1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 14
6 * Building GDB and GDBserver now requires a C++17 compiler.
7 For example, GCC 9 or later.
9 * GDB index now contains information about the main function. This speeds up
10 startup when it is being used for some large binaries.
15 Attempting to use both the 'r' and 'b' flags with the disassemble
16 command will now give an error. Previously the 'b' flag would
17 always override the 'r' flag.
21 ** New function gdb.notify_mi(NAME, DATA), that emits custom
22 GDB/MI async notification.
24 ** New read/write attribute gdb.Value.bytes that contains a bytes
25 object holding the contents of this value.
29 maintenance info linux-lwps
30 List all LWPs under control of the linux-nat target.
34 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
35 includes a new 512 bit lookup table register named ZT0.
37 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
38 a new matrix register named ZA, a new thread register TPIDR2 and a new vector
39 length register SVG (streaming vector granule). GDB also supports tracking
40 ZA state across signal frames.
42 Some features are still under development or are dependent on ABI specs that
43 are still in alpha stage. For example, manual function calls with ZA state
44 don't have any special handling, and tracking of SVG changes based on
45 DWARF information is still not implemented, but there are plans to do so in
48 * GDB now recognizes the NO_COLOR environment variable and disables
49 styling according to the spec. See https://no-color.org/.
50 Styling can be re-enabled with "set style enabled on".
52 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
53 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
56 * GDB now has some support for integer types larger than 64 bits.
58 * Removed targets and native configurations
60 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
61 AIX version is now AIX 7.1.
63 * Multi-target feature configuration
65 GDB now supports the individual configuration of remote targets' feature
66 sets. Based on the current selection of a target, the commands 'set remote
67 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
68 configure a target's feature packet and to display its configuration,
71 The individual packet sizes can be configured and shown using the commands
72 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
73 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
74 ** 'show remote memory-read-packet-size'
75 ** 'show remote memory-write-packet-size'.
77 The configuration of the packet itself, as well as the size of a memory-read
78 or memory-write packet applies to the currently selected target (if
79 available). If no target is selected, it applies to future remote
80 connections. Similarly, the show commands print the configuration of the
81 currently selected target. If no remote target is selected, the default
82 configuration for future connections is shown.
84 * GDB has initial built-in support for the Debugger Adapter Protocol.
85 This support requires that GDB be built with Python scripting
88 * For the break command, multiple uses of the 'thread' or 'task'
89 keywords will now give an error instead of just using the thread or
90 task id from the last instance of the keyword. E.g.:
91 break foo thread 1 thread 2
92 will now give an error rather than using 'thread 2'.
94 * For the watch command, multiple uses of the 'task' keyword will now
95 give an error instead of just using the task id from the last
96 instance of the keyword. E.g.:
97 watch my_var task 1 task 2
98 will now give an error rather than using 'task 2'. The 'thread'
99 keyword already gave an error when used multiple times with the
100 watch command, this remains unchanged.
102 * The 'set print elements' setting now helps when printing large arrays.
103 If an array would otherwise exceed max-value-size, but 'print elements'
104 is set such that the size of elements to print is less than or equal
105 to 'max-value-size', GDB will now still print the array, however only
106 'max-value-size' worth of data will be added into the value history.
108 * For both the break and watch commands, it is now invalid to use both
109 the 'thread' and 'task' keywords within the same command. For
110 example the following commnds will now give an error:
111 break foo thread 1 task 1
112 watch var thread 2 task 3
114 * The printf command now accepts a '%V' output format which will
115 format an expression just as the 'print' command would. Print
116 options can be placed withing '[...]' after the '%V' to modify how
117 the value is printed. E.g:
118 printf "%V", some_array
119 printf "%V[-array-indexes on]", some_array
120 will print the array without, or with array indexes included, just
121 as the array would be printed by the 'print' command. This
122 functionality is also available for dprintf when dprintf-style is
125 * When the printf command requires a string to be fetched from the
126 inferior, GDB now uses the existing 'max-value-size' setting to the
127 limit the memory allocated within GDB. The default 'max-value-size'
128 is 64k. To print longer strings you should increase
131 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
133 * The Ada 2022 target name symbol ('@') is now supported by the Ada
136 * The 'list' command now accepts '.' as an argument, which tells GDB to
137 print the location around the point of execution within the current frame.
138 If the inferior hasn't started yet, the command will print around the
139 beginning of the 'main' function.
141 * Using the 'list' command with no arguments in a situation where the
142 command would attempt to list past the end of the file now warns the
143 user that the end of file has been reached, refers the user to the
144 newly added '.' argument
146 * Breakpoints can now be inferior-specific. This is similar to the
147 existing thread-specific breakpoint support. Breakpoint conditions
148 can include the 'inferior' keyword followed by an inferior id (as
149 displayed in the 'info inferiors' output). It is invalid to use the
150 'inferior' keyword with either the 'thread' or 'task' keywords when
151 creating a breakpoint.
153 * New convenience function "$_shell", to execute a shell command and
154 return the result. This lets you run shell commands in expressions.
157 (gdb) p $_shell("true")
159 (gdb) p $_shell("false")
161 (gdb) break func if $_shell("some command") == 0
165 --additional-debug-dirs=PATHs
167 Provide a colon-separated list of additional directories to search for
168 separate debug info. These directories are added to the default value of
169 the 'debug-file-directory' GDB parameter.
173 set debug breakpoint on|off
174 show debug breakpoint
175 Print additional debug messages about breakpoint insertion and removal.
177 maintenance print record-instruction [ N ]
178 Print the recorded information for a given instruction. If N is not given
179 prints how GDB would undo the last instruction executed. If N is negative,
180 prints how GDB would undo the N-th previous instruction, and if N is
181 positive, it prints how GDB will redo the N-th following instruction.
183 maintenance info frame-unwinders
184 List the frame unwinders currently in effect, starting with the highest
187 maintenance wait-for-index-cache
188 Wait until all pending writes to the index cache have completed.
190 set always-read-ctf on|off
192 When off, CTF is only read if DWARF is not present. When on, CTF is
193 read regardless of whether DWARF is present. Off by default.
196 Get main symbol to identify entry point into program.
198 set tui mouse-events [on|off]
199 show tui mouse-events
200 When on (default), mouse clicks control the TUI and can be accessed by
201 Python extensions. When off, mouse clicks are handled by the terminal,
202 enabling terminal-native text selection.
206 ** MI version 1 has been removed.
208 ** mi now reports 'no-history' as a stop reason when hitting the end of the
209 reverse execution history.
211 ** When creating a thread-specific breakpoint using the '-p' option,
212 the -break-insert command would report the 'thread' field twice in
213 the reply. The content of both fields was always identical. This
214 has now been fixed; the 'thread' field will be reported just once
215 for thread-specific breakpoints, or not at all for breakpoints
216 without a thread restriction. The same is also true for the 'task'
217 field of an Ada task-specific breakpoint.
219 ** It is no longer possible to create a thread-specific breakpoint for
220 a thread that doesn't exist using '-break-insert -p ID'. Creating
221 breakpoints for non-existent threads is not allowed when using the
222 CLI, that the MI allowed it was a long standing bug, which has now
225 ** The '--simple-values' argument to the '-stack-list-arguments',
226 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
227 commands now takes reference types into account: that is, a value is now
228 considered simple if it is neither an array, structure, or union, nor a
229 reference to an array, structure, or union. (Previously all references were
230 considered simple.) Support for this feature can be verified by using the
231 '-list-features' command, which should contain "simple-values-ref-types".
233 ** The -break-insert command now accepts a '-g thread-group-id' option
234 to allow for the creation of inferior-specific breakpoints.
236 ** The bkpt tuple, which appears in breakpoint-created notifications,
237 and in the result of the -break-insert command can now include an
238 optional 'inferior' field for both the main breakpoint, and each
239 location, when the breakpoint is inferior-specific.
243 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
245 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
247 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
248 now be of type 'str' otherwise a TypeError will be raised.
250 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
251 values of type 'bool'. Changing this attribute will now
252 invalidate GDB's frame-cache, which means GDB will need to
253 rebuild its frame-cache when next required - either with, or
254 without the particular unwinder, depending on how 'enabled' was
257 ** New methods added to the gdb.PendingFrame class. These methods
258 have the same behaviour as the corresponding methods on
259 gdb.Frame. The new methods are:
261 - gdb.PendingFrame.name: Return the name for the frame's
263 - gdb.PendingFrame.is_valid: Return True if the pending frame
265 - gdb.PendingFrame.pc: Return the $pc register value for this
267 - gdb.PendingFrame.language: Return a string containing the
268 language for this frame, or None.
269 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
270 object for the current location within the pending frame, or
272 - gdb.PendingFrame.block: Return a gdb.Block for the current
273 pending frame, or None.
274 - gdb.PendingFrame.function: Return a gdb.Symbol for the
275 current pending frame, or None.
277 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
278 now use either an integer or a gdb.Value object for each of its
279 'sp', 'pc', and 'special' attributes.
281 ** A new class gdb.unwinder.FrameId has been added. Instances of
282 this class are constructed with 'sp' (stack-pointer) and 'pc'
283 (program-counter) values, and can be used as the frame-id when
284 calling gdb.PendingFrame.create_unwind_info.
286 ** It is now no longer possible to sub-class the
287 gdb.disassembler.DisassemblerResult type.
289 ** The Disassembler API from the gdb.disassembler module has been
290 extended to include styling support:
292 - The DisassemblerResult class can now be initialized with a list
293 of parts. Each part represents part of the disassembled
294 instruction along with the associated style information. This
295 list of parts can be accessed with the new
296 DisassemblerResult.parts property.
298 - New constants gdb.disassembler.STYLE_* representing all the
299 different styles part of an instruction might have.
301 - New methods DisassembleInfo.text_part and
302 DisassembleInfo.address_part which are used to create the new
303 styled parts of a disassembled instruction.
305 - Changes are backwards compatible, the older API can still be
306 used to disassemble instructions without styling.
308 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
309 GDB/MI command and returns the output as a Python dictionary.
311 ** New function gdb.block_signals(). This returns a context manager
312 that blocks any signals that GDB needs to handle itself.
314 ** New class gdb.Thread. This is a subclass of threading.Thread
315 that calls gdb.block_signals in its "start" method.
317 ** gdb.parse_and_eval now has a new "global_context" parameter.
318 This can be used to request that the parse only examine global
321 ** gdb.Inferior now has a new "arguments" attribute. This holds the
322 command-line arguments to the inferior, if known.
324 ** gdb.Inferior now has a new "main_name" attribute. This holds the
325 name of the inferior's "main", if known.
327 ** gdb.Inferior now has new methods "clear_env", "set_env", and
328 "unset_env". These can be used to modify the inferior's
329 environment before it is started.
331 ** gdb.Value now has the 'assign' method.
333 ** gdb.Value now has the 'to_array' method. This converts an
334 array-like Value to an array.
336 ** gdb.Progspace now has the new method "objfile_for_address". This
337 returns the gdb.Objfile, if any, that covers a given address.
339 ** gdb.Breakpoint now has an "inferior" attribute. If the
340 Breakpoint object is inferior specific then this attribute holds
341 the inferior-id (an integer). If the Breakpoint object is not
342 inferior specific, then this field contains None. This field can
345 ** gdb.Type now has the "is_array_like" and "is_string_like"
346 methods. These reflect GDB's internal idea of whether a type
347 might be array- or string-like, even if they do not have the
348 corresponding type code.
350 ** gdb.ValuePrinter is a new class that can be used as the base
351 class for the result of applying a pretty-printer. As a base
352 class, it signals to gdb that the printer may implement new
353 pretty-printer methods.
355 ** New attribute Progspace.symbol_file. This attribute holds the
356 gdb.Objfile that corresponds to Progspace.filename (when
357 Progspace.filename is not None), otherwise, this attribute is
360 ** New attribute Progspace.executable_filename. This attribute
361 holds a string containing a file name set by the "exec-file" or
362 "file" commands, or None if no executable file is set. This
363 isn't the exact string passed by the user to these commands; the
364 file name will have been partially resolved to an absolute file
367 ** A new executable_changed event registry is available. This event
368 emits ExecutableChangedEvent objects, which have 'progspace' (a
369 gdb.Progspace) and 'reload' (a Boolean) attributes. This event
370 is emitted when gdb.Progspace.executable_filename changes.
372 ** New event registries gdb.events.new_progspace and
373 gdb.events.free_progspace, these emit NewProgspaceEvent and
374 FreeProgspaceEvent event types respectively. Both of these event
375 types have a single 'progspace' attribute, which is the
376 gdb.Progspace that is either being added to GDB, or removed from
379 ** gdb.LazyString now implements the __str__ method.
381 *** Changes in GDB 13
383 * MI version 1 is deprecated, and will be removed in GDB 14.
385 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
386 reading memory tag data for AArch64 MTE from core files generated by
387 the gcore command or the Linux kernel.
389 When a process uses memory-mapped pages protected by memory tags (for
390 example, AArch64 MTE), this additional information will be recorded in
391 the core file in the event of a crash or if GDB generates a core file
392 from the current process state. GDB will show this additional information
393 automatically, or through one of the memory-tag subcommands.
395 * "info breakpoints" now displays enabled breakpoint locations of
396 disabled breakpoints as in the "y-" state. For example:
398 (gdb) info breakpoints
399 Num Type Disp Enb Address What
400 1 breakpoint keep n <MULTIPLE>
401 1.1 y- 0x00000000000011b6 in ...
402 1.2 y- 0x00000000000011c2 in ...
403 1.3 n 0x00000000000011ce in ...
405 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
406 aarch64 architectures.
408 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
410 * Remove support for building against Python 2, it is now only possible to
411 build GDB against Python 3.
413 * DBX mode has been removed.
415 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
416 emit to indicate where a breakpoint should be placed to break in a function
419 * Completion now also offers "NUMBER" for "set" commands that accept
420 a numeric argument and the "unlimited" keyword. For example:
422 (gdb) set width <TAB>
427 (gdb) complete set width
431 * Disassembler styling using libopcodes. GDB now supports
432 disassembler styling using libopcodes. This is only available for
433 some targets (currently x86 and RISC-V). For unsupported targets
434 Python Pygments is still used. For supported targets, libopcodes
435 styling is used by default.
437 * The Windows native target now supports target async.
439 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
441 * The format of 'disassemble /r' and 'record instruction-history /r'
442 has changed. The instruction bytes could now be grouped together,
443 and displayed in the endianness of the instruction. This is the
444 same layout as used by GNU objdump when disassembling.
446 There is now 'disassemble /b' and 'record instruction-history /b'
447 which will always display the instructions bytes one at a time in
448 memory order, that is, the byte at the lowest address first.
450 For both /r and /b GDB is now better at using whitespace in order to
451 align the disassembled instruction text.
453 * The TUI no longer styles the source and assembly code highlighted by
454 the current position indicator by default. You can however
455 re-enable styling using the new "set style tui-current-position"
458 * New convenience variable $_inferior_thread_count contains the number
459 of live threads in the current inferior.
461 * When a breakpoint with multiple code locations is hit, GDB now prints
462 the code location using the syntax <breakpoint_number>.<location_number>
464 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
466 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
467 and $_hit_locno to the hit breakpoint number and code location number.
468 This allows to disable the last hit breakpoint using
469 (gdb) disable $_hit_bpnum
470 or disable only the specific breakpoint code location using
471 (gdb) disable $_hit_bpnum.$_hit_locno
472 These commands can be used inside the command list of a breakpoint to
473 automatically disable the just encountered breakpoint (or the just
474 encountered specific breakpoint code location).
475 When a breakpoint has only one location, $_hit_locno is set to 1 so that
476 (gdb) disable $_hit_bpnum.$_hit_locno
478 (gdb) disable $_hit_bpnum
479 are both disabling the breakpoint.
483 maintenance set ignore-prologue-end-flag on|off
484 maintenance show ignore-prologue-end-flag
485 This setting, which is off by default, controls whether GDB ignores the
486 PROLOGUE-END flag from the line-table when skipping prologue. This can be
487 used to force GDB to use prologue analyzers if the line-table is constructed
488 from erroneous debug information.
490 set print nibbles [on|off]
492 This controls whether the 'print/t' command will display binary values
493 in groups of four bits, known as "nibbles". The default is 'off'.
495 maintenance set libopcodes-styling on|off
496 maintenance show libopcodes-styling
497 These can be used to force off libopcodes based styling, the Python
498 Pygments styling will then be used instead.
500 set style disassembler comment
501 show style disassembler comment
502 set style disassembler immediate
503 show style disassembler immediate
504 set style disassembler mnemonic
505 show style disassembler mnemonic
506 set style disassembler register
507 show style disassembler register
508 set style disassembler address
509 show style disassembler address
510 set style disassembler symbol
511 show style disassembler symbol
512 For targets that support libopcodes based styling, these settings
513 control how various aspects of the disassembler output are styled.
514 The 'disassembler address' and 'disassembler symbol' styles are
515 aliases for the 'address' and 'function' styles respectively.
517 maintenance print frame-id [ LEVEL ]
518 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
519 not given, then print the frame-id for the currently selected frame.
521 set debug infcall on|off
523 Print additional debug messages about inferior function calls.
525 set debug solib on|off
527 Print additional debug messages about shared library handling.
529 set style tui-current-position [on|off]
530 Whether to style the source and assembly code highlighted by the
531 TUI's current position indicator. The default is off.
533 set print characters LIMIT
534 show print characters
535 This new setting is like 'set print elements', but controls how many
536 characters of a string are printed. This functionality used to be
537 covered by 'set print elements', but it can be controlled separately
538 now. LIMIT can be set to a numerical value to request that particular
539 character count, to 'unlimited' to print all characters of a string,
540 or to 'elements', which is also the default, to follow the setting of
541 'set print elements' as it used to be.
543 print -characters LIMIT
544 This new option to the 'print' command has the same effect as a temporary
545 use of 'set print characters'.
549 document user-defined
550 It is now possible to document user-defined aliases.
551 When a user-defined alias is documented, the help and apropos commands
552 use the provided documentation instead of the documentation of the
554 Documenting a user-defined alias is particularly useful when the alias
555 is a set of nested 'with' commands to avoid showing the help of
556 the with command for an alias that will in fact launch the
557 last command given in the nested commands.
559 maintenance info line-table
560 Add a PROLOGUE-END column to the output which indicates that an
561 entry corresponds to an address where a breakpoint should be placed
562 to be at the first instruction past a function's prologue.
566 set debug aix-solib on|off
568 set debug solib-frv on|off
570 Removed in favor of "set/show debug solib".
572 maintenance info program-spaces
573 This command now includes a 'Core File' column which indicates the
574 name of the core file associated with each program space.
578 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
580 GNU/Linux/CSKY (gdbserver) csky*-*linux*
586 ** The async record stating the stopped reason 'breakpoint-hit' now
587 contains an optional field locno giving the code location number
588 when the breakpoint has multiple code locations.
592 ** GDB will now reformat the doc string for gdb.Command and
593 gdb.Parameter sub-classes to remove unnecessary leading
594 whitespace from each line before using the string as the help
597 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
598 that formats ADDRESS as 'address <symbol+offset>', where symbol is
599 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
600 This is the same format that GDB uses when printing address, symbol,
601 and offset information from the disassembler.
603 ** New function gdb.current_language that returns the name of the
604 current language. Unlike gdb.parameter('language'), this will
607 ** New method gdb.Frame.language that returns the name of the
610 ** New Python API for wrapping GDB's disassembler:
612 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
613 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
614 ARCH is either None or a string containing a bfd architecture
615 name. DISASSEMBLER is registered as a disassembler for
616 architecture ARCH, or for all architectures if ARCH is None.
617 The previous disassembler registered for ARCH is returned, this
618 can be None if no previous disassembler was registered.
620 - gdb.disassembler.Disassembler is the class from which all
621 disassemblers should inherit. Its constructor takes a string,
622 a name for the disassembler, which is currently only used in
623 some debug output. Sub-classes should override the __call__
624 method to perform disassembly, invoking __call__ on this base
625 class will raise an exception.
627 - gdb.disassembler.DisassembleInfo is the class used to describe
628 a single disassembly request from GDB. An instance of this
629 class is passed to the __call__ method of
630 gdb.disassembler.Disassembler and has the following read-only
631 attributes: 'address', and 'architecture', as well as the
632 following method: 'read_memory'.
634 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
635 calls GDB's builtin disassembler on INFO, which is a
636 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
637 optional, its default value is None. If MEMORY_SOURCE is not
638 None then it must be an object that has a 'read_memory' method.
640 - gdb.disassembler.DisassemblerResult is a class that can be used
641 to wrap the result of a call to a Disassembler. It has
642 read-only attributes 'length' and 'string'.
644 ** gdb.Objfile now has an attribute named "is_file". This is True
645 if the objfile comes from a file, and False otherwise.
647 ** New function gdb.print_options that returns a dictionary of the
648 prevailing print options, in the form accepted by
649 gdb.Value.format_string.
651 ** gdb.Value.format_string now uses the format provided by 'print',
652 if it is called during a 'print' or other similar operation.
654 ** gdb.Value.format_string now accepts the 'summary' keyword. This
655 can be used to request a shorter representation of a value, the
656 way that 'set print frame-arguments scalars' does.
658 ** New Python type gdb.BreakpointLocation.
659 The new attribute 'locations' of gdb.Breakpoint returns a list of
660 gdb.BreakpointLocation objects specifying the locations where the
661 breakpoint is inserted into the debuggee.
663 ** The gdb.register_window_type method now restricts the set of
664 acceptable window names. The first character of a window's name
665 must start with a character in the set [a-zA-Z], every subsequent
666 character of a window's name must be in the set [-_.a-zA-Z0-9].
668 * New features in the GDB remote stub, GDBserver
670 ** GDBserver is now supported on LoongArch GNU/Linux.
672 ** GDBserver is now supported on CSKY GNU/Linux.
674 * LoongArch floating-point support
676 GDB now supports floating-point on LoongArch GNU/Linux.
678 * AMD GPU ROCm debugging support
680 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
683 *** Changes in GDB 12
685 * DBX mode is deprecated, and will be removed in GDB 13
687 * GDB 12 is the last release of GDB that will support building against
688 Python 2. From GDB 13, it will only be possible to build GDB itself
689 with Python 3 support.
691 * The disable-randomization setting now works on Windows.
693 * Improved C++ template support
695 GDB now treats functions/types involving C++ templates like it does function
696 overloads. Users may omit parameter lists to set breakpoints on families of
697 template functions, including types/functions composed of multiple template types:
699 (gdb) break template_func(template_1, int)
701 The above will set breakpoints at every function `template_func' where
702 the first function parameter is any template type named `template_1' and
703 the second function parameter is `int'.
705 TAB completion also gains similar improvements.
707 * The FreeBSD native target now supports async mode.
713 Enable or disable multithreaded symbol loading. This is enabled
714 by default, but passing --disable-threading or --enable-threading=no
715 to configure will disable it.
717 Disabling this can cause a performance penalty when there are a lot of
718 symbols to load, but is useful for debugging purposes.
722 maint set backtrace-on-fatal-signal on|off
723 maint show backtrace-on-fatal-signal
724 This setting is 'on' by default. When 'on' GDB will print a limited
725 backtrace to stderr in the situation where GDB terminates with a
726 fatal signal. This only supported on some platforms where the
727 backtrace and backtrace_symbols_fd functions are available.
729 set source open on|off
731 This setting, which is on by default, controls whether GDB will try
732 to open source code files. Switching this off will stop GDB trying
733 to open and read source code files, which can be useful if the files
734 are located over a slow network connection.
738 These are now deprecated aliases for "set max-value-size" and
739 "show max-value-size".
741 task apply [all | TASK-IDS...] [FLAG]... COMMAND
742 Like "thread apply", but applies COMMAND to Ada tasks.
745 Watchpoints can now be restricted to a specific Ada task.
747 maint set internal-error backtrace on|off
748 maint show internal-error backtrace
749 maint set internal-warning backtrace on|off
750 maint show internal-warning backtrace
751 GDB can now print a backtrace of itself when it encounters either an
752 internal-error, or an internal-warning. This is on by default for
753 internal-error and off by default for internal-warning.
756 Deprecated and replaced by "set logging enabled on|off".
758 set logging enabled on|off
760 These commands set or show whether logging is enabled or disabled.
763 You can now exit GDB by using the new command "exit", in addition to
764 the existing "quit" command.
766 set debug threads on|off
768 Print additional debug messages about thread creation and deletion.
770 set debug linux-nat on|off
772 These new commands replaced the old 'set debug lin-lwp' and 'show
773 debug lin-lwp' respectively. Turning this setting on prints debug
774 messages relating to GDB's handling of native Linux inferiors.
776 maint flush source-cache
777 Flush the contents of the source code cache.
779 maint set gnu-source-highlight enabled on|off
780 maint show gnu-source-highlight enabled
781 Whether GDB should use the GNU Source Highlight library for adding
782 styling to source code. When off, the library will not be used, even
783 when available. When GNU Source Highlight isn't used, or can't add
784 styling to a particular source file, then the Python Pygments
785 library will be used instead.
787 set suppress-cli-notifications (on|off)
788 show suppress-cli-notifications
789 This controls whether printing the notifications is suppressed for CLI.
790 CLI notifications occur when you change the selected context
791 (i.e., the current inferior, thread and/or the frame), or when
792 the program being debugged stops (e.g., because of hitting a
793 breakpoint, completing source-stepping, an interrupt, etc.).
795 set style disassembler enabled on|off
796 show style disassembler enabled
797 If GDB is compiled with Python support, and the Python Pygments
798 package is available, then, when this setting is on, disassembler
799 output will have styling applied.
801 set ada source-charset
802 show ada source-charset
803 Set the character set encoding that is assumed for Ada symbols. Valid
804 values for this follow the values that can be passed to the GNAT
805 compiler via the '-gnati' option. The default is ISO-8859-1.
811 These are the new names for the old 'layout', 'focus', 'refresh',
812 and 'winheight' tui commands respectively. The old names still
813 exist as aliases to these new commands.
817 The new command 'tui window width', and the alias 'winwidth' allow
818 the width of a tui window to be adjusted when windows are laid out
823 Control the display of debug output about GDB's tui.
828 Printing of floating-point values with base-modifying formats like
829 /x has been changed to display the underlying bytes of the value in
830 the desired base. This was GDB's documented behavior, but was never
831 implemented correctly.
834 This command can now print a reply, if the reply includes
835 non-printable characters. Any non-printable characters are printed
836 as escaped hex, e.g. \x?? where '??' is replaces with the value of
837 the non-printable character.
840 The clone-inferior command now ensures that the TTY, CMD and ARGS
841 settings are copied from the original inferior to the new one.
842 All modifications to the environment variables done using the 'set
843 environment' or 'unset environment' commands are also copied to the new
846 set debug lin-lwp on|off
848 These commands have been removed from GDB. The new command 'set
849 debug linux-nat' and 'show debug linux-nat' should be used
853 This command now includes information about the width of the tui
854 windows in its output.
860 These commands are now aliases for the 'tui layout', 'tui focus',
861 'tui refresh', and 'tui window height' commands respectively.
863 * GDB's Ada parser now supports an extension for specifying the exact
864 byte contents of a floating-point literal. This can be useful for
865 setting floating-point registers to a precise value without loss of
866 precision. The syntax is an extension of the based literal syntax.
867 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
868 of the floating-point type, and the "f" is the marker for floating
873 ** The '-add-inferior' with no option flags now inherits the
874 connection of the current inferior, this restores the behaviour of
875 GDB as it was prior to GDB 10.
877 ** The '-add-inferior' command now accepts a '--no-connection'
878 option, which causes the new inferior to start without a
881 ** The default version of the MI interpreter is now 4 (-i=mi4).
883 ** The "script" field in breakpoint output (which is syntactically
884 incorrect in MI 3 and below) has changed in MI 4 to become a list.
885 This affects the following commands and events:
889 - =breakpoint-created
890 - =breakpoint-modified
892 The -fix-breakpoint-script-output command can be used to enable
893 this behavior with previous MI versions.
897 GNU/Linux/LoongArch loongarch*-*-linux*
905 ** New function gdb.add_history(), which takes a gdb.Value object
906 and adds the value it represents to GDB's history list. An
907 integer, the index of the new item in the history list, is
910 ** New function gdb.history_count(), which returns the number of
911 values in GDB's value history.
913 ** New gdb.events.gdb_exiting event. This event is called with a
914 gdb.GdbExitingEvent object which has the read-only attribute
915 'exit_code', which contains the value of the GDB exit code. This
916 event is triggered once GDB decides it is going to exit, but
917 before GDB starts to clean up its internal state.
919 ** New function gdb.architecture_names(), which returns a list
920 containing all of the possible Architecture.name() values. Each
923 ** New function gdb.Architecture.integer_type(), which returns an
924 integer type given a size and a signed-ness.
926 ** New gdb.TargetConnection object type that represents a connection
927 (as displayed by the 'info connections' command). A sub-class,
928 gdb.RemoteTargetConnection, is used to represent 'remote' and
929 'extended-remote' connections.
931 ** The gdb.Inferior type now has a 'connection' property which is an
932 instance of gdb.TargetConnection, the connection used by this
933 inferior. This can be None if the inferior has no connection.
935 ** New 'gdb.events.connection_removed' event registry, which emits a
936 'gdb.ConnectionEvent' when a connection is removed from GDB.
937 This event has a 'connection' property, a gdb.TargetConnection
938 object for the connection being removed.
940 ** New gdb.connections() function that returns a list of all
941 currently active connections.
943 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
944 is equivalent to the existing 'maint packet' CLI command; it
945 allows a user specified packet to be sent to the remote target.
947 ** New function gdb.host_charset(), returns a string, which is the
948 name of the current host charset.
950 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
953 ** New gdb.with_parameter(NAME, VALUE). This returns a context
954 manager that temporarily sets the gdb parameter NAME to VALUE,
955 then resets it when the context is exited.
957 ** The gdb.Value.format_string method now takes a 'styling'
958 argument, which is a boolean. When true, the returned string can
959 include escape sequences to apply styling. The styling will only
960 be present if styling is otherwise turned on in GDB (see 'help
961 set styling'). When false, which is the default if the argument
962 is not given, then no styling is applied to the returned string.
964 ** New read-only attribute gdb.InferiorThread.details, which is
965 either a string, containing additional, target specific thread
966 state information, or None, if there is no such additional
969 ** New read-only attribute gdb.Type.is_scalar, which is True for
970 scalar types, and False for all other types.
972 ** New read-only attribute gdb.Type.is_signed. This attribute
973 should only be read when Type.is_scalar is True, and will be True
974 for signed types, and False for all other types. Attempting to
975 read this attribute for non-scalar types will raise a ValueError.
977 ** It is now possible to add GDB/MI commands implemented in Python.
979 * New features in the GDB remote stub, GDBserver
981 ** GDBserver is now supported on OpenRISC GNU/Linux.
983 * New native configurations
985 GNU/Linux/OpenRISC or1k*-*-linux*
987 *** Changes in GDB 11
989 * The 'set disassembler-options' command now supports specifying options
992 * GDB now supports general memory tagging functionality if the underlying
993 architecture supports the proper primitives and hooks. Currently this is
994 enabled only for AArch64 MTE.
998 - Additional information when the inferior crashes with a SIGSEGV caused by
999 a memory tag violation.
1001 - A new modifier 'm' for the "x" command, which displays allocation tags for a
1002 particular memory range.
1004 - Display of memory tag mismatches by "print", for addresses and
1005 pointers, if memory tagging is supported by the architecture.
1007 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
1012 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
1014 The MI -break-insert and -dprintf-insert commands now support a
1015 new "--qualified" option that makes GDB interpret a specified
1016 function name as a complete fully-qualified name. This is the
1017 equivalent of the CLI's "break -qualified" and "dprintf
1020 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
1022 The MI -break-insert and -dprintf-insert commands now support a
1023 '--force-condition' flag to forcibly define a condition even when
1024 the condition is invalid at all locations of the breakpoint. This
1025 is equivalent to the '-force-condition' flag of the CLI's "break"
1028 ** '-break-condition --force'
1030 The MI -break-condition command now supports a '--force' flag to
1031 forcibly define a condition even when the condition is invalid at
1032 all locations of the selected breakpoint. This is equivalent to
1033 the '-force' flag of the CLI's "cond" command.
1035 ** '-file-list-exec-source-files [--group-by-objfile]
1036 [--basename | --dirname]
1039 The existing -file-list-exec-source-files command now takes an
1040 optional REGEXP which is used to filter the source files that are
1041 included in the results.
1043 By default REGEXP is matched against the full filename of the
1044 source file. When one of --basename or --dirname is given then
1045 REGEXP is only matched against the specified part of the full
1048 When the optional --group-by-objfile flag is used the output
1049 format is changed, the results are now a list of object files
1050 (executable and libraries) with the source files that are
1051 associated with each object file.
1053 The results from -file-list-exec-source-files now include a
1054 'debug-fully-read' field which takes the value 'true' or 'false'.
1055 A 'true' value indicates the source file is from a compilation
1056 unit that has had its debug information fully read in by GDB, a
1057 value of 'false' indicates GDB has only performed a partial scan
1058 of the debug information so far.
1060 * GDB now supports core file debugging for x86_64 Cygwin programs.
1062 * GDB will now look for the .gdbinit file in a config directory before
1063 looking for ~/.gdbinit. The file is searched for in the following
1064 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1065 $HOME/.gdbinit. On Apple hosts the search order is instead:
1066 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1068 * GDB now supports fixed point types which are described in DWARF
1069 as base types with a fixed-point encoding. Additionally, support
1070 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1073 For Ada, this allows support for fixed point types without requiring
1074 the use of the GNAT encoding (based on information added to the type's
1075 name following a GNAT-specific format).
1077 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1078 or ~/.gdbearlyinit if these files are present. These files are
1079 processed earlier than any of the other initialization files and
1080 can affect parts of GDB's startup that previously had already been
1081 completed before the initialization files were read, for example
1082 styling of the initial GDB greeting.
1084 * GDB now has two new options "--early-init-command" and
1085 "--early-init-eval-command" with corresponding short options "-eix"
1086 and "-eiex" that allow options (that would normally appear in a
1087 gdbearlyinit file) to be passed on the command line.
1089 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1090 now understood by GDB, and can be used to describe the vector
1091 registers of a target. The precise requirements of this register
1092 feature are documented in the GDB manual.
1094 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1095 supported by GDB and describes a new VPR register from the ARM MVE
1096 (Helium) extension. See the GDB manual for more information.
1100 ** TUI windows now support mouse actions. The mouse wheel scrolls
1101 the appropriate window.
1103 ** Key combinations that do not have a specific action on the
1104 focused window are passed to GDB. For example, you now can use
1105 Ctrl-Left/Ctrl-Right to move between words in the command window
1106 regardless of which window is in focus. Previously you would
1107 need to focus on the command window for such key combinations to
1112 set debug event-loop
1113 show debug event-loop
1114 Control the display of debug output about GDB's event loop.
1116 set print memory-tag-violations
1117 show print memory-tag-violations
1118 Control whether to display additional information about memory tag violations
1119 when printing pointers and addresses. Architecture support for memory
1120 tagging is required for this option to have an effect.
1122 maintenance flush symbol-cache
1123 maintenance flush register-cache
1124 These new commands are equivalent to the already existing commands
1125 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1127 maintenance flush dcache
1128 A new command to flush the dcache.
1130 maintenance info target-sections
1131 Print GDB's internal target sections table.
1133 maintenance info jit
1134 Print the JIT code objects in the inferior known to GDB.
1136 memory-tag show-logical-tag POINTER
1137 Print the logical tag for POINTER.
1138 memory-tag with-logical-tag POINTER TAG
1139 Print POINTER with logical tag TAG.
1140 memory-tag show-allocation-tag ADDRESS
1141 Print the allocation tag for ADDRESS.
1142 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1143 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1144 memory-tag check POINTER
1145 Validate that POINTER's logical tag matches the allocation tag.
1147 set startup-quietly on|off
1148 show startup-quietly
1149 When 'on', this causes GDB to act as if "-silent" were passed on the
1150 command line. This command needs to be added to an early
1151 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1154 set print type hex on|off
1156 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1157 and offsets of struct members. When 'off', decimal notation is used.
1159 set python ignore-environment on|off
1160 show python ignore-environment
1161 When 'on', this causes GDB's builtin Python to ignore any
1162 environment variables that would otherwise affect how Python
1163 behaves. This command needs to be added to an early initialization
1164 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1166 set python dont-write-bytecode auto|on|off
1167 show python dont-write-bytecode
1168 When 'on', this causes GDB's builtin Python to not write any
1169 byte-code (.pyc files) to disk. This command needs to be added to
1170 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1171 order to affect GDB. When 'off' byte-code will always be written.
1172 When set to 'auto' (the default) Python will check the
1173 PYTHONDONTWRITEBYTECODE environment variable.
1177 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1178 [-force-condition] [if CONDITION]
1179 This command would previously refuse setting a breakpoint if the
1180 CONDITION expression is invalid at a location. It now accepts and
1181 defines the breakpoint if there is at least one location at which
1182 the CONDITION is valid. The locations for which the CONDITION is
1183 invalid, are automatically disabled. If CONDITION is invalid at all
1184 of the locations, setting the breakpoint is still rejected. However,
1185 the '-force-condition' flag can be used in this case for forcing GDB to
1186 define the breakpoint, making all the current locations automatically
1187 disabled. This may be useful if the user knows the condition will
1188 become meaningful at a future location, e.g. due to a shared library
1191 condition [-force] N COND
1192 The behavior of this command is changed the same way for the 'break'
1193 command as explained above. The '-force' flag can be used to force
1194 GDB into defining the condition even when COND is invalid for all the
1195 current locations of breakpoint N.
1198 maintenance flush-symbol-cache
1199 These commands are deprecated in favor of the new commands
1200 'maintenance flush register-cache' and 'maintenance flush
1201 symbol-cache' respectively.
1203 set style version foreground COLOR
1204 set style version background COLOR
1205 set style version intensity VALUE
1206 Control the styling of GDB's version number text.
1209 When the ID parameter is omitted, then this command prints information
1210 about the current inferior. When the ID parameter is present, the
1211 behavior of the command is unchanged and have the inferior ID become
1212 the current inferior.
1214 maintenance info sections
1215 The ALLOBJ keyword has been replaced with an -all-objects command
1216 line flag. It is now possible to filter which sections are printed
1217 even when -all-objects is passed.
1219 ptype[/FLAGS] TYPE | EXPRESSION
1220 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1221 notation is used when printing sizes and offsets of struct members.
1222 When '/d' is set, decimal notation is used when printing sizes and
1223 offsets of struct members. Default behavior is given by 'show print
1227 The info sources command output has been restructured. The results
1228 are now based around a list of objfiles (executable and libraries),
1229 and for each objfile the source files that are part of that objfile
1232 * Removed targets and native configurations
1234 ARM Symbian arm*-*-symbianelf*
1236 * New remote packets
1239 Request the remote to send allocation tags for a particular memory range.
1241 Request the remote to store the specified allocation tags to the requested
1246 ** Improved support for rvalue reference values:
1247 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1248 value-referenced-value procedure now handles rvalue reference
1251 ** New procedures for obtaining value variants:
1252 value-reference-value, value-rvalue-reference-value and
1255 ** Temporary breakpoints can now be created with make-breakpoint and
1256 tested for using breakpoint-temporary?.
1260 ** Inferior objects now contain a read-only 'connection_num' attribute that
1261 gives the connection number as seen in 'info connections' and
1264 ** New method gdb.Frame.level() which returns the stack level of the
1267 ** New method gdb.PendingFrame.level() which returns the stack level
1268 of the frame object.
1270 ** When hitting a catchpoint, the Python API will now emit a
1271 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1272 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1274 ** Python TUI windows can now receive mouse click events. If the
1275 Window object implements the click method, it is called for each
1276 mouse click event in this window.
1278 *** Changes in GDB 10
1280 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1281 and "org.gnu.gdb.arc.aux". The old names are still supported but
1282 must be considered obsolete. They will be deprecated after some
1285 * Help and apropos commands will now show the documentation of a
1286 command only once, even if that command has one or more aliases.
1287 These commands now show the command name, then all of its aliases,
1288 and finally the description of the command.
1290 * 'help aliases' now shows only the user defined aliases. GDB predefined
1291 aliases are shown together with their aliased command.
1293 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1294 debugging information as well as source code.
1296 When built with debuginfod, GDB can automatically query debuginfod
1297 servers for the separate debug files and source code of the executable
1300 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1301 requires libdebuginfod, the debuginfod client library).
1303 debuginfod is distributed with elfutils, starting with version 0.178.
1305 You can get the latest version from https://sourceware.org/elfutils.
1307 * Multi-target debugging support
1309 GDB now supports debugging multiple target connections
1310 simultaneously. For example, you can now have each inferior
1311 connected to different remote servers running in different machines,
1312 or have one inferior debugging a local native process, an inferior
1313 debugging a core dump, etc.
1315 This support is experimental and comes with some limitations -- you
1316 can only resume multiple targets simultaneously if all targets
1317 support non-stop mode, and all remote stubs or servers must support
1318 the same set of remote protocol features exactly. See also "info
1319 connections" and "add-inferior -no-connection" below, and "maint set
1320 target-non-stop" in the user manual.
1322 * New features in the GDB remote stub, GDBserver
1324 ** GDBserver is now supported on ARC GNU/Linux.
1326 ** GDBserver is now supported on RISC-V GNU/Linux.
1328 ** GDBserver no longer supports these host triplets:
1330 i[34567]86-*-lynxos*
1339 i[34567]86-*-mingw32ce*
1341 * Debugging MS-Windows processes now sets $_exitsignal when the
1342 inferior is terminated by a signal, instead of setting $_exitcode.
1344 * Multithreaded symbol loading has now been enabled by default on systems
1345 that support it (see entry for GDB 9, below), providing faster
1346 performance for programs with many symbols.
1348 * The $_siginfo convenience variable now also works on Windows targets,
1349 and will display the EXCEPTION_RECORD of the last handled exception.
1351 * TUI windows can now be arranged horizontally.
1353 * The command history filename can now be set to the empty string
1354 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1355 the environment. The effect of setting this filename to the empty
1356 string is that GDB will not try to load any previous command
1359 * On Windows targets, it is now possible to debug 32-bit programs with a
1364 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1365 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1366 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1367 running process, this new option indicates whether to detect
1368 a mismatch between the current executable file loaded by GDB and the
1369 executable file used to start the process. If 'ask', the default,
1370 display a warning and ask the user whether to load the process
1371 executable file; if 'warn', just display a warning; if 'off', don't
1372 attempt to detect a mismatch.
1374 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1375 Define a new TUI layout, specifying its name and the windows that
1378 maintenance print xml-tdesc [FILE]
1379 Prints the current target description as an XML document. If the
1380 optional FILE is provided (which is an XML target description) then
1381 the target description is read from FILE into GDB, and then
1384 maintenance print core-file-backed-mappings
1385 Prints file-backed mappings loaded from a core file's note section.
1386 Output is expected to be similar to that of "info proc mappings".
1388 set debug fortran-array-slicing on|off
1389 show debug fortran-array-slicing
1390 Print debugging when taking slices of Fortran arrays.
1392 set fortran repack-array-slices on|off
1393 show fortran repack-array-slices
1394 When taking slices from Fortran arrays and strings, if the slice is
1395 non-contiguous within the original value then, when this option is
1396 on, the new value will be repacked into a single contiguous value.
1397 When this option is off, then the value returned will consist of a
1398 descriptor that describes the slice within the memory of the
1399 original parent value.
1403 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1404 The alias command can now specify default args for an alias.
1405 GDB automatically prepends the alias default args to the argument list
1406 provided explicitly by the user.
1407 For example, to have a backtrace with full details, you can define
1408 an alias 'bt_ALL' as
1409 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1410 -past-main -past-entry -full'.
1411 Alias default arguments can also use a set of nested 'with' commands,
1412 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1413 defines the alias pp10 that will pretty print a maximum of 10 elements
1414 of the given expression (if the expression is an array).
1418 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1419 BPF bpf-unknown-none
1424 ** gdb.register_window_type can be used to implement new TUI windows
1427 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1428 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1429 field of a dynamic type may have None for its "bitpos" attribute
1432 ** Commands written in Python can be in the "TUI" help class by
1433 registering with the new constant gdb.COMMAND_TUI.
1435 ** New method gdb.PendingFrame.architecture () to retrieve the
1436 architecture of the pending frame.
1438 ** New gdb.Architecture.registers method that returns a
1439 gdb.RegisterDescriptorIterator object, an iterator that returns
1440 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1441 way to query the registers available for an architecture.
1443 ** New gdb.Architecture.register_groups method that returns a
1444 gdb.RegisterGroupIterator object, an iterator that returns
1445 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1446 discover the available register groups.
1450 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1452 ** Procedures 'memory-port-read-buffer-size',
1453 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1454 and 'set-memory-port-write-buffer-size!' are deprecated. When
1455 using Guile 2.2 and later, users who need to control the size of
1456 a memory port's internal buffer can use the 'setvbuf' procedure.
1458 *** Changes in GDB 9
1460 * 'thread-exited' event is now available in the annotations interface.
1462 * New built-in convenience variables $_gdb_major and $_gdb_minor
1463 provide the GDB version. They are handy for conditionally using
1464 features available only in or since specific GDB versions, in
1465 scripts that should work error-free with many different versions,
1466 such as in system-wide init files.
1468 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1469 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1470 of the GDB settings and the GDB maintenance settings. They are handy
1471 for changing the logic of user defined commands depending on the
1472 current GDB settings.
1474 * GDB now supports Thread Local Storage (TLS) variables on several
1475 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1476 architectures require kernel changes. TLS is not yet supported for
1477 amd64 and i386 process core dumps.
1479 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1480 addresses that required unmasking are shown in the backtrace with the
1483 * Two new convenience functions $_cimag and $_creal that extract the
1484 imaginary and real parts respectively from complex numbers.
1486 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1487 provide the exitcode or exit status of the shell commands launched by
1488 GDB commands such as "shell", "pipe" and "make".
1490 * The command define-prefix can now define user defined prefix commands.
1491 User defined commands can now be defined using these user defined prefix
1494 * Command names can now use the . character.
1496 * The RX port now supports XML target descriptions.
1498 * GDB now shows the Ada task names at more places, e.g. in task switching
1501 * GDB can now be compiled with Python 3 on Windows.
1503 * New convenience variable $_ada_exception holds the address of the
1504 Ada exception being thrown. This is set by Ada-related catchpoints.
1506 * GDB can now place breakpoints on nested functions and subroutines in
1507 Fortran code. The '::' operator can be used between parent and
1508 child scopes when placing breakpoints, for example:
1510 (gdb) break outer_function::inner_function
1512 The 'outer_function::' prefix is only needed if 'inner_function' is
1513 not visible in the current scope.
1515 * In addition to the system-wide gdbinit file, if configured with
1516 --with-system-gdbinit-dir, GDB will now also load files in that directory
1517 as system gdbinit files, unless the -nx or -n flag is provided. Files
1518 with extensions .gdb, .py and .scm are supported as long as GDB was
1519 compiled with support for that language.
1521 * GDB now supports multithreaded symbol loading for higher performance.
1522 This feature is still in testing, so it is disabled by default. You
1523 can turn it on using 'maint set worker-threads unlimited'.
1527 ** The gdb.Value type has a new method 'format_string' which returns a
1528 string representing the value. The formatting is controlled by the
1529 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1530 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1531 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1533 ** gdb.Type has a new property 'objfile' which returns the objfile the
1534 type was defined in.
1536 ** The frame information printed by the python frame filtering code
1537 is now consistent with what the 'backtrace' command prints when
1538 there are no filters, or when the 'backtrace' '-no-filters' option
1541 ** The new function gdb.lookup_static_symbol can be used to look up
1542 symbols with static linkage.
1544 ** The new function gdb.lookup_static_symbols can be used to look up
1545 all static symbols with static linkage.
1547 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1548 'lookup_static_symbol' to lookup a symbol from this objfile only.
1550 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1551 this block (e.g. block['local_variable']).
1555 | [COMMAND] | SHELL_COMMAND
1556 | -d DELIM COMMAND DELIM SHELL_COMMAND
1557 pipe [COMMAND] | SHELL_COMMAND
1558 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1559 Executes COMMAND and sends its output to SHELL_COMMAND.
1560 With no COMMAND, repeat the last executed command
1561 and send its output to SHELL_COMMAND.
1563 define-prefix COMMAND
1564 Define or mark a command as a user-defined prefix command.
1566 with SETTING [VALUE] [-- COMMAND]
1567 w SETTING [VALUE] [-- COMMAND]
1568 Temporarily set SETTING, run COMMAND, and restore SETTING.
1569 Usage: with SETTING -- COMMAND
1570 With no COMMAND, repeats the last executed command.
1571 SETTING is any GDB setting you can change with the "set"
1572 subcommands. For example, 'with language c -- print someobj'
1573 temporarily switches to the C language in order to print someobj.
1574 Settings can be combined: 'w lang c -- w print elements unlimited --
1575 usercmd' switches to the C language and runs usercmd with no limit
1576 of array elements to print.
1578 maint with SETTING [VALUE] [-- COMMAND]
1579 Like "with", but works with "maintenance set" settings.
1581 set may-call-functions [on|off]
1582 show may-call-functions
1583 This controls whether GDB will attempt to call functions in
1584 the program, such as with expressions in the print command. It
1585 defaults to on. Calling functions in the program being debugged
1586 can have undesired side effects. It is now possible to forbid
1587 such function calls. If function calls are forbidden, GDB will throw
1588 an error when a command (such as print expression) calls a function
1591 set print finish [on|off]
1593 This controls whether the `finish' command will display the value
1594 that is returned by the current function. When `off', the value is
1595 still entered into the value history, but it is not printed. The
1599 show print max-depth
1600 Allows deeply nested structures to be simplified when printing by
1601 replacing deeply nested parts (beyond the max-depth) with ellipses.
1602 The default max-depth is 20, but this can be set to unlimited to get
1603 the old behavior back.
1605 set print raw-values [on|off]
1606 show print raw-values
1607 By default, GDB applies the enabled pretty printers when printing a
1608 value. This allows to ignore the enabled pretty printers for a series
1609 of commands. The default is 'off'.
1611 set logging debugredirect [on|off]
1612 By default, GDB debug output will go to both the terminal and the logfile.
1613 Set if you want debug output to go only to the log file.
1615 set style title foreground COLOR
1616 set style title background COLOR
1617 set style title intensity VALUE
1618 Control the styling of titles.
1620 set style highlight foreground COLOR
1621 set style highlight background COLOR
1622 set style highlight intensity VALUE
1623 Control the styling of highlightings.
1625 maint set worker-threads
1626 maint show worker-threads
1627 Control the number of worker threads that can be used by GDB. The
1628 default is 0. "unlimited" lets GDB choose a number that is
1629 reasonable. Currently worker threads are only used when demangling
1630 the names of linker symbols.
1632 set style tui-border foreground COLOR
1633 set style tui-border background COLOR
1634 Control the styling of TUI borders.
1636 set style tui-active-border foreground COLOR
1637 set style tui-active-border background COLOR
1638 Control the styling of the active TUI border.
1640 maint set test-settings KIND
1641 maint show test-settings KIND
1642 A set of commands used by the testsuite for exercising the settings
1645 maint set tui-resize-message [on|off]
1646 maint show tui-resize-message
1647 Control whether GDB prints a message each time the terminal is
1648 resized when in TUI mode. This is primarily useful for testing the
1651 set print frame-info [short-location|location|location-and-address
1652 |source-and-location|source-line|auto]
1653 show print frame-info
1654 This controls what frame information is printed by the commands printing
1655 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1656 'frame', 'stepi'. The python frame filtering also respect this setting.
1657 The 'backtrace' '-frame-info' option can override this global setting.
1659 set tui compact-source
1660 show tui compact-source
1662 Enable the "compact" display mode for the TUI source window. The
1663 compact display uses only as much space as is needed for the line
1664 numbers in the current file, and only a single space to separate the
1665 line numbers from the source.
1667 info modules [-q] [REGEXP]
1668 Return a list of Fortran modules matching REGEXP, or all modules if
1671 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1672 Return a list of functions within all modules, grouped by module.
1673 The list of functions can be restricted with the optional regular
1674 expressions. MODULE_REGEXP matches against the module name,
1675 TYPE_REGEXP matches against the function type signature, and REGEXP
1676 matches against the function name.
1678 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1679 Return a list of variables within all modules, grouped by module.
1680 The list of variables can be restricted with the optional regular
1681 expressions. MODULE_REGEXP matches against the module name,
1682 TYPE_REGEXP matches against the variable type, and REGEXP matches
1683 against the variable name.
1685 set debug remote-packet-max-chars
1686 show debug remote-packet-max-chars
1687 Controls the number of characters to output in a remote packet when using
1689 The default is 512 bytes.
1692 Lists the target connections currently in use.
1697 The "help" command uses the title style to enhance the
1698 readibility of its output by styling the classes and
1702 Similarly to "help", the "apropos" command also uses the
1703 title style for the command names. "apropos" accepts now
1704 a flag "-v" (verbose) to show the full documentation
1705 of matching commands and to use the highlight style to mark
1706 the documentation parts matching REGEXP.
1710 The GDB printf and eval commands can now print C-style and Ada-style
1711 string convenience variables without calling functions in the program.
1712 This allows to do formatted printing of strings without having
1713 a running inferior, or when debugging a core dump.
1715 info sources [-dirname | -basename] [--] [REGEXP]
1716 This command has now optional arguments to only print the files
1717 whose names match REGEXP. The arguments -dirname and -basename
1718 allow to restrict matching respectively to the dirname and basename
1722 The "show style" and its subcommands are now styling
1723 a style name in their output using its own style, to help
1724 the user visualize the different styles.
1726 set print frame-arguments
1727 The new value 'presence' indicates to only indicate the presence of
1728 arguments using ..., instead of printing argument names and values.
1730 set print raw-frame-arguments
1731 show print raw-frame-arguments
1733 These commands replace the similarly-named "set/show print raw
1734 frame-arguments" commands (now with a dash instead of a space). The
1735 old commands are now deprecated and may be removed in a future
1738 add-inferior [-no-connection]
1739 The add-inferior command now supports a "-no-connection" flag that
1740 makes the new inferior start with no target connection associated.
1741 By default, the new inferior inherits the target connection of the
1742 current inferior. See also "info connections".
1745 This command's output now includes a new "Connection" column
1746 indicating which target connection an inferior is bound to. See
1747 "info connections" above.
1749 maint test-options require-delimiter
1750 maint test-options unknown-is-error
1751 maint test-options unknown-is-operand
1752 maint show test-options-completion-result
1753 Commands used by the testsuite to validate the command options
1756 focus, winheight, +, -, >, <
1757 These commands are now case-sensitive.
1759 * New command options, command completion
1761 GDB now has a standard infrastructure to support dash-style command
1762 options ('-OPT'). One benefit is that commands that use it can
1763 easily support completion of command line arguments. Try "CMD
1764 -[TAB]" or "help CMD" to find options supported by a command. Over
1765 time, we intend to migrate most commands to this infrastructure. A
1766 number of commands got support for new command options in this
1769 ** The "print" and "compile print" commands now support a number of
1770 options that allow overriding relevant global print settings as
1771 set by "set print" subcommands:
1775 -array-indexes [on|off]
1776 -elements NUMBER|unlimited
1780 -raw-values [on|off]
1781 -repeats NUMBER|unlimited
1782 -static-members [on|off]
1787 Note that because the "print"/"compile print" commands accept
1788 arbitrary expressions which may look like options (including
1789 abbreviations), if you specify any command option, then you must
1790 use a double dash ("--") to mark the end of argument processing.
1792 ** The "backtrace" command now supports a number of options that
1793 allow overriding relevant global print settings as set by "set
1794 backtrace" and "set print" subcommands:
1796 -entry-values no|only|preferred|if-needed|both|compact|default
1797 -frame-arguments all|scalars|none
1798 -raw-frame-arguments [on|off]
1799 -frame-info auto|source-line|location|source-and-location
1800 |location-and-address|short-location
1802 -past-entry [on|off]
1804 In addition, the full/no-filters/hide qualifiers are now also
1805 exposed as command options too:
1811 ** The "frame apply", "tfaas" and "faas" commands similarly now
1812 support the following options:
1815 -past-entry [on|off]
1817 ** The new "info sources" options -dirname and -basename options
1818 are using the standard '-OPT' infrastructure.
1820 All options above can also be abbreviated. The argument of boolean
1821 (on/off) options can be 0/1 too, and also the argument is assumed
1822 "on" if omitted. This allows writing compact command invocations,
1825 (gdb) p -ra -p -o 0 -- *myptr
1827 The above is equivalent to:
1829 (gdb) print -raw-values -pretty -object off -- *myptr
1831 ** The "info types" command now supports the '-q' flag to disable
1832 printing of some header information in a similar fashion to "info
1833 variables" and "info functions".
1835 ** The "info variables", "info functions", and "whereis" commands
1836 now take a '-n' flag that excludes non-debug symbols (symbols
1837 from the symbol table, not from the debug info such as DWARF)
1840 * Completion improvements
1842 ** GDB can now complete the options of the "thread apply all" and
1843 "taas" commands, and their "-ascending" option can now be
1846 ** GDB can now complete the options of the "info threads", "info
1847 functions", "info variables", "info locals", and "info args"
1850 ** GDB can now complete the options of the "compile file" and
1851 "compile code" commands. The "compile file" command now
1852 completes on filenames.
1854 ** GDB can now complete the backtrace command's
1855 "full/no-filters/hide" qualifiers.
1857 * In settings, you can now abbreviate "unlimited".
1859 E.g., "set print elements u" is now equivalent to "set print
1860 elements unlimited".
1865 This lists all the possible completions for the rest of the line, if it
1866 were to be given as a command itself. This is intended for use by MI
1867 frontends in cases when separate CLI and MI channels cannot be used.
1869 -catch-throw, -catch-rethrow, and -catch-catch
1870 These can be used to catch C++ exceptions in a similar fashion to
1871 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1873 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1874 These commands are the MI equivalent of the CLI commands 'info
1875 functions', 'info types', and 'info variables' respectively.
1877 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1880 -symbol-info-module-functions and -symbol-info-module-variables.
1881 These commands are the MI equivalent of the CLI commands 'info
1882 module functions' and 'info module variables'.
1886 ** The default version of the MI interpreter is now 3 (-i=mi3).
1888 ** The output of information about multi-location breakpoints (which is
1889 syntactically incorrect in MI 2) has changed in MI 3. This affects
1890 the following commands and events:
1894 - =breakpoint-created
1895 - =breakpoint-modified
1897 The -fix-multi-location-breakpoint-output command can be used to enable
1898 this behavior with previous MI versions.
1900 ** Backtraces and frames include a new optional field addr_flags which is
1901 given after the addr field. On AArch64 this contains PAC if the address
1902 has been masked in the frame. On all other targets the field is not
1907 The testsuite now creates the files gdb.cmd (containing the arguments
1908 used to launch GDB) and gdb.in (containing all the commands sent to
1909 GDB) in the output directory for each test script. Multiple invocations
1910 are appended with .1, .2, .3 etc.
1912 * Building GDB and GDBserver now requires GNU make >= 3.82.
1914 Using another implementation of the make program or an earlier version of
1915 GNU make to build GDB or GDBserver is not supported.
1917 * Building GDB now requires GNU readline >= 7.0.
1919 GDB now bundles GNU readline 8.0, but if you choose to use
1920 --with-system-readline, only readline >= 7.0 can be used.
1922 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1923 from .inputrc to bind keys in this keymap. This feature is only
1924 available when gdb is built against GNU readline 8.0 or later.
1926 * Removed targets and native configurations
1928 GDB no longer supports debugging the Cell Broadband Engine. This includes
1929 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1930 of Cell/B.E. applications that use both the PPU and SPU architectures.
1936 * Removed targets and native configurations
1938 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1939 sparc*-*-solaris2.10
1941 *** Changes in GDB 8.3
1943 * GDB and GDBserver now support access to additional registers on
1944 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1947 * GDB now has experimental support for the compilation and injection of
1948 C++ source code into the inferior. This beta release does not include
1949 support for several language features, such as templates, constructors,
1952 This feature requires GCC 7.1 or higher built with libcp1.so
1955 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1956 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1957 'ADDRESS:PORT' method.
1959 * DWARF index cache: GDB can now automatically save indices of DWARF
1960 symbols on disk to speed up further loading of the same binaries.
1962 * Ada task switching is now supported on aarch64-elf targets when
1963 debugging a program using the Ravenscar Profile. For more information,
1964 see the "Tasking Support when using the Ravenscar Profile" section
1965 in the GDB user manual.
1967 * GDB in batch mode now exits with status 1 if the last command to be
1970 * The RISC-V target now supports target descriptions.
1972 * System call catchpoints now support system call aliases on FreeBSD.
1973 When the ABI of a system call changes in FreeBSD, this is
1974 implemented by leaving a compatibility system call using the old ABI
1975 at the existing number and allocating a new system call number for
1976 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1977 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1978 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1979 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1980 so that a system call catchpoint for the 'kevent' system call will
1981 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1982 binaries. This ensures that 'kevent' system calls are caught for
1983 binaries using either the old or new ABIs.
1985 * Terminal styling is now available for the CLI and the TUI. GNU
1986 Source Highlight can additionally be used to provide styling of
1987 source code snippets. See the "set style" commands, below, for more
1990 * Removed support for old demangling styles arm, edg, gnu, hp and
1995 set debug compile-cplus-types
1996 show debug compile-cplus-types
1997 Control the display of debug output about type conversion in the
1998 C++ compile feature. Commands have no effect while compiling
1999 for other languages.
2003 Control whether debug output about files/functions skipping is
2006 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
2007 Apply a command to some frames.
2008 FLAG arguments allow to control what output to produce and how to handle
2009 errors raised when applying COMMAND to a frame.
2012 Apply a command to all threads (ignoring errors and empty output).
2013 Shortcut for 'thread apply all -s COMMAND'.
2016 Apply a command to all frames (ignoring errors and empty output).
2017 Shortcut for 'frame apply all -s COMMAND'.
2020 Apply a command to all frames of all threads (ignoring errors and empty
2022 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
2024 maint set dwarf unwinders (on|off)
2025 maint show dwarf unwinders
2026 Control whether DWARF unwinders can be used.
2029 Display a list of open files for a process.
2033 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2034 These commands all now take a frame specification which
2035 is either a frame level, or one of the keywords 'level', 'address',
2036 'function', or 'view' followed by a parameter. Selecting a frame by
2037 address, or viewing a frame outside the current backtrace now
2038 requires the use of a keyword. Selecting a frame by level is
2039 unchanged. The MI comment "-stack-select-frame" is unchanged.
2041 target remote FILENAME
2042 target extended-remote FILENAME
2043 If FILENAME is a Unix domain socket, GDB will attempt to connect
2044 to this socket instead of opening FILENAME as a character device.
2046 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2047 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2048 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2049 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2050 These commands can now print only the searched entities
2051 matching the provided regexp(s), giving a condition
2052 on the entity names or entity types. The flag -q disables
2053 printing headers or informations messages.
2059 These commands now determine the syntax for the shown entities
2060 according to the language chosen by `set language'. In particular,
2061 `set language auto' means to automatically choose the language of
2064 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2065 The 'thread apply' command accepts new FLAG arguments.
2066 FLAG arguments allow to control what output to produce and how to handle
2067 errors raised when applying COMMAND to a thread.
2069 set tui tab-width NCHARS
2070 show tui tab-width NCHARS
2071 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2073 set style enabled [on|off]
2075 Enable or disable terminal styling. Styling is enabled by default
2076 on most hosts, but disabled by default when in batch mode.
2078 set style sources [on|off]
2080 Enable or disable source code styling. Source code styling is
2081 enabled by default, but only takes effect if styling in general is
2082 enabled, and if GDB was linked with GNU Source Highlight.
2084 set style filename foreground COLOR
2085 set style filename background COLOR
2086 set style filename intensity VALUE
2087 Control the styling of file names.
2089 set style function foreground COLOR
2090 set style function background COLOR
2091 set style function intensity VALUE
2092 Control the styling of function names.
2094 set style variable foreground COLOR
2095 set style variable background COLOR
2096 set style variable intensity VALUE
2097 Control the styling of variable names.
2099 set style address foreground COLOR
2100 set style address background COLOR
2101 set style address intensity VALUE
2102 Control the styling of addresses.
2106 ** The '-data-disassemble' MI command now accepts an '-a' option to
2107 disassemble the whole function surrounding the given program
2108 counter value or function name. Support for this feature can be
2109 verified by using the "-list-features" command, which should
2110 contain "data-disassemble-a-option".
2112 ** Command responses and notifications that include a frame now include
2113 the frame's architecture in a new "arch" attribute.
2115 * New native configurations
2117 GNU/Linux/RISC-V riscv*-*-linux*
2118 FreeBSD/riscv riscv*-*-freebsd*
2122 GNU/Linux/RISC-V riscv*-*-linux*
2123 CSKY ELF csky*-*-elf
2124 CSKY GNU/LINUX csky*-*-linux
2125 FreeBSD/riscv riscv*-*-freebsd*
2127 GNU/Linux/OpenRISC or1k*-*-linux*
2131 GDB no longer supports native debugging on versions of MS-Windows
2136 ** GDB no longer supports Python versions less than 2.6.
2138 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2139 space associated to that inferior.
2141 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2142 of objfiles associated to that program space.
2144 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2145 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2148 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2149 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2150 correct and did not work properly.
2152 ** The gdb.Value type has a new constructor, which is used to construct a
2153 gdb.Value from a Python buffer object and a gdb.Type.
2159 Enable or disable the undefined behavior sanitizer. This is
2160 disabled by default, but passing --enable-ubsan=yes or
2161 --enable-ubsan=auto to configure will enable it. Enabling this can
2162 cause a performance penalty. The undefined behavior sanitizer was
2163 first introduced in GCC 4.9.
2165 *** Changes in GDB 8.2
2167 * The 'set disassembler-options' command now supports specifying options
2168 for the MIPS target.
2170 * The 'symbol-file' command now accepts an '-o' option to add a relative
2171 offset to all sections.
2173 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2174 a relative offset to all sections, but it allows to override the load
2175 address of individual sections using '-s'.
2177 * The 'add-symbol-file' command no longer requires the second argument
2178 (address of the text section).
2180 * The endianness used with the 'set endian auto' mode in the absence of
2181 an executable selected for debugging is now the last endianness chosen
2182 either by one of the 'set endian big' and 'set endian little' commands
2183 or by inferring from the last executable used, rather than the startup
2186 * The pager now allows a "c" response, meaning to disable the pager
2187 for the rest of the current command.
2189 * The commands 'info variables/functions/types' now show the source line
2190 numbers of symbol definitions when available.
2192 * 'info proc' now works on running processes on FreeBSD systems and core
2193 files created on FreeBSD systems.
2195 * C expressions can now use _Alignof, and C++ expressions can now use
2198 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2199 the vector length while the process is running.
2205 Control display of debugging info regarding the FreeBSD native target.
2207 set|show varsize-limit
2208 This new setting allows the user to control the maximum size of Ada
2209 objects being printed when those objects have a variable type,
2210 instead of that maximum size being hardcoded to 65536 bytes.
2212 set|show record btrace cpu
2213 Controls the processor to be used for enabling errata workarounds for
2214 branch trace decode.
2216 maint check libthread-db
2217 Run integrity checks on the current inferior's thread debugging
2220 maint set check-libthread-db (on|off)
2221 maint show check-libthread-db
2222 Control whether to run integrity checks on inferior specific thread
2223 debugging libraries as they are loaded. The default is not to
2224 perform such checks.
2228 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2230 ** The commands attached to a breakpoint can be set by assigning to
2231 the breakpoint's "commands" field.
2233 ** gdb.execute can now execute multi-line gdb commands.
2235 ** The new functions gdb.convenience_variable and
2236 gdb.set_convenience_variable can be used to get and set the value
2237 of convenience variables.
2239 ** A gdb.Parameter will no longer print the "set" help text on an
2240 ordinary "set"; instead by default a "set" will be silent unless
2241 the get_set_string method returns a non-empty string.
2245 RiscV ELF riscv*-*-elf
2247 * Removed targets and native configurations
2249 m88k running OpenBSD m88*-*-openbsd*
2250 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2251 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2252 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2254 * Aarch64/Linux hardware watchpoints improvements
2256 Hardware watchpoints on unaligned addresses are now properly
2257 supported when running Linux kernel 4.10 or higher: read and access
2258 watchpoints are no longer spuriously missed, and all watchpoints
2259 lengths between 1 and 8 bytes are supported. On older kernels,
2260 watchpoints set on unaligned addresses are no longer missed, with
2261 the tradeoff that there is a possibility of false hits being
2266 --enable-codesign=CERT
2267 This can be used to invoke "codesign -s CERT" after building gdb.
2268 This option is useful on macOS, where code signing is required for
2269 gdb to work properly.
2271 --disable-gdbcli has been removed
2272 This is now silently accepted, but does nothing.
2274 *** Changes in GDB 8.1
2276 * GDB now supports dynamically creating arbitrary register groups specified
2277 in XML target descriptions. This allows for finer grain grouping of
2278 registers on systems with a large amount of registers.
2280 * The 'ptype' command now accepts a '/o' flag, which prints the
2281 offsets and sizes of fields in a struct, like the pahole(1) tool.
2283 * New "--readnever" command line option instructs GDB to not read each
2284 symbol file's symbolic debug information. This makes startup faster
2285 but at the expense of not being able to perform symbolic debugging.
2286 This option is intended for use cases where symbolic debugging will
2287 not be used, e.g., when you only need to dump the debuggee's core.
2289 * GDB now uses the GNU MPFR library, if available, to emulate target
2290 floating-point arithmetic during expression evaluation when the target
2291 uses different floating-point formats than the host. At least version
2292 3.1 of GNU MPFR is required.
2294 * GDB now supports access to the guarded-storage-control registers and the
2295 software-based guarded-storage broadcast control registers on IBM z14.
2297 * On Unix systems, GDB now supports transmitting environment variables
2298 that are to be set or unset to GDBserver. These variables will
2299 affect the environment to be passed to the remote inferior.
2301 To inform GDB of environment variables that are to be transmitted to
2302 GDBserver, use the "set environment" command. Only user set
2303 environment variables are sent to GDBserver.
2305 To inform GDB of environment variables that are to be unset before
2306 the remote inferior is started by the GDBserver, use the "unset
2307 environment" command.
2309 * Completion improvements
2311 ** GDB can now complete function parameters in linespecs and
2312 explicit locations without quoting. When setting breakpoints,
2313 quoting around functions names to help with TAB-completion is
2314 generally no longer necessary. For example, this now completes
2317 (gdb) b function(in[TAB]
2318 (gdb) b function(int)
2320 Related, GDB is no longer confused with completing functions in
2321 C++ anonymous namespaces:
2324 (gdb) b (anonymous namespace)::[TAB][TAB]
2325 (anonymous namespace)::a_function()
2326 (anonymous namespace)::b_function()
2328 ** GDB now has much improved linespec and explicit locations TAB
2329 completion support, that better understands what you're
2330 completing and offers better suggestions. For example, GDB no
2331 longer offers data symbols as possible completions when you're
2332 setting a breakpoint.
2334 ** GDB now TAB-completes label symbol names.
2336 ** The "complete" command now mimics TAB completion accurately.
2338 * New command line options (gcore)
2341 Dump all memory mappings.
2343 * Breakpoints on C++ functions are now set on all scopes by default
2345 By default, breakpoints on functions/methods are now interpreted as
2346 specifying all functions with the given name ignoring missing
2347 leading scopes (namespaces and classes).
2349 For example, assuming a C++ program with symbols named:
2354 both commands "break func()" and "break B::func()" set a breakpoint
2357 You can use the new flag "-qualified" to override this. This makes
2358 GDB interpret the specified function name as a complete
2359 fully-qualified name instead. For example, using the same C++
2360 program, the "break -q B::func" command sets a breakpoint on
2361 "B::func", only. A parameter has been added to the Python
2362 gdb.Breakpoint constructor to achieve the same result when creating
2363 a breakpoint from Python.
2365 * Breakpoints on functions marked with C++ ABI tags
2367 GDB can now set breakpoints on functions marked with C++ ABI tags
2368 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2369 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2371 Functions with a C++11 abi tag are demangled/displayed like this:
2373 function[abi:cxx11](int)
2376 You can now set a breakpoint on such functions simply as if they had
2379 (gdb) b function(int)
2381 Or if you need to disambiguate between tags, like:
2383 (gdb) b function[abi:other_tag](int)
2385 Tab completion was adjusted accordingly as well.
2389 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2390 gdb.new_thread are emitted. See the manual for further
2391 description of these.
2393 ** A new function, "gdb.rbreak" has been added to the Python API.
2394 This function allows the setting of a large number of breakpoints
2395 via a regex pattern in Python. See the manual for further details.
2397 ** Python breakpoints can now accept explicit locations. See the
2398 manual for a further description of this feature.
2401 * New features in the GDB remote stub, GDBserver
2403 ** GDBserver is now able to start inferior processes with a
2404 specified initial working directory.
2406 The user can set the desired working directory to be used from
2407 GDB using the new "set cwd" command.
2409 ** New "--selftest" command line option runs some GDBserver self
2410 tests. These self tests are disabled in releases.
2412 ** On Unix systems, GDBserver now does globbing expansion and variable
2413 substitution in inferior command line arguments.
2415 This is done by starting inferiors using a shell, like GDB does.
2416 See "set startup-with-shell" in the user manual for how to disable
2417 this from GDB when using "target extended-remote". When using
2418 "target remote", you can disable the startup with shell by using the
2419 new "--no-startup-with-shell" GDBserver command line option.
2421 ** On Unix systems, GDBserver now supports receiving environment
2422 variables that are to be set or unset from GDB. These variables
2423 will affect the environment to be passed to the inferior.
2425 * When catching an Ada exception raised with a message, GDB now prints
2426 the message in the catchpoint hit notification. In GDB/MI mode, that
2427 information is provided as an extra field named "exception-message"
2428 in the *stopped notification.
2430 * Trait objects can now be inspected When debugging Rust code. This
2431 requires compiler support which will appear in Rust 1.24.
2433 * New remote packets
2435 QEnvironmentHexEncoded
2436 Inform GDBserver of an environment variable that is to be passed to
2437 the inferior when starting it.
2440 Inform GDBserver of an environment variable that is to be unset
2441 before starting the remote inferior.
2444 Inform GDBserver that the environment should be reset (i.e.,
2445 user-set environment variables should be unset).
2448 Indicates whether the inferior must be started with a shell or not.
2451 Tell GDBserver that the inferior to be started should use a specific
2454 * The "maintenance print c-tdesc" command now takes an optional
2455 argument which is the file name of XML target description.
2457 * The "maintenance selftest" command now takes an optional argument to
2458 filter the tests to be run.
2460 * The "enable", and "disable" commands now accept a range of
2461 breakpoint locations, e.g. "enable 1.3-5".
2466 Set and show the current working directory for the inferior.
2468 set|show compile-gcc
2469 Set and show compilation command used for compiling and injecting code
2470 with the 'compile' commands.
2472 set debug separate-debug-file
2473 show debug separate-debug-file
2474 Control the display of debug output about separate debug file search.
2476 set dump-excluded-mappings
2477 show dump-excluded-mappings
2478 Control whether mappings marked with the VM_DONTDUMP flag should be
2479 dumped when generating a core file.
2481 maint info selftests
2482 List the registered selftests.
2485 Start the debugged program stopping at the first instruction.
2488 Control display of debugging messages related to OpenRISC targets.
2490 set|show print type nested-type-limit
2491 Set and show the limit of nesting level for nested types that the
2492 type printer will show.
2494 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2497 * Safer/improved support for debugging with no debug info
2499 GDB no longer assumes functions with no debug information return
2502 This means that GDB now refuses to call such functions unless you
2503 tell it the function's type, by either casting the call to the
2504 declared return type, or by casting the function to a function
2505 pointer of the right type, and calling that:
2507 (gdb) p getenv ("PATH")
2508 'getenv' has unknown return type; cast the call to its declared return type
2509 (gdb) p (char *) getenv ("PATH")
2510 $1 = 0x7fffffffe "/usr/local/bin:/"...
2511 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2512 $2 = 0x7fffffffe "/usr/local/bin:/"...
2514 Similarly, GDB no longer assumes that global variables with no debug
2515 info have type 'int', and refuses to print the variable's value
2516 unless you tell it the variable's type:
2519 'var' has unknown type; cast it to its declared type
2523 * New native configurations
2525 FreeBSD/aarch64 aarch64*-*-freebsd*
2526 FreeBSD/arm arm*-*-freebsd*
2530 FreeBSD/aarch64 aarch64*-*-freebsd*
2531 FreeBSD/arm arm*-*-freebsd*
2532 OpenRISC ELF or1k*-*-elf
2534 * Removed targets and native configurations
2536 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2538 *** Changes in GDB 8.0
2540 * GDB now supports access to the PKU register on GNU/Linux. The register is
2541 added by the Memory Protection Keys for Userspace feature which will be
2542 available in future Intel CPUs.
2544 * GDB now supports C++11 rvalue references.
2548 ** New functions to start, stop and access a running btrace recording.
2549 ** Rvalue references are now supported in gdb.Type.
2551 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2554 * Building GDB and GDBserver now requires a C++11 compiler.
2556 For example, GCC 4.8 or later.
2558 It is no longer possible to build GDB or GDBserver with a C
2559 compiler. The --disable-build-with-cxx configure option has been
2562 * Building GDB and GDBserver now requires GNU make >= 3.81.
2564 It is no longer supported to build GDB or GDBserver with another
2565 implementation of the make program or an earlier version of GNU make.
2567 * Native debugging on MS-Windows supports command-line redirection
2569 Command-line arguments used for starting programs on MS-Windows can
2570 now include redirection symbols supported by native Windows shells,
2571 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2572 as "run", "start", and "set args", as well as the corresponding MI
2575 * Support for thread names on MS-Windows.
2577 GDB now catches and handles the special exception that programs
2578 running on MS-Windows use to assign names to threads in the
2581 * Support for Java programs compiled with gcj has been removed.
2583 * User commands now accept an unlimited number of arguments.
2584 Previously, only up to 10 was accepted.
2586 * The "eval" command now expands user-defined command arguments.
2588 This makes it easier to process a variable number of arguments:
2593 eval "print $arg%d", $i
2598 * Target descriptions can now describe registers for sparc32 and sparc64.
2600 * GDB now supports DWARF version 5 (debug information format).
2601 Its .debug_names index is not yet supported.
2603 * New native configurations
2605 FreeBSD/mips mips*-*-freebsd
2609 Synopsys ARC arc*-*-elf32
2610 FreeBSD/mips mips*-*-freebsd
2612 * Removed targets and native configurations
2614 Alpha running FreeBSD alpha*-*-freebsd*
2615 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2620 Erases all the flash memory regions reported by the target.
2622 maint print arc arc-instruction address
2623 Print internal disassembler information about instruction at a given address.
2627 set disassembler-options
2628 show disassembler-options
2629 Controls the passing of target specific information to the disassembler.
2630 If it is necessary to specify more than one disassembler option then
2631 multiple options can be placed together into a comma separated list.
2632 The default value is the empty string. Currently, the only supported
2633 targets are ARM, PowerPC and S/390.
2638 Erases all the flash memory regions reported by the target. This is
2639 equivalent to the CLI command flash-erase.
2641 -file-list-shared-libraries
2642 List the shared libraries in the program. This is
2643 equivalent to the CLI command "info shared".
2646 Catchpoints stopping the program when Ada exceptions are
2647 handled. This is equivalent to the CLI command "catch handlers".
2649 *** Changes in GDB 7.12
2651 * GDB and GDBserver now build with a C++ compiler by default.
2653 The --enable-build-with-cxx configure option is now enabled by
2654 default. One must now explicitly configure with
2655 --disable-build-with-cxx in order to build with a C compiler. This
2656 option will be removed in a future release.
2658 * GDBserver now supports recording btrace without maintaining an active
2661 * GDB now supports a negative repeat count in the 'x' command to examine
2662 memory backward from the given address. For example:
2665 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2666 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2667 (gdb) x/-5i 0x0000000000400580
2668 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2669 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2670 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2671 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2672 0x40057b <main(int, char**)+25>:
2673 callq 0x400536 <Func1(int, char const*)>
2675 * Fortran: Support structures with fields of dynamic types and
2676 arrays of dynamic types.
2678 * The symbol dumping maintenance commands have new syntax.
2679 maint print symbols [-pc address] [--] [filename]
2680 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2681 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2682 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2683 maint print msymbols [-objfile objfile] [--] [filename]
2685 * GDB now supports multibit bitfields and enums in target register
2688 * New Python-based convenience function $_as_string(val), which returns
2689 the textual representation of a value. This function is especially
2690 useful to obtain the text label of an enum value.
2692 * Intel MPX bound violation handling.
2694 Segmentation faults caused by a Intel MPX boundary violation
2695 now display the kind of violation (upper or lower), the memory
2696 address accessed and the memory bounds, along with the usual
2697 signal received and code location.
2701 Program received signal SIGSEGV, Segmentation fault
2702 Upper bound violation while accessing address 0x7fffffffc3b3
2703 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2704 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2706 * Rust language support.
2707 GDB now supports debugging programs written in the Rust programming
2708 language. See https://www.rust-lang.org/ for more information about
2711 * Support for running interpreters on specified input/output devices
2713 GDB now supports a new mechanism that allows frontends to provide
2714 fully featured GDB console views, as a better alternative to
2715 building such views on top of the "-interpreter-exec console"
2716 command. See the new "new-ui" command below. With that command,
2717 frontends can now start GDB in the traditional command-line mode
2718 running in an embedded terminal emulator widget, and create a
2719 separate MI interpreter running on a specified i/o device. In this
2720 way, GDB handles line editing, history, tab completion, etc. in the
2721 console all by itself, and the GUI uses the separate MI interpreter
2722 for its own control and synchronization, invisible to the command
2725 * The "catch syscall" command catches groups of related syscalls.
2727 The "catch syscall" command now supports catching a group of related
2728 syscalls using the 'group:' or 'g:' prefix.
2733 skip -gfile file-glob-pattern
2734 skip -function function
2735 skip -rfunction regular-expression
2736 A generalized form of the skip command, with new support for
2737 glob-style file names and regular expressions for function names.
2738 Additionally, a file spec and a function spec may now be combined.
2740 maint info line-table REGEXP
2741 Display the contents of GDB's internal line table data structure.
2744 Run any GDB unit tests that were compiled in.
2747 Start a new user interface instance running INTERP as interpreter,
2748 using the TTY file for input/output.
2752 ** gdb.Breakpoint objects have a new attribute "pending", which
2753 indicates whether the breakpoint is pending.
2754 ** Three new breakpoint-related events have been added:
2755 gdb.breakpoint_created, gdb.breakpoint_modified, and
2756 gdb.breakpoint_deleted.
2758 signal-event EVENTID
2759 Signal ("set") the given MS-Windows event object. This is used in
2760 conjunction with the Windows JIT debugging (AeDebug) support, where
2761 the OS suspends a crashing process until a debugger can attach to
2762 it. Resuming the crashing process, in order to debug it, is done by
2763 signalling an event.
2765 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2766 was added in GDBserver, including JIT compiling fast tracepoint's
2767 conditional expression bytecode into native code.
2769 * Support for various remote target protocols and ROM monitors has
2772 target m32rsdi Remote M32R debugging over SDI
2773 target mips MIPS remote debugging protocol
2774 target pmon PMON ROM monitor
2775 target ddb NEC's DDB variant of PMON for Vr4300
2776 target rockhopper NEC RockHopper variant of PMON
2777 target lsi LSI variant of PMO
2779 * Support for tracepoints and fast tracepoints on powerpc-linux,
2780 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2781 including JIT compiling fast tracepoint's conditional expression
2782 bytecode into native code.
2784 * MI async record =record-started now includes the method and format used for
2785 recording. For example:
2787 =record-started,thread-group="i1",method="btrace",format="bts"
2789 * MI async record =thread-selected now includes the frame field. For example:
2791 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2795 Andes NDS32 nds32*-*-elf
2797 *** Changes in GDB 7.11
2799 * GDB now supports debugging kernel-based threads on FreeBSD.
2801 * Per-inferior thread numbers
2803 Thread numbers are now per inferior instead of global. If you're
2804 debugging multiple inferiors, GDB displays thread IDs using a
2805 qualified INF_NUM.THR_NUM form. For example:
2809 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2810 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2811 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2812 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2814 As consequence, thread numbers as visible in the $_thread
2815 convenience variable and in Python's InferiorThread.num attribute
2816 are no longer unique between inferiors.
2818 GDB now maintains a second thread ID per thread, referred to as the
2819 global thread ID, which is the new equivalent of thread numbers in
2820 previous releases. See also $_gthread below.
2822 For backwards compatibility, MI's thread IDs always refer to global
2825 * Commands that accept thread IDs now accept the qualified
2826 INF_NUM.THR_NUM form as well. For example:
2829 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2832 * In commands that accept a list of thread IDs, you can now refer to
2833 all threads of an inferior using a star wildcard. GDB accepts
2834 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2835 refer to all threads of the current inferior. For example, "info
2838 * You can use "info threads -gid" to display the global thread ID of
2841 * The new convenience variable $_gthread holds the global number of
2844 * The new convenience variable $_inferior holds the number of the
2847 * GDB now displays the ID and name of the thread that hit a breakpoint
2848 or received a signal, if your program is multi-threaded. For
2851 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2852 Thread 1 "main" received signal SIGINT, Interrupt.
2854 * Record btrace now supports non-stop mode.
2856 * Support for tracepoints on aarch64-linux was added in GDBserver.
2858 * The 'record instruction-history' command now indicates speculative execution
2859 when using the Intel Processor Trace recording format.
2861 * GDB now allows users to specify explicit locations, bypassing
2862 the linespec parser. This feature is also available to GDB/MI
2865 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2866 GDB now is able to debug both AArch64 applications and ARM applications
2869 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2870 including JIT compiling fast tracepoint's conditional expression bytecode
2873 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2875 * "info threads", "info inferiors", "info display", "info checkpoints"
2876 and "maint info program-spaces" now list the corresponding items in
2877 ascending ID order, for consistency with all other "info" commands.
2879 * In Ada, the overloads selection menu has been enhanced to display the
2880 parameter types and the return types for the matching overloaded subprograms.
2884 maint set target-non-stop (on|off|auto)
2885 maint show target-non-stop
2886 Control whether GDB targets always operate in non-stop mode even if
2887 "set non-stop" is "off". The default is "auto", meaning non-stop
2888 mode is enabled if supported by the target.
2890 maint set bfd-sharing
2891 maint show bfd-sharing
2892 Control the reuse of bfd objects.
2895 show debug bfd-cache
2896 Control display of debugging info regarding bfd caching.
2900 Control display of debugging info regarding FreeBSD threads.
2902 set remote multiprocess-extensions-packet
2903 show remote multiprocess-extensions-packet
2904 Set/show the use of the remote protocol multiprocess extensions.
2906 set remote thread-events
2907 show remote thread-events
2908 Set/show the use of thread create/exit events.
2910 set ada print-signatures on|off
2911 show ada print-signatures"
2912 Control whether parameter types and return types are displayed in overloads
2913 selection menus. It is activated (@code{on}) by default.
2917 Controls the maximum size of memory, in bytes, that GDB will
2918 allocate for value contents. Prevents incorrect programs from
2919 causing GDB to allocate overly large buffers. Default is 64k.
2921 * The "disassemble" command accepts a new modifier: /s.
2922 It prints mixed source+disassembly like /m with two differences:
2923 - disassembled instructions are now printed in program order, and
2924 - and source for all relevant files is now printed.
2925 The "/m" option is now considered deprecated: its "source-centric"
2926 output hasn't proved useful in practice.
2928 * The "record instruction-history" command accepts a new modifier: /s.
2929 It behaves exactly like /m and prints mixed source+disassembly.
2931 * The "set scheduler-locking" command supports a new mode "replay".
2932 It behaves like "off" in record mode and like "on" in replay mode.
2934 * Support for various ROM monitors has been removed:
2936 target dbug dBUG ROM monitor for Motorola ColdFire
2937 target picobug Motorola picobug monitor
2938 target dink32 DINK32 ROM monitor for PowerPC
2939 target m32r Renesas M32R/D ROM monitor
2940 target mon2000 mon2000 ROM monitor
2941 target ppcbug PPCBUG ROM monitor for PowerPC
2943 * Support for reading/writing memory and extracting values on architectures
2944 whose memory is addressable in units of any integral multiple of 8 bits.
2947 Allows to break when an Ada exception is handled.
2949 * New remote packets
2952 Indicates that an exec system call was executed.
2954 exec-events feature in qSupported
2955 The qSupported packet allows GDB to request support for exec
2956 events using the new 'gdbfeature' exec-event, and the qSupported
2957 response can contain the corresponding 'stubfeature'. Set and
2958 show commands can be used to display whether these features are enabled.
2961 Equivalent to interrupting with the ^C character, but works in
2964 thread created stop reason (T05 create:...)
2965 Indicates that the thread was just created and is stopped at entry.
2967 thread exit stop reply (w exitcode;tid)
2968 Indicates that the thread has terminated.
2971 Enables/disables thread create and exit event reporting. For
2972 example, this is used in non-stop mode when GDB stops a set of
2973 threads and synchronously waits for the their corresponding stop
2974 replies. Without exit events, if one of the threads exits, GDB
2975 would hang forever not knowing that it should no longer expect a
2976 stop for that same thread.
2979 Indicates that there are no resumed threads left in the target (all
2980 threads are stopped). The remote stub reports support for this stop
2981 reply to GDB's qSupported query.
2984 Enables/disables catching syscalls from the inferior process.
2985 The remote stub reports support for this packet to GDB's qSupported query.
2987 syscall_entry stop reason
2988 Indicates that a syscall was just called.
2990 syscall_return stop reason
2991 Indicates that a syscall just returned.
2993 * Extended-remote exec events
2995 ** GDB now has support for exec events on extended-remote Linux targets.
2996 For such targets with Linux kernels 2.5.46 and later, this enables
2997 follow-exec-mode and exec catchpoints.
2999 set remote exec-event-feature-packet
3000 show remote exec-event-feature-packet
3001 Set/show the use of the remote exec event feature.
3003 * Thread names in remote protocol
3005 The reply to qXfer:threads:read may now include a name attribute for each
3008 * Target remote mode fork and exec events
3010 ** GDB now has support for fork and exec events on target remote mode
3011 Linux targets. For such targets with Linux kernels 2.5.46 and later,
3012 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
3013 fork and exec catchpoints.
3015 * Remote syscall events
3017 ** GDB now has support for catch syscall on remote Linux targets,
3018 currently enabled on x86/x86_64 architectures.
3020 set remote catch-syscall-packet
3021 show remote catch-syscall-packet
3022 Set/show the use of the remote catch syscall feature.
3026 ** The -var-set-format command now accepts the zero-hexadecimal
3027 format. It outputs data in hexadecimal format with zero-padding on the
3032 ** gdb.InferiorThread objects have a new attribute "global_num",
3033 which refers to the thread's global thread ID. The existing
3034 "num" attribute now refers to the thread's per-inferior number.
3035 See "Per-inferior thread numbers" above.
3036 ** gdb.InferiorThread objects have a new attribute "inferior", which
3037 is the Inferior object the thread belongs to.
3039 *** Changes in GDB 7.10
3041 * Support for process record-replay and reverse debugging on aarch64*-linux*
3042 targets has been added. GDB now supports recording of A64 instruction set
3043 including advance SIMD instructions.
3045 * Support for Sun's version of the "stabs" debug file format has been removed.
3047 * GDB now honors the content of the file /proc/PID/coredump_filter
3048 (PID is the process ID) on GNU/Linux systems. This file can be used
3049 to specify the types of memory mappings that will be included in a
3050 corefile. For more information, please refer to the manual page of
3051 "core(5)". GDB also has a new command: "set use-coredump-filter
3052 on|off". It allows to set whether GDB will read the content of the
3053 /proc/PID/coredump_filter file when generating a corefile.
3055 * The "info os" command on GNU/Linux can now display information on
3057 "info os cpus" Listing of all cpus/cores on the system
3059 * GDB has two new commands: "set serial parity odd|even|none" and
3060 "show serial parity". These allows to set or show parity for the
3063 * The "info source" command now displays the producer string if it was
3064 present in the debug info. This typically includes the compiler version
3065 and may include things like its command line arguments.
3067 * The "info dll", an alias of the "info sharedlibrary" command,
3068 is now available on all platforms.
3070 * Directory names supplied to the "set sysroot" commands may be
3071 prefixed with "target:" to tell GDB to access shared libraries from
3072 the target system, be it local or remote. This replaces the prefix
3073 "remote:". The default sysroot has been changed from "" to
3074 "target:". "remote:" is automatically converted to "target:" for
3075 backward compatibility.
3077 * The system root specified by "set sysroot" will be prepended to the
3078 filename of the main executable (if reported to GDB as absolute by
3079 the operating system) when starting processes remotely, and when
3080 attaching to already-running local or remote processes.
3082 * GDB now supports automatic location and retrieval of executable
3083 files from remote targets. Remote debugging can now be initiated
3084 using only a "target remote" or "target extended-remote" command
3085 (no "set sysroot" or "file" commands are required). See "New remote
3088 * The "dump" command now supports verilog hex format.
3090 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3092 * On GNU/Linux, GDB and gdbserver are now able to access executable
3093 and shared library files without a "set sysroot" command when
3094 attaching to processes running in different mount namespaces from
3095 the debugger. This makes it possible to attach to processes in
3096 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3097 See "New remote packets" below.
3099 * The "tui reg" command now provides completion for all of the
3100 available register groups, including target specific groups.
3102 * The HISTSIZE environment variable is no longer read when determining
3103 the size of GDB's command history. GDB now instead reads the dedicated
3104 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3105 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3110 ** Memory ports can now be unbuffered.
3114 ** gdb.Objfile objects have a new attribute "username",
3115 which is the name of the objfile as specified by the user,
3116 without, for example, resolving symlinks.
3117 ** You can now write frame unwinders in Python.
3118 ** gdb.Type objects have a new method "optimized_out",
3119 returning optimized out gdb.Value instance of this type.
3120 ** gdb.Value objects have new methods "reference_value" and
3121 "const_value" which return a reference to the value and a
3122 "const" version of the value respectively.
3126 maint print symbol-cache
3127 Print the contents of the symbol cache.
3129 maint print symbol-cache-statistics
3130 Print statistics of symbol cache usage.
3132 maint flush-symbol-cache
3133 Flush the contents of the symbol cache.
3137 Start branch trace recording using Branch Trace Store (BTS) format.
3140 Evaluate expression by using the compiler and print result.
3144 Explicit commands for enabling and disabling tui mode.
3147 set mpx bound on i386 and amd64
3148 Support for bound table investigation on Intel MPX enabled applications.
3152 Start branch trace recording using Intel Processor Trace format.
3155 Print information about branch tracing internals.
3157 maint btrace packet-history
3158 Print the raw branch tracing data.
3160 maint btrace clear-packet-history
3161 Discard the stored raw branch tracing data.
3164 Discard all branch tracing data. It will be fetched and processed
3165 anew by the next "record" command.
3170 Renamed from "set debug dwarf2-die".
3171 show debug dwarf-die
3172 Renamed from "show debug dwarf2-die".
3174 set debug dwarf-read
3175 Renamed from "set debug dwarf2-read".
3176 show debug dwarf-read
3177 Renamed from "show debug dwarf2-read".
3179 maint set dwarf always-disassemble
3180 Renamed from "maint set dwarf2 always-disassemble".
3181 maint show dwarf always-disassemble
3182 Renamed from "maint show dwarf2 always-disassemble".
3184 maint set dwarf max-cache-age
3185 Renamed from "maint set dwarf2 max-cache-age".
3186 maint show dwarf max-cache-age
3187 Renamed from "maint show dwarf2 max-cache-age".
3189 set debug dwarf-line
3190 show debug dwarf-line
3191 Control display of debugging info regarding DWARF line processing.
3194 show max-completions
3195 Set the maximum number of candidates to be considered during
3196 completion. The default value is 200. This limit allows GDB
3197 to avoid generating large completion lists, the computation of
3198 which can cause the debugger to become temporarily unresponsive.
3200 set history remove-duplicates
3201 show history remove-duplicates
3202 Control the removal of duplicate history entries.
3204 maint set symbol-cache-size
3205 maint show symbol-cache-size
3206 Control the size of the symbol cache.
3208 set|show record btrace bts buffer-size
3209 Set and show the size of the ring buffer used for branch tracing in
3211 The obtained size may differ from the requested size. Use "info
3212 record" to see the obtained buffer size.
3214 set debug linux-namespaces
3215 show debug linux-namespaces
3216 Control display of debugging info regarding Linux namespaces.
3218 set|show record btrace pt buffer-size
3219 Set and show the size of the ring buffer used for branch tracing in
3220 Intel Processor Trace format.
3221 The obtained size may differ from the requested size. Use "info
3222 record" to see the obtained buffer size.
3224 maint set|show btrace pt skip-pad
3225 Set and show whether PAD packets are skipped when computing the
3228 * The command 'thread apply all' can now support new option '-ascending'
3229 to call its specified command for all threads in ascending order.
3231 * Python/Guile scripting
3233 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3234 special section named `.debug_gdb_scripts'.
3236 * New remote packets
3238 qXfer:btrace-conf:read
3239 Return the branch trace configuration for the current thread.
3241 Qbtrace-conf:bts:size
3242 Set the requested ring buffer size for branch tracing in BTS format.
3245 Enable Intel Processor Trace-based branch tracing for the current
3246 process. The remote stub reports support for this packet to GDB's
3249 Qbtrace-conf:pt:size
3250 Set the requested ring buffer size for branch tracing in Intel Processor
3254 Indicates a memory breakpoint instruction was executed, irrespective
3255 of whether it was GDB that planted the breakpoint or the breakpoint
3256 is hardcoded in the program. This is required for correct non-stop
3260 Indicates the target stopped for a hardware breakpoint. This is
3261 required for correct non-stop mode operation.
3264 Return information about files on the remote system.
3266 qXfer:exec-file:read
3267 Return the full absolute name of the file that was executed to
3268 create a process running on the remote system.
3271 Select the filesystem on which vFile: operations with filename
3272 arguments will operate. This is required for GDB to be able to
3273 access files on remote targets where the remote stub does not
3274 share a common filesystem with the inferior(s).
3277 Indicates that a fork system call was executed.
3280 Indicates that a vfork system call was executed.
3282 vforkdone stop reason
3283 Indicates that a vfork child of the specified process has executed
3284 an exec or exit, allowing the vfork parent to resume execution.
3286 fork-events and vfork-events features in qSupported
3287 The qSupported packet allows GDB to request support for fork and
3288 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3289 and the qSupported response can contain the corresponding
3290 'stubfeatures'. Set and show commands can be used to display
3291 whether these features are enabled.
3293 * Extended-remote fork events
3295 ** GDB now has support for fork events on extended-remote Linux
3296 targets. For targets with Linux kernels 2.5.60 and later, this
3297 enables follow-fork-mode and detach-on-fork for both fork and
3298 vfork, as well as fork and vfork catchpoints.
3300 * The info record command now shows the recording format and the
3301 branch tracing configuration for the current thread when using
3302 the btrace record target.
3303 For the BTS format, it shows the ring buffer size.
3305 * GDB now has support for DTrace USDT (Userland Static Defined
3306 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3308 * GDB now supports access to vector registers on S/390 GNU/Linux
3311 * Removed command line options
3313 -xdb HP-UX XDB compatibility mode.
3315 * Removed targets and native configurations
3317 HP/PA running HP-UX hppa*-*-hpux*
3318 Itanium running HP-UX ia64-*-hpux*
3320 * New configure options
3323 This configure option allows the user to build GDB with support for
3324 Intel Processor Trace (default: auto). This requires libipt.
3326 --with-libipt-prefix=PATH
3327 Specify the path to the version of libipt that GDB should use.
3328 $PATH/include should contain the intel-pt.h header and
3329 $PATH/lib should contain the libipt.so library.
3331 *** Changes in GDB 7.9.1
3335 ** Xmethods can now specify a result type.
3337 *** Changes in GDB 7.9
3339 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3343 ** You can now access frame registers from Python scripts.
3344 ** New attribute 'producer' for gdb.Symtab objects.
3345 ** gdb.Objfile objects have a new attribute "progspace",
3346 which is the gdb.Progspace object of the containing program space.
3347 ** gdb.Objfile objects have a new attribute "owner".
3348 ** gdb.Objfile objects have a new attribute "build_id",
3349 which is the build ID generated when the file was built.
3350 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3351 ** A new event "gdb.clear_objfiles" has been added, triggered when
3352 selecting a new file to debug.
3353 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3354 ** New function gdb.lookup_objfile.
3356 New events which are triggered when GDB modifies the state of the
3359 ** gdb.events.inferior_call_pre: Function call is about to be made.
3360 ** gdb.events.inferior_call_post: Function call has just been made.
3361 ** gdb.events.memory_changed: A memory location has been altered.
3362 ** gdb.events.register_changed: A register has been altered.
3364 * New Python-based convenience functions:
3366 ** $_caller_is(name [, number_of_frames])
3367 ** $_caller_matches(regexp [, number_of_frames])
3368 ** $_any_caller_is(name [, number_of_frames])
3369 ** $_any_caller_matches(regexp [, number_of_frames])
3371 * GDB now supports the compilation and injection of source code into
3372 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3373 to compile the source code to object code, and if successful, inject
3374 and execute that code within the current context of the inferior.
3375 Currently the C language is supported. The commands used to
3376 interface with this new feature are:
3378 compile code [-raw|-r] [--] [source code]
3379 compile file [-raw|-r] filename
3383 demangle [-l language] [--] name
3384 Demangle "name" in the specified language, or the current language
3385 if elided. This command is renamed from the "maint demangle" command.
3386 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3387 as "maint demangler-warning".
3389 queue-signal signal-name-or-number
3390 Queue a signal to be delivered to the thread when it is resumed.
3392 add-auto-load-scripts-directory directory
3393 Add entries to the list of directories from which to load auto-loaded
3396 maint print user-registers
3397 List all currently available "user" registers.
3399 compile code [-r|-raw] [--] [source code]
3400 Compile, inject, and execute in the inferior the executable object
3401 code produced by compiling the provided source code.
3403 compile file [-r|-raw] filename
3404 Compile and inject into the inferior the executable object code
3405 produced by compiling the source code stored in the filename
3408 * On resume, GDB now always passes the signal the program had stopped
3409 for to the thread the signal was sent to, even if the user changed
3410 threads before resuming. Previously GDB would often (but not
3411 always) deliver the signal to the thread that happens to be current
3414 * Conversely, the "signal" command now consistently delivers the
3415 requested signal to the current thread. GDB now asks for
3416 confirmation if the program had stopped for a signal and the user
3417 switched threads meanwhile.
3419 * "breakpoint always-inserted" modes "off" and "auto" merged.
3421 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3422 won't remove breakpoints from the target until all threads stop,
3423 even in non-stop mode. The "auto" mode has been removed, and "off"
3424 is now the default mode.
3428 set debug symbol-lookup
3429 show debug symbol-lookup
3430 Control display of debugging info regarding symbol lookup.
3434 ** The -list-thread-groups command outputs an exit-code field for
3435 inferiors that have exited.
3439 MIPS SDE mips*-sde*-elf*
3443 Support for these obsolete configurations has been removed.
3445 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3446 SGI Irix-5.x mips-*-irix5*
3447 SGI Irix-6.x mips-*-irix6*
3448 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3449 VAX running Ultrix vax-*-ultrix*
3451 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3452 and "assf"), have been removed. Use the "sharedlibrary" command, or
3453 its alias "share", instead.
3455 *** Changes in GDB 7.8
3457 * New command line options
3460 This is an alias for the --data-directory option.
3462 * GDB supports printing and modifying of variable length automatic arrays
3463 as specified in ISO C99.
3465 * The ARM simulator now supports instruction level tracing
3466 with or without disassembly.
3470 GDB now has support for scripting using Guile. Whether this is
3471 available is determined at configure time.
3472 Guile version 2.0 or greater is required.
3473 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3475 * New commands (for set/show, see "New options" below)
3479 Invoke CODE by passing it to the Guile interpreter.
3483 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3485 info auto-load guile-scripts [regexp]
3486 Print the list of automatically loaded Guile scripts.
3488 * The source command is now capable of sourcing Guile scripts.
3489 This feature is dependent on the debugger being built with Guile support.
3493 set print symbol-loading (off|brief|full)
3494 show print symbol-loading
3495 Control whether to print informational messages when loading symbol
3496 information for a file. The default is "full", but when debugging
3497 programs with large numbers of shared libraries the amount of output
3498 becomes less useful.
3500 set guile print-stack (none|message|full)
3501 show guile print-stack
3502 Show a stack trace when an error is encountered in a Guile script.
3504 set auto-load guile-scripts (on|off)
3505 show auto-load guile-scripts
3506 Control auto-loading of Guile script files.
3508 maint ada set ignore-descriptive-types (on|off)
3509 maint ada show ignore-descriptive-types
3510 Control whether the debugger should ignore descriptive types in Ada
3511 programs. The default is not to ignore the descriptive types. See
3512 the user manual for more details on descriptive types and the intended
3513 usage of this option.
3515 set auto-connect-native-target
3517 Control whether GDB is allowed to automatically connect to the
3518 native target for the run, attach, etc. commands when not connected
3519 to any target yet. See also "target native" below.
3521 set record btrace replay-memory-access (read-only|read-write)
3522 show record btrace replay-memory-access
3523 Control what memory accesses are allowed during replay.
3525 maint set target-async (on|off)
3526 maint show target-async
3527 This controls whether GDB targets operate in synchronous or
3528 asynchronous mode. Normally the default is asynchronous, if it is
3529 available; but this can be changed to more easily debug problems
3530 occurring only in synchronous mode.
3532 set mi-async (on|off)
3534 Control whether MI asynchronous mode is preferred. This supersedes
3535 "set target-async" of previous GDB versions.
3537 * "set target-async" is deprecated as a CLI option and is now an alias
3538 for "set mi-async" (only puts MI into async mode).
3540 * Background execution commands (e.g., "c&", "s&", etc.) are now
3541 possible ``out of the box'' if the target supports them. Previously
3542 the user would need to explicitly enable the possibility with the
3543 "set target-async on" command.
3545 * New features in the GDB remote stub, GDBserver
3547 ** New option --debug-format=option1[,option2,...] allows one to add
3548 additional text to each output. At present only timestamps
3549 are supported: --debug-format=timestamps.
3550 Timestamps can also be turned on with the
3551 "monitor set debug-format timestamps" command from GDB.
3553 * The 'record instruction-history' command now starts counting instructions
3554 at one. This also affects the instruction ranges reported by the
3555 'record function-call-history' command when given the /i modifier.
3557 * The command 'record function-call-history' supports a new modifier '/c' to
3558 indent the function names based on their call stack depth.
3559 The fields for the '/i' and '/l' modifier have been reordered.
3560 The source line range is now prefixed with 'at'.
3561 The instruction range is now prefixed with 'inst'.
3562 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3563 "record instruction-history" and "list" commands.
3565 * The ranges given as arguments to the 'record function-call-history' and
3566 'record instruction-history' commands are now inclusive.
3568 * The btrace record target now supports the 'record goto' command.
3569 For locations inside the execution trace, the back trace is computed
3570 based on the information stored in the execution trace.
3572 * The btrace record target supports limited reverse execution and replay.
3573 The target does not record data and therefore does not allow reading
3574 memory or registers.
3576 * The "catch syscall" command now works on s390*-linux* targets.
3578 * The "compare-sections" command is no longer specific to target
3579 remote. It now works with all targets.
3581 * All native targets are now consistently called "native".
3582 Consequently, the "target child", "target GNU", "target djgpp",
3583 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3584 commands have been replaced with "target native". The QNX/NTO port
3585 leaves the "procfs" target in place and adds a "native" target for
3586 consistency with other ports. The impact on users should be minimal
3587 as these commands previously either throwed an error, or were
3588 no-ops. The target's name is visible in the output of the following
3589 commands: "help target", "info target", "info files", "maint print
3592 * The "target native" command now connects to the native target. This
3593 can be used to launch native programs even when "set
3594 auto-connect-native-target" is set to off.
3596 * GDB now supports access to Intel MPX registers on GNU/Linux.
3598 * Support for Intel AVX-512 registers on GNU/Linux.
3599 Support displaying and modifying Intel AVX-512 registers
3600 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3602 * New remote packets
3604 qXfer:btrace:read's annex
3605 The qXfer:btrace:read packet supports a new annex 'delta' to read
3606 branch trace incrementally.
3610 ** Valid Python operations on gdb.Value objects representing
3611 structs/classes invoke the corresponding overloaded operators if
3613 ** New `Xmethods' feature in the Python API. Xmethods are
3614 additional methods or replacements for existing methods of a C++
3615 class. This feature is useful for those cases where a method
3616 defined in C++ source code could be inlined or optimized out by
3617 the compiler, making it unavailable to GDB.
3620 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3622 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3623 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3624 its alias "share", instead.
3626 * The commands "set remotebaud" and "show remotebaud" are no longer
3627 supported. Use "set serial baud" and "show serial baud" (respectively)
3632 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3633 target-async". The latter is left as a deprecated alias of the
3634 former for backward compatibility. If the target supports it,
3635 CLI background execution commands are now always possible by
3636 default, independently of whether the frontend stated a
3637 preference for asynchronous execution with "-gdb-set mi-async".
3638 Previously "-gdb-set target-async off" affected both MI execution
3639 commands and CLI execution commands.
3641 *** Changes in GDB 7.7
3643 * Improved support for process record-replay and reverse debugging on
3644 arm*-linux* targets. Support for thumb32 and syscall instruction
3645 recording has been added.
3647 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3649 * GDB now supports Fission DWP file format version 2.
3650 http://gcc.gnu.org/wiki/DebugFission
3652 * New convenience function "$_isvoid", to check whether an expression
3653 is void. A void expression is an expression where the type of the
3654 result is "void". For example, some convenience variables may be
3655 "void" when evaluated (e.g., "$_exitcode" before the execution of
3656 the program being debugged; or an undefined convenience variable).
3657 Another example, when calling a function whose return type is
3660 * The "maintenance print objfiles" command now takes an optional regexp.
3662 * The "catch syscall" command now works on arm*-linux* targets.
3664 * GDB now consistently shows "<not saved>" when printing values of
3665 registers the debug info indicates have not been saved in the frame
3666 and there's nowhere to retrieve them from
3667 (callee-saved/call-clobbered registers):
3672 (gdb) info registers rax
3675 Before, the former would print "<optimized out>", and the latter
3676 "*value not available*".
3678 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3683 ** Frame filters and frame decorators have been added.
3684 ** Temporary breakpoints are now supported.
3685 ** Line tables representation has been added.
3686 ** New attribute 'parent_type' for gdb.Field objects.
3687 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3688 ** New attribute 'name' for gdb.Type objects.
3692 Nios II ELF nios2*-*-elf
3693 Nios II GNU/Linux nios2*-*-linux
3694 Texas Instruments MSP430 msp430*-*-elf
3696 * Removed native configurations
3698 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3699 been removed. ELF variants of these configurations are kept supported.
3701 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3702 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3703 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3704 i[34567]86-*-openbsd3.[0-3]
3705 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3706 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3707 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3711 Like "catch throw", but catches a re-thrown exception.
3712 maint check-psymtabs
3713 Renamed from old "maint check-symtabs".
3715 Perform consistency checks on symtabs.
3716 maint expand-symtabs
3717 Expand symtabs matching an optional regexp.
3720 Display the details of GDB configure-time options.
3722 maint set|show per-command
3723 maint set|show per-command space
3724 maint set|show per-command time
3725 maint set|show per-command symtab
3726 Enable display of per-command gdb resource usage.
3728 remove-symbol-file FILENAME
3729 remove-symbol-file -a ADDRESS
3730 Remove a symbol file added via add-symbol-file. The file to remove
3731 can be identified by its filename or by an address that lies within
3732 the boundaries of this symbol file in memory.
3735 info exceptions REGEXP
3736 Display the list of Ada exceptions defined in the program being
3737 debugged. If provided, only the exceptions whose names match REGEXP
3742 set debug symfile off|on
3744 Control display of debugging info regarding reading symbol files and
3745 symbol tables within those files
3747 set print raw frame-arguments
3748 show print raw frame-arguments
3749 Set/show whether to print frame arguments in raw mode,
3750 disregarding any defined pretty-printers.
3752 set remote trace-status-packet
3753 show remote trace-status-packet
3754 Set/show the use of remote protocol qTStatus packet.
3758 Control display of debugging messages related to Nios II targets.
3762 Control whether target-assisted range stepping is enabled.
3764 set startup-with-shell
3765 show startup-with-shell
3766 Specifies whether Unix child processes are started via a shell or
3771 Use the target memory cache for accesses to the code segment. This
3772 improves performance of remote debugging (particularly disassembly).
3774 * You can now use a literal value 'unlimited' for options that
3775 interpret 0 or -1 as meaning "unlimited". E.g., "set
3776 trace-buffer-size unlimited" is now an alias for "set
3777 trace-buffer-size -1" and "set height unlimited" is now an alias for
3780 * The "set debug symtab-create" debugging option of GDB has been changed to
3781 accept a verbosity level. 0 means "off", 1 provides basic debugging
3782 output, and values of 2 or greater provides more verbose output.
3784 * New command-line options
3786 Display the details of GDB configure-time options.
3788 * The command 'tsave' can now support new option '-ctf' to save trace
3789 buffer in Common Trace Format.
3791 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3794 * GDB now implements the C++ 'typeid' operator.
3796 * The new convenience variable $_exception holds the exception being
3797 thrown or caught at an exception-related catchpoint.
3799 * The exception-related catchpoints, like "catch throw", now accept a
3800 regular expression which can be used to filter exceptions by type.
3802 * The new convenience variable $_exitsignal is automatically set to
3803 the terminating signal number when the program being debugged dies
3804 due to an uncaught signal.
3808 ** All MI commands now accept an optional "--language" option.
3809 Support for this feature can be verified by using the "-list-features"
3810 command, which should contain "language-option".
3812 ** The new command -info-gdb-mi-command allows the user to determine
3813 whether a GDB/MI command is supported or not.
3815 ** The "^error" result record returned when trying to execute an undefined
3816 GDB/MI command now provides a variable named "code" whose content is the
3817 "undefined-command" error code. Support for this feature can be verified
3818 by using the "-list-features" command, which should contain
3819 "undefined-command-error-code".
3821 ** The -trace-save MI command can optionally save trace buffer in Common
3824 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3826 ** The command -data-list-register-values now accepts an optional
3827 "--skip-unavailable" option. When used, only the available registers
3830 ** The new command -trace-frame-collected dumps collected variables,
3831 computed expressions, tvars, memory and registers in a traceframe.
3833 ** The commands -stack-list-locals, -stack-list-arguments and
3834 -stack-list-variables now accept an option "--skip-unavailable".
3835 When used, only the available locals or arguments are displayed.
3837 ** The -exec-run command now accepts an optional "--start" option.
3838 When used, the command follows the same semantics as the "start"
3839 command, stopping the program's execution at the start of its
3840 main subprogram. Support for this feature can be verified using
3841 the "-list-features" command, which should contain
3842 "exec-run-start-option".
3844 ** The new commands -catch-assert and -catch-exceptions insert
3845 catchpoints stopping the program when Ada exceptions are raised.
3847 ** The new command -info-ada-exceptions provides the equivalent of
3848 the new "info exceptions" command.
3850 * New system-wide configuration scripts
3851 A GDB installation now provides scripts suitable for use as system-wide
3852 configuration scripts for the following systems:
3856 * GDB now supports target-assigned range stepping with remote targets.
3857 This improves the performance of stepping source lines by reducing
3858 the number of control packets from/to GDB. See "New remote packets"
3861 * GDB now understands the element 'tvar' in the XML traceframe info.
3862 It has the id of the collected trace state variables.
3864 * On S/390 targets that provide the transactional-execution feature,
3865 the program interruption transaction diagnostic block (TDB) is now
3866 represented as a number of additional "registers" in GDB.
3868 * New remote packets
3872 The vCont packet supports a new 'r' action, that tells the remote
3873 stub to step through an address range itself, without GDB
3874 involvemement at each single-step.
3876 qXfer:libraries-svr4:read's annex
3877 The previously unused annex of the qXfer:libraries-svr4:read packet
3878 is now used to support passing an argument list. The remote stub
3879 reports support for this argument list to GDB's qSupported query.
3880 The defined arguments are "start" and "prev", used to reduce work
3881 necessary for library list updating, resulting in significant
3884 * New features in the GDB remote stub, GDBserver
3886 ** GDBserver now supports target-assisted range stepping. Currently
3887 enabled on x86/x86_64 GNU/Linux targets.
3889 ** GDBserver now adds element 'tvar' in the XML in the reply to
3890 'qXfer:traceframe-info:read'. It has the id of the collected
3891 trace state variables.
3893 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3896 * New 'z' formatter for printing and examining memory, this displays the
3897 value as hexadecimal zero padded on the left to the size of the type.
3899 * GDB can now use Windows x64 unwinding data.
3901 * The "set remotebaud" command has been replaced by "set serial baud".
3902 Similarly, "show remotebaud" has been replaced by "show serial baud".
3903 The "set remotebaud" and "show remotebaud" commands are still available
3904 to provide backward compatibility with older versions of GDB.
3906 *** Changes in GDB 7.6
3908 * Target record has been renamed to record-full.
3909 Record/replay is now enabled with the "record full" command.
3910 This also affects settings that are associated with full record/replay
3911 that have been moved from "set/show record" to "set/show record full":
3913 set|show record full insn-number-max
3914 set|show record full stop-at-limit
3915 set|show record full memory-query
3917 * A new record target "record-btrace" has been added. The new target
3918 uses hardware support to record the control-flow of a process. It
3919 does not support replaying the execution, but it implements the
3920 below new commands for investigating the recorded execution log.
3921 This new recording method can be enabled using:
3925 The "record-btrace" target is only available on Intel Atom processors
3926 and requires a Linux kernel 2.6.32 or later.
3928 * Two new commands have been added for record/replay to give information
3929 about the recorded execution without having to replay the execution.
3930 The commands are only supported by "record btrace".
3932 record instruction-history prints the execution history at
3933 instruction granularity
3935 record function-call-history prints the execution history at
3936 function granularity
3938 * New native configurations
3940 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3941 FreeBSD/powerpc powerpc*-*-freebsd
3942 x86_64/Cygwin x86_64-*-cygwin*
3943 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3947 ARM AArch64 aarch64*-*-elf
3948 ARM AArch64 GNU/Linux aarch64*-*-linux
3949 Lynx 178 PowerPC powerpc-*-lynx*178
3950 x86_64/Cygwin x86_64-*-cygwin*
3951 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3953 * If the configured location of system.gdbinit file (as given by the
3954 --with-system-gdbinit option at configure time) is in the
3955 data-directory (as specified by --with-gdb-datadir at configure
3956 time) or in one of its subdirectories, then GDB will look for the
3957 system-wide init file in the directory specified by the
3958 --data-directory command-line option.
3960 * New command line options:
3962 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3963 other initialization files, unlike -nx which disables all of them.
3965 * Removed command line options
3967 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3970 * The 'ptype' and 'whatis' commands now accept an argument to control
3973 * 'info proc' now works on some core files.
3977 ** Vectors can be created with gdb.Type.vector.
3979 ** Python's atexit.register now works in GDB.
3981 ** Types can be pretty-printed via a Python API.
3983 ** Python 3 is now supported (in addition to Python 2.4 or later)
3985 ** New class gdb.Architecture exposes GDB's internal representation
3986 of architecture in the Python API.
3988 ** New method Frame.architecture returns the gdb.Architecture object
3989 corresponding to the frame's architecture.
3991 * New Python-based convenience functions:
3993 ** $_memeq(buf1, buf2, length)
3994 ** $_streq(str1, str2)
3996 ** $_regex(str, regex)
3998 * The 'cd' command now defaults to using '~' (the home directory) if not
4001 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
4002 default for GCC since November 2000.
4004 * The command 'forward-search' can now be abbreviated as 'fo'.
4006 * The command 'info tracepoints' can now display 'installed on target'
4007 or 'not installed on target' for each non-pending location of tracepoint.
4009 * New configure options
4011 --enable-libmcheck/--disable-libmcheck
4012 By default, development versions are built with -lmcheck on hosts
4013 that support it, in order to help track memory corruption issues.
4014 Release versions, on the other hand, are built without -lmcheck
4015 by default. The --enable-libmcheck/--disable-libmcheck configure
4016 options allow the user to override that default.
4017 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
4018 This configure option allows the user to build GDB with
4019 libbabeltrace using which GDB can read Common Trace Format data.
4021 * New commands (for set/show, see "New options" below)
4024 Catch signals. This is similar to "handle", but allows commands and
4025 conditions to be attached.
4028 List the BFDs known to GDB.
4030 python-interactive [command]
4032 Start a Python interactive prompt, or evaluate the optional command
4033 and print the result of expressions.
4036 "py" is a new alias for "python".
4038 enable type-printer [name]...
4039 disable type-printer [name]...
4040 Enable or disable type printers.
4044 ** For the Renesas Super-H architecture, the "regs" command has been removed
4045 (has been deprecated in GDB 7.5), and "info all-registers" should be used
4050 set print type methods (on|off)
4051 show print type methods
4052 Control whether method declarations are displayed by "ptype".
4053 The default is to show them.
4055 set print type typedefs (on|off)
4056 show print type typedefs
4057 Control whether typedef definitions are displayed by "ptype".
4058 The default is to show them.
4060 set filename-display basename|relative|absolute
4061 show filename-display
4062 Control the way in which filenames is displayed.
4063 The default is "relative", which preserves previous behavior.
4065 set trace-buffer-size
4066 show trace-buffer-size
4067 Request target to change the size of trace buffer.
4069 set remote trace-buffer-size-packet auto|on|off
4070 show remote trace-buffer-size-packet
4071 Control the use of the remote protocol `QTBuffer:size' packet.
4075 Control display of debugging messages related to ARM AArch64.
4078 set debug coff-pe-read
4079 show debug coff-pe-read
4080 Control display of debugging messages related to reading of COFF/PE
4085 Control display of debugging messages related to Mach-O symbols
4088 set debug notification
4089 show debug notification
4090 Control display of debugging info for async remote notification.
4094 ** Command parameter changes are now notified using new async record
4095 "=cmd-param-changed".
4096 ** Trace frame changes caused by command "tfind" are now notified using
4097 new async record "=traceframe-changed".
4098 ** The creation, deletion and modification of trace state variables
4099 are now notified using new async records "=tsv-created",
4100 "=tsv-deleted" and "=tsv-modified".
4101 ** The start and stop of process record are now notified using new
4102 async record "=record-started" and "=record-stopped".
4103 ** Memory changes are now notified using new async record
4105 ** The data-disassemble command response will include a "fullname" field
4106 containing the absolute file name when source has been requested.
4107 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4108 command, to allow pattern filling of memory areas.
4109 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4110 library load/unload events.
4111 ** The response to breakpoint commands and breakpoint async records
4112 includes an "installed" field containing a boolean state about each
4113 non-pending tracepoint location is whether installed on target or not.
4114 ** Output of the "-trace-status" command includes a "trace-file" field
4115 containing the name of the trace file being examined. This field is
4116 optional, and only present when examining a trace file.
4117 ** The "fullname" field is now always present along with the "file" field,
4118 even if the file cannot be found by GDB.
4120 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4121 You must have the LZMA library available when configuring GDB for this
4122 feature to be enabled. For more information, see:
4123 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4125 * New remote packets
4128 Set the size of trace buffer. The remote stub reports support for this
4129 packet to gdb's qSupported query.
4132 Enable Branch Trace Store (BTS)-based branch tracing for the current
4133 thread. The remote stub reports support for this packet to gdb's
4137 Disable branch tracing for the current thread. The remote stub reports
4138 support for this packet to gdb's qSupported query.
4141 Read the traced branches for the current thread. The remote stub
4142 reports support for this packet to gdb's qSupported query.
4144 *** Changes in GDB 7.5
4146 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4147 for more x32 ABI info.
4149 * GDB now supports access to MIPS DSP registers on Linux targets.
4151 * GDB now supports debugging microMIPS binaries.
4153 * The "info os" command on GNU/Linux can now display information on
4154 several new classes of objects managed by the operating system:
4155 "info os procgroups" lists process groups
4156 "info os files" lists file descriptors
4157 "info os sockets" lists internet-domain sockets
4158 "info os shm" lists shared-memory regions
4159 "info os semaphores" lists semaphores
4160 "info os msg" lists message queues
4161 "info os modules" lists loaded kernel modules
4163 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4164 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4165 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4166 options and inspect the probe arguments using the new $_probe_arg family
4167 of convenience variables. You can obtain more information about SystemTap
4168 in <http://sourceware.org/systemtap/>.
4170 * GDB now supports reversible debugging on ARM, it allows you to
4171 debug basic ARM and THUMB instructions, and provides
4172 record/replay support.
4174 * The option "symbol-reloading" has been deleted as it is no longer used.
4178 ** GDB commands implemented in Python can now be put in command class
4181 ** The "maint set python print-stack on|off" is now deleted.
4183 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4184 apply "flag enum"-style pretty-printing to any enum.
4186 ** gdb.lookup_symbol can now work when there is no current frame.
4188 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4189 the source at which the symbol was defined.
4191 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4192 method 'value'. The former indicates whether the symbol needs a
4193 frame in order to compute its value, and the latter computes the
4196 ** A new method 'referenced_value' on gdb.Value objects which can
4197 dereference pointer as well as C++ reference values.
4199 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4200 which return the global and static blocks (as gdb.Block objects),
4201 of the underlying symbol table, respectively.
4203 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4204 object associated with a PC value.
4206 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4207 of the address range occupied by code for the current source line.
4209 * Go language support.
4210 GDB now supports debugging programs written in the Go programming
4213 * GDBserver now supports stdio connections.
4214 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4216 * The binary "gdbtui" can no longer be built or installed.
4217 Use "gdb -tui" instead.
4219 * GDB will now print "flag" enums specially. A flag enum is one where
4220 all the enumerator values have no bits in common when pairwise
4221 "and"ed. When printing a value whose type is a flag enum, GDB will
4222 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4223 (gdb) print (enum E) 3
4226 * The filename part of a linespec will now match trailing components
4227 of a source file name. For example, "break gcc/expr.c:1000" will
4228 now set a breakpoint in build/gcc/expr.c, but not
4229 build/libcpp/expr.c.
4231 * The "info proc" and "generate-core-file" commands will now also
4232 work on remote targets connected to GDBserver on Linux.
4234 * The command "info catch" has been removed. It has been disabled
4235 since December 2007.
4237 * The "catch exception" and "catch assert" commands now accept
4238 a condition at the end of the command, much like the "break"
4239 command does. For instance:
4241 (gdb) catch exception Constraint_Error if Barrier = True
4243 Previously, it was possible to add a condition to such catchpoints,
4244 but it had to be done as a second step, after the catchpoint had been
4245 created, using the "condition" command.
4247 * The "info static-tracepoint-marker" command will now also work on
4248 native Linux targets with in-process agent.
4250 * GDB can now set breakpoints on inlined functions.
4252 * The .gdb_index section has been updated to include symbols for
4253 inlined functions. GDB will ignore older .gdb_index sections by
4254 default, which could cause symbol files to be loaded more slowly
4255 until their .gdb_index sections can be recreated. The new command
4256 "set use-deprecated-index-sections on" will cause GDB to use any older
4257 .gdb_index sections it finds. This will restore performance, but the
4258 ability to set breakpoints on inlined functions will be lost in symbol
4259 files with older .gdb_index sections.
4261 The .gdb_index section has also been updated to record more information
4262 about each symbol. This speeds up the "info variables", "info functions"
4263 and "info types" commands when used with programs having the .gdb_index
4264 section, as well as speeding up debugging with shared libraries using
4265 the .gdb_index section.
4267 * Ada support for GDB/MI Variable Objects has been added.
4269 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4274 ** New command -info-os is the MI equivalent of "info os".
4276 ** Output logs ("set logging" and related) now include MI output.
4280 ** "set use-deprecated-index-sections on|off"
4281 "show use-deprecated-index-sections on|off"
4282 Controls the use of deprecated .gdb_index sections.
4284 ** "catch load" and "catch unload" can be used to stop when a shared
4285 library is loaded or unloaded, respectively.
4287 ** "enable count" can be used to auto-disable a breakpoint after
4290 ** "info vtbl" can be used to show the virtual method tables for
4291 C++ and Java objects.
4293 ** "explore" and its sub commands "explore value" and "explore type"
4294 can be used to recursively explore values and types of
4295 expressions. These commands are available only if GDB is
4296 configured with '--with-python'.
4298 ** "info auto-load" shows status of all kinds of auto-loaded files,
4299 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4300 sequences of commands files, "info auto-load python-scripts"
4301 shows status of auto-loading Python script files,
4302 "info auto-load local-gdbinit" shows status of loading init file
4303 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4304 status of inferior specific thread debugging shared library loading.
4306 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4307 and "show auto-load-scripts" commands have been deprecated, use their
4308 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4309 and "show auto-load python-scripts" counterparts instead.
4311 ** "dprintf location,format,args..." creates a dynamic printf, which
4312 is basically a breakpoint that does a printf and immediately
4313 resumes your program's execution, so it is like a printf that you
4314 can insert dynamically at runtime instead of at compiletime.
4316 ** "set print symbol"
4318 Controls whether GDB attempts to display the symbol, if any,
4319 corresponding to addresses it prints. This defaults to "on", but
4320 you can set it to "off" to restore GDB's previous behavior.
4322 * Deprecated commands
4324 ** For the Renesas Super-H architecture, the "regs" command has been
4325 deprecated, and "info all-registers" should be used instead.
4329 Renesas RL78 rl78-*-elf
4330 HP OpenVMS ia64 ia64-hp-openvms*
4332 * GDBserver supports evaluation of breakpoint conditions. When
4333 support is advertised by GDBserver, GDB may be told to send the
4334 breakpoint conditions in bytecode form to GDBserver. GDBserver
4335 will only report the breakpoint trigger to GDB when its condition
4340 set mips compression
4341 show mips compression
4342 Select the compressed ISA encoding used in functions that have no symbol
4343 information available. The encoding can be set to either of:
4346 and is updated automatically from ELF file flags if available.
4348 set breakpoint condition-evaluation
4349 show breakpoint condition-evaluation
4350 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4351 GDBserver ("target"). Default option "auto" chooses the most efficient
4353 This option can improve debugger efficiency depending on the speed of the
4357 Disable auto-loading globally.
4360 Show auto-loading setting of all kinds of auto-loaded files.
4362 set auto-load gdb-scripts on|off
4363 show auto-load gdb-scripts
4364 Control auto-loading of GDB canned sequences of commands files.
4366 set auto-load python-scripts on|off
4367 show auto-load python-scripts
4368 Control auto-loading of Python script files.
4370 set auto-load local-gdbinit on|off
4371 show auto-load local-gdbinit
4372 Control loading of init file (.gdbinit) from current directory.
4374 set auto-load libthread-db on|off
4375 show auto-load libthread-db
4376 Control auto-loading of inferior specific thread debugging shared library.
4378 set auto-load scripts-directory <dir1>[:<dir2>...]
4379 show auto-load scripts-directory
4380 Set a list of directories from which to load auto-loaded scripts.
4381 Automatically loaded Python scripts and GDB scripts are located in one
4382 of the directories listed by this option.
4383 The delimiter (':' above) may differ according to the host platform.
4385 set auto-load safe-path <dir1>[:<dir2>...]
4386 show auto-load safe-path
4387 Set a list of directories from which it is safe to auto-load files.
4388 The delimiter (':' above) may differ according to the host platform.
4390 set debug auto-load on|off
4391 show debug auto-load
4392 Control display of debugging info for auto-loading the files above.
4394 set dprintf-style gdb|call|agent
4396 Control the way in which a dynamic printf is performed; "gdb"
4397 requests a GDB printf command, while "call" causes dprintf to call a
4398 function in the inferior. "agent" requests that the target agent
4399 (such as GDBserver) do the printing.
4401 set dprintf-function <expr>
4402 show dprintf-function
4403 set dprintf-channel <expr>
4404 show dprintf-channel
4405 Set the function and optional first argument to the call when using
4406 the "call" style of dynamic printf.
4408 set disconnected-dprintf on|off
4409 show disconnected-dprintf
4410 Control whether agent-style dynamic printfs continue to be in effect
4411 after GDB disconnects.
4413 * New configure options
4415 --with-auto-load-dir
4416 Configure default value for the 'set auto-load scripts-directory'
4417 setting above. It defaults to '$debugdir:$datadir/auto-load',
4418 $debugdir representing global debugging info directories (available
4419 via 'show debug-file-directory') and $datadir representing GDB's data
4420 directory (available via 'show data-directory').
4422 --with-auto-load-safe-path
4423 Configure default value for the 'set auto-load safe-path' setting
4424 above. It defaults to the --with-auto-load-dir setting.
4426 --without-auto-load-safe-path
4427 Set 'set auto-load safe-path' to '/', effectively disabling this
4430 * New remote packets
4432 z0/z1 conditional breakpoints extension
4434 The z0/z1 breakpoint insertion packets have been extended to carry
4435 a list of conditional expressions over to the remote stub depending on the
4436 condition evaluation mode. The use of this extension can be controlled
4437 via the "set remote conditional-breakpoints-packet" command.
4441 Specify the signals which the remote stub may pass to the debugged
4442 program without GDB involvement.
4444 * New command line options
4446 --init-command=FILE, -ix Like --command, -x but execute it
4447 before loading inferior.
4448 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4449 execute it before loading inferior.
4451 *** Changes in GDB 7.4
4453 * GDB now handles ambiguous linespecs more consistently; the existing
4454 FILE:LINE support has been expanded to other types of linespecs. A
4455 breakpoint will now be set on all matching locations in all
4456 inferiors, and locations will be added or removed according to
4459 * GDB now allows you to skip uninteresting functions and files when
4460 stepping with the "skip function" and "skip file" commands.
4462 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4463 and "show remote hardware-watchpoint-length-limit". These allows to
4464 set or show the maximum length limit (in bytes) of a remote
4465 target hardware watchpoint.
4467 This allows e.g. to use "unlimited" hardware watchpoints with the
4468 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4469 watchpoints are slower than real hardware watchpoints but are
4470 significantly faster than gdb software watchpoints.
4474 ** The register_pretty_printer function in module gdb.printing now takes
4475 an optional `replace' argument. If True, the new printer replaces any
4478 ** The "maint set python print-stack on|off" command has been
4479 deprecated and will be deleted in GDB 7.5.
4480 A new command: "set python print-stack none|full|message" has
4481 replaced it. Additionally, the default for "print-stack" is
4482 now "message", which just prints the error message without
4485 ** A prompt substitution hook (prompt_hook) is now available to the
4488 ** A new Python module, gdb.prompt has been added to the GDB Python
4489 modules library. This module provides functionality for
4490 escape sequences in prompts (used by set/show
4491 extended-prompt). These escape sequences are replaced by their
4492 corresponding value.
4494 ** Python commands and convenience-functions located in
4495 'data-directory'/python/gdb/command and
4496 'data-directory'/python/gdb/function are now automatically loaded
4499 ** Blocks now provide four new attributes. global_block and
4500 static_block will return the global and static blocks
4501 respectively. is_static and is_global are boolean attributes
4502 that indicate if the block is one of those two types.
4504 ** Symbols now provide the "type" attribute, the type of the symbol.
4506 ** The "gdb.breakpoint" function has been deprecated in favor of
4509 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4510 of a function. This class is based on the "finish" command
4511 available in the CLI.
4513 ** Type objects for struct and union types now allow access to
4514 the fields using standard Python dictionary (mapping) methods.
4515 For example, "some_type['myfield']" now works, as does
4516 "some_type.items()".
4518 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4521 ** A new function, "deep_items" has been added to the gdb.types
4522 module in the GDB Python modules library. This function returns
4523 an iterator over the fields of a struct or union type. Unlike
4524 the standard Python "iteritems" method, it will recursively traverse
4525 any anonymous fields.
4529 ** "*stopped" events can report several new "reason"s, such as
4532 ** Breakpoint changes are now notified using new async records, like
4533 "=breakpoint-modified".
4535 ** New command -ada-task-info.
4537 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4538 $sdir specifies the default system locations of shared libraries.
4539 $pdir specifies the directory where the libpthread used by the application
4542 GDB no longer looks in $sdir and $pdir after it has searched the directories
4543 mentioned in libthread-db-search-path. If you want to search those
4544 directories, they must be specified in libthread-db-search-path.
4545 The default value of libthread-db-search-path on GNU/Linux and Solaris
4546 systems is now "$sdir:$pdir".
4548 $pdir is not supported by gdbserver, it is currently ignored.
4549 $sdir is supported by gdbserver.
4551 * New configure option --with-iconv-bin.
4552 When using the internationalization support like the one in the GNU C
4553 library, GDB will invoke the "iconv" program to get a list of supported
4554 character sets. If this program lives in a non-standard location, one can
4555 use this option to specify where to find it.
4557 * When natively debugging programs on PowerPC BookE processors running
4558 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4559 watchpoints, which specify a mask in addition to an address to watch.
4560 The mask specifies that some bits of an address (the bits which are
4561 reset in the mask) should be ignored when matching the address accessed
4562 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4563 section in the user manual for more details.
4565 * The new option --once causes GDBserver to stop listening for connections once
4566 the first connection is made. The listening port used by GDBserver will
4567 become available after that.
4569 * New commands "info macros" and "alias" have been added.
4571 * New function parameters suffix @entry specifies value of function parameter
4572 at the time the function got called. Entry values are available only since
4578 "!" is now an alias of the "shell" command.
4579 Note that no space is needed between "!" and SHELL COMMAND.
4583 watch EXPRESSION mask MASK_VALUE
4584 The watch command now supports the mask argument which allows creation
4585 of masked watchpoints, if the current architecture supports this feature.
4587 info auto-load-scripts [REGEXP]
4588 This command was formerly named "maintenance print section-scripts".
4589 It is now generally useful and is no longer a maintenance-only command.
4591 info macro [-all] [--] MACRO
4592 The info macro command has new options `-all' and `--'. The first for
4593 printing all definitions of a macro. The second for explicitly specifying
4594 the end of arguments and the beginning of the macro name in case the macro
4595 name starts with a hyphen.
4597 collect[/s] EXPRESSIONS
4598 The tracepoint collect command now takes an optional modifier "/s"
4599 that directs it to dereference pointer-to-character types and
4600 collect the bytes of memory up to a zero byte. The behavior is
4601 similar to what you see when you use the regular print command on a
4602 string. An optional integer following the "/s" sets a bound on the
4603 number of bytes that will be collected.
4606 The trace start command now interprets any supplied arguments as a
4607 note to be recorded with the trace run, with an effect similar to
4608 setting the variable trace-notes.
4611 The trace stop command now interprets any arguments as a note to be
4612 mentioned along with the tstatus report that the trace was stopped
4613 with a command. The effect is similar to setting the variable
4616 * Tracepoints can now be enabled and disabled at any time after a trace
4617 experiment has been started using the standard "enable" and "disable"
4618 commands. It is now possible to start a trace experiment with no enabled
4619 tracepoints; GDB will display a warning, but will allow the experiment to
4620 begin, assuming that tracepoints will be enabled as needed while the trace
4623 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4624 locations with 4-byte instructions, when they were previously
4625 limited to locations with instructions of 5 bytes or longer.
4629 set debug dwarf2-read
4630 show debug dwarf2-read
4631 Turns on or off display of debugging messages related to reading
4632 DWARF debug info. The default is off.
4634 set debug symtab-create
4635 show debug symtab-create
4636 Turns on or off display of debugging messages related to symbol table
4637 creation. The default is off.
4640 show extended-prompt
4641 Set the GDB prompt, and allow escape sequences to be inserted to
4642 display miscellaneous information (see 'help set extended-prompt'
4643 for the list of sequences). This prompt (and any information
4644 accessed through the escape sequences) is updated every time the
4645 prompt is displayed.
4647 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4648 show print entry-values
4649 Set printing of frame argument values at function entry. In some cases
4650 GDB can determine the value of function argument which was passed by the
4651 function caller, even if the value was modified inside the called function.
4653 set debug entry-values
4654 show debug entry-values
4655 Control display of debugging info for determining frame argument values at
4656 function entry and virtual tail call frames.
4658 set basenames-may-differ
4659 show basenames-may-differ
4660 Set whether a source file may have multiple base names.
4661 (A "base name" is the name of a file with the directory part removed.
4662 Example: The base name of "/home/user/hello.c" is "hello.c".)
4663 If set, GDB will canonicalize file names (e.g., expand symlinks)
4664 before comparing them. Canonicalization is an expensive operation,
4665 but it allows the same file be known by more than one base name.
4666 If not set (the default), all source files are assumed to have just
4667 one base name, and gdb will do file name comparisons more efficiently.
4673 Set a user name and notes for the current and any future trace runs.
4674 This is useful for long-running and/or disconnected traces, to
4675 inform others (or yourself) as to who is running the trace, supply
4676 contact information, or otherwise explain what is going on.
4678 set trace-stop-notes
4679 show trace-stop-notes
4680 Set a note attached to the trace run, that is displayed when the
4681 trace has been stopped by a tstop command. This is useful for
4682 instance as an explanation, if you are stopping a trace run that was
4683 started by someone else.
4685 * New remote packets
4689 Dynamically enable a tracepoint in a started trace experiment.
4693 Dynamically disable a tracepoint in a started trace experiment.
4697 Set the user and notes of the trace run.
4701 Query the current status of a tracepoint.
4705 Query the minimum length of instruction at which a fast tracepoint may
4708 * Dcache size (number of lines) and line-size are now runtime-configurable
4709 via "set dcache line" and "set dcache line-size" commands.
4713 Texas Instruments TMS320C6x tic6x-*-*
4717 Renesas RL78 rl78-*-elf
4719 *** Changes in GDB 7.3.1
4721 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4723 *** Changes in GDB 7.3
4725 * GDB has a new command: "thread find [REGEXP]".
4726 It finds the thread id whose name, target id, or thread extra info
4727 matches the given regular expression.
4729 * The "catch syscall" command now works on mips*-linux* targets.
4731 * The -data-disassemble MI command now supports modes 2 and 3 for
4732 dumping the instruction opcodes.
4734 * New command line options
4736 -data-directory DIR Specify DIR as the "data-directory".
4737 This is mostly for testing purposes.
4739 * The "maint set python auto-load on|off" command has been renamed to
4740 "set auto-load-scripts on|off".
4742 * GDB has a new command: "set directories".
4743 It is like the "dir" command except that it replaces the
4744 source path list instead of augmenting it.
4746 * GDB now understands thread names.
4748 On GNU/Linux, "info threads" will display the thread name as set by
4749 prctl or pthread_setname_np.
4751 There is also a new command, "thread name", which can be used to
4752 assign a name internally for GDB to display.
4755 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4756 has been integrated into GDB.
4760 ** The function gdb.Write now accepts an optional keyword 'stream'.
4761 This keyword, when provided, will direct the output to either
4762 stdout, stderr, or GDB's logging output.
4764 ** Parameters can now be be sub-classed in Python, and in particular
4765 you may implement the get_set_doc and get_show_doc functions.
4766 This improves how Parameter set/show documentation is processed
4767 and allows for more dynamic content.
4769 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4770 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4771 have an is_valid method.
4773 ** Breakpoints can now be sub-classed in Python, and in particular
4774 you may implement a 'stop' function that is executed each time
4775 the inferior reaches that breakpoint.
4777 ** New function gdb.lookup_global_symbol looks up a global symbol.
4779 ** GDB values in Python are now callable if the value represents a
4780 function. For example, if 'some_value' represents a function that
4781 takes two integer parameters and returns a value, you can call
4782 that function like so:
4784 result = some_value (10,20)
4786 ** Module gdb.types has been added.
4787 It contains a collection of utilities for working with gdb.Types objects:
4788 get_basic_type, has_field, make_enum_dict.
4790 ** Module gdb.printing has been added.
4791 It contains utilities for writing and registering pretty-printers.
4792 New classes: PrettyPrinter, SubPrettyPrinter,
4793 RegexpCollectionPrettyPrinter.
4794 New function: register_pretty_printer.
4796 ** New commands "info pretty-printers", "enable pretty-printer" and
4797 "disable pretty-printer" have been added.
4799 ** gdb.parameter("directories") is now available.
4801 ** New function gdb.newest_frame returns the newest frame in the
4804 ** The gdb.InferiorThread class has a new "name" attribute. This
4805 holds the thread's name.
4807 ** Python Support for Inferior events.
4808 Python scripts can add observers to be notified of events
4809 occurring in the process being debugged.
4810 The following events are currently supported:
4811 - gdb.events.cont Continue event.
4812 - gdb.events.exited Inferior exited event.
4813 - gdb.events.stop Signal received, and Breakpoint hit events.
4817 ** GDB now puts template parameters in scope when debugging in an
4818 instantiation. For example, if you have:
4820 template<int X> int func (void) { return X; }
4822 then if you step into func<5>, "print X" will show "5". This
4823 feature requires proper debuginfo support from the compiler; it
4824 was added to GCC 4.5.
4826 ** The motion commands "next", "finish", "until", and "advance" now
4827 work better when exceptions are thrown. In particular, GDB will
4828 no longer lose control of the inferior; instead, the GDB will
4829 stop the inferior at the point at which the exception is caught.
4830 This functionality requires a change in the exception handling
4831 code that was introduced in GCC 4.5.
4833 * GDB now follows GCC's rules on accessing volatile objects when
4834 reading or writing target state during expression evaluation.
4835 One notable difference to prior behavior is that "print x = 0"
4836 no longer generates a read of x; the value of the assignment is
4837 now always taken directly from the value being assigned.
4839 * GDB now has some support for using labels in the program's source in
4840 linespecs. For instance, you can use "advance label" to continue
4841 execution to a label.
4843 * GDB now has support for reading and writing a new .gdb_index
4844 section. This section holds a fast index of DWARF debugging
4845 information and can be used to greatly speed up GDB startup and
4846 operation. See the documentation for `save gdb-index' for details.
4848 * The "watch" command now accepts an optional "-location" argument.
4849 When used, this causes GDB to watch the memory referred to by the
4850 expression. Such a watchpoint is never deleted due to it going out
4853 * GDB now supports thread debugging of core dumps on GNU/Linux.
4855 GDB now activates thread debugging using the libthread_db library
4856 when debugging GNU/Linux core dumps, similarly to when debugging
4857 live processes. As a result, when debugging a core dump file, GDB
4858 is now able to display pthread_t ids of threads. For example, "info
4859 threads" shows the same output as when debugging the process when it
4860 was live. In earlier releases, you'd see something like this:
4863 * 1 LWP 6780 main () at main.c:10
4865 While now you see this:
4868 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4870 It is also now possible to inspect TLS variables when debugging core
4873 When debugging a core dump generated on a machine other than the one
4874 used to run GDB, you may need to point GDB at the correct
4875 libthread_db library with the "set libthread-db-search-path"
4876 command. See the user manual for more details on this command.
4878 * When natively debugging programs on PowerPC BookE processors running
4879 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4880 which stop execution of the inferior whenever it executes an instruction
4881 at any address within the specified range. See the "PowerPC Embedded"
4882 section in the user manual for more details.
4884 * New features in the GDB remote stub, GDBserver
4886 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4887 and i686 LynxOS (version 5.x).
4889 ** GDBserver is now supported on Blackfin Linux.
4891 * New native configurations
4893 ia64 HP-UX ia64-*-hpux*
4897 Analog Devices, Inc. Blackfin Processor bfin-*
4899 * Ada task switching is now supported on sparc-elf targets when
4900 debugging a program using the Ravenscar Profile. For more information,
4901 see the "Tasking Support when using the Ravenscar Profile" section
4902 in the GDB user manual.
4904 * Guile support was removed.
4906 * New features in the GNU simulator
4908 ** The --map-info flag lists all known core mappings.
4910 ** CFI flashes may be simulated via the "cfi" device.
4912 *** Changes in GDB 7.2
4914 * Shared library support for remote targets by default
4916 When GDB is configured for a generic, non-OS specific target, like
4917 for example, --target=arm-eabi or one of the many *-*-elf targets,
4918 GDB now queries remote stubs for loaded shared libraries using the
4919 `qXfer:libraries:read' packet. Previously, shared library support
4920 was always disabled for such configurations.
4924 ** Argument Dependent Lookup (ADL)
4926 In C++ ADL lookup directs function search to the namespaces of its
4927 arguments even if the namespace has not been imported.
4937 Here the compiler will search for `foo' in the namespace of 'b'
4938 and find A::foo. GDB now supports this. This construct is commonly
4939 used in the Standard Template Library for operators.
4941 ** Improved User Defined Operator Support
4943 In addition to member operators, GDB now supports lookup of operators
4944 defined in a namespace and imported with a `using' directive, operators
4945 defined in the global scope, operators imported implicitly from an
4946 anonymous namespace, and the ADL operators mentioned in the previous
4948 GDB now also supports proper overload resolution for all the previously
4949 mentioned flavors of operators.
4951 ** static const class members
4953 Printing of static const class members that are initialized in the
4954 class definition has been fixed.
4956 * Windows Thread Information Block access.
4958 On Windows targets, GDB now supports displaying the Windows Thread
4959 Information Block (TIB) structure. This structure is visible either
4960 by using the new command `info w32 thread-information-block' or, by
4961 dereferencing the new convenience variable named `$_tlb', a
4962 thread-specific pointer to the TIB. This feature is also supported
4963 when remote debugging using GDBserver.
4965 * Static tracepoints
4967 Static tracepoints are calls in the user program into a tracing
4968 library. One such library is a port of the LTTng kernel tracer to
4969 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4970 When debugging with GDBserver, GDB now supports combining the GDB
4971 tracepoint machinery with such libraries. For example: the user can
4972 use GDB to probe a static tracepoint marker (a call from the user
4973 program into the tracing library) with the new "strace" command (see
4974 "New commands" below). This creates a "static tracepoint" in the
4975 breakpoint list, that can be manipulated with the same feature set
4976 as fast and regular tracepoints. E.g., collect registers, local and
4977 global variables, collect trace state variables, and define
4978 tracepoint conditions. In addition, the user can collect extra
4979 static tracepoint marker specific data, by collecting the new
4980 $_sdata internal variable. When analyzing the trace buffer, you can
4981 inspect $_sdata like any other variable available to GDB. For more
4982 information, see the "Tracepoints" chapter in GDB user manual. New
4983 remote packets have been defined to support static tracepoints, see
4984 the "New remote packets" section below.
4986 * Better reconstruction of tracepoints after disconnected tracing
4988 GDB will attempt to download the original source form of tracepoint
4989 definitions when starting a trace run, and then will upload these
4990 upon reconnection to the target, resulting in a more accurate
4991 reconstruction of the tracepoints that are in use on the target.
4995 You can now exercise direct control over the ways that GDB can
4996 affect your program. For instance, you can disallow the setting of
4997 breakpoints, so that the program can run continuously (assuming
4998 non-stop mode). In addition, the "observer" variable is available
4999 to switch all of the different controls; in observer mode, GDB
5000 cannot affect the target's behavior at all, which is useful for
5001 tasks like diagnosing live systems in the field.
5003 * The new convenience variable $_thread holds the number of the
5006 * New remote packets
5010 Return the address of the Windows Thread Information Block of a given thread.
5014 In response to several of the tracepoint packets, the target may now
5015 also respond with a number of intermediate `qRelocInsn' request
5016 packets before the final result packet, to have GDB handle
5017 relocating an instruction to execute at a different address. This
5018 is particularly useful for stubs that support fast tracepoints. GDB
5019 reports support for this feature in the qSupported packet.
5023 List static tracepoint markers in the target program.
5027 List static tracepoint markers at a given address in the target
5030 qXfer:statictrace:read
5032 Read the static trace data collected (by a `collect $_sdata'
5033 tracepoint action). The remote stub reports support for this packet
5034 to gdb's qSupported query.
5038 Send the current settings of GDB's permission flags.
5042 Send part of the source (textual) form of a tracepoint definition,
5043 which includes location, conditional, and action list.
5045 * The source command now accepts a -s option to force searching for the
5046 script in the source search path even if the script name specifies
5049 * New features in the GDB remote stub, GDBserver
5051 - GDBserver now support tracepoints (including fast tracepoints, and
5052 static tracepoints). The feature is currently supported by the
5053 i386-linux and amd64-linux builds. See the "Tracepoints support
5054 in gdbserver" section in the manual for more information.
5056 GDBserver JIT compiles the tracepoint's conditional agent
5057 expression bytecode into native code whenever possible for low
5058 overhead dynamic tracepoints conditionals. For such tracepoints,
5059 an expression that examines program state is evaluated when the
5060 tracepoint is reached, in order to determine whether to capture
5061 trace data. If the condition is simple and false, processing the
5062 tracepoint finishes very quickly and no data is gathered.
5064 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5065 for static tracepoints support.
5067 - GDBserver now supports x86_64 Windows 64-bit debugging.
5069 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5070 it understands register description.
5072 * The --batch flag now disables pagination and queries.
5074 * X86 general purpose registers
5076 GDB now supports reading/writing byte, word and double-word x86
5077 general purpose registers directly. This means you can use, say,
5078 $ah or $ax to refer, respectively, to the byte register AH and
5079 16-bit word register AX that are actually portions of the 32-bit
5080 register EAX or 64-bit register RAX.
5082 * The `commands' command now accepts a range of breakpoints to modify.
5083 A plain `commands' following a command that creates multiple
5084 breakpoints affects all the breakpoints set by that command. This
5085 applies to breakpoints set by `rbreak', and also applies when a
5086 single `break' command creates multiple breakpoints (e.g.,
5087 breakpoints on overloaded c++ functions).
5089 * The `rbreak' command now accepts a filename specification as part of
5090 its argument, limiting the functions selected by the regex to those
5091 in the specified file.
5093 * Support for remote debugging Windows and SymbianOS shared libraries
5094 from Unix hosts has been improved. Non Windows GDB builds now can
5095 understand target reported file names that follow MS-DOS based file
5096 system semantics, such as file names that include drive letters and
5097 use the backslash character as directory separator. This makes it
5098 possible to transparently use the "set sysroot" and "set
5099 solib-search-path" on Unix hosts to point as host copies of the
5100 target's shared libraries. See the new command "set
5101 target-file-system-kind" described below, and the "Commands to
5102 specify files" section in the user manual for more information.
5106 eval template, expressions...
5107 Convert the values of one or more expressions under the control
5108 of the string template to a command line, and call it.
5110 set target-file-system-kind unix|dos-based|auto
5111 show target-file-system-kind
5112 Set or show the assumed file system kind for target reported file
5115 save breakpoints <filename>
5116 Save all current breakpoint definitions to a file suitable for use
5117 in a later debugging session. To read the saved breakpoint
5118 definitions, use the `source' command.
5120 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5123 info static-tracepoint-markers
5124 Display information about static tracepoint markers in the target.
5126 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5127 Define a static tracepoint by probing a marker at the given
5128 function, line, address, or marker ID.
5132 Enable and disable observer mode.
5134 set may-write-registers on|off
5135 set may-write-memory on|off
5136 set may-insert-breakpoints on|off
5137 set may-insert-tracepoints on|off
5138 set may-insert-fast-tracepoints on|off
5139 set may-interrupt on|off
5140 Set individual permissions for GDB effects on the target. Note that
5141 some of these settings can have undesirable or surprising
5142 consequences, particularly when changed in the middle of a session.
5143 For instance, disabling the writing of memory can prevent
5144 breakpoints from being inserted, cause single-stepping to fail, or
5145 even crash your program, if you disable after breakpoints have been
5146 inserted. However, GDB should not crash.
5148 set record memory-query on|off
5149 show record memory-query
5150 Control whether to stop the inferior if memory changes caused
5151 by an instruction cannot be recorded.
5156 The disassemble command now supports "start,+length" form of two arguments.
5160 ** GDB now provides a new directory location, called the python directory,
5161 where Python scripts written for GDB can be installed. The location
5162 of that directory is <data-directory>/python, where <data-directory>
5163 is the GDB data directory. For more details, see section `Scripting
5164 GDB using Python' in the manual.
5166 ** The GDB Python API now has access to breakpoints, symbols, symbol
5167 tables, program spaces, inferiors, threads and frame's code blocks.
5168 Additionally, GDB Parameters can now be created from the API, and
5169 manipulated via set/show in the CLI.
5171 ** New functions gdb.target_charset, gdb.target_wide_charset,
5172 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5174 ** New exception gdb.GdbError.
5176 ** Pretty-printers are now also looked up in the current program space.
5178 ** Pretty-printers can now be individually enabled and disabled.
5180 ** GDB now looks for names of Python scripts to auto-load in a
5181 special section named `.debug_gdb_scripts', in addition to looking
5182 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5184 * Tracepoint actions were unified with breakpoint commands. In particular,
5185 there are no longer differences in "info break" output for breakpoints and
5186 tracepoints and the "commands" command can be used for both tracepoints and
5187 regular breakpoints.
5191 ARM Symbian arm*-*-symbianelf*
5193 * D language support.
5194 GDB now supports debugging programs written in the D programming
5197 * GDB now supports the extended ptrace interface for PowerPC which is
5198 available since Linux kernel version 2.6.34. This automatically enables
5199 any hardware breakpoints and additional hardware watchpoints available in
5200 the processor. The old ptrace interface exposes just one hardware
5201 watchpoint and no hardware breakpoints.
5203 * GDB is now able to use the Data Value Compare (DVC) register available on
5204 embedded PowerPC processors to implement in hardware simple watchpoint
5205 conditions of the form:
5207 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5209 This works in native GDB running on Linux kernels with the extended ptrace
5210 interface mentioned above.
5212 *** Changes in GDB 7.1
5216 ** Namespace Support
5218 GDB now supports importing of namespaces in C++. This enables the
5219 user to inspect variables from imported namespaces. Support for
5220 namepace aliasing has also been added. So, if a namespace is
5221 aliased in the current scope (e.g. namepace C=A; ) the user can
5222 print variables using the alias (e.g. (gdb) print C::x).
5226 All known bugs relating to the printing of virtual base class were
5227 fixed. It is now possible to call overloaded static methods using a
5232 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5233 and reinterpret_cast<> are now handled by the C++ expression parser.
5237 Xilinx MicroBlaze microblaze-*-*
5242 Xilinx MicroBlaze microblaze
5245 * Multi-program debugging.
5247 GDB now has support for multi-program (a.k.a. multi-executable or
5248 multi-exec) debugging. This allows for debugging multiple inferiors
5249 simultaneously each running a different program under the same GDB
5250 session. See "Debugging Multiple Inferiors and Programs" in the
5251 manual for more information. This implied some user visible changes
5252 in the multi-inferior support. For example, "info inferiors" now
5253 lists inferiors that are not running yet or that have exited
5254 already. See also "New commands" and "New options" below.
5256 * New tracing features
5258 GDB's tracepoint facility now includes several new features:
5260 ** Trace state variables
5262 GDB tracepoints now include support for trace state variables, which
5263 are variables managed by the target agent during a tracing
5264 experiment. They are useful for tracepoints that trigger each
5265 other, so for instance one tracepoint can count hits in a variable,
5266 and then a second tracepoint has a condition that is true when the
5267 count reaches a particular value. Trace state variables share the
5268 $-syntax of GDB convenience variables, and can appear in both
5269 tracepoint actions and condition expressions. Use the "tvariable"
5270 command to create, and "info tvariables" to view; see "Trace State
5271 Variables" in the manual for more detail.
5275 GDB now includes an option for defining fast tracepoints, which
5276 targets may implement more efficiently, such as by installing a jump
5277 into the target agent rather than a trap instruction. The resulting
5278 speedup can be by two orders of magnitude or more, although the
5279 tradeoff is that some program locations on some target architectures
5280 might not allow fast tracepoint installation, for instance if the
5281 instruction to be replaced is shorter than the jump. To request a
5282 fast tracepoint, use the "ftrace" command, with syntax identical to
5283 the regular trace command.
5285 ** Disconnected tracing
5287 It is now possible to detach GDB from the target while it is running
5288 a trace experiment, then reconnect later to see how the experiment
5289 is going. In addition, a new variable disconnected-tracing lets you
5290 tell the target agent whether to continue running a trace if the
5291 connection is lost unexpectedly.
5295 GDB now has the ability to save the trace buffer into a file, and
5296 then use that file as a target, similarly to you can do with
5297 corefiles. You can select trace frames, print data that was
5298 collected in them, and use tstatus to display the state of the
5299 tracing run at the moment that it was saved. To create a trace
5300 file, use "tsave <filename>", and to use it, do "target tfile
5303 ** Circular trace buffer
5305 You can ask the target agent to handle the trace buffer as a
5306 circular buffer, discarding the oldest trace frames to make room for
5307 newer ones, by setting circular-trace-buffer to on. This feature may
5308 not be available for all target agents.
5313 The disassemble command, when invoked with two arguments, now requires
5314 the arguments to be comma-separated.
5317 The info variables command now displays variable definitions. Files
5318 which only declare a variable are not shown.
5321 The source command is now capable of sourcing Python scripts.
5322 This feature is dependent on the debugger being build with Python
5325 Related to this enhancement is also the introduction of a new command
5326 "set script-extension" (see below).
5328 * New commands (for set/show, see "New options" below)
5330 record save [<FILENAME>]
5331 Save a file (in core file format) containing the process record
5332 execution log for replay debugging at a later time.
5334 record restore <FILENAME>
5335 Restore the process record execution log that was saved at an
5336 earlier time, for replay debugging.
5338 add-inferior [-copies <N>] [-exec <FILENAME>]
5341 clone-inferior [-copies <N>] [ID]
5342 Make a new inferior ready to execute the same program another
5343 inferior has loaded.
5348 maint info program-spaces
5349 List the program spaces loaded into GDB.
5351 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5352 show remote interrupt-sequence
5353 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5354 as the sequence to the remote target in order to interrupt the execution.
5355 Ctrl-C is a default. Some system prefers BREAK which is high level of
5356 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5357 Magic SysRq g. It is BREAK signal and character 'g'.
5359 set remote interrupt-on-connect [on | off]
5360 show remote interrupt-on-connect
5361 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5362 remote target when gdb connects to it. This is needed when you debug
5365 set remotebreak [on | off]
5367 Deprecated. Use "set/show remote interrupt-sequence" instead.
5369 tvariable $NAME [ = EXP ]
5370 Create or modify a trace state variable.
5373 List trace state variables and their values.
5375 delete tvariable $NAME ...
5376 Delete one or more trace state variables.
5379 Evaluate the given expressions without collecting anything into the
5380 trace buffer. (Valid in tracepoint actions only.)
5382 ftrace FN / FILE:LINE / *ADDR
5383 Define a fast tracepoint at the given function, line, or address.
5385 * New expression syntax
5387 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5388 GDB now parses 0b101010 identically with 42.
5392 set follow-exec-mode new|same
5393 show follow-exec-mode
5394 Control whether GDB reuses the same inferior across an exec call or
5395 creates a new one. This is useful to be able to restart the old
5396 executable after the inferior having done an exec call.
5398 set default-collect EXPR, ...
5399 show default-collect
5400 Define a list of expressions to be collected at each tracepoint.
5401 This is a useful way to ensure essential items are not overlooked,
5402 such as registers or a critical global variable.
5404 set disconnected-tracing
5405 show disconnected-tracing
5406 If set to 1, the target is instructed to continue tracing if it
5407 loses its connection to GDB. If 0, the target is to stop tracing
5410 set circular-trace-buffer
5411 show circular-trace-buffer
5412 If set to on, the target is instructed to use a circular trace buffer
5413 and discard the oldest trace frames instead of stopping the trace due
5414 to a full trace buffer. If set to off, the trace stops when the buffer
5415 fills up. Some targets may not support this.
5417 set script-extension off|soft|strict
5418 show script-extension
5419 If set to "off", the debugger does not perform any script language
5420 recognition, and all sourced files are assumed to be GDB scripts.
5421 If set to "soft" (the default), files are sourced according to
5422 filename extension, falling back to GDB scripts if the first
5424 If set to "strict", files are sourced according to filename extension.
5426 set ada trust-PAD-over-XVS on|off
5427 show ada trust-PAD-over-XVS
5428 If off, activate a workaround against a bug in the debugging information
5429 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5430 the GCC sources for more information about the GNAT encoding and
5431 PAD types in particular). It is always safe to set this option to
5432 off, but this introduces a slight performance penalty. The default
5435 * Python API Improvements
5437 ** GDB provides the new class gdb.LazyString. This is useful in
5438 some pretty-printing cases. The new method gdb.Value.lazy_string
5439 provides a simple way to create objects of this type.
5441 ** The fields returned by gdb.Type.fields now have an
5442 `is_base_class' attribute.
5444 ** The new method gdb.Type.range returns the range of an array type.
5446 ** The new method gdb.parse_and_eval can be used to parse and
5447 evaluate an expression.
5449 * New remote packets
5452 Define a trace state variable.
5455 Get the current value of a trace state variable.
5458 Set desired tracing behavior upon disconnection.
5461 Set the trace buffer to be linear or circular.
5464 Get data about the tracepoints currently in use.
5468 Process record now works correctly with hardware watchpoints.
5470 Multiple bug fixes have been made to the mips-irix port, making it
5471 much more reliable. In particular:
5472 - Debugging threaded applications is now possible again. Previously,
5473 GDB would hang while starting the program, or while waiting for
5474 the program to stop at a breakpoint.
5475 - Attaching to a running process no longer hangs.
5476 - An error occurring while loading a core file has been fixed.
5477 - Changing the value of the PC register now works again. This fixes
5478 problems observed when using the "jump" command, or when calling
5479 a function from GDB, or even when assigning a new value to $pc.
5480 - With the "finish" and "return" commands, the return value for functions
5481 returning a small array is now correctly printed.
5482 - It is now possible to break on shared library code which gets executed
5483 during a shared library init phase (code executed while executing
5484 their .init section). Previously, the breakpoint would have no effect.
5485 - GDB is now able to backtrace through the signal handler for
5486 non-threaded programs.
5488 PIE (Position Independent Executable) programs debugging is now supported.
5489 This includes debugging execution of PIC (Position Independent Code) shared
5490 libraries although for that, it should be possible to run such libraries as an
5493 *** Changes in GDB 7.0
5495 * GDB now has an interface for JIT compilation. Applications that
5496 dynamically generate code can create symbol files in memory and register
5497 them with GDB. For users, the feature should work transparently, and
5498 for JIT developers, the interface is documented in the GDB manual in the
5499 "JIT Compilation Interface" chapter.
5501 * Tracepoints may now be conditional. The syntax is as for
5502 breakpoints; either an "if" clause appended to the "trace" command,
5503 or the "condition" command is available. GDB sends the condition to
5504 the target for evaluation using the same bytecode format as is used
5505 for tracepoint actions.
5507 * The disassemble command now supports: an optional /r modifier, print the
5508 raw instructions in hex as well as in symbolic form, and an optional /m
5509 modifier to print mixed source+assembly.
5511 * Process record and replay
5513 In a architecture environment that supports ``process record and
5514 replay'', ``process record and replay'' target can record a log of
5515 the process execution, and replay it with both forward and reverse
5518 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5519 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5520 set execution-direction {forward|reverse}, for targets that support
5523 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5524 feature is available with a native GDB running on kernel version
5527 * GDB now has support for multi-byte and wide character sets on the
5528 target. Strings whose character type is wchar_t, char16_t, or
5529 char32_t are now correctly printed. GDB supports wide- and unicode-
5530 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5531 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5532 `printf'. This feature requires iconv to work properly; if your
5533 system does not have a working iconv, GDB can use GNU libiconv. See
5534 the installation instructions for more information.
5536 * GDB now supports automatic retrieval of shared library files from
5537 remote targets. To use this feature, specify a system root that begins
5538 with the `remote:' prefix, either via the `set sysroot' command or via
5539 the `--with-sysroot' configure-time option.
5541 * "info sharedlibrary" now takes an optional regex of libraries to show,
5542 and it now reports if a shared library has no debugging information.
5544 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5545 now complete on file names.
5547 * When completing in expressions, gdb will attempt to limit
5548 completions to allowable structure or union fields, where appropriate.
5549 For instance, consider:
5551 # struct example { int f1; double f2; };
5552 # struct example variable;
5555 If the user types TAB at the end of this command line, the available
5556 completions will be "f1" and "f2".
5558 * Inlined functions are now supported. They show up in backtraces, and
5559 the "step", "next", and "finish" commands handle them automatically.
5561 * GDB now supports the token-splicing (##) and stringification (#)
5562 operators when expanding macros. It also supports variable-arity
5565 * GDB now supports inspecting extra signal information, exported by
5566 the new $_siginfo convenience variable. The feature is currently
5567 implemented on linux ARM, i386 and amd64.
5569 * GDB can now display the VFP floating point registers and NEON vector
5570 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5571 can provide these registers (requires Linux 2.6.30 or later). Remote
5572 and simulator targets may also provide them.
5574 * New remote packets
5577 Search memory for a sequence of bytes.
5580 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5581 operation over reliable transport links. Use of this packet is
5582 controlled by the `set remote noack-packet' command.
5585 Kill the process with the specified process ID. Use this in preference
5586 to `k' when multiprocess protocol extensions are supported.
5589 Obtains additional operating system information
5593 Read or write additional signal information.
5595 * Removed remote protocol undocumented extension
5597 An undocumented extension to the remote protocol's `S' stop reply
5598 packet that permitted the stub to pass a process id was removed.
5599 Remote servers should use the `T' stop reply packet instead.
5601 * GDB now supports multiple function calling conventions according to the
5602 DWARF-2 DW_AT_calling_convention function attribute.
5604 * The SH target utilizes the aforementioned change to distinguish between gcc
5605 and Renesas calling convention. It also adds the new CLI commands
5606 `set/show sh calling-convention'.
5608 * GDB can now read compressed debug sections, as produced by GNU gold
5609 with the --compress-debug-sections=zlib flag.
5611 * 64-bit core files are now supported on AIX.
5613 * Thread switching is now supported on Tru64.
5615 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5616 which will be allocated using malloc later in program execution.
5618 * The qXfer:libraries:read remote protocol packet now allows passing a
5619 list of section offsets.
5621 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5622 conditions handling signals delivered during attach or thread creation
5623 have also been fixed.
5625 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5626 From the user's standpoint, all unqualified instances of True and False
5627 are treated as the standard definitions, regardless of context.
5629 * GDB now parses C++ symbol and type names more flexibly. For
5632 template<typename T> class C { };
5635 GDB will now correctly handle all of:
5637 ptype C<char const *>
5638 ptype C<char const*>
5639 ptype C<const char *>
5640 ptype C<const char*>
5642 * New features in the GDB remote stub, gdbserver
5644 - The "--wrapper" command-line argument tells gdbserver to use a
5645 wrapper program to launch programs for debugging.
5647 - On PowerPC and S/390 targets, it is now possible to use a single
5648 gdbserver executable to debug both 32-bit and 64-bit programs.
5649 (This requires gdbserver itself to be built as a 64-bit executable.)
5651 - gdbserver uses the new noack protocol mode for TCP connections to
5652 reduce communications latency, if also supported and enabled in GDB.
5654 - Support for the sparc64-linux-gnu target is now included in
5657 - The amd64-linux build of gdbserver now supports debugging both
5658 32-bit and 64-bit programs.
5660 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5661 now support hardware watchpoints, and will use them automatically
5666 GDB now has support for scripting using Python. Whether this is
5667 available is determined at configure time.
5669 New GDB commands can now be written in Python.
5671 * Ada tasking support
5673 Ada tasks can now be inspected in GDB. The following commands have
5677 Print the list of Ada tasks.
5679 Print detailed information about task number N.
5681 Print the task number of the current task.
5683 Switch the context of debugging to task number N.
5685 * Support for user-defined prefixed commands. The "define" command can
5686 add new commands to existing prefixes, e.g. "target".
5688 * Multi-inferior, multi-process debugging.
5690 GDB now has generalized support for multi-inferior debugging. See
5691 "Debugging Multiple Inferiors" in the manual for more information.
5692 Although availability still depends on target support, the command
5693 set is more uniform now. The GNU/Linux specific multi-forks support
5694 has been migrated to this new framework. This implied some user
5695 visible changes; see "New commands" and also "Removed commands"
5698 * Target descriptions can now describe the target OS ABI. See the
5699 "Target Description Format" section in the user manual for more
5702 * Target descriptions can now describe "compatible" architectures
5703 to indicate that the target can execute applications for a different
5704 architecture in addition to those for the main target architecture.
5705 See the "Target Description Format" section in the user manual for
5708 * Multi-architecture debugging.
5710 GDB now includes general supports for debugging applications on
5711 hybrid systems that use more than one single processor architecture
5712 at the same time. Each such hybrid architecture still requires
5713 specific support to be added. The only hybrid architecture supported
5714 in this version of GDB is the Cell Broadband Engine.
5716 * GDB now supports integrated debugging of Cell/B.E. applications that
5717 use both the PPU and SPU architectures. To enable support for hybrid
5718 Cell/B.E. debugging, you need to configure GDB to support both the
5719 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5720 --enable-targets configure option.
5722 * Non-stop mode debugging.
5724 For some targets, GDB now supports an optional mode of operation in
5725 which you can examine stopped threads while other threads continue
5726 to execute freely. This is referred to as non-stop mode, with the
5727 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5728 section in the user manual for more information.
5730 To be able to support remote non-stop debugging, a remote stub needs
5731 to implement the non-stop mode remote protocol extensions, as
5732 described in the "Remote Non-Stop" section of the user manual. The
5733 GDB remote stub, gdbserver, has been adjusted to support these
5734 extensions on linux targets.
5736 * New commands (for set/show, see "New options" below)
5738 catch syscall [NAME(S) | NUMBER(S)]
5739 Catch system calls. Arguments, which should be names of system
5740 calls or their numbers, mean catch only those syscalls. Without
5741 arguments, every syscall will be caught. When the inferior issues
5742 any of the specified syscalls, GDB will stop and announce the system
5743 call, both when it is called and when its call returns. This
5744 feature is currently available with a native GDB running on the
5745 Linux Kernel, under the following architectures: x86, x86_64,
5746 PowerPC and PowerPC64.
5748 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5750 Search memory for a sequence of bytes.
5752 maint set python print-stack
5753 maint show python print-stack
5754 Show a stack trace when an error is encountered in a Python script.
5757 Invoke CODE by passing it to the Python interpreter.
5762 These allow macros to be defined, undefined, and listed
5766 Show operating system information about processes.
5769 List the inferiors currently under GDB's control.
5772 Switch focus to inferior number NUM.
5775 Detach from inferior number NUM.
5778 Kill inferior number NUM.
5782 set spu stop-on-load
5783 show spu stop-on-load
5784 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5786 set spu auto-flush-cache
5787 show spu auto-flush-cache
5788 Control whether to automatically flush the software-managed cache
5789 during Cell/B.E. debugging.
5791 set sh calling-convention
5792 show sh calling-convention
5793 Control the calling convention used when calling SH target functions.
5796 show debug timestamp
5797 Control display of timestamps with GDB debugging output.
5799 set disassemble-next-line
5800 show disassemble-next-line
5801 Control display of disassembled source lines or instructions when
5804 set remote noack-packet
5805 show remote noack-packet
5806 Set/show the use of remote protocol QStartNoAckMode packet. See above
5807 under "New remote packets."
5809 set remote query-attached-packet
5810 show remote query-attached-packet
5811 Control use of remote protocol `qAttached' (query-attached) packet.
5813 set remote read-siginfo-object
5814 show remote read-siginfo-object
5815 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5818 set remote write-siginfo-object
5819 show remote write-siginfo-object
5820 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5823 set remote reverse-continue
5824 show remote reverse-continue
5825 Control use of remote protocol 'bc' (reverse-continue) packet.
5827 set remote reverse-step
5828 show remote reverse-step
5829 Control use of remote protocol 'bs' (reverse-step) packet.
5831 set displaced-stepping
5832 show displaced-stepping
5833 Control displaced stepping mode. Displaced stepping is a way to
5834 single-step over breakpoints without removing them from the debuggee.
5835 Also known as "out-of-line single-stepping".
5838 show debug displaced
5839 Control display of debugging info for displaced stepping.
5841 maint set internal-error
5842 maint show internal-error
5843 Control what GDB does when an internal error is detected.
5845 maint set internal-warning
5846 maint show internal-warning
5847 Control what GDB does when an internal warning is detected.
5852 Use a wrapper program to launch programs for debugging.
5854 set multiple-symbols (all|ask|cancel)
5855 show multiple-symbols
5856 The value of this variable can be changed to adjust the debugger behavior
5857 when an expression or a breakpoint location contains an ambiguous symbol
5858 name (an overloaded function name, for instance).
5860 set breakpoint always-inserted
5861 show breakpoint always-inserted
5862 Keep breakpoints always inserted in the target, as opposed to inserting
5863 them when resuming the target, and removing them when the target stops.
5864 This option can improve debugger performance on slow remote targets.
5866 set arm fallback-mode (arm|thumb|auto)
5867 show arm fallback-mode
5868 set arm force-mode (arm|thumb|auto)
5870 These commands control how ARM GDB determines whether instructions
5871 are ARM or Thumb. The default for both settings is auto, which uses
5872 the current CPSR value for instructions without symbols; previous
5873 versions of GDB behaved as if "set arm fallback-mode arm".
5875 set arm unwind-secure-frames
5876 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5878 This can trigger security exceptions when unwinding exception stacks.
5880 set disable-randomization
5881 show disable-randomization
5882 Standalone programs run with the virtual address space randomization enabled
5883 by default on some platforms. This option keeps the addresses stable across
5884 multiple debugging sessions.
5888 Control whether other threads are stopped or not when some thread hits
5893 Requests that asynchronous execution is enabled in the target, if available.
5894 In this case, it's possible to resume target in the background, and interact
5895 with GDB while the target is running. "show target-async" displays the
5896 current state of asynchronous execution of the target.
5898 set target-wide-charset
5899 show target-wide-charset
5900 The target-wide-charset is the name of the character set that GDB
5901 uses when printing characters whose type is wchar_t.
5903 set tcp auto-retry (on|off)
5905 set tcp connect-timeout
5906 show tcp connect-timeout
5907 These commands allow GDB to retry failed TCP connections to a remote stub
5908 with a specified timeout period; this is useful if the stub is launched
5909 in parallel with GDB but may not be ready to accept connections immediately.
5911 set libthread-db-search-path
5912 show libthread-db-search-path
5913 Control list of directories which GDB will search for appropriate
5916 set schedule-multiple (on|off)
5917 show schedule-multiple
5918 Allow GDB to resume all threads of all processes or only threads of
5919 the current process.
5923 Use more aggressive caching for accesses to the stack. This improves
5924 performance of remote debugging (particularly backtraces) without
5925 affecting correctness.
5927 set interactive-mode (on|off|auto)
5928 show interactive-mode
5929 Control whether GDB runs in interactive mode (on) or not (off).
5930 When in interactive mode, GDB waits for the user to answer all
5931 queries. Otherwise, GDB does not wait and assumes the default
5932 answer. When set to auto (the default), GDB determines which
5933 mode to use based on the stdin settings.
5938 For program forks, this is replaced by the new more generic `info
5939 inferiors' command. To list checkpoints, you can still use the
5940 `info checkpoints' command, which was an alias for the `info forks'
5944 Replaced by the new `inferior' command. To switch between
5945 checkpoints, you can still use the `restart' command, which was an
5946 alias for the `fork' command.
5949 This is removed, since some targets don't have a notion of
5950 processes. To switch between processes, you can still use the
5951 `inferior' command using GDB's own inferior number.
5954 For program forks, this is replaced by the new more generic `kill
5955 inferior' command. To delete a checkpoint, you can still use the
5956 `delete checkpoint' command, which was an alias for the `delete
5960 For program forks, this is replaced by the new more generic `detach
5961 inferior' command. To detach a checkpoint, you can still use the
5962 `detach checkpoint' command, which was an alias for the `detach
5965 * New native configurations
5967 x86/x86_64 Darwin i[34567]86-*-darwin*
5969 x86_64 MinGW x86_64-*-mingw*
5973 Lattice Mico32 lm32-*
5974 x86 DICOS i[34567]86-*-dicos*
5975 x86_64 DICOS x86_64-*-dicos*
5978 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5979 (mingw32ce) debugging.
5985 These commands were actually not implemented on any target.
5987 *** Changes in GDB 6.8
5989 * New native configurations
5991 NetBSD/hppa hppa*-*netbsd*
5992 Xtensa GNU/Linux xtensa*-*-linux*
5996 NetBSD/hppa hppa*-*-netbsd*
5997 Xtensa GNU/Linux xtensa*-*-linux*
5999 * Change in command line behavior -- corefiles vs. process ids.
6001 When the '-p NUMBER' or '--pid NUMBER' options are used, and
6002 attaching to process NUMBER fails, GDB no longer attempts to open a
6003 core file named NUMBER. Attaching to a program using the -c option
6004 is no longer supported. Instead, use the '-p' or '--pid' options.
6006 * GDB can now be built as a native debugger for debugging Windows x86
6007 (mingw32) Portable Executable (PE) programs.
6009 * Pending breakpoints no longer change their number when their address
6012 * GDB now supports breakpoints with multiple locations,
6013 including breakpoints on C++ constructors, inside C++ templates,
6014 and in inlined functions.
6016 * GDB's ability to debug optimized code has been improved. GDB more
6017 accurately identifies function bodies and lexical blocks that occupy
6018 more than one contiguous range of addresses.
6020 * Target descriptions can now describe registers for PowerPC.
6022 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
6023 registers on PowerPC targets.
6025 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
6026 targets even when the libthread_db library is not available.
6028 * The GDB remote stub, gdbserver, now supports the new file transfer
6029 commands (remote put, remote get, and remote delete).
6031 * The GDB remote stub, gdbserver, now supports run and attach in
6032 extended-remote mode.
6034 * hppa*64*-*-hpux11* target broken
6035 The debugger is unable to start a program and fails with the following
6036 error: "Error trying to get information about dynamic linker".
6037 The gdb-6.7 release is also affected.
6039 * GDB now supports the --enable-targets= configure option to allow
6040 building a single GDB executable that supports multiple remote
6041 target architectures.
6043 * GDB now supports debugging C and C++ programs which use the
6044 Decimal Floating Point extension. In addition, the PowerPC target
6045 now has a set of pseudo-registers to inspect decimal float values
6046 stored in two consecutive float registers.
6048 * The -break-insert MI command can optionally create pending
6051 * Improved support for debugging Ada
6052 Many improvements to the Ada language support have been made. These
6054 - Better support for Ada2005 interface types
6055 - Improved handling of arrays and slices in general
6056 - Better support for Taft-amendment types
6057 - The '{type} ADDRESS' expression is now allowed on the left hand-side
6059 - Improved command completion in Ada
6062 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6067 set print frame-arguments (all|scalars|none)
6068 show print frame-arguments
6069 The value of this variable can be changed to control which argument
6070 values should be printed by the debugger when displaying a frame.
6075 Transfer files to and from a remote target, and delete remote files.
6082 Transfer files to and from a remote target, and delete remote files.
6084 * New remote packets
6091 Open, close, read, write, and delete files on the remote system.
6094 Attach to an existing process on the remote system, in extended-remote
6098 Run a new process on the remote system, in extended-remote mode.
6100 *** Changes in GDB 6.7
6102 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6103 bfd, libiberty and opcodes, as revealed by static analysis donated by
6104 Coverity, Inc. (http://scan.coverity.com).
6106 * When looking up multiply-defined global symbols, GDB will now prefer the
6107 symbol definition in the current shared library if it was built using the
6108 -Bsymbolic linker option.
6110 * When the Text User Interface (TUI) is not configured, GDB will now
6111 recognize the -tui command-line option and print a message that the TUI
6114 * The GDB remote stub, gdbserver, now has lower overhead for high
6115 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6117 * GDB for MIPS targets now autodetects whether a remote target provides
6118 32-bit or 64-bit register values.
6120 * Support for C++ member pointers has been improved.
6122 * GDB now understands XML target descriptions, which specify the
6123 target's overall architecture. GDB can read a description from
6124 a local file or over the remote serial protocol.
6126 * Vectors of single-byte data use a new integer type which is not
6127 automatically displayed as character or string data.
6129 * The /s format now works with the print command. It displays
6130 arrays of single-byte integers and pointers to single-byte integers
6133 * Target descriptions can now describe target-specific registers,
6134 for architectures which have implemented the support (currently
6135 only ARM, M68K, and MIPS).
6137 * GDB and the GDB remote stub, gdbserver, now support the XScale
6140 * The GDB remote stub, gdbserver, has been updated to support
6141 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6142 has been rewritten to use the standard GDB remote protocol.
6144 * GDB can now step into C++ functions which are called through thunks.
6146 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6148 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6149 layout. It also supports a TextSeg= and DataSeg= response when only
6150 segment base addresses (rather than offsets) are available.
6152 * The /i format now outputs any trailing branch delay slot instructions
6153 immediately following the last instruction within the count specified.
6155 * The GDB remote protocol "T" stop reply packet now supports a
6156 "library" response. Combined with the new "qXfer:libraries:read"
6157 packet, this response allows GDB to debug shared libraries on targets
6158 where the operating system manages the list of loaded libraries (e.g.
6159 Windows and SymbianOS).
6161 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6162 (DLLs) on Windows and Windows CE targets.
6164 * GDB now supports a faster verification that a .debug file matches its binary
6165 according to its build-id signature, if the signature is present.
6171 Enable or disable hardware flow control (RTS/CTS) on the serial port
6172 when debugging using remote targets.
6174 set mem inaccessible-by-default
6175 show mem inaccessible-by-default
6176 If the target supplies a memory map, for instance via the remote
6177 protocol's "qXfer:memory-map:read" packet, setting this variable
6178 prevents GDB from accessing memory outside the memory map. This
6179 is useful for targets with memory mapped registers or which react
6180 badly to accesses of unmapped address space.
6182 set breakpoint auto-hw
6183 show breakpoint auto-hw
6184 If the target supplies a memory map, for instance via the remote
6185 protocol's "qXfer:memory-map:read" packet, setting this variable
6186 lets GDB use hardware breakpoints automatically for memory regions
6187 where it can not use software breakpoints. This covers both the
6188 "break" command and internal breakpoints used for other commands
6189 including "next" and "finish".
6192 catch exception unhandled
6193 Stop the program execution when Ada exceptions are raised.
6196 Stop the program execution when an Ada assertion failed.
6200 Set an alternate system root for target files. This is a more
6201 general version of "set solib-absolute-prefix", which is now
6202 an alias to "set sysroot".
6205 Provide extended SPU facility status information. This set of
6206 commands is available only when debugging the Cell/B.E. SPU
6209 * New native configurations
6211 OpenBSD/sh sh*-*openbsd*
6214 unset tdesc filename
6216 Use the specified local file as an XML target description, and do
6217 not query the target for its built-in description.
6221 OpenBSD/sh sh*-*-openbsd*
6222 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6223 Toshiba Media Processor mep-elf
6225 * New remote packets
6228 Ignore the specified signals; pass them directly to the debugged program
6229 without stopping other threads or reporting them to GDB.
6231 qXfer:features:read:
6232 Read an XML target description from the target, which describes its
6237 Read or write contents of an spufs file on the target system. These
6238 packets are available only on the Cell/B.E. SPU architecture.
6240 qXfer:libraries:read:
6241 Report the loaded shared libraries. Combined with new "T" packet
6242 response, this packet allows GDB to debug shared libraries on
6243 targets where the operating system manages the list of loaded
6244 libraries (e.g. Windows and SymbianOS).
6248 Support for these obsolete configurations has been removed.
6256 i[34567]86-*-lynxos*
6257 i[34567]86-*-netware*
6258 i[34567]86-*-sco3.2v5*
6259 i[34567]86-*-sco3.2v4*
6261 i[34567]86-*-sysv4.2*
6264 i[34567]86-*-unixware2*
6265 i[34567]86-*-unixware*
6274 * Other removed features
6281 Various m68k-only ROM monitors.
6288 Various Renesas ROM monitors and debugging interfaces for SH and
6293 Support for a Macraigor serial interface to on-chip debugging.
6294 GDB does not directly support the newer parallel or USB
6299 A debug information format. The predecessor to DWARF 2 and
6300 DWARF 3, which are still supported.
6302 Support for the HP aCC compiler on HP-UX/PA-RISC
6304 SOM-encapsulated symbolic debugging information, automatic
6305 invocation of pxdb, and the aCC custom C++ ABI. This does not
6306 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6307 with aCC can still be debugged on an assembly level.
6309 MIPS ".pdr" sections
6311 A MIPS-specific format used to describe stack frame layout
6312 in debugging information.
6316 GDB could work with an older version of Guile to debug
6317 the interpreter and Scheme programs running in it.
6319 set mips stack-arg-size
6320 set mips saved-gpreg-size
6322 Use "set mips abi" to control parameter passing for MIPS.
6324 *** Changes in GDB 6.6
6329 Cell Broadband Engine SPU spu-elf
6331 * GDB can now be configured as a cross-debugger targeting native Windows
6332 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6333 running on a Windows system over TCP/IP to debug Windows programs.
6335 * The GDB remote stub, gdbserver, has been updated to support Windows and
6336 Cygwin debugging. Both single-threaded and multi-threaded programs are
6339 * The "set trust-readonly-sections" command works again. This command was
6340 broken in GDB 6.3, 6.4, and 6.5.
6342 * The "load" command now supports writing to flash memory, if the remote
6343 stub provides the required support.
6345 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6346 longer requires symbolic debug information (e.g. DWARF-2).
6351 unset substitute-path
6352 show substitute-path
6353 Manage a list of substitution rules that GDB uses to rewrite the name
6354 of the directories where the sources are located. This can be useful
6355 for instance when the sources were moved to a different location
6356 between compilation and debugging.
6360 Print each CLI command as it is executed. Each command is prefixed with
6361 a number of `+' symbols representing the nesting depth.
6362 The source command now has a `-v' option to enable the same feature.
6366 The ARM Demon monitor support (RDP protocol, "target rdp").
6368 Kernel Object Display, an embedded debugging feature which only worked with
6369 an obsolete version of Cisco IOS.
6371 The 'set download-write-size' and 'show download-write-size' commands.
6373 * New remote packets
6376 Tell a stub about GDB client features, and request remote target features.
6377 The first feature implemented is PacketSize, which allows the target to
6378 specify the size of packets it can handle - to minimize the number of
6379 packets required and improve performance when connected to a remote
6383 Fetch an OS auxilliary vector from the remote stub. This packet is a
6384 more efficient replacement for qPart:auxv:read.
6386 qXfer:memory-map:read:
6387 Fetch a memory map from the remote stub, including information about
6388 RAM, ROM, and flash memory devices.
6393 Erase and program a flash memory device.
6395 * Removed remote packets
6398 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6399 used it, and only gdbserver implemented it.
6401 *** Changes in GDB 6.5
6405 Renesas M32C/M16C m32c-elf
6407 Morpho Technologies ms1 ms1-elf
6411 init-if-undefined Initialize a convenience variable, but
6412 only if it doesn't already have a value.
6414 The following commands are presently only implemented for native GNU/Linux:
6416 checkpoint Save a snapshot of the program state.
6418 restart <n> Return the program state to a
6419 previously saved state.
6421 info checkpoints List currently saved checkpoints.
6423 delete-checkpoint <n> Delete a previously saved checkpoint.
6425 set|show detach-on-fork Tell gdb whether to detach from a newly
6426 forked process, or to keep debugging it.
6428 info forks List forks of the user program that
6429 are available to be debugged.
6431 fork <n> Switch to debugging one of several
6432 forks of the user program that are
6433 available to be debugged.
6435 delete-fork <n> Delete a fork from the list of forks
6436 that are available to be debugged (and
6437 kill the forked process).
6439 detach-fork <n> Delete a fork from the list of forks
6440 that are available to be debugged (and
6441 allow the process to continue).
6445 Morpho Technologies ms2 ms1-elf
6447 * Improved Windows host support
6449 GDB now builds as a cross debugger hosted on i686-mingw32, including
6450 native console support, and remote communications using either
6451 network sockets or serial ports.
6453 * Improved Modula-2 language support
6455 GDB can now print most types in the Modula-2 syntax. This includes:
6456 basic types, set types, record types, enumerated types, range types,
6457 pointer types and ARRAY types. Procedure var parameters are correctly
6458 printed and hexadecimal addresses and character constants are also
6459 written in the Modula-2 syntax. Best results can be obtained by using
6460 GNU Modula-2 together with the -gdwarf-2 command line option.
6464 The ARM rdi-share module.
6466 The Netware NLM debug server.
6468 *** Changes in GDB 6.4
6470 * New native configurations
6472 OpenBSD/arm arm*-*-openbsd*
6473 OpenBSD/mips64 mips64-*-openbsd*
6477 Morpho Technologies ms1 ms1-elf
6479 * New command line options
6481 --batch-silent As for --batch, but totally silent.
6482 --return-child-result The debugger will exist with the same value
6483 the child (debugged) program exited with.
6484 --eval-command COMMAND, -ex COMMAND
6485 Execute a single GDB CLI command. This may be
6486 specified multiple times and in conjunction
6487 with the --command (-x) option.
6489 * Deprecated commands removed
6491 The following commands, that were deprecated in 2000, have been
6495 set|show arm disassembly-flavor set|show arm disassembler
6496 othernames set arm disassembler
6497 set|show remotedebug set|show debug remote
6498 set|show archdebug set|show debug arch
6499 set|show eventdebug set|show debug event
6502 * New BSD user-level threads support
6504 It is now possible to debug programs using the user-level threads
6505 library on OpenBSD and FreeBSD. Currently supported (target)
6508 FreeBSD/amd64 x86_64-*-freebsd*
6509 FreeBSD/i386 i386-*-freebsd*
6510 OpenBSD/i386 i386-*-openbsd*
6512 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6513 are not yet supported.
6515 * New support for Matsushita MN10300 w/sim added
6516 (Work in progress). mn10300-elf.
6518 * REMOVED configurations and files
6520 VxWorks and the XDR protocol *-*-vxworks
6521 Motorola MCORE mcore-*-*
6522 National Semiconductor NS32000 ns32k-*-*
6524 * New "set print array-indexes" command
6526 After turning this setting "on", GDB prints the index of each element
6527 when displaying arrays. The default is "off" to preserve the previous
6530 * VAX floating point support
6532 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6534 * User-defined command support
6536 In addition to using $arg0..$arg9 for argument passing, it is now possible
6537 to use $argc to determine now many arguments have been passed. See the
6538 section on user-defined commands in the user manual for more information.
6540 *** Changes in GDB 6.3:
6542 * New command line option
6544 GDB now accepts -l followed by a number to set the timeout for remote
6547 * GDB works with GCC -feliminate-dwarf2-dups
6549 GDB now supports a more compact representation of DWARF-2 debug
6550 information using DW_FORM_ref_addr references. These are produced
6551 by GCC with the option -feliminate-dwarf2-dups and also by some
6552 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6553 to use -feliminate-dwarf2-dups.
6555 * Internationalization
6557 When supported by the host system, GDB will be built with
6558 internationalization (libintl). The task of marking up the sources is
6559 continued, we're looking forward to our first translation.
6563 Initial support for debugging programs compiled with the GNAT
6564 implementation of the Ada programming language has been integrated
6565 into GDB. In this release, support is limited to expression evaluation.
6567 * New native configurations
6569 GNU/Linux/m32r m32r-*-linux-gnu
6573 GDB's remote protocol now includes support for the 'p' packet. This
6574 packet is used to fetch individual registers from a remote inferior.
6576 * END-OF-LIFE registers[] compatibility module
6578 GDB's internal register infrastructure has been completely rewritten.
6579 The new infrastructure making possible the implementation of key new
6580 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6583 GDB 6.3 will be the last release to include the registers[]
6584 compatibility module that allowed out-of-date configurations to
6585 continue to work. This change directly impacts the following
6595 powerpc bdm protocol
6597 Unless there is activity to revive these configurations, they will be
6598 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6600 * OBSOLETE configurations and files
6602 Configurations that have been declared obsolete in this release have
6603 been commented out. Unless there is activity to revive these
6604 configurations, the next release of GDB will have their sources
6605 permanently REMOVED.
6614 *** Changes in GDB 6.2.1:
6616 * MIPS `break main; run' gave an heuristic-fence-post warning
6618 When attempting to run even a simple program, a warning about
6619 heuristic-fence-post being hit would be reported. This problem has
6622 * MIPS IRIX 'long double' crashed GDB
6624 When examining a long double variable, GDB would get a segmentation
6625 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6626 IRIX long double values).
6630 A bug in the VAX stack code was causing problems with the "next"
6631 command. This problem has been fixed.
6633 *** Changes in GDB 6.2:
6635 * Fix for ``many threads''
6637 On GNU/Linux systems that use the NPTL threads library, a program
6638 rapidly creating and deleting threads would confuse GDB leading to the
6641 ptrace: No such process.
6642 thread_db_get_info: cannot get thread info: generic error
6644 This problem has been fixed.
6646 * "-async" and "-noasync" options removed.
6648 Support for the broken "-noasync" option has been removed (it caused
6651 * New ``start'' command.
6653 This command runs the program until the beginning of the main procedure.
6655 * New BSD Kernel Data Access Library (libkvm) interface
6657 Using ``target kvm'' it is now possible to debug kernel core dumps and
6658 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6659 platforms. Currently supported (native-only) configurations are:
6661 FreeBSD/amd64 x86_64-*-freebsd*
6662 FreeBSD/i386 i?86-*-freebsd*
6663 NetBSD/i386 i?86-*-netbsd*
6664 NetBSD/m68k m68*-*-netbsd*
6665 NetBSD/sparc sparc-*-netbsd*
6666 OpenBSD/amd64 x86_64-*-openbsd*
6667 OpenBSD/i386 i?86-*-openbsd*
6668 OpenBSD/m68k m68*-openbsd*
6669 OpenBSD/sparc sparc-*-openbsd*
6671 * Signal trampoline code overhauled
6673 Many generic problems with GDB's signal handling code have been fixed.
6674 These include: backtraces through non-contiguous stacks; recognition
6675 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6676 call; backtrace through a signal trampoline; step into and out of
6677 signal handlers; and single-stepping in the signal trampoline.
6679 Please note that kernel bugs are a limiting factor here. These
6680 features have been shown to work on an s390 GNU/Linux system that
6681 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6683 * Cygwin support for DWARF 2 added.
6685 * New native configurations
6687 GNU/Linux/hppa hppa*-*-linux*
6688 OpenBSD/hppa hppa*-*-openbsd*
6689 OpenBSD/m68k m68*-*-openbsd*
6690 OpenBSD/m88k m88*-*-openbsd*
6691 OpenBSD/powerpc powerpc-*-openbsd*
6692 NetBSD/vax vax-*-netbsd*
6693 OpenBSD/vax vax-*-openbsd*
6695 * END-OF-LIFE frame compatibility module
6697 GDB's internal frame infrastructure has been completely rewritten.
6698 The new infrastructure making it possible to support key new features
6699 including DWARF 2 Call Frame Information. To aid in the task of
6700 migrating old configurations to this new infrastructure, a
6701 compatibility module, that allowed old configurations to continue to
6702 work, was also included.
6704 GDB 6.2 will be the last release to include this frame compatibility
6705 module. This change directly impacts the following configurations:
6715 Unless there is activity to revive these configurations, they will be
6716 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6718 * REMOVED configurations and files
6720 Sun 3, running SunOS 3 m68*-*-sunos3*
6721 Sun 3, running SunOS 4 m68*-*-sunos4*
6722 Sun 2, running SunOS 3 m68000-*-sunos3*
6723 Sun 2, running SunOS 4 m68000-*-sunos4*
6724 Motorola 680x0 running LynxOS m68*-*-lynxos*
6725 AT&T 3b1/Unix pc m68*-att-*
6726 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6727 decstation mips-dec-* mips-little-*
6728 riscos mips-*-riscos* mips-*-sysv*
6729 sonymips mips-sony-*
6730 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6732 *** Changes in GDB 6.1.1:
6734 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6736 The TUI (Text-mode User Interface) is now built as part of a default
6737 GDB configuration. It is enabled by either selecting the TUI with the
6738 command line option "-i=tui" or by running the separate "gdbtui"
6739 program. For more information on the TUI, see the manual "Debugging
6742 * Pending breakpoint support (also included in GDB 6.1)
6744 Support has been added to allow you to specify breakpoints in shared
6745 libraries that have not yet been loaded. If a breakpoint location
6746 cannot be found, and the "breakpoint pending" option is set to auto,
6747 GDB queries you if you wish to make the breakpoint pending on a future
6748 shared-library load. If and when GDB resolves the breakpoint symbol,
6749 the pending breakpoint is removed as one or more regular breakpoints
6752 Pending breakpoints are very useful for GCJ Java debugging.
6754 * Fixed ISO-C build problems
6756 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6757 non ISO-C code that stopped them being built using a more strict ISO-C
6758 compiler (e.g., IBM's C compiler).
6760 * Fixed build problem on IRIX 5
6762 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6763 wasn't able to compile compile on an IRIX 5 system.
6765 * Added execute permission to gdb/gdbserver/configure
6767 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6768 permission. This bug would cause configure to fail on a number of
6769 systems (Solaris, IRIX). Ref: server/519.
6771 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6773 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6774 has been updated to use constant array sizes.
6776 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6778 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6779 its generated DWARF Call Frame Info. This encoding was causing GDB to
6780 panic, that panic has been fixed. Ref: gdb/1628.
6782 * Fixed a problem when examining parameters in shared library code.
6784 When examining parameters in optimized shared library code generated
6785 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6786 not available''. GDB now correctly displays the variable's value.
6788 *** Changes in GDB 6.1:
6790 * Removed --with-mmalloc
6792 Support for the mmalloc memory manager has been removed, as it
6793 conflicted with the internal gdb byte cache.
6795 * Changes in AMD64 configurations
6797 The AMD64 target now includes the %cs and %ss registers. As a result
6798 the AMD64 remote protocol has changed; this affects the floating-point
6799 and SSE registers. If you rely on those registers for your debugging,
6800 you should upgrade gdbserver on the remote side.
6802 * Revised SPARC target
6804 The SPARC target has been completely revised, incorporating the
6805 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6806 support for LynxOS and SunOS 4 has been dropped. Calling functions
6807 from within GDB on operating systems with a non-executable stack
6808 (Solaris, OpenBSD) now works.
6812 GDB has a new C++ demangler which does a better job on the mangled
6813 names generated by current versions of g++. It also runs faster, so
6814 with this and other changes gdb should now start faster on large C++
6817 * DWARF 2 Location Expressions
6819 GDB support for location expressions has been extended to support function
6820 arguments and frame bases. Older versions of GDB could crash when they
6823 * C++ nested types and namespaces
6825 GDB's support for nested types and namespaces in C++ has been
6826 improved, especially if you use the DWARF 2 debugging format. (This
6827 is the default for recent versions of GCC on most platforms.)
6828 Specifically, if you have a class "Inner" defined within a class or
6829 namespace "Outer", then GDB realizes that the class's name is
6830 "Outer::Inner", not simply "Inner". This should greatly reduce the
6831 frequency of complaints about not finding RTTI symbols. In addition,
6832 if you are stopped at inside of a function defined within a namespace,
6833 GDB modifies its name lookup accordingly.
6835 * New native configurations
6837 NetBSD/amd64 x86_64-*-netbsd*
6838 OpenBSD/amd64 x86_64-*-openbsd*
6839 OpenBSD/alpha alpha*-*-openbsd*
6840 OpenBSD/sparc sparc-*-openbsd*
6841 OpenBSD/sparc64 sparc64-*-openbsd*
6843 * New debugging protocols
6845 M32R with SDI protocol m32r-*-elf*
6847 * "set prompt-escape-char" command deleted.
6849 The command "set prompt-escape-char" has been deleted. This command,
6850 and its very obscure effect on GDB's prompt, was never documented,
6851 tested, nor mentioned in the NEWS file.
6853 * OBSOLETE configurations and files
6855 Configurations that have been declared obsolete in this release have
6856 been commented out. Unless there is activity to revive these
6857 configurations, the next release of GDB will have their sources
6858 permanently REMOVED.
6860 Sun 3, running SunOS 3 m68*-*-sunos3*
6861 Sun 3, running SunOS 4 m68*-*-sunos4*
6862 Sun 2, running SunOS 3 m68000-*-sunos3*
6863 Sun 2, running SunOS 4 m68000-*-sunos4*
6864 Motorola 680x0 running LynxOS m68*-*-lynxos*
6865 AT&T 3b1/Unix pc m68*-att-*
6866 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6867 decstation mips-dec-* mips-little-*
6868 riscos mips-*-riscos* mips-*-sysv*
6869 sonymips mips-sony-*
6870 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6872 * REMOVED configurations and files
6874 SGI Irix-4.x mips-sgi-irix4 or iris4
6875 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6876 Z8000 simulator z8k-zilog-none or z8ksim
6877 Matsushita MN10200 w/simulator mn10200-*-*
6878 H8/500 simulator h8500-hitachi-hms or h8500hms
6879 HP/PA running BSD hppa*-*-bsd*
6880 HP/PA running OSF/1 hppa*-*-osf*
6881 HP/PA Pro target hppa*-*-pro*
6882 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6883 386BSD i[3456]86-*-bsd*
6884 Sequent family i[3456]86-sequent-sysv4*
6885 i[3456]86-sequent-sysv*
6886 i[3456]86-sequent-bsd*
6887 SPARC running LynxOS sparc-*-lynxos*
6888 SPARC running SunOS 4 sparc-*-sunos4*
6889 Tsqware Sparclet sparclet-*-*
6890 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6892 *** Changes in GDB 6.0:
6896 Support for debugging the Objective-C programming language has been
6897 integrated into GDB.
6899 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6901 DWARF 2's Call Frame Information makes available compiler generated
6902 information that more exactly describes the program's run-time stack.
6903 By using this information, GDB is able to provide more robust stack
6906 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6907 have been updated to use a new backtrace mechanism which includes
6908 DWARF 2 CFI support.
6912 GDB's remote protocol has been extended to include support for hosted
6913 file I/O (where the remote target uses GDB's file system). See GDB's
6914 remote protocol documentation for details.
6916 * All targets using the new architecture framework.
6918 All of GDB's targets have been updated to use the new internal
6919 architecture framework. The way is now open for future GDB releases
6920 to include cross-architecture native debugging support (i386 on amd64,
6923 * GNU/Linux's Thread Local Storage (TLS)
6925 GDB now includes support for for the GNU/Linux implementation of
6926 per-thread variables.
6928 * GNU/Linux's Native POSIX Thread Library (NPTL)
6930 GDB's thread code has been updated to work with either the new
6931 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6933 * Separate debug info.
6935 GDB, in conjunction with BINUTILS, now supports a mechanism for
6936 automatically loading debug information from a separate file. Instead
6937 of shipping full debug and non-debug versions of system libraries,
6938 system integrators can now instead ship just the stripped libraries
6939 and optional debug files.
6941 * DWARF 2 Location Expressions
6943 DWARF 2 Location Expressions allow the compiler to more completely
6944 describe the location of variables (even in optimized code) to the
6947 GDB now includes preliminary support for location expressions (support
6948 for DW_OP_piece is still missing).
6952 A number of long standing bugs that caused GDB to die while starting a
6953 Java application have been fixed. GDB's Java support is now
6954 considered "useable".
6956 * GNU/Linux support for fork, vfork, and exec.
6958 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6959 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6962 * GDB supports logging output to a file
6964 There are two new commands, "set logging" and "show logging", which can be
6965 used to capture GDB's output to a file.
6967 * The meaning of "detach" has changed for gdbserver
6969 The "detach" command will now resume the application, as documented. To
6970 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6973 * d10v, m68hc11 `regs' command deprecated
6975 The `info registers' command has been updated so that it displays the
6976 registers using a format identical to the old `regs' command.
6980 A new command, "maint set profile on/off", has been added. This command can
6981 be used to enable or disable profiling while running GDB, to profile a
6982 session or a set of commands. In addition there is a new configure switch,
6983 "--enable-profiling", which will cause GDB to be compiled with profiling
6984 data, for more informative profiling results.
6986 * Default MI syntax changed to "mi2".
6988 The default MI (machine interface) syntax, enabled by the command line
6989 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6990 "mi1", can be enabled by specifying the option "-i=mi1".
6992 Support for the original "mi0" syntax (included in GDB 5.0) has been
6995 Fix for gdb/192: removed extraneous space when displaying frame level.
6996 Fix for gdb/672: update changelist is now output in mi list format.
6997 Fix for gdb/702: a -var-assign that updates the value now shows up
6998 in a subsequent -var-update.
7000 * New native configurations.
7002 FreeBSD/amd64 x86_64-*-freebsd*
7004 * Multi-arched targets.
7006 HP/PA HPUX11 hppa*-*-hpux*
7007 Renesas M32R/D w/simulator m32r-*-elf*
7009 * OBSOLETE configurations and files
7011 Configurations that have been declared obsolete in this release have
7012 been commented out. Unless there is activity to revive these
7013 configurations, the next release of GDB will have their sources
7014 permanently REMOVED.
7016 Z8000 simulator z8k-zilog-none or z8ksim
7017 Matsushita MN10200 w/simulator mn10200-*-*
7018 H8/500 simulator h8500-hitachi-hms or h8500hms
7019 HP/PA running BSD hppa*-*-bsd*
7020 HP/PA running OSF/1 hppa*-*-osf*
7021 HP/PA Pro target hppa*-*-pro*
7022 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7023 Sequent family i[3456]86-sequent-sysv4*
7024 i[3456]86-sequent-sysv*
7025 i[3456]86-sequent-bsd*
7026 Tsqware Sparclet sparclet-*-*
7027 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7029 * REMOVED configurations and files
7032 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7033 IBM AIX PS/2 i[3456]86-*-aix
7034 i386 running Mach 3.0 i[3456]86-*-mach3*
7035 i386 running Mach i[3456]86-*-mach*
7036 i386 running OSF/1 i[3456]86-*osf1mk*
7037 HP/Apollo 68k Family m68*-apollo*-sysv*,
7039 m68*-hp-bsd*, m68*-hp-hpux*
7040 Argonaut Risc Chip (ARC) arc-*-*
7041 Mitsubishi D30V d30v-*-*
7042 Fujitsu FR30 fr30-*-elf*
7043 OS/9000 i[34]86-*-os9k
7044 I960 with MON960 i960-*-coff
7046 * MIPS $fp behavior changed
7048 The convenience variable $fp, for the MIPS, now consistently returns
7049 the address of the current frame's base. Previously, depending on the
7050 context, $fp could refer to either $sp or the current frame's base
7051 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
7052 The GNU Source-Level Debugger''.
7054 *** Changes in GDB 5.3:
7056 * GNU/Linux shared library multi-threaded performance improved.
7058 When debugging a multi-threaded application on GNU/Linux, GDB now uses
7059 `/proc', in preference to `ptrace' for memory reads. This may result
7060 in an improvement in the start-up time of multi-threaded, shared
7061 library applications when run under GDB. One GDB user writes: ``loads
7062 shared libs like mad''.
7064 * ``gdbserver'' now supports multi-threaded applications on some targets
7066 Support for debugging multi-threaded applications which use
7067 the GNU/Linux LinuxThreads package has been added for
7068 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
7069 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
7071 * GDB now supports C/C++ preprocessor macros.
7073 GDB now expands preprocessor macro invocations in C/C++ expressions,
7074 and provides various commands for showing macro definitions and how
7077 The new command `macro expand EXPRESSION' expands any macro
7078 invocations in expression, and shows the result.
7080 The new command `show macro MACRO-NAME' shows the definition of the
7081 macro named MACRO-NAME, and where it was defined.
7083 Most compilers don't include information about macros in the debugging
7084 information by default. In GCC 3.1, for example, you need to compile
7085 your program with the options `-gdwarf-2 -g3'. If the macro
7086 information is present in the executable, GDB will read it.
7088 * Multi-arched targets.
7090 DEC Alpha (partial) alpha*-*-*
7091 DEC VAX (partial) vax-*-*
7093 National Semiconductor NS32000 (partial) ns32k-*-*
7094 Motorola 68000 (partial) m68k-*-*
7095 Motorola MCORE mcore-*-*
7099 Fujitsu FRV architecture added by Red Hat frv*-*-*
7102 * New native configurations
7104 Alpha NetBSD alpha*-*-netbsd*
7105 SH NetBSD sh*-*-netbsdelf*
7106 MIPS NetBSD mips*-*-netbsd*
7107 UltraSPARC NetBSD sparc64-*-netbsd*
7109 * OBSOLETE configurations and files
7111 Configurations that have been declared obsolete in this release have
7112 been commented out. Unless there is activity to revive these
7113 configurations, the next release of GDB will have their sources
7114 permanently REMOVED.
7116 Mitsubishi D30V d30v-*-*
7117 OS/9000 i[34]86-*-os9k
7118 IBM AIX PS/2 i[3456]86-*-aix
7119 Fujitsu FR30 fr30-*-elf*
7120 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7121 Argonaut Risc Chip (ARC) arc-*-*
7122 i386 running Mach 3.0 i[3456]86-*-mach3*
7123 i386 running Mach i[3456]86-*-mach*
7124 i386 running OSF/1 i[3456]86-*osf1mk*
7125 HP/Apollo 68k Family m68*-apollo*-sysv*,
7127 m68*-hp-bsd*, m68*-hp-hpux*
7128 I960 with MON960 i960-*-coff
7130 * OBSOLETE languages
7132 CHILL, a Pascal like language used by telecommunications companies.
7134 * REMOVED configurations and files
7136 AMD 29k family via UDI a29k-amd-udi, udi29k
7137 A29K VxWorks a29k-*-vxworks
7138 AMD 29000 embedded, using EBMON a29k-none-none
7139 AMD 29000 embedded with COFF a29k-none-coff
7140 AMD 29000 embedded with a.out a29k-none-aout
7142 testsuite/gdb.hp/gdb.threads-hp/ directory
7144 * New command "set max-user-call-depth <nnn>"
7146 This command allows the user to limit the call depth of user-defined
7147 commands. The default is 1024.
7149 * Changes in FreeBSD/i386 native debugging.
7151 Support for the "generate-core-file" has been added.
7153 * New commands "dump", "append", and "restore".
7155 These commands allow data to be copied from target memory
7156 to a bfd-format or binary file (dump and append), and back
7157 from a file into memory (restore).
7159 * Improved "next/step" support on multi-processor Alpha Tru64.
7161 The previous single-step mechanism could cause unpredictable problems,
7162 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7163 of a software single-step mechanism prevents this.
7165 *** Changes in GDB 5.2.1:
7173 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7174 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7175 Fix, by Joel Brobecker imported from mainline.
7177 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7178 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7179 Fix, by Fred Fish, imported from mainline.
7181 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7182 Surprisingly enough, it works now.
7183 By Michal Ludvig, imported from mainline.
7185 i386 hardware watchpoint support:
7186 avoid misses on second run for some targets.
7187 By Pierre Muller, imported from mainline.
7189 *** Changes in GDB 5.2:
7191 * New command "set trust-readonly-sections on[off]".
7193 This command is a hint that tells gdb that read-only sections
7194 really are read-only (ie. that their contents will not change).
7195 In this mode, gdb will go to the object file rather than the
7196 target to read memory from read-only sections (such as ".text").
7197 This can be a significant performance improvement on some
7198 (notably embedded) targets.
7200 * New command "generate-core-file" (or "gcore").
7202 This new gdb command allows the user to drop a core file of the child
7203 process state at any time. So far it's been implemented only for
7204 GNU/Linux and Solaris, but should be relatively easily ported to other
7205 hosts. Argument is core file name (defaults to core.<pid>).
7207 * New command line option
7209 GDB now accepts --pid or -p followed by a process id.
7211 * Change in command line behavior -- corefiles vs. process ids.
7213 There is a subtle behavior in the way in which GDB handles
7214 command line arguments. The first non-flag argument is always
7215 a program to debug, but the second non-flag argument may either
7216 be a corefile or a process id. Previously, GDB would attempt to
7217 open the second argument as a corefile, and if that failed, would
7218 issue a superfluous error message and then attempt to attach it as
7219 a process. Now, if the second argument begins with a non-digit,
7220 it will be treated as a corefile. If it begins with a digit,
7221 GDB will attempt to attach it as a process, and if no such process
7222 is found, will then attempt to open it as a corefile.
7224 * Changes in ARM configurations.
7226 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7227 configuration is fully multi-arch.
7229 * New native configurations
7231 ARM NetBSD arm*-*-netbsd*
7232 x86 OpenBSD i[3456]86-*-openbsd*
7233 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7234 Sparc64 running FreeBSD sparc64-*-freebsd*
7238 Sanyo XStormy16 xstormy16-elf
7240 * OBSOLETE configurations and files
7242 Configurations that have been declared obsolete in this release have
7243 been commented out. Unless there is activity to revive these
7244 configurations, the next release of GDB will have their sources
7245 permanently REMOVED.
7247 AMD 29k family via UDI a29k-amd-udi, udi29k
7248 A29K VxWorks a29k-*-vxworks
7249 AMD 29000 embedded, using EBMON a29k-none-none
7250 AMD 29000 embedded with COFF a29k-none-coff
7251 AMD 29000 embedded with a.out a29k-none-aout
7253 testsuite/gdb.hp/gdb.threads-hp/ directory
7255 * REMOVED configurations and files
7257 TI TMS320C80 tic80-*-*
7259 PowerPC Solaris powerpcle-*-solaris*
7260 PowerPC Windows NT powerpcle-*-cygwin32
7261 PowerPC Netware powerpc-*-netware*
7262 Harris/CXUX m88k m88*-harris-cxux*
7263 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7264 ns32k-utek-sysv* ns32k-utek-*
7265 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7266 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7267 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7268 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7269 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7271 * Changes to command line processing
7273 The new `--args' feature can be used to specify command-line arguments
7274 for the inferior from gdb's command line.
7276 * Changes to key bindings
7278 There is a new `operate-and-get-next' function bound to `C-o'.
7280 *** Changes in GDB 5.1.1
7282 Fix compile problem on DJGPP.
7284 Fix a problem with floating-point registers on the i386 being
7287 Fix to stop GDB crashing on .debug_str debug info.
7289 Numerous documentation fixes.
7291 Numerous testsuite fixes.
7293 *** Changes in GDB 5.1:
7295 * New native configurations
7297 Alpha FreeBSD alpha*-*-freebsd*
7298 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7299 MIPS GNU/Linux mips*-*-linux*
7300 MIPS SGI Irix 6.x mips*-sgi-irix6*
7301 ia64 AIX ia64-*-aix*
7302 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7306 Motorola 68HC11 and 68HC12 m68hc11-elf
7308 UltraSparc running GNU/Linux sparc64-*-linux*
7310 * OBSOLETE configurations and files
7312 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7313 Harris/CXUX m88k m88*-harris-cxux*
7314 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7315 ns32k-utek-sysv* ns32k-utek-*
7316 TI TMS320C80 tic80-*-*
7318 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7319 PowerPC Solaris powerpcle-*-solaris*
7320 PowerPC Windows NT powerpcle-*-cygwin32
7321 PowerPC Netware powerpc-*-netware*
7322 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7323 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7324 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7325 Apple Macintosh (MPW) host N/A
7327 stuff.c (Program to stuff files into a specially prepared space in kdb)
7328 kdb-start.c (Main loop for the standalone kernel debugger)
7330 Configurations that have been declared obsolete in this release have
7331 been commented out. Unless there is activity to revive these
7332 configurations, the next release of GDB will have their sources
7333 permanently REMOVED.
7335 * REMOVED configurations and files
7337 Altos 3068 m68*-altos-*
7338 Convex c1-*-*, c2-*-*
7340 ARM RISCix arm-*-* (as host)
7344 * GDB has been converted to ISO C.
7346 GDB's source code has been converted to ISO C. In particular, the
7347 sources are fully protoized, and rely on standard headers being
7352 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7354 * The MI enabled by default.
7356 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7357 revised and enabled by default. Packages which use GDB as a debugging
7358 engine behind a UI or another front end are encouraged to switch to
7359 using the GDB/MI interface, instead of the old annotations interface
7360 which is now deprecated.
7362 * Support for debugging Pascal programs.
7364 GDB now includes support for debugging Pascal programs. The following
7365 main features are supported:
7367 - Pascal-specific data types such as sets;
7369 - automatic recognition of Pascal sources based on file-name
7372 - Pascal-style display of data types, variables, and functions;
7374 - a Pascal expression parser.
7376 However, some important features are not yet supported.
7378 - Pascal string operations are not supported at all;
7380 - there are some problems with boolean types;
7382 - Pascal type hexadecimal constants are not supported
7383 because they conflict with the internal variables format;
7385 - support for Pascal objects and classes is not full yet;
7387 - unlike Pascal, GDB is case-sensitive for symbol names.
7389 * Changes in completion.
7391 Commands such as `shell', `run' and `set args', which pass arguments
7392 to inferior programs, now complete on file names, similar to what
7393 users expect at the shell prompt.
7395 Commands which accept locations, such as `disassemble', `print',
7396 `breakpoint', `until', etc. now complete on filenames as well as
7397 program symbols. Thus, if you type "break foob TAB", and the source
7398 files linked into the programs include `foobar.c', that file name will
7399 be one of the candidates for completion. However, file names are not
7400 considered for completion after you typed a colon that delimits a file
7401 name from a name of a function in that file, as in "break foo.c:bar".
7403 `set demangle-style' completes on available demangling styles.
7405 * New platform-independent commands:
7407 It is now possible to define a post-hook for a command as well as a
7408 hook that runs before the command. For more details, see the
7409 documentation of `hookpost' in the GDB manual.
7411 * Changes in GNU/Linux native debugging.
7413 Support for debugging multi-threaded programs has been completely
7414 revised for all platforms except m68k and sparc. You can now debug as
7415 many threads as your system allows you to have.
7417 Attach/detach is supported for multi-threaded programs.
7419 Support for SSE registers was added for x86. This doesn't work for
7420 multi-threaded programs though.
7422 * Changes in MIPS configurations.
7424 Multi-arch support is enabled for all MIPS configurations.
7426 GDB can now be built as native debugger on SGI Irix 6.x systems for
7427 debugging n32 executables. (Debugging 64-bit executables is not yet
7430 * Unified support for hardware watchpoints in all x86 configurations.
7432 Most (if not all) native x86 configurations support hardware-assisted
7433 breakpoints and watchpoints in a unified manner. This support
7434 implements debug register sharing between watchpoints, which allows to
7435 put a virtually infinite number of watchpoints on the same address,
7436 and also supports watching regions up to 16 bytes with several debug
7439 The new maintenance command `maintenance show-debug-regs' toggles
7440 debugging print-outs in functions that insert, remove, and test
7441 watchpoints and hardware breakpoints.
7443 * Changes in the DJGPP native configuration.
7445 New command ``info dos sysinfo'' displays assorted information about
7446 the CPU, OS, memory, and DPMI server.
7448 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7449 display information about segment descriptors stored in GDT, LDT, and
7452 New commands ``info dos pde'' and ``info dos pte'' display entries
7453 from Page Directory and Page Tables (for now works with CWSDPMI only).
7454 New command ``info dos address-pte'' displays the Page Table entry for
7455 a given linear address.
7457 GDB can now pass command lines longer than 126 characters to the
7458 program being debugged (requires an update to the libdbg.a library
7459 which is part of the DJGPP development kit).
7461 DWARF2 debug info is now supported.
7463 It is now possible to `step' and `next' through calls to `longjmp'.
7465 * Changes in documentation.
7467 All GDB documentation was converted to GFDL, the GNU Free
7468 Documentation License.
7470 Tracepoints-related commands are now fully documented in the GDB
7473 TUI, the Text-mode User Interface, is now documented in the manual.
7475 Tracepoints-related commands are now fully documented in the GDB
7478 The "GDB Internals" manual now has an index. It also includes
7479 documentation of `ui_out' functions, GDB coding standards, x86
7480 hardware watchpoints, and memory region attributes.
7482 * GDB's version number moved to ``version.in''
7484 The Makefile variable VERSION has been replaced by the file
7485 ``version.in''. People creating GDB distributions should update the
7486 contents of this file.
7490 GUD support is now a standard part of the EMACS distribution.
7492 *** Changes in GDB 5.0:
7494 * Improved support for debugging FP programs on x86 targets
7496 Unified and much-improved support for debugging floating-point
7497 programs on all x86 targets. In particular, ``info float'' now
7498 displays the FP registers in the same format on all x86 targets, with
7499 greater level of detail.
7501 * Improvements and bugfixes in hardware-assisted watchpoints
7503 It is now possible to watch array elements, struct members, and
7504 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7505 on x86 targets no longer erroneously trigger when the address is
7508 * Improvements in the native DJGPP version of GDB
7510 The distribution now includes all the scripts and auxiliary files
7511 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7512 machines ``out of the box''.
7514 The DJGPP version can now debug programs that use signals. It is
7515 possible to catch signals that happened in the debuggee, deliver
7516 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7517 would kill the program being debugged.) Programs that hook hardware
7518 interrupts (keyboard, timer, etc.) can also be debugged.
7520 It is now possible to debug DJGPP programs that redirect their
7521 standard handles or switch them to raw (as opposed to cooked) mode, or
7522 even close them. The command ``run < foo > bar'' works as expected,
7523 and ``info terminal'' reports useful information about the debuggee's
7524 terminal, including raw/cooked mode, redirection, etc.
7526 The DJGPP version now uses termios functions for console I/O, which
7527 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7530 DOS-style file names with drive letters are now fully supported by
7533 It is now possible to debug DJGPP programs that switch their working
7534 directory. It is also possible to rerun the debuggee any number of
7535 times without restarting GDB; thus, you can use the same setup,
7536 breakpoints, etc. for many debugging sessions.
7538 * New native configurations
7540 ARM GNU/Linux arm*-*-linux*
7541 PowerPC GNU/Linux powerpc-*-linux*
7545 Motorola MCore mcore-*-*
7546 x86 VxWorks i[3456]86-*-vxworks*
7547 PowerPC VxWorks powerpc-*-vxworks*
7548 TI TMS320C80 tic80-*-*
7550 * OBSOLETE configurations
7552 Altos 3068 m68*-altos-*
7553 Convex c1-*-*, c2-*-*
7555 ARM RISCix arm-*-* (as host)
7558 Configurations that have been declared obsolete will be commented out,
7559 but the code will be left in place. If there is no activity to revive
7560 these configurations before the next release of GDB, the sources will
7561 be permanently REMOVED.
7563 * Gould support removed
7565 Support for the Gould PowerNode and NP1 has been removed.
7567 * New features for SVR4
7569 On SVR4 native platforms (such as Solaris), if you attach to a process
7570 without first loading a symbol file, GDB will now attempt to locate and
7571 load symbols from the running process's executable file.
7573 * Many C++ enhancements
7575 C++ support has been greatly improved. Overload resolution now works properly
7576 in almost all cases. RTTI support is on the way.
7578 * Remote targets can connect to a sub-program
7580 A popen(3) style serial-device has been added. This device starts a
7581 sub-process (such as a stand-alone simulator) and then communicates
7582 with that. The sub-program to run is specified using the syntax
7583 ``|<program> <args>'' vis:
7585 (gdb) set remotedebug 1
7586 (gdb) target extended-remote |mn10300-elf-sim program-args
7588 * MIPS 64 remote protocol
7590 A long standing bug in the mips64 remote protocol where by GDB
7591 expected certain 32 bit registers (ex SR) to be transfered as 32
7592 instead of 64 bits has been fixed.
7594 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7595 added to provide backward compatibility with older versions of GDB.
7597 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7599 The command ``set remotebinarydownload'' command has been replaced by
7600 ``set remote X-packet''. Other commands in ``set remote'' family
7601 include ``set remote P-packet''.
7603 * Breakpoint commands accept ranges.
7605 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7606 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7607 ``tracepoint passcount'' also accepts a range of tracepoints.
7609 * ``apropos'' command added.
7611 The ``apropos'' command searches through command names and
7612 documentation strings, printing out matches, making it much easier to
7613 try to find a command that does what you are looking for.
7617 A new machine oriented interface (MI) has been added to GDB. This
7618 interface is designed for debug environments running GDB as a separate
7619 process. This is part of the long term libGDB project. See the
7620 "GDB/MI" chapter of the GDB manual for further information. It can be
7621 enabled by configuring with:
7623 .../configure --enable-gdbmi
7625 *** Changes in GDB-4.18:
7627 * New native configurations
7629 HP-UX 10.20 hppa*-*-hpux10.20
7630 HP-UX 11.x hppa*-*-hpux11.0*
7631 M68K GNU/Linux m68*-*-linux*
7635 Fujitsu FR30 fr30-*-elf*
7636 Intel StrongARM strongarm-*-*
7637 Mitsubishi D30V d30v-*-*
7639 * OBSOLETE configurations
7641 Gould PowerNode, NP1 np1-*-*, pn-*-*
7643 Configurations that have been declared obsolete will be commented out,
7644 but the code will be left in place. If there is no activity to revive
7645 these configurations before the next release of GDB, the sources will
7646 be permanently REMOVED.
7650 As a compatibility experiment, GDB's source files buildsym.h and
7651 buildsym.c have been converted to pure standard C, no longer
7652 containing any K&R compatibility code. We believe that all systems in
7653 use today either come with a standard C compiler, or have a GCC port
7654 available. If this is not true, please report the affected
7655 configuration to bug-gdb@gnu.org immediately. See the README file for
7656 information about getting a standard C compiler if you don't have one
7661 GDB now uses readline 2.2.
7663 * set extension-language
7665 You can now control the mapping between filename extensions and source
7666 languages by using the `set extension-language' command. For instance,
7667 you can ask GDB to treat .c files as C++ by saying
7668 set extension-language .c c++
7669 The command `info extensions' lists all of the recognized extensions
7670 and their associated languages.
7672 * Setting processor type for PowerPC and RS/6000
7674 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7675 you can use the `set processor' command to specify what variant of the
7676 PowerPC family you are debugging. The command
7680 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7681 following PowerPC and RS6000 variants:
7683 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7684 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7686 403GC IBM PowerPC 403GC
7687 505 Motorola PowerPC 505
7688 860 Motorola PowerPC 860 or 850
7689 601 Motorola PowerPC 601
7690 602 Motorola PowerPC 602
7691 603 Motorola/IBM PowerPC 603 or 603e
7692 604 Motorola PowerPC 604 or 604e
7693 750 Motorola/IBM PowerPC 750 or 750
7695 At the moment, this command just tells GDB what to name the
7696 special-purpose processor registers. Since almost all the affected
7697 registers are inaccessible to user-level programs, this command is
7698 only useful for remote debugging in its present form.
7702 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7703 more extensive support for HP-UX. Added features include shared
7704 library support, kernel threads and hardware watchpoints for 11.00,
7705 support for HP's ANSI C and C++ compilers, and a compatibility mode
7706 for xdb and dbx commands.
7710 HP's donation includes the new concept of catchpoints, which is a
7711 generalization of the old catch command. On HP-UX, it is now possible
7712 to catch exec, fork, and vfork, as well as library loading.
7714 This means that the existing catch command has changed; its first
7715 argument now specifies the type of catch to be set up. See the
7716 output of "help catch" for a list of catchpoint types.
7718 * Debugging across forks
7720 On HP-UX, you can choose which process to debug when a fork() happens
7725 HP has donated a curses-based terminal user interface (TUI). To get
7726 it, build with --enable-tui. Although this can be enabled for any
7727 configuration, at present it only works for native HP debugging.
7729 * GDB remote protocol additions
7731 A new protocol packet 'X' that writes binary data is now available.
7732 Default behavior is to try 'X', then drop back to 'M' if the stub
7733 fails to respond. The settable variable `remotebinarydownload'
7734 allows explicit control over the use of 'X'.
7736 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7737 full 64-bit address. The command
7739 set remoteaddresssize 32
7741 can be used to revert to the old behaviour. For existing remote stubs
7742 the change should not be noticed, as the additional address information
7745 In order to assist in debugging stubs, you may use the maintenance
7746 command `packet' to send any text string to the stub. For instance,
7748 maint packet heythere
7750 sends the packet "$heythere#<checksum>". Note that it is very easy to
7751 disrupt a debugging session by sending the wrong packet at the wrong
7754 The compare-sections command allows you to compare section data on the
7755 target to what is in the executable file without uploading or
7756 downloading, by comparing CRC checksums.
7758 * Tracing can collect general expressions
7760 You may now collect general expressions at tracepoints. This requires
7761 further additions to the target-side stub; see tracepoint.c and
7762 doc/agentexpr.texi for further details.
7764 * mask-address variable for Mips
7766 For Mips targets, you may control the zeroing of the upper 32 bits of
7767 a 64-bit address by entering `set mask-address on'. This is mainly
7768 of interest to users of embedded R4xxx and R5xxx processors.
7770 * Higher serial baud rates
7772 GDB's serial code now allows you to specify baud rates 57600, 115200,
7773 230400, and 460800 baud. (Note that your host system may not be able
7774 to achieve all of these rates.)
7778 The i960 configuration now includes an initial implementation of a
7779 builtin simulator, contributed by Jim Wilson.
7782 *** Changes in GDB-4.17:
7784 * New native configurations
7786 Alpha GNU/Linux alpha*-*-linux*
7787 Unixware 2.x i[3456]86-unixware2*
7788 Irix 6.x mips*-sgi-irix6*
7789 PowerPC GNU/Linux powerpc-*-linux*
7790 PowerPC Solaris powerpcle-*-solaris*
7791 Sparc GNU/Linux sparc-*-linux*
7792 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7796 Argonaut Risc Chip (ARC) arc-*-*
7797 Hitachi H8/300S h8300*-*-*
7798 Matsushita MN10200 w/simulator mn10200-*-*
7799 Matsushita MN10300 w/simulator mn10300-*-*
7800 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7801 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7802 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7803 Mitsubishi D10V w/simulator d10v-*-*
7804 Mitsubishi M32R/D w/simulator m32r-*-elf*
7805 Tsqware Sparclet sparclet-*-*
7806 NEC V850 w/simulator v850-*-*
7808 * New debugging protocols
7810 ARM with RDI protocol arm*-*-*
7811 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7812 DDB and LSI variants of PMON protocol mips*-*-*
7813 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7814 PowerPC with SDS protocol powerpc{,le}-*-eabi
7815 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7819 All configurations can now understand and use the DWARF 2 debugging
7820 format. The choice is automatic, if the symbol file contains DWARF 2
7825 GDB now includes basic Java language support. This support is
7826 only useful with Java compilers that produce native machine code.
7828 * solib-absolute-prefix and solib-search-path
7830 For SunOS and SVR4 shared libraries, you may now set the prefix for
7831 loading absolute shared library symbol files, and the search path for
7832 locating non-absolute shared library symbol files.
7834 * Live range splitting
7836 GDB can now effectively debug code for which GCC has performed live
7837 range splitting as part of its optimization. See gdb/doc/LRS for
7838 more details on the expected format of the stabs information.
7842 GDB's support for the GNU Hurd, including thread debugging, has been
7843 updated to work with current versions of the Hurd.
7847 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7848 instruction set. ARM GDB automatically detects when Thumb
7849 instructions are in use, and adjusts disassembly and backtracing
7854 GDB's MIPS target configurations now handle the MIP16 16-bit
7859 GDB now includes support for overlays; if an executable has been
7860 linked such that multiple sections are based at the same address, GDB
7861 will decide which section to use for symbolic info. You can choose to
7862 control the decision manually, using overlay commands, or implement
7863 additional target-side support and use "overlay load-target" to bring
7864 in the overlay mapping. Do "help overlay" for more detail.
7868 The command "info symbol <address>" displays information about
7869 the symbol at the specified address.
7873 The standard remote protocol now includes an extension that allows
7874 asynchronous collection and display of trace data. This requires
7875 extensive support in the target-side debugging stub. Tracing mode
7876 includes a new interaction mode in GDB and new commands: see the
7877 file tracepoint.c for more details.
7881 Configurations for embedded MIPS now include a simulator contributed
7882 by Cygnus Solutions. The simulator supports the instruction sets
7883 of most MIPS variants.
7887 Sparc configurations may now include the ERC32 simulator contributed
7888 by the European Space Agency. The simulator is not built into
7889 Sparc targets by default; configure with --enable-sim to include it.
7893 For target configurations that may include multiple variants of a
7894 basic architecture (such as MIPS and SH), you may now set the
7895 architecture explicitly. "set arch" sets, "info arch" lists
7896 the possible architectures.
7898 *** Changes in GDB-4.16:
7900 * New native configurations
7902 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7903 M68K NetBSD m68k-*-netbsd*
7904 PowerPC AIX 4.x powerpc-*-aix*
7905 PowerPC MacOS powerpc-*-macos*
7906 PowerPC Windows NT powerpcle-*-cygwin32
7907 RS/6000 AIX 4.x rs6000-*-aix4*
7911 ARM with RDP protocol arm-*-*
7912 I960 with MON960 i960-*-coff
7913 MIPS VxWorks mips*-*-vxworks*
7914 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7915 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7917 Matra Sparclet sparclet-*-*
7921 The powerpc-eabi configuration now includes the PSIM simulator,
7922 contributed by Andrew Cagney, with assistance from Mike Meissner.
7923 PSIM is a very elaborate model of the PowerPC, including not only
7924 basic instruction set execution, but also details of execution unit
7925 performance and I/O hardware. See sim/ppc/README for more details.
7929 GDB now works with Solaris 2.5.
7931 * Windows 95/NT native
7933 GDB will now work as a native debugger on Windows 95 and Windows NT.
7934 To build it from source, you must use the "gnu-win32" environment,
7935 which uses a DLL to emulate enough of Unix to run the GNU tools.
7936 Further information, binaries, and sources are available at
7937 ftp.cygnus.com, under pub/gnu-win32.
7939 * dont-repeat command
7941 If a user-defined command includes the command `dont-repeat', then the
7942 command will not be repeated if the user just types return. This is
7943 useful if the command is time-consuming to run, so that accidental
7944 extra keystrokes don't run the same command many times.
7946 * Send break instead of ^C
7948 The standard remote protocol now includes an option to send a break
7949 rather than a ^C to the target in order to interrupt it. By default,
7950 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7952 * Remote protocol timeout
7954 The standard remote protocol includes a new variable `remotetimeout'
7955 that allows you to set the number of seconds before GDB gives up trying
7956 to read from the target. The default value is 2.
7958 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7960 By default GDB will automatically keep track of objects as they are
7961 loaded and unloaded by the dynamic linker. By using the command `set
7962 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7963 when shared library events occur, thus allowing you to set breakpoints
7964 in shared libraries which are explicitly loaded by the inferior.
7966 Note this feature does not work on hpux8. On hpux9 you must link
7967 /usr/lib/end.o into your program. This feature should work
7968 automatically on hpux10.
7970 * Irix 5.x hardware watchpoint support
7972 Irix 5 configurations now support the use of hardware watchpoints.
7974 * Mips protocol "SYN garbage limit"
7976 When debugging a Mips target using the `target mips' protocol, you
7977 may set the number of characters that GDB will ignore by setting
7978 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7979 every character. The default value is 1050.
7981 * Recording and replaying remote debug sessions
7983 If you set `remotelogfile' to the name of a file, gdb will write to it
7984 a recording of a remote debug session. This recording may then be
7985 replayed back to gdb using "gdbreplay". See gdbserver/README for
7986 details. This is useful when you have a problem with GDB while doing
7987 remote debugging; you can make a recording of the session and send it
7988 to someone else, who can then recreate the problem.
7990 * Speedups for remote debugging
7992 GDB includes speedups for downloading and stepping MIPS systems using
7993 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7994 and more efficient S-record downloading.
7996 * Memory use reductions and statistics collection
7998 GDB now uses less memory and reports statistics about memory usage.
7999 Try the `maint print statistics' command, for example.
8001 *** Changes in GDB-4.15:
8003 * Psymtabs for XCOFF
8005 The symbol reader for AIX GDB now uses partial symbol tables. This
8006 can greatly improve startup time, especially for large executables.
8008 * Remote targets use caching
8010 Remote targets now use a data cache to speed up communication with the
8011 remote side. The data cache could lead to incorrect results because
8012 it doesn't know about volatile variables, thus making it impossible to
8013 debug targets which use memory mapped I/O devices. `set remotecache
8014 off' turns the data cache off.
8016 * Remote targets may have threads
8018 The standard remote protocol now includes support for multiple threads
8019 in the target system, using new protocol commands 'H' and 'T'. See
8020 gdb/remote.c for details.
8024 If GDB is configured with `--enable-netrom', then it will include
8025 support for the NetROM ROM emulator from XLNT Designs. The NetROM
8026 acts as though it is a bank of ROM on the target board, but you can
8027 write into it over the network. GDB's support consists only of
8028 support for fast loading into the emulated ROM; to debug, you must use
8029 another protocol, such as standard remote protocol. The usual
8030 sequence is something like
8032 target nrom <netrom-hostname>
8034 target remote <netrom-hostname>:1235
8038 GDB now includes support for the Apple Macintosh, as a host only. It
8039 may be run as either an MPW tool or as a standalone application, and
8040 it can debug through the serial port. All the usual GDB commands are
8041 available, but to the target command, you must supply "serial" as the
8042 device type instead of "/dev/ttyXX". See mpw-README in the main
8043 directory for more information on how to build. The MPW configuration
8044 scripts */mpw-config.in support only a few targets, and only the
8045 mips-idt-ecoff target has been tested.
8049 GDB configuration now uses autoconf. This is not user-visible,
8050 but does simplify configuration and building.
8054 GDB now supports hpux10.
8056 *** Changes in GDB-4.14:
8058 * New native configurations
8060 x86 FreeBSD i[345]86-*-freebsd
8061 x86 NetBSD i[345]86-*-netbsd
8062 NS32k NetBSD ns32k-*-netbsd
8063 Sparc NetBSD sparc-*-netbsd
8067 A29K VxWorks a29k-*-vxworks
8068 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
8069 CPU32 EST-300 emulator m68*-*-est*
8070 PowerPC ELF powerpc-*-elf
8073 * Alpha OSF/1 support for procfs
8075 GDB now supports procfs under OSF/1-2.x and higher, which makes it
8076 possible to attach to running processes. As the mounting of the /proc
8077 filesystem is optional on the Alpha, GDB automatically determines
8078 the availability of /proc during startup. This can lead to problems
8079 if /proc is unmounted after GDB has been started.
8081 * Arguments to user-defined commands
8083 User commands may accept up to 10 arguments separated by whitespace.
8084 Arguments are accessed within the user command via $arg0..$arg9. A
8087 print $arg0 + $arg1 + $arg2
8089 To execute the command use:
8092 Defines the command "adder" which prints the sum of its three arguments.
8093 Note the arguments are text substitutions, so they may reference variables,
8094 use complex expressions, or even perform inferior function calls.
8096 * New `if' and `while' commands
8098 This makes it possible to write more sophisticated user-defined
8099 commands. Both commands take a single argument, which is the
8100 expression to evaluate, and must be followed by the commands to
8101 execute, one per line, if the expression is nonzero, the list being
8102 terminated by the word `end'. The `if' command list may include an
8103 `else' word, which causes the following commands to be executed only
8104 if the expression is zero.
8106 * Fortran source language mode
8108 GDB now includes partial support for Fortran 77. It will recognize
8109 Fortran programs and can evaluate a subset of Fortran expressions, but
8110 variables and functions may not be handled correctly. GDB will work
8111 with G77, but does not yet know much about symbols emitted by other
8114 * Better HPUX support
8116 Most debugging facilities now work on dynamic executables for HPPAs
8117 running hpux9 or later. You can attach to running dynamically linked
8118 processes, but by default the dynamic libraries will be read-only, so
8119 for instance you won't be able to put breakpoints in them. To change
8120 that behavior do the following before running the program:
8126 This will cause the libraries to be mapped private and read-write.
8127 To revert to the normal behavior, do this:
8133 You cannot set breakpoints or examine data in the library until after
8134 the library is loaded if the function/data symbols do not have
8137 GDB can now also read debug symbols produced by the HP C compiler on
8138 HPPAs (sorry, no C++, Fortran or 68k support).
8140 * Target byte order now dynamically selectable
8142 You can choose which byte order to use with a target system, via the
8143 commands "set endian big" and "set endian little", and you can see the
8144 current setting by using "show endian". You can also give the command
8145 "set endian auto", in which case GDB will use the byte order
8146 associated with the executable. Currently, only embedded MIPS
8147 configurations support dynamic selection of target byte order.
8149 * New DOS host serial code
8151 This version uses DPMI interrupts to handle buffered I/O, so you
8152 no longer need to run asynctsr when debugging boards connected to
8155 *** Changes in GDB-4.13:
8157 * New "complete" command
8159 This lists all the possible completions for the rest of the line, if it
8160 were to be given as a command itself. This is intended for use by emacs.
8162 * Trailing space optional in prompt
8164 "set prompt" no longer adds a space for you after the prompt you set. This
8165 allows you to set a prompt which ends in a space or one that does not.
8167 * Breakpoint hit counts
8169 "info break" now displays a count of the number of times the breakpoint
8170 has been hit. This is especially useful in conjunction with "ignore"; you
8171 can ignore a large number of breakpoint hits, look at the breakpoint info
8172 to see how many times the breakpoint was hit, then run again, ignoring one
8173 less than that number, and this will get you quickly to the last hit of
8176 * Ability to stop printing at NULL character
8178 "set print null-stop" will cause GDB to stop printing the characters of
8179 an array when the first NULL is encountered. This is useful when large
8180 arrays actually contain only short strings.
8182 * Shared library breakpoints
8184 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8185 breakpoints in shared libraries before the executable is run.
8187 * Hardware watchpoints
8189 There is a new hardware breakpoint for the watch command for sparclite
8190 targets. See gdb/sparclite/hw_breakpoint.note.
8192 Hardware watchpoints are also now supported under GNU/Linux.
8196 Annotations have been added. These are for use with graphical interfaces,
8197 and are still experimental. Currently only gdba.el uses these.
8199 * Improved Irix 5 support
8201 GDB now works properly with Irix 5.2.
8203 * Improved HPPA support
8205 GDB now works properly with the latest GCC and GAS.
8207 * New native configurations
8209 Sequent PTX4 i[34]86-sequent-ptx4
8210 HPPA running OSF/1 hppa*-*-osf*
8211 Atari TT running SVR4 m68*-*-sysv4*
8212 RS/6000 LynxOS rs6000-*-lynxos*
8216 OS/9000 i[34]86-*-os9k
8217 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8220 * Hitachi SH7000 and E7000-PC ICE support
8222 There is now support for communicating with the Hitachi E7000-PC ICE.
8223 This is available automatically when GDB is configured for the SH.
8227 As usual, a variety of small fixes and improvements, both generic
8228 and configuration-specific. See the ChangeLog for more detail.
8230 *** Changes in GDB-4.12:
8232 * Irix 5 is now supported
8236 GDB-4.12 on the HPPA has a number of changes which make it unable
8237 to debug the output from the currently released versions of GCC and
8238 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8239 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8240 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8243 *** Changes in GDB-4.11:
8245 * User visible changes:
8249 The "set remotedebug" option is now consistent between the mips remote
8250 target, remote targets using the gdb-specific protocol, UDI (AMD's
8251 debug protocol for the 29k) and the 88k bug monitor. It is now an
8252 integer specifying a debug level (normally 0 or 1, but 2 means more
8253 debugging info for the mips target).
8255 * DEC Alpha native support
8257 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8258 debug info, but GDB works fairly well with the DEC compiler and should
8259 work with a future GCC release. See the README file for a few
8260 Alpha-specific notes.
8262 * Preliminary thread implementation
8264 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8266 * LynxOS native and target support for 386
8268 This release has been hosted on LynxOS 2.2, and also can be configured
8269 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8272 * Improvements in C++ mangling/demangling.
8274 This release has much better g++ debugging, specifically in name
8275 mangling/demangling, virtual function calls, print virtual table,
8276 call methods, ...etc.
8278 *** Changes in GDB-4.10:
8280 * User visible changes:
8282 Remote debugging using the GDB-specific (`target remote') protocol now
8283 supports the `load' command. This is only useful if you have some
8284 other way of getting the stub to the target system, and you can put it
8285 somewhere in memory where it won't get clobbered by the download.
8287 Filename completion now works.
8289 When run under emacs mode, the "info line" command now causes the
8290 arrow to point to the line specified. Also, "info line" prints
8291 addresses in symbolic form (as well as hex).
8293 All vxworks based targets now support a user settable option, called
8294 vxworks-timeout. This option represents the number of seconds gdb
8295 should wait for responses to rpc's. You might want to use this if
8296 your vxworks target is, perhaps, a slow software simulator or happens
8297 to be on the far side of a thin network line.
8301 This release contains support for using a DEC alpha as a GDB host for
8302 cross debugging. Native alpha debugging is not supported yet.
8305 *** Changes in GDB-4.9:
8309 This is the first GDB release which is accompanied by a matching testsuite.
8310 The testsuite requires installation of dejagnu, which should be available
8311 via ftp from most sites that carry GNU software.
8315 'Cfront' style demangling has had its name changed to 'ARM' style, to
8316 emphasize that it was written from the specifications in the C++ Annotated
8317 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8318 disclaimers, it still generated too much confusion with users attempting to
8319 use gdb with AT&T cfront.
8323 GDB now uses a standard remote interface to a simulator library.
8324 So far, the library contains simulators for the Zilog Z8001/2, the
8325 Hitachi H8/300, H8/500 and Super-H.
8327 * New targets supported
8329 H8/300 simulator h8300-hitachi-hms or h8300hms
8330 H8/500 simulator h8500-hitachi-hms or h8500hms
8331 SH simulator sh-hitachi-hms or sh
8332 Z8000 simulator z8k-zilog-none or z8ksim
8333 IDT MIPS board over serial line mips-idt-ecoff
8335 Cross-debugging to GO32 targets is supported. It requires a custom
8336 version of the i386-stub.c module which is integrated with the
8337 GO32 memory extender.
8339 * New remote protocols
8341 MIPS remote debugging protocol.
8343 * New source languages supported
8345 This version includes preliminary support for Chill, a Pascal like language
8346 used by telecommunications companies. Chill support is also being integrated
8347 into the GNU compiler, but we don't know when it will be publically available.
8350 *** Changes in GDB-4.8:
8352 * HP Precision Architecture supported
8354 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8355 version of this support was available as a set of patches from the
8356 University of Utah. GDB does not support debugging of programs
8357 compiled with the HP compiler, because HP will not document their file
8358 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8359 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8361 Many problems in the preliminary version have been fixed.
8363 * Faster and better demangling
8365 We have improved template demangling and fixed numerous bugs in the GNU style
8366 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8367 character types (wchar_t) are now supported. Demangling of each symbol is now
8368 only done once, and is cached when the symbol table for a file is read in.
8369 This results in a small increase in memory usage for C programs, a moderate
8370 increase in memory usage for C++ programs, and a fantastic speedup in
8373 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8374 from the specifications in the Annotated Reference Manual, which AT&T's
8375 compiler does not actually implement.
8377 * G++ multiple inheritance compiler problem
8379 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8380 inheritance lattices was reworked to properly discover ambiguities. We
8381 recently found an example which causes this new algorithm to fail in a
8382 very subtle way, producing bad debug information for those classes.
8383 The file 'gcc.patch' (in this directory) can be applied to gcc to
8384 circumvent the problem. A future GCC release will contain a complete
8387 The previous G++ debug info problem (mentioned below for the gdb-4.7
8388 release) is fixed in gcc version 2.3.2.
8390 * Improved configure script
8392 The `configure' script will now attempt to guess your system type if
8393 you don't supply a host system type. The old scheme of supplying a
8394 host system triplet is preferable over using this. All the magic is
8395 done in the new `config.guess' script. Examine it for details.
8397 We have also brought our configure script much more in line with the FSF's
8398 version. It now supports the --with-xxx options. In particular,
8399 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8400 The resulting GDB will not be able to read arbitrary object file formats --
8401 only the format ``expected'' to be used on the configured target system.
8402 We hope to make this the default in a future release.
8404 * Documentation improvements
8406 There's new internal documentation on how to modify GDB, and how to
8407 produce clean changes to the code. We implore people to read it
8408 before submitting changes.
8410 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8411 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8412 `info' files are also provided. To build `info' files from scratch,
8413 you will need the latest `makeinfo' release, which will be available in
8414 a future texinfo-X.Y release.
8416 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8417 We're not sure exactly which versions have this problem, but it has
8418 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8419 or better. If that isn't possible, there is a patch in
8420 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8421 around this problem.
8425 GDB now supports array constants that can be used in expressions typed in by
8426 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8427 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8430 The new directory `gdb/sparclite' contains a program that demonstrates
8431 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8433 * New native hosts supported
8435 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8436 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8438 * New targets supported
8440 AMD 29k family via UDI a29k-amd-udi or udi29k
8442 * New file formats supported
8444 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8445 HPUX core files, and SCO 3.2v2 core files.
8449 Attaching to processes now works again; thanks for the many bug reports.
8451 We have also stomped on a bunch of core dumps caused by
8452 printf_filtered("%s") problems.
8454 We eliminated a copyright problem on the rpc and ptrace header files
8455 for VxWorks, which was discovered at the last minute during the 4.7
8456 release. You should now be able to build a VxWorks GDB.
8458 You can now interrupt gdb while an attached process is running. This
8459 will cause the attached process to stop, and give control back to GDB.
8461 We fixed problems caused by using too many file descriptors
8462 for reading symbols from object files and libraries. This was
8463 especially a problem for programs that used many (~100) shared
8466 The `step' command now only enters a subroutine if there is line number
8467 information for the subroutine. Otherwise it acts like the `next'
8468 command. Previously, `step' would enter subroutines if there was
8469 any debugging information about the routine. This avoids problems
8470 when using `cc -g1' on MIPS machines.
8472 * Internal improvements
8474 GDB's internal interfaces have been improved to make it easier to support
8475 debugging of multiple languages in the future.
8477 GDB now uses a common structure for symbol information internally.
8478 Minimal symbols (derived from linkage symbols in object files), partial
8479 symbols (from a quick scan of debug information), and full symbols
8480 contain a common subset of information, making it easier to write
8481 shared code that handles any of them.
8483 * New command line options
8485 We now accept --silent as an alias for --quiet.
8489 The memory-mapped-malloc library is now licensed under the GNU Library
8490 General Public License.
8492 *** Changes in GDB-4.7:
8494 * Host/native/target split
8496 GDB has had some major internal surgery to untangle the support for
8497 hosts and remote targets. Now, when you configure GDB for a remote
8498 target, it will no longer load in all of the support for debugging
8499 local programs on the host. When fully completed and tested, this will
8500 ensure that arbitrary host/target combinations are possible.
8502 The primary conceptual shift is to separate the non-portable code in
8503 GDB into three categories. Host specific code is required any time GDB
8504 is compiled on that host, regardless of the target. Target specific
8505 code relates to the peculiarities of the target, but can be compiled on
8506 any host. Native specific code is everything else: it can only be
8507 built when the host and target are the same system. Child process
8508 handling and core file support are two common `native' examples.
8510 GDB's use of /proc for controlling Unix child processes is now cleaner.
8511 It has been split out into a single module under the `target_ops' vector,
8512 plus two native-dependent functions for each system that uses /proc.
8514 * New hosts supported
8516 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8517 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8518 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8520 * New targets supported
8522 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8523 68030 and CPU32 m68030-*-*, m68332-*-*
8525 * New native hosts supported
8527 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8528 (386bsd is not well tested yet)
8529 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8531 * New file formats supported
8533 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8534 supports reading of `a.out.adobe' object files, which are an a.out
8535 format extended with minimal information about multiple sections.
8539 `show copying' is the same as the old `info copying'.
8540 `show warranty' is the same as `info warrantee'.
8541 These were renamed for consistency. The old commands continue to work.
8543 `info handle' is a new alias for `info signals'.
8545 You can now define pre-command hooks, which attach arbitrary command
8546 scripts to any command. The commands in the hook will be executed
8547 prior to the user's command. You can also create a hook which will be
8548 executed whenever the program stops. See gdb.texinfo.
8552 We now deal with Cfront style name mangling, and can even extract type
8553 info from mangled symbols. GDB can automatically figure out which
8554 symbol mangling style your C++ compiler uses.
8556 Calling of methods and virtual functions has been improved as well.
8560 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8561 fixed. This was due to mishandling of the extra N_SO stabs output
8564 We also finally got Ultrix 4.2 running in house, and fixed core file
8565 support, with help from a dozen people on the net.
8567 John M. Farrell discovered that the reason that single-stepping was so
8568 slow on all of the Mips based platforms (primarily SGI and DEC) was
8569 that we were trying to demangle and lookup a symbol used for internal
8570 purposes on every instruction that was being stepped through. Changing
8571 the name of that symbol so that it couldn't be mistaken for a C++
8572 mangled symbol sped things up a great deal.
8574 Rich Pixley sped up symbol lookups in general by getting much smarter
8575 about when C++ symbol mangling is necessary. This should make symbol
8576 completion (TAB on the command line) much faster. It's not as fast as
8577 we'd like, but it's significantly faster than gdb-4.6.
8581 A new user controllable variable 'call_scratch_address' can
8582 specify the location of a scratch area to be used when GDB
8583 calls a function in the target. This is necessary because the
8584 usual method of putting the scratch area on the stack does not work
8585 in systems that have separate instruction and data spaces.
8587 We integrated changes to support the 29k UDI (Universal Debugger
8588 Interface), but discovered at the last minute that we didn't have all
8589 of the appropriate copyright paperwork. We are working with AMD to
8590 resolve this, and hope to have it available soon.
8594 We have sped up the remote serial line protocol, especially for targets
8595 with lots of registers. It now supports a new `expedited status' ('T')
8596 message which can be used in place of the existing 'S' status message.
8597 This allows the remote stub to send only the registers that GDB
8598 needs to make a quick decision about single-stepping or conditional
8599 breakpoints, eliminating the need to fetch the entire register set for
8600 each instruction being stepped through.
8602 The GDB remote serial protocol now implements a write-through cache for
8603 registers, only re-reading the registers if the target has run.
8605 There is also a new remote serial stub for SPARC processors. You can
8606 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8607 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8608 processor with a serial port.
8612 Configure.in files have become much easier to read and modify. A new
8613 `table driven' format makes it more obvious what configurations are
8614 supported, and what files each one uses.
8618 There is a new opcodes library which will eventually contain all of the
8619 disassembly routines and opcode tables. At present, it only contains
8620 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8621 disassembler (binutils/objdump) to share these routines.
8623 The libiberty library is now copylefted under the GNU Library General
8624 Public License. This allows more liberal use, and was done so libg++
8625 can use it. This makes no difference to GDB, since the Library License
8626 grants all the rights from the General Public License.
8630 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8631 reference to the stabs symbol info used by the debugger. It is (as far
8632 as we know) the only published document on this fascinating topic. We
8633 encourage you to read it, compare it to the stabs information on your
8634 system, and send improvements on the document in general (to
8635 bug-gdb@prep.ai.mit.edu).
8637 And, of course, many bugs have been fixed.
8640 *** Changes in GDB-4.6:
8642 * Better support for C++ function names
8644 GDB now accepts as input the "demangled form" of C++ overloaded function
8645 names and member function names, and can do command completion on such names
8646 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8647 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8648 Make use of command completion, it is your friend.
8650 GDB also now accepts a variety of C++ mangled symbol formats. They are
8651 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8652 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8653 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8654 for the list of formats.
8656 * G++ symbol mangling problem
8658 Recent versions of gcc have a bug in how they emit debugging information for
8659 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8660 directory) can be applied to gcc to fix the problem. Alternatively, if you
8661 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8662 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8663 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8666 * New 'maintenance' command
8668 All of the commands related to hacking GDB internals have been moved out of
8669 the main command set, and now live behind the 'maintenance' command. This
8670 can also be abbreviated as 'mt'. The following changes were made:
8672 dump-me -> maintenance dump-me
8673 info all-breakpoints -> maintenance info breakpoints
8674 printmsyms -> maintenance print msyms
8675 printobjfiles -> maintenance print objfiles
8676 printpsyms -> maintenance print psymbols
8677 printsyms -> maintenance print symbols
8679 The following commands are new:
8681 maintenance demangle Call internal GDB demangler routine to
8682 demangle a C++ link name and prints the result.
8683 maintenance print type Print a type chain for a given symbol
8685 * Change to .gdbinit file processing
8687 We now read the $HOME/.gdbinit file before processing the argv arguments
8688 (e.g. reading symbol files or core files). This allows global parameters to
8689 be set, which will apply during the symbol reading. The ./.gdbinit is still
8690 read after argv processing.
8692 * New hosts supported
8694 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8696 GNU/Linux support i386-unknown-linux or linux
8698 We are also including code to support the HP/PA running BSD and HPUX. This
8699 is almost guaranteed not to work, as we didn't have time to test or build it
8700 for this release. We are including it so that the more adventurous (or
8701 masochistic) of you can play with it. We also had major problems with the
8702 fact that the compiler that we got from HP doesn't support the -g option.
8705 * New targets supported
8707 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8709 * More smarts about finding #include files
8711 GDB now remembers the compilation directory for all include files, and for
8712 all files from which C is generated (like yacc and lex sources). This
8713 greatly improves GDB's ability to find yacc/lex sources, and include files,
8714 especially if you are debugging your program from a directory different from
8715 the one that contains your sources.
8717 We also fixed a bug which caused difficulty with listing and setting
8718 breakpoints in include files which contain C code. (In the past, you had to
8719 try twice in order to list an include file that you hadn't looked at before.)
8721 * Interesting infernals change
8723 GDB now deals with arbitrary numbers of sections, where the symbols for each
8724 section must be relocated relative to that section's landing place in the
8725 target's address space. This work was needed to support ELF with embedded
8726 stabs used by Solaris-2.0.
8728 * Bug fixes (of course!)
8730 There have been loads of fixes for the following things:
8731 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8732 i960, stabs, DOS(GO32), procfs, etc...
8734 See the ChangeLog for details.
8736 *** Changes in GDB-4.5:
8738 * New machines supported (host and target)
8740 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8742 SGI Irix-4.x mips-sgi-irix4 or iris4
8744 * New malloc package
8746 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8747 Mmalloc is capable of handling multiple heaps of memory. It is also
8748 capable of saving a heap to a file, and then mapping it back in later.
8749 This can be used to greatly speedup the startup of GDB by using a
8750 pre-parsed symbol table which lives in a mmalloc managed heap. For
8751 more details, please read mmalloc/mmalloc.texi.
8755 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8756 'help info proc' for details.
8758 * MIPS ecoff symbol table format
8760 The code that reads MIPS symbol table format is now supported on all hosts.
8761 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8764 * File name changes for MS-DOS
8766 Many files in the config directories have been renamed to make it easier to
8767 support GDB on MS-DOSe systems (which have very restrictive file name
8768 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8769 environment) is close to working but has some remaining problems. Note
8770 that debugging of DOS programs is not supported, due to limitations
8771 in the ``operating system'', but it can be used to host cross-debugging.
8773 * Cross byte order fixes
8775 Many fixes have been made to support cross debugging of Sparc and MIPS
8776 targets from hosts whose byte order differs.
8778 * New -mapped and -readnow options
8780 If memory-mapped files are available on your system through the 'mmap'
8781 system call, you can use the -mapped option on the `file' or
8782 `symbol-file' commands to cause GDB to write the symbols from your
8783 program into a reusable file. If the program you are debugging is
8784 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8785 Future GDB debugging sessions will notice the presence of this file,
8786 and will quickly map in symbol information from it, rather than reading
8787 the symbol table from the executable program. Using the '-mapped'
8788 option in a GDB `file' or `symbol-file' command has the same effect as
8789 starting GDB with the '-mapped' command-line option.
8791 You can cause GDB to read the entire symbol table immediately by using
8792 the '-readnow' option with any of the commands that load symbol table
8793 information (or on the GDB command line). This makes the command
8794 slower, but makes future operations faster.
8796 The -mapped and -readnow options are typically combined in order to
8797 build a `fred.syms' file that contains complete symbol information.
8798 A simple GDB invocation to do nothing but build a `.syms' file for future
8801 gdb -batch -nx -mapped -readnow programname
8803 The `.syms' file is specific to the host machine on which GDB is run.
8804 It holds an exact image of GDB's internal symbol table. It cannot be
8805 shared across multiple host platforms.
8807 * longjmp() handling
8809 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8810 siglongjmp() without losing control. This feature has not yet been ported to
8811 all systems. It currently works on many 386 platforms, all MIPS-based
8812 platforms (SGI, DECstation, etc), and Sun3/4.
8816 Preliminary work has been put in to support the new Solaris OS from Sun. At
8817 this time, it can control and debug processes, but it is not capable of
8822 As always, many many bug fixes. The major areas were with g++, and mipsread.
8823 People using the MIPS-based platforms should experience fewer mysterious
8824 crashes and trashed symbol tables.
8826 *** Changes in GDB-4.4:
8828 * New machines supported (host and target)
8830 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8832 BSD Reno on Vax vax-dec-bsd
8833 Ultrix on Vax vax-dec-ultrix
8835 * New machines supported (target)
8837 AMD 29000 embedded, using EBMON a29k-none-none
8841 GDB continues to improve its handling of C++. `References' work better.
8842 The demangler has also been improved, and now deals with symbols mangled as
8843 per the Annotated C++ Reference Guide.
8845 GDB also now handles `stabs' symbol information embedded in MIPS
8846 `ecoff' symbol tables. Since the ecoff format was not easily
8847 extensible to handle new languages such as C++, this appeared to be a
8848 good way to put C++ debugging info into MIPS binaries. This option
8849 will be supported in the GNU C compiler, version 2, when it is
8852 * New features for SVR4
8854 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8855 shared libraries. Debugging dynamically linked programs should present
8856 only minor differences from debugging statically linked programs.
8858 The `info proc' command will print out information about any process
8859 on an SVR4 system (including the one you are debugging). At the moment,
8860 it prints the address mappings of the process.
8862 If you bring up GDB on another SVR4 system, please send mail to
8863 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8865 * Better dynamic linking support in SunOS
8867 Reading symbols from shared libraries which contain debugging symbols
8868 now works properly. However, there remain issues such as automatic
8869 skipping of `transfer vector' code during function calls, which
8870 make it harder to debug code in a shared library, than to debug the
8871 same code linked statically.
8875 GDB is now using the latest `getopt' routines from the FSF. This
8876 version accepts the -- prefix for options with long names. GDB will
8877 continue to accept the old forms (-option and +option) as well.
8878 Various single letter abbreviations for options have been explicity
8879 added to the option table so that they won't get overshadowed in the
8880 future by other options that begin with the same letter.
8884 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8885 Many assorted bugs have been handled. Many more remain to be handled.
8886 See the various ChangeLog files (primarily in gdb and bfd) for details.
8889 *** Changes in GDB-4.3:
8891 * New machines supported (host and target)
8893 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8894 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8895 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8897 * Almost SCO Unix support
8899 We had hoped to support:
8900 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8901 (except for core file support), but we discovered very late in the release
8902 that it has problems with process groups that render gdb unusable. Sorry
8903 about that. I encourage people to fix it and post the fixes.
8905 * Preliminary ELF and DWARF support
8907 GDB can read ELF object files on System V Release 4, and can handle
8908 debugging records for C, in DWARF format, in ELF files. This support
8909 is preliminary. If you bring up GDB on another SVR4 system, please
8910 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8915 GDB now uses the latest `readline' library. One user-visible change
8916 is that two tabs will list possible command completions, which previously
8917 required typing M-? (meta-question mark, or ESC ?).
8921 The `stepi' bug that many of you noticed has been squashed.
8922 Many bugs in C++ have been handled. Many more remain to be handled.
8923 See the various ChangeLog files (primarily in gdb and bfd) for details.
8925 * State of the MIPS world (in case you wondered):
8927 GDB can understand the symbol tables emitted by the compilers
8928 supplied by most vendors of MIPS-based machines, including DEC. These
8929 symbol tables are in a format that essentially nobody else uses.
8931 Some versions of gcc come with an assembler post-processor called
8932 mips-tfile. This program is required if you want to do source-level
8933 debugging of gcc-compiled programs. I believe FSF does not ship
8934 mips-tfile with gcc version 1, but it will eventually come with gcc
8937 Debugging of g++ output remains a problem. g++ version 1.xx does not
8938 really support it at all. (If you're lucky, you should be able to get
8939 line numbers and stack traces to work, but no parameters or local
8940 variables.) With some work it should be possible to improve the
8943 When gcc version 2 is released, you will have somewhat better luck.
8944 However, even then you will get confusing results for inheritance and
8947 We will eventually provide full debugging of g++ output on
8948 DECstations. This will probably involve some kind of stabs-in-ecoff
8949 encapulation, but the details have not been worked out yet.
8952 *** Changes in GDB-4.2:
8954 * Improved configuration
8956 Only one copy of `configure' exists now, and it is not self-modifying.
8957 Porting BFD is simpler.
8961 The `step' and `next' commands now only stop at the first instruction
8962 of a source line. This prevents the multiple stops that used to occur
8963 in switch statements, for-loops, etc. `Step' continues to stop if a
8964 function that has debugging information is called within the line.
8968 Lots of small bugs fixed. More remain.
8970 * New host supported (not target)
8972 Intel 386 PC clone running Mach i386-none-mach
8975 *** Changes in GDB-4.1:
8977 * Multiple source language support
8979 GDB now has internal scaffolding to handle several source languages.
8980 It determines the type of each source file from its filename extension,
8981 and will switch expression parsing and number formatting to match the
8982 language of the function in the currently selected stack frame.
8983 You can also specifically set the language to be used, with
8984 `set language c' or `set language modula-2'.
8988 GDB now has preliminary support for the GNU Modula-2 compiler,
8989 currently under development at the State University of New York at
8990 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8991 continue through the fall of 1991 and into 1992.
8993 Other Modula-2 compilers are currently not supported, and attempting to
8994 debug programs compiled with them will likely result in an error as the
8995 symbol table is read. Feel free to work on it, though!
8997 There are hooks in GDB for strict type checking and range checking,
8998 in the `Modula-2 philosophy', but they do not currently work.
9002 GDB can now write to executable and core files (e.g. patch
9003 a variable's value). You must turn this switch on, specify
9004 the file ("exec foo" or "core foo"), *then* modify it, e.g.
9005 by assigning a new value to a variable. Modifications take
9008 * Automatic SunOS shared library reading
9010 When you run your program, GDB automatically determines where its
9011 shared libraries (if any) have been loaded, and reads their symbols.
9012 The `share' command is no longer needed. This also works when
9013 examining core files.
9017 You can specify the number of lines that the `list' command shows.
9020 * New machines supported (host and target)
9022 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
9023 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
9024 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
9026 * New hosts supported (not targets)
9028 IBM RT/PC: romp-ibm-aix or rtpc
9030 * New targets supported (not hosts)
9032 AMD 29000 embedded with COFF a29k-none-coff
9033 AMD 29000 embedded with a.out a29k-none-aout
9034 Ultracomputer remote kernel debug a29k-nyu-kern
9036 * New remote interfaces
9042 *** Changes in GDB-4.0:
9046 Wide output is wrapped at good places to make the output more readable.
9048 Gdb now supports cross-debugging from a host machine of one type to a
9049 target machine of another type. Communication with the target system
9050 is over serial lines. The ``target'' command handles connecting to the
9051 remote system; the ``load'' command will download a program into the
9052 remote system. Serial stubs for the m68k and i386 are provided. Gdb
9053 also supports debugging of realtime processes running under VxWorks,
9054 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
9055 stub on the target system.
9057 New CPUs supported include the AMD 29000 and Intel 960.
9059 GDB now reads object files and symbol tables via a ``binary file''
9060 library, which allows a single copy of GDB to debug programs of multiple
9061 object file types such as a.out and coff.
9063 There is now a GDB reference card in "doc/refcard.tex". (Make targets
9064 refcard.dvi and refcard.ps are available to format it).
9067 * Control-Variable user interface simplified
9069 All variables that control the operation of the debugger can be set
9070 by the ``set'' command, and displayed by the ``show'' command.
9072 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
9073 ``Show prompt'' produces the response:
9074 Gdb's prompt is new-gdb=>.
9076 What follows are the NEW set commands. The command ``help set'' will
9077 print a complete list of old and new set commands. ``help set FOO''
9078 will give a longer description of the variable FOO. ``show'' will show
9079 all of the variable descriptions and their current settings.
9081 confirm on/off: Enables warning questions for operations that are
9082 hard to recover from, e.g. rerunning the program while
9083 it is already running. Default is ON.
9085 editing on/off: Enables EMACS style command line editing
9086 of input. Previous lines can be recalled with
9087 control-P, the current line can be edited with control-B,
9088 you can search for commands with control-R, etc.
9091 history filename NAME: NAME is where the gdb command history
9092 will be stored. The default is .gdb_history,
9093 or the value of the environment variable
9096 history size N: The size, in commands, of the command history. The
9097 default is 256, or the value of the environment variable
9100 history save on/off: If this value is set to ON, the history file will
9101 be saved after exiting gdb. If set to OFF, the
9102 file will not be saved. The default is OFF.
9104 history expansion on/off: If this value is set to ON, then csh-like
9105 history expansion will be performed on
9106 command line input. The default is OFF.
9108 radix N: Sets the default radix for input and output. It can be set
9109 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9110 in the current radix, so "set radix 10" is always a no-op.
9112 height N: This integer value is the number of lines on a page. Default
9113 is 24, the current `stty rows'' setting, or the ``li#''
9114 setting from the termcap entry matching the environment
9117 width N: This integer value is the number of characters on a line.
9118 Default is 80, the current `stty cols'' setting, or the ``co#''
9119 setting from the termcap entry matching the environment
9122 Note: ``set screensize'' is obsolete. Use ``set height'' and
9123 ``set width'' instead.
9125 print address on/off: Print memory addresses in various command displays,
9126 such as stack traces and structure values. Gdb looks
9127 more ``symbolic'' if you turn this off; it looks more
9128 ``machine level'' with it on. Default is ON.
9130 print array on/off: Prettyprint arrays. New convenient format! Default
9133 print demangle on/off: Print C++ symbols in "source" form if on,
9136 print asm-demangle on/off: Same, for assembler level printouts
9139 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9142 * Support for Epoch Environment.
9144 The epoch environment is a version of Emacs v18 with windowing. One
9145 new command, ``inspect'', is identical to ``print'', except that if you
9146 are running in the epoch environment, the value is printed in its own
9150 * Support for Shared Libraries
9152 GDB can now debug programs and core files that use SunOS shared libraries.
9153 Symbols from a shared library cannot be referenced
9154 before the shared library has been linked with the program (this
9155 happens after you type ``run'' and before the function main() is entered).
9156 At any time after this linking (including when examining core files
9157 from dynamically linked programs), gdb reads the symbols from each
9158 shared library when you type the ``sharedlibrary'' command.
9159 It can be abbreviated ``share''.
9161 sharedlibrary REGEXP: Load shared object library symbols for files
9162 matching a unix regular expression. No argument
9163 indicates to load symbols for all shared libraries.
9165 info sharedlibrary: Status of loaded shared libraries.
9170 A watchpoint stops execution of a program whenever the value of an
9171 expression changes. Checking for this slows down execution
9172 tremendously whenever you are in the scope of the expression, but is
9173 quite useful for catching tough ``bit-spreader'' or pointer misuse
9174 problems. Some machines such as the 386 have hardware for doing this
9175 more quickly, and future versions of gdb will use this hardware.
9177 watch EXP: Set a watchpoint (breakpoint) for an expression.
9179 info watchpoints: Information about your watchpoints.
9181 delete N: Deletes watchpoint number N (same as breakpoints).
9182 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9183 enable N: Re-enables watchpoint number N (same as breakpoints).
9186 * C++ multiple inheritance
9188 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9191 * C++ exception handling
9193 Gdb now supports limited C++ exception handling. Besides the existing
9194 ability to breakpoint on an exception handler, gdb can breakpoint on
9195 the raising of an exception (before the stack is peeled back to the
9198 catch FOO: If there is a FOO exception handler in the dynamic scope,
9199 set a breakpoint to catch exceptions which may be raised there.
9200 Multiple exceptions (``catch foo bar baz'') may be caught.
9202 info catch: Lists all exceptions which may be caught in the
9203 current stack frame.
9206 * Minor command changes
9208 The command ``call func (arg, arg, ...)'' now acts like the print
9209 command, except it does not print or save a value if the function's result
9210 is void. This is similar to dbx usage.
9212 The ``up'' and ``down'' commands now always print the frame they end up
9213 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9214 frames without printing.
9216 * New directory command
9218 'dir' now adds directories to the FRONT of the source search path.
9219 The path starts off empty. Source files that contain debug information
9220 about the directory in which they were compiled can be found even
9221 with an empty path; Sun CC and GCC include this information. If GDB can't
9222 find your source file in the current directory, type "dir .".
9224 * Configuring GDB for compilation
9226 For normal use, type ``./configure host''. See README or gdb.texinfo
9229 GDB now handles cross debugging. If you are remotely debugging between
9230 two different machines, type ``./configure host -target=targ''.
9231 Host is the machine where GDB will run; targ is the machine
9232 where the program that you are debugging will run.