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 set tui mouse-events [on|off]
137 show tui mouse-events
138 When on (default), mouse clicks control the TUI and can be accessed by
139 Python extensions. When off, mouse clicks are handled by the terminal,
140 enabling terminal-native text selection.
142 * New convenience function "$_shell", to execute a shell command and
143 return the result. This lets you run shell commands in expressions.
146 (gdb) p $_shell("true")
148 (gdb) p $_shell("false")
150 (gdb) break func if $_shell("some command") == 0
154 ** mi now reports 'no-history' as a stop reason when hitting the end of the
155 reverse execution history.
157 ** When creating a thread-specific breakpoint using the '-p' option,
158 the -break-insert command would report the 'thread' field twice in
159 the reply. The content of both fields was always identical. This
160 has now been fixed; the 'thread' field will be reported just once
161 for thread-specific breakpoints, or not at all for breakpoints
162 without a thread restriction. The same is also true for the 'task'
163 field of an Ada task-specific breakpoint.
165 ** It is no longer possible to create a thread-specific breakpoint for
166 a thread that doesn't exist using '-break-insert -p ID'. Creating
167 breakpoints for non-existent threads is not allowed when using the
168 CLI, that the MI allowed it was a long standing bug, which has now
171 ** The '--simple-values' argument to the '-stack-list-arguments',
172 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
173 commands now takes reference types into account: that is, a value is now
174 considered simple if it is neither an array, structure, or union, nor a
175 reference to an array, structure, or union. (Previously all references were
176 considered simple.) Support for this feature can be verified by using the
177 '-list-features' command, which should contain "simple-values-ref-types".
179 ** The -break-insert command now accepts a '-g thread-group-id' option
180 to allow for the creation of inferior-specific breakpoints.
182 ** The bkpt tuple, which appears in breakpoint-created notifications,
183 and in the result of the -break-insert command can now include an
184 optional 'inferior' field for both the main breakpoint, and each
185 location, when the breakpoint is inferior-specific.
189 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
191 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
193 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
194 now be of type 'str' otherwise a TypeError will be raised.
196 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
197 values of type 'bool'. Changing this attribute will now
198 invalidate GDB's frame-cache, which means GDB will need to
199 rebuild its frame-cache when next required - either with, or
200 without the particular unwinder, depending on how 'enabled' was
203 ** New methods added to the gdb.PendingFrame class. These methods
204 have the same behaviour as the corresponding methods on
205 gdb.Frame. The new methods are:
207 - gdb.PendingFrame.name: Return the name for the frame's
209 - gdb.PendingFrame.is_valid: Return True if the pending frame
211 - gdb.PendingFrame.pc: Return the $pc register value for this
213 - gdb.PendingFrame.language: Return a string containing the
214 language for this frame, or None.
215 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
216 object for the current location within the pending frame, or
218 - gdb.PendingFrame.block: Return a gdb.Block for the current
219 pending frame, or None.
220 - gdb.PendingFrame.function: Return a gdb.Symbol for the
221 current pending frame, or None.
223 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
224 now use either an integer or a gdb.Value object for each of its
225 'sp', 'pc', and 'special' attributes.
227 ** A new class gdb.unwinder.FrameId has been added. Instances of
228 this class are constructed with 'sp' (stack-pointer) and 'pc'
229 (program-counter) values, and can be used as the frame-id when
230 calling gdb.PendingFrame.create_unwind_info.
232 ** It is now no longer possible to sub-class the
233 gdb.disassembler.DisassemblerResult type.
235 ** The Disassembler API from the gdb.disassembler module has been
236 extended to include styling support:
238 - The DisassemblerResult class can now be initialized with a list
239 of parts. Each part represents part of the disassembled
240 instruction along with the associated style information. This
241 list of parts can be accessed with the new
242 DisassemblerResult.parts property.
244 - New constants gdb.disassembler.STYLE_* representing all the
245 different styles part of an instruction might have.
247 - New methods DisassembleInfo.text_part and
248 DisassembleInfo.address_part which are used to create the new
249 styled parts of a disassembled instruction.
251 - Changes are backwards compatible, the older API can still be
252 used to disassemble instructions without styling.
254 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
255 GDB/MI command and returns the output as a Python dictionary.
257 ** New function gdb.block_signals(). This returns a context manager
258 that blocks any signals that GDB needs to handle itself.
260 ** New class gdb.Thread. This is a subclass of threading.Thread
261 that calls gdb.block_signals in its "start" method.
263 ** gdb.parse_and_eval now has a new "global_context" parameter.
264 This can be used to request that the parse only examine global
267 ** gdb.Inferior now has a new "arguments" attribute. This holds the
268 command-line arguments to the inferior, if known.
270 ** gdb.Inferior now has a new "main_name" attribute. This holds the
271 name of the inferior's "main", if known.
273 ** gdb.Inferior now has new methods "clear_env", "set_env", and
274 "unset_env". These can be used to modify the inferior's
275 environment before it is started.
277 ** gdb.Value now has the 'assign' method.
279 ** gdb.Value now has the 'to_array' method. This converts an
280 array-like Value to an array.
282 ** gdb.Progspace now has the new method "objfile_for_address". This
283 returns the gdb.Objfile, if any, that covers a given address.
285 ** gdb.Breakpoint now has an "inferior" attribute. If the
286 Breakpoint object is inferior specific then this attribute holds
287 the inferior-id (an integer). If the Breakpoint object is not
288 inferior specific, then this field contains None. This field can
291 ** gdb.Type now has the "is_array_like" and "is_string_like"
292 methods. These reflect GDB's internal idea of whether a type
293 might be array- or string-like, even if they do not have the
294 corresponding type code.
296 ** gdb.ValuePrinter is a new class that can be used as the base
297 class for the result of applying a pretty-printer. As a base
298 class, it signals to gdb that the printer may implement new
299 pretty-printer methods.
301 *** Changes in GDB 13
303 * MI version 1 is deprecated, and will be removed in GDB 14.
305 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
306 reading memory tag data for AArch64 MTE from core files generated by
307 the gcore command or the Linux kernel.
309 When a process uses memory-mapped pages protected by memory tags (for
310 example, AArch64 MTE), this additional information will be recorded in
311 the core file in the event of a crash or if GDB generates a core file
312 from the current process state. GDB will show this additional information
313 automatically, or through one of the memory-tag subcommands.
315 * "info breakpoints" now displays enabled breakpoint locations of
316 disabled breakpoints as in the "y-" state. For example:
318 (gdb) info breakpoints
319 Num Type Disp Enb Address What
320 1 breakpoint keep n <MULTIPLE>
321 1.1 y- 0x00000000000011b6 in ...
322 1.2 y- 0x00000000000011c2 in ...
323 1.3 n 0x00000000000011ce in ...
325 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
326 aarch64 architectures.
328 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
330 * Remove support for building against Python 2, it is now only possible to
331 build GDB against Python 3.
333 * DBX mode has been removed.
335 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
336 emit to indicate where a breakpoint should be placed to break in a function
339 * Completion now also offers "NUMBER" for "set" commands that accept
340 a numeric argument and the "unlimited" keyword. For example:
342 (gdb) set width <TAB>
347 (gdb) complete set width
351 * Disassembler styling using libopcodes. GDB now supports
352 disassembler styling using libopcodes. This is only available for
353 some targets (currently x86 and RISC-V). For unsupported targets
354 Python Pygments is still used. For supported targets, libopcodes
355 styling is used by default.
357 * The Windows native target now supports target async.
359 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
361 * The format of 'disassemble /r' and 'record instruction-history /r'
362 has changed. The instruction bytes could now be grouped together,
363 and displayed in the endianness of the instruction. This is the
364 same layout as used by GNU objdump when disassembling.
366 There is now 'disassemble /b' and 'record instruction-history /b'
367 which will always display the instructions bytes one at a time in
368 memory order, that is, the byte at the lowest address first.
370 For both /r and /b GDB is now better at using whitespace in order to
371 align the disassembled instruction text.
373 * The TUI no longer styles the source and assembly code highlighted by
374 the current position indicator by default. You can however
375 re-enable styling using the new "set style tui-current-position"
378 * New convenience variable $_inferior_thread_count contains the number
379 of live threads in the current inferior.
381 * When a breakpoint with multiple code locations is hit, GDB now prints
382 the code location using the syntax <breakpoint_number>.<location_number>
384 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
386 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
387 and $_hit_locno to the hit breakpoint number and code location number.
388 This allows to disable the last hit breakpoint using
389 (gdb) disable $_hit_bpnum
390 or disable only the specific breakpoint code location using
391 (gdb) disable $_hit_bpnum.$_hit_locno
392 These commands can be used inside the command list of a breakpoint to
393 automatically disable the just encountered breakpoint (or the just
394 encountered specific breakpoint code location).
395 When a breakpoint has only one location, $_hit_locno is set to 1 so that
396 (gdb) disable $_hit_bpnum.$_hit_locno
398 (gdb) disable $_hit_bpnum
399 are both disabling the breakpoint.
403 maintenance set ignore-prologue-end-flag on|off
404 maintenance show ignore-prologue-end-flag
405 This setting, which is off by default, controls whether GDB ignores the
406 PROLOGUE-END flag from the line-table when skipping prologue. This can be
407 used to force GDB to use prologue analyzers if the line-table is constructed
408 from erroneous debug information.
410 set print nibbles [on|off]
412 This controls whether the 'print/t' command will display binary values
413 in groups of four bits, known as "nibbles". The default is 'off'.
415 maintenance set libopcodes-styling on|off
416 maintenance show libopcodes-styling
417 These can be used to force off libopcodes based styling, the Python
418 Pygments styling will then be used instead.
420 set style disassembler comment
421 show style disassembler comment
422 set style disassembler immediate
423 show style disassembler immediate
424 set style disassembler mnemonic
425 show style disassembler mnemonic
426 set style disassembler register
427 show style disassembler register
428 set style disassembler address
429 show style disassembler address
430 set style disassembler symbol
431 show style disassembler symbol
432 For targets that support libopcodes based styling, these settings
433 control how various aspects of the disassembler output are styled.
434 The 'disassembler address' and 'disassembler symbol' styles are
435 aliases for the 'address' and 'function' styles respectively.
437 maintenance print frame-id [ LEVEL ]
438 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
439 not given, then print the frame-id for the currently selected frame.
441 set debug infcall on|off
443 Print additional debug messages about inferior function calls.
445 set debug solib on|off
447 Print additional debug messages about shared library handling.
449 set style tui-current-position [on|off]
450 Whether to style the source and assembly code highlighted by the
451 TUI's current position indicator. The default is off.
453 set print characters LIMIT
454 show print characters
455 This new setting is like 'set print elements', but controls how many
456 characters of a string are printed. This functionality used to be
457 covered by 'set print elements', but it can be controlled separately
458 now. LIMIT can be set to a numerical value to request that particular
459 character count, to 'unlimited' to print all characters of a string,
460 or to 'elements', which is also the default, to follow the setting of
461 'set print elements' as it used to be.
463 print -characters LIMIT
464 This new option to the 'print' command has the same effect as a temporary
465 use of 'set print characters'.
469 document user-defined
470 It is now possible to document user-defined aliases.
471 When a user-defined alias is documented, the help and apropos commands
472 use the provided documentation instead of the documentation of the
474 Documenting a user-defined alias is particularly useful when the alias
475 is a set of nested 'with' commands to avoid showing the help of
476 the with command for an alias that will in fact launch the
477 last command given in the nested commands.
479 maintenance info line-table
480 Add a PROLOGUE-END column to the output which indicates that an
481 entry corresponds to an address where a breakpoint should be placed
482 to be at the first instruction past a function's prologue.
486 set debug aix-solib on|off
488 set debug solib-frv on|off
490 Removed in favor of "set/show debug solib".
492 maintenance info program-spaces
493 This command now includes a 'Core File' column which indicates the
494 name of the core file associated with each program space.
498 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
500 GNU/Linux/CSKY (gdbserver) csky*-*linux*
506 ** The async record stating the stopped reason 'breakpoint-hit' now
507 contains an optional field locno giving the code location number
508 when the breakpoint has multiple code locations.
512 ** GDB will now reformat the doc string for gdb.Command and
513 gdb.Parameter sub-classes to remove unnecessary leading
514 whitespace from each line before using the string as the help
517 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
518 that formats ADDRESS as 'address <symbol+offset>', where symbol is
519 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
520 This is the same format that GDB uses when printing address, symbol,
521 and offset information from the disassembler.
523 ** New function gdb.current_language that returns the name of the
524 current language. Unlike gdb.parameter('language'), this will
527 ** New method gdb.Frame.language that returns the name of the
530 ** New Python API for wrapping GDB's disassembler:
532 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
533 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
534 ARCH is either None or a string containing a bfd architecture
535 name. DISASSEMBLER is registered as a disassembler for
536 architecture ARCH, or for all architectures if ARCH is None.
537 The previous disassembler registered for ARCH is returned, this
538 can be None if no previous disassembler was registered.
540 - gdb.disassembler.Disassembler is the class from which all
541 disassemblers should inherit. Its constructor takes a string,
542 a name for the disassembler, which is currently only used in
543 some debug output. Sub-classes should override the __call__
544 method to perform disassembly, invoking __call__ on this base
545 class will raise an exception.
547 - gdb.disassembler.DisassembleInfo is the class used to describe
548 a single disassembly request from GDB. An instance of this
549 class is passed to the __call__ method of
550 gdb.disassembler.Disassembler and has the following read-only
551 attributes: 'address', and 'architecture', as well as the
552 following method: 'read_memory'.
554 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
555 calls GDB's builtin disassembler on INFO, which is a
556 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
557 optional, its default value is None. If MEMORY_SOURCE is not
558 None then it must be an object that has a 'read_memory' method.
560 - gdb.disassembler.DisassemblerResult is a class that can be used
561 to wrap the result of a call to a Disassembler. It has
562 read-only attributes 'length' and 'string'.
564 ** gdb.Objfile now has an attribute named "is_file". This is True
565 if the objfile comes from a file, and False otherwise.
567 ** New function gdb.print_options that returns a dictionary of the
568 prevailing print options, in the form accepted by
569 gdb.Value.format_string.
571 ** gdb.Value.format_string now uses the format provided by 'print',
572 if it is called during a 'print' or other similar operation.
574 ** gdb.Value.format_string now accepts the 'summary' keyword. This
575 can be used to request a shorter representation of a value, the
576 way that 'set print frame-arguments scalars' does.
578 ** New Python type gdb.BreakpointLocation.
579 The new attribute 'locations' of gdb.Breakpoint returns a list of
580 gdb.BreakpointLocation objects specifying the locations where the
581 breakpoint is inserted into the debuggee.
583 ** The gdb.register_window_type method now restricts the set of
584 acceptable window names. The first character of a window's name
585 must start with a character in the set [a-zA-Z], every subsequent
586 character of a window's name must be in the set [-_.a-zA-Z0-9].
588 * New features in the GDB remote stub, GDBserver
590 ** GDBserver is now supported on LoongArch GNU/Linux.
592 ** GDBserver is now supported on CSKY GNU/Linux.
594 * LoongArch floating-point support
596 GDB now supports floating-point on LoongArch GNU/Linux.
598 * AMD GPU ROCm debugging support
600 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
603 *** Changes in GDB 12
605 * DBX mode is deprecated, and will be removed in GDB 13
607 * GDB 12 is the last release of GDB that will support building against
608 Python 2. From GDB 13, it will only be possible to build GDB itself
609 with Python 3 support.
611 * The disable-randomization setting now works on Windows.
613 * Improved C++ template support
615 GDB now treats functions/types involving C++ templates like it does function
616 overloads. Users may omit parameter lists to set breakpoints on families of
617 template functions, including types/functions composed of multiple template types:
619 (gdb) break template_func(template_1, int)
621 The above will set breakpoints at every function `template_func' where
622 the first function parameter is any template type named `template_1' and
623 the second function parameter is `int'.
625 TAB completion also gains similar improvements.
627 * The FreeBSD native target now supports async mode.
633 Enable or disable multithreaded symbol loading. This is enabled
634 by default, but passing --disable-threading or --enable-threading=no
635 to configure will disable it.
637 Disabling this can cause a performance penalty when there are a lot of
638 symbols to load, but is useful for debugging purposes.
642 maint set backtrace-on-fatal-signal on|off
643 maint show backtrace-on-fatal-signal
644 This setting is 'on' by default. When 'on' GDB will print a limited
645 backtrace to stderr in the situation where GDB terminates with a
646 fatal signal. This only supported on some platforms where the
647 backtrace and backtrace_symbols_fd functions are available.
649 set source open on|off
651 This setting, which is on by default, controls whether GDB will try
652 to open source code files. Switching this off will stop GDB trying
653 to open and read source code files, which can be useful if the files
654 are located over a slow network connection.
658 These are now deprecated aliases for "set max-value-size" and
659 "show max-value-size".
661 task apply [all | TASK-IDS...] [FLAG]... COMMAND
662 Like "thread apply", but applies COMMAND to Ada tasks.
665 Watchpoints can now be restricted to a specific Ada task.
667 maint set internal-error backtrace on|off
668 maint show internal-error backtrace
669 maint set internal-warning backtrace on|off
670 maint show internal-warning backtrace
671 GDB can now print a backtrace of itself when it encounters either an
672 internal-error, or an internal-warning. This is on by default for
673 internal-error and off by default for internal-warning.
676 Deprecated and replaced by "set logging enabled on|off".
678 set logging enabled on|off
680 These commands set or show whether logging is enabled or disabled.
683 You can now exit GDB by using the new command "exit", in addition to
684 the existing "quit" command.
686 set debug threads on|off
688 Print additional debug messages about thread creation and deletion.
690 set debug linux-nat on|off
692 These new commands replaced the old 'set debug lin-lwp' and 'show
693 debug lin-lwp' respectively. Turning this setting on prints debug
694 messages relating to GDB's handling of native Linux inferiors.
696 maint flush source-cache
697 Flush the contents of the source code cache.
699 maint set gnu-source-highlight enabled on|off
700 maint show gnu-source-highlight enabled
701 Whether GDB should use the GNU Source Highlight library for adding
702 styling to source code. When off, the library will not be used, even
703 when available. When GNU Source Highlight isn't used, or can't add
704 styling to a particular source file, then the Python Pygments
705 library will be used instead.
707 set suppress-cli-notifications (on|off)
708 show suppress-cli-notifications
709 This controls whether printing the notifications is suppressed for CLI.
710 CLI notifications occur when you change the selected context
711 (i.e., the current inferior, thread and/or the frame), or when
712 the program being debugged stops (e.g., because of hitting a
713 breakpoint, completing source-stepping, an interrupt, etc.).
715 set style disassembler enabled on|off
716 show style disassembler enabled
717 If GDB is compiled with Python support, and the Python Pygments
718 package is available, then, when this setting is on, disassembler
719 output will have styling applied.
721 set ada source-charset
722 show ada source-charset
723 Set the character set encoding that is assumed for Ada symbols. Valid
724 values for this follow the values that can be passed to the GNAT
725 compiler via the '-gnati' option. The default is ISO-8859-1.
731 These are the new names for the old 'layout', 'focus', 'refresh',
732 and 'winheight' tui commands respectively. The old names still
733 exist as aliases to these new commands.
737 The new command 'tui window width', and the alias 'winwidth' allow
738 the width of a tui window to be adjusted when windows are laid out
743 Control the display of debug output about GDB's tui.
748 Printing of floating-point values with base-modifying formats like
749 /x has been changed to display the underlying bytes of the value in
750 the desired base. This was GDB's documented behavior, but was never
751 implemented correctly.
754 This command can now print a reply, if the reply includes
755 non-printable characters. Any non-printable characters are printed
756 as escaped hex, e.g. \x?? where '??' is replaces with the value of
757 the non-printable character.
760 The clone-inferior command now ensures that the TTY, CMD and ARGS
761 settings are copied from the original inferior to the new one.
762 All modifications to the environment variables done using the 'set
763 environment' or 'unset environment' commands are also copied to the new
766 set debug lin-lwp on|off
768 These commands have been removed from GDB. The new command 'set
769 debug linux-nat' and 'show debug linux-nat' should be used
773 This command now includes information about the width of the tui
774 windows in its output.
780 These commands are now aliases for the 'tui layout', 'tui focus',
781 'tui refresh', and 'tui window height' commands respectively.
783 * GDB's Ada parser now supports an extension for specifying the exact
784 byte contents of a floating-point literal. This can be useful for
785 setting floating-point registers to a precise value without loss of
786 precision. The syntax is an extension of the based literal syntax.
787 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
788 of the floating-point type, and the "f" is the marker for floating
793 ** The '-add-inferior' with no option flags now inherits the
794 connection of the current inferior, this restores the behaviour of
795 GDB as it was prior to GDB 10.
797 ** The '-add-inferior' command now accepts a '--no-connection'
798 option, which causes the new inferior to start without a
801 ** The default version of the MI interpreter is now 4 (-i=mi4).
803 ** The "script" field in breakpoint output (which is syntactically
804 incorrect in MI 3 and below) has changed in MI 4 to become a list.
805 This affects the following commands and events:
809 - =breakpoint-created
810 - =breakpoint-modified
812 The -fix-breakpoint-script-output command can be used to enable
813 this behavior with previous MI versions.
817 GNU/Linux/LoongArch loongarch*-*-linux*
825 ** New function gdb.add_history(), which takes a gdb.Value object
826 and adds the value it represents to GDB's history list. An
827 integer, the index of the new item in the history list, is
830 ** New function gdb.history_count(), which returns the number of
831 values in GDB's value history.
833 ** New gdb.events.gdb_exiting event. This event is called with a
834 gdb.GdbExitingEvent object which has the read-only attribute
835 'exit_code', which contains the value of the GDB exit code. This
836 event is triggered once GDB decides it is going to exit, but
837 before GDB starts to clean up its internal state.
839 ** New function gdb.architecture_names(), which returns a list
840 containing all of the possible Architecture.name() values. Each
843 ** New function gdb.Architecture.integer_type(), which returns an
844 integer type given a size and a signed-ness.
846 ** New gdb.TargetConnection object type that represents a connection
847 (as displayed by the 'info connections' command). A sub-class,
848 gdb.RemoteTargetConnection, is used to represent 'remote' and
849 'extended-remote' connections.
851 ** The gdb.Inferior type now has a 'connection' property which is an
852 instance of gdb.TargetConnection, the connection used by this
853 inferior. This can be None if the inferior has no connection.
855 ** New 'gdb.events.connection_removed' event registry, which emits a
856 'gdb.ConnectionEvent' when a connection is removed from GDB.
857 This event has a 'connection' property, a gdb.TargetConnection
858 object for the connection being removed.
860 ** New gdb.connections() function that returns a list of all
861 currently active connections.
863 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
864 is equivalent to the existing 'maint packet' CLI command; it
865 allows a user specified packet to be sent to the remote target.
867 ** New function gdb.host_charset(), returns a string, which is the
868 name of the current host charset.
870 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
873 ** New gdb.with_parameter(NAME, VALUE). This returns a context
874 manager that temporarily sets the gdb parameter NAME to VALUE,
875 then resets it when the context is exited.
877 ** The gdb.Value.format_string method now takes a 'styling'
878 argument, which is a boolean. When true, the returned string can
879 include escape sequences to apply styling. The styling will only
880 be present if styling is otherwise turned on in GDB (see 'help
881 set styling'). When false, which is the default if the argument
882 is not given, then no styling is applied to the returned string.
884 ** New read-only attribute gdb.InferiorThread.details, which is
885 either a string, containing additional, target specific thread
886 state information, or None, if there is no such additional
889 ** New read-only attribute gdb.Type.is_scalar, which is True for
890 scalar types, and False for all other types.
892 ** New read-only attribute gdb.Type.is_signed. This attribute
893 should only be read when Type.is_scalar is True, and will be True
894 for signed types, and False for all other types. Attempting to
895 read this attribute for non-scalar types will raise a ValueError.
897 ** It is now possible to add GDB/MI commands implemented in Python.
899 * New features in the GDB remote stub, GDBserver
901 ** GDBserver is now supported on OpenRISC GNU/Linux.
903 * New native configurations
905 GNU/Linux/OpenRISC or1k*-*-linux*
907 *** Changes in GDB 11
909 * The 'set disassembler-options' command now supports specifying options
912 * GDB now supports general memory tagging functionality if the underlying
913 architecture supports the proper primitives and hooks. Currently this is
914 enabled only for AArch64 MTE.
918 - Additional information when the inferior crashes with a SIGSEGV caused by
919 a memory tag violation.
921 - A new modifier 'm' for the "x" command, which displays allocation tags for a
922 particular memory range.
924 - Display of memory tag mismatches by "print", for addresses and
925 pointers, if memory tagging is supported by the architecture.
927 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
932 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
934 The MI -break-insert and -dprintf-insert commands now support a
935 new "--qualified" option that makes GDB interpret a specified
936 function name as a complete fully-qualified name. This is the
937 equivalent of the CLI's "break -qualified" and "dprintf
940 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
942 The MI -break-insert and -dprintf-insert commands now support a
943 '--force-condition' flag to forcibly define a condition even when
944 the condition is invalid at all locations of the breakpoint. This
945 is equivalent to the '-force-condition' flag of the CLI's "break"
948 ** '-break-condition --force'
950 The MI -break-condition command now supports a '--force' flag to
951 forcibly define a condition even when the condition is invalid at
952 all locations of the selected breakpoint. This is equivalent to
953 the '-force' flag of the CLI's "cond" command.
955 ** '-file-list-exec-source-files [--group-by-objfile]
956 [--basename | --dirname]
959 The existing -file-list-exec-source-files command now takes an
960 optional REGEXP which is used to filter the source files that are
961 included in the results.
963 By default REGEXP is matched against the full filename of the
964 source file. When one of --basename or --dirname is given then
965 REGEXP is only matched against the specified part of the full
968 When the optional --group-by-objfile flag is used the output
969 format is changed, the results are now a list of object files
970 (executable and libraries) with the source files that are
971 associated with each object file.
973 The results from -file-list-exec-source-files now include a
974 'debug-fully-read' field which takes the value 'true' or 'false'.
975 A 'true' value indicates the source file is from a compilation
976 unit that has had its debug information fully read in by GDB, a
977 value of 'false' indicates GDB has only performed a partial scan
978 of the debug information so far.
980 * GDB now supports core file debugging for x86_64 Cygwin programs.
982 * GDB will now look for the .gdbinit file in a config directory before
983 looking for ~/.gdbinit. The file is searched for in the following
984 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
985 $HOME/.gdbinit. On Apple hosts the search order is instead:
986 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
988 * GDB now supports fixed point types which are described in DWARF
989 as base types with a fixed-point encoding. Additionally, support
990 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
993 For Ada, this allows support for fixed point types without requiring
994 the use of the GNAT encoding (based on information added to the type's
995 name following a GNAT-specific format).
997 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
998 or ~/.gdbearlyinit if these files are present. These files are
999 processed earlier than any of the other initialization files and
1000 can affect parts of GDB's startup that previously had already been
1001 completed before the initialization files were read, for example
1002 styling of the initial GDB greeting.
1004 * GDB now has two new options "--early-init-command" and
1005 "--early-init-eval-command" with corresponding short options "-eix"
1006 and "-eiex" that allow options (that would normally appear in a
1007 gdbearlyinit file) to be passed on the command line.
1009 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1010 now understood by GDB, and can be used to describe the vector
1011 registers of a target. The precise requirements of this register
1012 feature are documented in the GDB manual.
1014 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1015 supported by GDB and describes a new VPR register from the ARM MVE
1016 (Helium) extension. See the GDB manual for more information.
1020 ** TUI windows now support mouse actions. The mouse wheel scrolls
1021 the appropriate window.
1023 ** Key combinations that do not have a specific action on the
1024 focused window are passed to GDB. For example, you now can use
1025 Ctrl-Left/Ctrl-Right to move between words in the command window
1026 regardless of which window is in focus. Previously you would
1027 need to focus on the command window for such key combinations to
1032 set debug event-loop
1033 show debug event-loop
1034 Control the display of debug output about GDB's event loop.
1036 set print memory-tag-violations
1037 show print memory-tag-violations
1038 Control whether to display additional information about memory tag violations
1039 when printing pointers and addresses. Architecture support for memory
1040 tagging is required for this option to have an effect.
1042 maintenance flush symbol-cache
1043 maintenance flush register-cache
1044 These new commands are equivalent to the already existing commands
1045 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1047 maintenance flush dcache
1048 A new command to flush the dcache.
1050 maintenance info target-sections
1051 Print GDB's internal target sections table.
1053 maintenance info jit
1054 Print the JIT code objects in the inferior known to GDB.
1056 memory-tag show-logical-tag POINTER
1057 Print the logical tag for POINTER.
1058 memory-tag with-logical-tag POINTER TAG
1059 Print POINTER with logical tag TAG.
1060 memory-tag show-allocation-tag ADDRESS
1061 Print the allocation tag for ADDRESS.
1062 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1063 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1064 memory-tag check POINTER
1065 Validate that POINTER's logical tag matches the allocation tag.
1067 set startup-quietly on|off
1068 show startup-quietly
1069 When 'on', this causes GDB to act as if "-silent" were passed on the
1070 command line. This command needs to be added to an early
1071 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1074 set print type hex on|off
1076 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1077 and offsets of struct members. When 'off', decimal notation is used.
1079 set python ignore-environment on|off
1080 show python ignore-environment
1081 When 'on', this causes GDB's builtin Python to ignore any
1082 environment variables that would otherwise affect how Python
1083 behaves. This command needs to be added to an early initialization
1084 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1086 set python dont-write-bytecode auto|on|off
1087 show python dont-write-bytecode
1088 When 'on', this causes GDB's builtin Python to not write any
1089 byte-code (.pyc files) to disk. This command needs to be added to
1090 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1091 order to affect GDB. When 'off' byte-code will always be written.
1092 When set to 'auto' (the default) Python will check the
1093 PYTHONDONTWRITEBYTECODE environment variable.
1097 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1098 [-force-condition] [if CONDITION]
1099 This command would previously refuse setting a breakpoint if the
1100 CONDITION expression is invalid at a location. It now accepts and
1101 defines the breakpoint if there is at least one location at which
1102 the CONDITION is valid. The locations for which the CONDITION is
1103 invalid, are automatically disabled. If CONDITION is invalid at all
1104 of the locations, setting the breakpoint is still rejected. However,
1105 the '-force-condition' flag can be used in this case for forcing GDB to
1106 define the breakpoint, making all the current locations automatically
1107 disabled. This may be useful if the user knows the condition will
1108 become meaningful at a future location, e.g. due to a shared library
1111 condition [-force] N COND
1112 The behavior of this command is changed the same way for the 'break'
1113 command as explained above. The '-force' flag can be used to force
1114 GDB into defining the condition even when COND is invalid for all the
1115 current locations of breakpoint N.
1118 maintenance flush-symbol-cache
1119 These commands are deprecated in favor of the new commands
1120 'maintenance flush register-cache' and 'maintenance flush
1121 symbol-cache' respectively.
1123 set style version foreground COLOR
1124 set style version background COLOR
1125 set style version intensity VALUE
1126 Control the styling of GDB's version number text.
1129 When the ID parameter is omitted, then this command prints information
1130 about the current inferior. When the ID parameter is present, the
1131 behavior of the command is unchanged and have the inferior ID become
1132 the current inferior.
1134 maintenance info sections
1135 The ALLOBJ keyword has been replaced with an -all-objects command
1136 line flag. It is now possible to filter which sections are printed
1137 even when -all-objects is passed.
1139 ptype[/FLAGS] TYPE | EXPRESSION
1140 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1141 notation is used when printing sizes and offsets of struct members.
1142 When '/d' is set, decimal notation is used when printing sizes and
1143 offsets of struct members. Default behavior is given by 'show print
1147 The info sources command output has been restructured. The results
1148 are now based around a list of objfiles (executable and libraries),
1149 and for each objfile the source files that are part of that objfile
1152 * Removed targets and native configurations
1154 ARM Symbian arm*-*-symbianelf*
1156 * New remote packets
1159 Request the remote to send allocation tags for a particular memory range.
1161 Request the remote to store the specified allocation tags to the requested
1166 ** Improved support for rvalue reference values:
1167 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1168 value-referenced-value procedure now handles rvalue reference
1171 ** New procedures for obtaining value variants:
1172 value-reference-value, value-rvalue-reference-value and
1175 ** Temporary breakpoints can now be created with make-breakpoint and
1176 tested for using breakpoint-temporary?.
1180 ** Inferior objects now contain a read-only 'connection_num' attribute that
1181 gives the connection number as seen in 'info connections' and
1184 ** New method gdb.Frame.level() which returns the stack level of the
1187 ** New method gdb.PendingFrame.level() which returns the stack level
1188 of the frame object.
1190 ** When hitting a catchpoint, the Python API will now emit a
1191 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1192 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1194 ** Python TUI windows can now receive mouse click events. If the
1195 Window object implements the click method, it is called for each
1196 mouse click event in this window.
1198 *** Changes in GDB 10
1200 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1201 and "org.gnu.gdb.arc.aux". The old names are still supported but
1202 must be considered obsolete. They will be deprecated after some
1205 * Help and apropos commands will now show the documentation of a
1206 command only once, even if that command has one or more aliases.
1207 These commands now show the command name, then all of its aliases,
1208 and finally the description of the command.
1210 * 'help aliases' now shows only the user defined aliases. GDB predefined
1211 aliases are shown together with their aliased command.
1213 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1214 debugging information as well as source code.
1216 When built with debuginfod, GDB can automatically query debuginfod
1217 servers for the separate debug files and source code of the executable
1220 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1221 requires libdebuginfod, the debuginfod client library).
1223 debuginfod is distributed with elfutils, starting with version 0.178.
1225 You can get the latest version from https://sourceware.org/elfutils.
1227 * Multi-target debugging support
1229 GDB now supports debugging multiple target connections
1230 simultaneously. For example, you can now have each inferior
1231 connected to different remote servers running in different machines,
1232 or have one inferior debugging a local native process, an inferior
1233 debugging a core dump, etc.
1235 This support is experimental and comes with some limitations -- you
1236 can only resume multiple targets simultaneously if all targets
1237 support non-stop mode, and all remote stubs or servers must support
1238 the same set of remote protocol features exactly. See also "info
1239 connections" and "add-inferior -no-connection" below, and "maint set
1240 target-non-stop" in the user manual.
1242 * New features in the GDB remote stub, GDBserver
1244 ** GDBserver is now supported on ARC GNU/Linux.
1246 ** GDBserver is now supported on RISC-V GNU/Linux.
1248 ** GDBserver no longer supports these host triplets:
1250 i[34567]86-*-lynxos*
1259 i[34567]86-*-mingw32ce*
1261 * Debugging MS-Windows processes now sets $_exitsignal when the
1262 inferior is terminated by a signal, instead of setting $_exitcode.
1264 * Multithreaded symbol loading has now been enabled by default on systems
1265 that support it (see entry for GDB 9, below), providing faster
1266 performance for programs with many symbols.
1268 * The $_siginfo convenience variable now also works on Windows targets,
1269 and will display the EXCEPTION_RECORD of the last handled exception.
1271 * TUI windows can now be arranged horizontally.
1273 * The command history filename can now be set to the empty string
1274 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1275 the environment. The effect of setting this filename to the empty
1276 string is that GDB will not try to load any previous command
1279 * On Windows targets, it is now possible to debug 32-bit programs with a
1284 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1285 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1286 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1287 running process, this new option indicates whether to detect
1288 a mismatch between the current executable file loaded by GDB and the
1289 executable file used to start the process. If 'ask', the default,
1290 display a warning and ask the user whether to load the process
1291 executable file; if 'warn', just display a warning; if 'off', don't
1292 attempt to detect a mismatch.
1294 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1295 Define a new TUI layout, specifying its name and the windows that
1298 maintenance print xml-tdesc [FILE]
1299 Prints the current target description as an XML document. If the
1300 optional FILE is provided (which is an XML target description) then
1301 the target description is read from FILE into GDB, and then
1304 maintenance print core-file-backed-mappings
1305 Prints file-backed mappings loaded from a core file's note section.
1306 Output is expected to be similar to that of "info proc mappings".
1308 set debug fortran-array-slicing on|off
1309 show debug fortran-array-slicing
1310 Print debugging when taking slices of Fortran arrays.
1312 set fortran repack-array-slices on|off
1313 show fortran repack-array-slices
1314 When taking slices from Fortran arrays and strings, if the slice is
1315 non-contiguous within the original value then, when this option is
1316 on, the new value will be repacked into a single contiguous value.
1317 When this option is off, then the value returned will consist of a
1318 descriptor that describes the slice within the memory of the
1319 original parent value.
1323 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1324 The alias command can now specify default args for an alias.
1325 GDB automatically prepends the alias default args to the argument list
1326 provided explicitly by the user.
1327 For example, to have a backtrace with full details, you can define
1328 an alias 'bt_ALL' as
1329 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1330 -past-main -past-entry -full'.
1331 Alias default arguments can also use a set of nested 'with' commands,
1332 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1333 defines the alias pp10 that will pretty print a maximum of 10 elements
1334 of the given expression (if the expression is an array).
1338 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1339 BPF bpf-unknown-none
1344 ** gdb.register_window_type can be used to implement new TUI windows
1347 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1348 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1349 field of a dynamic type may have None for its "bitpos" attribute
1352 ** Commands written in Python can be in the "TUI" help class by
1353 registering with the new constant gdb.COMMAND_TUI.
1355 ** New method gdb.PendingFrame.architecture () to retrieve the
1356 architecture of the pending frame.
1358 ** New gdb.Architecture.registers method that returns a
1359 gdb.RegisterDescriptorIterator object, an iterator that returns
1360 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1361 way to query the registers available for an architecture.
1363 ** New gdb.Architecture.register_groups method that returns a
1364 gdb.RegisterGroupIterator object, an iterator that returns
1365 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1366 discover the available register groups.
1370 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1372 ** Procedures 'memory-port-read-buffer-size',
1373 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1374 and 'set-memory-port-write-buffer-size!' are deprecated. When
1375 using Guile 2.2 and later, users who need to control the size of
1376 a memory port's internal buffer can use the 'setvbuf' procedure.
1378 *** Changes in GDB 9
1380 * 'thread-exited' event is now available in the annotations interface.
1382 * New built-in convenience variables $_gdb_major and $_gdb_minor
1383 provide the GDB version. They are handy for conditionally using
1384 features available only in or since specific GDB versions, in
1385 scripts that should work error-free with many different versions,
1386 such as in system-wide init files.
1388 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1389 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1390 of the GDB settings and the GDB maintenance settings. They are handy
1391 for changing the logic of user defined commands depending on the
1392 current GDB settings.
1394 * GDB now supports Thread Local Storage (TLS) variables on several
1395 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1396 architectures require kernel changes. TLS is not yet supported for
1397 amd64 and i386 process core dumps.
1399 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1400 addresses that required unmasking are shown in the backtrace with the
1403 * Two new convenience functions $_cimag and $_creal that extract the
1404 imaginary and real parts respectively from complex numbers.
1406 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1407 provide the exitcode or exit status of the shell commands launched by
1408 GDB commands such as "shell", "pipe" and "make".
1410 * The command define-prefix can now define user defined prefix commands.
1411 User defined commands can now be defined using these user defined prefix
1414 * Command names can now use the . character.
1416 * The RX port now supports XML target descriptions.
1418 * GDB now shows the Ada task names at more places, e.g. in task switching
1421 * GDB can now be compiled with Python 3 on Windows.
1423 * New convenience variable $_ada_exception holds the address of the
1424 Ada exception being thrown. This is set by Ada-related catchpoints.
1426 * GDB can now place breakpoints on nested functions and subroutines in
1427 Fortran code. The '::' operator can be used between parent and
1428 child scopes when placing breakpoints, for example:
1430 (gdb) break outer_function::inner_function
1432 The 'outer_function::' prefix is only needed if 'inner_function' is
1433 not visible in the current scope.
1435 * In addition to the system-wide gdbinit file, if configured with
1436 --with-system-gdbinit-dir, GDB will now also load files in that directory
1437 as system gdbinit files, unless the -nx or -n flag is provided. Files
1438 with extensions .gdb, .py and .scm are supported as long as GDB was
1439 compiled with support for that language.
1441 * GDB now supports multithreaded symbol loading for higher performance.
1442 This feature is still in testing, so it is disabled by default. You
1443 can turn it on using 'maint set worker-threads unlimited'.
1447 ** The gdb.Value type has a new method 'format_string' which returns a
1448 string representing the value. The formatting is controlled by the
1449 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1450 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1451 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1453 ** gdb.Type has a new property 'objfile' which returns the objfile the
1454 type was defined in.
1456 ** The frame information printed by the python frame filtering code
1457 is now consistent with what the 'backtrace' command prints when
1458 there are no filters, or when the 'backtrace' '-no-filters' option
1461 ** The new function gdb.lookup_static_symbol can be used to look up
1462 symbols with static linkage.
1464 ** The new function gdb.lookup_static_symbols can be used to look up
1465 all static symbols with static linkage.
1467 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1468 'lookup_static_symbol' to lookup a symbol from this objfile only.
1470 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1471 this block (e.g. block['local_variable']).
1475 | [COMMAND] | SHELL_COMMAND
1476 | -d DELIM COMMAND DELIM SHELL_COMMAND
1477 pipe [COMMAND] | SHELL_COMMAND
1478 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1479 Executes COMMAND and sends its output to SHELL_COMMAND.
1480 With no COMMAND, repeat the last executed command
1481 and send its output to SHELL_COMMAND.
1483 define-prefix COMMAND
1484 Define or mark a command as a user-defined prefix command.
1486 with SETTING [VALUE] [-- COMMAND]
1487 w SETTING [VALUE] [-- COMMAND]
1488 Temporarily set SETTING, run COMMAND, and restore SETTING.
1489 Usage: with SETTING -- COMMAND
1490 With no COMMAND, repeats the last executed command.
1491 SETTING is any GDB setting you can change with the "set"
1492 subcommands. For example, 'with language c -- print someobj'
1493 temporarily switches to the C language in order to print someobj.
1494 Settings can be combined: 'w lang c -- w print elements unlimited --
1495 usercmd' switches to the C language and runs usercmd with no limit
1496 of array elements to print.
1498 maint with SETTING [VALUE] [-- COMMAND]
1499 Like "with", but works with "maintenance set" settings.
1501 set may-call-functions [on|off]
1502 show may-call-functions
1503 This controls whether GDB will attempt to call functions in
1504 the program, such as with expressions in the print command. It
1505 defaults to on. Calling functions in the program being debugged
1506 can have undesired side effects. It is now possible to forbid
1507 such function calls. If function calls are forbidden, GDB will throw
1508 an error when a command (such as print expression) calls a function
1511 set print finish [on|off]
1513 This controls whether the `finish' command will display the value
1514 that is returned by the current function. When `off', the value is
1515 still entered into the value history, but it is not printed. The
1519 show print max-depth
1520 Allows deeply nested structures to be simplified when printing by
1521 replacing deeply nested parts (beyond the max-depth) with ellipses.
1522 The default max-depth is 20, but this can be set to unlimited to get
1523 the old behavior back.
1525 set print raw-values [on|off]
1526 show print raw-values
1527 By default, GDB applies the enabled pretty printers when printing a
1528 value. This allows to ignore the enabled pretty printers for a series
1529 of commands. The default is 'off'.
1531 set logging debugredirect [on|off]
1532 By default, GDB debug output will go to both the terminal and the logfile.
1533 Set if you want debug output to go only to the log file.
1535 set style title foreground COLOR
1536 set style title background COLOR
1537 set style title intensity VALUE
1538 Control the styling of titles.
1540 set style highlight foreground COLOR
1541 set style highlight background COLOR
1542 set style highlight intensity VALUE
1543 Control the styling of highlightings.
1545 maint set worker-threads
1546 maint show worker-threads
1547 Control the number of worker threads that can be used by GDB. The
1548 default is 0. "unlimited" lets GDB choose a number that is
1549 reasonable. Currently worker threads are only used when demangling
1550 the names of linker symbols.
1552 set style tui-border foreground COLOR
1553 set style tui-border background COLOR
1554 Control the styling of TUI borders.
1556 set style tui-active-border foreground COLOR
1557 set style tui-active-border background COLOR
1558 Control the styling of the active TUI border.
1560 maint set test-settings KIND
1561 maint show test-settings KIND
1562 A set of commands used by the testsuite for exercising the settings
1565 maint set tui-resize-message [on|off]
1566 maint show tui-resize-message
1567 Control whether GDB prints a message each time the terminal is
1568 resized when in TUI mode. This is primarily useful for testing the
1571 set print frame-info [short-location|location|location-and-address
1572 |source-and-location|source-line|auto]
1573 show print frame-info
1574 This controls what frame information is printed by the commands printing
1575 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1576 'frame', 'stepi'. The python frame filtering also respect this setting.
1577 The 'backtrace' '-frame-info' option can override this global setting.
1579 set tui compact-source
1580 show tui compact-source
1582 Enable the "compact" display mode for the TUI source window. The
1583 compact display uses only as much space as is needed for the line
1584 numbers in the current file, and only a single space to separate the
1585 line numbers from the source.
1587 info modules [-q] [REGEXP]
1588 Return a list of Fortran modules matching REGEXP, or all modules if
1591 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1592 Return a list of functions within all modules, grouped by module.
1593 The list of functions can be restricted with the optional regular
1594 expressions. MODULE_REGEXP matches against the module name,
1595 TYPE_REGEXP matches against the function type signature, and REGEXP
1596 matches against the function name.
1598 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1599 Return a list of variables within all modules, grouped by module.
1600 The list of variables can be restricted with the optional regular
1601 expressions. MODULE_REGEXP matches against the module name,
1602 TYPE_REGEXP matches against the variable type, and REGEXP matches
1603 against the variable name.
1605 set debug remote-packet-max-chars
1606 show debug remote-packet-max-chars
1607 Controls the number of characters to output in a remote packet when using
1609 The default is 512 bytes.
1612 Lists the target connections currently in use.
1617 The "help" command uses the title style to enhance the
1618 readibility of its output by styling the classes and
1622 Similarly to "help", the "apropos" command also uses the
1623 title style for the command names. "apropos" accepts now
1624 a flag "-v" (verbose) to show the full documentation
1625 of matching commands and to use the highlight style to mark
1626 the documentation parts matching REGEXP.
1630 The GDB printf and eval commands can now print C-style and Ada-style
1631 string convenience variables without calling functions in the program.
1632 This allows to do formatted printing of strings without having
1633 a running inferior, or when debugging a core dump.
1635 info sources [-dirname | -basename] [--] [REGEXP]
1636 This command has now optional arguments to only print the files
1637 whose names match REGEXP. The arguments -dirname and -basename
1638 allow to restrict matching respectively to the dirname and basename
1642 The "show style" and its subcommands are now styling
1643 a style name in their output using its own style, to help
1644 the user visualize the different styles.
1646 set print frame-arguments
1647 The new value 'presence' indicates to only indicate the presence of
1648 arguments using ..., instead of printing argument names and values.
1650 set print raw-frame-arguments
1651 show print raw-frame-arguments
1653 These commands replace the similarly-named "set/show print raw
1654 frame-arguments" commands (now with a dash instead of a space). The
1655 old commands are now deprecated and may be removed in a future
1658 add-inferior [-no-connection]
1659 The add-inferior command now supports a "-no-connection" flag that
1660 makes the new inferior start with no target connection associated.
1661 By default, the new inferior inherits the target connection of the
1662 current inferior. See also "info connections".
1665 This command's output now includes a new "Connection" column
1666 indicating which target connection an inferior is bound to. See
1667 "info connections" above.
1669 maint test-options require-delimiter
1670 maint test-options unknown-is-error
1671 maint test-options unknown-is-operand
1672 maint show test-options-completion-result
1673 Commands used by the testsuite to validate the command options
1676 focus, winheight, +, -, >, <
1677 These commands are now case-sensitive.
1679 * New command options, command completion
1681 GDB now has a standard infrastructure to support dash-style command
1682 options ('-OPT'). One benefit is that commands that use it can
1683 easily support completion of command line arguments. Try "CMD
1684 -[TAB]" or "help CMD" to find options supported by a command. Over
1685 time, we intend to migrate most commands to this infrastructure. A
1686 number of commands got support for new command options in this
1689 ** The "print" and "compile print" commands now support a number of
1690 options that allow overriding relevant global print settings as
1691 set by "set print" subcommands:
1695 -array-indexes [on|off]
1696 -elements NUMBER|unlimited
1700 -raw-values [on|off]
1701 -repeats NUMBER|unlimited
1702 -static-members [on|off]
1707 Note that because the "print"/"compile print" commands accept
1708 arbitrary expressions which may look like options (including
1709 abbreviations), if you specify any command option, then you must
1710 use a double dash ("--") to mark the end of argument processing.
1712 ** The "backtrace" command now supports a number of options that
1713 allow overriding relevant global print settings as set by "set
1714 backtrace" and "set print" subcommands:
1716 -entry-values no|only|preferred|if-needed|both|compact|default
1717 -frame-arguments all|scalars|none
1718 -raw-frame-arguments [on|off]
1719 -frame-info auto|source-line|location|source-and-location
1720 |location-and-address|short-location
1722 -past-entry [on|off]
1724 In addition, the full/no-filters/hide qualifiers are now also
1725 exposed as command options too:
1731 ** The "frame apply", "tfaas" and "faas" commands similarly now
1732 support the following options:
1735 -past-entry [on|off]
1737 ** The new "info sources" options -dirname and -basename options
1738 are using the standard '-OPT' infrastructure.
1740 All options above can also be abbreviated. The argument of boolean
1741 (on/off) options can be 0/1 too, and also the argument is assumed
1742 "on" if omitted. This allows writing compact command invocations,
1745 (gdb) p -ra -p -o 0 -- *myptr
1747 The above is equivalent to:
1749 (gdb) print -raw-values -pretty -object off -- *myptr
1751 ** The "info types" command now supports the '-q' flag to disable
1752 printing of some header information in a similar fashion to "info
1753 variables" and "info functions".
1755 ** The "info variables", "info functions", and "whereis" commands
1756 now take a '-n' flag that excludes non-debug symbols (symbols
1757 from the symbol table, not from the debug info such as DWARF)
1760 * Completion improvements
1762 ** GDB can now complete the options of the "thread apply all" and
1763 "taas" commands, and their "-ascending" option can now be
1766 ** GDB can now complete the options of the "info threads", "info
1767 functions", "info variables", "info locals", and "info args"
1770 ** GDB can now complete the options of the "compile file" and
1771 "compile code" commands. The "compile file" command now
1772 completes on filenames.
1774 ** GDB can now complete the backtrace command's
1775 "full/no-filters/hide" qualifiers.
1777 * In settings, you can now abbreviate "unlimited".
1779 E.g., "set print elements u" is now equivalent to "set print
1780 elements unlimited".
1785 This lists all the possible completions for the rest of the line, if it
1786 were to be given as a command itself. This is intended for use by MI
1787 frontends in cases when separate CLI and MI channels cannot be used.
1789 -catch-throw, -catch-rethrow, and -catch-catch
1790 These can be used to catch C++ exceptions in a similar fashion to
1791 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1793 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1794 These commands are the MI equivalent of the CLI commands 'info
1795 functions', 'info types', and 'info variables' respectively.
1797 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1800 -symbol-info-module-functions and -symbol-info-module-variables.
1801 These commands are the MI equivalent of the CLI commands 'info
1802 module functions' and 'info module variables'.
1806 ** The default version of the MI interpreter is now 3 (-i=mi3).
1808 ** The output of information about multi-location breakpoints (which is
1809 syntactically incorrect in MI 2) has changed in MI 3. This affects
1810 the following commands and events:
1814 - =breakpoint-created
1815 - =breakpoint-modified
1817 The -fix-multi-location-breakpoint-output command can be used to enable
1818 this behavior with previous MI versions.
1820 ** Backtraces and frames include a new optional field addr_flags which is
1821 given after the addr field. On AArch64 this contains PAC if the address
1822 has been masked in the frame. On all other targets the field is not
1827 The testsuite now creates the files gdb.cmd (containing the arguments
1828 used to launch GDB) and gdb.in (containing all the commands sent to
1829 GDB) in the output directory for each test script. Multiple invocations
1830 are appended with .1, .2, .3 etc.
1832 * Building GDB and GDBserver now requires GNU make >= 3.82.
1834 Using another implementation of the make program or an earlier version of
1835 GNU make to build GDB or GDBserver is not supported.
1837 * Building GDB now requires GNU readline >= 7.0.
1839 GDB now bundles GNU readline 8.0, but if you choose to use
1840 --with-system-readline, only readline >= 7.0 can be used.
1842 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1843 from .inputrc to bind keys in this keymap. This feature is only
1844 available when gdb is built against GNU readline 8.0 or later.
1846 * Removed targets and native configurations
1848 GDB no longer supports debugging the Cell Broadband Engine. This includes
1849 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1850 of Cell/B.E. applications that use both the PPU and SPU architectures.
1856 * Removed targets and native configurations
1858 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1859 sparc*-*-solaris2.10
1861 *** Changes in GDB 8.3
1863 * GDB and GDBserver now support access to additional registers on
1864 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1867 * GDB now has experimental support for the compilation and injection of
1868 C++ source code into the inferior. This beta release does not include
1869 support for several language features, such as templates, constructors,
1872 This feature requires GCC 7.1 or higher built with libcp1.so
1875 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1876 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1877 'ADDRESS:PORT' method.
1879 * DWARF index cache: GDB can now automatically save indices of DWARF
1880 symbols on disk to speed up further loading of the same binaries.
1882 * Ada task switching is now supported on aarch64-elf targets when
1883 debugging a program using the Ravenscar Profile. For more information,
1884 see the "Tasking Support when using the Ravenscar Profile" section
1885 in the GDB user manual.
1887 * GDB in batch mode now exits with status 1 if the last command to be
1890 * The RISC-V target now supports target descriptions.
1892 * System call catchpoints now support system call aliases on FreeBSD.
1893 When the ABI of a system call changes in FreeBSD, this is
1894 implemented by leaving a compatibility system call using the old ABI
1895 at the existing number and allocating a new system call number for
1896 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1897 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1898 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1899 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1900 so that a system call catchpoint for the 'kevent' system call will
1901 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1902 binaries. This ensures that 'kevent' system calls are caught for
1903 binaries using either the old or new ABIs.
1905 * Terminal styling is now available for the CLI and the TUI. GNU
1906 Source Highlight can additionally be used to provide styling of
1907 source code snippets. See the "set style" commands, below, for more
1910 * Removed support for old demangling styles arm, edg, gnu, hp and
1915 set debug compile-cplus-types
1916 show debug compile-cplus-types
1917 Control the display of debug output about type conversion in the
1918 C++ compile feature. Commands have no effect while compiling
1919 for other languages.
1923 Control whether debug output about files/functions skipping is
1926 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1927 Apply a command to some frames.
1928 FLAG arguments allow to control what output to produce and how to handle
1929 errors raised when applying COMMAND to a frame.
1932 Apply a command to all threads (ignoring errors and empty output).
1933 Shortcut for 'thread apply all -s COMMAND'.
1936 Apply a command to all frames (ignoring errors and empty output).
1937 Shortcut for 'frame apply all -s COMMAND'.
1940 Apply a command to all frames of all threads (ignoring errors and empty
1942 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1944 maint set dwarf unwinders (on|off)
1945 maint show dwarf unwinders
1946 Control whether DWARF unwinders can be used.
1949 Display a list of open files for a process.
1953 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1954 These commands all now take a frame specification which
1955 is either a frame level, or one of the keywords 'level', 'address',
1956 'function', or 'view' followed by a parameter. Selecting a frame by
1957 address, or viewing a frame outside the current backtrace now
1958 requires the use of a keyword. Selecting a frame by level is
1959 unchanged. The MI comment "-stack-select-frame" is unchanged.
1961 target remote FILENAME
1962 target extended-remote FILENAME
1963 If FILENAME is a Unix domain socket, GDB will attempt to connect
1964 to this socket instead of opening FILENAME as a character device.
1966 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1967 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1968 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1969 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1970 These commands can now print only the searched entities
1971 matching the provided regexp(s), giving a condition
1972 on the entity names or entity types. The flag -q disables
1973 printing headers or informations messages.
1979 These commands now determine the syntax for the shown entities
1980 according to the language chosen by `set language'. In particular,
1981 `set language auto' means to automatically choose the language of
1984 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1985 The 'thread apply' command accepts new FLAG arguments.
1986 FLAG arguments allow to control what output to produce and how to handle
1987 errors raised when applying COMMAND to a thread.
1989 set tui tab-width NCHARS
1990 show tui tab-width NCHARS
1991 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1993 set style enabled [on|off]
1995 Enable or disable terminal styling. Styling is enabled by default
1996 on most hosts, but disabled by default when in batch mode.
1998 set style sources [on|off]
2000 Enable or disable source code styling. Source code styling is
2001 enabled by default, but only takes effect if styling in general is
2002 enabled, and if GDB was linked with GNU Source Highlight.
2004 set style filename foreground COLOR
2005 set style filename background COLOR
2006 set style filename intensity VALUE
2007 Control the styling of file names.
2009 set style function foreground COLOR
2010 set style function background COLOR
2011 set style function intensity VALUE
2012 Control the styling of function names.
2014 set style variable foreground COLOR
2015 set style variable background COLOR
2016 set style variable intensity VALUE
2017 Control the styling of variable names.
2019 set style address foreground COLOR
2020 set style address background COLOR
2021 set style address intensity VALUE
2022 Control the styling of addresses.
2026 ** The '-data-disassemble' MI command now accepts an '-a' option to
2027 disassemble the whole function surrounding the given program
2028 counter value or function name. Support for this feature can be
2029 verified by using the "-list-features" command, which should
2030 contain "data-disassemble-a-option".
2032 ** Command responses and notifications that include a frame now include
2033 the frame's architecture in a new "arch" attribute.
2035 * New native configurations
2037 GNU/Linux/RISC-V riscv*-*-linux*
2038 FreeBSD/riscv riscv*-*-freebsd*
2042 GNU/Linux/RISC-V riscv*-*-linux*
2043 CSKY ELF csky*-*-elf
2044 CSKY GNU/LINUX csky*-*-linux
2045 FreeBSD/riscv riscv*-*-freebsd*
2047 GNU/Linux/OpenRISC or1k*-*-linux*
2051 GDB no longer supports native debugging on versions of MS-Windows
2056 ** GDB no longer supports Python versions less than 2.6.
2058 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2059 space associated to that inferior.
2061 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2062 of objfiles associated to that program space.
2064 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2065 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2068 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2069 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2070 correct and did not work properly.
2072 ** The gdb.Value type has a new constructor, which is used to construct a
2073 gdb.Value from a Python buffer object and a gdb.Type.
2079 Enable or disable the undefined behavior sanitizer. This is
2080 disabled by default, but passing --enable-ubsan=yes or
2081 --enable-ubsan=auto to configure will enable it. Enabling this can
2082 cause a performance penalty. The undefined behavior sanitizer was
2083 first introduced in GCC 4.9.
2085 *** Changes in GDB 8.2
2087 * The 'set disassembler-options' command now supports specifying options
2088 for the MIPS target.
2090 * The 'symbol-file' command now accepts an '-o' option to add a relative
2091 offset to all sections.
2093 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2094 a relative offset to all sections, but it allows to override the load
2095 address of individual sections using '-s'.
2097 * The 'add-symbol-file' command no longer requires the second argument
2098 (address of the text section).
2100 * The endianness used with the 'set endian auto' mode in the absence of
2101 an executable selected for debugging is now the last endianness chosen
2102 either by one of the 'set endian big' and 'set endian little' commands
2103 or by inferring from the last executable used, rather than the startup
2106 * The pager now allows a "c" response, meaning to disable the pager
2107 for the rest of the current command.
2109 * The commands 'info variables/functions/types' now show the source line
2110 numbers of symbol definitions when available.
2112 * 'info proc' now works on running processes on FreeBSD systems and core
2113 files created on FreeBSD systems.
2115 * C expressions can now use _Alignof, and C++ expressions can now use
2118 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2119 the vector length while the process is running.
2125 Control display of debugging info regarding the FreeBSD native target.
2127 set|show varsize-limit
2128 This new setting allows the user to control the maximum size of Ada
2129 objects being printed when those objects have a variable type,
2130 instead of that maximum size being hardcoded to 65536 bytes.
2132 set|show record btrace cpu
2133 Controls the processor to be used for enabling errata workarounds for
2134 branch trace decode.
2136 maint check libthread-db
2137 Run integrity checks on the current inferior's thread debugging
2140 maint set check-libthread-db (on|off)
2141 maint show check-libthread-db
2142 Control whether to run integrity checks on inferior specific thread
2143 debugging libraries as they are loaded. The default is not to
2144 perform such checks.
2148 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2150 ** The commands attached to a breakpoint can be set by assigning to
2151 the breakpoint's "commands" field.
2153 ** gdb.execute can now execute multi-line gdb commands.
2155 ** The new functions gdb.convenience_variable and
2156 gdb.set_convenience_variable can be used to get and set the value
2157 of convenience variables.
2159 ** A gdb.Parameter will no longer print the "set" help text on an
2160 ordinary "set"; instead by default a "set" will be silent unless
2161 the get_set_string method returns a non-empty string.
2165 RiscV ELF riscv*-*-elf
2167 * Removed targets and native configurations
2169 m88k running OpenBSD m88*-*-openbsd*
2170 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2171 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2172 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2174 * Aarch64/Linux hardware watchpoints improvements
2176 Hardware watchpoints on unaligned addresses are now properly
2177 supported when running Linux kernel 4.10 or higher: read and access
2178 watchpoints are no longer spuriously missed, and all watchpoints
2179 lengths between 1 and 8 bytes are supported. On older kernels,
2180 watchpoints set on unaligned addresses are no longer missed, with
2181 the tradeoff that there is a possibility of false hits being
2186 --enable-codesign=CERT
2187 This can be used to invoke "codesign -s CERT" after building gdb.
2188 This option is useful on macOS, where code signing is required for
2189 gdb to work properly.
2191 --disable-gdbcli has been removed
2192 This is now silently accepted, but does nothing.
2194 *** Changes in GDB 8.1
2196 * GDB now supports dynamically creating arbitrary register groups specified
2197 in XML target descriptions. This allows for finer grain grouping of
2198 registers on systems with a large amount of registers.
2200 * The 'ptype' command now accepts a '/o' flag, which prints the
2201 offsets and sizes of fields in a struct, like the pahole(1) tool.
2203 * New "--readnever" command line option instructs GDB to not read each
2204 symbol file's symbolic debug information. This makes startup faster
2205 but at the expense of not being able to perform symbolic debugging.
2206 This option is intended for use cases where symbolic debugging will
2207 not be used, e.g., when you only need to dump the debuggee's core.
2209 * GDB now uses the GNU MPFR library, if available, to emulate target
2210 floating-point arithmetic during expression evaluation when the target
2211 uses different floating-point formats than the host. At least version
2212 3.1 of GNU MPFR is required.
2214 * GDB now supports access to the guarded-storage-control registers and the
2215 software-based guarded-storage broadcast control registers on IBM z14.
2217 * On Unix systems, GDB now supports transmitting environment variables
2218 that are to be set or unset to GDBserver. These variables will
2219 affect the environment to be passed to the remote inferior.
2221 To inform GDB of environment variables that are to be transmitted to
2222 GDBserver, use the "set environment" command. Only user set
2223 environment variables are sent to GDBserver.
2225 To inform GDB of environment variables that are to be unset before
2226 the remote inferior is started by the GDBserver, use the "unset
2227 environment" command.
2229 * Completion improvements
2231 ** GDB can now complete function parameters in linespecs and
2232 explicit locations without quoting. When setting breakpoints,
2233 quoting around functions names to help with TAB-completion is
2234 generally no longer necessary. For example, this now completes
2237 (gdb) b function(in[TAB]
2238 (gdb) b function(int)
2240 Related, GDB is no longer confused with completing functions in
2241 C++ anonymous namespaces:
2244 (gdb) b (anonymous namespace)::[TAB][TAB]
2245 (anonymous namespace)::a_function()
2246 (anonymous namespace)::b_function()
2248 ** GDB now has much improved linespec and explicit locations TAB
2249 completion support, that better understands what you're
2250 completing and offers better suggestions. For example, GDB no
2251 longer offers data symbols as possible completions when you're
2252 setting a breakpoint.
2254 ** GDB now TAB-completes label symbol names.
2256 ** The "complete" command now mimics TAB completion accurately.
2258 * New command line options (gcore)
2261 Dump all memory mappings.
2263 * Breakpoints on C++ functions are now set on all scopes by default
2265 By default, breakpoints on functions/methods are now interpreted as
2266 specifying all functions with the given name ignoring missing
2267 leading scopes (namespaces and classes).
2269 For example, assuming a C++ program with symbols named:
2274 both commands "break func()" and "break B::func()" set a breakpoint
2277 You can use the new flag "-qualified" to override this. This makes
2278 GDB interpret the specified function name as a complete
2279 fully-qualified name instead. For example, using the same C++
2280 program, the "break -q B::func" command sets a breakpoint on
2281 "B::func", only. A parameter has been added to the Python
2282 gdb.Breakpoint constructor to achieve the same result when creating
2283 a breakpoint from Python.
2285 * Breakpoints on functions marked with C++ ABI tags
2287 GDB can now set breakpoints on functions marked with C++ ABI tags
2288 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2289 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2291 Functions with a C++11 abi tag are demangled/displayed like this:
2293 function[abi:cxx11](int)
2296 You can now set a breakpoint on such functions simply as if they had
2299 (gdb) b function(int)
2301 Or if you need to disambiguate between tags, like:
2303 (gdb) b function[abi:other_tag](int)
2305 Tab completion was adjusted accordingly as well.
2309 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2310 gdb.new_thread are emitted. See the manual for further
2311 description of these.
2313 ** A new function, "gdb.rbreak" has been added to the Python API.
2314 This function allows the setting of a large number of breakpoints
2315 via a regex pattern in Python. See the manual for further details.
2317 ** Python breakpoints can now accept explicit locations. See the
2318 manual for a further description of this feature.
2321 * New features in the GDB remote stub, GDBserver
2323 ** GDBserver is now able to start inferior processes with a
2324 specified initial working directory.
2326 The user can set the desired working directory to be used from
2327 GDB using the new "set cwd" command.
2329 ** New "--selftest" command line option runs some GDBserver self
2330 tests. These self tests are disabled in releases.
2332 ** On Unix systems, GDBserver now does globbing expansion and variable
2333 substitution in inferior command line arguments.
2335 This is done by starting inferiors using a shell, like GDB does.
2336 See "set startup-with-shell" in the user manual for how to disable
2337 this from GDB when using "target extended-remote". When using
2338 "target remote", you can disable the startup with shell by using the
2339 new "--no-startup-with-shell" GDBserver command line option.
2341 ** On Unix systems, GDBserver now supports receiving environment
2342 variables that are to be set or unset from GDB. These variables
2343 will affect the environment to be passed to the inferior.
2345 * When catching an Ada exception raised with a message, GDB now prints
2346 the message in the catchpoint hit notification. In GDB/MI mode, that
2347 information is provided as an extra field named "exception-message"
2348 in the *stopped notification.
2350 * Trait objects can now be inspected When debugging Rust code. This
2351 requires compiler support which will appear in Rust 1.24.
2353 * New remote packets
2355 QEnvironmentHexEncoded
2356 Inform GDBserver of an environment variable that is to be passed to
2357 the inferior when starting it.
2360 Inform GDBserver of an environment variable that is to be unset
2361 before starting the remote inferior.
2364 Inform GDBserver that the environment should be reset (i.e.,
2365 user-set environment variables should be unset).
2368 Indicates whether the inferior must be started with a shell or not.
2371 Tell GDBserver that the inferior to be started should use a specific
2374 * The "maintenance print c-tdesc" command now takes an optional
2375 argument which is the file name of XML target description.
2377 * The "maintenance selftest" command now takes an optional argument to
2378 filter the tests to be run.
2380 * The "enable", and "disable" commands now accept a range of
2381 breakpoint locations, e.g. "enable 1.3-5".
2386 Set and show the current working directory for the inferior.
2388 set|show compile-gcc
2389 Set and show compilation command used for compiling and injecting code
2390 with the 'compile' commands.
2392 set debug separate-debug-file
2393 show debug separate-debug-file
2394 Control the display of debug output about separate debug file search.
2396 set dump-excluded-mappings
2397 show dump-excluded-mappings
2398 Control whether mappings marked with the VM_DONTDUMP flag should be
2399 dumped when generating a core file.
2401 maint info selftests
2402 List the registered selftests.
2405 Start the debugged program stopping at the first instruction.
2408 Control display of debugging messages related to OpenRISC targets.
2410 set|show print type nested-type-limit
2411 Set and show the limit of nesting level for nested types that the
2412 type printer will show.
2414 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2417 * Safer/improved support for debugging with no debug info
2419 GDB no longer assumes functions with no debug information return
2422 This means that GDB now refuses to call such functions unless you
2423 tell it the function's type, by either casting the call to the
2424 declared return type, or by casting the function to a function
2425 pointer of the right type, and calling that:
2427 (gdb) p getenv ("PATH")
2428 'getenv' has unknown return type; cast the call to its declared return type
2429 (gdb) p (char *) getenv ("PATH")
2430 $1 = 0x7fffffffe "/usr/local/bin:/"...
2431 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2432 $2 = 0x7fffffffe "/usr/local/bin:/"...
2434 Similarly, GDB no longer assumes that global variables with no debug
2435 info have type 'int', and refuses to print the variable's value
2436 unless you tell it the variable's type:
2439 'var' has unknown type; cast it to its declared type
2443 * New native configurations
2445 FreeBSD/aarch64 aarch64*-*-freebsd*
2446 FreeBSD/arm arm*-*-freebsd*
2450 FreeBSD/aarch64 aarch64*-*-freebsd*
2451 FreeBSD/arm arm*-*-freebsd*
2452 OpenRISC ELF or1k*-*-elf
2454 * Removed targets and native configurations
2456 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2458 *** Changes in GDB 8.0
2460 * GDB now supports access to the PKU register on GNU/Linux. The register is
2461 added by the Memory Protection Keys for Userspace feature which will be
2462 available in future Intel CPUs.
2464 * GDB now supports C++11 rvalue references.
2468 ** New functions to start, stop and access a running btrace recording.
2469 ** Rvalue references are now supported in gdb.Type.
2471 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2474 * Building GDB and GDBserver now requires a C++11 compiler.
2476 For example, GCC 4.8 or later.
2478 It is no longer possible to build GDB or GDBserver with a C
2479 compiler. The --disable-build-with-cxx configure option has been
2482 * Building GDB and GDBserver now requires GNU make >= 3.81.
2484 It is no longer supported to build GDB or GDBserver with another
2485 implementation of the make program or an earlier version of GNU make.
2487 * Native debugging on MS-Windows supports command-line redirection
2489 Command-line arguments used for starting programs on MS-Windows can
2490 now include redirection symbols supported by native Windows shells,
2491 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2492 as "run", "start", and "set args", as well as the corresponding MI
2495 * Support for thread names on MS-Windows.
2497 GDB now catches and handles the special exception that programs
2498 running on MS-Windows use to assign names to threads in the
2501 * Support for Java programs compiled with gcj has been removed.
2503 * User commands now accept an unlimited number of arguments.
2504 Previously, only up to 10 was accepted.
2506 * The "eval" command now expands user-defined command arguments.
2508 This makes it easier to process a variable number of arguments:
2513 eval "print $arg%d", $i
2518 * Target descriptions can now describe registers for sparc32 and sparc64.
2520 * GDB now supports DWARF version 5 (debug information format).
2521 Its .debug_names index is not yet supported.
2523 * New native configurations
2525 FreeBSD/mips mips*-*-freebsd
2529 Synopsys ARC arc*-*-elf32
2530 FreeBSD/mips mips*-*-freebsd
2532 * Removed targets and native configurations
2534 Alpha running FreeBSD alpha*-*-freebsd*
2535 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2540 Erases all the flash memory regions reported by the target.
2542 maint print arc arc-instruction address
2543 Print internal disassembler information about instruction at a given address.
2547 set disassembler-options
2548 show disassembler-options
2549 Controls the passing of target specific information to the disassembler.
2550 If it is necessary to specify more than one disassembler option then
2551 multiple options can be placed together into a comma separated list.
2552 The default value is the empty string. Currently, the only supported
2553 targets are ARM, PowerPC and S/390.
2558 Erases all the flash memory regions reported by the target. This is
2559 equivalent to the CLI command flash-erase.
2561 -file-list-shared-libraries
2562 List the shared libraries in the program. This is
2563 equivalent to the CLI command "info shared".
2566 Catchpoints stopping the program when Ada exceptions are
2567 handled. This is equivalent to the CLI command "catch handlers".
2569 *** Changes in GDB 7.12
2571 * GDB and GDBserver now build with a C++ compiler by default.
2573 The --enable-build-with-cxx configure option is now enabled by
2574 default. One must now explicitly configure with
2575 --disable-build-with-cxx in order to build with a C compiler. This
2576 option will be removed in a future release.
2578 * GDBserver now supports recording btrace without maintaining an active
2581 * GDB now supports a negative repeat count in the 'x' command to examine
2582 memory backward from the given address. For example:
2585 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2586 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2587 (gdb) x/-5i 0x0000000000400580
2588 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2589 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2590 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2591 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2592 0x40057b <main(int, char**)+25>:
2593 callq 0x400536 <Func1(int, char const*)>
2595 * Fortran: Support structures with fields of dynamic types and
2596 arrays of dynamic types.
2598 * The symbol dumping maintenance commands have new syntax.
2599 maint print symbols [-pc address] [--] [filename]
2600 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2601 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2602 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2603 maint print msymbols [-objfile objfile] [--] [filename]
2605 * GDB now supports multibit bitfields and enums in target register
2608 * New Python-based convenience function $_as_string(val), which returns
2609 the textual representation of a value. This function is especially
2610 useful to obtain the text label of an enum value.
2612 * Intel MPX bound violation handling.
2614 Segmentation faults caused by a Intel MPX boundary violation
2615 now display the kind of violation (upper or lower), the memory
2616 address accessed and the memory bounds, along with the usual
2617 signal received and code location.
2621 Program received signal SIGSEGV, Segmentation fault
2622 Upper bound violation while accessing address 0x7fffffffc3b3
2623 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2624 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2626 * Rust language support.
2627 GDB now supports debugging programs written in the Rust programming
2628 language. See https://www.rust-lang.org/ for more information about
2631 * Support for running interpreters on specified input/output devices
2633 GDB now supports a new mechanism that allows frontends to provide
2634 fully featured GDB console views, as a better alternative to
2635 building such views on top of the "-interpreter-exec console"
2636 command. See the new "new-ui" command below. With that command,
2637 frontends can now start GDB in the traditional command-line mode
2638 running in an embedded terminal emulator widget, and create a
2639 separate MI interpreter running on a specified i/o device. In this
2640 way, GDB handles line editing, history, tab completion, etc. in the
2641 console all by itself, and the GUI uses the separate MI interpreter
2642 for its own control and synchronization, invisible to the command
2645 * The "catch syscall" command catches groups of related syscalls.
2647 The "catch syscall" command now supports catching a group of related
2648 syscalls using the 'group:' or 'g:' prefix.
2653 skip -gfile file-glob-pattern
2654 skip -function function
2655 skip -rfunction regular-expression
2656 A generalized form of the skip command, with new support for
2657 glob-style file names and regular expressions for function names.
2658 Additionally, a file spec and a function spec may now be combined.
2660 maint info line-table REGEXP
2661 Display the contents of GDB's internal line table data structure.
2664 Run any GDB unit tests that were compiled in.
2667 Start a new user interface instance running INTERP as interpreter,
2668 using the TTY file for input/output.
2672 ** gdb.Breakpoint objects have a new attribute "pending", which
2673 indicates whether the breakpoint is pending.
2674 ** Three new breakpoint-related events have been added:
2675 gdb.breakpoint_created, gdb.breakpoint_modified, and
2676 gdb.breakpoint_deleted.
2678 signal-event EVENTID
2679 Signal ("set") the given MS-Windows event object. This is used in
2680 conjunction with the Windows JIT debugging (AeDebug) support, where
2681 the OS suspends a crashing process until a debugger can attach to
2682 it. Resuming the crashing process, in order to debug it, is done by
2683 signalling an event.
2685 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2686 was added in GDBserver, including JIT compiling fast tracepoint's
2687 conditional expression bytecode into native code.
2689 * Support for various remote target protocols and ROM monitors has
2692 target m32rsdi Remote M32R debugging over SDI
2693 target mips MIPS remote debugging protocol
2694 target pmon PMON ROM monitor
2695 target ddb NEC's DDB variant of PMON for Vr4300
2696 target rockhopper NEC RockHopper variant of PMON
2697 target lsi LSI variant of PMO
2699 * Support for tracepoints and fast tracepoints on powerpc-linux,
2700 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2701 including JIT compiling fast tracepoint's conditional expression
2702 bytecode into native code.
2704 * MI async record =record-started now includes the method and format used for
2705 recording. For example:
2707 =record-started,thread-group="i1",method="btrace",format="bts"
2709 * MI async record =thread-selected now includes the frame field. For example:
2711 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2715 Andes NDS32 nds32*-*-elf
2717 *** Changes in GDB 7.11
2719 * GDB now supports debugging kernel-based threads on FreeBSD.
2721 * Per-inferior thread numbers
2723 Thread numbers are now per inferior instead of global. If you're
2724 debugging multiple inferiors, GDB displays thread IDs using a
2725 qualified INF_NUM.THR_NUM form. For example:
2729 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2730 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2731 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2732 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2734 As consequence, thread numbers as visible in the $_thread
2735 convenience variable and in Python's InferiorThread.num attribute
2736 are no longer unique between inferiors.
2738 GDB now maintains a second thread ID per thread, referred to as the
2739 global thread ID, which is the new equivalent of thread numbers in
2740 previous releases. See also $_gthread below.
2742 For backwards compatibility, MI's thread IDs always refer to global
2745 * Commands that accept thread IDs now accept the qualified
2746 INF_NUM.THR_NUM form as well. For example:
2749 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2752 * In commands that accept a list of thread IDs, you can now refer to
2753 all threads of an inferior using a star wildcard. GDB accepts
2754 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2755 refer to all threads of the current inferior. For example, "info
2758 * You can use "info threads -gid" to display the global thread ID of
2761 * The new convenience variable $_gthread holds the global number of
2764 * The new convenience variable $_inferior holds the number of the
2767 * GDB now displays the ID and name of the thread that hit a breakpoint
2768 or received a signal, if your program is multi-threaded. For
2771 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2772 Thread 1 "main" received signal SIGINT, Interrupt.
2774 * Record btrace now supports non-stop mode.
2776 * Support for tracepoints on aarch64-linux was added in GDBserver.
2778 * The 'record instruction-history' command now indicates speculative execution
2779 when using the Intel Processor Trace recording format.
2781 * GDB now allows users to specify explicit locations, bypassing
2782 the linespec parser. This feature is also available to GDB/MI
2785 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2786 GDB now is able to debug both AArch64 applications and ARM applications
2789 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2790 including JIT compiling fast tracepoint's conditional expression bytecode
2793 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2795 * "info threads", "info inferiors", "info display", "info checkpoints"
2796 and "maint info program-spaces" now list the corresponding items in
2797 ascending ID order, for consistency with all other "info" commands.
2799 * In Ada, the overloads selection menu has been enhanced to display the
2800 parameter types and the return types for the matching overloaded subprograms.
2804 maint set target-non-stop (on|off|auto)
2805 maint show target-non-stop
2806 Control whether GDB targets always operate in non-stop mode even if
2807 "set non-stop" is "off". The default is "auto", meaning non-stop
2808 mode is enabled if supported by the target.
2810 maint set bfd-sharing
2811 maint show bfd-sharing
2812 Control the reuse of bfd objects.
2815 show debug bfd-cache
2816 Control display of debugging info regarding bfd caching.
2820 Control display of debugging info regarding FreeBSD threads.
2822 set remote multiprocess-extensions-packet
2823 show remote multiprocess-extensions-packet
2824 Set/show the use of the remote protocol multiprocess extensions.
2826 set remote thread-events
2827 show remote thread-events
2828 Set/show the use of thread create/exit events.
2830 set ada print-signatures on|off
2831 show ada print-signatures"
2832 Control whether parameter types and return types are displayed in overloads
2833 selection menus. It is activated (@code{on}) by default.
2837 Controls the maximum size of memory, in bytes, that GDB will
2838 allocate for value contents. Prevents incorrect programs from
2839 causing GDB to allocate overly large buffers. Default is 64k.
2841 * The "disassemble" command accepts a new modifier: /s.
2842 It prints mixed source+disassembly like /m with two differences:
2843 - disassembled instructions are now printed in program order, and
2844 - and source for all relevant files is now printed.
2845 The "/m" option is now considered deprecated: its "source-centric"
2846 output hasn't proved useful in practice.
2848 * The "record instruction-history" command accepts a new modifier: /s.
2849 It behaves exactly like /m and prints mixed source+disassembly.
2851 * The "set scheduler-locking" command supports a new mode "replay".
2852 It behaves like "off" in record mode and like "on" in replay mode.
2854 * Support for various ROM monitors has been removed:
2856 target dbug dBUG ROM monitor for Motorola ColdFire
2857 target picobug Motorola picobug monitor
2858 target dink32 DINK32 ROM monitor for PowerPC
2859 target m32r Renesas M32R/D ROM monitor
2860 target mon2000 mon2000 ROM monitor
2861 target ppcbug PPCBUG ROM monitor for PowerPC
2863 * Support for reading/writing memory and extracting values on architectures
2864 whose memory is addressable in units of any integral multiple of 8 bits.
2867 Allows to break when an Ada exception is handled.
2869 * New remote packets
2872 Indicates that an exec system call was executed.
2874 exec-events feature in qSupported
2875 The qSupported packet allows GDB to request support for exec
2876 events using the new 'gdbfeature' exec-event, and the qSupported
2877 response can contain the corresponding 'stubfeature'. Set and
2878 show commands can be used to display whether these features are enabled.
2881 Equivalent to interrupting with the ^C character, but works in
2884 thread created stop reason (T05 create:...)
2885 Indicates that the thread was just created and is stopped at entry.
2887 thread exit stop reply (w exitcode;tid)
2888 Indicates that the thread has terminated.
2891 Enables/disables thread create and exit event reporting. For
2892 example, this is used in non-stop mode when GDB stops a set of
2893 threads and synchronously waits for the their corresponding stop
2894 replies. Without exit events, if one of the threads exits, GDB
2895 would hang forever not knowing that it should no longer expect a
2896 stop for that same thread.
2899 Indicates that there are no resumed threads left in the target (all
2900 threads are stopped). The remote stub reports support for this stop
2901 reply to GDB's qSupported query.
2904 Enables/disables catching syscalls from the inferior process.
2905 The remote stub reports support for this packet to GDB's qSupported query.
2907 syscall_entry stop reason
2908 Indicates that a syscall was just called.
2910 syscall_return stop reason
2911 Indicates that a syscall just returned.
2913 * Extended-remote exec events
2915 ** GDB now has support for exec events on extended-remote Linux targets.
2916 For such targets with Linux kernels 2.5.46 and later, this enables
2917 follow-exec-mode and exec catchpoints.
2919 set remote exec-event-feature-packet
2920 show remote exec-event-feature-packet
2921 Set/show the use of the remote exec event feature.
2923 * Thread names in remote protocol
2925 The reply to qXfer:threads:read may now include a name attribute for each
2928 * Target remote mode fork and exec events
2930 ** GDB now has support for fork and exec events on target remote mode
2931 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2932 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2933 fork and exec catchpoints.
2935 * Remote syscall events
2937 ** GDB now has support for catch syscall on remote Linux targets,
2938 currently enabled on x86/x86_64 architectures.
2940 set remote catch-syscall-packet
2941 show remote catch-syscall-packet
2942 Set/show the use of the remote catch syscall feature.
2946 ** The -var-set-format command now accepts the zero-hexadecimal
2947 format. It outputs data in hexadecimal format with zero-padding on the
2952 ** gdb.InferiorThread objects have a new attribute "global_num",
2953 which refers to the thread's global thread ID. The existing
2954 "num" attribute now refers to the thread's per-inferior number.
2955 See "Per-inferior thread numbers" above.
2956 ** gdb.InferiorThread objects have a new attribute "inferior", which
2957 is the Inferior object the thread belongs to.
2959 *** Changes in GDB 7.10
2961 * Support for process record-replay and reverse debugging on aarch64*-linux*
2962 targets has been added. GDB now supports recording of A64 instruction set
2963 including advance SIMD instructions.
2965 * Support for Sun's version of the "stabs" debug file format has been removed.
2967 * GDB now honors the content of the file /proc/PID/coredump_filter
2968 (PID is the process ID) on GNU/Linux systems. This file can be used
2969 to specify the types of memory mappings that will be included in a
2970 corefile. For more information, please refer to the manual page of
2971 "core(5)". GDB also has a new command: "set use-coredump-filter
2972 on|off". It allows to set whether GDB will read the content of the
2973 /proc/PID/coredump_filter file when generating a corefile.
2975 * The "info os" command on GNU/Linux can now display information on
2977 "info os cpus" Listing of all cpus/cores on the system
2979 * GDB has two new commands: "set serial parity odd|even|none" and
2980 "show serial parity". These allows to set or show parity for the
2983 * The "info source" command now displays the producer string if it was
2984 present in the debug info. This typically includes the compiler version
2985 and may include things like its command line arguments.
2987 * The "info dll", an alias of the "info sharedlibrary" command,
2988 is now available on all platforms.
2990 * Directory names supplied to the "set sysroot" commands may be
2991 prefixed with "target:" to tell GDB to access shared libraries from
2992 the target system, be it local or remote. This replaces the prefix
2993 "remote:". The default sysroot has been changed from "" to
2994 "target:". "remote:" is automatically converted to "target:" for
2995 backward compatibility.
2997 * The system root specified by "set sysroot" will be prepended to the
2998 filename of the main executable (if reported to GDB as absolute by
2999 the operating system) when starting processes remotely, and when
3000 attaching to already-running local or remote processes.
3002 * GDB now supports automatic location and retrieval of executable
3003 files from remote targets. Remote debugging can now be initiated
3004 using only a "target remote" or "target extended-remote" command
3005 (no "set sysroot" or "file" commands are required). See "New remote
3008 * The "dump" command now supports verilog hex format.
3010 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3012 * On GNU/Linux, GDB and gdbserver are now able to access executable
3013 and shared library files without a "set sysroot" command when
3014 attaching to processes running in different mount namespaces from
3015 the debugger. This makes it possible to attach to processes in
3016 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3017 See "New remote packets" below.
3019 * The "tui reg" command now provides completion for all of the
3020 available register groups, including target specific groups.
3022 * The HISTSIZE environment variable is no longer read when determining
3023 the size of GDB's command history. GDB now instead reads the dedicated
3024 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3025 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3030 ** Memory ports can now be unbuffered.
3034 ** gdb.Objfile objects have a new attribute "username",
3035 which is the name of the objfile as specified by the user,
3036 without, for example, resolving symlinks.
3037 ** You can now write frame unwinders in Python.
3038 ** gdb.Type objects have a new method "optimized_out",
3039 returning optimized out gdb.Value instance of this type.
3040 ** gdb.Value objects have new methods "reference_value" and
3041 "const_value" which return a reference to the value and a
3042 "const" version of the value respectively.
3046 maint print symbol-cache
3047 Print the contents of the symbol cache.
3049 maint print symbol-cache-statistics
3050 Print statistics of symbol cache usage.
3052 maint flush-symbol-cache
3053 Flush the contents of the symbol cache.
3057 Start branch trace recording using Branch Trace Store (BTS) format.
3060 Evaluate expression by using the compiler and print result.
3064 Explicit commands for enabling and disabling tui mode.
3067 set mpx bound on i386 and amd64
3068 Support for bound table investigation on Intel MPX enabled applications.
3072 Start branch trace recording using Intel Processor Trace format.
3075 Print information about branch tracing internals.
3077 maint btrace packet-history
3078 Print the raw branch tracing data.
3080 maint btrace clear-packet-history
3081 Discard the stored raw branch tracing data.
3084 Discard all branch tracing data. It will be fetched and processed
3085 anew by the next "record" command.
3090 Renamed from "set debug dwarf2-die".
3091 show debug dwarf-die
3092 Renamed from "show debug dwarf2-die".
3094 set debug dwarf-read
3095 Renamed from "set debug dwarf2-read".
3096 show debug dwarf-read
3097 Renamed from "show debug dwarf2-read".
3099 maint set dwarf always-disassemble
3100 Renamed from "maint set dwarf2 always-disassemble".
3101 maint show dwarf always-disassemble
3102 Renamed from "maint show dwarf2 always-disassemble".
3104 maint set dwarf max-cache-age
3105 Renamed from "maint set dwarf2 max-cache-age".
3106 maint show dwarf max-cache-age
3107 Renamed from "maint show dwarf2 max-cache-age".
3109 set debug dwarf-line
3110 show debug dwarf-line
3111 Control display of debugging info regarding DWARF line processing.
3114 show max-completions
3115 Set the maximum number of candidates to be considered during
3116 completion. The default value is 200. This limit allows GDB
3117 to avoid generating large completion lists, the computation of
3118 which can cause the debugger to become temporarily unresponsive.
3120 set history remove-duplicates
3121 show history remove-duplicates
3122 Control the removal of duplicate history entries.
3124 maint set symbol-cache-size
3125 maint show symbol-cache-size
3126 Control the size of the symbol cache.
3128 set|show record btrace bts buffer-size
3129 Set and show the size of the ring buffer used for branch tracing in
3131 The obtained size may differ from the requested size. Use "info
3132 record" to see the obtained buffer size.
3134 set debug linux-namespaces
3135 show debug linux-namespaces
3136 Control display of debugging info regarding Linux namespaces.
3138 set|show record btrace pt buffer-size
3139 Set and show the size of the ring buffer used for branch tracing in
3140 Intel Processor Trace format.
3141 The obtained size may differ from the requested size. Use "info
3142 record" to see the obtained buffer size.
3144 maint set|show btrace pt skip-pad
3145 Set and show whether PAD packets are skipped when computing the
3148 * The command 'thread apply all' can now support new option '-ascending'
3149 to call its specified command for all threads in ascending order.
3151 * Python/Guile scripting
3153 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3154 special section named `.debug_gdb_scripts'.
3156 * New remote packets
3158 qXfer:btrace-conf:read
3159 Return the branch trace configuration for the current thread.
3161 Qbtrace-conf:bts:size
3162 Set the requested ring buffer size for branch tracing in BTS format.
3165 Enable Intel Processor Trace-based branch tracing for the current
3166 process. The remote stub reports support for this packet to GDB's
3169 Qbtrace-conf:pt:size
3170 Set the requested ring buffer size for branch tracing in Intel Processor
3174 Indicates a memory breakpoint instruction was executed, irrespective
3175 of whether it was GDB that planted the breakpoint or the breakpoint
3176 is hardcoded in the program. This is required for correct non-stop
3180 Indicates the target stopped for a hardware breakpoint. This is
3181 required for correct non-stop mode operation.
3184 Return information about files on the remote system.
3186 qXfer:exec-file:read
3187 Return the full absolute name of the file that was executed to
3188 create a process running on the remote system.
3191 Select the filesystem on which vFile: operations with filename
3192 arguments will operate. This is required for GDB to be able to
3193 access files on remote targets where the remote stub does not
3194 share a common filesystem with the inferior(s).
3197 Indicates that a fork system call was executed.
3200 Indicates that a vfork system call was executed.
3202 vforkdone stop reason
3203 Indicates that a vfork child of the specified process has executed
3204 an exec or exit, allowing the vfork parent to resume execution.
3206 fork-events and vfork-events features in qSupported
3207 The qSupported packet allows GDB to request support for fork and
3208 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3209 and the qSupported response can contain the corresponding
3210 'stubfeatures'. Set and show commands can be used to display
3211 whether these features are enabled.
3213 * Extended-remote fork events
3215 ** GDB now has support for fork events on extended-remote Linux
3216 targets. For targets with Linux kernels 2.5.60 and later, this
3217 enables follow-fork-mode and detach-on-fork for both fork and
3218 vfork, as well as fork and vfork catchpoints.
3220 * The info record command now shows the recording format and the
3221 branch tracing configuration for the current thread when using
3222 the btrace record target.
3223 For the BTS format, it shows the ring buffer size.
3225 * GDB now has support for DTrace USDT (Userland Static Defined
3226 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3228 * GDB now supports access to vector registers on S/390 GNU/Linux
3231 * Removed command line options
3233 -xdb HP-UX XDB compatibility mode.
3235 * Removed targets and native configurations
3237 HP/PA running HP-UX hppa*-*-hpux*
3238 Itanium running HP-UX ia64-*-hpux*
3240 * New configure options
3243 This configure option allows the user to build GDB with support for
3244 Intel Processor Trace (default: auto). This requires libipt.
3246 --with-libipt-prefix=PATH
3247 Specify the path to the version of libipt that GDB should use.
3248 $PATH/include should contain the intel-pt.h header and
3249 $PATH/lib should contain the libipt.so library.
3251 *** Changes in GDB 7.9.1
3255 ** Xmethods can now specify a result type.
3257 *** Changes in GDB 7.9
3259 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3263 ** You can now access frame registers from Python scripts.
3264 ** New attribute 'producer' for gdb.Symtab objects.
3265 ** gdb.Objfile objects have a new attribute "progspace",
3266 which is the gdb.Progspace object of the containing program space.
3267 ** gdb.Objfile objects have a new attribute "owner".
3268 ** gdb.Objfile objects have a new attribute "build_id",
3269 which is the build ID generated when the file was built.
3270 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3271 ** A new event "gdb.clear_objfiles" has been added, triggered when
3272 selecting a new file to debug.
3273 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3274 ** New function gdb.lookup_objfile.
3276 New events which are triggered when GDB modifies the state of the
3279 ** gdb.events.inferior_call_pre: Function call is about to be made.
3280 ** gdb.events.inferior_call_post: Function call has just been made.
3281 ** gdb.events.memory_changed: A memory location has been altered.
3282 ** gdb.events.register_changed: A register has been altered.
3284 * New Python-based convenience functions:
3286 ** $_caller_is(name [, number_of_frames])
3287 ** $_caller_matches(regexp [, number_of_frames])
3288 ** $_any_caller_is(name [, number_of_frames])
3289 ** $_any_caller_matches(regexp [, number_of_frames])
3291 * GDB now supports the compilation and injection of source code into
3292 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3293 to compile the source code to object code, and if successful, inject
3294 and execute that code within the current context of the inferior.
3295 Currently the C language is supported. The commands used to
3296 interface with this new feature are:
3298 compile code [-raw|-r] [--] [source code]
3299 compile file [-raw|-r] filename
3303 demangle [-l language] [--] name
3304 Demangle "name" in the specified language, or the current language
3305 if elided. This command is renamed from the "maint demangle" command.
3306 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3307 as "maint demangler-warning".
3309 queue-signal signal-name-or-number
3310 Queue a signal to be delivered to the thread when it is resumed.
3312 add-auto-load-scripts-directory directory
3313 Add entries to the list of directories from which to load auto-loaded
3316 maint print user-registers
3317 List all currently available "user" registers.
3319 compile code [-r|-raw] [--] [source code]
3320 Compile, inject, and execute in the inferior the executable object
3321 code produced by compiling the provided source code.
3323 compile file [-r|-raw] filename
3324 Compile and inject into the inferior the executable object code
3325 produced by compiling the source code stored in the filename
3328 * On resume, GDB now always passes the signal the program had stopped
3329 for to the thread the signal was sent to, even if the user changed
3330 threads before resuming. Previously GDB would often (but not
3331 always) deliver the signal to the thread that happens to be current
3334 * Conversely, the "signal" command now consistently delivers the
3335 requested signal to the current thread. GDB now asks for
3336 confirmation if the program had stopped for a signal and the user
3337 switched threads meanwhile.
3339 * "breakpoint always-inserted" modes "off" and "auto" merged.
3341 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3342 won't remove breakpoints from the target until all threads stop,
3343 even in non-stop mode. The "auto" mode has been removed, and "off"
3344 is now the default mode.
3348 set debug symbol-lookup
3349 show debug symbol-lookup
3350 Control display of debugging info regarding symbol lookup.
3354 ** The -list-thread-groups command outputs an exit-code field for
3355 inferiors that have exited.
3359 MIPS SDE mips*-sde*-elf*
3363 Support for these obsolete configurations has been removed.
3365 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3366 SGI Irix-5.x mips-*-irix5*
3367 SGI Irix-6.x mips-*-irix6*
3368 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3369 VAX running Ultrix vax-*-ultrix*
3371 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3372 and "assf"), have been removed. Use the "sharedlibrary" command, or
3373 its alias "share", instead.
3375 *** Changes in GDB 7.8
3377 * New command line options
3380 This is an alias for the --data-directory option.
3382 * GDB supports printing and modifying of variable length automatic arrays
3383 as specified in ISO C99.
3385 * The ARM simulator now supports instruction level tracing
3386 with or without disassembly.
3390 GDB now has support for scripting using Guile. Whether this is
3391 available is determined at configure time.
3392 Guile version 2.0 or greater is required.
3393 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3395 * New commands (for set/show, see "New options" below)
3399 Invoke CODE by passing it to the Guile interpreter.
3403 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3405 info auto-load guile-scripts [regexp]
3406 Print the list of automatically loaded Guile scripts.
3408 * The source command is now capable of sourcing Guile scripts.
3409 This feature is dependent on the debugger being built with Guile support.
3413 set print symbol-loading (off|brief|full)
3414 show print symbol-loading
3415 Control whether to print informational messages when loading symbol
3416 information for a file. The default is "full", but when debugging
3417 programs with large numbers of shared libraries the amount of output
3418 becomes less useful.
3420 set guile print-stack (none|message|full)
3421 show guile print-stack
3422 Show a stack trace when an error is encountered in a Guile script.
3424 set auto-load guile-scripts (on|off)
3425 show auto-load guile-scripts
3426 Control auto-loading of Guile script files.
3428 maint ada set ignore-descriptive-types (on|off)
3429 maint ada show ignore-descriptive-types
3430 Control whether the debugger should ignore descriptive types in Ada
3431 programs. The default is not to ignore the descriptive types. See
3432 the user manual for more details on descriptive types and the intended
3433 usage of this option.
3435 set auto-connect-native-target
3437 Control whether GDB is allowed to automatically connect to the
3438 native target for the run, attach, etc. commands when not connected
3439 to any target yet. See also "target native" below.
3441 set record btrace replay-memory-access (read-only|read-write)
3442 show record btrace replay-memory-access
3443 Control what memory accesses are allowed during replay.
3445 maint set target-async (on|off)
3446 maint show target-async
3447 This controls whether GDB targets operate in synchronous or
3448 asynchronous mode. Normally the default is asynchronous, if it is
3449 available; but this can be changed to more easily debug problems
3450 occurring only in synchronous mode.
3452 set mi-async (on|off)
3454 Control whether MI asynchronous mode is preferred. This supersedes
3455 "set target-async" of previous GDB versions.
3457 * "set target-async" is deprecated as a CLI option and is now an alias
3458 for "set mi-async" (only puts MI into async mode).
3460 * Background execution commands (e.g., "c&", "s&", etc.) are now
3461 possible ``out of the box'' if the target supports them. Previously
3462 the user would need to explicitly enable the possibility with the
3463 "set target-async on" command.
3465 * New features in the GDB remote stub, GDBserver
3467 ** New option --debug-format=option1[,option2,...] allows one to add
3468 additional text to each output. At present only timestamps
3469 are supported: --debug-format=timestamps.
3470 Timestamps can also be turned on with the
3471 "monitor set debug-format timestamps" command from GDB.
3473 * The 'record instruction-history' command now starts counting instructions
3474 at one. This also affects the instruction ranges reported by the
3475 'record function-call-history' command when given the /i modifier.
3477 * The command 'record function-call-history' supports a new modifier '/c' to
3478 indent the function names based on their call stack depth.
3479 The fields for the '/i' and '/l' modifier have been reordered.
3480 The source line range is now prefixed with 'at'.
3481 The instruction range is now prefixed with 'inst'.
3482 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3483 "record instruction-history" and "list" commands.
3485 * The ranges given as arguments to the 'record function-call-history' and
3486 'record instruction-history' commands are now inclusive.
3488 * The btrace record target now supports the 'record goto' command.
3489 For locations inside the execution trace, the back trace is computed
3490 based on the information stored in the execution trace.
3492 * The btrace record target supports limited reverse execution and replay.
3493 The target does not record data and therefore does not allow reading
3494 memory or registers.
3496 * The "catch syscall" command now works on s390*-linux* targets.
3498 * The "compare-sections" command is no longer specific to target
3499 remote. It now works with all targets.
3501 * All native targets are now consistently called "native".
3502 Consequently, the "target child", "target GNU", "target djgpp",
3503 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3504 commands have been replaced with "target native". The QNX/NTO port
3505 leaves the "procfs" target in place and adds a "native" target for
3506 consistency with other ports. The impact on users should be minimal
3507 as these commands previously either throwed an error, or were
3508 no-ops. The target's name is visible in the output of the following
3509 commands: "help target", "info target", "info files", "maint print
3512 * The "target native" command now connects to the native target. This
3513 can be used to launch native programs even when "set
3514 auto-connect-native-target" is set to off.
3516 * GDB now supports access to Intel MPX registers on GNU/Linux.
3518 * Support for Intel AVX-512 registers on GNU/Linux.
3519 Support displaying and modifying Intel AVX-512 registers
3520 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3522 * New remote packets
3524 qXfer:btrace:read's annex
3525 The qXfer:btrace:read packet supports a new annex 'delta' to read
3526 branch trace incrementally.
3530 ** Valid Python operations on gdb.Value objects representing
3531 structs/classes invoke the corresponding overloaded operators if
3533 ** New `Xmethods' feature in the Python API. Xmethods are
3534 additional methods or replacements for existing methods of a C++
3535 class. This feature is useful for those cases where a method
3536 defined in C++ source code could be inlined or optimized out by
3537 the compiler, making it unavailable to GDB.
3540 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3542 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3543 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3544 its alias "share", instead.
3546 * The commands "set remotebaud" and "show remotebaud" are no longer
3547 supported. Use "set serial baud" and "show serial baud" (respectively)
3552 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3553 target-async". The latter is left as a deprecated alias of the
3554 former for backward compatibility. If the target supports it,
3555 CLI background execution commands are now always possible by
3556 default, independently of whether the frontend stated a
3557 preference for asynchronous execution with "-gdb-set mi-async".
3558 Previously "-gdb-set target-async off" affected both MI execution
3559 commands and CLI execution commands.
3561 *** Changes in GDB 7.7
3563 * Improved support for process record-replay and reverse debugging on
3564 arm*-linux* targets. Support for thumb32 and syscall instruction
3565 recording has been added.
3567 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3569 * GDB now supports Fission DWP file format version 2.
3570 http://gcc.gnu.org/wiki/DebugFission
3572 * New convenience function "$_isvoid", to check whether an expression
3573 is void. A void expression is an expression where the type of the
3574 result is "void". For example, some convenience variables may be
3575 "void" when evaluated (e.g., "$_exitcode" before the execution of
3576 the program being debugged; or an undefined convenience variable).
3577 Another example, when calling a function whose return type is
3580 * The "maintenance print objfiles" command now takes an optional regexp.
3582 * The "catch syscall" command now works on arm*-linux* targets.
3584 * GDB now consistently shows "<not saved>" when printing values of
3585 registers the debug info indicates have not been saved in the frame
3586 and there's nowhere to retrieve them from
3587 (callee-saved/call-clobbered registers):
3592 (gdb) info registers rax
3595 Before, the former would print "<optimized out>", and the latter
3596 "*value not available*".
3598 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3603 ** Frame filters and frame decorators have been added.
3604 ** Temporary breakpoints are now supported.
3605 ** Line tables representation has been added.
3606 ** New attribute 'parent_type' for gdb.Field objects.
3607 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3608 ** New attribute 'name' for gdb.Type objects.
3612 Nios II ELF nios2*-*-elf
3613 Nios II GNU/Linux nios2*-*-linux
3614 Texas Instruments MSP430 msp430*-*-elf
3616 * Removed native configurations
3618 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3619 been removed. ELF variants of these configurations are kept supported.
3621 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3622 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3623 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3624 i[34567]86-*-openbsd3.[0-3]
3625 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3626 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3627 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3631 Like "catch throw", but catches a re-thrown exception.
3632 maint check-psymtabs
3633 Renamed from old "maint check-symtabs".
3635 Perform consistency checks on symtabs.
3636 maint expand-symtabs
3637 Expand symtabs matching an optional regexp.
3640 Display the details of GDB configure-time options.
3642 maint set|show per-command
3643 maint set|show per-command space
3644 maint set|show per-command time
3645 maint set|show per-command symtab
3646 Enable display of per-command gdb resource usage.
3648 remove-symbol-file FILENAME
3649 remove-symbol-file -a ADDRESS
3650 Remove a symbol file added via add-symbol-file. The file to remove
3651 can be identified by its filename or by an address that lies within
3652 the boundaries of this symbol file in memory.
3655 info exceptions REGEXP
3656 Display the list of Ada exceptions defined in the program being
3657 debugged. If provided, only the exceptions whose names match REGEXP
3662 set debug symfile off|on
3664 Control display of debugging info regarding reading symbol files and
3665 symbol tables within those files
3667 set print raw frame-arguments
3668 show print raw frame-arguments
3669 Set/show whether to print frame arguments in raw mode,
3670 disregarding any defined pretty-printers.
3672 set remote trace-status-packet
3673 show remote trace-status-packet
3674 Set/show the use of remote protocol qTStatus packet.
3678 Control display of debugging messages related to Nios II targets.
3682 Control whether target-assisted range stepping is enabled.
3684 set startup-with-shell
3685 show startup-with-shell
3686 Specifies whether Unix child processes are started via a shell or
3691 Use the target memory cache for accesses to the code segment. This
3692 improves performance of remote debugging (particularly disassembly).
3694 * You can now use a literal value 'unlimited' for options that
3695 interpret 0 or -1 as meaning "unlimited". E.g., "set
3696 trace-buffer-size unlimited" is now an alias for "set
3697 trace-buffer-size -1" and "set height unlimited" is now an alias for
3700 * The "set debug symtab-create" debugging option of GDB has been changed to
3701 accept a verbosity level. 0 means "off", 1 provides basic debugging
3702 output, and values of 2 or greater provides more verbose output.
3704 * New command-line options
3706 Display the details of GDB configure-time options.
3708 * The command 'tsave' can now support new option '-ctf' to save trace
3709 buffer in Common Trace Format.
3711 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3714 * GDB now implements the C++ 'typeid' operator.
3716 * The new convenience variable $_exception holds the exception being
3717 thrown or caught at an exception-related catchpoint.
3719 * The exception-related catchpoints, like "catch throw", now accept a
3720 regular expression which can be used to filter exceptions by type.
3722 * The new convenience variable $_exitsignal is automatically set to
3723 the terminating signal number when the program being debugged dies
3724 due to an uncaught signal.
3728 ** All MI commands now accept an optional "--language" option.
3729 Support for this feature can be verified by using the "-list-features"
3730 command, which should contain "language-option".
3732 ** The new command -info-gdb-mi-command allows the user to determine
3733 whether a GDB/MI command is supported or not.
3735 ** The "^error" result record returned when trying to execute an undefined
3736 GDB/MI command now provides a variable named "code" whose content is the
3737 "undefined-command" error code. Support for this feature can be verified
3738 by using the "-list-features" command, which should contain
3739 "undefined-command-error-code".
3741 ** The -trace-save MI command can optionally save trace buffer in Common
3744 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3746 ** The command -data-list-register-values now accepts an optional
3747 "--skip-unavailable" option. When used, only the available registers
3750 ** The new command -trace-frame-collected dumps collected variables,
3751 computed expressions, tvars, memory and registers in a traceframe.
3753 ** The commands -stack-list-locals, -stack-list-arguments and
3754 -stack-list-variables now accept an option "--skip-unavailable".
3755 When used, only the available locals or arguments are displayed.
3757 ** The -exec-run command now accepts an optional "--start" option.
3758 When used, the command follows the same semantics as the "start"
3759 command, stopping the program's execution at the start of its
3760 main subprogram. Support for this feature can be verified using
3761 the "-list-features" command, which should contain
3762 "exec-run-start-option".
3764 ** The new commands -catch-assert and -catch-exceptions insert
3765 catchpoints stopping the program when Ada exceptions are raised.
3767 ** The new command -info-ada-exceptions provides the equivalent of
3768 the new "info exceptions" command.
3770 * New system-wide configuration scripts
3771 A GDB installation now provides scripts suitable for use as system-wide
3772 configuration scripts for the following systems:
3776 * GDB now supports target-assigned range stepping with remote targets.
3777 This improves the performance of stepping source lines by reducing
3778 the number of control packets from/to GDB. See "New remote packets"
3781 * GDB now understands the element 'tvar' in the XML traceframe info.
3782 It has the id of the collected trace state variables.
3784 * On S/390 targets that provide the transactional-execution feature,
3785 the program interruption transaction diagnostic block (TDB) is now
3786 represented as a number of additional "registers" in GDB.
3788 * New remote packets
3792 The vCont packet supports a new 'r' action, that tells the remote
3793 stub to step through an address range itself, without GDB
3794 involvemement at each single-step.
3796 qXfer:libraries-svr4:read's annex
3797 The previously unused annex of the qXfer:libraries-svr4:read packet
3798 is now used to support passing an argument list. The remote stub
3799 reports support for this argument list to GDB's qSupported query.
3800 The defined arguments are "start" and "prev", used to reduce work
3801 necessary for library list updating, resulting in significant
3804 * New features in the GDB remote stub, GDBserver
3806 ** GDBserver now supports target-assisted range stepping. Currently
3807 enabled on x86/x86_64 GNU/Linux targets.
3809 ** GDBserver now adds element 'tvar' in the XML in the reply to
3810 'qXfer:traceframe-info:read'. It has the id of the collected
3811 trace state variables.
3813 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3816 * New 'z' formatter for printing and examining memory, this displays the
3817 value as hexadecimal zero padded on the left to the size of the type.
3819 * GDB can now use Windows x64 unwinding data.
3821 * The "set remotebaud" command has been replaced by "set serial baud".
3822 Similarly, "show remotebaud" has been replaced by "show serial baud".
3823 The "set remotebaud" and "show remotebaud" commands are still available
3824 to provide backward compatibility with older versions of GDB.
3826 *** Changes in GDB 7.6
3828 * Target record has been renamed to record-full.
3829 Record/replay is now enabled with the "record full" command.
3830 This also affects settings that are associated with full record/replay
3831 that have been moved from "set/show record" to "set/show record full":
3833 set|show record full insn-number-max
3834 set|show record full stop-at-limit
3835 set|show record full memory-query
3837 * A new record target "record-btrace" has been added. The new target
3838 uses hardware support to record the control-flow of a process. It
3839 does not support replaying the execution, but it implements the
3840 below new commands for investigating the recorded execution log.
3841 This new recording method can be enabled using:
3845 The "record-btrace" target is only available on Intel Atom processors
3846 and requires a Linux kernel 2.6.32 or later.
3848 * Two new commands have been added for record/replay to give information
3849 about the recorded execution without having to replay the execution.
3850 The commands are only supported by "record btrace".
3852 record instruction-history prints the execution history at
3853 instruction granularity
3855 record function-call-history prints the execution history at
3856 function granularity
3858 * New native configurations
3860 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3861 FreeBSD/powerpc powerpc*-*-freebsd
3862 x86_64/Cygwin x86_64-*-cygwin*
3863 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3867 ARM AArch64 aarch64*-*-elf
3868 ARM AArch64 GNU/Linux aarch64*-*-linux
3869 Lynx 178 PowerPC powerpc-*-lynx*178
3870 x86_64/Cygwin x86_64-*-cygwin*
3871 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3873 * If the configured location of system.gdbinit file (as given by the
3874 --with-system-gdbinit option at configure time) is in the
3875 data-directory (as specified by --with-gdb-datadir at configure
3876 time) or in one of its subdirectories, then GDB will look for the
3877 system-wide init file in the directory specified by the
3878 --data-directory command-line option.
3880 * New command line options:
3882 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3883 other initialization files, unlike -nx which disables all of them.
3885 * Removed command line options
3887 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3890 * The 'ptype' and 'whatis' commands now accept an argument to control
3893 * 'info proc' now works on some core files.
3897 ** Vectors can be created with gdb.Type.vector.
3899 ** Python's atexit.register now works in GDB.
3901 ** Types can be pretty-printed via a Python API.
3903 ** Python 3 is now supported (in addition to Python 2.4 or later)
3905 ** New class gdb.Architecture exposes GDB's internal representation
3906 of architecture in the Python API.
3908 ** New method Frame.architecture returns the gdb.Architecture object
3909 corresponding to the frame's architecture.
3911 * New Python-based convenience functions:
3913 ** $_memeq(buf1, buf2, length)
3914 ** $_streq(str1, str2)
3916 ** $_regex(str, regex)
3918 * The 'cd' command now defaults to using '~' (the home directory) if not
3921 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3922 default for GCC since November 2000.
3924 * The command 'forward-search' can now be abbreviated as 'fo'.
3926 * The command 'info tracepoints' can now display 'installed on target'
3927 or 'not installed on target' for each non-pending location of tracepoint.
3929 * New configure options
3931 --enable-libmcheck/--disable-libmcheck
3932 By default, development versions are built with -lmcheck on hosts
3933 that support it, in order to help track memory corruption issues.
3934 Release versions, on the other hand, are built without -lmcheck
3935 by default. The --enable-libmcheck/--disable-libmcheck configure
3936 options allow the user to override that default.
3937 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3938 This configure option allows the user to build GDB with
3939 libbabeltrace using which GDB can read Common Trace Format data.
3941 * New commands (for set/show, see "New options" below)
3944 Catch signals. This is similar to "handle", but allows commands and
3945 conditions to be attached.
3948 List the BFDs known to GDB.
3950 python-interactive [command]
3952 Start a Python interactive prompt, or evaluate the optional command
3953 and print the result of expressions.
3956 "py" is a new alias for "python".
3958 enable type-printer [name]...
3959 disable type-printer [name]...
3960 Enable or disable type printers.
3964 ** For the Renesas Super-H architecture, the "regs" command has been removed
3965 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3970 set print type methods (on|off)
3971 show print type methods
3972 Control whether method declarations are displayed by "ptype".
3973 The default is to show them.
3975 set print type typedefs (on|off)
3976 show print type typedefs
3977 Control whether typedef definitions are displayed by "ptype".
3978 The default is to show them.
3980 set filename-display basename|relative|absolute
3981 show filename-display
3982 Control the way in which filenames is displayed.
3983 The default is "relative", which preserves previous behavior.
3985 set trace-buffer-size
3986 show trace-buffer-size
3987 Request target to change the size of trace buffer.
3989 set remote trace-buffer-size-packet auto|on|off
3990 show remote trace-buffer-size-packet
3991 Control the use of the remote protocol `QTBuffer:size' packet.
3995 Control display of debugging messages related to ARM AArch64.
3998 set debug coff-pe-read
3999 show debug coff-pe-read
4000 Control display of debugging messages related to reading of COFF/PE
4005 Control display of debugging messages related to Mach-O symbols
4008 set debug notification
4009 show debug notification
4010 Control display of debugging info for async remote notification.
4014 ** Command parameter changes are now notified using new async record
4015 "=cmd-param-changed".
4016 ** Trace frame changes caused by command "tfind" are now notified using
4017 new async record "=traceframe-changed".
4018 ** The creation, deletion and modification of trace state variables
4019 are now notified using new async records "=tsv-created",
4020 "=tsv-deleted" and "=tsv-modified".
4021 ** The start and stop of process record are now notified using new
4022 async record "=record-started" and "=record-stopped".
4023 ** Memory changes are now notified using new async record
4025 ** The data-disassemble command response will include a "fullname" field
4026 containing the absolute file name when source has been requested.
4027 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4028 command, to allow pattern filling of memory areas.
4029 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4030 library load/unload events.
4031 ** The response to breakpoint commands and breakpoint async records
4032 includes an "installed" field containing a boolean state about each
4033 non-pending tracepoint location is whether installed on target or not.
4034 ** Output of the "-trace-status" command includes a "trace-file" field
4035 containing the name of the trace file being examined. This field is
4036 optional, and only present when examining a trace file.
4037 ** The "fullname" field is now always present along with the "file" field,
4038 even if the file cannot be found by GDB.
4040 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4041 You must have the LZMA library available when configuring GDB for this
4042 feature to be enabled. For more information, see:
4043 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4045 * New remote packets
4048 Set the size of trace buffer. The remote stub reports support for this
4049 packet to gdb's qSupported query.
4052 Enable Branch Trace Store (BTS)-based branch tracing for the current
4053 thread. The remote stub reports support for this packet to gdb's
4057 Disable branch tracing for the current thread. The remote stub reports
4058 support for this packet to gdb's qSupported query.
4061 Read the traced branches for the current thread. The remote stub
4062 reports support for this packet to gdb's qSupported query.
4064 *** Changes in GDB 7.5
4066 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4067 for more x32 ABI info.
4069 * GDB now supports access to MIPS DSP registers on Linux targets.
4071 * GDB now supports debugging microMIPS binaries.
4073 * The "info os" command on GNU/Linux can now display information on
4074 several new classes of objects managed by the operating system:
4075 "info os procgroups" lists process groups
4076 "info os files" lists file descriptors
4077 "info os sockets" lists internet-domain sockets
4078 "info os shm" lists shared-memory regions
4079 "info os semaphores" lists semaphores
4080 "info os msg" lists message queues
4081 "info os modules" lists loaded kernel modules
4083 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4084 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4085 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4086 options and inspect the probe arguments using the new $_probe_arg family
4087 of convenience variables. You can obtain more information about SystemTap
4088 in <http://sourceware.org/systemtap/>.
4090 * GDB now supports reversible debugging on ARM, it allows you to
4091 debug basic ARM and THUMB instructions, and provides
4092 record/replay support.
4094 * The option "symbol-reloading" has been deleted as it is no longer used.
4098 ** GDB commands implemented in Python can now be put in command class
4101 ** The "maint set python print-stack on|off" is now deleted.
4103 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4104 apply "flag enum"-style pretty-printing to any enum.
4106 ** gdb.lookup_symbol can now work when there is no current frame.
4108 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4109 the source at which the symbol was defined.
4111 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4112 method 'value'. The former indicates whether the symbol needs a
4113 frame in order to compute its value, and the latter computes the
4116 ** A new method 'referenced_value' on gdb.Value objects which can
4117 dereference pointer as well as C++ reference values.
4119 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4120 which return the global and static blocks (as gdb.Block objects),
4121 of the underlying symbol table, respectively.
4123 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4124 object associated with a PC value.
4126 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4127 of the address range occupied by code for the current source line.
4129 * Go language support.
4130 GDB now supports debugging programs written in the Go programming
4133 * GDBserver now supports stdio connections.
4134 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4136 * The binary "gdbtui" can no longer be built or installed.
4137 Use "gdb -tui" instead.
4139 * GDB will now print "flag" enums specially. A flag enum is one where
4140 all the enumerator values have no bits in common when pairwise
4141 "and"ed. When printing a value whose type is a flag enum, GDB will
4142 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4143 (gdb) print (enum E) 3
4146 * The filename part of a linespec will now match trailing components
4147 of a source file name. For example, "break gcc/expr.c:1000" will
4148 now set a breakpoint in build/gcc/expr.c, but not
4149 build/libcpp/expr.c.
4151 * The "info proc" and "generate-core-file" commands will now also
4152 work on remote targets connected to GDBserver on Linux.
4154 * The command "info catch" has been removed. It has been disabled
4155 since December 2007.
4157 * The "catch exception" and "catch assert" commands now accept
4158 a condition at the end of the command, much like the "break"
4159 command does. For instance:
4161 (gdb) catch exception Constraint_Error if Barrier = True
4163 Previously, it was possible to add a condition to such catchpoints,
4164 but it had to be done as a second step, after the catchpoint had been
4165 created, using the "condition" command.
4167 * The "info static-tracepoint-marker" command will now also work on
4168 native Linux targets with in-process agent.
4170 * GDB can now set breakpoints on inlined functions.
4172 * The .gdb_index section has been updated to include symbols for
4173 inlined functions. GDB will ignore older .gdb_index sections by
4174 default, which could cause symbol files to be loaded more slowly
4175 until their .gdb_index sections can be recreated. The new command
4176 "set use-deprecated-index-sections on" will cause GDB to use any older
4177 .gdb_index sections it finds. This will restore performance, but the
4178 ability to set breakpoints on inlined functions will be lost in symbol
4179 files with older .gdb_index sections.
4181 The .gdb_index section has also been updated to record more information
4182 about each symbol. This speeds up the "info variables", "info functions"
4183 and "info types" commands when used with programs having the .gdb_index
4184 section, as well as speeding up debugging with shared libraries using
4185 the .gdb_index section.
4187 * Ada support for GDB/MI Variable Objects has been added.
4189 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4194 ** New command -info-os is the MI equivalent of "info os".
4196 ** Output logs ("set logging" and related) now include MI output.
4200 ** "set use-deprecated-index-sections on|off"
4201 "show use-deprecated-index-sections on|off"
4202 Controls the use of deprecated .gdb_index sections.
4204 ** "catch load" and "catch unload" can be used to stop when a shared
4205 library is loaded or unloaded, respectively.
4207 ** "enable count" can be used to auto-disable a breakpoint after
4210 ** "info vtbl" can be used to show the virtual method tables for
4211 C++ and Java objects.
4213 ** "explore" and its sub commands "explore value" and "explore type"
4214 can be used to recursively explore values and types of
4215 expressions. These commands are available only if GDB is
4216 configured with '--with-python'.
4218 ** "info auto-load" shows status of all kinds of auto-loaded files,
4219 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4220 sequences of commands files, "info auto-load python-scripts"
4221 shows status of auto-loading Python script files,
4222 "info auto-load local-gdbinit" shows status of loading init file
4223 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4224 status of inferior specific thread debugging shared library loading.
4226 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4227 and "show auto-load-scripts" commands have been deprecated, use their
4228 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4229 and "show auto-load python-scripts" counterparts instead.
4231 ** "dprintf location,format,args..." creates a dynamic printf, which
4232 is basically a breakpoint that does a printf and immediately
4233 resumes your program's execution, so it is like a printf that you
4234 can insert dynamically at runtime instead of at compiletime.
4236 ** "set print symbol"
4238 Controls whether GDB attempts to display the symbol, if any,
4239 corresponding to addresses it prints. This defaults to "on", but
4240 you can set it to "off" to restore GDB's previous behavior.
4242 * Deprecated commands
4244 ** For the Renesas Super-H architecture, the "regs" command has been
4245 deprecated, and "info all-registers" should be used instead.
4249 Renesas RL78 rl78-*-elf
4250 HP OpenVMS ia64 ia64-hp-openvms*
4252 * GDBserver supports evaluation of breakpoint conditions. When
4253 support is advertised by GDBserver, GDB may be told to send the
4254 breakpoint conditions in bytecode form to GDBserver. GDBserver
4255 will only report the breakpoint trigger to GDB when its condition
4260 set mips compression
4261 show mips compression
4262 Select the compressed ISA encoding used in functions that have no symbol
4263 information available. The encoding can be set to either of:
4266 and is updated automatically from ELF file flags if available.
4268 set breakpoint condition-evaluation
4269 show breakpoint condition-evaluation
4270 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4271 GDBserver ("target"). Default option "auto" chooses the most efficient
4273 This option can improve debugger efficiency depending on the speed of the
4277 Disable auto-loading globally.
4280 Show auto-loading setting of all kinds of auto-loaded files.
4282 set auto-load gdb-scripts on|off
4283 show auto-load gdb-scripts
4284 Control auto-loading of GDB canned sequences of commands files.
4286 set auto-load python-scripts on|off
4287 show auto-load python-scripts
4288 Control auto-loading of Python script files.
4290 set auto-load local-gdbinit on|off
4291 show auto-load local-gdbinit
4292 Control loading of init file (.gdbinit) from current directory.
4294 set auto-load libthread-db on|off
4295 show auto-load libthread-db
4296 Control auto-loading of inferior specific thread debugging shared library.
4298 set auto-load scripts-directory <dir1>[:<dir2>...]
4299 show auto-load scripts-directory
4300 Set a list of directories from which to load auto-loaded scripts.
4301 Automatically loaded Python scripts and GDB scripts are located in one
4302 of the directories listed by this option.
4303 The delimiter (':' above) may differ according to the host platform.
4305 set auto-load safe-path <dir1>[:<dir2>...]
4306 show auto-load safe-path
4307 Set a list of directories from which it is safe to auto-load files.
4308 The delimiter (':' above) may differ according to the host platform.
4310 set debug auto-load on|off
4311 show debug auto-load
4312 Control display of debugging info for auto-loading the files above.
4314 set dprintf-style gdb|call|agent
4316 Control the way in which a dynamic printf is performed; "gdb"
4317 requests a GDB printf command, while "call" causes dprintf to call a
4318 function in the inferior. "agent" requests that the target agent
4319 (such as GDBserver) do the printing.
4321 set dprintf-function <expr>
4322 show dprintf-function
4323 set dprintf-channel <expr>
4324 show dprintf-channel
4325 Set the function and optional first argument to the call when using
4326 the "call" style of dynamic printf.
4328 set disconnected-dprintf on|off
4329 show disconnected-dprintf
4330 Control whether agent-style dynamic printfs continue to be in effect
4331 after GDB disconnects.
4333 * New configure options
4335 --with-auto-load-dir
4336 Configure default value for the 'set auto-load scripts-directory'
4337 setting above. It defaults to '$debugdir:$datadir/auto-load',
4338 $debugdir representing global debugging info directories (available
4339 via 'show debug-file-directory') and $datadir representing GDB's data
4340 directory (available via 'show data-directory').
4342 --with-auto-load-safe-path
4343 Configure default value for the 'set auto-load safe-path' setting
4344 above. It defaults to the --with-auto-load-dir setting.
4346 --without-auto-load-safe-path
4347 Set 'set auto-load safe-path' to '/', effectively disabling this
4350 * New remote packets
4352 z0/z1 conditional breakpoints extension
4354 The z0/z1 breakpoint insertion packets have been extended to carry
4355 a list of conditional expressions over to the remote stub depending on the
4356 condition evaluation mode. The use of this extension can be controlled
4357 via the "set remote conditional-breakpoints-packet" command.
4361 Specify the signals which the remote stub may pass to the debugged
4362 program without GDB involvement.
4364 * New command line options
4366 --init-command=FILE, -ix Like --command, -x but execute it
4367 before loading inferior.
4368 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4369 execute it before loading inferior.
4371 *** Changes in GDB 7.4
4373 * GDB now handles ambiguous linespecs more consistently; the existing
4374 FILE:LINE support has been expanded to other types of linespecs. A
4375 breakpoint will now be set on all matching locations in all
4376 inferiors, and locations will be added or removed according to
4379 * GDB now allows you to skip uninteresting functions and files when
4380 stepping with the "skip function" and "skip file" commands.
4382 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4383 and "show remote hardware-watchpoint-length-limit". These allows to
4384 set or show the maximum length limit (in bytes) of a remote
4385 target hardware watchpoint.
4387 This allows e.g. to use "unlimited" hardware watchpoints with the
4388 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4389 watchpoints are slower than real hardware watchpoints but are
4390 significantly faster than gdb software watchpoints.
4394 ** The register_pretty_printer function in module gdb.printing now takes
4395 an optional `replace' argument. If True, the new printer replaces any
4398 ** The "maint set python print-stack on|off" command has been
4399 deprecated and will be deleted in GDB 7.5.
4400 A new command: "set python print-stack none|full|message" has
4401 replaced it. Additionally, the default for "print-stack" is
4402 now "message", which just prints the error message without
4405 ** A prompt substitution hook (prompt_hook) is now available to the
4408 ** A new Python module, gdb.prompt has been added to the GDB Python
4409 modules library. This module provides functionality for
4410 escape sequences in prompts (used by set/show
4411 extended-prompt). These escape sequences are replaced by their
4412 corresponding value.
4414 ** Python commands and convenience-functions located in
4415 'data-directory'/python/gdb/command and
4416 'data-directory'/python/gdb/function are now automatically loaded
4419 ** Blocks now provide four new attributes. global_block and
4420 static_block will return the global and static blocks
4421 respectively. is_static and is_global are boolean attributes
4422 that indicate if the block is one of those two types.
4424 ** Symbols now provide the "type" attribute, the type of the symbol.
4426 ** The "gdb.breakpoint" function has been deprecated in favor of
4429 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4430 of a function. This class is based on the "finish" command
4431 available in the CLI.
4433 ** Type objects for struct and union types now allow access to
4434 the fields using standard Python dictionary (mapping) methods.
4435 For example, "some_type['myfield']" now works, as does
4436 "some_type.items()".
4438 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4441 ** A new function, "deep_items" has been added to the gdb.types
4442 module in the GDB Python modules library. This function returns
4443 an iterator over the fields of a struct or union type. Unlike
4444 the standard Python "iteritems" method, it will recursively traverse
4445 any anonymous fields.
4449 ** "*stopped" events can report several new "reason"s, such as
4452 ** Breakpoint changes are now notified using new async records, like
4453 "=breakpoint-modified".
4455 ** New command -ada-task-info.
4457 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4458 $sdir specifies the default system locations of shared libraries.
4459 $pdir specifies the directory where the libpthread used by the application
4462 GDB no longer looks in $sdir and $pdir after it has searched the directories
4463 mentioned in libthread-db-search-path. If you want to search those
4464 directories, they must be specified in libthread-db-search-path.
4465 The default value of libthread-db-search-path on GNU/Linux and Solaris
4466 systems is now "$sdir:$pdir".
4468 $pdir is not supported by gdbserver, it is currently ignored.
4469 $sdir is supported by gdbserver.
4471 * New configure option --with-iconv-bin.
4472 When using the internationalization support like the one in the GNU C
4473 library, GDB will invoke the "iconv" program to get a list of supported
4474 character sets. If this program lives in a non-standard location, one can
4475 use this option to specify where to find it.
4477 * When natively debugging programs on PowerPC BookE processors running
4478 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4479 watchpoints, which specify a mask in addition to an address to watch.
4480 The mask specifies that some bits of an address (the bits which are
4481 reset in the mask) should be ignored when matching the address accessed
4482 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4483 section in the user manual for more details.
4485 * The new option --once causes GDBserver to stop listening for connections once
4486 the first connection is made. The listening port used by GDBserver will
4487 become available after that.
4489 * New commands "info macros" and "alias" have been added.
4491 * New function parameters suffix @entry specifies value of function parameter
4492 at the time the function got called. Entry values are available only since
4498 "!" is now an alias of the "shell" command.
4499 Note that no space is needed between "!" and SHELL COMMAND.
4503 watch EXPRESSION mask MASK_VALUE
4504 The watch command now supports the mask argument which allows creation
4505 of masked watchpoints, if the current architecture supports this feature.
4507 info auto-load-scripts [REGEXP]
4508 This command was formerly named "maintenance print section-scripts".
4509 It is now generally useful and is no longer a maintenance-only command.
4511 info macro [-all] [--] MACRO
4512 The info macro command has new options `-all' and `--'. The first for
4513 printing all definitions of a macro. The second for explicitly specifying
4514 the end of arguments and the beginning of the macro name in case the macro
4515 name starts with a hyphen.
4517 collect[/s] EXPRESSIONS
4518 The tracepoint collect command now takes an optional modifier "/s"
4519 that directs it to dereference pointer-to-character types and
4520 collect the bytes of memory up to a zero byte. The behavior is
4521 similar to what you see when you use the regular print command on a
4522 string. An optional integer following the "/s" sets a bound on the
4523 number of bytes that will be collected.
4526 The trace start command now interprets any supplied arguments as a
4527 note to be recorded with the trace run, with an effect similar to
4528 setting the variable trace-notes.
4531 The trace stop command now interprets any arguments as a note to be
4532 mentioned along with the tstatus report that the trace was stopped
4533 with a command. The effect is similar to setting the variable
4536 * Tracepoints can now be enabled and disabled at any time after a trace
4537 experiment has been started using the standard "enable" and "disable"
4538 commands. It is now possible to start a trace experiment with no enabled
4539 tracepoints; GDB will display a warning, but will allow the experiment to
4540 begin, assuming that tracepoints will be enabled as needed while the trace
4543 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4544 locations with 4-byte instructions, when they were previously
4545 limited to locations with instructions of 5 bytes or longer.
4549 set debug dwarf2-read
4550 show debug dwarf2-read
4551 Turns on or off display of debugging messages related to reading
4552 DWARF debug info. The default is off.
4554 set debug symtab-create
4555 show debug symtab-create
4556 Turns on or off display of debugging messages related to symbol table
4557 creation. The default is off.
4560 show extended-prompt
4561 Set the GDB prompt, and allow escape sequences to be inserted to
4562 display miscellaneous information (see 'help set extended-prompt'
4563 for the list of sequences). This prompt (and any information
4564 accessed through the escape sequences) is updated every time the
4565 prompt is displayed.
4567 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4568 show print entry-values
4569 Set printing of frame argument values at function entry. In some cases
4570 GDB can determine the value of function argument which was passed by the
4571 function caller, even if the value was modified inside the called function.
4573 set debug entry-values
4574 show debug entry-values
4575 Control display of debugging info for determining frame argument values at
4576 function entry and virtual tail call frames.
4578 set basenames-may-differ
4579 show basenames-may-differ
4580 Set whether a source file may have multiple base names.
4581 (A "base name" is the name of a file with the directory part removed.
4582 Example: The base name of "/home/user/hello.c" is "hello.c".)
4583 If set, GDB will canonicalize file names (e.g., expand symlinks)
4584 before comparing them. Canonicalization is an expensive operation,
4585 but it allows the same file be known by more than one base name.
4586 If not set (the default), all source files are assumed to have just
4587 one base name, and gdb will do file name comparisons more efficiently.
4593 Set a user name and notes for the current and any future trace runs.
4594 This is useful for long-running and/or disconnected traces, to
4595 inform others (or yourself) as to who is running the trace, supply
4596 contact information, or otherwise explain what is going on.
4598 set trace-stop-notes
4599 show trace-stop-notes
4600 Set a note attached to the trace run, that is displayed when the
4601 trace has been stopped by a tstop command. This is useful for
4602 instance as an explanation, if you are stopping a trace run that was
4603 started by someone else.
4605 * New remote packets
4609 Dynamically enable a tracepoint in a started trace experiment.
4613 Dynamically disable a tracepoint in a started trace experiment.
4617 Set the user and notes of the trace run.
4621 Query the current status of a tracepoint.
4625 Query the minimum length of instruction at which a fast tracepoint may
4628 * Dcache size (number of lines) and line-size are now runtime-configurable
4629 via "set dcache line" and "set dcache line-size" commands.
4633 Texas Instruments TMS320C6x tic6x-*-*
4637 Renesas RL78 rl78-*-elf
4639 *** Changes in GDB 7.3.1
4641 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4643 *** Changes in GDB 7.3
4645 * GDB has a new command: "thread find [REGEXP]".
4646 It finds the thread id whose name, target id, or thread extra info
4647 matches the given regular expression.
4649 * The "catch syscall" command now works on mips*-linux* targets.
4651 * The -data-disassemble MI command now supports modes 2 and 3 for
4652 dumping the instruction opcodes.
4654 * New command line options
4656 -data-directory DIR Specify DIR as the "data-directory".
4657 This is mostly for testing purposes.
4659 * The "maint set python auto-load on|off" command has been renamed to
4660 "set auto-load-scripts on|off".
4662 * GDB has a new command: "set directories".
4663 It is like the "dir" command except that it replaces the
4664 source path list instead of augmenting it.
4666 * GDB now understands thread names.
4668 On GNU/Linux, "info threads" will display the thread name as set by
4669 prctl or pthread_setname_np.
4671 There is also a new command, "thread name", which can be used to
4672 assign a name internally for GDB to display.
4675 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4676 has been integrated into GDB.
4680 ** The function gdb.Write now accepts an optional keyword 'stream'.
4681 This keyword, when provided, will direct the output to either
4682 stdout, stderr, or GDB's logging output.
4684 ** Parameters can now be be sub-classed in Python, and in particular
4685 you may implement the get_set_doc and get_show_doc functions.
4686 This improves how Parameter set/show documentation is processed
4687 and allows for more dynamic content.
4689 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4690 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4691 have an is_valid method.
4693 ** Breakpoints can now be sub-classed in Python, and in particular
4694 you may implement a 'stop' function that is executed each time
4695 the inferior reaches that breakpoint.
4697 ** New function gdb.lookup_global_symbol looks up a global symbol.
4699 ** GDB values in Python are now callable if the value represents a
4700 function. For example, if 'some_value' represents a function that
4701 takes two integer parameters and returns a value, you can call
4702 that function like so:
4704 result = some_value (10,20)
4706 ** Module gdb.types has been added.
4707 It contains a collection of utilities for working with gdb.Types objects:
4708 get_basic_type, has_field, make_enum_dict.
4710 ** Module gdb.printing has been added.
4711 It contains utilities for writing and registering pretty-printers.
4712 New classes: PrettyPrinter, SubPrettyPrinter,
4713 RegexpCollectionPrettyPrinter.
4714 New function: register_pretty_printer.
4716 ** New commands "info pretty-printers", "enable pretty-printer" and
4717 "disable pretty-printer" have been added.
4719 ** gdb.parameter("directories") is now available.
4721 ** New function gdb.newest_frame returns the newest frame in the
4724 ** The gdb.InferiorThread class has a new "name" attribute. This
4725 holds the thread's name.
4727 ** Python Support for Inferior events.
4728 Python scripts can add observers to be notified of events
4729 occurring in the process being debugged.
4730 The following events are currently supported:
4731 - gdb.events.cont Continue event.
4732 - gdb.events.exited Inferior exited event.
4733 - gdb.events.stop Signal received, and Breakpoint hit events.
4737 ** GDB now puts template parameters in scope when debugging in an
4738 instantiation. For example, if you have:
4740 template<int X> int func (void) { return X; }
4742 then if you step into func<5>, "print X" will show "5". This
4743 feature requires proper debuginfo support from the compiler; it
4744 was added to GCC 4.5.
4746 ** The motion commands "next", "finish", "until", and "advance" now
4747 work better when exceptions are thrown. In particular, GDB will
4748 no longer lose control of the inferior; instead, the GDB will
4749 stop the inferior at the point at which the exception is caught.
4750 This functionality requires a change in the exception handling
4751 code that was introduced in GCC 4.5.
4753 * GDB now follows GCC's rules on accessing volatile objects when
4754 reading or writing target state during expression evaluation.
4755 One notable difference to prior behavior is that "print x = 0"
4756 no longer generates a read of x; the value of the assignment is
4757 now always taken directly from the value being assigned.
4759 * GDB now has some support for using labels in the program's source in
4760 linespecs. For instance, you can use "advance label" to continue
4761 execution to a label.
4763 * GDB now has support for reading and writing a new .gdb_index
4764 section. This section holds a fast index of DWARF debugging
4765 information and can be used to greatly speed up GDB startup and
4766 operation. See the documentation for `save gdb-index' for details.
4768 * The "watch" command now accepts an optional "-location" argument.
4769 When used, this causes GDB to watch the memory referred to by the
4770 expression. Such a watchpoint is never deleted due to it going out
4773 * GDB now supports thread debugging of core dumps on GNU/Linux.
4775 GDB now activates thread debugging using the libthread_db library
4776 when debugging GNU/Linux core dumps, similarly to when debugging
4777 live processes. As a result, when debugging a core dump file, GDB
4778 is now able to display pthread_t ids of threads. For example, "info
4779 threads" shows the same output as when debugging the process when it
4780 was live. In earlier releases, you'd see something like this:
4783 * 1 LWP 6780 main () at main.c:10
4785 While now you see this:
4788 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4790 It is also now possible to inspect TLS variables when debugging core
4793 When debugging a core dump generated on a machine other than the one
4794 used to run GDB, you may need to point GDB at the correct
4795 libthread_db library with the "set libthread-db-search-path"
4796 command. See the user manual for more details on this command.
4798 * When natively debugging programs on PowerPC BookE processors running
4799 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4800 which stop execution of the inferior whenever it executes an instruction
4801 at any address within the specified range. See the "PowerPC Embedded"
4802 section in the user manual for more details.
4804 * New features in the GDB remote stub, GDBserver
4806 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4807 and i686 LynxOS (version 5.x).
4809 ** GDBserver is now supported on Blackfin Linux.
4811 * New native configurations
4813 ia64 HP-UX ia64-*-hpux*
4817 Analog Devices, Inc. Blackfin Processor bfin-*
4819 * Ada task switching is now supported on sparc-elf targets when
4820 debugging a program using the Ravenscar Profile. For more information,
4821 see the "Tasking Support when using the Ravenscar Profile" section
4822 in the GDB user manual.
4824 * Guile support was removed.
4826 * New features in the GNU simulator
4828 ** The --map-info flag lists all known core mappings.
4830 ** CFI flashes may be simulated via the "cfi" device.
4832 *** Changes in GDB 7.2
4834 * Shared library support for remote targets by default
4836 When GDB is configured for a generic, non-OS specific target, like
4837 for example, --target=arm-eabi or one of the many *-*-elf targets,
4838 GDB now queries remote stubs for loaded shared libraries using the
4839 `qXfer:libraries:read' packet. Previously, shared library support
4840 was always disabled for such configurations.
4844 ** Argument Dependent Lookup (ADL)
4846 In C++ ADL lookup directs function search to the namespaces of its
4847 arguments even if the namespace has not been imported.
4857 Here the compiler will search for `foo' in the namespace of 'b'
4858 and find A::foo. GDB now supports this. This construct is commonly
4859 used in the Standard Template Library for operators.
4861 ** Improved User Defined Operator Support
4863 In addition to member operators, GDB now supports lookup of operators
4864 defined in a namespace and imported with a `using' directive, operators
4865 defined in the global scope, operators imported implicitly from an
4866 anonymous namespace, and the ADL operators mentioned in the previous
4868 GDB now also supports proper overload resolution for all the previously
4869 mentioned flavors of operators.
4871 ** static const class members
4873 Printing of static const class members that are initialized in the
4874 class definition has been fixed.
4876 * Windows Thread Information Block access.
4878 On Windows targets, GDB now supports displaying the Windows Thread
4879 Information Block (TIB) structure. This structure is visible either
4880 by using the new command `info w32 thread-information-block' or, by
4881 dereferencing the new convenience variable named `$_tlb', a
4882 thread-specific pointer to the TIB. This feature is also supported
4883 when remote debugging using GDBserver.
4885 * Static tracepoints
4887 Static tracepoints are calls in the user program into a tracing
4888 library. One such library is a port of the LTTng kernel tracer to
4889 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4890 When debugging with GDBserver, GDB now supports combining the GDB
4891 tracepoint machinery with such libraries. For example: the user can
4892 use GDB to probe a static tracepoint marker (a call from the user
4893 program into the tracing library) with the new "strace" command (see
4894 "New commands" below). This creates a "static tracepoint" in the
4895 breakpoint list, that can be manipulated with the same feature set
4896 as fast and regular tracepoints. E.g., collect registers, local and
4897 global variables, collect trace state variables, and define
4898 tracepoint conditions. In addition, the user can collect extra
4899 static tracepoint marker specific data, by collecting the new
4900 $_sdata internal variable. When analyzing the trace buffer, you can
4901 inspect $_sdata like any other variable available to GDB. For more
4902 information, see the "Tracepoints" chapter in GDB user manual. New
4903 remote packets have been defined to support static tracepoints, see
4904 the "New remote packets" section below.
4906 * Better reconstruction of tracepoints after disconnected tracing
4908 GDB will attempt to download the original source form of tracepoint
4909 definitions when starting a trace run, and then will upload these
4910 upon reconnection to the target, resulting in a more accurate
4911 reconstruction of the tracepoints that are in use on the target.
4915 You can now exercise direct control over the ways that GDB can
4916 affect your program. For instance, you can disallow the setting of
4917 breakpoints, so that the program can run continuously (assuming
4918 non-stop mode). In addition, the "observer" variable is available
4919 to switch all of the different controls; in observer mode, GDB
4920 cannot affect the target's behavior at all, which is useful for
4921 tasks like diagnosing live systems in the field.
4923 * The new convenience variable $_thread holds the number of the
4926 * New remote packets
4930 Return the address of the Windows Thread Information Block of a given thread.
4934 In response to several of the tracepoint packets, the target may now
4935 also respond with a number of intermediate `qRelocInsn' request
4936 packets before the final result packet, to have GDB handle
4937 relocating an instruction to execute at a different address. This
4938 is particularly useful for stubs that support fast tracepoints. GDB
4939 reports support for this feature in the qSupported packet.
4943 List static tracepoint markers in the target program.
4947 List static tracepoint markers at a given address in the target
4950 qXfer:statictrace:read
4952 Read the static trace data collected (by a `collect $_sdata'
4953 tracepoint action). The remote stub reports support for this packet
4954 to gdb's qSupported query.
4958 Send the current settings of GDB's permission flags.
4962 Send part of the source (textual) form of a tracepoint definition,
4963 which includes location, conditional, and action list.
4965 * The source command now accepts a -s option to force searching for the
4966 script in the source search path even if the script name specifies
4969 * New features in the GDB remote stub, GDBserver
4971 - GDBserver now support tracepoints (including fast tracepoints, and
4972 static tracepoints). The feature is currently supported by the
4973 i386-linux and amd64-linux builds. See the "Tracepoints support
4974 in gdbserver" section in the manual for more information.
4976 GDBserver JIT compiles the tracepoint's conditional agent
4977 expression bytecode into native code whenever possible for low
4978 overhead dynamic tracepoints conditionals. For such tracepoints,
4979 an expression that examines program state is evaluated when the
4980 tracepoint is reached, in order to determine whether to capture
4981 trace data. If the condition is simple and false, processing the
4982 tracepoint finishes very quickly and no data is gathered.
4984 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4985 for static tracepoints support.
4987 - GDBserver now supports x86_64 Windows 64-bit debugging.
4989 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4990 it understands register description.
4992 * The --batch flag now disables pagination and queries.
4994 * X86 general purpose registers
4996 GDB now supports reading/writing byte, word and double-word x86
4997 general purpose registers directly. This means you can use, say,
4998 $ah or $ax to refer, respectively, to the byte register AH and
4999 16-bit word register AX that are actually portions of the 32-bit
5000 register EAX or 64-bit register RAX.
5002 * The `commands' command now accepts a range of breakpoints to modify.
5003 A plain `commands' following a command that creates multiple
5004 breakpoints affects all the breakpoints set by that command. This
5005 applies to breakpoints set by `rbreak', and also applies when a
5006 single `break' command creates multiple breakpoints (e.g.,
5007 breakpoints on overloaded c++ functions).
5009 * The `rbreak' command now accepts a filename specification as part of
5010 its argument, limiting the functions selected by the regex to those
5011 in the specified file.
5013 * Support for remote debugging Windows and SymbianOS shared libraries
5014 from Unix hosts has been improved. Non Windows GDB builds now can
5015 understand target reported file names that follow MS-DOS based file
5016 system semantics, such as file names that include drive letters and
5017 use the backslash character as directory separator. This makes it
5018 possible to transparently use the "set sysroot" and "set
5019 solib-search-path" on Unix hosts to point as host copies of the
5020 target's shared libraries. See the new command "set
5021 target-file-system-kind" described below, and the "Commands to
5022 specify files" section in the user manual for more information.
5026 eval template, expressions...
5027 Convert the values of one or more expressions under the control
5028 of the string template to a command line, and call it.
5030 set target-file-system-kind unix|dos-based|auto
5031 show target-file-system-kind
5032 Set or show the assumed file system kind for target reported file
5035 save breakpoints <filename>
5036 Save all current breakpoint definitions to a file suitable for use
5037 in a later debugging session. To read the saved breakpoint
5038 definitions, use the `source' command.
5040 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5043 info static-tracepoint-markers
5044 Display information about static tracepoint markers in the target.
5046 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5047 Define a static tracepoint by probing a marker at the given
5048 function, line, address, or marker ID.
5052 Enable and disable observer mode.
5054 set may-write-registers on|off
5055 set may-write-memory on|off
5056 set may-insert-breakpoints on|off
5057 set may-insert-tracepoints on|off
5058 set may-insert-fast-tracepoints on|off
5059 set may-interrupt on|off
5060 Set individual permissions for GDB effects on the target. Note that
5061 some of these settings can have undesirable or surprising
5062 consequences, particularly when changed in the middle of a session.
5063 For instance, disabling the writing of memory can prevent
5064 breakpoints from being inserted, cause single-stepping to fail, or
5065 even crash your program, if you disable after breakpoints have been
5066 inserted. However, GDB should not crash.
5068 set record memory-query on|off
5069 show record memory-query
5070 Control whether to stop the inferior if memory changes caused
5071 by an instruction cannot be recorded.
5076 The disassemble command now supports "start,+length" form of two arguments.
5080 ** GDB now provides a new directory location, called the python directory,
5081 where Python scripts written for GDB can be installed. The location
5082 of that directory is <data-directory>/python, where <data-directory>
5083 is the GDB data directory. For more details, see section `Scripting
5084 GDB using Python' in the manual.
5086 ** The GDB Python API now has access to breakpoints, symbols, symbol
5087 tables, program spaces, inferiors, threads and frame's code blocks.
5088 Additionally, GDB Parameters can now be created from the API, and
5089 manipulated via set/show in the CLI.
5091 ** New functions gdb.target_charset, gdb.target_wide_charset,
5092 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5094 ** New exception gdb.GdbError.
5096 ** Pretty-printers are now also looked up in the current program space.
5098 ** Pretty-printers can now be individually enabled and disabled.
5100 ** GDB now looks for names of Python scripts to auto-load in a
5101 special section named `.debug_gdb_scripts', in addition to looking
5102 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5104 * Tracepoint actions were unified with breakpoint commands. In particular,
5105 there are no longer differences in "info break" output for breakpoints and
5106 tracepoints and the "commands" command can be used for both tracepoints and
5107 regular breakpoints.
5111 ARM Symbian arm*-*-symbianelf*
5113 * D language support.
5114 GDB now supports debugging programs written in the D programming
5117 * GDB now supports the extended ptrace interface for PowerPC which is
5118 available since Linux kernel version 2.6.34. This automatically enables
5119 any hardware breakpoints and additional hardware watchpoints available in
5120 the processor. The old ptrace interface exposes just one hardware
5121 watchpoint and no hardware breakpoints.
5123 * GDB is now able to use the Data Value Compare (DVC) register available on
5124 embedded PowerPC processors to implement in hardware simple watchpoint
5125 conditions of the form:
5127 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5129 This works in native GDB running on Linux kernels with the extended ptrace
5130 interface mentioned above.
5132 *** Changes in GDB 7.1
5136 ** Namespace Support
5138 GDB now supports importing of namespaces in C++. This enables the
5139 user to inspect variables from imported namespaces. Support for
5140 namepace aliasing has also been added. So, if a namespace is
5141 aliased in the current scope (e.g. namepace C=A; ) the user can
5142 print variables using the alias (e.g. (gdb) print C::x).
5146 All known bugs relating to the printing of virtual base class were
5147 fixed. It is now possible to call overloaded static methods using a
5152 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5153 and reinterpret_cast<> are now handled by the C++ expression parser.
5157 Xilinx MicroBlaze microblaze-*-*
5162 Xilinx MicroBlaze microblaze
5165 * Multi-program debugging.
5167 GDB now has support for multi-program (a.k.a. multi-executable or
5168 multi-exec) debugging. This allows for debugging multiple inferiors
5169 simultaneously each running a different program under the same GDB
5170 session. See "Debugging Multiple Inferiors and Programs" in the
5171 manual for more information. This implied some user visible changes
5172 in the multi-inferior support. For example, "info inferiors" now
5173 lists inferiors that are not running yet or that have exited
5174 already. See also "New commands" and "New options" below.
5176 * New tracing features
5178 GDB's tracepoint facility now includes several new features:
5180 ** Trace state variables
5182 GDB tracepoints now include support for trace state variables, which
5183 are variables managed by the target agent during a tracing
5184 experiment. They are useful for tracepoints that trigger each
5185 other, so for instance one tracepoint can count hits in a variable,
5186 and then a second tracepoint has a condition that is true when the
5187 count reaches a particular value. Trace state variables share the
5188 $-syntax of GDB convenience variables, and can appear in both
5189 tracepoint actions and condition expressions. Use the "tvariable"
5190 command to create, and "info tvariables" to view; see "Trace State
5191 Variables" in the manual for more detail.
5195 GDB now includes an option for defining fast tracepoints, which
5196 targets may implement more efficiently, such as by installing a jump
5197 into the target agent rather than a trap instruction. The resulting
5198 speedup can be by two orders of magnitude or more, although the
5199 tradeoff is that some program locations on some target architectures
5200 might not allow fast tracepoint installation, for instance if the
5201 instruction to be replaced is shorter than the jump. To request a
5202 fast tracepoint, use the "ftrace" command, with syntax identical to
5203 the regular trace command.
5205 ** Disconnected tracing
5207 It is now possible to detach GDB from the target while it is running
5208 a trace experiment, then reconnect later to see how the experiment
5209 is going. In addition, a new variable disconnected-tracing lets you
5210 tell the target agent whether to continue running a trace if the
5211 connection is lost unexpectedly.
5215 GDB now has the ability to save the trace buffer into a file, and
5216 then use that file as a target, similarly to you can do with
5217 corefiles. You can select trace frames, print data that was
5218 collected in them, and use tstatus to display the state of the
5219 tracing run at the moment that it was saved. To create a trace
5220 file, use "tsave <filename>", and to use it, do "target tfile
5223 ** Circular trace buffer
5225 You can ask the target agent to handle the trace buffer as a
5226 circular buffer, discarding the oldest trace frames to make room for
5227 newer ones, by setting circular-trace-buffer to on. This feature may
5228 not be available for all target agents.
5233 The disassemble command, when invoked with two arguments, now requires
5234 the arguments to be comma-separated.
5237 The info variables command now displays variable definitions. Files
5238 which only declare a variable are not shown.
5241 The source command is now capable of sourcing Python scripts.
5242 This feature is dependent on the debugger being build with Python
5245 Related to this enhancement is also the introduction of a new command
5246 "set script-extension" (see below).
5248 * New commands (for set/show, see "New options" below)
5250 record save [<FILENAME>]
5251 Save a file (in core file format) containing the process record
5252 execution log for replay debugging at a later time.
5254 record restore <FILENAME>
5255 Restore the process record execution log that was saved at an
5256 earlier time, for replay debugging.
5258 add-inferior [-copies <N>] [-exec <FILENAME>]
5261 clone-inferior [-copies <N>] [ID]
5262 Make a new inferior ready to execute the same program another
5263 inferior has loaded.
5268 maint info program-spaces
5269 List the program spaces loaded into GDB.
5271 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5272 show remote interrupt-sequence
5273 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5274 as the sequence to the remote target in order to interrupt the execution.
5275 Ctrl-C is a default. Some system prefers BREAK which is high level of
5276 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5277 Magic SysRq g. It is BREAK signal and character 'g'.
5279 set remote interrupt-on-connect [on | off]
5280 show remote interrupt-on-connect
5281 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5282 remote target when gdb connects to it. This is needed when you debug
5285 set remotebreak [on | off]
5287 Deprecated. Use "set/show remote interrupt-sequence" instead.
5289 tvariable $NAME [ = EXP ]
5290 Create or modify a trace state variable.
5293 List trace state variables and their values.
5295 delete tvariable $NAME ...
5296 Delete one or more trace state variables.
5299 Evaluate the given expressions without collecting anything into the
5300 trace buffer. (Valid in tracepoint actions only.)
5302 ftrace FN / FILE:LINE / *ADDR
5303 Define a fast tracepoint at the given function, line, or address.
5305 * New expression syntax
5307 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5308 GDB now parses 0b101010 identically with 42.
5312 set follow-exec-mode new|same
5313 show follow-exec-mode
5314 Control whether GDB reuses the same inferior across an exec call or
5315 creates a new one. This is useful to be able to restart the old
5316 executable after the inferior having done an exec call.
5318 set default-collect EXPR, ...
5319 show default-collect
5320 Define a list of expressions to be collected at each tracepoint.
5321 This is a useful way to ensure essential items are not overlooked,
5322 such as registers or a critical global variable.
5324 set disconnected-tracing
5325 show disconnected-tracing
5326 If set to 1, the target is instructed to continue tracing if it
5327 loses its connection to GDB. If 0, the target is to stop tracing
5330 set circular-trace-buffer
5331 show circular-trace-buffer
5332 If set to on, the target is instructed to use a circular trace buffer
5333 and discard the oldest trace frames instead of stopping the trace due
5334 to a full trace buffer. If set to off, the trace stops when the buffer
5335 fills up. Some targets may not support this.
5337 set script-extension off|soft|strict
5338 show script-extension
5339 If set to "off", the debugger does not perform any script language
5340 recognition, and all sourced files are assumed to be GDB scripts.
5341 If set to "soft" (the default), files are sourced according to
5342 filename extension, falling back to GDB scripts if the first
5344 If set to "strict", files are sourced according to filename extension.
5346 set ada trust-PAD-over-XVS on|off
5347 show ada trust-PAD-over-XVS
5348 If off, activate a workaround against a bug in the debugging information
5349 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5350 the GCC sources for more information about the GNAT encoding and
5351 PAD types in particular). It is always safe to set this option to
5352 off, but this introduces a slight performance penalty. The default
5355 * Python API Improvements
5357 ** GDB provides the new class gdb.LazyString. This is useful in
5358 some pretty-printing cases. The new method gdb.Value.lazy_string
5359 provides a simple way to create objects of this type.
5361 ** The fields returned by gdb.Type.fields now have an
5362 `is_base_class' attribute.
5364 ** The new method gdb.Type.range returns the range of an array type.
5366 ** The new method gdb.parse_and_eval can be used to parse and
5367 evaluate an expression.
5369 * New remote packets
5372 Define a trace state variable.
5375 Get the current value of a trace state variable.
5378 Set desired tracing behavior upon disconnection.
5381 Set the trace buffer to be linear or circular.
5384 Get data about the tracepoints currently in use.
5388 Process record now works correctly with hardware watchpoints.
5390 Multiple bug fixes have been made to the mips-irix port, making it
5391 much more reliable. In particular:
5392 - Debugging threaded applications is now possible again. Previously,
5393 GDB would hang while starting the program, or while waiting for
5394 the program to stop at a breakpoint.
5395 - Attaching to a running process no longer hangs.
5396 - An error occurring while loading a core file has been fixed.
5397 - Changing the value of the PC register now works again. This fixes
5398 problems observed when using the "jump" command, or when calling
5399 a function from GDB, or even when assigning a new value to $pc.
5400 - With the "finish" and "return" commands, the return value for functions
5401 returning a small array is now correctly printed.
5402 - It is now possible to break on shared library code which gets executed
5403 during a shared library init phase (code executed while executing
5404 their .init section). Previously, the breakpoint would have no effect.
5405 - GDB is now able to backtrace through the signal handler for
5406 non-threaded programs.
5408 PIE (Position Independent Executable) programs debugging is now supported.
5409 This includes debugging execution of PIC (Position Independent Code) shared
5410 libraries although for that, it should be possible to run such libraries as an
5413 *** Changes in GDB 7.0
5415 * GDB now has an interface for JIT compilation. Applications that
5416 dynamically generate code can create symbol files in memory and register
5417 them with GDB. For users, the feature should work transparently, and
5418 for JIT developers, the interface is documented in the GDB manual in the
5419 "JIT Compilation Interface" chapter.
5421 * Tracepoints may now be conditional. The syntax is as for
5422 breakpoints; either an "if" clause appended to the "trace" command,
5423 or the "condition" command is available. GDB sends the condition to
5424 the target for evaluation using the same bytecode format as is used
5425 for tracepoint actions.
5427 * The disassemble command now supports: an optional /r modifier, print the
5428 raw instructions in hex as well as in symbolic form, and an optional /m
5429 modifier to print mixed source+assembly.
5431 * Process record and replay
5433 In a architecture environment that supports ``process record and
5434 replay'', ``process record and replay'' target can record a log of
5435 the process execution, and replay it with both forward and reverse
5438 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5439 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5440 set execution-direction {forward|reverse}, for targets that support
5443 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5444 feature is available with a native GDB running on kernel version
5447 * GDB now has support for multi-byte and wide character sets on the
5448 target. Strings whose character type is wchar_t, char16_t, or
5449 char32_t are now correctly printed. GDB supports wide- and unicode-
5450 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5451 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5452 `printf'. This feature requires iconv to work properly; if your
5453 system does not have a working iconv, GDB can use GNU libiconv. See
5454 the installation instructions for more information.
5456 * GDB now supports automatic retrieval of shared library files from
5457 remote targets. To use this feature, specify a system root that begins
5458 with the `remote:' prefix, either via the `set sysroot' command or via
5459 the `--with-sysroot' configure-time option.
5461 * "info sharedlibrary" now takes an optional regex of libraries to show,
5462 and it now reports if a shared library has no debugging information.
5464 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5465 now complete on file names.
5467 * When completing in expressions, gdb will attempt to limit
5468 completions to allowable structure or union fields, where appropriate.
5469 For instance, consider:
5471 # struct example { int f1; double f2; };
5472 # struct example variable;
5475 If the user types TAB at the end of this command line, the available
5476 completions will be "f1" and "f2".
5478 * Inlined functions are now supported. They show up in backtraces, and
5479 the "step", "next", and "finish" commands handle them automatically.
5481 * GDB now supports the token-splicing (##) and stringification (#)
5482 operators when expanding macros. It also supports variable-arity
5485 * GDB now supports inspecting extra signal information, exported by
5486 the new $_siginfo convenience variable. The feature is currently
5487 implemented on linux ARM, i386 and amd64.
5489 * GDB can now display the VFP floating point registers and NEON vector
5490 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5491 can provide these registers (requires Linux 2.6.30 or later). Remote
5492 and simulator targets may also provide them.
5494 * New remote packets
5497 Search memory for a sequence of bytes.
5500 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5501 operation over reliable transport links. Use of this packet is
5502 controlled by the `set remote noack-packet' command.
5505 Kill the process with the specified process ID. Use this in preference
5506 to `k' when multiprocess protocol extensions are supported.
5509 Obtains additional operating system information
5513 Read or write additional signal information.
5515 * Removed remote protocol undocumented extension
5517 An undocumented extension to the remote protocol's `S' stop reply
5518 packet that permitted the stub to pass a process id was removed.
5519 Remote servers should use the `T' stop reply packet instead.
5521 * GDB now supports multiple function calling conventions according to the
5522 DWARF-2 DW_AT_calling_convention function attribute.
5524 * The SH target utilizes the aforementioned change to distinguish between gcc
5525 and Renesas calling convention. It also adds the new CLI commands
5526 `set/show sh calling-convention'.
5528 * GDB can now read compressed debug sections, as produced by GNU gold
5529 with the --compress-debug-sections=zlib flag.
5531 * 64-bit core files are now supported on AIX.
5533 * Thread switching is now supported on Tru64.
5535 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5536 which will be allocated using malloc later in program execution.
5538 * The qXfer:libraries:read remote protocol packet now allows passing a
5539 list of section offsets.
5541 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5542 conditions handling signals delivered during attach or thread creation
5543 have also been fixed.
5545 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5546 From the user's standpoint, all unqualified instances of True and False
5547 are treated as the standard definitions, regardless of context.
5549 * GDB now parses C++ symbol and type names more flexibly. For
5552 template<typename T> class C { };
5555 GDB will now correctly handle all of:
5557 ptype C<char const *>
5558 ptype C<char const*>
5559 ptype C<const char *>
5560 ptype C<const char*>
5562 * New features in the GDB remote stub, gdbserver
5564 - The "--wrapper" command-line argument tells gdbserver to use a
5565 wrapper program to launch programs for debugging.
5567 - On PowerPC and S/390 targets, it is now possible to use a single
5568 gdbserver executable to debug both 32-bit and 64-bit programs.
5569 (This requires gdbserver itself to be built as a 64-bit executable.)
5571 - gdbserver uses the new noack protocol mode for TCP connections to
5572 reduce communications latency, if also supported and enabled in GDB.
5574 - Support for the sparc64-linux-gnu target is now included in
5577 - The amd64-linux build of gdbserver now supports debugging both
5578 32-bit and 64-bit programs.
5580 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5581 now support hardware watchpoints, and will use them automatically
5586 GDB now has support for scripting using Python. Whether this is
5587 available is determined at configure time.
5589 New GDB commands can now be written in Python.
5591 * Ada tasking support
5593 Ada tasks can now be inspected in GDB. The following commands have
5597 Print the list of Ada tasks.
5599 Print detailed information about task number N.
5601 Print the task number of the current task.
5603 Switch the context of debugging to task number N.
5605 * Support for user-defined prefixed commands. The "define" command can
5606 add new commands to existing prefixes, e.g. "target".
5608 * Multi-inferior, multi-process debugging.
5610 GDB now has generalized support for multi-inferior debugging. See
5611 "Debugging Multiple Inferiors" in the manual for more information.
5612 Although availability still depends on target support, the command
5613 set is more uniform now. The GNU/Linux specific multi-forks support
5614 has been migrated to this new framework. This implied some user
5615 visible changes; see "New commands" and also "Removed commands"
5618 * Target descriptions can now describe the target OS ABI. See the
5619 "Target Description Format" section in the user manual for more
5622 * Target descriptions can now describe "compatible" architectures
5623 to indicate that the target can execute applications for a different
5624 architecture in addition to those for the main target architecture.
5625 See the "Target Description Format" section in the user manual for
5628 * Multi-architecture debugging.
5630 GDB now includes general supports for debugging applications on
5631 hybrid systems that use more than one single processor architecture
5632 at the same time. Each such hybrid architecture still requires
5633 specific support to be added. The only hybrid architecture supported
5634 in this version of GDB is the Cell Broadband Engine.
5636 * GDB now supports integrated debugging of Cell/B.E. applications that
5637 use both the PPU and SPU architectures. To enable support for hybrid
5638 Cell/B.E. debugging, you need to configure GDB to support both the
5639 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5640 --enable-targets configure option.
5642 * Non-stop mode debugging.
5644 For some targets, GDB now supports an optional mode of operation in
5645 which you can examine stopped threads while other threads continue
5646 to execute freely. This is referred to as non-stop mode, with the
5647 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5648 section in the user manual for more information.
5650 To be able to support remote non-stop debugging, a remote stub needs
5651 to implement the non-stop mode remote protocol extensions, as
5652 described in the "Remote Non-Stop" section of the user manual. The
5653 GDB remote stub, gdbserver, has been adjusted to support these
5654 extensions on linux targets.
5656 * New commands (for set/show, see "New options" below)
5658 catch syscall [NAME(S) | NUMBER(S)]
5659 Catch system calls. Arguments, which should be names of system
5660 calls or their numbers, mean catch only those syscalls. Without
5661 arguments, every syscall will be caught. When the inferior issues
5662 any of the specified syscalls, GDB will stop and announce the system
5663 call, both when it is called and when its call returns. This
5664 feature is currently available with a native GDB running on the
5665 Linux Kernel, under the following architectures: x86, x86_64,
5666 PowerPC and PowerPC64.
5668 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5670 Search memory for a sequence of bytes.
5672 maint set python print-stack
5673 maint show python print-stack
5674 Show a stack trace when an error is encountered in a Python script.
5677 Invoke CODE by passing it to the Python interpreter.
5682 These allow macros to be defined, undefined, and listed
5686 Show operating system information about processes.
5689 List the inferiors currently under GDB's control.
5692 Switch focus to inferior number NUM.
5695 Detach from inferior number NUM.
5698 Kill inferior number NUM.
5702 set spu stop-on-load
5703 show spu stop-on-load
5704 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5706 set spu auto-flush-cache
5707 show spu auto-flush-cache
5708 Control whether to automatically flush the software-managed cache
5709 during Cell/B.E. debugging.
5711 set sh calling-convention
5712 show sh calling-convention
5713 Control the calling convention used when calling SH target functions.
5716 show debug timestamp
5717 Control display of timestamps with GDB debugging output.
5719 set disassemble-next-line
5720 show disassemble-next-line
5721 Control display of disassembled source lines or instructions when
5724 set remote noack-packet
5725 show remote noack-packet
5726 Set/show the use of remote protocol QStartNoAckMode packet. See above
5727 under "New remote packets."
5729 set remote query-attached-packet
5730 show remote query-attached-packet
5731 Control use of remote protocol `qAttached' (query-attached) packet.
5733 set remote read-siginfo-object
5734 show remote read-siginfo-object
5735 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5738 set remote write-siginfo-object
5739 show remote write-siginfo-object
5740 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5743 set remote reverse-continue
5744 show remote reverse-continue
5745 Control use of remote protocol 'bc' (reverse-continue) packet.
5747 set remote reverse-step
5748 show remote reverse-step
5749 Control use of remote protocol 'bs' (reverse-step) packet.
5751 set displaced-stepping
5752 show displaced-stepping
5753 Control displaced stepping mode. Displaced stepping is a way to
5754 single-step over breakpoints without removing them from the debuggee.
5755 Also known as "out-of-line single-stepping".
5758 show debug displaced
5759 Control display of debugging info for displaced stepping.
5761 maint set internal-error
5762 maint show internal-error
5763 Control what GDB does when an internal error is detected.
5765 maint set internal-warning
5766 maint show internal-warning
5767 Control what GDB does when an internal warning is detected.
5772 Use a wrapper program to launch programs for debugging.
5774 set multiple-symbols (all|ask|cancel)
5775 show multiple-symbols
5776 The value of this variable can be changed to adjust the debugger behavior
5777 when an expression or a breakpoint location contains an ambiguous symbol
5778 name (an overloaded function name, for instance).
5780 set breakpoint always-inserted
5781 show breakpoint always-inserted
5782 Keep breakpoints always inserted in the target, as opposed to inserting
5783 them when resuming the target, and removing them when the target stops.
5784 This option can improve debugger performance on slow remote targets.
5786 set arm fallback-mode (arm|thumb|auto)
5787 show arm fallback-mode
5788 set arm force-mode (arm|thumb|auto)
5790 These commands control how ARM GDB determines whether instructions
5791 are ARM or Thumb. The default for both settings is auto, which uses
5792 the current CPSR value for instructions without symbols; previous
5793 versions of GDB behaved as if "set arm fallback-mode arm".
5795 set arm unwind-secure-frames
5796 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5798 This can trigger security exceptions when unwinding exception stacks.
5800 set disable-randomization
5801 show disable-randomization
5802 Standalone programs run with the virtual address space randomization enabled
5803 by default on some platforms. This option keeps the addresses stable across
5804 multiple debugging sessions.
5808 Control whether other threads are stopped or not when some thread hits
5813 Requests that asynchronous execution is enabled in the target, if available.
5814 In this case, it's possible to resume target in the background, and interact
5815 with GDB while the target is running. "show target-async" displays the
5816 current state of asynchronous execution of the target.
5818 set target-wide-charset
5819 show target-wide-charset
5820 The target-wide-charset is the name of the character set that GDB
5821 uses when printing characters whose type is wchar_t.
5823 set tcp auto-retry (on|off)
5825 set tcp connect-timeout
5826 show tcp connect-timeout
5827 These commands allow GDB to retry failed TCP connections to a remote stub
5828 with a specified timeout period; this is useful if the stub is launched
5829 in parallel with GDB but may not be ready to accept connections immediately.
5831 set libthread-db-search-path
5832 show libthread-db-search-path
5833 Control list of directories which GDB will search for appropriate
5836 set schedule-multiple (on|off)
5837 show schedule-multiple
5838 Allow GDB to resume all threads of all processes or only threads of
5839 the current process.
5843 Use more aggressive caching for accesses to the stack. This improves
5844 performance of remote debugging (particularly backtraces) without
5845 affecting correctness.
5847 set interactive-mode (on|off|auto)
5848 show interactive-mode
5849 Control whether GDB runs in interactive mode (on) or not (off).
5850 When in interactive mode, GDB waits for the user to answer all
5851 queries. Otherwise, GDB does not wait and assumes the default
5852 answer. When set to auto (the default), GDB determines which
5853 mode to use based on the stdin settings.
5858 For program forks, this is replaced by the new more generic `info
5859 inferiors' command. To list checkpoints, you can still use the
5860 `info checkpoints' command, which was an alias for the `info forks'
5864 Replaced by the new `inferior' command. To switch between
5865 checkpoints, you can still use the `restart' command, which was an
5866 alias for the `fork' command.
5869 This is removed, since some targets don't have a notion of
5870 processes. To switch between processes, you can still use the
5871 `inferior' command using GDB's own inferior number.
5874 For program forks, this is replaced by the new more generic `kill
5875 inferior' command. To delete a checkpoint, you can still use the
5876 `delete checkpoint' command, which was an alias for the `delete
5880 For program forks, this is replaced by the new more generic `detach
5881 inferior' command. To detach a checkpoint, you can still use the
5882 `detach checkpoint' command, which was an alias for the `detach
5885 * New native configurations
5887 x86/x86_64 Darwin i[34567]86-*-darwin*
5889 x86_64 MinGW x86_64-*-mingw*
5893 Lattice Mico32 lm32-*
5894 x86 DICOS i[34567]86-*-dicos*
5895 x86_64 DICOS x86_64-*-dicos*
5898 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5899 (mingw32ce) debugging.
5905 These commands were actually not implemented on any target.
5907 *** Changes in GDB 6.8
5909 * New native configurations
5911 NetBSD/hppa hppa*-*netbsd*
5912 Xtensa GNU/Linux xtensa*-*-linux*
5916 NetBSD/hppa hppa*-*-netbsd*
5917 Xtensa GNU/Linux xtensa*-*-linux*
5919 * Change in command line behavior -- corefiles vs. process ids.
5921 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5922 attaching to process NUMBER fails, GDB no longer attempts to open a
5923 core file named NUMBER. Attaching to a program using the -c option
5924 is no longer supported. Instead, use the '-p' or '--pid' options.
5926 * GDB can now be built as a native debugger for debugging Windows x86
5927 (mingw32) Portable Executable (PE) programs.
5929 * Pending breakpoints no longer change their number when their address
5932 * GDB now supports breakpoints with multiple locations,
5933 including breakpoints on C++ constructors, inside C++ templates,
5934 and in inlined functions.
5936 * GDB's ability to debug optimized code has been improved. GDB more
5937 accurately identifies function bodies and lexical blocks that occupy
5938 more than one contiguous range of addresses.
5940 * Target descriptions can now describe registers for PowerPC.
5942 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5943 registers on PowerPC targets.
5945 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5946 targets even when the libthread_db library is not available.
5948 * The GDB remote stub, gdbserver, now supports the new file transfer
5949 commands (remote put, remote get, and remote delete).
5951 * The GDB remote stub, gdbserver, now supports run and attach in
5952 extended-remote mode.
5954 * hppa*64*-*-hpux11* target broken
5955 The debugger is unable to start a program and fails with the following
5956 error: "Error trying to get information about dynamic linker".
5957 The gdb-6.7 release is also affected.
5959 * GDB now supports the --enable-targets= configure option to allow
5960 building a single GDB executable that supports multiple remote
5961 target architectures.
5963 * GDB now supports debugging C and C++ programs which use the
5964 Decimal Floating Point extension. In addition, the PowerPC target
5965 now has a set of pseudo-registers to inspect decimal float values
5966 stored in two consecutive float registers.
5968 * The -break-insert MI command can optionally create pending
5971 * Improved support for debugging Ada
5972 Many improvements to the Ada language support have been made. These
5974 - Better support for Ada2005 interface types
5975 - Improved handling of arrays and slices in general
5976 - Better support for Taft-amendment types
5977 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5979 - Improved command completion in Ada
5982 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5987 set print frame-arguments (all|scalars|none)
5988 show print frame-arguments
5989 The value of this variable can be changed to control which argument
5990 values should be printed by the debugger when displaying a frame.
5995 Transfer files to and from a remote target, and delete remote files.
6002 Transfer files to and from a remote target, and delete remote files.
6004 * New remote packets
6011 Open, close, read, write, and delete files on the remote system.
6014 Attach to an existing process on the remote system, in extended-remote
6018 Run a new process on the remote system, in extended-remote mode.
6020 *** Changes in GDB 6.7
6022 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6023 bfd, libiberty and opcodes, as revealed by static analysis donated by
6024 Coverity, Inc. (http://scan.coverity.com).
6026 * When looking up multiply-defined global symbols, GDB will now prefer the
6027 symbol definition in the current shared library if it was built using the
6028 -Bsymbolic linker option.
6030 * When the Text User Interface (TUI) is not configured, GDB will now
6031 recognize the -tui command-line option and print a message that the TUI
6034 * The GDB remote stub, gdbserver, now has lower overhead for high
6035 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6037 * GDB for MIPS targets now autodetects whether a remote target provides
6038 32-bit or 64-bit register values.
6040 * Support for C++ member pointers has been improved.
6042 * GDB now understands XML target descriptions, which specify the
6043 target's overall architecture. GDB can read a description from
6044 a local file or over the remote serial protocol.
6046 * Vectors of single-byte data use a new integer type which is not
6047 automatically displayed as character or string data.
6049 * The /s format now works with the print command. It displays
6050 arrays of single-byte integers and pointers to single-byte integers
6053 * Target descriptions can now describe target-specific registers,
6054 for architectures which have implemented the support (currently
6055 only ARM, M68K, and MIPS).
6057 * GDB and the GDB remote stub, gdbserver, now support the XScale
6060 * The GDB remote stub, gdbserver, has been updated to support
6061 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6062 has been rewritten to use the standard GDB remote protocol.
6064 * GDB can now step into C++ functions which are called through thunks.
6066 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6068 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6069 layout. It also supports a TextSeg= and DataSeg= response when only
6070 segment base addresses (rather than offsets) are available.
6072 * The /i format now outputs any trailing branch delay slot instructions
6073 immediately following the last instruction within the count specified.
6075 * The GDB remote protocol "T" stop reply packet now supports a
6076 "library" response. Combined with the new "qXfer:libraries:read"
6077 packet, this response allows GDB to debug shared libraries on targets
6078 where the operating system manages the list of loaded libraries (e.g.
6079 Windows and SymbianOS).
6081 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6082 (DLLs) on Windows and Windows CE targets.
6084 * GDB now supports a faster verification that a .debug file matches its binary
6085 according to its build-id signature, if the signature is present.
6091 Enable or disable hardware flow control (RTS/CTS) on the serial port
6092 when debugging using remote targets.
6094 set mem inaccessible-by-default
6095 show mem inaccessible-by-default
6096 If the target supplies a memory map, for instance via the remote
6097 protocol's "qXfer:memory-map:read" packet, setting this variable
6098 prevents GDB from accessing memory outside the memory map. This
6099 is useful for targets with memory mapped registers or which react
6100 badly to accesses of unmapped address space.
6102 set breakpoint auto-hw
6103 show breakpoint auto-hw
6104 If the target supplies a memory map, for instance via the remote
6105 protocol's "qXfer:memory-map:read" packet, setting this variable
6106 lets GDB use hardware breakpoints automatically for memory regions
6107 where it can not use software breakpoints. This covers both the
6108 "break" command and internal breakpoints used for other commands
6109 including "next" and "finish".
6112 catch exception unhandled
6113 Stop the program execution when Ada exceptions are raised.
6116 Stop the program execution when an Ada assertion failed.
6120 Set an alternate system root for target files. This is a more
6121 general version of "set solib-absolute-prefix", which is now
6122 an alias to "set sysroot".
6125 Provide extended SPU facility status information. This set of
6126 commands is available only when debugging the Cell/B.E. SPU
6129 * New native configurations
6131 OpenBSD/sh sh*-*openbsd*
6134 unset tdesc filename
6136 Use the specified local file as an XML target description, and do
6137 not query the target for its built-in description.
6141 OpenBSD/sh sh*-*-openbsd*
6142 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6143 Toshiba Media Processor mep-elf
6145 * New remote packets
6148 Ignore the specified signals; pass them directly to the debugged program
6149 without stopping other threads or reporting them to GDB.
6151 qXfer:features:read:
6152 Read an XML target description from the target, which describes its
6157 Read or write contents of an spufs file on the target system. These
6158 packets are available only on the Cell/B.E. SPU architecture.
6160 qXfer:libraries:read:
6161 Report the loaded shared libraries. Combined with new "T" packet
6162 response, this packet allows GDB to debug shared libraries on
6163 targets where the operating system manages the list of loaded
6164 libraries (e.g. Windows and SymbianOS).
6168 Support for these obsolete configurations has been removed.
6176 i[34567]86-*-lynxos*
6177 i[34567]86-*-netware*
6178 i[34567]86-*-sco3.2v5*
6179 i[34567]86-*-sco3.2v4*
6181 i[34567]86-*-sysv4.2*
6184 i[34567]86-*-unixware2*
6185 i[34567]86-*-unixware*
6194 * Other removed features
6201 Various m68k-only ROM monitors.
6208 Various Renesas ROM monitors and debugging interfaces for SH and
6213 Support for a Macraigor serial interface to on-chip debugging.
6214 GDB does not directly support the newer parallel or USB
6219 A debug information format. The predecessor to DWARF 2 and
6220 DWARF 3, which are still supported.
6222 Support for the HP aCC compiler on HP-UX/PA-RISC
6224 SOM-encapsulated symbolic debugging information, automatic
6225 invocation of pxdb, and the aCC custom C++ ABI. This does not
6226 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6227 with aCC can still be debugged on an assembly level.
6229 MIPS ".pdr" sections
6231 A MIPS-specific format used to describe stack frame layout
6232 in debugging information.
6236 GDB could work with an older version of Guile to debug
6237 the interpreter and Scheme programs running in it.
6239 set mips stack-arg-size
6240 set mips saved-gpreg-size
6242 Use "set mips abi" to control parameter passing for MIPS.
6244 *** Changes in GDB 6.6
6249 Cell Broadband Engine SPU spu-elf
6251 * GDB can now be configured as a cross-debugger targeting native Windows
6252 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6253 running on a Windows system over TCP/IP to debug Windows programs.
6255 * The GDB remote stub, gdbserver, has been updated to support Windows and
6256 Cygwin debugging. Both single-threaded and multi-threaded programs are
6259 * The "set trust-readonly-sections" command works again. This command was
6260 broken in GDB 6.3, 6.4, and 6.5.
6262 * The "load" command now supports writing to flash memory, if the remote
6263 stub provides the required support.
6265 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6266 longer requires symbolic debug information (e.g. DWARF-2).
6271 unset substitute-path
6272 show substitute-path
6273 Manage a list of substitution rules that GDB uses to rewrite the name
6274 of the directories where the sources are located. This can be useful
6275 for instance when the sources were moved to a different location
6276 between compilation and debugging.
6280 Print each CLI command as it is executed. Each command is prefixed with
6281 a number of `+' symbols representing the nesting depth.
6282 The source command now has a `-v' option to enable the same feature.
6286 The ARM Demon monitor support (RDP protocol, "target rdp").
6288 Kernel Object Display, an embedded debugging feature which only worked with
6289 an obsolete version of Cisco IOS.
6291 The 'set download-write-size' and 'show download-write-size' commands.
6293 * New remote packets
6296 Tell a stub about GDB client features, and request remote target features.
6297 The first feature implemented is PacketSize, which allows the target to
6298 specify the size of packets it can handle - to minimize the number of
6299 packets required and improve performance when connected to a remote
6303 Fetch an OS auxilliary vector from the remote stub. This packet is a
6304 more efficient replacement for qPart:auxv:read.
6306 qXfer:memory-map:read:
6307 Fetch a memory map from the remote stub, including information about
6308 RAM, ROM, and flash memory devices.
6313 Erase and program a flash memory device.
6315 * Removed remote packets
6318 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6319 used it, and only gdbserver implemented it.
6321 *** Changes in GDB 6.5
6325 Renesas M32C/M16C m32c-elf
6327 Morpho Technologies ms1 ms1-elf
6331 init-if-undefined Initialize a convenience variable, but
6332 only if it doesn't already have a value.
6334 The following commands are presently only implemented for native GNU/Linux:
6336 checkpoint Save a snapshot of the program state.
6338 restart <n> Return the program state to a
6339 previously saved state.
6341 info checkpoints List currently saved checkpoints.
6343 delete-checkpoint <n> Delete a previously saved checkpoint.
6345 set|show detach-on-fork Tell gdb whether to detach from a newly
6346 forked process, or to keep debugging it.
6348 info forks List forks of the user program that
6349 are available to be debugged.
6351 fork <n> Switch to debugging one of several
6352 forks of the user program that are
6353 available to be debugged.
6355 delete-fork <n> Delete a fork from the list of forks
6356 that are available to be debugged (and
6357 kill the forked process).
6359 detach-fork <n> Delete a fork from the list of forks
6360 that are available to be debugged (and
6361 allow the process to continue).
6365 Morpho Technologies ms2 ms1-elf
6367 * Improved Windows host support
6369 GDB now builds as a cross debugger hosted on i686-mingw32, including
6370 native console support, and remote communications using either
6371 network sockets or serial ports.
6373 * Improved Modula-2 language support
6375 GDB can now print most types in the Modula-2 syntax. This includes:
6376 basic types, set types, record types, enumerated types, range types,
6377 pointer types and ARRAY types. Procedure var parameters are correctly
6378 printed and hexadecimal addresses and character constants are also
6379 written in the Modula-2 syntax. Best results can be obtained by using
6380 GNU Modula-2 together with the -gdwarf-2 command line option.
6384 The ARM rdi-share module.
6386 The Netware NLM debug server.
6388 *** Changes in GDB 6.4
6390 * New native configurations
6392 OpenBSD/arm arm*-*-openbsd*
6393 OpenBSD/mips64 mips64-*-openbsd*
6397 Morpho Technologies ms1 ms1-elf
6399 * New command line options
6401 --batch-silent As for --batch, but totally silent.
6402 --return-child-result The debugger will exist with the same value
6403 the child (debugged) program exited with.
6404 --eval-command COMMAND, -ex COMMAND
6405 Execute a single GDB CLI command. This may be
6406 specified multiple times and in conjunction
6407 with the --command (-x) option.
6409 * Deprecated commands removed
6411 The following commands, that were deprecated in 2000, have been
6415 set|show arm disassembly-flavor set|show arm disassembler
6416 othernames set arm disassembler
6417 set|show remotedebug set|show debug remote
6418 set|show archdebug set|show debug arch
6419 set|show eventdebug set|show debug event
6422 * New BSD user-level threads support
6424 It is now possible to debug programs using the user-level threads
6425 library on OpenBSD and FreeBSD. Currently supported (target)
6428 FreeBSD/amd64 x86_64-*-freebsd*
6429 FreeBSD/i386 i386-*-freebsd*
6430 OpenBSD/i386 i386-*-openbsd*
6432 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6433 are not yet supported.
6435 * New support for Matsushita MN10300 w/sim added
6436 (Work in progress). mn10300-elf.
6438 * REMOVED configurations and files
6440 VxWorks and the XDR protocol *-*-vxworks
6441 Motorola MCORE mcore-*-*
6442 National Semiconductor NS32000 ns32k-*-*
6444 * New "set print array-indexes" command
6446 After turning this setting "on", GDB prints the index of each element
6447 when displaying arrays. The default is "off" to preserve the previous
6450 * VAX floating point support
6452 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6454 * User-defined command support
6456 In addition to using $arg0..$arg9 for argument passing, it is now possible
6457 to use $argc to determine now many arguments have been passed. See the
6458 section on user-defined commands in the user manual for more information.
6460 *** Changes in GDB 6.3:
6462 * New command line option
6464 GDB now accepts -l followed by a number to set the timeout for remote
6467 * GDB works with GCC -feliminate-dwarf2-dups
6469 GDB now supports a more compact representation of DWARF-2 debug
6470 information using DW_FORM_ref_addr references. These are produced
6471 by GCC with the option -feliminate-dwarf2-dups and also by some
6472 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6473 to use -feliminate-dwarf2-dups.
6475 * Internationalization
6477 When supported by the host system, GDB will be built with
6478 internationalization (libintl). The task of marking up the sources is
6479 continued, we're looking forward to our first translation.
6483 Initial support for debugging programs compiled with the GNAT
6484 implementation of the Ada programming language has been integrated
6485 into GDB. In this release, support is limited to expression evaluation.
6487 * New native configurations
6489 GNU/Linux/m32r m32r-*-linux-gnu
6493 GDB's remote protocol now includes support for the 'p' packet. This
6494 packet is used to fetch individual registers from a remote inferior.
6496 * END-OF-LIFE registers[] compatibility module
6498 GDB's internal register infrastructure has been completely rewritten.
6499 The new infrastructure making possible the implementation of key new
6500 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6503 GDB 6.3 will be the last release to include the registers[]
6504 compatibility module that allowed out-of-date configurations to
6505 continue to work. This change directly impacts the following
6515 powerpc bdm protocol
6517 Unless there is activity to revive these configurations, they will be
6518 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6520 * OBSOLETE configurations and files
6522 Configurations that have been declared obsolete in this release have
6523 been commented out. Unless there is activity to revive these
6524 configurations, the next release of GDB will have their sources
6525 permanently REMOVED.
6534 *** Changes in GDB 6.2.1:
6536 * MIPS `break main; run' gave an heuristic-fence-post warning
6538 When attempting to run even a simple program, a warning about
6539 heuristic-fence-post being hit would be reported. This problem has
6542 * MIPS IRIX 'long double' crashed GDB
6544 When examining a long double variable, GDB would get a segmentation
6545 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6546 IRIX long double values).
6550 A bug in the VAX stack code was causing problems with the "next"
6551 command. This problem has been fixed.
6553 *** Changes in GDB 6.2:
6555 * Fix for ``many threads''
6557 On GNU/Linux systems that use the NPTL threads library, a program
6558 rapidly creating and deleting threads would confuse GDB leading to the
6561 ptrace: No such process.
6562 thread_db_get_info: cannot get thread info: generic error
6564 This problem has been fixed.
6566 * "-async" and "-noasync" options removed.
6568 Support for the broken "-noasync" option has been removed (it caused
6571 * New ``start'' command.
6573 This command runs the program until the beginning of the main procedure.
6575 * New BSD Kernel Data Access Library (libkvm) interface
6577 Using ``target kvm'' it is now possible to debug kernel core dumps and
6578 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6579 platforms. Currently supported (native-only) configurations are:
6581 FreeBSD/amd64 x86_64-*-freebsd*
6582 FreeBSD/i386 i?86-*-freebsd*
6583 NetBSD/i386 i?86-*-netbsd*
6584 NetBSD/m68k m68*-*-netbsd*
6585 NetBSD/sparc sparc-*-netbsd*
6586 OpenBSD/amd64 x86_64-*-openbsd*
6587 OpenBSD/i386 i?86-*-openbsd*
6588 OpenBSD/m68k m68*-openbsd*
6589 OpenBSD/sparc sparc-*-openbsd*
6591 * Signal trampoline code overhauled
6593 Many generic problems with GDB's signal handling code have been fixed.
6594 These include: backtraces through non-contiguous stacks; recognition
6595 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6596 call; backtrace through a signal trampoline; step into and out of
6597 signal handlers; and single-stepping in the signal trampoline.
6599 Please note that kernel bugs are a limiting factor here. These
6600 features have been shown to work on an s390 GNU/Linux system that
6601 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6603 * Cygwin support for DWARF 2 added.
6605 * New native configurations
6607 GNU/Linux/hppa hppa*-*-linux*
6608 OpenBSD/hppa hppa*-*-openbsd*
6609 OpenBSD/m68k m68*-*-openbsd*
6610 OpenBSD/m88k m88*-*-openbsd*
6611 OpenBSD/powerpc powerpc-*-openbsd*
6612 NetBSD/vax vax-*-netbsd*
6613 OpenBSD/vax vax-*-openbsd*
6615 * END-OF-LIFE frame compatibility module
6617 GDB's internal frame infrastructure has been completely rewritten.
6618 The new infrastructure making it possible to support key new features
6619 including DWARF 2 Call Frame Information. To aid in the task of
6620 migrating old configurations to this new infrastructure, a
6621 compatibility module, that allowed old configurations to continue to
6622 work, was also included.
6624 GDB 6.2 will be the last release to include this frame compatibility
6625 module. This change directly impacts the following configurations:
6635 Unless there is activity to revive these configurations, they will be
6636 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6638 * REMOVED configurations and files
6640 Sun 3, running SunOS 3 m68*-*-sunos3*
6641 Sun 3, running SunOS 4 m68*-*-sunos4*
6642 Sun 2, running SunOS 3 m68000-*-sunos3*
6643 Sun 2, running SunOS 4 m68000-*-sunos4*
6644 Motorola 680x0 running LynxOS m68*-*-lynxos*
6645 AT&T 3b1/Unix pc m68*-att-*
6646 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6647 decstation mips-dec-* mips-little-*
6648 riscos mips-*-riscos* mips-*-sysv*
6649 sonymips mips-sony-*
6650 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6652 *** Changes in GDB 6.1.1:
6654 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6656 The TUI (Text-mode User Interface) is now built as part of a default
6657 GDB configuration. It is enabled by either selecting the TUI with the
6658 command line option "-i=tui" or by running the separate "gdbtui"
6659 program. For more information on the TUI, see the manual "Debugging
6662 * Pending breakpoint support (also included in GDB 6.1)
6664 Support has been added to allow you to specify breakpoints in shared
6665 libraries that have not yet been loaded. If a breakpoint location
6666 cannot be found, and the "breakpoint pending" option is set to auto,
6667 GDB queries you if you wish to make the breakpoint pending on a future
6668 shared-library load. If and when GDB resolves the breakpoint symbol,
6669 the pending breakpoint is removed as one or more regular breakpoints
6672 Pending breakpoints are very useful for GCJ Java debugging.
6674 * Fixed ISO-C build problems
6676 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6677 non ISO-C code that stopped them being built using a more strict ISO-C
6678 compiler (e.g., IBM's C compiler).
6680 * Fixed build problem on IRIX 5
6682 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6683 wasn't able to compile compile on an IRIX 5 system.
6685 * Added execute permission to gdb/gdbserver/configure
6687 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6688 permission. This bug would cause configure to fail on a number of
6689 systems (Solaris, IRIX). Ref: server/519.
6691 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6693 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6694 has been updated to use constant array sizes.
6696 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6698 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6699 its generated DWARF Call Frame Info. This encoding was causing GDB to
6700 panic, that panic has been fixed. Ref: gdb/1628.
6702 * Fixed a problem when examining parameters in shared library code.
6704 When examining parameters in optimized shared library code generated
6705 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6706 not available''. GDB now correctly displays the variable's value.
6708 *** Changes in GDB 6.1:
6710 * Removed --with-mmalloc
6712 Support for the mmalloc memory manager has been removed, as it
6713 conflicted with the internal gdb byte cache.
6715 * Changes in AMD64 configurations
6717 The AMD64 target now includes the %cs and %ss registers. As a result
6718 the AMD64 remote protocol has changed; this affects the floating-point
6719 and SSE registers. If you rely on those registers for your debugging,
6720 you should upgrade gdbserver on the remote side.
6722 * Revised SPARC target
6724 The SPARC target has been completely revised, incorporating the
6725 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6726 support for LynxOS and SunOS 4 has been dropped. Calling functions
6727 from within GDB on operating systems with a non-executable stack
6728 (Solaris, OpenBSD) now works.
6732 GDB has a new C++ demangler which does a better job on the mangled
6733 names generated by current versions of g++. It also runs faster, so
6734 with this and other changes gdb should now start faster on large C++
6737 * DWARF 2 Location Expressions
6739 GDB support for location expressions has been extended to support function
6740 arguments and frame bases. Older versions of GDB could crash when they
6743 * C++ nested types and namespaces
6745 GDB's support for nested types and namespaces in C++ has been
6746 improved, especially if you use the DWARF 2 debugging format. (This
6747 is the default for recent versions of GCC on most platforms.)
6748 Specifically, if you have a class "Inner" defined within a class or
6749 namespace "Outer", then GDB realizes that the class's name is
6750 "Outer::Inner", not simply "Inner". This should greatly reduce the
6751 frequency of complaints about not finding RTTI symbols. In addition,
6752 if you are stopped at inside of a function defined within a namespace,
6753 GDB modifies its name lookup accordingly.
6755 * New native configurations
6757 NetBSD/amd64 x86_64-*-netbsd*
6758 OpenBSD/amd64 x86_64-*-openbsd*
6759 OpenBSD/alpha alpha*-*-openbsd*
6760 OpenBSD/sparc sparc-*-openbsd*
6761 OpenBSD/sparc64 sparc64-*-openbsd*
6763 * New debugging protocols
6765 M32R with SDI protocol m32r-*-elf*
6767 * "set prompt-escape-char" command deleted.
6769 The command "set prompt-escape-char" has been deleted. This command,
6770 and its very obscure effect on GDB's prompt, was never documented,
6771 tested, nor mentioned in the NEWS file.
6773 * OBSOLETE configurations and files
6775 Configurations that have been declared obsolete in this release have
6776 been commented out. Unless there is activity to revive these
6777 configurations, the next release of GDB will have their sources
6778 permanently REMOVED.
6780 Sun 3, running SunOS 3 m68*-*-sunos3*
6781 Sun 3, running SunOS 4 m68*-*-sunos4*
6782 Sun 2, running SunOS 3 m68000-*-sunos3*
6783 Sun 2, running SunOS 4 m68000-*-sunos4*
6784 Motorola 680x0 running LynxOS m68*-*-lynxos*
6785 AT&T 3b1/Unix pc m68*-att-*
6786 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6787 decstation mips-dec-* mips-little-*
6788 riscos mips-*-riscos* mips-*-sysv*
6789 sonymips mips-sony-*
6790 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6792 * REMOVED configurations and files
6794 SGI Irix-4.x mips-sgi-irix4 or iris4
6795 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6796 Z8000 simulator z8k-zilog-none or z8ksim
6797 Matsushita MN10200 w/simulator mn10200-*-*
6798 H8/500 simulator h8500-hitachi-hms or h8500hms
6799 HP/PA running BSD hppa*-*-bsd*
6800 HP/PA running OSF/1 hppa*-*-osf*
6801 HP/PA Pro target hppa*-*-pro*
6802 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6803 386BSD i[3456]86-*-bsd*
6804 Sequent family i[3456]86-sequent-sysv4*
6805 i[3456]86-sequent-sysv*
6806 i[3456]86-sequent-bsd*
6807 SPARC running LynxOS sparc-*-lynxos*
6808 SPARC running SunOS 4 sparc-*-sunos4*
6809 Tsqware Sparclet sparclet-*-*
6810 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6812 *** Changes in GDB 6.0:
6816 Support for debugging the Objective-C programming language has been
6817 integrated into GDB.
6819 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6821 DWARF 2's Call Frame Information makes available compiler generated
6822 information that more exactly describes the program's run-time stack.
6823 By using this information, GDB is able to provide more robust stack
6826 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6827 have been updated to use a new backtrace mechanism which includes
6828 DWARF 2 CFI support.
6832 GDB's remote protocol has been extended to include support for hosted
6833 file I/O (where the remote target uses GDB's file system). See GDB's
6834 remote protocol documentation for details.
6836 * All targets using the new architecture framework.
6838 All of GDB's targets have been updated to use the new internal
6839 architecture framework. The way is now open for future GDB releases
6840 to include cross-architecture native debugging support (i386 on amd64,
6843 * GNU/Linux's Thread Local Storage (TLS)
6845 GDB now includes support for for the GNU/Linux implementation of
6846 per-thread variables.
6848 * GNU/Linux's Native POSIX Thread Library (NPTL)
6850 GDB's thread code has been updated to work with either the new
6851 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6853 * Separate debug info.
6855 GDB, in conjunction with BINUTILS, now supports a mechanism for
6856 automatically loading debug information from a separate file. Instead
6857 of shipping full debug and non-debug versions of system libraries,
6858 system integrators can now instead ship just the stripped libraries
6859 and optional debug files.
6861 * DWARF 2 Location Expressions
6863 DWARF 2 Location Expressions allow the compiler to more completely
6864 describe the location of variables (even in optimized code) to the
6867 GDB now includes preliminary support for location expressions (support
6868 for DW_OP_piece is still missing).
6872 A number of long standing bugs that caused GDB to die while starting a
6873 Java application have been fixed. GDB's Java support is now
6874 considered "useable".
6876 * GNU/Linux support for fork, vfork, and exec.
6878 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6879 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6882 * GDB supports logging output to a file
6884 There are two new commands, "set logging" and "show logging", which can be
6885 used to capture GDB's output to a file.
6887 * The meaning of "detach" has changed for gdbserver
6889 The "detach" command will now resume the application, as documented. To
6890 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6893 * d10v, m68hc11 `regs' command deprecated
6895 The `info registers' command has been updated so that it displays the
6896 registers using a format identical to the old `regs' command.
6900 A new command, "maint set profile on/off", has been added. This command can
6901 be used to enable or disable profiling while running GDB, to profile a
6902 session or a set of commands. In addition there is a new configure switch,
6903 "--enable-profiling", which will cause GDB to be compiled with profiling
6904 data, for more informative profiling results.
6906 * Default MI syntax changed to "mi2".
6908 The default MI (machine interface) syntax, enabled by the command line
6909 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6910 "mi1", can be enabled by specifying the option "-i=mi1".
6912 Support for the original "mi0" syntax (included in GDB 5.0) has been
6915 Fix for gdb/192: removed extraneous space when displaying frame level.
6916 Fix for gdb/672: update changelist is now output in mi list format.
6917 Fix for gdb/702: a -var-assign that updates the value now shows up
6918 in a subsequent -var-update.
6920 * New native configurations.
6922 FreeBSD/amd64 x86_64-*-freebsd*
6924 * Multi-arched targets.
6926 HP/PA HPUX11 hppa*-*-hpux*
6927 Renesas M32R/D w/simulator m32r-*-elf*
6929 * OBSOLETE configurations and files
6931 Configurations that have been declared obsolete in this release have
6932 been commented out. Unless there is activity to revive these
6933 configurations, the next release of GDB will have their sources
6934 permanently REMOVED.
6936 Z8000 simulator z8k-zilog-none or z8ksim
6937 Matsushita MN10200 w/simulator mn10200-*-*
6938 H8/500 simulator h8500-hitachi-hms or h8500hms
6939 HP/PA running BSD hppa*-*-bsd*
6940 HP/PA running OSF/1 hppa*-*-osf*
6941 HP/PA Pro target hppa*-*-pro*
6942 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6943 Sequent family i[3456]86-sequent-sysv4*
6944 i[3456]86-sequent-sysv*
6945 i[3456]86-sequent-bsd*
6946 Tsqware Sparclet sparclet-*-*
6947 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6949 * REMOVED configurations and files
6952 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6953 IBM AIX PS/2 i[3456]86-*-aix
6954 i386 running Mach 3.0 i[3456]86-*-mach3*
6955 i386 running Mach i[3456]86-*-mach*
6956 i386 running OSF/1 i[3456]86-*osf1mk*
6957 HP/Apollo 68k Family m68*-apollo*-sysv*,
6959 m68*-hp-bsd*, m68*-hp-hpux*
6960 Argonaut Risc Chip (ARC) arc-*-*
6961 Mitsubishi D30V d30v-*-*
6962 Fujitsu FR30 fr30-*-elf*
6963 OS/9000 i[34]86-*-os9k
6964 I960 with MON960 i960-*-coff
6966 * MIPS $fp behavior changed
6968 The convenience variable $fp, for the MIPS, now consistently returns
6969 the address of the current frame's base. Previously, depending on the
6970 context, $fp could refer to either $sp or the current frame's base
6971 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6972 The GNU Source-Level Debugger''.
6974 *** Changes in GDB 5.3:
6976 * GNU/Linux shared library multi-threaded performance improved.
6978 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6979 `/proc', in preference to `ptrace' for memory reads. This may result
6980 in an improvement in the start-up time of multi-threaded, shared
6981 library applications when run under GDB. One GDB user writes: ``loads
6982 shared libs like mad''.
6984 * ``gdbserver'' now supports multi-threaded applications on some targets
6986 Support for debugging multi-threaded applications which use
6987 the GNU/Linux LinuxThreads package has been added for
6988 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6989 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6991 * GDB now supports C/C++ preprocessor macros.
6993 GDB now expands preprocessor macro invocations in C/C++ expressions,
6994 and provides various commands for showing macro definitions and how
6997 The new command `macro expand EXPRESSION' expands any macro
6998 invocations in expression, and shows the result.
7000 The new command `show macro MACRO-NAME' shows the definition of the
7001 macro named MACRO-NAME, and where it was defined.
7003 Most compilers don't include information about macros in the debugging
7004 information by default. In GCC 3.1, for example, you need to compile
7005 your program with the options `-gdwarf-2 -g3'. If the macro
7006 information is present in the executable, GDB will read it.
7008 * Multi-arched targets.
7010 DEC Alpha (partial) alpha*-*-*
7011 DEC VAX (partial) vax-*-*
7013 National Semiconductor NS32000 (partial) ns32k-*-*
7014 Motorola 68000 (partial) m68k-*-*
7015 Motorola MCORE mcore-*-*
7019 Fujitsu FRV architecture added by Red Hat frv*-*-*
7022 * New native configurations
7024 Alpha NetBSD alpha*-*-netbsd*
7025 SH NetBSD sh*-*-netbsdelf*
7026 MIPS NetBSD mips*-*-netbsd*
7027 UltraSPARC NetBSD sparc64-*-netbsd*
7029 * OBSOLETE configurations and files
7031 Configurations that have been declared obsolete in this release have
7032 been commented out. Unless there is activity to revive these
7033 configurations, the next release of GDB will have their sources
7034 permanently REMOVED.
7036 Mitsubishi D30V d30v-*-*
7037 OS/9000 i[34]86-*-os9k
7038 IBM AIX PS/2 i[3456]86-*-aix
7039 Fujitsu FR30 fr30-*-elf*
7040 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7041 Argonaut Risc Chip (ARC) arc-*-*
7042 i386 running Mach 3.0 i[3456]86-*-mach3*
7043 i386 running Mach i[3456]86-*-mach*
7044 i386 running OSF/1 i[3456]86-*osf1mk*
7045 HP/Apollo 68k Family m68*-apollo*-sysv*,
7047 m68*-hp-bsd*, m68*-hp-hpux*
7048 I960 with MON960 i960-*-coff
7050 * OBSOLETE languages
7052 CHILL, a Pascal like language used by telecommunications companies.
7054 * REMOVED configurations and files
7056 AMD 29k family via UDI a29k-amd-udi, udi29k
7057 A29K VxWorks a29k-*-vxworks
7058 AMD 29000 embedded, using EBMON a29k-none-none
7059 AMD 29000 embedded with COFF a29k-none-coff
7060 AMD 29000 embedded with a.out a29k-none-aout
7062 testsuite/gdb.hp/gdb.threads-hp/ directory
7064 * New command "set max-user-call-depth <nnn>"
7066 This command allows the user to limit the call depth of user-defined
7067 commands. The default is 1024.
7069 * Changes in FreeBSD/i386 native debugging.
7071 Support for the "generate-core-file" has been added.
7073 * New commands "dump", "append", and "restore".
7075 These commands allow data to be copied from target memory
7076 to a bfd-format or binary file (dump and append), and back
7077 from a file into memory (restore).
7079 * Improved "next/step" support on multi-processor Alpha Tru64.
7081 The previous single-step mechanism could cause unpredictable problems,
7082 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7083 of a software single-step mechanism prevents this.
7085 *** Changes in GDB 5.2.1:
7093 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7094 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7095 Fix, by Joel Brobecker imported from mainline.
7097 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7098 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7099 Fix, by Fred Fish, imported from mainline.
7101 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7102 Surprisingly enough, it works now.
7103 By Michal Ludvig, imported from mainline.
7105 i386 hardware watchpoint support:
7106 avoid misses on second run for some targets.
7107 By Pierre Muller, imported from mainline.
7109 *** Changes in GDB 5.2:
7111 * New command "set trust-readonly-sections on[off]".
7113 This command is a hint that tells gdb that read-only sections
7114 really are read-only (ie. that their contents will not change).
7115 In this mode, gdb will go to the object file rather than the
7116 target to read memory from read-only sections (such as ".text").
7117 This can be a significant performance improvement on some
7118 (notably embedded) targets.
7120 * New command "generate-core-file" (or "gcore").
7122 This new gdb command allows the user to drop a core file of the child
7123 process state at any time. So far it's been implemented only for
7124 GNU/Linux and Solaris, but should be relatively easily ported to other
7125 hosts. Argument is core file name (defaults to core.<pid>).
7127 * New command line option
7129 GDB now accepts --pid or -p followed by a process id.
7131 * Change in command line behavior -- corefiles vs. process ids.
7133 There is a subtle behavior in the way in which GDB handles
7134 command line arguments. The first non-flag argument is always
7135 a program to debug, but the second non-flag argument may either
7136 be a corefile or a process id. Previously, GDB would attempt to
7137 open the second argument as a corefile, and if that failed, would
7138 issue a superfluous error message and then attempt to attach it as
7139 a process. Now, if the second argument begins with a non-digit,
7140 it will be treated as a corefile. If it begins with a digit,
7141 GDB will attempt to attach it as a process, and if no such process
7142 is found, will then attempt to open it as a corefile.
7144 * Changes in ARM configurations.
7146 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7147 configuration is fully multi-arch.
7149 * New native configurations
7151 ARM NetBSD arm*-*-netbsd*
7152 x86 OpenBSD i[3456]86-*-openbsd*
7153 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7154 Sparc64 running FreeBSD sparc64-*-freebsd*
7158 Sanyo XStormy16 xstormy16-elf
7160 * OBSOLETE configurations and files
7162 Configurations that have been declared obsolete in this release have
7163 been commented out. Unless there is activity to revive these
7164 configurations, the next release of GDB will have their sources
7165 permanently REMOVED.
7167 AMD 29k family via UDI a29k-amd-udi, udi29k
7168 A29K VxWorks a29k-*-vxworks
7169 AMD 29000 embedded, using EBMON a29k-none-none
7170 AMD 29000 embedded with COFF a29k-none-coff
7171 AMD 29000 embedded with a.out a29k-none-aout
7173 testsuite/gdb.hp/gdb.threads-hp/ directory
7175 * REMOVED configurations and files
7177 TI TMS320C80 tic80-*-*
7179 PowerPC Solaris powerpcle-*-solaris*
7180 PowerPC Windows NT powerpcle-*-cygwin32
7181 PowerPC Netware powerpc-*-netware*
7182 Harris/CXUX m88k m88*-harris-cxux*
7183 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7184 ns32k-utek-sysv* ns32k-utek-*
7185 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7186 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7187 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7188 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7189 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7191 * Changes to command line processing
7193 The new `--args' feature can be used to specify command-line arguments
7194 for the inferior from gdb's command line.
7196 * Changes to key bindings
7198 There is a new `operate-and-get-next' function bound to `C-o'.
7200 *** Changes in GDB 5.1.1
7202 Fix compile problem on DJGPP.
7204 Fix a problem with floating-point registers on the i386 being
7207 Fix to stop GDB crashing on .debug_str debug info.
7209 Numerous documentation fixes.
7211 Numerous testsuite fixes.
7213 *** Changes in GDB 5.1:
7215 * New native configurations
7217 Alpha FreeBSD alpha*-*-freebsd*
7218 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7219 MIPS GNU/Linux mips*-*-linux*
7220 MIPS SGI Irix 6.x mips*-sgi-irix6*
7221 ia64 AIX ia64-*-aix*
7222 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7226 Motorola 68HC11 and 68HC12 m68hc11-elf
7228 UltraSparc running GNU/Linux sparc64-*-linux*
7230 * OBSOLETE configurations and files
7232 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7233 Harris/CXUX m88k m88*-harris-cxux*
7234 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7235 ns32k-utek-sysv* ns32k-utek-*
7236 TI TMS320C80 tic80-*-*
7238 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7239 PowerPC Solaris powerpcle-*-solaris*
7240 PowerPC Windows NT powerpcle-*-cygwin32
7241 PowerPC Netware powerpc-*-netware*
7242 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7243 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7244 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7245 Apple Macintosh (MPW) host N/A
7247 stuff.c (Program to stuff files into a specially prepared space in kdb)
7248 kdb-start.c (Main loop for the standalone kernel debugger)
7250 Configurations that have been declared obsolete in this release have
7251 been commented out. Unless there is activity to revive these
7252 configurations, the next release of GDB will have their sources
7253 permanently REMOVED.
7255 * REMOVED configurations and files
7257 Altos 3068 m68*-altos-*
7258 Convex c1-*-*, c2-*-*
7260 ARM RISCix arm-*-* (as host)
7264 * GDB has been converted to ISO C.
7266 GDB's source code has been converted to ISO C. In particular, the
7267 sources are fully protoized, and rely on standard headers being
7272 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7274 * The MI enabled by default.
7276 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7277 revised and enabled by default. Packages which use GDB as a debugging
7278 engine behind a UI or another front end are encouraged to switch to
7279 using the GDB/MI interface, instead of the old annotations interface
7280 which is now deprecated.
7282 * Support for debugging Pascal programs.
7284 GDB now includes support for debugging Pascal programs. The following
7285 main features are supported:
7287 - Pascal-specific data types such as sets;
7289 - automatic recognition of Pascal sources based on file-name
7292 - Pascal-style display of data types, variables, and functions;
7294 - a Pascal expression parser.
7296 However, some important features are not yet supported.
7298 - Pascal string operations are not supported at all;
7300 - there are some problems with boolean types;
7302 - Pascal type hexadecimal constants are not supported
7303 because they conflict with the internal variables format;
7305 - support for Pascal objects and classes is not full yet;
7307 - unlike Pascal, GDB is case-sensitive for symbol names.
7309 * Changes in completion.
7311 Commands such as `shell', `run' and `set args', which pass arguments
7312 to inferior programs, now complete on file names, similar to what
7313 users expect at the shell prompt.
7315 Commands which accept locations, such as `disassemble', `print',
7316 `breakpoint', `until', etc. now complete on filenames as well as
7317 program symbols. Thus, if you type "break foob TAB", and the source
7318 files linked into the programs include `foobar.c', that file name will
7319 be one of the candidates for completion. However, file names are not
7320 considered for completion after you typed a colon that delimits a file
7321 name from a name of a function in that file, as in "break foo.c:bar".
7323 `set demangle-style' completes on available demangling styles.
7325 * New platform-independent commands:
7327 It is now possible to define a post-hook for a command as well as a
7328 hook that runs before the command. For more details, see the
7329 documentation of `hookpost' in the GDB manual.
7331 * Changes in GNU/Linux native debugging.
7333 Support for debugging multi-threaded programs has been completely
7334 revised for all platforms except m68k and sparc. You can now debug as
7335 many threads as your system allows you to have.
7337 Attach/detach is supported for multi-threaded programs.
7339 Support for SSE registers was added for x86. This doesn't work for
7340 multi-threaded programs though.
7342 * Changes in MIPS configurations.
7344 Multi-arch support is enabled for all MIPS configurations.
7346 GDB can now be built as native debugger on SGI Irix 6.x systems for
7347 debugging n32 executables. (Debugging 64-bit executables is not yet
7350 * Unified support for hardware watchpoints in all x86 configurations.
7352 Most (if not all) native x86 configurations support hardware-assisted
7353 breakpoints and watchpoints in a unified manner. This support
7354 implements debug register sharing between watchpoints, which allows to
7355 put a virtually infinite number of watchpoints on the same address,
7356 and also supports watching regions up to 16 bytes with several debug
7359 The new maintenance command `maintenance show-debug-regs' toggles
7360 debugging print-outs in functions that insert, remove, and test
7361 watchpoints and hardware breakpoints.
7363 * Changes in the DJGPP native configuration.
7365 New command ``info dos sysinfo'' displays assorted information about
7366 the CPU, OS, memory, and DPMI server.
7368 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7369 display information about segment descriptors stored in GDT, LDT, and
7372 New commands ``info dos pde'' and ``info dos pte'' display entries
7373 from Page Directory and Page Tables (for now works with CWSDPMI only).
7374 New command ``info dos address-pte'' displays the Page Table entry for
7375 a given linear address.
7377 GDB can now pass command lines longer than 126 characters to the
7378 program being debugged (requires an update to the libdbg.a library
7379 which is part of the DJGPP development kit).
7381 DWARF2 debug info is now supported.
7383 It is now possible to `step' and `next' through calls to `longjmp'.
7385 * Changes in documentation.
7387 All GDB documentation was converted to GFDL, the GNU Free
7388 Documentation License.
7390 Tracepoints-related commands are now fully documented in the GDB
7393 TUI, the Text-mode User Interface, is now documented in the manual.
7395 Tracepoints-related commands are now fully documented in the GDB
7398 The "GDB Internals" manual now has an index. It also includes
7399 documentation of `ui_out' functions, GDB coding standards, x86
7400 hardware watchpoints, and memory region attributes.
7402 * GDB's version number moved to ``version.in''
7404 The Makefile variable VERSION has been replaced by the file
7405 ``version.in''. People creating GDB distributions should update the
7406 contents of this file.
7410 GUD support is now a standard part of the EMACS distribution.
7412 *** Changes in GDB 5.0:
7414 * Improved support for debugging FP programs on x86 targets
7416 Unified and much-improved support for debugging floating-point
7417 programs on all x86 targets. In particular, ``info float'' now
7418 displays the FP registers in the same format on all x86 targets, with
7419 greater level of detail.
7421 * Improvements and bugfixes in hardware-assisted watchpoints
7423 It is now possible to watch array elements, struct members, and
7424 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7425 on x86 targets no longer erroneously trigger when the address is
7428 * Improvements in the native DJGPP version of GDB
7430 The distribution now includes all the scripts and auxiliary files
7431 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7432 machines ``out of the box''.
7434 The DJGPP version can now debug programs that use signals. It is
7435 possible to catch signals that happened in the debuggee, deliver
7436 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7437 would kill the program being debugged.) Programs that hook hardware
7438 interrupts (keyboard, timer, etc.) can also be debugged.
7440 It is now possible to debug DJGPP programs that redirect their
7441 standard handles or switch them to raw (as opposed to cooked) mode, or
7442 even close them. The command ``run < foo > bar'' works as expected,
7443 and ``info terminal'' reports useful information about the debuggee's
7444 terminal, including raw/cooked mode, redirection, etc.
7446 The DJGPP version now uses termios functions for console I/O, which
7447 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7450 DOS-style file names with drive letters are now fully supported by
7453 It is now possible to debug DJGPP programs that switch their working
7454 directory. It is also possible to rerun the debuggee any number of
7455 times without restarting GDB; thus, you can use the same setup,
7456 breakpoints, etc. for many debugging sessions.
7458 * New native configurations
7460 ARM GNU/Linux arm*-*-linux*
7461 PowerPC GNU/Linux powerpc-*-linux*
7465 Motorola MCore mcore-*-*
7466 x86 VxWorks i[3456]86-*-vxworks*
7467 PowerPC VxWorks powerpc-*-vxworks*
7468 TI TMS320C80 tic80-*-*
7470 * OBSOLETE configurations
7472 Altos 3068 m68*-altos-*
7473 Convex c1-*-*, c2-*-*
7475 ARM RISCix arm-*-* (as host)
7478 Configurations that have been declared obsolete will be commented out,
7479 but the code will be left in place. If there is no activity to revive
7480 these configurations before the next release of GDB, the sources will
7481 be permanently REMOVED.
7483 * Gould support removed
7485 Support for the Gould PowerNode and NP1 has been removed.
7487 * New features for SVR4
7489 On SVR4 native platforms (such as Solaris), if you attach to a process
7490 without first loading a symbol file, GDB will now attempt to locate and
7491 load symbols from the running process's executable file.
7493 * Many C++ enhancements
7495 C++ support has been greatly improved. Overload resolution now works properly
7496 in almost all cases. RTTI support is on the way.
7498 * Remote targets can connect to a sub-program
7500 A popen(3) style serial-device has been added. This device starts a
7501 sub-process (such as a stand-alone simulator) and then communicates
7502 with that. The sub-program to run is specified using the syntax
7503 ``|<program> <args>'' vis:
7505 (gdb) set remotedebug 1
7506 (gdb) target extended-remote |mn10300-elf-sim program-args
7508 * MIPS 64 remote protocol
7510 A long standing bug in the mips64 remote protocol where by GDB
7511 expected certain 32 bit registers (ex SR) to be transfered as 32
7512 instead of 64 bits has been fixed.
7514 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7515 added to provide backward compatibility with older versions of GDB.
7517 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7519 The command ``set remotebinarydownload'' command has been replaced by
7520 ``set remote X-packet''. Other commands in ``set remote'' family
7521 include ``set remote P-packet''.
7523 * Breakpoint commands accept ranges.
7525 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7526 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7527 ``tracepoint passcount'' also accepts a range of tracepoints.
7529 * ``apropos'' command added.
7531 The ``apropos'' command searches through command names and
7532 documentation strings, printing out matches, making it much easier to
7533 try to find a command that does what you are looking for.
7537 A new machine oriented interface (MI) has been added to GDB. This
7538 interface is designed for debug environments running GDB as a separate
7539 process. This is part of the long term libGDB project. See the
7540 "GDB/MI" chapter of the GDB manual for further information. It can be
7541 enabled by configuring with:
7543 .../configure --enable-gdbmi
7545 *** Changes in GDB-4.18:
7547 * New native configurations
7549 HP-UX 10.20 hppa*-*-hpux10.20
7550 HP-UX 11.x hppa*-*-hpux11.0*
7551 M68K GNU/Linux m68*-*-linux*
7555 Fujitsu FR30 fr30-*-elf*
7556 Intel StrongARM strongarm-*-*
7557 Mitsubishi D30V d30v-*-*
7559 * OBSOLETE configurations
7561 Gould PowerNode, NP1 np1-*-*, pn-*-*
7563 Configurations that have been declared obsolete will be commented out,
7564 but the code will be left in place. If there is no activity to revive
7565 these configurations before the next release of GDB, the sources will
7566 be permanently REMOVED.
7570 As a compatibility experiment, GDB's source files buildsym.h and
7571 buildsym.c have been converted to pure standard C, no longer
7572 containing any K&R compatibility code. We believe that all systems in
7573 use today either come with a standard C compiler, or have a GCC port
7574 available. If this is not true, please report the affected
7575 configuration to bug-gdb@gnu.org immediately. See the README file for
7576 information about getting a standard C compiler if you don't have one
7581 GDB now uses readline 2.2.
7583 * set extension-language
7585 You can now control the mapping between filename extensions and source
7586 languages by using the `set extension-language' command. For instance,
7587 you can ask GDB to treat .c files as C++ by saying
7588 set extension-language .c c++
7589 The command `info extensions' lists all of the recognized extensions
7590 and their associated languages.
7592 * Setting processor type for PowerPC and RS/6000
7594 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7595 you can use the `set processor' command to specify what variant of the
7596 PowerPC family you are debugging. The command
7600 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7601 following PowerPC and RS6000 variants:
7603 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7604 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7606 403GC IBM PowerPC 403GC
7607 505 Motorola PowerPC 505
7608 860 Motorola PowerPC 860 or 850
7609 601 Motorola PowerPC 601
7610 602 Motorola PowerPC 602
7611 603 Motorola/IBM PowerPC 603 or 603e
7612 604 Motorola PowerPC 604 or 604e
7613 750 Motorola/IBM PowerPC 750 or 750
7615 At the moment, this command just tells GDB what to name the
7616 special-purpose processor registers. Since almost all the affected
7617 registers are inaccessible to user-level programs, this command is
7618 only useful for remote debugging in its present form.
7622 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7623 more extensive support for HP-UX. Added features include shared
7624 library support, kernel threads and hardware watchpoints for 11.00,
7625 support for HP's ANSI C and C++ compilers, and a compatibility mode
7626 for xdb and dbx commands.
7630 HP's donation includes the new concept of catchpoints, which is a
7631 generalization of the old catch command. On HP-UX, it is now possible
7632 to catch exec, fork, and vfork, as well as library loading.
7634 This means that the existing catch command has changed; its first
7635 argument now specifies the type of catch to be set up. See the
7636 output of "help catch" for a list of catchpoint types.
7638 * Debugging across forks
7640 On HP-UX, you can choose which process to debug when a fork() happens
7645 HP has donated a curses-based terminal user interface (TUI). To get
7646 it, build with --enable-tui. Although this can be enabled for any
7647 configuration, at present it only works for native HP debugging.
7649 * GDB remote protocol additions
7651 A new protocol packet 'X' that writes binary data is now available.
7652 Default behavior is to try 'X', then drop back to 'M' if the stub
7653 fails to respond. The settable variable `remotebinarydownload'
7654 allows explicit control over the use of 'X'.
7656 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7657 full 64-bit address. The command
7659 set remoteaddresssize 32
7661 can be used to revert to the old behaviour. For existing remote stubs
7662 the change should not be noticed, as the additional address information
7665 In order to assist in debugging stubs, you may use the maintenance
7666 command `packet' to send any text string to the stub. For instance,
7668 maint packet heythere
7670 sends the packet "$heythere#<checksum>". Note that it is very easy to
7671 disrupt a debugging session by sending the wrong packet at the wrong
7674 The compare-sections command allows you to compare section data on the
7675 target to what is in the executable file without uploading or
7676 downloading, by comparing CRC checksums.
7678 * Tracing can collect general expressions
7680 You may now collect general expressions at tracepoints. This requires
7681 further additions to the target-side stub; see tracepoint.c and
7682 doc/agentexpr.texi for further details.
7684 * mask-address variable for Mips
7686 For Mips targets, you may control the zeroing of the upper 32 bits of
7687 a 64-bit address by entering `set mask-address on'. This is mainly
7688 of interest to users of embedded R4xxx and R5xxx processors.
7690 * Higher serial baud rates
7692 GDB's serial code now allows you to specify baud rates 57600, 115200,
7693 230400, and 460800 baud. (Note that your host system may not be able
7694 to achieve all of these rates.)
7698 The i960 configuration now includes an initial implementation of a
7699 builtin simulator, contributed by Jim Wilson.
7702 *** Changes in GDB-4.17:
7704 * New native configurations
7706 Alpha GNU/Linux alpha*-*-linux*
7707 Unixware 2.x i[3456]86-unixware2*
7708 Irix 6.x mips*-sgi-irix6*
7709 PowerPC GNU/Linux powerpc-*-linux*
7710 PowerPC Solaris powerpcle-*-solaris*
7711 Sparc GNU/Linux sparc-*-linux*
7712 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7716 Argonaut Risc Chip (ARC) arc-*-*
7717 Hitachi H8/300S h8300*-*-*
7718 Matsushita MN10200 w/simulator mn10200-*-*
7719 Matsushita MN10300 w/simulator mn10300-*-*
7720 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7721 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7722 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7723 Mitsubishi D10V w/simulator d10v-*-*
7724 Mitsubishi M32R/D w/simulator m32r-*-elf*
7725 Tsqware Sparclet sparclet-*-*
7726 NEC V850 w/simulator v850-*-*
7728 * New debugging protocols
7730 ARM with RDI protocol arm*-*-*
7731 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7732 DDB and LSI variants of PMON protocol mips*-*-*
7733 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7734 PowerPC with SDS protocol powerpc{,le}-*-eabi
7735 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7739 All configurations can now understand and use the DWARF 2 debugging
7740 format. The choice is automatic, if the symbol file contains DWARF 2
7745 GDB now includes basic Java language support. This support is
7746 only useful with Java compilers that produce native machine code.
7748 * solib-absolute-prefix and solib-search-path
7750 For SunOS and SVR4 shared libraries, you may now set the prefix for
7751 loading absolute shared library symbol files, and the search path for
7752 locating non-absolute shared library symbol files.
7754 * Live range splitting
7756 GDB can now effectively debug code for which GCC has performed live
7757 range splitting as part of its optimization. See gdb/doc/LRS for
7758 more details on the expected format of the stabs information.
7762 GDB's support for the GNU Hurd, including thread debugging, has been
7763 updated to work with current versions of the Hurd.
7767 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7768 instruction set. ARM GDB automatically detects when Thumb
7769 instructions are in use, and adjusts disassembly and backtracing
7774 GDB's MIPS target configurations now handle the MIP16 16-bit
7779 GDB now includes support for overlays; if an executable has been
7780 linked such that multiple sections are based at the same address, GDB
7781 will decide which section to use for symbolic info. You can choose to
7782 control the decision manually, using overlay commands, or implement
7783 additional target-side support and use "overlay load-target" to bring
7784 in the overlay mapping. Do "help overlay" for more detail.
7788 The command "info symbol <address>" displays information about
7789 the symbol at the specified address.
7793 The standard remote protocol now includes an extension that allows
7794 asynchronous collection and display of trace data. This requires
7795 extensive support in the target-side debugging stub. Tracing mode
7796 includes a new interaction mode in GDB and new commands: see the
7797 file tracepoint.c for more details.
7801 Configurations for embedded MIPS now include a simulator contributed
7802 by Cygnus Solutions. The simulator supports the instruction sets
7803 of most MIPS variants.
7807 Sparc configurations may now include the ERC32 simulator contributed
7808 by the European Space Agency. The simulator is not built into
7809 Sparc targets by default; configure with --enable-sim to include it.
7813 For target configurations that may include multiple variants of a
7814 basic architecture (such as MIPS and SH), you may now set the
7815 architecture explicitly. "set arch" sets, "info arch" lists
7816 the possible architectures.
7818 *** Changes in GDB-4.16:
7820 * New native configurations
7822 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7823 M68K NetBSD m68k-*-netbsd*
7824 PowerPC AIX 4.x powerpc-*-aix*
7825 PowerPC MacOS powerpc-*-macos*
7826 PowerPC Windows NT powerpcle-*-cygwin32
7827 RS/6000 AIX 4.x rs6000-*-aix4*
7831 ARM with RDP protocol arm-*-*
7832 I960 with MON960 i960-*-coff
7833 MIPS VxWorks mips*-*-vxworks*
7834 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7835 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7837 Matra Sparclet sparclet-*-*
7841 The powerpc-eabi configuration now includes the PSIM simulator,
7842 contributed by Andrew Cagney, with assistance from Mike Meissner.
7843 PSIM is a very elaborate model of the PowerPC, including not only
7844 basic instruction set execution, but also details of execution unit
7845 performance and I/O hardware. See sim/ppc/README for more details.
7849 GDB now works with Solaris 2.5.
7851 * Windows 95/NT native
7853 GDB will now work as a native debugger on Windows 95 and Windows NT.
7854 To build it from source, you must use the "gnu-win32" environment,
7855 which uses a DLL to emulate enough of Unix to run the GNU tools.
7856 Further information, binaries, and sources are available at
7857 ftp.cygnus.com, under pub/gnu-win32.
7859 * dont-repeat command
7861 If a user-defined command includes the command `dont-repeat', then the
7862 command will not be repeated if the user just types return. This is
7863 useful if the command is time-consuming to run, so that accidental
7864 extra keystrokes don't run the same command many times.
7866 * Send break instead of ^C
7868 The standard remote protocol now includes an option to send a break
7869 rather than a ^C to the target in order to interrupt it. By default,
7870 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7872 * Remote protocol timeout
7874 The standard remote protocol includes a new variable `remotetimeout'
7875 that allows you to set the number of seconds before GDB gives up trying
7876 to read from the target. The default value is 2.
7878 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7880 By default GDB will automatically keep track of objects as they are
7881 loaded and unloaded by the dynamic linker. By using the command `set
7882 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7883 when shared library events occur, thus allowing you to set breakpoints
7884 in shared libraries which are explicitly loaded by the inferior.
7886 Note this feature does not work on hpux8. On hpux9 you must link
7887 /usr/lib/end.o into your program. This feature should work
7888 automatically on hpux10.
7890 * Irix 5.x hardware watchpoint support
7892 Irix 5 configurations now support the use of hardware watchpoints.
7894 * Mips protocol "SYN garbage limit"
7896 When debugging a Mips target using the `target mips' protocol, you
7897 may set the number of characters that GDB will ignore by setting
7898 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7899 every character. The default value is 1050.
7901 * Recording and replaying remote debug sessions
7903 If you set `remotelogfile' to the name of a file, gdb will write to it
7904 a recording of a remote debug session. This recording may then be
7905 replayed back to gdb using "gdbreplay". See gdbserver/README for
7906 details. This is useful when you have a problem with GDB while doing
7907 remote debugging; you can make a recording of the session and send it
7908 to someone else, who can then recreate the problem.
7910 * Speedups for remote debugging
7912 GDB includes speedups for downloading and stepping MIPS systems using
7913 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7914 and more efficient S-record downloading.
7916 * Memory use reductions and statistics collection
7918 GDB now uses less memory and reports statistics about memory usage.
7919 Try the `maint print statistics' command, for example.
7921 *** Changes in GDB-4.15:
7923 * Psymtabs for XCOFF
7925 The symbol reader for AIX GDB now uses partial symbol tables. This
7926 can greatly improve startup time, especially for large executables.
7928 * Remote targets use caching
7930 Remote targets now use a data cache to speed up communication with the
7931 remote side. The data cache could lead to incorrect results because
7932 it doesn't know about volatile variables, thus making it impossible to
7933 debug targets which use memory mapped I/O devices. `set remotecache
7934 off' turns the data cache off.
7936 * Remote targets may have threads
7938 The standard remote protocol now includes support for multiple threads
7939 in the target system, using new protocol commands 'H' and 'T'. See
7940 gdb/remote.c for details.
7944 If GDB is configured with `--enable-netrom', then it will include
7945 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7946 acts as though it is a bank of ROM on the target board, but you can
7947 write into it over the network. GDB's support consists only of
7948 support for fast loading into the emulated ROM; to debug, you must use
7949 another protocol, such as standard remote protocol. The usual
7950 sequence is something like
7952 target nrom <netrom-hostname>
7954 target remote <netrom-hostname>:1235
7958 GDB now includes support for the Apple Macintosh, as a host only. It
7959 may be run as either an MPW tool or as a standalone application, and
7960 it can debug through the serial port. All the usual GDB commands are
7961 available, but to the target command, you must supply "serial" as the
7962 device type instead of "/dev/ttyXX". See mpw-README in the main
7963 directory for more information on how to build. The MPW configuration
7964 scripts */mpw-config.in support only a few targets, and only the
7965 mips-idt-ecoff target has been tested.
7969 GDB configuration now uses autoconf. This is not user-visible,
7970 but does simplify configuration and building.
7974 GDB now supports hpux10.
7976 *** Changes in GDB-4.14:
7978 * New native configurations
7980 x86 FreeBSD i[345]86-*-freebsd
7981 x86 NetBSD i[345]86-*-netbsd
7982 NS32k NetBSD ns32k-*-netbsd
7983 Sparc NetBSD sparc-*-netbsd
7987 A29K VxWorks a29k-*-vxworks
7988 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7989 CPU32 EST-300 emulator m68*-*-est*
7990 PowerPC ELF powerpc-*-elf
7993 * Alpha OSF/1 support for procfs
7995 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7996 possible to attach to running processes. As the mounting of the /proc
7997 filesystem is optional on the Alpha, GDB automatically determines
7998 the availability of /proc during startup. This can lead to problems
7999 if /proc is unmounted after GDB has been started.
8001 * Arguments to user-defined commands
8003 User commands may accept up to 10 arguments separated by whitespace.
8004 Arguments are accessed within the user command via $arg0..$arg9. A
8007 print $arg0 + $arg1 + $arg2
8009 To execute the command use:
8012 Defines the command "adder" which prints the sum of its three arguments.
8013 Note the arguments are text substitutions, so they may reference variables,
8014 use complex expressions, or even perform inferior function calls.
8016 * New `if' and `while' commands
8018 This makes it possible to write more sophisticated user-defined
8019 commands. Both commands take a single argument, which is the
8020 expression to evaluate, and must be followed by the commands to
8021 execute, one per line, if the expression is nonzero, the list being
8022 terminated by the word `end'. The `if' command list may include an
8023 `else' word, which causes the following commands to be executed only
8024 if the expression is zero.
8026 * Fortran source language mode
8028 GDB now includes partial support for Fortran 77. It will recognize
8029 Fortran programs and can evaluate a subset of Fortran expressions, but
8030 variables and functions may not be handled correctly. GDB will work
8031 with G77, but does not yet know much about symbols emitted by other
8034 * Better HPUX support
8036 Most debugging facilities now work on dynamic executables for HPPAs
8037 running hpux9 or later. You can attach to running dynamically linked
8038 processes, but by default the dynamic libraries will be read-only, so
8039 for instance you won't be able to put breakpoints in them. To change
8040 that behavior do the following before running the program:
8046 This will cause the libraries to be mapped private and read-write.
8047 To revert to the normal behavior, do this:
8053 You cannot set breakpoints or examine data in the library until after
8054 the library is loaded if the function/data symbols do not have
8057 GDB can now also read debug symbols produced by the HP C compiler on
8058 HPPAs (sorry, no C++, Fortran or 68k support).
8060 * Target byte order now dynamically selectable
8062 You can choose which byte order to use with a target system, via the
8063 commands "set endian big" and "set endian little", and you can see the
8064 current setting by using "show endian". You can also give the command
8065 "set endian auto", in which case GDB will use the byte order
8066 associated with the executable. Currently, only embedded MIPS
8067 configurations support dynamic selection of target byte order.
8069 * New DOS host serial code
8071 This version uses DPMI interrupts to handle buffered I/O, so you
8072 no longer need to run asynctsr when debugging boards connected to
8075 *** Changes in GDB-4.13:
8077 * New "complete" command
8079 This lists all the possible completions for the rest of the line, if it
8080 were to be given as a command itself. This is intended for use by emacs.
8082 * Trailing space optional in prompt
8084 "set prompt" no longer adds a space for you after the prompt you set. This
8085 allows you to set a prompt which ends in a space or one that does not.
8087 * Breakpoint hit counts
8089 "info break" now displays a count of the number of times the breakpoint
8090 has been hit. This is especially useful in conjunction with "ignore"; you
8091 can ignore a large number of breakpoint hits, look at the breakpoint info
8092 to see how many times the breakpoint was hit, then run again, ignoring one
8093 less than that number, and this will get you quickly to the last hit of
8096 * Ability to stop printing at NULL character
8098 "set print null-stop" will cause GDB to stop printing the characters of
8099 an array when the first NULL is encountered. This is useful when large
8100 arrays actually contain only short strings.
8102 * Shared library breakpoints
8104 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8105 breakpoints in shared libraries before the executable is run.
8107 * Hardware watchpoints
8109 There is a new hardware breakpoint for the watch command for sparclite
8110 targets. See gdb/sparclite/hw_breakpoint.note.
8112 Hardware watchpoints are also now supported under GNU/Linux.
8116 Annotations have been added. These are for use with graphical interfaces,
8117 and are still experimental. Currently only gdba.el uses these.
8119 * Improved Irix 5 support
8121 GDB now works properly with Irix 5.2.
8123 * Improved HPPA support
8125 GDB now works properly with the latest GCC and GAS.
8127 * New native configurations
8129 Sequent PTX4 i[34]86-sequent-ptx4
8130 HPPA running OSF/1 hppa*-*-osf*
8131 Atari TT running SVR4 m68*-*-sysv4*
8132 RS/6000 LynxOS rs6000-*-lynxos*
8136 OS/9000 i[34]86-*-os9k
8137 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8140 * Hitachi SH7000 and E7000-PC ICE support
8142 There is now support for communicating with the Hitachi E7000-PC ICE.
8143 This is available automatically when GDB is configured for the SH.
8147 As usual, a variety of small fixes and improvements, both generic
8148 and configuration-specific. See the ChangeLog for more detail.
8150 *** Changes in GDB-4.12:
8152 * Irix 5 is now supported
8156 GDB-4.12 on the HPPA has a number of changes which make it unable
8157 to debug the output from the currently released versions of GCC and
8158 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8159 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8160 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8163 *** Changes in GDB-4.11:
8165 * User visible changes:
8169 The "set remotedebug" option is now consistent between the mips remote
8170 target, remote targets using the gdb-specific protocol, UDI (AMD's
8171 debug protocol for the 29k) and the 88k bug monitor. It is now an
8172 integer specifying a debug level (normally 0 or 1, but 2 means more
8173 debugging info for the mips target).
8175 * DEC Alpha native support
8177 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8178 debug info, but GDB works fairly well with the DEC compiler and should
8179 work with a future GCC release. See the README file for a few
8180 Alpha-specific notes.
8182 * Preliminary thread implementation
8184 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8186 * LynxOS native and target support for 386
8188 This release has been hosted on LynxOS 2.2, and also can be configured
8189 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8192 * Improvements in C++ mangling/demangling.
8194 This release has much better g++ debugging, specifically in name
8195 mangling/demangling, virtual function calls, print virtual table,
8196 call methods, ...etc.
8198 *** Changes in GDB-4.10:
8200 * User visible changes:
8202 Remote debugging using the GDB-specific (`target remote') protocol now
8203 supports the `load' command. This is only useful if you have some
8204 other way of getting the stub to the target system, and you can put it
8205 somewhere in memory where it won't get clobbered by the download.
8207 Filename completion now works.
8209 When run under emacs mode, the "info line" command now causes the
8210 arrow to point to the line specified. Also, "info line" prints
8211 addresses in symbolic form (as well as hex).
8213 All vxworks based targets now support a user settable option, called
8214 vxworks-timeout. This option represents the number of seconds gdb
8215 should wait for responses to rpc's. You might want to use this if
8216 your vxworks target is, perhaps, a slow software simulator or happens
8217 to be on the far side of a thin network line.
8221 This release contains support for using a DEC alpha as a GDB host for
8222 cross debugging. Native alpha debugging is not supported yet.
8225 *** Changes in GDB-4.9:
8229 This is the first GDB release which is accompanied by a matching testsuite.
8230 The testsuite requires installation of dejagnu, which should be available
8231 via ftp from most sites that carry GNU software.
8235 'Cfront' style demangling has had its name changed to 'ARM' style, to
8236 emphasize that it was written from the specifications in the C++ Annotated
8237 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8238 disclaimers, it still generated too much confusion with users attempting to
8239 use gdb with AT&T cfront.
8243 GDB now uses a standard remote interface to a simulator library.
8244 So far, the library contains simulators for the Zilog Z8001/2, the
8245 Hitachi H8/300, H8/500 and Super-H.
8247 * New targets supported
8249 H8/300 simulator h8300-hitachi-hms or h8300hms
8250 H8/500 simulator h8500-hitachi-hms or h8500hms
8251 SH simulator sh-hitachi-hms or sh
8252 Z8000 simulator z8k-zilog-none or z8ksim
8253 IDT MIPS board over serial line mips-idt-ecoff
8255 Cross-debugging to GO32 targets is supported. It requires a custom
8256 version of the i386-stub.c module which is integrated with the
8257 GO32 memory extender.
8259 * New remote protocols
8261 MIPS remote debugging protocol.
8263 * New source languages supported
8265 This version includes preliminary support for Chill, a Pascal like language
8266 used by telecommunications companies. Chill support is also being integrated
8267 into the GNU compiler, but we don't know when it will be publically available.
8270 *** Changes in GDB-4.8:
8272 * HP Precision Architecture supported
8274 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8275 version of this support was available as a set of patches from the
8276 University of Utah. GDB does not support debugging of programs
8277 compiled with the HP compiler, because HP will not document their file
8278 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8279 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8281 Many problems in the preliminary version have been fixed.
8283 * Faster and better demangling
8285 We have improved template demangling and fixed numerous bugs in the GNU style
8286 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8287 character types (wchar_t) are now supported. Demangling of each symbol is now
8288 only done once, and is cached when the symbol table for a file is read in.
8289 This results in a small increase in memory usage for C programs, a moderate
8290 increase in memory usage for C++ programs, and a fantastic speedup in
8293 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8294 from the specifications in the Annotated Reference Manual, which AT&T's
8295 compiler does not actually implement.
8297 * G++ multiple inheritance compiler problem
8299 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8300 inheritance lattices was reworked to properly discover ambiguities. We
8301 recently found an example which causes this new algorithm to fail in a
8302 very subtle way, producing bad debug information for those classes.
8303 The file 'gcc.patch' (in this directory) can be applied to gcc to
8304 circumvent the problem. A future GCC release will contain a complete
8307 The previous G++ debug info problem (mentioned below for the gdb-4.7
8308 release) is fixed in gcc version 2.3.2.
8310 * Improved configure script
8312 The `configure' script will now attempt to guess your system type if
8313 you don't supply a host system type. The old scheme of supplying a
8314 host system triplet is preferable over using this. All the magic is
8315 done in the new `config.guess' script. Examine it for details.
8317 We have also brought our configure script much more in line with the FSF's
8318 version. It now supports the --with-xxx options. In particular,
8319 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8320 The resulting GDB will not be able to read arbitrary object file formats --
8321 only the format ``expected'' to be used on the configured target system.
8322 We hope to make this the default in a future release.
8324 * Documentation improvements
8326 There's new internal documentation on how to modify GDB, and how to
8327 produce clean changes to the code. We implore people to read it
8328 before submitting changes.
8330 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8331 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8332 `info' files are also provided. To build `info' files from scratch,
8333 you will need the latest `makeinfo' release, which will be available in
8334 a future texinfo-X.Y release.
8336 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8337 We're not sure exactly which versions have this problem, but it has
8338 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8339 or better. If that isn't possible, there is a patch in
8340 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8341 around this problem.
8345 GDB now supports array constants that can be used in expressions typed in by
8346 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8347 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8350 The new directory `gdb/sparclite' contains a program that demonstrates
8351 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8353 * New native hosts supported
8355 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8356 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8358 * New targets supported
8360 AMD 29k family via UDI a29k-amd-udi or udi29k
8362 * New file formats supported
8364 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8365 HPUX core files, and SCO 3.2v2 core files.
8369 Attaching to processes now works again; thanks for the many bug reports.
8371 We have also stomped on a bunch of core dumps caused by
8372 printf_filtered("%s") problems.
8374 We eliminated a copyright problem on the rpc and ptrace header files
8375 for VxWorks, which was discovered at the last minute during the 4.7
8376 release. You should now be able to build a VxWorks GDB.
8378 You can now interrupt gdb while an attached process is running. This
8379 will cause the attached process to stop, and give control back to GDB.
8381 We fixed problems caused by using too many file descriptors
8382 for reading symbols from object files and libraries. This was
8383 especially a problem for programs that used many (~100) shared
8386 The `step' command now only enters a subroutine if there is line number
8387 information for the subroutine. Otherwise it acts like the `next'
8388 command. Previously, `step' would enter subroutines if there was
8389 any debugging information about the routine. This avoids problems
8390 when using `cc -g1' on MIPS machines.
8392 * Internal improvements
8394 GDB's internal interfaces have been improved to make it easier to support
8395 debugging of multiple languages in the future.
8397 GDB now uses a common structure for symbol information internally.
8398 Minimal symbols (derived from linkage symbols in object files), partial
8399 symbols (from a quick scan of debug information), and full symbols
8400 contain a common subset of information, making it easier to write
8401 shared code that handles any of them.
8403 * New command line options
8405 We now accept --silent as an alias for --quiet.
8409 The memory-mapped-malloc library is now licensed under the GNU Library
8410 General Public License.
8412 *** Changes in GDB-4.7:
8414 * Host/native/target split
8416 GDB has had some major internal surgery to untangle the support for
8417 hosts and remote targets. Now, when you configure GDB for a remote
8418 target, it will no longer load in all of the support for debugging
8419 local programs on the host. When fully completed and tested, this will
8420 ensure that arbitrary host/target combinations are possible.
8422 The primary conceptual shift is to separate the non-portable code in
8423 GDB into three categories. Host specific code is required any time GDB
8424 is compiled on that host, regardless of the target. Target specific
8425 code relates to the peculiarities of the target, but can be compiled on
8426 any host. Native specific code is everything else: it can only be
8427 built when the host and target are the same system. Child process
8428 handling and core file support are two common `native' examples.
8430 GDB's use of /proc for controlling Unix child processes is now cleaner.
8431 It has been split out into a single module under the `target_ops' vector,
8432 plus two native-dependent functions for each system that uses /proc.
8434 * New hosts supported
8436 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8437 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8438 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8440 * New targets supported
8442 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8443 68030 and CPU32 m68030-*-*, m68332-*-*
8445 * New native hosts supported
8447 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8448 (386bsd is not well tested yet)
8449 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8451 * New file formats supported
8453 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8454 supports reading of `a.out.adobe' object files, which are an a.out
8455 format extended with minimal information about multiple sections.
8459 `show copying' is the same as the old `info copying'.
8460 `show warranty' is the same as `info warrantee'.
8461 These were renamed for consistency. The old commands continue to work.
8463 `info handle' is a new alias for `info signals'.
8465 You can now define pre-command hooks, which attach arbitrary command
8466 scripts to any command. The commands in the hook will be executed
8467 prior to the user's command. You can also create a hook which will be
8468 executed whenever the program stops. See gdb.texinfo.
8472 We now deal with Cfront style name mangling, and can even extract type
8473 info from mangled symbols. GDB can automatically figure out which
8474 symbol mangling style your C++ compiler uses.
8476 Calling of methods and virtual functions has been improved as well.
8480 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8481 fixed. This was due to mishandling of the extra N_SO stabs output
8484 We also finally got Ultrix 4.2 running in house, and fixed core file
8485 support, with help from a dozen people on the net.
8487 John M. Farrell discovered that the reason that single-stepping was so
8488 slow on all of the Mips based platforms (primarily SGI and DEC) was
8489 that we were trying to demangle and lookup a symbol used for internal
8490 purposes on every instruction that was being stepped through. Changing
8491 the name of that symbol so that it couldn't be mistaken for a C++
8492 mangled symbol sped things up a great deal.
8494 Rich Pixley sped up symbol lookups in general by getting much smarter
8495 about when C++ symbol mangling is necessary. This should make symbol
8496 completion (TAB on the command line) much faster. It's not as fast as
8497 we'd like, but it's significantly faster than gdb-4.6.
8501 A new user controllable variable 'call_scratch_address' can
8502 specify the location of a scratch area to be used when GDB
8503 calls a function in the target. This is necessary because the
8504 usual method of putting the scratch area on the stack does not work
8505 in systems that have separate instruction and data spaces.
8507 We integrated changes to support the 29k UDI (Universal Debugger
8508 Interface), but discovered at the last minute that we didn't have all
8509 of the appropriate copyright paperwork. We are working with AMD to
8510 resolve this, and hope to have it available soon.
8514 We have sped up the remote serial line protocol, especially for targets
8515 with lots of registers. It now supports a new `expedited status' ('T')
8516 message which can be used in place of the existing 'S' status message.
8517 This allows the remote stub to send only the registers that GDB
8518 needs to make a quick decision about single-stepping or conditional
8519 breakpoints, eliminating the need to fetch the entire register set for
8520 each instruction being stepped through.
8522 The GDB remote serial protocol now implements a write-through cache for
8523 registers, only re-reading the registers if the target has run.
8525 There is also a new remote serial stub for SPARC processors. You can
8526 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8527 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8528 processor with a serial port.
8532 Configure.in files have become much easier to read and modify. A new
8533 `table driven' format makes it more obvious what configurations are
8534 supported, and what files each one uses.
8538 There is a new opcodes library which will eventually contain all of the
8539 disassembly routines and opcode tables. At present, it only contains
8540 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8541 disassembler (binutils/objdump) to share these routines.
8543 The libiberty library is now copylefted under the GNU Library General
8544 Public License. This allows more liberal use, and was done so libg++
8545 can use it. This makes no difference to GDB, since the Library License
8546 grants all the rights from the General Public License.
8550 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8551 reference to the stabs symbol info used by the debugger. It is (as far
8552 as we know) the only published document on this fascinating topic. We
8553 encourage you to read it, compare it to the stabs information on your
8554 system, and send improvements on the document in general (to
8555 bug-gdb@prep.ai.mit.edu).
8557 And, of course, many bugs have been fixed.
8560 *** Changes in GDB-4.6:
8562 * Better support for C++ function names
8564 GDB now accepts as input the "demangled form" of C++ overloaded function
8565 names and member function names, and can do command completion on such names
8566 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8567 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8568 Make use of command completion, it is your friend.
8570 GDB also now accepts a variety of C++ mangled symbol formats. They are
8571 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8572 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8573 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8574 for the list of formats.
8576 * G++ symbol mangling problem
8578 Recent versions of gcc have a bug in how they emit debugging information for
8579 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8580 directory) can be applied to gcc to fix the problem. Alternatively, if you
8581 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8582 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8583 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8586 * New 'maintenance' command
8588 All of the commands related to hacking GDB internals have been moved out of
8589 the main command set, and now live behind the 'maintenance' command. This
8590 can also be abbreviated as 'mt'. The following changes were made:
8592 dump-me -> maintenance dump-me
8593 info all-breakpoints -> maintenance info breakpoints
8594 printmsyms -> maintenance print msyms
8595 printobjfiles -> maintenance print objfiles
8596 printpsyms -> maintenance print psymbols
8597 printsyms -> maintenance print symbols
8599 The following commands are new:
8601 maintenance demangle Call internal GDB demangler routine to
8602 demangle a C++ link name and prints the result.
8603 maintenance print type Print a type chain for a given symbol
8605 * Change to .gdbinit file processing
8607 We now read the $HOME/.gdbinit file before processing the argv arguments
8608 (e.g. reading symbol files or core files). This allows global parameters to
8609 be set, which will apply during the symbol reading. The ./.gdbinit is still
8610 read after argv processing.
8612 * New hosts supported
8614 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8616 GNU/Linux support i386-unknown-linux or linux
8618 We are also including code to support the HP/PA running BSD and HPUX. This
8619 is almost guaranteed not to work, as we didn't have time to test or build it
8620 for this release. We are including it so that the more adventurous (or
8621 masochistic) of you can play with it. We also had major problems with the
8622 fact that the compiler that we got from HP doesn't support the -g option.
8625 * New targets supported
8627 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8629 * More smarts about finding #include files
8631 GDB now remembers the compilation directory for all include files, and for
8632 all files from which C is generated (like yacc and lex sources). This
8633 greatly improves GDB's ability to find yacc/lex sources, and include files,
8634 especially if you are debugging your program from a directory different from
8635 the one that contains your sources.
8637 We also fixed a bug which caused difficulty with listing and setting
8638 breakpoints in include files which contain C code. (In the past, you had to
8639 try twice in order to list an include file that you hadn't looked at before.)
8641 * Interesting infernals change
8643 GDB now deals with arbitrary numbers of sections, where the symbols for each
8644 section must be relocated relative to that section's landing place in the
8645 target's address space. This work was needed to support ELF with embedded
8646 stabs used by Solaris-2.0.
8648 * Bug fixes (of course!)
8650 There have been loads of fixes for the following things:
8651 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8652 i960, stabs, DOS(GO32), procfs, etc...
8654 See the ChangeLog for details.
8656 *** Changes in GDB-4.5:
8658 * New machines supported (host and target)
8660 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8662 SGI Irix-4.x mips-sgi-irix4 or iris4
8664 * New malloc package
8666 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8667 Mmalloc is capable of handling multiple heaps of memory. It is also
8668 capable of saving a heap to a file, and then mapping it back in later.
8669 This can be used to greatly speedup the startup of GDB by using a
8670 pre-parsed symbol table which lives in a mmalloc managed heap. For
8671 more details, please read mmalloc/mmalloc.texi.
8675 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8676 'help info proc' for details.
8678 * MIPS ecoff symbol table format
8680 The code that reads MIPS symbol table format is now supported on all hosts.
8681 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8684 * File name changes for MS-DOS
8686 Many files in the config directories have been renamed to make it easier to
8687 support GDB on MS-DOSe systems (which have very restrictive file name
8688 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8689 environment) is close to working but has some remaining problems. Note
8690 that debugging of DOS programs is not supported, due to limitations
8691 in the ``operating system'', but it can be used to host cross-debugging.
8693 * Cross byte order fixes
8695 Many fixes have been made to support cross debugging of Sparc and MIPS
8696 targets from hosts whose byte order differs.
8698 * New -mapped and -readnow options
8700 If memory-mapped files are available on your system through the 'mmap'
8701 system call, you can use the -mapped option on the `file' or
8702 `symbol-file' commands to cause GDB to write the symbols from your
8703 program into a reusable file. If the program you are debugging is
8704 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8705 Future GDB debugging sessions will notice the presence of this file,
8706 and will quickly map in symbol information from it, rather than reading
8707 the symbol table from the executable program. Using the '-mapped'
8708 option in a GDB `file' or `symbol-file' command has the same effect as
8709 starting GDB with the '-mapped' command-line option.
8711 You can cause GDB to read the entire symbol table immediately by using
8712 the '-readnow' option with any of the commands that load symbol table
8713 information (or on the GDB command line). This makes the command
8714 slower, but makes future operations faster.
8716 The -mapped and -readnow options are typically combined in order to
8717 build a `fred.syms' file that contains complete symbol information.
8718 A simple GDB invocation to do nothing but build a `.syms' file for future
8721 gdb -batch -nx -mapped -readnow programname
8723 The `.syms' file is specific to the host machine on which GDB is run.
8724 It holds an exact image of GDB's internal symbol table. It cannot be
8725 shared across multiple host platforms.
8727 * longjmp() handling
8729 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8730 siglongjmp() without losing control. This feature has not yet been ported to
8731 all systems. It currently works on many 386 platforms, all MIPS-based
8732 platforms (SGI, DECstation, etc), and Sun3/4.
8736 Preliminary work has been put in to support the new Solaris OS from Sun. At
8737 this time, it can control and debug processes, but it is not capable of
8742 As always, many many bug fixes. The major areas were with g++, and mipsread.
8743 People using the MIPS-based platforms should experience fewer mysterious
8744 crashes and trashed symbol tables.
8746 *** Changes in GDB-4.4:
8748 * New machines supported (host and target)
8750 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8752 BSD Reno on Vax vax-dec-bsd
8753 Ultrix on Vax vax-dec-ultrix
8755 * New machines supported (target)
8757 AMD 29000 embedded, using EBMON a29k-none-none
8761 GDB continues to improve its handling of C++. `References' work better.
8762 The demangler has also been improved, and now deals with symbols mangled as
8763 per the Annotated C++ Reference Guide.
8765 GDB also now handles `stabs' symbol information embedded in MIPS
8766 `ecoff' symbol tables. Since the ecoff format was not easily
8767 extensible to handle new languages such as C++, this appeared to be a
8768 good way to put C++ debugging info into MIPS binaries. This option
8769 will be supported in the GNU C compiler, version 2, when it is
8772 * New features for SVR4
8774 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8775 shared libraries. Debugging dynamically linked programs should present
8776 only minor differences from debugging statically linked programs.
8778 The `info proc' command will print out information about any process
8779 on an SVR4 system (including the one you are debugging). At the moment,
8780 it prints the address mappings of the process.
8782 If you bring up GDB on another SVR4 system, please send mail to
8783 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8785 * Better dynamic linking support in SunOS
8787 Reading symbols from shared libraries which contain debugging symbols
8788 now works properly. However, there remain issues such as automatic
8789 skipping of `transfer vector' code during function calls, which
8790 make it harder to debug code in a shared library, than to debug the
8791 same code linked statically.
8795 GDB is now using the latest `getopt' routines from the FSF. This
8796 version accepts the -- prefix for options with long names. GDB will
8797 continue to accept the old forms (-option and +option) as well.
8798 Various single letter abbreviations for options have been explicity
8799 added to the option table so that they won't get overshadowed in the
8800 future by other options that begin with the same letter.
8804 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8805 Many assorted bugs have been handled. Many more remain to be handled.
8806 See the various ChangeLog files (primarily in gdb and bfd) for details.
8809 *** Changes in GDB-4.3:
8811 * New machines supported (host and target)
8813 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8814 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8815 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8817 * Almost SCO Unix support
8819 We had hoped to support:
8820 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8821 (except for core file support), but we discovered very late in the release
8822 that it has problems with process groups that render gdb unusable. Sorry
8823 about that. I encourage people to fix it and post the fixes.
8825 * Preliminary ELF and DWARF support
8827 GDB can read ELF object files on System V Release 4, and can handle
8828 debugging records for C, in DWARF format, in ELF files. This support
8829 is preliminary. If you bring up GDB on another SVR4 system, please
8830 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8835 GDB now uses the latest `readline' library. One user-visible change
8836 is that two tabs will list possible command completions, which previously
8837 required typing M-? (meta-question mark, or ESC ?).
8841 The `stepi' bug that many of you noticed has been squashed.
8842 Many bugs in C++ have been handled. Many more remain to be handled.
8843 See the various ChangeLog files (primarily in gdb and bfd) for details.
8845 * State of the MIPS world (in case you wondered):
8847 GDB can understand the symbol tables emitted by the compilers
8848 supplied by most vendors of MIPS-based machines, including DEC. These
8849 symbol tables are in a format that essentially nobody else uses.
8851 Some versions of gcc come with an assembler post-processor called
8852 mips-tfile. This program is required if you want to do source-level
8853 debugging of gcc-compiled programs. I believe FSF does not ship
8854 mips-tfile with gcc version 1, but it will eventually come with gcc
8857 Debugging of g++ output remains a problem. g++ version 1.xx does not
8858 really support it at all. (If you're lucky, you should be able to get
8859 line numbers and stack traces to work, but no parameters or local
8860 variables.) With some work it should be possible to improve the
8863 When gcc version 2 is released, you will have somewhat better luck.
8864 However, even then you will get confusing results for inheritance and
8867 We will eventually provide full debugging of g++ output on
8868 DECstations. This will probably involve some kind of stabs-in-ecoff
8869 encapulation, but the details have not been worked out yet.
8872 *** Changes in GDB-4.2:
8874 * Improved configuration
8876 Only one copy of `configure' exists now, and it is not self-modifying.
8877 Porting BFD is simpler.
8881 The `step' and `next' commands now only stop at the first instruction
8882 of a source line. This prevents the multiple stops that used to occur
8883 in switch statements, for-loops, etc. `Step' continues to stop if a
8884 function that has debugging information is called within the line.
8888 Lots of small bugs fixed. More remain.
8890 * New host supported (not target)
8892 Intel 386 PC clone running Mach i386-none-mach
8895 *** Changes in GDB-4.1:
8897 * Multiple source language support
8899 GDB now has internal scaffolding to handle several source languages.
8900 It determines the type of each source file from its filename extension,
8901 and will switch expression parsing and number formatting to match the
8902 language of the function in the currently selected stack frame.
8903 You can also specifically set the language to be used, with
8904 `set language c' or `set language modula-2'.
8908 GDB now has preliminary support for the GNU Modula-2 compiler,
8909 currently under development at the State University of New York at
8910 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8911 continue through the fall of 1991 and into 1992.
8913 Other Modula-2 compilers are currently not supported, and attempting to
8914 debug programs compiled with them will likely result in an error as the
8915 symbol table is read. Feel free to work on it, though!
8917 There are hooks in GDB for strict type checking and range checking,
8918 in the `Modula-2 philosophy', but they do not currently work.
8922 GDB can now write to executable and core files (e.g. patch
8923 a variable's value). You must turn this switch on, specify
8924 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8925 by assigning a new value to a variable. Modifications take
8928 * Automatic SunOS shared library reading
8930 When you run your program, GDB automatically determines where its
8931 shared libraries (if any) have been loaded, and reads their symbols.
8932 The `share' command is no longer needed. This also works when
8933 examining core files.
8937 You can specify the number of lines that the `list' command shows.
8940 * New machines supported (host and target)
8942 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8943 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8944 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8946 * New hosts supported (not targets)
8948 IBM RT/PC: romp-ibm-aix or rtpc
8950 * New targets supported (not hosts)
8952 AMD 29000 embedded with COFF a29k-none-coff
8953 AMD 29000 embedded with a.out a29k-none-aout
8954 Ultracomputer remote kernel debug a29k-nyu-kern
8956 * New remote interfaces
8962 *** Changes in GDB-4.0:
8966 Wide output is wrapped at good places to make the output more readable.
8968 Gdb now supports cross-debugging from a host machine of one type to a
8969 target machine of another type. Communication with the target system
8970 is over serial lines. The ``target'' command handles connecting to the
8971 remote system; the ``load'' command will download a program into the
8972 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8973 also supports debugging of realtime processes running under VxWorks,
8974 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8975 stub on the target system.
8977 New CPUs supported include the AMD 29000 and Intel 960.
8979 GDB now reads object files and symbol tables via a ``binary file''
8980 library, which allows a single copy of GDB to debug programs of multiple
8981 object file types such as a.out and coff.
8983 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8984 refcard.dvi and refcard.ps are available to format it).
8987 * Control-Variable user interface simplified
8989 All variables that control the operation of the debugger can be set
8990 by the ``set'' command, and displayed by the ``show'' command.
8992 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8993 ``Show prompt'' produces the response:
8994 Gdb's prompt is new-gdb=>.
8996 What follows are the NEW set commands. The command ``help set'' will
8997 print a complete list of old and new set commands. ``help set FOO''
8998 will give a longer description of the variable FOO. ``show'' will show
8999 all of the variable descriptions and their current settings.
9001 confirm on/off: Enables warning questions for operations that are
9002 hard to recover from, e.g. rerunning the program while
9003 it is already running. Default is ON.
9005 editing on/off: Enables EMACS style command line editing
9006 of input. Previous lines can be recalled with
9007 control-P, the current line can be edited with control-B,
9008 you can search for commands with control-R, etc.
9011 history filename NAME: NAME is where the gdb command history
9012 will be stored. The default is .gdb_history,
9013 or the value of the environment variable
9016 history size N: The size, in commands, of the command history. The
9017 default is 256, or the value of the environment variable
9020 history save on/off: If this value is set to ON, the history file will
9021 be saved after exiting gdb. If set to OFF, the
9022 file will not be saved. The default is OFF.
9024 history expansion on/off: If this value is set to ON, then csh-like
9025 history expansion will be performed on
9026 command line input. The default is OFF.
9028 radix N: Sets the default radix for input and output. It can be set
9029 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9030 in the current radix, so "set radix 10" is always a no-op.
9032 height N: This integer value is the number of lines on a page. Default
9033 is 24, the current `stty rows'' setting, or the ``li#''
9034 setting from the termcap entry matching the environment
9037 width N: This integer value is the number of characters on a line.
9038 Default is 80, the current `stty cols'' setting, or the ``co#''
9039 setting from the termcap entry matching the environment
9042 Note: ``set screensize'' is obsolete. Use ``set height'' and
9043 ``set width'' instead.
9045 print address on/off: Print memory addresses in various command displays,
9046 such as stack traces and structure values. Gdb looks
9047 more ``symbolic'' if you turn this off; it looks more
9048 ``machine level'' with it on. Default is ON.
9050 print array on/off: Prettyprint arrays. New convenient format! Default
9053 print demangle on/off: Print C++ symbols in "source" form if on,
9056 print asm-demangle on/off: Same, for assembler level printouts
9059 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9062 * Support for Epoch Environment.
9064 The epoch environment is a version of Emacs v18 with windowing. One
9065 new command, ``inspect'', is identical to ``print'', except that if you
9066 are running in the epoch environment, the value is printed in its own
9070 * Support for Shared Libraries
9072 GDB can now debug programs and core files that use SunOS shared libraries.
9073 Symbols from a shared library cannot be referenced
9074 before the shared library has been linked with the program (this
9075 happens after you type ``run'' and before the function main() is entered).
9076 At any time after this linking (including when examining core files
9077 from dynamically linked programs), gdb reads the symbols from each
9078 shared library when you type the ``sharedlibrary'' command.
9079 It can be abbreviated ``share''.
9081 sharedlibrary REGEXP: Load shared object library symbols for files
9082 matching a unix regular expression. No argument
9083 indicates to load symbols for all shared libraries.
9085 info sharedlibrary: Status of loaded shared libraries.
9090 A watchpoint stops execution of a program whenever the value of an
9091 expression changes. Checking for this slows down execution
9092 tremendously whenever you are in the scope of the expression, but is
9093 quite useful for catching tough ``bit-spreader'' or pointer misuse
9094 problems. Some machines such as the 386 have hardware for doing this
9095 more quickly, and future versions of gdb will use this hardware.
9097 watch EXP: Set a watchpoint (breakpoint) for an expression.
9099 info watchpoints: Information about your watchpoints.
9101 delete N: Deletes watchpoint number N (same as breakpoints).
9102 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9103 enable N: Re-enables watchpoint number N (same as breakpoints).
9106 * C++ multiple inheritance
9108 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9111 * C++ exception handling
9113 Gdb now supports limited C++ exception handling. Besides the existing
9114 ability to breakpoint on an exception handler, gdb can breakpoint on
9115 the raising of an exception (before the stack is peeled back to the
9118 catch FOO: If there is a FOO exception handler in the dynamic scope,
9119 set a breakpoint to catch exceptions which may be raised there.
9120 Multiple exceptions (``catch foo bar baz'') may be caught.
9122 info catch: Lists all exceptions which may be caught in the
9123 current stack frame.
9126 * Minor command changes
9128 The command ``call func (arg, arg, ...)'' now acts like the print
9129 command, except it does not print or save a value if the function's result
9130 is void. This is similar to dbx usage.
9132 The ``up'' and ``down'' commands now always print the frame they end up
9133 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9134 frames without printing.
9136 * New directory command
9138 'dir' now adds directories to the FRONT of the source search path.
9139 The path starts off empty. Source files that contain debug information
9140 about the directory in which they were compiled can be found even
9141 with an empty path; Sun CC and GCC include this information. If GDB can't
9142 find your source file in the current directory, type "dir .".
9144 * Configuring GDB for compilation
9146 For normal use, type ``./configure host''. See README or gdb.texinfo
9149 GDB now handles cross debugging. If you are remotely debugging between
9150 two different machines, type ``./configure host -target=targ''.
9151 Host is the machine where GDB will run; targ is the machine
9152 where the program that you are debugging will run.