1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 13
6 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
7 includes a new 512 bit lookup table register named ZT0.
9 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
10 a new matrix register named ZA, a new thread register TPIDR2 and a new vector
11 length register SVG (streaming vector granule). GDB also supports tracking
12 ZA state across signal frames.
14 Some features are still under development or are dependent on ABI specs that
15 are still in alpha stage. For example, manual function calls with ZA state
16 don't have any special handling, and tracking of SVG changes based on
17 DWARF information is still not implemented, but there are plans to do so in
20 * GDB now recognizes the NO_COLOR environment variable and disables
21 styling according to the spec. See https://no-color.org/.
22 Styling can be re-enabled with "set style enabled on".
24 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
25 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
28 * GDB now has some support for integer types larger than 64 bits.
30 * Removed targets and native configurations
32 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
33 AIX version is now AIX 7.1.
35 * Multi-target feature configuration
37 GDB now supports the individual configuration of remote targets' feature
38 sets. Based on the current selection of a target, the commands 'set remote
39 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
40 configure a target's feature packet and to display its configuration,
43 The individual packet sizes can be configured and shown using the commands
44 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
45 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
46 ** 'show remote memory-read-packet-size'
47 ** 'show remote memory-write-packet-size'.
49 The configuration of the packet itself, as well as the size of a memory-read
50 or memory-write packet applies to the currently selected target (if
51 available). If no target is selected, it applies to future remote
52 connections. Similarly, the show commands print the configuration of the
53 currently selected target. If no remote target is selected, the default
54 configuration for future connections is shown.
56 * MI version 1 has been removed.
58 * GDB has initial built-in support for the Debugger Adapter Protocol.
59 This support requires that GDB be built with Python scripting
62 * For the break command, multiple uses of the 'thread' or 'task'
63 keywords will now give an error instead of just using the thread or
64 task id from the last instance of the keyword. E.g.:
65 break foo thread 1 thread 2
66 will now give an error rather than using 'thread 2'.
68 * For the watch command, multiple uses of the 'task' keyword will now
69 give an error instead of just using the task id from the last
70 instance of the keyword. E.g.:
71 watch my_var task 1 task 2
72 will now give an error rather than using 'task 2'. The 'thread'
73 keyword already gave an error when used multiple times with the
74 watch command, this remains unchanged.
76 * The 'set print elements' setting now helps when printing large arrays.
77 If an array would otherwise exceed max-value-size, but 'print elements'
78 is set such that the size of elements to print is less than or equal
79 to 'max-value-size', GDB will now still print the array, however only
80 'max-value-size' worth of data will be added into the value history.
82 * For both the break and watch commands, it is now invalid to use both
83 the 'thread' and 'task' keywords within the same command. For
84 example the following commnds will now give an error:
85 break foo thread 1 task 1
86 watch var thread 2 task 3
88 * The printf command now accepts a '%V' output format which will
89 format an expression just as the 'print' command would. Print
90 options can be placed withing '[...]' after the '%V' to modify how
91 the value is printed. E.g:
92 printf "%V", some_array
93 printf "%V[-array-indexes on]", some_array
94 will print the array without, or with array indexes included, just
95 as the array would be printed by the 'print' command. This
96 functionality is also available for dprintf when dprintf-style is
99 * When the printf command requires a string to be fetched from the
100 inferior, GDB now uses the existing 'max-value-size' setting to the
101 limit the memory allocated within GDB. The default 'max-value-size'
102 is 64k. To print longer strings you should increase
105 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
107 * The Ada 2022 target name symbol ('@') is now supported by the Ada
110 * The 'list' command now accepts '.' as an argument, which tells GDB to
111 print the location around the point of execution within the current frame.
112 If the inferior hasn't started yet, the command will print around the
113 beginning of the 'main' function.
115 * Using the 'list' command with no arguments in a situation where the
116 command would attempt to list past the end of the file now warns the
117 user that the end of file has been reached, refers the user to the
118 newly added '.' argument
120 * Breakpoints can now be inferior-specific. This is similar to the
121 existing thread-specific breakpoint support. Breakpoint conditions
122 can include the 'inferior' keyword followed by an inferior id (as
123 displayed in the 'info inferiors' output). It is invalid to use the
124 'inferior' keyword with either the 'thread' or 'task' keywords when
125 creating a breakpoint.
129 --additional-debug-dirs=PATHs
131 Provide a colon-separated list of additional directories to search for
132 separate debug info. These directories are added to the default value of
133 the 'debug-file-directory' GDB parameter.
137 set debug breakpoint on|off
138 show debug breakpoint
139 Print additional debug messages about breakpoint insertion and removal.
141 maintenance print record-instruction [ N ]
142 Print the recorded information for a given instruction. If N is not given
143 prints how GDB would undo the last instruction executed. If N is negative,
144 prints how GDB would undo the N-th previous instruction, and if N is
145 positive, it prints how GDB will redo the N-th following instruction.
147 maintenance info frame-unwinders
148 List the frame unwinders currently in effect, starting with the highest
151 maintenance wait-for-index-cache
152 Wait until all pending writes to the index cache have completed.
154 set always-read-ctf on|off
156 When off, CTF is only read if DWARF is not present. When on, CTF is
157 read regardless of whether DWARF is present. Off by default.
160 Get main symbol to identify entry point into program.
162 set tui mouse-events [on|off]
163 show tui mouse-events
164 When on (default), mouse clicks control the TUI and can be accessed by
165 Python extensions. When off, mouse clicks are handled by the terminal,
166 enabling terminal-native text selection.
168 * New convenience function "$_shell", to execute a shell command and
169 return the result. This lets you run shell commands in expressions.
172 (gdb) p $_shell("true")
174 (gdb) p $_shell("false")
176 (gdb) break func if $_shell("some command") == 0
180 ** mi now reports 'no-history' as a stop reason when hitting the end of the
181 reverse execution history.
183 ** When creating a thread-specific breakpoint using the '-p' option,
184 the -break-insert command would report the 'thread' field twice in
185 the reply. The content of both fields was always identical. This
186 has now been fixed; the 'thread' field will be reported just once
187 for thread-specific breakpoints, or not at all for breakpoints
188 without a thread restriction. The same is also true for the 'task'
189 field of an Ada task-specific breakpoint.
191 ** It is no longer possible to create a thread-specific breakpoint for
192 a thread that doesn't exist using '-break-insert -p ID'. Creating
193 breakpoints for non-existent threads is not allowed when using the
194 CLI, that the MI allowed it was a long standing bug, which has now
197 ** The '--simple-values' argument to the '-stack-list-arguments',
198 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
199 commands now takes reference types into account: that is, a value is now
200 considered simple if it is neither an array, structure, or union, nor a
201 reference to an array, structure, or union. (Previously all references were
202 considered simple.) Support for this feature can be verified by using the
203 '-list-features' command, which should contain "simple-values-ref-types".
205 ** The -break-insert command now accepts a '-g thread-group-id' option
206 to allow for the creation of inferior-specific breakpoints.
208 ** The bkpt tuple, which appears in breakpoint-created notifications,
209 and in the result of the -break-insert command can now include an
210 optional 'inferior' field for both the main breakpoint, and each
211 location, when the breakpoint is inferior-specific.
215 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
217 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
219 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
220 now be of type 'str' otherwise a TypeError will be raised.
222 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
223 values of type 'bool'. Changing this attribute will now
224 invalidate GDB's frame-cache, which means GDB will need to
225 rebuild its frame-cache when next required - either with, or
226 without the particular unwinder, depending on how 'enabled' was
229 ** New methods added to the gdb.PendingFrame class. These methods
230 have the same behaviour as the corresponding methods on
231 gdb.Frame. The new methods are:
233 - gdb.PendingFrame.name: Return the name for the frame's
235 - gdb.PendingFrame.is_valid: Return True if the pending frame
237 - gdb.PendingFrame.pc: Return the $pc register value for this
239 - gdb.PendingFrame.language: Return a string containing the
240 language for this frame, or None.
241 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
242 object for the current location within the pending frame, or
244 - gdb.PendingFrame.block: Return a gdb.Block for the current
245 pending frame, or None.
246 - gdb.PendingFrame.function: Return a gdb.Symbol for the
247 current pending frame, or None.
249 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
250 now use either an integer or a gdb.Value object for each of its
251 'sp', 'pc', and 'special' attributes.
253 ** A new class gdb.unwinder.FrameId has been added. Instances of
254 this class are constructed with 'sp' (stack-pointer) and 'pc'
255 (program-counter) values, and can be used as the frame-id when
256 calling gdb.PendingFrame.create_unwind_info.
258 ** It is now no longer possible to sub-class the
259 gdb.disassembler.DisassemblerResult type.
261 ** The Disassembler API from the gdb.disassembler module has been
262 extended to include styling support:
264 - The DisassemblerResult class can now be initialized with a list
265 of parts. Each part represents part of the disassembled
266 instruction along with the associated style information. This
267 list of parts can be accessed with the new
268 DisassemblerResult.parts property.
270 - New constants gdb.disassembler.STYLE_* representing all the
271 different styles part of an instruction might have.
273 - New methods DisassembleInfo.text_part and
274 DisassembleInfo.address_part which are used to create the new
275 styled parts of a disassembled instruction.
277 - Changes are backwards compatible, the older API can still be
278 used to disassemble instructions without styling.
280 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
281 GDB/MI command and returns the output as a Python dictionary.
283 ** New function gdb.block_signals(). This returns a context manager
284 that blocks any signals that GDB needs to handle itself.
286 ** New class gdb.Thread. This is a subclass of threading.Thread
287 that calls gdb.block_signals in its "start" method.
289 ** gdb.parse_and_eval now has a new "global_context" parameter.
290 This can be used to request that the parse only examine global
293 ** gdb.Inferior now has a new "arguments" attribute. This holds the
294 command-line arguments to the inferior, if known.
296 ** gdb.Inferior now has a new "main_name" attribute. This holds the
297 name of the inferior's "main", if known.
299 ** gdb.Inferior now has new methods "clear_env", "set_env", and
300 "unset_env". These can be used to modify the inferior's
301 environment before it is started.
303 ** gdb.Value now has the 'assign' method.
305 ** gdb.Value now has the 'to_array' method. This converts an
306 array-like Value to an array.
308 ** gdb.Progspace now has the new method "objfile_for_address". This
309 returns the gdb.Objfile, if any, that covers a given address.
311 ** gdb.Breakpoint now has an "inferior" attribute. If the
312 Breakpoint object is inferior specific then this attribute holds
313 the inferior-id (an integer). If the Breakpoint object is not
314 inferior specific, then this field contains None. This field can
317 ** gdb.Type now has the "is_array_like" and "is_string_like"
318 methods. These reflect GDB's internal idea of whether a type
319 might be array- or string-like, even if they do not have the
320 corresponding type code.
322 ** gdb.ValuePrinter is a new class that can be used as the base
323 class for the result of applying a pretty-printer. As a base
324 class, it signals to gdb that the printer may implement new
325 pretty-printer methods.
327 ** New attribute Progspace.symbol_file. This attribute holds the
328 gdb.Objfile that corresponds to Progspace.filename (when
329 Progspace.filename is not None), otherwise, this attribute is
332 ** New attribute Progspace.executable_filename. This attribute
333 holds a string containing a file name set by the "exec-file" or
334 "file" commands, or None if no executable file is set. This
335 isn't the exact string passed by the user to these commands; the
336 file name will have been partially resolved to an absolute file
339 ** A new executable_changed event registry is available. This event
340 emits ExecutableChangedEvent objects, which have 'progspace' (a
341 gdb.Progspace) and 'reload' (a Boolean) attributes. This event
342 is emitted when gdb.Progspace.executable_filename changes.
344 ** New event registries gdb.events.new_progspace and
345 gdb.events.free_progspace, these emit NewProgspaceEvent and
346 FreeProgspaceEvent event types respectively. Both of these event
347 types have a single 'progspace' attribute, which is the
348 gdb.Progspace that is either being added to GDB, or removed from
351 *** Changes in GDB 13
353 * MI version 1 is deprecated, and will be removed in GDB 14.
355 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
356 reading memory tag data for AArch64 MTE from core files generated by
357 the gcore command or the Linux kernel.
359 When a process uses memory-mapped pages protected by memory tags (for
360 example, AArch64 MTE), this additional information will be recorded in
361 the core file in the event of a crash or if GDB generates a core file
362 from the current process state. GDB will show this additional information
363 automatically, or through one of the memory-tag subcommands.
365 * "info breakpoints" now displays enabled breakpoint locations of
366 disabled breakpoints as in the "y-" state. For example:
368 (gdb) info breakpoints
369 Num Type Disp Enb Address What
370 1 breakpoint keep n <MULTIPLE>
371 1.1 y- 0x00000000000011b6 in ...
372 1.2 y- 0x00000000000011c2 in ...
373 1.3 n 0x00000000000011ce in ...
375 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
376 aarch64 architectures.
378 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
380 * Remove support for building against Python 2, it is now only possible to
381 build GDB against Python 3.
383 * DBX mode has been removed.
385 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
386 emit to indicate where a breakpoint should be placed to break in a function
389 * Completion now also offers "NUMBER" for "set" commands that accept
390 a numeric argument and the "unlimited" keyword. For example:
392 (gdb) set width <TAB>
397 (gdb) complete set width
401 * Disassembler styling using libopcodes. GDB now supports
402 disassembler styling using libopcodes. This is only available for
403 some targets (currently x86 and RISC-V). For unsupported targets
404 Python Pygments is still used. For supported targets, libopcodes
405 styling is used by default.
407 * The Windows native target now supports target async.
409 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
411 * The format of 'disassemble /r' and 'record instruction-history /r'
412 has changed. The instruction bytes could now be grouped together,
413 and displayed in the endianness of the instruction. This is the
414 same layout as used by GNU objdump when disassembling.
416 There is now 'disassemble /b' and 'record instruction-history /b'
417 which will always display the instructions bytes one at a time in
418 memory order, that is, the byte at the lowest address first.
420 For both /r and /b GDB is now better at using whitespace in order to
421 align the disassembled instruction text.
423 * The TUI no longer styles the source and assembly code highlighted by
424 the current position indicator by default. You can however
425 re-enable styling using the new "set style tui-current-position"
428 * New convenience variable $_inferior_thread_count contains the number
429 of live threads in the current inferior.
431 * When a breakpoint with multiple code locations is hit, GDB now prints
432 the code location using the syntax <breakpoint_number>.<location_number>
434 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
436 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
437 and $_hit_locno to the hit breakpoint number and code location number.
438 This allows to disable the last hit breakpoint using
439 (gdb) disable $_hit_bpnum
440 or disable only the specific breakpoint code location using
441 (gdb) disable $_hit_bpnum.$_hit_locno
442 These commands can be used inside the command list of a breakpoint to
443 automatically disable the just encountered breakpoint (or the just
444 encountered specific breakpoint code location).
445 When a breakpoint has only one location, $_hit_locno is set to 1 so that
446 (gdb) disable $_hit_bpnum.$_hit_locno
448 (gdb) disable $_hit_bpnum
449 are both disabling the breakpoint.
453 maintenance set ignore-prologue-end-flag on|off
454 maintenance show ignore-prologue-end-flag
455 This setting, which is off by default, controls whether GDB ignores the
456 PROLOGUE-END flag from the line-table when skipping prologue. This can be
457 used to force GDB to use prologue analyzers if the line-table is constructed
458 from erroneous debug information.
460 set print nibbles [on|off]
462 This controls whether the 'print/t' command will display binary values
463 in groups of four bits, known as "nibbles". The default is 'off'.
465 maintenance set libopcodes-styling on|off
466 maintenance show libopcodes-styling
467 These can be used to force off libopcodes based styling, the Python
468 Pygments styling will then be used instead.
470 set style disassembler comment
471 show style disassembler comment
472 set style disassembler immediate
473 show style disassembler immediate
474 set style disassembler mnemonic
475 show style disassembler mnemonic
476 set style disassembler register
477 show style disassembler register
478 set style disassembler address
479 show style disassembler address
480 set style disassembler symbol
481 show style disassembler symbol
482 For targets that support libopcodes based styling, these settings
483 control how various aspects of the disassembler output are styled.
484 The 'disassembler address' and 'disassembler symbol' styles are
485 aliases for the 'address' and 'function' styles respectively.
487 maintenance print frame-id [ LEVEL ]
488 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
489 not given, then print the frame-id for the currently selected frame.
491 set debug infcall on|off
493 Print additional debug messages about inferior function calls.
495 set debug solib on|off
497 Print additional debug messages about shared library handling.
499 set style tui-current-position [on|off]
500 Whether to style the source and assembly code highlighted by the
501 TUI's current position indicator. The default is off.
503 set print characters LIMIT
504 show print characters
505 This new setting is like 'set print elements', but controls how many
506 characters of a string are printed. This functionality used to be
507 covered by 'set print elements', but it can be controlled separately
508 now. LIMIT can be set to a numerical value to request that particular
509 character count, to 'unlimited' to print all characters of a string,
510 or to 'elements', which is also the default, to follow the setting of
511 'set print elements' as it used to be.
513 print -characters LIMIT
514 This new option to the 'print' command has the same effect as a temporary
515 use of 'set print characters'.
519 document user-defined
520 It is now possible to document user-defined aliases.
521 When a user-defined alias is documented, the help and apropos commands
522 use the provided documentation instead of the documentation of the
524 Documenting a user-defined alias is particularly useful when the alias
525 is a set of nested 'with' commands to avoid showing the help of
526 the with command for an alias that will in fact launch the
527 last command given in the nested commands.
529 maintenance info line-table
530 Add a PROLOGUE-END column to the output which indicates that an
531 entry corresponds to an address where a breakpoint should be placed
532 to be at the first instruction past a function's prologue.
536 set debug aix-solib on|off
538 set debug solib-frv on|off
540 Removed in favor of "set/show debug solib".
542 maintenance info program-spaces
543 This command now includes a 'Core File' column which indicates the
544 name of the core file associated with each program space.
548 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
550 GNU/Linux/CSKY (gdbserver) csky*-*linux*
556 ** The async record stating the stopped reason 'breakpoint-hit' now
557 contains an optional field locno giving the code location number
558 when the breakpoint has multiple code locations.
562 ** GDB will now reformat the doc string for gdb.Command and
563 gdb.Parameter sub-classes to remove unnecessary leading
564 whitespace from each line before using the string as the help
567 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
568 that formats ADDRESS as 'address <symbol+offset>', where symbol is
569 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
570 This is the same format that GDB uses when printing address, symbol,
571 and offset information from the disassembler.
573 ** New function gdb.current_language that returns the name of the
574 current language. Unlike gdb.parameter('language'), this will
577 ** New method gdb.Frame.language that returns the name of the
580 ** New Python API for wrapping GDB's disassembler:
582 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
583 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
584 ARCH is either None or a string containing a bfd architecture
585 name. DISASSEMBLER is registered as a disassembler for
586 architecture ARCH, or for all architectures if ARCH is None.
587 The previous disassembler registered for ARCH is returned, this
588 can be None if no previous disassembler was registered.
590 - gdb.disassembler.Disassembler is the class from which all
591 disassemblers should inherit. Its constructor takes a string,
592 a name for the disassembler, which is currently only used in
593 some debug output. Sub-classes should override the __call__
594 method to perform disassembly, invoking __call__ on this base
595 class will raise an exception.
597 - gdb.disassembler.DisassembleInfo is the class used to describe
598 a single disassembly request from GDB. An instance of this
599 class is passed to the __call__ method of
600 gdb.disassembler.Disassembler and has the following read-only
601 attributes: 'address', and 'architecture', as well as the
602 following method: 'read_memory'.
604 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
605 calls GDB's builtin disassembler on INFO, which is a
606 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
607 optional, its default value is None. If MEMORY_SOURCE is not
608 None then it must be an object that has a 'read_memory' method.
610 - gdb.disassembler.DisassemblerResult is a class that can be used
611 to wrap the result of a call to a Disassembler. It has
612 read-only attributes 'length' and 'string'.
614 ** gdb.Objfile now has an attribute named "is_file". This is True
615 if the objfile comes from a file, and False otherwise.
617 ** New function gdb.print_options that returns a dictionary of the
618 prevailing print options, in the form accepted by
619 gdb.Value.format_string.
621 ** gdb.Value.format_string now uses the format provided by 'print',
622 if it is called during a 'print' or other similar operation.
624 ** gdb.Value.format_string now accepts the 'summary' keyword. This
625 can be used to request a shorter representation of a value, the
626 way that 'set print frame-arguments scalars' does.
628 ** New Python type gdb.BreakpointLocation.
629 The new attribute 'locations' of gdb.Breakpoint returns a list of
630 gdb.BreakpointLocation objects specifying the locations where the
631 breakpoint is inserted into the debuggee.
633 ** The gdb.register_window_type method now restricts the set of
634 acceptable window names. The first character of a window's name
635 must start with a character in the set [a-zA-Z], every subsequent
636 character of a window's name must be in the set [-_.a-zA-Z0-9].
638 * New features in the GDB remote stub, GDBserver
640 ** GDBserver is now supported on LoongArch GNU/Linux.
642 ** GDBserver is now supported on CSKY GNU/Linux.
644 * LoongArch floating-point support
646 GDB now supports floating-point on LoongArch GNU/Linux.
648 * AMD GPU ROCm debugging support
650 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
653 *** Changes in GDB 12
655 * DBX mode is deprecated, and will be removed in GDB 13
657 * GDB 12 is the last release of GDB that will support building against
658 Python 2. From GDB 13, it will only be possible to build GDB itself
659 with Python 3 support.
661 * The disable-randomization setting now works on Windows.
663 * Improved C++ template support
665 GDB now treats functions/types involving C++ templates like it does function
666 overloads. Users may omit parameter lists to set breakpoints on families of
667 template functions, including types/functions composed of multiple template types:
669 (gdb) break template_func(template_1, int)
671 The above will set breakpoints at every function `template_func' where
672 the first function parameter is any template type named `template_1' and
673 the second function parameter is `int'.
675 TAB completion also gains similar improvements.
677 * The FreeBSD native target now supports async mode.
683 Enable or disable multithreaded symbol loading. This is enabled
684 by default, but passing --disable-threading or --enable-threading=no
685 to configure will disable it.
687 Disabling this can cause a performance penalty when there are a lot of
688 symbols to load, but is useful for debugging purposes.
692 maint set backtrace-on-fatal-signal on|off
693 maint show backtrace-on-fatal-signal
694 This setting is 'on' by default. When 'on' GDB will print a limited
695 backtrace to stderr in the situation where GDB terminates with a
696 fatal signal. This only supported on some platforms where the
697 backtrace and backtrace_symbols_fd functions are available.
699 set source open on|off
701 This setting, which is on by default, controls whether GDB will try
702 to open source code files. Switching this off will stop GDB trying
703 to open and read source code files, which can be useful if the files
704 are located over a slow network connection.
708 These are now deprecated aliases for "set max-value-size" and
709 "show max-value-size".
711 task apply [all | TASK-IDS...] [FLAG]... COMMAND
712 Like "thread apply", but applies COMMAND to Ada tasks.
715 Watchpoints can now be restricted to a specific Ada task.
717 maint set internal-error backtrace on|off
718 maint show internal-error backtrace
719 maint set internal-warning backtrace on|off
720 maint show internal-warning backtrace
721 GDB can now print a backtrace of itself when it encounters either an
722 internal-error, or an internal-warning. This is on by default for
723 internal-error and off by default for internal-warning.
726 Deprecated and replaced by "set logging enabled on|off".
728 set logging enabled on|off
730 These commands set or show whether logging is enabled or disabled.
733 You can now exit GDB by using the new command "exit", in addition to
734 the existing "quit" command.
736 set debug threads on|off
738 Print additional debug messages about thread creation and deletion.
740 set debug linux-nat on|off
742 These new commands replaced the old 'set debug lin-lwp' and 'show
743 debug lin-lwp' respectively. Turning this setting on prints debug
744 messages relating to GDB's handling of native Linux inferiors.
746 maint flush source-cache
747 Flush the contents of the source code cache.
749 maint set gnu-source-highlight enabled on|off
750 maint show gnu-source-highlight enabled
751 Whether GDB should use the GNU Source Highlight library for adding
752 styling to source code. When off, the library will not be used, even
753 when available. When GNU Source Highlight isn't used, or can't add
754 styling to a particular source file, then the Python Pygments
755 library will be used instead.
757 set suppress-cli-notifications (on|off)
758 show suppress-cli-notifications
759 This controls whether printing the notifications is suppressed for CLI.
760 CLI notifications occur when you change the selected context
761 (i.e., the current inferior, thread and/or the frame), or when
762 the program being debugged stops (e.g., because of hitting a
763 breakpoint, completing source-stepping, an interrupt, etc.).
765 set style disassembler enabled on|off
766 show style disassembler enabled
767 If GDB is compiled with Python support, and the Python Pygments
768 package is available, then, when this setting is on, disassembler
769 output will have styling applied.
771 set ada source-charset
772 show ada source-charset
773 Set the character set encoding that is assumed for Ada symbols. Valid
774 values for this follow the values that can be passed to the GNAT
775 compiler via the '-gnati' option. The default is ISO-8859-1.
781 These are the new names for the old 'layout', 'focus', 'refresh',
782 and 'winheight' tui commands respectively. The old names still
783 exist as aliases to these new commands.
787 The new command 'tui window width', and the alias 'winwidth' allow
788 the width of a tui window to be adjusted when windows are laid out
793 Control the display of debug output about GDB's tui.
798 Printing of floating-point values with base-modifying formats like
799 /x has been changed to display the underlying bytes of the value in
800 the desired base. This was GDB's documented behavior, but was never
801 implemented correctly.
804 This command can now print a reply, if the reply includes
805 non-printable characters. Any non-printable characters are printed
806 as escaped hex, e.g. \x?? where '??' is replaces with the value of
807 the non-printable character.
810 The clone-inferior command now ensures that the TTY, CMD and ARGS
811 settings are copied from the original inferior to the new one.
812 All modifications to the environment variables done using the 'set
813 environment' or 'unset environment' commands are also copied to the new
816 set debug lin-lwp on|off
818 These commands have been removed from GDB. The new command 'set
819 debug linux-nat' and 'show debug linux-nat' should be used
823 This command now includes information about the width of the tui
824 windows in its output.
830 These commands are now aliases for the 'tui layout', 'tui focus',
831 'tui refresh', and 'tui window height' commands respectively.
833 * GDB's Ada parser now supports an extension for specifying the exact
834 byte contents of a floating-point literal. This can be useful for
835 setting floating-point registers to a precise value without loss of
836 precision. The syntax is an extension of the based literal syntax.
837 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
838 of the floating-point type, and the "f" is the marker for floating
843 ** The '-add-inferior' with no option flags now inherits the
844 connection of the current inferior, this restores the behaviour of
845 GDB as it was prior to GDB 10.
847 ** The '-add-inferior' command now accepts a '--no-connection'
848 option, which causes the new inferior to start without a
851 ** The default version of the MI interpreter is now 4 (-i=mi4).
853 ** The "script" field in breakpoint output (which is syntactically
854 incorrect in MI 3 and below) has changed in MI 4 to become a list.
855 This affects the following commands and events:
859 - =breakpoint-created
860 - =breakpoint-modified
862 The -fix-breakpoint-script-output command can be used to enable
863 this behavior with previous MI versions.
867 GNU/Linux/LoongArch loongarch*-*-linux*
875 ** New function gdb.add_history(), which takes a gdb.Value object
876 and adds the value it represents to GDB's history list. An
877 integer, the index of the new item in the history list, is
880 ** New function gdb.history_count(), which returns the number of
881 values in GDB's value history.
883 ** New gdb.events.gdb_exiting event. This event is called with a
884 gdb.GdbExitingEvent object which has the read-only attribute
885 'exit_code', which contains the value of the GDB exit code. This
886 event is triggered once GDB decides it is going to exit, but
887 before GDB starts to clean up its internal state.
889 ** New function gdb.architecture_names(), which returns a list
890 containing all of the possible Architecture.name() values. Each
893 ** New function gdb.Architecture.integer_type(), which returns an
894 integer type given a size and a signed-ness.
896 ** New gdb.TargetConnection object type that represents a connection
897 (as displayed by the 'info connections' command). A sub-class,
898 gdb.RemoteTargetConnection, is used to represent 'remote' and
899 'extended-remote' connections.
901 ** The gdb.Inferior type now has a 'connection' property which is an
902 instance of gdb.TargetConnection, the connection used by this
903 inferior. This can be None if the inferior has no connection.
905 ** New 'gdb.events.connection_removed' event registry, which emits a
906 'gdb.ConnectionEvent' when a connection is removed from GDB.
907 This event has a 'connection' property, a gdb.TargetConnection
908 object for the connection being removed.
910 ** New gdb.connections() function that returns a list of all
911 currently active connections.
913 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
914 is equivalent to the existing 'maint packet' CLI command; it
915 allows a user specified packet to be sent to the remote target.
917 ** New function gdb.host_charset(), returns a string, which is the
918 name of the current host charset.
920 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
923 ** New gdb.with_parameter(NAME, VALUE). This returns a context
924 manager that temporarily sets the gdb parameter NAME to VALUE,
925 then resets it when the context is exited.
927 ** The gdb.Value.format_string method now takes a 'styling'
928 argument, which is a boolean. When true, the returned string can
929 include escape sequences to apply styling. The styling will only
930 be present if styling is otherwise turned on in GDB (see 'help
931 set styling'). When false, which is the default if the argument
932 is not given, then no styling is applied to the returned string.
934 ** New read-only attribute gdb.InferiorThread.details, which is
935 either a string, containing additional, target specific thread
936 state information, or None, if there is no such additional
939 ** New read-only attribute gdb.Type.is_scalar, which is True for
940 scalar types, and False for all other types.
942 ** New read-only attribute gdb.Type.is_signed. This attribute
943 should only be read when Type.is_scalar is True, and will be True
944 for signed types, and False for all other types. Attempting to
945 read this attribute for non-scalar types will raise a ValueError.
947 ** It is now possible to add GDB/MI commands implemented in Python.
949 * New features in the GDB remote stub, GDBserver
951 ** GDBserver is now supported on OpenRISC GNU/Linux.
953 * New native configurations
955 GNU/Linux/OpenRISC or1k*-*-linux*
957 *** Changes in GDB 11
959 * The 'set disassembler-options' command now supports specifying options
962 * GDB now supports general memory tagging functionality if the underlying
963 architecture supports the proper primitives and hooks. Currently this is
964 enabled only for AArch64 MTE.
968 - Additional information when the inferior crashes with a SIGSEGV caused by
969 a memory tag violation.
971 - A new modifier 'm' for the "x" command, which displays allocation tags for a
972 particular memory range.
974 - Display of memory tag mismatches by "print", for addresses and
975 pointers, if memory tagging is supported by the architecture.
977 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
982 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
984 The MI -break-insert and -dprintf-insert commands now support a
985 new "--qualified" option that makes GDB interpret a specified
986 function name as a complete fully-qualified name. This is the
987 equivalent of the CLI's "break -qualified" and "dprintf
990 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
992 The MI -break-insert and -dprintf-insert commands now support a
993 '--force-condition' flag to forcibly define a condition even when
994 the condition is invalid at all locations of the breakpoint. This
995 is equivalent to the '-force-condition' flag of the CLI's "break"
998 ** '-break-condition --force'
1000 The MI -break-condition command now supports a '--force' flag to
1001 forcibly define a condition even when the condition is invalid at
1002 all locations of the selected breakpoint. This is equivalent to
1003 the '-force' flag of the CLI's "cond" command.
1005 ** '-file-list-exec-source-files [--group-by-objfile]
1006 [--basename | --dirname]
1009 The existing -file-list-exec-source-files command now takes an
1010 optional REGEXP which is used to filter the source files that are
1011 included in the results.
1013 By default REGEXP is matched against the full filename of the
1014 source file. When one of --basename or --dirname is given then
1015 REGEXP is only matched against the specified part of the full
1018 When the optional --group-by-objfile flag is used the output
1019 format is changed, the results are now a list of object files
1020 (executable and libraries) with the source files that are
1021 associated with each object file.
1023 The results from -file-list-exec-source-files now include a
1024 'debug-fully-read' field which takes the value 'true' or 'false'.
1025 A 'true' value indicates the source file is from a compilation
1026 unit that has had its debug information fully read in by GDB, a
1027 value of 'false' indicates GDB has only performed a partial scan
1028 of the debug information so far.
1030 * GDB now supports core file debugging for x86_64 Cygwin programs.
1032 * GDB will now look for the .gdbinit file in a config directory before
1033 looking for ~/.gdbinit. The file is searched for in the following
1034 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1035 $HOME/.gdbinit. On Apple hosts the search order is instead:
1036 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1038 * GDB now supports fixed point types which are described in DWARF
1039 as base types with a fixed-point encoding. Additionally, support
1040 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1043 For Ada, this allows support for fixed point types without requiring
1044 the use of the GNAT encoding (based on information added to the type's
1045 name following a GNAT-specific format).
1047 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1048 or ~/.gdbearlyinit if these files are present. These files are
1049 processed earlier than any of the other initialization files and
1050 can affect parts of GDB's startup that previously had already been
1051 completed before the initialization files were read, for example
1052 styling of the initial GDB greeting.
1054 * GDB now has two new options "--early-init-command" and
1055 "--early-init-eval-command" with corresponding short options "-eix"
1056 and "-eiex" that allow options (that would normally appear in a
1057 gdbearlyinit file) to be passed on the command line.
1059 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1060 now understood by GDB, and can be used to describe the vector
1061 registers of a target. The precise requirements of this register
1062 feature are documented in the GDB manual.
1064 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1065 supported by GDB and describes a new VPR register from the ARM MVE
1066 (Helium) extension. See the GDB manual for more information.
1070 ** TUI windows now support mouse actions. The mouse wheel scrolls
1071 the appropriate window.
1073 ** Key combinations that do not have a specific action on the
1074 focused window are passed to GDB. For example, you now can use
1075 Ctrl-Left/Ctrl-Right to move between words in the command window
1076 regardless of which window is in focus. Previously you would
1077 need to focus on the command window for such key combinations to
1082 set debug event-loop
1083 show debug event-loop
1084 Control the display of debug output about GDB's event loop.
1086 set print memory-tag-violations
1087 show print memory-tag-violations
1088 Control whether to display additional information about memory tag violations
1089 when printing pointers and addresses. Architecture support for memory
1090 tagging is required for this option to have an effect.
1092 maintenance flush symbol-cache
1093 maintenance flush register-cache
1094 These new commands are equivalent to the already existing commands
1095 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1097 maintenance flush dcache
1098 A new command to flush the dcache.
1100 maintenance info target-sections
1101 Print GDB's internal target sections table.
1103 maintenance info jit
1104 Print the JIT code objects in the inferior known to GDB.
1106 memory-tag show-logical-tag POINTER
1107 Print the logical tag for POINTER.
1108 memory-tag with-logical-tag POINTER TAG
1109 Print POINTER with logical tag TAG.
1110 memory-tag show-allocation-tag ADDRESS
1111 Print the allocation tag for ADDRESS.
1112 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1113 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1114 memory-tag check POINTER
1115 Validate that POINTER's logical tag matches the allocation tag.
1117 set startup-quietly on|off
1118 show startup-quietly
1119 When 'on', this causes GDB to act as if "-silent" were passed on the
1120 command line. This command needs to be added to an early
1121 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1124 set print type hex on|off
1126 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1127 and offsets of struct members. When 'off', decimal notation is used.
1129 set python ignore-environment on|off
1130 show python ignore-environment
1131 When 'on', this causes GDB's builtin Python to ignore any
1132 environment variables that would otherwise affect how Python
1133 behaves. This command needs to be added to an early initialization
1134 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1136 set python dont-write-bytecode auto|on|off
1137 show python dont-write-bytecode
1138 When 'on', this causes GDB's builtin Python to not write any
1139 byte-code (.pyc files) to disk. This command needs to be added to
1140 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1141 order to affect GDB. When 'off' byte-code will always be written.
1142 When set to 'auto' (the default) Python will check the
1143 PYTHONDONTWRITEBYTECODE environment variable.
1147 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1148 [-force-condition] [if CONDITION]
1149 This command would previously refuse setting a breakpoint if the
1150 CONDITION expression is invalid at a location. It now accepts and
1151 defines the breakpoint if there is at least one location at which
1152 the CONDITION is valid. The locations for which the CONDITION is
1153 invalid, are automatically disabled. If CONDITION is invalid at all
1154 of the locations, setting the breakpoint is still rejected. However,
1155 the '-force-condition' flag can be used in this case for forcing GDB to
1156 define the breakpoint, making all the current locations automatically
1157 disabled. This may be useful if the user knows the condition will
1158 become meaningful at a future location, e.g. due to a shared library
1161 condition [-force] N COND
1162 The behavior of this command is changed the same way for the 'break'
1163 command as explained above. The '-force' flag can be used to force
1164 GDB into defining the condition even when COND is invalid for all the
1165 current locations of breakpoint N.
1168 maintenance flush-symbol-cache
1169 These commands are deprecated in favor of the new commands
1170 'maintenance flush register-cache' and 'maintenance flush
1171 symbol-cache' respectively.
1173 set style version foreground COLOR
1174 set style version background COLOR
1175 set style version intensity VALUE
1176 Control the styling of GDB's version number text.
1179 When the ID parameter is omitted, then this command prints information
1180 about the current inferior. When the ID parameter is present, the
1181 behavior of the command is unchanged and have the inferior ID become
1182 the current inferior.
1184 maintenance info sections
1185 The ALLOBJ keyword has been replaced with an -all-objects command
1186 line flag. It is now possible to filter which sections are printed
1187 even when -all-objects is passed.
1189 ptype[/FLAGS] TYPE | EXPRESSION
1190 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1191 notation is used when printing sizes and offsets of struct members.
1192 When '/d' is set, decimal notation is used when printing sizes and
1193 offsets of struct members. Default behavior is given by 'show print
1197 The info sources command output has been restructured. The results
1198 are now based around a list of objfiles (executable and libraries),
1199 and for each objfile the source files that are part of that objfile
1202 * Removed targets and native configurations
1204 ARM Symbian arm*-*-symbianelf*
1206 * New remote packets
1209 Request the remote to send allocation tags for a particular memory range.
1211 Request the remote to store the specified allocation tags to the requested
1216 ** Improved support for rvalue reference values:
1217 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1218 value-referenced-value procedure now handles rvalue reference
1221 ** New procedures for obtaining value variants:
1222 value-reference-value, value-rvalue-reference-value and
1225 ** Temporary breakpoints can now be created with make-breakpoint and
1226 tested for using breakpoint-temporary?.
1230 ** Inferior objects now contain a read-only 'connection_num' attribute that
1231 gives the connection number as seen in 'info connections' and
1234 ** New method gdb.Frame.level() which returns the stack level of the
1237 ** New method gdb.PendingFrame.level() which returns the stack level
1238 of the frame object.
1240 ** When hitting a catchpoint, the Python API will now emit a
1241 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1242 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1244 ** Python TUI windows can now receive mouse click events. If the
1245 Window object implements the click method, it is called for each
1246 mouse click event in this window.
1248 *** Changes in GDB 10
1250 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1251 and "org.gnu.gdb.arc.aux". The old names are still supported but
1252 must be considered obsolete. They will be deprecated after some
1255 * Help and apropos commands will now show the documentation of a
1256 command only once, even if that command has one or more aliases.
1257 These commands now show the command name, then all of its aliases,
1258 and finally the description of the command.
1260 * 'help aliases' now shows only the user defined aliases. GDB predefined
1261 aliases are shown together with their aliased command.
1263 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1264 debugging information as well as source code.
1266 When built with debuginfod, GDB can automatically query debuginfod
1267 servers for the separate debug files and source code of the executable
1270 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1271 requires libdebuginfod, the debuginfod client library).
1273 debuginfod is distributed with elfutils, starting with version 0.178.
1275 You can get the latest version from https://sourceware.org/elfutils.
1277 * Multi-target debugging support
1279 GDB now supports debugging multiple target connections
1280 simultaneously. For example, you can now have each inferior
1281 connected to different remote servers running in different machines,
1282 or have one inferior debugging a local native process, an inferior
1283 debugging a core dump, etc.
1285 This support is experimental and comes with some limitations -- you
1286 can only resume multiple targets simultaneously if all targets
1287 support non-stop mode, and all remote stubs or servers must support
1288 the same set of remote protocol features exactly. See also "info
1289 connections" and "add-inferior -no-connection" below, and "maint set
1290 target-non-stop" in the user manual.
1292 * New features in the GDB remote stub, GDBserver
1294 ** GDBserver is now supported on ARC GNU/Linux.
1296 ** GDBserver is now supported on RISC-V GNU/Linux.
1298 ** GDBserver no longer supports these host triplets:
1300 i[34567]86-*-lynxos*
1309 i[34567]86-*-mingw32ce*
1311 * Debugging MS-Windows processes now sets $_exitsignal when the
1312 inferior is terminated by a signal, instead of setting $_exitcode.
1314 * Multithreaded symbol loading has now been enabled by default on systems
1315 that support it (see entry for GDB 9, below), providing faster
1316 performance for programs with many symbols.
1318 * The $_siginfo convenience variable now also works on Windows targets,
1319 and will display the EXCEPTION_RECORD of the last handled exception.
1321 * TUI windows can now be arranged horizontally.
1323 * The command history filename can now be set to the empty string
1324 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1325 the environment. The effect of setting this filename to the empty
1326 string is that GDB will not try to load any previous command
1329 * On Windows targets, it is now possible to debug 32-bit programs with a
1334 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1335 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1336 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1337 running process, this new option indicates whether to detect
1338 a mismatch between the current executable file loaded by GDB and the
1339 executable file used to start the process. If 'ask', the default,
1340 display a warning and ask the user whether to load the process
1341 executable file; if 'warn', just display a warning; if 'off', don't
1342 attempt to detect a mismatch.
1344 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1345 Define a new TUI layout, specifying its name and the windows that
1348 maintenance print xml-tdesc [FILE]
1349 Prints the current target description as an XML document. If the
1350 optional FILE is provided (which is an XML target description) then
1351 the target description is read from FILE into GDB, and then
1354 maintenance print core-file-backed-mappings
1355 Prints file-backed mappings loaded from a core file's note section.
1356 Output is expected to be similar to that of "info proc mappings".
1358 set debug fortran-array-slicing on|off
1359 show debug fortran-array-slicing
1360 Print debugging when taking slices of Fortran arrays.
1362 set fortran repack-array-slices on|off
1363 show fortran repack-array-slices
1364 When taking slices from Fortran arrays and strings, if the slice is
1365 non-contiguous within the original value then, when this option is
1366 on, the new value will be repacked into a single contiguous value.
1367 When this option is off, then the value returned will consist of a
1368 descriptor that describes the slice within the memory of the
1369 original parent value.
1373 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1374 The alias command can now specify default args for an alias.
1375 GDB automatically prepends the alias default args to the argument list
1376 provided explicitly by the user.
1377 For example, to have a backtrace with full details, you can define
1378 an alias 'bt_ALL' as
1379 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1380 -past-main -past-entry -full'.
1381 Alias default arguments can also use a set of nested 'with' commands,
1382 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1383 defines the alias pp10 that will pretty print a maximum of 10 elements
1384 of the given expression (if the expression is an array).
1388 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1389 BPF bpf-unknown-none
1394 ** gdb.register_window_type can be used to implement new TUI windows
1397 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1398 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1399 field of a dynamic type may have None for its "bitpos" attribute
1402 ** Commands written in Python can be in the "TUI" help class by
1403 registering with the new constant gdb.COMMAND_TUI.
1405 ** New method gdb.PendingFrame.architecture () to retrieve the
1406 architecture of the pending frame.
1408 ** New gdb.Architecture.registers method that returns a
1409 gdb.RegisterDescriptorIterator object, an iterator that returns
1410 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1411 way to query the registers available for an architecture.
1413 ** New gdb.Architecture.register_groups method that returns a
1414 gdb.RegisterGroupIterator object, an iterator that returns
1415 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1416 discover the available register groups.
1420 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1422 ** Procedures 'memory-port-read-buffer-size',
1423 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1424 and 'set-memory-port-write-buffer-size!' are deprecated. When
1425 using Guile 2.2 and later, users who need to control the size of
1426 a memory port's internal buffer can use the 'setvbuf' procedure.
1428 *** Changes in GDB 9
1430 * 'thread-exited' event is now available in the annotations interface.
1432 * New built-in convenience variables $_gdb_major and $_gdb_minor
1433 provide the GDB version. They are handy for conditionally using
1434 features available only in or since specific GDB versions, in
1435 scripts that should work error-free with many different versions,
1436 such as in system-wide init files.
1438 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1439 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1440 of the GDB settings and the GDB maintenance settings. They are handy
1441 for changing the logic of user defined commands depending on the
1442 current GDB settings.
1444 * GDB now supports Thread Local Storage (TLS) variables on several
1445 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1446 architectures require kernel changes. TLS is not yet supported for
1447 amd64 and i386 process core dumps.
1449 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1450 addresses that required unmasking are shown in the backtrace with the
1453 * Two new convenience functions $_cimag and $_creal that extract the
1454 imaginary and real parts respectively from complex numbers.
1456 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1457 provide the exitcode or exit status of the shell commands launched by
1458 GDB commands such as "shell", "pipe" and "make".
1460 * The command define-prefix can now define user defined prefix commands.
1461 User defined commands can now be defined using these user defined prefix
1464 * Command names can now use the . character.
1466 * The RX port now supports XML target descriptions.
1468 * GDB now shows the Ada task names at more places, e.g. in task switching
1471 * GDB can now be compiled with Python 3 on Windows.
1473 * New convenience variable $_ada_exception holds the address of the
1474 Ada exception being thrown. This is set by Ada-related catchpoints.
1476 * GDB can now place breakpoints on nested functions and subroutines in
1477 Fortran code. The '::' operator can be used between parent and
1478 child scopes when placing breakpoints, for example:
1480 (gdb) break outer_function::inner_function
1482 The 'outer_function::' prefix is only needed if 'inner_function' is
1483 not visible in the current scope.
1485 * In addition to the system-wide gdbinit file, if configured with
1486 --with-system-gdbinit-dir, GDB will now also load files in that directory
1487 as system gdbinit files, unless the -nx or -n flag is provided. Files
1488 with extensions .gdb, .py and .scm are supported as long as GDB was
1489 compiled with support for that language.
1491 * GDB now supports multithreaded symbol loading for higher performance.
1492 This feature is still in testing, so it is disabled by default. You
1493 can turn it on using 'maint set worker-threads unlimited'.
1497 ** The gdb.Value type has a new method 'format_string' which returns a
1498 string representing the value. The formatting is controlled by the
1499 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1500 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1501 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1503 ** gdb.Type has a new property 'objfile' which returns the objfile the
1504 type was defined in.
1506 ** The frame information printed by the python frame filtering code
1507 is now consistent with what the 'backtrace' command prints when
1508 there are no filters, or when the 'backtrace' '-no-filters' option
1511 ** The new function gdb.lookup_static_symbol can be used to look up
1512 symbols with static linkage.
1514 ** The new function gdb.lookup_static_symbols can be used to look up
1515 all static symbols with static linkage.
1517 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1518 'lookup_static_symbol' to lookup a symbol from this objfile only.
1520 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1521 this block (e.g. block['local_variable']).
1525 | [COMMAND] | SHELL_COMMAND
1526 | -d DELIM COMMAND DELIM SHELL_COMMAND
1527 pipe [COMMAND] | SHELL_COMMAND
1528 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1529 Executes COMMAND and sends its output to SHELL_COMMAND.
1530 With no COMMAND, repeat the last executed command
1531 and send its output to SHELL_COMMAND.
1533 define-prefix COMMAND
1534 Define or mark a command as a user-defined prefix command.
1536 with SETTING [VALUE] [-- COMMAND]
1537 w SETTING [VALUE] [-- COMMAND]
1538 Temporarily set SETTING, run COMMAND, and restore SETTING.
1539 Usage: with SETTING -- COMMAND
1540 With no COMMAND, repeats the last executed command.
1541 SETTING is any GDB setting you can change with the "set"
1542 subcommands. For example, 'with language c -- print someobj'
1543 temporarily switches to the C language in order to print someobj.
1544 Settings can be combined: 'w lang c -- w print elements unlimited --
1545 usercmd' switches to the C language and runs usercmd with no limit
1546 of array elements to print.
1548 maint with SETTING [VALUE] [-- COMMAND]
1549 Like "with", but works with "maintenance set" settings.
1551 set may-call-functions [on|off]
1552 show may-call-functions
1553 This controls whether GDB will attempt to call functions in
1554 the program, such as with expressions in the print command. It
1555 defaults to on. Calling functions in the program being debugged
1556 can have undesired side effects. It is now possible to forbid
1557 such function calls. If function calls are forbidden, GDB will throw
1558 an error when a command (such as print expression) calls a function
1561 set print finish [on|off]
1563 This controls whether the `finish' command will display the value
1564 that is returned by the current function. When `off', the value is
1565 still entered into the value history, but it is not printed. The
1569 show print max-depth
1570 Allows deeply nested structures to be simplified when printing by
1571 replacing deeply nested parts (beyond the max-depth) with ellipses.
1572 The default max-depth is 20, but this can be set to unlimited to get
1573 the old behavior back.
1575 set print raw-values [on|off]
1576 show print raw-values
1577 By default, GDB applies the enabled pretty printers when printing a
1578 value. This allows to ignore the enabled pretty printers for a series
1579 of commands. The default is 'off'.
1581 set logging debugredirect [on|off]
1582 By default, GDB debug output will go to both the terminal and the logfile.
1583 Set if you want debug output to go only to the log file.
1585 set style title foreground COLOR
1586 set style title background COLOR
1587 set style title intensity VALUE
1588 Control the styling of titles.
1590 set style highlight foreground COLOR
1591 set style highlight background COLOR
1592 set style highlight intensity VALUE
1593 Control the styling of highlightings.
1595 maint set worker-threads
1596 maint show worker-threads
1597 Control the number of worker threads that can be used by GDB. The
1598 default is 0. "unlimited" lets GDB choose a number that is
1599 reasonable. Currently worker threads are only used when demangling
1600 the names of linker symbols.
1602 set style tui-border foreground COLOR
1603 set style tui-border background COLOR
1604 Control the styling of TUI borders.
1606 set style tui-active-border foreground COLOR
1607 set style tui-active-border background COLOR
1608 Control the styling of the active TUI border.
1610 maint set test-settings KIND
1611 maint show test-settings KIND
1612 A set of commands used by the testsuite for exercising the settings
1615 maint set tui-resize-message [on|off]
1616 maint show tui-resize-message
1617 Control whether GDB prints a message each time the terminal is
1618 resized when in TUI mode. This is primarily useful for testing the
1621 set print frame-info [short-location|location|location-and-address
1622 |source-and-location|source-line|auto]
1623 show print frame-info
1624 This controls what frame information is printed by the commands printing
1625 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1626 'frame', 'stepi'. The python frame filtering also respect this setting.
1627 The 'backtrace' '-frame-info' option can override this global setting.
1629 set tui compact-source
1630 show tui compact-source
1632 Enable the "compact" display mode for the TUI source window. The
1633 compact display uses only as much space as is needed for the line
1634 numbers in the current file, and only a single space to separate the
1635 line numbers from the source.
1637 info modules [-q] [REGEXP]
1638 Return a list of Fortran modules matching REGEXP, or all modules if
1641 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1642 Return a list of functions within all modules, grouped by module.
1643 The list of functions can be restricted with the optional regular
1644 expressions. MODULE_REGEXP matches against the module name,
1645 TYPE_REGEXP matches against the function type signature, and REGEXP
1646 matches against the function name.
1648 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1649 Return a list of variables within all modules, grouped by module.
1650 The list of variables can be restricted with the optional regular
1651 expressions. MODULE_REGEXP matches against the module name,
1652 TYPE_REGEXP matches against the variable type, and REGEXP matches
1653 against the variable name.
1655 set debug remote-packet-max-chars
1656 show debug remote-packet-max-chars
1657 Controls the number of characters to output in a remote packet when using
1659 The default is 512 bytes.
1662 Lists the target connections currently in use.
1667 The "help" command uses the title style to enhance the
1668 readibility of its output by styling the classes and
1672 Similarly to "help", the "apropos" command also uses the
1673 title style for the command names. "apropos" accepts now
1674 a flag "-v" (verbose) to show the full documentation
1675 of matching commands and to use the highlight style to mark
1676 the documentation parts matching REGEXP.
1680 The GDB printf and eval commands can now print C-style and Ada-style
1681 string convenience variables without calling functions in the program.
1682 This allows to do formatted printing of strings without having
1683 a running inferior, or when debugging a core dump.
1685 info sources [-dirname | -basename] [--] [REGEXP]
1686 This command has now optional arguments to only print the files
1687 whose names match REGEXP. The arguments -dirname and -basename
1688 allow to restrict matching respectively to the dirname and basename
1692 The "show style" and its subcommands are now styling
1693 a style name in their output using its own style, to help
1694 the user visualize the different styles.
1696 set print frame-arguments
1697 The new value 'presence' indicates to only indicate the presence of
1698 arguments using ..., instead of printing argument names and values.
1700 set print raw-frame-arguments
1701 show print raw-frame-arguments
1703 These commands replace the similarly-named "set/show print raw
1704 frame-arguments" commands (now with a dash instead of a space). The
1705 old commands are now deprecated and may be removed in a future
1708 add-inferior [-no-connection]
1709 The add-inferior command now supports a "-no-connection" flag that
1710 makes the new inferior start with no target connection associated.
1711 By default, the new inferior inherits the target connection of the
1712 current inferior. See also "info connections".
1715 This command's output now includes a new "Connection" column
1716 indicating which target connection an inferior is bound to. See
1717 "info connections" above.
1719 maint test-options require-delimiter
1720 maint test-options unknown-is-error
1721 maint test-options unknown-is-operand
1722 maint show test-options-completion-result
1723 Commands used by the testsuite to validate the command options
1726 focus, winheight, +, -, >, <
1727 These commands are now case-sensitive.
1729 * New command options, command completion
1731 GDB now has a standard infrastructure to support dash-style command
1732 options ('-OPT'). One benefit is that commands that use it can
1733 easily support completion of command line arguments. Try "CMD
1734 -[TAB]" or "help CMD" to find options supported by a command. Over
1735 time, we intend to migrate most commands to this infrastructure. A
1736 number of commands got support for new command options in this
1739 ** The "print" and "compile print" commands now support a number of
1740 options that allow overriding relevant global print settings as
1741 set by "set print" subcommands:
1745 -array-indexes [on|off]
1746 -elements NUMBER|unlimited
1750 -raw-values [on|off]
1751 -repeats NUMBER|unlimited
1752 -static-members [on|off]
1757 Note that because the "print"/"compile print" commands accept
1758 arbitrary expressions which may look like options (including
1759 abbreviations), if you specify any command option, then you must
1760 use a double dash ("--") to mark the end of argument processing.
1762 ** The "backtrace" command now supports a number of options that
1763 allow overriding relevant global print settings as set by "set
1764 backtrace" and "set print" subcommands:
1766 -entry-values no|only|preferred|if-needed|both|compact|default
1767 -frame-arguments all|scalars|none
1768 -raw-frame-arguments [on|off]
1769 -frame-info auto|source-line|location|source-and-location
1770 |location-and-address|short-location
1772 -past-entry [on|off]
1774 In addition, the full/no-filters/hide qualifiers are now also
1775 exposed as command options too:
1781 ** The "frame apply", "tfaas" and "faas" commands similarly now
1782 support the following options:
1785 -past-entry [on|off]
1787 ** The new "info sources" options -dirname and -basename options
1788 are using the standard '-OPT' infrastructure.
1790 All options above can also be abbreviated. The argument of boolean
1791 (on/off) options can be 0/1 too, and also the argument is assumed
1792 "on" if omitted. This allows writing compact command invocations,
1795 (gdb) p -ra -p -o 0 -- *myptr
1797 The above is equivalent to:
1799 (gdb) print -raw-values -pretty -object off -- *myptr
1801 ** The "info types" command now supports the '-q' flag to disable
1802 printing of some header information in a similar fashion to "info
1803 variables" and "info functions".
1805 ** The "info variables", "info functions", and "whereis" commands
1806 now take a '-n' flag that excludes non-debug symbols (symbols
1807 from the symbol table, not from the debug info such as DWARF)
1810 * Completion improvements
1812 ** GDB can now complete the options of the "thread apply all" and
1813 "taas" commands, and their "-ascending" option can now be
1816 ** GDB can now complete the options of the "info threads", "info
1817 functions", "info variables", "info locals", and "info args"
1820 ** GDB can now complete the options of the "compile file" and
1821 "compile code" commands. The "compile file" command now
1822 completes on filenames.
1824 ** GDB can now complete the backtrace command's
1825 "full/no-filters/hide" qualifiers.
1827 * In settings, you can now abbreviate "unlimited".
1829 E.g., "set print elements u" is now equivalent to "set print
1830 elements unlimited".
1835 This lists all the possible completions for the rest of the line, if it
1836 were to be given as a command itself. This is intended for use by MI
1837 frontends in cases when separate CLI and MI channels cannot be used.
1839 -catch-throw, -catch-rethrow, and -catch-catch
1840 These can be used to catch C++ exceptions in a similar fashion to
1841 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1843 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1844 These commands are the MI equivalent of the CLI commands 'info
1845 functions', 'info types', and 'info variables' respectively.
1847 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1850 -symbol-info-module-functions and -symbol-info-module-variables.
1851 These commands are the MI equivalent of the CLI commands 'info
1852 module functions' and 'info module variables'.
1856 ** The default version of the MI interpreter is now 3 (-i=mi3).
1858 ** The output of information about multi-location breakpoints (which is
1859 syntactically incorrect in MI 2) has changed in MI 3. This affects
1860 the following commands and events:
1864 - =breakpoint-created
1865 - =breakpoint-modified
1867 The -fix-multi-location-breakpoint-output command can be used to enable
1868 this behavior with previous MI versions.
1870 ** Backtraces and frames include a new optional field addr_flags which is
1871 given after the addr field. On AArch64 this contains PAC if the address
1872 has been masked in the frame. On all other targets the field is not
1877 The testsuite now creates the files gdb.cmd (containing the arguments
1878 used to launch GDB) and gdb.in (containing all the commands sent to
1879 GDB) in the output directory for each test script. Multiple invocations
1880 are appended with .1, .2, .3 etc.
1882 * Building GDB and GDBserver now requires GNU make >= 3.82.
1884 Using another implementation of the make program or an earlier version of
1885 GNU make to build GDB or GDBserver is not supported.
1887 * Building GDB now requires GNU readline >= 7.0.
1889 GDB now bundles GNU readline 8.0, but if you choose to use
1890 --with-system-readline, only readline >= 7.0 can be used.
1892 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1893 from .inputrc to bind keys in this keymap. This feature is only
1894 available when gdb is built against GNU readline 8.0 or later.
1896 * Removed targets and native configurations
1898 GDB no longer supports debugging the Cell Broadband Engine. This includes
1899 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1900 of Cell/B.E. applications that use both the PPU and SPU architectures.
1906 * Removed targets and native configurations
1908 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1909 sparc*-*-solaris2.10
1911 *** Changes in GDB 8.3
1913 * GDB and GDBserver now support access to additional registers on
1914 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1917 * GDB now has experimental support for the compilation and injection of
1918 C++ source code into the inferior. This beta release does not include
1919 support for several language features, such as templates, constructors,
1922 This feature requires GCC 7.1 or higher built with libcp1.so
1925 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1926 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1927 'ADDRESS:PORT' method.
1929 * DWARF index cache: GDB can now automatically save indices of DWARF
1930 symbols on disk to speed up further loading of the same binaries.
1932 * Ada task switching is now supported on aarch64-elf targets when
1933 debugging a program using the Ravenscar Profile. For more information,
1934 see the "Tasking Support when using the Ravenscar Profile" section
1935 in the GDB user manual.
1937 * GDB in batch mode now exits with status 1 if the last command to be
1940 * The RISC-V target now supports target descriptions.
1942 * System call catchpoints now support system call aliases on FreeBSD.
1943 When the ABI of a system call changes in FreeBSD, this is
1944 implemented by leaving a compatibility system call using the old ABI
1945 at the existing number and allocating a new system call number for
1946 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1947 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1948 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1949 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1950 so that a system call catchpoint for the 'kevent' system call will
1951 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1952 binaries. This ensures that 'kevent' system calls are caught for
1953 binaries using either the old or new ABIs.
1955 * Terminal styling is now available for the CLI and the TUI. GNU
1956 Source Highlight can additionally be used to provide styling of
1957 source code snippets. See the "set style" commands, below, for more
1960 * Removed support for old demangling styles arm, edg, gnu, hp and
1965 set debug compile-cplus-types
1966 show debug compile-cplus-types
1967 Control the display of debug output about type conversion in the
1968 C++ compile feature. Commands have no effect while compiling
1969 for other languages.
1973 Control whether debug output about files/functions skipping is
1976 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1977 Apply a command to some frames.
1978 FLAG arguments allow to control what output to produce and how to handle
1979 errors raised when applying COMMAND to a frame.
1982 Apply a command to all threads (ignoring errors and empty output).
1983 Shortcut for 'thread apply all -s COMMAND'.
1986 Apply a command to all frames (ignoring errors and empty output).
1987 Shortcut for 'frame apply all -s COMMAND'.
1990 Apply a command to all frames of all threads (ignoring errors and empty
1992 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1994 maint set dwarf unwinders (on|off)
1995 maint show dwarf unwinders
1996 Control whether DWARF unwinders can be used.
1999 Display a list of open files for a process.
2003 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2004 These commands all now take a frame specification which
2005 is either a frame level, or one of the keywords 'level', 'address',
2006 'function', or 'view' followed by a parameter. Selecting a frame by
2007 address, or viewing a frame outside the current backtrace now
2008 requires the use of a keyword. Selecting a frame by level is
2009 unchanged. The MI comment "-stack-select-frame" is unchanged.
2011 target remote FILENAME
2012 target extended-remote FILENAME
2013 If FILENAME is a Unix domain socket, GDB will attempt to connect
2014 to this socket instead of opening FILENAME as a character device.
2016 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2017 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2018 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2019 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2020 These commands can now print only the searched entities
2021 matching the provided regexp(s), giving a condition
2022 on the entity names or entity types. The flag -q disables
2023 printing headers or informations messages.
2029 These commands now determine the syntax for the shown entities
2030 according to the language chosen by `set language'. In particular,
2031 `set language auto' means to automatically choose the language of
2034 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2035 The 'thread apply' command accepts new FLAG arguments.
2036 FLAG arguments allow to control what output to produce and how to handle
2037 errors raised when applying COMMAND to a thread.
2039 set tui tab-width NCHARS
2040 show tui tab-width NCHARS
2041 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2043 set style enabled [on|off]
2045 Enable or disable terminal styling. Styling is enabled by default
2046 on most hosts, but disabled by default when in batch mode.
2048 set style sources [on|off]
2050 Enable or disable source code styling. Source code styling is
2051 enabled by default, but only takes effect if styling in general is
2052 enabled, and if GDB was linked with GNU Source Highlight.
2054 set style filename foreground COLOR
2055 set style filename background COLOR
2056 set style filename intensity VALUE
2057 Control the styling of file names.
2059 set style function foreground COLOR
2060 set style function background COLOR
2061 set style function intensity VALUE
2062 Control the styling of function names.
2064 set style variable foreground COLOR
2065 set style variable background COLOR
2066 set style variable intensity VALUE
2067 Control the styling of variable names.
2069 set style address foreground COLOR
2070 set style address background COLOR
2071 set style address intensity VALUE
2072 Control the styling of addresses.
2076 ** The '-data-disassemble' MI command now accepts an '-a' option to
2077 disassemble the whole function surrounding the given program
2078 counter value or function name. Support for this feature can be
2079 verified by using the "-list-features" command, which should
2080 contain "data-disassemble-a-option".
2082 ** Command responses and notifications that include a frame now include
2083 the frame's architecture in a new "arch" attribute.
2085 * New native configurations
2087 GNU/Linux/RISC-V riscv*-*-linux*
2088 FreeBSD/riscv riscv*-*-freebsd*
2092 GNU/Linux/RISC-V riscv*-*-linux*
2093 CSKY ELF csky*-*-elf
2094 CSKY GNU/LINUX csky*-*-linux
2095 FreeBSD/riscv riscv*-*-freebsd*
2097 GNU/Linux/OpenRISC or1k*-*-linux*
2101 GDB no longer supports native debugging on versions of MS-Windows
2106 ** GDB no longer supports Python versions less than 2.6.
2108 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2109 space associated to that inferior.
2111 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2112 of objfiles associated to that program space.
2114 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2115 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2118 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2119 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2120 correct and did not work properly.
2122 ** The gdb.Value type has a new constructor, which is used to construct a
2123 gdb.Value from a Python buffer object and a gdb.Type.
2129 Enable or disable the undefined behavior sanitizer. This is
2130 disabled by default, but passing --enable-ubsan=yes or
2131 --enable-ubsan=auto to configure will enable it. Enabling this can
2132 cause a performance penalty. The undefined behavior sanitizer was
2133 first introduced in GCC 4.9.
2135 *** Changes in GDB 8.2
2137 * The 'set disassembler-options' command now supports specifying options
2138 for the MIPS target.
2140 * The 'symbol-file' command now accepts an '-o' option to add a relative
2141 offset to all sections.
2143 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2144 a relative offset to all sections, but it allows to override the load
2145 address of individual sections using '-s'.
2147 * The 'add-symbol-file' command no longer requires the second argument
2148 (address of the text section).
2150 * The endianness used with the 'set endian auto' mode in the absence of
2151 an executable selected for debugging is now the last endianness chosen
2152 either by one of the 'set endian big' and 'set endian little' commands
2153 or by inferring from the last executable used, rather than the startup
2156 * The pager now allows a "c" response, meaning to disable the pager
2157 for the rest of the current command.
2159 * The commands 'info variables/functions/types' now show the source line
2160 numbers of symbol definitions when available.
2162 * 'info proc' now works on running processes on FreeBSD systems and core
2163 files created on FreeBSD systems.
2165 * C expressions can now use _Alignof, and C++ expressions can now use
2168 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2169 the vector length while the process is running.
2175 Control display of debugging info regarding the FreeBSD native target.
2177 set|show varsize-limit
2178 This new setting allows the user to control the maximum size of Ada
2179 objects being printed when those objects have a variable type,
2180 instead of that maximum size being hardcoded to 65536 bytes.
2182 set|show record btrace cpu
2183 Controls the processor to be used for enabling errata workarounds for
2184 branch trace decode.
2186 maint check libthread-db
2187 Run integrity checks on the current inferior's thread debugging
2190 maint set check-libthread-db (on|off)
2191 maint show check-libthread-db
2192 Control whether to run integrity checks on inferior specific thread
2193 debugging libraries as they are loaded. The default is not to
2194 perform such checks.
2198 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2200 ** The commands attached to a breakpoint can be set by assigning to
2201 the breakpoint's "commands" field.
2203 ** gdb.execute can now execute multi-line gdb commands.
2205 ** The new functions gdb.convenience_variable and
2206 gdb.set_convenience_variable can be used to get and set the value
2207 of convenience variables.
2209 ** A gdb.Parameter will no longer print the "set" help text on an
2210 ordinary "set"; instead by default a "set" will be silent unless
2211 the get_set_string method returns a non-empty string.
2215 RiscV ELF riscv*-*-elf
2217 * Removed targets and native configurations
2219 m88k running OpenBSD m88*-*-openbsd*
2220 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2221 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2222 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2224 * Aarch64/Linux hardware watchpoints improvements
2226 Hardware watchpoints on unaligned addresses are now properly
2227 supported when running Linux kernel 4.10 or higher: read and access
2228 watchpoints are no longer spuriously missed, and all watchpoints
2229 lengths between 1 and 8 bytes are supported. On older kernels,
2230 watchpoints set on unaligned addresses are no longer missed, with
2231 the tradeoff that there is a possibility of false hits being
2236 --enable-codesign=CERT
2237 This can be used to invoke "codesign -s CERT" after building gdb.
2238 This option is useful on macOS, where code signing is required for
2239 gdb to work properly.
2241 --disable-gdbcli has been removed
2242 This is now silently accepted, but does nothing.
2244 *** Changes in GDB 8.1
2246 * GDB now supports dynamically creating arbitrary register groups specified
2247 in XML target descriptions. This allows for finer grain grouping of
2248 registers on systems with a large amount of registers.
2250 * The 'ptype' command now accepts a '/o' flag, which prints the
2251 offsets and sizes of fields in a struct, like the pahole(1) tool.
2253 * New "--readnever" command line option instructs GDB to not read each
2254 symbol file's symbolic debug information. This makes startup faster
2255 but at the expense of not being able to perform symbolic debugging.
2256 This option is intended for use cases where symbolic debugging will
2257 not be used, e.g., when you only need to dump the debuggee's core.
2259 * GDB now uses the GNU MPFR library, if available, to emulate target
2260 floating-point arithmetic during expression evaluation when the target
2261 uses different floating-point formats than the host. At least version
2262 3.1 of GNU MPFR is required.
2264 * GDB now supports access to the guarded-storage-control registers and the
2265 software-based guarded-storage broadcast control registers on IBM z14.
2267 * On Unix systems, GDB now supports transmitting environment variables
2268 that are to be set or unset to GDBserver. These variables will
2269 affect the environment to be passed to the remote inferior.
2271 To inform GDB of environment variables that are to be transmitted to
2272 GDBserver, use the "set environment" command. Only user set
2273 environment variables are sent to GDBserver.
2275 To inform GDB of environment variables that are to be unset before
2276 the remote inferior is started by the GDBserver, use the "unset
2277 environment" command.
2279 * Completion improvements
2281 ** GDB can now complete function parameters in linespecs and
2282 explicit locations without quoting. When setting breakpoints,
2283 quoting around functions names to help with TAB-completion is
2284 generally no longer necessary. For example, this now completes
2287 (gdb) b function(in[TAB]
2288 (gdb) b function(int)
2290 Related, GDB is no longer confused with completing functions in
2291 C++ anonymous namespaces:
2294 (gdb) b (anonymous namespace)::[TAB][TAB]
2295 (anonymous namespace)::a_function()
2296 (anonymous namespace)::b_function()
2298 ** GDB now has much improved linespec and explicit locations TAB
2299 completion support, that better understands what you're
2300 completing and offers better suggestions. For example, GDB no
2301 longer offers data symbols as possible completions when you're
2302 setting a breakpoint.
2304 ** GDB now TAB-completes label symbol names.
2306 ** The "complete" command now mimics TAB completion accurately.
2308 * New command line options (gcore)
2311 Dump all memory mappings.
2313 * Breakpoints on C++ functions are now set on all scopes by default
2315 By default, breakpoints on functions/methods are now interpreted as
2316 specifying all functions with the given name ignoring missing
2317 leading scopes (namespaces and classes).
2319 For example, assuming a C++ program with symbols named:
2324 both commands "break func()" and "break B::func()" set a breakpoint
2327 You can use the new flag "-qualified" to override this. This makes
2328 GDB interpret the specified function name as a complete
2329 fully-qualified name instead. For example, using the same C++
2330 program, the "break -q B::func" command sets a breakpoint on
2331 "B::func", only. A parameter has been added to the Python
2332 gdb.Breakpoint constructor to achieve the same result when creating
2333 a breakpoint from Python.
2335 * Breakpoints on functions marked with C++ ABI tags
2337 GDB can now set breakpoints on functions marked with C++ ABI tags
2338 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2339 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2341 Functions with a C++11 abi tag are demangled/displayed like this:
2343 function[abi:cxx11](int)
2346 You can now set a breakpoint on such functions simply as if they had
2349 (gdb) b function(int)
2351 Or if you need to disambiguate between tags, like:
2353 (gdb) b function[abi:other_tag](int)
2355 Tab completion was adjusted accordingly as well.
2359 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2360 gdb.new_thread are emitted. See the manual for further
2361 description of these.
2363 ** A new function, "gdb.rbreak" has been added to the Python API.
2364 This function allows the setting of a large number of breakpoints
2365 via a regex pattern in Python. See the manual for further details.
2367 ** Python breakpoints can now accept explicit locations. See the
2368 manual for a further description of this feature.
2371 * New features in the GDB remote stub, GDBserver
2373 ** GDBserver is now able to start inferior processes with a
2374 specified initial working directory.
2376 The user can set the desired working directory to be used from
2377 GDB using the new "set cwd" command.
2379 ** New "--selftest" command line option runs some GDBserver self
2380 tests. These self tests are disabled in releases.
2382 ** On Unix systems, GDBserver now does globbing expansion and variable
2383 substitution in inferior command line arguments.
2385 This is done by starting inferiors using a shell, like GDB does.
2386 See "set startup-with-shell" in the user manual for how to disable
2387 this from GDB when using "target extended-remote". When using
2388 "target remote", you can disable the startup with shell by using the
2389 new "--no-startup-with-shell" GDBserver command line option.
2391 ** On Unix systems, GDBserver now supports receiving environment
2392 variables that are to be set or unset from GDB. These variables
2393 will affect the environment to be passed to the inferior.
2395 * When catching an Ada exception raised with a message, GDB now prints
2396 the message in the catchpoint hit notification. In GDB/MI mode, that
2397 information is provided as an extra field named "exception-message"
2398 in the *stopped notification.
2400 * Trait objects can now be inspected When debugging Rust code. This
2401 requires compiler support which will appear in Rust 1.24.
2403 * New remote packets
2405 QEnvironmentHexEncoded
2406 Inform GDBserver of an environment variable that is to be passed to
2407 the inferior when starting it.
2410 Inform GDBserver of an environment variable that is to be unset
2411 before starting the remote inferior.
2414 Inform GDBserver that the environment should be reset (i.e.,
2415 user-set environment variables should be unset).
2418 Indicates whether the inferior must be started with a shell or not.
2421 Tell GDBserver that the inferior to be started should use a specific
2424 * The "maintenance print c-tdesc" command now takes an optional
2425 argument which is the file name of XML target description.
2427 * The "maintenance selftest" command now takes an optional argument to
2428 filter the tests to be run.
2430 * The "enable", and "disable" commands now accept a range of
2431 breakpoint locations, e.g. "enable 1.3-5".
2436 Set and show the current working directory for the inferior.
2438 set|show compile-gcc
2439 Set and show compilation command used for compiling and injecting code
2440 with the 'compile' commands.
2442 set debug separate-debug-file
2443 show debug separate-debug-file
2444 Control the display of debug output about separate debug file search.
2446 set dump-excluded-mappings
2447 show dump-excluded-mappings
2448 Control whether mappings marked with the VM_DONTDUMP flag should be
2449 dumped when generating a core file.
2451 maint info selftests
2452 List the registered selftests.
2455 Start the debugged program stopping at the first instruction.
2458 Control display of debugging messages related to OpenRISC targets.
2460 set|show print type nested-type-limit
2461 Set and show the limit of nesting level for nested types that the
2462 type printer will show.
2464 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2467 * Safer/improved support for debugging with no debug info
2469 GDB no longer assumes functions with no debug information return
2472 This means that GDB now refuses to call such functions unless you
2473 tell it the function's type, by either casting the call to the
2474 declared return type, or by casting the function to a function
2475 pointer of the right type, and calling that:
2477 (gdb) p getenv ("PATH")
2478 'getenv' has unknown return type; cast the call to its declared return type
2479 (gdb) p (char *) getenv ("PATH")
2480 $1 = 0x7fffffffe "/usr/local/bin:/"...
2481 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2482 $2 = 0x7fffffffe "/usr/local/bin:/"...
2484 Similarly, GDB no longer assumes that global variables with no debug
2485 info have type 'int', and refuses to print the variable's value
2486 unless you tell it the variable's type:
2489 'var' has unknown type; cast it to its declared type
2493 * New native configurations
2495 FreeBSD/aarch64 aarch64*-*-freebsd*
2496 FreeBSD/arm arm*-*-freebsd*
2500 FreeBSD/aarch64 aarch64*-*-freebsd*
2501 FreeBSD/arm arm*-*-freebsd*
2502 OpenRISC ELF or1k*-*-elf
2504 * Removed targets and native configurations
2506 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2508 *** Changes in GDB 8.0
2510 * GDB now supports access to the PKU register on GNU/Linux. The register is
2511 added by the Memory Protection Keys for Userspace feature which will be
2512 available in future Intel CPUs.
2514 * GDB now supports C++11 rvalue references.
2518 ** New functions to start, stop and access a running btrace recording.
2519 ** Rvalue references are now supported in gdb.Type.
2521 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2524 * Building GDB and GDBserver now requires a C++11 compiler.
2526 For example, GCC 4.8 or later.
2528 It is no longer possible to build GDB or GDBserver with a C
2529 compiler. The --disable-build-with-cxx configure option has been
2532 * Building GDB and GDBserver now requires GNU make >= 3.81.
2534 It is no longer supported to build GDB or GDBserver with another
2535 implementation of the make program or an earlier version of GNU make.
2537 * Native debugging on MS-Windows supports command-line redirection
2539 Command-line arguments used for starting programs on MS-Windows can
2540 now include redirection symbols supported by native Windows shells,
2541 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2542 as "run", "start", and "set args", as well as the corresponding MI
2545 * Support for thread names on MS-Windows.
2547 GDB now catches and handles the special exception that programs
2548 running on MS-Windows use to assign names to threads in the
2551 * Support for Java programs compiled with gcj has been removed.
2553 * User commands now accept an unlimited number of arguments.
2554 Previously, only up to 10 was accepted.
2556 * The "eval" command now expands user-defined command arguments.
2558 This makes it easier to process a variable number of arguments:
2563 eval "print $arg%d", $i
2568 * Target descriptions can now describe registers for sparc32 and sparc64.
2570 * GDB now supports DWARF version 5 (debug information format).
2571 Its .debug_names index is not yet supported.
2573 * New native configurations
2575 FreeBSD/mips mips*-*-freebsd
2579 Synopsys ARC arc*-*-elf32
2580 FreeBSD/mips mips*-*-freebsd
2582 * Removed targets and native configurations
2584 Alpha running FreeBSD alpha*-*-freebsd*
2585 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2590 Erases all the flash memory regions reported by the target.
2592 maint print arc arc-instruction address
2593 Print internal disassembler information about instruction at a given address.
2597 set disassembler-options
2598 show disassembler-options
2599 Controls the passing of target specific information to the disassembler.
2600 If it is necessary to specify more than one disassembler option then
2601 multiple options can be placed together into a comma separated list.
2602 The default value is the empty string. Currently, the only supported
2603 targets are ARM, PowerPC and S/390.
2608 Erases all the flash memory regions reported by the target. This is
2609 equivalent to the CLI command flash-erase.
2611 -file-list-shared-libraries
2612 List the shared libraries in the program. This is
2613 equivalent to the CLI command "info shared".
2616 Catchpoints stopping the program when Ada exceptions are
2617 handled. This is equivalent to the CLI command "catch handlers".
2619 *** Changes in GDB 7.12
2621 * GDB and GDBserver now build with a C++ compiler by default.
2623 The --enable-build-with-cxx configure option is now enabled by
2624 default. One must now explicitly configure with
2625 --disable-build-with-cxx in order to build with a C compiler. This
2626 option will be removed in a future release.
2628 * GDBserver now supports recording btrace without maintaining an active
2631 * GDB now supports a negative repeat count in the 'x' command to examine
2632 memory backward from the given address. For example:
2635 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2636 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2637 (gdb) x/-5i 0x0000000000400580
2638 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2639 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2640 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2641 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2642 0x40057b <main(int, char**)+25>:
2643 callq 0x400536 <Func1(int, char const*)>
2645 * Fortran: Support structures with fields of dynamic types and
2646 arrays of dynamic types.
2648 * The symbol dumping maintenance commands have new syntax.
2649 maint print symbols [-pc address] [--] [filename]
2650 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2651 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2652 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2653 maint print msymbols [-objfile objfile] [--] [filename]
2655 * GDB now supports multibit bitfields and enums in target register
2658 * New Python-based convenience function $_as_string(val), which returns
2659 the textual representation of a value. This function is especially
2660 useful to obtain the text label of an enum value.
2662 * Intel MPX bound violation handling.
2664 Segmentation faults caused by a Intel MPX boundary violation
2665 now display the kind of violation (upper or lower), the memory
2666 address accessed and the memory bounds, along with the usual
2667 signal received and code location.
2671 Program received signal SIGSEGV, Segmentation fault
2672 Upper bound violation while accessing address 0x7fffffffc3b3
2673 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2674 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2676 * Rust language support.
2677 GDB now supports debugging programs written in the Rust programming
2678 language. See https://www.rust-lang.org/ for more information about
2681 * Support for running interpreters on specified input/output devices
2683 GDB now supports a new mechanism that allows frontends to provide
2684 fully featured GDB console views, as a better alternative to
2685 building such views on top of the "-interpreter-exec console"
2686 command. See the new "new-ui" command below. With that command,
2687 frontends can now start GDB in the traditional command-line mode
2688 running in an embedded terminal emulator widget, and create a
2689 separate MI interpreter running on a specified i/o device. In this
2690 way, GDB handles line editing, history, tab completion, etc. in the
2691 console all by itself, and the GUI uses the separate MI interpreter
2692 for its own control and synchronization, invisible to the command
2695 * The "catch syscall" command catches groups of related syscalls.
2697 The "catch syscall" command now supports catching a group of related
2698 syscalls using the 'group:' or 'g:' prefix.
2703 skip -gfile file-glob-pattern
2704 skip -function function
2705 skip -rfunction regular-expression
2706 A generalized form of the skip command, with new support for
2707 glob-style file names and regular expressions for function names.
2708 Additionally, a file spec and a function spec may now be combined.
2710 maint info line-table REGEXP
2711 Display the contents of GDB's internal line table data structure.
2714 Run any GDB unit tests that were compiled in.
2717 Start a new user interface instance running INTERP as interpreter,
2718 using the TTY file for input/output.
2722 ** gdb.Breakpoint objects have a new attribute "pending", which
2723 indicates whether the breakpoint is pending.
2724 ** Three new breakpoint-related events have been added:
2725 gdb.breakpoint_created, gdb.breakpoint_modified, and
2726 gdb.breakpoint_deleted.
2728 signal-event EVENTID
2729 Signal ("set") the given MS-Windows event object. This is used in
2730 conjunction with the Windows JIT debugging (AeDebug) support, where
2731 the OS suspends a crashing process until a debugger can attach to
2732 it. Resuming the crashing process, in order to debug it, is done by
2733 signalling an event.
2735 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2736 was added in GDBserver, including JIT compiling fast tracepoint's
2737 conditional expression bytecode into native code.
2739 * Support for various remote target protocols and ROM monitors has
2742 target m32rsdi Remote M32R debugging over SDI
2743 target mips MIPS remote debugging protocol
2744 target pmon PMON ROM monitor
2745 target ddb NEC's DDB variant of PMON for Vr4300
2746 target rockhopper NEC RockHopper variant of PMON
2747 target lsi LSI variant of PMO
2749 * Support for tracepoints and fast tracepoints on powerpc-linux,
2750 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2751 including JIT compiling fast tracepoint's conditional expression
2752 bytecode into native code.
2754 * MI async record =record-started now includes the method and format used for
2755 recording. For example:
2757 =record-started,thread-group="i1",method="btrace",format="bts"
2759 * MI async record =thread-selected now includes the frame field. For example:
2761 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2765 Andes NDS32 nds32*-*-elf
2767 *** Changes in GDB 7.11
2769 * GDB now supports debugging kernel-based threads on FreeBSD.
2771 * Per-inferior thread numbers
2773 Thread numbers are now per inferior instead of global. If you're
2774 debugging multiple inferiors, GDB displays thread IDs using a
2775 qualified INF_NUM.THR_NUM form. For example:
2779 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2780 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2781 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2782 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2784 As consequence, thread numbers as visible in the $_thread
2785 convenience variable and in Python's InferiorThread.num attribute
2786 are no longer unique between inferiors.
2788 GDB now maintains a second thread ID per thread, referred to as the
2789 global thread ID, which is the new equivalent of thread numbers in
2790 previous releases. See also $_gthread below.
2792 For backwards compatibility, MI's thread IDs always refer to global
2795 * Commands that accept thread IDs now accept the qualified
2796 INF_NUM.THR_NUM form as well. For example:
2799 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2802 * In commands that accept a list of thread IDs, you can now refer to
2803 all threads of an inferior using a star wildcard. GDB accepts
2804 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2805 refer to all threads of the current inferior. For example, "info
2808 * You can use "info threads -gid" to display the global thread ID of
2811 * The new convenience variable $_gthread holds the global number of
2814 * The new convenience variable $_inferior holds the number of the
2817 * GDB now displays the ID and name of the thread that hit a breakpoint
2818 or received a signal, if your program is multi-threaded. For
2821 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2822 Thread 1 "main" received signal SIGINT, Interrupt.
2824 * Record btrace now supports non-stop mode.
2826 * Support for tracepoints on aarch64-linux was added in GDBserver.
2828 * The 'record instruction-history' command now indicates speculative execution
2829 when using the Intel Processor Trace recording format.
2831 * GDB now allows users to specify explicit locations, bypassing
2832 the linespec parser. This feature is also available to GDB/MI
2835 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2836 GDB now is able to debug both AArch64 applications and ARM applications
2839 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2840 including JIT compiling fast tracepoint's conditional expression bytecode
2843 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2845 * "info threads", "info inferiors", "info display", "info checkpoints"
2846 and "maint info program-spaces" now list the corresponding items in
2847 ascending ID order, for consistency with all other "info" commands.
2849 * In Ada, the overloads selection menu has been enhanced to display the
2850 parameter types and the return types for the matching overloaded subprograms.
2854 maint set target-non-stop (on|off|auto)
2855 maint show target-non-stop
2856 Control whether GDB targets always operate in non-stop mode even if
2857 "set non-stop" is "off". The default is "auto", meaning non-stop
2858 mode is enabled if supported by the target.
2860 maint set bfd-sharing
2861 maint show bfd-sharing
2862 Control the reuse of bfd objects.
2865 show debug bfd-cache
2866 Control display of debugging info regarding bfd caching.
2870 Control display of debugging info regarding FreeBSD threads.
2872 set remote multiprocess-extensions-packet
2873 show remote multiprocess-extensions-packet
2874 Set/show the use of the remote protocol multiprocess extensions.
2876 set remote thread-events
2877 show remote thread-events
2878 Set/show the use of thread create/exit events.
2880 set ada print-signatures on|off
2881 show ada print-signatures"
2882 Control whether parameter types and return types are displayed in overloads
2883 selection menus. It is activated (@code{on}) by default.
2887 Controls the maximum size of memory, in bytes, that GDB will
2888 allocate for value contents. Prevents incorrect programs from
2889 causing GDB to allocate overly large buffers. Default is 64k.
2891 * The "disassemble" command accepts a new modifier: /s.
2892 It prints mixed source+disassembly like /m with two differences:
2893 - disassembled instructions are now printed in program order, and
2894 - and source for all relevant files is now printed.
2895 The "/m" option is now considered deprecated: its "source-centric"
2896 output hasn't proved useful in practice.
2898 * The "record instruction-history" command accepts a new modifier: /s.
2899 It behaves exactly like /m and prints mixed source+disassembly.
2901 * The "set scheduler-locking" command supports a new mode "replay".
2902 It behaves like "off" in record mode and like "on" in replay mode.
2904 * Support for various ROM monitors has been removed:
2906 target dbug dBUG ROM monitor for Motorola ColdFire
2907 target picobug Motorola picobug monitor
2908 target dink32 DINK32 ROM monitor for PowerPC
2909 target m32r Renesas M32R/D ROM monitor
2910 target mon2000 mon2000 ROM monitor
2911 target ppcbug PPCBUG ROM monitor for PowerPC
2913 * Support for reading/writing memory and extracting values on architectures
2914 whose memory is addressable in units of any integral multiple of 8 bits.
2917 Allows to break when an Ada exception is handled.
2919 * New remote packets
2922 Indicates that an exec system call was executed.
2924 exec-events feature in qSupported
2925 The qSupported packet allows GDB to request support for exec
2926 events using the new 'gdbfeature' exec-event, and the qSupported
2927 response can contain the corresponding 'stubfeature'. Set and
2928 show commands can be used to display whether these features are enabled.
2931 Equivalent to interrupting with the ^C character, but works in
2934 thread created stop reason (T05 create:...)
2935 Indicates that the thread was just created and is stopped at entry.
2937 thread exit stop reply (w exitcode;tid)
2938 Indicates that the thread has terminated.
2941 Enables/disables thread create and exit event reporting. For
2942 example, this is used in non-stop mode when GDB stops a set of
2943 threads and synchronously waits for the their corresponding stop
2944 replies. Without exit events, if one of the threads exits, GDB
2945 would hang forever not knowing that it should no longer expect a
2946 stop for that same thread.
2949 Indicates that there are no resumed threads left in the target (all
2950 threads are stopped). The remote stub reports support for this stop
2951 reply to GDB's qSupported query.
2954 Enables/disables catching syscalls from the inferior process.
2955 The remote stub reports support for this packet to GDB's qSupported query.
2957 syscall_entry stop reason
2958 Indicates that a syscall was just called.
2960 syscall_return stop reason
2961 Indicates that a syscall just returned.
2963 * Extended-remote exec events
2965 ** GDB now has support for exec events on extended-remote Linux targets.
2966 For such targets with Linux kernels 2.5.46 and later, this enables
2967 follow-exec-mode and exec catchpoints.
2969 set remote exec-event-feature-packet
2970 show remote exec-event-feature-packet
2971 Set/show the use of the remote exec event feature.
2973 * Thread names in remote protocol
2975 The reply to qXfer:threads:read may now include a name attribute for each
2978 * Target remote mode fork and exec events
2980 ** GDB now has support for fork and exec events on target remote mode
2981 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2982 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2983 fork and exec catchpoints.
2985 * Remote syscall events
2987 ** GDB now has support for catch syscall on remote Linux targets,
2988 currently enabled on x86/x86_64 architectures.
2990 set remote catch-syscall-packet
2991 show remote catch-syscall-packet
2992 Set/show the use of the remote catch syscall feature.
2996 ** The -var-set-format command now accepts the zero-hexadecimal
2997 format. It outputs data in hexadecimal format with zero-padding on the
3002 ** gdb.InferiorThread objects have a new attribute "global_num",
3003 which refers to the thread's global thread ID. The existing
3004 "num" attribute now refers to the thread's per-inferior number.
3005 See "Per-inferior thread numbers" above.
3006 ** gdb.InferiorThread objects have a new attribute "inferior", which
3007 is the Inferior object the thread belongs to.
3009 *** Changes in GDB 7.10
3011 * Support for process record-replay and reverse debugging on aarch64*-linux*
3012 targets has been added. GDB now supports recording of A64 instruction set
3013 including advance SIMD instructions.
3015 * Support for Sun's version of the "stabs" debug file format has been removed.
3017 * GDB now honors the content of the file /proc/PID/coredump_filter
3018 (PID is the process ID) on GNU/Linux systems. This file can be used
3019 to specify the types of memory mappings that will be included in a
3020 corefile. For more information, please refer to the manual page of
3021 "core(5)". GDB also has a new command: "set use-coredump-filter
3022 on|off". It allows to set whether GDB will read the content of the
3023 /proc/PID/coredump_filter file when generating a corefile.
3025 * The "info os" command on GNU/Linux can now display information on
3027 "info os cpus" Listing of all cpus/cores on the system
3029 * GDB has two new commands: "set serial parity odd|even|none" and
3030 "show serial parity". These allows to set or show parity for the
3033 * The "info source" command now displays the producer string if it was
3034 present in the debug info. This typically includes the compiler version
3035 and may include things like its command line arguments.
3037 * The "info dll", an alias of the "info sharedlibrary" command,
3038 is now available on all platforms.
3040 * Directory names supplied to the "set sysroot" commands may be
3041 prefixed with "target:" to tell GDB to access shared libraries from
3042 the target system, be it local or remote. This replaces the prefix
3043 "remote:". The default sysroot has been changed from "" to
3044 "target:". "remote:" is automatically converted to "target:" for
3045 backward compatibility.
3047 * The system root specified by "set sysroot" will be prepended to the
3048 filename of the main executable (if reported to GDB as absolute by
3049 the operating system) when starting processes remotely, and when
3050 attaching to already-running local or remote processes.
3052 * GDB now supports automatic location and retrieval of executable
3053 files from remote targets. Remote debugging can now be initiated
3054 using only a "target remote" or "target extended-remote" command
3055 (no "set sysroot" or "file" commands are required). See "New remote
3058 * The "dump" command now supports verilog hex format.
3060 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3062 * On GNU/Linux, GDB and gdbserver are now able to access executable
3063 and shared library files without a "set sysroot" command when
3064 attaching to processes running in different mount namespaces from
3065 the debugger. This makes it possible to attach to processes in
3066 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3067 See "New remote packets" below.
3069 * The "tui reg" command now provides completion for all of the
3070 available register groups, including target specific groups.
3072 * The HISTSIZE environment variable is no longer read when determining
3073 the size of GDB's command history. GDB now instead reads the dedicated
3074 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3075 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3080 ** Memory ports can now be unbuffered.
3084 ** gdb.Objfile objects have a new attribute "username",
3085 which is the name of the objfile as specified by the user,
3086 without, for example, resolving symlinks.
3087 ** You can now write frame unwinders in Python.
3088 ** gdb.Type objects have a new method "optimized_out",
3089 returning optimized out gdb.Value instance of this type.
3090 ** gdb.Value objects have new methods "reference_value" and
3091 "const_value" which return a reference to the value and a
3092 "const" version of the value respectively.
3096 maint print symbol-cache
3097 Print the contents of the symbol cache.
3099 maint print symbol-cache-statistics
3100 Print statistics of symbol cache usage.
3102 maint flush-symbol-cache
3103 Flush the contents of the symbol cache.
3107 Start branch trace recording using Branch Trace Store (BTS) format.
3110 Evaluate expression by using the compiler and print result.
3114 Explicit commands for enabling and disabling tui mode.
3117 set mpx bound on i386 and amd64
3118 Support for bound table investigation on Intel MPX enabled applications.
3122 Start branch trace recording using Intel Processor Trace format.
3125 Print information about branch tracing internals.
3127 maint btrace packet-history
3128 Print the raw branch tracing data.
3130 maint btrace clear-packet-history
3131 Discard the stored raw branch tracing data.
3134 Discard all branch tracing data. It will be fetched and processed
3135 anew by the next "record" command.
3140 Renamed from "set debug dwarf2-die".
3141 show debug dwarf-die
3142 Renamed from "show debug dwarf2-die".
3144 set debug dwarf-read
3145 Renamed from "set debug dwarf2-read".
3146 show debug dwarf-read
3147 Renamed from "show debug dwarf2-read".
3149 maint set dwarf always-disassemble
3150 Renamed from "maint set dwarf2 always-disassemble".
3151 maint show dwarf always-disassemble
3152 Renamed from "maint show dwarf2 always-disassemble".
3154 maint set dwarf max-cache-age
3155 Renamed from "maint set dwarf2 max-cache-age".
3156 maint show dwarf max-cache-age
3157 Renamed from "maint show dwarf2 max-cache-age".
3159 set debug dwarf-line
3160 show debug dwarf-line
3161 Control display of debugging info regarding DWARF line processing.
3164 show max-completions
3165 Set the maximum number of candidates to be considered during
3166 completion. The default value is 200. This limit allows GDB
3167 to avoid generating large completion lists, the computation of
3168 which can cause the debugger to become temporarily unresponsive.
3170 set history remove-duplicates
3171 show history remove-duplicates
3172 Control the removal of duplicate history entries.
3174 maint set symbol-cache-size
3175 maint show symbol-cache-size
3176 Control the size of the symbol cache.
3178 set|show record btrace bts buffer-size
3179 Set and show the size of the ring buffer used for branch tracing in
3181 The obtained size may differ from the requested size. Use "info
3182 record" to see the obtained buffer size.
3184 set debug linux-namespaces
3185 show debug linux-namespaces
3186 Control display of debugging info regarding Linux namespaces.
3188 set|show record btrace pt buffer-size
3189 Set and show the size of the ring buffer used for branch tracing in
3190 Intel Processor Trace format.
3191 The obtained size may differ from the requested size. Use "info
3192 record" to see the obtained buffer size.
3194 maint set|show btrace pt skip-pad
3195 Set and show whether PAD packets are skipped when computing the
3198 * The command 'thread apply all' can now support new option '-ascending'
3199 to call its specified command for all threads in ascending order.
3201 * Python/Guile scripting
3203 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3204 special section named `.debug_gdb_scripts'.
3206 * New remote packets
3208 qXfer:btrace-conf:read
3209 Return the branch trace configuration for the current thread.
3211 Qbtrace-conf:bts:size
3212 Set the requested ring buffer size for branch tracing in BTS format.
3215 Enable Intel Processor Trace-based branch tracing for the current
3216 process. The remote stub reports support for this packet to GDB's
3219 Qbtrace-conf:pt:size
3220 Set the requested ring buffer size for branch tracing in Intel Processor
3224 Indicates a memory breakpoint instruction was executed, irrespective
3225 of whether it was GDB that planted the breakpoint or the breakpoint
3226 is hardcoded in the program. This is required for correct non-stop
3230 Indicates the target stopped for a hardware breakpoint. This is
3231 required for correct non-stop mode operation.
3234 Return information about files on the remote system.
3236 qXfer:exec-file:read
3237 Return the full absolute name of the file that was executed to
3238 create a process running on the remote system.
3241 Select the filesystem on which vFile: operations with filename
3242 arguments will operate. This is required for GDB to be able to
3243 access files on remote targets where the remote stub does not
3244 share a common filesystem with the inferior(s).
3247 Indicates that a fork system call was executed.
3250 Indicates that a vfork system call was executed.
3252 vforkdone stop reason
3253 Indicates that a vfork child of the specified process has executed
3254 an exec or exit, allowing the vfork parent to resume execution.
3256 fork-events and vfork-events features in qSupported
3257 The qSupported packet allows GDB to request support for fork and
3258 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3259 and the qSupported response can contain the corresponding
3260 'stubfeatures'. Set and show commands can be used to display
3261 whether these features are enabled.
3263 * Extended-remote fork events
3265 ** GDB now has support for fork events on extended-remote Linux
3266 targets. For targets with Linux kernels 2.5.60 and later, this
3267 enables follow-fork-mode and detach-on-fork for both fork and
3268 vfork, as well as fork and vfork catchpoints.
3270 * The info record command now shows the recording format and the
3271 branch tracing configuration for the current thread when using
3272 the btrace record target.
3273 For the BTS format, it shows the ring buffer size.
3275 * GDB now has support for DTrace USDT (Userland Static Defined
3276 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3278 * GDB now supports access to vector registers on S/390 GNU/Linux
3281 * Removed command line options
3283 -xdb HP-UX XDB compatibility mode.
3285 * Removed targets and native configurations
3287 HP/PA running HP-UX hppa*-*-hpux*
3288 Itanium running HP-UX ia64-*-hpux*
3290 * New configure options
3293 This configure option allows the user to build GDB with support for
3294 Intel Processor Trace (default: auto). This requires libipt.
3296 --with-libipt-prefix=PATH
3297 Specify the path to the version of libipt that GDB should use.
3298 $PATH/include should contain the intel-pt.h header and
3299 $PATH/lib should contain the libipt.so library.
3301 *** Changes in GDB 7.9.1
3305 ** Xmethods can now specify a result type.
3307 *** Changes in GDB 7.9
3309 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3313 ** You can now access frame registers from Python scripts.
3314 ** New attribute 'producer' for gdb.Symtab objects.
3315 ** gdb.Objfile objects have a new attribute "progspace",
3316 which is the gdb.Progspace object of the containing program space.
3317 ** gdb.Objfile objects have a new attribute "owner".
3318 ** gdb.Objfile objects have a new attribute "build_id",
3319 which is the build ID generated when the file was built.
3320 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3321 ** A new event "gdb.clear_objfiles" has been added, triggered when
3322 selecting a new file to debug.
3323 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3324 ** New function gdb.lookup_objfile.
3326 New events which are triggered when GDB modifies the state of the
3329 ** gdb.events.inferior_call_pre: Function call is about to be made.
3330 ** gdb.events.inferior_call_post: Function call has just been made.
3331 ** gdb.events.memory_changed: A memory location has been altered.
3332 ** gdb.events.register_changed: A register has been altered.
3334 * New Python-based convenience functions:
3336 ** $_caller_is(name [, number_of_frames])
3337 ** $_caller_matches(regexp [, number_of_frames])
3338 ** $_any_caller_is(name [, number_of_frames])
3339 ** $_any_caller_matches(regexp [, number_of_frames])
3341 * GDB now supports the compilation and injection of source code into
3342 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3343 to compile the source code to object code, and if successful, inject
3344 and execute that code within the current context of the inferior.
3345 Currently the C language is supported. The commands used to
3346 interface with this new feature are:
3348 compile code [-raw|-r] [--] [source code]
3349 compile file [-raw|-r] filename
3353 demangle [-l language] [--] name
3354 Demangle "name" in the specified language, or the current language
3355 if elided. This command is renamed from the "maint demangle" command.
3356 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3357 as "maint demangler-warning".
3359 queue-signal signal-name-or-number
3360 Queue a signal to be delivered to the thread when it is resumed.
3362 add-auto-load-scripts-directory directory
3363 Add entries to the list of directories from which to load auto-loaded
3366 maint print user-registers
3367 List all currently available "user" registers.
3369 compile code [-r|-raw] [--] [source code]
3370 Compile, inject, and execute in the inferior the executable object
3371 code produced by compiling the provided source code.
3373 compile file [-r|-raw] filename
3374 Compile and inject into the inferior the executable object code
3375 produced by compiling the source code stored in the filename
3378 * On resume, GDB now always passes the signal the program had stopped
3379 for to the thread the signal was sent to, even if the user changed
3380 threads before resuming. Previously GDB would often (but not
3381 always) deliver the signal to the thread that happens to be current
3384 * Conversely, the "signal" command now consistently delivers the
3385 requested signal to the current thread. GDB now asks for
3386 confirmation if the program had stopped for a signal and the user
3387 switched threads meanwhile.
3389 * "breakpoint always-inserted" modes "off" and "auto" merged.
3391 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3392 won't remove breakpoints from the target until all threads stop,
3393 even in non-stop mode. The "auto" mode has been removed, and "off"
3394 is now the default mode.
3398 set debug symbol-lookup
3399 show debug symbol-lookup
3400 Control display of debugging info regarding symbol lookup.
3404 ** The -list-thread-groups command outputs an exit-code field for
3405 inferiors that have exited.
3409 MIPS SDE mips*-sde*-elf*
3413 Support for these obsolete configurations has been removed.
3415 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3416 SGI Irix-5.x mips-*-irix5*
3417 SGI Irix-6.x mips-*-irix6*
3418 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3419 VAX running Ultrix vax-*-ultrix*
3421 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3422 and "assf"), have been removed. Use the "sharedlibrary" command, or
3423 its alias "share", instead.
3425 *** Changes in GDB 7.8
3427 * New command line options
3430 This is an alias for the --data-directory option.
3432 * GDB supports printing and modifying of variable length automatic arrays
3433 as specified in ISO C99.
3435 * The ARM simulator now supports instruction level tracing
3436 with or without disassembly.
3440 GDB now has support for scripting using Guile. Whether this is
3441 available is determined at configure time.
3442 Guile version 2.0 or greater is required.
3443 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3445 * New commands (for set/show, see "New options" below)
3449 Invoke CODE by passing it to the Guile interpreter.
3453 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3455 info auto-load guile-scripts [regexp]
3456 Print the list of automatically loaded Guile scripts.
3458 * The source command is now capable of sourcing Guile scripts.
3459 This feature is dependent on the debugger being built with Guile support.
3463 set print symbol-loading (off|brief|full)
3464 show print symbol-loading
3465 Control whether to print informational messages when loading symbol
3466 information for a file. The default is "full", but when debugging
3467 programs with large numbers of shared libraries the amount of output
3468 becomes less useful.
3470 set guile print-stack (none|message|full)
3471 show guile print-stack
3472 Show a stack trace when an error is encountered in a Guile script.
3474 set auto-load guile-scripts (on|off)
3475 show auto-load guile-scripts
3476 Control auto-loading of Guile script files.
3478 maint ada set ignore-descriptive-types (on|off)
3479 maint ada show ignore-descriptive-types
3480 Control whether the debugger should ignore descriptive types in Ada
3481 programs. The default is not to ignore the descriptive types. See
3482 the user manual for more details on descriptive types and the intended
3483 usage of this option.
3485 set auto-connect-native-target
3487 Control whether GDB is allowed to automatically connect to the
3488 native target for the run, attach, etc. commands when not connected
3489 to any target yet. See also "target native" below.
3491 set record btrace replay-memory-access (read-only|read-write)
3492 show record btrace replay-memory-access
3493 Control what memory accesses are allowed during replay.
3495 maint set target-async (on|off)
3496 maint show target-async
3497 This controls whether GDB targets operate in synchronous or
3498 asynchronous mode. Normally the default is asynchronous, if it is
3499 available; but this can be changed to more easily debug problems
3500 occurring only in synchronous mode.
3502 set mi-async (on|off)
3504 Control whether MI asynchronous mode is preferred. This supersedes
3505 "set target-async" of previous GDB versions.
3507 * "set target-async" is deprecated as a CLI option and is now an alias
3508 for "set mi-async" (only puts MI into async mode).
3510 * Background execution commands (e.g., "c&", "s&", etc.) are now
3511 possible ``out of the box'' if the target supports them. Previously
3512 the user would need to explicitly enable the possibility with the
3513 "set target-async on" command.
3515 * New features in the GDB remote stub, GDBserver
3517 ** New option --debug-format=option1[,option2,...] allows one to add
3518 additional text to each output. At present only timestamps
3519 are supported: --debug-format=timestamps.
3520 Timestamps can also be turned on with the
3521 "monitor set debug-format timestamps" command from GDB.
3523 * The 'record instruction-history' command now starts counting instructions
3524 at one. This also affects the instruction ranges reported by the
3525 'record function-call-history' command when given the /i modifier.
3527 * The command 'record function-call-history' supports a new modifier '/c' to
3528 indent the function names based on their call stack depth.
3529 The fields for the '/i' and '/l' modifier have been reordered.
3530 The source line range is now prefixed with 'at'.
3531 The instruction range is now prefixed with 'inst'.
3532 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3533 "record instruction-history" and "list" commands.
3535 * The ranges given as arguments to the 'record function-call-history' and
3536 'record instruction-history' commands are now inclusive.
3538 * The btrace record target now supports the 'record goto' command.
3539 For locations inside the execution trace, the back trace is computed
3540 based on the information stored in the execution trace.
3542 * The btrace record target supports limited reverse execution and replay.
3543 The target does not record data and therefore does not allow reading
3544 memory or registers.
3546 * The "catch syscall" command now works on s390*-linux* targets.
3548 * The "compare-sections" command is no longer specific to target
3549 remote. It now works with all targets.
3551 * All native targets are now consistently called "native".
3552 Consequently, the "target child", "target GNU", "target djgpp",
3553 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3554 commands have been replaced with "target native". The QNX/NTO port
3555 leaves the "procfs" target in place and adds a "native" target for
3556 consistency with other ports. The impact on users should be minimal
3557 as these commands previously either throwed an error, or were
3558 no-ops. The target's name is visible in the output of the following
3559 commands: "help target", "info target", "info files", "maint print
3562 * The "target native" command now connects to the native target. This
3563 can be used to launch native programs even when "set
3564 auto-connect-native-target" is set to off.
3566 * GDB now supports access to Intel MPX registers on GNU/Linux.
3568 * Support for Intel AVX-512 registers on GNU/Linux.
3569 Support displaying and modifying Intel AVX-512 registers
3570 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3572 * New remote packets
3574 qXfer:btrace:read's annex
3575 The qXfer:btrace:read packet supports a new annex 'delta' to read
3576 branch trace incrementally.
3580 ** Valid Python operations on gdb.Value objects representing
3581 structs/classes invoke the corresponding overloaded operators if
3583 ** New `Xmethods' feature in the Python API. Xmethods are
3584 additional methods or replacements for existing methods of a C++
3585 class. This feature is useful for those cases where a method
3586 defined in C++ source code could be inlined or optimized out by
3587 the compiler, making it unavailable to GDB.
3590 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3592 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3593 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3594 its alias "share", instead.
3596 * The commands "set remotebaud" and "show remotebaud" are no longer
3597 supported. Use "set serial baud" and "show serial baud" (respectively)
3602 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3603 target-async". The latter is left as a deprecated alias of the
3604 former for backward compatibility. If the target supports it,
3605 CLI background execution commands are now always possible by
3606 default, independently of whether the frontend stated a
3607 preference for asynchronous execution with "-gdb-set mi-async".
3608 Previously "-gdb-set target-async off" affected both MI execution
3609 commands and CLI execution commands.
3611 *** Changes in GDB 7.7
3613 * Improved support for process record-replay and reverse debugging on
3614 arm*-linux* targets. Support for thumb32 and syscall instruction
3615 recording has been added.
3617 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3619 * GDB now supports Fission DWP file format version 2.
3620 http://gcc.gnu.org/wiki/DebugFission
3622 * New convenience function "$_isvoid", to check whether an expression
3623 is void. A void expression is an expression where the type of the
3624 result is "void". For example, some convenience variables may be
3625 "void" when evaluated (e.g., "$_exitcode" before the execution of
3626 the program being debugged; or an undefined convenience variable).
3627 Another example, when calling a function whose return type is
3630 * The "maintenance print objfiles" command now takes an optional regexp.
3632 * The "catch syscall" command now works on arm*-linux* targets.
3634 * GDB now consistently shows "<not saved>" when printing values of
3635 registers the debug info indicates have not been saved in the frame
3636 and there's nowhere to retrieve them from
3637 (callee-saved/call-clobbered registers):
3642 (gdb) info registers rax
3645 Before, the former would print "<optimized out>", and the latter
3646 "*value not available*".
3648 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3653 ** Frame filters and frame decorators have been added.
3654 ** Temporary breakpoints are now supported.
3655 ** Line tables representation has been added.
3656 ** New attribute 'parent_type' for gdb.Field objects.
3657 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3658 ** New attribute 'name' for gdb.Type objects.
3662 Nios II ELF nios2*-*-elf
3663 Nios II GNU/Linux nios2*-*-linux
3664 Texas Instruments MSP430 msp430*-*-elf
3666 * Removed native configurations
3668 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3669 been removed. ELF variants of these configurations are kept supported.
3671 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3672 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3673 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3674 i[34567]86-*-openbsd3.[0-3]
3675 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3676 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3677 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3681 Like "catch throw", but catches a re-thrown exception.
3682 maint check-psymtabs
3683 Renamed from old "maint check-symtabs".
3685 Perform consistency checks on symtabs.
3686 maint expand-symtabs
3687 Expand symtabs matching an optional regexp.
3690 Display the details of GDB configure-time options.
3692 maint set|show per-command
3693 maint set|show per-command space
3694 maint set|show per-command time
3695 maint set|show per-command symtab
3696 Enable display of per-command gdb resource usage.
3698 remove-symbol-file FILENAME
3699 remove-symbol-file -a ADDRESS
3700 Remove a symbol file added via add-symbol-file. The file to remove
3701 can be identified by its filename or by an address that lies within
3702 the boundaries of this symbol file in memory.
3705 info exceptions REGEXP
3706 Display the list of Ada exceptions defined in the program being
3707 debugged. If provided, only the exceptions whose names match REGEXP
3712 set debug symfile off|on
3714 Control display of debugging info regarding reading symbol files and
3715 symbol tables within those files
3717 set print raw frame-arguments
3718 show print raw frame-arguments
3719 Set/show whether to print frame arguments in raw mode,
3720 disregarding any defined pretty-printers.
3722 set remote trace-status-packet
3723 show remote trace-status-packet
3724 Set/show the use of remote protocol qTStatus packet.
3728 Control display of debugging messages related to Nios II targets.
3732 Control whether target-assisted range stepping is enabled.
3734 set startup-with-shell
3735 show startup-with-shell
3736 Specifies whether Unix child processes are started via a shell or
3741 Use the target memory cache for accesses to the code segment. This
3742 improves performance of remote debugging (particularly disassembly).
3744 * You can now use a literal value 'unlimited' for options that
3745 interpret 0 or -1 as meaning "unlimited". E.g., "set
3746 trace-buffer-size unlimited" is now an alias for "set
3747 trace-buffer-size -1" and "set height unlimited" is now an alias for
3750 * The "set debug symtab-create" debugging option of GDB has been changed to
3751 accept a verbosity level. 0 means "off", 1 provides basic debugging
3752 output, and values of 2 or greater provides more verbose output.
3754 * New command-line options
3756 Display the details of GDB configure-time options.
3758 * The command 'tsave' can now support new option '-ctf' to save trace
3759 buffer in Common Trace Format.
3761 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3764 * GDB now implements the C++ 'typeid' operator.
3766 * The new convenience variable $_exception holds the exception being
3767 thrown or caught at an exception-related catchpoint.
3769 * The exception-related catchpoints, like "catch throw", now accept a
3770 regular expression which can be used to filter exceptions by type.
3772 * The new convenience variable $_exitsignal is automatically set to
3773 the terminating signal number when the program being debugged dies
3774 due to an uncaught signal.
3778 ** All MI commands now accept an optional "--language" option.
3779 Support for this feature can be verified by using the "-list-features"
3780 command, which should contain "language-option".
3782 ** The new command -info-gdb-mi-command allows the user to determine
3783 whether a GDB/MI command is supported or not.
3785 ** The "^error" result record returned when trying to execute an undefined
3786 GDB/MI command now provides a variable named "code" whose content is the
3787 "undefined-command" error code. Support for this feature can be verified
3788 by using the "-list-features" command, which should contain
3789 "undefined-command-error-code".
3791 ** The -trace-save MI command can optionally save trace buffer in Common
3794 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3796 ** The command -data-list-register-values now accepts an optional
3797 "--skip-unavailable" option. When used, only the available registers
3800 ** The new command -trace-frame-collected dumps collected variables,
3801 computed expressions, tvars, memory and registers in a traceframe.
3803 ** The commands -stack-list-locals, -stack-list-arguments and
3804 -stack-list-variables now accept an option "--skip-unavailable".
3805 When used, only the available locals or arguments are displayed.
3807 ** The -exec-run command now accepts an optional "--start" option.
3808 When used, the command follows the same semantics as the "start"
3809 command, stopping the program's execution at the start of its
3810 main subprogram. Support for this feature can be verified using
3811 the "-list-features" command, which should contain
3812 "exec-run-start-option".
3814 ** The new commands -catch-assert and -catch-exceptions insert
3815 catchpoints stopping the program when Ada exceptions are raised.
3817 ** The new command -info-ada-exceptions provides the equivalent of
3818 the new "info exceptions" command.
3820 * New system-wide configuration scripts
3821 A GDB installation now provides scripts suitable for use as system-wide
3822 configuration scripts for the following systems:
3826 * GDB now supports target-assigned range stepping with remote targets.
3827 This improves the performance of stepping source lines by reducing
3828 the number of control packets from/to GDB. See "New remote packets"
3831 * GDB now understands the element 'tvar' in the XML traceframe info.
3832 It has the id of the collected trace state variables.
3834 * On S/390 targets that provide the transactional-execution feature,
3835 the program interruption transaction diagnostic block (TDB) is now
3836 represented as a number of additional "registers" in GDB.
3838 * New remote packets
3842 The vCont packet supports a new 'r' action, that tells the remote
3843 stub to step through an address range itself, without GDB
3844 involvemement at each single-step.
3846 qXfer:libraries-svr4:read's annex
3847 The previously unused annex of the qXfer:libraries-svr4:read packet
3848 is now used to support passing an argument list. The remote stub
3849 reports support for this argument list to GDB's qSupported query.
3850 The defined arguments are "start" and "prev", used to reduce work
3851 necessary for library list updating, resulting in significant
3854 * New features in the GDB remote stub, GDBserver
3856 ** GDBserver now supports target-assisted range stepping. Currently
3857 enabled on x86/x86_64 GNU/Linux targets.
3859 ** GDBserver now adds element 'tvar' in the XML in the reply to
3860 'qXfer:traceframe-info:read'. It has the id of the collected
3861 trace state variables.
3863 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3866 * New 'z' formatter for printing and examining memory, this displays the
3867 value as hexadecimal zero padded on the left to the size of the type.
3869 * GDB can now use Windows x64 unwinding data.
3871 * The "set remotebaud" command has been replaced by "set serial baud".
3872 Similarly, "show remotebaud" has been replaced by "show serial baud".
3873 The "set remotebaud" and "show remotebaud" commands are still available
3874 to provide backward compatibility with older versions of GDB.
3876 *** Changes in GDB 7.6
3878 * Target record has been renamed to record-full.
3879 Record/replay is now enabled with the "record full" command.
3880 This also affects settings that are associated with full record/replay
3881 that have been moved from "set/show record" to "set/show record full":
3883 set|show record full insn-number-max
3884 set|show record full stop-at-limit
3885 set|show record full memory-query
3887 * A new record target "record-btrace" has been added. The new target
3888 uses hardware support to record the control-flow of a process. It
3889 does not support replaying the execution, but it implements the
3890 below new commands for investigating the recorded execution log.
3891 This new recording method can be enabled using:
3895 The "record-btrace" target is only available on Intel Atom processors
3896 and requires a Linux kernel 2.6.32 or later.
3898 * Two new commands have been added for record/replay to give information
3899 about the recorded execution without having to replay the execution.
3900 The commands are only supported by "record btrace".
3902 record instruction-history prints the execution history at
3903 instruction granularity
3905 record function-call-history prints the execution history at
3906 function granularity
3908 * New native configurations
3910 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3911 FreeBSD/powerpc powerpc*-*-freebsd
3912 x86_64/Cygwin x86_64-*-cygwin*
3913 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3917 ARM AArch64 aarch64*-*-elf
3918 ARM AArch64 GNU/Linux aarch64*-*-linux
3919 Lynx 178 PowerPC powerpc-*-lynx*178
3920 x86_64/Cygwin x86_64-*-cygwin*
3921 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3923 * If the configured location of system.gdbinit file (as given by the
3924 --with-system-gdbinit option at configure time) is in the
3925 data-directory (as specified by --with-gdb-datadir at configure
3926 time) or in one of its subdirectories, then GDB will look for the
3927 system-wide init file in the directory specified by the
3928 --data-directory command-line option.
3930 * New command line options:
3932 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3933 other initialization files, unlike -nx which disables all of them.
3935 * Removed command line options
3937 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3940 * The 'ptype' and 'whatis' commands now accept an argument to control
3943 * 'info proc' now works on some core files.
3947 ** Vectors can be created with gdb.Type.vector.
3949 ** Python's atexit.register now works in GDB.
3951 ** Types can be pretty-printed via a Python API.
3953 ** Python 3 is now supported (in addition to Python 2.4 or later)
3955 ** New class gdb.Architecture exposes GDB's internal representation
3956 of architecture in the Python API.
3958 ** New method Frame.architecture returns the gdb.Architecture object
3959 corresponding to the frame's architecture.
3961 * New Python-based convenience functions:
3963 ** $_memeq(buf1, buf2, length)
3964 ** $_streq(str1, str2)
3966 ** $_regex(str, regex)
3968 * The 'cd' command now defaults to using '~' (the home directory) if not
3971 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3972 default for GCC since November 2000.
3974 * The command 'forward-search' can now be abbreviated as 'fo'.
3976 * The command 'info tracepoints' can now display 'installed on target'
3977 or 'not installed on target' for each non-pending location of tracepoint.
3979 * New configure options
3981 --enable-libmcheck/--disable-libmcheck
3982 By default, development versions are built with -lmcheck on hosts
3983 that support it, in order to help track memory corruption issues.
3984 Release versions, on the other hand, are built without -lmcheck
3985 by default. The --enable-libmcheck/--disable-libmcheck configure
3986 options allow the user to override that default.
3987 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3988 This configure option allows the user to build GDB with
3989 libbabeltrace using which GDB can read Common Trace Format data.
3991 * New commands (for set/show, see "New options" below)
3994 Catch signals. This is similar to "handle", but allows commands and
3995 conditions to be attached.
3998 List the BFDs known to GDB.
4000 python-interactive [command]
4002 Start a Python interactive prompt, or evaluate the optional command
4003 and print the result of expressions.
4006 "py" is a new alias for "python".
4008 enable type-printer [name]...
4009 disable type-printer [name]...
4010 Enable or disable type printers.
4014 ** For the Renesas Super-H architecture, the "regs" command has been removed
4015 (has been deprecated in GDB 7.5), and "info all-registers" should be used
4020 set print type methods (on|off)
4021 show print type methods
4022 Control whether method declarations are displayed by "ptype".
4023 The default is to show them.
4025 set print type typedefs (on|off)
4026 show print type typedefs
4027 Control whether typedef definitions are displayed by "ptype".
4028 The default is to show them.
4030 set filename-display basename|relative|absolute
4031 show filename-display
4032 Control the way in which filenames is displayed.
4033 The default is "relative", which preserves previous behavior.
4035 set trace-buffer-size
4036 show trace-buffer-size
4037 Request target to change the size of trace buffer.
4039 set remote trace-buffer-size-packet auto|on|off
4040 show remote trace-buffer-size-packet
4041 Control the use of the remote protocol `QTBuffer:size' packet.
4045 Control display of debugging messages related to ARM AArch64.
4048 set debug coff-pe-read
4049 show debug coff-pe-read
4050 Control display of debugging messages related to reading of COFF/PE
4055 Control display of debugging messages related to Mach-O symbols
4058 set debug notification
4059 show debug notification
4060 Control display of debugging info for async remote notification.
4064 ** Command parameter changes are now notified using new async record
4065 "=cmd-param-changed".
4066 ** Trace frame changes caused by command "tfind" are now notified using
4067 new async record "=traceframe-changed".
4068 ** The creation, deletion and modification of trace state variables
4069 are now notified using new async records "=tsv-created",
4070 "=tsv-deleted" and "=tsv-modified".
4071 ** The start and stop of process record are now notified using new
4072 async record "=record-started" and "=record-stopped".
4073 ** Memory changes are now notified using new async record
4075 ** The data-disassemble command response will include a "fullname" field
4076 containing the absolute file name when source has been requested.
4077 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4078 command, to allow pattern filling of memory areas.
4079 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4080 library load/unload events.
4081 ** The response to breakpoint commands and breakpoint async records
4082 includes an "installed" field containing a boolean state about each
4083 non-pending tracepoint location is whether installed on target or not.
4084 ** Output of the "-trace-status" command includes a "trace-file" field
4085 containing the name of the trace file being examined. This field is
4086 optional, and only present when examining a trace file.
4087 ** The "fullname" field is now always present along with the "file" field,
4088 even if the file cannot be found by GDB.
4090 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4091 You must have the LZMA library available when configuring GDB for this
4092 feature to be enabled. For more information, see:
4093 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4095 * New remote packets
4098 Set the size of trace buffer. The remote stub reports support for this
4099 packet to gdb's qSupported query.
4102 Enable Branch Trace Store (BTS)-based branch tracing for the current
4103 thread. The remote stub reports support for this packet to gdb's
4107 Disable branch tracing for the current thread. The remote stub reports
4108 support for this packet to gdb's qSupported query.
4111 Read the traced branches for the current thread. The remote stub
4112 reports support for this packet to gdb's qSupported query.
4114 *** Changes in GDB 7.5
4116 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4117 for more x32 ABI info.
4119 * GDB now supports access to MIPS DSP registers on Linux targets.
4121 * GDB now supports debugging microMIPS binaries.
4123 * The "info os" command on GNU/Linux can now display information on
4124 several new classes of objects managed by the operating system:
4125 "info os procgroups" lists process groups
4126 "info os files" lists file descriptors
4127 "info os sockets" lists internet-domain sockets
4128 "info os shm" lists shared-memory regions
4129 "info os semaphores" lists semaphores
4130 "info os msg" lists message queues
4131 "info os modules" lists loaded kernel modules
4133 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4134 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4135 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4136 options and inspect the probe arguments using the new $_probe_arg family
4137 of convenience variables. You can obtain more information about SystemTap
4138 in <http://sourceware.org/systemtap/>.
4140 * GDB now supports reversible debugging on ARM, it allows you to
4141 debug basic ARM and THUMB instructions, and provides
4142 record/replay support.
4144 * The option "symbol-reloading" has been deleted as it is no longer used.
4148 ** GDB commands implemented in Python can now be put in command class
4151 ** The "maint set python print-stack on|off" is now deleted.
4153 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4154 apply "flag enum"-style pretty-printing to any enum.
4156 ** gdb.lookup_symbol can now work when there is no current frame.
4158 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4159 the source at which the symbol was defined.
4161 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4162 method 'value'. The former indicates whether the symbol needs a
4163 frame in order to compute its value, and the latter computes the
4166 ** A new method 'referenced_value' on gdb.Value objects which can
4167 dereference pointer as well as C++ reference values.
4169 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4170 which return the global and static blocks (as gdb.Block objects),
4171 of the underlying symbol table, respectively.
4173 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4174 object associated with a PC value.
4176 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4177 of the address range occupied by code for the current source line.
4179 * Go language support.
4180 GDB now supports debugging programs written in the Go programming
4183 * GDBserver now supports stdio connections.
4184 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4186 * The binary "gdbtui" can no longer be built or installed.
4187 Use "gdb -tui" instead.
4189 * GDB will now print "flag" enums specially. A flag enum is one where
4190 all the enumerator values have no bits in common when pairwise
4191 "and"ed. When printing a value whose type is a flag enum, GDB will
4192 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4193 (gdb) print (enum E) 3
4196 * The filename part of a linespec will now match trailing components
4197 of a source file name. For example, "break gcc/expr.c:1000" will
4198 now set a breakpoint in build/gcc/expr.c, but not
4199 build/libcpp/expr.c.
4201 * The "info proc" and "generate-core-file" commands will now also
4202 work on remote targets connected to GDBserver on Linux.
4204 * The command "info catch" has been removed. It has been disabled
4205 since December 2007.
4207 * The "catch exception" and "catch assert" commands now accept
4208 a condition at the end of the command, much like the "break"
4209 command does. For instance:
4211 (gdb) catch exception Constraint_Error if Barrier = True
4213 Previously, it was possible to add a condition to such catchpoints,
4214 but it had to be done as a second step, after the catchpoint had been
4215 created, using the "condition" command.
4217 * The "info static-tracepoint-marker" command will now also work on
4218 native Linux targets with in-process agent.
4220 * GDB can now set breakpoints on inlined functions.
4222 * The .gdb_index section has been updated to include symbols for
4223 inlined functions. GDB will ignore older .gdb_index sections by
4224 default, which could cause symbol files to be loaded more slowly
4225 until their .gdb_index sections can be recreated. The new command
4226 "set use-deprecated-index-sections on" will cause GDB to use any older
4227 .gdb_index sections it finds. This will restore performance, but the
4228 ability to set breakpoints on inlined functions will be lost in symbol
4229 files with older .gdb_index sections.
4231 The .gdb_index section has also been updated to record more information
4232 about each symbol. This speeds up the "info variables", "info functions"
4233 and "info types" commands when used with programs having the .gdb_index
4234 section, as well as speeding up debugging with shared libraries using
4235 the .gdb_index section.
4237 * Ada support for GDB/MI Variable Objects has been added.
4239 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4244 ** New command -info-os is the MI equivalent of "info os".
4246 ** Output logs ("set logging" and related) now include MI output.
4250 ** "set use-deprecated-index-sections on|off"
4251 "show use-deprecated-index-sections on|off"
4252 Controls the use of deprecated .gdb_index sections.
4254 ** "catch load" and "catch unload" can be used to stop when a shared
4255 library is loaded or unloaded, respectively.
4257 ** "enable count" can be used to auto-disable a breakpoint after
4260 ** "info vtbl" can be used to show the virtual method tables for
4261 C++ and Java objects.
4263 ** "explore" and its sub commands "explore value" and "explore type"
4264 can be used to recursively explore values and types of
4265 expressions. These commands are available only if GDB is
4266 configured with '--with-python'.
4268 ** "info auto-load" shows status of all kinds of auto-loaded files,
4269 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4270 sequences of commands files, "info auto-load python-scripts"
4271 shows status of auto-loading Python script files,
4272 "info auto-load local-gdbinit" shows status of loading init file
4273 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4274 status of inferior specific thread debugging shared library loading.
4276 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4277 and "show auto-load-scripts" commands have been deprecated, use their
4278 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4279 and "show auto-load python-scripts" counterparts instead.
4281 ** "dprintf location,format,args..." creates a dynamic printf, which
4282 is basically a breakpoint that does a printf and immediately
4283 resumes your program's execution, so it is like a printf that you
4284 can insert dynamically at runtime instead of at compiletime.
4286 ** "set print symbol"
4288 Controls whether GDB attempts to display the symbol, if any,
4289 corresponding to addresses it prints. This defaults to "on", but
4290 you can set it to "off" to restore GDB's previous behavior.
4292 * Deprecated commands
4294 ** For the Renesas Super-H architecture, the "regs" command has been
4295 deprecated, and "info all-registers" should be used instead.
4299 Renesas RL78 rl78-*-elf
4300 HP OpenVMS ia64 ia64-hp-openvms*
4302 * GDBserver supports evaluation of breakpoint conditions. When
4303 support is advertised by GDBserver, GDB may be told to send the
4304 breakpoint conditions in bytecode form to GDBserver. GDBserver
4305 will only report the breakpoint trigger to GDB when its condition
4310 set mips compression
4311 show mips compression
4312 Select the compressed ISA encoding used in functions that have no symbol
4313 information available. The encoding can be set to either of:
4316 and is updated automatically from ELF file flags if available.
4318 set breakpoint condition-evaluation
4319 show breakpoint condition-evaluation
4320 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4321 GDBserver ("target"). Default option "auto" chooses the most efficient
4323 This option can improve debugger efficiency depending on the speed of the
4327 Disable auto-loading globally.
4330 Show auto-loading setting of all kinds of auto-loaded files.
4332 set auto-load gdb-scripts on|off
4333 show auto-load gdb-scripts
4334 Control auto-loading of GDB canned sequences of commands files.
4336 set auto-load python-scripts on|off
4337 show auto-load python-scripts
4338 Control auto-loading of Python script files.
4340 set auto-load local-gdbinit on|off
4341 show auto-load local-gdbinit
4342 Control loading of init file (.gdbinit) from current directory.
4344 set auto-load libthread-db on|off
4345 show auto-load libthread-db
4346 Control auto-loading of inferior specific thread debugging shared library.
4348 set auto-load scripts-directory <dir1>[:<dir2>...]
4349 show auto-load scripts-directory
4350 Set a list of directories from which to load auto-loaded scripts.
4351 Automatically loaded Python scripts and GDB scripts are located in one
4352 of the directories listed by this option.
4353 The delimiter (':' above) may differ according to the host platform.
4355 set auto-load safe-path <dir1>[:<dir2>...]
4356 show auto-load safe-path
4357 Set a list of directories from which it is safe to auto-load files.
4358 The delimiter (':' above) may differ according to the host platform.
4360 set debug auto-load on|off
4361 show debug auto-load
4362 Control display of debugging info for auto-loading the files above.
4364 set dprintf-style gdb|call|agent
4366 Control the way in which a dynamic printf is performed; "gdb"
4367 requests a GDB printf command, while "call" causes dprintf to call a
4368 function in the inferior. "agent" requests that the target agent
4369 (such as GDBserver) do the printing.
4371 set dprintf-function <expr>
4372 show dprintf-function
4373 set dprintf-channel <expr>
4374 show dprintf-channel
4375 Set the function and optional first argument to the call when using
4376 the "call" style of dynamic printf.
4378 set disconnected-dprintf on|off
4379 show disconnected-dprintf
4380 Control whether agent-style dynamic printfs continue to be in effect
4381 after GDB disconnects.
4383 * New configure options
4385 --with-auto-load-dir
4386 Configure default value for the 'set auto-load scripts-directory'
4387 setting above. It defaults to '$debugdir:$datadir/auto-load',
4388 $debugdir representing global debugging info directories (available
4389 via 'show debug-file-directory') and $datadir representing GDB's data
4390 directory (available via 'show data-directory').
4392 --with-auto-load-safe-path
4393 Configure default value for the 'set auto-load safe-path' setting
4394 above. It defaults to the --with-auto-load-dir setting.
4396 --without-auto-load-safe-path
4397 Set 'set auto-load safe-path' to '/', effectively disabling this
4400 * New remote packets
4402 z0/z1 conditional breakpoints extension
4404 The z0/z1 breakpoint insertion packets have been extended to carry
4405 a list of conditional expressions over to the remote stub depending on the
4406 condition evaluation mode. The use of this extension can be controlled
4407 via the "set remote conditional-breakpoints-packet" command.
4411 Specify the signals which the remote stub may pass to the debugged
4412 program without GDB involvement.
4414 * New command line options
4416 --init-command=FILE, -ix Like --command, -x but execute it
4417 before loading inferior.
4418 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4419 execute it before loading inferior.
4421 *** Changes in GDB 7.4
4423 * GDB now handles ambiguous linespecs more consistently; the existing
4424 FILE:LINE support has been expanded to other types of linespecs. A
4425 breakpoint will now be set on all matching locations in all
4426 inferiors, and locations will be added or removed according to
4429 * GDB now allows you to skip uninteresting functions and files when
4430 stepping with the "skip function" and "skip file" commands.
4432 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4433 and "show remote hardware-watchpoint-length-limit". These allows to
4434 set or show the maximum length limit (in bytes) of a remote
4435 target hardware watchpoint.
4437 This allows e.g. to use "unlimited" hardware watchpoints with the
4438 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4439 watchpoints are slower than real hardware watchpoints but are
4440 significantly faster than gdb software watchpoints.
4444 ** The register_pretty_printer function in module gdb.printing now takes
4445 an optional `replace' argument. If True, the new printer replaces any
4448 ** The "maint set python print-stack on|off" command has been
4449 deprecated and will be deleted in GDB 7.5.
4450 A new command: "set python print-stack none|full|message" has
4451 replaced it. Additionally, the default for "print-stack" is
4452 now "message", which just prints the error message without
4455 ** A prompt substitution hook (prompt_hook) is now available to the
4458 ** A new Python module, gdb.prompt has been added to the GDB Python
4459 modules library. This module provides functionality for
4460 escape sequences in prompts (used by set/show
4461 extended-prompt). These escape sequences are replaced by their
4462 corresponding value.
4464 ** Python commands and convenience-functions located in
4465 'data-directory'/python/gdb/command and
4466 'data-directory'/python/gdb/function are now automatically loaded
4469 ** Blocks now provide four new attributes. global_block and
4470 static_block will return the global and static blocks
4471 respectively. is_static and is_global are boolean attributes
4472 that indicate if the block is one of those two types.
4474 ** Symbols now provide the "type" attribute, the type of the symbol.
4476 ** The "gdb.breakpoint" function has been deprecated in favor of
4479 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4480 of a function. This class is based on the "finish" command
4481 available in the CLI.
4483 ** Type objects for struct and union types now allow access to
4484 the fields using standard Python dictionary (mapping) methods.
4485 For example, "some_type['myfield']" now works, as does
4486 "some_type.items()".
4488 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4491 ** A new function, "deep_items" has been added to the gdb.types
4492 module in the GDB Python modules library. This function returns
4493 an iterator over the fields of a struct or union type. Unlike
4494 the standard Python "iteritems" method, it will recursively traverse
4495 any anonymous fields.
4499 ** "*stopped" events can report several new "reason"s, such as
4502 ** Breakpoint changes are now notified using new async records, like
4503 "=breakpoint-modified".
4505 ** New command -ada-task-info.
4507 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4508 $sdir specifies the default system locations of shared libraries.
4509 $pdir specifies the directory where the libpthread used by the application
4512 GDB no longer looks in $sdir and $pdir after it has searched the directories
4513 mentioned in libthread-db-search-path. If you want to search those
4514 directories, they must be specified in libthread-db-search-path.
4515 The default value of libthread-db-search-path on GNU/Linux and Solaris
4516 systems is now "$sdir:$pdir".
4518 $pdir is not supported by gdbserver, it is currently ignored.
4519 $sdir is supported by gdbserver.
4521 * New configure option --with-iconv-bin.
4522 When using the internationalization support like the one in the GNU C
4523 library, GDB will invoke the "iconv" program to get a list of supported
4524 character sets. If this program lives in a non-standard location, one can
4525 use this option to specify where to find it.
4527 * When natively debugging programs on PowerPC BookE processors running
4528 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4529 watchpoints, which specify a mask in addition to an address to watch.
4530 The mask specifies that some bits of an address (the bits which are
4531 reset in the mask) should be ignored when matching the address accessed
4532 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4533 section in the user manual for more details.
4535 * The new option --once causes GDBserver to stop listening for connections once
4536 the first connection is made. The listening port used by GDBserver will
4537 become available after that.
4539 * New commands "info macros" and "alias" have been added.
4541 * New function parameters suffix @entry specifies value of function parameter
4542 at the time the function got called. Entry values are available only since
4548 "!" is now an alias of the "shell" command.
4549 Note that no space is needed between "!" and SHELL COMMAND.
4553 watch EXPRESSION mask MASK_VALUE
4554 The watch command now supports the mask argument which allows creation
4555 of masked watchpoints, if the current architecture supports this feature.
4557 info auto-load-scripts [REGEXP]
4558 This command was formerly named "maintenance print section-scripts".
4559 It is now generally useful and is no longer a maintenance-only command.
4561 info macro [-all] [--] MACRO
4562 The info macro command has new options `-all' and `--'. The first for
4563 printing all definitions of a macro. The second for explicitly specifying
4564 the end of arguments and the beginning of the macro name in case the macro
4565 name starts with a hyphen.
4567 collect[/s] EXPRESSIONS
4568 The tracepoint collect command now takes an optional modifier "/s"
4569 that directs it to dereference pointer-to-character types and
4570 collect the bytes of memory up to a zero byte. The behavior is
4571 similar to what you see when you use the regular print command on a
4572 string. An optional integer following the "/s" sets a bound on the
4573 number of bytes that will be collected.
4576 The trace start command now interprets any supplied arguments as a
4577 note to be recorded with the trace run, with an effect similar to
4578 setting the variable trace-notes.
4581 The trace stop command now interprets any arguments as a note to be
4582 mentioned along with the tstatus report that the trace was stopped
4583 with a command. The effect is similar to setting the variable
4586 * Tracepoints can now be enabled and disabled at any time after a trace
4587 experiment has been started using the standard "enable" and "disable"
4588 commands. It is now possible to start a trace experiment with no enabled
4589 tracepoints; GDB will display a warning, but will allow the experiment to
4590 begin, assuming that tracepoints will be enabled as needed while the trace
4593 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4594 locations with 4-byte instructions, when they were previously
4595 limited to locations with instructions of 5 bytes or longer.
4599 set debug dwarf2-read
4600 show debug dwarf2-read
4601 Turns on or off display of debugging messages related to reading
4602 DWARF debug info. The default is off.
4604 set debug symtab-create
4605 show debug symtab-create
4606 Turns on or off display of debugging messages related to symbol table
4607 creation. The default is off.
4610 show extended-prompt
4611 Set the GDB prompt, and allow escape sequences to be inserted to
4612 display miscellaneous information (see 'help set extended-prompt'
4613 for the list of sequences). This prompt (and any information
4614 accessed through the escape sequences) is updated every time the
4615 prompt is displayed.
4617 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4618 show print entry-values
4619 Set printing of frame argument values at function entry. In some cases
4620 GDB can determine the value of function argument which was passed by the
4621 function caller, even if the value was modified inside the called function.
4623 set debug entry-values
4624 show debug entry-values
4625 Control display of debugging info for determining frame argument values at
4626 function entry and virtual tail call frames.
4628 set basenames-may-differ
4629 show basenames-may-differ
4630 Set whether a source file may have multiple base names.
4631 (A "base name" is the name of a file with the directory part removed.
4632 Example: The base name of "/home/user/hello.c" is "hello.c".)
4633 If set, GDB will canonicalize file names (e.g., expand symlinks)
4634 before comparing them. Canonicalization is an expensive operation,
4635 but it allows the same file be known by more than one base name.
4636 If not set (the default), all source files are assumed to have just
4637 one base name, and gdb will do file name comparisons more efficiently.
4643 Set a user name and notes for the current and any future trace runs.
4644 This is useful for long-running and/or disconnected traces, to
4645 inform others (or yourself) as to who is running the trace, supply
4646 contact information, or otherwise explain what is going on.
4648 set trace-stop-notes
4649 show trace-stop-notes
4650 Set a note attached to the trace run, that is displayed when the
4651 trace has been stopped by a tstop command. This is useful for
4652 instance as an explanation, if you are stopping a trace run that was
4653 started by someone else.
4655 * New remote packets
4659 Dynamically enable a tracepoint in a started trace experiment.
4663 Dynamically disable a tracepoint in a started trace experiment.
4667 Set the user and notes of the trace run.
4671 Query the current status of a tracepoint.
4675 Query the minimum length of instruction at which a fast tracepoint may
4678 * Dcache size (number of lines) and line-size are now runtime-configurable
4679 via "set dcache line" and "set dcache line-size" commands.
4683 Texas Instruments TMS320C6x tic6x-*-*
4687 Renesas RL78 rl78-*-elf
4689 *** Changes in GDB 7.3.1
4691 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4693 *** Changes in GDB 7.3
4695 * GDB has a new command: "thread find [REGEXP]".
4696 It finds the thread id whose name, target id, or thread extra info
4697 matches the given regular expression.
4699 * The "catch syscall" command now works on mips*-linux* targets.
4701 * The -data-disassemble MI command now supports modes 2 and 3 for
4702 dumping the instruction opcodes.
4704 * New command line options
4706 -data-directory DIR Specify DIR as the "data-directory".
4707 This is mostly for testing purposes.
4709 * The "maint set python auto-load on|off" command has been renamed to
4710 "set auto-load-scripts on|off".
4712 * GDB has a new command: "set directories".
4713 It is like the "dir" command except that it replaces the
4714 source path list instead of augmenting it.
4716 * GDB now understands thread names.
4718 On GNU/Linux, "info threads" will display the thread name as set by
4719 prctl or pthread_setname_np.
4721 There is also a new command, "thread name", which can be used to
4722 assign a name internally for GDB to display.
4725 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4726 has been integrated into GDB.
4730 ** The function gdb.Write now accepts an optional keyword 'stream'.
4731 This keyword, when provided, will direct the output to either
4732 stdout, stderr, or GDB's logging output.
4734 ** Parameters can now be be sub-classed in Python, and in particular
4735 you may implement the get_set_doc and get_show_doc functions.
4736 This improves how Parameter set/show documentation is processed
4737 and allows for more dynamic content.
4739 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4740 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4741 have an is_valid method.
4743 ** Breakpoints can now be sub-classed in Python, and in particular
4744 you may implement a 'stop' function that is executed each time
4745 the inferior reaches that breakpoint.
4747 ** New function gdb.lookup_global_symbol looks up a global symbol.
4749 ** GDB values in Python are now callable if the value represents a
4750 function. For example, if 'some_value' represents a function that
4751 takes two integer parameters and returns a value, you can call
4752 that function like so:
4754 result = some_value (10,20)
4756 ** Module gdb.types has been added.
4757 It contains a collection of utilities for working with gdb.Types objects:
4758 get_basic_type, has_field, make_enum_dict.
4760 ** Module gdb.printing has been added.
4761 It contains utilities for writing and registering pretty-printers.
4762 New classes: PrettyPrinter, SubPrettyPrinter,
4763 RegexpCollectionPrettyPrinter.
4764 New function: register_pretty_printer.
4766 ** New commands "info pretty-printers", "enable pretty-printer" and
4767 "disable pretty-printer" have been added.
4769 ** gdb.parameter("directories") is now available.
4771 ** New function gdb.newest_frame returns the newest frame in the
4774 ** The gdb.InferiorThread class has a new "name" attribute. This
4775 holds the thread's name.
4777 ** Python Support for Inferior events.
4778 Python scripts can add observers to be notified of events
4779 occurring in the process being debugged.
4780 The following events are currently supported:
4781 - gdb.events.cont Continue event.
4782 - gdb.events.exited Inferior exited event.
4783 - gdb.events.stop Signal received, and Breakpoint hit events.
4787 ** GDB now puts template parameters in scope when debugging in an
4788 instantiation. For example, if you have:
4790 template<int X> int func (void) { return X; }
4792 then if you step into func<5>, "print X" will show "5". This
4793 feature requires proper debuginfo support from the compiler; it
4794 was added to GCC 4.5.
4796 ** The motion commands "next", "finish", "until", and "advance" now
4797 work better when exceptions are thrown. In particular, GDB will
4798 no longer lose control of the inferior; instead, the GDB will
4799 stop the inferior at the point at which the exception is caught.
4800 This functionality requires a change in the exception handling
4801 code that was introduced in GCC 4.5.
4803 * GDB now follows GCC's rules on accessing volatile objects when
4804 reading or writing target state during expression evaluation.
4805 One notable difference to prior behavior is that "print x = 0"
4806 no longer generates a read of x; the value of the assignment is
4807 now always taken directly from the value being assigned.
4809 * GDB now has some support for using labels in the program's source in
4810 linespecs. For instance, you can use "advance label" to continue
4811 execution to a label.
4813 * GDB now has support for reading and writing a new .gdb_index
4814 section. This section holds a fast index of DWARF debugging
4815 information and can be used to greatly speed up GDB startup and
4816 operation. See the documentation for `save gdb-index' for details.
4818 * The "watch" command now accepts an optional "-location" argument.
4819 When used, this causes GDB to watch the memory referred to by the
4820 expression. Such a watchpoint is never deleted due to it going out
4823 * GDB now supports thread debugging of core dumps on GNU/Linux.
4825 GDB now activates thread debugging using the libthread_db library
4826 when debugging GNU/Linux core dumps, similarly to when debugging
4827 live processes. As a result, when debugging a core dump file, GDB
4828 is now able to display pthread_t ids of threads. For example, "info
4829 threads" shows the same output as when debugging the process when it
4830 was live. In earlier releases, you'd see something like this:
4833 * 1 LWP 6780 main () at main.c:10
4835 While now you see this:
4838 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4840 It is also now possible to inspect TLS variables when debugging core
4843 When debugging a core dump generated on a machine other than the one
4844 used to run GDB, you may need to point GDB at the correct
4845 libthread_db library with the "set libthread-db-search-path"
4846 command. See the user manual for more details on this command.
4848 * When natively debugging programs on PowerPC BookE processors running
4849 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4850 which stop execution of the inferior whenever it executes an instruction
4851 at any address within the specified range. See the "PowerPC Embedded"
4852 section in the user manual for more details.
4854 * New features in the GDB remote stub, GDBserver
4856 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4857 and i686 LynxOS (version 5.x).
4859 ** GDBserver is now supported on Blackfin Linux.
4861 * New native configurations
4863 ia64 HP-UX ia64-*-hpux*
4867 Analog Devices, Inc. Blackfin Processor bfin-*
4869 * Ada task switching is now supported on sparc-elf targets when
4870 debugging a program using the Ravenscar Profile. For more information,
4871 see the "Tasking Support when using the Ravenscar Profile" section
4872 in the GDB user manual.
4874 * Guile support was removed.
4876 * New features in the GNU simulator
4878 ** The --map-info flag lists all known core mappings.
4880 ** CFI flashes may be simulated via the "cfi" device.
4882 *** Changes in GDB 7.2
4884 * Shared library support for remote targets by default
4886 When GDB is configured for a generic, non-OS specific target, like
4887 for example, --target=arm-eabi or one of the many *-*-elf targets,
4888 GDB now queries remote stubs for loaded shared libraries using the
4889 `qXfer:libraries:read' packet. Previously, shared library support
4890 was always disabled for such configurations.
4894 ** Argument Dependent Lookup (ADL)
4896 In C++ ADL lookup directs function search to the namespaces of its
4897 arguments even if the namespace has not been imported.
4907 Here the compiler will search for `foo' in the namespace of 'b'
4908 and find A::foo. GDB now supports this. This construct is commonly
4909 used in the Standard Template Library for operators.
4911 ** Improved User Defined Operator Support
4913 In addition to member operators, GDB now supports lookup of operators
4914 defined in a namespace and imported with a `using' directive, operators
4915 defined in the global scope, operators imported implicitly from an
4916 anonymous namespace, and the ADL operators mentioned in the previous
4918 GDB now also supports proper overload resolution for all the previously
4919 mentioned flavors of operators.
4921 ** static const class members
4923 Printing of static const class members that are initialized in the
4924 class definition has been fixed.
4926 * Windows Thread Information Block access.
4928 On Windows targets, GDB now supports displaying the Windows Thread
4929 Information Block (TIB) structure. This structure is visible either
4930 by using the new command `info w32 thread-information-block' or, by
4931 dereferencing the new convenience variable named `$_tlb', a
4932 thread-specific pointer to the TIB. This feature is also supported
4933 when remote debugging using GDBserver.
4935 * Static tracepoints
4937 Static tracepoints are calls in the user program into a tracing
4938 library. One such library is a port of the LTTng kernel tracer to
4939 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4940 When debugging with GDBserver, GDB now supports combining the GDB
4941 tracepoint machinery with such libraries. For example: the user can
4942 use GDB to probe a static tracepoint marker (a call from the user
4943 program into the tracing library) with the new "strace" command (see
4944 "New commands" below). This creates a "static tracepoint" in the
4945 breakpoint list, that can be manipulated with the same feature set
4946 as fast and regular tracepoints. E.g., collect registers, local and
4947 global variables, collect trace state variables, and define
4948 tracepoint conditions. In addition, the user can collect extra
4949 static tracepoint marker specific data, by collecting the new
4950 $_sdata internal variable. When analyzing the trace buffer, you can
4951 inspect $_sdata like any other variable available to GDB. For more
4952 information, see the "Tracepoints" chapter in GDB user manual. New
4953 remote packets have been defined to support static tracepoints, see
4954 the "New remote packets" section below.
4956 * Better reconstruction of tracepoints after disconnected tracing
4958 GDB will attempt to download the original source form of tracepoint
4959 definitions when starting a trace run, and then will upload these
4960 upon reconnection to the target, resulting in a more accurate
4961 reconstruction of the tracepoints that are in use on the target.
4965 You can now exercise direct control over the ways that GDB can
4966 affect your program. For instance, you can disallow the setting of
4967 breakpoints, so that the program can run continuously (assuming
4968 non-stop mode). In addition, the "observer" variable is available
4969 to switch all of the different controls; in observer mode, GDB
4970 cannot affect the target's behavior at all, which is useful for
4971 tasks like diagnosing live systems in the field.
4973 * The new convenience variable $_thread holds the number of the
4976 * New remote packets
4980 Return the address of the Windows Thread Information Block of a given thread.
4984 In response to several of the tracepoint packets, the target may now
4985 also respond with a number of intermediate `qRelocInsn' request
4986 packets before the final result packet, to have GDB handle
4987 relocating an instruction to execute at a different address. This
4988 is particularly useful for stubs that support fast tracepoints. GDB
4989 reports support for this feature in the qSupported packet.
4993 List static tracepoint markers in the target program.
4997 List static tracepoint markers at a given address in the target
5000 qXfer:statictrace:read
5002 Read the static trace data collected (by a `collect $_sdata'
5003 tracepoint action). The remote stub reports support for this packet
5004 to gdb's qSupported query.
5008 Send the current settings of GDB's permission flags.
5012 Send part of the source (textual) form of a tracepoint definition,
5013 which includes location, conditional, and action list.
5015 * The source command now accepts a -s option to force searching for the
5016 script in the source search path even if the script name specifies
5019 * New features in the GDB remote stub, GDBserver
5021 - GDBserver now support tracepoints (including fast tracepoints, and
5022 static tracepoints). The feature is currently supported by the
5023 i386-linux and amd64-linux builds. See the "Tracepoints support
5024 in gdbserver" section in the manual for more information.
5026 GDBserver JIT compiles the tracepoint's conditional agent
5027 expression bytecode into native code whenever possible for low
5028 overhead dynamic tracepoints conditionals. For such tracepoints,
5029 an expression that examines program state is evaluated when the
5030 tracepoint is reached, in order to determine whether to capture
5031 trace data. If the condition is simple and false, processing the
5032 tracepoint finishes very quickly and no data is gathered.
5034 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5035 for static tracepoints support.
5037 - GDBserver now supports x86_64 Windows 64-bit debugging.
5039 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5040 it understands register description.
5042 * The --batch flag now disables pagination and queries.
5044 * X86 general purpose registers
5046 GDB now supports reading/writing byte, word and double-word x86
5047 general purpose registers directly. This means you can use, say,
5048 $ah or $ax to refer, respectively, to the byte register AH and
5049 16-bit word register AX that are actually portions of the 32-bit
5050 register EAX or 64-bit register RAX.
5052 * The `commands' command now accepts a range of breakpoints to modify.
5053 A plain `commands' following a command that creates multiple
5054 breakpoints affects all the breakpoints set by that command. This
5055 applies to breakpoints set by `rbreak', and also applies when a
5056 single `break' command creates multiple breakpoints (e.g.,
5057 breakpoints on overloaded c++ functions).
5059 * The `rbreak' command now accepts a filename specification as part of
5060 its argument, limiting the functions selected by the regex to those
5061 in the specified file.
5063 * Support for remote debugging Windows and SymbianOS shared libraries
5064 from Unix hosts has been improved. Non Windows GDB builds now can
5065 understand target reported file names that follow MS-DOS based file
5066 system semantics, such as file names that include drive letters and
5067 use the backslash character as directory separator. This makes it
5068 possible to transparently use the "set sysroot" and "set
5069 solib-search-path" on Unix hosts to point as host copies of the
5070 target's shared libraries. See the new command "set
5071 target-file-system-kind" described below, and the "Commands to
5072 specify files" section in the user manual for more information.
5076 eval template, expressions...
5077 Convert the values of one or more expressions under the control
5078 of the string template to a command line, and call it.
5080 set target-file-system-kind unix|dos-based|auto
5081 show target-file-system-kind
5082 Set or show the assumed file system kind for target reported file
5085 save breakpoints <filename>
5086 Save all current breakpoint definitions to a file suitable for use
5087 in a later debugging session. To read the saved breakpoint
5088 definitions, use the `source' command.
5090 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5093 info static-tracepoint-markers
5094 Display information about static tracepoint markers in the target.
5096 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5097 Define a static tracepoint by probing a marker at the given
5098 function, line, address, or marker ID.
5102 Enable and disable observer mode.
5104 set may-write-registers on|off
5105 set may-write-memory on|off
5106 set may-insert-breakpoints on|off
5107 set may-insert-tracepoints on|off
5108 set may-insert-fast-tracepoints on|off
5109 set may-interrupt on|off
5110 Set individual permissions for GDB effects on the target. Note that
5111 some of these settings can have undesirable or surprising
5112 consequences, particularly when changed in the middle of a session.
5113 For instance, disabling the writing of memory can prevent
5114 breakpoints from being inserted, cause single-stepping to fail, or
5115 even crash your program, if you disable after breakpoints have been
5116 inserted. However, GDB should not crash.
5118 set record memory-query on|off
5119 show record memory-query
5120 Control whether to stop the inferior if memory changes caused
5121 by an instruction cannot be recorded.
5126 The disassemble command now supports "start,+length" form of two arguments.
5130 ** GDB now provides a new directory location, called the python directory,
5131 where Python scripts written for GDB can be installed. The location
5132 of that directory is <data-directory>/python, where <data-directory>
5133 is the GDB data directory. For more details, see section `Scripting
5134 GDB using Python' in the manual.
5136 ** The GDB Python API now has access to breakpoints, symbols, symbol
5137 tables, program spaces, inferiors, threads and frame's code blocks.
5138 Additionally, GDB Parameters can now be created from the API, and
5139 manipulated via set/show in the CLI.
5141 ** New functions gdb.target_charset, gdb.target_wide_charset,
5142 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5144 ** New exception gdb.GdbError.
5146 ** Pretty-printers are now also looked up in the current program space.
5148 ** Pretty-printers can now be individually enabled and disabled.
5150 ** GDB now looks for names of Python scripts to auto-load in a
5151 special section named `.debug_gdb_scripts', in addition to looking
5152 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5154 * Tracepoint actions were unified with breakpoint commands. In particular,
5155 there are no longer differences in "info break" output for breakpoints and
5156 tracepoints and the "commands" command can be used for both tracepoints and
5157 regular breakpoints.
5161 ARM Symbian arm*-*-symbianelf*
5163 * D language support.
5164 GDB now supports debugging programs written in the D programming
5167 * GDB now supports the extended ptrace interface for PowerPC which is
5168 available since Linux kernel version 2.6.34. This automatically enables
5169 any hardware breakpoints and additional hardware watchpoints available in
5170 the processor. The old ptrace interface exposes just one hardware
5171 watchpoint and no hardware breakpoints.
5173 * GDB is now able to use the Data Value Compare (DVC) register available on
5174 embedded PowerPC processors to implement in hardware simple watchpoint
5175 conditions of the form:
5177 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5179 This works in native GDB running on Linux kernels with the extended ptrace
5180 interface mentioned above.
5182 *** Changes in GDB 7.1
5186 ** Namespace Support
5188 GDB now supports importing of namespaces in C++. This enables the
5189 user to inspect variables from imported namespaces. Support for
5190 namepace aliasing has also been added. So, if a namespace is
5191 aliased in the current scope (e.g. namepace C=A; ) the user can
5192 print variables using the alias (e.g. (gdb) print C::x).
5196 All known bugs relating to the printing of virtual base class were
5197 fixed. It is now possible to call overloaded static methods using a
5202 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5203 and reinterpret_cast<> are now handled by the C++ expression parser.
5207 Xilinx MicroBlaze microblaze-*-*
5212 Xilinx MicroBlaze microblaze
5215 * Multi-program debugging.
5217 GDB now has support for multi-program (a.k.a. multi-executable or
5218 multi-exec) debugging. This allows for debugging multiple inferiors
5219 simultaneously each running a different program under the same GDB
5220 session. See "Debugging Multiple Inferiors and Programs" in the
5221 manual for more information. This implied some user visible changes
5222 in the multi-inferior support. For example, "info inferiors" now
5223 lists inferiors that are not running yet or that have exited
5224 already. See also "New commands" and "New options" below.
5226 * New tracing features
5228 GDB's tracepoint facility now includes several new features:
5230 ** Trace state variables
5232 GDB tracepoints now include support for trace state variables, which
5233 are variables managed by the target agent during a tracing
5234 experiment. They are useful for tracepoints that trigger each
5235 other, so for instance one tracepoint can count hits in a variable,
5236 and then a second tracepoint has a condition that is true when the
5237 count reaches a particular value. Trace state variables share the
5238 $-syntax of GDB convenience variables, and can appear in both
5239 tracepoint actions and condition expressions. Use the "tvariable"
5240 command to create, and "info tvariables" to view; see "Trace State
5241 Variables" in the manual for more detail.
5245 GDB now includes an option for defining fast tracepoints, which
5246 targets may implement more efficiently, such as by installing a jump
5247 into the target agent rather than a trap instruction. The resulting
5248 speedup can be by two orders of magnitude or more, although the
5249 tradeoff is that some program locations on some target architectures
5250 might not allow fast tracepoint installation, for instance if the
5251 instruction to be replaced is shorter than the jump. To request a
5252 fast tracepoint, use the "ftrace" command, with syntax identical to
5253 the regular trace command.
5255 ** Disconnected tracing
5257 It is now possible to detach GDB from the target while it is running
5258 a trace experiment, then reconnect later to see how the experiment
5259 is going. In addition, a new variable disconnected-tracing lets you
5260 tell the target agent whether to continue running a trace if the
5261 connection is lost unexpectedly.
5265 GDB now has the ability to save the trace buffer into a file, and
5266 then use that file as a target, similarly to you can do with
5267 corefiles. You can select trace frames, print data that was
5268 collected in them, and use tstatus to display the state of the
5269 tracing run at the moment that it was saved. To create a trace
5270 file, use "tsave <filename>", and to use it, do "target tfile
5273 ** Circular trace buffer
5275 You can ask the target agent to handle the trace buffer as a
5276 circular buffer, discarding the oldest trace frames to make room for
5277 newer ones, by setting circular-trace-buffer to on. This feature may
5278 not be available for all target agents.
5283 The disassemble command, when invoked with two arguments, now requires
5284 the arguments to be comma-separated.
5287 The info variables command now displays variable definitions. Files
5288 which only declare a variable are not shown.
5291 The source command is now capable of sourcing Python scripts.
5292 This feature is dependent on the debugger being build with Python
5295 Related to this enhancement is also the introduction of a new command
5296 "set script-extension" (see below).
5298 * New commands (for set/show, see "New options" below)
5300 record save [<FILENAME>]
5301 Save a file (in core file format) containing the process record
5302 execution log for replay debugging at a later time.
5304 record restore <FILENAME>
5305 Restore the process record execution log that was saved at an
5306 earlier time, for replay debugging.
5308 add-inferior [-copies <N>] [-exec <FILENAME>]
5311 clone-inferior [-copies <N>] [ID]
5312 Make a new inferior ready to execute the same program another
5313 inferior has loaded.
5318 maint info program-spaces
5319 List the program spaces loaded into GDB.
5321 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5322 show remote interrupt-sequence
5323 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5324 as the sequence to the remote target in order to interrupt the execution.
5325 Ctrl-C is a default. Some system prefers BREAK which is high level of
5326 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5327 Magic SysRq g. It is BREAK signal and character 'g'.
5329 set remote interrupt-on-connect [on | off]
5330 show remote interrupt-on-connect
5331 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5332 remote target when gdb connects to it. This is needed when you debug
5335 set remotebreak [on | off]
5337 Deprecated. Use "set/show remote interrupt-sequence" instead.
5339 tvariable $NAME [ = EXP ]
5340 Create or modify a trace state variable.
5343 List trace state variables and their values.
5345 delete tvariable $NAME ...
5346 Delete one or more trace state variables.
5349 Evaluate the given expressions without collecting anything into the
5350 trace buffer. (Valid in tracepoint actions only.)
5352 ftrace FN / FILE:LINE / *ADDR
5353 Define a fast tracepoint at the given function, line, or address.
5355 * New expression syntax
5357 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5358 GDB now parses 0b101010 identically with 42.
5362 set follow-exec-mode new|same
5363 show follow-exec-mode
5364 Control whether GDB reuses the same inferior across an exec call or
5365 creates a new one. This is useful to be able to restart the old
5366 executable after the inferior having done an exec call.
5368 set default-collect EXPR, ...
5369 show default-collect
5370 Define a list of expressions to be collected at each tracepoint.
5371 This is a useful way to ensure essential items are not overlooked,
5372 such as registers or a critical global variable.
5374 set disconnected-tracing
5375 show disconnected-tracing
5376 If set to 1, the target is instructed to continue tracing if it
5377 loses its connection to GDB. If 0, the target is to stop tracing
5380 set circular-trace-buffer
5381 show circular-trace-buffer
5382 If set to on, the target is instructed to use a circular trace buffer
5383 and discard the oldest trace frames instead of stopping the trace due
5384 to a full trace buffer. If set to off, the trace stops when the buffer
5385 fills up. Some targets may not support this.
5387 set script-extension off|soft|strict
5388 show script-extension
5389 If set to "off", the debugger does not perform any script language
5390 recognition, and all sourced files are assumed to be GDB scripts.
5391 If set to "soft" (the default), files are sourced according to
5392 filename extension, falling back to GDB scripts if the first
5394 If set to "strict", files are sourced according to filename extension.
5396 set ada trust-PAD-over-XVS on|off
5397 show ada trust-PAD-over-XVS
5398 If off, activate a workaround against a bug in the debugging information
5399 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5400 the GCC sources for more information about the GNAT encoding and
5401 PAD types in particular). It is always safe to set this option to
5402 off, but this introduces a slight performance penalty. The default
5405 * Python API Improvements
5407 ** GDB provides the new class gdb.LazyString. This is useful in
5408 some pretty-printing cases. The new method gdb.Value.lazy_string
5409 provides a simple way to create objects of this type.
5411 ** The fields returned by gdb.Type.fields now have an
5412 `is_base_class' attribute.
5414 ** The new method gdb.Type.range returns the range of an array type.
5416 ** The new method gdb.parse_and_eval can be used to parse and
5417 evaluate an expression.
5419 * New remote packets
5422 Define a trace state variable.
5425 Get the current value of a trace state variable.
5428 Set desired tracing behavior upon disconnection.
5431 Set the trace buffer to be linear or circular.
5434 Get data about the tracepoints currently in use.
5438 Process record now works correctly with hardware watchpoints.
5440 Multiple bug fixes have been made to the mips-irix port, making it
5441 much more reliable. In particular:
5442 - Debugging threaded applications is now possible again. Previously,
5443 GDB would hang while starting the program, or while waiting for
5444 the program to stop at a breakpoint.
5445 - Attaching to a running process no longer hangs.
5446 - An error occurring while loading a core file has been fixed.
5447 - Changing the value of the PC register now works again. This fixes
5448 problems observed when using the "jump" command, or when calling
5449 a function from GDB, or even when assigning a new value to $pc.
5450 - With the "finish" and "return" commands, the return value for functions
5451 returning a small array is now correctly printed.
5452 - It is now possible to break on shared library code which gets executed
5453 during a shared library init phase (code executed while executing
5454 their .init section). Previously, the breakpoint would have no effect.
5455 - GDB is now able to backtrace through the signal handler for
5456 non-threaded programs.
5458 PIE (Position Independent Executable) programs debugging is now supported.
5459 This includes debugging execution of PIC (Position Independent Code) shared
5460 libraries although for that, it should be possible to run such libraries as an
5463 *** Changes in GDB 7.0
5465 * GDB now has an interface for JIT compilation. Applications that
5466 dynamically generate code can create symbol files in memory and register
5467 them with GDB. For users, the feature should work transparently, and
5468 for JIT developers, the interface is documented in the GDB manual in the
5469 "JIT Compilation Interface" chapter.
5471 * Tracepoints may now be conditional. The syntax is as for
5472 breakpoints; either an "if" clause appended to the "trace" command,
5473 or the "condition" command is available. GDB sends the condition to
5474 the target for evaluation using the same bytecode format as is used
5475 for tracepoint actions.
5477 * The disassemble command now supports: an optional /r modifier, print the
5478 raw instructions in hex as well as in symbolic form, and an optional /m
5479 modifier to print mixed source+assembly.
5481 * Process record and replay
5483 In a architecture environment that supports ``process record and
5484 replay'', ``process record and replay'' target can record a log of
5485 the process execution, and replay it with both forward and reverse
5488 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5489 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5490 set execution-direction {forward|reverse}, for targets that support
5493 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5494 feature is available with a native GDB running on kernel version
5497 * GDB now has support for multi-byte and wide character sets on the
5498 target. Strings whose character type is wchar_t, char16_t, or
5499 char32_t are now correctly printed. GDB supports wide- and unicode-
5500 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5501 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5502 `printf'. This feature requires iconv to work properly; if your
5503 system does not have a working iconv, GDB can use GNU libiconv. See
5504 the installation instructions for more information.
5506 * GDB now supports automatic retrieval of shared library files from
5507 remote targets. To use this feature, specify a system root that begins
5508 with the `remote:' prefix, either via the `set sysroot' command or via
5509 the `--with-sysroot' configure-time option.
5511 * "info sharedlibrary" now takes an optional regex of libraries to show,
5512 and it now reports if a shared library has no debugging information.
5514 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5515 now complete on file names.
5517 * When completing in expressions, gdb will attempt to limit
5518 completions to allowable structure or union fields, where appropriate.
5519 For instance, consider:
5521 # struct example { int f1; double f2; };
5522 # struct example variable;
5525 If the user types TAB at the end of this command line, the available
5526 completions will be "f1" and "f2".
5528 * Inlined functions are now supported. They show up in backtraces, and
5529 the "step", "next", and "finish" commands handle them automatically.
5531 * GDB now supports the token-splicing (##) and stringification (#)
5532 operators when expanding macros. It also supports variable-arity
5535 * GDB now supports inspecting extra signal information, exported by
5536 the new $_siginfo convenience variable. The feature is currently
5537 implemented on linux ARM, i386 and amd64.
5539 * GDB can now display the VFP floating point registers and NEON vector
5540 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5541 can provide these registers (requires Linux 2.6.30 or later). Remote
5542 and simulator targets may also provide them.
5544 * New remote packets
5547 Search memory for a sequence of bytes.
5550 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5551 operation over reliable transport links. Use of this packet is
5552 controlled by the `set remote noack-packet' command.
5555 Kill the process with the specified process ID. Use this in preference
5556 to `k' when multiprocess protocol extensions are supported.
5559 Obtains additional operating system information
5563 Read or write additional signal information.
5565 * Removed remote protocol undocumented extension
5567 An undocumented extension to the remote protocol's `S' stop reply
5568 packet that permitted the stub to pass a process id was removed.
5569 Remote servers should use the `T' stop reply packet instead.
5571 * GDB now supports multiple function calling conventions according to the
5572 DWARF-2 DW_AT_calling_convention function attribute.
5574 * The SH target utilizes the aforementioned change to distinguish between gcc
5575 and Renesas calling convention. It also adds the new CLI commands
5576 `set/show sh calling-convention'.
5578 * GDB can now read compressed debug sections, as produced by GNU gold
5579 with the --compress-debug-sections=zlib flag.
5581 * 64-bit core files are now supported on AIX.
5583 * Thread switching is now supported on Tru64.
5585 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5586 which will be allocated using malloc later in program execution.
5588 * The qXfer:libraries:read remote protocol packet now allows passing a
5589 list of section offsets.
5591 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5592 conditions handling signals delivered during attach or thread creation
5593 have also been fixed.
5595 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5596 From the user's standpoint, all unqualified instances of True and False
5597 are treated as the standard definitions, regardless of context.
5599 * GDB now parses C++ symbol and type names more flexibly. For
5602 template<typename T> class C { };
5605 GDB will now correctly handle all of:
5607 ptype C<char const *>
5608 ptype C<char const*>
5609 ptype C<const char *>
5610 ptype C<const char*>
5612 * New features in the GDB remote stub, gdbserver
5614 - The "--wrapper" command-line argument tells gdbserver to use a
5615 wrapper program to launch programs for debugging.
5617 - On PowerPC and S/390 targets, it is now possible to use a single
5618 gdbserver executable to debug both 32-bit and 64-bit programs.
5619 (This requires gdbserver itself to be built as a 64-bit executable.)
5621 - gdbserver uses the new noack protocol mode for TCP connections to
5622 reduce communications latency, if also supported and enabled in GDB.
5624 - Support for the sparc64-linux-gnu target is now included in
5627 - The amd64-linux build of gdbserver now supports debugging both
5628 32-bit and 64-bit programs.
5630 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5631 now support hardware watchpoints, and will use them automatically
5636 GDB now has support for scripting using Python. Whether this is
5637 available is determined at configure time.
5639 New GDB commands can now be written in Python.
5641 * Ada tasking support
5643 Ada tasks can now be inspected in GDB. The following commands have
5647 Print the list of Ada tasks.
5649 Print detailed information about task number N.
5651 Print the task number of the current task.
5653 Switch the context of debugging to task number N.
5655 * Support for user-defined prefixed commands. The "define" command can
5656 add new commands to existing prefixes, e.g. "target".
5658 * Multi-inferior, multi-process debugging.
5660 GDB now has generalized support for multi-inferior debugging. See
5661 "Debugging Multiple Inferiors" in the manual for more information.
5662 Although availability still depends on target support, the command
5663 set is more uniform now. The GNU/Linux specific multi-forks support
5664 has been migrated to this new framework. This implied some user
5665 visible changes; see "New commands" and also "Removed commands"
5668 * Target descriptions can now describe the target OS ABI. See the
5669 "Target Description Format" section in the user manual for more
5672 * Target descriptions can now describe "compatible" architectures
5673 to indicate that the target can execute applications for a different
5674 architecture in addition to those for the main target architecture.
5675 See the "Target Description Format" section in the user manual for
5678 * Multi-architecture debugging.
5680 GDB now includes general supports for debugging applications on
5681 hybrid systems that use more than one single processor architecture
5682 at the same time. Each such hybrid architecture still requires
5683 specific support to be added. The only hybrid architecture supported
5684 in this version of GDB is the Cell Broadband Engine.
5686 * GDB now supports integrated debugging of Cell/B.E. applications that
5687 use both the PPU and SPU architectures. To enable support for hybrid
5688 Cell/B.E. debugging, you need to configure GDB to support both the
5689 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5690 --enable-targets configure option.
5692 * Non-stop mode debugging.
5694 For some targets, GDB now supports an optional mode of operation in
5695 which you can examine stopped threads while other threads continue
5696 to execute freely. This is referred to as non-stop mode, with the
5697 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5698 section in the user manual for more information.
5700 To be able to support remote non-stop debugging, a remote stub needs
5701 to implement the non-stop mode remote protocol extensions, as
5702 described in the "Remote Non-Stop" section of the user manual. The
5703 GDB remote stub, gdbserver, has been adjusted to support these
5704 extensions on linux targets.
5706 * New commands (for set/show, see "New options" below)
5708 catch syscall [NAME(S) | NUMBER(S)]
5709 Catch system calls. Arguments, which should be names of system
5710 calls or their numbers, mean catch only those syscalls. Without
5711 arguments, every syscall will be caught. When the inferior issues
5712 any of the specified syscalls, GDB will stop and announce the system
5713 call, both when it is called and when its call returns. This
5714 feature is currently available with a native GDB running on the
5715 Linux Kernel, under the following architectures: x86, x86_64,
5716 PowerPC and PowerPC64.
5718 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5720 Search memory for a sequence of bytes.
5722 maint set python print-stack
5723 maint show python print-stack
5724 Show a stack trace when an error is encountered in a Python script.
5727 Invoke CODE by passing it to the Python interpreter.
5732 These allow macros to be defined, undefined, and listed
5736 Show operating system information about processes.
5739 List the inferiors currently under GDB's control.
5742 Switch focus to inferior number NUM.
5745 Detach from inferior number NUM.
5748 Kill inferior number NUM.
5752 set spu stop-on-load
5753 show spu stop-on-load
5754 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5756 set spu auto-flush-cache
5757 show spu auto-flush-cache
5758 Control whether to automatically flush the software-managed cache
5759 during Cell/B.E. debugging.
5761 set sh calling-convention
5762 show sh calling-convention
5763 Control the calling convention used when calling SH target functions.
5766 show debug timestamp
5767 Control display of timestamps with GDB debugging output.
5769 set disassemble-next-line
5770 show disassemble-next-line
5771 Control display of disassembled source lines or instructions when
5774 set remote noack-packet
5775 show remote noack-packet
5776 Set/show the use of remote protocol QStartNoAckMode packet. See above
5777 under "New remote packets."
5779 set remote query-attached-packet
5780 show remote query-attached-packet
5781 Control use of remote protocol `qAttached' (query-attached) packet.
5783 set remote read-siginfo-object
5784 show remote read-siginfo-object
5785 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5788 set remote write-siginfo-object
5789 show remote write-siginfo-object
5790 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5793 set remote reverse-continue
5794 show remote reverse-continue
5795 Control use of remote protocol 'bc' (reverse-continue) packet.
5797 set remote reverse-step
5798 show remote reverse-step
5799 Control use of remote protocol 'bs' (reverse-step) packet.
5801 set displaced-stepping
5802 show displaced-stepping
5803 Control displaced stepping mode. Displaced stepping is a way to
5804 single-step over breakpoints without removing them from the debuggee.
5805 Also known as "out-of-line single-stepping".
5808 show debug displaced
5809 Control display of debugging info for displaced stepping.
5811 maint set internal-error
5812 maint show internal-error
5813 Control what GDB does when an internal error is detected.
5815 maint set internal-warning
5816 maint show internal-warning
5817 Control what GDB does when an internal warning is detected.
5822 Use a wrapper program to launch programs for debugging.
5824 set multiple-symbols (all|ask|cancel)
5825 show multiple-symbols
5826 The value of this variable can be changed to adjust the debugger behavior
5827 when an expression or a breakpoint location contains an ambiguous symbol
5828 name (an overloaded function name, for instance).
5830 set breakpoint always-inserted
5831 show breakpoint always-inserted
5832 Keep breakpoints always inserted in the target, as opposed to inserting
5833 them when resuming the target, and removing them when the target stops.
5834 This option can improve debugger performance on slow remote targets.
5836 set arm fallback-mode (arm|thumb|auto)
5837 show arm fallback-mode
5838 set arm force-mode (arm|thumb|auto)
5840 These commands control how ARM GDB determines whether instructions
5841 are ARM or Thumb. The default for both settings is auto, which uses
5842 the current CPSR value for instructions without symbols; previous
5843 versions of GDB behaved as if "set arm fallback-mode arm".
5845 set arm unwind-secure-frames
5846 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5848 This can trigger security exceptions when unwinding exception stacks.
5850 set disable-randomization
5851 show disable-randomization
5852 Standalone programs run with the virtual address space randomization enabled
5853 by default on some platforms. This option keeps the addresses stable across
5854 multiple debugging sessions.
5858 Control whether other threads are stopped or not when some thread hits
5863 Requests that asynchronous execution is enabled in the target, if available.
5864 In this case, it's possible to resume target in the background, and interact
5865 with GDB while the target is running. "show target-async" displays the
5866 current state of asynchronous execution of the target.
5868 set target-wide-charset
5869 show target-wide-charset
5870 The target-wide-charset is the name of the character set that GDB
5871 uses when printing characters whose type is wchar_t.
5873 set tcp auto-retry (on|off)
5875 set tcp connect-timeout
5876 show tcp connect-timeout
5877 These commands allow GDB to retry failed TCP connections to a remote stub
5878 with a specified timeout period; this is useful if the stub is launched
5879 in parallel with GDB but may not be ready to accept connections immediately.
5881 set libthread-db-search-path
5882 show libthread-db-search-path
5883 Control list of directories which GDB will search for appropriate
5886 set schedule-multiple (on|off)
5887 show schedule-multiple
5888 Allow GDB to resume all threads of all processes or only threads of
5889 the current process.
5893 Use more aggressive caching for accesses to the stack. This improves
5894 performance of remote debugging (particularly backtraces) without
5895 affecting correctness.
5897 set interactive-mode (on|off|auto)
5898 show interactive-mode
5899 Control whether GDB runs in interactive mode (on) or not (off).
5900 When in interactive mode, GDB waits for the user to answer all
5901 queries. Otherwise, GDB does not wait and assumes the default
5902 answer. When set to auto (the default), GDB determines which
5903 mode to use based on the stdin settings.
5908 For program forks, this is replaced by the new more generic `info
5909 inferiors' command. To list checkpoints, you can still use the
5910 `info checkpoints' command, which was an alias for the `info forks'
5914 Replaced by the new `inferior' command. To switch between
5915 checkpoints, you can still use the `restart' command, which was an
5916 alias for the `fork' command.
5919 This is removed, since some targets don't have a notion of
5920 processes. To switch between processes, you can still use the
5921 `inferior' command using GDB's own inferior number.
5924 For program forks, this is replaced by the new more generic `kill
5925 inferior' command. To delete a checkpoint, you can still use the
5926 `delete checkpoint' command, which was an alias for the `delete
5930 For program forks, this is replaced by the new more generic `detach
5931 inferior' command. To detach a checkpoint, you can still use the
5932 `detach checkpoint' command, which was an alias for the `detach
5935 * New native configurations
5937 x86/x86_64 Darwin i[34567]86-*-darwin*
5939 x86_64 MinGW x86_64-*-mingw*
5943 Lattice Mico32 lm32-*
5944 x86 DICOS i[34567]86-*-dicos*
5945 x86_64 DICOS x86_64-*-dicos*
5948 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5949 (mingw32ce) debugging.
5955 These commands were actually not implemented on any target.
5957 *** Changes in GDB 6.8
5959 * New native configurations
5961 NetBSD/hppa hppa*-*netbsd*
5962 Xtensa GNU/Linux xtensa*-*-linux*
5966 NetBSD/hppa hppa*-*-netbsd*
5967 Xtensa GNU/Linux xtensa*-*-linux*
5969 * Change in command line behavior -- corefiles vs. process ids.
5971 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5972 attaching to process NUMBER fails, GDB no longer attempts to open a
5973 core file named NUMBER. Attaching to a program using the -c option
5974 is no longer supported. Instead, use the '-p' or '--pid' options.
5976 * GDB can now be built as a native debugger for debugging Windows x86
5977 (mingw32) Portable Executable (PE) programs.
5979 * Pending breakpoints no longer change their number when their address
5982 * GDB now supports breakpoints with multiple locations,
5983 including breakpoints on C++ constructors, inside C++ templates,
5984 and in inlined functions.
5986 * GDB's ability to debug optimized code has been improved. GDB more
5987 accurately identifies function bodies and lexical blocks that occupy
5988 more than one contiguous range of addresses.
5990 * Target descriptions can now describe registers for PowerPC.
5992 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5993 registers on PowerPC targets.
5995 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5996 targets even when the libthread_db library is not available.
5998 * The GDB remote stub, gdbserver, now supports the new file transfer
5999 commands (remote put, remote get, and remote delete).
6001 * The GDB remote stub, gdbserver, now supports run and attach in
6002 extended-remote mode.
6004 * hppa*64*-*-hpux11* target broken
6005 The debugger is unable to start a program and fails with the following
6006 error: "Error trying to get information about dynamic linker".
6007 The gdb-6.7 release is also affected.
6009 * GDB now supports the --enable-targets= configure option to allow
6010 building a single GDB executable that supports multiple remote
6011 target architectures.
6013 * GDB now supports debugging C and C++ programs which use the
6014 Decimal Floating Point extension. In addition, the PowerPC target
6015 now has a set of pseudo-registers to inspect decimal float values
6016 stored in two consecutive float registers.
6018 * The -break-insert MI command can optionally create pending
6021 * Improved support for debugging Ada
6022 Many improvements to the Ada language support have been made. These
6024 - Better support for Ada2005 interface types
6025 - Improved handling of arrays and slices in general
6026 - Better support for Taft-amendment types
6027 - The '{type} ADDRESS' expression is now allowed on the left hand-side
6029 - Improved command completion in Ada
6032 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6037 set print frame-arguments (all|scalars|none)
6038 show print frame-arguments
6039 The value of this variable can be changed to control which argument
6040 values should be printed by the debugger when displaying a frame.
6045 Transfer files to and from a remote target, and delete remote files.
6052 Transfer files to and from a remote target, and delete remote files.
6054 * New remote packets
6061 Open, close, read, write, and delete files on the remote system.
6064 Attach to an existing process on the remote system, in extended-remote
6068 Run a new process on the remote system, in extended-remote mode.
6070 *** Changes in GDB 6.7
6072 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6073 bfd, libiberty and opcodes, as revealed by static analysis donated by
6074 Coverity, Inc. (http://scan.coverity.com).
6076 * When looking up multiply-defined global symbols, GDB will now prefer the
6077 symbol definition in the current shared library if it was built using the
6078 -Bsymbolic linker option.
6080 * When the Text User Interface (TUI) is not configured, GDB will now
6081 recognize the -tui command-line option and print a message that the TUI
6084 * The GDB remote stub, gdbserver, now has lower overhead for high
6085 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6087 * GDB for MIPS targets now autodetects whether a remote target provides
6088 32-bit or 64-bit register values.
6090 * Support for C++ member pointers has been improved.
6092 * GDB now understands XML target descriptions, which specify the
6093 target's overall architecture. GDB can read a description from
6094 a local file or over the remote serial protocol.
6096 * Vectors of single-byte data use a new integer type which is not
6097 automatically displayed as character or string data.
6099 * The /s format now works with the print command. It displays
6100 arrays of single-byte integers and pointers to single-byte integers
6103 * Target descriptions can now describe target-specific registers,
6104 for architectures which have implemented the support (currently
6105 only ARM, M68K, and MIPS).
6107 * GDB and the GDB remote stub, gdbserver, now support the XScale
6110 * The GDB remote stub, gdbserver, has been updated to support
6111 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6112 has been rewritten to use the standard GDB remote protocol.
6114 * GDB can now step into C++ functions which are called through thunks.
6116 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6118 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6119 layout. It also supports a TextSeg= and DataSeg= response when only
6120 segment base addresses (rather than offsets) are available.
6122 * The /i format now outputs any trailing branch delay slot instructions
6123 immediately following the last instruction within the count specified.
6125 * The GDB remote protocol "T" stop reply packet now supports a
6126 "library" response. Combined with the new "qXfer:libraries:read"
6127 packet, this response allows GDB to debug shared libraries on targets
6128 where the operating system manages the list of loaded libraries (e.g.
6129 Windows and SymbianOS).
6131 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6132 (DLLs) on Windows and Windows CE targets.
6134 * GDB now supports a faster verification that a .debug file matches its binary
6135 according to its build-id signature, if the signature is present.
6141 Enable or disable hardware flow control (RTS/CTS) on the serial port
6142 when debugging using remote targets.
6144 set mem inaccessible-by-default
6145 show mem inaccessible-by-default
6146 If the target supplies a memory map, for instance via the remote
6147 protocol's "qXfer:memory-map:read" packet, setting this variable
6148 prevents GDB from accessing memory outside the memory map. This
6149 is useful for targets with memory mapped registers or which react
6150 badly to accesses of unmapped address space.
6152 set breakpoint auto-hw
6153 show breakpoint auto-hw
6154 If the target supplies a memory map, for instance via the remote
6155 protocol's "qXfer:memory-map:read" packet, setting this variable
6156 lets GDB use hardware breakpoints automatically for memory regions
6157 where it can not use software breakpoints. This covers both the
6158 "break" command and internal breakpoints used for other commands
6159 including "next" and "finish".
6162 catch exception unhandled
6163 Stop the program execution when Ada exceptions are raised.
6166 Stop the program execution when an Ada assertion failed.
6170 Set an alternate system root for target files. This is a more
6171 general version of "set solib-absolute-prefix", which is now
6172 an alias to "set sysroot".
6175 Provide extended SPU facility status information. This set of
6176 commands is available only when debugging the Cell/B.E. SPU
6179 * New native configurations
6181 OpenBSD/sh sh*-*openbsd*
6184 unset tdesc filename
6186 Use the specified local file as an XML target description, and do
6187 not query the target for its built-in description.
6191 OpenBSD/sh sh*-*-openbsd*
6192 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6193 Toshiba Media Processor mep-elf
6195 * New remote packets
6198 Ignore the specified signals; pass them directly to the debugged program
6199 without stopping other threads or reporting them to GDB.
6201 qXfer:features:read:
6202 Read an XML target description from the target, which describes its
6207 Read or write contents of an spufs file on the target system. These
6208 packets are available only on the Cell/B.E. SPU architecture.
6210 qXfer:libraries:read:
6211 Report the loaded shared libraries. Combined with new "T" packet
6212 response, this packet allows GDB to debug shared libraries on
6213 targets where the operating system manages the list of loaded
6214 libraries (e.g. Windows and SymbianOS).
6218 Support for these obsolete configurations has been removed.
6226 i[34567]86-*-lynxos*
6227 i[34567]86-*-netware*
6228 i[34567]86-*-sco3.2v5*
6229 i[34567]86-*-sco3.2v4*
6231 i[34567]86-*-sysv4.2*
6234 i[34567]86-*-unixware2*
6235 i[34567]86-*-unixware*
6244 * Other removed features
6251 Various m68k-only ROM monitors.
6258 Various Renesas ROM monitors and debugging interfaces for SH and
6263 Support for a Macraigor serial interface to on-chip debugging.
6264 GDB does not directly support the newer parallel or USB
6269 A debug information format. The predecessor to DWARF 2 and
6270 DWARF 3, which are still supported.
6272 Support for the HP aCC compiler on HP-UX/PA-RISC
6274 SOM-encapsulated symbolic debugging information, automatic
6275 invocation of pxdb, and the aCC custom C++ ABI. This does not
6276 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6277 with aCC can still be debugged on an assembly level.
6279 MIPS ".pdr" sections
6281 A MIPS-specific format used to describe stack frame layout
6282 in debugging information.
6286 GDB could work with an older version of Guile to debug
6287 the interpreter and Scheme programs running in it.
6289 set mips stack-arg-size
6290 set mips saved-gpreg-size
6292 Use "set mips abi" to control parameter passing for MIPS.
6294 *** Changes in GDB 6.6
6299 Cell Broadband Engine SPU spu-elf
6301 * GDB can now be configured as a cross-debugger targeting native Windows
6302 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6303 running on a Windows system over TCP/IP to debug Windows programs.
6305 * The GDB remote stub, gdbserver, has been updated to support Windows and
6306 Cygwin debugging. Both single-threaded and multi-threaded programs are
6309 * The "set trust-readonly-sections" command works again. This command was
6310 broken in GDB 6.3, 6.4, and 6.5.
6312 * The "load" command now supports writing to flash memory, if the remote
6313 stub provides the required support.
6315 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6316 longer requires symbolic debug information (e.g. DWARF-2).
6321 unset substitute-path
6322 show substitute-path
6323 Manage a list of substitution rules that GDB uses to rewrite the name
6324 of the directories where the sources are located. This can be useful
6325 for instance when the sources were moved to a different location
6326 between compilation and debugging.
6330 Print each CLI command as it is executed. Each command is prefixed with
6331 a number of `+' symbols representing the nesting depth.
6332 The source command now has a `-v' option to enable the same feature.
6336 The ARM Demon monitor support (RDP protocol, "target rdp").
6338 Kernel Object Display, an embedded debugging feature which only worked with
6339 an obsolete version of Cisco IOS.
6341 The 'set download-write-size' and 'show download-write-size' commands.
6343 * New remote packets
6346 Tell a stub about GDB client features, and request remote target features.
6347 The first feature implemented is PacketSize, which allows the target to
6348 specify the size of packets it can handle - to minimize the number of
6349 packets required and improve performance when connected to a remote
6353 Fetch an OS auxilliary vector from the remote stub. This packet is a
6354 more efficient replacement for qPart:auxv:read.
6356 qXfer:memory-map:read:
6357 Fetch a memory map from the remote stub, including information about
6358 RAM, ROM, and flash memory devices.
6363 Erase and program a flash memory device.
6365 * Removed remote packets
6368 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6369 used it, and only gdbserver implemented it.
6371 *** Changes in GDB 6.5
6375 Renesas M32C/M16C m32c-elf
6377 Morpho Technologies ms1 ms1-elf
6381 init-if-undefined Initialize a convenience variable, but
6382 only if it doesn't already have a value.
6384 The following commands are presently only implemented for native GNU/Linux:
6386 checkpoint Save a snapshot of the program state.
6388 restart <n> Return the program state to a
6389 previously saved state.
6391 info checkpoints List currently saved checkpoints.
6393 delete-checkpoint <n> Delete a previously saved checkpoint.
6395 set|show detach-on-fork Tell gdb whether to detach from a newly
6396 forked process, or to keep debugging it.
6398 info forks List forks of the user program that
6399 are available to be debugged.
6401 fork <n> Switch to debugging one of several
6402 forks of the user program that are
6403 available to be debugged.
6405 delete-fork <n> Delete a fork from the list of forks
6406 that are available to be debugged (and
6407 kill the forked process).
6409 detach-fork <n> Delete a fork from the list of forks
6410 that are available to be debugged (and
6411 allow the process to continue).
6415 Morpho Technologies ms2 ms1-elf
6417 * Improved Windows host support
6419 GDB now builds as a cross debugger hosted on i686-mingw32, including
6420 native console support, and remote communications using either
6421 network sockets or serial ports.
6423 * Improved Modula-2 language support
6425 GDB can now print most types in the Modula-2 syntax. This includes:
6426 basic types, set types, record types, enumerated types, range types,
6427 pointer types and ARRAY types. Procedure var parameters are correctly
6428 printed and hexadecimal addresses and character constants are also
6429 written in the Modula-2 syntax. Best results can be obtained by using
6430 GNU Modula-2 together with the -gdwarf-2 command line option.
6434 The ARM rdi-share module.
6436 The Netware NLM debug server.
6438 *** Changes in GDB 6.4
6440 * New native configurations
6442 OpenBSD/arm arm*-*-openbsd*
6443 OpenBSD/mips64 mips64-*-openbsd*
6447 Morpho Technologies ms1 ms1-elf
6449 * New command line options
6451 --batch-silent As for --batch, but totally silent.
6452 --return-child-result The debugger will exist with the same value
6453 the child (debugged) program exited with.
6454 --eval-command COMMAND, -ex COMMAND
6455 Execute a single GDB CLI command. This may be
6456 specified multiple times and in conjunction
6457 with the --command (-x) option.
6459 * Deprecated commands removed
6461 The following commands, that were deprecated in 2000, have been
6465 set|show arm disassembly-flavor set|show arm disassembler
6466 othernames set arm disassembler
6467 set|show remotedebug set|show debug remote
6468 set|show archdebug set|show debug arch
6469 set|show eventdebug set|show debug event
6472 * New BSD user-level threads support
6474 It is now possible to debug programs using the user-level threads
6475 library on OpenBSD and FreeBSD. Currently supported (target)
6478 FreeBSD/amd64 x86_64-*-freebsd*
6479 FreeBSD/i386 i386-*-freebsd*
6480 OpenBSD/i386 i386-*-openbsd*
6482 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6483 are not yet supported.
6485 * New support for Matsushita MN10300 w/sim added
6486 (Work in progress). mn10300-elf.
6488 * REMOVED configurations and files
6490 VxWorks and the XDR protocol *-*-vxworks
6491 Motorola MCORE mcore-*-*
6492 National Semiconductor NS32000 ns32k-*-*
6494 * New "set print array-indexes" command
6496 After turning this setting "on", GDB prints the index of each element
6497 when displaying arrays. The default is "off" to preserve the previous
6500 * VAX floating point support
6502 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6504 * User-defined command support
6506 In addition to using $arg0..$arg9 for argument passing, it is now possible
6507 to use $argc to determine now many arguments have been passed. See the
6508 section on user-defined commands in the user manual for more information.
6510 *** Changes in GDB 6.3:
6512 * New command line option
6514 GDB now accepts -l followed by a number to set the timeout for remote
6517 * GDB works with GCC -feliminate-dwarf2-dups
6519 GDB now supports a more compact representation of DWARF-2 debug
6520 information using DW_FORM_ref_addr references. These are produced
6521 by GCC with the option -feliminate-dwarf2-dups and also by some
6522 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6523 to use -feliminate-dwarf2-dups.
6525 * Internationalization
6527 When supported by the host system, GDB will be built with
6528 internationalization (libintl). The task of marking up the sources is
6529 continued, we're looking forward to our first translation.
6533 Initial support for debugging programs compiled with the GNAT
6534 implementation of the Ada programming language has been integrated
6535 into GDB. In this release, support is limited to expression evaluation.
6537 * New native configurations
6539 GNU/Linux/m32r m32r-*-linux-gnu
6543 GDB's remote protocol now includes support for the 'p' packet. This
6544 packet is used to fetch individual registers from a remote inferior.
6546 * END-OF-LIFE registers[] compatibility module
6548 GDB's internal register infrastructure has been completely rewritten.
6549 The new infrastructure making possible the implementation of key new
6550 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6553 GDB 6.3 will be the last release to include the registers[]
6554 compatibility module that allowed out-of-date configurations to
6555 continue to work. This change directly impacts the following
6565 powerpc bdm protocol
6567 Unless there is activity to revive these configurations, they will be
6568 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6570 * OBSOLETE configurations and files
6572 Configurations that have been declared obsolete in this release have
6573 been commented out. Unless there is activity to revive these
6574 configurations, the next release of GDB will have their sources
6575 permanently REMOVED.
6584 *** Changes in GDB 6.2.1:
6586 * MIPS `break main; run' gave an heuristic-fence-post warning
6588 When attempting to run even a simple program, a warning about
6589 heuristic-fence-post being hit would be reported. This problem has
6592 * MIPS IRIX 'long double' crashed GDB
6594 When examining a long double variable, GDB would get a segmentation
6595 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6596 IRIX long double values).
6600 A bug in the VAX stack code was causing problems with the "next"
6601 command. This problem has been fixed.
6603 *** Changes in GDB 6.2:
6605 * Fix for ``many threads''
6607 On GNU/Linux systems that use the NPTL threads library, a program
6608 rapidly creating and deleting threads would confuse GDB leading to the
6611 ptrace: No such process.
6612 thread_db_get_info: cannot get thread info: generic error
6614 This problem has been fixed.
6616 * "-async" and "-noasync" options removed.
6618 Support for the broken "-noasync" option has been removed (it caused
6621 * New ``start'' command.
6623 This command runs the program until the beginning of the main procedure.
6625 * New BSD Kernel Data Access Library (libkvm) interface
6627 Using ``target kvm'' it is now possible to debug kernel core dumps and
6628 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6629 platforms. Currently supported (native-only) configurations are:
6631 FreeBSD/amd64 x86_64-*-freebsd*
6632 FreeBSD/i386 i?86-*-freebsd*
6633 NetBSD/i386 i?86-*-netbsd*
6634 NetBSD/m68k m68*-*-netbsd*
6635 NetBSD/sparc sparc-*-netbsd*
6636 OpenBSD/amd64 x86_64-*-openbsd*
6637 OpenBSD/i386 i?86-*-openbsd*
6638 OpenBSD/m68k m68*-openbsd*
6639 OpenBSD/sparc sparc-*-openbsd*
6641 * Signal trampoline code overhauled
6643 Many generic problems with GDB's signal handling code have been fixed.
6644 These include: backtraces through non-contiguous stacks; recognition
6645 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6646 call; backtrace through a signal trampoline; step into and out of
6647 signal handlers; and single-stepping in the signal trampoline.
6649 Please note that kernel bugs are a limiting factor here. These
6650 features have been shown to work on an s390 GNU/Linux system that
6651 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6653 * Cygwin support for DWARF 2 added.
6655 * New native configurations
6657 GNU/Linux/hppa hppa*-*-linux*
6658 OpenBSD/hppa hppa*-*-openbsd*
6659 OpenBSD/m68k m68*-*-openbsd*
6660 OpenBSD/m88k m88*-*-openbsd*
6661 OpenBSD/powerpc powerpc-*-openbsd*
6662 NetBSD/vax vax-*-netbsd*
6663 OpenBSD/vax vax-*-openbsd*
6665 * END-OF-LIFE frame compatibility module
6667 GDB's internal frame infrastructure has been completely rewritten.
6668 The new infrastructure making it possible to support key new features
6669 including DWARF 2 Call Frame Information. To aid in the task of
6670 migrating old configurations to this new infrastructure, a
6671 compatibility module, that allowed old configurations to continue to
6672 work, was also included.
6674 GDB 6.2 will be the last release to include this frame compatibility
6675 module. This change directly impacts the following configurations:
6685 Unless there is activity to revive these configurations, they will be
6686 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6688 * REMOVED configurations and files
6690 Sun 3, running SunOS 3 m68*-*-sunos3*
6691 Sun 3, running SunOS 4 m68*-*-sunos4*
6692 Sun 2, running SunOS 3 m68000-*-sunos3*
6693 Sun 2, running SunOS 4 m68000-*-sunos4*
6694 Motorola 680x0 running LynxOS m68*-*-lynxos*
6695 AT&T 3b1/Unix pc m68*-att-*
6696 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6697 decstation mips-dec-* mips-little-*
6698 riscos mips-*-riscos* mips-*-sysv*
6699 sonymips mips-sony-*
6700 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6702 *** Changes in GDB 6.1.1:
6704 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6706 The TUI (Text-mode User Interface) is now built as part of a default
6707 GDB configuration. It is enabled by either selecting the TUI with the
6708 command line option "-i=tui" or by running the separate "gdbtui"
6709 program. For more information on the TUI, see the manual "Debugging
6712 * Pending breakpoint support (also included in GDB 6.1)
6714 Support has been added to allow you to specify breakpoints in shared
6715 libraries that have not yet been loaded. If a breakpoint location
6716 cannot be found, and the "breakpoint pending" option is set to auto,
6717 GDB queries you if you wish to make the breakpoint pending on a future
6718 shared-library load. If and when GDB resolves the breakpoint symbol,
6719 the pending breakpoint is removed as one or more regular breakpoints
6722 Pending breakpoints are very useful for GCJ Java debugging.
6724 * Fixed ISO-C build problems
6726 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6727 non ISO-C code that stopped them being built using a more strict ISO-C
6728 compiler (e.g., IBM's C compiler).
6730 * Fixed build problem on IRIX 5
6732 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6733 wasn't able to compile compile on an IRIX 5 system.
6735 * Added execute permission to gdb/gdbserver/configure
6737 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6738 permission. This bug would cause configure to fail on a number of
6739 systems (Solaris, IRIX). Ref: server/519.
6741 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6743 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6744 has been updated to use constant array sizes.
6746 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6748 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6749 its generated DWARF Call Frame Info. This encoding was causing GDB to
6750 panic, that panic has been fixed. Ref: gdb/1628.
6752 * Fixed a problem when examining parameters in shared library code.
6754 When examining parameters in optimized shared library code generated
6755 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6756 not available''. GDB now correctly displays the variable's value.
6758 *** Changes in GDB 6.1:
6760 * Removed --with-mmalloc
6762 Support for the mmalloc memory manager has been removed, as it
6763 conflicted with the internal gdb byte cache.
6765 * Changes in AMD64 configurations
6767 The AMD64 target now includes the %cs and %ss registers. As a result
6768 the AMD64 remote protocol has changed; this affects the floating-point
6769 and SSE registers. If you rely on those registers for your debugging,
6770 you should upgrade gdbserver on the remote side.
6772 * Revised SPARC target
6774 The SPARC target has been completely revised, incorporating the
6775 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6776 support for LynxOS and SunOS 4 has been dropped. Calling functions
6777 from within GDB on operating systems with a non-executable stack
6778 (Solaris, OpenBSD) now works.
6782 GDB has a new C++ demangler which does a better job on the mangled
6783 names generated by current versions of g++. It also runs faster, so
6784 with this and other changes gdb should now start faster on large C++
6787 * DWARF 2 Location Expressions
6789 GDB support for location expressions has been extended to support function
6790 arguments and frame bases. Older versions of GDB could crash when they
6793 * C++ nested types and namespaces
6795 GDB's support for nested types and namespaces in C++ has been
6796 improved, especially if you use the DWARF 2 debugging format. (This
6797 is the default for recent versions of GCC on most platforms.)
6798 Specifically, if you have a class "Inner" defined within a class or
6799 namespace "Outer", then GDB realizes that the class's name is
6800 "Outer::Inner", not simply "Inner". This should greatly reduce the
6801 frequency of complaints about not finding RTTI symbols. In addition,
6802 if you are stopped at inside of a function defined within a namespace,
6803 GDB modifies its name lookup accordingly.
6805 * New native configurations
6807 NetBSD/amd64 x86_64-*-netbsd*
6808 OpenBSD/amd64 x86_64-*-openbsd*
6809 OpenBSD/alpha alpha*-*-openbsd*
6810 OpenBSD/sparc sparc-*-openbsd*
6811 OpenBSD/sparc64 sparc64-*-openbsd*
6813 * New debugging protocols
6815 M32R with SDI protocol m32r-*-elf*
6817 * "set prompt-escape-char" command deleted.
6819 The command "set prompt-escape-char" has been deleted. This command,
6820 and its very obscure effect on GDB's prompt, was never documented,
6821 tested, nor mentioned in the NEWS file.
6823 * OBSOLETE configurations and files
6825 Configurations that have been declared obsolete in this release have
6826 been commented out. Unless there is activity to revive these
6827 configurations, the next release of GDB will have their sources
6828 permanently REMOVED.
6830 Sun 3, running SunOS 3 m68*-*-sunos3*
6831 Sun 3, running SunOS 4 m68*-*-sunos4*
6832 Sun 2, running SunOS 3 m68000-*-sunos3*
6833 Sun 2, running SunOS 4 m68000-*-sunos4*
6834 Motorola 680x0 running LynxOS m68*-*-lynxos*
6835 AT&T 3b1/Unix pc m68*-att-*
6836 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6837 decstation mips-dec-* mips-little-*
6838 riscos mips-*-riscos* mips-*-sysv*
6839 sonymips mips-sony-*
6840 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6842 * REMOVED configurations and files
6844 SGI Irix-4.x mips-sgi-irix4 or iris4
6845 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6846 Z8000 simulator z8k-zilog-none or z8ksim
6847 Matsushita MN10200 w/simulator mn10200-*-*
6848 H8/500 simulator h8500-hitachi-hms or h8500hms
6849 HP/PA running BSD hppa*-*-bsd*
6850 HP/PA running OSF/1 hppa*-*-osf*
6851 HP/PA Pro target hppa*-*-pro*
6852 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6853 386BSD i[3456]86-*-bsd*
6854 Sequent family i[3456]86-sequent-sysv4*
6855 i[3456]86-sequent-sysv*
6856 i[3456]86-sequent-bsd*
6857 SPARC running LynxOS sparc-*-lynxos*
6858 SPARC running SunOS 4 sparc-*-sunos4*
6859 Tsqware Sparclet sparclet-*-*
6860 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6862 *** Changes in GDB 6.0:
6866 Support for debugging the Objective-C programming language has been
6867 integrated into GDB.
6869 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6871 DWARF 2's Call Frame Information makes available compiler generated
6872 information that more exactly describes the program's run-time stack.
6873 By using this information, GDB is able to provide more robust stack
6876 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6877 have been updated to use a new backtrace mechanism which includes
6878 DWARF 2 CFI support.
6882 GDB's remote protocol has been extended to include support for hosted
6883 file I/O (where the remote target uses GDB's file system). See GDB's
6884 remote protocol documentation for details.
6886 * All targets using the new architecture framework.
6888 All of GDB's targets have been updated to use the new internal
6889 architecture framework. The way is now open for future GDB releases
6890 to include cross-architecture native debugging support (i386 on amd64,
6893 * GNU/Linux's Thread Local Storage (TLS)
6895 GDB now includes support for for the GNU/Linux implementation of
6896 per-thread variables.
6898 * GNU/Linux's Native POSIX Thread Library (NPTL)
6900 GDB's thread code has been updated to work with either the new
6901 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6903 * Separate debug info.
6905 GDB, in conjunction with BINUTILS, now supports a mechanism for
6906 automatically loading debug information from a separate file. Instead
6907 of shipping full debug and non-debug versions of system libraries,
6908 system integrators can now instead ship just the stripped libraries
6909 and optional debug files.
6911 * DWARF 2 Location Expressions
6913 DWARF 2 Location Expressions allow the compiler to more completely
6914 describe the location of variables (even in optimized code) to the
6917 GDB now includes preliminary support for location expressions (support
6918 for DW_OP_piece is still missing).
6922 A number of long standing bugs that caused GDB to die while starting a
6923 Java application have been fixed. GDB's Java support is now
6924 considered "useable".
6926 * GNU/Linux support for fork, vfork, and exec.
6928 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6929 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6932 * GDB supports logging output to a file
6934 There are two new commands, "set logging" and "show logging", which can be
6935 used to capture GDB's output to a file.
6937 * The meaning of "detach" has changed for gdbserver
6939 The "detach" command will now resume the application, as documented. To
6940 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6943 * d10v, m68hc11 `regs' command deprecated
6945 The `info registers' command has been updated so that it displays the
6946 registers using a format identical to the old `regs' command.
6950 A new command, "maint set profile on/off", has been added. This command can
6951 be used to enable or disable profiling while running GDB, to profile a
6952 session or a set of commands. In addition there is a new configure switch,
6953 "--enable-profiling", which will cause GDB to be compiled with profiling
6954 data, for more informative profiling results.
6956 * Default MI syntax changed to "mi2".
6958 The default MI (machine interface) syntax, enabled by the command line
6959 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6960 "mi1", can be enabled by specifying the option "-i=mi1".
6962 Support for the original "mi0" syntax (included in GDB 5.0) has been
6965 Fix for gdb/192: removed extraneous space when displaying frame level.
6966 Fix for gdb/672: update changelist is now output in mi list format.
6967 Fix for gdb/702: a -var-assign that updates the value now shows up
6968 in a subsequent -var-update.
6970 * New native configurations.
6972 FreeBSD/amd64 x86_64-*-freebsd*
6974 * Multi-arched targets.
6976 HP/PA HPUX11 hppa*-*-hpux*
6977 Renesas M32R/D w/simulator m32r-*-elf*
6979 * OBSOLETE configurations and files
6981 Configurations that have been declared obsolete in this release have
6982 been commented out. Unless there is activity to revive these
6983 configurations, the next release of GDB will have their sources
6984 permanently REMOVED.
6986 Z8000 simulator z8k-zilog-none or z8ksim
6987 Matsushita MN10200 w/simulator mn10200-*-*
6988 H8/500 simulator h8500-hitachi-hms or h8500hms
6989 HP/PA running BSD hppa*-*-bsd*
6990 HP/PA running OSF/1 hppa*-*-osf*
6991 HP/PA Pro target hppa*-*-pro*
6992 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6993 Sequent family i[3456]86-sequent-sysv4*
6994 i[3456]86-sequent-sysv*
6995 i[3456]86-sequent-bsd*
6996 Tsqware Sparclet sparclet-*-*
6997 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6999 * REMOVED configurations and files
7002 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7003 IBM AIX PS/2 i[3456]86-*-aix
7004 i386 running Mach 3.0 i[3456]86-*-mach3*
7005 i386 running Mach i[3456]86-*-mach*
7006 i386 running OSF/1 i[3456]86-*osf1mk*
7007 HP/Apollo 68k Family m68*-apollo*-sysv*,
7009 m68*-hp-bsd*, m68*-hp-hpux*
7010 Argonaut Risc Chip (ARC) arc-*-*
7011 Mitsubishi D30V d30v-*-*
7012 Fujitsu FR30 fr30-*-elf*
7013 OS/9000 i[34]86-*-os9k
7014 I960 with MON960 i960-*-coff
7016 * MIPS $fp behavior changed
7018 The convenience variable $fp, for the MIPS, now consistently returns
7019 the address of the current frame's base. Previously, depending on the
7020 context, $fp could refer to either $sp or the current frame's base
7021 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
7022 The GNU Source-Level Debugger''.
7024 *** Changes in GDB 5.3:
7026 * GNU/Linux shared library multi-threaded performance improved.
7028 When debugging a multi-threaded application on GNU/Linux, GDB now uses
7029 `/proc', in preference to `ptrace' for memory reads. This may result
7030 in an improvement in the start-up time of multi-threaded, shared
7031 library applications when run under GDB. One GDB user writes: ``loads
7032 shared libs like mad''.
7034 * ``gdbserver'' now supports multi-threaded applications on some targets
7036 Support for debugging multi-threaded applications which use
7037 the GNU/Linux LinuxThreads package has been added for
7038 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
7039 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
7041 * GDB now supports C/C++ preprocessor macros.
7043 GDB now expands preprocessor macro invocations in C/C++ expressions,
7044 and provides various commands for showing macro definitions and how
7047 The new command `macro expand EXPRESSION' expands any macro
7048 invocations in expression, and shows the result.
7050 The new command `show macro MACRO-NAME' shows the definition of the
7051 macro named MACRO-NAME, and where it was defined.
7053 Most compilers don't include information about macros in the debugging
7054 information by default. In GCC 3.1, for example, you need to compile
7055 your program with the options `-gdwarf-2 -g3'. If the macro
7056 information is present in the executable, GDB will read it.
7058 * Multi-arched targets.
7060 DEC Alpha (partial) alpha*-*-*
7061 DEC VAX (partial) vax-*-*
7063 National Semiconductor NS32000 (partial) ns32k-*-*
7064 Motorola 68000 (partial) m68k-*-*
7065 Motorola MCORE mcore-*-*
7069 Fujitsu FRV architecture added by Red Hat frv*-*-*
7072 * New native configurations
7074 Alpha NetBSD alpha*-*-netbsd*
7075 SH NetBSD sh*-*-netbsdelf*
7076 MIPS NetBSD mips*-*-netbsd*
7077 UltraSPARC NetBSD sparc64-*-netbsd*
7079 * OBSOLETE configurations and files
7081 Configurations that have been declared obsolete in this release have
7082 been commented out. Unless there is activity to revive these
7083 configurations, the next release of GDB will have their sources
7084 permanently REMOVED.
7086 Mitsubishi D30V d30v-*-*
7087 OS/9000 i[34]86-*-os9k
7088 IBM AIX PS/2 i[3456]86-*-aix
7089 Fujitsu FR30 fr30-*-elf*
7090 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7091 Argonaut Risc Chip (ARC) arc-*-*
7092 i386 running Mach 3.0 i[3456]86-*-mach3*
7093 i386 running Mach i[3456]86-*-mach*
7094 i386 running OSF/1 i[3456]86-*osf1mk*
7095 HP/Apollo 68k Family m68*-apollo*-sysv*,
7097 m68*-hp-bsd*, m68*-hp-hpux*
7098 I960 with MON960 i960-*-coff
7100 * OBSOLETE languages
7102 CHILL, a Pascal like language used by telecommunications companies.
7104 * REMOVED configurations and files
7106 AMD 29k family via UDI a29k-amd-udi, udi29k
7107 A29K VxWorks a29k-*-vxworks
7108 AMD 29000 embedded, using EBMON a29k-none-none
7109 AMD 29000 embedded with COFF a29k-none-coff
7110 AMD 29000 embedded with a.out a29k-none-aout
7112 testsuite/gdb.hp/gdb.threads-hp/ directory
7114 * New command "set max-user-call-depth <nnn>"
7116 This command allows the user to limit the call depth of user-defined
7117 commands. The default is 1024.
7119 * Changes in FreeBSD/i386 native debugging.
7121 Support for the "generate-core-file" has been added.
7123 * New commands "dump", "append", and "restore".
7125 These commands allow data to be copied from target memory
7126 to a bfd-format or binary file (dump and append), and back
7127 from a file into memory (restore).
7129 * Improved "next/step" support on multi-processor Alpha Tru64.
7131 The previous single-step mechanism could cause unpredictable problems,
7132 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7133 of a software single-step mechanism prevents this.
7135 *** Changes in GDB 5.2.1:
7143 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7144 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7145 Fix, by Joel Brobecker imported from mainline.
7147 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7148 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7149 Fix, by Fred Fish, imported from mainline.
7151 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7152 Surprisingly enough, it works now.
7153 By Michal Ludvig, imported from mainline.
7155 i386 hardware watchpoint support:
7156 avoid misses on second run for some targets.
7157 By Pierre Muller, imported from mainline.
7159 *** Changes in GDB 5.2:
7161 * New command "set trust-readonly-sections on[off]".
7163 This command is a hint that tells gdb that read-only sections
7164 really are read-only (ie. that their contents will not change).
7165 In this mode, gdb will go to the object file rather than the
7166 target to read memory from read-only sections (such as ".text").
7167 This can be a significant performance improvement on some
7168 (notably embedded) targets.
7170 * New command "generate-core-file" (or "gcore").
7172 This new gdb command allows the user to drop a core file of the child
7173 process state at any time. So far it's been implemented only for
7174 GNU/Linux and Solaris, but should be relatively easily ported to other
7175 hosts. Argument is core file name (defaults to core.<pid>).
7177 * New command line option
7179 GDB now accepts --pid or -p followed by a process id.
7181 * Change in command line behavior -- corefiles vs. process ids.
7183 There is a subtle behavior in the way in which GDB handles
7184 command line arguments. The first non-flag argument is always
7185 a program to debug, but the second non-flag argument may either
7186 be a corefile or a process id. Previously, GDB would attempt to
7187 open the second argument as a corefile, and if that failed, would
7188 issue a superfluous error message and then attempt to attach it as
7189 a process. Now, if the second argument begins with a non-digit,
7190 it will be treated as a corefile. If it begins with a digit,
7191 GDB will attempt to attach it as a process, and if no such process
7192 is found, will then attempt to open it as a corefile.
7194 * Changes in ARM configurations.
7196 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7197 configuration is fully multi-arch.
7199 * New native configurations
7201 ARM NetBSD arm*-*-netbsd*
7202 x86 OpenBSD i[3456]86-*-openbsd*
7203 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7204 Sparc64 running FreeBSD sparc64-*-freebsd*
7208 Sanyo XStormy16 xstormy16-elf
7210 * OBSOLETE configurations and files
7212 Configurations that have been declared obsolete in this release have
7213 been commented out. Unless there is activity to revive these
7214 configurations, the next release of GDB will have their sources
7215 permanently REMOVED.
7217 AMD 29k family via UDI a29k-amd-udi, udi29k
7218 A29K VxWorks a29k-*-vxworks
7219 AMD 29000 embedded, using EBMON a29k-none-none
7220 AMD 29000 embedded with COFF a29k-none-coff
7221 AMD 29000 embedded with a.out a29k-none-aout
7223 testsuite/gdb.hp/gdb.threads-hp/ directory
7225 * REMOVED configurations and files
7227 TI TMS320C80 tic80-*-*
7229 PowerPC Solaris powerpcle-*-solaris*
7230 PowerPC Windows NT powerpcle-*-cygwin32
7231 PowerPC Netware powerpc-*-netware*
7232 Harris/CXUX m88k m88*-harris-cxux*
7233 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7234 ns32k-utek-sysv* ns32k-utek-*
7235 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7236 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7237 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7238 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7239 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7241 * Changes to command line processing
7243 The new `--args' feature can be used to specify command-line arguments
7244 for the inferior from gdb's command line.
7246 * Changes to key bindings
7248 There is a new `operate-and-get-next' function bound to `C-o'.
7250 *** Changes in GDB 5.1.1
7252 Fix compile problem on DJGPP.
7254 Fix a problem with floating-point registers on the i386 being
7257 Fix to stop GDB crashing on .debug_str debug info.
7259 Numerous documentation fixes.
7261 Numerous testsuite fixes.
7263 *** Changes in GDB 5.1:
7265 * New native configurations
7267 Alpha FreeBSD alpha*-*-freebsd*
7268 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7269 MIPS GNU/Linux mips*-*-linux*
7270 MIPS SGI Irix 6.x mips*-sgi-irix6*
7271 ia64 AIX ia64-*-aix*
7272 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7276 Motorola 68HC11 and 68HC12 m68hc11-elf
7278 UltraSparc running GNU/Linux sparc64-*-linux*
7280 * OBSOLETE configurations and files
7282 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7283 Harris/CXUX m88k m88*-harris-cxux*
7284 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7285 ns32k-utek-sysv* ns32k-utek-*
7286 TI TMS320C80 tic80-*-*
7288 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7289 PowerPC Solaris powerpcle-*-solaris*
7290 PowerPC Windows NT powerpcle-*-cygwin32
7291 PowerPC Netware powerpc-*-netware*
7292 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7293 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7294 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7295 Apple Macintosh (MPW) host N/A
7297 stuff.c (Program to stuff files into a specially prepared space in kdb)
7298 kdb-start.c (Main loop for the standalone kernel debugger)
7300 Configurations that have been declared obsolete in this release have
7301 been commented out. Unless there is activity to revive these
7302 configurations, the next release of GDB will have their sources
7303 permanently REMOVED.
7305 * REMOVED configurations and files
7307 Altos 3068 m68*-altos-*
7308 Convex c1-*-*, c2-*-*
7310 ARM RISCix arm-*-* (as host)
7314 * GDB has been converted to ISO C.
7316 GDB's source code has been converted to ISO C. In particular, the
7317 sources are fully protoized, and rely on standard headers being
7322 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7324 * The MI enabled by default.
7326 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7327 revised and enabled by default. Packages which use GDB as a debugging
7328 engine behind a UI or another front end are encouraged to switch to
7329 using the GDB/MI interface, instead of the old annotations interface
7330 which is now deprecated.
7332 * Support for debugging Pascal programs.
7334 GDB now includes support for debugging Pascal programs. The following
7335 main features are supported:
7337 - Pascal-specific data types such as sets;
7339 - automatic recognition of Pascal sources based on file-name
7342 - Pascal-style display of data types, variables, and functions;
7344 - a Pascal expression parser.
7346 However, some important features are not yet supported.
7348 - Pascal string operations are not supported at all;
7350 - there are some problems with boolean types;
7352 - Pascal type hexadecimal constants are not supported
7353 because they conflict with the internal variables format;
7355 - support for Pascal objects and classes is not full yet;
7357 - unlike Pascal, GDB is case-sensitive for symbol names.
7359 * Changes in completion.
7361 Commands such as `shell', `run' and `set args', which pass arguments
7362 to inferior programs, now complete on file names, similar to what
7363 users expect at the shell prompt.
7365 Commands which accept locations, such as `disassemble', `print',
7366 `breakpoint', `until', etc. now complete on filenames as well as
7367 program symbols. Thus, if you type "break foob TAB", and the source
7368 files linked into the programs include `foobar.c', that file name will
7369 be one of the candidates for completion. However, file names are not
7370 considered for completion after you typed a colon that delimits a file
7371 name from a name of a function in that file, as in "break foo.c:bar".
7373 `set demangle-style' completes on available demangling styles.
7375 * New platform-independent commands:
7377 It is now possible to define a post-hook for a command as well as a
7378 hook that runs before the command. For more details, see the
7379 documentation of `hookpost' in the GDB manual.
7381 * Changes in GNU/Linux native debugging.
7383 Support for debugging multi-threaded programs has been completely
7384 revised for all platforms except m68k and sparc. You can now debug as
7385 many threads as your system allows you to have.
7387 Attach/detach is supported for multi-threaded programs.
7389 Support for SSE registers was added for x86. This doesn't work for
7390 multi-threaded programs though.
7392 * Changes in MIPS configurations.
7394 Multi-arch support is enabled for all MIPS configurations.
7396 GDB can now be built as native debugger on SGI Irix 6.x systems for
7397 debugging n32 executables. (Debugging 64-bit executables is not yet
7400 * Unified support for hardware watchpoints in all x86 configurations.
7402 Most (if not all) native x86 configurations support hardware-assisted
7403 breakpoints and watchpoints in a unified manner. This support
7404 implements debug register sharing between watchpoints, which allows to
7405 put a virtually infinite number of watchpoints on the same address,
7406 and also supports watching regions up to 16 bytes with several debug
7409 The new maintenance command `maintenance show-debug-regs' toggles
7410 debugging print-outs in functions that insert, remove, and test
7411 watchpoints and hardware breakpoints.
7413 * Changes in the DJGPP native configuration.
7415 New command ``info dos sysinfo'' displays assorted information about
7416 the CPU, OS, memory, and DPMI server.
7418 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7419 display information about segment descriptors stored in GDT, LDT, and
7422 New commands ``info dos pde'' and ``info dos pte'' display entries
7423 from Page Directory and Page Tables (for now works with CWSDPMI only).
7424 New command ``info dos address-pte'' displays the Page Table entry for
7425 a given linear address.
7427 GDB can now pass command lines longer than 126 characters to the
7428 program being debugged (requires an update to the libdbg.a library
7429 which is part of the DJGPP development kit).
7431 DWARF2 debug info is now supported.
7433 It is now possible to `step' and `next' through calls to `longjmp'.
7435 * Changes in documentation.
7437 All GDB documentation was converted to GFDL, the GNU Free
7438 Documentation License.
7440 Tracepoints-related commands are now fully documented in the GDB
7443 TUI, the Text-mode User Interface, is now documented in the manual.
7445 Tracepoints-related commands are now fully documented in the GDB
7448 The "GDB Internals" manual now has an index. It also includes
7449 documentation of `ui_out' functions, GDB coding standards, x86
7450 hardware watchpoints, and memory region attributes.
7452 * GDB's version number moved to ``version.in''
7454 The Makefile variable VERSION has been replaced by the file
7455 ``version.in''. People creating GDB distributions should update the
7456 contents of this file.
7460 GUD support is now a standard part of the EMACS distribution.
7462 *** Changes in GDB 5.0:
7464 * Improved support for debugging FP programs on x86 targets
7466 Unified and much-improved support for debugging floating-point
7467 programs on all x86 targets. In particular, ``info float'' now
7468 displays the FP registers in the same format on all x86 targets, with
7469 greater level of detail.
7471 * Improvements and bugfixes in hardware-assisted watchpoints
7473 It is now possible to watch array elements, struct members, and
7474 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7475 on x86 targets no longer erroneously trigger when the address is
7478 * Improvements in the native DJGPP version of GDB
7480 The distribution now includes all the scripts and auxiliary files
7481 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7482 machines ``out of the box''.
7484 The DJGPP version can now debug programs that use signals. It is
7485 possible to catch signals that happened in the debuggee, deliver
7486 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7487 would kill the program being debugged.) Programs that hook hardware
7488 interrupts (keyboard, timer, etc.) can also be debugged.
7490 It is now possible to debug DJGPP programs that redirect their
7491 standard handles or switch them to raw (as opposed to cooked) mode, or
7492 even close them. The command ``run < foo > bar'' works as expected,
7493 and ``info terminal'' reports useful information about the debuggee's
7494 terminal, including raw/cooked mode, redirection, etc.
7496 The DJGPP version now uses termios functions for console I/O, which
7497 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7500 DOS-style file names with drive letters are now fully supported by
7503 It is now possible to debug DJGPP programs that switch their working
7504 directory. It is also possible to rerun the debuggee any number of
7505 times without restarting GDB; thus, you can use the same setup,
7506 breakpoints, etc. for many debugging sessions.
7508 * New native configurations
7510 ARM GNU/Linux arm*-*-linux*
7511 PowerPC GNU/Linux powerpc-*-linux*
7515 Motorola MCore mcore-*-*
7516 x86 VxWorks i[3456]86-*-vxworks*
7517 PowerPC VxWorks powerpc-*-vxworks*
7518 TI TMS320C80 tic80-*-*
7520 * OBSOLETE configurations
7522 Altos 3068 m68*-altos-*
7523 Convex c1-*-*, c2-*-*
7525 ARM RISCix arm-*-* (as host)
7528 Configurations that have been declared obsolete will be commented out,
7529 but the code will be left in place. If there is no activity to revive
7530 these configurations before the next release of GDB, the sources will
7531 be permanently REMOVED.
7533 * Gould support removed
7535 Support for the Gould PowerNode and NP1 has been removed.
7537 * New features for SVR4
7539 On SVR4 native platforms (such as Solaris), if you attach to a process
7540 without first loading a symbol file, GDB will now attempt to locate and
7541 load symbols from the running process's executable file.
7543 * Many C++ enhancements
7545 C++ support has been greatly improved. Overload resolution now works properly
7546 in almost all cases. RTTI support is on the way.
7548 * Remote targets can connect to a sub-program
7550 A popen(3) style serial-device has been added. This device starts a
7551 sub-process (such as a stand-alone simulator) and then communicates
7552 with that. The sub-program to run is specified using the syntax
7553 ``|<program> <args>'' vis:
7555 (gdb) set remotedebug 1
7556 (gdb) target extended-remote |mn10300-elf-sim program-args
7558 * MIPS 64 remote protocol
7560 A long standing bug in the mips64 remote protocol where by GDB
7561 expected certain 32 bit registers (ex SR) to be transfered as 32
7562 instead of 64 bits has been fixed.
7564 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7565 added to provide backward compatibility with older versions of GDB.
7567 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7569 The command ``set remotebinarydownload'' command has been replaced by
7570 ``set remote X-packet''. Other commands in ``set remote'' family
7571 include ``set remote P-packet''.
7573 * Breakpoint commands accept ranges.
7575 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7576 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7577 ``tracepoint passcount'' also accepts a range of tracepoints.
7579 * ``apropos'' command added.
7581 The ``apropos'' command searches through command names and
7582 documentation strings, printing out matches, making it much easier to
7583 try to find a command that does what you are looking for.
7587 A new machine oriented interface (MI) has been added to GDB. This
7588 interface is designed for debug environments running GDB as a separate
7589 process. This is part of the long term libGDB project. See the
7590 "GDB/MI" chapter of the GDB manual for further information. It can be
7591 enabled by configuring with:
7593 .../configure --enable-gdbmi
7595 *** Changes in GDB-4.18:
7597 * New native configurations
7599 HP-UX 10.20 hppa*-*-hpux10.20
7600 HP-UX 11.x hppa*-*-hpux11.0*
7601 M68K GNU/Linux m68*-*-linux*
7605 Fujitsu FR30 fr30-*-elf*
7606 Intel StrongARM strongarm-*-*
7607 Mitsubishi D30V d30v-*-*
7609 * OBSOLETE configurations
7611 Gould PowerNode, NP1 np1-*-*, pn-*-*
7613 Configurations that have been declared obsolete will be commented out,
7614 but the code will be left in place. If there is no activity to revive
7615 these configurations before the next release of GDB, the sources will
7616 be permanently REMOVED.
7620 As a compatibility experiment, GDB's source files buildsym.h and
7621 buildsym.c have been converted to pure standard C, no longer
7622 containing any K&R compatibility code. We believe that all systems in
7623 use today either come with a standard C compiler, or have a GCC port
7624 available. If this is not true, please report the affected
7625 configuration to bug-gdb@gnu.org immediately. See the README file for
7626 information about getting a standard C compiler if you don't have one
7631 GDB now uses readline 2.2.
7633 * set extension-language
7635 You can now control the mapping between filename extensions and source
7636 languages by using the `set extension-language' command. For instance,
7637 you can ask GDB to treat .c files as C++ by saying
7638 set extension-language .c c++
7639 The command `info extensions' lists all of the recognized extensions
7640 and their associated languages.
7642 * Setting processor type for PowerPC and RS/6000
7644 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7645 you can use the `set processor' command to specify what variant of the
7646 PowerPC family you are debugging. The command
7650 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7651 following PowerPC and RS6000 variants:
7653 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7654 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7656 403GC IBM PowerPC 403GC
7657 505 Motorola PowerPC 505
7658 860 Motorola PowerPC 860 or 850
7659 601 Motorola PowerPC 601
7660 602 Motorola PowerPC 602
7661 603 Motorola/IBM PowerPC 603 or 603e
7662 604 Motorola PowerPC 604 or 604e
7663 750 Motorola/IBM PowerPC 750 or 750
7665 At the moment, this command just tells GDB what to name the
7666 special-purpose processor registers. Since almost all the affected
7667 registers are inaccessible to user-level programs, this command is
7668 only useful for remote debugging in its present form.
7672 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7673 more extensive support for HP-UX. Added features include shared
7674 library support, kernel threads and hardware watchpoints for 11.00,
7675 support for HP's ANSI C and C++ compilers, and a compatibility mode
7676 for xdb and dbx commands.
7680 HP's donation includes the new concept of catchpoints, which is a
7681 generalization of the old catch command. On HP-UX, it is now possible
7682 to catch exec, fork, and vfork, as well as library loading.
7684 This means that the existing catch command has changed; its first
7685 argument now specifies the type of catch to be set up. See the
7686 output of "help catch" for a list of catchpoint types.
7688 * Debugging across forks
7690 On HP-UX, you can choose which process to debug when a fork() happens
7695 HP has donated a curses-based terminal user interface (TUI). To get
7696 it, build with --enable-tui. Although this can be enabled for any
7697 configuration, at present it only works for native HP debugging.
7699 * GDB remote protocol additions
7701 A new protocol packet 'X' that writes binary data is now available.
7702 Default behavior is to try 'X', then drop back to 'M' if the stub
7703 fails to respond. The settable variable `remotebinarydownload'
7704 allows explicit control over the use of 'X'.
7706 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7707 full 64-bit address. The command
7709 set remoteaddresssize 32
7711 can be used to revert to the old behaviour. For existing remote stubs
7712 the change should not be noticed, as the additional address information
7715 In order to assist in debugging stubs, you may use the maintenance
7716 command `packet' to send any text string to the stub. For instance,
7718 maint packet heythere
7720 sends the packet "$heythere#<checksum>". Note that it is very easy to
7721 disrupt a debugging session by sending the wrong packet at the wrong
7724 The compare-sections command allows you to compare section data on the
7725 target to what is in the executable file without uploading or
7726 downloading, by comparing CRC checksums.
7728 * Tracing can collect general expressions
7730 You may now collect general expressions at tracepoints. This requires
7731 further additions to the target-side stub; see tracepoint.c and
7732 doc/agentexpr.texi for further details.
7734 * mask-address variable for Mips
7736 For Mips targets, you may control the zeroing of the upper 32 bits of
7737 a 64-bit address by entering `set mask-address on'. This is mainly
7738 of interest to users of embedded R4xxx and R5xxx processors.
7740 * Higher serial baud rates
7742 GDB's serial code now allows you to specify baud rates 57600, 115200,
7743 230400, and 460800 baud. (Note that your host system may not be able
7744 to achieve all of these rates.)
7748 The i960 configuration now includes an initial implementation of a
7749 builtin simulator, contributed by Jim Wilson.
7752 *** Changes in GDB-4.17:
7754 * New native configurations
7756 Alpha GNU/Linux alpha*-*-linux*
7757 Unixware 2.x i[3456]86-unixware2*
7758 Irix 6.x mips*-sgi-irix6*
7759 PowerPC GNU/Linux powerpc-*-linux*
7760 PowerPC Solaris powerpcle-*-solaris*
7761 Sparc GNU/Linux sparc-*-linux*
7762 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7766 Argonaut Risc Chip (ARC) arc-*-*
7767 Hitachi H8/300S h8300*-*-*
7768 Matsushita MN10200 w/simulator mn10200-*-*
7769 Matsushita MN10300 w/simulator mn10300-*-*
7770 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7771 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7772 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7773 Mitsubishi D10V w/simulator d10v-*-*
7774 Mitsubishi M32R/D w/simulator m32r-*-elf*
7775 Tsqware Sparclet sparclet-*-*
7776 NEC V850 w/simulator v850-*-*
7778 * New debugging protocols
7780 ARM with RDI protocol arm*-*-*
7781 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7782 DDB and LSI variants of PMON protocol mips*-*-*
7783 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7784 PowerPC with SDS protocol powerpc{,le}-*-eabi
7785 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7789 All configurations can now understand and use the DWARF 2 debugging
7790 format. The choice is automatic, if the symbol file contains DWARF 2
7795 GDB now includes basic Java language support. This support is
7796 only useful with Java compilers that produce native machine code.
7798 * solib-absolute-prefix and solib-search-path
7800 For SunOS and SVR4 shared libraries, you may now set the prefix for
7801 loading absolute shared library symbol files, and the search path for
7802 locating non-absolute shared library symbol files.
7804 * Live range splitting
7806 GDB can now effectively debug code for which GCC has performed live
7807 range splitting as part of its optimization. See gdb/doc/LRS for
7808 more details on the expected format of the stabs information.
7812 GDB's support for the GNU Hurd, including thread debugging, has been
7813 updated to work with current versions of the Hurd.
7817 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7818 instruction set. ARM GDB automatically detects when Thumb
7819 instructions are in use, and adjusts disassembly and backtracing
7824 GDB's MIPS target configurations now handle the MIP16 16-bit
7829 GDB now includes support for overlays; if an executable has been
7830 linked such that multiple sections are based at the same address, GDB
7831 will decide which section to use for symbolic info. You can choose to
7832 control the decision manually, using overlay commands, or implement
7833 additional target-side support and use "overlay load-target" to bring
7834 in the overlay mapping. Do "help overlay" for more detail.
7838 The command "info symbol <address>" displays information about
7839 the symbol at the specified address.
7843 The standard remote protocol now includes an extension that allows
7844 asynchronous collection and display of trace data. This requires
7845 extensive support in the target-side debugging stub. Tracing mode
7846 includes a new interaction mode in GDB and new commands: see the
7847 file tracepoint.c for more details.
7851 Configurations for embedded MIPS now include a simulator contributed
7852 by Cygnus Solutions. The simulator supports the instruction sets
7853 of most MIPS variants.
7857 Sparc configurations may now include the ERC32 simulator contributed
7858 by the European Space Agency. The simulator is not built into
7859 Sparc targets by default; configure with --enable-sim to include it.
7863 For target configurations that may include multiple variants of a
7864 basic architecture (such as MIPS and SH), you may now set the
7865 architecture explicitly. "set arch" sets, "info arch" lists
7866 the possible architectures.
7868 *** Changes in GDB-4.16:
7870 * New native configurations
7872 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7873 M68K NetBSD m68k-*-netbsd*
7874 PowerPC AIX 4.x powerpc-*-aix*
7875 PowerPC MacOS powerpc-*-macos*
7876 PowerPC Windows NT powerpcle-*-cygwin32
7877 RS/6000 AIX 4.x rs6000-*-aix4*
7881 ARM with RDP protocol arm-*-*
7882 I960 with MON960 i960-*-coff
7883 MIPS VxWorks mips*-*-vxworks*
7884 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7885 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7887 Matra Sparclet sparclet-*-*
7891 The powerpc-eabi configuration now includes the PSIM simulator,
7892 contributed by Andrew Cagney, with assistance from Mike Meissner.
7893 PSIM is a very elaborate model of the PowerPC, including not only
7894 basic instruction set execution, but also details of execution unit
7895 performance and I/O hardware. See sim/ppc/README for more details.
7899 GDB now works with Solaris 2.5.
7901 * Windows 95/NT native
7903 GDB will now work as a native debugger on Windows 95 and Windows NT.
7904 To build it from source, you must use the "gnu-win32" environment,
7905 which uses a DLL to emulate enough of Unix to run the GNU tools.
7906 Further information, binaries, and sources are available at
7907 ftp.cygnus.com, under pub/gnu-win32.
7909 * dont-repeat command
7911 If a user-defined command includes the command `dont-repeat', then the
7912 command will not be repeated if the user just types return. This is
7913 useful if the command is time-consuming to run, so that accidental
7914 extra keystrokes don't run the same command many times.
7916 * Send break instead of ^C
7918 The standard remote protocol now includes an option to send a break
7919 rather than a ^C to the target in order to interrupt it. By default,
7920 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7922 * Remote protocol timeout
7924 The standard remote protocol includes a new variable `remotetimeout'
7925 that allows you to set the number of seconds before GDB gives up trying
7926 to read from the target. The default value is 2.
7928 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7930 By default GDB will automatically keep track of objects as they are
7931 loaded and unloaded by the dynamic linker. By using the command `set
7932 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7933 when shared library events occur, thus allowing you to set breakpoints
7934 in shared libraries which are explicitly loaded by the inferior.
7936 Note this feature does not work on hpux8. On hpux9 you must link
7937 /usr/lib/end.o into your program. This feature should work
7938 automatically on hpux10.
7940 * Irix 5.x hardware watchpoint support
7942 Irix 5 configurations now support the use of hardware watchpoints.
7944 * Mips protocol "SYN garbage limit"
7946 When debugging a Mips target using the `target mips' protocol, you
7947 may set the number of characters that GDB will ignore by setting
7948 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7949 every character. The default value is 1050.
7951 * Recording and replaying remote debug sessions
7953 If you set `remotelogfile' to the name of a file, gdb will write to it
7954 a recording of a remote debug session. This recording may then be
7955 replayed back to gdb using "gdbreplay". See gdbserver/README for
7956 details. This is useful when you have a problem with GDB while doing
7957 remote debugging; you can make a recording of the session and send it
7958 to someone else, who can then recreate the problem.
7960 * Speedups for remote debugging
7962 GDB includes speedups for downloading and stepping MIPS systems using
7963 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7964 and more efficient S-record downloading.
7966 * Memory use reductions and statistics collection
7968 GDB now uses less memory and reports statistics about memory usage.
7969 Try the `maint print statistics' command, for example.
7971 *** Changes in GDB-4.15:
7973 * Psymtabs for XCOFF
7975 The symbol reader for AIX GDB now uses partial symbol tables. This
7976 can greatly improve startup time, especially for large executables.
7978 * Remote targets use caching
7980 Remote targets now use a data cache to speed up communication with the
7981 remote side. The data cache could lead to incorrect results because
7982 it doesn't know about volatile variables, thus making it impossible to
7983 debug targets which use memory mapped I/O devices. `set remotecache
7984 off' turns the data cache off.
7986 * Remote targets may have threads
7988 The standard remote protocol now includes support for multiple threads
7989 in the target system, using new protocol commands 'H' and 'T'. See
7990 gdb/remote.c for details.
7994 If GDB is configured with `--enable-netrom', then it will include
7995 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7996 acts as though it is a bank of ROM on the target board, but you can
7997 write into it over the network. GDB's support consists only of
7998 support for fast loading into the emulated ROM; to debug, you must use
7999 another protocol, such as standard remote protocol. The usual
8000 sequence is something like
8002 target nrom <netrom-hostname>
8004 target remote <netrom-hostname>:1235
8008 GDB now includes support for the Apple Macintosh, as a host only. It
8009 may be run as either an MPW tool or as a standalone application, and
8010 it can debug through the serial port. All the usual GDB commands are
8011 available, but to the target command, you must supply "serial" as the
8012 device type instead of "/dev/ttyXX". See mpw-README in the main
8013 directory for more information on how to build. The MPW configuration
8014 scripts */mpw-config.in support only a few targets, and only the
8015 mips-idt-ecoff target has been tested.
8019 GDB configuration now uses autoconf. This is not user-visible,
8020 but does simplify configuration and building.
8024 GDB now supports hpux10.
8026 *** Changes in GDB-4.14:
8028 * New native configurations
8030 x86 FreeBSD i[345]86-*-freebsd
8031 x86 NetBSD i[345]86-*-netbsd
8032 NS32k NetBSD ns32k-*-netbsd
8033 Sparc NetBSD sparc-*-netbsd
8037 A29K VxWorks a29k-*-vxworks
8038 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
8039 CPU32 EST-300 emulator m68*-*-est*
8040 PowerPC ELF powerpc-*-elf
8043 * Alpha OSF/1 support for procfs
8045 GDB now supports procfs under OSF/1-2.x and higher, which makes it
8046 possible to attach to running processes. As the mounting of the /proc
8047 filesystem is optional on the Alpha, GDB automatically determines
8048 the availability of /proc during startup. This can lead to problems
8049 if /proc is unmounted after GDB has been started.
8051 * Arguments to user-defined commands
8053 User commands may accept up to 10 arguments separated by whitespace.
8054 Arguments are accessed within the user command via $arg0..$arg9. A
8057 print $arg0 + $arg1 + $arg2
8059 To execute the command use:
8062 Defines the command "adder" which prints the sum of its three arguments.
8063 Note the arguments are text substitutions, so they may reference variables,
8064 use complex expressions, or even perform inferior function calls.
8066 * New `if' and `while' commands
8068 This makes it possible to write more sophisticated user-defined
8069 commands. Both commands take a single argument, which is the
8070 expression to evaluate, and must be followed by the commands to
8071 execute, one per line, if the expression is nonzero, the list being
8072 terminated by the word `end'. The `if' command list may include an
8073 `else' word, which causes the following commands to be executed only
8074 if the expression is zero.
8076 * Fortran source language mode
8078 GDB now includes partial support for Fortran 77. It will recognize
8079 Fortran programs and can evaluate a subset of Fortran expressions, but
8080 variables and functions may not be handled correctly. GDB will work
8081 with G77, but does not yet know much about symbols emitted by other
8084 * Better HPUX support
8086 Most debugging facilities now work on dynamic executables for HPPAs
8087 running hpux9 or later. You can attach to running dynamically linked
8088 processes, but by default the dynamic libraries will be read-only, so
8089 for instance you won't be able to put breakpoints in them. To change
8090 that behavior do the following before running the program:
8096 This will cause the libraries to be mapped private and read-write.
8097 To revert to the normal behavior, do this:
8103 You cannot set breakpoints or examine data in the library until after
8104 the library is loaded if the function/data symbols do not have
8107 GDB can now also read debug symbols produced by the HP C compiler on
8108 HPPAs (sorry, no C++, Fortran or 68k support).
8110 * Target byte order now dynamically selectable
8112 You can choose which byte order to use with a target system, via the
8113 commands "set endian big" and "set endian little", and you can see the
8114 current setting by using "show endian". You can also give the command
8115 "set endian auto", in which case GDB will use the byte order
8116 associated with the executable. Currently, only embedded MIPS
8117 configurations support dynamic selection of target byte order.
8119 * New DOS host serial code
8121 This version uses DPMI interrupts to handle buffered I/O, so you
8122 no longer need to run asynctsr when debugging boards connected to
8125 *** Changes in GDB-4.13:
8127 * New "complete" command
8129 This lists all the possible completions for the rest of the line, if it
8130 were to be given as a command itself. This is intended for use by emacs.
8132 * Trailing space optional in prompt
8134 "set prompt" no longer adds a space for you after the prompt you set. This
8135 allows you to set a prompt which ends in a space or one that does not.
8137 * Breakpoint hit counts
8139 "info break" now displays a count of the number of times the breakpoint
8140 has been hit. This is especially useful in conjunction with "ignore"; you
8141 can ignore a large number of breakpoint hits, look at the breakpoint info
8142 to see how many times the breakpoint was hit, then run again, ignoring one
8143 less than that number, and this will get you quickly to the last hit of
8146 * Ability to stop printing at NULL character
8148 "set print null-stop" will cause GDB to stop printing the characters of
8149 an array when the first NULL is encountered. This is useful when large
8150 arrays actually contain only short strings.
8152 * Shared library breakpoints
8154 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8155 breakpoints in shared libraries before the executable is run.
8157 * Hardware watchpoints
8159 There is a new hardware breakpoint for the watch command for sparclite
8160 targets. See gdb/sparclite/hw_breakpoint.note.
8162 Hardware watchpoints are also now supported under GNU/Linux.
8166 Annotations have been added. These are for use with graphical interfaces,
8167 and are still experimental. Currently only gdba.el uses these.
8169 * Improved Irix 5 support
8171 GDB now works properly with Irix 5.2.
8173 * Improved HPPA support
8175 GDB now works properly with the latest GCC and GAS.
8177 * New native configurations
8179 Sequent PTX4 i[34]86-sequent-ptx4
8180 HPPA running OSF/1 hppa*-*-osf*
8181 Atari TT running SVR4 m68*-*-sysv4*
8182 RS/6000 LynxOS rs6000-*-lynxos*
8186 OS/9000 i[34]86-*-os9k
8187 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8190 * Hitachi SH7000 and E7000-PC ICE support
8192 There is now support for communicating with the Hitachi E7000-PC ICE.
8193 This is available automatically when GDB is configured for the SH.
8197 As usual, a variety of small fixes and improvements, both generic
8198 and configuration-specific. See the ChangeLog for more detail.
8200 *** Changes in GDB-4.12:
8202 * Irix 5 is now supported
8206 GDB-4.12 on the HPPA has a number of changes which make it unable
8207 to debug the output from the currently released versions of GCC and
8208 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8209 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8210 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8213 *** Changes in GDB-4.11:
8215 * User visible changes:
8219 The "set remotedebug" option is now consistent between the mips remote
8220 target, remote targets using the gdb-specific protocol, UDI (AMD's
8221 debug protocol for the 29k) and the 88k bug monitor. It is now an
8222 integer specifying a debug level (normally 0 or 1, but 2 means more
8223 debugging info for the mips target).
8225 * DEC Alpha native support
8227 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8228 debug info, but GDB works fairly well with the DEC compiler and should
8229 work with a future GCC release. See the README file for a few
8230 Alpha-specific notes.
8232 * Preliminary thread implementation
8234 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8236 * LynxOS native and target support for 386
8238 This release has been hosted on LynxOS 2.2, and also can be configured
8239 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8242 * Improvements in C++ mangling/demangling.
8244 This release has much better g++ debugging, specifically in name
8245 mangling/demangling, virtual function calls, print virtual table,
8246 call methods, ...etc.
8248 *** Changes in GDB-4.10:
8250 * User visible changes:
8252 Remote debugging using the GDB-specific (`target remote') protocol now
8253 supports the `load' command. This is only useful if you have some
8254 other way of getting the stub to the target system, and you can put it
8255 somewhere in memory where it won't get clobbered by the download.
8257 Filename completion now works.
8259 When run under emacs mode, the "info line" command now causes the
8260 arrow to point to the line specified. Also, "info line" prints
8261 addresses in symbolic form (as well as hex).
8263 All vxworks based targets now support a user settable option, called
8264 vxworks-timeout. This option represents the number of seconds gdb
8265 should wait for responses to rpc's. You might want to use this if
8266 your vxworks target is, perhaps, a slow software simulator or happens
8267 to be on the far side of a thin network line.
8271 This release contains support for using a DEC alpha as a GDB host for
8272 cross debugging. Native alpha debugging is not supported yet.
8275 *** Changes in GDB-4.9:
8279 This is the first GDB release which is accompanied by a matching testsuite.
8280 The testsuite requires installation of dejagnu, which should be available
8281 via ftp from most sites that carry GNU software.
8285 'Cfront' style demangling has had its name changed to 'ARM' style, to
8286 emphasize that it was written from the specifications in the C++ Annotated
8287 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8288 disclaimers, it still generated too much confusion with users attempting to
8289 use gdb with AT&T cfront.
8293 GDB now uses a standard remote interface to a simulator library.
8294 So far, the library contains simulators for the Zilog Z8001/2, the
8295 Hitachi H8/300, H8/500 and Super-H.
8297 * New targets supported
8299 H8/300 simulator h8300-hitachi-hms or h8300hms
8300 H8/500 simulator h8500-hitachi-hms or h8500hms
8301 SH simulator sh-hitachi-hms or sh
8302 Z8000 simulator z8k-zilog-none or z8ksim
8303 IDT MIPS board over serial line mips-idt-ecoff
8305 Cross-debugging to GO32 targets is supported. It requires a custom
8306 version of the i386-stub.c module which is integrated with the
8307 GO32 memory extender.
8309 * New remote protocols
8311 MIPS remote debugging protocol.
8313 * New source languages supported
8315 This version includes preliminary support for Chill, a Pascal like language
8316 used by telecommunications companies. Chill support is also being integrated
8317 into the GNU compiler, but we don't know when it will be publically available.
8320 *** Changes in GDB-4.8:
8322 * HP Precision Architecture supported
8324 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8325 version of this support was available as a set of patches from the
8326 University of Utah. GDB does not support debugging of programs
8327 compiled with the HP compiler, because HP will not document their file
8328 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8329 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8331 Many problems in the preliminary version have been fixed.
8333 * Faster and better demangling
8335 We have improved template demangling and fixed numerous bugs in the GNU style
8336 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8337 character types (wchar_t) are now supported. Demangling of each symbol is now
8338 only done once, and is cached when the symbol table for a file is read in.
8339 This results in a small increase in memory usage for C programs, a moderate
8340 increase in memory usage for C++ programs, and a fantastic speedup in
8343 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8344 from the specifications in the Annotated Reference Manual, which AT&T's
8345 compiler does not actually implement.
8347 * G++ multiple inheritance compiler problem
8349 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8350 inheritance lattices was reworked to properly discover ambiguities. We
8351 recently found an example which causes this new algorithm to fail in a
8352 very subtle way, producing bad debug information for those classes.
8353 The file 'gcc.patch' (in this directory) can be applied to gcc to
8354 circumvent the problem. A future GCC release will contain a complete
8357 The previous G++ debug info problem (mentioned below for the gdb-4.7
8358 release) is fixed in gcc version 2.3.2.
8360 * Improved configure script
8362 The `configure' script will now attempt to guess your system type if
8363 you don't supply a host system type. The old scheme of supplying a
8364 host system triplet is preferable over using this. All the magic is
8365 done in the new `config.guess' script. Examine it for details.
8367 We have also brought our configure script much more in line with the FSF's
8368 version. It now supports the --with-xxx options. In particular,
8369 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8370 The resulting GDB will not be able to read arbitrary object file formats --
8371 only the format ``expected'' to be used on the configured target system.
8372 We hope to make this the default in a future release.
8374 * Documentation improvements
8376 There's new internal documentation on how to modify GDB, and how to
8377 produce clean changes to the code. We implore people to read it
8378 before submitting changes.
8380 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8381 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8382 `info' files are also provided. To build `info' files from scratch,
8383 you will need the latest `makeinfo' release, which will be available in
8384 a future texinfo-X.Y release.
8386 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8387 We're not sure exactly which versions have this problem, but it has
8388 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8389 or better. If that isn't possible, there is a patch in
8390 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8391 around this problem.
8395 GDB now supports array constants that can be used in expressions typed in by
8396 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8397 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8400 The new directory `gdb/sparclite' contains a program that demonstrates
8401 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8403 * New native hosts supported
8405 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8406 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8408 * New targets supported
8410 AMD 29k family via UDI a29k-amd-udi or udi29k
8412 * New file formats supported
8414 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8415 HPUX core files, and SCO 3.2v2 core files.
8419 Attaching to processes now works again; thanks for the many bug reports.
8421 We have also stomped on a bunch of core dumps caused by
8422 printf_filtered("%s") problems.
8424 We eliminated a copyright problem on the rpc and ptrace header files
8425 for VxWorks, which was discovered at the last minute during the 4.7
8426 release. You should now be able to build a VxWorks GDB.
8428 You can now interrupt gdb while an attached process is running. This
8429 will cause the attached process to stop, and give control back to GDB.
8431 We fixed problems caused by using too many file descriptors
8432 for reading symbols from object files and libraries. This was
8433 especially a problem for programs that used many (~100) shared
8436 The `step' command now only enters a subroutine if there is line number
8437 information for the subroutine. Otherwise it acts like the `next'
8438 command. Previously, `step' would enter subroutines if there was
8439 any debugging information about the routine. This avoids problems
8440 when using `cc -g1' on MIPS machines.
8442 * Internal improvements
8444 GDB's internal interfaces have been improved to make it easier to support
8445 debugging of multiple languages in the future.
8447 GDB now uses a common structure for symbol information internally.
8448 Minimal symbols (derived from linkage symbols in object files), partial
8449 symbols (from a quick scan of debug information), and full symbols
8450 contain a common subset of information, making it easier to write
8451 shared code that handles any of them.
8453 * New command line options
8455 We now accept --silent as an alias for --quiet.
8459 The memory-mapped-malloc library is now licensed under the GNU Library
8460 General Public License.
8462 *** Changes in GDB-4.7:
8464 * Host/native/target split
8466 GDB has had some major internal surgery to untangle the support for
8467 hosts and remote targets. Now, when you configure GDB for a remote
8468 target, it will no longer load in all of the support for debugging
8469 local programs on the host. When fully completed and tested, this will
8470 ensure that arbitrary host/target combinations are possible.
8472 The primary conceptual shift is to separate the non-portable code in
8473 GDB into three categories. Host specific code is required any time GDB
8474 is compiled on that host, regardless of the target. Target specific
8475 code relates to the peculiarities of the target, but can be compiled on
8476 any host. Native specific code is everything else: it can only be
8477 built when the host and target are the same system. Child process
8478 handling and core file support are two common `native' examples.
8480 GDB's use of /proc for controlling Unix child processes is now cleaner.
8481 It has been split out into a single module under the `target_ops' vector,
8482 plus two native-dependent functions for each system that uses /proc.
8484 * New hosts supported
8486 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8487 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8488 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8490 * New targets supported
8492 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8493 68030 and CPU32 m68030-*-*, m68332-*-*
8495 * New native hosts supported
8497 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8498 (386bsd is not well tested yet)
8499 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8501 * New file formats supported
8503 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8504 supports reading of `a.out.adobe' object files, which are an a.out
8505 format extended with minimal information about multiple sections.
8509 `show copying' is the same as the old `info copying'.
8510 `show warranty' is the same as `info warrantee'.
8511 These were renamed for consistency. The old commands continue to work.
8513 `info handle' is a new alias for `info signals'.
8515 You can now define pre-command hooks, which attach arbitrary command
8516 scripts to any command. The commands in the hook will be executed
8517 prior to the user's command. You can also create a hook which will be
8518 executed whenever the program stops. See gdb.texinfo.
8522 We now deal with Cfront style name mangling, and can even extract type
8523 info from mangled symbols. GDB can automatically figure out which
8524 symbol mangling style your C++ compiler uses.
8526 Calling of methods and virtual functions has been improved as well.
8530 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8531 fixed. This was due to mishandling of the extra N_SO stabs output
8534 We also finally got Ultrix 4.2 running in house, and fixed core file
8535 support, with help from a dozen people on the net.
8537 John M. Farrell discovered that the reason that single-stepping was so
8538 slow on all of the Mips based platforms (primarily SGI and DEC) was
8539 that we were trying to demangle and lookup a symbol used for internal
8540 purposes on every instruction that was being stepped through. Changing
8541 the name of that symbol so that it couldn't be mistaken for a C++
8542 mangled symbol sped things up a great deal.
8544 Rich Pixley sped up symbol lookups in general by getting much smarter
8545 about when C++ symbol mangling is necessary. This should make symbol
8546 completion (TAB on the command line) much faster. It's not as fast as
8547 we'd like, but it's significantly faster than gdb-4.6.
8551 A new user controllable variable 'call_scratch_address' can
8552 specify the location of a scratch area to be used when GDB
8553 calls a function in the target. This is necessary because the
8554 usual method of putting the scratch area on the stack does not work
8555 in systems that have separate instruction and data spaces.
8557 We integrated changes to support the 29k UDI (Universal Debugger
8558 Interface), but discovered at the last minute that we didn't have all
8559 of the appropriate copyright paperwork. We are working with AMD to
8560 resolve this, and hope to have it available soon.
8564 We have sped up the remote serial line protocol, especially for targets
8565 with lots of registers. It now supports a new `expedited status' ('T')
8566 message which can be used in place of the existing 'S' status message.
8567 This allows the remote stub to send only the registers that GDB
8568 needs to make a quick decision about single-stepping or conditional
8569 breakpoints, eliminating the need to fetch the entire register set for
8570 each instruction being stepped through.
8572 The GDB remote serial protocol now implements a write-through cache for
8573 registers, only re-reading the registers if the target has run.
8575 There is also a new remote serial stub for SPARC processors. You can
8576 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8577 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8578 processor with a serial port.
8582 Configure.in files have become much easier to read and modify. A new
8583 `table driven' format makes it more obvious what configurations are
8584 supported, and what files each one uses.
8588 There is a new opcodes library which will eventually contain all of the
8589 disassembly routines and opcode tables. At present, it only contains
8590 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8591 disassembler (binutils/objdump) to share these routines.
8593 The libiberty library is now copylefted under the GNU Library General
8594 Public License. This allows more liberal use, and was done so libg++
8595 can use it. This makes no difference to GDB, since the Library License
8596 grants all the rights from the General Public License.
8600 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8601 reference to the stabs symbol info used by the debugger. It is (as far
8602 as we know) the only published document on this fascinating topic. We
8603 encourage you to read it, compare it to the stabs information on your
8604 system, and send improvements on the document in general (to
8605 bug-gdb@prep.ai.mit.edu).
8607 And, of course, many bugs have been fixed.
8610 *** Changes in GDB-4.6:
8612 * Better support for C++ function names
8614 GDB now accepts as input the "demangled form" of C++ overloaded function
8615 names and member function names, and can do command completion on such names
8616 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8617 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8618 Make use of command completion, it is your friend.
8620 GDB also now accepts a variety of C++ mangled symbol formats. They are
8621 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8622 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8623 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8624 for the list of formats.
8626 * G++ symbol mangling problem
8628 Recent versions of gcc have a bug in how they emit debugging information for
8629 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8630 directory) can be applied to gcc to fix the problem. Alternatively, if you
8631 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8632 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8633 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8636 * New 'maintenance' command
8638 All of the commands related to hacking GDB internals have been moved out of
8639 the main command set, and now live behind the 'maintenance' command. This
8640 can also be abbreviated as 'mt'. The following changes were made:
8642 dump-me -> maintenance dump-me
8643 info all-breakpoints -> maintenance info breakpoints
8644 printmsyms -> maintenance print msyms
8645 printobjfiles -> maintenance print objfiles
8646 printpsyms -> maintenance print psymbols
8647 printsyms -> maintenance print symbols
8649 The following commands are new:
8651 maintenance demangle Call internal GDB demangler routine to
8652 demangle a C++ link name and prints the result.
8653 maintenance print type Print a type chain for a given symbol
8655 * Change to .gdbinit file processing
8657 We now read the $HOME/.gdbinit file before processing the argv arguments
8658 (e.g. reading symbol files or core files). This allows global parameters to
8659 be set, which will apply during the symbol reading. The ./.gdbinit is still
8660 read after argv processing.
8662 * New hosts supported
8664 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8666 GNU/Linux support i386-unknown-linux or linux
8668 We are also including code to support the HP/PA running BSD and HPUX. This
8669 is almost guaranteed not to work, as we didn't have time to test or build it
8670 for this release. We are including it so that the more adventurous (or
8671 masochistic) of you can play with it. We also had major problems with the
8672 fact that the compiler that we got from HP doesn't support the -g option.
8675 * New targets supported
8677 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8679 * More smarts about finding #include files
8681 GDB now remembers the compilation directory for all include files, and for
8682 all files from which C is generated (like yacc and lex sources). This
8683 greatly improves GDB's ability to find yacc/lex sources, and include files,
8684 especially if you are debugging your program from a directory different from
8685 the one that contains your sources.
8687 We also fixed a bug which caused difficulty with listing and setting
8688 breakpoints in include files which contain C code. (In the past, you had to
8689 try twice in order to list an include file that you hadn't looked at before.)
8691 * Interesting infernals change
8693 GDB now deals with arbitrary numbers of sections, where the symbols for each
8694 section must be relocated relative to that section's landing place in the
8695 target's address space. This work was needed to support ELF with embedded
8696 stabs used by Solaris-2.0.
8698 * Bug fixes (of course!)
8700 There have been loads of fixes for the following things:
8701 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8702 i960, stabs, DOS(GO32), procfs, etc...
8704 See the ChangeLog for details.
8706 *** Changes in GDB-4.5:
8708 * New machines supported (host and target)
8710 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8712 SGI Irix-4.x mips-sgi-irix4 or iris4
8714 * New malloc package
8716 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8717 Mmalloc is capable of handling multiple heaps of memory. It is also
8718 capable of saving a heap to a file, and then mapping it back in later.
8719 This can be used to greatly speedup the startup of GDB by using a
8720 pre-parsed symbol table which lives in a mmalloc managed heap. For
8721 more details, please read mmalloc/mmalloc.texi.
8725 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8726 'help info proc' for details.
8728 * MIPS ecoff symbol table format
8730 The code that reads MIPS symbol table format is now supported on all hosts.
8731 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8734 * File name changes for MS-DOS
8736 Many files in the config directories have been renamed to make it easier to
8737 support GDB on MS-DOSe systems (which have very restrictive file name
8738 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8739 environment) is close to working but has some remaining problems. Note
8740 that debugging of DOS programs is not supported, due to limitations
8741 in the ``operating system'', but it can be used to host cross-debugging.
8743 * Cross byte order fixes
8745 Many fixes have been made to support cross debugging of Sparc and MIPS
8746 targets from hosts whose byte order differs.
8748 * New -mapped and -readnow options
8750 If memory-mapped files are available on your system through the 'mmap'
8751 system call, you can use the -mapped option on the `file' or
8752 `symbol-file' commands to cause GDB to write the symbols from your
8753 program into a reusable file. If the program you are debugging is
8754 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8755 Future GDB debugging sessions will notice the presence of this file,
8756 and will quickly map in symbol information from it, rather than reading
8757 the symbol table from the executable program. Using the '-mapped'
8758 option in a GDB `file' or `symbol-file' command has the same effect as
8759 starting GDB with the '-mapped' command-line option.
8761 You can cause GDB to read the entire symbol table immediately by using
8762 the '-readnow' option with any of the commands that load symbol table
8763 information (or on the GDB command line). This makes the command
8764 slower, but makes future operations faster.
8766 The -mapped and -readnow options are typically combined in order to
8767 build a `fred.syms' file that contains complete symbol information.
8768 A simple GDB invocation to do nothing but build a `.syms' file for future
8771 gdb -batch -nx -mapped -readnow programname
8773 The `.syms' file is specific to the host machine on which GDB is run.
8774 It holds an exact image of GDB's internal symbol table. It cannot be
8775 shared across multiple host platforms.
8777 * longjmp() handling
8779 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8780 siglongjmp() without losing control. This feature has not yet been ported to
8781 all systems. It currently works on many 386 platforms, all MIPS-based
8782 platforms (SGI, DECstation, etc), and Sun3/4.
8786 Preliminary work has been put in to support the new Solaris OS from Sun. At
8787 this time, it can control and debug processes, but it is not capable of
8792 As always, many many bug fixes. The major areas were with g++, and mipsread.
8793 People using the MIPS-based platforms should experience fewer mysterious
8794 crashes and trashed symbol tables.
8796 *** Changes in GDB-4.4:
8798 * New machines supported (host and target)
8800 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8802 BSD Reno on Vax vax-dec-bsd
8803 Ultrix on Vax vax-dec-ultrix
8805 * New machines supported (target)
8807 AMD 29000 embedded, using EBMON a29k-none-none
8811 GDB continues to improve its handling of C++. `References' work better.
8812 The demangler has also been improved, and now deals with symbols mangled as
8813 per the Annotated C++ Reference Guide.
8815 GDB also now handles `stabs' symbol information embedded in MIPS
8816 `ecoff' symbol tables. Since the ecoff format was not easily
8817 extensible to handle new languages such as C++, this appeared to be a
8818 good way to put C++ debugging info into MIPS binaries. This option
8819 will be supported in the GNU C compiler, version 2, when it is
8822 * New features for SVR4
8824 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8825 shared libraries. Debugging dynamically linked programs should present
8826 only minor differences from debugging statically linked programs.
8828 The `info proc' command will print out information about any process
8829 on an SVR4 system (including the one you are debugging). At the moment,
8830 it prints the address mappings of the process.
8832 If you bring up GDB on another SVR4 system, please send mail to
8833 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8835 * Better dynamic linking support in SunOS
8837 Reading symbols from shared libraries which contain debugging symbols
8838 now works properly. However, there remain issues such as automatic
8839 skipping of `transfer vector' code during function calls, which
8840 make it harder to debug code in a shared library, than to debug the
8841 same code linked statically.
8845 GDB is now using the latest `getopt' routines from the FSF. This
8846 version accepts the -- prefix for options with long names. GDB will
8847 continue to accept the old forms (-option and +option) as well.
8848 Various single letter abbreviations for options have been explicity
8849 added to the option table so that they won't get overshadowed in the
8850 future by other options that begin with the same letter.
8854 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8855 Many assorted bugs have been handled. Many more remain to be handled.
8856 See the various ChangeLog files (primarily in gdb and bfd) for details.
8859 *** Changes in GDB-4.3:
8861 * New machines supported (host and target)
8863 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8864 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8865 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8867 * Almost SCO Unix support
8869 We had hoped to support:
8870 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8871 (except for core file support), but we discovered very late in the release
8872 that it has problems with process groups that render gdb unusable. Sorry
8873 about that. I encourage people to fix it and post the fixes.
8875 * Preliminary ELF and DWARF support
8877 GDB can read ELF object files on System V Release 4, and can handle
8878 debugging records for C, in DWARF format, in ELF files. This support
8879 is preliminary. If you bring up GDB on another SVR4 system, please
8880 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8885 GDB now uses the latest `readline' library. One user-visible change
8886 is that two tabs will list possible command completions, which previously
8887 required typing M-? (meta-question mark, or ESC ?).
8891 The `stepi' bug that many of you noticed has been squashed.
8892 Many bugs in C++ have been handled. Many more remain to be handled.
8893 See the various ChangeLog files (primarily in gdb and bfd) for details.
8895 * State of the MIPS world (in case you wondered):
8897 GDB can understand the symbol tables emitted by the compilers
8898 supplied by most vendors of MIPS-based machines, including DEC. These
8899 symbol tables are in a format that essentially nobody else uses.
8901 Some versions of gcc come with an assembler post-processor called
8902 mips-tfile. This program is required if you want to do source-level
8903 debugging of gcc-compiled programs. I believe FSF does not ship
8904 mips-tfile with gcc version 1, but it will eventually come with gcc
8907 Debugging of g++ output remains a problem. g++ version 1.xx does not
8908 really support it at all. (If you're lucky, you should be able to get
8909 line numbers and stack traces to work, but no parameters or local
8910 variables.) With some work it should be possible to improve the
8913 When gcc version 2 is released, you will have somewhat better luck.
8914 However, even then you will get confusing results for inheritance and
8917 We will eventually provide full debugging of g++ output on
8918 DECstations. This will probably involve some kind of stabs-in-ecoff
8919 encapulation, but the details have not been worked out yet.
8922 *** Changes in GDB-4.2:
8924 * Improved configuration
8926 Only one copy of `configure' exists now, and it is not self-modifying.
8927 Porting BFD is simpler.
8931 The `step' and `next' commands now only stop at the first instruction
8932 of a source line. This prevents the multiple stops that used to occur
8933 in switch statements, for-loops, etc. `Step' continues to stop if a
8934 function that has debugging information is called within the line.
8938 Lots of small bugs fixed. More remain.
8940 * New host supported (not target)
8942 Intel 386 PC clone running Mach i386-none-mach
8945 *** Changes in GDB-4.1:
8947 * Multiple source language support
8949 GDB now has internal scaffolding to handle several source languages.
8950 It determines the type of each source file from its filename extension,
8951 and will switch expression parsing and number formatting to match the
8952 language of the function in the currently selected stack frame.
8953 You can also specifically set the language to be used, with
8954 `set language c' or `set language modula-2'.
8958 GDB now has preliminary support for the GNU Modula-2 compiler,
8959 currently under development at the State University of New York at
8960 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8961 continue through the fall of 1991 and into 1992.
8963 Other Modula-2 compilers are currently not supported, and attempting to
8964 debug programs compiled with them will likely result in an error as the
8965 symbol table is read. Feel free to work on it, though!
8967 There are hooks in GDB for strict type checking and range checking,
8968 in the `Modula-2 philosophy', but they do not currently work.
8972 GDB can now write to executable and core files (e.g. patch
8973 a variable's value). You must turn this switch on, specify
8974 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8975 by assigning a new value to a variable. Modifications take
8978 * Automatic SunOS shared library reading
8980 When you run your program, GDB automatically determines where its
8981 shared libraries (if any) have been loaded, and reads their symbols.
8982 The `share' command is no longer needed. This also works when
8983 examining core files.
8987 You can specify the number of lines that the `list' command shows.
8990 * New machines supported (host and target)
8992 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8993 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8994 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8996 * New hosts supported (not targets)
8998 IBM RT/PC: romp-ibm-aix or rtpc
9000 * New targets supported (not hosts)
9002 AMD 29000 embedded with COFF a29k-none-coff
9003 AMD 29000 embedded with a.out a29k-none-aout
9004 Ultracomputer remote kernel debug a29k-nyu-kern
9006 * New remote interfaces
9012 *** Changes in GDB-4.0:
9016 Wide output is wrapped at good places to make the output more readable.
9018 Gdb now supports cross-debugging from a host machine of one type to a
9019 target machine of another type. Communication with the target system
9020 is over serial lines. The ``target'' command handles connecting to the
9021 remote system; the ``load'' command will download a program into the
9022 remote system. Serial stubs for the m68k and i386 are provided. Gdb
9023 also supports debugging of realtime processes running under VxWorks,
9024 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
9025 stub on the target system.
9027 New CPUs supported include the AMD 29000 and Intel 960.
9029 GDB now reads object files and symbol tables via a ``binary file''
9030 library, which allows a single copy of GDB to debug programs of multiple
9031 object file types such as a.out and coff.
9033 There is now a GDB reference card in "doc/refcard.tex". (Make targets
9034 refcard.dvi and refcard.ps are available to format it).
9037 * Control-Variable user interface simplified
9039 All variables that control the operation of the debugger can be set
9040 by the ``set'' command, and displayed by the ``show'' command.
9042 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
9043 ``Show prompt'' produces the response:
9044 Gdb's prompt is new-gdb=>.
9046 What follows are the NEW set commands. The command ``help set'' will
9047 print a complete list of old and new set commands. ``help set FOO''
9048 will give a longer description of the variable FOO. ``show'' will show
9049 all of the variable descriptions and their current settings.
9051 confirm on/off: Enables warning questions for operations that are
9052 hard to recover from, e.g. rerunning the program while
9053 it is already running. Default is ON.
9055 editing on/off: Enables EMACS style command line editing
9056 of input. Previous lines can be recalled with
9057 control-P, the current line can be edited with control-B,
9058 you can search for commands with control-R, etc.
9061 history filename NAME: NAME is where the gdb command history
9062 will be stored. The default is .gdb_history,
9063 or the value of the environment variable
9066 history size N: The size, in commands, of the command history. The
9067 default is 256, or the value of the environment variable
9070 history save on/off: If this value is set to ON, the history file will
9071 be saved after exiting gdb. If set to OFF, the
9072 file will not be saved. The default is OFF.
9074 history expansion on/off: If this value is set to ON, then csh-like
9075 history expansion will be performed on
9076 command line input. The default is OFF.
9078 radix N: Sets the default radix for input and output. It can be set
9079 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9080 in the current radix, so "set radix 10" is always a no-op.
9082 height N: This integer value is the number of lines on a page. Default
9083 is 24, the current `stty rows'' setting, or the ``li#''
9084 setting from the termcap entry matching the environment
9087 width N: This integer value is the number of characters on a line.
9088 Default is 80, the current `stty cols'' setting, or the ``co#''
9089 setting from the termcap entry matching the environment
9092 Note: ``set screensize'' is obsolete. Use ``set height'' and
9093 ``set width'' instead.
9095 print address on/off: Print memory addresses in various command displays,
9096 such as stack traces and structure values. Gdb looks
9097 more ``symbolic'' if you turn this off; it looks more
9098 ``machine level'' with it on. Default is ON.
9100 print array on/off: Prettyprint arrays. New convenient format! Default
9103 print demangle on/off: Print C++ symbols in "source" form if on,
9106 print asm-demangle on/off: Same, for assembler level printouts
9109 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9112 * Support for Epoch Environment.
9114 The epoch environment is a version of Emacs v18 with windowing. One
9115 new command, ``inspect'', is identical to ``print'', except that if you
9116 are running in the epoch environment, the value is printed in its own
9120 * Support for Shared Libraries
9122 GDB can now debug programs and core files that use SunOS shared libraries.
9123 Symbols from a shared library cannot be referenced
9124 before the shared library has been linked with the program (this
9125 happens after you type ``run'' and before the function main() is entered).
9126 At any time after this linking (including when examining core files
9127 from dynamically linked programs), gdb reads the symbols from each
9128 shared library when you type the ``sharedlibrary'' command.
9129 It can be abbreviated ``share''.
9131 sharedlibrary REGEXP: Load shared object library symbols for files
9132 matching a unix regular expression. No argument
9133 indicates to load symbols for all shared libraries.
9135 info sharedlibrary: Status of loaded shared libraries.
9140 A watchpoint stops execution of a program whenever the value of an
9141 expression changes. Checking for this slows down execution
9142 tremendously whenever you are in the scope of the expression, but is
9143 quite useful for catching tough ``bit-spreader'' or pointer misuse
9144 problems. Some machines such as the 386 have hardware for doing this
9145 more quickly, and future versions of gdb will use this hardware.
9147 watch EXP: Set a watchpoint (breakpoint) for an expression.
9149 info watchpoints: Information about your watchpoints.
9151 delete N: Deletes watchpoint number N (same as breakpoints).
9152 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9153 enable N: Re-enables watchpoint number N (same as breakpoints).
9156 * C++ multiple inheritance
9158 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9161 * C++ exception handling
9163 Gdb now supports limited C++ exception handling. Besides the existing
9164 ability to breakpoint on an exception handler, gdb can breakpoint on
9165 the raising of an exception (before the stack is peeled back to the
9168 catch FOO: If there is a FOO exception handler in the dynamic scope,
9169 set a breakpoint to catch exceptions which may be raised there.
9170 Multiple exceptions (``catch foo bar baz'') may be caught.
9172 info catch: Lists all exceptions which may be caught in the
9173 current stack frame.
9176 * Minor command changes
9178 The command ``call func (arg, arg, ...)'' now acts like the print
9179 command, except it does not print or save a value if the function's result
9180 is void. This is similar to dbx usage.
9182 The ``up'' and ``down'' commands now always print the frame they end up
9183 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9184 frames without printing.
9186 * New directory command
9188 'dir' now adds directories to the FRONT of the source search path.
9189 The path starts off empty. Source files that contain debug information
9190 about the directory in which they were compiled can be found even
9191 with an empty path; Sun CC and GCC include this information. If GDB can't
9192 find your source file in the current directory, type "dir .".
9194 * Configuring GDB for compilation
9196 For normal use, type ``./configure host''. See README or gdb.texinfo
9199 GDB now handles cross debugging. If you are remotely debugging between
9200 two different machines, type ``./configure host -target=targ''.
9201 Host is the machine where GDB will run; targ is the machine
9202 where the program that you are debugging will run.