 | 6364 | This is the base testsuite. The tests in it should apply to all |
25822942 | 6365 | configurations of @value{GDBN} (but generic native-only tests may live here). |
085dd6e6 | 6366 | The test programs should be in the subset of C that is valid K&R, |
56caf160 | 6367 | ANSI/ISO, and C++ (@code{#ifdef}s are allowed if necessary, for instance |
085dd6e6 JM |
6368 | for prototypes). |
6369 | ||
6370 | @item gdb.@var{lang} | |
56caf160 | 6371 | Language-specific tests for any language @var{lang} besides C. Examples are |
085dd6e6 JM |
6372 | @file{gdb.c++} and @file{gdb.java}. |
6373 | ||
6374 | @item gdb.@var{platform} | |
085dd6e6 JM |
6375 | Non-portable tests. The tests are specific to a specific configuration |
6376 | (host or target), such as HP-UX or eCos. Example is @file{gdb.hp}, for | |
6377 | HP-UX. | |
6378 | ||
6379 | @item gdb.@var{compiler} | |
085dd6e6 JM |
6380 | Tests specific to a particular compiler. As of this writing (June |
6381 | 1999), there aren't currently any groups of tests in this category that | |
6382 | couldn't just as sensibly be made platform-specific, but one could | |
56caf160 EZ |
6383 | imagine a @file{gdb.gcc}, for tests of @value{GDBN}'s handling of GCC |
6384 | extensions. | |
085dd6e6 JM |
6385 | |
6386 | @item gdb.@var{subsystem} | |
25822942 | 6387 | Tests that exercise a specific @value{GDBN} subsystem in more depth. For |
085dd6e6 JM |
6388 | instance, @file{gdb.disasm} exercises various disassemblers, while |
6389 | @file{gdb.stabs} tests pathways through the stabs symbol reader. | |
085dd6e6 JM |
6390 | @end table |
6391 | ||
6392 | @section Writing Tests | |
56caf160 | 6393 | @cindex writing tests |
085dd6e6 | 6394 | |
25822942 | 6395 | In many areas, the @value{GDBN} tests are already quite comprehensive; you |
085dd6e6 JM |
6396 | should be able to copy existing tests to handle new cases. |
6397 | ||
6398 | You should try to use @code{gdb_test} whenever possible, since it | |
6399 | includes cases to handle all the unexpected errors that might happen. | |
6400 | However, it doesn't cost anything to add new test procedures; for | |
6401 | instance, @file{gdb.base/exprs.exp} defines a @code{test_expr} that | |
6402 | calls @code{gdb_test} multiple times. | |
6403 | ||
6404 | Only use @code{send_gdb} and @code{gdb_expect} when absolutely | |
25822942 | 6405 | necessary, such as when @value{GDBN} has several valid responses to a command. |
085dd6e6 JM |
6406 | |
6407 | The source language programs do @emph{not} need to be in a consistent | |
25822942 | 6408 | style. Since @value{GDBN} is used to debug programs written in many different |
085dd6e6 | 6409 | styles, it's worth having a mix of styles in the testsuite; for |
25822942 | 6410 | instance, some @value{GDBN} bugs involving the display of source lines would |
085dd6e6 JM |
6411 | never manifest themselves if the programs used GNU coding style |
6412 | uniformly. | |
6413 | ||
c906108c SS |
6414 | @node Hints |
6415 | ||
6416 | @chapter Hints | |
6417 | ||
6418 | Check the @file{README} file, it often has useful information that does not | |
6419 | appear anywhere else in the directory. | |
6420 | ||
6421 | @menu | |
25822942 | 6422 | * Getting Started:: Getting started working on @value{GDBN} |
33e16fad | 6423 | * Debugging GDB:: Debugging @value{GDBN} with itself |
c906108c SS |
6424 | @end menu |
6425 | ||
6426 | @node Getting Started,,, Hints | |
6427 | ||
6428 | @section Getting Started | |
6429 | ||
25822942 | 6430 | @value{GDBN} is a large and complicated program, and if you first starting to |
c906108c SS |
6431 | work on it, it can be hard to know where to start. Fortunately, if you |
6432 | know how to go about it, there are ways to figure out what is going on. | |
6433 | ||
25822942 DB |
6434 | This manual, the @value{GDBN} Internals manual, has information which applies |
6435 | generally to many parts of @value{GDBN}. | |
c906108c SS |
6436 | |
6437 | Information about particular functions or data structures are located in | |
6438 | comments with those functions or data structures. If you run across a | |
6439 | function or a global variable which does not have a comment correctly | |
25822942 | 6440 | explaining what is does, this can be thought of as a bug in @value{GDBN}; feel |
c906108c SS |
6441 | free to submit a bug report, with a suggested comment if you can figure |
6442 | out what the comment should say. If you find a comment which is | |
6443 | actually wrong, be especially sure to report that. | |
6444 | ||
6445 | Comments explaining the function of macros defined in host, target, or | |
6446 | native dependent files can be in several places. Sometimes they are | |
6447 | repeated every place the macro is defined. Sometimes they are where the | |
6448 | macro is used. Sometimes there is a header file which supplies a | |
6449 | default definition of the macro, and the comment is there. This manual | |
6450 | also documents all the available macros. | |
6451 | @c (@pxref{Host Conditionals}, @pxref{Target | |
6452 | @c Conditionals}, @pxref{Native Conditionals}, and @pxref{Obsolete | |
6453 | @c Conditionals}) | |
6454 | ||
56caf160 EZ |
6455 | Start with the header files. Once you have some idea of how |
6456 | @value{GDBN}'s internal symbol tables are stored (see @file{symtab.h}, | |
6457 | @file{gdbtypes.h}), you will find it much easier to understand the | |
6458 | code which uses and creates those symbol tables. | |
c906108c SS |
6459 | |
6460 | You may wish to process the information you are getting somehow, to | |
6461 | enhance your understanding of it. Summarize it, translate it to another | |
25822942 | 6462 | language, add some (perhaps trivial or non-useful) feature to @value{GDBN}, use |
c906108c SS |
6463 | the code to predict what a test case would do and write the test case |
6464 | and verify your prediction, etc. If you are reading code and your eyes | |
6465 | are starting to glaze over, this is a sign you need to use a more active | |
6466 | approach. | |
6467 | ||
25822942 | 6468 | Once you have a part of @value{GDBN} to start with, you can find more |
c906108c SS |
6469 | specifically the part you are looking for by stepping through each |
6470 | function with the @code{next} command. Do not use @code{step} or you | |
6471 | will quickly get distracted; when the function you are stepping through | |
6472 | calls another function try only to get a big-picture understanding | |
6473 | (perhaps using the comment at the beginning of the function being | |
6474 | called) of what it does. This way you can identify which of the | |
6475 | functions being called by the function you are stepping through is the | |
6476 | one which you are interested in. You may need to examine the data | |
6477 | structures generated at each stage, with reference to the comments in | |
6478 | the header files explaining what the data structures are supposed to | |
6479 | look like. | |
6480 | ||
6481 | Of course, this same technique can be used if you are just reading the | |
6482 | code, rather than actually stepping through it. The same general | |
6483 | principle applies---when the code you are looking at calls something | |
6484 | else, just try to understand generally what the code being called does, | |
6485 | rather than worrying about all its details. | |
6486 | ||
56caf160 EZ |
6487 | @cindex command implementation |
6488 | A good place to start when tracking down some particular area is with | |
6489 | a command which invokes that feature. Suppose you want to know how | |
6490 | single-stepping works. As a @value{GDBN} user, you know that the | |
6491 | @code{step} command invokes single-stepping. The command is invoked | |
6492 | via command tables (see @file{command.h}); by convention the function | |
6493 | which actually performs the command is formed by taking the name of | |
6494 | the command and adding @samp{_command}, or in the case of an | |
6495 | @code{info} subcommand, @samp{_info}. For example, the @code{step} | |
6496 | command invokes the @code{step_command} function and the @code{info | |
6497 | display} command invokes @code{display_info}. When this convention is | |
6498 | not followed, you might have to use @code{grep} or @kbd{M-x | |
6499 | tags-search} in emacs, or run @value{GDBN} on itself and set a | |
6500 | breakpoint in @code{execute_command}. | |
6501 | ||
6502 | @cindex @code{bug-gdb} mailing list | |
c906108c SS |
6503 | If all of the above fail, it may be appropriate to ask for information |
6504 | on @code{bug-gdb}. But @emph{never} post a generic question like ``I was | |
6505 | wondering if anyone could give me some tips about understanding | |
25822942 | 6506 | @value{GDBN}''---if we had some magic secret we would put it in this manual. |
c906108c SS |
6507 | Suggestions for improving the manual are always welcome, of course. |
6508 | ||
33e16fad | 6509 | @node Debugging GDB,,,Hints |
c906108c | 6510 | |
25822942 | 6511 | @section Debugging @value{GDBN} with itself |
56caf160 | 6512 | @cindex debugging @value{GDBN} |
c906108c | 6513 | |
25822942 | 6514 | If @value{GDBN} is limping on your machine, this is the preferred way to get it |
c906108c SS |
6515 | fully functional. Be warned that in some ancient Unix systems, like |
6516 | Ultrix 4.2, a program can't be running in one process while it is being | |
56caf160 | 6517 | debugged in another. Rather than typing the command @kbd{@w{./gdb |
c906108c | 6518 | ./gdb}}, which works on Suns and such, you can copy @file{gdb} to |
56caf160 | 6519 | @file{gdb2} and then type @kbd{@w{./gdb ./gdb2}}. |
c906108c | 6520 | |
25822942 | 6521 | When you run @value{GDBN} in the @value{GDBN} source directory, it will read a |
c906108c SS |
6522 | @file{.gdbinit} file that sets up some simple things to make debugging |
6523 | gdb easier. The @code{info} command, when executed without a subcommand | |
25822942 | 6524 | in a @value{GDBN} being debugged by gdb, will pop you back up to the top level |
c906108c SS |
6525 | gdb. See @file{.gdbinit} for details. |
6526 | ||
6527 | If you use emacs, you will probably want to do a @code{make TAGS} after | |
6528 | you configure your distribution; this will put the machine dependent | |
6529 | routines for your local machine where they will be accessed first by | |
6530 | @kbd{M-.} | |
6531 | ||
25822942 | 6532 | Also, make sure that you've either compiled @value{GDBN} with your local cc, or |
c906108c SS |
6533 | have run @code{fixincludes} if you are compiling with gcc. |
6534 | ||
6535 | @section Submitting Patches | |
6536 | ||
56caf160 | 6537 | @cindex submitting patches |
c906108c | 6538 | Thanks for thinking of offering your changes back to the community of |
25822942 | 6539 | @value{GDBN} users. In general we like to get well designed enhancements. |
c906108c SS |
6540 | Thanks also for checking in advance about the best way to transfer the |
6541 | changes. | |
6542 | ||
25822942 DB |
6543 | The @value{GDBN} maintainers will only install ``cleanly designed'' patches. |
6544 | This manual summarizes what we believe to be clean design for @value{GDBN}. | |
c906108c SS |
6545 | |
6546 | If the maintainers don't have time to put the patch in when it arrives, | |
6547 | or if there is any question about a patch, it goes into a large queue | |
6548 | with everyone else's patches and bug reports. | |
6549 | ||
56caf160 | 6550 | @cindex legal papers for code contributions |
c906108c SS |
6551 | The legal issue is that to incorporate substantial changes requires a |
6552 | copyright assignment from you and/or your employer, granting ownership | |
6553 | of the changes to the Free Software Foundation. You can get the | |
9e0b60a8 JM |
6554 | standard documents for doing this by sending mail to @code{gnu@@gnu.org} |
6555 | and asking for it. We recommend that people write in "All programs | |
6556 | owned by the Free Software Foundation" as "NAME OF PROGRAM", so that | |
56caf160 EZ |
6557 | changes in many programs (not just @value{GDBN}, but GAS, Emacs, GCC, |
6558 | etc) can be | |
9e0b60a8 | 6559 | contributed with only one piece of legalese pushed through the |
be9c6c35 | 6560 | bureaucracy and filed with the FSF. We can't start merging changes until |
9e0b60a8 JM |
6561 | this paperwork is received by the FSF (their rules, which we follow |
6562 | since we maintain it for them). | |
c906108c SS |
6563 | |
6564 | Technically, the easiest way to receive changes is to receive each | |
56caf160 EZ |
6565 | feature as a small context diff or unidiff, suitable for @code{patch}. |
6566 | Each message sent to me should include the changes to C code and | |
6567 | header files for a single feature, plus @file{ChangeLog} entries for | |
6568 | each directory where files were modified, and diffs for any changes | |
6569 | needed to the manuals (@file{gdb/doc/gdb.texinfo} or | |
6570 | @file{gdb/doc/gdbint.texinfo}). If there are a lot of changes for a | |
6571 | single feature, they can be split down into multiple messages. | |
9e0b60a8 JM |
6572 | |
6573 | In this way, if we read and like the feature, we can add it to the | |
c906108c | 6574 | sources with a single patch command, do some testing, and check it in. |
56caf160 EZ |
6575 | If you leave out the @file{ChangeLog}, we have to write one. If you leave |
6576 | out the doc, we have to puzzle out what needs documenting. Etc., etc. | |
c906108c | 6577 | |
9e0b60a8 JM |
6578 | The reason to send each change in a separate message is that we will not |
6579 | install some of the changes. They'll be returned to you with questions | |
6580 | or comments. If we're doing our job correctly, the message back to you | |
c906108c | 6581 | will say what you have to fix in order to make the change acceptable. |
9e0b60a8 JM |
6582 | The reason to have separate messages for separate features is so that |
6583 | the acceptable changes can be installed while one or more changes are | |
6584 | being reworked. If multiple features are sent in a single message, we | |
6585 | tend to not put in the effort to sort out the acceptable changes from | |
6586 | the unacceptable, so none of the features get installed until all are | |
6587 | acceptable. | |
6588 | ||
6589 | If this sounds painful or authoritarian, well, it is. But we get a lot | |
6590 | of bug reports and a lot of patches, and many of them don't get | |
6591 | installed because we don't have the time to finish the job that the bug | |
c906108c SS |
6592 | reporter or the contributor could have done. Patches that arrive |
6593 | complete, working, and well designed, tend to get installed on the day | |
9e0b60a8 JM |
6594 | they arrive. The others go into a queue and get installed as time |
6595 | permits, which, since the maintainers have many demands to meet, may not | |
6596 | be for quite some time. | |
c906108c | 6597 | |
56caf160 | 6598 | Please send patches directly to |
47b95330 | 6599 | @email{gdb-patches@@sources.redhat.com, the @value{GDBN} maintainers}. |
c906108c SS |
6600 | |
6601 | @section Obsolete Conditionals | |
56caf160 | 6602 | @cindex obsolete code |
c906108c | 6603 | |
25822942 | 6604 | Fragments of old code in @value{GDBN} sometimes reference or set the following |
c906108c SS |
6605 | configuration macros. They should not be used by new code, and old uses |
6606 | should be removed as those parts of the debugger are otherwise touched. | |
6607 | ||
6608 | @table @code | |
c906108c SS |
6609 | @item STACK_END_ADDR |
6610 | This macro used to define where the end of the stack appeared, for use | |
6611 | in interpreting core file formats that don't record this address in the | |
25822942 DB |
6612 | core file itself. This information is now configured in BFD, and @value{GDBN} |
6613 | gets the info portably from there. The values in @value{GDBN}'s configuration | |
c906108c | 6614 | files should be moved into BFD configuration files (if needed there), |
25822942 | 6615 | and deleted from all of @value{GDBN}'s config files. |
c906108c SS |
6616 | |
6617 | Any @file{@var{foo}-xdep.c} file that references STACK_END_ADDR | |
6618 | is so old that it has never been converted to use BFD. Now that's old! | |
6619 | ||
c906108c SS |
6620 | @end table |
6621 | ||
bcd7e15f | 6622 | @include observer.texi |
aab4e0ec AC |
6623 | @include fdl.texi |
6624 | ||
56caf160 EZ |
6625 | @node Index |
6626 | @unnumbered Index | |
6627 | ||
6628 | @printindex cp | |
6629 | ||
c906108c | 6630 | @bye |