1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 13
6 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
7 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
10 * GDB now has some support for integer types larger than 64 bits.
12 * Removed targets and native configurations
14 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
15 AIX version is now AIX 7.1.
17 * Multi-target feature configuration
19 GDB now supports the individual configuration of remote targets' feature
20 sets. Based on the current selection of a target, the commands 'set remote
21 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
22 configure a target's feature packet and to display its configuration,
25 The individual packet sizes can be configured and shown using the commands
26 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
27 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
28 ** 'show remote memory-read-packet-size'
29 ** 'show remote memory-write-packet-size'.
31 The configuration of the packet itself, as well as the size of a memory-read
32 or memory-write packet applies to the currently selected target (if
33 available). If no target is selected, it applies to future remote
34 connections. Similarly, the show commands print the configuration of the
35 currently selected target. If no remote target is selected, the default
36 configuration for future connections is shown.
38 * MI version 1 has been removed.
40 * GDB has initial built-in support for the Debugger Adapter Protocol.
41 This support requires that GDB be built with Python scripting
44 * For the break command, multiple uses of the 'thread' or 'task'
45 keywords will now give an error instead of just using the thread or
46 task id from the last instance of the keyword. E.g.:
47 break foo thread 1 thread 2
48 will now give an error rather than using 'thread 2'.
50 * For the watch command, multiple uses of the 'task' keyword will now
51 give an error instead of just using the task id from the last
52 instance of the keyword. E.g.:
53 watch my_var task 1 task 2
54 will now give an error rather than using 'task 2'. The 'thread'
55 keyword already gave an error when used multiple times with the
56 watch command, this remains unchanged.
58 * The 'set print elements' setting now helps when printing large arrays.
59 If an array would otherwise exceed max-value-size, but 'print elements'
60 is set such that the size of elements to print is less than or equal
61 to 'max-value-size', GDB will now still print the array, however only
62 'max-value-size' worth of data will be added into the value history.
64 * For both the break and watch commands, it is now invalid to use both
65 the 'thread' and 'task' keywords within the same command. For
66 example the following commnds will now give an error:
67 break foo thread 1 task 1
68 watch var thread 2 task 3
70 * The printf command now accepts a '%V' output format which will
71 format an expression just as the 'print' command would. Print
72 options can be placed withing '[...]' after the '%V' to modify how
73 the value is printed. E.g:
74 printf "%V", some_array
75 printf "%V[-array-indexes on]", some_array
76 will print the array without, or with array indexes included, just
77 as the array would be printed by the 'print' command. This
78 functionality is also available for dprintf when dprintf-style is
81 * When the printf command requires a string to be fetched from the
82 inferior, GDB now uses the existing 'max-value-size' setting to the
83 limit the memory allocated within GDB. The default 'max-value-size'
84 is 64k. To print longer strings you should increase
87 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
89 * The Ada 2022 target name symbol ('@') is now supported by the Ada
92 * The 'list' command now accepts '.' as an argument, which tells GDB to
93 print the location around the point of execution within the current frame.
94 If the inferior hasn't started yet, the command will print around the
95 beginning of the 'main' function.
97 * Using the 'list' command with no arguments in a situation where the
98 command would attempt to list past the end of the file now warns the
99 user that the end of file has been reached, refers the user to the
100 newly added '.' argument
102 * Breakpoints can now be inferior-specific. This is similar to the
103 existing thread-specific breakpoint support. Breakpoint conditions
104 can include the 'inferior' keyword followed by an inferior id (as
105 displayed in the 'info inferiors' output). It is invalid to use the
106 'inferior' keyword with either the 'thread' or 'task' keywords when
107 creating a breakpoint.
111 set debug breakpoint on|off
112 show debug breakpoint
113 Print additional debug messages about breakpoint insertion and removal.
115 maintenance print record-instruction [ N ]
116 Print the recorded information for a given instruction. If N is not given
117 prints how GDB would undo the last instruction executed. If N is negative,
118 prints how GDB would undo the N-th previous instruction, and if N is
119 positive, it prints how GDB will redo the N-th following instruction.
121 maintenance info frame-unwinders
122 List the frame unwinders currently in effect, starting with the highest
125 maintenance wait-for-index-cache
126 Wait until all pending writes to the index cache have completed.
128 set always-read-ctf on|off
130 When off, CTF is only read if DWARF is not present. When on, CTF is
131 read regardless of whether DWARF is present. Off by default.
134 Get main symbol to identify entry point into program.
136 * New convenience function "$_shell", to execute a shell command and
137 return the result. This lets you run shell commands in expressions.
140 (gdb) p $_shell("true")
142 (gdb) p $_shell("false")
144 (gdb) break func if $_shell("some command") == 0
148 ** mi now reports 'no-history' as a stop reason when hitting the end of the
149 reverse execution history.
151 ** When creating a thread-specific breakpoint using the '-p' option,
152 the -break-insert command would report the 'thread' field twice in
153 the reply. The content of both fields was always identical. This
154 has now been fixed; the 'thread' field will be reported just once
155 for thread-specific breakpoints, or not at all for breakpoints
156 without a thread restriction. The same is also true for the 'task'
157 field of an Ada task-specific breakpoint.
159 ** It is no longer possible to create a thread-specific breakpoint for
160 a thread that doesn't exist using '-break-insert -p ID'. Creating
161 breakpoints for non-existent threads is not allowed when using the
162 CLI, that the MI allowed it was a long standing bug, which has now
165 ** The '--simple-values' argument to the '-stack-list-arguments',
166 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
167 commands now takes reference types into account: that is, a value is now
168 considered simple if it is neither an array, structure, or union, nor a
169 reference to an array, structure, or union. (Previously all references were
170 considered simple.) Support for this feature can be verified by using the
171 '-list-features' command, which should contain "simple-values-ref-types".
173 ** The -break-insert command now accepts a '-g thread-group-id' option
174 to allow for the creation of inferior-specific breakpoints.
176 ** The bkpt tuple, which appears in breakpoint-created notifications,
177 and in the result of the -break-insert command can now include an
178 optional 'inferior' field for both the main breakpoint, and each
179 location, when the breakpoint is inferior-specific.
183 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
185 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
187 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
188 now be of type 'str' otherwise a TypeError will be raised.
190 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
191 values of type 'bool'. Changing this attribute will now
192 invalidate GDB's frame-cache, which means GDB will need to
193 rebuild its frame-cache when next required - either with, or
194 without the particular unwinder, depending on how 'enabled' was
197 ** New methods added to the gdb.PendingFrame class. These methods
198 have the same behaviour as the corresponding methods on
199 gdb.Frame. The new methods are:
201 - gdb.PendingFrame.name: Return the name for the frame's
203 - gdb.PendingFrame.is_valid: Return True if the pending frame
205 - gdb.PendingFrame.pc: Return the $pc register value for this
207 - gdb.PendingFrame.language: Return a string containing the
208 language for this frame, or None.
209 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
210 object for the current location within the pending frame, or
212 - gdb.PendingFrame.block: Return a gdb.Block for the current
213 pending frame, or None.
214 - gdb.PendingFrame.function: Return a gdb.Symbol for the
215 current pending frame, or None.
217 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
218 now use either an integer or a gdb.Value object for each of its
219 'sp', 'pc', and 'special' attributes.
221 ** A new class gdb.unwinder.FrameId has been added. Instances of
222 this class are constructed with 'sp' (stack-pointer) and 'pc'
223 (program-counter) values, and can be used as the frame-id when
224 calling gdb.PendingFrame.create_unwind_info.
226 ** It is now no longer possible to sub-class the
227 gdb.disassembler.DisassemblerResult type.
229 ** The Disassembler API from the gdb.disassembler module has been
230 extended to include styling support:
232 - The DisassemblerResult class can now be initialized with a list
233 of parts. Each part represents part of the disassembled
234 instruction along with the associated style information. This
235 list of parts can be accessed with the new
236 DisassemblerResult.parts property.
238 - New constants gdb.disassembler.STYLE_* representing all the
239 different styles part of an instruction might have.
241 - New methods DisassembleInfo.text_part and
242 DisassembleInfo.address_part which are used to create the new
243 styled parts of a disassembled instruction.
245 - Changes are backwards compatible, the older API can still be
246 used to disassemble instructions without styling.
248 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
249 GDB/MI command and returns the output as a Python dictionary.
251 ** New function gdb.block_signals(). This returns a context manager
252 that blocks any signals that GDB needs to handle itself.
254 ** New class gdb.Thread. This is a subclass of threading.Thread
255 that calls gdb.block_signals in its "start" method.
257 ** gdb.parse_and_eval now has a new "global_context" parameter.
258 This can be used to request that the parse only examine global
261 ** gdb.Inferior now has a new "arguments" attribute. This holds the
262 command-line arguments to the inferior, if known.
264 ** gdb.Inferior now has a new "main_name" attribute. This holds the
265 name of the inferior's "main", if known.
267 ** gdb.Inferior now has new methods "clear_env", "set_env", and
268 "unset_env". These can be used to modify the inferior's
269 environment before it is started.
271 ** gdb.Value now has the 'assign' method.
273 ** gdb.Value now has the 'to_array' method. This converts an
274 array-like Value to an array.
276 ** gdb.Progspace now has the new method "objfile_for_address". This
277 returns the gdb.Objfile, if any, that covers a given address.
279 ** gdb.Breakpoint now has an "inferior" attribute. If the
280 Breakpoint object is inferior specific then this attribute holds
281 the inferior-id (an integer). If the Breakpoint object is not
282 inferior specific, then this field contains None. This field can
285 ** gdb.Type now has the "is_array_like" and "is_string_like"
286 methods. These reflect GDB's internal idea of whether a type
287 might be array- or string-like, even if they do not have the
288 corresponding type code.
290 *** Changes in GDB 13
292 * MI version 1 is deprecated, and will be removed in GDB 14.
294 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
295 reading memory tag data for AArch64 MTE from core files generated by
296 the gcore command or the Linux kernel.
298 When a process uses memory-mapped pages protected by memory tags (for
299 example, AArch64 MTE), this additional information will be recorded in
300 the core file in the event of a crash or if GDB generates a core file
301 from the current process state. GDB will show this additional information
302 automatically, or through one of the memory-tag subcommands.
304 * "info breakpoints" now displays enabled breakpoint locations of
305 disabled breakpoints as in the "y-" state. For example:
307 (gdb) info breakpoints
308 Num Type Disp Enb Address What
309 1 breakpoint keep n <MULTIPLE>
310 1.1 y- 0x00000000000011b6 in ...
311 1.2 y- 0x00000000000011c2 in ...
312 1.3 n 0x00000000000011ce in ...
314 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
315 aarch64 architectures.
317 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
319 * Remove support for building against Python 2, it is now only possible to
320 build GDB against Python 3.
322 * DBX mode has been removed.
324 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
325 emit to indicate where a breakpoint should be placed to break in a function
328 * Completion now also offers "NUMBER" for "set" commands that accept
329 a numeric argument and the "unlimited" keyword. For example:
331 (gdb) set width <TAB>
336 (gdb) complete set width
340 * Disassembler styling using libopcodes. GDB now supports
341 disassembler styling using libopcodes. This is only available for
342 some targets (currently x86 and RISC-V). For unsupported targets
343 Python Pygments is still used. For supported targets, libopcodes
344 styling is used by default.
346 * The Windows native target now supports target async.
348 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
350 * The format of 'disassemble /r' and 'record instruction-history /r'
351 has changed. The instruction bytes could now be grouped together,
352 and displayed in the endianness of the instruction. This is the
353 same layout as used by GNU objdump when disassembling.
355 There is now 'disassemble /b' and 'record instruction-history /b'
356 which will always display the instructions bytes one at a time in
357 memory order, that is, the byte at the lowest address first.
359 For both /r and /b GDB is now better at using whitespace in order to
360 align the disassembled instruction text.
362 * The TUI no longer styles the source and assembly code highlighted by
363 the current position indicator by default. You can however
364 re-enable styling using the new "set style tui-current-position"
367 * New convenience variable $_inferior_thread_count contains the number
368 of live threads in the current inferior.
370 * When a breakpoint with multiple code locations is hit, GDB now prints
371 the code location using the syntax <breakpoint_number>.<location_number>
373 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
375 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
376 and $_hit_locno to the hit breakpoint number and code location number.
377 This allows to disable the last hit breakpoint using
378 (gdb) disable $_hit_bpnum
379 or disable only the specific breakpoint code location using
380 (gdb) disable $_hit_bpnum.$_hit_locno
381 These commands can be used inside the command list of a breakpoint to
382 automatically disable the just encountered breakpoint (or the just
383 encountered specific breakpoint code location).
384 When a breakpoint has only one location, $_hit_locno is set to 1 so that
385 (gdb) disable $_hit_bpnum.$_hit_locno
387 (gdb) disable $_hit_bpnum
388 are both disabling the breakpoint.
392 maintenance set ignore-prologue-end-flag on|off
393 maintenance show ignore-prologue-end-flag
394 This setting, which is off by default, controls whether GDB ignores the
395 PROLOGUE-END flag from the line-table when skipping prologue. This can be
396 used to force GDB to use prologue analyzers if the line-table is constructed
397 from erroneous debug information.
399 set print nibbles [on|off]
401 This controls whether the 'print/t' command will display binary values
402 in groups of four bits, known as "nibbles". The default is 'off'.
404 maintenance set libopcodes-styling on|off
405 maintenance show libopcodes-styling
406 These can be used to force off libopcodes based styling, the Python
407 Pygments styling will then be used instead.
409 set style disassembler comment
410 show style disassembler comment
411 set style disassembler immediate
412 show style disassembler immediate
413 set style disassembler mnemonic
414 show style disassembler mnemonic
415 set style disassembler register
416 show style disassembler register
417 set style disassembler address
418 show style disassembler address
419 set style disassembler symbol
420 show style disassembler symbol
421 For targets that support libopcodes based styling, these settings
422 control how various aspects of the disassembler output are styled.
423 The 'disassembler address' and 'disassembler symbol' styles are
424 aliases for the 'address' and 'function' styles respectively.
426 maintenance print frame-id [ LEVEL ]
427 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
428 not given, then print the frame-id for the currently selected frame.
430 set debug infcall on|off
432 Print additional debug messages about inferior function calls.
434 set debug solib on|off
436 Print additional debug messages about shared library handling.
438 set style tui-current-position [on|off]
439 Whether to style the source and assembly code highlighted by the
440 TUI's current position indicator. The default is off.
442 set print characters LIMIT
443 show print characters
444 This new setting is like 'set print elements', but controls how many
445 characters of a string are printed. This functionality used to be
446 covered by 'set print elements', but it can be controlled separately
447 now. LIMIT can be set to a numerical value to request that particular
448 character count, to 'unlimited' to print all characters of a string,
449 or to 'elements', which is also the default, to follow the setting of
450 'set print elements' as it used to be.
452 print -characters LIMIT
453 This new option to the 'print' command has the same effect as a temporary
454 use of 'set print characters'.
458 document user-defined
459 It is now possible to document user-defined aliases.
460 When a user-defined alias is documented, the help and apropos commands
461 use the provided documentation instead of the documentation of the
463 Documenting a user-defined alias is particularly useful when the alias
464 is a set of nested 'with' commands to avoid showing the help of
465 the with command for an alias that will in fact launch the
466 last command given in the nested commands.
468 maintenance info line-table
469 Add a PROLOGUE-END column to the output which indicates that an
470 entry corresponds to an address where a breakpoint should be placed
471 to be at the first instruction past a function's prologue.
475 set debug aix-solib on|off
477 set debug solib-frv on|off
479 Removed in favor of "set/show debug solib".
481 maintenance info program-spaces
482 This command now includes a 'Core File' column which indicates the
483 name of the core file associated with each program space.
487 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
489 GNU/Linux/CSKY (gdbserver) csky*-*linux*
495 ** The async record stating the stopped reason 'breakpoint-hit' now
496 contains an optional field locno giving the code location number
497 when the breakpoint has multiple code locations.
501 ** GDB will now reformat the doc string for gdb.Command and
502 gdb.Parameter sub-classes to remove unnecessary leading
503 whitespace from each line before using the string as the help
506 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
507 that formats ADDRESS as 'address <symbol+offset>', where symbol is
508 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
509 This is the same format that GDB uses when printing address, symbol,
510 and offset information from the disassembler.
512 ** New function gdb.current_language that returns the name of the
513 current language. Unlike gdb.parameter('language'), this will
516 ** New method gdb.Frame.language that returns the name of the
519 ** New Python API for wrapping GDB's disassembler:
521 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
522 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
523 ARCH is either None or a string containing a bfd architecture
524 name. DISASSEMBLER is registered as a disassembler for
525 architecture ARCH, or for all architectures if ARCH is None.
526 The previous disassembler registered for ARCH is returned, this
527 can be None if no previous disassembler was registered.
529 - gdb.disassembler.Disassembler is the class from which all
530 disassemblers should inherit. Its constructor takes a string,
531 a name for the disassembler, which is currently only used in
532 some debug output. Sub-classes should override the __call__
533 method to perform disassembly, invoking __call__ on this base
534 class will raise an exception.
536 - gdb.disassembler.DisassembleInfo is the class used to describe
537 a single disassembly request from GDB. An instance of this
538 class is passed to the __call__ method of
539 gdb.disassembler.Disassembler and has the following read-only
540 attributes: 'address', and 'architecture', as well as the
541 following method: 'read_memory'.
543 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
544 calls GDB's builtin disassembler on INFO, which is a
545 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
546 optional, its default value is None. If MEMORY_SOURCE is not
547 None then it must be an object that has a 'read_memory' method.
549 - gdb.disassembler.DisassemblerResult is a class that can be used
550 to wrap the result of a call to a Disassembler. It has
551 read-only attributes 'length' and 'string'.
553 ** gdb.Objfile now has an attribute named "is_file". This is True
554 if the objfile comes from a file, and False otherwise.
556 ** New function gdb.print_options that returns a dictionary of the
557 prevailing print options, in the form accepted by
558 gdb.Value.format_string.
560 ** gdb.Value.format_string now uses the format provided by 'print',
561 if it is called during a 'print' or other similar operation.
563 ** gdb.Value.format_string now accepts the 'summary' keyword. This
564 can be used to request a shorter representation of a value, the
565 way that 'set print frame-arguments scalars' does.
567 ** New Python type gdb.BreakpointLocation.
568 The new attribute 'locations' of gdb.Breakpoint returns a list of
569 gdb.BreakpointLocation objects specifying the locations where the
570 breakpoint is inserted into the debuggee.
572 ** The gdb.register_window_type method now restricts the set of
573 acceptable window names. The first character of a window's name
574 must start with a character in the set [a-zA-Z], every subsequent
575 character of a window's name must be in the set [-_.a-zA-Z0-9].
577 * New features in the GDB remote stub, GDBserver
579 ** GDBserver is now supported on LoongArch GNU/Linux.
581 ** GDBserver is now supported on CSKY GNU/Linux.
583 * LoongArch floating-point support
585 GDB now supports floating-point on LoongArch GNU/Linux.
587 * AMD GPU ROCm debugging support
589 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
592 *** Changes in GDB 12
594 * DBX mode is deprecated, and will be removed in GDB 13
596 * GDB 12 is the last release of GDB that will support building against
597 Python 2. From GDB 13, it will only be possible to build GDB itself
598 with Python 3 support.
600 * The disable-randomization setting now works on Windows.
602 * Improved C++ template support
604 GDB now treats functions/types involving C++ templates like it does function
605 overloads. Users may omit parameter lists to set breakpoints on families of
606 template functions, including types/functions composed of multiple template types:
608 (gdb) break template_func(template_1, int)
610 The above will set breakpoints at every function `template_func' where
611 the first function parameter is any template type named `template_1' and
612 the second function parameter is `int'.
614 TAB completion also gains similar improvements.
616 * The FreeBSD native target now supports async mode.
622 Enable or disable multithreaded symbol loading. This is enabled
623 by default, but passing --disable-threading or --enable-threading=no
624 to configure will disable it.
626 Disabling this can cause a performance penalty when there are a lot of
627 symbols to load, but is useful for debugging purposes.
631 maint set backtrace-on-fatal-signal on|off
632 maint show backtrace-on-fatal-signal
633 This setting is 'on' by default. When 'on' GDB will print a limited
634 backtrace to stderr in the situation where GDB terminates with a
635 fatal signal. This only supported on some platforms where the
636 backtrace and backtrace_symbols_fd functions are available.
638 set source open on|off
640 This setting, which is on by default, controls whether GDB will try
641 to open source code files. Switching this off will stop GDB trying
642 to open and read source code files, which can be useful if the files
643 are located over a slow network connection.
647 These are now deprecated aliases for "set max-value-size" and
648 "show max-value-size".
650 task apply [all | TASK-IDS...] [FLAG]... COMMAND
651 Like "thread apply", but applies COMMAND to Ada tasks.
654 Watchpoints can now be restricted to a specific Ada task.
656 maint set internal-error backtrace on|off
657 maint show internal-error backtrace
658 maint set internal-warning backtrace on|off
659 maint show internal-warning backtrace
660 GDB can now print a backtrace of itself when it encounters either an
661 internal-error, or an internal-warning. This is on by default for
662 internal-error and off by default for internal-warning.
665 Deprecated and replaced by "set logging enabled on|off".
667 set logging enabled on|off
669 These commands set or show whether logging is enabled or disabled.
672 You can now exit GDB by using the new command "exit", in addition to
673 the existing "quit" command.
675 set debug threads on|off
677 Print additional debug messages about thread creation and deletion.
679 set debug linux-nat on|off
681 These new commands replaced the old 'set debug lin-lwp' and 'show
682 debug lin-lwp' respectively. Turning this setting on prints debug
683 messages relating to GDB's handling of native Linux inferiors.
685 maint flush source-cache
686 Flush the contents of the source code cache.
688 maint set gnu-source-highlight enabled on|off
689 maint show gnu-source-highlight enabled
690 Whether GDB should use the GNU Source Highlight library for adding
691 styling to source code. When off, the library will not be used, even
692 when available. When GNU Source Highlight isn't used, or can't add
693 styling to a particular source file, then the Python Pygments
694 library will be used instead.
696 set suppress-cli-notifications (on|off)
697 show suppress-cli-notifications
698 This controls whether printing the notifications is suppressed for CLI.
699 CLI notifications occur when you change the selected context
700 (i.e., the current inferior, thread and/or the frame), or when
701 the program being debugged stops (e.g., because of hitting a
702 breakpoint, completing source-stepping, an interrupt, etc.).
704 set style disassembler enabled on|off
705 show style disassembler enabled
706 If GDB is compiled with Python support, and the Python Pygments
707 package is available, then, when this setting is on, disassembler
708 output will have styling applied.
710 set ada source-charset
711 show ada source-charset
712 Set the character set encoding that is assumed for Ada symbols. Valid
713 values for this follow the values that can be passed to the GNAT
714 compiler via the '-gnati' option. The default is ISO-8859-1.
720 These are the new names for the old 'layout', 'focus', 'refresh',
721 and 'winheight' tui commands respectively. The old names still
722 exist as aliases to these new commands.
726 The new command 'tui window width', and the alias 'winwidth' allow
727 the width of a tui window to be adjusted when windows are laid out
732 Control the display of debug output about GDB's tui.
737 Printing of floating-point values with base-modifying formats like
738 /x has been changed to display the underlying bytes of the value in
739 the desired base. This was GDB's documented behavior, but was never
740 implemented correctly.
743 This command can now print a reply, if the reply includes
744 non-printable characters. Any non-printable characters are printed
745 as escaped hex, e.g. \x?? where '??' is replaces with the value of
746 the non-printable character.
749 The clone-inferior command now ensures that the TTY, CMD and ARGS
750 settings are copied from the original inferior to the new one.
751 All modifications to the environment variables done using the 'set
752 environment' or 'unset environment' commands are also copied to the new
755 set debug lin-lwp on|off
757 These commands have been removed from GDB. The new command 'set
758 debug linux-nat' and 'show debug linux-nat' should be used
762 This command now includes information about the width of the tui
763 windows in its output.
769 These commands are now aliases for the 'tui layout', 'tui focus',
770 'tui refresh', and 'tui window height' commands respectively.
772 * GDB's Ada parser now supports an extension for specifying the exact
773 byte contents of a floating-point literal. This can be useful for
774 setting floating-point registers to a precise value without loss of
775 precision. The syntax is an extension of the based literal syntax.
776 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
777 of the floating-point type, and the "f" is the marker for floating
782 ** The '-add-inferior' with no option flags now inherits the
783 connection of the current inferior, this restores the behaviour of
784 GDB as it was prior to GDB 10.
786 ** The '-add-inferior' command now accepts a '--no-connection'
787 option, which causes the new inferior to start without a
790 ** The default version of the MI interpreter is now 4 (-i=mi4).
792 ** The "script" field in breakpoint output (which is syntactically
793 incorrect in MI 3 and below) has changed in MI 4 to become a list.
794 This affects the following commands and events:
798 - =breakpoint-created
799 - =breakpoint-modified
801 The -fix-breakpoint-script-output command can be used to enable
802 this behavior with previous MI versions.
806 GNU/Linux/LoongArch loongarch*-*-linux*
814 ** New function gdb.add_history(), which takes a gdb.Value object
815 and adds the value it represents to GDB's history list. An
816 integer, the index of the new item in the history list, is
819 ** New function gdb.history_count(), which returns the number of
820 values in GDB's value history.
822 ** New gdb.events.gdb_exiting event. This event is called with a
823 gdb.GdbExitingEvent object which has the read-only attribute
824 'exit_code', which contains the value of the GDB exit code. This
825 event is triggered once GDB decides it is going to exit, but
826 before GDB starts to clean up its internal state.
828 ** New function gdb.architecture_names(), which returns a list
829 containing all of the possible Architecture.name() values. Each
832 ** New function gdb.Architecture.integer_type(), which returns an
833 integer type given a size and a signed-ness.
835 ** New gdb.TargetConnection object type that represents a connection
836 (as displayed by the 'info connections' command). A sub-class,
837 gdb.RemoteTargetConnection, is used to represent 'remote' and
838 'extended-remote' connections.
840 ** The gdb.Inferior type now has a 'connection' property which is an
841 instance of gdb.TargetConnection, the connection used by this
842 inferior. This can be None if the inferior has no connection.
844 ** New 'gdb.events.connection_removed' event registry, which emits a
845 'gdb.ConnectionEvent' when a connection is removed from GDB.
846 This event has a 'connection' property, a gdb.TargetConnection
847 object for the connection being removed.
849 ** New gdb.connections() function that returns a list of all
850 currently active connections.
852 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
853 is equivalent to the existing 'maint packet' CLI command; it
854 allows a user specified packet to be sent to the remote target.
856 ** New function gdb.host_charset(), returns a string, which is the
857 name of the current host charset.
859 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
862 ** New gdb.with_parameter(NAME, VALUE). This returns a context
863 manager that temporarily sets the gdb parameter NAME to VALUE,
864 then resets it when the context is exited.
866 ** The gdb.Value.format_string method now takes a 'styling'
867 argument, which is a boolean. When true, the returned string can
868 include escape sequences to apply styling. The styling will only
869 be present if styling is otherwise turned on in GDB (see 'help
870 set styling'). When false, which is the default if the argument
871 is not given, then no styling is applied to the returned string.
873 ** New read-only attribute gdb.InferiorThread.details, which is
874 either a string, containing additional, target specific thread
875 state information, or None, if there is no such additional
878 ** New read-only attribute gdb.Type.is_scalar, which is True for
879 scalar types, and False for all other types.
881 ** New read-only attribute gdb.Type.is_signed. This attribute
882 should only be read when Type.is_scalar is True, and will be True
883 for signed types, and False for all other types. Attempting to
884 read this attribute for non-scalar types will raise a ValueError.
886 ** It is now possible to add GDB/MI commands implemented in Python.
888 * New features in the GDB remote stub, GDBserver
890 ** GDBserver is now supported on OpenRISC GNU/Linux.
892 * New native configurations
894 GNU/Linux/OpenRISC or1k*-*-linux*
896 *** Changes in GDB 11
898 * The 'set disassembler-options' command now supports specifying options
901 * GDB now supports general memory tagging functionality if the underlying
902 architecture supports the proper primitives and hooks. Currently this is
903 enabled only for AArch64 MTE.
907 - Additional information when the inferior crashes with a SIGSEGV caused by
908 a memory tag violation.
910 - A new modifier 'm' for the "x" command, which displays allocation tags for a
911 particular memory range.
913 - Display of memory tag mismatches by "print", for addresses and
914 pointers, if memory tagging is supported by the architecture.
916 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
921 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
923 The MI -break-insert and -dprintf-insert commands now support a
924 new "--qualified" option that makes GDB interpret a specified
925 function name as a complete fully-qualified name. This is the
926 equivalent of the CLI's "break -qualified" and "dprintf
929 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
931 The MI -break-insert and -dprintf-insert commands now support a
932 '--force-condition' flag to forcibly define a condition even when
933 the condition is invalid at all locations of the breakpoint. This
934 is equivalent to the '-force-condition' flag of the CLI's "break"
937 ** '-break-condition --force'
939 The MI -break-condition command now supports a '--force' flag to
940 forcibly define a condition even when the condition is invalid at
941 all locations of the selected breakpoint. This is equivalent to
942 the '-force' flag of the CLI's "cond" command.
944 ** '-file-list-exec-source-files [--group-by-objfile]
945 [--basename | --dirname]
948 The existing -file-list-exec-source-files command now takes an
949 optional REGEXP which is used to filter the source files that are
950 included in the results.
952 By default REGEXP is matched against the full filename of the
953 source file. When one of --basename or --dirname is given then
954 REGEXP is only matched against the specified part of the full
957 When the optional --group-by-objfile flag is used the output
958 format is changed, the results are now a list of object files
959 (executable and libraries) with the source files that are
960 associated with each object file.
962 The results from -file-list-exec-source-files now include a
963 'debug-fully-read' field which takes the value 'true' or 'false'.
964 A 'true' value indicates the source file is from a compilation
965 unit that has had its debug information fully read in by GDB, a
966 value of 'false' indicates GDB has only performed a partial scan
967 of the debug information so far.
969 * GDB now supports core file debugging for x86_64 Cygwin programs.
971 * GDB will now look for the .gdbinit file in a config directory before
972 looking for ~/.gdbinit. The file is searched for in the following
973 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
974 $HOME/.gdbinit. On Apple hosts the search order is instead:
975 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
977 * GDB now supports fixed point types which are described in DWARF
978 as base types with a fixed-point encoding. Additionally, support
979 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
982 For Ada, this allows support for fixed point types without requiring
983 the use of the GNAT encoding (based on information added to the type's
984 name following a GNAT-specific format).
986 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
987 or ~/.gdbearlyinit if these files are present. These files are
988 processed earlier than any of the other initialization files and
989 can affect parts of GDB's startup that previously had already been
990 completed before the initialization files were read, for example
991 styling of the initial GDB greeting.
993 * GDB now has two new options "--early-init-command" and
994 "--early-init-eval-command" with corresponding short options "-eix"
995 and "-eiex" that allow options (that would normally appear in a
996 gdbearlyinit file) to be passed on the command line.
998 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
999 now understood by GDB, and can be used to describe the vector
1000 registers of a target. The precise requirements of this register
1001 feature are documented in the GDB manual.
1003 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1004 supported by GDB and describes a new VPR register from the ARM MVE
1005 (Helium) extension. See the GDB manual for more information.
1009 ** TUI windows now support mouse actions. The mouse wheel scrolls
1010 the appropriate window.
1012 ** Key combinations that do not have a specific action on the
1013 focused window are passed to GDB. For example, you now can use
1014 Ctrl-Left/Ctrl-Right to move between words in the command window
1015 regardless of which window is in focus. Previously you would
1016 need to focus on the command window for such key combinations to
1021 set debug event-loop
1022 show debug event-loop
1023 Control the display of debug output about GDB's event loop.
1025 set print memory-tag-violations
1026 show print memory-tag-violations
1027 Control whether to display additional information about memory tag violations
1028 when printing pointers and addresses. Architecture support for memory
1029 tagging is required for this option to have an effect.
1031 maintenance flush symbol-cache
1032 maintenance flush register-cache
1033 These new commands are equivalent to the already existing commands
1034 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1036 maintenance flush dcache
1037 A new command to flush the dcache.
1039 maintenance info target-sections
1040 Print GDB's internal target sections table.
1042 maintenance info jit
1043 Print the JIT code objects in the inferior known to GDB.
1045 memory-tag show-logical-tag POINTER
1046 Print the logical tag for POINTER.
1047 memory-tag with-logical-tag POINTER TAG
1048 Print POINTER with logical tag TAG.
1049 memory-tag show-allocation-tag ADDRESS
1050 Print the allocation tag for ADDRESS.
1051 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1052 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1053 memory-tag check POINTER
1054 Validate that POINTER's logical tag matches the allocation tag.
1056 set startup-quietly on|off
1057 show startup-quietly
1058 When 'on', this causes GDB to act as if "-silent" were passed on the
1059 command line. This command needs to be added to an early
1060 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1063 set print type hex on|off
1065 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1066 and offsets of struct members. When 'off', decimal notation is used.
1068 set python ignore-environment on|off
1069 show python ignore-environment
1070 When 'on', this causes GDB's builtin Python to ignore any
1071 environment variables that would otherwise affect how Python
1072 behaves. This command needs to be added to an early initialization
1073 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1075 set python dont-write-bytecode auto|on|off
1076 show python dont-write-bytecode
1077 When 'on', this causes GDB's builtin Python to not write any
1078 byte-code (.pyc files) to disk. This command needs to be added to
1079 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1080 order to affect GDB. When 'off' byte-code will always be written.
1081 When set to 'auto' (the default) Python will check the
1082 PYTHONDONTWRITEBYTECODE environment variable.
1086 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1087 [-force-condition] [if CONDITION]
1088 This command would previously refuse setting a breakpoint if the
1089 CONDITION expression is invalid at a location. It now accepts and
1090 defines the breakpoint if there is at least one location at which
1091 the CONDITION is valid. The locations for which the CONDITION is
1092 invalid, are automatically disabled. If CONDITION is invalid at all
1093 of the locations, setting the breakpoint is still rejected. However,
1094 the '-force-condition' flag can be used in this case for forcing GDB to
1095 define the breakpoint, making all the current locations automatically
1096 disabled. This may be useful if the user knows the condition will
1097 become meaningful at a future location, e.g. due to a shared library
1100 condition [-force] N COND
1101 The behavior of this command is changed the same way for the 'break'
1102 command as explained above. The '-force' flag can be used to force
1103 GDB into defining the condition even when COND is invalid for all the
1104 current locations of breakpoint N.
1107 maintenance flush-symbol-cache
1108 These commands are deprecated in favor of the new commands
1109 'maintenance flush register-cache' and 'maintenance flush
1110 symbol-cache' respectively.
1112 set style version foreground COLOR
1113 set style version background COLOR
1114 set style version intensity VALUE
1115 Control the styling of GDB's version number text.
1118 When the ID parameter is omitted, then this command prints information
1119 about the current inferior. When the ID parameter is present, the
1120 behavior of the command is unchanged and have the inferior ID become
1121 the current inferior.
1123 maintenance info sections
1124 The ALLOBJ keyword has been replaced with an -all-objects command
1125 line flag. It is now possible to filter which sections are printed
1126 even when -all-objects is passed.
1128 ptype[/FLAGS] TYPE | EXPRESSION
1129 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1130 notation is used when printing sizes and offsets of struct members.
1131 When '/d' is set, decimal notation is used when printing sizes and
1132 offsets of struct members. Default behavior is given by 'show print
1136 The info sources command output has been restructured. The results
1137 are now based around a list of objfiles (executable and libraries),
1138 and for each objfile the source files that are part of that objfile
1141 * Removed targets and native configurations
1143 ARM Symbian arm*-*-symbianelf*
1145 * New remote packets
1148 Request the remote to send allocation tags for a particular memory range.
1150 Request the remote to store the specified allocation tags to the requested
1155 ** Improved support for rvalue reference values:
1156 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1157 value-referenced-value procedure now handles rvalue reference
1160 ** New procedures for obtaining value variants:
1161 value-reference-value, value-rvalue-reference-value and
1164 ** Temporary breakpoints can now be created with make-breakpoint and
1165 tested for using breakpoint-temporary?.
1169 ** Inferior objects now contain a read-only 'connection_num' attribute that
1170 gives the connection number as seen in 'info connections' and
1173 ** New method gdb.Frame.level() which returns the stack level of the
1176 ** New method gdb.PendingFrame.level() which returns the stack level
1177 of the frame object.
1179 ** When hitting a catchpoint, the Python API will now emit a
1180 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1181 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1183 ** Python TUI windows can now receive mouse click events. If the
1184 Window object implements the click method, it is called for each
1185 mouse click event in this window.
1187 *** Changes in GDB 10
1189 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1190 and "org.gnu.gdb.arc.aux". The old names are still supported but
1191 must be considered obsolete. They will be deprecated after some
1194 * Help and apropos commands will now show the documentation of a
1195 command only once, even if that command has one or more aliases.
1196 These commands now show the command name, then all of its aliases,
1197 and finally the description of the command.
1199 * 'help aliases' now shows only the user defined aliases. GDB predefined
1200 aliases are shown together with their aliased command.
1202 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1203 debugging information as well as source code.
1205 When built with debuginfod, GDB can automatically query debuginfod
1206 servers for the separate debug files and source code of the executable
1209 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1210 requires libdebuginfod, the debuginfod client library).
1212 debuginfod is distributed with elfutils, starting with version 0.178.
1214 You can get the latest version from https://sourceware.org/elfutils.
1216 * Multi-target debugging support
1218 GDB now supports debugging multiple target connections
1219 simultaneously. For example, you can now have each inferior
1220 connected to different remote servers running in different machines,
1221 or have one inferior debugging a local native process, an inferior
1222 debugging a core dump, etc.
1224 This support is experimental and comes with some limitations -- you
1225 can only resume multiple targets simultaneously if all targets
1226 support non-stop mode, and all remote stubs or servers must support
1227 the same set of remote protocol features exactly. See also "info
1228 connections" and "add-inferior -no-connection" below, and "maint set
1229 target-non-stop" in the user manual.
1231 * New features in the GDB remote stub, GDBserver
1233 ** GDBserver is now supported on ARC GNU/Linux.
1235 ** GDBserver is now supported on RISC-V GNU/Linux.
1237 ** GDBserver no longer supports these host triplets:
1239 i[34567]86-*-lynxos*
1248 i[34567]86-*-mingw32ce*
1250 * Debugging MS-Windows processes now sets $_exitsignal when the
1251 inferior is terminated by a signal, instead of setting $_exitcode.
1253 * Multithreaded symbol loading has now been enabled by default on systems
1254 that support it (see entry for GDB 9, below), providing faster
1255 performance for programs with many symbols.
1257 * The $_siginfo convenience variable now also works on Windows targets,
1258 and will display the EXCEPTION_RECORD of the last handled exception.
1260 * TUI windows can now be arranged horizontally.
1262 * The command history filename can now be set to the empty string
1263 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1264 the environment. The effect of setting this filename to the empty
1265 string is that GDB will not try to load any previous command
1268 * On Windows targets, it is now possible to debug 32-bit programs with a
1273 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1274 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1275 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1276 running process, this new option indicates whether to detect
1277 a mismatch between the current executable file loaded by GDB and the
1278 executable file used to start the process. If 'ask', the default,
1279 display a warning and ask the user whether to load the process
1280 executable file; if 'warn', just display a warning; if 'off', don't
1281 attempt to detect a mismatch.
1283 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1284 Define a new TUI layout, specifying its name and the windows that
1287 maintenance print xml-tdesc [FILE]
1288 Prints the current target description as an XML document. If the
1289 optional FILE is provided (which is an XML target description) then
1290 the target description is read from FILE into GDB, and then
1293 maintenance print core-file-backed-mappings
1294 Prints file-backed mappings loaded from a core file's note section.
1295 Output is expected to be similar to that of "info proc mappings".
1297 set debug fortran-array-slicing on|off
1298 show debug fortran-array-slicing
1299 Print debugging when taking slices of Fortran arrays.
1301 set fortran repack-array-slices on|off
1302 show fortran repack-array-slices
1303 When taking slices from Fortran arrays and strings, if the slice is
1304 non-contiguous within the original value then, when this option is
1305 on, the new value will be repacked into a single contiguous value.
1306 When this option is off, then the value returned will consist of a
1307 descriptor that describes the slice within the memory of the
1308 original parent value.
1312 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1313 The alias command can now specify default args for an alias.
1314 GDB automatically prepends the alias default args to the argument list
1315 provided explicitly by the user.
1316 For example, to have a backtrace with full details, you can define
1317 an alias 'bt_ALL' as
1318 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1319 -past-main -past-entry -full'.
1320 Alias default arguments can also use a set of nested 'with' commands,
1321 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1322 defines the alias pp10 that will pretty print a maximum of 10 elements
1323 of the given expression (if the expression is an array).
1327 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1328 BPF bpf-unknown-none
1333 ** gdb.register_window_type can be used to implement new TUI windows
1336 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1337 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1338 field of a dynamic type may have None for its "bitpos" attribute
1341 ** Commands written in Python can be in the "TUI" help class by
1342 registering with the new constant gdb.COMMAND_TUI.
1344 ** New method gdb.PendingFrame.architecture () to retrieve the
1345 architecture of the pending frame.
1347 ** New gdb.Architecture.registers method that returns a
1348 gdb.RegisterDescriptorIterator object, an iterator that returns
1349 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1350 way to query the registers available for an architecture.
1352 ** New gdb.Architecture.register_groups method that returns a
1353 gdb.RegisterGroupIterator object, an iterator that returns
1354 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1355 discover the available register groups.
1359 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1361 ** Procedures 'memory-port-read-buffer-size',
1362 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1363 and 'set-memory-port-write-buffer-size!' are deprecated. When
1364 using Guile 2.2 and later, users who need to control the size of
1365 a memory port's internal buffer can use the 'setvbuf' procedure.
1367 *** Changes in GDB 9
1369 * 'thread-exited' event is now available in the annotations interface.
1371 * New built-in convenience variables $_gdb_major and $_gdb_minor
1372 provide the GDB version. They are handy for conditionally using
1373 features available only in or since specific GDB versions, in
1374 scripts that should work error-free with many different versions,
1375 such as in system-wide init files.
1377 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1378 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1379 of the GDB settings and the GDB maintenance settings. They are handy
1380 for changing the logic of user defined commands depending on the
1381 current GDB settings.
1383 * GDB now supports Thread Local Storage (TLS) variables on several
1384 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1385 architectures require kernel changes. TLS is not yet supported for
1386 amd64 and i386 process core dumps.
1388 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1389 addresses that required unmasking are shown in the backtrace with the
1392 * Two new convenience functions $_cimag and $_creal that extract the
1393 imaginary and real parts respectively from complex numbers.
1395 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1396 provide the exitcode or exit status of the shell commands launched by
1397 GDB commands such as "shell", "pipe" and "make".
1399 * The command define-prefix can now define user defined prefix commands.
1400 User defined commands can now be defined using these user defined prefix
1403 * Command names can now use the . character.
1405 * The RX port now supports XML target descriptions.
1407 * GDB now shows the Ada task names at more places, e.g. in task switching
1410 * GDB can now be compiled with Python 3 on Windows.
1412 * New convenience variable $_ada_exception holds the address of the
1413 Ada exception being thrown. This is set by Ada-related catchpoints.
1415 * GDB can now place breakpoints on nested functions and subroutines in
1416 Fortran code. The '::' operator can be used between parent and
1417 child scopes when placing breakpoints, for example:
1419 (gdb) break outer_function::inner_function
1421 The 'outer_function::' prefix is only needed if 'inner_function' is
1422 not visible in the current scope.
1424 * In addition to the system-wide gdbinit file, if configured with
1425 --with-system-gdbinit-dir, GDB will now also load files in that directory
1426 as system gdbinit files, unless the -nx or -n flag is provided. Files
1427 with extensions .gdb, .py and .scm are supported as long as GDB was
1428 compiled with support for that language.
1430 * GDB now supports multithreaded symbol loading for higher performance.
1431 This feature is still in testing, so it is disabled by default. You
1432 can turn it on using 'maint set worker-threads unlimited'.
1436 ** The gdb.Value type has a new method 'format_string' which returns a
1437 string representing the value. The formatting is controlled by the
1438 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1439 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1440 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1442 ** gdb.Type has a new property 'objfile' which returns the objfile the
1443 type was defined in.
1445 ** The frame information printed by the python frame filtering code
1446 is now consistent with what the 'backtrace' command prints when
1447 there are no filters, or when the 'backtrace' '-no-filters' option
1450 ** The new function gdb.lookup_static_symbol can be used to look up
1451 symbols with static linkage.
1453 ** The new function gdb.lookup_static_symbols can be used to look up
1454 all static symbols with static linkage.
1456 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1457 'lookup_static_symbol' to lookup a symbol from this objfile only.
1459 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1460 this block (e.g. block['local_variable']).
1464 | [COMMAND] | SHELL_COMMAND
1465 | -d DELIM COMMAND DELIM SHELL_COMMAND
1466 pipe [COMMAND] | SHELL_COMMAND
1467 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1468 Executes COMMAND and sends its output to SHELL_COMMAND.
1469 With no COMMAND, repeat the last executed command
1470 and send its output to SHELL_COMMAND.
1472 define-prefix COMMAND
1473 Define or mark a command as a user-defined prefix command.
1475 with SETTING [VALUE] [-- COMMAND]
1476 w SETTING [VALUE] [-- COMMAND]
1477 Temporarily set SETTING, run COMMAND, and restore SETTING.
1478 Usage: with SETTING -- COMMAND
1479 With no COMMAND, repeats the last executed command.
1480 SETTING is any GDB setting you can change with the "set"
1481 subcommands. For example, 'with language c -- print someobj'
1482 temporarily switches to the C language in order to print someobj.
1483 Settings can be combined: 'w lang c -- w print elements unlimited --
1484 usercmd' switches to the C language and runs usercmd with no limit
1485 of array elements to print.
1487 maint with SETTING [VALUE] [-- COMMAND]
1488 Like "with", but works with "maintenance set" settings.
1490 set may-call-functions [on|off]
1491 show may-call-functions
1492 This controls whether GDB will attempt to call functions in
1493 the program, such as with expressions in the print command. It
1494 defaults to on. Calling functions in the program being debugged
1495 can have undesired side effects. It is now possible to forbid
1496 such function calls. If function calls are forbidden, GDB will throw
1497 an error when a command (such as print expression) calls a function
1500 set print finish [on|off]
1502 This controls whether the `finish' command will display the value
1503 that is returned by the current function. When `off', the value is
1504 still entered into the value history, but it is not printed. The
1508 show print max-depth
1509 Allows deeply nested structures to be simplified when printing by
1510 replacing deeply nested parts (beyond the max-depth) with ellipses.
1511 The default max-depth is 20, but this can be set to unlimited to get
1512 the old behavior back.
1514 set print raw-values [on|off]
1515 show print raw-values
1516 By default, GDB applies the enabled pretty printers when printing a
1517 value. This allows to ignore the enabled pretty printers for a series
1518 of commands. The default is 'off'.
1520 set logging debugredirect [on|off]
1521 By default, GDB debug output will go to both the terminal and the logfile.
1522 Set if you want debug output to go only to the log file.
1524 set style title foreground COLOR
1525 set style title background COLOR
1526 set style title intensity VALUE
1527 Control the styling of titles.
1529 set style highlight foreground COLOR
1530 set style highlight background COLOR
1531 set style highlight intensity VALUE
1532 Control the styling of highlightings.
1534 maint set worker-threads
1535 maint show worker-threads
1536 Control the number of worker threads that can be used by GDB. The
1537 default is 0. "unlimited" lets GDB choose a number that is
1538 reasonable. Currently worker threads are only used when demangling
1539 the names of linker symbols.
1541 set style tui-border foreground COLOR
1542 set style tui-border background COLOR
1543 Control the styling of TUI borders.
1545 set style tui-active-border foreground COLOR
1546 set style tui-active-border background COLOR
1547 Control the styling of the active TUI border.
1549 maint set test-settings KIND
1550 maint show test-settings KIND
1551 A set of commands used by the testsuite for exercising the settings
1554 maint set tui-resize-message [on|off]
1555 maint show tui-resize-message
1556 Control whether GDB prints a message each time the terminal is
1557 resized when in TUI mode. This is primarily useful for testing the
1560 set print frame-info [short-location|location|location-and-address
1561 |source-and-location|source-line|auto]
1562 show print frame-info
1563 This controls what frame information is printed by the commands printing
1564 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1565 'frame', 'stepi'. The python frame filtering also respect this setting.
1566 The 'backtrace' '-frame-info' option can override this global setting.
1568 set tui compact-source
1569 show tui compact-source
1571 Enable the "compact" display mode for the TUI source window. The
1572 compact display uses only as much space as is needed for the line
1573 numbers in the current file, and only a single space to separate the
1574 line numbers from the source.
1576 info modules [-q] [REGEXP]
1577 Return a list of Fortran modules matching REGEXP, or all modules if
1580 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1581 Return a list of functions within all modules, grouped by module.
1582 The list of functions can be restricted with the optional regular
1583 expressions. MODULE_REGEXP matches against the module name,
1584 TYPE_REGEXP matches against the function type signature, and REGEXP
1585 matches against the function name.
1587 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1588 Return a list of variables within all modules, grouped by module.
1589 The list of variables can be restricted with the optional regular
1590 expressions. MODULE_REGEXP matches against the module name,
1591 TYPE_REGEXP matches against the variable type, and REGEXP matches
1592 against the variable name.
1594 set debug remote-packet-max-chars
1595 show debug remote-packet-max-chars
1596 Controls the number of characters to output in a remote packet when using
1598 The default is 512 bytes.
1601 Lists the target connections currently in use.
1606 The "help" command uses the title style to enhance the
1607 readibility of its output by styling the classes and
1611 Similarly to "help", the "apropos" command also uses the
1612 title style for the command names. "apropos" accepts now
1613 a flag "-v" (verbose) to show the full documentation
1614 of matching commands and to use the highlight style to mark
1615 the documentation parts matching REGEXP.
1619 The GDB printf and eval commands can now print C-style and Ada-style
1620 string convenience variables without calling functions in the program.
1621 This allows to do formatted printing of strings without having
1622 a running inferior, or when debugging a core dump.
1624 info sources [-dirname | -basename] [--] [REGEXP]
1625 This command has now optional arguments to only print the files
1626 whose names match REGEXP. The arguments -dirname and -basename
1627 allow to restrict matching respectively to the dirname and basename
1631 The "show style" and its subcommands are now styling
1632 a style name in their output using its own style, to help
1633 the user visualize the different styles.
1635 set print frame-arguments
1636 The new value 'presence' indicates to only indicate the presence of
1637 arguments using ..., instead of printing argument names and values.
1639 set print raw-frame-arguments
1640 show print raw-frame-arguments
1642 These commands replace the similarly-named "set/show print raw
1643 frame-arguments" commands (now with a dash instead of a space). The
1644 old commands are now deprecated and may be removed in a future
1647 add-inferior [-no-connection]
1648 The add-inferior command now supports a "-no-connection" flag that
1649 makes the new inferior start with no target connection associated.
1650 By default, the new inferior inherits the target connection of the
1651 current inferior. See also "info connections".
1654 This command's output now includes a new "Connection" column
1655 indicating which target connection an inferior is bound to. See
1656 "info connections" above.
1658 maint test-options require-delimiter
1659 maint test-options unknown-is-error
1660 maint test-options unknown-is-operand
1661 maint show test-options-completion-result
1662 Commands used by the testsuite to validate the command options
1665 focus, winheight, +, -, >, <
1666 These commands are now case-sensitive.
1668 * New command options, command completion
1670 GDB now has a standard infrastructure to support dash-style command
1671 options ('-OPT'). One benefit is that commands that use it can
1672 easily support completion of command line arguments. Try "CMD
1673 -[TAB]" or "help CMD" to find options supported by a command. Over
1674 time, we intend to migrate most commands to this infrastructure. A
1675 number of commands got support for new command options in this
1678 ** The "print" and "compile print" commands now support a number of
1679 options that allow overriding relevant global print settings as
1680 set by "set print" subcommands:
1684 -array-indexes [on|off]
1685 -elements NUMBER|unlimited
1689 -raw-values [on|off]
1690 -repeats NUMBER|unlimited
1691 -static-members [on|off]
1696 Note that because the "print"/"compile print" commands accept
1697 arbitrary expressions which may look like options (including
1698 abbreviations), if you specify any command option, then you must
1699 use a double dash ("--") to mark the end of argument processing.
1701 ** The "backtrace" command now supports a number of options that
1702 allow overriding relevant global print settings as set by "set
1703 backtrace" and "set print" subcommands:
1705 -entry-values no|only|preferred|if-needed|both|compact|default
1706 -frame-arguments all|scalars|none
1707 -raw-frame-arguments [on|off]
1708 -frame-info auto|source-line|location|source-and-location
1709 |location-and-address|short-location
1711 -past-entry [on|off]
1713 In addition, the full/no-filters/hide qualifiers are now also
1714 exposed as command options too:
1720 ** The "frame apply", "tfaas" and "faas" commands similarly now
1721 support the following options:
1724 -past-entry [on|off]
1726 ** The new "info sources" options -dirname and -basename options
1727 are using the standard '-OPT' infrastructure.
1729 All options above can also be abbreviated. The argument of boolean
1730 (on/off) options can be 0/1 too, and also the argument is assumed
1731 "on" if omitted. This allows writing compact command invocations,
1734 (gdb) p -ra -p -o 0 -- *myptr
1736 The above is equivalent to:
1738 (gdb) print -raw-values -pretty -object off -- *myptr
1740 ** The "info types" command now supports the '-q' flag to disable
1741 printing of some header information in a similar fashion to "info
1742 variables" and "info functions".
1744 ** The "info variables", "info functions", and "whereis" commands
1745 now take a '-n' flag that excludes non-debug symbols (symbols
1746 from the symbol table, not from the debug info such as DWARF)
1749 * Completion improvements
1751 ** GDB can now complete the options of the "thread apply all" and
1752 "taas" commands, and their "-ascending" option can now be
1755 ** GDB can now complete the options of the "info threads", "info
1756 functions", "info variables", "info locals", and "info args"
1759 ** GDB can now complete the options of the "compile file" and
1760 "compile code" commands. The "compile file" command now
1761 completes on filenames.
1763 ** GDB can now complete the backtrace command's
1764 "full/no-filters/hide" qualifiers.
1766 * In settings, you can now abbreviate "unlimited".
1768 E.g., "set print elements u" is now equivalent to "set print
1769 elements unlimited".
1774 This lists all the possible completions for the rest of the line, if it
1775 were to be given as a command itself. This is intended for use by MI
1776 frontends in cases when separate CLI and MI channels cannot be used.
1778 -catch-throw, -catch-rethrow, and -catch-catch
1779 These can be used to catch C++ exceptions in a similar fashion to
1780 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1782 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1783 These commands are the MI equivalent of the CLI commands 'info
1784 functions', 'info types', and 'info variables' respectively.
1786 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1789 -symbol-info-module-functions and -symbol-info-module-variables.
1790 These commands are the MI equivalent of the CLI commands 'info
1791 module functions' and 'info module variables'.
1795 ** The default version of the MI interpreter is now 3 (-i=mi3).
1797 ** The output of information about multi-location breakpoints (which is
1798 syntactically incorrect in MI 2) has changed in MI 3. This affects
1799 the following commands and events:
1803 - =breakpoint-created
1804 - =breakpoint-modified
1806 The -fix-multi-location-breakpoint-output command can be used to enable
1807 this behavior with previous MI versions.
1809 ** Backtraces and frames include a new optional field addr_flags which is
1810 given after the addr field. On AArch64 this contains PAC if the address
1811 has been masked in the frame. On all other targets the field is not
1816 The testsuite now creates the files gdb.cmd (containing the arguments
1817 used to launch GDB) and gdb.in (containing all the commands sent to
1818 GDB) in the output directory for each test script. Multiple invocations
1819 are appended with .1, .2, .3 etc.
1821 * Building GDB and GDBserver now requires GNU make >= 3.82.
1823 Using another implementation of the make program or an earlier version of
1824 GNU make to build GDB or GDBserver is not supported.
1826 * Building GDB now requires GNU readline >= 7.0.
1828 GDB now bundles GNU readline 8.0, but if you choose to use
1829 --with-system-readline, only readline >= 7.0 can be used.
1831 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1832 from .inputrc to bind keys in this keymap. This feature is only
1833 available when gdb is built against GNU readline 8.0 or later.
1835 * Removed targets and native configurations
1837 GDB no longer supports debugging the Cell Broadband Engine. This includes
1838 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1839 of Cell/B.E. applications that use both the PPU and SPU architectures.
1845 * Removed targets and native configurations
1847 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1848 sparc*-*-solaris2.10
1850 *** Changes in GDB 8.3
1852 * GDB and GDBserver now support access to additional registers on
1853 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1856 * GDB now has experimental support for the compilation and injection of
1857 C++ source code into the inferior. This beta release does not include
1858 support for several language features, such as templates, constructors,
1861 This feature requires GCC 7.1 or higher built with libcp1.so
1864 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1865 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1866 'ADDRESS:PORT' method.
1868 * DWARF index cache: GDB can now automatically save indices of DWARF
1869 symbols on disk to speed up further loading of the same binaries.
1871 * Ada task switching is now supported on aarch64-elf targets when
1872 debugging a program using the Ravenscar Profile. For more information,
1873 see the "Tasking Support when using the Ravenscar Profile" section
1874 in the GDB user manual.
1876 * GDB in batch mode now exits with status 1 if the last command to be
1879 * The RISC-V target now supports target descriptions.
1881 * System call catchpoints now support system call aliases on FreeBSD.
1882 When the ABI of a system call changes in FreeBSD, this is
1883 implemented by leaving a compatibility system call using the old ABI
1884 at the existing number and allocating a new system call number for
1885 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1886 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1887 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1888 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1889 so that a system call catchpoint for the 'kevent' system call will
1890 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1891 binaries. This ensures that 'kevent' system calls are caught for
1892 binaries using either the old or new ABIs.
1894 * Terminal styling is now available for the CLI and the TUI. GNU
1895 Source Highlight can additionally be used to provide styling of
1896 source code snippets. See the "set style" commands, below, for more
1899 * Removed support for old demangling styles arm, edg, gnu, hp and
1904 set debug compile-cplus-types
1905 show debug compile-cplus-types
1906 Control the display of debug output about type conversion in the
1907 C++ compile feature. Commands have no effect while compiling
1908 for other languages.
1912 Control whether debug output about files/functions skipping is
1915 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1916 Apply a command to some frames.
1917 FLAG arguments allow to control what output to produce and how to handle
1918 errors raised when applying COMMAND to a frame.
1921 Apply a command to all threads (ignoring errors and empty output).
1922 Shortcut for 'thread apply all -s COMMAND'.
1925 Apply a command to all frames (ignoring errors and empty output).
1926 Shortcut for 'frame apply all -s COMMAND'.
1929 Apply a command to all frames of all threads (ignoring errors and empty
1931 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1933 maint set dwarf unwinders (on|off)
1934 maint show dwarf unwinders
1935 Control whether DWARF unwinders can be used.
1938 Display a list of open files for a process.
1942 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1943 These commands all now take a frame specification which
1944 is either a frame level, or one of the keywords 'level', 'address',
1945 'function', or 'view' followed by a parameter. Selecting a frame by
1946 address, or viewing a frame outside the current backtrace now
1947 requires the use of a keyword. Selecting a frame by level is
1948 unchanged. The MI comment "-stack-select-frame" is unchanged.
1950 target remote FILENAME
1951 target extended-remote FILENAME
1952 If FILENAME is a Unix domain socket, GDB will attempt to connect
1953 to this socket instead of opening FILENAME as a character device.
1955 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1956 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1957 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1958 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1959 These commands can now print only the searched entities
1960 matching the provided regexp(s), giving a condition
1961 on the entity names or entity types. The flag -q disables
1962 printing headers or informations messages.
1968 These commands now determine the syntax for the shown entities
1969 according to the language chosen by `set language'. In particular,
1970 `set language auto' means to automatically choose the language of
1973 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1974 The 'thread apply' command accepts new FLAG arguments.
1975 FLAG arguments allow to control what output to produce and how to handle
1976 errors raised when applying COMMAND to a thread.
1978 set tui tab-width NCHARS
1979 show tui tab-width NCHARS
1980 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1982 set style enabled [on|off]
1984 Enable or disable terminal styling. Styling is enabled by default
1985 on most hosts, but disabled by default when in batch mode.
1987 set style sources [on|off]
1989 Enable or disable source code styling. Source code styling is
1990 enabled by default, but only takes effect if styling in general is
1991 enabled, and if GDB was linked with GNU Source Highlight.
1993 set style filename foreground COLOR
1994 set style filename background COLOR
1995 set style filename intensity VALUE
1996 Control the styling of file names.
1998 set style function foreground COLOR
1999 set style function background COLOR
2000 set style function intensity VALUE
2001 Control the styling of function names.
2003 set style variable foreground COLOR
2004 set style variable background COLOR
2005 set style variable intensity VALUE
2006 Control the styling of variable names.
2008 set style address foreground COLOR
2009 set style address background COLOR
2010 set style address intensity VALUE
2011 Control the styling of addresses.
2015 ** The '-data-disassemble' MI command now accepts an '-a' option to
2016 disassemble the whole function surrounding the given program
2017 counter value or function name. Support for this feature can be
2018 verified by using the "-list-features" command, which should
2019 contain "data-disassemble-a-option".
2021 ** Command responses and notifications that include a frame now include
2022 the frame's architecture in a new "arch" attribute.
2024 * New native configurations
2026 GNU/Linux/RISC-V riscv*-*-linux*
2027 FreeBSD/riscv riscv*-*-freebsd*
2031 GNU/Linux/RISC-V riscv*-*-linux*
2032 CSKY ELF csky*-*-elf
2033 CSKY GNU/LINUX csky*-*-linux
2034 FreeBSD/riscv riscv*-*-freebsd*
2036 GNU/Linux/OpenRISC or1k*-*-linux*
2040 GDB no longer supports native debugging on versions of MS-Windows
2045 ** GDB no longer supports Python versions less than 2.6.
2047 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2048 space associated to that inferior.
2050 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2051 of objfiles associated to that program space.
2053 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2054 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2057 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2058 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2059 correct and did not work properly.
2061 ** The gdb.Value type has a new constructor, which is used to construct a
2062 gdb.Value from a Python buffer object and a gdb.Type.
2068 Enable or disable the undefined behavior sanitizer. This is
2069 disabled by default, but passing --enable-ubsan=yes or
2070 --enable-ubsan=auto to configure will enable it. Enabling this can
2071 cause a performance penalty. The undefined behavior sanitizer was
2072 first introduced in GCC 4.9.
2074 *** Changes in GDB 8.2
2076 * The 'set disassembler-options' command now supports specifying options
2077 for the MIPS target.
2079 * The 'symbol-file' command now accepts an '-o' option to add a relative
2080 offset to all sections.
2082 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2083 a relative offset to all sections, but it allows to override the load
2084 address of individual sections using '-s'.
2086 * The 'add-symbol-file' command no longer requires the second argument
2087 (address of the text section).
2089 * The endianness used with the 'set endian auto' mode in the absence of
2090 an executable selected for debugging is now the last endianness chosen
2091 either by one of the 'set endian big' and 'set endian little' commands
2092 or by inferring from the last executable used, rather than the startup
2095 * The pager now allows a "c" response, meaning to disable the pager
2096 for the rest of the current command.
2098 * The commands 'info variables/functions/types' now show the source line
2099 numbers of symbol definitions when available.
2101 * 'info proc' now works on running processes on FreeBSD systems and core
2102 files created on FreeBSD systems.
2104 * C expressions can now use _Alignof, and C++ expressions can now use
2107 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2108 the vector length while the process is running.
2114 Control display of debugging info regarding the FreeBSD native target.
2116 set|show varsize-limit
2117 This new setting allows the user to control the maximum size of Ada
2118 objects being printed when those objects have a variable type,
2119 instead of that maximum size being hardcoded to 65536 bytes.
2121 set|show record btrace cpu
2122 Controls the processor to be used for enabling errata workarounds for
2123 branch trace decode.
2125 maint check libthread-db
2126 Run integrity checks on the current inferior's thread debugging
2129 maint set check-libthread-db (on|off)
2130 maint show check-libthread-db
2131 Control whether to run integrity checks on inferior specific thread
2132 debugging libraries as they are loaded. The default is not to
2133 perform such checks.
2137 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2139 ** The commands attached to a breakpoint can be set by assigning to
2140 the breakpoint's "commands" field.
2142 ** gdb.execute can now execute multi-line gdb commands.
2144 ** The new functions gdb.convenience_variable and
2145 gdb.set_convenience_variable can be used to get and set the value
2146 of convenience variables.
2148 ** A gdb.Parameter will no longer print the "set" help text on an
2149 ordinary "set"; instead by default a "set" will be silent unless
2150 the get_set_string method returns a non-empty string.
2154 RiscV ELF riscv*-*-elf
2156 * Removed targets and native configurations
2158 m88k running OpenBSD m88*-*-openbsd*
2159 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2160 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2161 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2163 * Aarch64/Linux hardware watchpoints improvements
2165 Hardware watchpoints on unaligned addresses are now properly
2166 supported when running Linux kernel 4.10 or higher: read and access
2167 watchpoints are no longer spuriously missed, and all watchpoints
2168 lengths between 1 and 8 bytes are supported. On older kernels,
2169 watchpoints set on unaligned addresses are no longer missed, with
2170 the tradeoff that there is a possibility of false hits being
2175 --enable-codesign=CERT
2176 This can be used to invoke "codesign -s CERT" after building gdb.
2177 This option is useful on macOS, where code signing is required for
2178 gdb to work properly.
2180 --disable-gdbcli has been removed
2181 This is now silently accepted, but does nothing.
2183 *** Changes in GDB 8.1
2185 * GDB now supports dynamically creating arbitrary register groups specified
2186 in XML target descriptions. This allows for finer grain grouping of
2187 registers on systems with a large amount of registers.
2189 * The 'ptype' command now accepts a '/o' flag, which prints the
2190 offsets and sizes of fields in a struct, like the pahole(1) tool.
2192 * New "--readnever" command line option instructs GDB to not read each
2193 symbol file's symbolic debug information. This makes startup faster
2194 but at the expense of not being able to perform symbolic debugging.
2195 This option is intended for use cases where symbolic debugging will
2196 not be used, e.g., when you only need to dump the debuggee's core.
2198 * GDB now uses the GNU MPFR library, if available, to emulate target
2199 floating-point arithmetic during expression evaluation when the target
2200 uses different floating-point formats than the host. At least version
2201 3.1 of GNU MPFR is required.
2203 * GDB now supports access to the guarded-storage-control registers and the
2204 software-based guarded-storage broadcast control registers on IBM z14.
2206 * On Unix systems, GDB now supports transmitting environment variables
2207 that are to be set or unset to GDBserver. These variables will
2208 affect the environment to be passed to the remote inferior.
2210 To inform GDB of environment variables that are to be transmitted to
2211 GDBserver, use the "set environment" command. Only user set
2212 environment variables are sent to GDBserver.
2214 To inform GDB of environment variables that are to be unset before
2215 the remote inferior is started by the GDBserver, use the "unset
2216 environment" command.
2218 * Completion improvements
2220 ** GDB can now complete function parameters in linespecs and
2221 explicit locations without quoting. When setting breakpoints,
2222 quoting around functions names to help with TAB-completion is
2223 generally no longer necessary. For example, this now completes
2226 (gdb) b function(in[TAB]
2227 (gdb) b function(int)
2229 Related, GDB is no longer confused with completing functions in
2230 C++ anonymous namespaces:
2233 (gdb) b (anonymous namespace)::[TAB][TAB]
2234 (anonymous namespace)::a_function()
2235 (anonymous namespace)::b_function()
2237 ** GDB now has much improved linespec and explicit locations TAB
2238 completion support, that better understands what you're
2239 completing and offers better suggestions. For example, GDB no
2240 longer offers data symbols as possible completions when you're
2241 setting a breakpoint.
2243 ** GDB now TAB-completes label symbol names.
2245 ** The "complete" command now mimics TAB completion accurately.
2247 * New command line options (gcore)
2250 Dump all memory mappings.
2252 * Breakpoints on C++ functions are now set on all scopes by default
2254 By default, breakpoints on functions/methods are now interpreted as
2255 specifying all functions with the given name ignoring missing
2256 leading scopes (namespaces and classes).
2258 For example, assuming a C++ program with symbols named:
2263 both commands "break func()" and "break B::func()" set a breakpoint
2266 You can use the new flag "-qualified" to override this. This makes
2267 GDB interpret the specified function name as a complete
2268 fully-qualified name instead. For example, using the same C++
2269 program, the "break -q B::func" command sets a breakpoint on
2270 "B::func", only. A parameter has been added to the Python
2271 gdb.Breakpoint constructor to achieve the same result when creating
2272 a breakpoint from Python.
2274 * Breakpoints on functions marked with C++ ABI tags
2276 GDB can now set breakpoints on functions marked with C++ ABI tags
2277 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2278 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2280 Functions with a C++11 abi tag are demangled/displayed like this:
2282 function[abi:cxx11](int)
2285 You can now set a breakpoint on such functions simply as if they had
2288 (gdb) b function(int)
2290 Or if you need to disambiguate between tags, like:
2292 (gdb) b function[abi:other_tag](int)
2294 Tab completion was adjusted accordingly as well.
2298 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2299 gdb.new_thread are emitted. See the manual for further
2300 description of these.
2302 ** A new function, "gdb.rbreak" has been added to the Python API.
2303 This function allows the setting of a large number of breakpoints
2304 via a regex pattern in Python. See the manual for further details.
2306 ** Python breakpoints can now accept explicit locations. See the
2307 manual for a further description of this feature.
2310 * New features in the GDB remote stub, GDBserver
2312 ** GDBserver is now able to start inferior processes with a
2313 specified initial working directory.
2315 The user can set the desired working directory to be used from
2316 GDB using the new "set cwd" command.
2318 ** New "--selftest" command line option runs some GDBserver self
2319 tests. These self tests are disabled in releases.
2321 ** On Unix systems, GDBserver now does globbing expansion and variable
2322 substitution in inferior command line arguments.
2324 This is done by starting inferiors using a shell, like GDB does.
2325 See "set startup-with-shell" in the user manual for how to disable
2326 this from GDB when using "target extended-remote". When using
2327 "target remote", you can disable the startup with shell by using the
2328 new "--no-startup-with-shell" GDBserver command line option.
2330 ** On Unix systems, GDBserver now supports receiving environment
2331 variables that are to be set or unset from GDB. These variables
2332 will affect the environment to be passed to the inferior.
2334 * When catching an Ada exception raised with a message, GDB now prints
2335 the message in the catchpoint hit notification. In GDB/MI mode, that
2336 information is provided as an extra field named "exception-message"
2337 in the *stopped notification.
2339 * Trait objects can now be inspected When debugging Rust code. This
2340 requires compiler support which will appear in Rust 1.24.
2342 * New remote packets
2344 QEnvironmentHexEncoded
2345 Inform GDBserver of an environment variable that is to be passed to
2346 the inferior when starting it.
2349 Inform GDBserver of an environment variable that is to be unset
2350 before starting the remote inferior.
2353 Inform GDBserver that the environment should be reset (i.e.,
2354 user-set environment variables should be unset).
2357 Indicates whether the inferior must be started with a shell or not.
2360 Tell GDBserver that the inferior to be started should use a specific
2363 * The "maintenance print c-tdesc" command now takes an optional
2364 argument which is the file name of XML target description.
2366 * The "maintenance selftest" command now takes an optional argument to
2367 filter the tests to be run.
2369 * The "enable", and "disable" commands now accept a range of
2370 breakpoint locations, e.g. "enable 1.3-5".
2375 Set and show the current working directory for the inferior.
2377 set|show compile-gcc
2378 Set and show compilation command used for compiling and injecting code
2379 with the 'compile' commands.
2381 set debug separate-debug-file
2382 show debug separate-debug-file
2383 Control the display of debug output about separate debug file search.
2385 set dump-excluded-mappings
2386 show dump-excluded-mappings
2387 Control whether mappings marked with the VM_DONTDUMP flag should be
2388 dumped when generating a core file.
2390 maint info selftests
2391 List the registered selftests.
2394 Start the debugged program stopping at the first instruction.
2397 Control display of debugging messages related to OpenRISC targets.
2399 set|show print type nested-type-limit
2400 Set and show the limit of nesting level for nested types that the
2401 type printer will show.
2403 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2406 * Safer/improved support for debugging with no debug info
2408 GDB no longer assumes functions with no debug information return
2411 This means that GDB now refuses to call such functions unless you
2412 tell it the function's type, by either casting the call to the
2413 declared return type, or by casting the function to a function
2414 pointer of the right type, and calling that:
2416 (gdb) p getenv ("PATH")
2417 'getenv' has unknown return type; cast the call to its declared return type
2418 (gdb) p (char *) getenv ("PATH")
2419 $1 = 0x7fffffffe "/usr/local/bin:/"...
2420 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2421 $2 = 0x7fffffffe "/usr/local/bin:/"...
2423 Similarly, GDB no longer assumes that global variables with no debug
2424 info have type 'int', and refuses to print the variable's value
2425 unless you tell it the variable's type:
2428 'var' has unknown type; cast it to its declared type
2432 * New native configurations
2434 FreeBSD/aarch64 aarch64*-*-freebsd*
2435 FreeBSD/arm arm*-*-freebsd*
2439 FreeBSD/aarch64 aarch64*-*-freebsd*
2440 FreeBSD/arm arm*-*-freebsd*
2441 OpenRISC ELF or1k*-*-elf
2443 * Removed targets and native configurations
2445 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2447 *** Changes in GDB 8.0
2449 * GDB now supports access to the PKU register on GNU/Linux. The register is
2450 added by the Memory Protection Keys for Userspace feature which will be
2451 available in future Intel CPUs.
2453 * GDB now supports C++11 rvalue references.
2457 ** New functions to start, stop and access a running btrace recording.
2458 ** Rvalue references are now supported in gdb.Type.
2460 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2463 * Building GDB and GDBserver now requires a C++11 compiler.
2465 For example, GCC 4.8 or later.
2467 It is no longer possible to build GDB or GDBserver with a C
2468 compiler. The --disable-build-with-cxx configure option has been
2471 * Building GDB and GDBserver now requires GNU make >= 3.81.
2473 It is no longer supported to build GDB or GDBserver with another
2474 implementation of the make program or an earlier version of GNU make.
2476 * Native debugging on MS-Windows supports command-line redirection
2478 Command-line arguments used for starting programs on MS-Windows can
2479 now include redirection symbols supported by native Windows shells,
2480 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2481 as "run", "start", and "set args", as well as the corresponding MI
2484 * Support for thread names on MS-Windows.
2486 GDB now catches and handles the special exception that programs
2487 running on MS-Windows use to assign names to threads in the
2490 * Support for Java programs compiled with gcj has been removed.
2492 * User commands now accept an unlimited number of arguments.
2493 Previously, only up to 10 was accepted.
2495 * The "eval" command now expands user-defined command arguments.
2497 This makes it easier to process a variable number of arguments:
2502 eval "print $arg%d", $i
2507 * Target descriptions can now describe registers for sparc32 and sparc64.
2509 * GDB now supports DWARF version 5 (debug information format).
2510 Its .debug_names index is not yet supported.
2512 * New native configurations
2514 FreeBSD/mips mips*-*-freebsd
2518 Synopsys ARC arc*-*-elf32
2519 FreeBSD/mips mips*-*-freebsd
2521 * Removed targets and native configurations
2523 Alpha running FreeBSD alpha*-*-freebsd*
2524 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2529 Erases all the flash memory regions reported by the target.
2531 maint print arc arc-instruction address
2532 Print internal disassembler information about instruction at a given address.
2536 set disassembler-options
2537 show disassembler-options
2538 Controls the passing of target specific information to the disassembler.
2539 If it is necessary to specify more than one disassembler option then
2540 multiple options can be placed together into a comma separated list.
2541 The default value is the empty string. Currently, the only supported
2542 targets are ARM, PowerPC and S/390.
2547 Erases all the flash memory regions reported by the target. This is
2548 equivalent to the CLI command flash-erase.
2550 -file-list-shared-libraries
2551 List the shared libraries in the program. This is
2552 equivalent to the CLI command "info shared".
2555 Catchpoints stopping the program when Ada exceptions are
2556 handled. This is equivalent to the CLI command "catch handlers".
2558 *** Changes in GDB 7.12
2560 * GDB and GDBserver now build with a C++ compiler by default.
2562 The --enable-build-with-cxx configure option is now enabled by
2563 default. One must now explicitly configure with
2564 --disable-build-with-cxx in order to build with a C compiler. This
2565 option will be removed in a future release.
2567 * GDBserver now supports recording btrace without maintaining an active
2570 * GDB now supports a negative repeat count in the 'x' command to examine
2571 memory backward from the given address. For example:
2574 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2575 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2576 (gdb) x/-5i 0x0000000000400580
2577 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2578 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2579 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2580 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2581 0x40057b <main(int, char**)+25>:
2582 callq 0x400536 <Func1(int, char const*)>
2584 * Fortran: Support structures with fields of dynamic types and
2585 arrays of dynamic types.
2587 * The symbol dumping maintenance commands have new syntax.
2588 maint print symbols [-pc address] [--] [filename]
2589 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2590 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2591 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2592 maint print msymbols [-objfile objfile] [--] [filename]
2594 * GDB now supports multibit bitfields and enums in target register
2597 * New Python-based convenience function $_as_string(val), which returns
2598 the textual representation of a value. This function is especially
2599 useful to obtain the text label of an enum value.
2601 * Intel MPX bound violation handling.
2603 Segmentation faults caused by a Intel MPX boundary violation
2604 now display the kind of violation (upper or lower), the memory
2605 address accessed and the memory bounds, along with the usual
2606 signal received and code location.
2610 Program received signal SIGSEGV, Segmentation fault
2611 Upper bound violation while accessing address 0x7fffffffc3b3
2612 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2613 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2615 * Rust language support.
2616 GDB now supports debugging programs written in the Rust programming
2617 language. See https://www.rust-lang.org/ for more information about
2620 * Support for running interpreters on specified input/output devices
2622 GDB now supports a new mechanism that allows frontends to provide
2623 fully featured GDB console views, as a better alternative to
2624 building such views on top of the "-interpreter-exec console"
2625 command. See the new "new-ui" command below. With that command,
2626 frontends can now start GDB in the traditional command-line mode
2627 running in an embedded terminal emulator widget, and create a
2628 separate MI interpreter running on a specified i/o device. In this
2629 way, GDB handles line editing, history, tab completion, etc. in the
2630 console all by itself, and the GUI uses the separate MI interpreter
2631 for its own control and synchronization, invisible to the command
2634 * The "catch syscall" command catches groups of related syscalls.
2636 The "catch syscall" command now supports catching a group of related
2637 syscalls using the 'group:' or 'g:' prefix.
2642 skip -gfile file-glob-pattern
2643 skip -function function
2644 skip -rfunction regular-expression
2645 A generalized form of the skip command, with new support for
2646 glob-style file names and regular expressions for function names.
2647 Additionally, a file spec and a function spec may now be combined.
2649 maint info line-table REGEXP
2650 Display the contents of GDB's internal line table data structure.
2653 Run any GDB unit tests that were compiled in.
2656 Start a new user interface instance running INTERP as interpreter,
2657 using the TTY file for input/output.
2661 ** gdb.Breakpoint objects have a new attribute "pending", which
2662 indicates whether the breakpoint is pending.
2663 ** Three new breakpoint-related events have been added:
2664 gdb.breakpoint_created, gdb.breakpoint_modified, and
2665 gdb.breakpoint_deleted.
2667 signal-event EVENTID
2668 Signal ("set") the given MS-Windows event object. This is used in
2669 conjunction with the Windows JIT debugging (AeDebug) support, where
2670 the OS suspends a crashing process until a debugger can attach to
2671 it. Resuming the crashing process, in order to debug it, is done by
2672 signalling an event.
2674 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2675 was added in GDBserver, including JIT compiling fast tracepoint's
2676 conditional expression bytecode into native code.
2678 * Support for various remote target protocols and ROM monitors has
2681 target m32rsdi Remote M32R debugging over SDI
2682 target mips MIPS remote debugging protocol
2683 target pmon PMON ROM monitor
2684 target ddb NEC's DDB variant of PMON for Vr4300
2685 target rockhopper NEC RockHopper variant of PMON
2686 target lsi LSI variant of PMO
2688 * Support for tracepoints and fast tracepoints on powerpc-linux,
2689 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2690 including JIT compiling fast tracepoint's conditional expression
2691 bytecode into native code.
2693 * MI async record =record-started now includes the method and format used for
2694 recording. For example:
2696 =record-started,thread-group="i1",method="btrace",format="bts"
2698 * MI async record =thread-selected now includes the frame field. For example:
2700 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2704 Andes NDS32 nds32*-*-elf
2706 *** Changes in GDB 7.11
2708 * GDB now supports debugging kernel-based threads on FreeBSD.
2710 * Per-inferior thread numbers
2712 Thread numbers are now per inferior instead of global. If you're
2713 debugging multiple inferiors, GDB displays thread IDs using a
2714 qualified INF_NUM.THR_NUM form. For example:
2718 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2719 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2720 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2721 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2723 As consequence, thread numbers as visible in the $_thread
2724 convenience variable and in Python's InferiorThread.num attribute
2725 are no longer unique between inferiors.
2727 GDB now maintains a second thread ID per thread, referred to as the
2728 global thread ID, which is the new equivalent of thread numbers in
2729 previous releases. See also $_gthread below.
2731 For backwards compatibility, MI's thread IDs always refer to global
2734 * Commands that accept thread IDs now accept the qualified
2735 INF_NUM.THR_NUM form as well. For example:
2738 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2741 * In commands that accept a list of thread IDs, you can now refer to
2742 all threads of an inferior using a star wildcard. GDB accepts
2743 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2744 refer to all threads of the current inferior. For example, "info
2747 * You can use "info threads -gid" to display the global thread ID of
2750 * The new convenience variable $_gthread holds the global number of
2753 * The new convenience variable $_inferior holds the number of the
2756 * GDB now displays the ID and name of the thread that hit a breakpoint
2757 or received a signal, if your program is multi-threaded. For
2760 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2761 Thread 1 "main" received signal SIGINT, Interrupt.
2763 * Record btrace now supports non-stop mode.
2765 * Support for tracepoints on aarch64-linux was added in GDBserver.
2767 * The 'record instruction-history' command now indicates speculative execution
2768 when using the Intel Processor Trace recording format.
2770 * GDB now allows users to specify explicit locations, bypassing
2771 the linespec parser. This feature is also available to GDB/MI
2774 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2775 GDB now is able to debug both AArch64 applications and ARM applications
2778 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2779 including JIT compiling fast tracepoint's conditional expression bytecode
2782 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2784 * "info threads", "info inferiors", "info display", "info checkpoints"
2785 and "maint info program-spaces" now list the corresponding items in
2786 ascending ID order, for consistency with all other "info" commands.
2788 * In Ada, the overloads selection menu has been enhanced to display the
2789 parameter types and the return types for the matching overloaded subprograms.
2793 maint set target-non-stop (on|off|auto)
2794 maint show target-non-stop
2795 Control whether GDB targets always operate in non-stop mode even if
2796 "set non-stop" is "off". The default is "auto", meaning non-stop
2797 mode is enabled if supported by the target.
2799 maint set bfd-sharing
2800 maint show bfd-sharing
2801 Control the reuse of bfd objects.
2804 show debug bfd-cache
2805 Control display of debugging info regarding bfd caching.
2809 Control display of debugging info regarding FreeBSD threads.
2811 set remote multiprocess-extensions-packet
2812 show remote multiprocess-extensions-packet
2813 Set/show the use of the remote protocol multiprocess extensions.
2815 set remote thread-events
2816 show remote thread-events
2817 Set/show the use of thread create/exit events.
2819 set ada print-signatures on|off
2820 show ada print-signatures"
2821 Control whether parameter types and return types are displayed in overloads
2822 selection menus. It is activated (@code{on}) by default.
2826 Controls the maximum size of memory, in bytes, that GDB will
2827 allocate for value contents. Prevents incorrect programs from
2828 causing GDB to allocate overly large buffers. Default is 64k.
2830 * The "disassemble" command accepts a new modifier: /s.
2831 It prints mixed source+disassembly like /m with two differences:
2832 - disassembled instructions are now printed in program order, and
2833 - and source for all relevant files is now printed.
2834 The "/m" option is now considered deprecated: its "source-centric"
2835 output hasn't proved useful in practice.
2837 * The "record instruction-history" command accepts a new modifier: /s.
2838 It behaves exactly like /m and prints mixed source+disassembly.
2840 * The "set scheduler-locking" command supports a new mode "replay".
2841 It behaves like "off" in record mode and like "on" in replay mode.
2843 * Support for various ROM monitors has been removed:
2845 target dbug dBUG ROM monitor for Motorola ColdFire
2846 target picobug Motorola picobug monitor
2847 target dink32 DINK32 ROM monitor for PowerPC
2848 target m32r Renesas M32R/D ROM monitor
2849 target mon2000 mon2000 ROM monitor
2850 target ppcbug PPCBUG ROM monitor for PowerPC
2852 * Support for reading/writing memory and extracting values on architectures
2853 whose memory is addressable in units of any integral multiple of 8 bits.
2856 Allows to break when an Ada exception is handled.
2858 * New remote packets
2861 Indicates that an exec system call was executed.
2863 exec-events feature in qSupported
2864 The qSupported packet allows GDB to request support for exec
2865 events using the new 'gdbfeature' exec-event, and the qSupported
2866 response can contain the corresponding 'stubfeature'. Set and
2867 show commands can be used to display whether these features are enabled.
2870 Equivalent to interrupting with the ^C character, but works in
2873 thread created stop reason (T05 create:...)
2874 Indicates that the thread was just created and is stopped at entry.
2876 thread exit stop reply (w exitcode;tid)
2877 Indicates that the thread has terminated.
2880 Enables/disables thread create and exit event reporting. For
2881 example, this is used in non-stop mode when GDB stops a set of
2882 threads and synchronously waits for the their corresponding stop
2883 replies. Without exit events, if one of the threads exits, GDB
2884 would hang forever not knowing that it should no longer expect a
2885 stop for that same thread.
2888 Indicates that there are no resumed threads left in the target (all
2889 threads are stopped). The remote stub reports support for this stop
2890 reply to GDB's qSupported query.
2893 Enables/disables catching syscalls from the inferior process.
2894 The remote stub reports support for this packet to GDB's qSupported query.
2896 syscall_entry stop reason
2897 Indicates that a syscall was just called.
2899 syscall_return stop reason
2900 Indicates that a syscall just returned.
2902 * Extended-remote exec events
2904 ** GDB now has support for exec events on extended-remote Linux targets.
2905 For such targets with Linux kernels 2.5.46 and later, this enables
2906 follow-exec-mode and exec catchpoints.
2908 set remote exec-event-feature-packet
2909 show remote exec-event-feature-packet
2910 Set/show the use of the remote exec event feature.
2912 * Thread names in remote protocol
2914 The reply to qXfer:threads:read may now include a name attribute for each
2917 * Target remote mode fork and exec events
2919 ** GDB now has support for fork and exec events on target remote mode
2920 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2921 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2922 fork and exec catchpoints.
2924 * Remote syscall events
2926 ** GDB now has support for catch syscall on remote Linux targets,
2927 currently enabled on x86/x86_64 architectures.
2929 set remote catch-syscall-packet
2930 show remote catch-syscall-packet
2931 Set/show the use of the remote catch syscall feature.
2935 ** The -var-set-format command now accepts the zero-hexadecimal
2936 format. It outputs data in hexadecimal format with zero-padding on the
2941 ** gdb.InferiorThread objects have a new attribute "global_num",
2942 which refers to the thread's global thread ID. The existing
2943 "num" attribute now refers to the thread's per-inferior number.
2944 See "Per-inferior thread numbers" above.
2945 ** gdb.InferiorThread objects have a new attribute "inferior", which
2946 is the Inferior object the thread belongs to.
2948 *** Changes in GDB 7.10
2950 * Support for process record-replay and reverse debugging on aarch64*-linux*
2951 targets has been added. GDB now supports recording of A64 instruction set
2952 including advance SIMD instructions.
2954 * Support for Sun's version of the "stabs" debug file format has been removed.
2956 * GDB now honors the content of the file /proc/PID/coredump_filter
2957 (PID is the process ID) on GNU/Linux systems. This file can be used
2958 to specify the types of memory mappings that will be included in a
2959 corefile. For more information, please refer to the manual page of
2960 "core(5)". GDB also has a new command: "set use-coredump-filter
2961 on|off". It allows to set whether GDB will read the content of the
2962 /proc/PID/coredump_filter file when generating a corefile.
2964 * The "info os" command on GNU/Linux can now display information on
2966 "info os cpus" Listing of all cpus/cores on the system
2968 * GDB has two new commands: "set serial parity odd|even|none" and
2969 "show serial parity". These allows to set or show parity for the
2972 * The "info source" command now displays the producer string if it was
2973 present in the debug info. This typically includes the compiler version
2974 and may include things like its command line arguments.
2976 * The "info dll", an alias of the "info sharedlibrary" command,
2977 is now available on all platforms.
2979 * Directory names supplied to the "set sysroot" commands may be
2980 prefixed with "target:" to tell GDB to access shared libraries from
2981 the target system, be it local or remote. This replaces the prefix
2982 "remote:". The default sysroot has been changed from "" to
2983 "target:". "remote:" is automatically converted to "target:" for
2984 backward compatibility.
2986 * The system root specified by "set sysroot" will be prepended to the
2987 filename of the main executable (if reported to GDB as absolute by
2988 the operating system) when starting processes remotely, and when
2989 attaching to already-running local or remote processes.
2991 * GDB now supports automatic location and retrieval of executable
2992 files from remote targets. Remote debugging can now be initiated
2993 using only a "target remote" or "target extended-remote" command
2994 (no "set sysroot" or "file" commands are required). See "New remote
2997 * The "dump" command now supports verilog hex format.
2999 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3001 * On GNU/Linux, GDB and gdbserver are now able to access executable
3002 and shared library files without a "set sysroot" command when
3003 attaching to processes running in different mount namespaces from
3004 the debugger. This makes it possible to attach to processes in
3005 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3006 See "New remote packets" below.
3008 * The "tui reg" command now provides completion for all of the
3009 available register groups, including target specific groups.
3011 * The HISTSIZE environment variable is no longer read when determining
3012 the size of GDB's command history. GDB now instead reads the dedicated
3013 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3014 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3019 ** Memory ports can now be unbuffered.
3023 ** gdb.Objfile objects have a new attribute "username",
3024 which is the name of the objfile as specified by the user,
3025 without, for example, resolving symlinks.
3026 ** You can now write frame unwinders in Python.
3027 ** gdb.Type objects have a new method "optimized_out",
3028 returning optimized out gdb.Value instance of this type.
3029 ** gdb.Value objects have new methods "reference_value" and
3030 "const_value" which return a reference to the value and a
3031 "const" version of the value respectively.
3035 maint print symbol-cache
3036 Print the contents of the symbol cache.
3038 maint print symbol-cache-statistics
3039 Print statistics of symbol cache usage.
3041 maint flush-symbol-cache
3042 Flush the contents of the symbol cache.
3046 Start branch trace recording using Branch Trace Store (BTS) format.
3049 Evaluate expression by using the compiler and print result.
3053 Explicit commands for enabling and disabling tui mode.
3056 set mpx bound on i386 and amd64
3057 Support for bound table investigation on Intel MPX enabled applications.
3061 Start branch trace recording using Intel Processor Trace format.
3064 Print information about branch tracing internals.
3066 maint btrace packet-history
3067 Print the raw branch tracing data.
3069 maint btrace clear-packet-history
3070 Discard the stored raw branch tracing data.
3073 Discard all branch tracing data. It will be fetched and processed
3074 anew by the next "record" command.
3079 Renamed from "set debug dwarf2-die".
3080 show debug dwarf-die
3081 Renamed from "show debug dwarf2-die".
3083 set debug dwarf-read
3084 Renamed from "set debug dwarf2-read".
3085 show debug dwarf-read
3086 Renamed from "show debug dwarf2-read".
3088 maint set dwarf always-disassemble
3089 Renamed from "maint set dwarf2 always-disassemble".
3090 maint show dwarf always-disassemble
3091 Renamed from "maint show dwarf2 always-disassemble".
3093 maint set dwarf max-cache-age
3094 Renamed from "maint set dwarf2 max-cache-age".
3095 maint show dwarf max-cache-age
3096 Renamed from "maint show dwarf2 max-cache-age".
3098 set debug dwarf-line
3099 show debug dwarf-line
3100 Control display of debugging info regarding DWARF line processing.
3103 show max-completions
3104 Set the maximum number of candidates to be considered during
3105 completion. The default value is 200. This limit allows GDB
3106 to avoid generating large completion lists, the computation of
3107 which can cause the debugger to become temporarily unresponsive.
3109 set history remove-duplicates
3110 show history remove-duplicates
3111 Control the removal of duplicate history entries.
3113 maint set symbol-cache-size
3114 maint show symbol-cache-size
3115 Control the size of the symbol cache.
3117 set|show record btrace bts buffer-size
3118 Set and show the size of the ring buffer used for branch tracing in
3120 The obtained size may differ from the requested size. Use "info
3121 record" to see the obtained buffer size.
3123 set debug linux-namespaces
3124 show debug linux-namespaces
3125 Control display of debugging info regarding Linux namespaces.
3127 set|show record btrace pt buffer-size
3128 Set and show the size of the ring buffer used for branch tracing in
3129 Intel Processor Trace format.
3130 The obtained size may differ from the requested size. Use "info
3131 record" to see the obtained buffer size.
3133 maint set|show btrace pt skip-pad
3134 Set and show whether PAD packets are skipped when computing the
3137 * The command 'thread apply all' can now support new option '-ascending'
3138 to call its specified command for all threads in ascending order.
3140 * Python/Guile scripting
3142 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3143 special section named `.debug_gdb_scripts'.
3145 * New remote packets
3147 qXfer:btrace-conf:read
3148 Return the branch trace configuration for the current thread.
3150 Qbtrace-conf:bts:size
3151 Set the requested ring buffer size for branch tracing in BTS format.
3154 Enable Intel Processor Trace-based branch tracing for the current
3155 process. The remote stub reports support for this packet to GDB's
3158 Qbtrace-conf:pt:size
3159 Set the requested ring buffer size for branch tracing in Intel Processor
3163 Indicates a memory breakpoint instruction was executed, irrespective
3164 of whether it was GDB that planted the breakpoint or the breakpoint
3165 is hardcoded in the program. This is required for correct non-stop
3169 Indicates the target stopped for a hardware breakpoint. This is
3170 required for correct non-stop mode operation.
3173 Return information about files on the remote system.
3175 qXfer:exec-file:read
3176 Return the full absolute name of the file that was executed to
3177 create a process running on the remote system.
3180 Select the filesystem on which vFile: operations with filename
3181 arguments will operate. This is required for GDB to be able to
3182 access files on remote targets where the remote stub does not
3183 share a common filesystem with the inferior(s).
3186 Indicates that a fork system call was executed.
3189 Indicates that a vfork system call was executed.
3191 vforkdone stop reason
3192 Indicates that a vfork child of the specified process has executed
3193 an exec or exit, allowing the vfork parent to resume execution.
3195 fork-events and vfork-events features in qSupported
3196 The qSupported packet allows GDB to request support for fork and
3197 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3198 and the qSupported response can contain the corresponding
3199 'stubfeatures'. Set and show commands can be used to display
3200 whether these features are enabled.
3202 * Extended-remote fork events
3204 ** GDB now has support for fork events on extended-remote Linux
3205 targets. For targets with Linux kernels 2.5.60 and later, this
3206 enables follow-fork-mode and detach-on-fork for both fork and
3207 vfork, as well as fork and vfork catchpoints.
3209 * The info record command now shows the recording format and the
3210 branch tracing configuration for the current thread when using
3211 the btrace record target.
3212 For the BTS format, it shows the ring buffer size.
3214 * GDB now has support for DTrace USDT (Userland Static Defined
3215 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3217 * GDB now supports access to vector registers on S/390 GNU/Linux
3220 * Removed command line options
3222 -xdb HP-UX XDB compatibility mode.
3224 * Removed targets and native configurations
3226 HP/PA running HP-UX hppa*-*-hpux*
3227 Itanium running HP-UX ia64-*-hpux*
3229 * New configure options
3232 This configure option allows the user to build GDB with support for
3233 Intel Processor Trace (default: auto). This requires libipt.
3235 --with-libipt-prefix=PATH
3236 Specify the path to the version of libipt that GDB should use.
3237 $PATH/include should contain the intel-pt.h header and
3238 $PATH/lib should contain the libipt.so library.
3240 *** Changes in GDB 7.9.1
3244 ** Xmethods can now specify a result type.
3246 *** Changes in GDB 7.9
3248 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3252 ** You can now access frame registers from Python scripts.
3253 ** New attribute 'producer' for gdb.Symtab objects.
3254 ** gdb.Objfile objects have a new attribute "progspace",
3255 which is the gdb.Progspace object of the containing program space.
3256 ** gdb.Objfile objects have a new attribute "owner".
3257 ** gdb.Objfile objects have a new attribute "build_id",
3258 which is the build ID generated when the file was built.
3259 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3260 ** A new event "gdb.clear_objfiles" has been added, triggered when
3261 selecting a new file to debug.
3262 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3263 ** New function gdb.lookup_objfile.
3265 New events which are triggered when GDB modifies the state of the
3268 ** gdb.events.inferior_call_pre: Function call is about to be made.
3269 ** gdb.events.inferior_call_post: Function call has just been made.
3270 ** gdb.events.memory_changed: A memory location has been altered.
3271 ** gdb.events.register_changed: A register has been altered.
3273 * New Python-based convenience functions:
3275 ** $_caller_is(name [, number_of_frames])
3276 ** $_caller_matches(regexp [, number_of_frames])
3277 ** $_any_caller_is(name [, number_of_frames])
3278 ** $_any_caller_matches(regexp [, number_of_frames])
3280 * GDB now supports the compilation and injection of source code into
3281 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3282 to compile the source code to object code, and if successful, inject
3283 and execute that code within the current context of the inferior.
3284 Currently the C language is supported. The commands used to
3285 interface with this new feature are:
3287 compile code [-raw|-r] [--] [source code]
3288 compile file [-raw|-r] filename
3292 demangle [-l language] [--] name
3293 Demangle "name" in the specified language, or the current language
3294 if elided. This command is renamed from the "maint demangle" command.
3295 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3296 as "maint demangler-warning".
3298 queue-signal signal-name-or-number
3299 Queue a signal to be delivered to the thread when it is resumed.
3301 add-auto-load-scripts-directory directory
3302 Add entries to the list of directories from which to load auto-loaded
3305 maint print user-registers
3306 List all currently available "user" registers.
3308 compile code [-r|-raw] [--] [source code]
3309 Compile, inject, and execute in the inferior the executable object
3310 code produced by compiling the provided source code.
3312 compile file [-r|-raw] filename
3313 Compile and inject into the inferior the executable object code
3314 produced by compiling the source code stored in the filename
3317 * On resume, GDB now always passes the signal the program had stopped
3318 for to the thread the signal was sent to, even if the user changed
3319 threads before resuming. Previously GDB would often (but not
3320 always) deliver the signal to the thread that happens to be current
3323 * Conversely, the "signal" command now consistently delivers the
3324 requested signal to the current thread. GDB now asks for
3325 confirmation if the program had stopped for a signal and the user
3326 switched threads meanwhile.
3328 * "breakpoint always-inserted" modes "off" and "auto" merged.
3330 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3331 won't remove breakpoints from the target until all threads stop,
3332 even in non-stop mode. The "auto" mode has been removed, and "off"
3333 is now the default mode.
3337 set debug symbol-lookup
3338 show debug symbol-lookup
3339 Control display of debugging info regarding symbol lookup.
3343 ** The -list-thread-groups command outputs an exit-code field for
3344 inferiors that have exited.
3348 MIPS SDE mips*-sde*-elf*
3352 Support for these obsolete configurations has been removed.
3354 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3355 SGI Irix-5.x mips-*-irix5*
3356 SGI Irix-6.x mips-*-irix6*
3357 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3358 VAX running Ultrix vax-*-ultrix*
3360 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3361 and "assf"), have been removed. Use the "sharedlibrary" command, or
3362 its alias "share", instead.
3364 *** Changes in GDB 7.8
3366 * New command line options
3369 This is an alias for the --data-directory option.
3371 * GDB supports printing and modifying of variable length automatic arrays
3372 as specified in ISO C99.
3374 * The ARM simulator now supports instruction level tracing
3375 with or without disassembly.
3379 GDB now has support for scripting using Guile. Whether this is
3380 available is determined at configure time.
3381 Guile version 2.0 or greater is required.
3382 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3384 * New commands (for set/show, see "New options" below)
3388 Invoke CODE by passing it to the Guile interpreter.
3392 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3394 info auto-load guile-scripts [regexp]
3395 Print the list of automatically loaded Guile scripts.
3397 * The source command is now capable of sourcing Guile scripts.
3398 This feature is dependent on the debugger being built with Guile support.
3402 set print symbol-loading (off|brief|full)
3403 show print symbol-loading
3404 Control whether to print informational messages when loading symbol
3405 information for a file. The default is "full", but when debugging
3406 programs with large numbers of shared libraries the amount of output
3407 becomes less useful.
3409 set guile print-stack (none|message|full)
3410 show guile print-stack
3411 Show a stack trace when an error is encountered in a Guile script.
3413 set auto-load guile-scripts (on|off)
3414 show auto-load guile-scripts
3415 Control auto-loading of Guile script files.
3417 maint ada set ignore-descriptive-types (on|off)
3418 maint ada show ignore-descriptive-types
3419 Control whether the debugger should ignore descriptive types in Ada
3420 programs. The default is not to ignore the descriptive types. See
3421 the user manual for more details on descriptive types and the intended
3422 usage of this option.
3424 set auto-connect-native-target
3426 Control whether GDB is allowed to automatically connect to the
3427 native target for the run, attach, etc. commands when not connected
3428 to any target yet. See also "target native" below.
3430 set record btrace replay-memory-access (read-only|read-write)
3431 show record btrace replay-memory-access
3432 Control what memory accesses are allowed during replay.
3434 maint set target-async (on|off)
3435 maint show target-async
3436 This controls whether GDB targets operate in synchronous or
3437 asynchronous mode. Normally the default is asynchronous, if it is
3438 available; but this can be changed to more easily debug problems
3439 occurring only in synchronous mode.
3441 set mi-async (on|off)
3443 Control whether MI asynchronous mode is preferred. This supersedes
3444 "set target-async" of previous GDB versions.
3446 * "set target-async" is deprecated as a CLI option and is now an alias
3447 for "set mi-async" (only puts MI into async mode).
3449 * Background execution commands (e.g., "c&", "s&", etc.) are now
3450 possible ``out of the box'' if the target supports them. Previously
3451 the user would need to explicitly enable the possibility with the
3452 "set target-async on" command.
3454 * New features in the GDB remote stub, GDBserver
3456 ** New option --debug-format=option1[,option2,...] allows one to add
3457 additional text to each output. At present only timestamps
3458 are supported: --debug-format=timestamps.
3459 Timestamps can also be turned on with the
3460 "monitor set debug-format timestamps" command from GDB.
3462 * The 'record instruction-history' command now starts counting instructions
3463 at one. This also affects the instruction ranges reported by the
3464 'record function-call-history' command when given the /i modifier.
3466 * The command 'record function-call-history' supports a new modifier '/c' to
3467 indent the function names based on their call stack depth.
3468 The fields for the '/i' and '/l' modifier have been reordered.
3469 The source line range is now prefixed with 'at'.
3470 The instruction range is now prefixed with 'inst'.
3471 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3472 "record instruction-history" and "list" commands.
3474 * The ranges given as arguments to the 'record function-call-history' and
3475 'record instruction-history' commands are now inclusive.
3477 * The btrace record target now supports the 'record goto' command.
3478 For locations inside the execution trace, the back trace is computed
3479 based on the information stored in the execution trace.
3481 * The btrace record target supports limited reverse execution and replay.
3482 The target does not record data and therefore does not allow reading
3483 memory or registers.
3485 * The "catch syscall" command now works on s390*-linux* targets.
3487 * The "compare-sections" command is no longer specific to target
3488 remote. It now works with all targets.
3490 * All native targets are now consistently called "native".
3491 Consequently, the "target child", "target GNU", "target djgpp",
3492 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3493 commands have been replaced with "target native". The QNX/NTO port
3494 leaves the "procfs" target in place and adds a "native" target for
3495 consistency with other ports. The impact on users should be minimal
3496 as these commands previously either throwed an error, or were
3497 no-ops. The target's name is visible in the output of the following
3498 commands: "help target", "info target", "info files", "maint print
3501 * The "target native" command now connects to the native target. This
3502 can be used to launch native programs even when "set
3503 auto-connect-native-target" is set to off.
3505 * GDB now supports access to Intel MPX registers on GNU/Linux.
3507 * Support for Intel AVX-512 registers on GNU/Linux.
3508 Support displaying and modifying Intel AVX-512 registers
3509 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3511 * New remote packets
3513 qXfer:btrace:read's annex
3514 The qXfer:btrace:read packet supports a new annex 'delta' to read
3515 branch trace incrementally.
3519 ** Valid Python operations on gdb.Value objects representing
3520 structs/classes invoke the corresponding overloaded operators if
3522 ** New `Xmethods' feature in the Python API. Xmethods are
3523 additional methods or replacements for existing methods of a C++
3524 class. This feature is useful for those cases where a method
3525 defined in C++ source code could be inlined or optimized out by
3526 the compiler, making it unavailable to GDB.
3529 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3531 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3532 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3533 its alias "share", instead.
3535 * The commands "set remotebaud" and "show remotebaud" are no longer
3536 supported. Use "set serial baud" and "show serial baud" (respectively)
3541 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3542 target-async". The latter is left as a deprecated alias of the
3543 former for backward compatibility. If the target supports it,
3544 CLI background execution commands are now always possible by
3545 default, independently of whether the frontend stated a
3546 preference for asynchronous execution with "-gdb-set mi-async".
3547 Previously "-gdb-set target-async off" affected both MI execution
3548 commands and CLI execution commands.
3550 *** Changes in GDB 7.7
3552 * Improved support for process record-replay and reverse debugging on
3553 arm*-linux* targets. Support for thumb32 and syscall instruction
3554 recording has been added.
3556 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3558 * GDB now supports Fission DWP file format version 2.
3559 http://gcc.gnu.org/wiki/DebugFission
3561 * New convenience function "$_isvoid", to check whether an expression
3562 is void. A void expression is an expression where the type of the
3563 result is "void". For example, some convenience variables may be
3564 "void" when evaluated (e.g., "$_exitcode" before the execution of
3565 the program being debugged; or an undefined convenience variable).
3566 Another example, when calling a function whose return type is
3569 * The "maintenance print objfiles" command now takes an optional regexp.
3571 * The "catch syscall" command now works on arm*-linux* targets.
3573 * GDB now consistently shows "<not saved>" when printing values of
3574 registers the debug info indicates have not been saved in the frame
3575 and there's nowhere to retrieve them from
3576 (callee-saved/call-clobbered registers):
3581 (gdb) info registers rax
3584 Before, the former would print "<optimized out>", and the latter
3585 "*value not available*".
3587 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3592 ** Frame filters and frame decorators have been added.
3593 ** Temporary breakpoints are now supported.
3594 ** Line tables representation has been added.
3595 ** New attribute 'parent_type' for gdb.Field objects.
3596 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3597 ** New attribute 'name' for gdb.Type objects.
3601 Nios II ELF nios2*-*-elf
3602 Nios II GNU/Linux nios2*-*-linux
3603 Texas Instruments MSP430 msp430*-*-elf
3605 * Removed native configurations
3607 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3608 been removed. ELF variants of these configurations are kept supported.
3610 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3611 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3612 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3613 i[34567]86-*-openbsd3.[0-3]
3614 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3615 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3616 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3620 Like "catch throw", but catches a re-thrown exception.
3621 maint check-psymtabs
3622 Renamed from old "maint check-symtabs".
3624 Perform consistency checks on symtabs.
3625 maint expand-symtabs
3626 Expand symtabs matching an optional regexp.
3629 Display the details of GDB configure-time options.
3631 maint set|show per-command
3632 maint set|show per-command space
3633 maint set|show per-command time
3634 maint set|show per-command symtab
3635 Enable display of per-command gdb resource usage.
3637 remove-symbol-file FILENAME
3638 remove-symbol-file -a ADDRESS
3639 Remove a symbol file added via add-symbol-file. The file to remove
3640 can be identified by its filename or by an address that lies within
3641 the boundaries of this symbol file in memory.
3644 info exceptions REGEXP
3645 Display the list of Ada exceptions defined in the program being
3646 debugged. If provided, only the exceptions whose names match REGEXP
3651 set debug symfile off|on
3653 Control display of debugging info regarding reading symbol files and
3654 symbol tables within those files
3656 set print raw frame-arguments
3657 show print raw frame-arguments
3658 Set/show whether to print frame arguments in raw mode,
3659 disregarding any defined pretty-printers.
3661 set remote trace-status-packet
3662 show remote trace-status-packet
3663 Set/show the use of remote protocol qTStatus packet.
3667 Control display of debugging messages related to Nios II targets.
3671 Control whether target-assisted range stepping is enabled.
3673 set startup-with-shell
3674 show startup-with-shell
3675 Specifies whether Unix child processes are started via a shell or
3680 Use the target memory cache for accesses to the code segment. This
3681 improves performance of remote debugging (particularly disassembly).
3683 * You can now use a literal value 'unlimited' for options that
3684 interpret 0 or -1 as meaning "unlimited". E.g., "set
3685 trace-buffer-size unlimited" is now an alias for "set
3686 trace-buffer-size -1" and "set height unlimited" is now an alias for
3689 * The "set debug symtab-create" debugging option of GDB has been changed to
3690 accept a verbosity level. 0 means "off", 1 provides basic debugging
3691 output, and values of 2 or greater provides more verbose output.
3693 * New command-line options
3695 Display the details of GDB configure-time options.
3697 * The command 'tsave' can now support new option '-ctf' to save trace
3698 buffer in Common Trace Format.
3700 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3703 * GDB now implements the C++ 'typeid' operator.
3705 * The new convenience variable $_exception holds the exception being
3706 thrown or caught at an exception-related catchpoint.
3708 * The exception-related catchpoints, like "catch throw", now accept a
3709 regular expression which can be used to filter exceptions by type.
3711 * The new convenience variable $_exitsignal is automatically set to
3712 the terminating signal number when the program being debugged dies
3713 due to an uncaught signal.
3717 ** All MI commands now accept an optional "--language" option.
3718 Support for this feature can be verified by using the "-list-features"
3719 command, which should contain "language-option".
3721 ** The new command -info-gdb-mi-command allows the user to determine
3722 whether a GDB/MI command is supported or not.
3724 ** The "^error" result record returned when trying to execute an undefined
3725 GDB/MI command now provides a variable named "code" whose content is the
3726 "undefined-command" error code. Support for this feature can be verified
3727 by using the "-list-features" command, which should contain
3728 "undefined-command-error-code".
3730 ** The -trace-save MI command can optionally save trace buffer in Common
3733 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3735 ** The command -data-list-register-values now accepts an optional
3736 "--skip-unavailable" option. When used, only the available registers
3739 ** The new command -trace-frame-collected dumps collected variables,
3740 computed expressions, tvars, memory and registers in a traceframe.
3742 ** The commands -stack-list-locals, -stack-list-arguments and
3743 -stack-list-variables now accept an option "--skip-unavailable".
3744 When used, only the available locals or arguments are displayed.
3746 ** The -exec-run command now accepts an optional "--start" option.
3747 When used, the command follows the same semantics as the "start"
3748 command, stopping the program's execution at the start of its
3749 main subprogram. Support for this feature can be verified using
3750 the "-list-features" command, which should contain
3751 "exec-run-start-option".
3753 ** The new commands -catch-assert and -catch-exceptions insert
3754 catchpoints stopping the program when Ada exceptions are raised.
3756 ** The new command -info-ada-exceptions provides the equivalent of
3757 the new "info exceptions" command.
3759 * New system-wide configuration scripts
3760 A GDB installation now provides scripts suitable for use as system-wide
3761 configuration scripts for the following systems:
3765 * GDB now supports target-assigned range stepping with remote targets.
3766 This improves the performance of stepping source lines by reducing
3767 the number of control packets from/to GDB. See "New remote packets"
3770 * GDB now understands the element 'tvar' in the XML traceframe info.
3771 It has the id of the collected trace state variables.
3773 * On S/390 targets that provide the transactional-execution feature,
3774 the program interruption transaction diagnostic block (TDB) is now
3775 represented as a number of additional "registers" in GDB.
3777 * New remote packets
3781 The vCont packet supports a new 'r' action, that tells the remote
3782 stub to step through an address range itself, without GDB
3783 involvemement at each single-step.
3785 qXfer:libraries-svr4:read's annex
3786 The previously unused annex of the qXfer:libraries-svr4:read packet
3787 is now used to support passing an argument list. The remote stub
3788 reports support for this argument list to GDB's qSupported query.
3789 The defined arguments are "start" and "prev", used to reduce work
3790 necessary for library list updating, resulting in significant
3793 * New features in the GDB remote stub, GDBserver
3795 ** GDBserver now supports target-assisted range stepping. Currently
3796 enabled on x86/x86_64 GNU/Linux targets.
3798 ** GDBserver now adds element 'tvar' in the XML in the reply to
3799 'qXfer:traceframe-info:read'. It has the id of the collected
3800 trace state variables.
3802 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3805 * New 'z' formatter for printing and examining memory, this displays the
3806 value as hexadecimal zero padded on the left to the size of the type.
3808 * GDB can now use Windows x64 unwinding data.
3810 * The "set remotebaud" command has been replaced by "set serial baud".
3811 Similarly, "show remotebaud" has been replaced by "show serial baud".
3812 The "set remotebaud" and "show remotebaud" commands are still available
3813 to provide backward compatibility with older versions of GDB.
3815 *** Changes in GDB 7.6
3817 * Target record has been renamed to record-full.
3818 Record/replay is now enabled with the "record full" command.
3819 This also affects settings that are associated with full record/replay
3820 that have been moved from "set/show record" to "set/show record full":
3822 set|show record full insn-number-max
3823 set|show record full stop-at-limit
3824 set|show record full memory-query
3826 * A new record target "record-btrace" has been added. The new target
3827 uses hardware support to record the control-flow of a process. It
3828 does not support replaying the execution, but it implements the
3829 below new commands for investigating the recorded execution log.
3830 This new recording method can be enabled using:
3834 The "record-btrace" target is only available on Intel Atom processors
3835 and requires a Linux kernel 2.6.32 or later.
3837 * Two new commands have been added for record/replay to give information
3838 about the recorded execution without having to replay the execution.
3839 The commands are only supported by "record btrace".
3841 record instruction-history prints the execution history at
3842 instruction granularity
3844 record function-call-history prints the execution history at
3845 function granularity
3847 * New native configurations
3849 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3850 FreeBSD/powerpc powerpc*-*-freebsd
3851 x86_64/Cygwin x86_64-*-cygwin*
3852 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3856 ARM AArch64 aarch64*-*-elf
3857 ARM AArch64 GNU/Linux aarch64*-*-linux
3858 Lynx 178 PowerPC powerpc-*-lynx*178
3859 x86_64/Cygwin x86_64-*-cygwin*
3860 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3862 * If the configured location of system.gdbinit file (as given by the
3863 --with-system-gdbinit option at configure time) is in the
3864 data-directory (as specified by --with-gdb-datadir at configure
3865 time) or in one of its subdirectories, then GDB will look for the
3866 system-wide init file in the directory specified by the
3867 --data-directory command-line option.
3869 * New command line options:
3871 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3872 other initialization files, unlike -nx which disables all of them.
3874 * Removed command line options
3876 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3879 * The 'ptype' and 'whatis' commands now accept an argument to control
3882 * 'info proc' now works on some core files.
3886 ** Vectors can be created with gdb.Type.vector.
3888 ** Python's atexit.register now works in GDB.
3890 ** Types can be pretty-printed via a Python API.
3892 ** Python 3 is now supported (in addition to Python 2.4 or later)
3894 ** New class gdb.Architecture exposes GDB's internal representation
3895 of architecture in the Python API.
3897 ** New method Frame.architecture returns the gdb.Architecture object
3898 corresponding to the frame's architecture.
3900 * New Python-based convenience functions:
3902 ** $_memeq(buf1, buf2, length)
3903 ** $_streq(str1, str2)
3905 ** $_regex(str, regex)
3907 * The 'cd' command now defaults to using '~' (the home directory) if not
3910 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3911 default for GCC since November 2000.
3913 * The command 'forward-search' can now be abbreviated as 'fo'.
3915 * The command 'info tracepoints' can now display 'installed on target'
3916 or 'not installed on target' for each non-pending location of tracepoint.
3918 * New configure options
3920 --enable-libmcheck/--disable-libmcheck
3921 By default, development versions are built with -lmcheck on hosts
3922 that support it, in order to help track memory corruption issues.
3923 Release versions, on the other hand, are built without -lmcheck
3924 by default. The --enable-libmcheck/--disable-libmcheck configure
3925 options allow the user to override that default.
3926 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3927 This configure option allows the user to build GDB with
3928 libbabeltrace using which GDB can read Common Trace Format data.
3930 * New commands (for set/show, see "New options" below)
3933 Catch signals. This is similar to "handle", but allows commands and
3934 conditions to be attached.
3937 List the BFDs known to GDB.
3939 python-interactive [command]
3941 Start a Python interactive prompt, or evaluate the optional command
3942 and print the result of expressions.
3945 "py" is a new alias for "python".
3947 enable type-printer [name]...
3948 disable type-printer [name]...
3949 Enable or disable type printers.
3953 ** For the Renesas Super-H architecture, the "regs" command has been removed
3954 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3959 set print type methods (on|off)
3960 show print type methods
3961 Control whether method declarations are displayed by "ptype".
3962 The default is to show them.
3964 set print type typedefs (on|off)
3965 show print type typedefs
3966 Control whether typedef definitions are displayed by "ptype".
3967 The default is to show them.
3969 set filename-display basename|relative|absolute
3970 show filename-display
3971 Control the way in which filenames is displayed.
3972 The default is "relative", which preserves previous behavior.
3974 set trace-buffer-size
3975 show trace-buffer-size
3976 Request target to change the size of trace buffer.
3978 set remote trace-buffer-size-packet auto|on|off
3979 show remote trace-buffer-size-packet
3980 Control the use of the remote protocol `QTBuffer:size' packet.
3984 Control display of debugging messages related to ARM AArch64.
3987 set debug coff-pe-read
3988 show debug coff-pe-read
3989 Control display of debugging messages related to reading of COFF/PE
3994 Control display of debugging messages related to Mach-O symbols
3997 set debug notification
3998 show debug notification
3999 Control display of debugging info for async remote notification.
4003 ** Command parameter changes are now notified using new async record
4004 "=cmd-param-changed".
4005 ** Trace frame changes caused by command "tfind" are now notified using
4006 new async record "=traceframe-changed".
4007 ** The creation, deletion and modification of trace state variables
4008 are now notified using new async records "=tsv-created",
4009 "=tsv-deleted" and "=tsv-modified".
4010 ** The start and stop of process record are now notified using new
4011 async record "=record-started" and "=record-stopped".
4012 ** Memory changes are now notified using new async record
4014 ** The data-disassemble command response will include a "fullname" field
4015 containing the absolute file name when source has been requested.
4016 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4017 command, to allow pattern filling of memory areas.
4018 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4019 library load/unload events.
4020 ** The response to breakpoint commands and breakpoint async records
4021 includes an "installed" field containing a boolean state about each
4022 non-pending tracepoint location is whether installed on target or not.
4023 ** Output of the "-trace-status" command includes a "trace-file" field
4024 containing the name of the trace file being examined. This field is
4025 optional, and only present when examining a trace file.
4026 ** The "fullname" field is now always present along with the "file" field,
4027 even if the file cannot be found by GDB.
4029 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4030 You must have the LZMA library available when configuring GDB for this
4031 feature to be enabled. For more information, see:
4032 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4034 * New remote packets
4037 Set the size of trace buffer. The remote stub reports support for this
4038 packet to gdb's qSupported query.
4041 Enable Branch Trace Store (BTS)-based branch tracing for the current
4042 thread. The remote stub reports support for this packet to gdb's
4046 Disable branch tracing for the current thread. The remote stub reports
4047 support for this packet to gdb's qSupported query.
4050 Read the traced branches for the current thread. The remote stub
4051 reports support for this packet to gdb's qSupported query.
4053 *** Changes in GDB 7.5
4055 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4056 for more x32 ABI info.
4058 * GDB now supports access to MIPS DSP registers on Linux targets.
4060 * GDB now supports debugging microMIPS binaries.
4062 * The "info os" command on GNU/Linux can now display information on
4063 several new classes of objects managed by the operating system:
4064 "info os procgroups" lists process groups
4065 "info os files" lists file descriptors
4066 "info os sockets" lists internet-domain sockets
4067 "info os shm" lists shared-memory regions
4068 "info os semaphores" lists semaphores
4069 "info os msg" lists message queues
4070 "info os modules" lists loaded kernel modules
4072 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4073 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4074 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4075 options and inspect the probe arguments using the new $_probe_arg family
4076 of convenience variables. You can obtain more information about SystemTap
4077 in <http://sourceware.org/systemtap/>.
4079 * GDB now supports reversible debugging on ARM, it allows you to
4080 debug basic ARM and THUMB instructions, and provides
4081 record/replay support.
4083 * The option "symbol-reloading" has been deleted as it is no longer used.
4087 ** GDB commands implemented in Python can now be put in command class
4090 ** The "maint set python print-stack on|off" is now deleted.
4092 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4093 apply "flag enum"-style pretty-printing to any enum.
4095 ** gdb.lookup_symbol can now work when there is no current frame.
4097 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4098 the source at which the symbol was defined.
4100 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4101 method 'value'. The former indicates whether the symbol needs a
4102 frame in order to compute its value, and the latter computes the
4105 ** A new method 'referenced_value' on gdb.Value objects which can
4106 dereference pointer as well as C++ reference values.
4108 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4109 which return the global and static blocks (as gdb.Block objects),
4110 of the underlying symbol table, respectively.
4112 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4113 object associated with a PC value.
4115 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4116 of the address range occupied by code for the current source line.
4118 * Go language support.
4119 GDB now supports debugging programs written in the Go programming
4122 * GDBserver now supports stdio connections.
4123 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4125 * The binary "gdbtui" can no longer be built or installed.
4126 Use "gdb -tui" instead.
4128 * GDB will now print "flag" enums specially. A flag enum is one where
4129 all the enumerator values have no bits in common when pairwise
4130 "and"ed. When printing a value whose type is a flag enum, GDB will
4131 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4132 (gdb) print (enum E) 3
4135 * The filename part of a linespec will now match trailing components
4136 of a source file name. For example, "break gcc/expr.c:1000" will
4137 now set a breakpoint in build/gcc/expr.c, but not
4138 build/libcpp/expr.c.
4140 * The "info proc" and "generate-core-file" commands will now also
4141 work on remote targets connected to GDBserver on Linux.
4143 * The command "info catch" has been removed. It has been disabled
4144 since December 2007.
4146 * The "catch exception" and "catch assert" commands now accept
4147 a condition at the end of the command, much like the "break"
4148 command does. For instance:
4150 (gdb) catch exception Constraint_Error if Barrier = True
4152 Previously, it was possible to add a condition to such catchpoints,
4153 but it had to be done as a second step, after the catchpoint had been
4154 created, using the "condition" command.
4156 * The "info static-tracepoint-marker" command will now also work on
4157 native Linux targets with in-process agent.
4159 * GDB can now set breakpoints on inlined functions.
4161 * The .gdb_index section has been updated to include symbols for
4162 inlined functions. GDB will ignore older .gdb_index sections by
4163 default, which could cause symbol files to be loaded more slowly
4164 until their .gdb_index sections can be recreated. The new command
4165 "set use-deprecated-index-sections on" will cause GDB to use any older
4166 .gdb_index sections it finds. This will restore performance, but the
4167 ability to set breakpoints on inlined functions will be lost in symbol
4168 files with older .gdb_index sections.
4170 The .gdb_index section has also been updated to record more information
4171 about each symbol. This speeds up the "info variables", "info functions"
4172 and "info types" commands when used with programs having the .gdb_index
4173 section, as well as speeding up debugging with shared libraries using
4174 the .gdb_index section.
4176 * Ada support for GDB/MI Variable Objects has been added.
4178 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4183 ** New command -info-os is the MI equivalent of "info os".
4185 ** Output logs ("set logging" and related) now include MI output.
4189 ** "set use-deprecated-index-sections on|off"
4190 "show use-deprecated-index-sections on|off"
4191 Controls the use of deprecated .gdb_index sections.
4193 ** "catch load" and "catch unload" can be used to stop when a shared
4194 library is loaded or unloaded, respectively.
4196 ** "enable count" can be used to auto-disable a breakpoint after
4199 ** "info vtbl" can be used to show the virtual method tables for
4200 C++ and Java objects.
4202 ** "explore" and its sub commands "explore value" and "explore type"
4203 can be used to recursively explore values and types of
4204 expressions. These commands are available only if GDB is
4205 configured with '--with-python'.
4207 ** "info auto-load" shows status of all kinds of auto-loaded files,
4208 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4209 sequences of commands files, "info auto-load python-scripts"
4210 shows status of auto-loading Python script files,
4211 "info auto-load local-gdbinit" shows status of loading init file
4212 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4213 status of inferior specific thread debugging shared library loading.
4215 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4216 and "show auto-load-scripts" commands have been deprecated, use their
4217 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4218 and "show auto-load python-scripts" counterparts instead.
4220 ** "dprintf location,format,args..." creates a dynamic printf, which
4221 is basically a breakpoint that does a printf and immediately
4222 resumes your program's execution, so it is like a printf that you
4223 can insert dynamically at runtime instead of at compiletime.
4225 ** "set print symbol"
4227 Controls whether GDB attempts to display the symbol, if any,
4228 corresponding to addresses it prints. This defaults to "on", but
4229 you can set it to "off" to restore GDB's previous behavior.
4231 * Deprecated commands
4233 ** For the Renesas Super-H architecture, the "regs" command has been
4234 deprecated, and "info all-registers" should be used instead.
4238 Renesas RL78 rl78-*-elf
4239 HP OpenVMS ia64 ia64-hp-openvms*
4241 * GDBserver supports evaluation of breakpoint conditions. When
4242 support is advertised by GDBserver, GDB may be told to send the
4243 breakpoint conditions in bytecode form to GDBserver. GDBserver
4244 will only report the breakpoint trigger to GDB when its condition
4249 set mips compression
4250 show mips compression
4251 Select the compressed ISA encoding used in functions that have no symbol
4252 information available. The encoding can be set to either of:
4255 and is updated automatically from ELF file flags if available.
4257 set breakpoint condition-evaluation
4258 show breakpoint condition-evaluation
4259 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4260 GDBserver ("target"). Default option "auto" chooses the most efficient
4262 This option can improve debugger efficiency depending on the speed of the
4266 Disable auto-loading globally.
4269 Show auto-loading setting of all kinds of auto-loaded files.
4271 set auto-load gdb-scripts on|off
4272 show auto-load gdb-scripts
4273 Control auto-loading of GDB canned sequences of commands files.
4275 set auto-load python-scripts on|off
4276 show auto-load python-scripts
4277 Control auto-loading of Python script files.
4279 set auto-load local-gdbinit on|off
4280 show auto-load local-gdbinit
4281 Control loading of init file (.gdbinit) from current directory.
4283 set auto-load libthread-db on|off
4284 show auto-load libthread-db
4285 Control auto-loading of inferior specific thread debugging shared library.
4287 set auto-load scripts-directory <dir1>[:<dir2>...]
4288 show auto-load scripts-directory
4289 Set a list of directories from which to load auto-loaded scripts.
4290 Automatically loaded Python scripts and GDB scripts are located in one
4291 of the directories listed by this option.
4292 The delimiter (':' above) may differ according to the host platform.
4294 set auto-load safe-path <dir1>[:<dir2>...]
4295 show auto-load safe-path
4296 Set a list of directories from which it is safe to auto-load files.
4297 The delimiter (':' above) may differ according to the host platform.
4299 set debug auto-load on|off
4300 show debug auto-load
4301 Control display of debugging info for auto-loading the files above.
4303 set dprintf-style gdb|call|agent
4305 Control the way in which a dynamic printf is performed; "gdb"
4306 requests a GDB printf command, while "call" causes dprintf to call a
4307 function in the inferior. "agent" requests that the target agent
4308 (such as GDBserver) do the printing.
4310 set dprintf-function <expr>
4311 show dprintf-function
4312 set dprintf-channel <expr>
4313 show dprintf-channel
4314 Set the function and optional first argument to the call when using
4315 the "call" style of dynamic printf.
4317 set disconnected-dprintf on|off
4318 show disconnected-dprintf
4319 Control whether agent-style dynamic printfs continue to be in effect
4320 after GDB disconnects.
4322 * New configure options
4324 --with-auto-load-dir
4325 Configure default value for the 'set auto-load scripts-directory'
4326 setting above. It defaults to '$debugdir:$datadir/auto-load',
4327 $debugdir representing global debugging info directories (available
4328 via 'show debug-file-directory') and $datadir representing GDB's data
4329 directory (available via 'show data-directory').
4331 --with-auto-load-safe-path
4332 Configure default value for the 'set auto-load safe-path' setting
4333 above. It defaults to the --with-auto-load-dir setting.
4335 --without-auto-load-safe-path
4336 Set 'set auto-load safe-path' to '/', effectively disabling this
4339 * New remote packets
4341 z0/z1 conditional breakpoints extension
4343 The z0/z1 breakpoint insertion packets have been extended to carry
4344 a list of conditional expressions over to the remote stub depending on the
4345 condition evaluation mode. The use of this extension can be controlled
4346 via the "set remote conditional-breakpoints-packet" command.
4350 Specify the signals which the remote stub may pass to the debugged
4351 program without GDB involvement.
4353 * New command line options
4355 --init-command=FILE, -ix Like --command, -x but execute it
4356 before loading inferior.
4357 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4358 execute it before loading inferior.
4360 *** Changes in GDB 7.4
4362 * GDB now handles ambiguous linespecs more consistently; the existing
4363 FILE:LINE support has been expanded to other types of linespecs. A
4364 breakpoint will now be set on all matching locations in all
4365 inferiors, and locations will be added or removed according to
4368 * GDB now allows you to skip uninteresting functions and files when
4369 stepping with the "skip function" and "skip file" commands.
4371 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4372 and "show remote hardware-watchpoint-length-limit". These allows to
4373 set or show the maximum length limit (in bytes) of a remote
4374 target hardware watchpoint.
4376 This allows e.g. to use "unlimited" hardware watchpoints with the
4377 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4378 watchpoints are slower than real hardware watchpoints but are
4379 significantly faster than gdb software watchpoints.
4383 ** The register_pretty_printer function in module gdb.printing now takes
4384 an optional `replace' argument. If True, the new printer replaces any
4387 ** The "maint set python print-stack on|off" command has been
4388 deprecated and will be deleted in GDB 7.5.
4389 A new command: "set python print-stack none|full|message" has
4390 replaced it. Additionally, the default for "print-stack" is
4391 now "message", which just prints the error message without
4394 ** A prompt substitution hook (prompt_hook) is now available to the
4397 ** A new Python module, gdb.prompt has been added to the GDB Python
4398 modules library. This module provides functionality for
4399 escape sequences in prompts (used by set/show
4400 extended-prompt). These escape sequences are replaced by their
4401 corresponding value.
4403 ** Python commands and convenience-functions located in
4404 'data-directory'/python/gdb/command and
4405 'data-directory'/python/gdb/function are now automatically loaded
4408 ** Blocks now provide four new attributes. global_block and
4409 static_block will return the global and static blocks
4410 respectively. is_static and is_global are boolean attributes
4411 that indicate if the block is one of those two types.
4413 ** Symbols now provide the "type" attribute, the type of the symbol.
4415 ** The "gdb.breakpoint" function has been deprecated in favor of
4418 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4419 of a function. This class is based on the "finish" command
4420 available in the CLI.
4422 ** Type objects for struct and union types now allow access to
4423 the fields using standard Python dictionary (mapping) methods.
4424 For example, "some_type['myfield']" now works, as does
4425 "some_type.items()".
4427 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4430 ** A new function, "deep_items" has been added to the gdb.types
4431 module in the GDB Python modules library. This function returns
4432 an iterator over the fields of a struct or union type. Unlike
4433 the standard Python "iteritems" method, it will recursively traverse
4434 any anonymous fields.
4438 ** "*stopped" events can report several new "reason"s, such as
4441 ** Breakpoint changes are now notified using new async records, like
4442 "=breakpoint-modified".
4444 ** New command -ada-task-info.
4446 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4447 $sdir specifies the default system locations of shared libraries.
4448 $pdir specifies the directory where the libpthread used by the application
4451 GDB no longer looks in $sdir and $pdir after it has searched the directories
4452 mentioned in libthread-db-search-path. If you want to search those
4453 directories, they must be specified in libthread-db-search-path.
4454 The default value of libthread-db-search-path on GNU/Linux and Solaris
4455 systems is now "$sdir:$pdir".
4457 $pdir is not supported by gdbserver, it is currently ignored.
4458 $sdir is supported by gdbserver.
4460 * New configure option --with-iconv-bin.
4461 When using the internationalization support like the one in the GNU C
4462 library, GDB will invoke the "iconv" program to get a list of supported
4463 character sets. If this program lives in a non-standard location, one can
4464 use this option to specify where to find it.
4466 * When natively debugging programs on PowerPC BookE processors running
4467 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4468 watchpoints, which specify a mask in addition to an address to watch.
4469 The mask specifies that some bits of an address (the bits which are
4470 reset in the mask) should be ignored when matching the address accessed
4471 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4472 section in the user manual for more details.
4474 * The new option --once causes GDBserver to stop listening for connections once
4475 the first connection is made. The listening port used by GDBserver will
4476 become available after that.
4478 * New commands "info macros" and "alias" have been added.
4480 * New function parameters suffix @entry specifies value of function parameter
4481 at the time the function got called. Entry values are available only since
4487 "!" is now an alias of the "shell" command.
4488 Note that no space is needed between "!" and SHELL COMMAND.
4492 watch EXPRESSION mask MASK_VALUE
4493 The watch command now supports the mask argument which allows creation
4494 of masked watchpoints, if the current architecture supports this feature.
4496 info auto-load-scripts [REGEXP]
4497 This command was formerly named "maintenance print section-scripts".
4498 It is now generally useful and is no longer a maintenance-only command.
4500 info macro [-all] [--] MACRO
4501 The info macro command has new options `-all' and `--'. The first for
4502 printing all definitions of a macro. The second for explicitly specifying
4503 the end of arguments and the beginning of the macro name in case the macro
4504 name starts with a hyphen.
4506 collect[/s] EXPRESSIONS
4507 The tracepoint collect command now takes an optional modifier "/s"
4508 that directs it to dereference pointer-to-character types and
4509 collect the bytes of memory up to a zero byte. The behavior is
4510 similar to what you see when you use the regular print command on a
4511 string. An optional integer following the "/s" sets a bound on the
4512 number of bytes that will be collected.
4515 The trace start command now interprets any supplied arguments as a
4516 note to be recorded with the trace run, with an effect similar to
4517 setting the variable trace-notes.
4520 The trace stop command now interprets any arguments as a note to be
4521 mentioned along with the tstatus report that the trace was stopped
4522 with a command. The effect is similar to setting the variable
4525 * Tracepoints can now be enabled and disabled at any time after a trace
4526 experiment has been started using the standard "enable" and "disable"
4527 commands. It is now possible to start a trace experiment with no enabled
4528 tracepoints; GDB will display a warning, but will allow the experiment to
4529 begin, assuming that tracepoints will be enabled as needed while the trace
4532 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4533 locations with 4-byte instructions, when they were previously
4534 limited to locations with instructions of 5 bytes or longer.
4538 set debug dwarf2-read
4539 show debug dwarf2-read
4540 Turns on or off display of debugging messages related to reading
4541 DWARF debug info. The default is off.
4543 set debug symtab-create
4544 show debug symtab-create
4545 Turns on or off display of debugging messages related to symbol table
4546 creation. The default is off.
4549 show extended-prompt
4550 Set the GDB prompt, and allow escape sequences to be inserted to
4551 display miscellaneous information (see 'help set extended-prompt'
4552 for the list of sequences). This prompt (and any information
4553 accessed through the escape sequences) is updated every time the
4554 prompt is displayed.
4556 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4557 show print entry-values
4558 Set printing of frame argument values at function entry. In some cases
4559 GDB can determine the value of function argument which was passed by the
4560 function caller, even if the value was modified inside the called function.
4562 set debug entry-values
4563 show debug entry-values
4564 Control display of debugging info for determining frame argument values at
4565 function entry and virtual tail call frames.
4567 set basenames-may-differ
4568 show basenames-may-differ
4569 Set whether a source file may have multiple base names.
4570 (A "base name" is the name of a file with the directory part removed.
4571 Example: The base name of "/home/user/hello.c" is "hello.c".)
4572 If set, GDB will canonicalize file names (e.g., expand symlinks)
4573 before comparing them. Canonicalization is an expensive operation,
4574 but it allows the same file be known by more than one base name.
4575 If not set (the default), all source files are assumed to have just
4576 one base name, and gdb will do file name comparisons more efficiently.
4582 Set a user name and notes for the current and any future trace runs.
4583 This is useful for long-running and/or disconnected traces, to
4584 inform others (or yourself) as to who is running the trace, supply
4585 contact information, or otherwise explain what is going on.
4587 set trace-stop-notes
4588 show trace-stop-notes
4589 Set a note attached to the trace run, that is displayed when the
4590 trace has been stopped by a tstop command. This is useful for
4591 instance as an explanation, if you are stopping a trace run that was
4592 started by someone else.
4594 * New remote packets
4598 Dynamically enable a tracepoint in a started trace experiment.
4602 Dynamically disable a tracepoint in a started trace experiment.
4606 Set the user and notes of the trace run.
4610 Query the current status of a tracepoint.
4614 Query the minimum length of instruction at which a fast tracepoint may
4617 * Dcache size (number of lines) and line-size are now runtime-configurable
4618 via "set dcache line" and "set dcache line-size" commands.
4622 Texas Instruments TMS320C6x tic6x-*-*
4626 Renesas RL78 rl78-*-elf
4628 *** Changes in GDB 7.3.1
4630 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4632 *** Changes in GDB 7.3
4634 * GDB has a new command: "thread find [REGEXP]".
4635 It finds the thread id whose name, target id, or thread extra info
4636 matches the given regular expression.
4638 * The "catch syscall" command now works on mips*-linux* targets.
4640 * The -data-disassemble MI command now supports modes 2 and 3 for
4641 dumping the instruction opcodes.
4643 * New command line options
4645 -data-directory DIR Specify DIR as the "data-directory".
4646 This is mostly for testing purposes.
4648 * The "maint set python auto-load on|off" command has been renamed to
4649 "set auto-load-scripts on|off".
4651 * GDB has a new command: "set directories".
4652 It is like the "dir" command except that it replaces the
4653 source path list instead of augmenting it.
4655 * GDB now understands thread names.
4657 On GNU/Linux, "info threads" will display the thread name as set by
4658 prctl or pthread_setname_np.
4660 There is also a new command, "thread name", which can be used to
4661 assign a name internally for GDB to display.
4664 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4665 has been integrated into GDB.
4669 ** The function gdb.Write now accepts an optional keyword 'stream'.
4670 This keyword, when provided, will direct the output to either
4671 stdout, stderr, or GDB's logging output.
4673 ** Parameters can now be be sub-classed in Python, and in particular
4674 you may implement the get_set_doc and get_show_doc functions.
4675 This improves how Parameter set/show documentation is processed
4676 and allows for more dynamic content.
4678 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4679 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4680 have an is_valid method.
4682 ** Breakpoints can now be sub-classed in Python, and in particular
4683 you may implement a 'stop' function that is executed each time
4684 the inferior reaches that breakpoint.
4686 ** New function gdb.lookup_global_symbol looks up a global symbol.
4688 ** GDB values in Python are now callable if the value represents a
4689 function. For example, if 'some_value' represents a function that
4690 takes two integer parameters and returns a value, you can call
4691 that function like so:
4693 result = some_value (10,20)
4695 ** Module gdb.types has been added.
4696 It contains a collection of utilities for working with gdb.Types objects:
4697 get_basic_type, has_field, make_enum_dict.
4699 ** Module gdb.printing has been added.
4700 It contains utilities for writing and registering pretty-printers.
4701 New classes: PrettyPrinter, SubPrettyPrinter,
4702 RegexpCollectionPrettyPrinter.
4703 New function: register_pretty_printer.
4705 ** New commands "info pretty-printers", "enable pretty-printer" and
4706 "disable pretty-printer" have been added.
4708 ** gdb.parameter("directories") is now available.
4710 ** New function gdb.newest_frame returns the newest frame in the
4713 ** The gdb.InferiorThread class has a new "name" attribute. This
4714 holds the thread's name.
4716 ** Python Support for Inferior events.
4717 Python scripts can add observers to be notified of events
4718 occurring in the process being debugged.
4719 The following events are currently supported:
4720 - gdb.events.cont Continue event.
4721 - gdb.events.exited Inferior exited event.
4722 - gdb.events.stop Signal received, and Breakpoint hit events.
4726 ** GDB now puts template parameters in scope when debugging in an
4727 instantiation. For example, if you have:
4729 template<int X> int func (void) { return X; }
4731 then if you step into func<5>, "print X" will show "5". This
4732 feature requires proper debuginfo support from the compiler; it
4733 was added to GCC 4.5.
4735 ** The motion commands "next", "finish", "until", and "advance" now
4736 work better when exceptions are thrown. In particular, GDB will
4737 no longer lose control of the inferior; instead, the GDB will
4738 stop the inferior at the point at which the exception is caught.
4739 This functionality requires a change in the exception handling
4740 code that was introduced in GCC 4.5.
4742 * GDB now follows GCC's rules on accessing volatile objects when
4743 reading or writing target state during expression evaluation.
4744 One notable difference to prior behavior is that "print x = 0"
4745 no longer generates a read of x; the value of the assignment is
4746 now always taken directly from the value being assigned.
4748 * GDB now has some support for using labels in the program's source in
4749 linespecs. For instance, you can use "advance label" to continue
4750 execution to a label.
4752 * GDB now has support for reading and writing a new .gdb_index
4753 section. This section holds a fast index of DWARF debugging
4754 information and can be used to greatly speed up GDB startup and
4755 operation. See the documentation for `save gdb-index' for details.
4757 * The "watch" command now accepts an optional "-location" argument.
4758 When used, this causes GDB to watch the memory referred to by the
4759 expression. Such a watchpoint is never deleted due to it going out
4762 * GDB now supports thread debugging of core dumps on GNU/Linux.
4764 GDB now activates thread debugging using the libthread_db library
4765 when debugging GNU/Linux core dumps, similarly to when debugging
4766 live processes. As a result, when debugging a core dump file, GDB
4767 is now able to display pthread_t ids of threads. For example, "info
4768 threads" shows the same output as when debugging the process when it
4769 was live. In earlier releases, you'd see something like this:
4772 * 1 LWP 6780 main () at main.c:10
4774 While now you see this:
4777 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4779 It is also now possible to inspect TLS variables when debugging core
4782 When debugging a core dump generated on a machine other than the one
4783 used to run GDB, you may need to point GDB at the correct
4784 libthread_db library with the "set libthread-db-search-path"
4785 command. See the user manual for more details on this command.
4787 * When natively debugging programs on PowerPC BookE processors running
4788 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4789 which stop execution of the inferior whenever it executes an instruction
4790 at any address within the specified range. See the "PowerPC Embedded"
4791 section in the user manual for more details.
4793 * New features in the GDB remote stub, GDBserver
4795 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4796 and i686 LynxOS (version 5.x).
4798 ** GDBserver is now supported on Blackfin Linux.
4800 * New native configurations
4802 ia64 HP-UX ia64-*-hpux*
4806 Analog Devices, Inc. Blackfin Processor bfin-*
4808 * Ada task switching is now supported on sparc-elf targets when
4809 debugging a program using the Ravenscar Profile. For more information,
4810 see the "Tasking Support when using the Ravenscar Profile" section
4811 in the GDB user manual.
4813 * Guile support was removed.
4815 * New features in the GNU simulator
4817 ** The --map-info flag lists all known core mappings.
4819 ** CFI flashes may be simulated via the "cfi" device.
4821 *** Changes in GDB 7.2
4823 * Shared library support for remote targets by default
4825 When GDB is configured for a generic, non-OS specific target, like
4826 for example, --target=arm-eabi or one of the many *-*-elf targets,
4827 GDB now queries remote stubs for loaded shared libraries using the
4828 `qXfer:libraries:read' packet. Previously, shared library support
4829 was always disabled for such configurations.
4833 ** Argument Dependent Lookup (ADL)
4835 In C++ ADL lookup directs function search to the namespaces of its
4836 arguments even if the namespace has not been imported.
4846 Here the compiler will search for `foo' in the namespace of 'b'
4847 and find A::foo. GDB now supports this. This construct is commonly
4848 used in the Standard Template Library for operators.
4850 ** Improved User Defined Operator Support
4852 In addition to member operators, GDB now supports lookup of operators
4853 defined in a namespace and imported with a `using' directive, operators
4854 defined in the global scope, operators imported implicitly from an
4855 anonymous namespace, and the ADL operators mentioned in the previous
4857 GDB now also supports proper overload resolution for all the previously
4858 mentioned flavors of operators.
4860 ** static const class members
4862 Printing of static const class members that are initialized in the
4863 class definition has been fixed.
4865 * Windows Thread Information Block access.
4867 On Windows targets, GDB now supports displaying the Windows Thread
4868 Information Block (TIB) structure. This structure is visible either
4869 by using the new command `info w32 thread-information-block' or, by
4870 dereferencing the new convenience variable named `$_tlb', a
4871 thread-specific pointer to the TIB. This feature is also supported
4872 when remote debugging using GDBserver.
4874 * Static tracepoints
4876 Static tracepoints are calls in the user program into a tracing
4877 library. One such library is a port of the LTTng kernel tracer to
4878 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4879 When debugging with GDBserver, GDB now supports combining the GDB
4880 tracepoint machinery with such libraries. For example: the user can
4881 use GDB to probe a static tracepoint marker (a call from the user
4882 program into the tracing library) with the new "strace" command (see
4883 "New commands" below). This creates a "static tracepoint" in the
4884 breakpoint list, that can be manipulated with the same feature set
4885 as fast and regular tracepoints. E.g., collect registers, local and
4886 global variables, collect trace state variables, and define
4887 tracepoint conditions. In addition, the user can collect extra
4888 static tracepoint marker specific data, by collecting the new
4889 $_sdata internal variable. When analyzing the trace buffer, you can
4890 inspect $_sdata like any other variable available to GDB. For more
4891 information, see the "Tracepoints" chapter in GDB user manual. New
4892 remote packets have been defined to support static tracepoints, see
4893 the "New remote packets" section below.
4895 * Better reconstruction of tracepoints after disconnected tracing
4897 GDB will attempt to download the original source form of tracepoint
4898 definitions when starting a trace run, and then will upload these
4899 upon reconnection to the target, resulting in a more accurate
4900 reconstruction of the tracepoints that are in use on the target.
4904 You can now exercise direct control over the ways that GDB can
4905 affect your program. For instance, you can disallow the setting of
4906 breakpoints, so that the program can run continuously (assuming
4907 non-stop mode). In addition, the "observer" variable is available
4908 to switch all of the different controls; in observer mode, GDB
4909 cannot affect the target's behavior at all, which is useful for
4910 tasks like diagnosing live systems in the field.
4912 * The new convenience variable $_thread holds the number of the
4915 * New remote packets
4919 Return the address of the Windows Thread Information Block of a given thread.
4923 In response to several of the tracepoint packets, the target may now
4924 also respond with a number of intermediate `qRelocInsn' request
4925 packets before the final result packet, to have GDB handle
4926 relocating an instruction to execute at a different address. This
4927 is particularly useful for stubs that support fast tracepoints. GDB
4928 reports support for this feature in the qSupported packet.
4932 List static tracepoint markers in the target program.
4936 List static tracepoint markers at a given address in the target
4939 qXfer:statictrace:read
4941 Read the static trace data collected (by a `collect $_sdata'
4942 tracepoint action). The remote stub reports support for this packet
4943 to gdb's qSupported query.
4947 Send the current settings of GDB's permission flags.
4951 Send part of the source (textual) form of a tracepoint definition,
4952 which includes location, conditional, and action list.
4954 * The source command now accepts a -s option to force searching for the
4955 script in the source search path even if the script name specifies
4958 * New features in the GDB remote stub, GDBserver
4960 - GDBserver now support tracepoints (including fast tracepoints, and
4961 static tracepoints). The feature is currently supported by the
4962 i386-linux and amd64-linux builds. See the "Tracepoints support
4963 in gdbserver" section in the manual for more information.
4965 GDBserver JIT compiles the tracepoint's conditional agent
4966 expression bytecode into native code whenever possible for low
4967 overhead dynamic tracepoints conditionals. For such tracepoints,
4968 an expression that examines program state is evaluated when the
4969 tracepoint is reached, in order to determine whether to capture
4970 trace data. If the condition is simple and false, processing the
4971 tracepoint finishes very quickly and no data is gathered.
4973 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4974 for static tracepoints support.
4976 - GDBserver now supports x86_64 Windows 64-bit debugging.
4978 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4979 it understands register description.
4981 * The --batch flag now disables pagination and queries.
4983 * X86 general purpose registers
4985 GDB now supports reading/writing byte, word and double-word x86
4986 general purpose registers directly. This means you can use, say,
4987 $ah or $ax to refer, respectively, to the byte register AH and
4988 16-bit word register AX that are actually portions of the 32-bit
4989 register EAX or 64-bit register RAX.
4991 * The `commands' command now accepts a range of breakpoints to modify.
4992 A plain `commands' following a command that creates multiple
4993 breakpoints affects all the breakpoints set by that command. This
4994 applies to breakpoints set by `rbreak', and also applies when a
4995 single `break' command creates multiple breakpoints (e.g.,
4996 breakpoints on overloaded c++ functions).
4998 * The `rbreak' command now accepts a filename specification as part of
4999 its argument, limiting the functions selected by the regex to those
5000 in the specified file.
5002 * Support for remote debugging Windows and SymbianOS shared libraries
5003 from Unix hosts has been improved. Non Windows GDB builds now can
5004 understand target reported file names that follow MS-DOS based file
5005 system semantics, such as file names that include drive letters and
5006 use the backslash character as directory separator. This makes it
5007 possible to transparently use the "set sysroot" and "set
5008 solib-search-path" on Unix hosts to point as host copies of the
5009 target's shared libraries. See the new command "set
5010 target-file-system-kind" described below, and the "Commands to
5011 specify files" section in the user manual for more information.
5015 eval template, expressions...
5016 Convert the values of one or more expressions under the control
5017 of the string template to a command line, and call it.
5019 set target-file-system-kind unix|dos-based|auto
5020 show target-file-system-kind
5021 Set or show the assumed file system kind for target reported file
5024 save breakpoints <filename>
5025 Save all current breakpoint definitions to a file suitable for use
5026 in a later debugging session. To read the saved breakpoint
5027 definitions, use the `source' command.
5029 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5032 info static-tracepoint-markers
5033 Display information about static tracepoint markers in the target.
5035 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5036 Define a static tracepoint by probing a marker at the given
5037 function, line, address, or marker ID.
5041 Enable and disable observer mode.
5043 set may-write-registers on|off
5044 set may-write-memory on|off
5045 set may-insert-breakpoints on|off
5046 set may-insert-tracepoints on|off
5047 set may-insert-fast-tracepoints on|off
5048 set may-interrupt on|off
5049 Set individual permissions for GDB effects on the target. Note that
5050 some of these settings can have undesirable or surprising
5051 consequences, particularly when changed in the middle of a session.
5052 For instance, disabling the writing of memory can prevent
5053 breakpoints from being inserted, cause single-stepping to fail, or
5054 even crash your program, if you disable after breakpoints have been
5055 inserted. However, GDB should not crash.
5057 set record memory-query on|off
5058 show record memory-query
5059 Control whether to stop the inferior if memory changes caused
5060 by an instruction cannot be recorded.
5065 The disassemble command now supports "start,+length" form of two arguments.
5069 ** GDB now provides a new directory location, called the python directory,
5070 where Python scripts written for GDB can be installed. The location
5071 of that directory is <data-directory>/python, where <data-directory>
5072 is the GDB data directory. For more details, see section `Scripting
5073 GDB using Python' in the manual.
5075 ** The GDB Python API now has access to breakpoints, symbols, symbol
5076 tables, program spaces, inferiors, threads and frame's code blocks.
5077 Additionally, GDB Parameters can now be created from the API, and
5078 manipulated via set/show in the CLI.
5080 ** New functions gdb.target_charset, gdb.target_wide_charset,
5081 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5083 ** New exception gdb.GdbError.
5085 ** Pretty-printers are now also looked up in the current program space.
5087 ** Pretty-printers can now be individually enabled and disabled.
5089 ** GDB now looks for names of Python scripts to auto-load in a
5090 special section named `.debug_gdb_scripts', in addition to looking
5091 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5093 * Tracepoint actions were unified with breakpoint commands. In particular,
5094 there are no longer differences in "info break" output for breakpoints and
5095 tracepoints and the "commands" command can be used for both tracepoints and
5096 regular breakpoints.
5100 ARM Symbian arm*-*-symbianelf*
5102 * D language support.
5103 GDB now supports debugging programs written in the D programming
5106 * GDB now supports the extended ptrace interface for PowerPC which is
5107 available since Linux kernel version 2.6.34. This automatically enables
5108 any hardware breakpoints and additional hardware watchpoints available in
5109 the processor. The old ptrace interface exposes just one hardware
5110 watchpoint and no hardware breakpoints.
5112 * GDB is now able to use the Data Value Compare (DVC) register available on
5113 embedded PowerPC processors to implement in hardware simple watchpoint
5114 conditions of the form:
5116 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5118 This works in native GDB running on Linux kernels with the extended ptrace
5119 interface mentioned above.
5121 *** Changes in GDB 7.1
5125 ** Namespace Support
5127 GDB now supports importing of namespaces in C++. This enables the
5128 user to inspect variables from imported namespaces. Support for
5129 namepace aliasing has also been added. So, if a namespace is
5130 aliased in the current scope (e.g. namepace C=A; ) the user can
5131 print variables using the alias (e.g. (gdb) print C::x).
5135 All known bugs relating to the printing of virtual base class were
5136 fixed. It is now possible to call overloaded static methods using a
5141 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5142 and reinterpret_cast<> are now handled by the C++ expression parser.
5146 Xilinx MicroBlaze microblaze-*-*
5151 Xilinx MicroBlaze microblaze
5154 * Multi-program debugging.
5156 GDB now has support for multi-program (a.k.a. multi-executable or
5157 multi-exec) debugging. This allows for debugging multiple inferiors
5158 simultaneously each running a different program under the same GDB
5159 session. See "Debugging Multiple Inferiors and Programs" in the
5160 manual for more information. This implied some user visible changes
5161 in the multi-inferior support. For example, "info inferiors" now
5162 lists inferiors that are not running yet or that have exited
5163 already. See also "New commands" and "New options" below.
5165 * New tracing features
5167 GDB's tracepoint facility now includes several new features:
5169 ** Trace state variables
5171 GDB tracepoints now include support for trace state variables, which
5172 are variables managed by the target agent during a tracing
5173 experiment. They are useful for tracepoints that trigger each
5174 other, so for instance one tracepoint can count hits in a variable,
5175 and then a second tracepoint has a condition that is true when the
5176 count reaches a particular value. Trace state variables share the
5177 $-syntax of GDB convenience variables, and can appear in both
5178 tracepoint actions and condition expressions. Use the "tvariable"
5179 command to create, and "info tvariables" to view; see "Trace State
5180 Variables" in the manual for more detail.
5184 GDB now includes an option for defining fast tracepoints, which
5185 targets may implement more efficiently, such as by installing a jump
5186 into the target agent rather than a trap instruction. The resulting
5187 speedup can be by two orders of magnitude or more, although the
5188 tradeoff is that some program locations on some target architectures
5189 might not allow fast tracepoint installation, for instance if the
5190 instruction to be replaced is shorter than the jump. To request a
5191 fast tracepoint, use the "ftrace" command, with syntax identical to
5192 the regular trace command.
5194 ** Disconnected tracing
5196 It is now possible to detach GDB from the target while it is running
5197 a trace experiment, then reconnect later to see how the experiment
5198 is going. In addition, a new variable disconnected-tracing lets you
5199 tell the target agent whether to continue running a trace if the
5200 connection is lost unexpectedly.
5204 GDB now has the ability to save the trace buffer into a file, and
5205 then use that file as a target, similarly to you can do with
5206 corefiles. You can select trace frames, print data that was
5207 collected in them, and use tstatus to display the state of the
5208 tracing run at the moment that it was saved. To create a trace
5209 file, use "tsave <filename>", and to use it, do "target tfile
5212 ** Circular trace buffer
5214 You can ask the target agent to handle the trace buffer as a
5215 circular buffer, discarding the oldest trace frames to make room for
5216 newer ones, by setting circular-trace-buffer to on. This feature may
5217 not be available for all target agents.
5222 The disassemble command, when invoked with two arguments, now requires
5223 the arguments to be comma-separated.
5226 The info variables command now displays variable definitions. Files
5227 which only declare a variable are not shown.
5230 The source command is now capable of sourcing Python scripts.
5231 This feature is dependent on the debugger being build with Python
5234 Related to this enhancement is also the introduction of a new command
5235 "set script-extension" (see below).
5237 * New commands (for set/show, see "New options" below)
5239 record save [<FILENAME>]
5240 Save a file (in core file format) containing the process record
5241 execution log for replay debugging at a later time.
5243 record restore <FILENAME>
5244 Restore the process record execution log that was saved at an
5245 earlier time, for replay debugging.
5247 add-inferior [-copies <N>] [-exec <FILENAME>]
5250 clone-inferior [-copies <N>] [ID]
5251 Make a new inferior ready to execute the same program another
5252 inferior has loaded.
5257 maint info program-spaces
5258 List the program spaces loaded into GDB.
5260 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5261 show remote interrupt-sequence
5262 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5263 as the sequence to the remote target in order to interrupt the execution.
5264 Ctrl-C is a default. Some system prefers BREAK which is high level of
5265 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5266 Magic SysRq g. It is BREAK signal and character 'g'.
5268 set remote interrupt-on-connect [on | off]
5269 show remote interrupt-on-connect
5270 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5271 remote target when gdb connects to it. This is needed when you debug
5274 set remotebreak [on | off]
5276 Deprecated. Use "set/show remote interrupt-sequence" instead.
5278 tvariable $NAME [ = EXP ]
5279 Create or modify a trace state variable.
5282 List trace state variables and their values.
5284 delete tvariable $NAME ...
5285 Delete one or more trace state variables.
5288 Evaluate the given expressions without collecting anything into the
5289 trace buffer. (Valid in tracepoint actions only.)
5291 ftrace FN / FILE:LINE / *ADDR
5292 Define a fast tracepoint at the given function, line, or address.
5294 * New expression syntax
5296 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5297 GDB now parses 0b101010 identically with 42.
5301 set follow-exec-mode new|same
5302 show follow-exec-mode
5303 Control whether GDB reuses the same inferior across an exec call or
5304 creates a new one. This is useful to be able to restart the old
5305 executable after the inferior having done an exec call.
5307 set default-collect EXPR, ...
5308 show default-collect
5309 Define a list of expressions to be collected at each tracepoint.
5310 This is a useful way to ensure essential items are not overlooked,
5311 such as registers or a critical global variable.
5313 set disconnected-tracing
5314 show disconnected-tracing
5315 If set to 1, the target is instructed to continue tracing if it
5316 loses its connection to GDB. If 0, the target is to stop tracing
5319 set circular-trace-buffer
5320 show circular-trace-buffer
5321 If set to on, the target is instructed to use a circular trace buffer
5322 and discard the oldest trace frames instead of stopping the trace due
5323 to a full trace buffer. If set to off, the trace stops when the buffer
5324 fills up. Some targets may not support this.
5326 set script-extension off|soft|strict
5327 show script-extension
5328 If set to "off", the debugger does not perform any script language
5329 recognition, and all sourced files are assumed to be GDB scripts.
5330 If set to "soft" (the default), files are sourced according to
5331 filename extension, falling back to GDB scripts if the first
5333 If set to "strict", files are sourced according to filename extension.
5335 set ada trust-PAD-over-XVS on|off
5336 show ada trust-PAD-over-XVS
5337 If off, activate a workaround against a bug in the debugging information
5338 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5339 the GCC sources for more information about the GNAT encoding and
5340 PAD types in particular). It is always safe to set this option to
5341 off, but this introduces a slight performance penalty. The default
5344 * Python API Improvements
5346 ** GDB provides the new class gdb.LazyString. This is useful in
5347 some pretty-printing cases. The new method gdb.Value.lazy_string
5348 provides a simple way to create objects of this type.
5350 ** The fields returned by gdb.Type.fields now have an
5351 `is_base_class' attribute.
5353 ** The new method gdb.Type.range returns the range of an array type.
5355 ** The new method gdb.parse_and_eval can be used to parse and
5356 evaluate an expression.
5358 * New remote packets
5361 Define a trace state variable.
5364 Get the current value of a trace state variable.
5367 Set desired tracing behavior upon disconnection.
5370 Set the trace buffer to be linear or circular.
5373 Get data about the tracepoints currently in use.
5377 Process record now works correctly with hardware watchpoints.
5379 Multiple bug fixes have been made to the mips-irix port, making it
5380 much more reliable. In particular:
5381 - Debugging threaded applications is now possible again. Previously,
5382 GDB would hang while starting the program, or while waiting for
5383 the program to stop at a breakpoint.
5384 - Attaching to a running process no longer hangs.
5385 - An error occurring while loading a core file has been fixed.
5386 - Changing the value of the PC register now works again. This fixes
5387 problems observed when using the "jump" command, or when calling
5388 a function from GDB, or even when assigning a new value to $pc.
5389 - With the "finish" and "return" commands, the return value for functions
5390 returning a small array is now correctly printed.
5391 - It is now possible to break on shared library code which gets executed
5392 during a shared library init phase (code executed while executing
5393 their .init section). Previously, the breakpoint would have no effect.
5394 - GDB is now able to backtrace through the signal handler for
5395 non-threaded programs.
5397 PIE (Position Independent Executable) programs debugging is now supported.
5398 This includes debugging execution of PIC (Position Independent Code) shared
5399 libraries although for that, it should be possible to run such libraries as an
5402 *** Changes in GDB 7.0
5404 * GDB now has an interface for JIT compilation. Applications that
5405 dynamically generate code can create symbol files in memory and register
5406 them with GDB. For users, the feature should work transparently, and
5407 for JIT developers, the interface is documented in the GDB manual in the
5408 "JIT Compilation Interface" chapter.
5410 * Tracepoints may now be conditional. The syntax is as for
5411 breakpoints; either an "if" clause appended to the "trace" command,
5412 or the "condition" command is available. GDB sends the condition to
5413 the target for evaluation using the same bytecode format as is used
5414 for tracepoint actions.
5416 * The disassemble command now supports: an optional /r modifier, print the
5417 raw instructions in hex as well as in symbolic form, and an optional /m
5418 modifier to print mixed source+assembly.
5420 * Process record and replay
5422 In a architecture environment that supports ``process record and
5423 replay'', ``process record and replay'' target can record a log of
5424 the process execution, and replay it with both forward and reverse
5427 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5428 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5429 set execution-direction {forward|reverse}, for targets that support
5432 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5433 feature is available with a native GDB running on kernel version
5436 * GDB now has support for multi-byte and wide character sets on the
5437 target. Strings whose character type is wchar_t, char16_t, or
5438 char32_t are now correctly printed. GDB supports wide- and unicode-
5439 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5440 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5441 `printf'. This feature requires iconv to work properly; if your
5442 system does not have a working iconv, GDB can use GNU libiconv. See
5443 the installation instructions for more information.
5445 * GDB now supports automatic retrieval of shared library files from
5446 remote targets. To use this feature, specify a system root that begins
5447 with the `remote:' prefix, either via the `set sysroot' command or via
5448 the `--with-sysroot' configure-time option.
5450 * "info sharedlibrary" now takes an optional regex of libraries to show,
5451 and it now reports if a shared library has no debugging information.
5453 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5454 now complete on file names.
5456 * When completing in expressions, gdb will attempt to limit
5457 completions to allowable structure or union fields, where appropriate.
5458 For instance, consider:
5460 # struct example { int f1; double f2; };
5461 # struct example variable;
5464 If the user types TAB at the end of this command line, the available
5465 completions will be "f1" and "f2".
5467 * Inlined functions are now supported. They show up in backtraces, and
5468 the "step", "next", and "finish" commands handle them automatically.
5470 * GDB now supports the token-splicing (##) and stringification (#)
5471 operators when expanding macros. It also supports variable-arity
5474 * GDB now supports inspecting extra signal information, exported by
5475 the new $_siginfo convenience variable. The feature is currently
5476 implemented on linux ARM, i386 and amd64.
5478 * GDB can now display the VFP floating point registers and NEON vector
5479 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5480 can provide these registers (requires Linux 2.6.30 or later). Remote
5481 and simulator targets may also provide them.
5483 * New remote packets
5486 Search memory for a sequence of bytes.
5489 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5490 operation over reliable transport links. Use of this packet is
5491 controlled by the `set remote noack-packet' command.
5494 Kill the process with the specified process ID. Use this in preference
5495 to `k' when multiprocess protocol extensions are supported.
5498 Obtains additional operating system information
5502 Read or write additional signal information.
5504 * Removed remote protocol undocumented extension
5506 An undocumented extension to the remote protocol's `S' stop reply
5507 packet that permitted the stub to pass a process id was removed.
5508 Remote servers should use the `T' stop reply packet instead.
5510 * GDB now supports multiple function calling conventions according to the
5511 DWARF-2 DW_AT_calling_convention function attribute.
5513 * The SH target utilizes the aforementioned change to distinguish between gcc
5514 and Renesas calling convention. It also adds the new CLI commands
5515 `set/show sh calling-convention'.
5517 * GDB can now read compressed debug sections, as produced by GNU gold
5518 with the --compress-debug-sections=zlib flag.
5520 * 64-bit core files are now supported on AIX.
5522 * Thread switching is now supported on Tru64.
5524 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5525 which will be allocated using malloc later in program execution.
5527 * The qXfer:libraries:read remote protocol packet now allows passing a
5528 list of section offsets.
5530 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5531 conditions handling signals delivered during attach or thread creation
5532 have also been fixed.
5534 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5535 From the user's standpoint, all unqualified instances of True and False
5536 are treated as the standard definitions, regardless of context.
5538 * GDB now parses C++ symbol and type names more flexibly. For
5541 template<typename T> class C { };
5544 GDB will now correctly handle all of:
5546 ptype C<char const *>
5547 ptype C<char const*>
5548 ptype C<const char *>
5549 ptype C<const char*>
5551 * New features in the GDB remote stub, gdbserver
5553 - The "--wrapper" command-line argument tells gdbserver to use a
5554 wrapper program to launch programs for debugging.
5556 - On PowerPC and S/390 targets, it is now possible to use a single
5557 gdbserver executable to debug both 32-bit and 64-bit programs.
5558 (This requires gdbserver itself to be built as a 64-bit executable.)
5560 - gdbserver uses the new noack protocol mode for TCP connections to
5561 reduce communications latency, if also supported and enabled in GDB.
5563 - Support for the sparc64-linux-gnu target is now included in
5566 - The amd64-linux build of gdbserver now supports debugging both
5567 32-bit and 64-bit programs.
5569 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5570 now support hardware watchpoints, and will use them automatically
5575 GDB now has support for scripting using Python. Whether this is
5576 available is determined at configure time.
5578 New GDB commands can now be written in Python.
5580 * Ada tasking support
5582 Ada tasks can now be inspected in GDB. The following commands have
5586 Print the list of Ada tasks.
5588 Print detailed information about task number N.
5590 Print the task number of the current task.
5592 Switch the context of debugging to task number N.
5594 * Support for user-defined prefixed commands. The "define" command can
5595 add new commands to existing prefixes, e.g. "target".
5597 * Multi-inferior, multi-process debugging.
5599 GDB now has generalized support for multi-inferior debugging. See
5600 "Debugging Multiple Inferiors" in the manual for more information.
5601 Although availability still depends on target support, the command
5602 set is more uniform now. The GNU/Linux specific multi-forks support
5603 has been migrated to this new framework. This implied some user
5604 visible changes; see "New commands" and also "Removed commands"
5607 * Target descriptions can now describe the target OS ABI. See the
5608 "Target Description Format" section in the user manual for more
5611 * Target descriptions can now describe "compatible" architectures
5612 to indicate that the target can execute applications for a different
5613 architecture in addition to those for the main target architecture.
5614 See the "Target Description Format" section in the user manual for
5617 * Multi-architecture debugging.
5619 GDB now includes general supports for debugging applications on
5620 hybrid systems that use more than one single processor architecture
5621 at the same time. Each such hybrid architecture still requires
5622 specific support to be added. The only hybrid architecture supported
5623 in this version of GDB is the Cell Broadband Engine.
5625 * GDB now supports integrated debugging of Cell/B.E. applications that
5626 use both the PPU and SPU architectures. To enable support for hybrid
5627 Cell/B.E. debugging, you need to configure GDB to support both the
5628 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5629 --enable-targets configure option.
5631 * Non-stop mode debugging.
5633 For some targets, GDB now supports an optional mode of operation in
5634 which you can examine stopped threads while other threads continue
5635 to execute freely. This is referred to as non-stop mode, with the
5636 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5637 section in the user manual for more information.
5639 To be able to support remote non-stop debugging, a remote stub needs
5640 to implement the non-stop mode remote protocol extensions, as
5641 described in the "Remote Non-Stop" section of the user manual. The
5642 GDB remote stub, gdbserver, has been adjusted to support these
5643 extensions on linux targets.
5645 * New commands (for set/show, see "New options" below)
5647 catch syscall [NAME(S) | NUMBER(S)]
5648 Catch system calls. Arguments, which should be names of system
5649 calls or their numbers, mean catch only those syscalls. Without
5650 arguments, every syscall will be caught. When the inferior issues
5651 any of the specified syscalls, GDB will stop and announce the system
5652 call, both when it is called and when its call returns. This
5653 feature is currently available with a native GDB running on the
5654 Linux Kernel, under the following architectures: x86, x86_64,
5655 PowerPC and PowerPC64.
5657 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5659 Search memory for a sequence of bytes.
5661 maint set python print-stack
5662 maint show python print-stack
5663 Show a stack trace when an error is encountered in a Python script.
5666 Invoke CODE by passing it to the Python interpreter.
5671 These allow macros to be defined, undefined, and listed
5675 Show operating system information about processes.
5678 List the inferiors currently under GDB's control.
5681 Switch focus to inferior number NUM.
5684 Detach from inferior number NUM.
5687 Kill inferior number NUM.
5691 set spu stop-on-load
5692 show spu stop-on-load
5693 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5695 set spu auto-flush-cache
5696 show spu auto-flush-cache
5697 Control whether to automatically flush the software-managed cache
5698 during Cell/B.E. debugging.
5700 set sh calling-convention
5701 show sh calling-convention
5702 Control the calling convention used when calling SH target functions.
5705 show debug timestamp
5706 Control display of timestamps with GDB debugging output.
5708 set disassemble-next-line
5709 show disassemble-next-line
5710 Control display of disassembled source lines or instructions when
5713 set remote noack-packet
5714 show remote noack-packet
5715 Set/show the use of remote protocol QStartNoAckMode packet. See above
5716 under "New remote packets."
5718 set remote query-attached-packet
5719 show remote query-attached-packet
5720 Control use of remote protocol `qAttached' (query-attached) packet.
5722 set remote read-siginfo-object
5723 show remote read-siginfo-object
5724 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5727 set remote write-siginfo-object
5728 show remote write-siginfo-object
5729 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5732 set remote reverse-continue
5733 show remote reverse-continue
5734 Control use of remote protocol 'bc' (reverse-continue) packet.
5736 set remote reverse-step
5737 show remote reverse-step
5738 Control use of remote protocol 'bs' (reverse-step) packet.
5740 set displaced-stepping
5741 show displaced-stepping
5742 Control displaced stepping mode. Displaced stepping is a way to
5743 single-step over breakpoints without removing them from the debuggee.
5744 Also known as "out-of-line single-stepping".
5747 show debug displaced
5748 Control display of debugging info for displaced stepping.
5750 maint set internal-error
5751 maint show internal-error
5752 Control what GDB does when an internal error is detected.
5754 maint set internal-warning
5755 maint show internal-warning
5756 Control what GDB does when an internal warning is detected.
5761 Use a wrapper program to launch programs for debugging.
5763 set multiple-symbols (all|ask|cancel)
5764 show multiple-symbols
5765 The value of this variable can be changed to adjust the debugger behavior
5766 when an expression or a breakpoint location contains an ambiguous symbol
5767 name (an overloaded function name, for instance).
5769 set breakpoint always-inserted
5770 show breakpoint always-inserted
5771 Keep breakpoints always inserted in the target, as opposed to inserting
5772 them when resuming the target, and removing them when the target stops.
5773 This option can improve debugger performance on slow remote targets.
5775 set arm fallback-mode (arm|thumb|auto)
5776 show arm fallback-mode
5777 set arm force-mode (arm|thumb|auto)
5779 These commands control how ARM GDB determines whether instructions
5780 are ARM or Thumb. The default for both settings is auto, which uses
5781 the current CPSR value for instructions without symbols; previous
5782 versions of GDB behaved as if "set arm fallback-mode arm".
5784 set arm unwind-secure-frames
5785 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5787 This can trigger security exceptions when unwinding exception stacks.
5789 set disable-randomization
5790 show disable-randomization
5791 Standalone programs run with the virtual address space randomization enabled
5792 by default on some platforms. This option keeps the addresses stable across
5793 multiple debugging sessions.
5797 Control whether other threads are stopped or not when some thread hits
5802 Requests that asynchronous execution is enabled in the target, if available.
5803 In this case, it's possible to resume target in the background, and interact
5804 with GDB while the target is running. "show target-async" displays the
5805 current state of asynchronous execution of the target.
5807 set target-wide-charset
5808 show target-wide-charset
5809 The target-wide-charset is the name of the character set that GDB
5810 uses when printing characters whose type is wchar_t.
5812 set tcp auto-retry (on|off)
5814 set tcp connect-timeout
5815 show tcp connect-timeout
5816 These commands allow GDB to retry failed TCP connections to a remote stub
5817 with a specified timeout period; this is useful if the stub is launched
5818 in parallel with GDB but may not be ready to accept connections immediately.
5820 set libthread-db-search-path
5821 show libthread-db-search-path
5822 Control list of directories which GDB will search for appropriate
5825 set schedule-multiple (on|off)
5826 show schedule-multiple
5827 Allow GDB to resume all threads of all processes or only threads of
5828 the current process.
5832 Use more aggressive caching for accesses to the stack. This improves
5833 performance of remote debugging (particularly backtraces) without
5834 affecting correctness.
5836 set interactive-mode (on|off|auto)
5837 show interactive-mode
5838 Control whether GDB runs in interactive mode (on) or not (off).
5839 When in interactive mode, GDB waits for the user to answer all
5840 queries. Otherwise, GDB does not wait and assumes the default
5841 answer. When set to auto (the default), GDB determines which
5842 mode to use based on the stdin settings.
5847 For program forks, this is replaced by the new more generic `info
5848 inferiors' command. To list checkpoints, you can still use the
5849 `info checkpoints' command, which was an alias for the `info forks'
5853 Replaced by the new `inferior' command. To switch between
5854 checkpoints, you can still use the `restart' command, which was an
5855 alias for the `fork' command.
5858 This is removed, since some targets don't have a notion of
5859 processes. To switch between processes, you can still use the
5860 `inferior' command using GDB's own inferior number.
5863 For program forks, this is replaced by the new more generic `kill
5864 inferior' command. To delete a checkpoint, you can still use the
5865 `delete checkpoint' command, which was an alias for the `delete
5869 For program forks, this is replaced by the new more generic `detach
5870 inferior' command. To detach a checkpoint, you can still use the
5871 `detach checkpoint' command, which was an alias for the `detach
5874 * New native configurations
5876 x86/x86_64 Darwin i[34567]86-*-darwin*
5878 x86_64 MinGW x86_64-*-mingw*
5882 Lattice Mico32 lm32-*
5883 x86 DICOS i[34567]86-*-dicos*
5884 x86_64 DICOS x86_64-*-dicos*
5887 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5888 (mingw32ce) debugging.
5894 These commands were actually not implemented on any target.
5896 *** Changes in GDB 6.8
5898 * New native configurations
5900 NetBSD/hppa hppa*-*netbsd*
5901 Xtensa GNU/Linux xtensa*-*-linux*
5905 NetBSD/hppa hppa*-*-netbsd*
5906 Xtensa GNU/Linux xtensa*-*-linux*
5908 * Change in command line behavior -- corefiles vs. process ids.
5910 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5911 attaching to process NUMBER fails, GDB no longer attempts to open a
5912 core file named NUMBER. Attaching to a program using the -c option
5913 is no longer supported. Instead, use the '-p' or '--pid' options.
5915 * GDB can now be built as a native debugger for debugging Windows x86
5916 (mingw32) Portable Executable (PE) programs.
5918 * Pending breakpoints no longer change their number when their address
5921 * GDB now supports breakpoints with multiple locations,
5922 including breakpoints on C++ constructors, inside C++ templates,
5923 and in inlined functions.
5925 * GDB's ability to debug optimized code has been improved. GDB more
5926 accurately identifies function bodies and lexical blocks that occupy
5927 more than one contiguous range of addresses.
5929 * Target descriptions can now describe registers for PowerPC.
5931 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5932 registers on PowerPC targets.
5934 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5935 targets even when the libthread_db library is not available.
5937 * The GDB remote stub, gdbserver, now supports the new file transfer
5938 commands (remote put, remote get, and remote delete).
5940 * The GDB remote stub, gdbserver, now supports run and attach in
5941 extended-remote mode.
5943 * hppa*64*-*-hpux11* target broken
5944 The debugger is unable to start a program and fails with the following
5945 error: "Error trying to get information about dynamic linker".
5946 The gdb-6.7 release is also affected.
5948 * GDB now supports the --enable-targets= configure option to allow
5949 building a single GDB executable that supports multiple remote
5950 target architectures.
5952 * GDB now supports debugging C and C++ programs which use the
5953 Decimal Floating Point extension. In addition, the PowerPC target
5954 now has a set of pseudo-registers to inspect decimal float values
5955 stored in two consecutive float registers.
5957 * The -break-insert MI command can optionally create pending
5960 * Improved support for debugging Ada
5961 Many improvements to the Ada language support have been made. These
5963 - Better support for Ada2005 interface types
5964 - Improved handling of arrays and slices in general
5965 - Better support for Taft-amendment types
5966 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5968 - Improved command completion in Ada
5971 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5976 set print frame-arguments (all|scalars|none)
5977 show print frame-arguments
5978 The value of this variable can be changed to control which argument
5979 values should be printed by the debugger when displaying a frame.
5984 Transfer files to and from a remote target, and delete remote files.
5991 Transfer files to and from a remote target, and delete remote files.
5993 * New remote packets
6000 Open, close, read, write, and delete files on the remote system.
6003 Attach to an existing process on the remote system, in extended-remote
6007 Run a new process on the remote system, in extended-remote mode.
6009 *** Changes in GDB 6.7
6011 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6012 bfd, libiberty and opcodes, as revealed by static analysis donated by
6013 Coverity, Inc. (http://scan.coverity.com).
6015 * When looking up multiply-defined global symbols, GDB will now prefer the
6016 symbol definition in the current shared library if it was built using the
6017 -Bsymbolic linker option.
6019 * When the Text User Interface (TUI) is not configured, GDB will now
6020 recognize the -tui command-line option and print a message that the TUI
6023 * The GDB remote stub, gdbserver, now has lower overhead for high
6024 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6026 * GDB for MIPS targets now autodetects whether a remote target provides
6027 32-bit or 64-bit register values.
6029 * Support for C++ member pointers has been improved.
6031 * GDB now understands XML target descriptions, which specify the
6032 target's overall architecture. GDB can read a description from
6033 a local file or over the remote serial protocol.
6035 * Vectors of single-byte data use a new integer type which is not
6036 automatically displayed as character or string data.
6038 * The /s format now works with the print command. It displays
6039 arrays of single-byte integers and pointers to single-byte integers
6042 * Target descriptions can now describe target-specific registers,
6043 for architectures which have implemented the support (currently
6044 only ARM, M68K, and MIPS).
6046 * GDB and the GDB remote stub, gdbserver, now support the XScale
6049 * The GDB remote stub, gdbserver, has been updated to support
6050 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6051 has been rewritten to use the standard GDB remote protocol.
6053 * GDB can now step into C++ functions which are called through thunks.
6055 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6057 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6058 layout. It also supports a TextSeg= and DataSeg= response when only
6059 segment base addresses (rather than offsets) are available.
6061 * The /i format now outputs any trailing branch delay slot instructions
6062 immediately following the last instruction within the count specified.
6064 * The GDB remote protocol "T" stop reply packet now supports a
6065 "library" response. Combined with the new "qXfer:libraries:read"
6066 packet, this response allows GDB to debug shared libraries on targets
6067 where the operating system manages the list of loaded libraries (e.g.
6068 Windows and SymbianOS).
6070 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6071 (DLLs) on Windows and Windows CE targets.
6073 * GDB now supports a faster verification that a .debug file matches its binary
6074 according to its build-id signature, if the signature is present.
6080 Enable or disable hardware flow control (RTS/CTS) on the serial port
6081 when debugging using remote targets.
6083 set mem inaccessible-by-default
6084 show mem inaccessible-by-default
6085 If the target supplies a memory map, for instance via the remote
6086 protocol's "qXfer:memory-map:read" packet, setting this variable
6087 prevents GDB from accessing memory outside the memory map. This
6088 is useful for targets with memory mapped registers or which react
6089 badly to accesses of unmapped address space.
6091 set breakpoint auto-hw
6092 show breakpoint auto-hw
6093 If the target supplies a memory map, for instance via the remote
6094 protocol's "qXfer:memory-map:read" packet, setting this variable
6095 lets GDB use hardware breakpoints automatically for memory regions
6096 where it can not use software breakpoints. This covers both the
6097 "break" command and internal breakpoints used for other commands
6098 including "next" and "finish".
6101 catch exception unhandled
6102 Stop the program execution when Ada exceptions are raised.
6105 Stop the program execution when an Ada assertion failed.
6109 Set an alternate system root for target files. This is a more
6110 general version of "set solib-absolute-prefix", which is now
6111 an alias to "set sysroot".
6114 Provide extended SPU facility status information. This set of
6115 commands is available only when debugging the Cell/B.E. SPU
6118 * New native configurations
6120 OpenBSD/sh sh*-*openbsd*
6123 unset tdesc filename
6125 Use the specified local file as an XML target description, and do
6126 not query the target for its built-in description.
6130 OpenBSD/sh sh*-*-openbsd*
6131 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6132 Toshiba Media Processor mep-elf
6134 * New remote packets
6137 Ignore the specified signals; pass them directly to the debugged program
6138 without stopping other threads or reporting them to GDB.
6140 qXfer:features:read:
6141 Read an XML target description from the target, which describes its
6146 Read or write contents of an spufs file on the target system. These
6147 packets are available only on the Cell/B.E. SPU architecture.
6149 qXfer:libraries:read:
6150 Report the loaded shared libraries. Combined with new "T" packet
6151 response, this packet allows GDB to debug shared libraries on
6152 targets where the operating system manages the list of loaded
6153 libraries (e.g. Windows and SymbianOS).
6157 Support for these obsolete configurations has been removed.
6165 i[34567]86-*-lynxos*
6166 i[34567]86-*-netware*
6167 i[34567]86-*-sco3.2v5*
6168 i[34567]86-*-sco3.2v4*
6170 i[34567]86-*-sysv4.2*
6173 i[34567]86-*-unixware2*
6174 i[34567]86-*-unixware*
6183 * Other removed features
6190 Various m68k-only ROM monitors.
6197 Various Renesas ROM monitors and debugging interfaces for SH and
6202 Support for a Macraigor serial interface to on-chip debugging.
6203 GDB does not directly support the newer parallel or USB
6208 A debug information format. The predecessor to DWARF 2 and
6209 DWARF 3, which are still supported.
6211 Support for the HP aCC compiler on HP-UX/PA-RISC
6213 SOM-encapsulated symbolic debugging information, automatic
6214 invocation of pxdb, and the aCC custom C++ ABI. This does not
6215 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6216 with aCC can still be debugged on an assembly level.
6218 MIPS ".pdr" sections
6220 A MIPS-specific format used to describe stack frame layout
6221 in debugging information.
6225 GDB could work with an older version of Guile to debug
6226 the interpreter and Scheme programs running in it.
6228 set mips stack-arg-size
6229 set mips saved-gpreg-size
6231 Use "set mips abi" to control parameter passing for MIPS.
6233 *** Changes in GDB 6.6
6238 Cell Broadband Engine SPU spu-elf
6240 * GDB can now be configured as a cross-debugger targeting native Windows
6241 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6242 running on a Windows system over TCP/IP to debug Windows programs.
6244 * The GDB remote stub, gdbserver, has been updated to support Windows and
6245 Cygwin debugging. Both single-threaded and multi-threaded programs are
6248 * The "set trust-readonly-sections" command works again. This command was
6249 broken in GDB 6.3, 6.4, and 6.5.
6251 * The "load" command now supports writing to flash memory, if the remote
6252 stub provides the required support.
6254 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6255 longer requires symbolic debug information (e.g. DWARF-2).
6260 unset substitute-path
6261 show substitute-path
6262 Manage a list of substitution rules that GDB uses to rewrite the name
6263 of the directories where the sources are located. This can be useful
6264 for instance when the sources were moved to a different location
6265 between compilation and debugging.
6269 Print each CLI command as it is executed. Each command is prefixed with
6270 a number of `+' symbols representing the nesting depth.
6271 The source command now has a `-v' option to enable the same feature.
6275 The ARM Demon monitor support (RDP protocol, "target rdp").
6277 Kernel Object Display, an embedded debugging feature which only worked with
6278 an obsolete version of Cisco IOS.
6280 The 'set download-write-size' and 'show download-write-size' commands.
6282 * New remote packets
6285 Tell a stub about GDB client features, and request remote target features.
6286 The first feature implemented is PacketSize, which allows the target to
6287 specify the size of packets it can handle - to minimize the number of
6288 packets required and improve performance when connected to a remote
6292 Fetch an OS auxilliary vector from the remote stub. This packet is a
6293 more efficient replacement for qPart:auxv:read.
6295 qXfer:memory-map:read:
6296 Fetch a memory map from the remote stub, including information about
6297 RAM, ROM, and flash memory devices.
6302 Erase and program a flash memory device.
6304 * Removed remote packets
6307 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6308 used it, and only gdbserver implemented it.
6310 *** Changes in GDB 6.5
6314 Renesas M32C/M16C m32c-elf
6316 Morpho Technologies ms1 ms1-elf
6320 init-if-undefined Initialize a convenience variable, but
6321 only if it doesn't already have a value.
6323 The following commands are presently only implemented for native GNU/Linux:
6325 checkpoint Save a snapshot of the program state.
6327 restart <n> Return the program state to a
6328 previously saved state.
6330 info checkpoints List currently saved checkpoints.
6332 delete-checkpoint <n> Delete a previously saved checkpoint.
6334 set|show detach-on-fork Tell gdb whether to detach from a newly
6335 forked process, or to keep debugging it.
6337 info forks List forks of the user program that
6338 are available to be debugged.
6340 fork <n> Switch to debugging one of several
6341 forks of the user program that are
6342 available to be debugged.
6344 delete-fork <n> Delete a fork from the list of forks
6345 that are available to be debugged (and
6346 kill the forked process).
6348 detach-fork <n> Delete a fork from the list of forks
6349 that are available to be debugged (and
6350 allow the process to continue).
6354 Morpho Technologies ms2 ms1-elf
6356 * Improved Windows host support
6358 GDB now builds as a cross debugger hosted on i686-mingw32, including
6359 native console support, and remote communications using either
6360 network sockets or serial ports.
6362 * Improved Modula-2 language support
6364 GDB can now print most types in the Modula-2 syntax. This includes:
6365 basic types, set types, record types, enumerated types, range types,
6366 pointer types and ARRAY types. Procedure var parameters are correctly
6367 printed and hexadecimal addresses and character constants are also
6368 written in the Modula-2 syntax. Best results can be obtained by using
6369 GNU Modula-2 together with the -gdwarf-2 command line option.
6373 The ARM rdi-share module.
6375 The Netware NLM debug server.
6377 *** Changes in GDB 6.4
6379 * New native configurations
6381 OpenBSD/arm arm*-*-openbsd*
6382 OpenBSD/mips64 mips64-*-openbsd*
6386 Morpho Technologies ms1 ms1-elf
6388 * New command line options
6390 --batch-silent As for --batch, but totally silent.
6391 --return-child-result The debugger will exist with the same value
6392 the child (debugged) program exited with.
6393 --eval-command COMMAND, -ex COMMAND
6394 Execute a single GDB CLI command. This may be
6395 specified multiple times and in conjunction
6396 with the --command (-x) option.
6398 * Deprecated commands removed
6400 The following commands, that were deprecated in 2000, have been
6404 set|show arm disassembly-flavor set|show arm disassembler
6405 othernames set arm disassembler
6406 set|show remotedebug set|show debug remote
6407 set|show archdebug set|show debug arch
6408 set|show eventdebug set|show debug event
6411 * New BSD user-level threads support
6413 It is now possible to debug programs using the user-level threads
6414 library on OpenBSD and FreeBSD. Currently supported (target)
6417 FreeBSD/amd64 x86_64-*-freebsd*
6418 FreeBSD/i386 i386-*-freebsd*
6419 OpenBSD/i386 i386-*-openbsd*
6421 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6422 are not yet supported.
6424 * New support for Matsushita MN10300 w/sim added
6425 (Work in progress). mn10300-elf.
6427 * REMOVED configurations and files
6429 VxWorks and the XDR protocol *-*-vxworks
6430 Motorola MCORE mcore-*-*
6431 National Semiconductor NS32000 ns32k-*-*
6433 * New "set print array-indexes" command
6435 After turning this setting "on", GDB prints the index of each element
6436 when displaying arrays. The default is "off" to preserve the previous
6439 * VAX floating point support
6441 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6443 * User-defined command support
6445 In addition to using $arg0..$arg9 for argument passing, it is now possible
6446 to use $argc to determine now many arguments have been passed. See the
6447 section on user-defined commands in the user manual for more information.
6449 *** Changes in GDB 6.3:
6451 * New command line option
6453 GDB now accepts -l followed by a number to set the timeout for remote
6456 * GDB works with GCC -feliminate-dwarf2-dups
6458 GDB now supports a more compact representation of DWARF-2 debug
6459 information using DW_FORM_ref_addr references. These are produced
6460 by GCC with the option -feliminate-dwarf2-dups and also by some
6461 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6462 to use -feliminate-dwarf2-dups.
6464 * Internationalization
6466 When supported by the host system, GDB will be built with
6467 internationalization (libintl). The task of marking up the sources is
6468 continued, we're looking forward to our first translation.
6472 Initial support for debugging programs compiled with the GNAT
6473 implementation of the Ada programming language has been integrated
6474 into GDB. In this release, support is limited to expression evaluation.
6476 * New native configurations
6478 GNU/Linux/m32r m32r-*-linux-gnu
6482 GDB's remote protocol now includes support for the 'p' packet. This
6483 packet is used to fetch individual registers from a remote inferior.
6485 * END-OF-LIFE registers[] compatibility module
6487 GDB's internal register infrastructure has been completely rewritten.
6488 The new infrastructure making possible the implementation of key new
6489 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6492 GDB 6.3 will be the last release to include the registers[]
6493 compatibility module that allowed out-of-date configurations to
6494 continue to work. This change directly impacts the following
6504 powerpc bdm protocol
6506 Unless there is activity to revive these configurations, they will be
6507 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6509 * OBSOLETE configurations and files
6511 Configurations that have been declared obsolete in this release have
6512 been commented out. Unless there is activity to revive these
6513 configurations, the next release of GDB will have their sources
6514 permanently REMOVED.
6523 *** Changes in GDB 6.2.1:
6525 * MIPS `break main; run' gave an heuristic-fence-post warning
6527 When attempting to run even a simple program, a warning about
6528 heuristic-fence-post being hit would be reported. This problem has
6531 * MIPS IRIX 'long double' crashed GDB
6533 When examining a long double variable, GDB would get a segmentation
6534 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6535 IRIX long double values).
6539 A bug in the VAX stack code was causing problems with the "next"
6540 command. This problem has been fixed.
6542 *** Changes in GDB 6.2:
6544 * Fix for ``many threads''
6546 On GNU/Linux systems that use the NPTL threads library, a program
6547 rapidly creating and deleting threads would confuse GDB leading to the
6550 ptrace: No such process.
6551 thread_db_get_info: cannot get thread info: generic error
6553 This problem has been fixed.
6555 * "-async" and "-noasync" options removed.
6557 Support for the broken "-noasync" option has been removed (it caused
6560 * New ``start'' command.
6562 This command runs the program until the beginning of the main procedure.
6564 * New BSD Kernel Data Access Library (libkvm) interface
6566 Using ``target kvm'' it is now possible to debug kernel core dumps and
6567 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6568 platforms. Currently supported (native-only) configurations are:
6570 FreeBSD/amd64 x86_64-*-freebsd*
6571 FreeBSD/i386 i?86-*-freebsd*
6572 NetBSD/i386 i?86-*-netbsd*
6573 NetBSD/m68k m68*-*-netbsd*
6574 NetBSD/sparc sparc-*-netbsd*
6575 OpenBSD/amd64 x86_64-*-openbsd*
6576 OpenBSD/i386 i?86-*-openbsd*
6577 OpenBSD/m68k m68*-openbsd*
6578 OpenBSD/sparc sparc-*-openbsd*
6580 * Signal trampoline code overhauled
6582 Many generic problems with GDB's signal handling code have been fixed.
6583 These include: backtraces through non-contiguous stacks; recognition
6584 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6585 call; backtrace through a signal trampoline; step into and out of
6586 signal handlers; and single-stepping in the signal trampoline.
6588 Please note that kernel bugs are a limiting factor here. These
6589 features have been shown to work on an s390 GNU/Linux system that
6590 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6592 * Cygwin support for DWARF 2 added.
6594 * New native configurations
6596 GNU/Linux/hppa hppa*-*-linux*
6597 OpenBSD/hppa hppa*-*-openbsd*
6598 OpenBSD/m68k m68*-*-openbsd*
6599 OpenBSD/m88k m88*-*-openbsd*
6600 OpenBSD/powerpc powerpc-*-openbsd*
6601 NetBSD/vax vax-*-netbsd*
6602 OpenBSD/vax vax-*-openbsd*
6604 * END-OF-LIFE frame compatibility module
6606 GDB's internal frame infrastructure has been completely rewritten.
6607 The new infrastructure making it possible to support key new features
6608 including DWARF 2 Call Frame Information. To aid in the task of
6609 migrating old configurations to this new infrastructure, a
6610 compatibility module, that allowed old configurations to continue to
6611 work, was also included.
6613 GDB 6.2 will be the last release to include this frame compatibility
6614 module. This change directly impacts the following configurations:
6624 Unless there is activity to revive these configurations, they will be
6625 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6627 * REMOVED configurations and files
6629 Sun 3, running SunOS 3 m68*-*-sunos3*
6630 Sun 3, running SunOS 4 m68*-*-sunos4*
6631 Sun 2, running SunOS 3 m68000-*-sunos3*
6632 Sun 2, running SunOS 4 m68000-*-sunos4*
6633 Motorola 680x0 running LynxOS m68*-*-lynxos*
6634 AT&T 3b1/Unix pc m68*-att-*
6635 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6636 decstation mips-dec-* mips-little-*
6637 riscos mips-*-riscos* mips-*-sysv*
6638 sonymips mips-sony-*
6639 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6641 *** Changes in GDB 6.1.1:
6643 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6645 The TUI (Text-mode User Interface) is now built as part of a default
6646 GDB configuration. It is enabled by either selecting the TUI with the
6647 command line option "-i=tui" or by running the separate "gdbtui"
6648 program. For more information on the TUI, see the manual "Debugging
6651 * Pending breakpoint support (also included in GDB 6.1)
6653 Support has been added to allow you to specify breakpoints in shared
6654 libraries that have not yet been loaded. If a breakpoint location
6655 cannot be found, and the "breakpoint pending" option is set to auto,
6656 GDB queries you if you wish to make the breakpoint pending on a future
6657 shared-library load. If and when GDB resolves the breakpoint symbol,
6658 the pending breakpoint is removed as one or more regular breakpoints
6661 Pending breakpoints are very useful for GCJ Java debugging.
6663 * Fixed ISO-C build problems
6665 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6666 non ISO-C code that stopped them being built using a more strict ISO-C
6667 compiler (e.g., IBM's C compiler).
6669 * Fixed build problem on IRIX 5
6671 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6672 wasn't able to compile compile on an IRIX 5 system.
6674 * Added execute permission to gdb/gdbserver/configure
6676 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6677 permission. This bug would cause configure to fail on a number of
6678 systems (Solaris, IRIX). Ref: server/519.
6680 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6682 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6683 has been updated to use constant array sizes.
6685 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6687 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6688 its generated DWARF Call Frame Info. This encoding was causing GDB to
6689 panic, that panic has been fixed. Ref: gdb/1628.
6691 * Fixed a problem when examining parameters in shared library code.
6693 When examining parameters in optimized shared library code generated
6694 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6695 not available''. GDB now correctly displays the variable's value.
6697 *** Changes in GDB 6.1:
6699 * Removed --with-mmalloc
6701 Support for the mmalloc memory manager has been removed, as it
6702 conflicted with the internal gdb byte cache.
6704 * Changes in AMD64 configurations
6706 The AMD64 target now includes the %cs and %ss registers. As a result
6707 the AMD64 remote protocol has changed; this affects the floating-point
6708 and SSE registers. If you rely on those registers for your debugging,
6709 you should upgrade gdbserver on the remote side.
6711 * Revised SPARC target
6713 The SPARC target has been completely revised, incorporating the
6714 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6715 support for LynxOS and SunOS 4 has been dropped. Calling functions
6716 from within GDB on operating systems with a non-executable stack
6717 (Solaris, OpenBSD) now works.
6721 GDB has a new C++ demangler which does a better job on the mangled
6722 names generated by current versions of g++. It also runs faster, so
6723 with this and other changes gdb should now start faster on large C++
6726 * DWARF 2 Location Expressions
6728 GDB support for location expressions has been extended to support function
6729 arguments and frame bases. Older versions of GDB could crash when they
6732 * C++ nested types and namespaces
6734 GDB's support for nested types and namespaces in C++ has been
6735 improved, especially if you use the DWARF 2 debugging format. (This
6736 is the default for recent versions of GCC on most platforms.)
6737 Specifically, if you have a class "Inner" defined within a class or
6738 namespace "Outer", then GDB realizes that the class's name is
6739 "Outer::Inner", not simply "Inner". This should greatly reduce the
6740 frequency of complaints about not finding RTTI symbols. In addition,
6741 if you are stopped at inside of a function defined within a namespace,
6742 GDB modifies its name lookup accordingly.
6744 * New native configurations
6746 NetBSD/amd64 x86_64-*-netbsd*
6747 OpenBSD/amd64 x86_64-*-openbsd*
6748 OpenBSD/alpha alpha*-*-openbsd*
6749 OpenBSD/sparc sparc-*-openbsd*
6750 OpenBSD/sparc64 sparc64-*-openbsd*
6752 * New debugging protocols
6754 M32R with SDI protocol m32r-*-elf*
6756 * "set prompt-escape-char" command deleted.
6758 The command "set prompt-escape-char" has been deleted. This command,
6759 and its very obscure effect on GDB's prompt, was never documented,
6760 tested, nor mentioned in the NEWS file.
6762 * OBSOLETE configurations and files
6764 Configurations that have been declared obsolete in this release have
6765 been commented out. Unless there is activity to revive these
6766 configurations, the next release of GDB will have their sources
6767 permanently REMOVED.
6769 Sun 3, running SunOS 3 m68*-*-sunos3*
6770 Sun 3, running SunOS 4 m68*-*-sunos4*
6771 Sun 2, running SunOS 3 m68000-*-sunos3*
6772 Sun 2, running SunOS 4 m68000-*-sunos4*
6773 Motorola 680x0 running LynxOS m68*-*-lynxos*
6774 AT&T 3b1/Unix pc m68*-att-*
6775 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6776 decstation mips-dec-* mips-little-*
6777 riscos mips-*-riscos* mips-*-sysv*
6778 sonymips mips-sony-*
6779 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6781 * REMOVED configurations and files
6783 SGI Irix-4.x mips-sgi-irix4 or iris4
6784 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6785 Z8000 simulator z8k-zilog-none or z8ksim
6786 Matsushita MN10200 w/simulator mn10200-*-*
6787 H8/500 simulator h8500-hitachi-hms or h8500hms
6788 HP/PA running BSD hppa*-*-bsd*
6789 HP/PA running OSF/1 hppa*-*-osf*
6790 HP/PA Pro target hppa*-*-pro*
6791 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6792 386BSD i[3456]86-*-bsd*
6793 Sequent family i[3456]86-sequent-sysv4*
6794 i[3456]86-sequent-sysv*
6795 i[3456]86-sequent-bsd*
6796 SPARC running LynxOS sparc-*-lynxos*
6797 SPARC running SunOS 4 sparc-*-sunos4*
6798 Tsqware Sparclet sparclet-*-*
6799 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6801 *** Changes in GDB 6.0:
6805 Support for debugging the Objective-C programming language has been
6806 integrated into GDB.
6808 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6810 DWARF 2's Call Frame Information makes available compiler generated
6811 information that more exactly describes the program's run-time stack.
6812 By using this information, GDB is able to provide more robust stack
6815 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6816 have been updated to use a new backtrace mechanism which includes
6817 DWARF 2 CFI support.
6821 GDB's remote protocol has been extended to include support for hosted
6822 file I/O (where the remote target uses GDB's file system). See GDB's
6823 remote protocol documentation for details.
6825 * All targets using the new architecture framework.
6827 All of GDB's targets have been updated to use the new internal
6828 architecture framework. The way is now open for future GDB releases
6829 to include cross-architecture native debugging support (i386 on amd64,
6832 * GNU/Linux's Thread Local Storage (TLS)
6834 GDB now includes support for for the GNU/Linux implementation of
6835 per-thread variables.
6837 * GNU/Linux's Native POSIX Thread Library (NPTL)
6839 GDB's thread code has been updated to work with either the new
6840 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6842 * Separate debug info.
6844 GDB, in conjunction with BINUTILS, now supports a mechanism for
6845 automatically loading debug information from a separate file. Instead
6846 of shipping full debug and non-debug versions of system libraries,
6847 system integrators can now instead ship just the stripped libraries
6848 and optional debug files.
6850 * DWARF 2 Location Expressions
6852 DWARF 2 Location Expressions allow the compiler to more completely
6853 describe the location of variables (even in optimized code) to the
6856 GDB now includes preliminary support for location expressions (support
6857 for DW_OP_piece is still missing).
6861 A number of long standing bugs that caused GDB to die while starting a
6862 Java application have been fixed. GDB's Java support is now
6863 considered "useable".
6865 * GNU/Linux support for fork, vfork, and exec.
6867 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6868 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6871 * GDB supports logging output to a file
6873 There are two new commands, "set logging" and "show logging", which can be
6874 used to capture GDB's output to a file.
6876 * The meaning of "detach" has changed for gdbserver
6878 The "detach" command will now resume the application, as documented. To
6879 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6882 * d10v, m68hc11 `regs' command deprecated
6884 The `info registers' command has been updated so that it displays the
6885 registers using a format identical to the old `regs' command.
6889 A new command, "maint set profile on/off", has been added. This command can
6890 be used to enable or disable profiling while running GDB, to profile a
6891 session or a set of commands. In addition there is a new configure switch,
6892 "--enable-profiling", which will cause GDB to be compiled with profiling
6893 data, for more informative profiling results.
6895 * Default MI syntax changed to "mi2".
6897 The default MI (machine interface) syntax, enabled by the command line
6898 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6899 "mi1", can be enabled by specifying the option "-i=mi1".
6901 Support for the original "mi0" syntax (included in GDB 5.0) has been
6904 Fix for gdb/192: removed extraneous space when displaying frame level.
6905 Fix for gdb/672: update changelist is now output in mi list format.
6906 Fix for gdb/702: a -var-assign that updates the value now shows up
6907 in a subsequent -var-update.
6909 * New native configurations.
6911 FreeBSD/amd64 x86_64-*-freebsd*
6913 * Multi-arched targets.
6915 HP/PA HPUX11 hppa*-*-hpux*
6916 Renesas M32R/D w/simulator m32r-*-elf*
6918 * OBSOLETE configurations and files
6920 Configurations that have been declared obsolete in this release have
6921 been commented out. Unless there is activity to revive these
6922 configurations, the next release of GDB will have their sources
6923 permanently REMOVED.
6925 Z8000 simulator z8k-zilog-none or z8ksim
6926 Matsushita MN10200 w/simulator mn10200-*-*
6927 H8/500 simulator h8500-hitachi-hms or h8500hms
6928 HP/PA running BSD hppa*-*-bsd*
6929 HP/PA running OSF/1 hppa*-*-osf*
6930 HP/PA Pro target hppa*-*-pro*
6931 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6932 Sequent family i[3456]86-sequent-sysv4*
6933 i[3456]86-sequent-sysv*
6934 i[3456]86-sequent-bsd*
6935 Tsqware Sparclet sparclet-*-*
6936 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6938 * REMOVED configurations and files
6941 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6942 IBM AIX PS/2 i[3456]86-*-aix
6943 i386 running Mach 3.0 i[3456]86-*-mach3*
6944 i386 running Mach i[3456]86-*-mach*
6945 i386 running OSF/1 i[3456]86-*osf1mk*
6946 HP/Apollo 68k Family m68*-apollo*-sysv*,
6948 m68*-hp-bsd*, m68*-hp-hpux*
6949 Argonaut Risc Chip (ARC) arc-*-*
6950 Mitsubishi D30V d30v-*-*
6951 Fujitsu FR30 fr30-*-elf*
6952 OS/9000 i[34]86-*-os9k
6953 I960 with MON960 i960-*-coff
6955 * MIPS $fp behavior changed
6957 The convenience variable $fp, for the MIPS, now consistently returns
6958 the address of the current frame's base. Previously, depending on the
6959 context, $fp could refer to either $sp or the current frame's base
6960 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6961 The GNU Source-Level Debugger''.
6963 *** Changes in GDB 5.3:
6965 * GNU/Linux shared library multi-threaded performance improved.
6967 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6968 `/proc', in preference to `ptrace' for memory reads. This may result
6969 in an improvement in the start-up time of multi-threaded, shared
6970 library applications when run under GDB. One GDB user writes: ``loads
6971 shared libs like mad''.
6973 * ``gdbserver'' now supports multi-threaded applications on some targets
6975 Support for debugging multi-threaded applications which use
6976 the GNU/Linux LinuxThreads package has been added for
6977 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6978 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6980 * GDB now supports C/C++ preprocessor macros.
6982 GDB now expands preprocessor macro invocations in C/C++ expressions,
6983 and provides various commands for showing macro definitions and how
6986 The new command `macro expand EXPRESSION' expands any macro
6987 invocations in expression, and shows the result.
6989 The new command `show macro MACRO-NAME' shows the definition of the
6990 macro named MACRO-NAME, and where it was defined.
6992 Most compilers don't include information about macros in the debugging
6993 information by default. In GCC 3.1, for example, you need to compile
6994 your program with the options `-gdwarf-2 -g3'. If the macro
6995 information is present in the executable, GDB will read it.
6997 * Multi-arched targets.
6999 DEC Alpha (partial) alpha*-*-*
7000 DEC VAX (partial) vax-*-*
7002 National Semiconductor NS32000 (partial) ns32k-*-*
7003 Motorola 68000 (partial) m68k-*-*
7004 Motorola MCORE mcore-*-*
7008 Fujitsu FRV architecture added by Red Hat frv*-*-*
7011 * New native configurations
7013 Alpha NetBSD alpha*-*-netbsd*
7014 SH NetBSD sh*-*-netbsdelf*
7015 MIPS NetBSD mips*-*-netbsd*
7016 UltraSPARC NetBSD sparc64-*-netbsd*
7018 * OBSOLETE configurations and files
7020 Configurations that have been declared obsolete in this release have
7021 been commented out. Unless there is activity to revive these
7022 configurations, the next release of GDB will have their sources
7023 permanently REMOVED.
7025 Mitsubishi D30V d30v-*-*
7026 OS/9000 i[34]86-*-os9k
7027 IBM AIX PS/2 i[3456]86-*-aix
7028 Fujitsu FR30 fr30-*-elf*
7029 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7030 Argonaut Risc Chip (ARC) arc-*-*
7031 i386 running Mach 3.0 i[3456]86-*-mach3*
7032 i386 running Mach i[3456]86-*-mach*
7033 i386 running OSF/1 i[3456]86-*osf1mk*
7034 HP/Apollo 68k Family m68*-apollo*-sysv*,
7036 m68*-hp-bsd*, m68*-hp-hpux*
7037 I960 with MON960 i960-*-coff
7039 * OBSOLETE languages
7041 CHILL, a Pascal like language used by telecommunications companies.
7043 * REMOVED configurations and files
7045 AMD 29k family via UDI a29k-amd-udi, udi29k
7046 A29K VxWorks a29k-*-vxworks
7047 AMD 29000 embedded, using EBMON a29k-none-none
7048 AMD 29000 embedded with COFF a29k-none-coff
7049 AMD 29000 embedded with a.out a29k-none-aout
7051 testsuite/gdb.hp/gdb.threads-hp/ directory
7053 * New command "set max-user-call-depth <nnn>"
7055 This command allows the user to limit the call depth of user-defined
7056 commands. The default is 1024.
7058 * Changes in FreeBSD/i386 native debugging.
7060 Support for the "generate-core-file" has been added.
7062 * New commands "dump", "append", and "restore".
7064 These commands allow data to be copied from target memory
7065 to a bfd-format or binary file (dump and append), and back
7066 from a file into memory (restore).
7068 * Improved "next/step" support on multi-processor Alpha Tru64.
7070 The previous single-step mechanism could cause unpredictable problems,
7071 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7072 of a software single-step mechanism prevents this.
7074 *** Changes in GDB 5.2.1:
7082 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7083 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7084 Fix, by Joel Brobecker imported from mainline.
7086 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7087 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7088 Fix, by Fred Fish, imported from mainline.
7090 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7091 Surprisingly enough, it works now.
7092 By Michal Ludvig, imported from mainline.
7094 i386 hardware watchpoint support:
7095 avoid misses on second run for some targets.
7096 By Pierre Muller, imported from mainline.
7098 *** Changes in GDB 5.2:
7100 * New command "set trust-readonly-sections on[off]".
7102 This command is a hint that tells gdb that read-only sections
7103 really are read-only (ie. that their contents will not change).
7104 In this mode, gdb will go to the object file rather than the
7105 target to read memory from read-only sections (such as ".text").
7106 This can be a significant performance improvement on some
7107 (notably embedded) targets.
7109 * New command "generate-core-file" (or "gcore").
7111 This new gdb command allows the user to drop a core file of the child
7112 process state at any time. So far it's been implemented only for
7113 GNU/Linux and Solaris, but should be relatively easily ported to other
7114 hosts. Argument is core file name (defaults to core.<pid>).
7116 * New command line option
7118 GDB now accepts --pid or -p followed by a process id.
7120 * Change in command line behavior -- corefiles vs. process ids.
7122 There is a subtle behavior in the way in which GDB handles
7123 command line arguments. The first non-flag argument is always
7124 a program to debug, but the second non-flag argument may either
7125 be a corefile or a process id. Previously, GDB would attempt to
7126 open the second argument as a corefile, and if that failed, would
7127 issue a superfluous error message and then attempt to attach it as
7128 a process. Now, if the second argument begins with a non-digit,
7129 it will be treated as a corefile. If it begins with a digit,
7130 GDB will attempt to attach it as a process, and if no such process
7131 is found, will then attempt to open it as a corefile.
7133 * Changes in ARM configurations.
7135 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7136 configuration is fully multi-arch.
7138 * New native configurations
7140 ARM NetBSD arm*-*-netbsd*
7141 x86 OpenBSD i[3456]86-*-openbsd*
7142 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7143 Sparc64 running FreeBSD sparc64-*-freebsd*
7147 Sanyo XStormy16 xstormy16-elf
7149 * OBSOLETE configurations and files
7151 Configurations that have been declared obsolete in this release have
7152 been commented out. Unless there is activity to revive these
7153 configurations, the next release of GDB will have their sources
7154 permanently REMOVED.
7156 AMD 29k family via UDI a29k-amd-udi, udi29k
7157 A29K VxWorks a29k-*-vxworks
7158 AMD 29000 embedded, using EBMON a29k-none-none
7159 AMD 29000 embedded with COFF a29k-none-coff
7160 AMD 29000 embedded with a.out a29k-none-aout
7162 testsuite/gdb.hp/gdb.threads-hp/ directory
7164 * REMOVED configurations and files
7166 TI TMS320C80 tic80-*-*
7168 PowerPC Solaris powerpcle-*-solaris*
7169 PowerPC Windows NT powerpcle-*-cygwin32
7170 PowerPC Netware powerpc-*-netware*
7171 Harris/CXUX m88k m88*-harris-cxux*
7172 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7173 ns32k-utek-sysv* ns32k-utek-*
7174 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7175 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7176 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7177 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7178 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7180 * Changes to command line processing
7182 The new `--args' feature can be used to specify command-line arguments
7183 for the inferior from gdb's command line.
7185 * Changes to key bindings
7187 There is a new `operate-and-get-next' function bound to `C-o'.
7189 *** Changes in GDB 5.1.1
7191 Fix compile problem on DJGPP.
7193 Fix a problem with floating-point registers on the i386 being
7196 Fix to stop GDB crashing on .debug_str debug info.
7198 Numerous documentation fixes.
7200 Numerous testsuite fixes.
7202 *** Changes in GDB 5.1:
7204 * New native configurations
7206 Alpha FreeBSD alpha*-*-freebsd*
7207 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7208 MIPS GNU/Linux mips*-*-linux*
7209 MIPS SGI Irix 6.x mips*-sgi-irix6*
7210 ia64 AIX ia64-*-aix*
7211 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7215 Motorola 68HC11 and 68HC12 m68hc11-elf
7217 UltraSparc running GNU/Linux sparc64-*-linux*
7219 * OBSOLETE configurations and files
7221 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7222 Harris/CXUX m88k m88*-harris-cxux*
7223 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7224 ns32k-utek-sysv* ns32k-utek-*
7225 TI TMS320C80 tic80-*-*
7227 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7228 PowerPC Solaris powerpcle-*-solaris*
7229 PowerPC Windows NT powerpcle-*-cygwin32
7230 PowerPC Netware powerpc-*-netware*
7231 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7232 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7233 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7234 Apple Macintosh (MPW) host N/A
7236 stuff.c (Program to stuff files into a specially prepared space in kdb)
7237 kdb-start.c (Main loop for the standalone kernel debugger)
7239 Configurations that have been declared obsolete in this release have
7240 been commented out. Unless there is activity to revive these
7241 configurations, the next release of GDB will have their sources
7242 permanently REMOVED.
7244 * REMOVED configurations and files
7246 Altos 3068 m68*-altos-*
7247 Convex c1-*-*, c2-*-*
7249 ARM RISCix arm-*-* (as host)
7253 * GDB has been converted to ISO C.
7255 GDB's source code has been converted to ISO C. In particular, the
7256 sources are fully protoized, and rely on standard headers being
7261 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7263 * The MI enabled by default.
7265 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7266 revised and enabled by default. Packages which use GDB as a debugging
7267 engine behind a UI or another front end are encouraged to switch to
7268 using the GDB/MI interface, instead of the old annotations interface
7269 which is now deprecated.
7271 * Support for debugging Pascal programs.
7273 GDB now includes support for debugging Pascal programs. The following
7274 main features are supported:
7276 - Pascal-specific data types such as sets;
7278 - automatic recognition of Pascal sources based on file-name
7281 - Pascal-style display of data types, variables, and functions;
7283 - a Pascal expression parser.
7285 However, some important features are not yet supported.
7287 - Pascal string operations are not supported at all;
7289 - there are some problems with boolean types;
7291 - Pascal type hexadecimal constants are not supported
7292 because they conflict with the internal variables format;
7294 - support for Pascal objects and classes is not full yet;
7296 - unlike Pascal, GDB is case-sensitive for symbol names.
7298 * Changes in completion.
7300 Commands such as `shell', `run' and `set args', which pass arguments
7301 to inferior programs, now complete on file names, similar to what
7302 users expect at the shell prompt.
7304 Commands which accept locations, such as `disassemble', `print',
7305 `breakpoint', `until', etc. now complete on filenames as well as
7306 program symbols. Thus, if you type "break foob TAB", and the source
7307 files linked into the programs include `foobar.c', that file name will
7308 be one of the candidates for completion. However, file names are not
7309 considered for completion after you typed a colon that delimits a file
7310 name from a name of a function in that file, as in "break foo.c:bar".
7312 `set demangle-style' completes on available demangling styles.
7314 * New platform-independent commands:
7316 It is now possible to define a post-hook for a command as well as a
7317 hook that runs before the command. For more details, see the
7318 documentation of `hookpost' in the GDB manual.
7320 * Changes in GNU/Linux native debugging.
7322 Support for debugging multi-threaded programs has been completely
7323 revised for all platforms except m68k and sparc. You can now debug as
7324 many threads as your system allows you to have.
7326 Attach/detach is supported for multi-threaded programs.
7328 Support for SSE registers was added for x86. This doesn't work for
7329 multi-threaded programs though.
7331 * Changes in MIPS configurations.
7333 Multi-arch support is enabled for all MIPS configurations.
7335 GDB can now be built as native debugger on SGI Irix 6.x systems for
7336 debugging n32 executables. (Debugging 64-bit executables is not yet
7339 * Unified support for hardware watchpoints in all x86 configurations.
7341 Most (if not all) native x86 configurations support hardware-assisted
7342 breakpoints and watchpoints in a unified manner. This support
7343 implements debug register sharing between watchpoints, which allows to
7344 put a virtually infinite number of watchpoints on the same address,
7345 and also supports watching regions up to 16 bytes with several debug
7348 The new maintenance command `maintenance show-debug-regs' toggles
7349 debugging print-outs in functions that insert, remove, and test
7350 watchpoints and hardware breakpoints.
7352 * Changes in the DJGPP native configuration.
7354 New command ``info dos sysinfo'' displays assorted information about
7355 the CPU, OS, memory, and DPMI server.
7357 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7358 display information about segment descriptors stored in GDT, LDT, and
7361 New commands ``info dos pde'' and ``info dos pte'' display entries
7362 from Page Directory and Page Tables (for now works with CWSDPMI only).
7363 New command ``info dos address-pte'' displays the Page Table entry for
7364 a given linear address.
7366 GDB can now pass command lines longer than 126 characters to the
7367 program being debugged (requires an update to the libdbg.a library
7368 which is part of the DJGPP development kit).
7370 DWARF2 debug info is now supported.
7372 It is now possible to `step' and `next' through calls to `longjmp'.
7374 * Changes in documentation.
7376 All GDB documentation was converted to GFDL, the GNU Free
7377 Documentation License.
7379 Tracepoints-related commands are now fully documented in the GDB
7382 TUI, the Text-mode User Interface, is now documented in the manual.
7384 Tracepoints-related commands are now fully documented in the GDB
7387 The "GDB Internals" manual now has an index. It also includes
7388 documentation of `ui_out' functions, GDB coding standards, x86
7389 hardware watchpoints, and memory region attributes.
7391 * GDB's version number moved to ``version.in''
7393 The Makefile variable VERSION has been replaced by the file
7394 ``version.in''. People creating GDB distributions should update the
7395 contents of this file.
7399 GUD support is now a standard part of the EMACS distribution.
7401 *** Changes in GDB 5.0:
7403 * Improved support for debugging FP programs on x86 targets
7405 Unified and much-improved support for debugging floating-point
7406 programs on all x86 targets. In particular, ``info float'' now
7407 displays the FP registers in the same format on all x86 targets, with
7408 greater level of detail.
7410 * Improvements and bugfixes in hardware-assisted watchpoints
7412 It is now possible to watch array elements, struct members, and
7413 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7414 on x86 targets no longer erroneously trigger when the address is
7417 * Improvements in the native DJGPP version of GDB
7419 The distribution now includes all the scripts and auxiliary files
7420 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7421 machines ``out of the box''.
7423 The DJGPP version can now debug programs that use signals. It is
7424 possible to catch signals that happened in the debuggee, deliver
7425 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7426 would kill the program being debugged.) Programs that hook hardware
7427 interrupts (keyboard, timer, etc.) can also be debugged.
7429 It is now possible to debug DJGPP programs that redirect their
7430 standard handles or switch them to raw (as opposed to cooked) mode, or
7431 even close them. The command ``run < foo > bar'' works as expected,
7432 and ``info terminal'' reports useful information about the debuggee's
7433 terminal, including raw/cooked mode, redirection, etc.
7435 The DJGPP version now uses termios functions for console I/O, which
7436 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7439 DOS-style file names with drive letters are now fully supported by
7442 It is now possible to debug DJGPP programs that switch their working
7443 directory. It is also possible to rerun the debuggee any number of
7444 times without restarting GDB; thus, you can use the same setup,
7445 breakpoints, etc. for many debugging sessions.
7447 * New native configurations
7449 ARM GNU/Linux arm*-*-linux*
7450 PowerPC GNU/Linux powerpc-*-linux*
7454 Motorola MCore mcore-*-*
7455 x86 VxWorks i[3456]86-*-vxworks*
7456 PowerPC VxWorks powerpc-*-vxworks*
7457 TI TMS320C80 tic80-*-*
7459 * OBSOLETE configurations
7461 Altos 3068 m68*-altos-*
7462 Convex c1-*-*, c2-*-*
7464 ARM RISCix arm-*-* (as host)
7467 Configurations that have been declared obsolete will be commented out,
7468 but the code will be left in place. If there is no activity to revive
7469 these configurations before the next release of GDB, the sources will
7470 be permanently REMOVED.
7472 * Gould support removed
7474 Support for the Gould PowerNode and NP1 has been removed.
7476 * New features for SVR4
7478 On SVR4 native platforms (such as Solaris), if you attach to a process
7479 without first loading a symbol file, GDB will now attempt to locate and
7480 load symbols from the running process's executable file.
7482 * Many C++ enhancements
7484 C++ support has been greatly improved. Overload resolution now works properly
7485 in almost all cases. RTTI support is on the way.
7487 * Remote targets can connect to a sub-program
7489 A popen(3) style serial-device has been added. This device starts a
7490 sub-process (such as a stand-alone simulator) and then communicates
7491 with that. The sub-program to run is specified using the syntax
7492 ``|<program> <args>'' vis:
7494 (gdb) set remotedebug 1
7495 (gdb) target extended-remote |mn10300-elf-sim program-args
7497 * MIPS 64 remote protocol
7499 A long standing bug in the mips64 remote protocol where by GDB
7500 expected certain 32 bit registers (ex SR) to be transfered as 32
7501 instead of 64 bits has been fixed.
7503 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7504 added to provide backward compatibility with older versions of GDB.
7506 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7508 The command ``set remotebinarydownload'' command has been replaced by
7509 ``set remote X-packet''. Other commands in ``set remote'' family
7510 include ``set remote P-packet''.
7512 * Breakpoint commands accept ranges.
7514 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7515 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7516 ``tracepoint passcount'' also accepts a range of tracepoints.
7518 * ``apropos'' command added.
7520 The ``apropos'' command searches through command names and
7521 documentation strings, printing out matches, making it much easier to
7522 try to find a command that does what you are looking for.
7526 A new machine oriented interface (MI) has been added to GDB. This
7527 interface is designed for debug environments running GDB as a separate
7528 process. This is part of the long term libGDB project. See the
7529 "GDB/MI" chapter of the GDB manual for further information. It can be
7530 enabled by configuring with:
7532 .../configure --enable-gdbmi
7534 *** Changes in GDB-4.18:
7536 * New native configurations
7538 HP-UX 10.20 hppa*-*-hpux10.20
7539 HP-UX 11.x hppa*-*-hpux11.0*
7540 M68K GNU/Linux m68*-*-linux*
7544 Fujitsu FR30 fr30-*-elf*
7545 Intel StrongARM strongarm-*-*
7546 Mitsubishi D30V d30v-*-*
7548 * OBSOLETE configurations
7550 Gould PowerNode, NP1 np1-*-*, pn-*-*
7552 Configurations that have been declared obsolete will be commented out,
7553 but the code will be left in place. If there is no activity to revive
7554 these configurations before the next release of GDB, the sources will
7555 be permanently REMOVED.
7559 As a compatibility experiment, GDB's source files buildsym.h and
7560 buildsym.c have been converted to pure standard C, no longer
7561 containing any K&R compatibility code. We believe that all systems in
7562 use today either come with a standard C compiler, or have a GCC port
7563 available. If this is not true, please report the affected
7564 configuration to bug-gdb@gnu.org immediately. See the README file for
7565 information about getting a standard C compiler if you don't have one
7570 GDB now uses readline 2.2.
7572 * set extension-language
7574 You can now control the mapping between filename extensions and source
7575 languages by using the `set extension-language' command. For instance,
7576 you can ask GDB to treat .c files as C++ by saying
7577 set extension-language .c c++
7578 The command `info extensions' lists all of the recognized extensions
7579 and their associated languages.
7581 * Setting processor type for PowerPC and RS/6000
7583 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7584 you can use the `set processor' command to specify what variant of the
7585 PowerPC family you are debugging. The command
7589 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7590 following PowerPC and RS6000 variants:
7592 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7593 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7595 403GC IBM PowerPC 403GC
7596 505 Motorola PowerPC 505
7597 860 Motorola PowerPC 860 or 850
7598 601 Motorola PowerPC 601
7599 602 Motorola PowerPC 602
7600 603 Motorola/IBM PowerPC 603 or 603e
7601 604 Motorola PowerPC 604 or 604e
7602 750 Motorola/IBM PowerPC 750 or 750
7604 At the moment, this command just tells GDB what to name the
7605 special-purpose processor registers. Since almost all the affected
7606 registers are inaccessible to user-level programs, this command is
7607 only useful for remote debugging in its present form.
7611 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7612 more extensive support for HP-UX. Added features include shared
7613 library support, kernel threads and hardware watchpoints for 11.00,
7614 support for HP's ANSI C and C++ compilers, and a compatibility mode
7615 for xdb and dbx commands.
7619 HP's donation includes the new concept of catchpoints, which is a
7620 generalization of the old catch command. On HP-UX, it is now possible
7621 to catch exec, fork, and vfork, as well as library loading.
7623 This means that the existing catch command has changed; its first
7624 argument now specifies the type of catch to be set up. See the
7625 output of "help catch" for a list of catchpoint types.
7627 * Debugging across forks
7629 On HP-UX, you can choose which process to debug when a fork() happens
7634 HP has donated a curses-based terminal user interface (TUI). To get
7635 it, build with --enable-tui. Although this can be enabled for any
7636 configuration, at present it only works for native HP debugging.
7638 * GDB remote protocol additions
7640 A new protocol packet 'X' that writes binary data is now available.
7641 Default behavior is to try 'X', then drop back to 'M' if the stub
7642 fails to respond. The settable variable `remotebinarydownload'
7643 allows explicit control over the use of 'X'.
7645 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7646 full 64-bit address. The command
7648 set remoteaddresssize 32
7650 can be used to revert to the old behaviour. For existing remote stubs
7651 the change should not be noticed, as the additional address information
7654 In order to assist in debugging stubs, you may use the maintenance
7655 command `packet' to send any text string to the stub. For instance,
7657 maint packet heythere
7659 sends the packet "$heythere#<checksum>". Note that it is very easy to
7660 disrupt a debugging session by sending the wrong packet at the wrong
7663 The compare-sections command allows you to compare section data on the
7664 target to what is in the executable file without uploading or
7665 downloading, by comparing CRC checksums.
7667 * Tracing can collect general expressions
7669 You may now collect general expressions at tracepoints. This requires
7670 further additions to the target-side stub; see tracepoint.c and
7671 doc/agentexpr.texi for further details.
7673 * mask-address variable for Mips
7675 For Mips targets, you may control the zeroing of the upper 32 bits of
7676 a 64-bit address by entering `set mask-address on'. This is mainly
7677 of interest to users of embedded R4xxx and R5xxx processors.
7679 * Higher serial baud rates
7681 GDB's serial code now allows you to specify baud rates 57600, 115200,
7682 230400, and 460800 baud. (Note that your host system may not be able
7683 to achieve all of these rates.)
7687 The i960 configuration now includes an initial implementation of a
7688 builtin simulator, contributed by Jim Wilson.
7691 *** Changes in GDB-4.17:
7693 * New native configurations
7695 Alpha GNU/Linux alpha*-*-linux*
7696 Unixware 2.x i[3456]86-unixware2*
7697 Irix 6.x mips*-sgi-irix6*
7698 PowerPC GNU/Linux powerpc-*-linux*
7699 PowerPC Solaris powerpcle-*-solaris*
7700 Sparc GNU/Linux sparc-*-linux*
7701 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7705 Argonaut Risc Chip (ARC) arc-*-*
7706 Hitachi H8/300S h8300*-*-*
7707 Matsushita MN10200 w/simulator mn10200-*-*
7708 Matsushita MN10300 w/simulator mn10300-*-*
7709 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7710 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7711 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7712 Mitsubishi D10V w/simulator d10v-*-*
7713 Mitsubishi M32R/D w/simulator m32r-*-elf*
7714 Tsqware Sparclet sparclet-*-*
7715 NEC V850 w/simulator v850-*-*
7717 * New debugging protocols
7719 ARM with RDI protocol arm*-*-*
7720 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7721 DDB and LSI variants of PMON protocol mips*-*-*
7722 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7723 PowerPC with SDS protocol powerpc{,le}-*-eabi
7724 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7728 All configurations can now understand and use the DWARF 2 debugging
7729 format. The choice is automatic, if the symbol file contains DWARF 2
7734 GDB now includes basic Java language support. This support is
7735 only useful with Java compilers that produce native machine code.
7737 * solib-absolute-prefix and solib-search-path
7739 For SunOS and SVR4 shared libraries, you may now set the prefix for
7740 loading absolute shared library symbol files, and the search path for
7741 locating non-absolute shared library symbol files.
7743 * Live range splitting
7745 GDB can now effectively debug code for which GCC has performed live
7746 range splitting as part of its optimization. See gdb/doc/LRS for
7747 more details on the expected format of the stabs information.
7751 GDB's support for the GNU Hurd, including thread debugging, has been
7752 updated to work with current versions of the Hurd.
7756 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7757 instruction set. ARM GDB automatically detects when Thumb
7758 instructions are in use, and adjusts disassembly and backtracing
7763 GDB's MIPS target configurations now handle the MIP16 16-bit
7768 GDB now includes support for overlays; if an executable has been
7769 linked such that multiple sections are based at the same address, GDB
7770 will decide which section to use for symbolic info. You can choose to
7771 control the decision manually, using overlay commands, or implement
7772 additional target-side support and use "overlay load-target" to bring
7773 in the overlay mapping. Do "help overlay" for more detail.
7777 The command "info symbol <address>" displays information about
7778 the symbol at the specified address.
7782 The standard remote protocol now includes an extension that allows
7783 asynchronous collection and display of trace data. This requires
7784 extensive support in the target-side debugging stub. Tracing mode
7785 includes a new interaction mode in GDB and new commands: see the
7786 file tracepoint.c for more details.
7790 Configurations for embedded MIPS now include a simulator contributed
7791 by Cygnus Solutions. The simulator supports the instruction sets
7792 of most MIPS variants.
7796 Sparc configurations may now include the ERC32 simulator contributed
7797 by the European Space Agency. The simulator is not built into
7798 Sparc targets by default; configure with --enable-sim to include it.
7802 For target configurations that may include multiple variants of a
7803 basic architecture (such as MIPS and SH), you may now set the
7804 architecture explicitly. "set arch" sets, "info arch" lists
7805 the possible architectures.
7807 *** Changes in GDB-4.16:
7809 * New native configurations
7811 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7812 M68K NetBSD m68k-*-netbsd*
7813 PowerPC AIX 4.x powerpc-*-aix*
7814 PowerPC MacOS powerpc-*-macos*
7815 PowerPC Windows NT powerpcle-*-cygwin32
7816 RS/6000 AIX 4.x rs6000-*-aix4*
7820 ARM with RDP protocol arm-*-*
7821 I960 with MON960 i960-*-coff
7822 MIPS VxWorks mips*-*-vxworks*
7823 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7824 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7826 Matra Sparclet sparclet-*-*
7830 The powerpc-eabi configuration now includes the PSIM simulator,
7831 contributed by Andrew Cagney, with assistance from Mike Meissner.
7832 PSIM is a very elaborate model of the PowerPC, including not only
7833 basic instruction set execution, but also details of execution unit
7834 performance and I/O hardware. See sim/ppc/README for more details.
7838 GDB now works with Solaris 2.5.
7840 * Windows 95/NT native
7842 GDB will now work as a native debugger on Windows 95 and Windows NT.
7843 To build it from source, you must use the "gnu-win32" environment,
7844 which uses a DLL to emulate enough of Unix to run the GNU tools.
7845 Further information, binaries, and sources are available at
7846 ftp.cygnus.com, under pub/gnu-win32.
7848 * dont-repeat command
7850 If a user-defined command includes the command `dont-repeat', then the
7851 command will not be repeated if the user just types return. This is
7852 useful if the command is time-consuming to run, so that accidental
7853 extra keystrokes don't run the same command many times.
7855 * Send break instead of ^C
7857 The standard remote protocol now includes an option to send a break
7858 rather than a ^C to the target in order to interrupt it. By default,
7859 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7861 * Remote protocol timeout
7863 The standard remote protocol includes a new variable `remotetimeout'
7864 that allows you to set the number of seconds before GDB gives up trying
7865 to read from the target. The default value is 2.
7867 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7869 By default GDB will automatically keep track of objects as they are
7870 loaded and unloaded by the dynamic linker. By using the command `set
7871 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7872 when shared library events occur, thus allowing you to set breakpoints
7873 in shared libraries which are explicitly loaded by the inferior.
7875 Note this feature does not work on hpux8. On hpux9 you must link
7876 /usr/lib/end.o into your program. This feature should work
7877 automatically on hpux10.
7879 * Irix 5.x hardware watchpoint support
7881 Irix 5 configurations now support the use of hardware watchpoints.
7883 * Mips protocol "SYN garbage limit"
7885 When debugging a Mips target using the `target mips' protocol, you
7886 may set the number of characters that GDB will ignore by setting
7887 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7888 every character. The default value is 1050.
7890 * Recording and replaying remote debug sessions
7892 If you set `remotelogfile' to the name of a file, gdb will write to it
7893 a recording of a remote debug session. This recording may then be
7894 replayed back to gdb using "gdbreplay". See gdbserver/README for
7895 details. This is useful when you have a problem with GDB while doing
7896 remote debugging; you can make a recording of the session and send it
7897 to someone else, who can then recreate the problem.
7899 * Speedups for remote debugging
7901 GDB includes speedups for downloading and stepping MIPS systems using
7902 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7903 and more efficient S-record downloading.
7905 * Memory use reductions and statistics collection
7907 GDB now uses less memory and reports statistics about memory usage.
7908 Try the `maint print statistics' command, for example.
7910 *** Changes in GDB-4.15:
7912 * Psymtabs for XCOFF
7914 The symbol reader for AIX GDB now uses partial symbol tables. This
7915 can greatly improve startup time, especially for large executables.
7917 * Remote targets use caching
7919 Remote targets now use a data cache to speed up communication with the
7920 remote side. The data cache could lead to incorrect results because
7921 it doesn't know about volatile variables, thus making it impossible to
7922 debug targets which use memory mapped I/O devices. `set remotecache
7923 off' turns the data cache off.
7925 * Remote targets may have threads
7927 The standard remote protocol now includes support for multiple threads
7928 in the target system, using new protocol commands 'H' and 'T'. See
7929 gdb/remote.c for details.
7933 If GDB is configured with `--enable-netrom', then it will include
7934 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7935 acts as though it is a bank of ROM on the target board, but you can
7936 write into it over the network. GDB's support consists only of
7937 support for fast loading into the emulated ROM; to debug, you must use
7938 another protocol, such as standard remote protocol. The usual
7939 sequence is something like
7941 target nrom <netrom-hostname>
7943 target remote <netrom-hostname>:1235
7947 GDB now includes support for the Apple Macintosh, as a host only. It
7948 may be run as either an MPW tool or as a standalone application, and
7949 it can debug through the serial port. All the usual GDB commands are
7950 available, but to the target command, you must supply "serial" as the
7951 device type instead of "/dev/ttyXX". See mpw-README in the main
7952 directory for more information on how to build. The MPW configuration
7953 scripts */mpw-config.in support only a few targets, and only the
7954 mips-idt-ecoff target has been tested.
7958 GDB configuration now uses autoconf. This is not user-visible,
7959 but does simplify configuration and building.
7963 GDB now supports hpux10.
7965 *** Changes in GDB-4.14:
7967 * New native configurations
7969 x86 FreeBSD i[345]86-*-freebsd
7970 x86 NetBSD i[345]86-*-netbsd
7971 NS32k NetBSD ns32k-*-netbsd
7972 Sparc NetBSD sparc-*-netbsd
7976 A29K VxWorks a29k-*-vxworks
7977 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7978 CPU32 EST-300 emulator m68*-*-est*
7979 PowerPC ELF powerpc-*-elf
7982 * Alpha OSF/1 support for procfs
7984 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7985 possible to attach to running processes. As the mounting of the /proc
7986 filesystem is optional on the Alpha, GDB automatically determines
7987 the availability of /proc during startup. This can lead to problems
7988 if /proc is unmounted after GDB has been started.
7990 * Arguments to user-defined commands
7992 User commands may accept up to 10 arguments separated by whitespace.
7993 Arguments are accessed within the user command via $arg0..$arg9. A
7996 print $arg0 + $arg1 + $arg2
7998 To execute the command use:
8001 Defines the command "adder" which prints the sum of its three arguments.
8002 Note the arguments are text substitutions, so they may reference variables,
8003 use complex expressions, or even perform inferior function calls.
8005 * New `if' and `while' commands
8007 This makes it possible to write more sophisticated user-defined
8008 commands. Both commands take a single argument, which is the
8009 expression to evaluate, and must be followed by the commands to
8010 execute, one per line, if the expression is nonzero, the list being
8011 terminated by the word `end'. The `if' command list may include an
8012 `else' word, which causes the following commands to be executed only
8013 if the expression is zero.
8015 * Fortran source language mode
8017 GDB now includes partial support for Fortran 77. It will recognize
8018 Fortran programs and can evaluate a subset of Fortran expressions, but
8019 variables and functions may not be handled correctly. GDB will work
8020 with G77, but does not yet know much about symbols emitted by other
8023 * Better HPUX support
8025 Most debugging facilities now work on dynamic executables for HPPAs
8026 running hpux9 or later. You can attach to running dynamically linked
8027 processes, but by default the dynamic libraries will be read-only, so
8028 for instance you won't be able to put breakpoints in them. To change
8029 that behavior do the following before running the program:
8035 This will cause the libraries to be mapped private and read-write.
8036 To revert to the normal behavior, do this:
8042 You cannot set breakpoints or examine data in the library until after
8043 the library is loaded if the function/data symbols do not have
8046 GDB can now also read debug symbols produced by the HP C compiler on
8047 HPPAs (sorry, no C++, Fortran or 68k support).
8049 * Target byte order now dynamically selectable
8051 You can choose which byte order to use with a target system, via the
8052 commands "set endian big" and "set endian little", and you can see the
8053 current setting by using "show endian". You can also give the command
8054 "set endian auto", in which case GDB will use the byte order
8055 associated with the executable. Currently, only embedded MIPS
8056 configurations support dynamic selection of target byte order.
8058 * New DOS host serial code
8060 This version uses DPMI interrupts to handle buffered I/O, so you
8061 no longer need to run asynctsr when debugging boards connected to
8064 *** Changes in GDB-4.13:
8066 * New "complete" command
8068 This lists all the possible completions for the rest of the line, if it
8069 were to be given as a command itself. This is intended for use by emacs.
8071 * Trailing space optional in prompt
8073 "set prompt" no longer adds a space for you after the prompt you set. This
8074 allows you to set a prompt which ends in a space or one that does not.
8076 * Breakpoint hit counts
8078 "info break" now displays a count of the number of times the breakpoint
8079 has been hit. This is especially useful in conjunction with "ignore"; you
8080 can ignore a large number of breakpoint hits, look at the breakpoint info
8081 to see how many times the breakpoint was hit, then run again, ignoring one
8082 less than that number, and this will get you quickly to the last hit of
8085 * Ability to stop printing at NULL character
8087 "set print null-stop" will cause GDB to stop printing the characters of
8088 an array when the first NULL is encountered. This is useful when large
8089 arrays actually contain only short strings.
8091 * Shared library breakpoints
8093 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8094 breakpoints in shared libraries before the executable is run.
8096 * Hardware watchpoints
8098 There is a new hardware breakpoint for the watch command for sparclite
8099 targets. See gdb/sparclite/hw_breakpoint.note.
8101 Hardware watchpoints are also now supported under GNU/Linux.
8105 Annotations have been added. These are for use with graphical interfaces,
8106 and are still experimental. Currently only gdba.el uses these.
8108 * Improved Irix 5 support
8110 GDB now works properly with Irix 5.2.
8112 * Improved HPPA support
8114 GDB now works properly with the latest GCC and GAS.
8116 * New native configurations
8118 Sequent PTX4 i[34]86-sequent-ptx4
8119 HPPA running OSF/1 hppa*-*-osf*
8120 Atari TT running SVR4 m68*-*-sysv4*
8121 RS/6000 LynxOS rs6000-*-lynxos*
8125 OS/9000 i[34]86-*-os9k
8126 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8129 * Hitachi SH7000 and E7000-PC ICE support
8131 There is now support for communicating with the Hitachi E7000-PC ICE.
8132 This is available automatically when GDB is configured for the SH.
8136 As usual, a variety of small fixes and improvements, both generic
8137 and configuration-specific. See the ChangeLog for more detail.
8139 *** Changes in GDB-4.12:
8141 * Irix 5 is now supported
8145 GDB-4.12 on the HPPA has a number of changes which make it unable
8146 to debug the output from the currently released versions of GCC and
8147 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8148 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8149 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8152 *** Changes in GDB-4.11:
8154 * User visible changes:
8158 The "set remotedebug" option is now consistent between the mips remote
8159 target, remote targets using the gdb-specific protocol, UDI (AMD's
8160 debug protocol for the 29k) and the 88k bug monitor. It is now an
8161 integer specifying a debug level (normally 0 or 1, but 2 means more
8162 debugging info for the mips target).
8164 * DEC Alpha native support
8166 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8167 debug info, but GDB works fairly well with the DEC compiler and should
8168 work with a future GCC release. See the README file for a few
8169 Alpha-specific notes.
8171 * Preliminary thread implementation
8173 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8175 * LynxOS native and target support for 386
8177 This release has been hosted on LynxOS 2.2, and also can be configured
8178 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8181 * Improvements in C++ mangling/demangling.
8183 This release has much better g++ debugging, specifically in name
8184 mangling/demangling, virtual function calls, print virtual table,
8185 call methods, ...etc.
8187 *** Changes in GDB-4.10:
8189 * User visible changes:
8191 Remote debugging using the GDB-specific (`target remote') protocol now
8192 supports the `load' command. This is only useful if you have some
8193 other way of getting the stub to the target system, and you can put it
8194 somewhere in memory where it won't get clobbered by the download.
8196 Filename completion now works.
8198 When run under emacs mode, the "info line" command now causes the
8199 arrow to point to the line specified. Also, "info line" prints
8200 addresses in symbolic form (as well as hex).
8202 All vxworks based targets now support a user settable option, called
8203 vxworks-timeout. This option represents the number of seconds gdb
8204 should wait for responses to rpc's. You might want to use this if
8205 your vxworks target is, perhaps, a slow software simulator or happens
8206 to be on the far side of a thin network line.
8210 This release contains support for using a DEC alpha as a GDB host for
8211 cross debugging. Native alpha debugging is not supported yet.
8214 *** Changes in GDB-4.9:
8218 This is the first GDB release which is accompanied by a matching testsuite.
8219 The testsuite requires installation of dejagnu, which should be available
8220 via ftp from most sites that carry GNU software.
8224 'Cfront' style demangling has had its name changed to 'ARM' style, to
8225 emphasize that it was written from the specifications in the C++ Annotated
8226 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8227 disclaimers, it still generated too much confusion with users attempting to
8228 use gdb with AT&T cfront.
8232 GDB now uses a standard remote interface to a simulator library.
8233 So far, the library contains simulators for the Zilog Z8001/2, the
8234 Hitachi H8/300, H8/500 and Super-H.
8236 * New targets supported
8238 H8/300 simulator h8300-hitachi-hms or h8300hms
8239 H8/500 simulator h8500-hitachi-hms or h8500hms
8240 SH simulator sh-hitachi-hms or sh
8241 Z8000 simulator z8k-zilog-none or z8ksim
8242 IDT MIPS board over serial line mips-idt-ecoff
8244 Cross-debugging to GO32 targets is supported. It requires a custom
8245 version of the i386-stub.c module which is integrated with the
8246 GO32 memory extender.
8248 * New remote protocols
8250 MIPS remote debugging protocol.
8252 * New source languages supported
8254 This version includes preliminary support for Chill, a Pascal like language
8255 used by telecommunications companies. Chill support is also being integrated
8256 into the GNU compiler, but we don't know when it will be publically available.
8259 *** Changes in GDB-4.8:
8261 * HP Precision Architecture supported
8263 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8264 version of this support was available as a set of patches from the
8265 University of Utah. GDB does not support debugging of programs
8266 compiled with the HP compiler, because HP will not document their file
8267 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8268 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8270 Many problems in the preliminary version have been fixed.
8272 * Faster and better demangling
8274 We have improved template demangling and fixed numerous bugs in the GNU style
8275 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8276 character types (wchar_t) are now supported. Demangling of each symbol is now
8277 only done once, and is cached when the symbol table for a file is read in.
8278 This results in a small increase in memory usage for C programs, a moderate
8279 increase in memory usage for C++ programs, and a fantastic speedup in
8282 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8283 from the specifications in the Annotated Reference Manual, which AT&T's
8284 compiler does not actually implement.
8286 * G++ multiple inheritance compiler problem
8288 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8289 inheritance lattices was reworked to properly discover ambiguities. We
8290 recently found an example which causes this new algorithm to fail in a
8291 very subtle way, producing bad debug information for those classes.
8292 The file 'gcc.patch' (in this directory) can be applied to gcc to
8293 circumvent the problem. A future GCC release will contain a complete
8296 The previous G++ debug info problem (mentioned below for the gdb-4.7
8297 release) is fixed in gcc version 2.3.2.
8299 * Improved configure script
8301 The `configure' script will now attempt to guess your system type if
8302 you don't supply a host system type. The old scheme of supplying a
8303 host system triplet is preferable over using this. All the magic is
8304 done in the new `config.guess' script. Examine it for details.
8306 We have also brought our configure script much more in line with the FSF's
8307 version. It now supports the --with-xxx options. In particular,
8308 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8309 The resulting GDB will not be able to read arbitrary object file formats --
8310 only the format ``expected'' to be used on the configured target system.
8311 We hope to make this the default in a future release.
8313 * Documentation improvements
8315 There's new internal documentation on how to modify GDB, and how to
8316 produce clean changes to the code. We implore people to read it
8317 before submitting changes.
8319 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8320 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8321 `info' files are also provided. To build `info' files from scratch,
8322 you will need the latest `makeinfo' release, which will be available in
8323 a future texinfo-X.Y release.
8325 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8326 We're not sure exactly which versions have this problem, but it has
8327 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8328 or better. If that isn't possible, there is a patch in
8329 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8330 around this problem.
8334 GDB now supports array constants that can be used in expressions typed in by
8335 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8336 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8339 The new directory `gdb/sparclite' contains a program that demonstrates
8340 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8342 * New native hosts supported
8344 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8345 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8347 * New targets supported
8349 AMD 29k family via UDI a29k-amd-udi or udi29k
8351 * New file formats supported
8353 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8354 HPUX core files, and SCO 3.2v2 core files.
8358 Attaching to processes now works again; thanks for the many bug reports.
8360 We have also stomped on a bunch of core dumps caused by
8361 printf_filtered("%s") problems.
8363 We eliminated a copyright problem on the rpc and ptrace header files
8364 for VxWorks, which was discovered at the last minute during the 4.7
8365 release. You should now be able to build a VxWorks GDB.
8367 You can now interrupt gdb while an attached process is running. This
8368 will cause the attached process to stop, and give control back to GDB.
8370 We fixed problems caused by using too many file descriptors
8371 for reading symbols from object files and libraries. This was
8372 especially a problem for programs that used many (~100) shared
8375 The `step' command now only enters a subroutine if there is line number
8376 information for the subroutine. Otherwise it acts like the `next'
8377 command. Previously, `step' would enter subroutines if there was
8378 any debugging information about the routine. This avoids problems
8379 when using `cc -g1' on MIPS machines.
8381 * Internal improvements
8383 GDB's internal interfaces have been improved to make it easier to support
8384 debugging of multiple languages in the future.
8386 GDB now uses a common structure for symbol information internally.
8387 Minimal symbols (derived from linkage symbols in object files), partial
8388 symbols (from a quick scan of debug information), and full symbols
8389 contain a common subset of information, making it easier to write
8390 shared code that handles any of them.
8392 * New command line options
8394 We now accept --silent as an alias for --quiet.
8398 The memory-mapped-malloc library is now licensed under the GNU Library
8399 General Public License.
8401 *** Changes in GDB-4.7:
8403 * Host/native/target split
8405 GDB has had some major internal surgery to untangle the support for
8406 hosts and remote targets. Now, when you configure GDB for a remote
8407 target, it will no longer load in all of the support for debugging
8408 local programs on the host. When fully completed and tested, this will
8409 ensure that arbitrary host/target combinations are possible.
8411 The primary conceptual shift is to separate the non-portable code in
8412 GDB into three categories. Host specific code is required any time GDB
8413 is compiled on that host, regardless of the target. Target specific
8414 code relates to the peculiarities of the target, but can be compiled on
8415 any host. Native specific code is everything else: it can only be
8416 built when the host and target are the same system. Child process
8417 handling and core file support are two common `native' examples.
8419 GDB's use of /proc for controlling Unix child processes is now cleaner.
8420 It has been split out into a single module under the `target_ops' vector,
8421 plus two native-dependent functions for each system that uses /proc.
8423 * New hosts supported
8425 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8426 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8427 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8429 * New targets supported
8431 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8432 68030 and CPU32 m68030-*-*, m68332-*-*
8434 * New native hosts supported
8436 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8437 (386bsd is not well tested yet)
8438 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8440 * New file formats supported
8442 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8443 supports reading of `a.out.adobe' object files, which are an a.out
8444 format extended with minimal information about multiple sections.
8448 `show copying' is the same as the old `info copying'.
8449 `show warranty' is the same as `info warrantee'.
8450 These were renamed for consistency. The old commands continue to work.
8452 `info handle' is a new alias for `info signals'.
8454 You can now define pre-command hooks, which attach arbitrary command
8455 scripts to any command. The commands in the hook will be executed
8456 prior to the user's command. You can also create a hook which will be
8457 executed whenever the program stops. See gdb.texinfo.
8461 We now deal with Cfront style name mangling, and can even extract type
8462 info from mangled symbols. GDB can automatically figure out which
8463 symbol mangling style your C++ compiler uses.
8465 Calling of methods and virtual functions has been improved as well.
8469 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8470 fixed. This was due to mishandling of the extra N_SO stabs output
8473 We also finally got Ultrix 4.2 running in house, and fixed core file
8474 support, with help from a dozen people on the net.
8476 John M. Farrell discovered that the reason that single-stepping was so
8477 slow on all of the Mips based platforms (primarily SGI and DEC) was
8478 that we were trying to demangle and lookup a symbol used for internal
8479 purposes on every instruction that was being stepped through. Changing
8480 the name of that symbol so that it couldn't be mistaken for a C++
8481 mangled symbol sped things up a great deal.
8483 Rich Pixley sped up symbol lookups in general by getting much smarter
8484 about when C++ symbol mangling is necessary. This should make symbol
8485 completion (TAB on the command line) much faster. It's not as fast as
8486 we'd like, but it's significantly faster than gdb-4.6.
8490 A new user controllable variable 'call_scratch_address' can
8491 specify the location of a scratch area to be used when GDB
8492 calls a function in the target. This is necessary because the
8493 usual method of putting the scratch area on the stack does not work
8494 in systems that have separate instruction and data spaces.
8496 We integrated changes to support the 29k UDI (Universal Debugger
8497 Interface), but discovered at the last minute that we didn't have all
8498 of the appropriate copyright paperwork. We are working with AMD to
8499 resolve this, and hope to have it available soon.
8503 We have sped up the remote serial line protocol, especially for targets
8504 with lots of registers. It now supports a new `expedited status' ('T')
8505 message which can be used in place of the existing 'S' status message.
8506 This allows the remote stub to send only the registers that GDB
8507 needs to make a quick decision about single-stepping or conditional
8508 breakpoints, eliminating the need to fetch the entire register set for
8509 each instruction being stepped through.
8511 The GDB remote serial protocol now implements a write-through cache for
8512 registers, only re-reading the registers if the target has run.
8514 There is also a new remote serial stub for SPARC processors. You can
8515 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8516 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8517 processor with a serial port.
8521 Configure.in files have become much easier to read and modify. A new
8522 `table driven' format makes it more obvious what configurations are
8523 supported, and what files each one uses.
8527 There is a new opcodes library which will eventually contain all of the
8528 disassembly routines and opcode tables. At present, it only contains
8529 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8530 disassembler (binutils/objdump) to share these routines.
8532 The libiberty library is now copylefted under the GNU Library General
8533 Public License. This allows more liberal use, and was done so libg++
8534 can use it. This makes no difference to GDB, since the Library License
8535 grants all the rights from the General Public License.
8539 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8540 reference to the stabs symbol info used by the debugger. It is (as far
8541 as we know) the only published document on this fascinating topic. We
8542 encourage you to read it, compare it to the stabs information on your
8543 system, and send improvements on the document in general (to
8544 bug-gdb@prep.ai.mit.edu).
8546 And, of course, many bugs have been fixed.
8549 *** Changes in GDB-4.6:
8551 * Better support for C++ function names
8553 GDB now accepts as input the "demangled form" of C++ overloaded function
8554 names and member function names, and can do command completion on such names
8555 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8556 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8557 Make use of command completion, it is your friend.
8559 GDB also now accepts a variety of C++ mangled symbol formats. They are
8560 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8561 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8562 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8563 for the list of formats.
8565 * G++ symbol mangling problem
8567 Recent versions of gcc have a bug in how they emit debugging information for
8568 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8569 directory) can be applied to gcc to fix the problem. Alternatively, if you
8570 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8571 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8572 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8575 * New 'maintenance' command
8577 All of the commands related to hacking GDB internals have been moved out of
8578 the main command set, and now live behind the 'maintenance' command. This
8579 can also be abbreviated as 'mt'. The following changes were made:
8581 dump-me -> maintenance dump-me
8582 info all-breakpoints -> maintenance info breakpoints
8583 printmsyms -> maintenance print msyms
8584 printobjfiles -> maintenance print objfiles
8585 printpsyms -> maintenance print psymbols
8586 printsyms -> maintenance print symbols
8588 The following commands are new:
8590 maintenance demangle Call internal GDB demangler routine to
8591 demangle a C++ link name and prints the result.
8592 maintenance print type Print a type chain for a given symbol
8594 * Change to .gdbinit file processing
8596 We now read the $HOME/.gdbinit file before processing the argv arguments
8597 (e.g. reading symbol files or core files). This allows global parameters to
8598 be set, which will apply during the symbol reading. The ./.gdbinit is still
8599 read after argv processing.
8601 * New hosts supported
8603 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8605 GNU/Linux support i386-unknown-linux or linux
8607 We are also including code to support the HP/PA running BSD and HPUX. This
8608 is almost guaranteed not to work, as we didn't have time to test or build it
8609 for this release. We are including it so that the more adventurous (or
8610 masochistic) of you can play with it. We also had major problems with the
8611 fact that the compiler that we got from HP doesn't support the -g option.
8614 * New targets supported
8616 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8618 * More smarts about finding #include files
8620 GDB now remembers the compilation directory for all include files, and for
8621 all files from which C is generated (like yacc and lex sources). This
8622 greatly improves GDB's ability to find yacc/lex sources, and include files,
8623 especially if you are debugging your program from a directory different from
8624 the one that contains your sources.
8626 We also fixed a bug which caused difficulty with listing and setting
8627 breakpoints in include files which contain C code. (In the past, you had to
8628 try twice in order to list an include file that you hadn't looked at before.)
8630 * Interesting infernals change
8632 GDB now deals with arbitrary numbers of sections, where the symbols for each
8633 section must be relocated relative to that section's landing place in the
8634 target's address space. This work was needed to support ELF with embedded
8635 stabs used by Solaris-2.0.
8637 * Bug fixes (of course!)
8639 There have been loads of fixes for the following things:
8640 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8641 i960, stabs, DOS(GO32), procfs, etc...
8643 See the ChangeLog for details.
8645 *** Changes in GDB-4.5:
8647 * New machines supported (host and target)
8649 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8651 SGI Irix-4.x mips-sgi-irix4 or iris4
8653 * New malloc package
8655 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8656 Mmalloc is capable of handling multiple heaps of memory. It is also
8657 capable of saving a heap to a file, and then mapping it back in later.
8658 This can be used to greatly speedup the startup of GDB by using a
8659 pre-parsed symbol table which lives in a mmalloc managed heap. For
8660 more details, please read mmalloc/mmalloc.texi.
8664 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8665 'help info proc' for details.
8667 * MIPS ecoff symbol table format
8669 The code that reads MIPS symbol table format is now supported on all hosts.
8670 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8673 * File name changes for MS-DOS
8675 Many files in the config directories have been renamed to make it easier to
8676 support GDB on MS-DOSe systems (which have very restrictive file name
8677 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8678 environment) is close to working but has some remaining problems. Note
8679 that debugging of DOS programs is not supported, due to limitations
8680 in the ``operating system'', but it can be used to host cross-debugging.
8682 * Cross byte order fixes
8684 Many fixes have been made to support cross debugging of Sparc and MIPS
8685 targets from hosts whose byte order differs.
8687 * New -mapped and -readnow options
8689 If memory-mapped files are available on your system through the 'mmap'
8690 system call, you can use the -mapped option on the `file' or
8691 `symbol-file' commands to cause GDB to write the symbols from your
8692 program into a reusable file. If the program you are debugging is
8693 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8694 Future GDB debugging sessions will notice the presence of this file,
8695 and will quickly map in symbol information from it, rather than reading
8696 the symbol table from the executable program. Using the '-mapped'
8697 option in a GDB `file' or `symbol-file' command has the same effect as
8698 starting GDB with the '-mapped' command-line option.
8700 You can cause GDB to read the entire symbol table immediately by using
8701 the '-readnow' option with any of the commands that load symbol table
8702 information (or on the GDB command line). This makes the command
8703 slower, but makes future operations faster.
8705 The -mapped and -readnow options are typically combined in order to
8706 build a `fred.syms' file that contains complete symbol information.
8707 A simple GDB invocation to do nothing but build a `.syms' file for future
8710 gdb -batch -nx -mapped -readnow programname
8712 The `.syms' file is specific to the host machine on which GDB is run.
8713 It holds an exact image of GDB's internal symbol table. It cannot be
8714 shared across multiple host platforms.
8716 * longjmp() handling
8718 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8719 siglongjmp() without losing control. This feature has not yet been ported to
8720 all systems. It currently works on many 386 platforms, all MIPS-based
8721 platforms (SGI, DECstation, etc), and Sun3/4.
8725 Preliminary work has been put in to support the new Solaris OS from Sun. At
8726 this time, it can control and debug processes, but it is not capable of
8731 As always, many many bug fixes. The major areas were with g++, and mipsread.
8732 People using the MIPS-based platforms should experience fewer mysterious
8733 crashes and trashed symbol tables.
8735 *** Changes in GDB-4.4:
8737 * New machines supported (host and target)
8739 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8741 BSD Reno on Vax vax-dec-bsd
8742 Ultrix on Vax vax-dec-ultrix
8744 * New machines supported (target)
8746 AMD 29000 embedded, using EBMON a29k-none-none
8750 GDB continues to improve its handling of C++. `References' work better.
8751 The demangler has also been improved, and now deals with symbols mangled as
8752 per the Annotated C++ Reference Guide.
8754 GDB also now handles `stabs' symbol information embedded in MIPS
8755 `ecoff' symbol tables. Since the ecoff format was not easily
8756 extensible to handle new languages such as C++, this appeared to be a
8757 good way to put C++ debugging info into MIPS binaries. This option
8758 will be supported in the GNU C compiler, version 2, when it is
8761 * New features for SVR4
8763 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8764 shared libraries. Debugging dynamically linked programs should present
8765 only minor differences from debugging statically linked programs.
8767 The `info proc' command will print out information about any process
8768 on an SVR4 system (including the one you are debugging). At the moment,
8769 it prints the address mappings of the process.
8771 If you bring up GDB on another SVR4 system, please send mail to
8772 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8774 * Better dynamic linking support in SunOS
8776 Reading symbols from shared libraries which contain debugging symbols
8777 now works properly. However, there remain issues such as automatic
8778 skipping of `transfer vector' code during function calls, which
8779 make it harder to debug code in a shared library, than to debug the
8780 same code linked statically.
8784 GDB is now using the latest `getopt' routines from the FSF. This
8785 version accepts the -- prefix for options with long names. GDB will
8786 continue to accept the old forms (-option and +option) as well.
8787 Various single letter abbreviations for options have been explicity
8788 added to the option table so that they won't get overshadowed in the
8789 future by other options that begin with the same letter.
8793 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8794 Many assorted bugs have been handled. Many more remain to be handled.
8795 See the various ChangeLog files (primarily in gdb and bfd) for details.
8798 *** Changes in GDB-4.3:
8800 * New machines supported (host and target)
8802 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8803 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8804 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8806 * Almost SCO Unix support
8808 We had hoped to support:
8809 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8810 (except for core file support), but we discovered very late in the release
8811 that it has problems with process groups that render gdb unusable. Sorry
8812 about that. I encourage people to fix it and post the fixes.
8814 * Preliminary ELF and DWARF support
8816 GDB can read ELF object files on System V Release 4, and can handle
8817 debugging records for C, in DWARF format, in ELF files. This support
8818 is preliminary. If you bring up GDB on another SVR4 system, please
8819 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8824 GDB now uses the latest `readline' library. One user-visible change
8825 is that two tabs will list possible command completions, which previously
8826 required typing M-? (meta-question mark, or ESC ?).
8830 The `stepi' bug that many of you noticed has been squashed.
8831 Many bugs in C++ have been handled. Many more remain to be handled.
8832 See the various ChangeLog files (primarily in gdb and bfd) for details.
8834 * State of the MIPS world (in case you wondered):
8836 GDB can understand the symbol tables emitted by the compilers
8837 supplied by most vendors of MIPS-based machines, including DEC. These
8838 symbol tables are in a format that essentially nobody else uses.
8840 Some versions of gcc come with an assembler post-processor called
8841 mips-tfile. This program is required if you want to do source-level
8842 debugging of gcc-compiled programs. I believe FSF does not ship
8843 mips-tfile with gcc version 1, but it will eventually come with gcc
8846 Debugging of g++ output remains a problem. g++ version 1.xx does not
8847 really support it at all. (If you're lucky, you should be able to get
8848 line numbers and stack traces to work, but no parameters or local
8849 variables.) With some work it should be possible to improve the
8852 When gcc version 2 is released, you will have somewhat better luck.
8853 However, even then you will get confusing results for inheritance and
8856 We will eventually provide full debugging of g++ output on
8857 DECstations. This will probably involve some kind of stabs-in-ecoff
8858 encapulation, but the details have not been worked out yet.
8861 *** Changes in GDB-4.2:
8863 * Improved configuration
8865 Only one copy of `configure' exists now, and it is not self-modifying.
8866 Porting BFD is simpler.
8870 The `step' and `next' commands now only stop at the first instruction
8871 of a source line. This prevents the multiple stops that used to occur
8872 in switch statements, for-loops, etc. `Step' continues to stop if a
8873 function that has debugging information is called within the line.
8877 Lots of small bugs fixed. More remain.
8879 * New host supported (not target)
8881 Intel 386 PC clone running Mach i386-none-mach
8884 *** Changes in GDB-4.1:
8886 * Multiple source language support
8888 GDB now has internal scaffolding to handle several source languages.
8889 It determines the type of each source file from its filename extension,
8890 and will switch expression parsing and number formatting to match the
8891 language of the function in the currently selected stack frame.
8892 You can also specifically set the language to be used, with
8893 `set language c' or `set language modula-2'.
8897 GDB now has preliminary support for the GNU Modula-2 compiler,
8898 currently under development at the State University of New York at
8899 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8900 continue through the fall of 1991 and into 1992.
8902 Other Modula-2 compilers are currently not supported, and attempting to
8903 debug programs compiled with them will likely result in an error as the
8904 symbol table is read. Feel free to work on it, though!
8906 There are hooks in GDB for strict type checking and range checking,
8907 in the `Modula-2 philosophy', but they do not currently work.
8911 GDB can now write to executable and core files (e.g. patch
8912 a variable's value). You must turn this switch on, specify
8913 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8914 by assigning a new value to a variable. Modifications take
8917 * Automatic SunOS shared library reading
8919 When you run your program, GDB automatically determines where its
8920 shared libraries (if any) have been loaded, and reads their symbols.
8921 The `share' command is no longer needed. This also works when
8922 examining core files.
8926 You can specify the number of lines that the `list' command shows.
8929 * New machines supported (host and target)
8931 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8932 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8933 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8935 * New hosts supported (not targets)
8937 IBM RT/PC: romp-ibm-aix or rtpc
8939 * New targets supported (not hosts)
8941 AMD 29000 embedded with COFF a29k-none-coff
8942 AMD 29000 embedded with a.out a29k-none-aout
8943 Ultracomputer remote kernel debug a29k-nyu-kern
8945 * New remote interfaces
8951 *** Changes in GDB-4.0:
8955 Wide output is wrapped at good places to make the output more readable.
8957 Gdb now supports cross-debugging from a host machine of one type to a
8958 target machine of another type. Communication with the target system
8959 is over serial lines. The ``target'' command handles connecting to the
8960 remote system; the ``load'' command will download a program into the
8961 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8962 also supports debugging of realtime processes running under VxWorks,
8963 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8964 stub on the target system.
8966 New CPUs supported include the AMD 29000 and Intel 960.
8968 GDB now reads object files and symbol tables via a ``binary file''
8969 library, which allows a single copy of GDB to debug programs of multiple
8970 object file types such as a.out and coff.
8972 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8973 refcard.dvi and refcard.ps are available to format it).
8976 * Control-Variable user interface simplified
8978 All variables that control the operation of the debugger can be set
8979 by the ``set'' command, and displayed by the ``show'' command.
8981 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8982 ``Show prompt'' produces the response:
8983 Gdb's prompt is new-gdb=>.
8985 What follows are the NEW set commands. The command ``help set'' will
8986 print a complete list of old and new set commands. ``help set FOO''
8987 will give a longer description of the variable FOO. ``show'' will show
8988 all of the variable descriptions and their current settings.
8990 confirm on/off: Enables warning questions for operations that are
8991 hard to recover from, e.g. rerunning the program while
8992 it is already running. Default is ON.
8994 editing on/off: Enables EMACS style command line editing
8995 of input. Previous lines can be recalled with
8996 control-P, the current line can be edited with control-B,
8997 you can search for commands with control-R, etc.
9000 history filename NAME: NAME is where the gdb command history
9001 will be stored. The default is .gdb_history,
9002 or the value of the environment variable
9005 history size N: The size, in commands, of the command history. The
9006 default is 256, or the value of the environment variable
9009 history save on/off: If this value is set to ON, the history file will
9010 be saved after exiting gdb. If set to OFF, the
9011 file will not be saved. The default is OFF.
9013 history expansion on/off: If this value is set to ON, then csh-like
9014 history expansion will be performed on
9015 command line input. The default is OFF.
9017 radix N: Sets the default radix for input and output. It can be set
9018 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9019 in the current radix, so "set radix 10" is always a no-op.
9021 height N: This integer value is the number of lines on a page. Default
9022 is 24, the current `stty rows'' setting, or the ``li#''
9023 setting from the termcap entry matching the environment
9026 width N: This integer value is the number of characters on a line.
9027 Default is 80, the current `stty cols'' setting, or the ``co#''
9028 setting from the termcap entry matching the environment
9031 Note: ``set screensize'' is obsolete. Use ``set height'' and
9032 ``set width'' instead.
9034 print address on/off: Print memory addresses in various command displays,
9035 such as stack traces and structure values. Gdb looks
9036 more ``symbolic'' if you turn this off; it looks more
9037 ``machine level'' with it on. Default is ON.
9039 print array on/off: Prettyprint arrays. New convenient format! Default
9042 print demangle on/off: Print C++ symbols in "source" form if on,
9045 print asm-demangle on/off: Same, for assembler level printouts
9048 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9051 * Support for Epoch Environment.
9053 The epoch environment is a version of Emacs v18 with windowing. One
9054 new command, ``inspect'', is identical to ``print'', except that if you
9055 are running in the epoch environment, the value is printed in its own
9059 * Support for Shared Libraries
9061 GDB can now debug programs and core files that use SunOS shared libraries.
9062 Symbols from a shared library cannot be referenced
9063 before the shared library has been linked with the program (this
9064 happens after you type ``run'' and before the function main() is entered).
9065 At any time after this linking (including when examining core files
9066 from dynamically linked programs), gdb reads the symbols from each
9067 shared library when you type the ``sharedlibrary'' command.
9068 It can be abbreviated ``share''.
9070 sharedlibrary REGEXP: Load shared object library symbols for files
9071 matching a unix regular expression. No argument
9072 indicates to load symbols for all shared libraries.
9074 info sharedlibrary: Status of loaded shared libraries.
9079 A watchpoint stops execution of a program whenever the value of an
9080 expression changes. Checking for this slows down execution
9081 tremendously whenever you are in the scope of the expression, but is
9082 quite useful for catching tough ``bit-spreader'' or pointer misuse
9083 problems. Some machines such as the 386 have hardware for doing this
9084 more quickly, and future versions of gdb will use this hardware.
9086 watch EXP: Set a watchpoint (breakpoint) for an expression.
9088 info watchpoints: Information about your watchpoints.
9090 delete N: Deletes watchpoint number N (same as breakpoints).
9091 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9092 enable N: Re-enables watchpoint number N (same as breakpoints).
9095 * C++ multiple inheritance
9097 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9100 * C++ exception handling
9102 Gdb now supports limited C++ exception handling. Besides the existing
9103 ability to breakpoint on an exception handler, gdb can breakpoint on
9104 the raising of an exception (before the stack is peeled back to the
9107 catch FOO: If there is a FOO exception handler in the dynamic scope,
9108 set a breakpoint to catch exceptions which may be raised there.
9109 Multiple exceptions (``catch foo bar baz'') may be caught.
9111 info catch: Lists all exceptions which may be caught in the
9112 current stack frame.
9115 * Minor command changes
9117 The command ``call func (arg, arg, ...)'' now acts like the print
9118 command, except it does not print or save a value if the function's result
9119 is void. This is similar to dbx usage.
9121 The ``up'' and ``down'' commands now always print the frame they end up
9122 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9123 frames without printing.
9125 * New directory command
9127 'dir' now adds directories to the FRONT of the source search path.
9128 The path starts off empty. Source files that contain debug information
9129 about the directory in which they were compiled can be found even
9130 with an empty path; Sun CC and GCC include this information. If GDB can't
9131 find your source file in the current directory, type "dir .".
9133 * Configuring GDB for compilation
9135 For normal use, type ``./configure host''. See README or gdb.texinfo
9138 GDB now handles cross debugging. If you are remotely debugging between
9139 two different machines, type ``./configure host -target=targ''.
9140 Host is the machine where GDB will run; targ is the machine
9141 where the program that you are debugging will run.